add aufs2 kernel patches, update aufs2-util to match

4 files changed, 33825 insertions, 7 deletions

diff --git a/package/aufs2-util/Makefile b/package/aufs2-util/Makefile
index 14ceeb4c7..f42767dbe 100644
--- a/package/aufs2-util/Makefile
+++ b/package/aufs2-util/Makefile
@@ -4,16 +4,16 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=		aufs2-util
-PKG_VERSION:=		2-301210
+PKG_VERSION:=		2-100111
 PKG_RELEASE:=		1
-PKG_MD5SUM:=		83b07d6a6d43362dfc234ecff11367f3
+PKG_MD5SUM:=		1854f5ab560dd375b22f6e2b747cb412
 PKG_DESCR:=		aufs2 utilities
 PKG_SECTION:=		fs
 PKG_URL:=		http://aufs.sf.net/
 
 # created from git via:
-# $ git archive --format tar origin/aufs2 | \
-#          gzip -9 -c >aufs2-util-2-$(date +%d%m%g).tar.gz
+# $ git archive --format tar aufs2.1 | \
+#          gzip -9 -c >../aufs2-util-2-$(date +%d%m%g).tar.gz
 
 PKG_SITES:=		http://nwl.cc/~n0-1/
 WRKDIST=		${WRKDIR}
@@ -29,8 +29,7 @@ $(eval $(call PKG_template,AUFS2_UTIL,${PKG_NAME},${PKG_VERSION}-${PKG_RELEASE},
 $(eval $(call PKG_template,LIBAU,libau,${PKG_VERSION}-${PKG_RELEASE},${PKG_DEPENDS},${PKGSD_LIBAU},${PKG_SECTION}))
 
 CONFIG_STYLE:=		manual
-TCFLAGS+=		-I${LINUX_DIR}/include
-XAKE_FLAGS+=		Install=install
+XAKE_FLAGS+=		Install=install HOSTCPPFLAGS="-I${LINUX_HEADER_DIR}/include"
 
 post-install:
 	$(INSTALL_DIR) $(IDIR_AUFS2_UTIL)/sbin
@@ -40,7 +39,7 @@ post-install:
 	$(INSTALL_BIN) ${WRKINST}/usr/bin/au{brsync,chk} \
 		$(IDIR_AUFS2_UTIL)/usr/bin
 	$(INSTALL_DIR) $(IDIR_AUFS2_UTIL)/etc/default
-	$(INSTALL_BIN) ${WRKINST}/etc/default/aufs \
+	$(INSTALL_DATA) ${WRKINST}/etc/default/aufs \
 		$(IDIR_AUFS2_UTIL)/etc/default
 	$(INSTALL_DIR) $(IDIR_LIBAU)/usr/lib
 	${CP} ${WRKINST}/usr/lib/libau* ${IDIR_LIBAU}/usr/lib
diff --git a/package/aufs2-util/patches/patch-Makefile b/package/aufs2-util/patches/patch-Makefile
new file mode 100644
index 000000000..d77ea81ec
--- /dev/null
+++ b/package/aufs2-util/patches/patch-Makefile
@@ -0,0 +1,47 @@
+--- w-aufs2-util-2-100111-1.orig/Makefile	2011-01-07 05:00:54.000000000 +0100
++++ w-aufs2-util-2-100111-1/Makefile	2011-01-10 23:43:23.000000000 +0100
+@@ -15,6 +15,11 @@
+ # along with this program; if not, write to the Free Software
+ # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301	 USA
+ 
++c2sh c2tmac: CC = ${HOSTCC}
++c2sh c2tmac: CFLAGS= ${HOSTCFLAGS}
++c2sh c2tmac: LDFLAGS= ${HOSTLDFLAGS}
++c2sh c2tmac: CPPFLAGS= ${HOSTCPPFLAGS} -I./libau -I${LINUX_HEADER_DIR}/include
++
+ CFLAGS += -I./libau
+ CFLAGS += -O -Wall
+ 
+@@ -28,13 +33,10 @@ LibUtilObj = proc_mnt.o br.o plink.o mta
+ LibUtilHdr = au_util.h
+ export
+ 
+-all: ver_test ${Man} ${Bin} ${Etc}
++all: ${Man} ${Bin} ${Etc}
+ 	${MAKE} -C libau $@
+ 	ln -sf ./libau/libau*.so .
+ 
+-ver_test: ver
+-	./ver
+-
+ ${Bin}: LDFLAGS += -static -s
+ ${Bin}: LDLIBS = -L. -lautil
+ ${BinObj}: %.o: %.c ${LibUtilHdr} ${LibUtil}
+@@ -63,7 +65,7 @@ aufs.5: aufs.in.5 c2tmac
+ 	}' aufs.in.5 >> $@
+ 	chmod a-w $@
+ 
+-.INTERMEDIATE: c2sh c2tmac ver
++.INTERMEDIATE: c2sh c2tmac
+ 
+ Install = install -o root -g root -p
+ install_sbin: File = mount.aufs umount.aufs auplink
+@@ -77,7 +79,7 @@ install_etc: File = etc_default_aufs
+ install_etc: Tgt = ${DESTDIR}/etc/default/aufs
+ install_etc: ${File}
+ 	install -d $(dir ${Tgt})
+-	${Install} -m 644 -T ${File} ${Tgt}
++	${Install} -m 644 ${File} ${Tgt}
+ install_man: File = aufs.5
+ install_man: Tgt = ${DESTDIR}/usr/share/man/man5
+ install_man: ${File}
diff --git a/target/linux/patches/2.6.36/aufs2.patch b/target/linux/patches/2.6.36/aufs2.patch
new file mode 100644
index 000000000..e9e5fc277
--- /dev/null
+++ b/target/linux/patches/2.6.36/aufs2.patch
@@ -0,0 +1,33532 @@
+diff -Nur linux-2.6.36.orig/fs/Kconfig linux-2.6.36/fs/Kconfig
+--- linux-2.6.36.orig/fs/Kconfig	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/Kconfig	2011-01-10 19:52:38.000000000 +0100
+@@ -189,6 +189,7 @@
+ source "fs/sysv/Kconfig"
+ source "fs/ufs/Kconfig"
+ source "fs/exofs/Kconfig"
++source "fs/aufs/Kconfig"
+ 
+ endif # MISC_FILESYSTEMS
+ 
+diff -Nur linux-2.6.36.orig/fs/Makefile linux-2.6.36/fs/Makefile
+--- linux-2.6.36.orig/fs/Makefile	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/Makefile	2011-01-10 19:52:38.000000000 +0100
+@@ -126,3 +126,4 @@
+ obj-$(CONFIG_GFS2_FS)           += gfs2/
+ obj-$(CONFIG_EXOFS_FS)          += exofs/
+ obj-$(CONFIG_CEPH_FS)		+= ceph/
++obj-$(CONFIG_AUFS_FS)           += aufs/
+diff -Nur linux-2.6.36.orig/fs/aufs/Kconfig linux-2.6.36/fs/aufs/Kconfig
+--- linux-2.6.36.orig/fs/aufs/Kconfig	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/Kconfig	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,180 @@
++config AUFS_FS
++	tristate "Aufs (Advanced multi layered unification filesystem) support"
++	depends on EXPERIMENTAL
++	help
++	Aufs is a stackable unification filesystem such as Unionfs,
++	which unifies several directories and provides a merged single
++	directory.
++	In the early days, aufs was entirely re-designed and
++	re-implemented Unionfs Version 1.x series. Introducing many
++	original ideas, approaches and improvements, it becomes totally
++	different from Unionfs while keeping the basic features.
++
++if AUFS_FS
++choice
++	prompt "Maximum number of branches"
++	default AUFS_BRANCH_MAX_127
++	help
++	Specifies the maximum number of branches (or member directories)
++	in a single aufs. The larger value consumes more system
++	resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_127
++	bool "127"
++	help
++	Specifies the maximum number of branches (or member directories)
++	in a single aufs. The larger value consumes more system
++	resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_511
++	bool "511"
++	help
++	Specifies the maximum number of branches (or member directories)
++	in a single aufs. The larger value consumes more system
++	resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_1023
++	bool "1023"
++	help
++	Specifies the maximum number of branches (or member directories)
++	in a single aufs. The larger value consumes more system
++	resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_32767
++	bool "32767"
++	help
++	Specifies the maximum number of branches (or member directories)
++	in a single aufs. The larger value consumes more system
++	resources and has a minor impact to performance.
++endchoice
++
++config AUFS_SBILIST
++	bool
++	depends on AUFS_MAGIC_SYSRQ || PROC_FS
++	default y
++	help
++	Automatic configuration for internal use.
++	When aufs supports Magic SysRq or /proc, enabled automatically.
++
++config AUFS_HNOTIFY
++	bool "Detect direct branch access (bypassing aufs)"
++	help
++	If you want to modify files on branches directly, eg. bypassing aufs,
++	and want aufs to detect the changes of them fully, then enable this
++	option and use 'udba=notify' mount option.
++	Currently there is only one available configuration, "fsnotify".
++	It will have a negative impact to the performance.
++	See detail in aufs.5.
++
++choice
++	prompt "method" if AUFS_HNOTIFY
++	default AUFS_HFSNOTIFY
++config AUFS_HFSNOTIFY
++	bool "fsnotify"
++	select FSNOTIFY
++endchoice
++
++config AUFS_EXPORT
++	bool "NFS-exportable aufs"
++	depends on (AUFS_FS = y && EXPORTFS = y) || (AUFS_FS = m && EXPORTFS)
++	help
++	If you want to export your mounted aufs via NFS, then enable this
++	option. There are several requirements for this configuration.
++	See detail in aufs.5.
++
++config AUFS_INO_T_64
++	bool
++	depends on AUFS_EXPORT
++	depends on 64BIT && !(ALPHA || S390)
++	default y
++	help
++	Automatic configuration for internal use.
++	/* typedef unsigned long/int __kernel_ino_t */
++	/* alpha and s390x are int */
++
++config AUFS_RDU
++	bool "Readdir in userspace"
++	help
++	Aufs has two methods to provide a merged view for a directory,
++	by a user-space library and by kernel-space natively. The latter
++	is always enabled but sometimes large and slow.
++	If you enable this option, install the library in aufs2-util
++	package, and set some environment variables for your readdir(3),
++	then the work will be handled in user-space which generally
++	shows better performance in most cases.
++	See detail in aufs.5.
++
++config AUFS_SP_IATTR
++	bool "Respect the attributes (mtime/ctime mainly) of special files"
++	help
++	When you write something to a special file, some attributes of it
++	(mtime/ctime mainly) may be updated. Generally such updates are
++	less important (actually some device drivers and NFS ignore
++	it). But some applications (such like test program) requires
++	such updates. If you need these updates, then enable this
++	configuration which introduces some overhead.
++	Currently this configuration handles FIFO only.
++
++config AUFS_SHWH
++	bool "Show whiteouts"
++	help
++	If you want to make the whiteouts in aufs visible, then enable
++	this option and specify 'shwh' mount option. Although it may
++	sounds like philosophy or something, but in technically it
++	simply shows the name of whiteout with keeping its behaviour.
++
++config AUFS_BR_RAMFS
++	bool "Ramfs (initramfs/rootfs) as an aufs branch"
++	help
++	If you want to use ramfs as an aufs branch fs, then enable this
++	option. Generally tmpfs is recommended.
++	Aufs prohibited them to be a branch fs by default, because
++	initramfs becomes unusable after switch_root or something
++	generally. If you sets initramfs as an aufs branch and boot your
++	system by switch_root, you will meet a problem easily since the
++	files in initramfs may be inaccessible.
++	Unless you are going to use ramfs as an aufs branch fs without
++	switch_root or something, leave it N.
++
++config AUFS_BR_FUSE
++	bool "Fuse fs as an aufs branch"
++	depends on FUSE_FS
++	select AUFS_POLL
++	help
++	If you want to use fuse-based userspace filesystem as an aufs
++	branch fs, then enable this option.
++	It implements the internal poll(2) operation which is
++	implemented by fuse only (curretnly).
++
++config AUFS_POLL
++	bool
++	help
++	Automatic configuration for internal use.
++
++config AUFS_BR_HFSPLUS
++	bool "Hfsplus as an aufs branch"
++	depends on HFSPLUS_FS
++	default y
++	help
++	If you want to use hfsplus fs as an aufs branch fs, then enable
++	this option. This option introduces a small overhead at
++	copying-up a file on hfsplus.
++
++config AUFS_BDEV_LOOP
++	bool
++	depends on BLK_DEV_LOOP
++	default y
++	help
++	Automatic configuration for internal use.
++	Convert =[ym] into =y.
++
++config AUFS_DEBUG
++	bool "Debug aufs"
++	help
++	Enable this to compile aufs internal debug code.
++	It will have a negative impact to the performance.
++
++config AUFS_MAGIC_SYSRQ
++	bool
++	depends on AUFS_DEBUG && MAGIC_SYSRQ
++	default y
++	help
++	Automatic configuration for internal use.
++	When aufs supports Magic SysRq, enabled automatically.
++endif
+diff -Nur linux-2.6.36.orig/fs/aufs/Makefile linux-2.6.36/fs/aufs/Makefile
+--- linux-2.6.36.orig/fs/aufs/Makefile	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/Makefile	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,38 @@
++
++include ${src}/magic.mk
++ifeq (${CONFIG_AUFS_FS},m)
++include ${src}/conf.mk
++endif
++-include ${src}/priv_def.mk
++
++# cf. include/linux/kernel.h
++# enable pr_debug
++ccflags-y += -DDEBUG
++# sparse doesn't allow spaces
++ccflags-y += -D'pr_fmt(fmt)=AUFS_NAME"\040%s:%d:%s[%d]:\040"fmt,__func__,__LINE__,current->comm,current->pid'
++
++obj-$(CONFIG_AUFS_FS) += aufs.o
++aufs-y := module.o sbinfo.o super.o branch.o xino.o sysaufs.o opts.o \
++	wkq.o vfsub.o dcsub.o \
++	cpup.o whout.o wbr_policy.o \
++	dinfo.o dentry.o \
++	dynop.o \
++	finfo.o file.o f_op.o \
++	dir.o vdir.o \
++	iinfo.o inode.o i_op.o i_op_add.o i_op_del.o i_op_ren.o \
++	ioctl.o
++
++# all are boolean
++aufs-$(CONFIG_PROC_FS) += procfs.o plink.o
++aufs-$(CONFIG_SYSFS) += sysfs.o
++aufs-$(CONFIG_DEBUG_FS) += dbgaufs.o
++aufs-$(CONFIG_AUFS_BDEV_LOOP) += loop.o
++aufs-$(CONFIG_AUFS_HNOTIFY) += hnotify.o
++aufs-$(CONFIG_AUFS_HFSNOTIFY) += hfsnotify.o
++aufs-$(CONFIG_AUFS_EXPORT) += export.o
++aufs-$(CONFIG_AUFS_POLL) += poll.o
++aufs-$(CONFIG_AUFS_RDU) += rdu.o
++aufs-$(CONFIG_AUFS_SP_IATTR) += f_op_sp.o
++aufs-$(CONFIG_AUFS_BR_HFSPLUS) += hfsplus.o
++aufs-$(CONFIG_AUFS_DEBUG) += debug.o
++aufs-$(CONFIG_AUFS_MAGIC_SYSRQ) += sysrq.o
+diff -Nur linux-2.6.36.orig/fs/aufs/aufs.h linux-2.6.36/fs/aufs/aufs.h
+--- linux-2.6.36.orig/fs/aufs/aufs.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/aufs.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,61 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * all header files
++ */
++
++#ifndef __AUFS_H__
++#define __AUFS_H__
++
++#ifdef __KERNEL__
++
++#define AuStub(type, name, body, ...) \
++	static inline type name(__VA_ARGS__) { body; }
++
++#define AuStubVoid(name, ...) \
++	AuStub(void, name, , __VA_ARGS__)
++#define AuStubInt0(name, ...) \
++	AuStub(int, name, return 0, __VA_ARGS__)
++
++#include "debug.h"
++
++#include "branch.h"
++#include "cpup.h"
++#include "dcsub.h"
++#include "dbgaufs.h"
++#include "dentry.h"
++#include "dir.h"
++#include "dynop.h"
++#include "file.h"
++#include "fstype.h"
++#include "inode.h"
++#include "loop.h"
++#include "module.h"
++/* never include ./mtx.h */
++#include "opts.h"
++#include "rwsem.h"
++#include "spl.h"
++#include "super.h"
++#include "sysaufs.h"
++#include "vfsub.h"
++#include "whout.h"
++#include "wkq.h"
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/branch.c linux-2.6.36/fs/aufs/branch.c
+--- linux-2.6.36.orig/fs/aufs/branch.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/branch.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1071 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * branch management
++ */
++
++#include <linux/file.h>
++#include <linux/statfs.h>
++#include "aufs.h"
++
++/*
++ * free a single branch
++ */
++static void au_br_do_free(struct au_branch *br)
++{
++	int i;
++	struct au_wbr *wbr;
++	struct au_dykey **key;
++
++	au_hnotify_fin_br(br);
++
++	if (br->br_xino.xi_file)
++		fput(br->br_xino.xi_file);
++	mutex_destroy(&br->br_xino.xi_nondir_mtx);
++
++	AuDebugOn(atomic_read(&br->br_count));
++
++	wbr = br->br_wbr;
++	if (wbr) {
++		for (i = 0; i < AuBrWh_Last; i++)
++			dput(wbr->wbr_wh[i]);
++		AuDebugOn(atomic_read(&wbr->wbr_wh_running));
++		AuRwDestroy(&wbr->wbr_wh_rwsem);
++	}
++
++	key = br->br_dykey;
++	for (i = 0; i < AuBrDynOp; i++, key++)
++		if (*key)
++			au_dy_put(*key);
++		else
++			break;
++
++	mntput(br->br_mnt);
++	kfree(wbr);
++	kfree(br);
++}
++
++/*
++ * frees all branches
++ */
++void au_br_free(struct au_sbinfo *sbinfo)
++{
++	aufs_bindex_t bmax;
++	struct au_branch **br;
++
++	AuRwMustWriteLock(&sbinfo->si_rwsem);
++
++	bmax = sbinfo->si_bend + 1;
++	br = sbinfo->si_branch;
++	while (bmax--)
++		au_br_do_free(*br++);
++}
++
++/*
++ * find the index of a branch which is specified by @br_id.
++ */
++int au_br_index(struct super_block *sb, aufs_bindex_t br_id)
++{
++	aufs_bindex_t bindex, bend;
++
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++)
++		if (au_sbr_id(sb, bindex) == br_id)
++			return bindex;
++	return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * add a branch
++ */
++
++static int test_overlap(struct super_block *sb, struct dentry *h_adding,
++			struct dentry *h_root)
++{
++	if (unlikely(h_adding == h_root
++		     || au_test_loopback_overlap(sb, h_adding)))
++		return 1;
++	if (h_adding->d_sb != h_root->d_sb)
++		return 0;
++	return au_test_subdir(h_adding, h_root)
++		|| au_test_subdir(h_root, h_adding);
++}
++
++/*
++ * returns a newly allocated branch. @new_nbranch is a number of branches
++ * after adding a branch.
++ */
++static struct au_branch *au_br_alloc(struct super_block *sb, int new_nbranch,
++				     int perm)
++{
++	struct au_branch *add_branch;
++	struct dentry *root;
++	int err;
++
++	err = -ENOMEM;
++	root = sb->s_root;
++	add_branch = kmalloc(sizeof(*add_branch), GFP_NOFS);
++	if (unlikely(!add_branch))
++		goto out;
++
++	err = au_hnotify_init_br(add_branch, perm);
++	if (unlikely(err))
++		goto out_br;
++
++	add_branch->br_wbr = NULL;
++	if (au_br_writable(perm)) {
++		/* may be freed separately at changing the branch permission */
++		add_branch->br_wbr = kmalloc(sizeof(*add_branch->br_wbr),
++					     GFP_NOFS);
++		if (unlikely(!add_branch->br_wbr))
++			goto out_hnotify;
++	}
++
++	err = au_sbr_realloc(au_sbi(sb), new_nbranch);
++	if (!err)
++		err = au_di_realloc(au_di(root), new_nbranch);
++	if (!err)
++		err = au_ii_realloc(au_ii(root->d_inode), new_nbranch);
++	if (!err)
++		return add_branch; /* success */
++
++	kfree(add_branch->br_wbr);
++
++out_hnotify:
++	au_hnotify_fin_br(add_branch);
++out_br:
++	kfree(add_branch);
++out:
++	return ERR_PTR(err);
++}
++
++/*
++ * test if the branch permission is legal or not.
++ */
++static int test_br(struct inode *inode, int brperm, char *path)
++{
++	int err;
++
++	err = (au_br_writable(brperm) && IS_RDONLY(inode));
++	if (!err)
++		goto out;
++
++	err = -EINVAL;
++	pr_err("write permission for readonly mount or inode, %s\n", path);
++
++out:
++	return err;
++}
++
++/*
++ * returns:
++ * 0: success, the caller will add it
++ * plus: success, it is already unified, the caller should ignore it
++ * minus: error
++ */
++static int test_add(struct super_block *sb, struct au_opt_add *add, int remount)
++{
++	int err;
++	aufs_bindex_t bend, bindex;
++	struct dentry *root;
++	struct inode *inode, *h_inode;
++
++	root = sb->s_root;
++	bend = au_sbend(sb);
++	if (unlikely(bend >= 0
++		     && au_find_dbindex(root, add->path.dentry) >= 0)) {
++		err = 1;
++		if (!remount) {
++			err = -EINVAL;
++			pr_err("%s duplicated\n", add->pathname);
++		}
++		goto out;
++	}
++
++	err = -ENOSPC; /* -E2BIG; */
++	if (unlikely(AUFS_BRANCH_MAX <= add->bindex
++		     || AUFS_BRANCH_MAX - 1 <= bend)) {
++		pr_err("number of branches exceeded %s\n", add->pathname);
++		goto out;
++	}
++
++	err = -EDOM;
++	if (unlikely(add->bindex < 0 || bend + 1 < add->bindex)) {
++		pr_err("bad index %d\n", add->bindex);
++		goto out;
++	}
++
++	inode = add->path.dentry->d_inode;
++	err = -ENOENT;
++	if (unlikely(!inode->i_nlink)) {
++		pr_err("no existence %s\n", add->pathname);
++		goto out;
++	}
++
++	err = -EINVAL;
++	if (unlikely(inode->i_sb == sb)) {
++		pr_err("%s must be outside\n", add->pathname);
++		goto out;
++	}
++
++	if (unlikely(au_test_fs_unsuppoted(inode->i_sb))) {
++		pr_err("unsupported filesystem, %s (%s)\n",
++		       add->pathname, au_sbtype(inode->i_sb));
++		goto out;
++	}
++
++	err = test_br(add->path.dentry->d_inode, add->perm, add->pathname);
++	if (unlikely(err))
++		goto out;
++
++	if (bend < 0)
++		return 0; /* success */
++
++	err = -EINVAL;
++	for (bindex = 0; bindex <= bend; bindex++)
++		if (unlikely(test_overlap(sb, add->path.dentry,
++					  au_h_dptr(root, bindex)))) {
++			pr_err("%s is overlapped\n", add->pathname);
++			goto out;
++		}
++
++	err = 0;
++	if (au_opt_test(au_mntflags(sb), WARN_PERM)) {
++		h_inode = au_h_dptr(root, 0)->d_inode;
++		if ((h_inode->i_mode & S_IALLUGO) != (inode->i_mode & S_IALLUGO)
++		    || h_inode->i_uid != inode->i_uid
++		    || h_inode->i_gid != inode->i_gid)
++			pr_warning("uid/gid/perm %s %u/%u/0%o, %u/%u/0%o\n",
++				   add->pathname,
++				   inode->i_uid, inode->i_gid,
++				   (inode->i_mode & S_IALLUGO),
++				   h_inode->i_uid, h_inode->i_gid,
++				   (h_inode->i_mode & S_IALLUGO));
++	}
++
++out:
++	return err;
++}
++
++/*
++ * initialize or clean the whiteouts for an adding branch
++ */
++static int au_br_init_wh(struct super_block *sb, struct au_branch *br,
++			 int new_perm, struct dentry *h_root)
++{
++	int err, old_perm;
++	aufs_bindex_t bindex;
++	struct mutex *h_mtx;
++	struct au_wbr *wbr;
++	struct au_hinode *hdir;
++
++	wbr = br->br_wbr;
++	old_perm = br->br_perm;
++	br->br_perm = new_perm;
++	hdir = NULL;
++	h_mtx = NULL;
++	bindex = au_br_index(sb, br->br_id);
++	if (0 <= bindex) {
++		hdir = au_hi(sb->s_root->d_inode, bindex);
++		au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++	} else {
++		h_mtx = &h_root->d_inode->i_mutex;
++		mutex_lock_nested(h_mtx, AuLsc_I_PARENT);
++	}
++	if (!wbr)
++		err = au_wh_init(h_root, br, sb);
++	else {
++		wbr_wh_write_lock(wbr);
++		err = au_wh_init(h_root, br, sb);
++		wbr_wh_write_unlock(wbr);
++	}
++	if (hdir)
++		au_hn_imtx_unlock(hdir);
++	else
++		mutex_unlock(h_mtx);
++	br->br_perm = old_perm;
++
++	if (!err && wbr && !au_br_writable(new_perm)) {
++		kfree(wbr);
++		br->br_wbr = NULL;
++	}
++
++	return err;
++}
++
++static int au_wbr_init(struct au_branch *br, struct super_block *sb,
++		       int perm, struct path *path)
++{
++	int err;
++	struct kstatfs kst;
++	struct au_wbr *wbr;
++	struct dentry *h_dentry;
++
++	wbr = br->br_wbr;
++	au_rw_init(&wbr->wbr_wh_rwsem);
++	memset(wbr->wbr_wh, 0, sizeof(wbr->wbr_wh));
++	atomic_set(&wbr->wbr_wh_running, 0);
++	wbr->wbr_bytes = 0;
++
++	/*
++	 * a limit for rmdir/rename a dir
++	 * cf. AUFS_MAX_NAMELEN in include/linux/aufs_type.h
++	 */
++	err = vfs_statfs(path, &kst);
++	if (unlikely(err))
++		goto out;
++	err = -EINVAL;
++	h_dentry = path->dentry;
++	if (kst.f_namelen >= NAME_MAX)
++		err = au_br_init_wh(sb, br, perm, h_dentry);
++	else
++		pr_err("%.*s(%s), unsupported namelen %ld\n",
++		       AuDLNPair(h_dentry), au_sbtype(h_dentry->d_sb),
++		       kst.f_namelen);
++
++out:
++	return err;
++}
++
++/* intialize a new branch */
++static int au_br_init(struct au_branch *br, struct super_block *sb,
++		      struct au_opt_add *add)
++{
++	int err;
++
++	err = 0;
++	memset(&br->br_xino, 0, sizeof(br->br_xino));
++	mutex_init(&br->br_xino.xi_nondir_mtx);
++	br->br_perm = add->perm;
++	br->br_mnt = add->path.mnt; /* set first, mntget() later */
++	spin_lock_init(&br->br_dykey_lock);
++	memset(br->br_dykey, 0, sizeof(br->br_dykey));
++	atomic_set(&br->br_count, 0);
++	br->br_xino_upper = AUFS_XINO_TRUNC_INIT;
++	atomic_set(&br->br_xino_running, 0);
++	br->br_id = au_new_br_id(sb);
++	AuDebugOn(br->br_id < 0);
++
++	if (au_br_writable(add->perm)) {
++		err = au_wbr_init(br, sb, add->perm, &add->path);
++		if (unlikely(err))
++			goto out_err;
++	}
++
++	if (au_opt_test(au_mntflags(sb), XINO)) {
++		err = au_xino_br(sb, br, add->path.dentry->d_inode->i_ino,
++				 au_sbr(sb, 0)->br_xino.xi_file, /*do_test*/1);
++		if (unlikely(err)) {
++			AuDebugOn(br->br_xino.xi_file);
++			goto out_err;
++		}
++	}
++
++	sysaufs_br_init(br);
++	mntget(add->path.mnt);
++	goto out; /* success */
++
++out_err:
++	br->br_mnt = NULL;
++out:
++	return err;
++}
++
++static void au_br_do_add_brp(struct au_sbinfo *sbinfo, aufs_bindex_t bindex,
++			     struct au_branch *br, aufs_bindex_t bend,
++			     aufs_bindex_t amount)
++{
++	struct au_branch **brp;
++
++	AuRwMustWriteLock(&sbinfo->si_rwsem);
++
++	brp = sbinfo->si_branch + bindex;
++	memmove(brp + 1, brp, sizeof(*brp) * amount);
++	*brp = br;
++	sbinfo->si_bend++;
++	if (unlikely(bend < 0))
++		sbinfo->si_bend = 0;
++}
++
++static void au_br_do_add_hdp(struct au_dinfo *dinfo, aufs_bindex_t bindex,
++			     aufs_bindex_t bend, aufs_bindex_t amount)
++{
++	struct au_hdentry *hdp;
++
++	AuRwMustWriteLock(&dinfo->di_rwsem);
++
++	hdp = dinfo->di_hdentry + bindex;
++	memmove(hdp + 1, hdp, sizeof(*hdp) * amount);
++	au_h_dentry_init(hdp);
++	dinfo->di_bend++;
++	if (unlikely(bend < 0))
++		dinfo->di_bstart = 0;
++}
++
++static void au_br_do_add_hip(struct au_iinfo *iinfo, aufs_bindex_t bindex,
++			     aufs_bindex_t bend, aufs_bindex_t amount)
++{
++	struct au_hinode *hip;
++
++	AuRwMustWriteLock(&iinfo->ii_rwsem);
++
++	hip = iinfo->ii_hinode + bindex;
++	memmove(hip + 1, hip, sizeof(*hip) * amount);
++	hip->hi_inode = NULL;
++	au_hn_init(hip);
++	iinfo->ii_bend++;
++	if (unlikely(bend < 0))
++		iinfo->ii_bstart = 0;
++}
++
++static void au_br_do_add(struct super_block *sb, struct dentry *h_dentry,
++			 struct au_branch *br, aufs_bindex_t bindex)
++{
++	struct dentry *root;
++	struct inode *root_inode;
++	aufs_bindex_t bend, amount;
++
++	root = sb->s_root;
++	root_inode = root->d_inode;
++	bend = au_sbend(sb);
++	amount = bend + 1 - bindex;
++	au_br_do_add_brp(au_sbi(sb), bindex, br, bend, amount);
++	au_br_do_add_hdp(au_di(root), bindex, bend, amount);
++	au_br_do_add_hip(au_ii(root_inode), bindex, bend, amount);
++	au_set_h_dptr(root, bindex, dget(h_dentry));
++	au_set_h_iptr(root_inode, bindex, au_igrab(h_dentry->d_inode),
++		      /*flags*/0);
++}
++
++int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount)
++{
++	int err;
++	aufs_bindex_t bend, add_bindex;
++	struct dentry *root, *h_dentry;
++	struct inode *root_inode;
++	struct au_branch *add_branch;
++
++	root = sb->s_root;
++	root_inode = root->d_inode;
++	IMustLock(root_inode);
++	err = test_add(sb, add, remount);
++	if (unlikely(err < 0))
++		goto out;
++	if (err) {
++		err = 0;
++		goto out; /* success */
++	}
++
++	bend = au_sbend(sb);
++	add_branch = au_br_alloc(sb, bend + 2, add->perm);
++	err = PTR_ERR(add_branch);
++	if (IS_ERR(add_branch))
++		goto out;
++
++	err = au_br_init(add_branch, sb, add);
++	if (unlikely(err)) {
++		au_br_do_free(add_branch);
++		goto out;
++	}
++
++	add_bindex = add->bindex;
++	h_dentry = add->path.dentry;
++	if (!remount)
++		au_br_do_add(sb, h_dentry, add_branch, add_bindex);
++	else {
++		sysaufs_brs_del(sb, add_bindex);
++		au_br_do_add(sb, h_dentry, add_branch, add_bindex);
++		sysaufs_brs_add(sb, add_bindex);
++	}
++
++	if (!add_bindex) {
++		au_cpup_attr_all(root_inode, /*force*/1);
++		sb->s_maxbytes = h_dentry->d_sb->s_maxbytes;
++	} else
++		au_add_nlink(root_inode, h_dentry->d_inode);
++
++	/*
++	 * this test/set prevents aufs from handling unnecesary notify events
++	 * of xino files, in a case of re-adding a writable branch which was
++	 * once detached from aufs.
++	 */
++	if (au_xino_brid(sb) < 0
++	    && au_br_writable(add_branch->br_perm)
++	    && !au_test_fs_bad_xino(h_dentry->d_sb)
++	    && add_branch->br_xino.xi_file
++	    && add_branch->br_xino.xi_file->f_dentry->d_parent == h_dentry)
++		au_xino_brid_set(sb, add_branch->br_id);
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * delete a branch
++ */
++
++/* to show the line number, do not make it inlined function */
++#define AuVerbose(do_info, fmt, ...) do { \
++	if (do_info) \
++		pr_info(fmt, ##__VA_ARGS__); \
++} while (0)
++
++/*
++ * test if the branch is deletable or not.
++ */
++static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
++			    unsigned int sigen, const unsigned int verbose)
++{
++	int err, i, j, ndentry;
++	aufs_bindex_t bstart, bend;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry *d;
++	struct inode *inode;
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	err = au_dcsub_pages(&dpages, root, NULL, NULL);
++	if (unlikely(err))
++		goto out_dpages;
++
++	for (i = 0; !err && i < dpages.ndpage; i++) {
++		dpage = dpages.dpages + i;
++		ndentry = dpage->ndentry;
++		for (j = 0; !err && j < ndentry; j++) {
++			d = dpage->dentries[j];
++			AuDebugOn(!atomic_read(&d->d_count));
++			if (!au_digen_test(d, sigen)) {
++				di_read_lock_child(d, AuLock_IR);
++				if (unlikely(au_dbrange_test(d))) {
++					di_read_unlock(d, AuLock_IR);
++					continue;
++				}
++			} else {
++				di_write_lock_child(d);
++				if (unlikely(au_dbrange_test(d))) {
++					di_write_unlock(d);
++					continue;
++				}
++				err = au_reval_dpath(d, sigen);
++				if (!err)
++					di_downgrade_lock(d, AuLock_IR);
++				else {
++					di_write_unlock(d);
++					break;
++				}
++			}
++
++			/* AuDbgDentry(d); */
++			inode = d->d_inode;
++			bstart = au_dbstart(d);
++			bend = au_dbend(d);
++			if (bstart <= bindex
++			    && bindex <= bend
++			    && au_h_dptr(d, bindex)
++			    && ((inode && !S_ISDIR(inode->i_mode))
++				|| bstart == bend)) {
++				err = -EBUSY;
++				AuVerbose(verbose, "busy %.*s\n", AuDLNPair(d));
++				AuDbgDentry(d);
++			}
++			di_read_unlock(d, AuLock_IR);
++		}
++	}
++
++out_dpages:
++	au_dpages_free(&dpages);
++out:
++	return err;
++}
++
++static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
++			   unsigned int sigen, const unsigned int verbose)
++{
++	int err;
++	unsigned long long max, ull;
++	struct inode *i, **array;
++	aufs_bindex_t bstart, bend;
++
++	array = au_iarray_alloc(sb, &max);
++	err = PTR_ERR(array);
++	if (IS_ERR(array))
++		goto out;
++
++	err = 0;
++	AuDbg("b%d\n", bindex);
++	for (ull = 0; !err && ull < max; ull++) {
++		i = array[ull];
++		if (i->i_ino == AUFS_ROOT_INO)
++			continue;
++
++		/* AuDbgInode(i); */
++		if (au_iigen(i) == sigen)
++			ii_read_lock_child(i);
++		else {
++			ii_write_lock_child(i);
++			err = au_refresh_hinode_self(i);
++			au_iigen_dec(i);
++			if (!err)
++				ii_downgrade_lock(i);
++			else {
++				ii_write_unlock(i);
++				break;
++			}
++		}
++
++		bstart = au_ibstart(i);
++		bend = au_ibend(i);
++		if (bstart <= bindex
++		    && bindex <= bend
++		    && au_h_iptr(i, bindex)
++		    && (!S_ISDIR(i->i_mode) || bstart == bend)) {
++			err = -EBUSY;
++			AuVerbose(verbose, "busy i%lu\n", i->i_ino);
++			AuDbgInode(i);
++		}
++		ii_read_unlock(i);
++	}
++	au_iarray_free(array, max);
++
++out:
++	return err;
++}
++
++static int test_children_busy(struct dentry *root, aufs_bindex_t bindex,
++			      const unsigned int verbose)
++{
++	int err;
++	unsigned int sigen;
++
++	sigen = au_sigen(root->d_sb);
++	DiMustNoWaiters(root);
++	IiMustNoWaiters(root->d_inode);
++	di_write_unlock(root);
++	err = test_dentry_busy(root, bindex, sigen, verbose);
++	if (!err)
++		err = test_inode_busy(root->d_sb, bindex, sigen, verbose);
++	di_write_lock_child(root); /* aufs_write_lock() calls ..._child() */
++
++	return err;
++}
++
++static void au_br_do_del_brp(struct au_sbinfo *sbinfo,
++			     const aufs_bindex_t bindex,
++			     const aufs_bindex_t bend)
++{
++	struct au_branch **brp, **p;
++
++	AuRwMustWriteLock(&sbinfo->si_rwsem);
++
++	brp = sbinfo->si_branch + bindex;
++	if (bindex < bend)
++		memmove(brp, brp + 1, sizeof(*brp) * (bend - bindex));
++	sbinfo->si_branch[0 + bend] = NULL;
++	sbinfo->si_bend--;
++
++	p = krealloc(sbinfo->si_branch, sizeof(*p) * bend, GFP_NOFS);
++	if (p)
++		sbinfo->si_branch = p;
++	/* harmless error */
++}
++
++static void au_br_do_del_hdp(struct au_dinfo *dinfo, const aufs_bindex_t bindex,
++			     const aufs_bindex_t bend)
++{
++	struct au_hdentry *hdp, *p;
++
++	AuRwMustWriteLock(&dinfo->di_rwsem);
++
++	hdp = dinfo->di_hdentry;
++	if (bindex < bend)
++		memmove(hdp + bindex, hdp + bindex + 1,
++			sizeof(*hdp) * (bend - bindex));
++	hdp[0 + bend].hd_dentry = NULL;
++	dinfo->di_bend--;
++
++	p = krealloc(hdp, sizeof(*p) * bend, GFP_NOFS);
++	if (p)
++		dinfo->di_hdentry = p;
++	/* harmless error */
++}
++
++static void au_br_do_del_hip(struct au_iinfo *iinfo, const aufs_bindex_t bindex,
++			     const aufs_bindex_t bend)
++{
++	struct au_hinode *hip, *p;
++
++	AuRwMustWriteLock(&iinfo->ii_rwsem);
++
++	hip = iinfo->ii_hinode + bindex;
++	if (bindex < bend)
++		memmove(hip, hip + 1, sizeof(*hip) * (bend - bindex));
++	iinfo->ii_hinode[0 + bend].hi_inode = NULL;
++	au_hn_init(iinfo->ii_hinode + bend);
++	iinfo->ii_bend--;
++
++	p = krealloc(iinfo->ii_hinode, sizeof(*p) * bend, GFP_NOFS);
++	if (p)
++		iinfo->ii_hinode = p;
++	/* harmless error */
++}
++
++static void au_br_do_del(struct super_block *sb, aufs_bindex_t bindex,
++			 struct au_branch *br)
++{
++	aufs_bindex_t bend;
++	struct au_sbinfo *sbinfo;
++	struct dentry *root;
++	struct inode *inode;
++
++	SiMustWriteLock(sb);
++
++	root = sb->s_root;
++	inode = root->d_inode;
++	sbinfo = au_sbi(sb);
++	bend = sbinfo->si_bend;
++
++	dput(au_h_dptr(root, bindex));
++	au_hiput(au_hi(inode, bindex));
++	au_br_do_free(br);
++
++	au_br_do_del_brp(sbinfo, bindex, bend);
++	au_br_do_del_hdp(au_di(root), bindex, bend);
++	au_br_do_del_hip(au_ii(inode), bindex, bend);
++}
++
++int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount)
++{
++	int err, rerr, i;
++	unsigned int mnt_flags;
++	aufs_bindex_t bindex, bend, br_id;
++	unsigned char do_wh, verbose;
++	struct au_branch *br;
++	struct au_wbr *wbr;
++
++	err = 0;
++	bindex = au_find_dbindex(sb->s_root, del->h_path.dentry);
++	if (bindex < 0) {
++		if (remount)
++			goto out; /* success */
++		err = -ENOENT;
++		pr_err("%s no such branch\n", del->pathname);
++		goto out;
++	}
++	AuDbg("bindex b%d\n", bindex);
++
++	err = -EBUSY;
++	mnt_flags = au_mntflags(sb);
++	verbose = !!au_opt_test(mnt_flags, VERBOSE);
++	bend = au_sbend(sb);
++	if (unlikely(!bend)) {
++		AuVerbose(verbose, "no more branches left\n");
++		goto out;
++	}
++	br = au_sbr(sb, bindex);
++	i = atomic_read(&br->br_count);
++	if (unlikely(i)) {
++		AuVerbose(verbose, "%d file(s) opened\n", i);
++		goto out;
++	}
++
++	wbr = br->br_wbr;
++	do_wh = wbr && (wbr->wbr_whbase || wbr->wbr_plink || wbr->wbr_orph);
++	if (do_wh) {
++		/* instead of WbrWhMustWriteLock(wbr) */
++		SiMustWriteLock(sb);
++		for (i = 0; i < AuBrWh_Last; i++) {
++			dput(wbr->wbr_wh[i]);
++			wbr->wbr_wh[i] = NULL;
++		}
++	}
++
++	err = test_children_busy(sb->s_root, bindex, verbose);
++	if (unlikely(err)) {
++		if (do_wh)
++			goto out_wh;
++		goto out;
++	}
++
++	err = 0;
++	br_id = br->br_id;
++	if (!remount)
++		au_br_do_del(sb, bindex, br);
++	else {
++		sysaufs_brs_del(sb, bindex);
++		au_br_do_del(sb, bindex, br);
++		sysaufs_brs_add(sb, bindex);
++	}
++
++	if (!bindex) {
++		au_cpup_attr_all(sb->s_root->d_inode, /*force*/1);
++		sb->s_maxbytes = au_sbr_sb(sb, 0)->s_maxbytes;
++	} else
++		au_sub_nlink(sb->s_root->d_inode, del->h_path.dentry->d_inode);
++	if (au_opt_test(mnt_flags, PLINK))
++		au_plink_half_refresh(sb, br_id);
++
++	if (au_xino_brid(sb) == br_id)
++		au_xino_brid_set(sb, -1);
++	goto out; /* success */
++
++out_wh:
++	/* revert */
++	rerr = au_br_init_wh(sb, br, br->br_perm, del->h_path.dentry);
++	if (rerr)
++		pr_warning("failed re-creating base whiteout, %s. (%d)\n",
++			   del->pathname, rerr);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * change a branch permission
++ */
++
++static void au_warn_ima(void)
++{
++#ifdef CONFIG_IMA
++	/* since it doesn't support mark_files_ro() */
++	AuWarn1("RW -> RO makes IMA to produce wrong message\n");
++#endif
++}
++
++static int do_need_sigen_inc(int a, int b)
++{
++	return au_br_whable(a) && !au_br_whable(b);
++}
++
++static int need_sigen_inc(int old, int new)
++{
++	return do_need_sigen_inc(old, new)
++		|| do_need_sigen_inc(new, old);
++}
++
++static unsigned long long au_farray_cb(void *a,
++				       unsigned long long max __maybe_unused,
++				       void *arg)
++{
++	unsigned long long n;
++	struct file **p, *f;
++	struct super_block *sb = arg;
++
++	n = 0;
++	p = a;
++	lg_global_lock(files_lglock);
++	do_file_list_for_each_entry(sb, f) {
++		if (au_fi(f)
++		    && !special_file(f->f_dentry->d_inode->i_mode)) {
++			get_file(f);
++			*p++ = f;
++			n++;
++			AuDebugOn(n > max);
++		}
++	} while_file_list_for_each_entry;
++	lg_global_unlock(files_lglock);
++
++	return n;
++}
++
++static struct file **au_farray_alloc(struct super_block *sb,
++				     unsigned long long *max)
++{
++	*max = atomic_long_read(&au_sbi(sb)->si_nfiles);
++	return au_array_alloc(max, au_farray_cb, sb);
++}
++
++static void au_farray_free(struct file **a, unsigned long long max)
++{
++	unsigned long long ull;
++
++	for (ull = 0; ull < max; ull++)
++		if (a[ull])
++			fput(a[ull]);
++	au_array_free(a);
++}
++
++static int au_br_mod_files_ro(struct super_block *sb, aufs_bindex_t bindex)
++{
++	int err, do_warn;
++	unsigned long long ull, max;
++	aufs_bindex_t br_id;
++	struct file *file, *hf, **array;
++	struct inode *inode;
++	struct au_hfile *hfile;
++
++	array = au_farray_alloc(sb, &max);
++	err = PTR_ERR(array);
++	if (IS_ERR(array))
++		goto out;
++
++	do_warn = 0;
++	br_id = au_sbr_id(sb, bindex);
++	for (ull = 0; ull < max; ull++) {
++		file = array[ull];
++
++		/* AuDbg("%.*s\n", AuDLNPair(file->f_dentry)); */
++		fi_read_lock(file);
++		if (unlikely(au_test_mmapped(file))) {
++			err = -EBUSY;
++			AuDbgFile(file);
++			FiMustNoWaiters(file);
++			fi_read_unlock(file);
++			goto out_array;
++		}
++
++		inode = file->f_dentry->d_inode;
++		hfile = &au_fi(file)->fi_htop;
++		hf = hfile->hf_file;
++		if (!S_ISREG(inode->i_mode)
++		    || !(file->f_mode & FMODE_WRITE)
++		    || hfile->hf_br->br_id != br_id
++		    || !(hf->f_mode & FMODE_WRITE))
++			array[ull] = NULL;
++		else {
++			do_warn = 1;
++			get_file(file);
++		}
++
++		FiMustNoWaiters(file);
++		fi_read_unlock(file);
++		fput(file);
++	}
++
++	err = 0;
++	if (do_warn)
++		au_warn_ima();
++
++	for (ull = 0; ull < max; ull++) {
++		file = array[ull];
++		if (!file)
++			continue;
++
++		/* todo: already flushed? */
++		/* cf. fs/super.c:mark_files_ro() */
++		/* fi_read_lock(file); */
++		hfile = &au_fi(file)->fi_htop;
++		hf = hfile->hf_file;
++		/* fi_read_unlock(file); */
++		spin_lock(&hf->f_lock);
++		hf->f_mode &= ~FMODE_WRITE;
++		spin_unlock(&hf->f_lock);
++		if (!file_check_writeable(hf)) {
++			file_release_write(hf);
++			mnt_drop_write(hf->f_vfsmnt);
++		}
++	}
++
++out_array:
++	au_farray_free(array, max);
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
++	      int *do_refresh)
++{
++	int err, rerr;
++	aufs_bindex_t bindex;
++	struct path path;
++	struct dentry *root;
++	struct au_branch *br;
++
++	root = sb->s_root;
++	bindex = au_find_dbindex(root, mod->h_root);
++	if (bindex < 0) {
++		if (remount)
++			return 0; /* success */
++		err = -ENOENT;
++		pr_err("%s no such branch\n", mod->path);
++		goto out;
++	}
++	AuDbg("bindex b%d\n", bindex);
++
++	err = test_br(mod->h_root->d_inode, mod->perm, mod->path);
++	if (unlikely(err))
++		goto out;
++
++	br = au_sbr(sb, bindex);
++	if (br->br_perm == mod->perm)
++		return 0; /* success */
++
++	if (au_br_writable(br->br_perm)) {
++		/* remove whiteout base */
++		err = au_br_init_wh(sb, br, mod->perm, mod->h_root);
++		if (unlikely(err))
++			goto out;
++
++		if (!au_br_writable(mod->perm)) {
++			/* rw --> ro, file might be mmapped */
++			DiMustNoWaiters(root);
++			IiMustNoWaiters(root->d_inode);
++			di_write_unlock(root);
++			err = au_br_mod_files_ro(sb, bindex);
++			/* aufs_write_lock() calls ..._child() */
++			di_write_lock_child(root);
++
++			if (unlikely(err)) {
++				rerr = -ENOMEM;
++				br->br_wbr = kmalloc(sizeof(*br->br_wbr),
++						     GFP_NOFS);
++				if (br->br_wbr) {
++					path.mnt = br->br_mnt;
++					path.dentry = mod->h_root;
++					rerr = au_wbr_init(br, sb, br->br_perm,
++							   &path);
++				}
++				if (unlikely(rerr)) {
++					AuIOErr("nested error %d (%d)\n",
++						rerr, err);
++					br->br_perm = mod->perm;
++				}
++			}
++		}
++	} else if (au_br_writable(mod->perm)) {
++		/* ro --> rw */
++		err = -ENOMEM;
++		br->br_wbr = kmalloc(sizeof(*br->br_wbr), GFP_NOFS);
++		if (br->br_wbr) {
++			path.mnt = br->br_mnt;
++			path.dentry = mod->h_root;
++			err = au_wbr_init(br, sb, mod->perm, &path);
++			if (unlikely(err)) {
++				kfree(br->br_wbr);
++				br->br_wbr = NULL;
++			}
++		}
++	}
++
++	if (!err) {
++		*do_refresh |= need_sigen_inc(br->br_perm, mod->perm);
++		br->br_perm = mod->perm;
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/branch.h linux-2.6.36/fs/aufs/branch.h
+--- linux-2.6.36.orig/fs/aufs/branch.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/branch.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,229 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * branch filesystems and xino for them
++ */
++
++#ifndef __AUFS_BRANCH_H__
++#define __AUFS_BRANCH_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/mount.h>
++#include <linux/aufs_type.h>
++#include "dynop.h"
++#include "rwsem.h"
++#include "super.h"
++
++/* ---------------------------------------------------------------------- */
++
++/* a xino file */
++struct au_xino_file {
++	struct file		*xi_file;
++	struct mutex		xi_nondir_mtx;
++
++	/* todo: make xino files an array to support huge inode number */
++
++#ifdef CONFIG_DEBUG_FS
++	struct dentry		 *xi_dbgaufs;
++#endif
++};
++
++/* members for writable branch only */
++enum {AuBrWh_BASE, AuBrWh_PLINK, AuBrWh_ORPH, AuBrWh_Last};
++struct au_wbr {
++	struct au_rwsem		wbr_wh_rwsem;
++	struct dentry		*wbr_wh[AuBrWh_Last];
++	atomic_t		wbr_wh_running;
++#define wbr_whbase		wbr_wh[AuBrWh_BASE]	/* whiteout base */
++#define wbr_plink		wbr_wh[AuBrWh_PLINK]	/* pseudo-link dir */
++#define wbr_orph		wbr_wh[AuBrWh_ORPH]	/* dir for orphans */
++
++	/* mfs mode */
++	unsigned long long	wbr_bytes;
++};
++
++/* ext2 has 3 types of operations at least, ext3 has 4 */
++#define AuBrDynOp (AuDyLast * 4)
++
++/* protected by superblock rwsem */
++struct au_branch {
++	struct au_xino_file	br_xino;
++
++	aufs_bindex_t		br_id;
++
++	int			br_perm;
++	struct vfsmount		*br_mnt;
++	spinlock_t		br_dykey_lock;
++	struct au_dykey		*br_dykey[AuBrDynOp];
++	atomic_t		br_count;
++
++	struct au_wbr		*br_wbr;
++
++	/* xino truncation */
++	blkcnt_t		br_xino_upper;	/* watermark in blocks */
++	atomic_t		br_xino_running;
++
++#ifdef CONFIG_AUFS_HFSNOTIFY
++	struct fsnotify_group	*br_hfsn_group;
++	struct fsnotify_ops	br_hfsn_ops;
++#endif
++
++#ifdef CONFIG_SYSFS
++	/* an entry under sysfs per mount-point */
++	char			br_name[8];
++	struct attribute	br_attr;
++#endif
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* branch permission and attribute */
++enum {
++	AuBrPerm_RW,		/* writable, linkable wh */
++	AuBrPerm_RO,		/* readonly, no wh */
++	AuBrPerm_RR,		/* natively readonly, no wh */
++
++	AuBrPerm_RWNoLinkWH,	/* un-linkable whiteouts */
++
++	AuBrPerm_ROWH,		/* whiteout-able */
++	AuBrPerm_RRWH,		/* whiteout-able */
++
++	AuBrPerm_Last
++};
++
++static inline int au_br_writable(int brperm)
++{
++	return brperm == AuBrPerm_RW || brperm == AuBrPerm_RWNoLinkWH;
++}
++
++static inline int au_br_whable(int brperm)
++{
++	return brperm == AuBrPerm_RW
++		|| brperm == AuBrPerm_ROWH
++		|| brperm == AuBrPerm_RRWH;
++}
++
++static inline int au_br_rdonly(struct au_branch *br)
++{
++	return ((br->br_mnt->mnt_sb->s_flags & MS_RDONLY)
++		|| !au_br_writable(br->br_perm))
++		? -EROFS : 0;
++}
++
++static inline int au_br_hnotifyable(int brperm __maybe_unused)
++{
++#ifdef CONFIG_AUFS_HNOTIFY
++	return brperm != AuBrPerm_RR && brperm != AuBrPerm_RRWH;
++#else
++	return 0;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* branch.c */
++struct au_sbinfo;
++void au_br_free(struct au_sbinfo *sinfo);
++int au_br_index(struct super_block *sb, aufs_bindex_t br_id);
++struct au_opt_add;
++int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount);
++struct au_opt_del;
++int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount);
++struct au_opt_mod;
++int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
++	      int *do_refresh);
++
++/* xino.c */
++static const loff_t au_loff_max = LLONG_MAX;
++
++int au_xib_trunc(struct super_block *sb);
++ssize_t xino_fread(au_readf_t func, struct file *file, void *buf, size_t size,
++		   loff_t *pos);
++ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
++		    loff_t *pos);
++struct file *au_xino_create2(struct file *base_file, struct file *copy_src);
++struct file *au_xino_create(struct super_block *sb, char *fname, int silent);
++ino_t au_xino_new_ino(struct super_block *sb);
++void au_xino_delete_inode(struct inode *inode, const int unlinked);
++int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++		  ino_t ino);
++int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++		 ino_t *ino);
++int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t hino,
++	       struct file *base_file, int do_test);
++int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex);
++
++struct au_opt_xino;
++int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount);
++void au_xino_clr(struct super_block *sb);
++struct file *au_xino_def(struct super_block *sb);
++int au_xino_path(struct seq_file *seq, struct file *file);
++
++/* ---------------------------------------------------------------------- */
++
++/* Superblock to branch */
++static inline
++aufs_bindex_t au_sbr_id(struct super_block *sb, aufs_bindex_t bindex)
++{
++	return au_sbr(sb, bindex)->br_id;
++}
++
++static inline
++struct vfsmount *au_sbr_mnt(struct super_block *sb, aufs_bindex_t bindex)
++{
++	return au_sbr(sb, bindex)->br_mnt;
++}
++
++static inline
++struct super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex)
++{
++	return au_sbr_mnt(sb, bindex)->mnt_sb;
++}
++
++static inline void au_sbr_put(struct super_block *sb, aufs_bindex_t bindex)
++{
++	atomic_dec(&au_sbr(sb, bindex)->br_count);
++}
++
++static inline int au_sbr_perm(struct super_block *sb, aufs_bindex_t bindex)
++{
++	return au_sbr(sb, bindex)->br_perm;
++}
++
++static inline int au_sbr_whable(struct super_block *sb, aufs_bindex_t bindex)
++{
++	return au_br_whable(au_sbr_perm(sb, bindex));
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * wbr_wh_read_lock, wbr_wh_write_lock
++ * wbr_wh_read_unlock, wbr_wh_write_unlock, wbr_wh_downgrade_lock
++ */
++AuSimpleRwsemFuncs(wbr_wh, struct au_wbr *wbr, &wbr->wbr_wh_rwsem);
++
++#define WbrWhMustNoWaiters(wbr)	AuRwMustNoWaiters(&wbr->wbr_wh_rwsem)
++#define WbrWhMustAnyLock(wbr)	AuRwMustAnyLock(&wbr->wbr_wh_rwsem)
++#define WbrWhMustWriteLock(wbr)	AuRwMustWriteLock(&wbr->wbr_wh_rwsem)
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_BRANCH_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/conf.mk linux-2.6.36/fs/aufs/conf.mk
+--- linux-2.6.36.orig/fs/aufs/conf.mk	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/conf.mk	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,37 @@
++
++AuConfStr = CONFIG_AUFS_FS=${CONFIG_AUFS_FS}
++
++define AuConf
++ifdef ${1}
++AuConfStr += ${1}=${${1}}
++endif
++endef
++
++AuConfAll = BRANCH_MAX_127 BRANCH_MAX_511 BRANCH_MAX_1023 BRANCH_MAX_32767 \
++	SBILIST \
++	HNOTIFY HFSNOTIFY \
++	EXPORT INO_T_64 \
++	RDU \
++	SP_IATTR \
++	SHWH \
++	BR_RAMFS \
++	BR_FUSE POLL \
++	BR_HFSPLUS \
++	BDEV_LOOP \
++	DEBUG MAGIC_SYSRQ
++$(foreach i, ${AuConfAll}, \
++	$(eval $(call AuConf,CONFIG_AUFS_${i})))
++
++AuConfName = ${obj}/conf.str
++${AuConfName}.tmp: FORCE
++	@echo ${AuConfStr} | tr ' ' '\n' | sed -e 's/^/"/' -e 's/$$/\\n"/' > $@
++${AuConfName}: ${AuConfName}.tmp
++	@diff -q $< $@ > /dev/null 2>&1 || { \
++	echo '  GEN    ' $@; \
++	cp -p $< $@; \
++	}
++FORCE:
++clean-files += ${AuConfName} ${AuConfName}.tmp
++${obj}/sysfs.o: ${AuConfName}
++
++-include ${srctree}/${src}/conf_priv.mk
+diff -Nur linux-2.6.36.orig/fs/aufs/cpup.c linux-2.6.36/fs/aufs/cpup.c
+--- linux-2.6.36.orig/fs/aufs/cpup.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/cpup.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1063 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * copy-up functions, see wbr_policy.c for copy-down
++ */
++
++#include <linux/file.h>
++#include <linux/fs_stack.h>
++#include <linux/mm.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++void au_cpup_attr_flags(struct inode *dst, struct inode *src)
++{
++	const unsigned int mask = S_DEAD | S_SWAPFILE | S_PRIVATE
++		| S_NOATIME | S_NOCMTIME;
++
++	dst->i_flags |= src->i_flags & ~mask;
++	if (au_test_fs_notime(dst->i_sb))
++		dst->i_flags |= S_NOATIME | S_NOCMTIME;
++}
++
++void au_cpup_attr_timesizes(struct inode *inode)
++{
++	struct inode *h_inode;
++
++	h_inode = au_h_iptr(inode, au_ibstart(inode));
++	fsstack_copy_attr_times(inode, h_inode);
++	fsstack_copy_inode_size(inode, h_inode);
++}
++
++void au_cpup_attr_nlink(struct inode *inode, int force)
++{
++	struct inode *h_inode;
++	struct super_block *sb;
++	aufs_bindex_t bindex, bend;
++
++	sb = inode->i_sb;
++	bindex = au_ibstart(inode);
++	h_inode = au_h_iptr(inode, bindex);
++	if (!force
++	    && !S_ISDIR(h_inode->i_mode)
++	    && au_opt_test(au_mntflags(sb), PLINK)
++	    && au_plink_test(inode))
++		return;
++
++	inode->i_nlink = h_inode->i_nlink;
++
++	/*
++	 * fewer nlink makes find(1) noisy, but larger nlink doesn't.
++	 * it may includes whplink directory.
++	 */
++	if (S_ISDIR(h_inode->i_mode)) {
++		bend = au_ibend(inode);
++		for (bindex++; bindex <= bend; bindex++) {
++			h_inode = au_h_iptr(inode, bindex);
++			if (h_inode)
++				au_add_nlink(inode, h_inode);
++		}
++	}
++}
++
++void au_cpup_attr_changeable(struct inode *inode)
++{
++	struct inode *h_inode;
++
++	h_inode = au_h_iptr(inode, au_ibstart(inode));
++	inode->i_mode = h_inode->i_mode;
++	inode->i_uid = h_inode->i_uid;
++	inode->i_gid = h_inode->i_gid;
++	au_cpup_attr_timesizes(inode);
++	au_cpup_attr_flags(inode, h_inode);
++}
++
++void au_cpup_igen(struct inode *inode, struct inode *h_inode)
++{
++	struct au_iinfo *iinfo = au_ii(inode);
++
++	IiMustWriteLock(inode);
++
++	iinfo->ii_higen = h_inode->i_generation;
++	iinfo->ii_hsb1 = h_inode->i_sb;
++}
++
++void au_cpup_attr_all(struct inode *inode, int force)
++{
++	struct inode *h_inode;
++
++	h_inode = au_h_iptr(inode, au_ibstart(inode));
++	au_cpup_attr_changeable(inode);
++	if (inode->i_nlink > 0)
++		au_cpup_attr_nlink(inode, force);
++	inode->i_rdev = h_inode->i_rdev;
++	inode->i_blkbits = h_inode->i_blkbits;
++	au_cpup_igen(inode, h_inode);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* Note: dt_dentry and dt_h_dentry are not dget/dput-ed */
++
++/* keep the timestamps of the parent dir when cpup */
++void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
++		    struct path *h_path)
++{
++	struct inode *h_inode;
++
++	dt->dt_dentry = dentry;
++	dt->dt_h_path = *h_path;
++	h_inode = h_path->dentry->d_inode;
++	dt->dt_atime = h_inode->i_atime;
++	dt->dt_mtime = h_inode->i_mtime;
++	/* smp_mb(); */
++}
++
++void au_dtime_revert(struct au_dtime *dt)
++{
++	struct iattr attr;
++	int err;
++
++	attr.ia_atime = dt->dt_atime;
++	attr.ia_mtime = dt->dt_mtime;
++	attr.ia_valid = ATTR_FORCE | ATTR_MTIME | ATTR_MTIME_SET
++		| ATTR_ATIME | ATTR_ATIME_SET;
++
++	err = vfsub_notify_change(&dt->dt_h_path, &attr);
++	if (unlikely(err))
++		pr_warning("restoring timestamps failed(%d). ignored\n", err);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static noinline_for_stack
++int cpup_iattr(struct dentry *dst, aufs_bindex_t bindex, struct dentry *h_src)
++{
++	int err, sbits;
++	struct iattr ia;
++	struct path h_path;
++	struct inode *h_isrc, *h_idst;
++
++	h_path.dentry = au_h_dptr(dst, bindex);
++	h_idst = h_path.dentry->d_inode;
++	h_path.mnt = au_sbr_mnt(dst->d_sb, bindex);
++	h_isrc = h_src->d_inode;
++	ia.ia_valid = ATTR_FORCE | ATTR_UID | ATTR_GID
++		| ATTR_ATIME | ATTR_MTIME
++		| ATTR_ATIME_SET | ATTR_MTIME_SET;
++	ia.ia_uid = h_isrc->i_uid;
++	ia.ia_gid = h_isrc->i_gid;
++	ia.ia_atime = h_isrc->i_atime;
++	ia.ia_mtime = h_isrc->i_mtime;
++	if (h_idst->i_mode != h_isrc->i_mode
++	    && !S_ISLNK(h_idst->i_mode)) {
++		ia.ia_valid |= ATTR_MODE;
++		ia.ia_mode = h_isrc->i_mode;
++	}
++	sbits = !!(h_isrc->i_mode & (S_ISUID | S_ISGID));
++	au_cpup_attr_flags(h_idst, h_isrc);
++	err = vfsub_notify_change(&h_path, &ia);
++
++	/* is this nfs only? */
++	if (!err && sbits && au_test_nfs(h_path.dentry->d_sb)) {
++		ia.ia_valid = ATTR_FORCE | ATTR_MODE;
++		ia.ia_mode = h_isrc->i_mode;
++		err = vfsub_notify_change(&h_path, &ia);
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_copy_file(struct file *dst, struct file *src, loff_t len,
++			   char *buf, unsigned long blksize)
++{
++	int err;
++	size_t sz, rbytes, wbytes;
++	unsigned char all_zero;
++	char *p, *zp;
++	struct mutex *h_mtx;
++	/* reduce stack usage */
++	struct iattr *ia;
++
++	zp = page_address(ZERO_PAGE(0));
++	if (unlikely(!zp))
++		return -ENOMEM; /* possible? */
++
++	err = 0;
++	all_zero = 0;
++	while (len) {
++		AuDbg("len %lld\n", len);
++		sz = blksize;
++		if (len < blksize)
++			sz = len;
++
++		rbytes = 0;
++		/* todo: signal_pending? */
++		while (!rbytes || err == -EAGAIN || err == -EINTR) {
++			rbytes = vfsub_read_k(src, buf, sz, &src->f_pos);
++			err = rbytes;
++		}
++		if (unlikely(err < 0))
++			break;
++
++		all_zero = 0;
++		if (len >= rbytes && rbytes == blksize)
++			all_zero = !memcmp(buf, zp, rbytes);
++		if (!all_zero) {
++			wbytes = rbytes;
++			p = buf;
++			while (wbytes) {
++				size_t b;
++
++				b = vfsub_write_k(dst, p, wbytes, &dst->f_pos);
++				err = b;
++				/* todo: signal_pending? */
++				if (unlikely(err == -EAGAIN || err == -EINTR))
++					continue;
++				if (unlikely(err < 0))
++					break;
++				wbytes -= b;
++				p += b;
++			}
++		} else {
++			loff_t res;
++
++			AuLabel(hole);
++			res = vfsub_llseek(dst, rbytes, SEEK_CUR);
++			err = res;
++			if (unlikely(res < 0))
++				break;
++		}
++		len -= rbytes;
++		err = 0;
++	}
++
++	/* the last block may be a hole */
++	if (!err && all_zero) {
++		AuLabel(last hole);
++
++		err = 1;
++		if (au_test_nfs(dst->f_dentry->d_sb)) {
++			/* nfs requires this step to make last hole */
++			/* is this only nfs? */
++			do {
++				/* todo: signal_pending? */
++				err = vfsub_write_k(dst, "\0", 1, &dst->f_pos);
++			} while (err == -EAGAIN || err == -EINTR);
++			if (err == 1)
++				dst->f_pos--;
++		}
++
++		if (err == 1) {
++			ia = (void *)buf;
++			ia->ia_size = dst->f_pos;
++			ia->ia_valid = ATTR_SIZE | ATTR_FILE;
++			ia->ia_file = dst;
++			h_mtx = &dst->f_dentry->d_inode->i_mutex;
++			mutex_lock_nested(h_mtx, AuLsc_I_CHILD2);
++			err = vfsub_notify_change(&dst->f_path, ia);
++			mutex_unlock(h_mtx);
++		}
++	}
++
++	return err;
++}
++
++int au_copy_file(struct file *dst, struct file *src, loff_t len)
++{
++	int err;
++	unsigned long blksize;
++	unsigned char do_kfree;
++	char *buf;
++
++	err = -ENOMEM;
++	blksize = dst->f_dentry->d_sb->s_blocksize;
++	if (!blksize || PAGE_SIZE < blksize)
++		blksize = PAGE_SIZE;
++	AuDbg("blksize %lu\n", blksize);
++	do_kfree = (blksize != PAGE_SIZE && blksize >= sizeof(struct iattr *));
++	if (do_kfree)
++		buf = kmalloc(blksize, GFP_NOFS);
++	else
++		buf = (void *)__get_free_page(GFP_NOFS);
++	if (unlikely(!buf))
++		goto out;
++
++	if (len > (1 << 22))
++		AuDbg("copying a large file %lld\n", (long long)len);
++
++	src->f_pos = 0;
++	dst->f_pos = 0;
++	err = au_do_copy_file(dst, src, len, buf, blksize);
++	if (do_kfree)
++		kfree(buf);
++	else
++		free_page((unsigned long)buf);
++
++out:
++	return err;
++}
++
++/*
++ * to support a sparse file which is opened with O_APPEND,
++ * we need to close the file.
++ */
++static int au_cp_regular(struct dentry *dentry, aufs_bindex_t bdst,
++			 aufs_bindex_t bsrc, loff_t len)
++{
++	int err, i;
++	enum { SRC, DST };
++	struct {
++		aufs_bindex_t bindex;
++		unsigned int flags;
++		struct dentry *dentry;
++		struct file *file;
++		void *label, *label_file;
++	} *f, file[] = {
++		{
++			.bindex = bsrc,
++			.flags = O_RDONLY | O_NOATIME | O_LARGEFILE,
++			.file = NULL,
++			.label = &&out,
++			.label_file = &&out_src
++		},
++		{
++			.bindex = bdst,
++			.flags = O_WRONLY | O_NOATIME | O_LARGEFILE,
++			.file = NULL,
++			.label = &&out_src,
++			.label_file = &&out_dst
++		}
++	};
++	struct super_block *sb;
++
++	/* bsrc branch can be ro/rw. */
++	sb = dentry->d_sb;
++	f = file;
++	for (i = 0; i < 2; i++, f++) {
++		f->dentry = au_h_dptr(dentry, f->bindex);
++		f->file = au_h_open(dentry, f->bindex, f->flags, /*file*/NULL);
++		err = PTR_ERR(f->file);
++		if (IS_ERR(f->file))
++			goto *f->label;
++		err = -EINVAL;
++		if (unlikely(!f->file->f_op))
++			goto *f->label_file;
++	}
++
++	/* try stopping to update while we copyup */
++	IMustLock(file[SRC].dentry->d_inode);
++	err = au_copy_file(file[DST].file, file[SRC].file, len);
++
++out_dst:
++	fput(file[DST].file);
++	au_sbr_put(sb, file[DST].bindex);
++out_src:
++	fput(file[SRC].file);
++	au_sbr_put(sb, file[SRC].bindex);
++out:
++	return err;
++}
++
++static int au_do_cpup_regular(struct dentry *dentry, aufs_bindex_t bdst,
++			      aufs_bindex_t bsrc, loff_t len,
++			      struct inode *h_dir, struct path *h_path)
++{
++	int err, rerr;
++	loff_t l;
++
++	err = 0;
++	l = i_size_read(au_h_iptr(dentry->d_inode, bsrc));
++	if (len == -1 || l < len)
++		len = l;
++	if (len)
++		err = au_cp_regular(dentry, bdst, bsrc, len);
++	if (!err)
++		goto out; /* success */
++
++	rerr = vfsub_unlink(h_dir, h_path, /*force*/0);
++	if (rerr) {
++		AuIOErr("failed unlinking cpup-ed %.*s(%d, %d)\n",
++			AuDLNPair(h_path->dentry), err, rerr);
++		err = -EIO;
++	}
++
++out:
++	return err;
++}
++
++static int au_do_cpup_symlink(struct path *h_path, struct dentry *h_src,
++			      struct inode *h_dir)
++{
++	int err, symlen;
++	mm_segment_t old_fs;
++	union {
++		char *k;
++		char __user *u;
++	} sym;
++
++	err = -ENOSYS;
++	if (unlikely(!h_src->d_inode->i_op->readlink))
++		goto out;
++
++	err = -ENOMEM;
++	sym.k = __getname_gfp(GFP_NOFS);
++	if (unlikely(!sym.k))
++		goto out;
++
++	old_fs = get_fs();
++	set_fs(KERNEL_DS);
++	symlen = h_src->d_inode->i_op->readlink(h_src, sym.u, PATH_MAX);
++	err = symlen;
++	set_fs(old_fs);
++
++	if (symlen > 0) {
++		sym.k[symlen] = 0;
++		err = vfsub_symlink(h_dir, h_path, sym.k);
++	}
++	__putname(sym.k);
++
++out:
++	return err;
++}
++
++/* return with the lower dst inode is locked */
++static noinline_for_stack
++int cpup_entry(struct dentry *dentry, aufs_bindex_t bdst,
++	       aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++	       struct dentry *dst_parent)
++{
++	int err;
++	umode_t mode;
++	unsigned int mnt_flags;
++	unsigned char isdir;
++	const unsigned char do_dt = !!au_ftest_cpup(flags, DTIME);
++	struct au_dtime dt;
++	struct path h_path;
++	struct dentry *h_src, *h_dst, *h_parent;
++	struct inode *h_inode, *h_dir;
++	struct super_block *sb;
++
++	/* bsrc branch can be ro/rw. */
++	h_src = au_h_dptr(dentry, bsrc);
++	h_inode = h_src->d_inode;
++	AuDebugOn(h_inode != au_h_iptr(dentry->d_inode, bsrc));
++
++	/* try stopping to be referenced while we are creating */
++	h_dst = au_h_dptr(dentry, bdst);
++	h_parent = h_dst->d_parent; /* dir inode is locked */
++	h_dir = h_parent->d_inode;
++	IMustLock(h_dir);
++	AuDebugOn(h_parent != h_dst->d_parent);
++
++	sb = dentry->d_sb;
++	h_path.mnt = au_sbr_mnt(sb, bdst);
++	if (do_dt) {
++		h_path.dentry = h_parent;
++		au_dtime_store(&dt, dst_parent, &h_path);
++	}
++	h_path.dentry = h_dst;
++
++	isdir = 0;
++	mode = h_inode->i_mode;
++	switch (mode & S_IFMT) {
++	case S_IFREG:
++		/* try stopping to update while we are referencing */
++		IMustLock(h_inode);
++		err = vfsub_create(h_dir, &h_path, mode | S_IWUSR);
++		if (!err)
++			err = au_do_cpup_regular
++				(dentry, bdst, bsrc, len,
++				 au_h_iptr(dst_parent->d_inode, bdst), &h_path);
++		break;
++	case S_IFDIR:
++		isdir = 1;
++		err = vfsub_mkdir(h_dir, &h_path, mode);
++		if (!err) {
++			/*
++			 * strange behaviour from the users view,
++			 * particularry setattr case
++			 */
++			if (au_ibstart(dst_parent->d_inode) == bdst)
++				au_cpup_attr_nlink(dst_parent->d_inode,
++						   /*force*/1);
++			au_cpup_attr_nlink(dentry->d_inode, /*force*/1);
++		}
++		break;
++	case S_IFLNK:
++		err = au_do_cpup_symlink(&h_path, h_src, h_dir);
++		break;
++	case S_IFCHR:
++	case S_IFBLK:
++		AuDebugOn(!capable(CAP_MKNOD));
++		/*FALLTHROUGH*/
++	case S_IFIFO:
++	case S_IFSOCK:
++		err = vfsub_mknod(h_dir, &h_path, mode, h_inode->i_rdev);
++		break;
++	default:
++		AuIOErr("Unknown inode type 0%o\n", mode);
++		err = -EIO;
++	}
++
++	mnt_flags = au_mntflags(sb);
++	if (!au_opt_test(mnt_flags, UDBA_NONE)
++	    && !isdir
++	    && au_opt_test(mnt_flags, XINO)
++	    && h_inode->i_nlink == 1
++	    /* todo: unnecessary? */
++	    /* && dentry->d_inode->i_nlink == 1 */
++	    && bdst < bsrc
++	    && !au_ftest_cpup(flags, KEEPLINO))
++		au_xino_write(sb, bsrc, h_inode->i_ino, /*ino*/0);
++		/* ignore this error */
++
++	if (do_dt)
++		au_dtime_revert(&dt);
++	return err;
++}
++
++/*
++ * copyup the @dentry from @bsrc to @bdst.
++ * the caller must set the both of lower dentries.
++ * @len is for truncating when it is -1 copyup the entire file.
++ * in link/rename cases, @dst_parent may be different from the real one.
++ */
++static int au_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++			  aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++			  struct dentry *dst_parent)
++{
++	int err, rerr;
++	aufs_bindex_t old_ibstart;
++	unsigned char isdir, plink;
++	struct au_dtime dt;
++	struct path h_path;
++	struct dentry *h_src, *h_dst, *h_parent;
++	struct inode *dst_inode, *h_dir, *inode;
++	struct super_block *sb;
++
++	AuDebugOn(bsrc <= bdst);
++
++	sb = dentry->d_sb;
++	h_path.mnt = au_sbr_mnt(sb, bdst);
++	h_dst = au_h_dptr(dentry, bdst);
++	h_parent = h_dst->d_parent; /* dir inode is locked */
++	h_dir = h_parent->d_inode;
++	IMustLock(h_dir);
++
++	h_src = au_h_dptr(dentry, bsrc);
++	inode = dentry->d_inode;
++
++	if (!dst_parent)
++		dst_parent = dget_parent(dentry);
++	else
++		dget(dst_parent);
++
++	plink = !!au_opt_test(au_mntflags(sb), PLINK);
++	dst_inode = au_h_iptr(inode, bdst);
++	if (dst_inode) {
++		if (unlikely(!plink)) {
++			err = -EIO;
++			AuIOErr("hi%lu(i%lu) exists on b%d "
++				"but plink is disabled\n",
++				dst_inode->i_ino, inode->i_ino, bdst);
++			goto out;
++		}
++
++		if (dst_inode->i_nlink) {
++			const int do_dt = au_ftest_cpup(flags, DTIME);
++
++			h_src = au_plink_lkup(inode, bdst);
++			err = PTR_ERR(h_src);
++			if (IS_ERR(h_src))
++				goto out;
++			if (unlikely(!h_src->d_inode)) {
++				err = -EIO;
++				AuIOErr("i%lu exists on a upper branch "
++					"but not pseudo-linked\n",
++					inode->i_ino);
++				dput(h_src);
++				goto out;
++			}
++
++			if (do_dt) {
++				h_path.dentry = h_parent;
++				au_dtime_store(&dt, dst_parent, &h_path);
++			}
++			h_path.dentry = h_dst;
++			err = vfsub_link(h_src, h_dir, &h_path);
++			if (do_dt)
++				au_dtime_revert(&dt);
++			dput(h_src);
++			goto out;
++		} else
++			/* todo: cpup_wh_file? */
++			/* udba work */
++			au_update_ibrange(inode, /*do_put_zero*/1);
++	}
++
++	old_ibstart = au_ibstart(inode);
++	err = cpup_entry(dentry, bdst, bsrc, len, flags, dst_parent);
++	if (unlikely(err))
++		goto out;
++	dst_inode = h_dst->d_inode;
++	mutex_lock_nested(&dst_inode->i_mutex, AuLsc_I_CHILD2);
++
++	err = cpup_iattr(dentry, bdst, h_src);
++	isdir = S_ISDIR(dst_inode->i_mode);
++	if (!err) {
++		if (bdst < old_ibstart) {
++			if (S_ISREG(inode->i_mode)) {
++				err = au_dy_iaop(inode, bdst, dst_inode);
++				if (unlikely(err))
++					goto out_rev;
++			}
++			au_set_ibstart(inode, bdst);
++		}
++		au_set_h_iptr(inode, bdst, au_igrab(dst_inode),
++			      au_hi_flags(inode, isdir));
++		mutex_unlock(&dst_inode->i_mutex);
++		if (!isdir
++		    && h_src->d_inode->i_nlink > 1
++		    && plink)
++			au_plink_append(inode, bdst, h_dst);
++		goto out; /* success */
++	}
++
++	/* revert */
++out_rev:
++	h_path.dentry = h_parent;
++	mutex_unlock(&dst_inode->i_mutex);
++	au_dtime_store(&dt, dst_parent, &h_path);
++	h_path.dentry = h_dst;
++	if (!isdir)
++		rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
++	else
++		rerr = vfsub_rmdir(h_dir, &h_path);
++	au_dtime_revert(&dt);
++	if (rerr) {
++		AuIOErr("failed removing broken entry(%d, %d)\n", err, rerr);
++		err = -EIO;
++	}
++
++out:
++	dput(dst_parent);
++	return err;
++}
++
++struct au_cpup_single_args {
++	int *errp;
++	struct dentry *dentry;
++	aufs_bindex_t bdst, bsrc;
++	loff_t len;
++	unsigned int flags;
++	struct dentry *dst_parent;
++};
++
++static void au_call_cpup_single(void *args)
++{
++	struct au_cpup_single_args *a = args;
++	*a->errp = au_cpup_single(a->dentry, a->bdst, a->bsrc, a->len,
++				  a->flags, a->dst_parent);
++}
++
++int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++		       aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++		       struct dentry *dst_parent)
++{
++	int err, wkq_err;
++	umode_t mode;
++	struct dentry *h_dentry;
++
++	h_dentry = au_h_dptr(dentry, bsrc);
++	mode = h_dentry->d_inode->i_mode & S_IFMT;
++	if ((mode != S_IFCHR && mode != S_IFBLK)
++	    || capable(CAP_MKNOD))
++		err = au_cpup_single(dentry, bdst, bsrc, len, flags,
++				     dst_parent);
++	else {
++		struct au_cpup_single_args args = {
++			.errp		= &err,
++			.dentry		= dentry,
++			.bdst		= bdst,
++			.bsrc		= bsrc,
++			.len		= len,
++			.flags		= flags,
++			.dst_parent	= dst_parent
++		};
++		wkq_err = au_wkq_wait(au_call_cpup_single, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	return err;
++}
++
++/*
++ * copyup the @dentry from the first active lower branch to @bdst,
++ * using au_cpup_single().
++ */
++static int au_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++			  unsigned int flags)
++{
++	int err;
++	aufs_bindex_t bsrc, bend;
++
++	bend = au_dbend(dentry);
++	for (bsrc = bdst + 1; bsrc <= bend; bsrc++)
++		if (au_h_dptr(dentry, bsrc))
++			break;
++
++	err = au_lkup_neg(dentry, bdst);
++	if (!err) {
++		err = au_cpup_single(dentry, bdst, bsrc, len, flags, NULL);
++		if (!err)
++			return 0; /* success */
++
++		/* revert */
++		au_set_h_dptr(dentry, bdst, NULL);
++		au_set_dbstart(dentry, bsrc);
++	}
++
++	return err;
++}
++
++struct au_cpup_simple_args {
++	int *errp;
++	struct dentry *dentry;
++	aufs_bindex_t bdst;
++	loff_t len;
++	unsigned int flags;
++};
++
++static void au_call_cpup_simple(void *args)
++{
++	struct au_cpup_simple_args *a = args;
++	*a->errp = au_cpup_simple(a->dentry, a->bdst, a->len, a->flags);
++}
++
++int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++		       unsigned int flags)
++{
++	int err, wkq_err;
++	unsigned char do_sio;
++	struct dentry *parent;
++	struct inode *h_dir;
++
++	parent = dget_parent(dentry);
++	h_dir = au_h_iptr(parent->d_inode, bdst);
++	do_sio = !!au_test_h_perm_sio(h_dir, MAY_EXEC | MAY_WRITE);
++	if (!do_sio) {
++		/*
++		 * testing CAP_MKNOD is for generic fs,
++		 * but CAP_FSETID is for xfs only, currently.
++		 */
++		umode_t mode = dentry->d_inode->i_mode;
++		do_sio = (((mode & (S_IFCHR | S_IFBLK))
++			   && !capable(CAP_MKNOD))
++			  || ((mode & (S_ISUID | S_ISGID))
++			      && !capable(CAP_FSETID)));
++	}
++	if (!do_sio)
++		err = au_cpup_simple(dentry, bdst, len, flags);
++	else {
++		struct au_cpup_simple_args args = {
++			.errp		= &err,
++			.dentry		= dentry,
++			.bdst		= bdst,
++			.len		= len,
++			.flags		= flags
++		};
++		wkq_err = au_wkq_wait(au_call_cpup_simple, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	dput(parent);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * copyup the deleted file for writing.
++ */
++static int au_do_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst,
++			 struct dentry *wh_dentry, struct file *file,
++			 loff_t len)
++{
++	int err;
++	aufs_bindex_t bstart;
++	struct au_dinfo *dinfo;
++	struct dentry *h_d_dst, *h_d_start;
++	struct au_hdentry *hdp;
++
++	dinfo = au_di(dentry);
++	AuRwMustWriteLock(&dinfo->di_rwsem);
++
++	bstart = dinfo->di_bstart;
++	hdp = dinfo->di_hdentry;
++	h_d_dst = hdp[0 + bdst].hd_dentry;
++	dinfo->di_bstart = bdst;
++	hdp[0 + bdst].hd_dentry = wh_dentry;
++	if (file) {
++		h_d_start = hdp[0 + bstart].hd_dentry;
++		hdp[0 + bstart].hd_dentry = au_hf_top(file)->f_dentry;
++	}
++	err = au_cpup_single(dentry, bdst, bstart, len, !AuCpup_DTIME,
++			     /*h_parent*/NULL);
++	if (file) {
++		if (!err)
++			err = au_reopen_nondir(file);
++		hdp[0 + bstart].hd_dentry = h_d_start;
++	}
++	hdp[0 + bdst].hd_dentry = h_d_dst;
++	dinfo->di_bstart = bstart;
++
++	return err;
++}
++
++static int au_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++		      struct file *file)
++{
++	int err;
++	struct au_dtime dt;
++	struct dentry *parent, *h_parent, *wh_dentry;
++	struct au_branch *br;
++	struct path h_path;
++
++	br = au_sbr(dentry->d_sb, bdst);
++	parent = dget_parent(dentry);
++	h_parent = au_h_dptr(parent, bdst);
++	wh_dentry = au_whtmp_lkup(h_parent, br, &dentry->d_name);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out;
++
++	h_path.dentry = h_parent;
++	h_path.mnt = br->br_mnt;
++	au_dtime_store(&dt, parent, &h_path);
++	err = au_do_cpup_wh(dentry, bdst, wh_dentry, file, len);
++	if (unlikely(err))
++		goto out_wh;
++
++	dget(wh_dentry);
++	h_path.dentry = wh_dentry;
++	if (!S_ISDIR(wh_dentry->d_inode->i_mode))
++		err = vfsub_unlink(h_parent->d_inode, &h_path, /*force*/0);
++	else
++		err = vfsub_rmdir(h_parent->d_inode, &h_path);
++	if (unlikely(err)) {
++		AuIOErr("failed remove copied-up tmp file %.*s(%d)\n",
++			AuDLNPair(wh_dentry), err);
++		err = -EIO;
++	}
++	au_dtime_revert(&dt);
++	au_set_hi_wh(dentry->d_inode, bdst, wh_dentry);
++
++out_wh:
++	dput(wh_dentry);
++out:
++	dput(parent);
++	return err;
++}
++
++struct au_cpup_wh_args {
++	int *errp;
++	struct dentry *dentry;
++	aufs_bindex_t bdst;
++	loff_t len;
++	struct file *file;
++};
++
++static void au_call_cpup_wh(void *args)
++{
++	struct au_cpup_wh_args *a = args;
++	*a->errp = au_cpup_wh(a->dentry, a->bdst, a->len, a->file);
++}
++
++int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++		   struct file *file)
++{
++	int err, wkq_err;
++	struct dentry *parent, *h_orph, *h_parent, *h_dentry;
++	struct inode *dir, *h_dir, *h_tmpdir, *h_inode;
++	struct au_wbr *wbr;
++
++	parent = dget_parent(dentry);
++	dir = parent->d_inode;
++	h_orph = NULL;
++	h_parent = NULL;
++	h_dir = au_igrab(au_h_iptr(dir, bdst));
++	h_tmpdir = h_dir;
++	if (!h_dir->i_nlink) {
++		wbr = au_sbr(dentry->d_sb, bdst)->br_wbr;
++		h_orph = wbr->wbr_orph;
++
++		h_parent = dget(au_h_dptr(parent, bdst));
++		au_set_h_dptr(parent, bdst, dget(h_orph));
++		h_tmpdir = h_orph->d_inode;
++		au_set_h_iptr(dir, bdst, au_igrab(h_tmpdir), /*flags*/0);
++
++		/* this temporary unlock is safe */
++		if (file)
++			h_dentry = au_hf_top(file)->f_dentry;
++		else
++			h_dentry = au_h_dptr(dentry, au_dbstart(dentry));
++		h_inode = h_dentry->d_inode;
++		IMustLock(h_inode);
++		mutex_unlock(&h_inode->i_mutex);
++		mutex_lock_nested(&h_tmpdir->i_mutex, AuLsc_I_PARENT3);
++		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++		/* todo: au_h_open_pre()? */
++	}
++
++	if (!au_test_h_perm_sio(h_tmpdir, MAY_EXEC | MAY_WRITE))
++		err = au_cpup_wh(dentry, bdst, len, file);
++	else {
++		struct au_cpup_wh_args args = {
++			.errp	= &err,
++			.dentry	= dentry,
++			.bdst	= bdst,
++			.len	= len,
++			.file	= file
++		};
++		wkq_err = au_wkq_wait(au_call_cpup_wh, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	if (h_orph) {
++		mutex_unlock(&h_tmpdir->i_mutex);
++		/* todo: au_h_open_post()? */
++		au_set_h_iptr(dir, bdst, au_igrab(h_dir), /*flags*/0);
++		au_set_h_dptr(parent, bdst, h_parent);
++	}
++	iput(h_dir);
++	dput(parent);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * generic routine for both of copy-up and copy-down.
++ */
++/* cf. revalidate function in file.c */
++int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst,
++	       int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
++			 struct dentry *h_parent, void *arg),
++	       void *arg)
++{
++	int err;
++	struct au_pin pin;
++	struct dentry *d, *parent, *h_parent, *real_parent;
++
++	err = 0;
++	parent = dget_parent(dentry);
++	if (IS_ROOT(parent))
++		goto out;
++
++	au_pin_init(&pin, dentry, bdst, AuLsc_DI_PARENT2, AuLsc_I_PARENT2,
++		    au_opt_udba(dentry->d_sb), AuPin_MNT_WRITE);
++
++	/* do not use au_dpage */
++	real_parent = parent;
++	while (1) {
++		dput(parent);
++		parent = dget_parent(dentry);
++		h_parent = au_h_dptr(parent, bdst);
++		if (h_parent)
++			goto out; /* success */
++
++		/* find top dir which is necessary to cpup */
++		do {
++			d = parent;
++			dput(parent);
++			parent = dget_parent(d);
++			di_read_lock_parent3(parent, !AuLock_IR);
++			h_parent = au_h_dptr(parent, bdst);
++			di_read_unlock(parent, !AuLock_IR);
++		} while (!h_parent);
++
++		if (d != real_parent)
++			di_write_lock_child3(d);
++
++		/* somebody else might create while we were sleeping */
++		if (!au_h_dptr(d, bdst) || !au_h_dptr(d, bdst)->d_inode) {
++			if (au_h_dptr(d, bdst))
++				au_update_dbstart(d);
++
++			au_pin_set_dentry(&pin, d);
++			err = au_do_pin(&pin);
++			if (!err) {
++				err = cp(d, bdst, h_parent, arg);
++				au_unpin(&pin);
++			}
++		}
++
++		if (d != real_parent)
++			di_write_unlock(d);
++		if (unlikely(err))
++			break;
++	}
++
++out:
++	dput(parent);
++	return err;
++}
++
++static int au_cpup_dir(struct dentry *dentry, aufs_bindex_t bdst,
++		       struct dentry *h_parent __maybe_unused ,
++		       void *arg __maybe_unused)
++{
++	return au_sio_cpup_simple(dentry, bdst, -1, AuCpup_DTIME);
++}
++
++int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++	return au_cp_dirs(dentry, bdst, au_cpup_dir, NULL);
++}
++
++int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++	int err;
++	struct dentry *parent;
++	struct inode *dir;
++
++	parent = dget_parent(dentry);
++	dir = parent->d_inode;
++	err = 0;
++	if (au_h_iptr(dir, bdst))
++		goto out;
++
++	di_read_unlock(parent, AuLock_IR);
++	di_write_lock_parent(parent);
++	/* someone else might change our inode while we were sleeping */
++	if (!au_h_iptr(dir, bdst))
++		err = au_cpup_dirs(dentry, bdst);
++	di_downgrade_lock(parent, AuLock_IR);
++
++out:
++	dput(parent);
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/cpup.h linux-2.6.36/fs/aufs/cpup.h
+--- linux-2.6.36.orig/fs/aufs/cpup.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/cpup.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,83 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * copy-up/down functions
++ */
++
++#ifndef __AUFS_CPUP_H__
++#define __AUFS_CPUP_H__
++
++#ifdef __KERNEL__
++
++#include <linux/path.h>
++#include <linux/time.h>
++#include <linux/aufs_type.h>
++
++struct inode;
++struct file;
++
++void au_cpup_attr_flags(struct inode *dst, struct inode *src);
++void au_cpup_attr_timesizes(struct inode *inode);
++void au_cpup_attr_nlink(struct inode *inode, int force);
++void au_cpup_attr_changeable(struct inode *inode);
++void au_cpup_igen(struct inode *inode, struct inode *h_inode);
++void au_cpup_attr_all(struct inode *inode, int force);
++
++/* ---------------------------------------------------------------------- */
++
++/* cpup flags */
++#define AuCpup_DTIME	1		/* do dtime_store/revert */
++#define AuCpup_KEEPLINO	(1 << 1)	/* do not clear the lower xino,
++					   for link(2) */
++#define au_ftest_cpup(flags, name)	((flags) & AuCpup_##name)
++#define au_fset_cpup(flags, name) \
++	do { (flags) |= AuCpup_##name; } while (0)
++#define au_fclr_cpup(flags, name) \
++	do { (flags) &= ~AuCpup_##name; } while (0)
++
++int au_copy_file(struct file *dst, struct file *src, loff_t len);
++int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++		       aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++		       struct dentry *dst_parent);
++int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++		       unsigned int flags);
++int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++		   struct file *file);
++
++int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst,
++	       int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
++			 struct dentry *h_parent, void *arg),
++	       void *arg);
++int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++
++/* ---------------------------------------------------------------------- */
++
++/* keep timestamps when copyup */
++struct au_dtime {
++	struct dentry *dt_dentry;
++	struct path dt_h_path;
++	struct timespec dt_atime, dt_mtime;
++};
++void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
++		    struct path *h_path);
++void au_dtime_revert(struct au_dtime *dt);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_CPUP_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/dbgaufs.c linux-2.6.36/fs/aufs/dbgaufs.c
+--- linux-2.6.36.orig/fs/aufs/dbgaufs.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dbgaufs.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,334 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * debugfs interface
++ */
++
++#include <linux/debugfs.h>
++#include "aufs.h"
++
++#ifndef CONFIG_SYSFS
++#error DEBUG_FS depends upon SYSFS
++#endif
++
++static struct dentry *dbgaufs;
++static const mode_t dbgaufs_mode = S_IRUSR | S_IRGRP | S_IROTH;
++
++/* 20 is max digits length of ulong 64 */
++struct dbgaufs_arg {
++	int n;
++	char a[20 * 4];
++};
++
++/*
++ * common function for all XINO files
++ */
++static int dbgaufs_xi_release(struct inode *inode __maybe_unused,
++			      struct file *file)
++{
++	kfree(file->private_data);
++	return 0;
++}
++
++static int dbgaufs_xi_open(struct file *xf, struct file *file, int do_fcnt)
++{
++	int err;
++	struct kstat st;
++	struct dbgaufs_arg *p;
++
++	err = -ENOMEM;
++	p = kmalloc(sizeof(*p), GFP_NOFS);
++	if (unlikely(!p))
++		goto out;
++
++	err = 0;
++	p->n = 0;
++	file->private_data = p;
++	if (!xf)
++		goto out;
++
++	err = vfs_getattr(xf->f_vfsmnt, xf->f_dentry, &st);
++	if (!err) {
++		if (do_fcnt)
++			p->n = snprintf
++				(p->a, sizeof(p->a), "%ld, %llux%lu %lld\n",
++				 (long)file_count(xf), st.blocks, st.blksize,
++				 (long long)st.size);
++		else
++			p->n = snprintf(p->a, sizeof(p->a), "%llux%lu %lld\n",
++					st.blocks, st.blksize,
++					(long long)st.size);
++		AuDebugOn(p->n >= sizeof(p->a));
++	} else {
++		p->n = snprintf(p->a, sizeof(p->a), "err %d\n", err);
++		err = 0;
++	}
++
++out:
++	return err;
++
++}
++
++static ssize_t dbgaufs_xi_read(struct file *file, char __user *buf,
++			       size_t count, loff_t *ppos)
++{
++	struct dbgaufs_arg *p;
++
++	p = file->private_data;
++	return simple_read_from_buffer(buf, count, ppos, p->a, p->n);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int dbgaufs_xib_open(struct inode *inode, struct file *file)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++	struct super_block *sb;
++
++	sbinfo = inode->i_private;
++	sb = sbinfo->si_sb;
++	si_noflush_read_lock(sb);
++	err = dbgaufs_xi_open(sbinfo->si_xib, file, /*do_fcnt*/0);
++	si_read_unlock(sb);
++	return err;
++}
++
++static const struct file_operations dbgaufs_xib_fop = {
++	.owner		= THIS_MODULE,
++	.open		= dbgaufs_xib_open,
++	.release	= dbgaufs_xi_release,
++	.read		= dbgaufs_xi_read
++};
++
++/* ---------------------------------------------------------------------- */
++
++#define DbgaufsXi_PREFIX "xi"
++
++static int dbgaufs_xino_open(struct inode *inode, struct file *file)
++{
++	int err;
++	long l;
++	struct au_sbinfo *sbinfo;
++	struct super_block *sb;
++	struct file *xf;
++	struct qstr *name;
++
++	err = -ENOENT;
++	xf = NULL;
++	name = &file->f_dentry->d_name;
++	if (unlikely(name->len < sizeof(DbgaufsXi_PREFIX)
++		     || memcmp(name->name, DbgaufsXi_PREFIX,
++			       sizeof(DbgaufsXi_PREFIX) - 1)))
++		goto out;
++	err = strict_strtol(name->name + sizeof(DbgaufsXi_PREFIX) - 1, 10, &l);
++	if (unlikely(err))
++		goto out;
++
++	sbinfo = inode->i_private;
++	sb = sbinfo->si_sb;
++	si_noflush_read_lock(sb);
++	if (l <= au_sbend(sb)) {
++		xf = au_sbr(sb, (aufs_bindex_t)l)->br_xino.xi_file;
++		err = dbgaufs_xi_open(xf, file, /*do_fcnt*/1);
++	} else
++		err = -ENOENT;
++	si_read_unlock(sb);
++
++out:
++	return err;
++}
++
++static const struct file_operations dbgaufs_xino_fop = {
++	.owner		= THIS_MODULE,
++	.open		= dbgaufs_xino_open,
++	.release	= dbgaufs_xi_release,
++	.read		= dbgaufs_xi_read
++};
++
++void dbgaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++	aufs_bindex_t bend;
++	struct au_branch *br;
++	struct au_xino_file *xi;
++
++	if (!au_sbi(sb)->si_dbgaufs)
++		return;
++
++	bend = au_sbend(sb);
++	for (; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		xi = &br->br_xino;
++		if (xi->xi_dbgaufs) {
++			debugfs_remove(xi->xi_dbgaufs);
++			xi->xi_dbgaufs = NULL;
++		}
++	}
++}
++
++void dbgaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++	struct au_sbinfo *sbinfo;
++	struct dentry *parent;
++	struct au_branch *br;
++	struct au_xino_file *xi;
++	aufs_bindex_t bend;
++	char name[sizeof(DbgaufsXi_PREFIX) + 5]; /* "xi" bindex NULL */
++
++	sbinfo = au_sbi(sb);
++	parent = sbinfo->si_dbgaufs;
++	if (!parent)
++		return;
++
++	bend = au_sbend(sb);
++	for (; bindex <= bend; bindex++) {
++		snprintf(name, sizeof(name), DbgaufsXi_PREFIX "%d", bindex);
++		br = au_sbr(sb, bindex);
++		xi = &br->br_xino;
++		AuDebugOn(xi->xi_dbgaufs);
++		xi->xi_dbgaufs = debugfs_create_file(name, dbgaufs_mode, parent,
++						     sbinfo, &dbgaufs_xino_fop);
++		/* ignore an error */
++		if (unlikely(!xi->xi_dbgaufs))
++			AuWarn1("failed %s under debugfs\n", name);
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_EXPORT
++static int dbgaufs_xigen_open(struct inode *inode, struct file *file)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++	struct super_block *sb;
++
++	sbinfo = inode->i_private;
++	sb = sbinfo->si_sb;
++	si_noflush_read_lock(sb);
++	err = dbgaufs_xi_open(sbinfo->si_xigen, file, /*do_fcnt*/0);
++	si_read_unlock(sb);
++	return err;
++}
++
++static const struct file_operations dbgaufs_xigen_fop = {
++	.owner		= THIS_MODULE,
++	.open		= dbgaufs_xigen_open,
++	.release	= dbgaufs_xi_release,
++	.read		= dbgaufs_xi_read
++};
++
++static int dbgaufs_xigen_init(struct au_sbinfo *sbinfo)
++{
++	int err;
++
++	/*
++	 * This function is a dynamic '__init' fucntion actually,
++	 * so the tiny check for si_rwsem is unnecessary.
++	 */
++	/* AuRwMustWriteLock(&sbinfo->si_rwsem); */
++
++	err = -EIO;
++	sbinfo->si_dbgaufs_xigen = debugfs_create_file
++		("xigen", dbgaufs_mode, sbinfo->si_dbgaufs, sbinfo,
++		 &dbgaufs_xigen_fop);
++	if (sbinfo->si_dbgaufs_xigen)
++		err = 0;
++
++	return err;
++}
++#else
++static int dbgaufs_xigen_init(struct au_sbinfo *sbinfo)
++{
++	return 0;
++}
++#endif /* CONFIG_AUFS_EXPORT */
++
++/* ---------------------------------------------------------------------- */
++
++void dbgaufs_si_fin(struct au_sbinfo *sbinfo)
++{
++	/*
++	 * This function is a dynamic '__init' fucntion actually,
++	 * so the tiny check for si_rwsem is unnecessary.
++	 */
++	/* AuRwMustWriteLock(&sbinfo->si_rwsem); */
++
++	debugfs_remove_recursive(sbinfo->si_dbgaufs);
++	sbinfo->si_dbgaufs = NULL;
++	kobject_put(&sbinfo->si_kobj);
++}
++
++int dbgaufs_si_init(struct au_sbinfo *sbinfo)
++{
++	int err;
++	char name[SysaufsSiNameLen];
++
++	/*
++	 * This function is a dynamic '__init' fucntion actually,
++	 * so the tiny check for si_rwsem is unnecessary.
++	 */
++	/* AuRwMustWriteLock(&sbinfo->si_rwsem); */
++
++	err = -ENOENT;
++	if (!dbgaufs) {
++		AuErr1("/debug/aufs is uninitialized\n");
++		goto out;
++	}
++
++	err = -EIO;
++	sysaufs_name(sbinfo, name);
++	sbinfo->si_dbgaufs = debugfs_create_dir(name, dbgaufs);
++	if (unlikely(!sbinfo->si_dbgaufs))
++		goto out;
++	kobject_get(&sbinfo->si_kobj);
++
++	sbinfo->si_dbgaufs_xib = debugfs_create_file
++		("xib", dbgaufs_mode, sbinfo->si_dbgaufs, sbinfo,
++		 &dbgaufs_xib_fop);
++	if (unlikely(!sbinfo->si_dbgaufs_xib))
++		goto out_dir;
++
++	err = dbgaufs_xigen_init(sbinfo);
++	if (!err)
++		goto out; /* success */
++
++out_dir:
++	dbgaufs_si_fin(sbinfo);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void dbgaufs_fin(void)
++{
++	debugfs_remove(dbgaufs);
++}
++
++int __init dbgaufs_init(void)
++{
++	int err;
++
++	err = -EIO;
++	dbgaufs = debugfs_create_dir(AUFS_NAME, NULL);
++	if (dbgaufs)
++		err = 0;
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/dbgaufs.h linux-2.6.36/fs/aufs/dbgaufs.h
+--- linux-2.6.36.orig/fs/aufs/dbgaufs.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dbgaufs.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,52 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * debugfs interface
++ */
++
++#ifndef __DBGAUFS_H__
++#define __DBGAUFS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/init.h>
++#include <linux/aufs_type.h>
++
++struct super_block;
++struct au_sbinfo;
++
++#ifdef CONFIG_DEBUG_FS
++/* dbgaufs.c */
++void dbgaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
++void dbgaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
++void dbgaufs_si_fin(struct au_sbinfo *sbinfo);
++int dbgaufs_si_init(struct au_sbinfo *sbinfo);
++void dbgaufs_fin(void);
++int __init dbgaufs_init(void);
++#else
++AuStubVoid(dbgaufs_brs_del, struct super_block *sb, aufs_bindex_t bindex)
++AuStubVoid(dbgaufs_brs_add, struct super_block *sb, aufs_bindex_t bindex)
++AuStubVoid(dbgaufs_si_fin, struct au_sbinfo *sbinfo)
++AuStubInt0(dbgaufs_si_init, struct au_sbinfo *sbinfo)
++AuStubVoid(dbgaufs_fin, void)
++AuStubInt0(__init dbgaufs_init, void)
++#endif /* CONFIG_DEBUG_FS */
++
++#endif /* __KERNEL__ */
++#endif /* __DBGAUFS_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/dcsub.c linux-2.6.36/fs/aufs/dcsub.c
+--- linux-2.6.36.orig/fs/aufs/dcsub.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dcsub.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,210 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sub-routines for dentry cache
++ */
++
++#include "aufs.h"
++
++static void au_dpage_free(struct au_dpage *dpage)
++{
++	int i;
++	struct dentry **p;
++
++	p = dpage->dentries;
++	for (i = 0; i < dpage->ndentry; i++)
++		dput(*p++);
++	free_page((unsigned long)dpage->dentries);
++}
++
++int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp)
++{
++	int err;
++	void *p;
++
++	err = -ENOMEM;
++	dpages->dpages = kmalloc(sizeof(*dpages->dpages), gfp);
++	if (unlikely(!dpages->dpages))
++		goto out;
++
++	p = (void *)__get_free_page(gfp);
++	if (unlikely(!p))
++		goto out_dpages;
++
++	dpages->dpages[0].ndentry = 0;
++	dpages->dpages[0].dentries = p;
++	dpages->ndpage = 1;
++	return 0; /* success */
++
++out_dpages:
++	kfree(dpages->dpages);
++out:
++	return err;
++}
++
++void au_dpages_free(struct au_dcsub_pages *dpages)
++{
++	int i;
++	struct au_dpage *p;
++
++	p = dpages->dpages;
++	for (i = 0; i < dpages->ndpage; i++)
++		au_dpage_free(p++);
++	kfree(dpages->dpages);
++}
++
++static int au_dpages_append(struct au_dcsub_pages *dpages,
++			    struct dentry *dentry, gfp_t gfp)
++{
++	int err, sz;
++	struct au_dpage *dpage;
++	void *p;
++
++	dpage = dpages->dpages + dpages->ndpage - 1;
++	sz = PAGE_SIZE / sizeof(dentry);
++	if (unlikely(dpage->ndentry >= sz)) {
++		AuLabel(new dpage);
++		err = -ENOMEM;
++		sz = dpages->ndpage * sizeof(*dpages->dpages);
++		p = au_kzrealloc(dpages->dpages, sz,
++				 sz + sizeof(*dpages->dpages), gfp);
++		if (unlikely(!p))
++			goto out;
++
++		dpages->dpages = p;
++		dpage = dpages->dpages + dpages->ndpage;
++		p = (void *)__get_free_page(gfp);
++		if (unlikely(!p))
++			goto out;
++
++		dpage->ndentry = 0;
++		dpage->dentries = p;
++		dpages->ndpage++;
++	}
++
++	/* d_count can be zero */
++	dpage->dentries[dpage->ndentry++] = dget_locked(dentry);
++	return 0; /* success */
++
++out:
++	return err;
++}
++
++int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
++		   au_dpages_test test, void *arg)
++{
++	int err;
++	struct dentry *this_parent = root;
++	struct list_head *next;
++	struct super_block *sb = root->d_sb;
++
++	err = 0;
++	spin_lock(&dcache_lock);
++repeat:
++	next = this_parent->d_subdirs.next;
++resume:
++	if (this_parent->d_sb == sb
++	    && !IS_ROOT(this_parent)
++	    && au_di(this_parent)
++	    && (!test || test(this_parent, arg))) {
++		err = au_dpages_append(dpages, this_parent, GFP_ATOMIC);
++		if (unlikely(err))
++			goto out;
++	}
++
++	while (next != &this_parent->d_subdirs) {
++		struct list_head *tmp = next;
++		struct dentry *dentry = list_entry(tmp, struct dentry,
++						   d_u.d_child);
++		next = tmp->next;
++		if (!list_empty(&dentry->d_subdirs)) {
++			this_parent = dentry;
++			goto repeat;
++		}
++		if (dentry->d_sb == sb
++		    && au_di(dentry)
++		    && (!test || test(dentry, arg))) {
++			err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++			if (unlikely(err))
++				goto out;
++		}
++	}
++
++	if (this_parent != root) {
++		next = this_parent->d_u.d_child.next;
++		this_parent = this_parent->d_parent; /* dcache_lock is locked */
++		goto resume;
++	}
++out:
++	spin_unlock(&dcache_lock);
++	return err;
++}
++
++int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
++		       int do_include, au_dpages_test test, void *arg)
++{
++	int err;
++
++	err = 0;
++	spin_lock(&dcache_lock);
++	if (do_include && (!test || test(dentry, arg))) {
++		err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++		if (unlikely(err))
++			goto out;
++	}
++	while (!IS_ROOT(dentry)) {
++		dentry = dentry->d_parent; /* dcache_lock is locked */
++		if (!test || test(dentry, arg)) {
++			err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++			if (unlikely(err))
++				break;
++		}
++	}
++
++out:
++	spin_unlock(&dcache_lock);
++
++	return err;
++}
++
++static inline int au_dcsub_dpages_aufs(struct dentry *dentry, void *arg)
++{
++	return au_di(dentry) && dentry->d_sb == arg;
++}
++
++int au_dcsub_pages_rev_aufs(struct au_dcsub_pages *dpages,
++			    struct dentry *dentry, int do_include)
++{
++	return au_dcsub_pages_rev(dpages, dentry, do_include,
++				  au_dcsub_dpages_aufs, dentry->d_sb);
++}
++
++int au_test_subdir(struct dentry *d1, struct dentry *d2)
++{
++	struct path path[2] = {
++		{
++			.dentry = d1
++		},
++		{
++			.dentry = d2
++		}
++	};
++
++	return path_is_under(path + 0, path + 1);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/dcsub.h linux-2.6.36/fs/aufs/dcsub.h
+--- linux-2.6.36.orig/fs/aufs/dcsub.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dcsub.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,100 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sub-routines for dentry cache
++ */
++
++#ifndef __AUFS_DCSUB_H__
++#define __AUFS_DCSUB_H__
++
++#ifdef __KERNEL__
++
++#include <linux/dcache.h>
++#include <linux/fs.h>
++#include <linux/types.h>
++
++struct dentry;
++
++struct au_dpage {
++	int ndentry;
++	struct dentry **dentries;
++};
++
++struct au_dcsub_pages {
++	int ndpage;
++	struct au_dpage *dpages;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* dcsub.c */
++int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp);
++void au_dpages_free(struct au_dcsub_pages *dpages);
++typedef int (*au_dpages_test)(struct dentry *dentry, void *arg);
++int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
++		   au_dpages_test test, void *arg);
++int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
++		       int do_include, au_dpages_test test, void *arg);
++int au_dcsub_pages_rev_aufs(struct au_dcsub_pages *dpages,
++			    struct dentry *dentry, int do_include);
++int au_test_subdir(struct dentry *d1, struct dentry *d2);
++
++/* ---------------------------------------------------------------------- */
++
++static inline int au_d_removed(struct dentry *d)
++{
++	return !IS_ROOT(d) && d_unhashed(d);
++}
++
++static inline int au_d_hashed_positive(struct dentry *d)
++{
++	int err;
++	struct inode *inode = d->d_inode;
++	err = 0;
++	if (unlikely(d_unhashed(d) || !inode || !inode->i_nlink))
++		err = -ENOENT;
++	return err;
++}
++
++static inline int au_d_alive(struct dentry *d)
++{
++	int err;
++	struct inode *inode;
++	err = 0;
++	if (!IS_ROOT(d))
++		err = au_d_hashed_positive(d);
++	else {
++		inode = d->d_inode;
++		if (unlikely(au_d_removed(d) || !inode || !inode->i_nlink))
++			err = -ENOENT;
++	}
++	return err;
++}
++
++static inline int au_alive_dir(struct dentry *d)
++{
++	int err;
++	err = au_d_alive(d);
++	if (unlikely(err || IS_DEADDIR(d->d_inode)))
++		err = -ENOENT;
++	return err;
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DCSUB_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/debug.c linux-2.6.36/fs/aufs/debug.c
+--- linux-2.6.36.orig/fs/aufs/debug.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/debug.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,468 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * debug print functions
++ */
++
++#include <linux/module.h>
++#include <linux/vt_kern.h>
++#include "aufs.h"
++
++int aufs_debug;
++MODULE_PARM_DESC(debug, "debug print");
++module_param_named(debug, aufs_debug, int, S_IRUGO | S_IWUSR | S_IWGRP);
++
++char *au_plevel = KERN_DEBUG;
++#define dpri(fmt, ...) do {					\
++	if ((au_plevel						\
++	     && strcmp(au_plevel, KERN_DEBUG))			\
++	    || au_debug_test())					\
++		printk("%s" fmt, au_plevel, ##__VA_ARGS__);	\
++} while (0)
++
++/* ---------------------------------------------------------------------- */
++
++void au_dpri_whlist(struct au_nhash *whlist)
++{
++	unsigned long ul, n;
++	struct hlist_head *head;
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos;
++
++	n = whlist->nh_num;
++	head = whlist->nh_head;
++	for (ul = 0; ul < n; ul++) {
++		hlist_for_each_entry(tpos, pos, head, wh_hash)
++			dpri("b%d, %.*s, %d\n",
++			     tpos->wh_bindex,
++			     tpos->wh_str.len, tpos->wh_str.name,
++			     tpos->wh_str.len);
++		head++;
++	}
++}
++
++void au_dpri_vdir(struct au_vdir *vdir)
++{
++	unsigned long ul;
++	union au_vdir_deblk_p p;
++	unsigned char *o;
++
++	if (!vdir || IS_ERR(vdir)) {
++		dpri("err %ld\n", PTR_ERR(vdir));
++		return;
++	}
++
++	dpri("deblk %u, nblk %lu, deblk %p, last{%lu, %p}, ver %lu\n",
++	     vdir->vd_deblk_sz, vdir->vd_nblk, vdir->vd_deblk,
++	     vdir->vd_last.ul, vdir->vd_last.p.deblk, vdir->vd_version);
++	for (ul = 0; ul < vdir->vd_nblk; ul++) {
++		p.deblk = vdir->vd_deblk[ul];
++		o = p.deblk;
++		dpri("[%lu]: %p\n", ul, o);
++	}
++}
++
++static int do_pri_inode(aufs_bindex_t bindex, struct inode *inode,
++			struct dentry *wh)
++{
++	char *n = NULL;
++	int l = 0;
++
++	if (!inode || IS_ERR(inode)) {
++		dpri("i%d: err %ld\n", bindex, PTR_ERR(inode));
++		return -1;
++	}
++
++	/* the type of i_blocks depends upon CONFIG_LSF */
++	BUILD_BUG_ON(sizeof(inode->i_blocks) != sizeof(unsigned long)
++		     && sizeof(inode->i_blocks) != sizeof(u64));
++	if (wh) {
++		n = (void *)wh->d_name.name;
++		l = wh->d_name.len;
++	}
++
++	dpri("i%d: i%lu, %s, cnt %d, nl %u, 0%o, sz %llu, blk %llu,"
++	     " ct %lld, np %lu, st 0x%lx, f 0x%x, v %llu, g %x%s%.*s\n",
++	     bindex,
++	     inode->i_ino, inode->i_sb ? au_sbtype(inode->i_sb) : "??",
++	     atomic_read(&inode->i_count), inode->i_nlink, inode->i_mode,
++	     i_size_read(inode), (unsigned long long)inode->i_blocks,
++	     (long long)timespec_to_ns(&inode->i_ctime) & 0x0ffff,
++	     inode->i_mapping ? inode->i_mapping->nrpages : 0,
++	     inode->i_state, inode->i_flags, inode->i_version,
++	     inode->i_generation,
++	     l ? ", wh " : "", l, n);
++	return 0;
++}
++
++void au_dpri_inode(struct inode *inode)
++{
++	struct au_iinfo *iinfo;
++	aufs_bindex_t bindex;
++	int err;
++
++	err = do_pri_inode(-1, inode, NULL);
++	if (err || !au_test_aufs(inode->i_sb))
++		return;
++
++	iinfo = au_ii(inode);
++	if (!iinfo)
++		return;
++	dpri("i-1: bstart %d, bend %d, gen %d\n",
++	     iinfo->ii_bstart, iinfo->ii_bend, au_iigen(inode));
++	if (iinfo->ii_bstart < 0)
++		return;
++	for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend; bindex++)
++		do_pri_inode(bindex, iinfo->ii_hinode[0 + bindex].hi_inode,
++			     iinfo->ii_hinode[0 + bindex].hi_whdentry);
++}
++
++static int do_pri_dentry(aufs_bindex_t bindex, struct dentry *dentry)
++{
++	struct dentry *wh = NULL;
++
++	if (!dentry || IS_ERR(dentry)) {
++		dpri("d%d: err %ld\n", bindex, PTR_ERR(dentry));
++		return -1;
++	}
++	/* do not call dget_parent() here */
++	dpri("d%d: %.*s?/%.*s, %s, cnt %d, flags 0x%x\n",
++	     bindex,
++	     AuDLNPair(dentry->d_parent), AuDLNPair(dentry),
++	     dentry->d_sb ? au_sbtype(dentry->d_sb) : "??",
++	     atomic_read(&dentry->d_count), dentry->d_flags);
++	if (bindex >= 0 && dentry->d_inode && au_test_aufs(dentry->d_sb)) {
++		struct au_iinfo *iinfo = au_ii(dentry->d_inode);
++		if (iinfo)
++			wh = iinfo->ii_hinode[0 + bindex].hi_whdentry;
++	}
++	do_pri_inode(bindex, dentry->d_inode, wh);
++	return 0;
++}
++
++void au_dpri_dentry(struct dentry *dentry)
++{
++	struct au_dinfo *dinfo;
++	aufs_bindex_t bindex;
++	int err;
++	struct au_hdentry *hdp;
++
++	err = do_pri_dentry(-1, dentry);
++	if (err || !au_test_aufs(dentry->d_sb))
++		return;
++
++	dinfo = au_di(dentry);
++	if (!dinfo)
++		return;
++	dpri("d-1: bstart %d, bend %d, bwh %d, bdiropq %d, gen %d\n",
++	     dinfo->di_bstart, dinfo->di_bend,
++	     dinfo->di_bwh, dinfo->di_bdiropq, au_digen(dentry));
++	if (dinfo->di_bstart < 0)
++		return;
++	hdp = dinfo->di_hdentry;
++	for (bindex = dinfo->di_bstart; bindex <= dinfo->di_bend; bindex++)
++		do_pri_dentry(bindex, hdp[0 + bindex].hd_dentry);
++}
++
++static int do_pri_file(aufs_bindex_t bindex, struct file *file)
++{
++	char a[32];
++
++	if (!file || IS_ERR(file)) {
++		dpri("f%d: err %ld\n", bindex, PTR_ERR(file));
++		return -1;
++	}
++	a[0] = 0;
++	if (bindex < 0
++	    && file->f_dentry
++	    && au_test_aufs(file->f_dentry->d_sb)
++	    && au_fi(file))
++		snprintf(a, sizeof(a), ", gen %d, mmapped %d",
++			 au_figen(file), !!au_fi(file)->fi_hvmop);
++	dpri("f%d: mode 0x%x, flags 0%o, cnt %ld, v %llu, pos %llu%s\n",
++	     bindex, file->f_mode, file->f_flags, (long)file_count(file),
++	     file->f_version, file->f_pos, a);
++	if (file->f_dentry)
++		do_pri_dentry(bindex, file->f_dentry);
++	return 0;
++}
++
++void au_dpri_file(struct file *file)
++{
++	struct au_finfo *finfo;
++	struct au_fidir *fidir;
++	struct au_hfile *hfile;
++	aufs_bindex_t bindex;
++	int err;
++
++	err = do_pri_file(-1, file);
++	if (err || !file->f_dentry || !au_test_aufs(file->f_dentry->d_sb))
++		return;
++
++	finfo = au_fi(file);
++	if (!finfo)
++		return;
++	if (finfo->fi_btop < 0)
++		return;
++	fidir = finfo->fi_hdir;
++	if (!fidir)
++		do_pri_file(finfo->fi_btop, finfo->fi_htop.hf_file);
++	else
++		for (bindex = finfo->fi_btop;
++		     bindex >= 0 && bindex <= fidir->fd_bbot;
++		     bindex++) {
++			hfile = fidir->fd_hfile + bindex;
++			do_pri_file(bindex, hfile ? hfile->hf_file : NULL);
++		}
++}
++
++static int do_pri_br(aufs_bindex_t bindex, struct au_branch *br)
++{
++	struct vfsmount *mnt;
++	struct super_block *sb;
++
++	if (!br || IS_ERR(br))
++		goto out;
++	mnt = br->br_mnt;
++	if (!mnt || IS_ERR(mnt))
++		goto out;
++	sb = mnt->mnt_sb;
++	if (!sb || IS_ERR(sb))
++		goto out;
++
++	dpri("s%d: {perm 0x%x, cnt %d, wbr %p}, "
++	     "%s, dev 0x%02x%02x, flags 0x%lx, cnt %d, active %d, "
++	     "xino %d\n",
++	     bindex, br->br_perm, atomic_read(&br->br_count), br->br_wbr,
++	     au_sbtype(sb), MAJOR(sb->s_dev), MINOR(sb->s_dev),
++	     sb->s_flags, sb->s_count,
++	     atomic_read(&sb->s_active), !!br->br_xino.xi_file);
++	return 0;
++
++out:
++	dpri("s%d: err %ld\n", bindex, PTR_ERR(br));
++	return -1;
++}
++
++void au_dpri_sb(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++	aufs_bindex_t bindex;
++	int err;
++	/* to reuduce stack size */
++	struct {
++		struct vfsmount mnt;
++		struct au_branch fake;
++	} *a;
++
++	/* this function can be called from magic sysrq */
++	a = kzalloc(sizeof(*a), GFP_ATOMIC);
++	if (unlikely(!a)) {
++		dpri("no memory\n");
++		return;
++	}
++
++	a->mnt.mnt_sb = sb;
++	a->fake.br_perm = 0;
++	a->fake.br_mnt = &a->mnt;
++	a->fake.br_xino.xi_file = NULL;
++	atomic_set(&a->fake.br_count, 0);
++	smp_mb(); /* atomic_set */
++	err = do_pri_br(-1, &a->fake);
++	kfree(a);
++	dpri("dev 0x%x\n", sb->s_dev);
++	if (err || !au_test_aufs(sb))
++		return;
++
++	sbinfo = au_sbi(sb);
++	if (!sbinfo)
++		return;
++	dpri("nw %d, gen %u, kobj %d\n",
++	     atomic_read(&sbinfo->si_nowait.nw_len), sbinfo->si_generation,
++	     atomic_read(&sbinfo->si_kobj.kref.refcount));
++	for (bindex = 0; bindex <= sbinfo->si_bend; bindex++)
++		do_pri_br(bindex, sbinfo->si_branch[0 + bindex]);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_dbg_sleep_jiffy(int jiffy)
++{
++	while (jiffy)
++		jiffy = schedule_timeout_uninterruptible(jiffy);
++}
++
++void au_dbg_iattr(struct iattr *ia)
++{
++#define AuBit(name)	if (ia->ia_valid & ATTR_ ## name) \
++				dpri(#name "\n")
++	AuBit(MODE);
++	AuBit(UID);
++	AuBit(GID);
++	AuBit(SIZE);
++	AuBit(ATIME);
++	AuBit(MTIME);
++	AuBit(CTIME);
++	AuBit(ATIME_SET);
++	AuBit(MTIME_SET);
++	AuBit(FORCE);
++	AuBit(ATTR_FLAG);
++	AuBit(KILL_SUID);
++	AuBit(KILL_SGID);
++	AuBit(FILE);
++	AuBit(KILL_PRIV);
++	AuBit(OPEN);
++	AuBit(TIMES_SET);
++#undef	AuBit
++	dpri("ia_file %p\n", ia->ia_file);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void __au_dbg_verify_dinode(struct dentry *dentry, const char *func, int line)
++{
++	struct inode *h_inode, *inode = dentry->d_inode;
++	struct dentry *h_dentry;
++	aufs_bindex_t bindex, bend, bi;
++
++	if (!inode /* || au_di(dentry)->di_lsc == AuLsc_DI_TMP */)
++		return;
++
++	bend = au_dbend(dentry);
++	bi = au_ibend(inode);
++	if (bi < bend)
++		bend = bi;
++	bindex = au_dbstart(dentry);
++	bi = au_ibstart(inode);
++	if (bi > bindex)
++		bindex = bi;
++
++	for (; bindex <= bend; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++		h_inode = au_h_iptr(inode, bindex);
++		if (unlikely(h_inode != h_dentry->d_inode)) {
++			int old = au_debug_test();
++			if (!old)
++				au_debug(1);
++			AuDbg("b%d, %s:%d\n", bindex, func, line);
++			AuDbgDentry(dentry);
++			AuDbgInode(inode);
++			if (!old)
++				au_debug(0);
++			BUG();
++		}
++	}
++}
++
++void au_dbg_verify_dir_parent(struct dentry *dentry, unsigned int sigen)
++{
++	struct dentry *parent;
++
++	parent = dget_parent(dentry);
++	AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
++	AuDebugOn(IS_ROOT(dentry));
++	AuDebugOn(au_digen_test(parent, sigen));
++	dput(parent);
++}
++
++void au_dbg_verify_nondir_parent(struct dentry *dentry, unsigned int sigen)
++{
++	struct dentry *parent;
++	struct inode *inode;
++
++	parent = dget_parent(dentry);
++	inode = dentry->d_inode;
++	AuDebugOn(inode && S_ISDIR(dentry->d_inode->i_mode));
++	AuDebugOn(au_digen_test(parent, sigen));
++	dput(parent);
++}
++
++void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen)
++{
++	int err, i, j;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry **dentries;
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	AuDebugOn(err);
++	err = au_dcsub_pages_rev_aufs(&dpages, parent, /*do_include*/1);
++	AuDebugOn(err);
++	for (i = dpages.ndpage - 1; !err && i >= 0; i--) {
++		dpage = dpages.dpages + i;
++		dentries = dpage->dentries;
++		for (j = dpage->ndentry - 1; !err && j >= 0; j--)
++			AuDebugOn(au_digen_test(dentries[j], sigen));
++	}
++	au_dpages_free(&dpages);
++}
++
++void au_dbg_verify_kthread(void)
++{
++	if (current->flags & PF_WQ_WORKER) {
++		au_dbg_blocked();
++		WARN_ON(1);
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_debug_sbinfo_init(struct au_sbinfo *sbinfo __maybe_unused)
++{
++#ifdef AuForceNoPlink
++	au_opt_clr(sbinfo->si_mntflags, PLINK);
++#endif
++#ifdef AuForceNoXino
++	au_opt_clr(sbinfo->si_mntflags, XINO);
++#endif
++#ifdef AuForceNoRefrof
++	au_opt_clr(sbinfo->si_mntflags, REFROF);
++#endif
++#ifdef AuForceHnotify
++	au_opt_set_udba(sbinfo->si_mntflags, UDBA_HNOTIFY);
++#endif
++#ifdef AuForceRd0
++	sbinfo->si_rdblk = 0;
++	sbinfo->si_rdhash = 0;
++#endif
++}
++
++int __init au_debug_init(void)
++{
++	aufs_bindex_t bindex;
++	struct au_vdir_destr destr;
++
++	bindex = -1;
++	AuDebugOn(bindex >= 0);
++
++	destr.len = -1;
++	AuDebugOn(destr.len < NAME_MAX);
++
++#ifdef CONFIG_4KSTACKS
++	pr_warning("CONFIG_4KSTACKS is defined.\n");
++#endif
++
++#ifdef AuForceNoBrs
++	sysaufs_brs = 0;
++#endif
++
++	return 0;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/debug.h linux-2.6.36/fs/aufs/debug.h
+--- linux-2.6.36.orig/fs/aufs/debug.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/debug.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,245 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * debug print functions
++ */
++
++#ifndef __AUFS_DEBUG_H__
++#define __AUFS_DEBUG_H__
++
++#ifdef __KERNEL__
++
++#include <asm/system.h>
++#include <linux/bug.h>
++/* #include <linux/err.h> */
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/kallsyms.h>
++/* #include <linux/kernel.h> */
++#include <linux/delay.h>
++/* #include <linux/kd.h> */
++#include <linux/sysrq.h>
++#include <linux/aufs_type.h>
++
++#include <asm/system.h>
++
++#ifdef CONFIG_AUFS_DEBUG
++#define AuDebugOn(a)		BUG_ON(a)
++
++/* module parameter */
++extern int aufs_debug;
++static inline void au_debug(int n)
++{
++	aufs_debug = n;
++	smp_mb();
++}
++
++static inline int au_debug_test(void)
++{
++	return aufs_debug;
++}
++#else
++#define AuDebugOn(a)		do {} while (0)
++AuStubVoid(au_debug, int n)
++AuStubInt0(au_debug_test, void)
++#endif /* CONFIG_AUFS_DEBUG */
++
++/* ---------------------------------------------------------------------- */
++
++/* debug print */
++
++#define AuDbg(fmt, ...) do { \
++	if (au_debug_test()) \
++		pr_debug("DEBUG: " fmt, ##__VA_ARGS__); \
++} while (0)
++#define AuLabel(l)		AuDbg(#l "\n")
++#define AuIOErr(fmt, ...)	pr_err("I/O Error, " fmt, ##__VA_ARGS__)
++#define AuWarn1(fmt, ...) do { \
++	static unsigned char _c; \
++	if (!_c++) \
++		pr_warning(fmt, ##__VA_ARGS__); \
++} while (0)
++
++#define AuErr1(fmt, ...) do { \
++	static unsigned char _c; \
++	if (!_c++) \
++		pr_err(fmt, ##__VA_ARGS__); \
++} while (0)
++
++#define AuIOErr1(fmt, ...) do { \
++	static unsigned char _c; \
++	if (!_c++) \
++		AuIOErr(fmt, ##__VA_ARGS__); \
++} while (0)
++
++#define AuUnsupportMsg	"This operation is not supported." \
++			" Please report this application to aufs-users ML."
++#define AuUnsupport(fmt, ...) do { \
++	pr_err(AuUnsupportMsg "\n" fmt, ##__VA_ARGS__); \
++	dump_stack(); \
++} while (0)
++
++#define AuTraceErr(e) do { \
++	if (unlikely((e) < 0)) \
++		AuDbg("err %d\n", (int)(e)); \
++} while (0)
++
++#define AuTraceErrPtr(p) do { \
++	if (IS_ERR(p)) \
++		AuDbg("err %ld\n", PTR_ERR(p)); \
++} while (0)
++
++/* dirty macros for debug print, use with "%.*s" and caution */
++#define AuLNPair(qstr)		(qstr)->len, (qstr)->name
++#define AuDLNPair(d)		AuLNPair(&(d)->d_name)
++
++/* ---------------------------------------------------------------------- */
++
++struct au_sbinfo;
++struct au_finfo;
++struct dentry;
++#ifdef CONFIG_AUFS_DEBUG
++extern char *au_plevel;
++struct au_nhash;
++void au_dpri_whlist(struct au_nhash *whlist);
++struct au_vdir;
++void au_dpri_vdir(struct au_vdir *vdir);
++struct inode;
++void au_dpri_inode(struct inode *inode);
++void au_dpri_dentry(struct dentry *dentry);
++struct file;
++void au_dpri_file(struct file *filp);
++struct super_block;
++void au_dpri_sb(struct super_block *sb);
++
++void au_dbg_sleep_jiffy(int jiffy);
++struct iattr;
++void au_dbg_iattr(struct iattr *ia);
++
++#define au_dbg_verify_dinode(d) __au_dbg_verify_dinode(d, __func__, __LINE__)
++void __au_dbg_verify_dinode(struct dentry *dentry, const char *func, int line);
++void au_dbg_verify_dir_parent(struct dentry *dentry, unsigned int sigen);
++void au_dbg_verify_nondir_parent(struct dentry *dentry, unsigned int sigen);
++void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen);
++void au_dbg_verify_kthread(void);
++
++int __init au_debug_init(void);
++void au_debug_sbinfo_init(struct au_sbinfo *sbinfo);
++#define AuDbgWhlist(w) do { \
++	AuDbg(#w "\n"); \
++	au_dpri_whlist(w); \
++} while (0)
++
++#define AuDbgVdir(v) do { \
++	AuDbg(#v "\n"); \
++	au_dpri_vdir(v); \
++} while (0)
++
++#define AuDbgInode(i) do { \
++	AuDbg(#i "\n"); \
++	au_dpri_inode(i); \
++} while (0)
++
++#define AuDbgDentry(d) do { \
++	AuDbg(#d "\n"); \
++	au_dpri_dentry(d); \
++} while (0)
++
++#define AuDbgFile(f) do { \
++	AuDbg(#f "\n"); \
++	au_dpri_file(f); \
++} while (0)
++
++#define AuDbgSb(sb) do { \
++	AuDbg(#sb "\n"); \
++	au_dpri_sb(sb); \
++} while (0)
++
++#define AuDbgSleep(sec) do { \
++	AuDbg("sleep %d sec\n", sec); \
++	ssleep(sec); \
++} while (0)
++
++#define AuDbgSleepJiffy(jiffy) do { \
++	AuDbg("sleep %d jiffies\n", jiffy); \
++	au_dbg_sleep_jiffy(jiffy); \
++} while (0)
++
++#define AuDbgIAttr(ia) do { \
++	AuDbg("ia_valid 0x%x\n", (ia)->ia_valid); \
++	au_dbg_iattr(ia); \
++} while (0)
++
++#define AuDbgSym(addr) do {				\
++	char sym[KSYM_SYMBOL_LEN];			\
++	sprint_symbol(sym, (unsigned long)addr);	\
++	AuDbg("%s\n", sym);				\
++} while (0)
++
++#define AuInfoSym(addr) do {				\
++	char sym[KSYM_SYMBOL_LEN];			\
++	sprint_symbol(sym, (unsigned long)addr);	\
++	AuInfo("%s\n", sym);				\
++} while (0)
++#else
++AuStubVoid(au_dbg_verify_dinode, struct dentry *dentry)
++AuStubVoid(au_dbg_verify_dir_parent, struct dentry *dentry, unsigned int sigen)
++AuStubVoid(au_dbg_verify_nondir_parent, struct dentry *dentry,
++	   unsigned int sigen)
++AuStubVoid(au_dbg_verify_gen, struct dentry *parent, unsigned int sigen)
++AuStubVoid(au_dbg_verify_kthread, void)
++AuStubInt0(__init au_debug_init, void)
++AuStubVoid(au_debug_sbinfo_init, struct au_sbinfo *sbinfo)
++
++#define AuDbgWhlist(w)		do {} while (0)
++#define AuDbgVdir(v)		do {} while (0)
++#define AuDbgInode(i)		do {} while (0)
++#define AuDbgDentry(d)		do {} while (0)
++#define AuDbgFile(f)		do {} while (0)
++#define AuDbgSb(sb)		do {} while (0)
++#define AuDbgSleep(sec)		do {} while (0)
++#define AuDbgSleepJiffy(jiffy)	do {} while (0)
++#define AuDbgIAttr(ia)		do {} while (0)
++#define AuDbgSym(addr)		do {} while (0)
++#define AuInfoSym(addr)		do {} while (0)
++#endif /* CONFIG_AUFS_DEBUG */
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_MAGIC_SYSRQ
++int __init au_sysrq_init(void);
++void au_sysrq_fin(void);
++
++#ifdef CONFIG_HW_CONSOLE
++#define au_dbg_blocked() do { \
++	WARN_ON(1); \
++	handle_sysrq('w'); \
++} while (0)
++#else
++AuStubVoid(au_dbg_blocked, void)
++#endif
++
++#else
++AuStubInt0(__init au_sysrq_init, void)
++AuStubVoid(au_sysrq_fin, void)
++AuStubVoid(au_dbg_blocked, void)
++#endif /* CONFIG_AUFS_MAGIC_SYSRQ */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DEBUG_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/dentry.c linux-2.6.36/fs/aufs/dentry.c
+--- linux-2.6.36.orig/fs/aufs/dentry.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dentry.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1131 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * lookup and dentry operations
++ */
++
++#include <linux/namei.h>
++#include "aufs.h"
++
++static void au_h_nd(struct nameidata *h_nd, struct nameidata *nd)
++{
++	if (nd) {
++		*h_nd = *nd;
++
++		/*
++		 * gave up supporting LOOKUP_CREATE/OPEN for lower fs,
++		 * due to whiteout and branch permission.
++		 */
++		h_nd->flags &= ~(/*LOOKUP_PARENT |*/ LOOKUP_OPEN | LOOKUP_CREATE
++				 | LOOKUP_FOLLOW | LOOKUP_EXCL);
++		/* unnecessary? */
++		h_nd->intent.open.file = NULL;
++	} else
++		memset(h_nd, 0, sizeof(*h_nd));
++}
++
++struct au_lkup_one_args {
++	struct dentry **errp;
++	struct qstr *name;
++	struct dentry *h_parent;
++	struct au_branch *br;
++	struct nameidata *nd;
++};
++
++struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent,
++			   struct au_branch *br, struct nameidata *nd)
++{
++	struct dentry *h_dentry;
++	int err;
++	struct nameidata h_nd;
++
++	if (au_test_fs_null_nd(h_parent->d_sb))
++		return vfsub_lookup_one_len(name->name, h_parent, name->len);
++
++	au_h_nd(&h_nd, nd);
++	h_nd.path.dentry = h_parent;
++	h_nd.path.mnt = br->br_mnt;
++
++	err = __lookup_one_len(name->name, &h_nd.last, NULL, name->len);
++	h_dentry = ERR_PTR(err);
++	if (!err) {
++		path_get(&h_nd.path);
++		h_dentry = vfsub_lookup_hash(&h_nd);
++		path_put(&h_nd.path);
++	}
++
++	AuTraceErrPtr(h_dentry);
++	return h_dentry;
++}
++
++static void au_call_lkup_one(void *args)
++{
++	struct au_lkup_one_args *a = args;
++	*a->errp = au_lkup_one(a->name, a->h_parent, a->br, a->nd);
++}
++
++#define AuLkup_ALLOW_NEG	1
++#define au_ftest_lkup(flags, name)	((flags) & AuLkup_##name)
++#define au_fset_lkup(flags, name) \
++	do { (flags) |= AuLkup_##name; } while (0)
++#define au_fclr_lkup(flags, name) \
++	do { (flags) &= ~AuLkup_##name; } while (0)
++
++struct au_do_lookup_args {
++	unsigned int		flags;
++	mode_t			type;
++	struct nameidata	*nd;
++};
++
++/*
++ * returns positive/negative dentry, NULL or an error.
++ * NULL means whiteout-ed or not-found.
++ */
++static struct dentry*
++au_do_lookup(struct dentry *h_parent, struct dentry *dentry,
++	     aufs_bindex_t bindex, struct qstr *wh_name,
++	     struct au_do_lookup_args *args)
++{
++	struct dentry *h_dentry;
++	struct inode *h_inode, *inode;
++	struct au_branch *br;
++	int wh_found, opq;
++	unsigned char wh_able;
++	const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG);
++
++	wh_found = 0;
++	br = au_sbr(dentry->d_sb, bindex);
++	wh_able = !!au_br_whable(br->br_perm);
++	if (wh_able)
++		wh_found = au_wh_test(h_parent, wh_name, br, /*try_sio*/0);
++	h_dentry = ERR_PTR(wh_found);
++	if (!wh_found)
++		goto real_lookup;
++	if (unlikely(wh_found < 0))
++		goto out;
++
++	/* We found a whiteout */
++	/* au_set_dbend(dentry, bindex); */
++	au_set_dbwh(dentry, bindex);
++	if (!allow_neg)
++		return NULL; /* success */
++
++real_lookup:
++	h_dentry = au_lkup_one(&dentry->d_name, h_parent, br, args->nd);
++	if (IS_ERR(h_dentry))
++		goto out;
++
++	h_inode = h_dentry->d_inode;
++	if (!h_inode) {
++		if (!allow_neg)
++			goto out_neg;
++	} else if (wh_found
++		   || (args->type && args->type != (h_inode->i_mode & S_IFMT)))
++		goto out_neg;
++
++	if (au_dbend(dentry) <= bindex)
++		au_set_dbend(dentry, bindex);
++	if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
++		au_set_dbstart(dentry, bindex);
++	au_set_h_dptr(dentry, bindex, h_dentry);
++
++	inode = dentry->d_inode;
++	if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able
++	    || (inode && !S_ISDIR(inode->i_mode)))
++		goto out; /* success */
++
++	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++	opq = au_diropq_test(h_dentry, br);
++	mutex_unlock(&h_inode->i_mutex);
++	if (opq > 0)
++		au_set_dbdiropq(dentry, bindex);
++	else if (unlikely(opq < 0)) {
++		au_set_h_dptr(dentry, bindex, NULL);
++		h_dentry = ERR_PTR(opq);
++	}
++	goto out;
++
++out_neg:
++	dput(h_dentry);
++	h_dentry = NULL;
++out:
++	return h_dentry;
++}
++
++static int au_test_shwh(struct super_block *sb, const struct qstr *name)
++{
++	if (unlikely(!au_opt_test(au_mntflags(sb), SHWH)
++		     && !strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)))
++		return -EPERM;
++	return 0;
++}
++
++/*
++ * returns the number of lower positive dentries,
++ * otherwise an error.
++ * can be called at unlinking with @type is zero.
++ */
++int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
++		   struct nameidata *nd)
++{
++	int npositive, err;
++	aufs_bindex_t bindex, btail, bdiropq;
++	unsigned char isdir;
++	struct qstr whname;
++	struct au_do_lookup_args args = {
++		.flags	= 0,
++		.type	= type,
++		.nd	= nd
++	};
++	const struct qstr *name = &dentry->d_name;
++	struct dentry *parent;
++	struct inode *inode;
++
++	err = au_test_shwh(dentry->d_sb, name);
++	if (unlikely(err))
++		goto out;
++
++	err = au_wh_name_alloc(&whname, name);
++	if (unlikely(err))
++		goto out;
++
++	inode = dentry->d_inode;
++	isdir = !!(inode && S_ISDIR(inode->i_mode));
++	if (!type)
++		au_fset_lkup(args.flags, ALLOW_NEG);
++
++	npositive = 0;
++	parent = dget_parent(dentry);
++	btail = au_dbtaildir(parent);
++	for (bindex = bstart; bindex <= btail; bindex++) {
++		struct dentry *h_parent, *h_dentry;
++		struct inode *h_inode, *h_dir;
++
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (h_dentry) {
++			if (h_dentry->d_inode)
++				npositive++;
++			if (type != S_IFDIR)
++				break;
++			continue;
++		}
++		h_parent = au_h_dptr(parent, bindex);
++		if (!h_parent)
++			continue;
++		h_dir = h_parent->d_inode;
++		if (!h_dir || !S_ISDIR(h_dir->i_mode))
++			continue;
++
++		mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++		h_dentry = au_do_lookup(h_parent, dentry, bindex, &whname,
++					&args);
++		mutex_unlock(&h_dir->i_mutex);
++		err = PTR_ERR(h_dentry);
++		if (IS_ERR(h_dentry))
++			goto out_parent;
++		au_fclr_lkup(args.flags, ALLOW_NEG);
++
++		if (au_dbwh(dentry) >= 0)
++			break;
++		if (!h_dentry)
++			continue;
++		h_inode = h_dentry->d_inode;
++		if (!h_inode)
++			continue;
++		npositive++;
++		if (!args.type)
++			args.type = h_inode->i_mode & S_IFMT;
++		if (args.type != S_IFDIR)
++			break;
++		else if (isdir) {
++			/* the type of lower may be different */
++			bdiropq = au_dbdiropq(dentry);
++			if (bdiropq >= 0 && bdiropq <= bindex)
++				break;
++		}
++	}
++
++	if (npositive) {
++		AuLabel(positive);
++		au_update_dbstart(dentry);
++	}
++	err = npositive;
++	if (unlikely(!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE)
++		     && au_dbstart(dentry) < 0)) {
++		err = -EIO;
++		AuIOErr("both of real entry and whiteout found, %.*s, err %d\n",
++			AuDLNPair(dentry), err);
++	}
++
++out_parent:
++	dput(parent);
++	kfree(whname.name);
++out:
++	return err;
++}
++
++struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent,
++			       struct au_branch *br)
++{
++	struct dentry *dentry;
++	int wkq_err;
++
++	if (!au_test_h_perm_sio(parent->d_inode, MAY_EXEC))
++		dentry = au_lkup_one(name, parent, br, /*nd*/NULL);
++	else {
++		struct au_lkup_one_args args = {
++			.errp		= &dentry,
++			.name		= name,
++			.h_parent	= parent,
++			.br		= br,
++			.nd		= NULL
++		};
++
++		wkq_err = au_wkq_wait(au_call_lkup_one, &args);
++		if (unlikely(wkq_err))
++			dentry = ERR_PTR(wkq_err);
++	}
++
++	return dentry;
++}
++
++/*
++ * lookup @dentry on @bindex which should be negative.
++ */
++int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	int err;
++	struct dentry *parent, *h_parent, *h_dentry;
++
++	parent = dget_parent(dentry);
++	h_parent = au_h_dptr(parent, bindex);
++	h_dentry = au_sio_lkup_one(&dentry->d_name, h_parent,
++				   au_sbr(dentry->d_sb, bindex));
++	err = PTR_ERR(h_dentry);
++	if (IS_ERR(h_dentry))
++		goto out;
++	if (unlikely(h_dentry->d_inode)) {
++		err = -EIO;
++		AuIOErr("%.*s should be negative on b%d.\n",
++			AuDLNPair(h_dentry), bindex);
++		dput(h_dentry);
++		goto out;
++	}
++
++	err = 0;
++	if (bindex < au_dbstart(dentry))
++		au_set_dbstart(dentry, bindex);
++	if (au_dbend(dentry) < bindex)
++		au_set_dbend(dentry, bindex);
++	au_set_h_dptr(dentry, bindex, h_dentry);
++
++out:
++	dput(parent);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* subset of struct inode */
++struct au_iattr {
++	unsigned long		i_ino;
++	/* unsigned int		i_nlink; */
++	uid_t			i_uid;
++	gid_t			i_gid;
++	u64			i_version;
++/*
++	loff_t			i_size;
++	blkcnt_t		i_blocks;
++*/
++	umode_t			i_mode;
++};
++
++static void au_iattr_save(struct au_iattr *ia, struct inode *h_inode)
++{
++	ia->i_ino = h_inode->i_ino;
++	/* ia->i_nlink = h_inode->i_nlink; */
++	ia->i_uid = h_inode->i_uid;
++	ia->i_gid = h_inode->i_gid;
++	ia->i_version = h_inode->i_version;
++/*
++	ia->i_size = h_inode->i_size;
++	ia->i_blocks = h_inode->i_blocks;
++*/
++	ia->i_mode = (h_inode->i_mode & S_IFMT);
++}
++
++static int au_iattr_test(struct au_iattr *ia, struct inode *h_inode)
++{
++	return ia->i_ino != h_inode->i_ino
++		/* || ia->i_nlink != h_inode->i_nlink */
++		|| ia->i_uid != h_inode->i_uid
++		|| ia->i_gid != h_inode->i_gid
++		|| ia->i_version != h_inode->i_version
++/*
++		|| ia->i_size != h_inode->i_size
++		|| ia->i_blocks != h_inode->i_blocks
++*/
++		|| ia->i_mode != (h_inode->i_mode & S_IFMT);
++}
++
++static int au_h_verify_dentry(struct dentry *h_dentry, struct dentry *h_parent,
++			      struct au_branch *br)
++{
++	int err;
++	struct au_iattr ia;
++	struct inode *h_inode;
++	struct dentry *h_d;
++	struct super_block *h_sb;
++
++	err = 0;
++	memset(&ia, -1, sizeof(ia));
++	h_sb = h_dentry->d_sb;
++	h_inode = h_dentry->d_inode;
++	if (h_inode)
++		au_iattr_save(&ia, h_inode);
++	else if (au_test_nfs(h_sb) || au_test_fuse(h_sb))
++		/* nfs d_revalidate may return 0 for negative dentry */
++		/* fuse d_revalidate always return 0 for negative dentry */
++		goto out;
++
++	/* main purpose is namei.c:cached_lookup() and d_revalidate */
++	h_d = au_lkup_one(&h_dentry->d_name, h_parent, br, /*nd*/NULL);
++	err = PTR_ERR(h_d);
++	if (IS_ERR(h_d))
++		goto out;
++
++	err = 0;
++	if (unlikely(h_d != h_dentry
++		     || h_d->d_inode != h_inode
++		     || (h_inode && au_iattr_test(&ia, h_inode))))
++		err = au_busy_or_stale();
++	dput(h_d);
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir,
++		struct dentry *h_parent, struct au_branch *br)
++{
++	int err;
++
++	err = 0;
++	if (udba == AuOpt_UDBA_REVAL) {
++		IMustLock(h_dir);
++		err = (h_dentry->d_parent->d_inode != h_dir);
++	} else if (udba == AuOpt_UDBA_HNOTIFY)
++		err = au_h_verify_dentry(h_dentry, h_parent, br);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_refresh_hdentry(struct dentry *dentry, struct dentry *parent)
++{
++	int err;
++	aufs_bindex_t new_bindex, bindex, bend, bwh, bdiropq;
++	struct au_hdentry tmp, *p, *q;
++	struct au_dinfo *dinfo;
++	struct super_block *sb;
++
++	DiMustWriteLock(dentry);
++
++	sb = dentry->d_sb;
++	dinfo = au_di(dentry);
++	bend = dinfo->di_bend;
++	bwh = dinfo->di_bwh;
++	bdiropq = dinfo->di_bdiropq;
++	p = dinfo->di_hdentry + dinfo->di_bstart;
++	for (bindex = dinfo->di_bstart; bindex <= bend; bindex++, p++) {
++		if (!p->hd_dentry)
++			continue;
++
++		new_bindex = au_br_index(sb, p->hd_id);
++		if (new_bindex == bindex)
++			continue;
++
++		if (dinfo->di_bwh == bindex)
++			bwh = new_bindex;
++		if (dinfo->di_bdiropq == bindex)
++			bdiropq = new_bindex;
++		if (new_bindex < 0) {
++			au_hdput(p);
++			p->hd_dentry = NULL;
++			continue;
++		}
++
++		/* swap two lower dentries, and loop again */
++		q = dinfo->di_hdentry + new_bindex;
++		tmp = *q;
++		*q = *p;
++		*p = tmp;
++		if (tmp.hd_dentry) {
++			bindex--;
++			p--;
++		}
++	}
++
++	dinfo->di_bwh = -1;
++	if (bwh >= 0 && bwh <= au_sbend(sb) && au_sbr_whable(sb, bwh))
++		dinfo->di_bwh = bwh;
++
++	dinfo->di_bdiropq = -1;
++	if (bdiropq >= 0
++	    && bdiropq <= au_sbend(sb)
++	    && au_sbr_whable(sb, bdiropq))
++		dinfo->di_bdiropq = bdiropq;
++
++	err = -EIO;
++	dinfo->di_bstart = -1;
++	dinfo->di_bend = -1;
++	bend = au_dbend(parent);
++	p = dinfo->di_hdentry;
++	for (bindex = 0; bindex <= bend; bindex++, p++)
++		if (p->hd_dentry) {
++			dinfo->di_bstart = bindex;
++			break;
++		}
++
++	if (dinfo->di_bstart >= 0) {
++		p = dinfo->di_hdentry + bend;
++		for (bindex = bend; bindex >= 0; bindex--, p--)
++			if (p->hd_dentry) {
++				dinfo->di_bend = bindex;
++				err = 0;
++				break;
++			}
++	}
++
++	return err;
++}
++
++static void au_do_hide(struct dentry *dentry)
++{
++	struct inode *inode;
++
++	inode = dentry->d_inode;
++	if (inode) {
++		if (!S_ISDIR(inode->i_mode)) {
++			if (inode->i_nlink && !d_unhashed(dentry))
++				drop_nlink(inode);
++		} else {
++			clear_nlink(inode);
++			/* stop next lookup */
++			inode->i_flags |= S_DEAD;
++		}
++		smp_mb(); /* necessary? */
++	}
++	d_drop(dentry);
++}
++
++static int au_hide_children(struct dentry *parent)
++{
++	int err, i, j, ndentry;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry *dentry;
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	err = au_dcsub_pages(&dpages, parent, NULL, NULL);
++	if (unlikely(err))
++		goto out_dpages;
++
++	/* in reverse order */
++	for (i = dpages.ndpage - 1; i >= 0; i--) {
++		dpage = dpages.dpages + i;
++		ndentry = dpage->ndentry;
++		for (j = ndentry - 1; j >= 0; j--) {
++			dentry = dpage->dentries[j];
++			if (dentry != parent)
++				au_do_hide(dentry);
++		}
++	}
++
++out_dpages:
++	au_dpages_free(&dpages);
++out:
++	return err;
++}
++
++static void au_hide(struct dentry *dentry)
++{
++	int err;
++	struct inode *inode;
++
++	AuDbgDentry(dentry);
++	inode = dentry->d_inode;
++	if (inode && S_ISDIR(inode->i_mode)) {
++		/* shrink_dcache_parent(dentry); */
++		err = au_hide_children(dentry);
++		if (unlikely(err))
++			AuIOErr("%.*s, failed hiding children, ignored %d\n",
++				AuDLNPair(dentry), err);
++	}
++	au_do_hide(dentry);
++}
++
++/*
++ * By adding a dirty branch, a cached dentry may be affected in various ways.
++ *
++ * a dirty branch is added
++ * - on the top of layers
++ * - in the middle of layers
++ * - to the bottom of layers
++ *
++ * on the added branch there exists
++ * - a whiteout
++ * - a diropq
++ * - a same named entry
++ *   + exist
++ *     * negative --> positive
++ *     * positive --> positive
++ *	 - type is unchanged
++ *	 - type is changed
++ *   + doesn't exist
++ *     * negative --> negative
++ *     * positive --> negative (rejected by au_br_del() for non-dir case)
++ * - none
++ */
++static int au_refresh_by_dinfo(struct dentry *dentry, struct au_dinfo *dinfo,
++			       struct au_dinfo *tmp)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	struct {
++		struct dentry *dentry;
++		struct inode *inode;
++		mode_t mode;
++	} orig_h, tmp_h;
++	struct au_hdentry *hd;
++	struct inode *inode, *h_inode;
++	struct dentry *h_dentry;
++
++	err = 0;
++	AuDebugOn(dinfo->di_bstart < 0);
++	orig_h.dentry = dinfo->di_hdentry[dinfo->di_bstart].hd_dentry;
++	orig_h.inode = orig_h.dentry->d_inode;
++	orig_h.mode = 0;
++	if (orig_h.inode)
++		orig_h.mode = orig_h.inode->i_mode & S_IFMT;
++	memset(&tmp_h, 0, sizeof(tmp_h));
++	if (tmp->di_bstart >= 0) {
++		tmp_h.dentry = tmp->di_hdentry[tmp->di_bstart].hd_dentry;
++		tmp_h.inode = tmp_h.dentry->d_inode;
++		if (tmp_h.inode)
++			tmp_h.mode = tmp_h.inode->i_mode & S_IFMT;
++	}
++
++	inode = dentry->d_inode;
++	if (!orig_h.inode) {
++		AuDbg("nagative originally\n");
++		if (inode) {
++			au_hide(dentry);
++			goto out;
++		}
++		AuDebugOn(inode);
++		AuDebugOn(dinfo->di_bstart != dinfo->di_bend);
++		AuDebugOn(dinfo->di_bdiropq != -1);
++
++		if (!tmp_h.inode) {
++			AuDbg("negative --> negative\n");
++			/* should have only one negative lower */
++			if (tmp->di_bstart >= 0
++			    && tmp->di_bstart < dinfo->di_bstart) {
++				AuDebugOn(tmp->di_bstart != tmp->di_bend);
++				AuDebugOn(dinfo->di_bstart != dinfo->di_bend);
++				au_set_h_dptr(dentry, dinfo->di_bstart, NULL);
++				au_di_cp(dinfo, tmp);
++				hd = tmp->di_hdentry + tmp->di_bstart;
++				au_set_h_dptr(dentry, tmp->di_bstart,
++					      dget(hd->hd_dentry));
++			}
++			au_dbg_verify_dinode(dentry);
++		} else {
++			AuDbg("negative --> positive\n");
++			/*
++			 * similar to the behaviour of creating with bypassing
++			 * aufs.
++			 * unhash it in order to force an error in the
++			 * succeeding create operation.
++			 * we should not set S_DEAD here.
++			 */
++			d_drop(dentry);
++			/* au_di_swap(tmp, dinfo); */
++			au_dbg_verify_dinode(dentry);
++		}
++	} else {
++		AuDbg("positive originally\n");
++		/* inode may be NULL */
++		AuDebugOn(inode && (inode->i_mode & S_IFMT) != orig_h.mode);
++		if (!tmp_h.inode) {
++			AuDbg("positive --> negative\n");
++			/* or bypassing aufs */
++			au_hide(dentry);
++			if (tmp->di_bwh >= 0 && tmp->di_bwh <= dinfo->di_bstart)
++				dinfo->di_bwh = tmp->di_bwh;
++			if (inode)
++				err = au_refresh_hinode_self(inode);
++			au_dbg_verify_dinode(dentry);
++		} else if (orig_h.mode == tmp_h.mode) {
++			AuDbg("positive --> positive, same type\n");
++			if (!S_ISDIR(orig_h.mode)
++			    && dinfo->di_bstart > tmp->di_bstart) {
++				/*
++				 * similar to the behaviour of removing and
++				 * creating.
++				 */
++				au_hide(dentry);
++				if (inode)
++					err = au_refresh_hinode_self(inode);
++				au_dbg_verify_dinode(dentry);
++			} else {
++				/* fill empty slots */
++				if (dinfo->di_bstart > tmp->di_bstart)
++					dinfo->di_bstart = tmp->di_bstart;
++				if (dinfo->di_bend < tmp->di_bend)
++					dinfo->di_bend = tmp->di_bend;
++				dinfo->di_bwh = tmp->di_bwh;
++				dinfo->di_bdiropq = tmp->di_bdiropq;
++				hd = tmp->di_hdentry;
++				bend = dinfo->di_bend;
++				for (bindex = tmp->di_bstart; bindex <= bend;
++				     bindex++) {
++					if (au_h_dptr(dentry, bindex))
++						continue;
++					h_dentry = hd[bindex].hd_dentry;
++					if (!h_dentry)
++						continue;
++					h_inode = h_dentry->d_inode;
++					AuDebugOn(!h_inode);
++					AuDebugOn(orig_h.mode
++						  != (h_inode->i_mode
++						      & S_IFMT));
++					au_set_h_dptr(dentry, bindex,
++						      dget(h_dentry));
++				}
++				err = au_refresh_hinode(inode, dentry);
++				au_dbg_verify_dinode(dentry);
++			}
++		} else {
++			AuDbg("positive --> positive, different type\n");
++			/* similar to the behaviour of removing and creating */
++			au_hide(dentry);
++			if (inode)
++				err = au_refresh_hinode_self(inode);
++			au_dbg_verify_dinode(dentry);
++		}
++	}
++
++out:
++	return err;
++}
++
++int au_refresh_dentry(struct dentry *dentry, struct dentry *parent)
++{
++	int err, ebrange;
++	unsigned int sigen;
++	struct au_dinfo *dinfo, *tmp;
++	struct super_block *sb;
++	struct inode *inode;
++
++	DiMustWriteLock(dentry);
++	AuDebugOn(IS_ROOT(dentry));
++	AuDebugOn(!parent->d_inode);
++
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	sigen = au_sigen(sb);
++	err = au_digen_test(parent, sigen);
++	if (unlikely(err))
++		goto out;
++
++	dinfo = au_di(dentry);
++	err = au_di_realloc(dinfo, au_sbend(sb) + 1);
++	if (unlikely(err))
++		goto out;
++	ebrange = au_dbrange_test(dentry);
++	if (!ebrange)
++		ebrange = au_do_refresh_hdentry(dentry, parent);
++
++	if (d_unhashed(dentry) || ebrange) {
++		AuDebugOn(au_dbstart(dentry) < 0 && au_dbend(dentry) >= 0);
++		if (inode)
++			err = au_refresh_hinode_self(inode);
++		au_dbg_verify_dinode(dentry);
++		if (!err)
++			goto out_dgen; /* success */
++		goto out;
++	}
++
++	/* temporary dinfo */
++	AuDbgDentry(dentry);
++	err = -ENOMEM;
++	tmp = au_di_alloc(sb, AuLsc_DI_TMP);
++	if (unlikely(!tmp))
++		goto out;
++	au_di_swap(tmp, dinfo);
++	/* returns the number of positive dentries */
++	/*
++	 * if current working dir is removed, it returns an error.
++	 * but the dentry is legal.
++	 */
++	err = au_lkup_dentry(dentry, /*bstart*/0, /*type*/0, /*nd*/NULL);
++	AuDbgDentry(dentry);
++	au_di_swap(tmp, dinfo);
++	if (err == -ENOENT)
++		err = 0;
++	if (err >= 0) {
++		/* compare/refresh by dinfo */
++		AuDbgDentry(dentry);
++		err = au_refresh_by_dinfo(dentry, dinfo, tmp);
++		au_dbg_verify_dinode(dentry);
++		AuTraceErr(err);
++	}
++	au_rw_write_unlock(&tmp->di_rwsem);
++	au_di_free(tmp);
++	if (unlikely(err))
++		goto out;
++
++out_dgen:
++	au_update_digen(dentry);
++out:
++	if (unlikely(err && !(dentry->d_flags & DCACHE_NFSFS_RENAMED))) {
++		AuIOErr("failed refreshing %.*s, %d\n",
++			AuDLNPair(dentry), err);
++		AuDbgDentry(dentry);
++	}
++	AuTraceErr(err);
++	return err;
++}
++
++static noinline_for_stack
++int au_do_h_d_reval(struct dentry *h_dentry, struct nameidata *nd,
++		    struct dentry *dentry, aufs_bindex_t bindex)
++{
++	int err, valid;
++	int (*reval)(struct dentry *, struct nameidata *);
++
++	err = 0;
++	reval = NULL;
++	if (h_dentry->d_op)
++		reval = h_dentry->d_op->d_revalidate;
++	if (!reval)
++		goto out;
++
++	AuDbg("b%d\n", bindex);
++	if (au_test_fs_null_nd(h_dentry->d_sb))
++		/* it may return tri-state */
++		valid = reval(h_dentry, NULL);
++	else {
++		struct nameidata h_nd;
++		int locked;
++		struct dentry *parent;
++
++		au_h_nd(&h_nd, nd);
++		parent = nd->path.dentry;
++		locked = (nd && nd->path.dentry != dentry);
++		if (locked)
++			di_read_lock_parent(parent, AuLock_IR);
++		BUG_ON(bindex > au_dbend(parent));
++		h_nd.path.dentry = au_h_dptr(parent, bindex);
++		BUG_ON(!h_nd.path.dentry);
++		h_nd.path.mnt = au_sbr(parent->d_sb, bindex)->br_mnt;
++		path_get(&h_nd.path);
++		valid = reval(h_dentry, &h_nd);
++		path_put(&h_nd.path);
++		if (locked)
++			di_read_unlock(parent, AuLock_IR);
++	}
++
++	if (unlikely(valid < 0))
++		err = valid;
++	else if (!valid)
++		err = -EINVAL;
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++/* todo: remove this */
++static int h_d_revalidate(struct dentry *dentry, struct inode *inode,
++			  struct nameidata *nd, int do_udba)
++{
++	int err;
++	umode_t mode, h_mode;
++	aufs_bindex_t bindex, btail, bstart, ibs, ibe;
++	unsigned char plus, unhashed, is_root, h_plus;
++	struct inode *h_inode, *h_cached_inode;
++	struct dentry *h_dentry;
++	struct qstr *name, *h_name;
++
++	err = 0;
++	plus = 0;
++	mode = 0;
++	ibs = -1;
++	ibe = -1;
++	unhashed = !!d_unhashed(dentry);
++	is_root = !!IS_ROOT(dentry);
++	name = &dentry->d_name;
++
++	/*
++	 * Theoretically, REVAL test should be unnecessary in case of
++	 * {FS,I}NOTIFY.
++	 * But {fs,i}notify doesn't fire some necessary events,
++	 *	IN_ATTRIB for atime/nlink/pageio
++	 *	IN_DELETE for NFS dentry
++	 * Let's do REVAL test too.
++	 */
++	if (do_udba && inode) {
++		mode = (inode->i_mode & S_IFMT);
++		plus = (inode->i_nlink > 0);
++		ibs = au_ibstart(inode);
++		ibe = au_ibend(inode);
++	}
++
++	bstart = au_dbstart(dentry);
++	btail = bstart;
++	if (inode && S_ISDIR(inode->i_mode))
++		btail = au_dbtaildir(dentry);
++	for (bindex = bstart; bindex <= btail; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++
++		AuDbg("b%d, %.*s\n", bindex, AuDLNPair(h_dentry));
++		h_name = &h_dentry->d_name;
++		if (unlikely(do_udba
++			     && !is_root
++			     && (unhashed != !!d_unhashed(h_dentry)
++				 || name->len != h_name->len
++				 || memcmp(name->name, h_name->name, name->len))
++			    )) {
++			AuDbg("unhash 0x%x 0x%x, %.*s %.*s\n",
++				  unhashed, d_unhashed(h_dentry),
++				  AuDLNPair(dentry), AuDLNPair(h_dentry));
++			goto err;
++		}
++
++		err = au_do_h_d_reval(h_dentry, nd, dentry, bindex);
++		if (unlikely(err))
++			/* do not goto err, to keep the errno */
++			break;
++
++		/* todo: plink too? */
++		if (!do_udba)
++			continue;
++
++		/* UDBA tests */
++		h_inode = h_dentry->d_inode;
++		if (unlikely(!!inode != !!h_inode))
++			goto err;
++
++		h_plus = plus;
++		h_mode = mode;
++		h_cached_inode = h_inode;
++		if (h_inode) {
++			h_mode = (h_inode->i_mode & S_IFMT);
++			h_plus = (h_inode->i_nlink > 0);
++		}
++		if (inode && ibs <= bindex && bindex <= ibe)
++			h_cached_inode = au_h_iptr(inode, bindex);
++
++		if (unlikely(plus != h_plus
++			     || mode != h_mode
++			     || h_cached_inode != h_inode))
++			goto err;
++		continue;
++
++	err:
++		err = -EINVAL;
++		break;
++	}
++
++	return err;
++}
++
++/* todo: consolidate with do_refresh() and au_reval_for_attr() */
++static int simple_reval_dpath(struct dentry *dentry, unsigned int sigen)
++{
++	int err;
++	struct dentry *parent;
++
++	if (!au_digen_test(dentry, sigen))
++		return 0;
++
++	parent = dget_parent(dentry);
++	di_read_lock_parent(parent, AuLock_IR);
++	AuDebugOn(au_digen_test(parent, sigen));
++	au_dbg_verify_gen(parent, sigen);
++	err = au_refresh_dentry(dentry, parent);
++	di_read_unlock(parent, AuLock_IR);
++	dput(parent);
++	AuTraceErr(err);
++	return err;
++}
++
++int au_reval_dpath(struct dentry *dentry, unsigned int sigen)
++{
++	int err;
++	struct dentry *d, *parent;
++	struct inode *inode;
++
++	if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIR))
++		return simple_reval_dpath(dentry, sigen);
++
++	/* slow loop, keep it simple and stupid */
++	/* cf: au_cpup_dirs() */
++	err = 0;
++	parent = NULL;
++	while (au_digen_test(dentry, sigen)) {
++		d = dentry;
++		while (1) {
++			dput(parent);
++			parent = dget_parent(d);
++			if (!au_digen_test(parent, sigen))
++				break;
++			d = parent;
++		}
++
++		inode = d->d_inode;
++		if (d != dentry)
++			di_write_lock_child2(d);
++
++		/* someone might update our dentry while we were sleeping */
++		if (au_digen_test(d, sigen)) {
++			/*
++			 * todo: consolidate with simple_reval_dpath(),
++			 * do_refresh() and au_reval_for_attr().
++			 */
++			di_read_lock_parent(parent, AuLock_IR);
++			err = au_refresh_dentry(d, parent);
++			di_read_unlock(parent, AuLock_IR);
++		}
++
++		if (d != dentry)
++			di_write_unlock(d);
++		dput(parent);
++		if (unlikely(err))
++			break;
++	}
++
++	return err;
++}
++
++/*
++ * if valid returns 1, otherwise 0.
++ */
++static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
++{
++	int valid, err;
++	unsigned int sigen;
++	unsigned char do_udba;
++	struct super_block *sb;
++	struct inode *inode;
++
++	valid = 0;
++	if (unlikely(!au_di(dentry)))
++		goto out;
++
++	valid = 1;
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	/*
++	 * todo: very ugly
++	 * i_mutex of parent dir may be held,
++	 * but we should not return 'invalid' due to busy.
++	 */
++	err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM);
++	if (unlikely(err)) {
++		valid = err;
++		AuTraceErr(err);
++		goto out;
++	}
++	if (unlikely(au_dbrange_test(dentry))) {
++		err = -EINVAL;
++		AuTraceErr(err);
++		goto out_dgrade;
++	}
++
++	sigen = au_sigen(sb);
++	if (au_digen_test(dentry, sigen)) {
++		AuDebugOn(IS_ROOT(dentry));
++		err = au_reval_dpath(dentry, sigen);
++		if (unlikely(err)) {
++			AuTraceErr(err);
++			goto out_dgrade;
++		}
++	}
++	di_downgrade_lock(dentry, AuLock_IR);
++
++	err = -EINVAL;
++	if (inode && (IS_DEADDIR(inode) || !inode->i_nlink))
++		goto out_inval;
++
++	do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
++	if (do_udba && inode) {
++		aufs_bindex_t bstart = au_ibstart(inode);
++		struct inode *h_inode;
++
++		if (bstart >= 0) {
++			h_inode = au_h_iptr(inode, bstart);
++			if (h_inode && au_test_higen(inode, h_inode))
++				goto out_inval;
++		}
++	}
++
++	err = h_d_revalidate(dentry, inode, nd, do_udba);
++	if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) {
++		err = -EIO;
++		AuDbg("both of real entry and whiteout found, %.*s, err %d\n",
++		      AuDLNPair(dentry), err);
++	}
++	goto out_inval;
++
++out_dgrade:
++	di_downgrade_lock(dentry, AuLock_IR);
++out_inval:
++	aufs_read_unlock(dentry, AuLock_IR);
++	AuTraceErr(err);
++	valid = !err;
++out:
++	if (!valid) {
++		AuDbg("%.*s invalid, %d\n", AuDLNPair(dentry), valid);
++		d_drop(dentry);
++	}
++	return valid;
++}
++
++static void aufs_d_release(struct dentry *dentry)
++{
++	if (au_di(dentry)) {
++		au_di_fin(dentry);
++		au_hn_di_reinit(dentry);
++	}
++}
++
++const struct dentry_operations aufs_dop = {
++	.d_revalidate	= aufs_d_revalidate,
++	.d_release	= aufs_d_release
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/dentry.h linux-2.6.36/fs/aufs/dentry.h
+--- linux-2.6.36.orig/fs/aufs/dentry.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dentry.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,237 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * lookup and dentry operations
++ */
++
++#ifndef __AUFS_DENTRY_H__
++#define __AUFS_DENTRY_H__
++
++#ifdef __KERNEL__
++
++#include <linux/dcache.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++struct au_hdentry {
++	struct dentry		*hd_dentry;
++	aufs_bindex_t		hd_id;
++};
++
++struct au_dinfo {
++	atomic_t		di_generation;
++
++	struct au_rwsem		di_rwsem;
++	aufs_bindex_t		di_bstart, di_bend, di_bwh, di_bdiropq;
++	struct au_hdentry	*di_hdentry;
++} ____cacheline_aligned_in_smp;
++
++/* ---------------------------------------------------------------------- */
++
++/* dentry.c */
++extern const struct dentry_operations aufs_dop;
++struct au_branch;
++struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent,
++			   struct au_branch *br, struct nameidata *nd);
++struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent,
++			       struct au_branch *br);
++int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir,
++		struct dentry *h_parent, struct au_branch *br);
++
++int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
++		   struct nameidata *nd);
++int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex);
++int au_refresh_dentry(struct dentry *dentry, struct dentry *parent);
++int au_reval_dpath(struct dentry *dentry, unsigned int sigen);
++
++/* dinfo.c */
++void au_di_init_once(void *_di);
++struct au_dinfo *au_di_alloc(struct super_block *sb, unsigned int lsc);
++void au_di_free(struct au_dinfo *dinfo);
++void au_di_swap(struct au_dinfo *a, struct au_dinfo *b);
++void au_di_cp(struct au_dinfo *dst, struct au_dinfo *src);
++int au_di_init(struct dentry *dentry);
++void au_di_fin(struct dentry *dentry);
++int au_di_realloc(struct au_dinfo *dinfo, int nbr);
++
++void di_read_lock(struct dentry *d, int flags, unsigned int lsc);
++void di_read_unlock(struct dentry *d, int flags);
++void di_downgrade_lock(struct dentry *d, int flags);
++void di_write_lock(struct dentry *d, unsigned int lsc);
++void di_write_unlock(struct dentry *d);
++void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir);
++void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir);
++void di_write_unlock2(struct dentry *d1, struct dentry *d2);
++
++struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex);
++aufs_bindex_t au_dbtail(struct dentry *dentry);
++aufs_bindex_t au_dbtaildir(struct dentry *dentry);
++
++void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
++		   struct dentry *h_dentry);
++int au_digen_test(struct dentry *dentry, unsigned int sigen);
++int au_dbrange_test(struct dentry *dentry);
++void au_update_digen(struct dentry *dentry);
++void au_update_dbrange(struct dentry *dentry, int do_put_zero);
++void au_update_dbstart(struct dentry *dentry);
++void au_update_dbend(struct dentry *dentry);
++int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_dinfo *au_di(struct dentry *dentry)
++{
++	return dentry->d_fsdata;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for dinfo */
++enum {
++	AuLsc_DI_CHILD,		/* child first */
++	AuLsc_DI_CHILD2,	/* rename(2), link(2), and cpup at hnotify */
++	AuLsc_DI_CHILD3,	/* copyup dirs */
++	AuLsc_DI_PARENT,
++	AuLsc_DI_PARENT2,
++	AuLsc_DI_PARENT3,
++	AuLsc_DI_TMP		/* temp for replacing dinfo */
++};
++
++/*
++ * di_read_lock_child, di_write_lock_child,
++ * di_read_lock_child2, di_write_lock_child2,
++ * di_read_lock_child3, di_write_lock_child3,
++ * di_read_lock_parent, di_write_lock_parent,
++ * di_read_lock_parent2, di_write_lock_parent2,
++ * di_read_lock_parent3, di_write_lock_parent3,
++ */
++#define AuReadLockFunc(name, lsc) \
++static inline void di_read_lock_##name(struct dentry *d, int flags) \
++{ di_read_lock(d, flags, AuLsc_DI_##lsc); }
++
++#define AuWriteLockFunc(name, lsc) \
++static inline void di_write_lock_##name(struct dentry *d) \
++{ di_write_lock(d, AuLsc_DI_##lsc); }
++
++#define AuRWLockFuncs(name, lsc) \
++	AuReadLockFunc(name, lsc) \
++	AuWriteLockFunc(name, lsc)
++
++AuRWLockFuncs(child, CHILD);
++AuRWLockFuncs(child2, CHILD2);
++AuRWLockFuncs(child3, CHILD3);
++AuRWLockFuncs(parent, PARENT);
++AuRWLockFuncs(parent2, PARENT2);
++AuRWLockFuncs(parent3, PARENT3);
++
++#undef AuReadLockFunc
++#undef AuWriteLockFunc
++#undef AuRWLockFuncs
++
++#define DiMustNoWaiters(d)	AuRwMustNoWaiters(&au_di(d)->di_rwsem)
++#define DiMustAnyLock(d)	AuRwMustAnyLock(&au_di(d)->di_rwsem)
++#define DiMustWriteLock(d)	AuRwMustWriteLock(&au_di(d)->di_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: memory barrier? */
++static inline unsigned int au_digen(struct dentry *d)
++{
++	return atomic_read(&au_di(d)->di_generation);
++}
++
++static inline void au_h_dentry_init(struct au_hdentry *hdentry)
++{
++	hdentry->hd_dentry = NULL;
++}
++
++static inline void au_hdput(struct au_hdentry *hd)
++{
++	if (hd)
++		dput(hd->hd_dentry);
++}
++
++static inline aufs_bindex_t au_dbstart(struct dentry *dentry)
++{
++	DiMustAnyLock(dentry);
++	return au_di(dentry)->di_bstart;
++}
++
++static inline aufs_bindex_t au_dbend(struct dentry *dentry)
++{
++	DiMustAnyLock(dentry);
++	return au_di(dentry)->di_bend;
++}
++
++static inline aufs_bindex_t au_dbwh(struct dentry *dentry)
++{
++	DiMustAnyLock(dentry);
++	return au_di(dentry)->di_bwh;
++}
++
++static inline aufs_bindex_t au_dbdiropq(struct dentry *dentry)
++{
++	DiMustAnyLock(dentry);
++	return au_di(dentry)->di_bdiropq;
++}
++
++/* todo: hard/soft set? */
++static inline void au_set_dbstart(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	DiMustWriteLock(dentry);
++	au_di(dentry)->di_bstart = bindex;
++}
++
++static inline void au_set_dbend(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	DiMustWriteLock(dentry);
++	au_di(dentry)->di_bend = bindex;
++}
++
++static inline void au_set_dbwh(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	DiMustWriteLock(dentry);
++	/* dbwh can be outside of bstart - bend range */
++	au_di(dentry)->di_bwh = bindex;
++}
++
++static inline void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	DiMustWriteLock(dentry);
++	au_di(dentry)->di_bdiropq = bindex;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_HNOTIFY
++static inline void au_digen_dec(struct dentry *d)
++{
++	atomic_dec(&au_di(d)->di_generation);
++}
++
++static inline void au_hn_di_reinit(struct dentry *dentry)
++{
++	dentry->d_fsdata = NULL;
++}
++#else
++AuStubVoid(au_hn_di_reinit, struct dentry *dentry __maybe_unused)
++#endif /* CONFIG_AUFS_HNOTIFY */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DENTRY_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/dinfo.c linux-2.6.36/fs/aufs/dinfo.c
+--- linux-2.6.36.orig/fs/aufs/dinfo.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dinfo.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,494 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * dentry private data
++ */
++
++#include "aufs.h"
++
++void au_di_init_once(void *_dinfo)
++{
++	struct au_dinfo *dinfo = _dinfo;
++	static struct lock_class_key aufs_di;
++
++	au_rw_init(&dinfo->di_rwsem);
++	au_rw_class(&dinfo->di_rwsem, &aufs_di);
++}
++
++struct au_dinfo *au_di_alloc(struct super_block *sb, unsigned int lsc)
++{
++	struct au_dinfo *dinfo;
++	int nbr, i;
++
++	dinfo = au_cache_alloc_dinfo();
++	if (unlikely(!dinfo))
++		goto out;
++
++	nbr = au_sbend(sb) + 1;
++	if (nbr <= 0)
++		nbr = 1;
++	dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry), GFP_NOFS);
++	if (dinfo->di_hdentry) {
++		au_rw_write_lock_nested(&dinfo->di_rwsem, lsc);
++		dinfo->di_bstart = -1;
++		dinfo->di_bend = -1;
++		dinfo->di_bwh = -1;
++		dinfo->di_bdiropq = -1;
++		for (i = 0; i < nbr; i++)
++			dinfo->di_hdentry[i].hd_id = -1;
++		goto out;
++	}
++
++	au_cache_free_dinfo(dinfo);
++	dinfo = NULL;
++
++out:
++	return dinfo;
++}
++
++void au_di_free(struct au_dinfo *dinfo)
++{
++	struct au_hdentry *p;
++	aufs_bindex_t bend, bindex;
++
++	/* dentry may not be revalidated */
++	bindex = dinfo->di_bstart;
++	if (bindex >= 0) {
++		bend = dinfo->di_bend;
++		p = dinfo->di_hdentry + bindex;
++		while (bindex++ <= bend)
++			au_hdput(p++);
++	}
++	kfree(dinfo->di_hdentry);
++	au_cache_free_dinfo(dinfo);
++}
++
++void au_di_swap(struct au_dinfo *a, struct au_dinfo *b)
++{
++	struct au_hdentry *p;
++	aufs_bindex_t bi;
++
++	AuRwMustWriteLock(&a->di_rwsem);
++	AuRwMustWriteLock(&b->di_rwsem);
++
++#define DiSwap(v, name)				\
++	do {					\
++		v = a->di_##name;		\
++		a->di_##name = b->di_##name;	\
++		b->di_##name = v;		\
++	} while (0)
++
++	DiSwap(p, hdentry);
++	DiSwap(bi, bstart);
++	DiSwap(bi, bend);
++	DiSwap(bi, bwh);
++	DiSwap(bi, bdiropq);
++	/* smp_mb(); */
++
++#undef DiSwap
++}
++
++void au_di_cp(struct au_dinfo *dst, struct au_dinfo *src)
++{
++	AuRwMustWriteLock(&dst->di_rwsem);
++	AuRwMustWriteLock(&src->di_rwsem);
++
++	dst->di_bstart = src->di_bstart;
++	dst->di_bend = src->di_bend;
++	dst->di_bwh = src->di_bwh;
++	dst->di_bdiropq = src->di_bdiropq;
++	/* smp_mb(); */
++}
++
++int au_di_init(struct dentry *dentry)
++{
++	int err;
++	struct super_block *sb;
++	struct au_dinfo *dinfo;
++
++	err = 0;
++	sb = dentry->d_sb;
++	dinfo = au_di_alloc(sb, AuLsc_DI_CHILD);
++	if (dinfo) {
++		atomic_set(&dinfo->di_generation, au_sigen(sb));
++		/* smp_mb(); */ /* atomic_set */
++		dentry->d_op = &aufs_dop;
++		dentry->d_fsdata = dinfo;
++	} else
++		err = -ENOMEM;
++
++	return err;
++}
++
++void au_di_fin(struct dentry *dentry)
++{
++	struct au_dinfo *dinfo;
++
++	dinfo = au_di(dentry);
++	AuRwDestroy(&dinfo->di_rwsem);
++	au_di_free(dinfo);
++}
++
++int au_di_realloc(struct au_dinfo *dinfo, int nbr)
++{
++	int err, sz;
++	struct au_hdentry *hdp;
++
++	AuRwMustWriteLock(&dinfo->di_rwsem);
++
++	err = -ENOMEM;
++	sz = sizeof(*hdp) * (dinfo->di_bend + 1);
++	if (!sz)
++		sz = sizeof(*hdp);
++	hdp = au_kzrealloc(dinfo->di_hdentry, sz, sizeof(*hdp) * nbr, GFP_NOFS);
++	if (hdp) {
++		dinfo->di_hdentry = hdp;
++		err = 0;
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void do_ii_write_lock(struct inode *inode, unsigned int lsc)
++{
++	switch (lsc) {
++	case AuLsc_DI_CHILD:
++		ii_write_lock_child(inode);
++		break;
++	case AuLsc_DI_CHILD2:
++		ii_write_lock_child2(inode);
++		break;
++	case AuLsc_DI_CHILD3:
++		ii_write_lock_child3(inode);
++		break;
++	case AuLsc_DI_PARENT:
++		ii_write_lock_parent(inode);
++		break;
++	case AuLsc_DI_PARENT2:
++		ii_write_lock_parent2(inode);
++		break;
++	case AuLsc_DI_PARENT3:
++		ii_write_lock_parent3(inode);
++		break;
++	default:
++		BUG();
++	}
++}
++
++static void do_ii_read_lock(struct inode *inode, unsigned int lsc)
++{
++	switch (lsc) {
++	case AuLsc_DI_CHILD:
++		ii_read_lock_child(inode);
++		break;
++	case AuLsc_DI_CHILD2:
++		ii_read_lock_child2(inode);
++		break;
++	case AuLsc_DI_CHILD3:
++		ii_read_lock_child3(inode);
++		break;
++	case AuLsc_DI_PARENT:
++		ii_read_lock_parent(inode);
++		break;
++	case AuLsc_DI_PARENT2:
++		ii_read_lock_parent2(inode);
++		break;
++	case AuLsc_DI_PARENT3:
++		ii_read_lock_parent3(inode);
++		break;
++	default:
++		BUG();
++	}
++}
++
++void di_read_lock(struct dentry *d, int flags, unsigned int lsc)
++{
++	au_rw_read_lock_nested(&au_di(d)->di_rwsem, lsc);
++	if (d->d_inode) {
++		if (au_ftest_lock(flags, IW))
++			do_ii_write_lock(d->d_inode, lsc);
++		else if (au_ftest_lock(flags, IR))
++			do_ii_read_lock(d->d_inode, lsc);
++	}
++}
++
++void di_read_unlock(struct dentry *d, int flags)
++{
++	if (d->d_inode) {
++		if (au_ftest_lock(flags, IW)) {
++			au_dbg_verify_dinode(d);
++			ii_write_unlock(d->d_inode);
++		} else if (au_ftest_lock(flags, IR)) {
++			au_dbg_verify_dinode(d);
++			ii_read_unlock(d->d_inode);
++		}
++	}
++	au_rw_read_unlock(&au_di(d)->di_rwsem);
++}
++
++void di_downgrade_lock(struct dentry *d, int flags)
++{
++	if (d->d_inode && au_ftest_lock(flags, IR))
++		ii_downgrade_lock(d->d_inode);
++	au_rw_dgrade_lock(&au_di(d)->di_rwsem);
++}
++
++void di_write_lock(struct dentry *d, unsigned int lsc)
++{
++	au_rw_write_lock_nested(&au_di(d)->di_rwsem, lsc);
++	if (d->d_inode)
++		do_ii_write_lock(d->d_inode, lsc);
++}
++
++void di_write_unlock(struct dentry *d)
++{
++	au_dbg_verify_dinode(d);
++	if (d->d_inode)
++		ii_write_unlock(d->d_inode);
++	au_rw_write_unlock(&au_di(d)->di_rwsem);
++}
++
++void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir)
++{
++	AuDebugOn(d1 == d2
++		  || d1->d_inode == d2->d_inode
++		  || d1->d_sb != d2->d_sb);
++
++	if (isdir && au_test_subdir(d1, d2)) {
++		di_write_lock_child(d1);
++		di_write_lock_child2(d2);
++	} else {
++		/* there should be no races */
++		di_write_lock_child(d2);
++		di_write_lock_child2(d1);
++	}
++}
++
++void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir)
++{
++	AuDebugOn(d1 == d2
++		  || d1->d_inode == d2->d_inode
++		  || d1->d_sb != d2->d_sb);
++
++	if (isdir && au_test_subdir(d1, d2)) {
++		di_write_lock_parent(d1);
++		di_write_lock_parent2(d2);
++	} else {
++		/* there should be no races */
++		di_write_lock_parent(d2);
++		di_write_lock_parent2(d1);
++	}
++}
++
++void di_write_unlock2(struct dentry *d1, struct dentry *d2)
++{
++	di_write_unlock(d1);
++	if (d1->d_inode == d2->d_inode)
++		au_rw_write_unlock(&au_di(d2)->di_rwsem);
++	else
++		di_write_unlock(d2);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	struct dentry *d;
++
++	DiMustAnyLock(dentry);
++
++	if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
++		return NULL;
++	AuDebugOn(bindex < 0);
++	d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry;
++	AuDebugOn(d && (atomic_read(&d->d_count) <= 0));
++	return d;
++}
++
++aufs_bindex_t au_dbtail(struct dentry *dentry)
++{
++	aufs_bindex_t bend, bwh;
++
++	bend = au_dbend(dentry);
++	if (0 <= bend) {
++		bwh = au_dbwh(dentry);
++		if (!bwh)
++			return bwh;
++		if (0 < bwh && bwh < bend)
++			return bwh - 1;
++	}
++	return bend;
++}
++
++aufs_bindex_t au_dbtaildir(struct dentry *dentry)
++{
++	aufs_bindex_t bend, bopq;
++
++	bend = au_dbtail(dentry);
++	if (0 <= bend) {
++		bopq = au_dbdiropq(dentry);
++		if (0 <= bopq && bopq < bend)
++			bend = bopq;
++	}
++	return bend;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
++		   struct dentry *h_dentry)
++{
++	struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
++	struct au_branch *br;
++
++	DiMustWriteLock(dentry);
++
++	au_hdput(hd);
++	hd->hd_dentry = h_dentry;
++	if (h_dentry) {
++		br = au_sbr(dentry->d_sb, bindex);
++		hd->hd_id = br->br_id;
++	}
++}
++
++int au_dbrange_test(struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bstart, bend;
++
++	err = 0;
++	bstart = au_dbstart(dentry);
++	bend = au_dbend(dentry);
++	if (bstart >= 0)
++		AuDebugOn(bend < 0 && bstart > bend);
++	else {
++		err = -EIO;
++		AuDebugOn(bend >= 0);
++	}
++
++	return err;
++}
++
++int au_digen_test(struct dentry *dentry, unsigned int sigen)
++{
++	int err;
++
++	err = 0;
++	if (unlikely(au_digen(dentry) != sigen
++		     || au_iigen_test(dentry->d_inode, sigen)))
++		err = -EIO;
++
++	return err;
++}
++
++void au_update_digen(struct dentry *dentry)
++{
++	atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb));
++	/* smp_mb(); */ /* atomic_set */
++}
++
++void au_update_dbrange(struct dentry *dentry, int do_put_zero)
++{
++	struct au_dinfo *dinfo;
++	struct dentry *h_d;
++	struct au_hdentry *hdp;
++
++	DiMustWriteLock(dentry);
++
++	dinfo = au_di(dentry);
++	if (!dinfo || dinfo->di_bstart < 0)
++		return;
++
++	hdp = dinfo->di_hdentry;
++	if (do_put_zero) {
++		aufs_bindex_t bindex, bend;
++
++		bend = dinfo->di_bend;
++		for (bindex = dinfo->di_bstart; bindex <= bend; bindex++) {
++			h_d = hdp[0 + bindex].hd_dentry;
++			if (h_d && !h_d->d_inode)
++				au_set_h_dptr(dentry, bindex, NULL);
++		}
++	}
++
++	dinfo->di_bstart = -1;
++	while (++dinfo->di_bstart <= dinfo->di_bend)
++		if (hdp[0 + dinfo->di_bstart].hd_dentry)
++			break;
++	if (dinfo->di_bstart > dinfo->di_bend) {
++		dinfo->di_bstart = -1;
++		dinfo->di_bend = -1;
++		return;
++	}
++
++	dinfo->di_bend++;
++	while (0 <= --dinfo->di_bend)
++		if (hdp[0 + dinfo->di_bend].hd_dentry)
++			break;
++	AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0);
++}
++
++void au_update_dbstart(struct dentry *dentry)
++{
++	aufs_bindex_t bindex, bend;
++	struct dentry *h_dentry;
++
++	bend = au_dbend(dentry);
++	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++		if (h_dentry->d_inode) {
++			au_set_dbstart(dentry, bindex);
++			return;
++		}
++		au_set_h_dptr(dentry, bindex, NULL);
++	}
++}
++
++void au_update_dbend(struct dentry *dentry)
++{
++	aufs_bindex_t bindex, bstart;
++	struct dentry *h_dentry;
++
++	bstart = au_dbstart(dentry);
++	for (bindex = au_dbend(dentry); bindex >= bstart; bindex--) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++		if (h_dentry->d_inode) {
++			au_set_dbend(dentry, bindex);
++			return;
++		}
++		au_set_h_dptr(dentry, bindex, NULL);
++	}
++}
++
++int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry)
++{
++	aufs_bindex_t bindex, bend;
++
++	bend = au_dbend(dentry);
++	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++)
++		if (au_h_dptr(dentry, bindex) == h_dentry)
++			return bindex;
++	return -1;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/dir.c linux-2.6.36/fs/aufs/dir.c
+--- linux-2.6.36.orig/fs/aufs/dir.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dir.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,648 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * directory operations
++ */
++
++#include <linux/file.h>
++#include <linux/fs_stack.h>
++#include "aufs.h"
++
++void au_add_nlink(struct inode *dir, struct inode *h_dir)
++{
++	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
++
++	dir->i_nlink += h_dir->i_nlink - 2;
++	if (h_dir->i_nlink < 2)
++		dir->i_nlink += 2;
++}
++
++void au_sub_nlink(struct inode *dir, struct inode *h_dir)
++{
++	AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
++
++	dir->i_nlink -= h_dir->i_nlink - 2;
++	if (h_dir->i_nlink < 2)
++		dir->i_nlink -= 2;
++}
++
++loff_t au_dir_size(struct file *file, struct dentry *dentry)
++{
++	loff_t sz;
++	aufs_bindex_t bindex, bend;
++	struct file *h_file;
++	struct dentry *h_dentry;
++
++	sz = 0;
++	if (file) {
++		AuDebugOn(!file->f_dentry);
++		AuDebugOn(!file->f_dentry->d_inode);
++		AuDebugOn(!S_ISDIR(file->f_dentry->d_inode->i_mode));
++
++		bend = au_fbend_dir(file);
++		for (bindex = au_fbstart(file);
++		     bindex <= bend && sz < KMALLOC_MAX_SIZE;
++		     bindex++) {
++			h_file = au_hf_dir(file, bindex);
++			if (h_file
++			    && h_file->f_dentry
++			    && h_file->f_dentry->d_inode)
++				sz += i_size_read(h_file->f_dentry->d_inode);
++		}
++	} else {
++		AuDebugOn(!dentry);
++		AuDebugOn(!dentry->d_inode);
++		AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode));
++
++		bend = au_dbtaildir(dentry);
++		for (bindex = au_dbstart(dentry);
++		     bindex <= bend && sz < KMALLOC_MAX_SIZE;
++		     bindex++) {
++			h_dentry = au_h_dptr(dentry, bindex);
++			if (h_dentry && h_dentry->d_inode)
++				sz += i_size_read(h_dentry->d_inode);
++		}
++	}
++	if (sz < KMALLOC_MAX_SIZE)
++		sz = roundup_pow_of_two(sz);
++	if (sz > KMALLOC_MAX_SIZE)
++		sz = KMALLOC_MAX_SIZE;
++	else if (sz < NAME_MAX) {
++		BUILD_BUG_ON(AUFS_RDBLK_DEF < NAME_MAX);
++		sz = AUFS_RDBLK_DEF;
++	}
++	return sz;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int reopen_dir(struct file *file)
++{
++	int err;
++	unsigned int flags;
++	aufs_bindex_t bindex, btail, bstart;
++	struct dentry *dentry, *h_dentry;
++	struct file *h_file;
++
++	/* open all lower dirs */
++	dentry = file->f_dentry;
++	bstart = au_dbstart(dentry);
++	for (bindex = au_fbstart(file); bindex < bstart; bindex++)
++		au_set_h_fptr(file, bindex, NULL);
++	au_set_fbstart(file, bstart);
++
++	btail = au_dbtaildir(dentry);
++	for (bindex = au_fbend_dir(file); btail < bindex; bindex--)
++		au_set_h_fptr(file, bindex, NULL);
++	au_set_fbend_dir(file, btail);
++
++	flags = vfsub_file_flags(file);
++	for (bindex = bstart; bindex <= btail; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++		h_file = au_hf_dir(file, bindex);
++		if (h_file)
++			continue;
++
++		h_file = au_h_open(dentry, bindex, flags, file);
++		err = PTR_ERR(h_file);
++		if (IS_ERR(h_file))
++			goto out; /* close all? */
++		au_set_h_fptr(file, bindex, h_file);
++	}
++	au_update_figen(file);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++	err = 0;
++
++out:
++	return err;
++}
++
++static int do_open_dir(struct file *file, int flags)
++{
++	int err;
++	aufs_bindex_t bindex, btail;
++	struct dentry *dentry, *h_dentry;
++	struct file *h_file;
++
++	FiMustWriteLock(file);
++
++	dentry = file->f_dentry;
++	err = au_alive_dir(dentry);
++	if (unlikely(err))
++		goto out;
++
++	file->f_version = dentry->d_inode->i_version;
++	bindex = au_dbstart(dentry);
++	au_set_fbstart(file, bindex);
++	btail = au_dbtaildir(dentry);
++	au_set_fbend_dir(file, btail);
++	for (; !err && bindex <= btail; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (!h_dentry)
++			continue;
++
++		h_file = au_h_open(dentry, bindex, flags, file);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			break;
++		}
++		au_set_h_fptr(file, bindex, h_file);
++	}
++	au_update_figen(file);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++	if (!err)
++		return 0; /* success */
++
++	/* close all */
++	for (bindex = au_fbstart(file); bindex <= btail; bindex++)
++		au_set_h_fptr(file, bindex, NULL);
++	au_set_fbstart(file, -1);
++	au_set_fbend_dir(file, -1);
++
++out:
++	return err;
++}
++
++static int aufs_open_dir(struct inode *inode __maybe_unused,
++			 struct file *file)
++{
++	int err;
++	struct super_block *sb;
++	struct au_fidir *fidir;
++
++	err = -ENOMEM;
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	fidir = au_fidir_alloc(sb);
++	if (fidir) {
++		err = au_do_open(file, do_open_dir, fidir);
++		if (unlikely(err))
++			kfree(fidir);
++	}
++	si_read_unlock(sb);
++	return err;
++}
++
++static int aufs_release_dir(struct inode *inode __maybe_unused,
++			    struct file *file)
++{
++	struct au_vdir *vdir_cache;
++	struct super_block *sb;
++	struct au_finfo *finfo;
++	struct au_fidir *fidir;
++	aufs_bindex_t bindex, bend;
++
++	sb = file->f_dentry->d_sb;
++	finfo = au_fi(file);
++	fidir = finfo->fi_hdir;
++	if (fidir) {
++		/* remove me from sb->s_files */
++		file_sb_list_del(file);
++
++		vdir_cache = fidir->fd_vdir_cache; /* lock-free */
++		if (vdir_cache)
++			au_vdir_free(vdir_cache);
++
++		bindex = finfo->fi_btop;
++		if (bindex >= 0) {
++			/*
++			 * calls fput() instead of filp_close(),
++			 * since no dnotify or lock for the lower file.
++			 */
++			bend = fidir->fd_bbot;
++			for (; bindex <= bend; bindex++)
++				au_set_h_fptr(file, bindex, NULL);
++		}
++		kfree(fidir);
++		finfo->fi_hdir = NULL;
++	}
++	au_finfo_fin(file);
++	return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_flush_dir(struct file *file, fl_owner_t id)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	struct file *h_file;
++
++	err = 0;
++	bend = au_fbend_dir(file);
++	for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
++		h_file = au_hf_dir(file, bindex);
++		if (h_file)
++			err = vfsub_flush(h_file, id);
++	}
++	return err;
++}
++
++static int aufs_flush_dir(struct file *file, fl_owner_t id)
++{
++	return au_do_flush(file, id, au_do_flush_dir);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_fsync_dir_no_file(struct dentry *dentry, int datasync)
++{
++	int err;
++	aufs_bindex_t bend, bindex;
++	struct inode *inode;
++	struct super_block *sb;
++
++	err = 0;
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	IMustLock(inode);
++	bend = au_dbend(dentry);
++	for (bindex = au_dbstart(dentry); !err && bindex <= bend; bindex++) {
++		struct path h_path;
++		struct inode *h_inode;
++
++		if (au_test_ro(sb, bindex, inode))
++			continue;
++		h_path.dentry = au_h_dptr(dentry, bindex);
++		if (!h_path.dentry)
++			continue;
++		h_inode = h_path.dentry->d_inode;
++		if (!h_inode)
++			continue;
++
++		/* no mnt_want_write() */
++		/* cf. fs/nsfd/vfs.c and fs/nfsd/nfs4recover.c */
++		/* todo: inotiry fired? */
++		h_path.mnt = au_sbr_mnt(sb, bindex);
++		mutex_lock(&h_inode->i_mutex);
++		err = filemap_fdatawrite(h_inode->i_mapping);
++		AuDebugOn(!h_inode->i_fop);
++		if (!err && h_inode->i_fop->fsync)
++			err = h_inode->i_fop->fsync(NULL, datasync);
++		if (!err)
++			err = filemap_fdatawrite(h_inode->i_mapping);
++		if (!err)
++			vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++		mutex_unlock(&h_inode->i_mutex);
++	}
++
++	return err;
++}
++
++static int au_do_fsync_dir(struct file *file, int datasync)
++{
++	int err;
++	aufs_bindex_t bend, bindex;
++	struct file *h_file;
++	struct super_block *sb;
++	struct inode *inode;
++	struct mutex *h_mtx;
++
++	err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	sb = file->f_dentry->d_sb;
++	inode = file->f_dentry->d_inode;
++	bend = au_fbend_dir(file);
++	for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
++		h_file = au_hf_dir(file, bindex);
++		if (!h_file || au_test_ro(sb, bindex, inode))
++			continue;
++
++		err = vfs_fsync(h_file, datasync);
++		if (!err) {
++			h_mtx = &h_file->f_dentry->d_inode->i_mutex;
++			mutex_lock(h_mtx);
++			vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++			/*ignore*/
++			mutex_unlock(h_mtx);
++		}
++	}
++
++out:
++	return err;
++}
++
++/*
++ * @file may be NULL
++ */
++static int aufs_fsync_dir(struct file *file, int datasync)
++{
++	int err;
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	IMustLock(dentry->d_inode);
++
++	err = 0;
++	sb = dentry->d_sb;
++	si_noflush_read_lock(sb);
++	if (file)
++		err = au_do_fsync_dir(file, datasync);
++	else {
++		di_write_lock_child(dentry);
++		err = au_do_fsync_dir_no_file(dentry, datasync);
++	}
++	au_cpup_attr_timesizes(dentry->d_inode);
++	di_write_unlock(dentry);
++	if (file)
++		fi_write_unlock(file);
++
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_readdir(struct file *file, void *dirent, filldir_t filldir)
++{
++	int err;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	IMustLock(inode);
++
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++	err = au_alive_dir(dentry);
++	if (!err)
++		err = au_vdir_init(file);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++
++	if (!au_test_nfsd()) {
++		err = au_vdir_fill_de(file, dirent, filldir);
++		fsstack_copy_attr_atime(inode,
++					au_h_iptr(inode, au_ibstart(inode)));
++	} else {
++		/*
++		 * nfsd filldir may call lookup_one_len(), vfs_getattr(),
++		 * encode_fh() and others.
++		 */
++		struct inode *h_inode = au_h_iptr(inode, au_ibstart(inode));
++
++		di_read_unlock(dentry, AuLock_IR);
++		si_read_unlock(sb);
++		err = au_vdir_fill_de(file, dirent, filldir);
++		fsstack_copy_attr_atime(inode, h_inode);
++		fi_write_unlock(file);
++
++		AuTraceErr(err);
++		return err;
++	}
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#define AuTestEmpty_WHONLY	1
++#define AuTestEmpty_CALLED	(1 << 1)
++#define AuTestEmpty_SHWH	(1 << 2)
++#define au_ftest_testempty(flags, name)	((flags) & AuTestEmpty_##name)
++#define au_fset_testempty(flags, name) \
++	do { (flags) |= AuTestEmpty_##name; } while (0)
++#define au_fclr_testempty(flags, name) \
++	do { (flags) &= ~AuTestEmpty_##name; } while (0)
++
++#ifndef CONFIG_AUFS_SHWH
++#undef AuTestEmpty_SHWH
++#define AuTestEmpty_SHWH	0
++#endif
++
++struct test_empty_arg {
++	struct au_nhash *whlist;
++	unsigned int flags;
++	int err;
++	aufs_bindex_t bindex;
++};
++
++static int test_empty_cb(void *__arg, const char *__name, int namelen,
++			 loff_t offset __maybe_unused, u64 ino,
++			 unsigned int d_type)
++{
++	struct test_empty_arg *arg = __arg;
++	char *name = (void *)__name;
++
++	arg->err = 0;
++	au_fset_testempty(arg->flags, CALLED);
++	/* smp_mb(); */
++	if (name[0] == '.'
++	    && (namelen == 1 || (name[1] == '.' && namelen == 2)))
++		goto out; /* success */
++
++	if (namelen <= AUFS_WH_PFX_LEN
++	    || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++		if (au_ftest_testempty(arg->flags, WHONLY)
++		    && !au_nhash_test_known_wh(arg->whlist, name, namelen))
++			arg->err = -ENOTEMPTY;
++		goto out;
++	}
++
++	name += AUFS_WH_PFX_LEN;
++	namelen -= AUFS_WH_PFX_LEN;
++	if (!au_nhash_test_known_wh(arg->whlist, name, namelen))
++		arg->err = au_nhash_append_wh
++			(arg->whlist, name, namelen, ino, d_type, arg->bindex,
++			 au_ftest_testempty(arg->flags, SHWH));
++
++out:
++	/* smp_mb(); */
++	AuTraceErr(arg->err);
++	return arg->err;
++}
++
++static int do_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
++{
++	int err;
++	struct file *h_file;
++
++	h_file = au_h_open(dentry, arg->bindex,
++			   O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_LARGEFILE,
++			   /*file*/NULL);
++	err = PTR_ERR(h_file);
++	if (IS_ERR(h_file))
++		goto out;
++
++	err = 0;
++	if (!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE)
++	    && !h_file->f_dentry->d_inode->i_nlink)
++		goto out_put;
++
++	do {
++		arg->err = 0;
++		au_fclr_testempty(arg->flags, CALLED);
++		/* smp_mb(); */
++		err = vfsub_readdir(h_file, test_empty_cb, arg);
++		if (err >= 0)
++			err = arg->err;
++	} while (!err && au_ftest_testempty(arg->flags, CALLED));
++
++out_put:
++	fput(h_file);
++	au_sbr_put(dentry->d_sb, arg->bindex);
++out:
++	return err;
++}
++
++struct do_test_empty_args {
++	int *errp;
++	struct dentry *dentry;
++	struct test_empty_arg *arg;
++};
++
++static void call_do_test_empty(void *args)
++{
++	struct do_test_empty_args *a = args;
++	*a->errp = do_test_empty(a->dentry, a->arg);
++}
++
++static int sio_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
++{
++	int err, wkq_err;
++	struct dentry *h_dentry;
++	struct inode *h_inode;
++
++	h_dentry = au_h_dptr(dentry, arg->bindex);
++	h_inode = h_dentry->d_inode;
++	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++	err = au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_READ);
++	mutex_unlock(&h_inode->i_mutex);
++	if (!err)
++		err = do_test_empty(dentry, arg);
++	else {
++		struct do_test_empty_args args = {
++			.errp	= &err,
++			.dentry	= dentry,
++			.arg	= arg
++		};
++		unsigned int flags = arg->flags;
++
++		wkq_err = au_wkq_wait(call_do_test_empty, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++		arg->flags = flags;
++	}
++
++	return err;
++}
++
++int au_test_empty_lower(struct dentry *dentry)
++{
++	int err;
++	unsigned int rdhash;
++	aufs_bindex_t bindex, bstart, btail;
++	struct au_nhash whlist;
++	struct test_empty_arg arg;
++
++	SiMustAnyLock(dentry->d_sb);
++
++	rdhash = au_sbi(dentry->d_sb)->si_rdhash;
++	if (!rdhash)
++		rdhash = au_rdhash_est(au_dir_size(/*file*/NULL, dentry));
++	err = au_nhash_alloc(&whlist, rdhash, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++
++	arg.flags = 0;
++	arg.whlist = &whlist;
++	bstart = au_dbstart(dentry);
++	if (au_opt_test(au_mntflags(dentry->d_sb), SHWH))
++		au_fset_testempty(arg.flags, SHWH);
++	arg.bindex = bstart;
++	err = do_test_empty(dentry, &arg);
++	if (unlikely(err))
++		goto out_whlist;
++
++	au_fset_testempty(arg.flags, WHONLY);
++	btail = au_dbtaildir(dentry);
++	for (bindex = bstart + 1; !err && bindex <= btail; bindex++) {
++		struct dentry *h_dentry;
++
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (h_dentry && h_dentry->d_inode) {
++			arg.bindex = bindex;
++			err = do_test_empty(dentry, &arg);
++		}
++	}
++
++out_whlist:
++	au_nhash_wh_free(&whlist);
++out:
++	return err;
++}
++
++int au_test_empty(struct dentry *dentry, struct au_nhash *whlist)
++{
++	int err;
++	struct test_empty_arg arg;
++	aufs_bindex_t bindex, btail;
++
++	err = 0;
++	arg.whlist = whlist;
++	arg.flags = AuTestEmpty_WHONLY;
++	if (au_opt_test(au_mntflags(dentry->d_sb), SHWH))
++		au_fset_testempty(arg.flags, SHWH);
++	btail = au_dbtaildir(dentry);
++	for (bindex = au_dbstart(dentry); !err && bindex <= btail; bindex++) {
++		struct dentry *h_dentry;
++
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (h_dentry && h_dentry->d_inode) {
++			arg.bindex = bindex;
++			err = sio_test_empty(dentry, &arg);
++		}
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++const struct file_operations aufs_dir_fop = {
++	.owner		= THIS_MODULE,
++	.read		= generic_read_dir,
++	.readdir	= aufs_readdir,
++	.unlocked_ioctl	= aufs_ioctl_dir,
++#ifdef CONFIG_COMPAT
++	.compat_ioctl	= aufs_compat_ioctl_dir,
++#endif
++	.open		= aufs_open_dir,
++	.release	= aufs_release_dir,
++	.flush		= aufs_flush_dir,
++	.fsync		= aufs_fsync_dir
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/dir.h linux-2.6.36/fs/aufs/dir.h
+--- linux-2.6.36.orig/fs/aufs/dir.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dir.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,138 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * directory operations
++ */
++
++#ifndef __AUFS_DIR_H__
++#define __AUFS_DIR_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++
++/* ---------------------------------------------------------------------- */
++
++/* need to be faster and smaller */
++
++struct au_nhash {
++	unsigned int		nh_num;
++	struct hlist_head	*nh_head;
++};
++
++struct au_vdir_destr {
++	unsigned char	len;
++	unsigned char	name[0];
++} __packed;
++
++struct au_vdir_dehstr {
++	struct hlist_node	hash;
++	struct au_vdir_destr	*str;
++} ____cacheline_aligned_in_smp;
++
++struct au_vdir_de {
++	ino_t			de_ino;
++	unsigned char		de_type;
++	/* caution: packed */
++	struct au_vdir_destr	de_str;
++} __packed;
++
++struct au_vdir_wh {
++	struct hlist_node	wh_hash;
++#ifdef CONFIG_AUFS_SHWH
++	ino_t			wh_ino;
++	aufs_bindex_t		wh_bindex;
++	unsigned char		wh_type;
++#else
++	aufs_bindex_t		wh_bindex;
++#endif
++	/* caution: packed */
++	struct au_vdir_destr	wh_str;
++} __packed;
++
++union au_vdir_deblk_p {
++	unsigned char		*deblk;
++	struct au_vdir_de	*de;
++};
++
++struct au_vdir {
++	unsigned char	**vd_deblk;
++	unsigned long	vd_nblk;
++	struct {
++		unsigned long		ul;
++		union au_vdir_deblk_p	p;
++	} vd_last;
++
++	unsigned long	vd_version;
++	unsigned int	vd_deblk_sz;
++	unsigned long	vd_jiffy;
++} ____cacheline_aligned_in_smp;
++
++/* ---------------------------------------------------------------------- */
++
++/* dir.c */
++extern const struct file_operations aufs_dir_fop;
++void au_add_nlink(struct inode *dir, struct inode *h_dir);
++void au_sub_nlink(struct inode *dir, struct inode *h_dir);
++loff_t au_dir_size(struct file *file, struct dentry *dentry);
++int au_test_empty_lower(struct dentry *dentry);
++int au_test_empty(struct dentry *dentry, struct au_nhash *whlist);
++
++/* vdir.c */
++unsigned int au_rdhash_est(loff_t sz);
++int au_nhash_alloc(struct au_nhash *nhash, unsigned int num_hash, gfp_t gfp);
++void au_nhash_wh_free(struct au_nhash *whlist);
++int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
++			    int limit);
++int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int nlen);
++int au_nhash_append_wh(struct au_nhash *whlist, char *name, int nlen, ino_t ino,
++		       unsigned int d_type, aufs_bindex_t bindex,
++		       unsigned char shwh);
++void au_vdir_free(struct au_vdir *vdir);
++int au_vdir_init(struct file *file);
++int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir);
++
++/* ioctl.c */
++long aufs_ioctl_dir(struct file *file, unsigned int cmd, unsigned long arg);
++
++#ifdef CONFIG_AUFS_RDU
++/* rdu.c */
++long au_rdu_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
++#ifdef CONFIG_COMPAT
++long au_rdu_compat_ioctl(struct file *file, unsigned int cmd,
++			 unsigned long arg);
++#endif
++#else
++static inline long au_rdu_ioctl(struct file *file, unsigned int cmd,
++				unsigned long arg)
++{
++	return -EINVAL;
++}
++#ifdef CONFIG_COMPAT
++static inline long au_rdu_compat_ioctl(struct file *file, unsigned int cmd,
++				       unsigned long arg)
++{
++	return -EINVAL;
++}
++#endif
++#endif
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DIR_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/dynop.c linux-2.6.36/fs/aufs/dynop.c
+--- linux-2.6.36.orig/fs/aufs/dynop.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dynop.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,425 @@
++/*
++ * Copyright (C) 2010-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * dynamically customizable operations for regular files
++ */
++
++#include "aufs.h"
++
++#define DyPrSym(key)	AuDbgSym(key->dk_op.dy_hop)
++
++/*
++ * How large will these lists be?
++ * Usually just a few elements, 20-30 at most for each, I guess.
++ */
++static struct au_splhead dynop[AuDyLast];
++
++static struct au_dykey *dy_gfind_get(struct au_splhead *spl, const void *h_op)
++{
++	struct au_dykey *key, *tmp;
++	struct list_head *head;
++
++	key = NULL;
++	head = &spl->head;
++	rcu_read_lock();
++	list_for_each_entry_rcu(tmp, head, dk_list)
++		if (tmp->dk_op.dy_hop == h_op) {
++			key = tmp;
++			kref_get(&key->dk_kref);
++			break;
++		}
++	rcu_read_unlock();
++
++	return key;
++}
++
++static struct au_dykey *dy_bradd(struct au_branch *br, struct au_dykey *key)
++{
++	struct au_dykey **k, *found;
++	const void *h_op = key->dk_op.dy_hop;
++	int i;
++
++	found = NULL;
++	k = br->br_dykey;
++	for (i = 0; i < AuBrDynOp; i++)
++		if (k[i]) {
++			if (k[i]->dk_op.dy_hop == h_op) {
++				found = k[i];
++				break;
++			}
++		} else
++			break;
++	if (!found) {
++		spin_lock(&br->br_dykey_lock);
++		for (; i < AuBrDynOp; i++)
++			if (k[i]) {
++				if (k[i]->dk_op.dy_hop == h_op) {
++					found = k[i];
++					break;
++				}
++			} else {
++				k[i] = key;
++				break;
++			}
++		spin_unlock(&br->br_dykey_lock);
++		BUG_ON(i == AuBrDynOp); /* expand the array */
++	}
++
++	return found;
++}
++
++/* kref_get() if @key is already added */
++static struct au_dykey *dy_gadd(struct au_splhead *spl, struct au_dykey *key)
++{
++	struct au_dykey *tmp, *found;
++	struct list_head *head;
++	const void *h_op = key->dk_op.dy_hop;
++
++	found = NULL;
++	head = &spl->head;
++	spin_lock(&spl->spin);
++	list_for_each_entry(tmp, head, dk_list)
++		if (tmp->dk_op.dy_hop == h_op) {
++			kref_get(&tmp->dk_kref);
++			found = tmp;
++			break;
++		}
++	if (!found)
++		list_add_rcu(&key->dk_list, head);
++	spin_unlock(&spl->spin);
++
++	if (!found)
++		DyPrSym(key);
++	return found;
++}
++
++static void dy_free_rcu(struct rcu_head *rcu)
++{
++	struct au_dykey *key;
++
++	key = container_of(rcu, struct au_dykey, dk_rcu);
++	DyPrSym(key);
++	kfree(key);
++}
++
++static void dy_free(struct kref *kref)
++{
++	struct au_dykey *key;
++	struct au_splhead *spl;
++
++	key = container_of(kref, struct au_dykey, dk_kref);
++	spl = dynop + key->dk_op.dy_type;
++	au_spl_del_rcu(&key->dk_list, spl);
++	call_rcu(&key->dk_rcu, dy_free_rcu);
++}
++
++void au_dy_put(struct au_dykey *key)
++{
++	kref_put(&key->dk_kref, dy_free);
++}
++
++/* ---------------------------------------------------------------------- */
++
++#define DyDbgSize(cnt, op)	AuDebugOn(cnt != sizeof(op)/sizeof(void *))
++
++#ifdef CONFIG_AUFS_DEBUG
++#define DyDbgDeclare(cnt)	unsigned int cnt = 0
++#define DyDbgInc(cnt)		do { cnt++; } while (0)
++#else
++#define DyDbgDeclare(cnt)	do {} while (0)
++#define DyDbgInc(cnt)		do {} while (0)
++#endif
++
++#define DySet(func, dst, src, h_op, h_sb) do {				\
++	DyDbgInc(cnt);							\
++	if (h_op->func) {						\
++		if (src.func)						\
++			dst.func = src.func;				\
++		else							\
++			AuDbg("%s %s\n", au_sbtype(h_sb), #func);	\
++	}								\
++} while (0)
++
++#define DySetForce(func, dst, src) do {		\
++	AuDebugOn(!src.func);			\
++	DyDbgInc(cnt);				\
++	dst.func = src.func;			\
++} while (0)
++
++#define DySetAop(func) \
++	DySet(func, dyaop->da_op, aufs_aop, h_aop, h_sb)
++#define DySetAopForce(func) \
++	DySetForce(func, dyaop->da_op, aufs_aop)
++
++static void dy_aop(struct au_dykey *key, const void *h_op,
++		   struct super_block *h_sb __maybe_unused)
++{
++	struct au_dyaop *dyaop = (void *)key;
++	const struct address_space_operations *h_aop = h_op;
++	DyDbgDeclare(cnt);
++
++	AuDbg("%s\n", au_sbtype(h_sb));
++
++	DySetAop(writepage);
++	DySetAopForce(readpage);	/* force */
++	DySetAop(sync_page);
++	DySetAop(writepages);
++	DySetAop(set_page_dirty);
++	DySetAop(readpages);
++	DySetAop(write_begin);
++	DySetAop(write_end);
++	DySetAop(bmap);
++	DySetAop(invalidatepage);
++	DySetAop(releasepage);
++	/* these two will be changed according to an aufs mount option */
++	DySetAop(direct_IO);
++	DySetAop(get_xip_mem);
++	DySetAop(migratepage);
++	DySetAop(launder_page);
++	DySetAop(is_partially_uptodate);
++	DySetAop(error_remove_page);
++
++	DyDbgSize(cnt, *h_aop);
++	dyaop->da_get_xip_mem = h_aop->get_xip_mem;
++}
++
++#define DySetVmop(func) \
++	DySet(func, dyvmop->dv_op, aufs_vm_ops, h_vmop, h_sb)
++#define DySetVmopForce(func) \
++	DySetForce(func, dyvmop->dv_op, aufs_vm_ops)
++
++static void dy_vmop(struct au_dykey *key, const void *h_op,
++		    struct super_block *h_sb __maybe_unused)
++{
++	struct au_dyvmop *dyvmop = (void *)key;
++	const struct vm_operations_struct *h_vmop = h_op;
++	DyDbgDeclare(cnt);
++
++	AuDbg("%s\n", au_sbtype(h_sb));
++
++	DySetVmop(open);
++	DySetVmop(close);
++	DySetVmop(fault);
++	DySetVmop(page_mkwrite);
++	DySetVmop(access);
++#ifdef CONFIG_NUMA
++	DySetVmop(set_policy);
++	DySetVmop(get_policy);
++	DySetVmop(migrate);
++#endif
++
++	DyDbgSize(cnt, *h_vmop);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void dy_bug(struct kref *kref)
++{
++	BUG();
++}
++
++static struct au_dykey *dy_get(struct au_dynop *op, struct au_branch *br)
++{
++	struct au_dykey *key, *old;
++	struct au_splhead *spl;
++	struct op {
++		unsigned int sz;
++		void (*set)(struct au_dykey *key, const void *h_op,
++			    struct super_block *h_sb __maybe_unused);
++	};
++	static const struct op a[] = {
++		[AuDy_AOP] = {
++			.sz	= sizeof(struct au_dyaop),
++			.set	= dy_aop
++		},
++		[AuDy_VMOP] = {
++			.sz	= sizeof(struct au_dyvmop),
++			.set	= dy_vmop
++		}
++	};
++	const struct op *p;
++
++	spl = dynop + op->dy_type;
++	key = dy_gfind_get(spl, op->dy_hop);
++	if (key)
++		goto out_add; /* success */
++
++	p = a + op->dy_type;
++	key = kzalloc(p->sz, GFP_NOFS);
++	if (unlikely(!key)) {
++		key = ERR_PTR(-ENOMEM);
++		goto out;
++	}
++
++	key->dk_op.dy_hop = op->dy_hop;
++	kref_init(&key->dk_kref);
++	p->set(key, op->dy_hop, br->br_mnt->mnt_sb);
++	old = dy_gadd(spl, key);
++	if (old) {
++		kfree(key);
++		key = old;
++	}
++
++out_add:
++	old = dy_bradd(br, key);
++	if (old)
++		/* its ref-count should never be zero here */
++		kref_put(&key->dk_kref, dy_bug);
++out:
++	return key;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * Aufs prohibits O_DIRECT by defaut even if the branch supports it.
++ * This behaviour is neccessary to return an error from open(O_DIRECT) instead
++ * of the succeeding I/O. The dio mount option enables O_DIRECT and makes
++ * open(O_DIRECT) always succeed, but the succeeding I/O may return an error.
++ * See the aufs manual in detail.
++ *
++ * To keep this behaviour, aufs has to set NULL to ->get_xip_mem too, and the
++ * performance of fadvise() and madvise() may be affected.
++ */
++static void dy_adx(struct au_dyaop *dyaop, int do_dx)
++{
++	if (!do_dx) {
++		dyaop->da_op.direct_IO = NULL;
++		dyaop->da_op.get_xip_mem = NULL;
++	} else {
++		dyaop->da_op.direct_IO = aufs_aop.direct_IO;
++		dyaop->da_op.get_xip_mem = aufs_aop.get_xip_mem;
++		if (!dyaop->da_get_xip_mem)
++			dyaop->da_op.get_xip_mem = NULL;
++	}
++}
++
++static struct au_dyaop *dy_aget(struct au_branch *br,
++				const struct address_space_operations *h_aop,
++				int do_dx)
++{
++	struct au_dyaop *dyaop;
++	struct au_dynop op;
++
++	op.dy_type = AuDy_AOP;
++	op.dy_haop = h_aop;
++	dyaop = (void *)dy_get(&op, br);
++	if (IS_ERR(dyaop))
++		goto out;
++	dy_adx(dyaop, do_dx);
++
++out:
++	return dyaop;
++}
++
++int au_dy_iaop(struct inode *inode, aufs_bindex_t bindex,
++		struct inode *h_inode)
++{
++	int err, do_dx;
++	struct super_block *sb;
++	struct au_branch *br;
++	struct au_dyaop *dyaop;
++
++	AuDebugOn(!S_ISREG(h_inode->i_mode));
++	IiMustWriteLock(inode);
++
++	sb = inode->i_sb;
++	br = au_sbr(sb, bindex);
++	do_dx = !!au_opt_test(au_mntflags(sb), DIO);
++	dyaop = dy_aget(br, h_inode->i_mapping->a_ops, do_dx);
++	err = PTR_ERR(dyaop);
++	if (IS_ERR(dyaop))
++		/* unnecessary to call dy_fput() */
++		goto out;
++
++	err = 0;
++	inode->i_mapping->a_ops = &dyaop->da_op;
++
++out:
++	return err;
++}
++
++/*
++ * Is it safe to replace a_ops during the inode/file is in operation?
++ * Yes, I hope so.
++ */
++int au_dy_irefresh(struct inode *inode)
++{
++	int err;
++	aufs_bindex_t bstart;
++	struct inode *h_inode;
++
++	err = 0;
++	if (S_ISREG(inode->i_mode)) {
++		bstart = au_ibstart(inode);
++		h_inode = au_h_iptr(inode, bstart);
++		err = au_dy_iaop(inode, bstart, h_inode);
++	}
++	return err;
++}
++
++void au_dy_arefresh(int do_dx)
++{
++	struct au_splhead *spl;
++	struct list_head *head;
++	struct au_dykey *key;
++
++	spl = dynop + AuDy_AOP;
++	head = &spl->head;
++	spin_lock(&spl->spin);
++	list_for_each_entry(key, head, dk_list)
++		dy_adx((void *)key, do_dx);
++	spin_unlock(&spl->spin);
++}
++
++const struct vm_operations_struct *
++au_dy_vmop(struct file *file, struct au_branch *br,
++	   const struct vm_operations_struct *h_vmop)
++{
++	struct au_dyvmop *dyvmop;
++	struct au_dynop op;
++
++	op.dy_type = AuDy_VMOP;
++	op.dy_hvmop = h_vmop;
++	dyvmop = (void *)dy_get(&op, br);
++	if (IS_ERR(dyvmop))
++		return (void *)dyvmop;
++	return &dyvmop->dv_op;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void __init au_dy_init(void)
++{
++	int i;
++
++	/* make sure that 'struct au_dykey *' can be any type */
++	BUILD_BUG_ON(offsetof(struct au_dyaop, da_key));
++	BUILD_BUG_ON(offsetof(struct au_dyvmop, dv_key));
++
++	for (i = 0; i < AuDyLast; i++)
++		au_spl_init(dynop + i);
++}
++
++void au_dy_fin(void)
++{
++	int i;
++
++	for (i = 0; i < AuDyLast; i++)
++		WARN_ON(!list_empty(&dynop[i].head));
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/dynop.h linux-2.6.36/fs/aufs/dynop.h
+--- linux-2.6.36.orig/fs/aufs/dynop.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/dynop.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,89 @@
++/*
++ * Copyright (C) 2010-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * dynamically customizable operations (for regular files only)
++ */
++
++#ifndef __AUFS_DYNOP_H__
++#define __AUFS_DYNOP_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/mm.h>
++#include <linux/rcupdate.h>
++#include <linux/aufs_type.h>
++#include "inode.h"
++
++enum {AuDy_AOP, AuDy_VMOP, AuDyLast};
++
++struct au_dynop {
++	int						dy_type;
++	union {
++		const void				*dy_hop;
++		const struct address_space_operations	*dy_haop;
++		const struct vm_operations_struct	*dy_hvmop;
++	};
++};
++
++struct au_dykey {
++	union {
++		struct list_head	dk_list;
++		struct rcu_head		dk_rcu;
++	};
++	struct au_dynop		dk_op;
++
++	/*
++	 * during I am in the branch local array, kref is gotten. when the
++	 * branch is removed, kref is put.
++	 */
++	struct kref		dk_kref;
++};
++
++/* stop unioning since their sizes are very different from each other */
++struct au_dyaop {
++	struct au_dykey			da_key;
++	struct address_space_operations	da_op; /* not const */
++	int (*da_get_xip_mem)(struct address_space *, pgoff_t, int,
++			      void **, unsigned long *);
++};
++
++struct au_dyvmop {
++	struct au_dykey			dv_key;
++	struct vm_operations_struct	dv_op; /* not const */
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* dynop.c */
++struct au_branch;
++void au_dy_put(struct au_dykey *key);
++int au_dy_iaop(struct inode *inode, aufs_bindex_t bindex,
++		struct inode *h_inode);
++int au_dy_irefresh(struct inode *inode);
++void au_dy_arefresh(int do_dio);
++const struct vm_operations_struct *
++au_dy_vmop(struct file *file, struct au_branch *br,
++	   const struct vm_operations_struct *h_vmop);
++
++void __init au_dy_init(void);
++void au_dy_fin(void);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DYNOP_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/export.c linux-2.6.36/fs/aufs/export.c
+--- linux-2.6.36.orig/fs/aufs/export.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/export.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,798 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * export via nfs
++ */
++
++#include <linux/exportfs.h>
++#include <linux/file.h>
++#include <linux/mnt_namespace.h>
++#include <linux/namei.h>
++#include <linux/nsproxy.h>
++#include <linux/random.h>
++#include <linux/writeback.h>
++#include "aufs.h"
++
++union conv {
++#ifdef CONFIG_AUFS_INO_T_64
++	__u32 a[2];
++#else
++	__u32 a[1];
++#endif
++	ino_t ino;
++};
++
++static ino_t decode_ino(__u32 *a)
++{
++	union conv u;
++
++	BUILD_BUG_ON(sizeof(u.ino) != sizeof(u.a));
++	u.a[0] = a[0];
++#ifdef CONFIG_AUFS_INO_T_64
++	u.a[1] = a[1];
++#endif
++	return u.ino;
++}
++
++static void encode_ino(__u32 *a, ino_t ino)
++{
++	union conv u;
++
++	u.ino = ino;
++	a[0] = u.a[0];
++#ifdef CONFIG_AUFS_INO_T_64
++	a[1] = u.a[1];
++#endif
++}
++
++/* NFS file handle */
++enum {
++	Fh_br_id,
++	Fh_sigen,
++#ifdef CONFIG_AUFS_INO_T_64
++	/* support 64bit inode number */
++	Fh_ino1,
++	Fh_ino2,
++	Fh_dir_ino1,
++	Fh_dir_ino2,
++#else
++	Fh_ino1,
++	Fh_dir_ino1,
++#endif
++	Fh_igen,
++	Fh_h_type,
++	Fh_tail,
++
++	Fh_ino = Fh_ino1,
++	Fh_dir_ino = Fh_dir_ino1
++};
++
++static int au_test_anon(struct dentry *dentry)
++{
++	return !!(dentry->d_flags & DCACHE_DISCONNECTED);
++}
++
++/* ---------------------------------------------------------------------- */
++/* inode generation external table */
++
++void au_xigen_inc(struct inode *inode)
++{
++	loff_t pos;
++	ssize_t sz;
++	__u32 igen;
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++
++	sb = inode->i_sb;
++	AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
++
++	sbinfo = au_sbi(sb);
++	pos = inode->i_ino;
++	pos *= sizeof(igen);
++	igen = inode->i_generation + 1;
++	sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
++			 sizeof(igen), &pos);
++	if (sz == sizeof(igen))
++		return; /* success */
++
++	if (unlikely(sz >= 0))
++		AuIOErr("xigen error (%zd)\n", sz);
++}
++
++int au_xigen_new(struct inode *inode)
++{
++	int err;
++	loff_t pos;
++	ssize_t sz;
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++	struct file *file;
++
++	err = 0;
++	/* todo: dirty, at mount time */
++	if (inode->i_ino == AUFS_ROOT_INO)
++		goto out;
++	sb = inode->i_sb;
++	SiMustAnyLock(sb);
++	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
++		goto out;
++
++	err = -EFBIG;
++	pos = inode->i_ino;
++	if (unlikely(au_loff_max / sizeof(inode->i_generation) - 1 < pos)) {
++		AuIOErr1("too large i%lld\n", pos);
++		goto out;
++	}
++	pos *= sizeof(inode->i_generation);
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	file = sbinfo->si_xigen;
++	BUG_ON(!file);
++
++	if (i_size_read(file->f_dentry->d_inode)
++	    < pos + sizeof(inode->i_generation)) {
++		inode->i_generation = atomic_inc_return(&sbinfo->si_xigen_next);
++		sz = xino_fwrite(sbinfo->si_xwrite, file, &inode->i_generation,
++				 sizeof(inode->i_generation), &pos);
++	} else
++		sz = xino_fread(sbinfo->si_xread, file, &inode->i_generation,
++				sizeof(inode->i_generation), &pos);
++	if (sz == sizeof(inode->i_generation))
++		goto out; /* success */
++
++	err = sz;
++	if (unlikely(sz >= 0)) {
++		err = -EIO;
++		AuIOErr("xigen error (%zd)\n", sz);
++	}
++
++out:
++	return err;
++}
++
++int au_xigen_set(struct super_block *sb, struct file *base)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++	struct file *file;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	file = au_xino_create2(base, sbinfo->si_xigen);
++	err = PTR_ERR(file);
++	if (IS_ERR(file))
++		goto out;
++	err = 0;
++	if (sbinfo->si_xigen)
++		fput(sbinfo->si_xigen);
++	sbinfo->si_xigen = file;
++
++out:
++	return err;
++}
++
++void au_xigen_clr(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	if (sbinfo->si_xigen) {
++		fput(sbinfo->si_xigen);
++		sbinfo->si_xigen = NULL;
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *decode_by_ino(struct super_block *sb, ino_t ino,
++				    ino_t dir_ino)
++{
++	struct dentry *dentry, *d;
++	struct inode *inode;
++	unsigned int sigen;
++
++	dentry = NULL;
++	inode = ilookup(sb, ino);
++	if (!inode)
++		goto out;
++
++	dentry = ERR_PTR(-ESTALE);
++	sigen = au_sigen(sb);
++	if (unlikely(is_bad_inode(inode)
++		     || IS_DEADDIR(inode)
++		     || sigen != au_iigen(inode)))
++		goto out_iput;
++
++	dentry = NULL;
++	if (!dir_ino || S_ISDIR(inode->i_mode))
++		dentry = d_find_alias(inode);
++	else {
++		spin_lock(&dcache_lock);
++		list_for_each_entry(d, &inode->i_dentry, d_alias)
++			if (!au_test_anon(d)
++			    && d->d_parent->d_inode->i_ino == dir_ino) {
++				dentry = dget_locked(d);
++				break;
++			}
++		spin_unlock(&dcache_lock);
++	}
++	if (unlikely(dentry && au_digen_test(dentry, sigen))) {
++		dput(dentry);
++		dentry = ERR_PTR(-ESTALE);
++	}
++
++out_iput:
++	iput(inode);
++out:
++	return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: dirty? */
++/* if exportfs_decode_fh() passed vfsmount*, we could be happy */
++
++struct au_compare_mnt_args {
++	/* input */
++	struct super_block *sb;
++
++	/* output */
++	struct vfsmount *mnt;
++};
++
++static int au_compare_mnt(struct vfsmount *mnt, void *arg)
++{
++	struct au_compare_mnt_args *a = arg;
++
++	if (mnt->mnt_sb != a->sb)
++		return 0;
++	a->mnt = mntget(mnt);
++	return 1;
++}
++
++static struct vfsmount *au_mnt_get(struct super_block *sb)
++{
++	int err;
++	struct au_compare_mnt_args args = {
++		.sb = sb
++	};
++	struct mnt_namespace *ns;
++
++	br_read_lock(vfsmount_lock);
++	/* no get/put ?? */
++	AuDebugOn(!current->nsproxy);
++	ns = current->nsproxy->mnt_ns;
++	AuDebugOn(!ns);
++	err = iterate_mounts(au_compare_mnt, &args, ns->root);
++	br_read_unlock(vfsmount_lock);
++	AuDebugOn(!err);
++	AuDebugOn(!args.mnt);
++	return args.mnt;
++}
++
++struct au_nfsd_si_lock {
++	unsigned int sigen;
++	aufs_bindex_t bindex, br_id;
++	unsigned char force_lock;
++};
++
++static int si_nfsd_read_lock(struct super_block *sb,
++			     struct au_nfsd_si_lock *nsi_lock)
++{
++	int err;
++	aufs_bindex_t bindex;
++
++	si_read_lock(sb, AuLock_FLUSH);
++
++	/* branch id may be wrapped around */
++	err = 0;
++	bindex = au_br_index(sb, nsi_lock->br_id);
++	if (bindex >= 0 && nsi_lock->sigen + AUFS_BRANCH_MAX > au_sigen(sb))
++		goto out; /* success */
++
++	err = -ESTALE;
++	bindex = -1;
++	if (!nsi_lock->force_lock)
++		si_read_unlock(sb);
++
++out:
++	nsi_lock->bindex = bindex;
++	return err;
++}
++
++struct find_name_by_ino {
++	int called, found;
++	ino_t ino;
++	char *name;
++	int namelen;
++};
++
++static int
++find_name_by_ino(void *arg, const char *name, int namelen, loff_t offset,
++		 u64 ino, unsigned int d_type)
++{
++	struct find_name_by_ino *a = arg;
++
++	a->called++;
++	if (a->ino != ino)
++		return 0;
++
++	memcpy(a->name, name, namelen);
++	a->namelen = namelen;
++	a->found = 1;
++	return 1;
++}
++
++static struct dentry *au_lkup_by_ino(struct path *path, ino_t ino,
++				     struct au_nfsd_si_lock *nsi_lock)
++{
++	struct dentry *dentry, *parent;
++	struct file *file;
++	struct inode *dir;
++	struct find_name_by_ino arg;
++	int err;
++
++	parent = path->dentry;
++	if (nsi_lock)
++		si_read_unlock(parent->d_sb);
++	file = vfsub_dentry_open(path, au_dir_roflags);
++	dentry = (void *)file;
++	if (IS_ERR(file))
++		goto out;
++
++	dentry = ERR_PTR(-ENOMEM);
++	arg.name = __getname_gfp(GFP_NOFS);
++	if (unlikely(!arg.name))
++		goto out_file;
++	arg.ino = ino;
++	arg.found = 0;
++	do {
++		arg.called = 0;
++		/* smp_mb(); */
++		err = vfsub_readdir(file, find_name_by_ino, &arg);
++	} while (!err && !arg.found && arg.called);
++	dentry = ERR_PTR(err);
++	if (unlikely(err))
++		goto out_name;
++	dentry = ERR_PTR(-ENOENT);
++	if (!arg.found)
++		goto out_name;
++
++	/* do not call au_lkup_one() */
++	dir = parent->d_inode;
++	mutex_lock(&dir->i_mutex);
++	dentry = vfsub_lookup_one_len(arg.name, parent, arg.namelen);
++	mutex_unlock(&dir->i_mutex);
++	AuTraceErrPtr(dentry);
++	if (IS_ERR(dentry))
++		goto out_name;
++	AuDebugOn(au_test_anon(dentry));
++	if (unlikely(!dentry->d_inode)) {
++		dput(dentry);
++		dentry = ERR_PTR(-ENOENT);
++	}
++
++out_name:
++	__putname(arg.name);
++out_file:
++	fput(file);
++out:
++	if (unlikely(nsi_lock
++		     && si_nfsd_read_lock(parent->d_sb, nsi_lock) < 0))
++		if (!IS_ERR(dentry)) {
++			dput(dentry);
++			dentry = ERR_PTR(-ESTALE);
++		}
++	AuTraceErrPtr(dentry);
++	return dentry;
++}
++
++static struct dentry *decode_by_dir_ino(struct super_block *sb, ino_t ino,
++					ino_t dir_ino,
++					struct au_nfsd_si_lock *nsi_lock)
++{
++	struct dentry *dentry;
++	struct path path;
++
++	if (dir_ino != AUFS_ROOT_INO) {
++		path.dentry = decode_by_ino(sb, dir_ino, 0);
++		dentry = path.dentry;
++		if (!path.dentry || IS_ERR(path.dentry))
++			goto out;
++		AuDebugOn(au_test_anon(path.dentry));
++	} else
++		path.dentry = dget(sb->s_root);
++
++	path.mnt = au_mnt_get(sb);
++	dentry = au_lkup_by_ino(&path, ino, nsi_lock);
++	path_put(&path);
++
++out:
++	AuTraceErrPtr(dentry);
++	return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int h_acceptable(void *expv, struct dentry *dentry)
++{
++	return 1;
++}
++
++static char *au_build_path(struct dentry *h_parent, struct path *h_rootpath,
++			   char *buf, int len, struct super_block *sb)
++{
++	char *p;
++	int n;
++	struct path path;
++
++	p = d_path(h_rootpath, buf, len);
++	if (IS_ERR(p))
++		goto out;
++	n = strlen(p);
++
++	path.mnt = h_rootpath->mnt;
++	path.dentry = h_parent;
++	p = d_path(&path, buf, len);
++	if (IS_ERR(p))
++		goto out;
++	if (n != 1)
++		p += n;
++
++	path.mnt = au_mnt_get(sb);
++	path.dentry = sb->s_root;
++	p = d_path(&path, buf, len - strlen(p));
++	mntput(path.mnt);
++	if (IS_ERR(p))
++		goto out;
++	if (n != 1)
++		p[strlen(p)] = '/';
++
++out:
++	AuTraceErrPtr(p);
++	return p;
++}
++
++static
++struct dentry *decode_by_path(struct super_block *sb, ino_t ino, __u32 *fh,
++			      int fh_len, struct au_nfsd_si_lock *nsi_lock)
++{
++	struct dentry *dentry, *h_parent, *root;
++	struct super_block *h_sb;
++	char *pathname, *p;
++	struct vfsmount *h_mnt;
++	struct au_branch *br;
++	int err;
++	struct path path;
++
++	br = au_sbr(sb, nsi_lock->bindex);
++	h_mnt = br->br_mnt;
++	h_sb = h_mnt->mnt_sb;
++	/* todo: call lower fh_to_dentry()? fh_to_parent()? */
++	h_parent = exportfs_decode_fh(h_mnt, (void *)(fh + Fh_tail),
++				      fh_len - Fh_tail, fh[Fh_h_type],
++				      h_acceptable, /*context*/NULL);
++	dentry = h_parent;
++	if (unlikely(!h_parent || IS_ERR(h_parent))) {
++		AuWarn1("%s decode_fh failed, %ld\n",
++			au_sbtype(h_sb), PTR_ERR(h_parent));
++		goto out;
++	}
++	dentry = NULL;
++	if (unlikely(au_test_anon(h_parent))) {
++		AuWarn1("%s decode_fh returned a disconnected dentry\n",
++			au_sbtype(h_sb));
++		goto out_h_parent;
++	}
++
++	dentry = ERR_PTR(-ENOMEM);
++	pathname = (void *)__get_free_page(GFP_NOFS);
++	if (unlikely(!pathname))
++		goto out_h_parent;
++
++	root = sb->s_root;
++	path.mnt = h_mnt;
++	di_read_lock_parent(root, !AuLock_IR);
++	path.dentry = au_h_dptr(root, nsi_lock->bindex);
++	di_read_unlock(root, !AuLock_IR);
++	p = au_build_path(h_parent, &path, pathname, PAGE_SIZE, sb);
++	dentry = (void *)p;
++	if (IS_ERR(p))
++		goto out_pathname;
++
++	si_read_unlock(sb);
++	err = vfsub_kern_path(p, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
++	dentry = ERR_PTR(err);
++	if (unlikely(err))
++		goto out_relock;
++
++	dentry = ERR_PTR(-ENOENT);
++	AuDebugOn(au_test_anon(path.dentry));
++	if (unlikely(!path.dentry->d_inode))
++		goto out_path;
++
++	if (ino != path.dentry->d_inode->i_ino)
++		dentry = au_lkup_by_ino(&path, ino, /*nsi_lock*/NULL);
++	else
++		dentry = dget(path.dentry);
++
++out_path:
++	path_put(&path);
++out_relock:
++	if (unlikely(si_nfsd_read_lock(sb, nsi_lock) < 0))
++		if (!IS_ERR(dentry)) {
++			dput(dentry);
++			dentry = ERR_PTR(-ESTALE);
++		}
++out_pathname:
++	free_page((unsigned long)pathname);
++out_h_parent:
++	dput(h_parent);
++out:
++	AuTraceErrPtr(dentry);
++	return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *
++aufs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
++		  int fh_type)
++{
++	struct dentry *dentry;
++	__u32 *fh = fid->raw;
++	struct au_branch *br;
++	ino_t ino, dir_ino;
++	struct au_nfsd_si_lock nsi_lock = {
++		.force_lock	= 0
++	};
++
++	dentry = ERR_PTR(-ESTALE);
++	/* it should never happen, but the file handle is unreliable */
++	if (unlikely(fh_len < Fh_tail))
++		goto out;
++	nsi_lock.sigen = fh[Fh_sigen];
++	nsi_lock.br_id = fh[Fh_br_id];
++
++	/* branch id may be wrapped around */
++	br = NULL;
++	if (unlikely(si_nfsd_read_lock(sb, &nsi_lock)))
++		goto out;
++	nsi_lock.force_lock = 1;
++
++	/* is this inode still cached? */
++	ino = decode_ino(fh + Fh_ino);
++	/* it should never happen */
++	if (unlikely(ino == AUFS_ROOT_INO))
++		goto out;
++
++	dir_ino = decode_ino(fh + Fh_dir_ino);
++	dentry = decode_by_ino(sb, ino, dir_ino);
++	if (IS_ERR(dentry))
++		goto out_unlock;
++	if (dentry)
++		goto accept;
++
++	/* is the parent dir cached? */
++	br = au_sbr(sb, nsi_lock.bindex);
++	atomic_inc(&br->br_count);
++	dentry = decode_by_dir_ino(sb, ino, dir_ino, &nsi_lock);
++	if (IS_ERR(dentry))
++		goto out_unlock;
++	if (dentry)
++		goto accept;
++
++	/* lookup path */
++	dentry = decode_by_path(sb, ino, fh, fh_len, &nsi_lock);
++	if (IS_ERR(dentry))
++		goto out_unlock;
++	if (unlikely(!dentry))
++		/* todo?: make it ESTALE */
++		goto out_unlock;
++
++accept:
++	if (!au_digen_test(dentry, au_sigen(sb))
++	    && dentry->d_inode->i_generation == fh[Fh_igen])
++		goto out_unlock; /* success */
++
++	dput(dentry);
++	dentry = ERR_PTR(-ESTALE);
++out_unlock:
++	if (br)
++		atomic_dec(&br->br_count);
++	si_read_unlock(sb);
++out:
++	AuTraceErrPtr(dentry);
++	return dentry;
++}
++
++#if 0 /* reserved for future use */
++/* support subtreecheck option */
++static struct dentry *aufs_fh_to_parent(struct super_block *sb, struct fid *fid,
++					int fh_len, int fh_type)
++{
++	struct dentry *parent;
++	__u32 *fh = fid->raw;
++	ino_t dir_ino;
++
++	dir_ino = decode_ino(fh + Fh_dir_ino);
++	parent = decode_by_ino(sb, dir_ino, 0);
++	if (IS_ERR(parent))
++		goto out;
++	if (!parent)
++		parent = decode_by_path(sb, au_br_index(sb, fh[Fh_br_id]),
++					dir_ino, fh, fh_len);
++
++out:
++	AuTraceErrPtr(parent);
++	return parent;
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
++			  int connectable)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	struct super_block *sb, *h_sb;
++	struct inode *inode;
++	struct dentry *parent, *h_parent;
++	struct au_branch *br;
++
++	AuDebugOn(au_test_anon(dentry));
++
++	parent = NULL;
++	err = -ENOSPC;
++	if (unlikely(*max_len <= Fh_tail)) {
++		AuWarn1("NFSv2 client (max_len %d)?\n", *max_len);
++		goto out;
++	}
++
++	err = FILEID_ROOT;
++	if (IS_ROOT(dentry)) {
++		AuDebugOn(dentry->d_inode->i_ino != AUFS_ROOT_INO);
++		goto out;
++	}
++
++	h_parent = NULL;
++	err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_IR | AuLock_GEN);
++	if (unlikely(err))
++		goto out;
++
++	inode = dentry->d_inode;
++	AuDebugOn(!inode);
++	sb = dentry->d_sb;
++#ifdef CONFIG_AUFS_DEBUG
++	if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
++		AuWarn1("NFS-exporting requires xino\n");
++#endif
++	err = -EIO;
++	parent = dget_parent(dentry);
++	di_read_lock_parent(parent, !AuLock_IR);
++	bend = au_dbtaildir(parent);
++	for (bindex = au_dbstart(parent); bindex <= bend; bindex++) {
++		h_parent = au_h_dptr(parent, bindex);
++		if (h_parent) {
++			dget(h_parent);
++			break;
++		}
++	}
++	if (unlikely(!h_parent))
++		goto out_unlock;
++
++	err = -EPERM;
++	br = au_sbr(sb, bindex);
++	h_sb = br->br_mnt->mnt_sb;
++	if (unlikely(!h_sb->s_export_op)) {
++		AuErr1("%s branch is not exportable\n", au_sbtype(h_sb));
++		goto out_dput;
++	}
++
++	fh[Fh_br_id] = br->br_id;
++	fh[Fh_sigen] = au_sigen(sb);
++	encode_ino(fh + Fh_ino, inode->i_ino);
++	encode_ino(fh + Fh_dir_ino, parent->d_inode->i_ino);
++	fh[Fh_igen] = inode->i_generation;
++
++	*max_len -= Fh_tail;
++	fh[Fh_h_type] = exportfs_encode_fh(h_parent, (void *)(fh + Fh_tail),
++					   max_len,
++					   /*connectable or subtreecheck*/0);
++	err = fh[Fh_h_type];
++	*max_len += Fh_tail;
++	/* todo: macros? */
++	if (err != 255)
++		err = 99;
++	else
++		AuWarn1("%s encode_fh failed\n", au_sbtype(h_sb));
++
++out_dput:
++	dput(h_parent);
++out_unlock:
++	di_read_unlock(parent, !AuLock_IR);
++	dput(parent);
++	aufs_read_unlock(dentry, AuLock_IR);
++out:
++	if (unlikely(err < 0))
++		err = 255;
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_commit_metadata(struct inode *inode)
++{
++	int err;
++	aufs_bindex_t bindex;
++	struct super_block *sb;
++	struct inode *h_inode;
++	int (*f)(struct inode *inode);
++
++	sb = inode->i_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	ii_write_lock_child(inode);
++	bindex = au_ibstart(inode);
++	AuDebugOn(bindex < 0);
++	h_inode = au_h_iptr(inode, bindex);
++
++	f = h_inode->i_sb->s_export_op->commit_metadata;
++	if (f)
++		err = f(h_inode);
++	else {
++		struct writeback_control wbc = {
++			.sync_mode	= WB_SYNC_ALL,
++			.nr_to_write	= 0 /* metadata only */
++		};
++
++		err = sync_inode(h_inode, &wbc);
++	}
++
++	au_cpup_attr_timesizes(inode);
++	ii_write_unlock(inode);
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct export_operations aufs_export_op = {
++	.fh_to_dentry		= aufs_fh_to_dentry,
++	/* .fh_to_parent	= aufs_fh_to_parent, */
++	.encode_fh		= aufs_encode_fh,
++	.commit_metadata	= aufs_commit_metadata
++};
++
++void au_export_init(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++	__u32 u;
++
++	sb->s_export_op = &aufs_export_op;
++	sbinfo = au_sbi(sb);
++	sbinfo->si_xigen = NULL;
++	get_random_bytes(&u, sizeof(u));
++	BUILD_BUG_ON(sizeof(u) != sizeof(int));
++	atomic_set(&sbinfo->si_xigen_next, u);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/f_op.c linux-2.6.36/fs/aufs/f_op.c
+--- linux-2.6.36.orig/fs/aufs/f_op.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/f_op.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,906 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * file and vm operations
++ */
++
++#include <linux/file.h>
++#include <linux/fs_stack.h>
++#include <linux/mman.h>
++#include <linux/mm.h>
++#include <linux/security.h>
++#include "aufs.h"
++
++int au_do_open_nondir(struct file *file, int flags)
++{
++	int err;
++	aufs_bindex_t bindex;
++	struct file *h_file;
++	struct dentry *dentry;
++	struct au_finfo *finfo;
++
++	FiMustWriteLock(file);
++
++	dentry = file->f_dentry;
++	err = au_d_alive(dentry);
++	if (unlikely(err))
++		goto out;
++
++	finfo = au_fi(file);
++	memset(&finfo->fi_htop, 0, sizeof(finfo->fi_htop));
++	finfo->fi_hvmop = NULL;
++	bindex = au_dbstart(dentry);
++	h_file = au_h_open(dentry, bindex, flags, file);
++	if (IS_ERR(h_file))
++		err = PTR_ERR(h_file);
++	else {
++		au_set_fbstart(file, bindex);
++		au_set_h_fptr(file, bindex, h_file);
++		au_update_figen(file);
++		/* todo: necessary? */
++		/* file->f_ra = h_file->f_ra; */
++	}
++
++out:
++	return err;
++}
++
++static int aufs_open_nondir(struct inode *inode __maybe_unused,
++			    struct file *file)
++{
++	int err;
++	struct super_block *sb;
++
++	AuDbg("%.*s, f_ flags 0x%x, f_mode 0x%x\n",
++	      AuDLNPair(file->f_dentry), vfsub_file_flags(file),
++	      file->f_mode);
++
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	err = au_do_open(file, au_do_open_nondir, /*fidir*/NULL);
++	si_read_unlock(sb);
++	return err;
++}
++
++int aufs_release_nondir(struct inode *inode __maybe_unused, struct file *file)
++{
++	struct au_finfo *finfo;
++	aufs_bindex_t bindex;
++
++	finfo = au_fi(file);
++	bindex = finfo->fi_btop;
++	if (bindex >= 0) {
++		/* remove me from sb->s_files */
++		file_sb_list_del(file);
++		au_set_h_fptr(file, bindex, NULL);
++	}
++
++	au_finfo_fin(file);
++	return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_flush_nondir(struct file *file, fl_owner_t id)
++{
++	int err;
++	struct file *h_file;
++
++	err = 0;
++	h_file = au_hf_top(file);
++	if (h_file)
++		err = vfsub_flush(h_file, id);
++	return err;
++}
++
++static int aufs_flush_nondir(struct file *file, fl_owner_t id)
++{
++	return au_do_flush(file, id, au_do_flush_nondir);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static ssize_t aufs_read(struct file *file, char __user *buf, size_t count,
++			 loff_t *ppos)
++{
++	ssize_t err;
++	struct dentry *dentry;
++	struct file *h_file;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++	if (unlikely(err))
++		goto out;
++
++	h_file = au_hf_top(file);
++	err = vfsub_read_u(h_file, buf, count, ppos);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++
++	di_read_unlock(dentry, AuLock_IR);
++	fi_read_unlock(file);
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++/*
++ * todo: very ugly
++ * it locks both of i_mutex and si_rwsem for read in safe.
++ * if the plink maintenance mode continues forever (that is the problem),
++ * may loop forever.
++ */
++static void au_mtx_and_read_lock(struct inode *inode)
++{
++	int err;
++	struct super_block *sb = inode->i_sb;
++
++	while (1) {
++		mutex_lock(&inode->i_mutex);
++		err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++		if (!err)
++			break;
++		mutex_unlock(&inode->i_mutex);
++		si_read_lock(sb, AuLock_NOPLMW);
++		si_read_unlock(sb);
++	}
++}
++
++static ssize_t aufs_write(struct file *file, const char __user *ubuf,
++			  size_t count, loff_t *ppos)
++{
++	ssize_t err;
++	struct au_pin pin;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *h_file;
++	char __user *buf = (char __user *)ubuf;
++
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	au_mtx_and_read_lock(inode);
++
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	err = au_ready_to_write(file, -1, &pin);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++
++	h_file = au_hf_top(file);
++	au_unpin(&pin);
++	err = vfsub_write_u(h_file, buf, count, ppos);
++	au_cpup_attr_timesizes(inode);
++	inode->i_mode = h_file->f_dentry->d_inode->i_mode;
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out:
++	si_read_unlock(inode->i_sb);
++	mutex_unlock(&inode->i_mutex);
++	return err;
++}
++
++static ssize_t au_do_aio(struct file *h_file, int rw, struct kiocb *kio,
++			 const struct iovec *iov, unsigned long nv, loff_t pos)
++{
++	ssize_t err;
++	struct file *file;
++	ssize_t (*func)(struct kiocb *, const struct iovec *, unsigned long,
++			loff_t);
++
++	err = security_file_permission(h_file, rw);
++	if (unlikely(err))
++		goto out;
++
++	err = -ENOSYS;
++	func = NULL;
++	if (rw == MAY_READ)
++		func = h_file->f_op->aio_read;
++	else if (rw == MAY_WRITE)
++		func = h_file->f_op->aio_write;
++	if (func) {
++		file = kio->ki_filp;
++		kio->ki_filp = h_file;
++		err = func(kio, iov, nv, pos);
++		kio->ki_filp = file;
++	} else
++		/* currently there is no such fs */
++		WARN_ON_ONCE(1);
++
++out:
++	return err;
++}
++
++static ssize_t aufs_aio_read(struct kiocb *kio, const struct iovec *iov,
++			     unsigned long nv, loff_t pos)
++{
++	ssize_t err;
++	struct file *file, *h_file;
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	file = kio->ki_filp;
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++	if (unlikely(err))
++		goto out;
++
++	h_file = au_hf_top(file);
++	err = au_do_aio(h_file, MAY_READ, kio, iov, nv, pos);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++	di_read_unlock(dentry, AuLock_IR);
++	fi_read_unlock(file);
++
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++static ssize_t aufs_aio_write(struct kiocb *kio, const struct iovec *iov,
++			      unsigned long nv, loff_t pos)
++{
++	ssize_t err;
++	struct au_pin pin;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *file, *h_file;
++
++	file = kio->ki_filp;
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	au_mtx_and_read_lock(inode);
++
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	err = au_ready_to_write(file, -1, &pin);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++
++	au_unpin(&pin);
++	h_file = au_hf_top(file);
++	err = au_do_aio(h_file, MAY_WRITE, kio, iov, nv, pos);
++	au_cpup_attr_timesizes(inode);
++	inode->i_mode = h_file->f_dentry->d_inode->i_mode;
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out:
++	si_read_unlock(inode->i_sb);
++	mutex_unlock(&inode->i_mutex);
++	return err;
++}
++
++static ssize_t aufs_splice_read(struct file *file, loff_t *ppos,
++				struct pipe_inode_info *pipe, size_t len,
++				unsigned int flags)
++{
++	ssize_t err;
++	struct file *h_file;
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++	if (unlikely(err))
++		goto out;
++
++	err = -EINVAL;
++	h_file = au_hf_top(file);
++	if (au_test_loopback_kthread()) {
++		file->f_mapping = h_file->f_mapping;
++		smp_mb(); /* unnecessary? */
++	}
++	err = vfsub_splice_to(h_file, ppos, pipe, len, flags);
++	/* todo: necessasry? */
++	/* file->f_ra = h_file->f_ra; */
++	fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++
++	di_read_unlock(dentry, AuLock_IR);
++	fi_read_unlock(file);
++
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++static ssize_t
++aufs_splice_write(struct pipe_inode_info *pipe, struct file *file, loff_t *ppos,
++		  size_t len, unsigned int flags)
++{
++	ssize_t err;
++	struct au_pin pin;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *h_file;
++
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	au_mtx_and_read_lock(inode);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	err = au_ready_to_write(file, -1, &pin);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++
++	h_file = au_hf_top(file);
++	au_unpin(&pin);
++	err = vfsub_splice_from(pipe, h_file, ppos, len, flags);
++	au_cpup_attr_timesizes(inode);
++	inode->i_mode = h_file->f_dentry->d_inode->i_mode;
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out:
++	si_read_unlock(inode->i_sb);
++	mutex_unlock(&inode->i_mutex);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct file *au_safe_file(struct vm_area_struct *vma)
++{
++	struct file *file;
++
++	file = vma->vm_file;
++	if (au_fi(file) && au_test_aufs(file->f_dentry->d_sb))
++		return file;
++	return NULL;
++}
++
++static void au_reset_file(struct vm_area_struct *vma, struct file *file)
++{
++	vma->vm_file = file;
++	/* smp_mb(); */ /* flush vm_file */
++}
++
++static int aufs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
++{
++	int err;
++	static DECLARE_WAIT_QUEUE_HEAD(wq);
++	struct file *file, *h_file;
++	struct au_finfo *finfo;
++
++	/* todo: non-robr mode, user vm_file as it is? */
++	wait_event(wq, (file = au_safe_file(vma)));
++
++	/* do not revalidate, no si lock */
++	finfo = au_fi(file);
++	AuDebugOn(finfo->fi_hdir);
++	h_file = finfo->fi_htop.hf_file;
++	AuDebugOn(!h_file || !finfo->fi_hvmop);
++
++	mutex_lock(&finfo->fi_vm_mtx);
++	vma->vm_file = h_file;
++	err = finfo->fi_hvmop->fault(vma, vmf);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++	au_reset_file(vma, file);
++	mutex_unlock(&finfo->fi_vm_mtx);
++#if 0 /* def CONFIG_SMP */
++	/* wake_up_nr(&wq, online_cpu - 1); */
++	wake_up_all(&wq);
++#else
++	wake_up(&wq);
++#endif
++
++	return err;
++}
++
++static int aufs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
++{
++	int err;
++	static DECLARE_WAIT_QUEUE_HEAD(wq);
++	struct file *file, *h_file;
++	struct au_finfo *finfo;
++
++	wait_event(wq, (file = au_safe_file(vma)));
++
++	finfo = au_fi(file);
++	AuDebugOn(finfo->fi_hdir);
++	h_file = finfo->fi_htop.hf_file;
++	AuDebugOn(!h_file || !finfo->fi_hvmop);
++
++	mutex_lock(&finfo->fi_vm_mtx);
++	vma->vm_file = h_file;
++	err = finfo->fi_hvmop->page_mkwrite(vma, vmf);
++	au_reset_file(vma, file);
++	mutex_unlock(&finfo->fi_vm_mtx);
++	wake_up(&wq);
++
++	return err;
++}
++
++static void aufs_vm_close(struct vm_area_struct *vma)
++{
++	static DECLARE_WAIT_QUEUE_HEAD(wq);
++	struct file *file, *h_file;
++	struct au_finfo *finfo;
++
++	wait_event(wq, (file = au_safe_file(vma)));
++
++	finfo = au_fi(file);
++	AuDebugOn(finfo->fi_hdir);
++	h_file = finfo->fi_htop.hf_file;
++	AuDebugOn(!h_file || !finfo->fi_hvmop);
++
++	mutex_lock(&finfo->fi_vm_mtx);
++	vma->vm_file = h_file;
++	finfo->fi_hvmop->close(vma);
++	au_reset_file(vma, file);
++	mutex_unlock(&finfo->fi_vm_mtx);
++	wake_up(&wq);
++}
++
++const struct vm_operations_struct aufs_vm_ops = {
++	.close		= aufs_vm_close,
++	.fault		= aufs_fault,
++	.page_mkwrite	= aufs_page_mkwrite
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* cf. linux/include/linux/mman.h: calc_vm_prot_bits() */
++#define AuConv_VM_PROT(f, b)	_calc_vm_trans(f, VM_##b, PROT_##b)
++
++static unsigned long au_arch_prot_conv(unsigned long flags)
++{
++	/* currently ppc64 only */
++#ifdef CONFIG_PPC64
++	/* cf. linux/arch/powerpc/include/asm/mman.h */
++	AuDebugOn(arch_calc_vm_prot_bits(-1) != VM_SAO);
++	return AuConv_VM_PROT(flags, SAO);
++#else
++	AuDebugOn(arch_calc_vm_prot_bits(-1));
++	return 0;
++#endif
++}
++
++static unsigned long au_prot_conv(unsigned long flags)
++{
++	return AuConv_VM_PROT(flags, READ)
++		| AuConv_VM_PROT(flags, WRITE)
++		| AuConv_VM_PROT(flags, EXEC)
++		| au_arch_prot_conv(flags);
++}
++
++/* cf. linux/include/linux/mman.h: calc_vm_flag_bits() */
++#define AuConv_VM_MAP(f, b)	_calc_vm_trans(f, VM_##b, MAP_##b)
++
++static unsigned long au_flag_conv(unsigned long flags)
++{
++	return AuConv_VM_MAP(flags, GROWSDOWN)
++		| AuConv_VM_MAP(flags, DENYWRITE)
++		| AuConv_VM_MAP(flags, EXECUTABLE)
++		| AuConv_VM_MAP(flags, LOCKED);
++}
++
++static struct vm_operations_struct *
++au_hvmop(struct file *h_file, struct vm_area_struct *vma, unsigned long *flags)
++{
++	struct vm_operations_struct *h_vmop;
++	unsigned long prot;
++	int err;
++
++	h_vmop = ERR_PTR(-ENODEV);
++	if (!h_file->f_op || !h_file->f_op->mmap)
++		goto out;
++
++	prot = au_prot_conv(vma->vm_flags);
++	err = security_file_mmap(h_file, /*reqprot*/prot, prot,
++				 au_flag_conv(vma->vm_flags), vma->vm_start, 0);
++	h_vmop = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	err = h_file->f_op->mmap(h_file, vma);
++	h_vmop = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	/* oops, it became 'const' */
++	h_vmop = (struct vm_operations_struct *)vma->vm_ops;
++	*flags = vma->vm_flags;
++	err = do_munmap(current->mm, vma->vm_start,
++			vma->vm_end - vma->vm_start);
++	if (unlikely(err)) {
++		AuIOErr("failed internal unmapping %.*s, %d\n",
++			AuDLNPair(h_file->f_dentry), err);
++		h_vmop = ERR_PTR(-EIO);
++	}
++
++out:
++	return h_vmop;
++}
++
++/*
++ * This is another ugly approach to keep the lock order, particularly
++ * mm->mmap_sem and aufs rwsem. The previous approach was reverted and you can
++ * find it in git-log, if you want.
++ *
++ * native readdir: i_mutex, copy_to_user, mmap_sem
++ * aufs readdir: i_mutex, rwsem, nested-i_mutex, copy_to_user, mmap_sem
++ *
++ * Before aufs_mmap() mmap_sem is acquired already, but aufs_mmap() has to
++ * acquire aufs rwsem. It introduces a circular locking dependency.
++ * To address this problem, aufs_mmap() delegates the part which requires aufs
++ * rwsem to its internal workqueue.
++ */
++
++/* very ugly approach */
++#include "mtx.h"
++
++struct au_mmap_pre_args {
++	/* input */
++	struct file *file;
++	struct vm_area_struct *vma;
++
++	/* output */
++	int *errp;
++	struct file *h_file;
++	struct au_branch *br;
++	int mmapped;
++};
++
++static int au_mmap_pre(struct file *file, struct vm_area_struct *vma,
++		       struct file **h_file, struct au_branch **br,
++		       int *mmapped)
++{
++	int err;
++	aufs_bindex_t bstart;
++	const unsigned char wlock
++		= !!(file->f_mode & FMODE_WRITE) && (vma->vm_flags & VM_SHARED);
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	*mmapped = !!au_test_mmapped(file);
++	if (wlock) {
++		struct au_pin pin;
++
++		err = au_ready_to_write(file, -1, &pin);
++		di_write_unlock(dentry);
++		if (unlikely(err))
++			goto out_unlock;
++		au_unpin(&pin);
++	} else
++		di_write_unlock(dentry);
++	bstart = au_fbstart(file);
++	*br = au_sbr(sb, bstart);
++	*h_file = au_hf_top(file);
++	get_file(*h_file);
++	au_fi_mmap_lock(file);
++
++out_unlock:
++	fi_write_unlock(file);
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++static void au_call_mmap_pre(void *args)
++{
++	struct au_mmap_pre_args *a = args;
++	*a->errp = au_mmap_pre(a->file, a->vma, &a->h_file, &a->br,
++			       &a->mmapped);
++}
++
++static int aufs_mmap(struct file *file, struct vm_area_struct *vma)
++{
++	int err, wkq_err;
++	unsigned long h_vmflags;
++	struct au_finfo *finfo;
++	struct dentry *h_dentry;
++	struct vm_operations_struct *h_vmop, *vmop;
++	struct au_mmap_pre_args args = {
++		.file		= file,
++		.vma		= vma,
++		.errp		= &err
++	};
++
++	wkq_err = au_wkq_wait_pre(au_call_mmap_pre, &args);
++	if (unlikely(wkq_err))
++		err = wkq_err;
++	if (unlikely(err))
++		goto out;
++	finfo = au_fi(file);
++	mutex_set_owner(&finfo->fi_mmap);
++
++	h_dentry = args.h_file->f_dentry;
++	if (!args.mmapped && au_test_fs_bad_mapping(h_dentry->d_sb)) {
++		/*
++		 * by this assignment, f_mapping will differs from aufs inode
++		 * i_mapping.
++		 * if someone else mixes the use of f_dentry->d_inode and
++		 * f_mapping->host, then a problem may arise.
++		 */
++		file->f_mapping = args.h_file->f_mapping;
++	}
++
++	/* always try this internal mmap to get vma flags */
++	h_vmflags = 0; /* gcc warning */
++	h_vmop = au_hvmop(args.h_file, vma, &h_vmflags);
++	err = PTR_ERR(h_vmop);
++	if (IS_ERR(h_vmop))
++		goto out_unlock;
++	AuDebugOn(args.mmapped && h_vmop != finfo->fi_hvmop);
++
++	vmop = (void *)au_dy_vmop(file, args.br, h_vmop);
++	err = PTR_ERR(vmop);
++	if (IS_ERR(vmop))
++		goto out_unlock;
++
++	/*
++	 * unnecessary to handle MAP_DENYWRITE and deny_write_access()?
++	 * currently MAP_DENYWRITE from userspace is ignored, but elf loader
++	 * sets it. when FMODE_EXEC is set (by open_exec() or sys_uselib()),
++	 * both of the aufs file and the lower file is deny_write_access()-ed.
++	 * finally I hope we can skip handlling MAP_DENYWRITE here.
++	 */
++	err = generic_file_mmap(file, vma);
++	if (unlikely(err))
++		goto out_unlock;
++
++	vma->vm_ops = vmop;
++	vma->vm_flags = h_vmflags;
++	if (!args.mmapped)
++		finfo->fi_hvmop = h_vmop;
++
++	vfsub_file_accessed(args.h_file);
++	/* update without lock, I don't think it a problem */
++	fsstack_copy_attr_atime(file->f_dentry->d_inode, h_dentry->d_inode);
++
++out_unlock:
++	au_fi_mmap_unlock(file);
++	fput(args.h_file);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_fsync_nondir(struct file *file, int datasync)
++{
++	int err;
++	struct au_pin pin;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *h_file;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	IMustLock(file->f_mapping->host);
++	if (inode != file->f_mapping->host) {
++		mutex_unlock(&file->f_mapping->host->i_mutex);
++		mutex_lock(&inode->i_mutex);
++	}
++	IMustLock(inode);
++
++	sb = dentry->d_sb;
++	err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++	if (unlikely(err))
++		goto out;
++
++	err = 0; /* -EBADF; */ /* posix? */
++	if (unlikely(!(file->f_mode & FMODE_WRITE)))
++		goto out_si;
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out_si;
++
++	err = au_ready_to_write(file, -1, &pin);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++	au_unpin(&pin);
++
++	err = -EINVAL;
++	h_file = au_hf_top(file);
++	if (h_file->f_op && h_file->f_op->fsync) {
++		struct mutex *h_mtx;
++
++		/*
++		 * no filemap_fdatawrite() since aufs file has no its own
++		 * mapping, but dir.
++		 */
++		h_mtx = &h_file->f_dentry->d_inode->i_mutex;
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		err = h_file->f_op->fsync(h_file, datasync);
++		if (!err)
++			vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++		/*ignore*/
++		au_cpup_attr_timesizes(inode);
++		mutex_unlock(h_mtx);
++	}
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out_si:
++	si_read_unlock(sb);
++out:
++	if (inode != file->f_mapping->host) {
++		mutex_unlock(&inode->i_mutex);
++		mutex_lock(&file->f_mapping->host->i_mutex);
++	}
++	return err;
++}
++
++/* no one supports this operation, currently */
++#if 0
++static int aufs_aio_fsync_nondir(struct kiocb *kio, int datasync)
++{
++	int err;
++	struct au_pin pin;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *file, *h_file;
++
++	file = kio->ki_filp;
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	au_mtx_and_read_lock(inode);
++
++	err = 0; /* -EBADF; */ /* posix? */
++	if (unlikely(!(file->f_mode & FMODE_WRITE)))
++		goto out;
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++	if (unlikely(err))
++		goto out;
++
++	err = au_ready_to_write(file, -1, &pin);
++	di_downgrade_lock(dentry, AuLock_IR);
++	if (unlikely(err))
++		goto out_unlock;
++	au_unpin(&pin);
++
++	err = -ENOSYS;
++	h_file = au_hf_top(file);
++	if (h_file->f_op && h_file->f_op->aio_fsync) {
++		struct dentry *h_d;
++		struct mutex *h_mtx;
++
++		h_d = h_file->f_dentry;
++		h_mtx = &h_d->d_inode->i_mutex;
++		if (!is_sync_kiocb(kio)) {
++			get_file(h_file);
++			fput(file);
++		}
++		kio->ki_filp = h_file;
++		err = h_file->f_op->aio_fsync(kio, datasync);
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		if (!err)
++			vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++		/*ignore*/
++		au_cpup_attr_timesizes(inode);
++		mutex_unlock(h_mtx);
++	}
++
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++out:
++	si_read_unlock(inode->sb);
++	mutex_unlock(&inode->i_mutex);
++	return err;
++}
++#endif
++
++static int aufs_fasync(int fd, struct file *file, int flag)
++{
++	int err;
++	struct file *h_file;
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++	if (unlikely(err))
++		goto out;
++
++	h_file = au_hf_top(file);
++	if (h_file->f_op && h_file->f_op->fasync)
++		err = h_file->f_op->fasync(fd, h_file, flag);
++
++	di_read_unlock(dentry, AuLock_IR);
++	fi_read_unlock(file);
++
++out:
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* no one supports this operation, currently */
++#if 0
++static ssize_t aufs_sendpage(struct file *file, struct page *page, int offset,
++			     size_t len, loff_t *pos , int more)
++{
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++const struct file_operations aufs_file_fop = {
++	.owner		= THIS_MODULE,
++	/*
++	 * while generic_file_llseek/_unlocked() don't use BKL,
++	 * don't use it since it operates file->f_mapping->host.
++	 * in aufs, it may be a real file and may confuse users by UDBA.
++	 */
++	/* .llseek		= generic_file_llseek, */
++
++	.read		= aufs_read,
++	.write		= aufs_write,
++	.aio_read	= aufs_aio_read,
++	.aio_write	= aufs_aio_write,
++#ifdef CONFIG_AUFS_POLL
++	.poll		= aufs_poll,
++#endif
++	.unlocked_ioctl	= aufs_ioctl_nondir,
++#ifdef CONFIG_COMPAT
++	.compat_ioctl	= aufs_ioctl_nondir, /* same */
++#endif
++	.mmap		= aufs_mmap,
++	.open		= aufs_open_nondir,
++	.flush		= aufs_flush_nondir,
++	.release	= aufs_release_nondir,
++	.fsync		= aufs_fsync_nondir,
++	/* .aio_fsync	= aufs_aio_fsync_nondir, */
++	.fasync		= aufs_fasync,
++	/* .sendpage	= aufs_sendpage, */
++	.splice_write	= aufs_splice_write,
++	.splice_read	= aufs_splice_read,
++#if 0
++	.aio_splice_write = aufs_aio_splice_write,
++	.aio_splice_read  = aufs_aio_splice_read
++#endif
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/f_op_sp.c linux-2.6.36/fs/aufs/f_op_sp.c
+--- linux-2.6.36.orig/fs/aufs/f_op_sp.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/f_op_sp.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,299 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * file operations for special files.
++ * while they exist in aufs virtually,
++ * their file I/O is handled out of aufs.
++ */
++
++#include <linux/fs_stack.h>
++#include "aufs.h"
++
++static ssize_t aufs_aio_read_sp(struct kiocb *kio, const struct iovec *iov,
++				unsigned long nv, loff_t pos)
++{
++	ssize_t err;
++	aufs_bindex_t bstart;
++	unsigned char wbr;
++	struct file *file, *h_file;
++	struct super_block *sb;
++
++	file = kio->ki_filp;
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	fi_read_lock(file);
++	bstart = au_fbstart(file);
++	h_file = au_hf_top(file);
++	fi_read_unlock(file);
++	wbr = !!au_br_writable(au_sbr(sb, bstart)->br_perm);
++	si_read_unlock(sb);
++
++	/* do not change the file in kio */
++	AuDebugOn(!h_file->f_op || !h_file->f_op->aio_read);
++	err = h_file->f_op->aio_read(kio, iov, nv, pos);
++	if (err > 0 && wbr)
++		file_accessed(h_file);
++
++	return err;
++}
++
++static ssize_t aufs_aio_write_sp(struct kiocb *kio, const struct iovec *iov,
++				 unsigned long nv, loff_t pos)
++{
++	ssize_t err;
++	aufs_bindex_t bstart;
++	unsigned char wbr;
++	struct super_block *sb;
++	struct file *file, *h_file;
++
++	file = kio->ki_filp;
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	fi_read_lock(file);
++	bstart = au_fbstart(file);
++	h_file = au_hf_top(file);
++	fi_read_unlock(file);
++	wbr = !!au_br_writable(au_sbr(sb, bstart)->br_perm);
++	si_read_unlock(sb);
++
++	/* do not change the file in kio */
++	AuDebugOn(!h_file->f_op || !h_file->f_op->aio_write);
++	err = h_file->f_op->aio_write(kio, iov, nv, pos);
++	if (err > 0 && wbr)
++		file_update_time(h_file);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_release_sp(struct inode *inode, struct file *file)
++{
++	int err;
++	struct file *h_file;
++
++	fi_read_lock(file);
++	h_file = au_hf_top(file);
++	fi_read_unlock(file);
++	/* close this fifo in aufs */
++	err = h_file->f_op->release(inode, file); /* ignore */
++	aufs_release_nondir(inode, file); /* ignore */
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* currently, support only FIFO */
++enum {
++	AuSp_FIFO, AuSp_FIFO_R, AuSp_FIFO_W, AuSp_FIFO_RW,
++	/* AuSp_SOCK, AuSp_CHR, AuSp_BLK, */
++	AuSp_Last
++};
++static int aufs_open_sp(struct inode *inode, struct file *file);
++static struct au_sp_fop {
++	int			done;
++	struct file_operations	fop;	/* not 'const' */
++	spinlock_t		spin;
++} au_sp_fop[AuSp_Last] = {
++	[AuSp_FIFO] = {
++		.fop	= {
++			.owner	= THIS_MODULE,
++			.open	= aufs_open_sp
++		}
++	}
++};
++
++static void au_init_fop_sp(struct file *file)
++{
++	struct au_sp_fop *p;
++	int i;
++	struct file *h_file;
++
++	p = au_sp_fop;
++	if (unlikely(!p->done)) {
++		/* initialize first time only */
++		static DEFINE_SPINLOCK(spin);
++
++		spin_lock(&spin);
++		if (!p->done) {
++			BUILD_BUG_ON(sizeof(au_sp_fop)/sizeof(*au_sp_fop)
++				     != AuSp_Last);
++			for (i = 0; i < AuSp_Last; i++)
++				spin_lock_init(&p[i].spin);
++			p->done = 1;
++		}
++		spin_unlock(&spin);
++	}
++
++	switch (file->f_mode & (FMODE_READ | FMODE_WRITE)) {
++	case FMODE_READ:
++		i = AuSp_FIFO_R;
++		break;
++	case FMODE_WRITE:
++		i = AuSp_FIFO_W;
++		break;
++	case FMODE_READ | FMODE_WRITE:
++		i = AuSp_FIFO_RW;
++		break;
++	default:
++		BUG();
++	}
++
++	p += i;
++	if (unlikely(!p->done)) {
++		/* initialize first time only */
++		h_file = au_hf_top(file);
++		spin_lock(&p->spin);
++		if (!p->done) {
++			p->fop = *h_file->f_op;
++			p->fop.owner = THIS_MODULE;
++			if (p->fop.aio_read)
++				p->fop.aio_read = aufs_aio_read_sp;
++			if (p->fop.aio_write)
++				p->fop.aio_write = aufs_aio_write_sp;
++			p->fop.release = aufs_release_sp;
++			p->done = 1;
++		}
++		spin_unlock(&p->spin);
++	}
++	file->f_op = &p->fop;
++}
++
++static int au_cpup_sp(struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bcpup;
++	struct au_pin pin;
++	struct au_wr_dir_args wr_dir_args = {
++		.force_btgt	= -1,
++		.flags		= 0
++	};
++
++	AuDbg("%.*s\n", AuDLNPair(dentry));
++
++	di_read_unlock(dentry, AuLock_IR);
++	di_write_lock_child(dentry);
++	err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args);
++	if (unlikely(err < 0))
++		goto out;
++	bcpup = err;
++	err = 0;
++	if (bcpup == au_dbstart(dentry))
++		goto out; /* success */
++
++	err = au_pin(&pin, dentry, bcpup, au_opt_udba(dentry->d_sb),
++		     AuPin_MNT_WRITE);
++	if (!err) {
++		err = au_sio_cpup_simple(dentry, bcpup, -1, AuCpup_DTIME);
++		au_unpin(&pin);
++	}
++
++out:
++	di_downgrade_lock(dentry, AuLock_IR);
++	return err;
++}
++
++static int au_do_open_sp(struct file *file, int flags)
++{
++	int err;
++	struct dentry *dentry;
++	struct super_block *sb;
++	struct file *h_file;
++	struct inode *h_inode;
++
++	dentry = file->f_dentry;
++	AuDbg("%.*s\n", AuDLNPair(dentry));
++
++	/*
++	 * try copying-up.
++	 * operate on the ro branch is not an error.
++	 */
++	au_cpup_sp(dentry); /* ignore */
++
++	/* prepare h_file */
++	err = au_do_open_nondir(file, vfsub_file_flags(file));
++	if (unlikely(err))
++		goto out;
++
++	sb = dentry->d_sb;
++	h_file = au_hf_top(file);
++	h_inode = h_file->f_dentry->d_inode;
++	di_read_unlock(dentry, AuLock_IR);
++	fi_write_unlock(file);
++	si_read_unlock(sb);
++	/* open this fifo in aufs */
++	err = h_inode->i_fop->open(file->f_dentry->d_inode, file);
++	si_noflush_read_lock(sb);
++	fi_write_lock(file);
++	di_read_lock_child(dentry, AuLock_IR);
++	if (!err)
++		au_init_fop_sp(file);
++
++out:
++	return err;
++}
++
++static int aufs_open_sp(struct inode *inode, struct file *file)
++{
++	int err;
++	struct super_block *sb;
++
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	err = au_do_open(file, au_do_open_sp, /*fidir*/NULL);
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_init_special_fop(struct inode *inode, umode_t mode, dev_t rdev)
++{
++	init_special_inode(inode, mode, rdev);
++
++	switch (mode & S_IFMT) {
++	case S_IFIFO:
++		inode->i_fop = &au_sp_fop[AuSp_FIFO].fop;
++		/*FALLTHROUGH*/
++	case S_IFCHR:
++	case S_IFBLK:
++	case S_IFSOCK:
++		break;
++	default:
++		AuDebugOn(1);
++	}
++}
++
++int au_special_file(umode_t mode)
++{
++	int ret;
++
++	ret = 0;
++	switch (mode & S_IFMT) {
++	case S_IFIFO:
++#if 0
++	case S_IFCHR:
++	case S_IFBLK:
++	case S_IFSOCK:
++#endif
++		ret = 1;
++	}
++
++	return ret;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/file.c linux-2.6.36/fs/aufs/file.c
+--- linux-2.6.36.orig/fs/aufs/file.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/file.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,676 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * handling file/dir, and address_space operation
++ */
++
++#include <linux/file.h>
++#include <linux/fsnotify.h>
++#include <linux/namei.h>
++#include <linux/pagemap.h>
++#include "aufs.h"
++
++/* drop flags for writing */
++unsigned int au_file_roflags(unsigned int flags)
++{
++	flags &= ~(O_WRONLY | O_RDWR | O_APPEND | O_CREAT | O_TRUNC);
++	flags |= O_RDONLY | O_NOATIME;
++	return flags;
++}
++
++/* common functions to regular file and dir */
++struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
++		       struct file *file)
++{
++	struct file *h_file;
++	struct dentry *h_dentry;
++	struct inode *h_inode;
++	struct super_block *sb;
++	struct au_branch *br;
++	struct path h_path;
++	int err, exec_flag;
++
++	/* a race condition can happen between open and unlink/rmdir */
++	h_file = ERR_PTR(-ENOENT);
++	h_dentry = au_h_dptr(dentry, bindex);
++	if (au_test_nfsd() && !h_dentry)
++		goto out;
++	h_inode = h_dentry->d_inode;
++	if (au_test_nfsd() && !h_inode)
++		goto out;
++	if (unlikely((!d_unhashed(dentry) && au_d_removed(h_dentry))
++		     || !h_inode
++		     /* || !dentry->d_inode->i_nlink */
++		    ))
++		goto out;
++
++	sb = dentry->d_sb;
++	br = au_sbr(sb, bindex);
++	h_file = ERR_PTR(-EACCES);
++	exec_flag = flags & vfsub_fmode_to_uint(FMODE_EXEC);
++	if (exec_flag && (br->br_mnt->mnt_flags & MNT_NOEXEC))
++		goto out;
++
++	/* drop flags for writing */
++	if (au_test_ro(sb, bindex, dentry->d_inode))
++		flags = au_file_roflags(flags);
++	flags &= ~O_CREAT;
++	atomic_inc(&br->br_count);
++	h_path.dentry = h_dentry;
++	h_path.mnt = br->br_mnt;
++	if (!au_special_file(h_inode->i_mode))
++		h_file = vfsub_dentry_open(&h_path, flags);
++	else {
++		/* this block depends upon the configuration */
++		di_read_unlock(dentry, AuLock_IR);
++		fi_write_unlock(file);
++		si_read_unlock(sb);
++		h_file = vfsub_dentry_open(&h_path, flags);
++		si_noflush_read_lock(sb);
++		fi_write_lock(file);
++		di_read_lock_child(dentry, AuLock_IR);
++	}
++	if (IS_ERR(h_file))
++		goto out_br;
++
++	if (exec_flag) {
++		err = deny_write_access(h_file);
++		if (unlikely(err)) {
++			fput(h_file);
++			h_file = ERR_PTR(err);
++			goto out_br;
++		}
++	}
++	fsnotify_open(h_file);
++	goto out; /* success */
++
++out_br:
++	atomic_dec(&br->br_count);
++out:
++	return h_file;
++}
++
++int au_do_open(struct file *file, int (*open)(struct file *file, int flags),
++	       struct au_fidir *fidir)
++{
++	int err;
++	struct dentry *dentry;
++
++	err = au_finfo_init(file, fidir);
++	if (unlikely(err))
++		goto out;
++
++	dentry = file->f_dentry;
++	di_read_lock_child(dentry, AuLock_IR);
++	err = open(file, vfsub_file_flags(file));
++	di_read_unlock(dentry, AuLock_IR);
++
++	fi_write_unlock(file);
++	if (unlikely(err)) {
++		au_fi(file)->fi_hdir = NULL;
++		au_finfo_fin(file);
++	}
++
++out:
++	return err;
++}
++
++int au_reopen_nondir(struct file *file)
++{
++	int err;
++	aufs_bindex_t bstart;
++	struct dentry *dentry;
++	struct file *h_file, *h_file_tmp;
++
++	dentry = file->f_dentry;
++	AuDebugOn(au_special_file(dentry->d_inode->i_mode));
++	bstart = au_dbstart(dentry);
++	h_file_tmp = NULL;
++	if (au_fbstart(file) == bstart) {
++		h_file = au_hf_top(file);
++		if (file->f_mode == h_file->f_mode)
++			return 0; /* success */
++		h_file_tmp = h_file;
++		get_file(h_file_tmp);
++		au_set_h_fptr(file, bstart, NULL);
++	}
++	AuDebugOn(au_fi(file)->fi_hdir);
++	AuDebugOn(au_fbstart(file) < bstart);
++
++	h_file = au_h_open(dentry, bstart, vfsub_file_flags(file) & ~O_TRUNC,
++			   file);
++	err = PTR_ERR(h_file);
++	if (IS_ERR(h_file))
++		goto out; /* todo: close all? */
++
++	err = 0;
++	au_set_fbstart(file, bstart);
++	au_set_h_fptr(file, bstart, h_file);
++	au_update_figen(file);
++	/* todo: necessary? */
++	/* file->f_ra = h_file->f_ra; */
++
++out:
++	if (h_file_tmp)
++		fput(h_file_tmp);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_reopen_wh(struct file *file, aufs_bindex_t btgt,
++			struct dentry *hi_wh)
++{
++	int err;
++	aufs_bindex_t bstart;
++	struct au_dinfo *dinfo;
++	struct dentry *h_dentry;
++	struct au_hdentry *hdp;
++
++	dinfo = au_di(file->f_dentry);
++	AuRwMustWriteLock(&dinfo->di_rwsem);
++
++	bstart = dinfo->di_bstart;
++	dinfo->di_bstart = btgt;
++	hdp = dinfo->di_hdentry;
++	h_dentry = hdp[0 + btgt].hd_dentry;
++	hdp[0 + btgt].hd_dentry = hi_wh;
++	err = au_reopen_nondir(file);
++	hdp[0 + btgt].hd_dentry = h_dentry;
++	dinfo->di_bstart = bstart;
++
++	return err;
++}
++
++static int au_ready_to_write_wh(struct file *file, loff_t len,
++				aufs_bindex_t bcpup)
++{
++	int err;
++	struct inode *inode, *h_inode;
++	struct dentry *dentry, *h_dentry, *hi_wh;
++
++	dentry = file->f_dentry;
++	au_update_dbstart(dentry);
++	inode = dentry->d_inode;
++	h_inode = NULL;
++	if (au_dbstart(dentry) <= bcpup && au_dbend(dentry) >= bcpup) {
++		h_dentry = au_h_dptr(dentry, bcpup);
++		if (h_dentry)
++			h_inode = h_dentry->d_inode;
++	}
++	hi_wh = au_hi_wh(inode, bcpup);
++	if (!hi_wh && !h_inode)
++		err = au_sio_cpup_wh(dentry, bcpup, len, file);
++	else
++		/* already copied-up after unlink */
++		err = au_reopen_wh(file, bcpup, hi_wh);
++
++	if (!err
++	    && inode->i_nlink > 1
++	    && au_opt_test(au_mntflags(dentry->d_sb), PLINK))
++		au_plink_append(inode, bcpup, au_h_dptr(dentry, bcpup));
++
++	return err;
++}
++
++/*
++ * prepare the @file for writing.
++ */
++int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
++{
++	int err;
++	aufs_bindex_t bstart, bcpup, dbstart;
++	struct dentry *dentry, *parent, *h_dentry;
++	struct inode *h_inode, *inode;
++	struct super_block *sb;
++	struct file *h_file;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	AuDebugOn(au_special_file(inode->i_mode));
++	bstart = au_fbstart(file);
++	err = au_test_ro(sb, bstart, inode);
++	if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
++		err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
++		goto out;
++	}
++
++	/* need to cpup or reopen */
++	parent = dget_parent(dentry);
++	di_write_lock_parent(parent);
++	err = AuWbrCopyup(au_sbi(sb), dentry);
++	bcpup = err;
++	if (unlikely(err < 0))
++		goto out_dgrade;
++	err = 0;
++
++	if (!d_unhashed(dentry) && !au_h_dptr(parent, bcpup)) {
++		err = au_cpup_dirs(dentry, bcpup);
++		if (unlikely(err))
++			goto out_dgrade;
++	}
++
++	err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
++		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++	if (unlikely(err))
++		goto out_dgrade;
++
++	h_dentry = au_hf_top(file)->f_dentry;
++	h_inode = h_dentry->d_inode;
++	dbstart = au_dbstart(dentry);
++	if (dbstart <= bcpup) {
++		h_dentry = au_h_dptr(dentry, bcpup);
++		AuDebugOn(!h_dentry);
++		h_inode = h_dentry->d_inode;
++		AuDebugOn(!h_inode);
++		bstart = bcpup;
++	}
++
++	if (dbstart <= bcpup		/* just reopen */
++	    || !d_unhashed(dentry)	/* copyup and reopen */
++		) {
++		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++		h_file = au_h_open_pre(dentry, bstart);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			h_file = NULL;
++		} else {
++			di_downgrade_lock(parent, AuLock_IR);
++			if (dbstart > bcpup)
++				err = au_sio_cpup_simple(dentry, bcpup, len,
++							 AuCpup_DTIME);
++			if (!err)
++				err = au_reopen_nondir(file);
++		}
++		mutex_unlock(&h_inode->i_mutex);
++		au_h_open_post(dentry, bstart, h_file);
++	} else {			/* copyup as wh and reopen */
++		/*
++		 * since writable hfsplus branch is not supported,
++		 * h_open_pre/post() are unnecessary.
++		 */
++		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++		err = au_ready_to_write_wh(file, len, bcpup);
++		di_downgrade_lock(parent, AuLock_IR);
++		mutex_unlock(&h_inode->i_mutex);
++	}
++
++	if (!err) {
++		au_pin_set_parent_lflag(pin, /*lflag*/0);
++		goto out_dput; /* success */
++	}
++	au_unpin(pin);
++	goto out_unlock;
++
++out_dgrade:
++	di_downgrade_lock(parent, AuLock_IR);
++out_unlock:
++	di_read_unlock(parent, AuLock_IR);
++out_dput:
++	dput(parent);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_do_flush(struct file *file, fl_owner_t id,
++		int (*flush)(struct file *file, fl_owner_t id))
++{
++	int err;
++	struct dentry *dentry;
++	struct super_block *sb;
++	struct inode *inode;
++
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	si_noflush_read_lock(sb);
++	fi_read_lock(file);
++	ii_read_lock_child(inode);
++
++	err = flush(file, id);
++	au_cpup_attr_timesizes(inode);
++
++	ii_read_unlock(inode);
++	fi_read_unlock(file);
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_file_refresh_by_inode(struct file *file, int *need_reopen)
++{
++	int err;
++	aufs_bindex_t bstart;
++	struct au_pin pin;
++	struct au_finfo *finfo;
++	struct dentry *dentry, *parent, *hi_wh;
++	struct inode *inode;
++	struct super_block *sb;
++
++	FiMustWriteLock(file);
++
++	err = 0;
++	finfo = au_fi(file);
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	bstart = au_ibstart(inode);
++	if (bstart == finfo->fi_btop || IS_ROOT(dentry))
++		goto out;
++
++	parent = dget_parent(dentry);
++	if (au_test_ro(sb, bstart, inode)) {
++		di_read_lock_parent(parent, !AuLock_IR);
++		err = AuWbrCopyup(au_sbi(sb), dentry);
++		bstart = err;
++		di_read_unlock(parent, !AuLock_IR);
++		if (unlikely(err < 0))
++			goto out_parent;
++		err = 0;
++	}
++
++	di_read_lock_parent(parent, AuLock_IR);
++	hi_wh = au_hi_wh(inode, bstart);
++	if (!S_ISDIR(inode->i_mode)
++	    && au_opt_test(au_mntflags(sb), PLINK)
++	    && au_plink_test(inode)
++	    && !d_unhashed(dentry)) {
++		err = au_test_and_cpup_dirs(dentry, bstart);
++		if (unlikely(err))
++			goto out_unlock;
++
++		/* always superio. */
++		err = au_pin(&pin, dentry, bstart, AuOpt_UDBA_NONE,
++			     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++		if (!err)
++			err = au_sio_cpup_simple(dentry, bstart, -1,
++						 AuCpup_DTIME);
++		au_unpin(&pin);
++	} else if (hi_wh) {
++		/* already copied-up after unlink */
++		err = au_reopen_wh(file, bstart, hi_wh);
++		*need_reopen = 0;
++	}
++
++out_unlock:
++	di_read_unlock(parent, AuLock_IR);
++out_parent:
++	dput(parent);
++out:
++	return err;
++}
++
++static void au_do_refresh_dir(struct file *file)
++{
++	aufs_bindex_t bindex, bend, new_bindex, brid;
++	struct au_hfile *p, tmp, *q;
++	struct au_finfo *finfo;
++	struct super_block *sb;
++	struct au_fidir *fidir;
++
++	FiMustWriteLock(file);
++
++	sb = file->f_dentry->d_sb;
++	finfo = au_fi(file);
++	fidir = finfo->fi_hdir;
++	AuDebugOn(!fidir);
++	p = fidir->fd_hfile + finfo->fi_btop;
++	brid = p->hf_br->br_id;
++	bend = fidir->fd_bbot;
++	for (bindex = finfo->fi_btop; bindex <= bend; bindex++, p++) {
++		if (!p->hf_file)
++			continue;
++
++		new_bindex = au_br_index(sb, p->hf_br->br_id);
++		if (new_bindex == bindex)
++			continue;
++		if (new_bindex < 0) {
++			au_set_h_fptr(file, bindex, NULL);
++			continue;
++		}
++
++		/* swap two lower inode, and loop again */
++		q = fidir->fd_hfile + new_bindex;
++		tmp = *q;
++		*q = *p;
++		*p = tmp;
++		if (tmp.hf_file) {
++			bindex--;
++			p--;
++		}
++	}
++
++	p = fidir->fd_hfile;
++	if (!au_test_mmapped(file) && !au_d_removed(file->f_dentry)) {
++		bend = au_sbend(sb);
++		for (finfo->fi_btop = 0; finfo->fi_btop <= bend;
++		     finfo->fi_btop++, p++)
++			if (p->hf_file) {
++				if (p->hf_file->f_dentry
++				    && p->hf_file->f_dentry->d_inode)
++					break;
++				else
++					au_hfput(p, file);
++			}
++	} else {
++		bend = au_br_index(sb, brid);
++		for (finfo->fi_btop = 0; finfo->fi_btop < bend;
++		     finfo->fi_btop++, p++)
++			if (p->hf_file)
++				au_hfput(p, file);
++		bend = au_sbend(sb);
++	}
++
++	p = fidir->fd_hfile + bend;
++	for (fidir->fd_bbot = bend; fidir->fd_bbot >= finfo->fi_btop;
++	     fidir->fd_bbot--, p--)
++		if (p->hf_file) {
++			if (p->hf_file->f_dentry
++			    && p->hf_file->f_dentry->d_inode)
++				break;
++			else
++				au_hfput(p, file);
++		}
++	AuDebugOn(fidir->fd_bbot < finfo->fi_btop);
++}
++
++/*
++ * after branch manipulating, refresh the file.
++ */
++static int refresh_file(struct file *file, int (*reopen)(struct file *file))
++{
++	int err, need_reopen;
++	aufs_bindex_t bend, bindex;
++	struct dentry *dentry;
++	struct au_finfo *finfo;
++	struct au_hfile *hfile;
++
++	dentry = file->f_dentry;
++	finfo = au_fi(file);
++	if (!finfo->fi_hdir) {
++		hfile = &finfo->fi_htop;
++		AuDebugOn(!hfile->hf_file);
++		bindex = au_br_index(dentry->d_sb, hfile->hf_br->br_id);
++		AuDebugOn(bindex < 0);
++		if (bindex != finfo->fi_btop)
++			au_set_fbstart(file, bindex);
++	} else {
++		err = au_fidir_realloc(finfo, au_sbend(dentry->d_sb) + 1);
++		if (unlikely(err))
++			goto out;
++		au_do_refresh_dir(file);
++	}
++
++	err = 0;
++	need_reopen = 1;
++	if (!au_test_mmapped(file))
++		err = au_file_refresh_by_inode(file, &need_reopen);
++	if (!err && need_reopen && !au_d_removed(dentry))
++		err = reopen(file);
++	if (!err) {
++		au_update_figen(file);
++		goto out; /* success */
++	}
++
++	/* error, close all lower files */
++	if (finfo->fi_hdir) {
++		bend = au_fbend_dir(file);
++		for (bindex = au_fbstart(file); bindex <= bend; bindex++)
++			au_set_h_fptr(file, bindex, NULL);
++	}
++
++out:
++	return err;
++}
++
++/* common function to regular file and dir */
++int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
++			  int wlock)
++{
++	int err;
++	unsigned int sigen, figen;
++	aufs_bindex_t bstart;
++	unsigned char pseudo_link;
++	struct dentry *dentry;
++	struct inode *inode;
++
++	err = 0;
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++	AuDebugOn(au_special_file(inode->i_mode));
++	sigen = au_sigen(dentry->d_sb);
++	fi_write_lock(file);
++	figen = au_figen(file);
++	di_write_lock_child(dentry);
++	bstart = au_dbstart(dentry);
++	pseudo_link = (bstart != au_ibstart(inode));
++	if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
++		if (!wlock) {
++			di_downgrade_lock(dentry, AuLock_IR);
++			fi_downgrade_lock(file);
++		}
++		goto out; /* success */
++	}
++
++	AuDbg("sigen %d, figen %d\n", sigen, figen);
++	if (au_digen_test(dentry, sigen)) {
++		err = au_reval_dpath(dentry, sigen);
++		AuDebugOn(!err && au_digen_test(dentry, sigen));
++	}
++
++	if (!err)
++		err = refresh_file(file, reopen);
++	if (!err) {
++		if (!wlock) {
++			di_downgrade_lock(dentry, AuLock_IR);
++			fi_downgrade_lock(file);
++		}
++	} else {
++		di_write_unlock(dentry);
++		fi_write_unlock(file);
++	}
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* cf. aufs_nopage() */
++/* for madvise(2) */
++static int aufs_readpage(struct file *file __maybe_unused, struct page *page)
++{
++	unlock_page(page);
++	return 0;
++}
++
++/* it will never be called, but necessary to support O_DIRECT */
++static ssize_t aufs_direct_IO(int rw, struct kiocb *iocb,
++			      const struct iovec *iov, loff_t offset,
++			      unsigned long nr_segs)
++{ BUG(); return 0; }
++
++/*
++ * it will never be called, but madvise and fadvise behaves differently
++ * when get_xip_mem is defined
++ */
++static int aufs_get_xip_mem(struct address_space *mapping, pgoff_t pgoff,
++			    int create, void **kmem, unsigned long *pfn)
++{ BUG(); return 0; }
++
++/* they will never be called. */
++#ifdef CONFIG_AUFS_DEBUG
++static int aufs_write_begin(struct file *file, struct address_space *mapping,
++			    loff_t pos, unsigned len, unsigned flags,
++			    struct page **pagep, void **fsdata)
++{ AuUnsupport(); return 0; }
++static int aufs_write_end(struct file *file, struct address_space *mapping,
++			  loff_t pos, unsigned len, unsigned copied,
++			  struct page *page, void *fsdata)
++{ AuUnsupport(); return 0; }
++static int aufs_writepage(struct page *page, struct writeback_control *wbc)
++{ AuUnsupport(); return 0; }
++static void aufs_sync_page(struct page *page)
++{ AuUnsupport(); }
++
++static int aufs_set_page_dirty(struct page *page)
++{ AuUnsupport(); return 0; }
++static void aufs_invalidatepage(struct page *page, unsigned long offset)
++{ AuUnsupport(); }
++static int aufs_releasepage(struct page *page, gfp_t gfp)
++{ AuUnsupport(); return 0; }
++static int aufs_migratepage(struct address_space *mapping, struct page *newpage,
++			    struct page *page)
++{ AuUnsupport(); return 0; }
++static int aufs_launder_page(struct page *page)
++{ AuUnsupport(); return 0; }
++static int aufs_is_partially_uptodate(struct page *page,
++				      read_descriptor_t *desc,
++				      unsigned long from)
++{ AuUnsupport(); return 0; }
++static int aufs_error_remove_page(struct address_space *mapping,
++				  struct page *page)
++{ AuUnsupport(); return 0; }
++#endif /* CONFIG_AUFS_DEBUG */
++
++const struct address_space_operations aufs_aop = {
++	.readpage		= aufs_readpage,
++	.direct_IO		= aufs_direct_IO,
++	.get_xip_mem		= aufs_get_xip_mem,
++#ifdef CONFIG_AUFS_DEBUG
++	.writepage		= aufs_writepage,
++	.sync_page		= aufs_sync_page,
++	/* no writepages, because of writepage */
++	.set_page_dirty		= aufs_set_page_dirty,
++	/* no readpages, because of readpage */
++	.write_begin		= aufs_write_begin,
++	.write_end		= aufs_write_end,
++	/* no bmap, no block device */
++	.invalidatepage		= aufs_invalidatepage,
++	.releasepage		= aufs_releasepage,
++	.migratepage		= aufs_migratepage,
++	.launder_page		= aufs_launder_page,
++	.is_partially_uptodate	= aufs_is_partially_uptodate,
++	.error_remove_page	= aufs_error_remove_page
++#endif /* CONFIG_AUFS_DEBUG */
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/file.h linux-2.6.36/fs/aufs/file.h
+--- linux-2.6.36.orig/fs/aufs/file.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/file.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,238 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * file operations
++ */
++
++#ifndef __AUFS_FILE_H__
++#define __AUFS_FILE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/poll.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++struct au_branch;
++struct au_hfile {
++	struct file		*hf_file;
++	struct au_branch	*hf_br;
++};
++
++struct au_vdir;
++struct au_fidir {
++	aufs_bindex_t		fd_bbot;
++	aufs_bindex_t		fd_nent;
++	struct au_vdir		*fd_vdir_cache;
++	struct au_hfile		fd_hfile[];
++};
++
++static inline int au_fidir_sz(int nent)
++{
++	AuDebugOn(nent < 0);
++	return sizeof(struct au_fidir) + sizeof(struct au_hfile) * nent;
++}
++
++struct au_finfo {
++	atomic_t		fi_generation;
++
++	struct au_rwsem		fi_rwsem;
++	aufs_bindex_t		fi_btop;
++
++	/* do not union them */
++	struct {				/* for non-dir */
++		struct au_hfile			fi_htop;
++		struct vm_operations_struct	*fi_hvmop;
++		struct mutex			fi_vm_mtx;
++		struct mutex			fi_mmap;
++	};
++	struct au_fidir		*fi_hdir;	/* for dir only */
++} ____cacheline_aligned_in_smp;
++
++/* ---------------------------------------------------------------------- */
++
++/* file.c */
++extern const struct address_space_operations aufs_aop;
++unsigned int au_file_roflags(unsigned int flags);
++struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
++		       struct file *file);
++int au_do_open(struct file *file, int (*open)(struct file *file, int flags),
++	       struct au_fidir *fidir);
++int au_reopen_nondir(struct file *file);
++struct au_pin;
++int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin);
++int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
++			  int wlock);
++int au_do_flush(struct file *file, fl_owner_t id,
++		int (*flush)(struct file *file, fl_owner_t id));
++
++/* poll.c */
++#ifdef CONFIG_AUFS_POLL
++unsigned int aufs_poll(struct file *file, poll_table *wait);
++#endif
++
++#ifdef CONFIG_AUFS_BR_HFSPLUS
++/* hfsplus.c */
++struct file *au_h_open_pre(struct dentry *dentry, aufs_bindex_t bindex);
++void au_h_open_post(struct dentry *dentry, aufs_bindex_t bindex,
++		    struct file *h_file);
++#else
++static inline
++struct file *au_h_open_pre(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	return NULL;
++}
++
++AuStubVoid(au_h_open_post, struct dentry *dentry, aufs_bindex_t bindex,
++	   struct file *h_file);
++#endif
++
++/* f_op.c */
++extern const struct file_operations aufs_file_fop;
++extern const struct vm_operations_struct aufs_vm_ops;
++int au_do_open_nondir(struct file *file, int flags);
++int aufs_release_nondir(struct inode *inode __maybe_unused, struct file *file);
++
++#ifdef CONFIG_AUFS_SP_IATTR
++/* f_op_sp.c */
++int au_special_file(umode_t mode);
++void au_init_special_fop(struct inode *inode, umode_t mode, dev_t rdev);
++#else
++AuStubInt0(au_special_file, umode_t mode)
++static inline void au_init_special_fop(struct inode *inode, umode_t mode,
++				       dev_t rdev)
++{
++	init_special_inode(inode, mode, rdev);
++}
++#endif
++
++/* finfo.c */
++void au_hfput(struct au_hfile *hf, struct file *file);
++void au_set_h_fptr(struct file *file, aufs_bindex_t bindex,
++		   struct file *h_file);
++
++void au_update_figen(struct file *file);
++void au_fi_mmap_lock(struct file *file);
++void au_fi_mmap_unlock(struct file *file);
++struct au_fidir *au_fidir_alloc(struct super_block *sb);
++int au_fidir_realloc(struct au_finfo *finfo, int nbr);
++
++void au_fi_init_once(void *_fi);
++void au_finfo_fin(struct file *file);
++int au_finfo_init(struct file *file, struct au_fidir *fidir);
++
++/* ioctl.c */
++long aufs_ioctl_nondir(struct file *file, unsigned int cmd, unsigned long arg);
++#ifdef CONFIG_COMPAT
++long aufs_compat_ioctl_dir(struct file *file, unsigned int cmd,
++			   unsigned long arg);
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_finfo *au_fi(struct file *file)
++{
++	return file->private_data;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * fi_read_lock, fi_write_lock,
++ * fi_read_unlock, fi_write_unlock, fi_downgrade_lock
++ */
++AuSimpleRwsemFuncs(fi, struct file *f, &au_fi(f)->fi_rwsem);
++
++#define FiMustNoWaiters(f)	AuRwMustNoWaiters(&au_fi(f)->fi_rwsem)
++#define FiMustAnyLock(f)	AuRwMustAnyLock(&au_fi(f)->fi_rwsem)
++#define FiMustWriteLock(f)	AuRwMustWriteLock(&au_fi(f)->fi_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: hard/soft set? */
++static inline aufs_bindex_t au_fbstart(struct file *file)
++{
++	FiMustAnyLock(file);
++	return au_fi(file)->fi_btop;
++}
++
++static inline aufs_bindex_t au_fbend_dir(struct file *file)
++{
++	FiMustAnyLock(file);
++	AuDebugOn(!au_fi(file)->fi_hdir);
++	return au_fi(file)->fi_hdir->fd_bbot;
++}
++
++static inline struct au_vdir *au_fvdir_cache(struct file *file)
++{
++	FiMustAnyLock(file);
++	AuDebugOn(!au_fi(file)->fi_hdir);
++	return au_fi(file)->fi_hdir->fd_vdir_cache;
++}
++
++static inline void au_set_fbstart(struct file *file, aufs_bindex_t bindex)
++{
++	FiMustWriteLock(file);
++	au_fi(file)->fi_btop = bindex;
++}
++
++static inline void au_set_fbend_dir(struct file *file, aufs_bindex_t bindex)
++{
++	FiMustWriteLock(file);
++	AuDebugOn(!au_fi(file)->fi_hdir);
++	au_fi(file)->fi_hdir->fd_bbot = bindex;
++}
++
++static inline void au_set_fvdir_cache(struct file *file,
++				      struct au_vdir *vdir_cache)
++{
++	FiMustWriteLock(file);
++	AuDebugOn(!au_fi(file)->fi_hdir);
++	au_fi(file)->fi_hdir->fd_vdir_cache = vdir_cache;
++}
++
++static inline struct file *au_hf_top(struct file *file)
++{
++	FiMustAnyLock(file);
++	AuDebugOn(au_fi(file)->fi_hdir);
++	return au_fi(file)->fi_htop.hf_file;
++}
++
++static inline struct file *au_hf_dir(struct file *file, aufs_bindex_t bindex)
++{
++	FiMustAnyLock(file);
++	AuDebugOn(!au_fi(file)->fi_hdir);
++	return au_fi(file)->fi_hdir->fd_hfile[0 + bindex].hf_file;
++}
++
++/* todo: memory barrier? */
++static inline unsigned int au_figen(struct file *f)
++{
++	return atomic_read(&au_fi(f)->fi_generation);
++}
++
++static inline int au_test_mmapped(struct file *f)
++{
++	FiMustAnyLock(f);
++	return !!(au_fi(f)->fi_hvmop);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_FILE_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/finfo.c linux-2.6.36/fs/aufs/finfo.c
+--- linux-2.6.36.orig/fs/aufs/finfo.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/finfo.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,174 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * file private data
++ */
++
++#include <linux/file.h>
++#include "aufs.h"
++
++void au_hfput(struct au_hfile *hf, struct file *file)
++{
++	/* todo: direct access f_flags */
++	if (vfsub_file_flags(file) & vfsub_fmode_to_uint(FMODE_EXEC))
++		allow_write_access(hf->hf_file);
++	fput(hf->hf_file);
++	hf->hf_file = NULL;
++	atomic_dec(&hf->hf_br->br_count);
++	hf->hf_br = NULL;
++}
++
++void au_set_h_fptr(struct file *file, aufs_bindex_t bindex, struct file *val)
++{
++	struct au_finfo *finfo = au_fi(file);
++	struct au_hfile *hf;
++	struct au_fidir *fidir;
++
++	fidir = finfo->fi_hdir;
++	if (!fidir) {
++		AuDebugOn(finfo->fi_btop != bindex);
++		hf = &finfo->fi_htop;
++	} else
++		hf = fidir->fd_hfile + bindex;
++
++	if (hf && hf->hf_file)
++		au_hfput(hf, file);
++	if (val) {
++		FiMustWriteLock(file);
++		hf->hf_file = val;
++		hf->hf_br = au_sbr(file->f_dentry->d_sb, bindex);
++	}
++}
++
++void au_update_figen(struct file *file)
++{
++	atomic_set(&au_fi(file)->fi_generation, au_digen(file->f_dentry));
++	/* smp_mb(); */ /* atomic_set */
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_fi_mmap_lock(struct file *file)
++{
++	FiMustWriteLock(file);
++	lockdep_off();
++	mutex_lock(&au_fi(file)->fi_mmap);
++	lockdep_on();
++}
++
++void au_fi_mmap_unlock(struct file *file)
++{
++	lockdep_off();
++	mutex_unlock(&au_fi(file)->fi_mmap);
++	lockdep_on();
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_fidir *au_fidir_alloc(struct super_block *sb)
++{
++	struct au_fidir *fidir;
++	int nbr;
++
++	nbr = au_sbend(sb) + 1;
++	if (nbr < 2)
++		nbr = 2; /* initial allocate for 2 branches */
++	fidir = kzalloc(au_fidir_sz(nbr), GFP_NOFS);
++	if (fidir) {
++		fidir->fd_bbot = -1;
++		fidir->fd_nent = nbr;
++		fidir->fd_vdir_cache = NULL;
++	}
++
++	return fidir;
++}
++
++int au_fidir_realloc(struct au_finfo *finfo, int nbr)
++{
++	int err;
++	struct au_fidir *fidir, *p;
++
++	AuRwMustWriteLock(&finfo->fi_rwsem);
++	fidir = finfo->fi_hdir;
++	AuDebugOn(!fidir);
++
++	err = -ENOMEM;
++	p = au_kzrealloc(fidir, au_fidir_sz(fidir->fd_nent), au_fidir_sz(nbr),
++			 GFP_NOFS);
++	if (p) {
++		p->fd_nent = nbr;
++		finfo->fi_hdir = p;
++		err = 0;
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_finfo_fin(struct file *file)
++{
++	struct au_finfo *finfo;
++
++	au_nfiles_dec(file->f_dentry->d_sb);
++
++	finfo = au_fi(file);
++	AuDebugOn(finfo->fi_hdir);
++	AuRwDestroy(&finfo->fi_rwsem);
++	au_cache_free_finfo(finfo);
++}
++
++void au_fi_init_once(void *_finfo)
++{
++	struct au_finfo *finfo = _finfo;
++	static struct lock_class_key aufs_fi, aufs_fi_vm, aufs_fi_mmap;
++
++	au_rw_init(&finfo->fi_rwsem);
++	au_rw_class(&finfo->fi_rwsem, &aufs_fi);
++	mutex_init(&finfo->fi_vm_mtx);
++	lockdep_set_class(&finfo->fi_vm_mtx, &aufs_fi_vm);
++	mutex_init(&finfo->fi_mmap);
++	lockdep_set_class(&finfo->fi_mmap, &aufs_fi_mmap);
++}
++
++int au_finfo_init(struct file *file, struct au_fidir *fidir)
++{
++	int err;
++	struct au_finfo *finfo;
++	struct dentry *dentry;
++
++	err = -ENOMEM;
++	dentry = file->f_dentry;
++	finfo = au_cache_alloc_finfo();
++	if (unlikely(!finfo))
++		goto out;
++
++	err = 0;
++	au_nfiles_inc(dentry->d_sb);
++	au_rw_write_lock(&finfo->fi_rwsem);
++	finfo->fi_btop = -1;
++	finfo->fi_hdir = fidir;
++	atomic_set(&finfo->fi_generation, au_digen(dentry));
++	/* smp_mb(); */ /* atomic_set */
++
++	file->private_data = finfo;
++
++out:
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/fstype.h linux-2.6.36/fs/aufs/fstype.h
+--- linux-2.6.36.orig/fs/aufs/fstype.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/fstype.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,497 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * judging filesystem type
++ */
++
++#ifndef __AUFS_FSTYPE_H__
++#define __AUFS_FSTYPE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/magic.h>
++#include <linux/romfs_fs.h>
++#include <linux/aufs_type.h>
++
++static inline int au_test_aufs(struct super_block *sb)
++{
++	return sb->s_magic == AUFS_SUPER_MAGIC;
++}
++
++static inline const char *au_sbtype(struct super_block *sb)
++{
++	return sb->s_type->name;
++}
++
++static inline int au_test_iso9660(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ROMFS_FS) || defined(CONFIG_ROMFS_FS_MODULE)
++	return sb->s_magic == ROMFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_romfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ISO9660_FS) || defined(CONFIG_ISO9660_FS_MODULE)
++	return sb->s_magic == ISOFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_cramfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CRAMFS) || defined(CONFIG_CRAMFS_MODULE)
++	return sb->s_magic == CRAMFS_MAGIC;
++#endif
++	return 0;
++}
++
++static inline int au_test_nfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_NFS_FS) || defined(CONFIG_NFS_FS_MODULE)
++	return sb->s_magic == NFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_fuse(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_FUSE_FS) || defined(CONFIG_FUSE_FS_MODULE)
++	return sb->s_magic == FUSE_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_xfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_XFS_FS) || defined(CONFIG_XFS_FS_MODULE)
++	return sb->s_magic == XFS_SB_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_tmpfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_TMPFS
++	return sb->s_magic == TMPFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_ecryptfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ECRYPT_FS) || defined(CONFIG_ECRYPT_FS_MODULE)
++	return !strcmp(au_sbtype(sb), "ecryptfs");
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_smbfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SMB_FS) || defined(CONFIG_SMB_FS_MODULE)
++	return sb->s_magic == SMB_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_ocfs2(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_OCFS2_FS) || defined(CONFIG_OCFS2_FS_MODULE)
++	return sb->s_magic == OCFS2_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_ocfs2_dlmfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_OCFS2_FS_O2CB) || defined(CONFIG_OCFS2_FS_O2CB_MODULE)
++	return sb->s_magic == DLMFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_coda(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CODA_FS) || defined(CONFIG_CODA_FS_MODULE)
++	return sb->s_magic == CODA_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_v9fs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_9P_FS) || defined(CONFIG_9P_FS_MODULE)
++	return sb->s_magic == V9FS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_ext4(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_EXT4DEV_FS) || defined(CONFIG_EXT4DEV_FS_MODULE)
++	return sb->s_magic == EXT4_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_sysv(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SYSV_FS) || defined(CONFIG_SYSV_FS_MODULE)
++	return !strcmp(au_sbtype(sb), "sysv");
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_ramfs(struct super_block *sb)
++{
++	return sb->s_magic == RAMFS_MAGIC;
++}
++
++static inline int au_test_ubifs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_UBIFS_FS) || defined(CONFIG_UBIFS_FS_MODULE)
++	return sb->s_magic == UBIFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_procfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_PROC_FS
++	return sb->s_magic == PROC_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_sysfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_SYSFS
++	return sb->s_magic == SYSFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_configfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CONFIGFS_FS) || defined(CONFIG_CONFIGFS_FS_MODULE)
++	return sb->s_magic == CONFIGFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_minix(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_MINIX_FS) || defined(CONFIG_MINIX_FS_MODULE)
++	return sb->s_magic == MINIX3_SUPER_MAGIC
++		|| sb->s_magic == MINIX2_SUPER_MAGIC
++		|| sb->s_magic == MINIX2_SUPER_MAGIC2
++		|| sb->s_magic == MINIX_SUPER_MAGIC
++		|| sb->s_magic == MINIX_SUPER_MAGIC2;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_cifs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CIFS_FS) || defined(CONFIGCIFS_FS_MODULE)
++	return sb->s_magic == CIFS_MAGIC_NUMBER;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_fat(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_FAT_FS) || defined(CONFIG_FAT_FS_MODULE)
++	return sb->s_magic == MSDOS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_msdos(struct super_block *sb)
++{
++	return au_test_fat(sb);
++}
++
++static inline int au_test_vfat(struct super_block *sb)
++{
++	return au_test_fat(sb);
++}
++
++static inline int au_test_securityfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_SECURITYFS
++	return sb->s_magic == SECURITYFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_squashfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SQUASHFS) || defined(CONFIG_SQUASHFS_MODULE)
++	return sb->s_magic == SQUASHFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_btrfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_BTRFS_FS) || defined(CONFIG_BTRFS_FS_MODULE)
++	return sb->s_magic == BTRFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_xenfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_XENFS) || defined(CONFIG_XENFS_MODULE)
++	return sb->s_magic == XENFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_debugfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_DEBUG_FS
++	return sb->s_magic == DEBUGFS_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_nilfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_NILFS) || defined(CONFIG_NILFS_MODULE)
++	return sb->s_magic == NILFS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++static inline int au_test_hfsplus(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_HFSPLUS_FS) || defined(CONFIG_HFSPLUS_FS_MODULE)
++	return sb->s_magic == HFSPLUS_SUPER_MAGIC;
++#else
++	return 0;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * they can't be an aufs branch.
++ */
++static inline int au_test_fs_unsuppoted(struct super_block *sb)
++{
++	return
++#ifndef CONFIG_AUFS_BR_RAMFS
++		au_test_ramfs(sb) ||
++#endif
++		au_test_procfs(sb)
++		|| au_test_sysfs(sb)
++		|| au_test_configfs(sb)
++		|| au_test_debugfs(sb)
++		|| au_test_securityfs(sb)
++		|| au_test_xenfs(sb)
++		|| au_test_ecryptfs(sb)
++		/* || !strcmp(au_sbtype(sb), "unionfs") */
++		|| au_test_aufs(sb); /* will be supported in next version */
++}
++
++/*
++ * If the filesystem supports NFS-export, then it has to support NULL as
++ * a nameidata parameter for ->create(), ->lookup() and ->d_revalidate().
++ * We can apply this principle when we handle a lower filesystem.
++ */
++static inline int au_test_fs_null_nd(struct super_block *sb)
++{
++	return !!sb->s_export_op;
++}
++
++static inline int au_test_fs_remote(struct super_block *sb)
++{
++	return !au_test_tmpfs(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++		&& !au_test_ramfs(sb)
++#endif
++		&& !(sb->s_type->fs_flags & FS_REQUIRES_DEV);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * Note: these functions (below) are created after reading ->getattr() in all
++ * filesystems under linux/fs. it means we have to do so in every update...
++ */
++
++/*
++ * some filesystems require getattr to refresh the inode attributes before
++ * referencing.
++ * in most cases, we can rely on the inode attribute in NFS (or every remote fs)
++ * and leave the work for d_revalidate()
++ */
++static inline int au_test_fs_refresh_iattr(struct super_block *sb)
++{
++	return au_test_nfs(sb)
++		|| au_test_fuse(sb)
++		/* || au_test_smbfs(sb) */	/* untested */
++		/* || au_test_ocfs2(sb) */	/* untested */
++		/* || au_test_btrfs(sb) */	/* untested */
++		/* || au_test_coda(sb) */	/* untested */
++		/* || au_test_v9fs(sb) */	/* untested */
++		;
++}
++
++/*
++ * filesystems which don't maintain i_size or i_blocks.
++ */
++static inline int au_test_fs_bad_iattr_size(struct super_block *sb)
++{
++	return au_test_xfs(sb)
++		|| au_test_btrfs(sb)
++		|| au_test_ubifs(sb)
++		|| au_test_hfsplus(sb)	/* maintained, but incorrect */
++		/* || au_test_ext4(sb) */	/* untested */
++		/* || au_test_ocfs2(sb) */	/* untested */
++		/* || au_test_ocfs2_dlmfs(sb) */ /* untested */
++		/* || au_test_sysv(sb) */	/* untested */
++		/* || au_test_minix(sb) */	/* untested */
++		;
++}
++
++/*
++ * filesystems which don't store the correct value in some of their inode
++ * attributes.
++ */
++static inline int au_test_fs_bad_iattr(struct super_block *sb)
++{
++	return au_test_fs_bad_iattr_size(sb)
++		/* || au_test_cifs(sb) */	/* untested */
++		|| au_test_fat(sb)
++		|| au_test_msdos(sb)
++		|| au_test_vfat(sb);
++}
++
++/* they don't check i_nlink in link(2) */
++static inline int au_test_fs_no_limit_nlink(struct super_block *sb)
++{
++	return au_test_tmpfs(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++		|| au_test_ramfs(sb)
++#endif
++		|| au_test_ubifs(sb)
++		|| au_test_btrfs(sb)
++		|| au_test_hfsplus(sb);
++}
++
++/*
++ * filesystems which sets S_NOATIME and S_NOCMTIME.
++ */
++static inline int au_test_fs_notime(struct super_block *sb)
++{
++	return au_test_nfs(sb)
++		|| au_test_fuse(sb)
++		|| au_test_ubifs(sb)
++		/* || au_test_cifs(sb) */	/* untested */
++		;
++}
++
++/*
++ * filesystems which requires replacing i_mapping.
++ */
++static inline int au_test_fs_bad_mapping(struct super_block *sb)
++{
++	return au_test_fuse(sb)
++		|| au_test_ubifs(sb);
++}
++
++/* temporary support for i#1 in cramfs */
++static inline int au_test_fs_unique_ino(struct inode *inode)
++{
++	if (au_test_cramfs(inode->i_sb))
++		return inode->i_ino != 1;
++	return 1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * the filesystem where the xino files placed must support i/o after unlink and
++ * maintain i_size and i_blocks.
++ */
++static inline int au_test_fs_bad_xino(struct super_block *sb)
++{
++	return au_test_fs_remote(sb)
++		|| au_test_fs_bad_iattr_size(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++		|| !(au_test_ramfs(sb) || au_test_fs_null_nd(sb))
++#else
++		|| !au_test_fs_null_nd(sb) /* to keep xino code simple */
++#endif
++		/* don't want unnecessary work for xino */
++		|| au_test_aufs(sb)
++		|| au_test_ecryptfs(sb)
++		|| au_test_nilfs(sb);
++}
++
++static inline int au_test_fs_trunc_xino(struct super_block *sb)
++{
++	return au_test_tmpfs(sb)
++		|| au_test_ramfs(sb);
++}
++
++/*
++ * test if the @sb is real-readonly.
++ */
++static inline int au_test_fs_rr(struct super_block *sb)
++{
++	return au_test_squashfs(sb)
++		|| au_test_iso9660(sb)
++		|| au_test_cramfs(sb)
++		|| au_test_romfs(sb);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_FSTYPE_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/hfsnotify.c linux-2.6.36/fs/aufs/hfsnotify.c
+--- linux-2.6.36.orig/fs/aufs/hfsnotify.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/hfsnotify.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,247 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * fsnotify for the lower directories
++ */
++
++#include "aufs.h"
++
++/* FS_IN_IGNORED is unnecessary */
++static const __u32 AuHfsnMask = (FS_MOVED_TO | FS_MOVED_FROM | FS_DELETE
++				 | FS_CREATE | FS_EVENT_ON_CHILD);
++static DECLARE_WAIT_QUEUE_HEAD(au_hfsn_wq);
++
++static void au_hfsn_free_mark(struct fsnotify_mark *mark)
++{
++	struct au_hnotify *hn = container_of(mark, struct au_hnotify,
++					     hn_mark);
++	AuDbg("here\n");
++	hn->hn_mark_dead = 1;
++	smp_mb();
++	wake_up_all(&au_hfsn_wq);
++}
++
++static int au_hfsn_alloc(struct au_hinode *hinode)
++{
++	struct au_hnotify *hn;
++	struct super_block *sb;
++	struct au_branch *br;
++	struct fsnotify_mark *mark;
++	aufs_bindex_t bindex;
++
++	hn = hinode->hi_notify;
++	sb = hn->hn_aufs_inode->i_sb;
++	bindex = au_br_index(sb, hinode->hi_id);
++	br = au_sbr(sb, bindex);
++	hn->hn_mark_dead = 0;
++	mark = &hn->hn_mark;
++	fsnotify_init_mark(mark, au_hfsn_free_mark);
++	mark->mask = AuHfsnMask;
++	/*
++	 * by udba rename or rmdir, aufs assign a new inode to the known
++	 * h_inode, so specify 1 to allow dups.
++	 */
++	return fsnotify_add_mark(mark, br->br_hfsn_group, hinode->hi_inode,
++				 /*mnt*/NULL, /*allow_dups*/1);
++}
++
++static void au_hfsn_free(struct au_hinode *hinode)
++{
++	struct au_hnotify *hn;
++	struct fsnotify_mark *mark;
++
++	hn = hinode->hi_notify;
++	mark = &hn->hn_mark;
++	fsnotify_destroy_mark(mark);
++	fsnotify_put_mark(mark);
++
++	/* TODO: bad approach */
++	wait_event(au_hfsn_wq, hn->hn_mark_dead);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void au_hfsn_ctl(struct au_hinode *hinode, int do_set)
++{
++	struct fsnotify_mark *mark;
++
++	mark = &hinode->hi_notify->hn_mark;
++	spin_lock(&mark->lock);
++	if (do_set) {
++		AuDebugOn(mark->mask & AuHfsnMask);
++		mark->mask |= AuHfsnMask;
++	} else {
++		AuDebugOn(!(mark->mask & AuHfsnMask));
++		mark->mask &= ~AuHfsnMask;
++	}
++	spin_unlock(&mark->lock);
++	/* fsnotify_recalc_inode_mask(hinode->hi_inode); */
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* #define AuDbgHnotify */
++#ifdef AuDbgHnotify
++static char *au_hfsn_name(u32 mask)
++{
++#ifdef CONFIG_AUFS_DEBUG
++#define test_ret(flag)	if (mask & flag) \
++				return #flag;
++	test_ret(FS_ACCESS);
++	test_ret(FS_MODIFY);
++	test_ret(FS_ATTRIB);
++	test_ret(FS_CLOSE_WRITE);
++	test_ret(FS_CLOSE_NOWRITE);
++	test_ret(FS_OPEN);
++	test_ret(FS_MOVED_FROM);
++	test_ret(FS_MOVED_TO);
++	test_ret(FS_CREATE);
++	test_ret(FS_DELETE);
++	test_ret(FS_DELETE_SELF);
++	test_ret(FS_MOVE_SELF);
++	test_ret(FS_UNMOUNT);
++	test_ret(FS_Q_OVERFLOW);
++	test_ret(FS_IN_IGNORED);
++	test_ret(FS_IN_ISDIR);
++	test_ret(FS_IN_ONESHOT);
++	test_ret(FS_EVENT_ON_CHILD);
++	return "";
++#undef test_ret
++#else
++	return "??";
++#endif
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static int au_hfsn_handle_event(struct fsnotify_group *group,
++				struct fsnotify_mark *inode_mark,
++				struct fsnotify_mark *vfsmount_mark,
++				struct fsnotify_event *event)
++{
++	int err;
++	struct au_hnotify *hnotify;
++	struct inode *h_dir, *h_inode;
++	__u32 mask;
++	struct qstr h_child_qstr = {
++		.name	= event->file_name,
++		.len	= event->name_len
++	};
++
++	AuDebugOn(event->data_type != FSNOTIFY_EVENT_INODE);
++
++	err = 0;
++	/* if FS_UNMOUNT happens, there must be another bug */
++	mask = event->mask;
++	AuDebugOn(mask & FS_UNMOUNT);
++	if (mask & (FS_IN_IGNORED | FS_UNMOUNT))
++		goto out;
++
++	h_dir = event->to_tell;
++	h_inode = event->inode;
++#ifdef AuDbgHnotify
++	au_debug(1);
++	if (1 || h_child_qstr.len != sizeof(AUFS_XINO_FNAME) - 1
++	    || strncmp(h_child_qstr.name, AUFS_XINO_FNAME, h_child_qstr.len)) {
++		AuDbg("i%lu, mask 0x%x %s, hcname %.*s, hi%lu\n",
++		      h_dir->i_ino, mask, au_hfsn_name(mask),
++		      AuLNPair(&h_child_qstr), h_inode ? h_inode->i_ino : 0);
++		/* WARN_ON(1); */
++	}
++	au_debug(0);
++#endif
++
++	AuDebugOn(!inode_mark);
++	hnotify = container_of(inode_mark, struct au_hnotify, hn_mark);
++	err = au_hnotify(h_dir, hnotify, mask, &h_child_qstr, h_inode);
++
++out:
++	return err;
++}
++
++/* isn't it waste to ask every registered 'group'? */
++/* copied from linux/fs/notify/inotify/inotify_fsnotiry.c */
++/* it should be exported to modules */
++static bool au_hfsn_should_send_event(struct fsnotify_group *group,
++				      struct inode *h_inode,
++				      struct fsnotify_mark *inode_mark,
++				      struct fsnotify_mark *vfsmount_mark,
++				      __u32 mask, void *data, int data_type)
++{
++	mask = (mask & ~FS_EVENT_ON_CHILD);
++	return inode_mark->mask & mask;
++}
++
++static struct fsnotify_ops au_hfsn_ops = {
++	.should_send_event	= au_hfsn_should_send_event,
++	.handle_event		= au_hfsn_handle_event
++};
++
++/* ---------------------------------------------------------------------- */
++
++static void au_hfsn_fin_br(struct au_branch *br)
++{
++	if (br->br_hfsn_group)
++		fsnotify_put_group(br->br_hfsn_group);
++}
++
++static int au_hfsn_init_br(struct au_branch *br, int perm)
++{
++	br->br_hfsn_group = NULL;
++	br->br_hfsn_ops = au_hfsn_ops;
++	return 0;
++}
++
++static int au_hfsn_reset_br(unsigned int udba, struct au_branch *br, int perm)
++{
++	int err;
++
++	err = 0;
++	if (udba != AuOpt_UDBA_HNOTIFY
++	    || !au_br_hnotifyable(perm)) {
++		au_hfsn_fin_br(br);
++		br->br_hfsn_group = NULL;
++		goto out;
++	}
++
++	if (br->br_hfsn_group)
++		goto out;
++
++	br->br_hfsn_group = fsnotify_alloc_group(&br->br_hfsn_ops);
++	if (IS_ERR(br->br_hfsn_group)) {
++		err = PTR_ERR(br->br_hfsn_group);
++		pr_err("fsnotify_alloc_group() failed, %d\n", err);
++		br->br_hfsn_group = NULL;
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++const struct au_hnotify_op au_hnotify_op = {
++	.ctl		= au_hfsn_ctl,
++	.alloc		= au_hfsn_alloc,
++	.free		= au_hfsn_free,
++
++	.reset_br	= au_hfsn_reset_br,
++	.fin_br		= au_hfsn_fin_br,
++	.init_br	= au_hfsn_init_br
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/hfsplus.c linux-2.6.36/fs/aufs/hfsplus.c
+--- linux-2.6.36.orig/fs/aufs/hfsplus.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/hfsplus.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,58 @@
++/*
++ * Copyright (C) 2010-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * special support for filesystems which aqucires an inode mutex
++ * at final closing a file, eg, hfsplus.
++ *
++ * This trick is very simple and stupid, just to open the file before really
++ * neceeary open to tell hfsplus that this is not the final closing.
++ * The caller should call au_h_open_pre() after acquiring the inode mutex,
++ * and au_h_open_post() after releasing it.
++ */
++
++#include <linux/file.h>
++#include "aufs.h"
++
++struct file *au_h_open_pre(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	struct file *h_file;
++	struct dentry *h_dentry;
++
++	h_dentry = au_h_dptr(dentry, bindex);
++	AuDebugOn(!h_dentry);
++	AuDebugOn(!h_dentry->d_inode);
++	IMustLock(h_dentry->d_inode);
++
++	h_file = NULL;
++	if (au_test_hfsplus(h_dentry->d_sb)
++	    && S_ISREG(h_dentry->d_inode->i_mode))
++		h_file = au_h_open(dentry, bindex,
++				   O_RDONLY | O_NOATIME | O_LARGEFILE,
++				   /*file*/NULL);
++	return h_file;
++}
++
++void au_h_open_post(struct dentry *dentry, aufs_bindex_t bindex,
++		    struct file *h_file)
++{
++	if (h_file) {
++		fput(h_file);
++		au_sbr_put(dentry->d_sb, bindex);
++	}
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/hnotify.c linux-2.6.36/fs/aufs/hnotify.c
+--- linux-2.6.36.orig/fs/aufs/hnotify.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/hnotify.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,694 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * abstraction to notify the direct changes on lower directories
++ */
++
++#include "aufs.h"
++
++int au_hn_alloc(struct au_hinode *hinode, struct inode *inode)
++{
++	int err;
++	struct au_hnotify *hn;
++
++	err = -ENOMEM;
++	hn = au_cache_alloc_hnotify();
++	if (hn) {
++		hn->hn_aufs_inode = inode;
++		hinode->hi_notify = hn;
++		err = au_hnotify_op.alloc(hinode);
++		AuTraceErr(err);
++		if (unlikely(err)) {
++			hinode->hi_notify = NULL;
++			au_cache_free_hnotify(hn);
++			/*
++			 * The upper dir was removed by udba, but the same named
++			 * dir left. In this case, aufs assignes a new inode
++			 * number and set the monitor again.
++			 * For the lower dir, the old monitnor is still left.
++			 */
++			if (err == -EEXIST)
++				err = 0;
++		}
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++void au_hn_free(struct au_hinode *hinode)
++{
++	struct au_hnotify *hn;
++
++	hn = hinode->hi_notify;
++	if (hn) {
++		au_hnotify_op.free(hinode);
++		au_cache_free_hnotify(hn);
++		hinode->hi_notify = NULL;
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_hn_ctl(struct au_hinode *hinode, int do_set)
++{
++	if (hinode->hi_notify)
++		au_hnotify_op.ctl(hinode, do_set);
++}
++
++void au_hn_reset(struct inode *inode, unsigned int flags)
++{
++	aufs_bindex_t bindex, bend;
++	struct inode *hi;
++	struct dentry *iwhdentry;
++
++	bend = au_ibend(inode);
++	for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
++		hi = au_h_iptr(inode, bindex);
++		if (!hi)
++			continue;
++
++		/* mutex_lock_nested(&hi->i_mutex, AuLsc_I_CHILD); */
++		iwhdentry = au_hi_wh(inode, bindex);
++		if (iwhdentry)
++			dget(iwhdentry);
++		au_igrab(hi);
++		au_set_h_iptr(inode, bindex, NULL, 0);
++		au_set_h_iptr(inode, bindex, au_igrab(hi),
++			      flags & ~AuHi_XINO);
++		iput(hi);
++		dput(iwhdentry);
++		/* mutex_unlock(&hi->i_mutex); */
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int hn_xino(struct inode *inode, struct inode *h_inode)
++{
++	int err;
++	aufs_bindex_t bindex, bend, bfound, bstart;
++	struct inode *h_i;
++
++	err = 0;
++	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++		pr_warning("branch root dir was changed\n");
++		goto out;
++	}
++
++	bfound = -1;
++	bend = au_ibend(inode);
++	bstart = au_ibstart(inode);
++#if 0 /* reserved for future use */
++	if (bindex == bend) {
++		/* keep this ino in rename case */
++		goto out;
++	}
++#endif
++	for (bindex = bstart; bindex <= bend; bindex++)
++		if (au_h_iptr(inode, bindex) == h_inode) {
++			bfound = bindex;
++			break;
++		}
++	if (bfound < 0)
++		goto out;
++
++	for (bindex = bstart; bindex <= bend; bindex++) {
++		h_i = au_h_iptr(inode, bindex);
++		if (!h_i)
++			continue;
++
++		err = au_xino_write(inode->i_sb, bindex, h_i->i_ino, /*ino*/0);
++		/* ignore this error */
++		/* bad action? */
++	}
++
++	/* children inode number will be broken */
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static int hn_gen_tree(struct dentry *dentry)
++{
++	int err, i, j, ndentry;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry **dentries;
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	err = au_dcsub_pages(&dpages, dentry, NULL, NULL);
++	if (unlikely(err))
++		goto out_dpages;
++
++	for (i = 0; i < dpages.ndpage; i++) {
++		dpage = dpages.dpages + i;
++		dentries = dpage->dentries;
++		ndentry = dpage->ndentry;
++		for (j = 0; j < ndentry; j++) {
++			struct dentry *d;
++
++			d = dentries[j];
++			if (IS_ROOT(d))
++				continue;
++
++			au_digen_dec(d);
++			if (d->d_inode)
++				/* todo: reset children xino?
++				   cached children only? */
++				au_iigen_dec(d->d_inode);
++		}
++	}
++
++out_dpages:
++	au_dpages_free(&dpages);
++
++	/* discard children */
++	dentry_unhash(dentry);
++	dput(dentry);
++out:
++	return err;
++}
++
++/*
++ * return 0 if processed.
++ */
++static int hn_gen_by_inode(char *name, unsigned int nlen, struct inode *inode,
++			   const unsigned int isdir)
++{
++	int err;
++	struct dentry *d;
++	struct qstr *dname;
++
++	err = 1;
++	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++		pr_warning("branch root dir was changed\n");
++		err = 0;
++		goto out;
++	}
++
++	if (!isdir) {
++		AuDebugOn(!name);
++		au_iigen_dec(inode);
++		spin_lock(&dcache_lock);
++		list_for_each_entry(d, &inode->i_dentry, d_alias) {
++			dname = &d->d_name;
++			if (dname->len != nlen
++			    && memcmp(dname->name, name, nlen))
++				continue;
++			err = 0;
++			au_digen_dec(d);
++			break;
++		}
++		spin_unlock(&dcache_lock);
++	} else {
++		au_fset_si(au_sbi(inode->i_sb), FAILED_REFRESH_DIR);
++		d = d_find_alias(inode);
++		if (!d) {
++			au_iigen_dec(inode);
++			goto out;
++		}
++
++		dname = &d->d_name;
++		if (dname->len == nlen && !memcmp(dname->name, name, nlen))
++			err = hn_gen_tree(d);
++		dput(d);
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static int hn_gen_by_name(struct dentry *dentry, const unsigned int isdir)
++{
++	int err;
++	struct inode *inode;
++
++	inode = dentry->d_inode;
++	if (IS_ROOT(dentry)
++	    /* || (inode && inode->i_ino == AUFS_ROOT_INO) */
++		) {
++		pr_warning("branch root dir was changed\n");
++		return 0;
++	}
++
++	err = 0;
++	if (!isdir) {
++		au_digen_dec(dentry);
++		if (inode)
++			au_iigen_dec(inode);
++	} else {
++		au_fset_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIR);
++		if (inode)
++			err = hn_gen_tree(dentry);
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* hnotify job flags */
++#define AuHnJob_XINO0		1
++#define AuHnJob_GEN		(1 << 1)
++#define AuHnJob_DIRENT		(1 << 2)
++#define AuHnJob_ISDIR		(1 << 3)
++#define AuHnJob_TRYXINO0	(1 << 4)
++#define AuHnJob_MNTPNT		(1 << 5)
++#define au_ftest_hnjob(flags, name)	((flags) & AuHnJob_##name)
++#define au_fset_hnjob(flags, name) \
++	do { (flags) |= AuHnJob_##name; } while (0)
++#define au_fclr_hnjob(flags, name) \
++	do { (flags) &= ~AuHnJob_##name; } while (0)
++
++enum {
++	AuHn_CHILD,
++	AuHn_PARENT,
++	AuHnLast
++};
++
++struct au_hnotify_args {
++	struct inode *h_dir, *dir, *h_child_inode;
++	u32 mask;
++	unsigned int flags[AuHnLast];
++	unsigned int h_child_nlen;
++	char h_child_name[];
++};
++
++struct hn_job_args {
++	unsigned int flags;
++	struct inode *inode, *h_inode, *dir, *h_dir;
++	struct dentry *dentry;
++	char *h_name;
++	int h_nlen;
++};
++
++static int hn_job(struct hn_job_args *a)
++{
++	const unsigned int isdir = au_ftest_hnjob(a->flags, ISDIR);
++
++	/* reset xino */
++	if (au_ftest_hnjob(a->flags, XINO0) && a->inode)
++		hn_xino(a->inode, a->h_inode); /* ignore this error */
++
++	if (au_ftest_hnjob(a->flags, TRYXINO0)
++	    && a->inode
++	    && a->h_inode) {
++		mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++		if (!a->h_inode->i_nlink)
++			hn_xino(a->inode, a->h_inode); /* ignore this error */
++		mutex_unlock(&a->h_inode->i_mutex);
++	}
++
++	/* make the generation obsolete */
++	if (au_ftest_hnjob(a->flags, GEN)) {
++		int err = -1;
++		if (a->inode)
++			err = hn_gen_by_inode(a->h_name, a->h_nlen, a->inode,
++					      isdir);
++		if (err && a->dentry)
++			hn_gen_by_name(a->dentry, isdir);
++		/* ignore this error */
++	}
++
++	/* make dir entries obsolete */
++	if (au_ftest_hnjob(a->flags, DIRENT) && a->inode) {
++		struct au_vdir *vdir;
++
++		vdir = au_ivdir(a->inode);
++		if (vdir)
++			vdir->vd_jiffy = 0;
++		/* IMustLock(a->inode); */
++		/* a->inode->i_version++; */
++	}
++
++	/* can do nothing but warn */
++	if (au_ftest_hnjob(a->flags, MNTPNT)
++	    && a->dentry
++	    && d_mountpoint(a->dentry))
++		pr_warning("mount-point %.*s is removed or renamed\n",
++			   AuDLNPair(a->dentry));
++
++	return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *lookup_wlock_by_name(char *name, unsigned int nlen,
++					   struct inode *dir)
++{
++	struct dentry *dentry, *d, *parent;
++	struct qstr *dname;
++
++	parent = d_find_alias(dir);
++	if (!parent)
++		return NULL;
++
++	dentry = NULL;
++	spin_lock(&dcache_lock);
++	list_for_each_entry(d, &parent->d_subdirs, d_u.d_child) {
++		/* AuDbg("%.*s\n", AuDLNPair(d)); */
++		dname = &d->d_name;
++		if (dname->len != nlen || memcmp(dname->name, name, nlen))
++			continue;
++		if (au_di(d))
++			au_digen_dec(d);
++		else
++			continue;
++		if (!atomic_read(&d->d_count))
++			continue;
++
++		dentry = dget(d);
++		break;
++	}
++	spin_unlock(&dcache_lock);
++	dput(parent);
++
++	if (dentry)
++		di_write_lock_child(dentry);
++
++	return dentry;
++}
++
++static struct inode *lookup_wlock_by_ino(struct super_block *sb,
++					 aufs_bindex_t bindex, ino_t h_ino)
++{
++	struct inode *inode;
++	ino_t ino;
++	int err;
++
++	inode = NULL;
++	err = au_xino_read(sb, bindex, h_ino, &ino);
++	if (!err && ino)
++		inode = ilookup(sb, ino);
++	if (!inode)
++		goto out;
++
++	if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++		pr_warning("wrong root branch\n");
++		iput(inode);
++		inode = NULL;
++		goto out;
++	}
++
++	ii_write_lock_child(inode);
++
++out:
++	return inode;
++}
++
++static void au_hn_bh(void *_args)
++{
++	struct au_hnotify_args *a = _args;
++	struct super_block *sb;
++	aufs_bindex_t bindex, bend, bfound;
++	unsigned char xino, try_iput;
++	int err;
++	struct inode *inode;
++	ino_t h_ino;
++	struct hn_job_args args;
++	struct dentry *dentry;
++	struct au_sbinfo *sbinfo;
++
++	AuDebugOn(!_args);
++	AuDebugOn(!a->h_dir);
++	AuDebugOn(!a->dir);
++	AuDebugOn(!a->mask);
++	AuDbg("mask 0x%x, i%lu, hi%lu, hci%lu\n",
++	      a->mask, a->dir->i_ino, a->h_dir->i_ino,
++	      a->h_child_inode ? a->h_child_inode->i_ino : 0);
++
++	inode = NULL;
++	dentry = NULL;
++	/*
++	 * do not lock a->dir->i_mutex here
++	 * because of d_revalidate() may cause a deadlock.
++	 */
++	sb = a->dir->i_sb;
++	AuDebugOn(!sb);
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!sbinfo);
++	si_write_lock(sb, AuLock_NOPLMW);
++
++	ii_read_lock_parent(a->dir);
++	bfound = -1;
++	bend = au_ibend(a->dir);
++	for (bindex = au_ibstart(a->dir); bindex <= bend; bindex++)
++		if (au_h_iptr(a->dir, bindex) == a->h_dir) {
++			bfound = bindex;
++			break;
++		}
++	ii_read_unlock(a->dir);
++	if (unlikely(bfound < 0))
++		goto out;
++
++	xino = !!au_opt_test(au_mntflags(sb), XINO);
++	h_ino = 0;
++	if (a->h_child_inode)
++		h_ino = a->h_child_inode->i_ino;
++
++	if (a->h_child_nlen
++	    && (au_ftest_hnjob(a->flags[AuHn_CHILD], GEN)
++		|| au_ftest_hnjob(a->flags[AuHn_CHILD], MNTPNT)))
++		dentry = lookup_wlock_by_name(a->h_child_name, a->h_child_nlen,
++					      a->dir);
++	try_iput = 0;
++	if (dentry)
++		inode = dentry->d_inode;
++	if (xino && !inode && h_ino
++	    && (au_ftest_hnjob(a->flags[AuHn_CHILD], XINO0)
++		|| au_ftest_hnjob(a->flags[AuHn_CHILD], TRYXINO0)
++		|| au_ftest_hnjob(a->flags[AuHn_CHILD], GEN))) {
++		inode = lookup_wlock_by_ino(sb, bfound, h_ino);
++		try_iput = 1;
++	    }
++
++	args.flags = a->flags[AuHn_CHILD];
++	args.dentry = dentry;
++	args.inode = inode;
++	args.h_inode = a->h_child_inode;
++	args.dir = a->dir;
++	args.h_dir = a->h_dir;
++	args.h_name = a->h_child_name;
++	args.h_nlen = a->h_child_nlen;
++	err = hn_job(&args);
++	if (dentry) {
++		if (au_di(dentry))
++			di_write_unlock(dentry);
++		dput(dentry);
++	}
++	if (inode && try_iput) {
++		ii_write_unlock(inode);
++		iput(inode);
++	}
++
++	ii_write_lock_parent(a->dir);
++	args.flags = a->flags[AuHn_PARENT];
++	args.dentry = NULL;
++	args.inode = a->dir;
++	args.h_inode = a->h_dir;
++	args.dir = NULL;
++	args.h_dir = NULL;
++	args.h_name = NULL;
++	args.h_nlen = 0;
++	err = hn_job(&args);
++	ii_write_unlock(a->dir);
++
++out:
++	iput(a->h_child_inode);
++	iput(a->h_dir);
++	iput(a->dir);
++	si_write_unlock(sb);
++	au_nwt_done(&sbinfo->si_nowait);
++	kfree(a);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_hnotify(struct inode *h_dir, struct au_hnotify *hnotify, u32 mask,
++	       struct qstr *h_child_qstr, struct inode *h_child_inode)
++{
++	int err, len;
++	unsigned int flags[AuHnLast];
++	unsigned char isdir, isroot, wh;
++	struct inode *dir;
++	struct au_hnotify_args *args;
++	char *p, *h_child_name;
++
++	err = 0;
++	AuDebugOn(!hnotify || !hnotify->hn_aufs_inode);
++	dir = igrab(hnotify->hn_aufs_inode);
++	if (!dir)
++		goto out;
++
++	isroot = (dir->i_ino == AUFS_ROOT_INO);
++	wh = 0;
++	h_child_name = (void *)h_child_qstr->name;
++	len = h_child_qstr->len;
++	if (h_child_name) {
++		if (len > AUFS_WH_PFX_LEN
++		    && !memcmp(h_child_name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++			h_child_name += AUFS_WH_PFX_LEN;
++			len -= AUFS_WH_PFX_LEN;
++			wh = 1;
++		}
++	}
++
++	isdir = 0;
++	if (h_child_inode)
++		isdir = !!S_ISDIR(h_child_inode->i_mode);
++	flags[AuHn_PARENT] = AuHnJob_ISDIR;
++	flags[AuHn_CHILD] = 0;
++	if (isdir)
++		flags[AuHn_CHILD] = AuHnJob_ISDIR;
++	au_fset_hnjob(flags[AuHn_PARENT], DIRENT);
++	au_fset_hnjob(flags[AuHn_CHILD], GEN);
++	switch (mask & FS_EVENTS_POSS_ON_CHILD) {
++	case FS_MOVED_FROM:
++	case FS_MOVED_TO:
++		au_fset_hnjob(flags[AuHn_CHILD], XINO0);
++		au_fset_hnjob(flags[AuHn_CHILD], MNTPNT);
++		/*FALLTHROUGH*/
++	case FS_CREATE:
++		AuDebugOn(!h_child_name || !h_child_inode);
++		break;
++
++	case FS_DELETE:
++		/*
++		 * aufs never be able to get this child inode.
++		 * revalidation should be in d_revalidate()
++		 * by checking i_nlink, i_generation or d_unhashed().
++		 */
++		AuDebugOn(!h_child_name);
++		au_fset_hnjob(flags[AuHn_CHILD], TRYXINO0);
++		au_fset_hnjob(flags[AuHn_CHILD], MNTPNT);
++		break;
++
++	default:
++		AuDebugOn(1);
++	}
++
++	if (wh)
++		h_child_inode = NULL;
++
++	err = -ENOMEM;
++	/* iput() and kfree() will be called in au_hnotify() */
++	args = kmalloc(sizeof(*args) + len + 1, GFP_NOFS);
++	if (unlikely(!args)) {
++		AuErr1("no memory\n");
++		iput(dir);
++		goto out;
++	}
++	args->flags[AuHn_PARENT] = flags[AuHn_PARENT];
++	args->flags[AuHn_CHILD] = flags[AuHn_CHILD];
++	args->mask = mask;
++	args->dir = dir;
++	args->h_dir = igrab(h_dir);
++	if (h_child_inode)
++		h_child_inode = igrab(h_child_inode); /* can be NULL */
++	args->h_child_inode = h_child_inode;
++	args->h_child_nlen = len;
++	if (len) {
++		p = (void *)args;
++		p += sizeof(*args);
++		memcpy(p, h_child_name, len);
++		p[len] = 0;
++	}
++
++	err = au_wkq_nowait(au_hn_bh, args, dir->i_sb);
++	if (unlikely(err)) {
++		pr_err("wkq %d\n", err);
++		iput(args->h_child_inode);
++		iput(args->h_dir);
++		iput(args->dir);
++		kfree(args);
++	}
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_hnotify_reset_br(unsigned int udba, struct au_branch *br, int perm)
++{
++	int err;
++
++	AuDebugOn(!(udba & AuOptMask_UDBA));
++
++	err = 0;
++	if (au_hnotify_op.reset_br)
++		err = au_hnotify_op.reset_br(udba, br, perm);
++
++	return err;
++}
++
++int au_hnotify_init_br(struct au_branch *br, int perm)
++{
++	int err;
++
++	err = 0;
++	if (au_hnotify_op.init_br)
++		err = au_hnotify_op.init_br(br, perm);
++
++	return err;
++}
++
++void au_hnotify_fin_br(struct au_branch *br)
++{
++	if (au_hnotify_op.fin_br)
++		au_hnotify_op.fin_br(br);
++}
++
++static void au_hn_destroy_cache(void)
++{
++	kmem_cache_destroy(au_cachep[AuCache_HNOTIFY]);
++	au_cachep[AuCache_HNOTIFY] = NULL;
++}
++
++int __init au_hnotify_init(void)
++{
++	int err;
++
++	err = -ENOMEM;
++	au_cachep[AuCache_HNOTIFY] = AuCache(au_hnotify);
++	if (au_cachep[AuCache_HNOTIFY]) {
++		err = 0;
++		if (au_hnotify_op.init)
++			err = au_hnotify_op.init();
++		if (unlikely(err))
++			au_hn_destroy_cache();
++	}
++	AuTraceErr(err);
++	return err;
++}
++
++void au_hnotify_fin(void)
++{
++	if (au_hnotify_op.fin)
++		au_hnotify_op.fin();
++	/* cf. au_cache_fin() */
++	if (au_cachep[AuCache_HNOTIFY])
++		au_hn_destroy_cache();
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/i_op.c linux-2.6.36/fs/aufs/i_op.c
+--- linux-2.6.36.orig/fs/aufs/i_op.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/i_op.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,971 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode operations (except add/del/rename)
++ */
++
++#include <linux/device_cgroup.h>
++#include <linux/fs_stack.h>
++#include <linux/mm.h>
++#include <linux/namei.h>
++#include <linux/security.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++static int h_permission(struct inode *h_inode, int mask,
++			struct vfsmount *h_mnt, int brperm)
++{
++	int err;
++	const unsigned char write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
++
++	err = -EACCES;
++	if ((write_mask && IS_IMMUTABLE(h_inode))
++	    || ((mask & MAY_EXEC)
++		&& S_ISREG(h_inode->i_mode)
++		&& ((h_mnt->mnt_flags & MNT_NOEXEC)
++		    || !(h_inode->i_mode & S_IXUGO))))
++		goto out;
++
++	/*
++	 * - skip the lower fs test in the case of write to ro branch.
++	 * - nfs dir permission write check is optimized, but a policy for
++	 *   link/rename requires a real check.
++	 */
++	if ((write_mask && !au_br_writable(brperm))
++	    || (au_test_nfs(h_inode->i_sb) && S_ISDIR(h_inode->i_mode)
++		&& write_mask && !(mask & MAY_READ))
++	    || !h_inode->i_op->permission) {
++		/* AuLabel(generic_permission); */
++		err = generic_permission(h_inode, mask,
++					 h_inode->i_op->check_acl);
++	} else {
++		/* AuLabel(h_inode->permission); */
++		err = h_inode->i_op->permission(h_inode, mask);
++		AuTraceErr(err);
++	}
++
++	if (!err)
++		err = devcgroup_inode_permission(h_inode, mask);
++	if (!err)
++		err = security_inode_permission(h_inode, mask);
++
++#if 0
++	if (!err) {
++		/* todo: do we need to call ima_path_check()? */
++		struct path h_path = {
++			.dentry	=
++			.mnt	= h_mnt
++		};
++		err = ima_path_check(&h_path,
++				     mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
++				     IMA_COUNT_LEAVE);
++	}
++#endif
++
++out:
++	return err;
++}
++
++static int aufs_permission(struct inode *inode, int mask)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	const unsigned char isdir = !!S_ISDIR(inode->i_mode),
++		write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
++	struct inode *h_inode;
++	struct super_block *sb;
++	struct au_branch *br;
++
++	sb = inode->i_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	ii_read_lock_child(inode);
++#if 0
++	err = au_iigen_test(inode, au_sigen(sb));
++	if (unlikely(err))
++		goto out;
++#endif
++
++	if (!isdir || write_mask) {
++		err = au_busy_or_stale();
++		h_inode = au_h_iptr(inode, au_ibstart(inode));
++		if (unlikely(!h_inode
++			     || (h_inode->i_mode & S_IFMT)
++			     != (inode->i_mode & S_IFMT)))
++			goto out;
++
++		err = 0;
++		bindex = au_ibstart(inode);
++		br = au_sbr(sb, bindex);
++		err = h_permission(h_inode, mask, br->br_mnt, br->br_perm);
++		if (write_mask
++		    && !err
++		    && !special_file(h_inode->i_mode)) {
++			/* test whether the upper writable branch exists */
++			err = -EROFS;
++			for (; bindex >= 0; bindex--)
++				if (!au_br_rdonly(au_sbr(sb, bindex))) {
++					err = 0;
++					break;
++				}
++		}
++		goto out;
++	}
++
++	/* non-write to dir */
++	err = 0;
++	bend = au_ibend(inode);
++	for (bindex = au_ibstart(inode); !err && bindex <= bend; bindex++) {
++		h_inode = au_h_iptr(inode, bindex);
++		if (h_inode) {
++			err = au_busy_or_stale();
++			if (unlikely(!S_ISDIR(h_inode->i_mode)))
++				break;
++
++			br = au_sbr(sb, bindex);
++			err = h_permission(h_inode, mask, br->br_mnt,
++					   br->br_perm);
++		}
++	}
++
++out:
++	ii_read_unlock(inode);
++	si_read_unlock(sb);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry,
++				  struct nameidata *nd)
++{
++	struct dentry *ret, *parent;
++	struct inode *inode;
++	struct super_block *sb;
++	int err, npositive;
++
++	IMustLock(dir);
++
++	sb = dir->i_sb;
++	err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++	ret = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	ret = ERR_PTR(-ENAMETOOLONG);
++	if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
++		goto out_si;
++	err = au_di_init(dentry);
++	ret = ERR_PTR(err);
++	if (unlikely(err))
++		goto out_si;
++
++	npositive = 0; /* suppress a warning */
++	parent = dentry->d_parent; /* dir inode is locked */
++	di_read_lock_parent(parent, AuLock_IR);
++	err = au_alive_dir(parent);
++	if (!err)
++		err = au_digen_test(parent, au_sigen(sb));
++	if (!err) {
++		npositive = au_lkup_dentry(dentry, au_dbstart(parent),
++					   /*type*/0, nd);
++		err = npositive;
++	}
++	di_read_unlock(parent, AuLock_IR);
++	ret = ERR_PTR(err);
++	if (unlikely(err < 0))
++		goto out_unlock;
++
++	inode = NULL;
++	if (npositive) {
++		inode = au_new_inode(dentry, /*must_new*/0);
++		ret = (void *)inode;
++	}
++	if (IS_ERR(inode))
++		goto out_unlock;
++
++	ret = d_splice_alias(inode, dentry);
++	if (unlikely(IS_ERR(ret) && inode)) {
++		ii_write_unlock(inode);
++		iput(inode);
++	}
++
++out_unlock:
++	di_write_unlock(dentry);
++out_si:
++	si_read_unlock(sb);
++out:
++	return ret;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_wr_dir_cpup(struct dentry *dentry, struct dentry *parent,
++			  const unsigned char add_entry, aufs_bindex_t bcpup,
++			  aufs_bindex_t bstart)
++{
++	int err;
++	struct dentry *h_parent;
++	struct inode *h_dir;
++
++	if (add_entry)
++		IMustLock(parent->d_inode);
++	else
++		di_write_lock_parent(parent);
++
++	err = 0;
++	if (!au_h_dptr(parent, bcpup)) {
++		if (bstart < bcpup)
++			err = au_cpdown_dirs(dentry, bcpup);
++		else
++			err = au_cpup_dirs(dentry, bcpup);
++	}
++	if (!err && add_entry) {
++		h_parent = au_h_dptr(parent, bcpup);
++		h_dir = h_parent->d_inode;
++		mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++		err = au_lkup_neg(dentry, bcpup);
++		/* todo: no unlock here */
++		mutex_unlock(&h_dir->i_mutex);
++
++		AuDbg("bcpup %d\n", bcpup);
++		if (!err) {
++			if (!dentry->d_inode)
++				au_set_h_dptr(dentry, bstart, NULL);
++			au_update_dbrange(dentry, /*do_put_zero*/0);
++		}
++	}
++
++	if (!add_entry)
++		di_write_unlock(parent);
++	if (!err)
++		err = bcpup; /* success */
++
++	AuTraceErr(err);
++	return err;
++}
++
++/*
++ * decide the branch and the parent dir where we will create a new entry.
++ * returns new bindex or an error.
++ * copyup the parent dir if needed.
++ */
++int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
++	      struct au_wr_dir_args *args)
++{
++	int err;
++	aufs_bindex_t bcpup, bstart, src_bstart;
++	const unsigned char add_entry = !!au_ftest_wrdir(args->flags,
++							 ADD_ENTRY);
++	struct super_block *sb;
++	struct dentry *parent;
++	struct au_sbinfo *sbinfo;
++
++	sb = dentry->d_sb;
++	sbinfo = au_sbi(sb);
++	parent = dget_parent(dentry);
++	bstart = au_dbstart(dentry);
++	bcpup = bstart;
++	if (args->force_btgt < 0) {
++		if (src_dentry) {
++			src_bstart = au_dbstart(src_dentry);
++			if (src_bstart < bstart)
++				bcpup = src_bstart;
++		} else if (add_entry) {
++			err = AuWbrCreate(sbinfo, dentry,
++					  au_ftest_wrdir(args->flags, ISDIR));
++			bcpup = err;
++		}
++
++		if (bcpup < 0 || au_test_ro(sb, bcpup, dentry->d_inode)) {
++			if (add_entry)
++				err = AuWbrCopyup(sbinfo, dentry);
++			else {
++				if (!IS_ROOT(dentry)) {
++					di_read_lock_parent(parent, !AuLock_IR);
++					err = AuWbrCopyup(sbinfo, dentry);
++					di_read_unlock(parent, !AuLock_IR);
++				} else
++					err = AuWbrCopyup(sbinfo, dentry);
++			}
++			bcpup = err;
++			if (unlikely(err < 0))
++				goto out;
++		}
++	} else {
++		bcpup = args->force_btgt;
++		AuDebugOn(au_test_ro(sb, bcpup, dentry->d_inode));
++	}
++
++	AuDbg("bstart %d, bcpup %d\n", bstart, bcpup);
++	err = bcpup;
++	if (bcpup == bstart)
++		goto out; /* success */
++
++	/* copyup the new parent into the branch we process */
++	err = au_wr_dir_cpup(dentry, parent, add_entry, bcpup, bstart);
++	if (err >= 0) {
++		if (!dentry->d_inode) {
++			au_set_h_dptr(dentry, bstart, NULL);
++			au_set_dbstart(dentry, bcpup);
++			au_set_dbend(dentry, bcpup);
++		}
++		AuDebugOn(add_entry && !au_h_dptr(dentry, bcpup));
++	}
++
++out:
++	dput(parent);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *au_pinned_h_parent(struct au_pin *pin)
++{
++	if (pin && pin->parent)
++		return au_h_dptr(pin->parent, pin->bindex);
++	return NULL;
++}
++
++void au_unpin(struct au_pin *p)
++{
++	if (p->h_mnt && au_ftest_pin(p->flags, MNT_WRITE))
++		mnt_drop_write(p->h_mnt);
++	if (!p->hdir)
++		return;
++
++	au_hn_imtx_unlock(p->hdir);
++	if (!au_ftest_pin(p->flags, DI_LOCKED))
++		di_read_unlock(p->parent, AuLock_IR);
++	iput(p->hdir->hi_inode);
++	dput(p->parent);
++	p->parent = NULL;
++	p->hdir = NULL;
++	p->h_mnt = NULL;
++}
++
++int au_do_pin(struct au_pin *p)
++{
++	int err;
++	struct super_block *sb;
++	struct dentry *h_dentry, *h_parent;
++	struct au_branch *br;
++	struct inode *h_dir;
++
++	err = 0;
++	sb = p->dentry->d_sb;
++	br = au_sbr(sb, p->bindex);
++	if (IS_ROOT(p->dentry)) {
++		if (au_ftest_pin(p->flags, MNT_WRITE)) {
++			p->h_mnt = br->br_mnt;
++			err = mnt_want_write(p->h_mnt);
++			if (unlikely(err)) {
++				au_fclr_pin(p->flags, MNT_WRITE);
++				goto out_err;
++			}
++		}
++		goto out;
++	}
++
++	h_dentry = NULL;
++	if (p->bindex <= au_dbend(p->dentry))
++		h_dentry = au_h_dptr(p->dentry, p->bindex);
++
++	p->parent = dget_parent(p->dentry);
++	if (!au_ftest_pin(p->flags, DI_LOCKED))
++		di_read_lock(p->parent, AuLock_IR, p->lsc_di);
++
++	h_dir = NULL;
++	h_parent = au_h_dptr(p->parent, p->bindex);
++	p->hdir = au_hi(p->parent->d_inode, p->bindex);
++	if (p->hdir)
++		h_dir = p->hdir->hi_inode;
++
++	/*
++	 * udba case, or
++	 * if DI_LOCKED is not set, then p->parent may be different
++	 * and h_parent can be NULL.
++	 */
++	if (unlikely(!p->hdir || !h_dir || !h_parent)) {
++		err = -EBUSY;
++		if (!au_ftest_pin(p->flags, DI_LOCKED))
++			di_read_unlock(p->parent, AuLock_IR);
++		dput(p->parent);
++		p->parent = NULL;
++		goto out_err;
++	}
++
++	au_igrab(h_dir);
++	au_hn_imtx_lock_nested(p->hdir, p->lsc_hi);
++
++	if (unlikely(p->hdir->hi_inode != h_parent->d_inode)) {
++		err = -EBUSY;
++		goto out_unpin;
++	}
++	if (h_dentry) {
++		err = au_h_verify(h_dentry, p->udba, h_dir, h_parent, br);
++		if (unlikely(err)) {
++			au_fclr_pin(p->flags, MNT_WRITE);
++			goto out_unpin;
++		}
++	}
++
++	if (au_ftest_pin(p->flags, MNT_WRITE)) {
++		p->h_mnt = br->br_mnt;
++		err = mnt_want_write(p->h_mnt);
++		if (unlikely(err)) {
++			au_fclr_pin(p->flags, MNT_WRITE);
++			goto out_unpin;
++		}
++	}
++	goto out; /* success */
++
++out_unpin:
++	au_unpin(p);
++out_err:
++	pr_err("err %d\n", err);
++	err = au_busy_or_stale();
++out:
++	return err;
++}
++
++void au_pin_init(struct au_pin *p, struct dentry *dentry,
++		 aufs_bindex_t bindex, int lsc_di, int lsc_hi,
++		 unsigned int udba, unsigned char flags)
++{
++	p->dentry = dentry;
++	p->udba = udba;
++	p->lsc_di = lsc_di;
++	p->lsc_hi = lsc_hi;
++	p->flags = flags;
++	p->bindex = bindex;
++
++	p->parent = NULL;
++	p->hdir = NULL;
++	p->h_mnt = NULL;
++}
++
++int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
++	   unsigned int udba, unsigned char flags)
++{
++	au_pin_init(pin, dentry, bindex, AuLsc_DI_PARENT, AuLsc_I_PARENT2,
++		    udba, flags);
++	return au_do_pin(pin);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * ->setattr() and ->getattr() are called in various cases.
++ * chmod, stat: dentry is revalidated.
++ * fchmod, fstat: file and dentry are not revalidated, additionally they may be
++ *		  unhashed.
++ * for ->setattr(), ia->ia_file is passed from ftruncate only.
++ */
++/* todo: consolidate with do_refresh() and simple_reval_dpath() */
++static int au_reval_for_attr(struct dentry *dentry, unsigned int sigen)
++{
++	int err;
++	struct inode *inode;
++	struct dentry *parent;
++
++	err = 0;
++	inode = dentry->d_inode;
++	if (au_digen_test(dentry, sigen)) {
++		parent = dget_parent(dentry);
++		di_read_lock_parent(parent, AuLock_IR);
++		err = au_refresh_dentry(dentry, parent);
++		di_read_unlock(parent, AuLock_IR);
++		dput(parent);
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++#define AuIcpup_DID_CPUP	1
++#define au_ftest_icpup(flags, name)	((flags) & AuIcpup_##name)
++#define au_fset_icpup(flags, name) \
++	do { (flags) |= AuIcpup_##name; } while (0)
++#define au_fclr_icpup(flags, name) \
++	do { (flags) &= ~AuIcpup_##name; } while (0)
++
++struct au_icpup_args {
++	unsigned char flags;
++	unsigned char pin_flags;
++	aufs_bindex_t btgt;
++	unsigned int udba;
++	struct au_pin pin;
++	struct path h_path;
++	struct inode *h_inode;
++};
++
++static int au_pin_and_icpup(struct dentry *dentry, struct iattr *ia,
++			    struct au_icpup_args *a)
++{
++	int err;
++	loff_t sz;
++	aufs_bindex_t bstart, ibstart;
++	struct dentry *hi_wh, *parent;
++	struct inode *inode;
++	struct file *h_file;
++	struct au_wr_dir_args wr_dir_args = {
++		.force_btgt	= -1,
++		.flags		= 0
++	};
++
++	bstart = au_dbstart(dentry);
++	inode = dentry->d_inode;
++	if (S_ISDIR(inode->i_mode))
++		au_fset_wrdir(wr_dir_args.flags, ISDIR);
++	/* plink or hi_wh() case */
++	ibstart = au_ibstart(inode);
++	if (bstart != ibstart && !au_test_ro(inode->i_sb, ibstart, inode))
++		wr_dir_args.force_btgt = ibstart;
++	err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args);
++	if (unlikely(err < 0))
++		goto out;
++	a->btgt = err;
++	if (err != bstart)
++		au_fset_icpup(a->flags, DID_CPUP);
++
++	err = 0;
++	a->pin_flags = AuPin_MNT_WRITE;
++	parent = NULL;
++	if (!IS_ROOT(dentry)) {
++		au_fset_pin(a->pin_flags, DI_LOCKED);
++		parent = dget_parent(dentry);
++		di_write_lock_parent(parent);
++	}
++
++	err = au_pin(&a->pin, dentry, a->btgt, a->udba, a->pin_flags);
++	if (unlikely(err))
++		goto out_parent;
++
++	a->h_path.dentry = au_h_dptr(dentry, bstart);
++	a->h_inode = a->h_path.dentry->d_inode;
++	mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++	sz = -1;
++	if ((ia->ia_valid & ATTR_SIZE) && ia->ia_size < i_size_read(a->h_inode))
++		sz = ia->ia_size;
++
++	h_file = NULL;
++	hi_wh = NULL;
++	if (au_ftest_icpup(a->flags, DID_CPUP) && au_d_removed(dentry)) {
++		hi_wh = au_hi_wh(inode, a->btgt);
++		if (!hi_wh) {
++			err = au_sio_cpup_wh(dentry, a->btgt, sz, /*file*/NULL);
++			if (unlikely(err))
++				goto out_unlock;
++			hi_wh = au_hi_wh(inode, a->btgt);
++			/* todo: revalidate hi_wh? */
++		}
++	}
++
++	if (parent) {
++		au_pin_set_parent_lflag(&a->pin, /*lflag*/0);
++		di_downgrade_lock(parent, AuLock_IR);
++		dput(parent);
++		parent = NULL;
++	}
++	if (!au_ftest_icpup(a->flags, DID_CPUP))
++		goto out; /* success */
++
++	if (!d_unhashed(dentry)) {
++		h_file = au_h_open_pre(dentry, bstart);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			h_file = NULL;
++		} else
++			err = au_sio_cpup_simple(dentry, a->btgt, sz,
++						 AuCpup_DTIME);
++		if (!err)
++			a->h_path.dentry = au_h_dptr(dentry, a->btgt);
++	} else if (!hi_wh)
++		a->h_path.dentry = au_h_dptr(dentry, a->btgt);
++	else
++		a->h_path.dentry = hi_wh; /* do not dget here */
++
++out_unlock:
++	mutex_unlock(&a->h_inode->i_mutex);
++	au_h_open_post(dentry, bstart, h_file);
++	a->h_inode = a->h_path.dentry->d_inode;
++	if (!err) {
++		mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++		goto out; /* success */
++	}
++
++	au_unpin(&a->pin);
++out_parent:
++	if (parent) {
++		di_write_unlock(parent);
++		dput(parent);
++	}
++out:
++	return err;
++}
++
++static int aufs_setattr(struct dentry *dentry, struct iattr *ia)
++{
++	int err;
++	struct inode *inode;
++	struct super_block *sb;
++	struct file *file;
++	struct au_icpup_args *a;
++
++	inode = dentry->d_inode;
++	IMustLock(inode);
++
++	err = -ENOMEM;
++	a = kzalloc(sizeof(*a), GFP_NOFS);
++	if (unlikely(!a))
++		goto out;
++
++	if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
++		ia->ia_valid &= ~ATTR_MODE;
++
++	file = NULL;
++	sb = dentry->d_sb;
++	err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++	if (unlikely(err))
++		goto out_kfree;
++
++	if (ia->ia_valid & ATTR_FILE) {
++		/* currently ftruncate(2) only */
++		AuDebugOn(!S_ISREG(inode->i_mode));
++		file = ia->ia_file;
++		err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++		if (unlikely(err))
++			goto out_si;
++		ia->ia_file = au_hf_top(file);
++		a->udba = AuOpt_UDBA_NONE;
++	} else {
++		/* fchmod() doesn't pass ia_file */
++		a->udba = au_opt_udba(sb);
++		/* no au_d_removed(), to set UDBA_NONE for root */
++		if (d_unhashed(dentry))
++			a->udba = AuOpt_UDBA_NONE;
++		di_write_lock_child(dentry);
++		if (a->udba != AuOpt_UDBA_NONE) {
++			AuDebugOn(IS_ROOT(dentry));
++			err = au_reval_for_attr(dentry, au_sigen(sb));
++			if (unlikely(err))
++				goto out_dentry;
++		}
++	}
++
++	err = au_pin_and_icpup(dentry, ia, a);
++	if (unlikely(err < 0))
++		goto out_dentry;
++	if (au_ftest_icpup(a->flags, DID_CPUP)) {
++		ia->ia_file = NULL;
++		ia->ia_valid &= ~ATTR_FILE;
++	}
++
++	a->h_path.mnt = au_sbr_mnt(sb, a->btgt);
++	if ((ia->ia_valid & (ATTR_MODE | ATTR_CTIME))
++	    == (ATTR_MODE | ATTR_CTIME)) {
++		err = security_path_chmod(a->h_path.dentry, a->h_path.mnt,
++					  ia->ia_mode);
++		if (unlikely(err))
++			goto out_unlock;
++	} else if ((ia->ia_valid & (ATTR_UID | ATTR_GID))
++		   && (ia->ia_valid & ATTR_CTIME)) {
++		err = security_path_chown(&a->h_path, ia->ia_uid, ia->ia_gid);
++		if (unlikely(err))
++			goto out_unlock;
++	}
++
++	if (ia->ia_valid & ATTR_SIZE) {
++		struct file *f;
++
++		if (ia->ia_size < i_size_read(inode))
++			/* unmap only */
++			truncate_setsize(inode, ia->ia_size);
++
++		f = NULL;
++		if (ia->ia_valid & ATTR_FILE)
++			f = ia->ia_file;
++		mutex_unlock(&a->h_inode->i_mutex);
++		err = vfsub_trunc(&a->h_path, ia->ia_size, ia->ia_valid, f);
++		mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++	} else
++		err = vfsub_notify_change(&a->h_path, ia);
++	if (!err)
++		au_cpup_attr_changeable(inode);
++
++out_unlock:
++	mutex_unlock(&a->h_inode->i_mutex);
++	au_unpin(&a->pin);
++	if (unlikely(err))
++		au_update_dbstart(dentry);
++out_dentry:
++	di_write_unlock(dentry);
++	if (file) {
++		fi_write_unlock(file);
++		ia->ia_file = file;
++		ia->ia_valid |= ATTR_FILE;
++	}
++out_si:
++	si_read_unlock(sb);
++out_kfree:
++	kfree(a);
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static void au_refresh_iattr(struct inode *inode, struct kstat *st,
++			     unsigned int nlink)
++{
++	inode->i_mode = st->mode;
++	inode->i_uid = st->uid;
++	inode->i_gid = st->gid;
++	inode->i_atime = st->atime;
++	inode->i_mtime = st->mtime;
++	inode->i_ctime = st->ctime;
++
++	au_cpup_attr_nlink(inode, /*force*/0);
++	if (S_ISDIR(inode->i_mode)) {
++		inode->i_nlink -= nlink;
++		inode->i_nlink += st->nlink;
++	}
++
++	spin_lock(&inode->i_lock);
++	inode->i_blocks = st->blocks;
++	i_size_write(inode, st->size);
++	spin_unlock(&inode->i_lock);
++}
++
++static int aufs_getattr(struct vfsmount *mnt __maybe_unused,
++			struct dentry *dentry, struct kstat *st)
++{
++	int err;
++	unsigned int mnt_flags;
++	aufs_bindex_t bindex;
++	unsigned char udba_none, positive;
++	struct super_block *sb, *h_sb;
++	struct inode *inode;
++	struct vfsmount *h_mnt;
++	struct dentry *h_dentry;
++
++	sb = dentry->d_sb;
++	inode = dentry->d_inode;
++	err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++	if (unlikely(err))
++		goto out;
++	mnt_flags = au_mntflags(sb);
++	udba_none = !!au_opt_test(mnt_flags, UDBA_NONE);
++
++	/* support fstat(2) */
++	if (!au_d_removed(dentry) && !udba_none) {
++		unsigned int sigen = au_sigen(sb);
++		err = au_digen_test(dentry, sigen);
++		if (!err) {
++			di_read_lock_child(dentry, AuLock_IR);
++			err = au_dbrange_test(dentry);
++			if (unlikely(err))
++				goto out_unlock;
++		} else {
++			AuDebugOn(IS_ROOT(dentry));
++			di_write_lock_child(dentry);
++			err = au_dbrange_test(dentry);
++			if (!err)
++				err = au_reval_for_attr(dentry, sigen);
++			di_downgrade_lock(dentry, AuLock_IR);
++			if (unlikely(err))
++				goto out_unlock;
++		}
++	} else
++		di_read_lock_child(dentry, AuLock_IR);
++
++	bindex = au_ibstart(inode);
++	h_mnt = au_sbr_mnt(sb, bindex);
++	h_sb = h_mnt->mnt_sb;
++	if (!au_test_fs_bad_iattr(h_sb) && udba_none)
++		goto out_fill; /* success */
++
++	h_dentry = NULL;
++	if (au_dbstart(dentry) == bindex)
++		h_dentry = dget(au_h_dptr(dentry, bindex));
++	else if (au_opt_test(mnt_flags, PLINK) && au_plink_test(inode)) {
++		h_dentry = au_plink_lkup(inode, bindex);
++		if (IS_ERR(h_dentry))
++			goto out_fill; /* pretending success */
++	}
++	/* illegally overlapped or something */
++	if (unlikely(!h_dentry))
++		goto out_fill; /* pretending success */
++
++	positive = !!h_dentry->d_inode;
++	if (positive)
++		err = vfs_getattr(h_mnt, h_dentry, st);
++	dput(h_dentry);
++	if (!err) {
++		if (positive)
++			au_refresh_iattr(inode, st, h_dentry->d_inode->i_nlink);
++		goto out_fill; /* success */
++	}
++	AuTraceErr(err);
++	goto out_unlock;
++
++out_fill:
++	generic_fillattr(inode, st);
++out_unlock:
++	di_read_unlock(dentry, AuLock_IR);
++	si_read_unlock(sb);
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int h_readlink(struct dentry *dentry, int bindex, char __user *buf,
++		      int bufsiz)
++{
++	int err;
++	struct super_block *sb;
++	struct dentry *h_dentry;
++
++	err = -EINVAL;
++	h_dentry = au_h_dptr(dentry, bindex);
++	if (unlikely(!h_dentry->d_inode->i_op->readlink))
++		goto out;
++
++	err = security_inode_readlink(h_dentry);
++	if (unlikely(err))
++		goto out;
++
++	sb = dentry->d_sb;
++	if (!au_test_ro(sb, bindex, dentry->d_inode)) {
++		vfsub_touch_atime(au_sbr_mnt(sb, bindex), h_dentry);
++		fsstack_copy_attr_atime(dentry->d_inode, h_dentry->d_inode);
++	}
++	err = h_dentry->d_inode->i_op->readlink(h_dentry, buf, bufsiz);
++
++out:
++	return err;
++}
++
++static int aufs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
++{
++	int err;
++
++	err = aufs_read_lock(dentry, AuLock_IR | AuLock_GEN);
++	if (unlikely(err))
++		goto out;
++	err = au_d_hashed_positive(dentry);
++	if (!err)
++		err = h_readlink(dentry, au_dbstart(dentry), buf, bufsiz);
++	aufs_read_unlock(dentry, AuLock_IR);
++
++out:
++	return err;
++}
++
++static void *aufs_follow_link(struct dentry *dentry, struct nameidata *nd)
++{
++	int err;
++	mm_segment_t old_fs;
++	union {
++		char *k;
++		char __user *u;
++	} buf;
++
++	err = -ENOMEM;
++	buf.k = __getname_gfp(GFP_NOFS);
++	if (unlikely(!buf.k))
++		goto out;
++
++	err = aufs_read_lock(dentry, AuLock_IR | AuLock_GEN);
++	if (unlikely(err))
++		goto out_name;
++
++	err = au_d_hashed_positive(dentry);
++	if (!err) {
++		old_fs = get_fs();
++		set_fs(KERNEL_DS);
++		err = h_readlink(dentry, au_dbstart(dentry), buf.u, PATH_MAX);
++		set_fs(old_fs);
++	}
++	aufs_read_unlock(dentry, AuLock_IR);
++
++	if (err >= 0) {
++		buf.k[err] = 0;
++		/* will be freed by put_link */
++		nd_set_link(nd, buf.k);
++		return NULL; /* success */
++	}
++
++out_name:
++	__putname(buf.k);
++out:
++	path_put(&nd->path);
++	AuTraceErr(err);
++	return ERR_PTR(err);
++}
++
++static void aufs_put_link(struct dentry *dentry __maybe_unused,
++			  struct nameidata *nd, void *cookie __maybe_unused)
++{
++	__putname(nd_get_link(nd));
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void aufs_truncate_range(struct inode *inode __maybe_unused,
++				loff_t start __maybe_unused,
++				loff_t end __maybe_unused)
++{
++	AuUnsupport();
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct inode_operations aufs_symlink_iop = {
++	.permission	= aufs_permission,
++	.setattr	= aufs_setattr,
++	.getattr	= aufs_getattr,
++	.readlink	= aufs_readlink,
++	.follow_link	= aufs_follow_link,
++	.put_link	= aufs_put_link
++};
++
++struct inode_operations aufs_dir_iop = {
++	.create		= aufs_create,
++	.lookup		= aufs_lookup,
++	.link		= aufs_link,
++	.unlink		= aufs_unlink,
++	.symlink	= aufs_symlink,
++	.mkdir		= aufs_mkdir,
++	.rmdir		= aufs_rmdir,
++	.mknod		= aufs_mknod,
++	.rename		= aufs_rename,
++
++	.permission	= aufs_permission,
++	.setattr	= aufs_setattr,
++	.getattr	= aufs_getattr
++};
++
++struct inode_operations aufs_iop = {
++	.permission	= aufs_permission,
++	.setattr	= aufs_setattr,
++	.getattr	= aufs_getattr,
++	.truncate_range	= aufs_truncate_range
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/i_op_add.c linux-2.6.36/fs/aufs/i_op_add.c
+--- linux-2.6.36.orig/fs/aufs/i_op_add.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/i_op_add.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,702 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode operations (add entry)
++ */
++
++#include "aufs.h"
++
++/*
++ * final procedure of adding a new entry, except link(2).
++ * remove whiteout, instantiate, copyup the parent dir's times and size
++ * and update version.
++ * if it failed, re-create the removed whiteout.
++ */
++static int epilog(struct inode *dir, aufs_bindex_t bindex,
++		  struct dentry *wh_dentry, struct dentry *dentry)
++{
++	int err, rerr;
++	aufs_bindex_t bwh;
++	struct path h_path;
++	struct inode *inode, *h_dir;
++	struct dentry *wh;
++
++	bwh = -1;
++	if (wh_dentry) {
++		h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
++		IMustLock(h_dir);
++		AuDebugOn(au_h_iptr(dir, bindex) != h_dir);
++		bwh = au_dbwh(dentry);
++		h_path.dentry = wh_dentry;
++		h_path.mnt = au_sbr_mnt(dir->i_sb, bindex);
++		err = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path,
++					  dentry);
++		if (unlikely(err))
++			goto out;
++	}
++
++	inode = au_new_inode(dentry, /*must_new*/1);
++	if (!IS_ERR(inode)) {
++		d_instantiate(dentry, inode);
++		dir = dentry->d_parent->d_inode; /* dir inode is locked */
++		IMustLock(dir);
++		if (au_ibstart(dir) == au_dbstart(dentry))
++			au_cpup_attr_timesizes(dir);
++		dir->i_version++;
++		return 0; /* success */
++	}
++
++	err = PTR_ERR(inode);
++	if (!wh_dentry)
++		goto out;
++
++	/* revert */
++	/* dir inode is locked */
++	wh = au_wh_create(dentry, bwh, wh_dentry->d_parent);
++	rerr = PTR_ERR(wh);
++	if (IS_ERR(wh)) {
++		AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
++			AuDLNPair(dentry), err, rerr);
++		err = -EIO;
++	} else
++		dput(wh);
++
++out:
++	return err;
++}
++
++static int au_d_may_add(struct dentry *dentry)
++{
++	int err;
++
++	err = 0;
++	if (unlikely(d_unhashed(dentry)))
++		err = -ENOENT;
++	if (unlikely(dentry->d_inode))
++		err = -EEXIST;
++	return err;
++}
++
++/*
++ * simple tests for the adding inode operations.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
++	       struct dentry *h_parent, int isdir)
++{
++	int err;
++	umode_t h_mode;
++	struct dentry *h_dentry;
++	struct inode *h_inode;
++
++	err = -ENAMETOOLONG;
++	if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
++		goto out;
++
++	h_dentry = au_h_dptr(dentry, bindex);
++	h_inode = h_dentry->d_inode;
++	if (!dentry->d_inode) {
++		err = -EEXIST;
++		if (unlikely(h_inode))
++			goto out;
++	} else {
++		/* rename(2) case */
++		err = -EIO;
++		if (unlikely(!h_inode || !h_inode->i_nlink))
++			goto out;
++
++		h_mode = h_inode->i_mode;
++		if (!isdir) {
++			err = -EISDIR;
++			if (unlikely(S_ISDIR(h_mode)))
++				goto out;
++		} else if (unlikely(!S_ISDIR(h_mode))) {
++			err = -ENOTDIR;
++			goto out;
++		}
++	}
++
++	err = 0;
++	/* expected parent dir is locked */
++	if (unlikely(h_parent != h_dentry->d_parent))
++		err = -EIO;
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++/*
++ * initial procedure of adding a new entry.
++ * prepare writable branch and the parent dir, lock it,
++ * and lookup whiteout for the new entry.
++ */
++static struct dentry*
++lock_hdir_lkup_wh(struct dentry *dentry, struct au_dtime *dt,
++		  struct dentry *src_dentry, struct au_pin *pin,
++		  struct au_wr_dir_args *wr_dir_args)
++{
++	struct dentry *wh_dentry, *h_parent;
++	struct super_block *sb;
++	struct au_branch *br;
++	int err;
++	unsigned int udba;
++	aufs_bindex_t bcpup;
++
++	AuDbg("%.*s\n", AuDLNPair(dentry));
++
++	err = au_wr_dir(dentry, src_dentry, wr_dir_args);
++	bcpup = err;
++	wh_dentry = ERR_PTR(err);
++	if (unlikely(err < 0))
++		goto out;
++
++	sb = dentry->d_sb;
++	udba = au_opt_udba(sb);
++	err = au_pin(pin, dentry, bcpup, udba,
++		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++	wh_dentry = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	h_parent = au_pinned_h_parent(pin);
++	if (udba != AuOpt_UDBA_NONE
++	    && au_dbstart(dentry) == bcpup)
++		err = au_may_add(dentry, bcpup, h_parent,
++				 au_ftest_wrdir(wr_dir_args->flags, ISDIR));
++	else if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
++		err = -ENAMETOOLONG;
++	wh_dentry = ERR_PTR(err);
++	if (unlikely(err))
++		goto out_unpin;
++
++	br = au_sbr(sb, bcpup);
++	if (dt) {
++		struct path tmp = {
++			.dentry	= h_parent,
++			.mnt	= br->br_mnt
++		};
++		au_dtime_store(dt, au_pinned_parent(pin), &tmp);
++	}
++
++	wh_dentry = NULL;
++	if (bcpup != au_dbwh(dentry))
++		goto out; /* success */
++
++	wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
++
++out_unpin:
++	if (IS_ERR(wh_dentry))
++		au_unpin(pin);
++out:
++	return wh_dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++enum { Mknod, Symlink, Creat };
++struct simple_arg {
++	int type;
++	union {
++		struct {
++			int mode;
++			struct nameidata *nd;
++		} c;
++		struct {
++			const char *symname;
++		} s;
++		struct {
++			int mode;
++			dev_t dev;
++		} m;
++	} u;
++};
++
++static int add_simple(struct inode *dir, struct dentry *dentry,
++		      struct simple_arg *arg)
++{
++	int err;
++	aufs_bindex_t bstart;
++	unsigned char created;
++	struct au_dtime dt;
++	struct au_pin pin;
++	struct path h_path;
++	struct dentry *wh_dentry, *parent;
++	struct inode *h_dir;
++	struct au_wr_dir_args wr_dir_args = {
++		.force_btgt	= -1,
++		.flags		= AuWrDir_ADD_ENTRY
++	};
++
++	AuDbg("%.*s\n", AuDLNPair(dentry));
++	IMustLock(dir);
++
++	parent = dentry->d_parent; /* dir inode is locked */
++	err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
++	if (unlikely(err))
++		goto out;
++	err = au_d_may_add(dentry);
++	if (unlikely(err))
++		goto out_unlock;
++	di_write_lock_parent(parent);
++	wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL, &pin,
++				      &wr_dir_args);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_parent;
++
++	bstart = au_dbstart(dentry);
++	h_path.dentry = au_h_dptr(dentry, bstart);
++	h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
++	h_dir = au_pinned_h_dir(&pin);
++	switch (arg->type) {
++	case Creat:
++		err = vfsub_create(h_dir, &h_path, arg->u.c.mode);
++		break;
++	case Symlink:
++		err = vfsub_symlink(h_dir, &h_path, arg->u.s.symname);
++		break;
++	case Mknod:
++		err = vfsub_mknod(h_dir, &h_path, arg->u.m.mode, arg->u.m.dev);
++		break;
++	default:
++		BUG();
++	}
++	created = !err;
++	if (!err)
++		err = epilog(dir, bstart, wh_dentry, dentry);
++
++	/* revert */
++	if (unlikely(created && err && h_path.dentry->d_inode)) {
++		int rerr;
++		rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
++		if (rerr) {
++			AuIOErr("%.*s revert failure(%d, %d)\n",
++				AuDLNPair(dentry), err, rerr);
++			err = -EIO;
++		}
++		au_dtime_revert(&dt);
++	}
++
++	au_unpin(&pin);
++	dput(wh_dentry);
++
++out_parent:
++	di_write_unlock(parent);
++out_unlock:
++	if (unlikely(err)) {
++		au_update_dbstart(dentry);
++		d_drop(dentry);
++	}
++	aufs_read_unlock(dentry, AuLock_DW);
++out:
++	return err;
++}
++
++int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
++{
++	struct simple_arg arg = {
++		.type = Mknod,
++		.u.m = {
++			.mode	= mode,
++			.dev	= dev
++		}
++	};
++	return add_simple(dir, dentry, &arg);
++}
++
++int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
++{
++	struct simple_arg arg = {
++		.type = Symlink,
++		.u.s.symname = symname
++	};
++	return add_simple(dir, dentry, &arg);
++}
++
++int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
++		struct nameidata *nd)
++{
++	struct simple_arg arg = {
++		.type = Creat,
++		.u.c = {
++			.mode	= mode,
++			.nd	= nd
++		}
++	};
++	return add_simple(dir, dentry, &arg);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_link_args {
++	aufs_bindex_t bdst, bsrc;
++	struct au_pin pin;
++	struct path h_path;
++	struct dentry *src_parent, *parent;
++};
++
++static int au_cpup_before_link(struct dentry *src_dentry,
++			       struct au_link_args *a)
++{
++	int err;
++	struct dentry *h_src_dentry;
++	struct mutex *h_mtx;
++	struct file *h_file;
++
++	di_read_lock_parent(a->src_parent, AuLock_IR);
++	err = au_test_and_cpup_dirs(src_dentry, a->bdst);
++	if (unlikely(err))
++		goto out;
++
++	h_src_dentry = au_h_dptr(src_dentry, a->bsrc);
++	h_mtx = &h_src_dentry->d_inode->i_mutex;
++	err = au_pin(&a->pin, src_dentry, a->bdst,
++		     au_opt_udba(src_dentry->d_sb),
++		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++	if (unlikely(err))
++		goto out;
++	mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++	h_file = au_h_open_pre(src_dentry, a->bsrc);
++	if (IS_ERR(h_file)) {
++		err = PTR_ERR(h_file);
++		h_file = NULL;
++	} else
++		err = au_sio_cpup_simple(src_dentry, a->bdst, a->bsrc,
++					 AuCpup_DTIME /* | AuCpup_KEEPLINO */);
++	mutex_unlock(h_mtx);
++	au_h_open_post(src_dentry, a->bsrc, h_file);
++	au_unpin(&a->pin);
++
++out:
++	di_read_unlock(a->src_parent, AuLock_IR);
++	return err;
++}
++
++static int au_cpup_or_link(struct dentry *src_dentry, struct au_link_args *a)
++{
++	int err;
++	unsigned char plink;
++	struct inode *h_inode, *inode;
++	struct dentry *h_src_dentry;
++	struct super_block *sb;
++	struct file *h_file;
++
++	plink = 0;
++	h_inode = NULL;
++	sb = src_dentry->d_sb;
++	inode = src_dentry->d_inode;
++	if (au_ibstart(inode) <= a->bdst)
++		h_inode = au_h_iptr(inode, a->bdst);
++	if (!h_inode || !h_inode->i_nlink) {
++		/* copyup src_dentry as the name of dentry. */
++		au_set_dbstart(src_dentry, a->bdst);
++		au_set_h_dptr(src_dentry, a->bdst, dget(a->h_path.dentry));
++		h_inode = au_h_dptr(src_dentry, a->bsrc)->d_inode;
++		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++		h_file = au_h_open_pre(src_dentry, a->bsrc);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			h_file = NULL;
++		} else
++			err = au_sio_cpup_single(src_dentry, a->bdst, a->bsrc,
++						 -1, AuCpup_KEEPLINO,
++						 a->parent);
++		mutex_unlock(&h_inode->i_mutex);
++		au_h_open_post(src_dentry, a->bsrc, h_file);
++		au_set_h_dptr(src_dentry, a->bdst, NULL);
++		au_set_dbstart(src_dentry, a->bsrc);
++	} else {
++		/* the inode of src_dentry already exists on a.bdst branch */
++		h_src_dentry = d_find_alias(h_inode);
++		if (!h_src_dentry && au_plink_test(inode)) {
++			plink = 1;
++			h_src_dentry = au_plink_lkup(inode, a->bdst);
++			err = PTR_ERR(h_src_dentry);
++			if (IS_ERR(h_src_dentry))
++				goto out;
++
++			if (unlikely(!h_src_dentry->d_inode)) {
++				dput(h_src_dentry);
++				h_src_dentry = NULL;
++			}
++
++		}
++		if (h_src_dentry) {
++			err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
++					 &a->h_path);
++			dput(h_src_dentry);
++		} else {
++			AuIOErr("no dentry found for hi%lu on b%d\n",
++				h_inode->i_ino, a->bdst);
++			err = -EIO;
++		}
++	}
++
++	if (!err && !plink)
++		au_plink_append(inode, a->bdst, a->h_path.dentry);
++
++out:
++	return err;
++}
++
++int aufs_link(struct dentry *src_dentry, struct inode *dir,
++	      struct dentry *dentry)
++{
++	int err, rerr;
++	struct au_dtime dt;
++	struct au_link_args *a;
++	struct dentry *wh_dentry, *h_src_dentry;
++	struct inode *inode;
++	struct super_block *sb;
++	struct au_wr_dir_args wr_dir_args = {
++		/* .force_btgt	= -1, */
++		.flags		= AuWrDir_ADD_ENTRY
++	};
++
++	IMustLock(dir);
++	inode = src_dentry->d_inode;
++	IMustLock(inode);
++
++	err = -ENOMEM;
++	a = kzalloc(sizeof(*a), GFP_NOFS);
++	if (unlikely(!a))
++		goto out;
++
++	a->parent = dentry->d_parent; /* dir inode is locked */
++	err = aufs_read_and_write_lock2(dentry, src_dentry,
++					AuLock_NOPLM | AuLock_GEN);
++	if (unlikely(err))
++		goto out_kfree;
++	err = au_d_hashed_positive(src_dentry);
++	if (unlikely(err))
++		goto out_unlock;
++	err = au_d_may_add(dentry);
++	if (unlikely(err))
++		goto out_unlock;
++
++	a->src_parent = dget_parent(src_dentry);
++	wr_dir_args.force_btgt = au_dbstart(src_dentry);
++
++	di_write_lock_parent(a->parent);
++	wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
++	wh_dentry = lock_hdir_lkup_wh(dentry, &dt, src_dentry, &a->pin,
++				      &wr_dir_args);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_parent;
++
++	err = 0;
++	sb = dentry->d_sb;
++	a->bdst = au_dbstart(dentry);
++	a->h_path.dentry = au_h_dptr(dentry, a->bdst);
++	a->h_path.mnt = au_sbr_mnt(sb, a->bdst);
++	a->bsrc = au_dbstart(src_dentry);
++	if (au_opt_test(au_mntflags(sb), PLINK)) {
++		if (a->bdst < a->bsrc
++		    /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */)
++			err = au_cpup_or_link(src_dentry, a);
++		else {
++			h_src_dentry = au_h_dptr(src_dentry, a->bdst);
++			err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
++					 &a->h_path);
++		}
++	} else {
++		/*
++		 * copyup src_dentry to the branch we process,
++		 * and then link(2) to it.
++		 */
++		if (a->bdst < a->bsrc
++		    /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */) {
++			au_unpin(&a->pin);
++			di_write_unlock(a->parent);
++			err = au_cpup_before_link(src_dentry, a);
++			di_write_lock_parent(a->parent);
++			if (!err)
++				err = au_pin(&a->pin, dentry, a->bdst,
++					     au_opt_udba(sb),
++					     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++			if (unlikely(err))
++				goto out_wh;
++		}
++		if (!err) {
++			h_src_dentry = au_h_dptr(src_dentry, a->bdst);
++			err = -ENOENT;
++			if (h_src_dentry && h_src_dentry->d_inode)
++				err = vfsub_link(h_src_dentry,
++						 au_pinned_h_dir(&a->pin),
++						 &a->h_path);
++		}
++	}
++	if (unlikely(err))
++		goto out_unpin;
++
++	if (wh_dentry) {
++		a->h_path.dentry = wh_dentry;
++		err = au_wh_unlink_dentry(au_pinned_h_dir(&a->pin), &a->h_path,
++					  dentry);
++		if (unlikely(err))
++			goto out_revert;
++	}
++
++	dir->i_version++;
++	if (au_ibstart(dir) == au_dbstart(dentry))
++		au_cpup_attr_timesizes(dir);
++	inc_nlink(inode);
++	inode->i_ctime = dir->i_ctime;
++	d_instantiate(dentry, au_igrab(inode));
++	if (d_unhashed(a->h_path.dentry))
++		/* some filesystem calls d_drop() */
++		d_drop(dentry);
++	goto out_unpin; /* success */
++
++out_revert:
++	rerr = vfsub_unlink(au_pinned_h_dir(&a->pin), &a->h_path, /*force*/0);
++	if (unlikely(rerr)) {
++		AuIOErr("%.*s reverting failed(%d, %d)\n",
++			AuDLNPair(dentry), err, rerr);
++		err = -EIO;
++	}
++	au_dtime_revert(&dt);
++out_unpin:
++	au_unpin(&a->pin);
++out_wh:
++	dput(wh_dentry);
++out_parent:
++	di_write_unlock(a->parent);
++	dput(a->src_parent);
++out_unlock:
++	if (unlikely(err)) {
++		au_update_dbstart(dentry);
++		d_drop(dentry);
++	}
++	aufs_read_and_write_unlock2(dentry, src_dentry);
++out_kfree:
++	kfree(a);
++out:
++	return err;
++}
++
++int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
++{
++	int err, rerr;
++	aufs_bindex_t bindex;
++	unsigned char diropq;
++	struct path h_path;
++	struct dentry *wh_dentry, *parent, *opq_dentry;
++	struct mutex *h_mtx;
++	struct super_block *sb;
++	struct {
++		struct au_pin pin;
++		struct au_dtime dt;
++	} *a; /* reduce the stack usage */
++	struct au_wr_dir_args wr_dir_args = {
++		.force_btgt	= -1,
++		.flags		= AuWrDir_ADD_ENTRY | AuWrDir_ISDIR
++	};
++
++	IMustLock(dir);
++
++	err = -ENOMEM;
++	a = kmalloc(sizeof(*a), GFP_NOFS);
++	if (unlikely(!a))
++		goto out;
++
++	err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
++	if (unlikely(err))
++		goto out_free;
++	err = au_d_may_add(dentry);
++	if (unlikely(err))
++		goto out_unlock;
++
++	parent = dentry->d_parent; /* dir inode is locked */
++	di_write_lock_parent(parent);
++	wh_dentry = lock_hdir_lkup_wh(dentry, &a->dt, /*src_dentry*/NULL,
++				      &a->pin, &wr_dir_args);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_parent;
++
++	sb = dentry->d_sb;
++	bindex = au_dbstart(dentry);
++	h_path.dentry = au_h_dptr(dentry, bindex);
++	h_path.mnt = au_sbr_mnt(sb, bindex);
++	err = vfsub_mkdir(au_pinned_h_dir(&a->pin), &h_path, mode);
++	if (unlikely(err))
++		goto out_unpin;
++
++	/* make the dir opaque */
++	diropq = 0;
++	h_mtx = &h_path.dentry->d_inode->i_mutex;
++	if (wh_dentry
++	    || au_opt_test(au_mntflags(sb), ALWAYS_DIROPQ)) {
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		opq_dentry = au_diropq_create(dentry, bindex);
++		mutex_unlock(h_mtx);
++		err = PTR_ERR(opq_dentry);
++		if (IS_ERR(opq_dentry))
++			goto out_dir;
++		dput(opq_dentry);
++		diropq = 1;
++	}
++
++	err = epilog(dir, bindex, wh_dentry, dentry);
++	if (!err) {
++		inc_nlink(dir);
++		goto out_unpin; /* success */
++	}
++
++	/* revert */
++	if (diropq) {
++		AuLabel(revert opq);
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		rerr = au_diropq_remove(dentry, bindex);
++		mutex_unlock(h_mtx);
++		if (rerr) {
++			AuIOErr("%.*s reverting diropq failed(%d, %d)\n",
++				AuDLNPair(dentry), err, rerr);
++			err = -EIO;
++		}
++	}
++
++out_dir:
++	AuLabel(revert dir);
++	rerr = vfsub_rmdir(au_pinned_h_dir(&a->pin), &h_path);
++	if (rerr) {
++		AuIOErr("%.*s reverting dir failed(%d, %d)\n",
++			AuDLNPair(dentry), err, rerr);
++		err = -EIO;
++	}
++	au_dtime_revert(&a->dt);
++out_unpin:
++	au_unpin(&a->pin);
++	dput(wh_dentry);
++out_parent:
++	di_write_unlock(parent);
++out_unlock:
++	if (unlikely(err)) {
++		au_update_dbstart(dentry);
++		d_drop(dentry);
++	}
++	aufs_read_unlock(dentry, AuLock_DW);
++out_free:
++	kfree(a);
++out:
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/i_op_del.c linux-2.6.36/fs/aufs/i_op_del.c
+--- linux-2.6.36.orig/fs/aufs/i_op_del.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/i_op_del.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,481 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode operations (del entry)
++ */
++
++#include "aufs.h"
++
++/*
++ * decide if a new whiteout for @dentry is necessary or not.
++ * when it is necessary, prepare the parent dir for the upper branch whose
++ * branch index is @bcpup for creation. the actual creation of the whiteout will
++ * be done by caller.
++ * return value:
++ * 0: wh is unnecessary
++ * plus: wh is necessary
++ * minus: error
++ */
++int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup)
++{
++	int need_wh, err;
++	aufs_bindex_t bstart;
++	struct super_block *sb;
++
++	sb = dentry->d_sb;
++	bstart = au_dbstart(dentry);
++	if (*bcpup < 0) {
++		*bcpup = bstart;
++		if (au_test_ro(sb, bstart, dentry->d_inode)) {
++			err = AuWbrCopyup(au_sbi(sb), dentry);
++			*bcpup = err;
++			if (unlikely(err < 0))
++				goto out;
++		}
++	} else
++		AuDebugOn(bstart < *bcpup
++			  || au_test_ro(sb, *bcpup, dentry->d_inode));
++	AuDbg("bcpup %d, bstart %d\n", *bcpup, bstart);
++
++	if (*bcpup != bstart) {
++		err = au_cpup_dirs(dentry, *bcpup);
++		if (unlikely(err))
++			goto out;
++		need_wh = 1;
++	} else {
++		struct au_dinfo *dinfo, *tmp;
++
++		need_wh = -ENOMEM;
++		dinfo = au_di(dentry);
++		tmp = au_di_alloc(sb, AuLsc_DI_TMP);
++		if (tmp) {
++			au_di_cp(tmp, dinfo);
++			au_di_swap(tmp, dinfo);
++			/* returns the number of positive dentries */
++			need_wh = au_lkup_dentry(dentry, bstart + 1, /*type*/0,
++						 /*nd*/NULL);
++			au_di_swap(tmp, dinfo);
++			au_rw_write_unlock(&tmp->di_rwsem);
++			au_di_free(tmp);
++		}
++	}
++	AuDbg("need_wh %d\n", need_wh);
++	err = need_wh;
++
++out:
++	return err;
++}
++
++/*
++ * simple tests for the del-entry operations.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
++	       struct dentry *h_parent, int isdir)
++{
++	int err;
++	umode_t h_mode;
++	struct dentry *h_dentry, *h_latest;
++	struct inode *h_inode;
++
++	h_dentry = au_h_dptr(dentry, bindex);
++	h_inode = h_dentry->d_inode;
++	if (dentry->d_inode) {
++		err = -ENOENT;
++		if (unlikely(!h_inode || !h_inode->i_nlink))
++			goto out;
++
++		h_mode = h_inode->i_mode;
++		if (!isdir) {
++			err = -EISDIR;
++			if (unlikely(S_ISDIR(h_mode)))
++				goto out;
++		} else if (unlikely(!S_ISDIR(h_mode))) {
++			err = -ENOTDIR;
++			goto out;
++		}
++	} else {
++		/* rename(2) case */
++		err = -EIO;
++		if (unlikely(h_inode))
++			goto out;
++	}
++
++	err = -ENOENT;
++	/* expected parent dir is locked */
++	if (unlikely(h_parent != h_dentry->d_parent))
++		goto out;
++	err = 0;
++
++	/*
++	 * rmdir a dir may break the consistency on some filesystem.
++	 * let's try heavy test.
++	 */
++	err = -EACCES;
++	if (unlikely(au_test_h_perm(h_parent->d_inode, MAY_EXEC | MAY_WRITE)))
++		goto out;
++
++	h_latest = au_sio_lkup_one(&dentry->d_name, h_parent,
++				   au_sbr(dentry->d_sb, bindex));
++	err = -EIO;
++	if (IS_ERR(h_latest))
++		goto out;
++	if (h_latest == h_dentry)
++		err = 0;
++	dput(h_latest);
++
++out:
++	return err;
++}
++
++/*
++ * decide the branch where we operate for @dentry. the branch index will be set
++ * @rbcpup. after diciding it, 'pin' it and store the timestamps of the parent
++ * dir for reverting.
++ * when a new whiteout is necessary, create it.
++ */
++static struct dentry*
++lock_hdir_create_wh(struct dentry *dentry, int isdir, aufs_bindex_t *rbcpup,
++		    struct au_dtime *dt, struct au_pin *pin)
++{
++	struct dentry *wh_dentry;
++	struct super_block *sb;
++	struct path h_path;
++	int err, need_wh;
++	unsigned int udba;
++	aufs_bindex_t bcpup;
++
++	need_wh = au_wr_dir_need_wh(dentry, isdir, rbcpup);
++	wh_dentry = ERR_PTR(need_wh);
++	if (unlikely(need_wh < 0))
++		goto out;
++
++	sb = dentry->d_sb;
++	udba = au_opt_udba(sb);
++	bcpup = *rbcpup;
++	err = au_pin(pin, dentry, bcpup, udba,
++		     AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++	wh_dentry = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	h_path.dentry = au_pinned_h_parent(pin);
++	if (udba != AuOpt_UDBA_NONE
++	    && au_dbstart(dentry) == bcpup) {
++		err = au_may_del(dentry, bcpup, h_path.dentry, isdir);
++		wh_dentry = ERR_PTR(err);
++		if (unlikely(err))
++			goto out_unpin;
++	}
++
++	h_path.mnt = au_sbr_mnt(sb, bcpup);
++	au_dtime_store(dt, au_pinned_parent(pin), &h_path);
++	wh_dentry = NULL;
++	if (!need_wh)
++		goto out; /* success, no need to create whiteout */
++
++	wh_dentry = au_wh_create(dentry, bcpup, h_path.dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_unpin;
++
++	/* returns with the parent is locked and wh_dentry is dget-ed */
++	goto out; /* success */
++
++out_unpin:
++	au_unpin(pin);
++out:
++	return wh_dentry;
++}
++
++/*
++ * when removing a dir, rename it to a unique temporary whiteout-ed name first
++ * in order to be revertible and save time for removing many child whiteouts
++ * under the dir.
++ * returns 1 when there are too many child whiteout and caller should remove
++ * them asynchronously. returns 0 when the number of children is enough small to
++ * remove now or the branch fs is a remote fs.
++ * otherwise return an error.
++ */
++static int renwh_and_rmdir(struct dentry *dentry, aufs_bindex_t bindex,
++			   struct au_nhash *whlist, struct inode *dir)
++{
++	int rmdir_later, err, dirwh;
++	struct dentry *h_dentry;
++	struct super_block *sb;
++
++	sb = dentry->d_sb;
++	SiMustAnyLock(sb);
++	h_dentry = au_h_dptr(dentry, bindex);
++	err = au_whtmp_ren(h_dentry, au_sbr(sb, bindex));
++	if (unlikely(err))
++		goto out;
++
++	/* stop monitoring */
++	au_hn_free(au_hi(dentry->d_inode, bindex));
++
++	if (!au_test_fs_remote(h_dentry->d_sb)) {
++		dirwh = au_sbi(sb)->si_dirwh;
++		rmdir_later = (dirwh <= 1);
++		if (!rmdir_later)
++			rmdir_later = au_nhash_test_longer_wh(whlist, bindex,
++							      dirwh);
++		if (rmdir_later)
++			return rmdir_later;
++	}
++
++	err = au_whtmp_rmdir(dir, bindex, h_dentry, whlist);
++	if (unlikely(err)) {
++		AuIOErr("rmdir %.*s, b%d failed, %d. ignored\n",
++			AuDLNPair(h_dentry), bindex, err);
++		err = 0;
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++/*
++ * final procedure for deleting a entry.
++ * maintain dentry and iattr.
++ */
++static void epilog(struct inode *dir, struct dentry *dentry,
++		   aufs_bindex_t bindex)
++{
++	struct inode *inode;
++
++	inode = dentry->d_inode;
++	d_drop(dentry);
++	inode->i_ctime = dir->i_ctime;
++
++	if (au_ibstart(dir) == bindex)
++		au_cpup_attr_timesizes(dir);
++	dir->i_version++;
++}
++
++/*
++ * when an error happened, remove the created whiteout and revert everything.
++ */
++static int do_revert(int err, struct inode *dir, aufs_bindex_t bindex,
++		     aufs_bindex_t bwh, struct dentry *wh_dentry,
++		     struct dentry *dentry, struct au_dtime *dt)
++{
++	int rerr;
++	struct path h_path = {
++		.dentry	= wh_dentry,
++		.mnt	= au_sbr_mnt(dir->i_sb, bindex)
++	};
++
++	rerr = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path, dentry);
++	if (!rerr) {
++		au_set_dbwh(dentry, bwh);
++		au_dtime_revert(dt);
++		return 0;
++	}
++
++	AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
++		AuDLNPair(dentry), err, rerr);
++	return -EIO;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int aufs_unlink(struct inode *dir, struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bwh, bindex, bstart;
++	struct au_dtime dt;
++	struct au_pin pin;
++	struct path h_path;
++	struct inode *inode, *h_dir;
++	struct dentry *parent, *wh_dentry;
++
++	IMustLock(dir);
++
++	err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
++	if (unlikely(err))
++		goto out;
++	err = au_d_hashed_positive(dentry);
++	if (unlikely(err))
++		goto out_unlock;
++	inode = dentry->d_inode;
++	IMustLock(inode);
++	err = -EISDIR;
++	if (unlikely(S_ISDIR(inode->i_mode)))
++		goto out_unlock; /* possible? */
++
++	bstart = au_dbstart(dentry);
++	bwh = au_dbwh(dentry);
++	bindex = -1;
++	parent = dentry->d_parent; /* dir inode is locked */
++	di_write_lock_parent(parent);
++	wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &dt, &pin);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_parent;
++
++	h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
++	h_path.dentry = au_h_dptr(dentry, bstart);
++	dget(h_path.dentry);
++	if (bindex == bstart) {
++		h_dir = au_pinned_h_dir(&pin);
++		err = vfsub_unlink(h_dir, &h_path, /*force*/0);
++	} else {
++		/* dir inode is locked */
++		h_dir = wh_dentry->d_parent->d_inode;
++		IMustLock(h_dir);
++		err = 0;
++	}
++
++	if (!err) {
++		vfsub_drop_nlink(inode);
++		epilog(dir, dentry, bindex);
++
++		/* update target timestamps */
++		if (bindex == bstart) {
++			vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++			inode->i_ctime = h_path.dentry->d_inode->i_ctime;
++		} else
++			/* todo: this timestamp may be reverted later */
++			inode->i_ctime = h_dir->i_ctime;
++		goto out_unpin; /* success */
++	}
++
++	/* revert */
++	if (wh_dentry) {
++		int rerr;
++
++		rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry, &dt);
++		if (rerr)
++			err = rerr;
++	}
++
++out_unpin:
++	au_unpin(&pin);
++	dput(wh_dentry);
++	dput(h_path.dentry);
++out_parent:
++	di_write_unlock(parent);
++out_unlock:
++	aufs_read_unlock(dentry, AuLock_DW);
++out:
++	return err;
++}
++
++int aufs_rmdir(struct inode *dir, struct dentry *dentry)
++{
++	int err, rmdir_later;
++	aufs_bindex_t bwh, bindex, bstart;
++	struct au_dtime dt;
++	struct au_pin pin;
++	struct inode *inode;
++	struct dentry *parent, *wh_dentry, *h_dentry;
++	struct au_whtmp_rmdir *args;
++
++	IMustLock(dir);
++
++	err = aufs_read_lock(dentry, AuLock_DW | AuLock_FLUSH | AuLock_GEN);
++	if (unlikely(err))
++		goto out;
++
++	/* VFS already unhashes it */
++	inode = dentry->d_inode;
++	err = -ENOENT;
++	if (unlikely(!inode || !inode->i_nlink
++		     || IS_DEADDIR(inode)))
++		goto out_unlock;
++	IMustLock(inode);
++	err = -ENOTDIR;
++	if (unlikely(!S_ISDIR(inode->i_mode)))
++		goto out_unlock; /* possible? */
++
++	err = -ENOMEM;
++	args = au_whtmp_rmdir_alloc(dir->i_sb, GFP_NOFS);
++	if (unlikely(!args))
++		goto out_unlock;
++
++	parent = dentry->d_parent; /* dir inode is locked */
++	di_write_lock_parent(parent);
++	err = au_test_empty(dentry, &args->whlist);
++	if (unlikely(err))
++		goto out_parent;
++
++	bstart = au_dbstart(dentry);
++	bwh = au_dbwh(dentry);
++	bindex = -1;
++	wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/1, &bindex, &dt, &pin);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out_parent;
++
++	h_dentry = au_h_dptr(dentry, bstart);
++	dget(h_dentry);
++	rmdir_later = 0;
++	if (bindex == bstart) {
++		err = renwh_and_rmdir(dentry, bstart, &args->whlist, dir);
++		if (err > 0) {
++			rmdir_later = err;
++			err = 0;
++		}
++	} else {
++		/* stop monitoring */
++		au_hn_free(au_hi(inode, bstart));
++
++		/* dir inode is locked */
++		IMustLock(wh_dentry->d_parent->d_inode);
++		err = 0;
++	}
++
++	if (!err) {
++		vfsub_dead_dir(inode);
++		au_set_dbdiropq(dentry, -1);
++		epilog(dir, dentry, bindex);
++
++		if (rmdir_later) {
++			au_whtmp_kick_rmdir(dir, bstart, h_dentry, args);
++			args = NULL;
++		}
++
++		goto out_unpin; /* success */
++	}
++
++	/* revert */
++	AuLabel(revert);
++	if (wh_dentry) {
++		int rerr;
++
++		rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry, &dt);
++		if (rerr)
++			err = rerr;
++	}
++
++out_unpin:
++	au_unpin(&pin);
++	dput(wh_dentry);
++	dput(h_dentry);
++out_parent:
++	di_write_unlock(parent);
++	if (args)
++		au_whtmp_rmdir_free(args);
++out_unlock:
++	aufs_read_unlock(dentry, AuLock_DW);
++out:
++	AuTraceErr(err);
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/i_op_ren.c linux-2.6.36/fs/aufs/i_op_ren.c
+--- linux-2.6.36.orig/fs/aufs/i_op_ren.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/i_op_ren.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1017 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode operation (rename entry)
++ * todo: this is crazy monster
++ */
++
++#include "aufs.h"
++
++enum { AuSRC, AuDST, AuSrcDst };
++enum { AuPARENT, AuCHILD, AuParentChild };
++
++#define AuRen_ISDIR	1
++#define AuRen_ISSAMEDIR	(1 << 1)
++#define AuRen_WHSRC	(1 << 2)
++#define AuRen_WHDST	(1 << 3)
++#define AuRen_MNT_WRITE	(1 << 4)
++#define AuRen_DT_DSTDIR	(1 << 5)
++#define AuRen_DIROPQ	(1 << 6)
++#define AuRen_CPUP	(1 << 7)
++#define au_ftest_ren(flags, name)	((flags) & AuRen_##name)
++#define au_fset_ren(flags, name) \
++	do { (flags) |= AuRen_##name; } while (0)
++#define au_fclr_ren(flags, name) \
++	do { (flags) &= ~AuRen_##name; } while (0)
++
++struct au_ren_args {
++	struct {
++		struct dentry *dentry, *h_dentry, *parent, *h_parent,
++			*wh_dentry;
++		struct inode *dir, *inode;
++		struct au_hinode *hdir;
++		struct au_dtime dt[AuParentChild];
++		aufs_bindex_t bstart;
++	} sd[AuSrcDst];
++
++#define src_dentry	sd[AuSRC].dentry
++#define src_dir		sd[AuSRC].dir
++#define src_inode	sd[AuSRC].inode
++#define src_h_dentry	sd[AuSRC].h_dentry
++#define src_parent	sd[AuSRC].parent
++#define src_h_parent	sd[AuSRC].h_parent
++#define src_wh_dentry	sd[AuSRC].wh_dentry
++#define src_hdir	sd[AuSRC].hdir
++#define src_h_dir	sd[AuSRC].hdir->hi_inode
++#define src_dt		sd[AuSRC].dt
++#define src_bstart	sd[AuSRC].bstart
++
++#define dst_dentry	sd[AuDST].dentry
++#define dst_dir		sd[AuDST].dir
++#define dst_inode	sd[AuDST].inode
++#define dst_h_dentry	sd[AuDST].h_dentry
++#define dst_parent	sd[AuDST].parent
++#define dst_h_parent	sd[AuDST].h_parent
++#define dst_wh_dentry	sd[AuDST].wh_dentry
++#define dst_hdir	sd[AuDST].hdir
++#define dst_h_dir	sd[AuDST].hdir->hi_inode
++#define dst_dt		sd[AuDST].dt
++#define dst_bstart	sd[AuDST].bstart
++
++	struct dentry *h_trap;
++	struct au_branch *br;
++	struct au_hinode *src_hinode;
++	struct path h_path;
++	struct au_nhash whlist;
++	aufs_bindex_t btgt, src_bwh, src_bdiropq;
++
++	unsigned int flags;
++
++	struct au_whtmp_rmdir *thargs;
++	struct dentry *h_dst;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * functions for reverting.
++ * when an error happened in a single rename systemcall, we should revert
++ * everything as if nothing happend.
++ * we don't need to revert the copied-up/down the parent dir since they are
++ * harmless.
++ */
++
++#define RevertFailure(fmt, ...) do { \
++	AuIOErr("revert failure: " fmt " (%d, %d)\n", \
++		##__VA_ARGS__, err, rerr); \
++	err = -EIO; \
++} while (0)
++
++static void au_ren_rev_diropq(int err, struct au_ren_args *a)
++{
++	int rerr;
++
++	au_hn_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
++	rerr = au_diropq_remove(a->src_dentry, a->btgt);
++	au_hn_imtx_unlock(a->src_hinode);
++	au_set_dbdiropq(a->src_dentry, a->src_bdiropq);
++	if (rerr)
++		RevertFailure("remove diropq %.*s", AuDLNPair(a->src_dentry));
++}
++
++static void au_ren_rev_rename(int err, struct au_ren_args *a)
++{
++	int rerr;
++
++	a->h_path.dentry = au_lkup_one(&a->src_dentry->d_name, a->src_h_parent,
++				       a->br, /*nd*/NULL);
++	rerr = PTR_ERR(a->h_path.dentry);
++	if (IS_ERR(a->h_path.dentry)) {
++		RevertFailure("au_lkup_one %.*s", AuDLNPair(a->src_dentry));
++		return;
++	}
++
++	rerr = vfsub_rename(a->dst_h_dir,
++			    au_h_dptr(a->src_dentry, a->btgt),
++			    a->src_h_dir, &a->h_path);
++	d_drop(a->h_path.dentry);
++	dput(a->h_path.dentry);
++	/* au_set_h_dptr(a->src_dentry, a->btgt, NULL); */
++	if (rerr)
++		RevertFailure("rename %.*s", AuDLNPair(a->src_dentry));
++}
++
++static void au_ren_rev_cpup(int err, struct au_ren_args *a)
++{
++	int rerr;
++
++	a->h_path.dentry = a->dst_h_dentry;
++	rerr = vfsub_unlink(a->dst_h_dir, &a->h_path, /*force*/0);
++	au_set_h_dptr(a->src_dentry, a->btgt, NULL);
++	au_set_dbstart(a->src_dentry, a->src_bstart);
++	if (rerr)
++		RevertFailure("unlink %.*s", AuDLNPair(a->dst_h_dentry));
++}
++
++static void au_ren_rev_whtmp(int err, struct au_ren_args *a)
++{
++	int rerr;
++
++	a->h_path.dentry = au_lkup_one(&a->dst_dentry->d_name, a->dst_h_parent,
++				       a->br, /*nd*/NULL);
++	rerr = PTR_ERR(a->h_path.dentry);
++	if (IS_ERR(a->h_path.dentry)) {
++		RevertFailure("lookup %.*s", AuDLNPair(a->dst_dentry));
++		return;
++	}
++	if (a->h_path.dentry->d_inode) {
++		d_drop(a->h_path.dentry);
++		dput(a->h_path.dentry);
++		return;
++	}
++
++	rerr = vfsub_rename(a->dst_h_dir, a->h_dst, a->dst_h_dir, &a->h_path);
++	d_drop(a->h_path.dentry);
++	dput(a->h_path.dentry);
++	if (!rerr)
++		au_set_h_dptr(a->dst_dentry, a->btgt, dget(a->h_dst));
++	else
++		RevertFailure("rename %.*s", AuDLNPair(a->h_dst));
++}
++
++static void au_ren_rev_whsrc(int err, struct au_ren_args *a)
++{
++	int rerr;
++
++	a->h_path.dentry = a->src_wh_dentry;
++	rerr = au_wh_unlink_dentry(a->src_h_dir, &a->h_path, a->src_dentry);
++	au_set_dbwh(a->src_dentry, a->src_bwh);
++	if (rerr)
++		RevertFailure("unlink %.*s", AuDLNPair(a->src_wh_dentry));
++}
++#undef RevertFailure
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * when we have to copyup the renaming entry, do it with the rename-target name
++ * in order to minimize the cost (the later actual rename is unnecessary).
++ * otherwise rename it on the target branch.
++ */
++static int au_ren_or_cpup(struct au_ren_args *a)
++{
++	int err;
++	struct dentry *d;
++
++	d = a->src_dentry;
++	if (au_dbstart(d) == a->btgt) {
++		a->h_path.dentry = a->dst_h_dentry;
++		if (au_ftest_ren(a->flags, DIROPQ)
++		    && au_dbdiropq(d) == a->btgt)
++			au_fclr_ren(a->flags, DIROPQ);
++		AuDebugOn(au_dbstart(d) != a->btgt);
++		err = vfsub_rename(a->src_h_dir, au_h_dptr(d, a->btgt),
++				   a->dst_h_dir, &a->h_path);
++	} else {
++		struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
++		struct file *h_file;
++
++		au_fset_ren(a->flags, CPUP);
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		au_set_dbstart(d, a->btgt);
++		au_set_h_dptr(d, a->btgt, dget(a->dst_h_dentry));
++		h_file = au_h_open_pre(d, a->src_bstart);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			h_file = NULL;
++		} else
++			err = au_sio_cpup_single(d, a->btgt, a->src_bstart, -1,
++						 !AuCpup_DTIME, a->dst_parent);
++		mutex_unlock(h_mtx);
++		au_h_open_post(d, a->src_bstart, h_file);
++		if (!err) {
++			d = a->dst_dentry;
++			au_set_h_dptr(d, a->btgt, NULL);
++			au_update_dbstart(d);
++		} else {
++			au_set_h_dptr(d, a->btgt, NULL);
++			au_set_dbstart(d, a->src_bstart);
++		}
++	}
++	if (!err && a->h_dst)
++		/* it will be set to dinfo later */
++		dget(a->h_dst);
++
++	return err;
++}
++
++/* cf. aufs_rmdir() */
++static int au_ren_del_whtmp(struct au_ren_args *a)
++{
++	int err;
++	struct inode *dir;
++
++	dir = a->dst_dir;
++	SiMustAnyLock(dir->i_sb);
++	if (!au_nhash_test_longer_wh(&a->whlist, a->btgt,
++				     au_sbi(dir->i_sb)->si_dirwh)
++	    || au_test_fs_remote(a->h_dst->d_sb)) {
++		err = au_whtmp_rmdir(dir, a->btgt, a->h_dst, &a->whlist);
++		if (unlikely(err))
++			pr_warning("failed removing whtmp dir %.*s (%d), "
++				   "ignored.\n", AuDLNPair(a->h_dst), err);
++	} else {
++		au_nhash_wh_free(&a->thargs->whlist);
++		a->thargs->whlist = a->whlist;
++		a->whlist.nh_num = 0;
++		au_whtmp_kick_rmdir(dir, a->btgt, a->h_dst, a->thargs);
++		dput(a->h_dst);
++		a->thargs = NULL;
++	}
++
++	return 0;
++}
++
++/* make it 'opaque' dir. */
++static int au_ren_diropq(struct au_ren_args *a)
++{
++	int err;
++	struct dentry *diropq;
++
++	err = 0;
++	a->src_bdiropq = au_dbdiropq(a->src_dentry);
++	a->src_hinode = au_hi(a->src_inode, a->btgt);
++	au_hn_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
++	diropq = au_diropq_create(a->src_dentry, a->btgt);
++	au_hn_imtx_unlock(a->src_hinode);
++	if (IS_ERR(diropq))
++		err = PTR_ERR(diropq);
++	dput(diropq);
++
++	return err;
++}
++
++static int do_rename(struct au_ren_args *a)
++{
++	int err;
++	struct dentry *d, *h_d;
++
++	/* prepare workqueue args for asynchronous rmdir */
++	h_d = a->dst_h_dentry;
++	if (au_ftest_ren(a->flags, ISDIR) && h_d->d_inode) {
++		err = -ENOMEM;
++		a->thargs = au_whtmp_rmdir_alloc(a->src_dentry->d_sb, GFP_NOFS);
++		if (unlikely(!a->thargs))
++			goto out;
++		a->h_dst = dget(h_d);
++	}
++
++	/* create whiteout for src_dentry */
++	if (au_ftest_ren(a->flags, WHSRC)) {
++		a->src_bwh = au_dbwh(a->src_dentry);
++		AuDebugOn(a->src_bwh >= 0);
++		a->src_wh_dentry
++			= au_wh_create(a->src_dentry, a->btgt, a->src_h_parent);
++		err = PTR_ERR(a->src_wh_dentry);
++		if (IS_ERR(a->src_wh_dentry))
++			goto out_thargs;
++	}
++
++	/* lookup whiteout for dentry */
++	if (au_ftest_ren(a->flags, WHDST)) {
++		h_d = au_wh_lkup(a->dst_h_parent, &a->dst_dentry->d_name,
++				 a->br);
++		err = PTR_ERR(h_d);
++		if (IS_ERR(h_d))
++			goto out_whsrc;
++		if (!h_d->d_inode)
++			dput(h_d);
++		else
++			a->dst_wh_dentry = h_d;
++	}
++
++	/* rename dentry to tmpwh */
++	if (a->thargs) {
++		err = au_whtmp_ren(a->dst_h_dentry, a->br);
++		if (unlikely(err))
++			goto out_whdst;
++
++		d = a->dst_dentry;
++		au_set_h_dptr(d, a->btgt, NULL);
++		err = au_lkup_neg(d, a->btgt);
++		if (unlikely(err))
++			goto out_whtmp;
++		a->dst_h_dentry = au_h_dptr(d, a->btgt);
++	}
++
++	/* cpup src */
++	if (a->dst_h_dentry->d_inode && a->src_bstart != a->btgt) {
++		struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
++		struct file *h_file;
++
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		AuDebugOn(au_dbstart(a->src_dentry) != a->src_bstart);
++		h_file = au_h_open_pre(a->src_dentry, a->src_bstart);
++		if (IS_ERR(h_file)) {
++			err = PTR_ERR(h_file);
++			h_file = NULL;
++		} else
++			err = au_sio_cpup_simple(a->src_dentry, a->btgt, -1,
++						 !AuCpup_DTIME);
++		mutex_unlock(h_mtx);
++		au_h_open_post(a->src_dentry, a->src_bstart, h_file);
++		if (unlikely(err))
++			goto out_whtmp;
++	}
++
++	/* rename by vfs_rename or cpup */
++	d = a->dst_dentry;
++	if (au_ftest_ren(a->flags, ISDIR)
++	    && (a->dst_wh_dentry
++		|| au_dbdiropq(d) == a->btgt
++		/* hide the lower to keep xino */
++		|| a->btgt < au_dbend(d)
++		|| au_opt_test(au_mntflags(d->d_sb), ALWAYS_DIROPQ)))
++		au_fset_ren(a->flags, DIROPQ);
++	err = au_ren_or_cpup(a);
++	if (unlikely(err))
++		/* leave the copied-up one */
++		goto out_whtmp;
++
++	/* make dir opaque */
++	if (au_ftest_ren(a->flags, DIROPQ)) {
++		err = au_ren_diropq(a);
++		if (unlikely(err))
++			goto out_rename;
++	}
++
++	/* update target timestamps */
++	AuDebugOn(au_dbstart(a->src_dentry) != a->btgt);
++	a->h_path.dentry = au_h_dptr(a->src_dentry, a->btgt);
++	vfsub_update_h_iattr(&a->h_path, /*did*/NULL); /*ignore*/
++	a->src_inode->i_ctime = a->h_path.dentry->d_inode->i_ctime;
++
++	/* remove whiteout for dentry */
++	if (a->dst_wh_dentry) {
++		a->h_path.dentry = a->dst_wh_dentry;
++		err = au_wh_unlink_dentry(a->dst_h_dir, &a->h_path,
++					  a->dst_dentry);
++		if (unlikely(err))
++			goto out_diropq;
++	}
++
++	/* remove whtmp */
++	if (a->thargs)
++		au_ren_del_whtmp(a); /* ignore this error */
++
++	err = 0;
++	goto out_success;
++
++out_diropq:
++	if (au_ftest_ren(a->flags, DIROPQ))
++		au_ren_rev_diropq(err, a);
++out_rename:
++	if (!au_ftest_ren(a->flags, CPUP))
++		au_ren_rev_rename(err, a);
++	else
++		au_ren_rev_cpup(err, a);
++	dput(a->h_dst);
++out_whtmp:
++	if (a->thargs)
++		au_ren_rev_whtmp(err, a);
++out_whdst:
++	dput(a->dst_wh_dentry);
++	a->dst_wh_dentry = NULL;
++out_whsrc:
++	if (a->src_wh_dentry)
++		au_ren_rev_whsrc(err, a);
++out_success:
++	dput(a->src_wh_dentry);
++	dput(a->dst_wh_dentry);
++out_thargs:
++	if (a->thargs) {
++		dput(a->h_dst);
++		au_whtmp_rmdir_free(a->thargs);
++		a->thargs = NULL;
++	}
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * test if @dentry dir can be rename destination or not.
++ * success means, it is a logically empty dir.
++ */
++static int may_rename_dstdir(struct dentry *dentry, struct au_nhash *whlist)
++{
++	return au_test_empty(dentry, whlist);
++}
++
++/*
++ * test if @dentry dir can be rename source or not.
++ * if it can, return 0 and @children is filled.
++ * success means,
++ * - it is a logically empty dir.
++ * - or, it exists on writable branch and has no children including whiteouts
++ *       on the lower branch.
++ */
++static int may_rename_srcdir(struct dentry *dentry, aufs_bindex_t btgt)
++{
++	int err;
++	unsigned int rdhash;
++	aufs_bindex_t bstart;
++
++	bstart = au_dbstart(dentry);
++	if (bstart != btgt) {
++		struct au_nhash whlist;
++
++		SiMustAnyLock(dentry->d_sb);
++		rdhash = au_sbi(dentry->d_sb)->si_rdhash;
++		if (!rdhash)
++			rdhash = au_rdhash_est(au_dir_size(/*file*/NULL,
++							   dentry));
++		err = au_nhash_alloc(&whlist, rdhash, GFP_NOFS);
++		if (unlikely(err))
++			goto out;
++		err = au_test_empty(dentry, &whlist);
++		au_nhash_wh_free(&whlist);
++		goto out;
++	}
++
++	if (bstart == au_dbtaildir(dentry))
++		return 0; /* success */
++
++	err = au_test_empty_lower(dentry);
++
++out:
++	if (err == -ENOTEMPTY) {
++		AuWarn1("renaming dir who has child(ren) on multiple branches,"
++			" is not supported\n");
++		err = -EXDEV;
++	}
++	return err;
++}
++
++/* side effect: sets whlist and h_dentry */
++static int au_ren_may_dir(struct au_ren_args *a)
++{
++	int err;
++	unsigned int rdhash;
++	struct dentry *d;
++
++	d = a->dst_dentry;
++	SiMustAnyLock(d->d_sb);
++
++	err = 0;
++	if (au_ftest_ren(a->flags, ISDIR) && a->dst_inode) {
++		rdhash = au_sbi(d->d_sb)->si_rdhash;
++		if (!rdhash)
++			rdhash = au_rdhash_est(au_dir_size(/*file*/NULL, d));
++		err = au_nhash_alloc(&a->whlist, rdhash, GFP_NOFS);
++		if (unlikely(err))
++			goto out;
++
++		au_set_dbstart(d, a->dst_bstart);
++		err = may_rename_dstdir(d, &a->whlist);
++		au_set_dbstart(d, a->btgt);
++	}
++	a->dst_h_dentry = au_h_dptr(d, au_dbstart(d));
++	if (unlikely(err))
++		goto out;
++
++	d = a->src_dentry;
++	a->src_h_dentry = au_h_dptr(d, au_dbstart(d));
++	if (au_ftest_ren(a->flags, ISDIR)) {
++		err = may_rename_srcdir(d, a->btgt);
++		if (unlikely(err)) {
++			au_nhash_wh_free(&a->whlist);
++			a->whlist.nh_num = 0;
++		}
++	}
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * simple tests for rename.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++static int au_may_ren(struct au_ren_args *a)
++{
++	int err, isdir;
++	struct inode *h_inode;
++
++	if (a->src_bstart == a->btgt) {
++		err = au_may_del(a->src_dentry, a->btgt, a->src_h_parent,
++				 au_ftest_ren(a->flags, ISDIR));
++		if (unlikely(err))
++			goto out;
++		err = -EINVAL;
++		if (unlikely(a->src_h_dentry == a->h_trap))
++			goto out;
++	}
++
++	err = 0;
++	if (a->dst_bstart != a->btgt)
++		goto out;
++
++	err = -EIO;
++	h_inode = a->dst_h_dentry->d_inode;
++	isdir = !!au_ftest_ren(a->flags, ISDIR);
++	if (!a->dst_dentry->d_inode) {
++		if (unlikely(h_inode))
++			goto out;
++		err = au_may_add(a->dst_dentry, a->btgt, a->dst_h_parent,
++				 isdir);
++	} else {
++		if (unlikely(!h_inode || !h_inode->i_nlink))
++			goto out;
++		err = au_may_del(a->dst_dentry, a->btgt, a->dst_h_parent,
++				 isdir);
++		if (unlikely(err))
++			goto out;
++		err = -ENOTEMPTY;
++		if (unlikely(a->dst_h_dentry == a->h_trap))
++			goto out;
++		err = 0;
++	}
++
++out:
++	if (unlikely(err == -ENOENT || err == -EEXIST))
++		err = -EIO;
++	AuTraceErr(err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * locking order
++ * (VFS)
++ * - src_dir and dir by lock_rename()
++ * - inode if exitsts
++ * (aufs)
++ * - lock all
++ *   + src_dentry and dentry by aufs_read_and_write_lock2() which calls,
++ *     + si_read_lock
++ *     + di_write_lock2_child()
++ *       + di_write_lock_child()
++ *	   + ii_write_lock_child()
++ *       + di_write_lock_child2()
++ *	   + ii_write_lock_child2()
++ *     + src_parent and parent
++ *       + di_write_lock_parent()
++ *	   + ii_write_lock_parent()
++ *       + di_write_lock_parent2()
++ *	   + ii_write_lock_parent2()
++ *   + lower src_dir and dir by vfsub_lock_rename()
++ *   + verify the every relationships between child and parent. if any
++ *     of them failed, unlock all and return -EBUSY.
++ */
++static void au_ren_unlock(struct au_ren_args *a)
++{
++	struct super_block *sb;
++
++	sb = a->dst_dentry->d_sb;
++	if (au_ftest_ren(a->flags, MNT_WRITE))
++		mnt_drop_write(a->br->br_mnt);
++	vfsub_unlock_rename(a->src_h_parent, a->src_hdir,
++			    a->dst_h_parent, a->dst_hdir);
++}
++
++static int au_ren_lock(struct au_ren_args *a)
++{
++	int err;
++	unsigned int udba;
++
++	err = 0;
++	a->src_h_parent = au_h_dptr(a->src_parent, a->btgt);
++	a->src_hdir = au_hi(a->src_dir, a->btgt);
++	a->dst_h_parent = au_h_dptr(a->dst_parent, a->btgt);
++	a->dst_hdir = au_hi(a->dst_dir, a->btgt);
++	a->h_trap = vfsub_lock_rename(a->src_h_parent, a->src_hdir,
++				      a->dst_h_parent, a->dst_hdir);
++	udba = au_opt_udba(a->src_dentry->d_sb);
++	if (unlikely(a->src_hdir->hi_inode != a->src_h_parent->d_inode
++		     || a->dst_hdir->hi_inode != a->dst_h_parent->d_inode))
++		err = au_busy_or_stale();
++	if (!err && au_dbstart(a->src_dentry) == a->btgt)
++		err = au_h_verify(a->src_h_dentry, udba,
++				  a->src_h_parent->d_inode, a->src_h_parent,
++				  a->br);
++	if (!err && au_dbstart(a->dst_dentry) == a->btgt)
++		err = au_h_verify(a->dst_h_dentry, udba,
++				  a->dst_h_parent->d_inode, a->dst_h_parent,
++				  a->br);
++	if (!err) {
++		err = mnt_want_write(a->br->br_mnt);
++		if (unlikely(err))
++			goto out_unlock;
++		au_fset_ren(a->flags, MNT_WRITE);
++		goto out; /* success */
++	}
++
++	err = au_busy_or_stale();
++
++out_unlock:
++	au_ren_unlock(a);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void au_ren_refresh_dir(struct au_ren_args *a)
++{
++	struct inode *dir;
++
++	dir = a->dst_dir;
++	dir->i_version++;
++	if (au_ftest_ren(a->flags, ISDIR)) {
++		/* is this updating defined in POSIX? */
++		au_cpup_attr_timesizes(a->src_inode);
++		au_cpup_attr_nlink(dir, /*force*/1);
++	}
++
++	if (au_ibstart(dir) == a->btgt)
++		au_cpup_attr_timesizes(dir);
++
++	if (au_ftest_ren(a->flags, ISSAMEDIR))
++		return;
++
++	dir = a->src_dir;
++	dir->i_version++;
++	if (au_ftest_ren(a->flags, ISDIR))
++		au_cpup_attr_nlink(dir, /*force*/1);
++	if (au_ibstart(dir) == a->btgt)
++		au_cpup_attr_timesizes(dir);
++}
++
++static void au_ren_refresh(struct au_ren_args *a)
++{
++	aufs_bindex_t bend, bindex;
++	struct dentry *d, *h_d;
++	struct inode *i, *h_i;
++	struct super_block *sb;
++
++	d = a->dst_dentry;
++	d_drop(d);
++	if (a->h_dst)
++		/* already dget-ed by au_ren_or_cpup() */
++		au_set_h_dptr(d, a->btgt, a->h_dst);
++
++	i = a->dst_inode;
++	if (i) {
++		if (!au_ftest_ren(a->flags, ISDIR))
++			vfsub_drop_nlink(i);
++		else {
++			vfsub_dead_dir(i);
++			au_cpup_attr_timesizes(i);
++		}
++		au_update_dbrange(d, /*do_put_zero*/1);
++	} else {
++		bend = a->btgt;
++		for (bindex = au_dbstart(d); bindex < bend; bindex++)
++			au_set_h_dptr(d, bindex, NULL);
++		bend = au_dbend(d);
++		for (bindex = a->btgt + 1; bindex <= bend; bindex++)
++			au_set_h_dptr(d, bindex, NULL);
++		au_update_dbrange(d, /*do_put_zero*/0);
++	}
++
++	d = a->src_dentry;
++	au_set_dbwh(d, -1);
++	bend = au_dbend(d);
++	for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
++		h_d = au_h_dptr(d, bindex);
++		if (h_d)
++			au_set_h_dptr(d, bindex, NULL);
++	}
++	au_set_dbend(d, a->btgt);
++
++	sb = d->d_sb;
++	i = a->src_inode;
++	if (au_opt_test(au_mntflags(sb), PLINK) && au_plink_test(i))
++		return; /* success */
++
++	bend = au_ibend(i);
++	for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
++		h_i = au_h_iptr(i, bindex);
++		if (h_i) {
++			au_xino_write(sb, bindex, h_i->i_ino, /*ino*/0);
++			/* ignore this error */
++			au_set_h_iptr(i, bindex, NULL, 0);
++		}
++	}
++	au_set_ibend(i, a->btgt);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* mainly for link(2) and rename(2) */
++int au_wbr(struct dentry *dentry, aufs_bindex_t btgt)
++{
++	aufs_bindex_t bdiropq, bwh;
++	struct dentry *parent;
++	struct au_branch *br;
++
++	parent = dentry->d_parent;
++	IMustLock(parent->d_inode); /* dir is locked */
++
++	bdiropq = au_dbdiropq(parent);
++	bwh = au_dbwh(dentry);
++	br = au_sbr(dentry->d_sb, btgt);
++	if (au_br_rdonly(br)
++	    || (0 <= bdiropq && bdiropq < btgt)
++	    || (0 <= bwh && bwh < btgt))
++		btgt = -1;
++
++	AuDbg("btgt %d\n", btgt);
++	return btgt;
++}
++
++/* sets src_bstart, dst_bstart and btgt */
++static int au_ren_wbr(struct au_ren_args *a)
++{
++	int err;
++	struct au_wr_dir_args wr_dir_args = {
++		/* .force_btgt	= -1, */
++		.flags		= AuWrDir_ADD_ENTRY
++	};
++
++	a->src_bstart = au_dbstart(a->src_dentry);
++	a->dst_bstart = au_dbstart(a->dst_dentry);
++	if (au_ftest_ren(a->flags, ISDIR))
++		au_fset_wrdir(wr_dir_args.flags, ISDIR);
++	wr_dir_args.force_btgt = a->src_bstart;
++	if (a->dst_inode && a->dst_bstart < a->src_bstart)
++		wr_dir_args.force_btgt = a->dst_bstart;
++	wr_dir_args.force_btgt = au_wbr(a->dst_dentry, wr_dir_args.force_btgt);
++	err = au_wr_dir(a->dst_dentry, a->src_dentry, &wr_dir_args);
++	a->btgt = err;
++
++	return err;
++}
++
++static void au_ren_dt(struct au_ren_args *a)
++{
++	a->h_path.dentry = a->src_h_parent;
++	au_dtime_store(a->src_dt + AuPARENT, a->src_parent, &a->h_path);
++	if (!au_ftest_ren(a->flags, ISSAMEDIR)) {
++		a->h_path.dentry = a->dst_h_parent;
++		au_dtime_store(a->dst_dt + AuPARENT, a->dst_parent, &a->h_path);
++	}
++
++	au_fclr_ren(a->flags, DT_DSTDIR);
++	if (!au_ftest_ren(a->flags, ISDIR))
++		return;
++
++	a->h_path.dentry = a->src_h_dentry;
++	au_dtime_store(a->src_dt + AuCHILD, a->src_dentry, &a->h_path);
++	if (a->dst_h_dentry->d_inode) {
++		au_fset_ren(a->flags, DT_DSTDIR);
++		a->h_path.dentry = a->dst_h_dentry;
++		au_dtime_store(a->dst_dt + AuCHILD, a->dst_dentry, &a->h_path);
++	}
++}
++
++static void au_ren_rev_dt(int err, struct au_ren_args *a)
++{
++	struct dentry *h_d;
++	struct mutex *h_mtx;
++
++	au_dtime_revert(a->src_dt + AuPARENT);
++	if (!au_ftest_ren(a->flags, ISSAMEDIR))
++		au_dtime_revert(a->dst_dt + AuPARENT);
++
++	if (au_ftest_ren(a->flags, ISDIR) && err != -EIO) {
++		h_d = a->src_dt[AuCHILD].dt_h_path.dentry;
++		h_mtx = &h_d->d_inode->i_mutex;
++		mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++		au_dtime_revert(a->src_dt + AuCHILD);
++		mutex_unlock(h_mtx);
++
++		if (au_ftest_ren(a->flags, DT_DSTDIR)) {
++			h_d = a->dst_dt[AuCHILD].dt_h_path.dentry;
++			h_mtx = &h_d->d_inode->i_mutex;
++			mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++			au_dtime_revert(a->dst_dt + AuCHILD);
++			mutex_unlock(h_mtx);
++		}
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++int aufs_rename(struct inode *_src_dir, struct dentry *_src_dentry,
++		struct inode *_dst_dir, struct dentry *_dst_dentry)
++{
++	int err, flags;
++	/* reduce stack space */
++	struct au_ren_args *a;
++
++	AuDbg("%.*s, %.*s\n", AuDLNPair(_src_dentry), AuDLNPair(_dst_dentry));
++	IMustLock(_src_dir);
++	IMustLock(_dst_dir);
++
++	err = -ENOMEM;
++	BUILD_BUG_ON(sizeof(*a) > PAGE_SIZE);
++	a = kzalloc(sizeof(*a), GFP_NOFS);
++	if (unlikely(!a))
++		goto out;
++
++	a->src_dir = _src_dir;
++	a->src_dentry = _src_dentry;
++	a->src_inode = a->src_dentry->d_inode;
++	a->src_parent = a->src_dentry->d_parent; /* dir inode is locked */
++	a->dst_dir = _dst_dir;
++	a->dst_dentry = _dst_dentry;
++	a->dst_inode = a->dst_dentry->d_inode;
++	a->dst_parent = a->dst_dentry->d_parent; /* dir inode is locked */
++	if (a->dst_inode) {
++		IMustLock(a->dst_inode);
++		au_igrab(a->dst_inode);
++	}
++
++	err = -ENOTDIR;
++	flags = AuLock_FLUSH | AuLock_NOPLM | AuLock_GEN;
++	if (S_ISDIR(a->src_inode->i_mode)) {
++		au_fset_ren(a->flags, ISDIR);
++		if (unlikely(a->dst_inode && !S_ISDIR(a->dst_inode->i_mode)))
++			goto out_free;
++		err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
++						AuLock_DIR | flags);
++	} else
++		err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
++						flags);
++	if (unlikely(err))
++		goto out_free;
++
++	err = au_d_hashed_positive(a->src_dentry);
++	if (unlikely(err))
++		goto out_unlock;
++	err = -ENOENT;
++	if (a->dst_inode) {
++		/*
++		 * If it is a dir, VFS unhash dst_dentry before this
++		 * function. It means we cannot rely upon d_unhashed().
++		 */
++		if (unlikely(!a->dst_inode->i_nlink))
++			goto out_unlock;
++		if (!S_ISDIR(a->dst_inode->i_mode)) {
++			err = au_d_hashed_positive(a->dst_dentry);
++			if (unlikely(err))
++				goto out_unlock;
++		} else if (unlikely(IS_DEADDIR(a->dst_inode)))
++			goto out_unlock;
++	} else if (unlikely(d_unhashed(a->dst_dentry)))
++		goto out_unlock;
++
++	au_fset_ren(a->flags, ISSAMEDIR); /* temporary */
++	di_write_lock_parent(a->dst_parent);
++
++	/* which branch we process */
++	err = au_ren_wbr(a);
++	if (unlikely(err < 0))
++		goto out_parent;
++	a->br = au_sbr(a->dst_dentry->d_sb, a->btgt);
++	a->h_path.mnt = a->br->br_mnt;
++
++	/* are they available to be renamed */
++	err = au_ren_may_dir(a);
++	if (unlikely(err))
++		goto out_children;
++
++	/* prepare the writable parent dir on the same branch */
++	if (a->dst_bstart == a->btgt) {
++		au_fset_ren(a->flags, WHDST);
++	} else {
++		err = au_cpup_dirs(a->dst_dentry, a->btgt);
++		if (unlikely(err))
++			goto out_children;
++	}
++
++	if (a->src_dir != a->dst_dir) {
++		/*
++		 * this temporary unlock is safe,
++		 * because both dir->i_mutex are locked.
++		 */
++		di_write_unlock(a->dst_parent);
++		di_write_lock_parent(a->src_parent);
++		err = au_wr_dir_need_wh(a->src_dentry,
++					au_ftest_ren(a->flags, ISDIR),
++					&a->btgt);
++		di_write_unlock(a->src_parent);
++		di_write_lock2_parent(a->src_parent, a->dst_parent, /*isdir*/1);
++		au_fclr_ren(a->flags, ISSAMEDIR);
++	} else
++		err = au_wr_dir_need_wh(a->src_dentry,
++					au_ftest_ren(a->flags, ISDIR),
++					&a->btgt);
++	if (unlikely(err < 0))
++		goto out_children;
++	if (err)
++		au_fset_ren(a->flags, WHSRC);
++
++	/* lock them all */
++	err = au_ren_lock(a);
++	if (unlikely(err))
++		goto out_children;
++
++	if (!au_opt_test(au_mntflags(a->dst_dir->i_sb), UDBA_NONE))
++		err = au_may_ren(a);
++	else if (unlikely(a->dst_dentry->d_name.len > AUFS_MAX_NAMELEN))
++		err = -ENAMETOOLONG;
++	if (unlikely(err))
++		goto out_hdir;
++
++	/* store timestamps to be revertible */
++	au_ren_dt(a);
++
++	/* here we go */
++	err = do_rename(a);
++	if (unlikely(err))
++		goto out_dt;
++
++	/* update dir attributes */
++	au_ren_refresh_dir(a);
++
++	/* dput/iput all lower dentries */
++	au_ren_refresh(a);
++
++	goto out_hdir; /* success */
++
++out_dt:
++	au_ren_rev_dt(err, a);
++out_hdir:
++	au_ren_unlock(a);
++out_children:
++	au_nhash_wh_free(&a->whlist);
++	if (err && a->dst_inode && a->dst_bstart != a->btgt) {
++		AuDbg("bstart %d, btgt %d\n", a->dst_bstart, a->btgt);
++		au_set_h_dptr(a->dst_dentry, a->btgt, NULL);
++		au_set_dbstart(a->dst_dentry, a->dst_bstart);
++	}
++out_parent:
++	if (!err)
++		d_move(a->src_dentry, a->dst_dentry);
++	else {
++		au_update_dbstart(a->dst_dentry);
++		if (!a->dst_inode)
++			d_drop(a->dst_dentry);
++	}
++	if (au_ftest_ren(a->flags, ISSAMEDIR))
++		di_write_unlock(a->dst_parent);
++	else
++		di_write_unlock2(a->src_parent, a->dst_parent);
++out_unlock:
++	aufs_read_and_write_unlock2(a->dst_dentry, a->src_dentry);
++out_free:
++	iput(a->dst_inode);
++	if (a->thargs)
++		au_whtmp_rmdir_free(a->thargs);
++	kfree(a);
++out:
++	AuTraceErr(err);
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/iinfo.c linux-2.6.36/fs/aufs/iinfo.c
+--- linux-2.6.36.orig/fs/aufs/iinfo.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/iinfo.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,263 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode private data
++ */
++
++#include "aufs.h"
++
++struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex)
++{
++	struct inode *h_inode;
++
++	IiMustAnyLock(inode);
++
++	h_inode = au_ii(inode)->ii_hinode[0 + bindex].hi_inode;
++	AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
++	return h_inode;
++}
++
++/* todo: hard/soft set? */
++void au_hiput(struct au_hinode *hinode)
++{
++	au_hn_free(hinode);
++	dput(hinode->hi_whdentry);
++	iput(hinode->hi_inode);
++}
++
++unsigned int au_hi_flags(struct inode *inode, int isdir)
++{
++	unsigned int flags;
++	const unsigned int mnt_flags = au_mntflags(inode->i_sb);
++
++	flags = 0;
++	if (au_opt_test(mnt_flags, XINO))
++		au_fset_hi(flags, XINO);
++	if (isdir && au_opt_test(mnt_flags, UDBA_HNOTIFY))
++		au_fset_hi(flags, HNOTIFY);
++	return flags;
++}
++
++void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
++		   struct inode *h_inode, unsigned int flags)
++{
++	struct au_hinode *hinode;
++	struct inode *hi;
++	struct au_iinfo *iinfo = au_ii(inode);
++
++	IiMustWriteLock(inode);
++
++	hinode = iinfo->ii_hinode + bindex;
++	hi = hinode->hi_inode;
++	AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
++
++	if (hi)
++		au_hiput(hinode);
++	hinode->hi_inode = h_inode;
++	if (h_inode) {
++		int err;
++		struct super_block *sb = inode->i_sb;
++		struct au_branch *br;
++
++		AuDebugOn(inode->i_mode
++			  && (h_inode->i_mode & S_IFMT)
++			  != (inode->i_mode & S_IFMT));
++		if (bindex == iinfo->ii_bstart)
++			au_cpup_igen(inode, h_inode);
++		br = au_sbr(sb, bindex);
++		hinode->hi_id = br->br_id;
++		if (au_ftest_hi(flags, XINO)) {
++			err = au_xino_write(sb, bindex, h_inode->i_ino,
++					    inode->i_ino);
++			if (unlikely(err))
++				AuIOErr1("failed au_xino_write() %d\n", err);
++		}
++
++		if (au_ftest_hi(flags, HNOTIFY)
++		    && au_br_hnotifyable(br->br_perm)) {
++			err = au_hn_alloc(hinode, inode);
++			if (unlikely(err))
++				AuIOErr1("au_hn_alloc() %d\n", err);
++		}
++	}
++}
++
++void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
++		  struct dentry *h_wh)
++{
++	struct au_hinode *hinode;
++
++	IiMustWriteLock(inode);
++
++	hinode = au_ii(inode)->ii_hinode + bindex;
++	AuDebugOn(hinode->hi_whdentry);
++	hinode->hi_whdentry = h_wh;
++}
++
++void au_update_iigen(struct inode *inode)
++{
++	atomic_set(&au_ii(inode)->ii_generation, au_sigen(inode->i_sb));
++	/* smp_mb(); */ /* atomic_set */
++}
++
++/* it may be called at remount time, too */
++void au_update_ibrange(struct inode *inode, int do_put_zero)
++{
++	struct au_iinfo *iinfo;
++	aufs_bindex_t bindex, bend;
++
++	iinfo = au_ii(inode);
++	if (!iinfo)
++		return;
++
++	IiMustWriteLock(inode);
++
++	if (do_put_zero && iinfo->ii_bstart >= 0) {
++		for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
++		     bindex++) {
++			struct inode *h_i;
++
++			h_i = iinfo->ii_hinode[0 + bindex].hi_inode;
++			if (h_i && !h_i->i_nlink)
++				au_set_h_iptr(inode, bindex, NULL, 0);
++		}
++	}
++
++	iinfo->ii_bstart = -1;
++	iinfo->ii_bend = -1;
++	bend = au_sbend(inode->i_sb);
++	for (bindex = 0; bindex <= bend; bindex++)
++		if (iinfo->ii_hinode[0 + bindex].hi_inode) {
++			iinfo->ii_bstart = bindex;
++			break;
++		}
++	if (iinfo->ii_bstart >= 0)
++		for (bindex = bend; bindex >= iinfo->ii_bstart; bindex--)
++			if (iinfo->ii_hinode[0 + bindex].hi_inode) {
++				iinfo->ii_bend = bindex;
++				break;
++			}
++	AuDebugOn(iinfo->ii_bstart > iinfo->ii_bend);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_icntnr_init_once(void *_c)
++{
++	struct au_icntnr *c = _c;
++	struct au_iinfo *iinfo = &c->iinfo;
++	static struct lock_class_key aufs_ii;
++
++	au_rw_init(&iinfo->ii_rwsem);
++	au_rw_class(&iinfo->ii_rwsem, &aufs_ii);
++	inode_init_once(&c->vfs_inode);
++}
++
++int au_iinfo_init(struct inode *inode)
++{
++	struct au_iinfo *iinfo;
++	struct super_block *sb;
++	int nbr, i;
++
++	sb = inode->i_sb;
++	iinfo = &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
++	nbr = au_sbend(sb) + 1;
++	if (unlikely(nbr <= 0))
++		nbr = 1;
++	iinfo->ii_hinode = kcalloc(nbr, sizeof(*iinfo->ii_hinode), GFP_NOFS);
++	if (iinfo->ii_hinode) {
++		au_ninodes_inc(sb);
++		for (i = 0; i < nbr; i++)
++			iinfo->ii_hinode[i].hi_id = -1;
++
++		atomic_set(&iinfo->ii_generation, au_sigen(sb));
++		/* smp_mb(); */ /* atomic_set */
++		iinfo->ii_bstart = -1;
++		iinfo->ii_bend = -1;
++		iinfo->ii_vdir = NULL;
++		return 0;
++	}
++	return -ENOMEM;
++}
++
++int au_ii_realloc(struct au_iinfo *iinfo, int nbr)
++{
++	int err, sz;
++	struct au_hinode *hip;
++
++	AuRwMustWriteLock(&iinfo->ii_rwsem);
++
++	err = -ENOMEM;
++	sz = sizeof(*hip) * (iinfo->ii_bend + 1);
++	if (!sz)
++		sz = sizeof(*hip);
++	hip = au_kzrealloc(iinfo->ii_hinode, sz, sizeof(*hip) * nbr, GFP_NOFS);
++	if (hip) {
++		iinfo->ii_hinode = hip;
++		err = 0;
++	}
++
++	return err;
++}
++
++void au_iinfo_fin(struct inode *inode)
++{
++	struct au_iinfo *iinfo;
++	struct au_hinode *hi;
++	struct super_block *sb;
++	aufs_bindex_t bindex, bend;
++	const unsigned char unlinked = !inode->i_nlink;
++
++	iinfo = au_ii(inode);
++	/* bad_inode case */
++	if (!iinfo)
++		return;
++
++	sb = inode->i_sb;
++	au_ninodes_dec(sb);
++	if (si_pid_test(sb))
++		au_xino_delete_inode(inode, unlinked);
++	else {
++		/*
++		 * it is safe to hide the dependency between sbinfo and
++		 * sb->s_umount.
++		 */
++		lockdep_off();
++		si_noflush_read_lock(sb);
++		au_xino_delete_inode(inode, unlinked);
++		si_read_unlock(sb);
++		lockdep_on();
++	}
++
++	if (iinfo->ii_vdir)
++		au_vdir_free(iinfo->ii_vdir);
++
++	bindex = iinfo->ii_bstart;
++	if (bindex >= 0) {
++		hi = iinfo->ii_hinode + bindex;
++		bend = iinfo->ii_bend;
++		while (bindex++ <= bend) {
++			if (hi->hi_inode)
++				au_hiput(hi);
++			hi++;
++		}
++	}
++	kfree(iinfo->ii_hinode);
++	AuRwDestroy(&iinfo->ii_rwsem);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/inode.c linux-2.6.36/fs/aufs/inode.c
+--- linux-2.6.36.orig/fs/aufs/inode.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/inode.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,471 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode functions
++ */
++
++#include "aufs.h"
++
++struct inode *au_igrab(struct inode *inode)
++{
++	if (inode) {
++		AuDebugOn(!atomic_read(&inode->i_count));
++		atomic_inc(&inode->i_count);
++	}
++	return inode;
++}
++
++static void au_refresh_hinode_attr(struct inode *inode, int do_version)
++{
++	au_cpup_attr_all(inode, /*force*/0);
++	au_update_iigen(inode);
++	if (do_version)
++		inode->i_version++;
++}
++
++static int au_ii_refresh(struct inode *inode, int *update)
++{
++	int err, e;
++	umode_t type;
++	aufs_bindex_t bindex, new_bindex;
++	struct super_block *sb;
++	struct au_iinfo *iinfo;
++	struct au_hinode *p, *q, tmp;
++
++	IiMustWriteLock(inode);
++
++	*update = 0;
++	sb = inode->i_sb;
++	type = inode->i_mode & S_IFMT;
++	iinfo = au_ii(inode);
++	err = au_ii_realloc(iinfo, au_sbend(sb) + 1);
++	if (unlikely(err))
++		goto out;
++
++	AuDebugOn(iinfo->ii_bstart < 0);
++	p = iinfo->ii_hinode + iinfo->ii_bstart;
++	for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
++	     bindex++, p++) {
++		if (!p->hi_inode)
++			continue;
++
++		AuDebugOn(type != (p->hi_inode->i_mode & S_IFMT));
++		new_bindex = au_br_index(sb, p->hi_id);
++		if (new_bindex == bindex)
++			continue;
++
++		if (new_bindex < 0) {
++			*update = 1;
++			au_hiput(p);
++			p->hi_inode = NULL;
++			continue;
++		}
++
++		if (new_bindex < iinfo->ii_bstart)
++			iinfo->ii_bstart = new_bindex;
++		if (iinfo->ii_bend < new_bindex)
++			iinfo->ii_bend = new_bindex;
++		/* swap two lower inode, and loop again */
++		q = iinfo->ii_hinode + new_bindex;
++		tmp = *q;
++		*q = *p;
++		*p = tmp;
++		if (tmp.hi_inode) {
++			bindex--;
++			p--;
++		}
++	}
++	au_update_ibrange(inode, /*do_put_zero*/0);
++	e = au_dy_irefresh(inode);
++	if (unlikely(e && !err))
++		err = e;
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++int au_refresh_hinode_self(struct inode *inode)
++{
++	int err, update;
++
++	err = au_ii_refresh(inode, &update);
++	if (!err)
++		au_refresh_hinode_attr(inode, update && S_ISDIR(inode->i_mode));
++
++	AuTraceErr(err);
++	return err;
++}
++
++int au_refresh_hinode(struct inode *inode, struct dentry *dentry)
++{
++	int err, e, update;
++	unsigned int flags;
++	umode_t mode;
++	aufs_bindex_t bindex, bend;
++	unsigned char isdir;
++	struct au_hinode *p;
++	struct au_iinfo *iinfo;
++
++	err = au_ii_refresh(inode, &update);
++	if (unlikely(err))
++		goto out;
++
++	update = 0;
++	iinfo = au_ii(inode);
++	p = iinfo->ii_hinode + iinfo->ii_bstart;
++	mode = (inode->i_mode & S_IFMT);
++	isdir = S_ISDIR(mode);
++	flags = au_hi_flags(inode, isdir);
++	bend = au_dbend(dentry);
++	for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
++		struct inode *h_i;
++		struct dentry *h_d;
++
++		h_d = au_h_dptr(dentry, bindex);
++		if (!h_d || !h_d->d_inode)
++			continue;
++
++		AuDebugOn(mode != (h_d->d_inode->i_mode & S_IFMT));
++		if (iinfo->ii_bstart <= bindex && bindex <= iinfo->ii_bend) {
++			h_i = au_h_iptr(inode, bindex);
++			if (h_i) {
++				if (h_i == h_d->d_inode)
++					continue;
++				err = -EIO;
++				break;
++			}
++		}
++		if (bindex < iinfo->ii_bstart)
++			iinfo->ii_bstart = bindex;
++		if (iinfo->ii_bend < bindex)
++			iinfo->ii_bend = bindex;
++		au_set_h_iptr(inode, bindex, au_igrab(h_d->d_inode), flags);
++		update = 1;
++	}
++	au_update_ibrange(inode, /*do_put_zero*/0);
++	e = au_dy_irefresh(inode);
++	if (unlikely(e && !err))
++		err = e;
++	if (!err)
++		au_refresh_hinode_attr(inode, update && isdir);
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static int set_inode(struct inode *inode, struct dentry *dentry)
++{
++	int err;
++	unsigned int flags;
++	umode_t mode;
++	aufs_bindex_t bindex, bstart, btail;
++	unsigned char isdir;
++	struct dentry *h_dentry;
++	struct inode *h_inode;
++	struct au_iinfo *iinfo;
++
++	IiMustWriteLock(inode);
++
++	err = 0;
++	isdir = 0;
++	bstart = au_dbstart(dentry);
++	h_inode = au_h_dptr(dentry, bstart)->d_inode;
++	mode = h_inode->i_mode;
++	switch (mode & S_IFMT) {
++	case S_IFREG:
++		btail = au_dbtail(dentry);
++		inode->i_op = &aufs_iop;
++		inode->i_fop = &aufs_file_fop;
++		err = au_dy_iaop(inode, bstart, h_inode);
++		if (unlikely(err))
++			goto out;
++		break;
++	case S_IFDIR:
++		isdir = 1;
++		btail = au_dbtaildir(dentry);
++		inode->i_op = &aufs_dir_iop;
++		inode->i_fop = &aufs_dir_fop;
++		break;
++	case S_IFLNK:
++		btail = au_dbtail(dentry);
++		inode->i_op = &aufs_symlink_iop;
++		break;
++	case S_IFBLK:
++	case S_IFCHR:
++	case S_IFIFO:
++	case S_IFSOCK:
++		btail = au_dbtail(dentry);
++		inode->i_op = &aufs_iop;
++		au_init_special_fop(inode, mode, h_inode->i_rdev);
++		break;
++	default:
++		AuIOErr("Unknown file type 0%o\n", mode);
++		err = -EIO;
++		goto out;
++	}
++
++	/* do not set hnotify for whiteouted dirs (SHWH mode) */
++	flags = au_hi_flags(inode, isdir);
++	if (au_opt_test(au_mntflags(dentry->d_sb), SHWH)
++	    && au_ftest_hi(flags, HNOTIFY)
++	    && dentry->d_name.len > AUFS_WH_PFX_LEN
++	    && !memcmp(dentry->d_name.name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))
++		au_fclr_hi(flags, HNOTIFY);
++	iinfo = au_ii(inode);
++	iinfo->ii_bstart = bstart;
++	iinfo->ii_bend = btail;
++	for (bindex = bstart; bindex <= btail; bindex++) {
++		h_dentry = au_h_dptr(dentry, bindex);
++		if (h_dentry)
++			au_set_h_iptr(inode, bindex,
++				      au_igrab(h_dentry->d_inode), flags);
++	}
++	au_cpup_attr_all(inode, /*force*/1);
++
++out:
++	return err;
++}
++
++/*
++ * successful returns with iinfo write_locked
++ * minus: errno
++ * zero: success, matched
++ * plus: no error, but unmatched
++ */
++static int reval_inode(struct inode *inode, struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	struct inode *h_inode, *h_dinode;
++
++	/*
++	 * before this function, if aufs got any iinfo lock, it must be only
++	 * one, the parent dir.
++	 * it can happen by UDBA and the obsoleted inode number.
++	 */
++	err = -EIO;
++	if (unlikely(inode->i_ino == parent_ino(dentry)))
++		goto out;
++
++	err = 1;
++	ii_write_lock_new_child(inode);
++	h_dinode = au_h_dptr(dentry, au_dbstart(dentry))->d_inode;
++	bend = au_ibend(inode);
++	for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
++		h_inode = au_h_iptr(inode, bindex);
++		if (h_inode && h_inode == h_dinode) {
++			err = 0;
++			if (au_iigen_test(inode, au_digen(dentry)))
++				err = au_refresh_hinode(inode, dentry);
++			break;
++		}
++	}
++
++	if (unlikely(err))
++		ii_write_unlock(inode);
++out:
++	return err;
++}
++
++int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++	   unsigned int d_type, ino_t *ino)
++{
++	int err;
++	struct mutex *mtx;
++
++	/* prevent hardlinked inode number from race condition */
++	mtx = NULL;
++	if (d_type != DT_DIR) {
++		mtx = &au_sbr(sb, bindex)->br_xino.xi_nondir_mtx;
++		mutex_lock(mtx);
++	}
++	err = au_xino_read(sb, bindex, h_ino, ino);
++	if (unlikely(err))
++		goto out;
++
++	if (!*ino) {
++		err = -EIO;
++		*ino = au_xino_new_ino(sb);
++		if (unlikely(!*ino))
++			goto out;
++		err = au_xino_write(sb, bindex, h_ino, *ino);
++		if (unlikely(err))
++			goto out;
++	}
++
++out:
++	if (mtx)
++		mutex_unlock(mtx);
++	return err;
++}
++
++/* successful returns with iinfo write_locked */
++/* todo: return with unlocked? */
++struct inode *au_new_inode(struct dentry *dentry, int must_new)
++{
++	struct inode *inode, *h_inode;
++	struct dentry *h_dentry;
++	struct super_block *sb;
++	struct mutex *mtx;
++	ino_t h_ino, ino;
++	int err;
++	aufs_bindex_t bstart;
++
++	sb = dentry->d_sb;
++	bstart = au_dbstart(dentry);
++	h_dentry = au_h_dptr(dentry, bstart);
++	h_inode = h_dentry->d_inode;
++	h_ino = h_inode->i_ino;
++
++	/*
++	 * stop 'race'-ing between hardlinks under different
++	 * parents.
++	 */
++	mtx = NULL;
++	if (!S_ISDIR(h_inode->i_mode))
++		mtx = &au_sbr(sb, bstart)->br_xino.xi_nondir_mtx;
++
++new_ino:
++	if (mtx)
++		mutex_lock(mtx);
++	err = au_xino_read(sb, bstart, h_ino, &ino);
++	inode = ERR_PTR(err);
++	if (unlikely(err))
++		goto out;
++
++	if (!ino) {
++		ino = au_xino_new_ino(sb);
++		if (unlikely(!ino)) {
++			inode = ERR_PTR(-EIO);
++			goto out;
++		}
++	}
++
++	AuDbg("i%lu\n", (unsigned long)ino);
++	inode = au_iget_locked(sb, ino);
++	err = PTR_ERR(inode);
++	if (IS_ERR(inode))
++		goto out;
++
++	AuDbg("%lx, new %d\n", inode->i_state, !!(inode->i_state & I_NEW));
++	if (inode->i_state & I_NEW) {
++		ii_write_lock_new_child(inode);
++		err = set_inode(inode, dentry);
++		if (!err) {
++			unlock_new_inode(inode);
++			goto out; /* success */
++		}
++
++		/*
++		 * iget_failed() calls iput(), but we need to call
++		 * ii_write_unlock() after iget_failed(). so dirty hack for
++		 * i_count.
++		 */
++		atomic_inc(&inode->i_count);
++		iget_failed(inode);
++		ii_write_unlock(inode);
++		au_xino_write(sb, bstart, h_ino, /*ino*/0);
++		/* ignore this error */
++		goto out_iput;
++	} else if (!must_new && !IS_DEADDIR(inode) && inode->i_nlink) {
++		/*
++		 * horrible race condition between lookup, readdir and copyup
++		 * (or something).
++		 */
++		if (mtx)
++			mutex_unlock(mtx);
++		err = reval_inode(inode, dentry);
++		if (unlikely(err < 0)) {
++			mtx = NULL;
++			goto out_iput;
++		}
++
++		if (!err) {
++			mtx = NULL;
++			goto out; /* success */
++		} else if (mtx)
++			mutex_lock(mtx);
++	}
++
++	if (unlikely(au_test_fs_unique_ino(h_dentry->d_inode)))
++		AuWarn1("Warning: Un-notified UDBA or repeatedly renamed dir,"
++			" b%d, %s, %.*s, hi%lu, i%lu.\n",
++			bstart, au_sbtype(h_dentry->d_sb), AuDLNPair(dentry),
++			(unsigned long)h_ino, (unsigned long)ino);
++	ino = 0;
++	err = au_xino_write(sb, bstart, h_ino, /*ino*/0);
++	if (!err) {
++		iput(inode);
++		if (mtx)
++			mutex_unlock(mtx);
++		goto new_ino;
++	}
++
++out_iput:
++	iput(inode);
++	inode = ERR_PTR(err);
++out:
++	if (mtx)
++		mutex_unlock(mtx);
++	return inode;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
++	       struct inode *inode)
++{
++	int err;
++
++	err = au_br_rdonly(au_sbr(sb, bindex));
++
++	/* pseudo-link after flushed may happen out of bounds */
++	if (!err
++	    && inode
++	    && au_ibstart(inode) <= bindex
++	    && bindex <= au_ibend(inode)) {
++		/*
++		 * permission check is unnecessary since vfsub routine
++		 * will be called later
++		 */
++		struct inode *hi = au_h_iptr(inode, bindex);
++		if (hi)
++			err = IS_IMMUTABLE(hi) ? -EROFS : 0;
++	}
++
++	return err;
++}
++
++int au_test_h_perm(struct inode *h_inode, int mask)
++{
++	if (!current_fsuid())
++		return 0;
++	return inode_permission(h_inode, mask);
++}
++
++int au_test_h_perm_sio(struct inode *h_inode, int mask)
++{
++	if (au_test_nfs(h_inode->i_sb)
++	    && (mask & MAY_WRITE)
++	    && S_ISDIR(h_inode->i_mode))
++		mask |= MAY_READ; /* force permission check */
++	return au_test_h_perm(h_inode, mask);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/inode.h linux-2.6.36/fs/aufs/inode.h
+--- linux-2.6.36.orig/fs/aufs/inode.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/inode.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,546 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * inode operations
++ */
++
++#ifndef __AUFS_INODE_H__
++#define __AUFS_INODE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/fsnotify.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++struct vfsmount;
++
++struct au_hnotify {
++#ifdef CONFIG_AUFS_HNOTIFY
++#ifdef CONFIG_AUFS_HFSNOTIFY
++	/* never use fsnotify_add_vfsmount_mark() */
++	struct fsnotify_mark		hn_mark;
++	int				hn_mark_dead;
++#endif
++	struct inode			*hn_aufs_inode;	/* no get/put */
++#endif
++} ____cacheline_aligned_in_smp;
++
++struct au_hinode {
++	struct inode		*hi_inode;
++	aufs_bindex_t		hi_id;
++#ifdef CONFIG_AUFS_HNOTIFY
++	struct au_hnotify	*hi_notify;
++#endif
++
++	/* reference to the copied-up whiteout with get/put */
++	struct dentry		*hi_whdentry;
++};
++
++struct au_vdir;
++struct au_iinfo {
++	atomic_t		ii_generation;
++	struct super_block	*ii_hsb1;	/* no get/put */
++
++	struct au_rwsem		ii_rwsem;
++	aufs_bindex_t		ii_bstart, ii_bend;
++	__u32			ii_higen;
++	struct au_hinode	*ii_hinode;
++	struct au_vdir		*ii_vdir;
++};
++
++struct au_icntnr {
++	struct au_iinfo iinfo;
++	struct inode vfs_inode;
++} ____cacheline_aligned_in_smp;
++
++/* au_pin flags */
++#define AuPin_DI_LOCKED		1
++#define AuPin_MNT_WRITE		(1 << 1)
++#define au_ftest_pin(flags, name)	((flags) & AuPin_##name)
++#define au_fset_pin(flags, name) \
++	do { (flags) |= AuPin_##name; } while (0)
++#define au_fclr_pin(flags, name) \
++	do { (flags) &= ~AuPin_##name; } while (0)
++
++struct au_pin {
++	/* input */
++	struct dentry *dentry;
++	unsigned int udba;
++	unsigned char lsc_di, lsc_hi, flags;
++	aufs_bindex_t bindex;
++
++	/* output */
++	struct dentry *parent;
++	struct au_hinode *hdir;
++	struct vfsmount *h_mnt;
++};
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_iinfo *au_ii(struct inode *inode)
++{
++	struct au_iinfo *iinfo;
++
++	iinfo = &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
++	if (iinfo->ii_hinode)
++		return iinfo;
++	return NULL; /* debugging bad_inode case */
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* inode.c */
++struct inode *au_igrab(struct inode *inode);
++int au_refresh_hinode_self(struct inode *inode);
++int au_refresh_hinode(struct inode *inode, struct dentry *dentry);
++int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++	   unsigned int d_type, ino_t *ino);
++struct inode *au_new_inode(struct dentry *dentry, int must_new);
++int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
++	       struct inode *inode);
++int au_test_h_perm(struct inode *h_inode, int mask);
++int au_test_h_perm_sio(struct inode *h_inode, int mask);
++
++static inline int au_wh_ino(struct super_block *sb, aufs_bindex_t bindex,
++			    ino_t h_ino, unsigned int d_type, ino_t *ino)
++{
++#ifdef CONFIG_AUFS_SHWH
++	return au_ino(sb, bindex, h_ino, d_type, ino);
++#else
++	return 0;
++#endif
++}
++
++/* i_op.c */
++extern struct inode_operations aufs_iop, aufs_symlink_iop, aufs_dir_iop;
++
++/* au_wr_dir flags */
++#define AuWrDir_ADD_ENTRY	1
++#define AuWrDir_ISDIR		(1 << 1)
++#define au_ftest_wrdir(flags, name)	((flags) & AuWrDir_##name)
++#define au_fset_wrdir(flags, name) \
++	do { (flags) |= AuWrDir_##name; } while (0)
++#define au_fclr_wrdir(flags, name) \
++	do { (flags) &= ~AuWrDir_##name; } while (0)
++
++struct au_wr_dir_args {
++	aufs_bindex_t force_btgt;
++	unsigned char flags;
++};
++int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
++	      struct au_wr_dir_args *args);
++
++struct dentry *au_pinned_h_parent(struct au_pin *pin);
++void au_pin_init(struct au_pin *pin, struct dentry *dentry,
++		 aufs_bindex_t bindex, int lsc_di, int lsc_hi,
++		 unsigned int udba, unsigned char flags);
++int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
++	   unsigned int udba, unsigned char flags) __must_check;
++int au_do_pin(struct au_pin *pin) __must_check;
++void au_unpin(struct au_pin *pin);
++
++/* i_op_add.c */
++int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
++	       struct dentry *h_parent, int isdir);
++int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev);
++int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname);
++int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
++		struct nameidata *nd);
++int aufs_link(struct dentry *src_dentry, struct inode *dir,
++	      struct dentry *dentry);
++int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
++
++/* i_op_del.c */
++int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup);
++int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
++	       struct dentry *h_parent, int isdir);
++int aufs_unlink(struct inode *dir, struct dentry *dentry);
++int aufs_rmdir(struct inode *dir, struct dentry *dentry);
++
++/* i_op_ren.c */
++int au_wbr(struct dentry *dentry, aufs_bindex_t btgt);
++int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
++		struct inode *dir, struct dentry *dentry);
++
++/* iinfo.c */
++struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex);
++void au_hiput(struct au_hinode *hinode);
++void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
++		  struct dentry *h_wh);
++unsigned int au_hi_flags(struct inode *inode, int isdir);
++
++/* hinode flags */
++#define AuHi_XINO	1
++#define AuHi_HNOTIFY	(1 << 1)
++#define au_ftest_hi(flags, name)	((flags) & AuHi_##name)
++#define au_fset_hi(flags, name) \
++	do { (flags) |= AuHi_##name; } while (0)
++#define au_fclr_hi(flags, name) \
++	do { (flags) &= ~AuHi_##name; } while (0)
++
++#ifndef CONFIG_AUFS_HNOTIFY
++#undef AuHi_HNOTIFY
++#define AuHi_HNOTIFY	0
++#endif
++
++void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
++		   struct inode *h_inode, unsigned int flags);
++
++void au_update_iigen(struct inode *inode);
++void au_update_ibrange(struct inode *inode, int do_put_zero);
++
++void au_icntnr_init_once(void *_c);
++int au_iinfo_init(struct inode *inode);
++void au_iinfo_fin(struct inode *inode);
++int au_ii_realloc(struct au_iinfo *iinfo, int nbr);
++
++#ifdef CONFIG_PROC_FS
++/* plink.c */
++int au_plink_maint(struct super_block *sb, int flags);
++void au_plink_maint_leave(struct au_sbinfo *sbinfo);
++int au_plink_maint_enter(struct super_block *sb);
++#ifdef CONFIG_AUFS_DEBUG
++void au_plink_list(struct super_block *sb);
++#else
++AuStubVoid(au_plink_list, struct super_block *sb)
++#endif
++int au_plink_test(struct inode *inode);
++struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex);
++void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
++		     struct dentry *h_dentry);
++void au_plink_put(struct super_block *sb, int verbose);
++void au_plink_clean(struct super_block *sb, int verbose);
++void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id);
++#else
++AuStubInt0(au_plink_maint, struct super_block *sb, int flags);
++AuStubVoid(au_plink_maint_leave, struct au_sbinfo *sbinfo);
++AuStubInt0(au_plink_maint_enter, struct super_block *sb);
++AuStubVoid(au_plink_list, struct super_block *sb);
++AuStubInt0(au_plink_test, struct inode *inode);
++AuStub(struct dentry *, au_plink_lkup, return NULL,
++       struct inode *inode, aufs_bindex_t bindex);
++AuStubVoid(au_plink_append, struct inode *inode, aufs_bindex_t bindex,
++	   struct dentry *h_dentry);
++AuStubVoid(au_plink_put, struct super_block *sb, int verbose);
++AuStubVoid(au_plink_clean, struct super_block *sb, int verbose);
++AuStubVoid(au_plink_half_refresh, struct super_block *sb, aufs_bindex_t br_id);
++#endif /* CONFIG_PROC_FS */
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for iinfo */
++enum {
++	AuLsc_II_CHILD,		/* child first */
++	AuLsc_II_CHILD2,	/* rename(2), link(2), and cpup at hnotify */
++	AuLsc_II_CHILD3,	/* copyup dirs */
++	AuLsc_II_PARENT,	/* see AuLsc_I_PARENT in vfsub.h */
++	AuLsc_II_PARENT2,
++	AuLsc_II_PARENT3,	/* copyup dirs */
++	AuLsc_II_NEW_CHILD
++};
++
++/*
++ * ii_read_lock_child, ii_write_lock_child,
++ * ii_read_lock_child2, ii_write_lock_child2,
++ * ii_read_lock_child3, ii_write_lock_child3,
++ * ii_read_lock_parent, ii_write_lock_parent,
++ * ii_read_lock_parent2, ii_write_lock_parent2,
++ * ii_read_lock_parent3, ii_write_lock_parent3,
++ * ii_read_lock_new_child, ii_write_lock_new_child,
++ */
++#define AuReadLockFunc(name, lsc) \
++static inline void ii_read_lock_##name(struct inode *i) \
++{ \
++	au_rw_read_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
++}
++
++#define AuWriteLockFunc(name, lsc) \
++static inline void ii_write_lock_##name(struct inode *i) \
++{ \
++	au_rw_write_lock_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
++}
++
++#define AuRWLockFuncs(name, lsc) \
++	AuReadLockFunc(name, lsc) \
++	AuWriteLockFunc(name, lsc)
++
++AuRWLockFuncs(child, CHILD);
++AuRWLockFuncs(child2, CHILD2);
++AuRWLockFuncs(child3, CHILD3);
++AuRWLockFuncs(parent, PARENT);
++AuRWLockFuncs(parent2, PARENT2);
++AuRWLockFuncs(parent3, PARENT3);
++AuRWLockFuncs(new_child, NEW_CHILD);
++
++#undef AuReadLockFunc
++#undef AuWriteLockFunc
++#undef AuRWLockFuncs
++
++/*
++ * ii_read_unlock, ii_write_unlock, ii_downgrade_lock
++ */
++AuSimpleUnlockRwsemFuncs(ii, struct inode *i, &au_ii(i)->ii_rwsem);
++
++#define IiMustNoWaiters(i)	AuRwMustNoWaiters(&au_ii(i)->ii_rwsem)
++#define IiMustAnyLock(i)	AuRwMustAnyLock(&au_ii(i)->ii_rwsem)
++#define IiMustWriteLock(i)	AuRwMustWriteLock(&au_ii(i)->ii_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++static inline void au_icntnr_init(struct au_icntnr *c)
++{
++#ifdef CONFIG_AUFS_DEBUG
++	c->vfs_inode.i_mode = 0;
++#endif
++}
++
++static inline unsigned int au_iigen(struct inode *inode)
++{
++	return atomic_read(&au_ii(inode)->ii_generation);
++}
++
++/* tiny test for inode number */
++/* tmpfs generation is too rough */
++static inline int au_test_higen(struct inode *inode, struct inode *h_inode)
++{
++	struct au_iinfo *iinfo;
++
++	iinfo = au_ii(inode);
++	AuRwMustAnyLock(&iinfo->ii_rwsem);
++	return !(iinfo->ii_hsb1 == h_inode->i_sb
++		 && iinfo->ii_higen == h_inode->i_generation);
++}
++
++static inline void au_iigen_dec(struct inode *inode)
++{
++	atomic_dec(&au_ii(inode)->ii_generation);
++}
++
++static inline int au_iigen_test(struct inode *inode, unsigned int sigen)
++{
++	int err;
++
++	err = 0;
++	if (unlikely(inode && au_iigen(inode) != sigen))
++		err = -EIO;
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline aufs_bindex_t au_ii_br_id(struct inode *inode,
++					aufs_bindex_t bindex)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_hinode[0 + bindex].hi_id;
++}
++
++static inline aufs_bindex_t au_ibstart(struct inode *inode)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_bstart;
++}
++
++static inline aufs_bindex_t au_ibend(struct inode *inode)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_bend;
++}
++
++static inline struct au_vdir *au_ivdir(struct inode *inode)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_vdir;
++}
++
++static inline struct dentry *au_hi_wh(struct inode *inode, aufs_bindex_t bindex)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_hinode[0 + bindex].hi_whdentry;
++}
++
++static inline void au_set_ibstart(struct inode *inode, aufs_bindex_t bindex)
++{
++	IiMustWriteLock(inode);
++	au_ii(inode)->ii_bstart = bindex;
++}
++
++static inline void au_set_ibend(struct inode *inode, aufs_bindex_t bindex)
++{
++	IiMustWriteLock(inode);
++	au_ii(inode)->ii_bend = bindex;
++}
++
++static inline void au_set_ivdir(struct inode *inode, struct au_vdir *vdir)
++{
++	IiMustWriteLock(inode);
++	au_ii(inode)->ii_vdir = vdir;
++}
++
++static inline struct au_hinode *au_hi(struct inode *inode, aufs_bindex_t bindex)
++{
++	IiMustAnyLock(inode);
++	return au_ii(inode)->ii_hinode + bindex;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct dentry *au_pinned_parent(struct au_pin *pin)
++{
++	if (pin)
++		return pin->parent;
++	return NULL;
++}
++
++static inline struct inode *au_pinned_h_dir(struct au_pin *pin)
++{
++	if (pin && pin->hdir)
++		return pin->hdir->hi_inode;
++	return NULL;
++}
++
++static inline struct au_hinode *au_pinned_hdir(struct au_pin *pin)
++{
++	if (pin)
++		return pin->hdir;
++	return NULL;
++}
++
++static inline void au_pin_set_dentry(struct au_pin *pin, struct dentry *dentry)
++{
++	if (pin)
++		pin->dentry = dentry;
++}
++
++static inline void au_pin_set_parent_lflag(struct au_pin *pin,
++					   unsigned char lflag)
++{
++	if (pin) {
++		if (lflag)
++			au_fset_pin(pin->flags, DI_LOCKED);
++		else
++			au_fclr_pin(pin->flags, DI_LOCKED);
++	}
++}
++
++static inline void au_pin_set_parent(struct au_pin *pin, struct dentry *parent)
++{
++	if (pin) {
++		dput(pin->parent);
++		pin->parent = dget(parent);
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_branch;
++#ifdef CONFIG_AUFS_HNOTIFY
++struct au_hnotify_op {
++	void (*ctl)(struct au_hinode *hinode, int do_set);
++	int (*alloc)(struct au_hinode *hinode);
++	void (*free)(struct au_hinode *hinode);
++
++	void (*fin)(void);
++	int (*init)(void);
++
++	int (*reset_br)(unsigned int udba, struct au_branch *br, int perm);
++	void (*fin_br)(struct au_branch *br);
++	int (*init_br)(struct au_branch *br, int perm);
++};
++
++/* hnotify.c */
++int au_hn_alloc(struct au_hinode *hinode, struct inode *inode);
++void au_hn_free(struct au_hinode *hinode);
++void au_hn_ctl(struct au_hinode *hinode, int do_set);
++void au_hn_reset(struct inode *inode, unsigned int flags);
++int au_hnotify(struct inode *h_dir, struct au_hnotify *hnotify, u32 mask,
++	       struct qstr *h_child_qstr, struct inode *h_child_inode);
++int au_hnotify_reset_br(unsigned int udba, struct au_branch *br, int perm);
++int au_hnotify_init_br(struct au_branch *br, int perm);
++void au_hnotify_fin_br(struct au_branch *br);
++int __init au_hnotify_init(void);
++void au_hnotify_fin(void);
++
++/* hfsnotify.c */
++extern const struct au_hnotify_op au_hnotify_op;
++
++static inline
++void au_hn_init(struct au_hinode *hinode)
++{
++	hinode->hi_notify = NULL;
++}
++
++#else
++static inline
++int au_hn_alloc(struct au_hinode *hinode __maybe_unused,
++		struct inode *inode __maybe_unused)
++{
++	return -EOPNOTSUPP;
++}
++
++AuStubVoid(au_hn_free, struct au_hinode *hinode __maybe_unused)
++AuStubVoid(au_hn_ctl, struct au_hinode *hinode __maybe_unused,
++	   int do_set __maybe_unused)
++AuStubVoid(au_hn_reset, struct inode *inode __maybe_unused,
++	   unsigned int flags __maybe_unused)
++AuStubInt0(au_hnotify_reset_br, unsigned int udba __maybe_unused,
++	   struct au_branch *br __maybe_unused,
++	   int perm __maybe_unused)
++AuStubInt0(au_hnotify_init_br, struct au_branch *br __maybe_unused,
++	   int perm __maybe_unused)
++AuStubVoid(au_hnotify_fin_br, struct au_branch *br __maybe_unused)
++AuStubInt0(__init au_hnotify_init, void)
++AuStubVoid(au_hnotify_fin, void)
++AuStubVoid(au_hn_init, struct au_hinode *hinode __maybe_unused)
++#endif /* CONFIG_AUFS_HNOTIFY */
++
++static inline void au_hn_suspend(struct au_hinode *hdir)
++{
++	au_hn_ctl(hdir, /*do_set*/0);
++}
++
++static inline void au_hn_resume(struct au_hinode *hdir)
++{
++	au_hn_ctl(hdir, /*do_set*/1);
++}
++
++static inline void au_hn_imtx_lock(struct au_hinode *hdir)
++{
++	mutex_lock(&hdir->hi_inode->i_mutex);
++	au_hn_suspend(hdir);
++}
++
++static inline void au_hn_imtx_lock_nested(struct au_hinode *hdir,
++					  unsigned int sc __maybe_unused)
++{
++	mutex_lock_nested(&hdir->hi_inode->i_mutex, sc);
++	au_hn_suspend(hdir);
++}
++
++static inline void au_hn_imtx_unlock(struct au_hinode *hdir)
++{
++	au_hn_resume(hdir);
++	mutex_unlock(&hdir->hi_inode->i_mutex);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_INODE_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/ioctl.c linux-2.6.36/fs/aufs/ioctl.c
+--- linux-2.6.36.orig/fs/aufs/ioctl.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/ioctl.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,150 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * ioctl
++ * plink-management and readdir in userspace.
++ * assist the pathconf(3) wrapper library.
++ */
++
++#include <linux/file.h>
++#include "aufs.h"
++
++static int au_wbr_fd(struct path *path)
++{
++	int err, fd;
++	aufs_bindex_t wbi, bindex, bend;
++	struct file *h_file;
++	struct super_block *sb;
++	struct dentry *root;
++	struct au_branch *wbr;
++
++	err = get_unused_fd();
++	if (unlikely(err < 0))
++		goto out;
++	fd = err;
++
++	wbi = 0;
++	sb = path->dentry->d_sb;
++	root = sb->s_root;
++	aufs_read_lock(root, AuLock_IR);
++	wbr = au_sbr(sb, wbi);
++	if (!(path->mnt->mnt_flags & MNT_READONLY)
++	    && !au_br_writable(wbr->br_perm)) {
++		bend = au_sbend(sb);
++		for (bindex = 1; bindex <= bend; bindex++) {
++			wbr = au_sbr(sb, bindex);
++			if (au_br_writable(wbr->br_perm)) {
++				wbi = bindex;
++				break;
++			}
++		}
++		wbr = au_sbr(sb, wbi);
++	}
++	AuDbg("wbi %d\n", wbi);
++	h_file = au_h_open(root, wbi, O_RDONLY | O_DIRECTORY | O_LARGEFILE,
++			   NULL);
++	aufs_read_unlock(root, AuLock_IR);
++	err = PTR_ERR(h_file);
++	if (IS_ERR(h_file))
++		goto out_fd;
++
++	atomic_dec(&wbr->br_count); /* cf. au_h_open() */
++	fd_install(fd, h_file);
++	err = fd;
++	goto out; /* success */
++
++out_fd:
++	put_unused_fd(fd);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++long aufs_ioctl_dir(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	long err;
++
++	switch (cmd) {
++	case AUFS_CTL_RDU:
++	case AUFS_CTL_RDU_INO:
++		err = au_rdu_ioctl(file, cmd, arg);
++		break;
++
++	case AUFS_CTL_WBR_FD:
++		err = au_wbr_fd(&file->f_path);
++		break;
++
++	default:
++		/* do not call the lower */
++		AuDbg("0x%x\n", cmd);
++		err = -ENOTTY;
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++long aufs_ioctl_nondir(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	long err;
++
++	switch (cmd) {
++	case AUFS_CTL_WBR_FD:
++		err = au_wbr_fd(&file->f_path);
++		break;
++
++	default:
++		/* do not call the lower */
++		AuDbg("0x%x\n", cmd);
++		err = -ENOTTY;
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++#ifdef CONFIG_COMPAT
++long aufs_compat_ioctl_dir(struct file *file, unsigned int cmd,
++			   unsigned long arg)
++{
++	long err;
++
++	switch (cmd) {
++	case AUFS_CTL_RDU:
++	case AUFS_CTL_RDU_INO:
++		err = au_rdu_compat_ioctl(file, cmd, arg);
++		break;
++
++	default:
++		err = aufs_ioctl_dir(file, cmd, arg);
++	}
++
++	AuTraceErr(err);
++	return err;
++}
++
++#if 0 /* unused yet */
++long aufs_compat_ioctl_nondir(struct file *file, unsigned int cmd,
++			      unsigned long arg)
++{
++	return aufs_ioctl_nondir(file, cmd, (unsigned long)compat_ptr(arg));
++}
++#endif
++#endif
+diff -Nur linux-2.6.36.orig/fs/aufs/loop.c linux-2.6.36/fs/aufs/loop.c
+--- linux-2.6.36.orig/fs/aufs/loop.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/loop.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,63 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * support for loopback block device as a branch
++ */
++
++#include <linux/loop.h>
++#include "aufs.h"
++
++/*
++ * test if two lower dentries have overlapping branches.
++ */
++int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_adding)
++{
++	struct super_block *h_sb;
++	struct loop_device *l;
++
++	h_sb = h_adding->d_sb;
++	if (MAJOR(h_sb->s_dev) != LOOP_MAJOR)
++		return 0;
++
++	l = h_sb->s_bdev->bd_disk->private_data;
++	h_adding = l->lo_backing_file->f_dentry;
++	/*
++	 * h_adding can be local NFS.
++	 * in this case aufs cannot detect the loop.
++	 */
++	if (unlikely(h_adding->d_sb == sb))
++		return 1;
++	return !!au_test_subdir(h_adding, sb->s_root);
++}
++
++/* true if a kernel thread named 'loop[0-9].*' accesses a file */
++int au_test_loopback_kthread(void)
++{
++	int ret;
++	struct task_struct *tsk = current;
++
++	ret = 0;
++	if (tsk->flags & PF_KTHREAD) {
++		const char c = tsk->comm[4];
++		ret = ('0' <= c && c <= '9'
++		       && !strncmp(tsk->comm, "loop", 4));
++	}
++
++	return ret;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/loop.h linux-2.6.36/fs/aufs/loop.h
+--- linux-2.6.36.orig/fs/aufs/loop.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/loop.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,42 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * support for loopback mount as a branch
++ */
++
++#ifndef __AUFS_LOOP_H__
++#define __AUFS_LOOP_H__
++
++#ifdef __KERNEL__
++
++struct dentry;
++struct super_block;
++
++#ifdef CONFIG_AUFS_BDEV_LOOP
++/* loop.c */
++int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_adding);
++int au_test_loopback_kthread(void);
++#else
++AuStubInt0(au_test_loopback_overlap, struct super_block *sb,
++	   struct dentry *h_adding)
++AuStubInt0(au_test_loopback_kthread, void)
++#endif /* BLK_DEV_LOOP */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_LOOP_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/magic.mk linux-2.6.36/fs/aufs/magic.mk
+--- linux-2.6.36.orig/fs/aufs/magic.mk	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/magic.mk	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,54 @@
++
++# defined in ${srctree}/fs/fuse/inode.c
++# tristate
++ifdef CONFIG_FUSE_FS
++ccflags-y += -DFUSE_SUPER_MAGIC=0x65735546
++endif
++
++# defined in ${srctree}/fs/ocfs2/ocfs2_fs.h
++# tristate
++ifdef CONFIG_OCFS2_FS
++ccflags-y += -DOCFS2_SUPER_MAGIC=0x7461636f
++endif
++
++# defined in ${srctree}/fs/ocfs2/dlm/userdlm.h
++# tristate
++ifdef CONFIG_OCFS2_FS_O2CB
++ccflags-y += -DDLMFS_MAGIC=0x76a9f425
++endif
++
++# defined in ${srctree}/fs/cifs/cifsfs.c
++# tristate
++ifdef CONFIG_CIFS_FS
++ccflags-y += -DCIFS_MAGIC_NUMBER=0xFF534D42
++endif
++
++# defined in ${srctree}/fs/xfs/xfs_sb.h
++# tristate
++ifdef CONFIG_XFS_FS
++ccflags-y += -DXFS_SB_MAGIC=0x58465342
++endif
++
++# defined in ${srctree}/fs/configfs/mount.c
++# tristate
++ifdef CONFIG_CONFIGFS_FS
++ccflags-y += -DCONFIGFS_MAGIC=0x62656570
++endif
++
++# defined in ${srctree}/fs/9p/v9fs.h
++# tristate
++ifdef CONFIG_9P_FS
++ccflags-y += -DV9FS_MAGIC=0x01021997
++endif
++
++# defined in ${srctree}/fs/ubifs/ubifs.h
++# tristate
++ifdef CONFIG_UBIFS_FS
++ccflags-y += -DUBIFS_SUPER_MAGIC=0x24051905
++endif
++
++# defined in ${srctree}/fs/hfsplus/hfsplus_raw.h
++# tristate
++ifdef CONFIG_HFSPLUS_FS
++ccflags-y += -DHFSPLUS_SUPER_MAGIC=0x482b
++endif
+diff -Nur linux-2.6.36.orig/fs/aufs/module.c linux-2.6.36/fs/aufs/module.c
+--- linux-2.6.36.orig/fs/aufs/module.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/module.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,182 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * module global variables and operations
++ */
++
++#include <linux/module.h>
++#include <linux/seq_file.h>
++#include "aufs.h"
++
++void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp)
++{
++	if (new_sz <= nused)
++		return p;
++
++	p = krealloc(p, new_sz, gfp);
++	if (p)
++		memset(p + nused, 0, new_sz - nused);
++	return p;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * aufs caches
++ */
++struct kmem_cache *au_cachep[AuCache_Last];
++static int __init au_cache_init(void)
++{
++	au_cachep[AuCache_DINFO] = AuCacheCtor(au_dinfo, au_di_init_once);
++	if (au_cachep[AuCache_DINFO])
++		au_cachep[AuCache_ICNTNR] = AuCacheCtor(au_icntnr,
++							au_icntnr_init_once);
++	if (au_cachep[AuCache_ICNTNR])
++		au_cachep[AuCache_FINFO] = AuCacheCtor(au_finfo,
++						       au_fi_init_once);
++	if (au_cachep[AuCache_FINFO])
++		au_cachep[AuCache_VDIR] = AuCache(au_vdir);
++	if (au_cachep[AuCache_VDIR])
++		au_cachep[AuCache_DEHSTR] = AuCache(au_vdir_dehstr);
++	if (au_cachep[AuCache_DEHSTR])
++		return 0;
++
++	return -ENOMEM;
++}
++
++static void au_cache_fin(void)
++{
++	int i;
++
++	/* including AuCache_HNOTIFY */
++	for (i = 0; i < AuCache_Last; i++)
++		if (au_cachep[i]) {
++			kmem_cache_destroy(au_cachep[i]);
++			au_cachep[i] = NULL;
++		}
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_dir_roflags;
++
++#ifdef CONFIG_AUFS_SBILIST
++struct au_splhead au_sbilist;
++#endif
++
++/*
++ * functions for module interface.
++ */
++MODULE_LICENSE("GPL");
++/* MODULE_LICENSE("GPL v2"); */
++MODULE_AUTHOR("Junjiro R. Okajima <aufs-users@lists.sourceforge.net>");
++MODULE_DESCRIPTION(AUFS_NAME
++	" -- Advanced multi layered unification filesystem");
++MODULE_VERSION(AUFS_VERSION);
++
++/* this module parameter has no meaning when SYSFS is disabled */
++int sysaufs_brs = 1;
++MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN");
++module_param_named(brs, sysaufs_brs, int, S_IRUGO);
++
++/* ---------------------------------------------------------------------- */
++
++static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */
++
++int au_seq_path(struct seq_file *seq, struct path *path)
++{
++	return seq_path(seq, path, au_esc_chars);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int __init aufs_init(void)
++{
++	int err, i;
++	char *p;
++
++	p = au_esc_chars;
++	for (i = 1; i <= ' '; i++)
++		*p++ = i;
++	*p++ = '\\';
++	*p++ = '\x7f';
++	*p = 0;
++
++	au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE);
++
++	au_sbilist_init();
++	sysaufs_brs_init();
++	au_debug_init();
++	au_dy_init();
++	err = sysaufs_init();
++	if (unlikely(err))
++		goto out;
++	err = au_procfs_init();
++	if (unlikely(err))
++		goto out_sysaufs;
++	err = au_wkq_init();
++	if (unlikely(err))
++		goto out_procfs;
++	err = au_hnotify_init();
++	if (unlikely(err))
++		goto out_wkq;
++	err = au_sysrq_init();
++	if (unlikely(err))
++		goto out_hin;
++	err = au_cache_init();
++	if (unlikely(err))
++		goto out_sysrq;
++	err = register_filesystem(&aufs_fs_type);
++	if (unlikely(err))
++		goto out_cache;
++	/* since we define pr_fmt, call printk directly */
++	printk(KERN_INFO AUFS_NAME " " AUFS_VERSION "\n");
++	goto out; /* success */
++
++out_cache:
++	au_cache_fin();
++out_sysrq:
++	au_sysrq_fin();
++out_hin:
++	au_hnotify_fin();
++out_wkq:
++	au_wkq_fin();
++out_procfs:
++	au_procfs_fin();
++out_sysaufs:
++	sysaufs_fin();
++	au_dy_fin();
++out:
++	return err;
++}
++
++static void __exit aufs_exit(void)
++{
++	unregister_filesystem(&aufs_fs_type);
++	au_cache_fin();
++	au_sysrq_fin();
++	au_hnotify_fin();
++	au_wkq_fin();
++	au_procfs_fin();
++	sysaufs_fin();
++	au_dy_fin();
++}
++
++module_init(aufs_init);
++module_exit(aufs_exit);
+diff -Nur linux-2.6.36.orig/fs/aufs/module.h linux-2.6.36/fs/aufs/module.h
+--- linux-2.6.36.orig/fs/aufs/module.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/module.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,91 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * module initialization and module-global
++ */
++
++#ifndef __AUFS_MODULE_H__
++#define __AUFS_MODULE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/slab.h>
++
++struct path;
++struct seq_file;
++
++/* module parameters */
++extern int sysaufs_brs;
++
++/* ---------------------------------------------------------------------- */
++
++extern int au_dir_roflags;
++
++void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp);
++int au_seq_path(struct seq_file *seq, struct path *path);
++
++#ifdef CONFIG_PROC_FS
++/* procfs.c */
++int __init au_procfs_init(void);
++void au_procfs_fin(void);
++#else
++AuStubInt0(au_procfs_init, void);
++AuStubVoid(au_procfs_fin, void);
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++/* kmem cache */
++enum {
++	AuCache_DINFO,
++	AuCache_ICNTNR,
++	AuCache_FINFO,
++	AuCache_VDIR,
++	AuCache_DEHSTR,
++#ifdef CONFIG_AUFS_HNOTIFY
++	AuCache_HNOTIFY,
++#endif
++	AuCache_Last
++};
++
++#define AuCacheFlags		(SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD)
++#define AuCache(type)		KMEM_CACHE(type, AuCacheFlags)
++#define AuCacheCtor(type, ctor)	\
++	kmem_cache_create(#type, sizeof(struct type), \
++			  __alignof__(struct type), AuCacheFlags, ctor)
++
++extern struct kmem_cache *au_cachep[];
++
++#define AuCacheFuncs(name, index) \
++static inline struct au_##name *au_cache_alloc_##name(void) \
++{ return kmem_cache_alloc(au_cachep[AuCache_##index], GFP_NOFS); } \
++static inline void au_cache_free_##name(struct au_##name *p) \
++{ kmem_cache_free(au_cachep[AuCache_##index], p); }
++
++AuCacheFuncs(dinfo, DINFO);
++AuCacheFuncs(icntnr, ICNTNR);
++AuCacheFuncs(finfo, FINFO);
++AuCacheFuncs(vdir, VDIR);
++AuCacheFuncs(vdir_dehstr, DEHSTR);
++#ifdef CONFIG_AUFS_HNOTIFY
++AuCacheFuncs(hnotify, HNOTIFY);
++#endif
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_MODULE_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/mtx.h linux-2.6.36/fs/aufs/mtx.h
+--- linux-2.6.36.orig/fs/aufs/mtx.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/mtx.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,48 @@
++/*
++ * Copyright (C) 2010-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * very ugly approach for aufs_mmap()
++ * never include this file from other than f_op.c.
++ * see f_op.c in detail.
++ */
++
++#ifndef __AUFS_MTX_H__
++#define __AUFS_MTX_H__
++
++#ifdef __KERNEL__
++
++/* copied from ../kernel/mutex{,-debug}.h */
++struct mutex;
++struct thread_info;
++#ifdef CONFIG_DEBUG_MUTEXES
++static inline void mutex_set_owner(struct mutex *lock)
++{
++	lock->owner = current_thread_info();
++}
++#else
++static inline void mutex_set_owner(struct mutex *lock)
++{
++#ifdef CONFIG_SMP
++	lock->owner = current_thread_info();
++#endif
++}
++#endif
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_MTX_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/opts.c linux-2.6.36/fs/aufs/opts.c
+--- linux-2.6.36.orig/fs/aufs/opts.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/opts.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1595 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * mount options/flags
++ */
++
++#include <linux/file.h>
++#include <linux/jiffies.h>
++#include <linux/namei.h>
++#include <linux/types.h> /* a distribution requires */
++#include <linux/parser.h>
++#include "aufs.h"
++
++/* ---------------------------------------------------------------------- */
++
++enum {
++	Opt_br,
++	Opt_add, Opt_del, Opt_mod, Opt_reorder, Opt_append, Opt_prepend,
++	Opt_idel, Opt_imod, Opt_ireorder,
++	Opt_dirwh, Opt_rdcache, Opt_rdblk, Opt_rdhash, Opt_rendir,
++	Opt_rdblk_def, Opt_rdhash_def,
++	Opt_xino, Opt_zxino, Opt_noxino,
++	Opt_trunc_xino, Opt_trunc_xino_v, Opt_notrunc_xino,
++	Opt_trunc_xino_path, Opt_itrunc_xino,
++	Opt_trunc_xib, Opt_notrunc_xib,
++	Opt_shwh, Opt_noshwh,
++	Opt_plink, Opt_noplink, Opt_list_plink,
++	Opt_udba,
++	Opt_dio, Opt_nodio,
++	/* Opt_lock, Opt_unlock, */
++	Opt_cmd, Opt_cmd_args,
++	Opt_diropq_a, Opt_diropq_w,
++	Opt_warn_perm, Opt_nowarn_perm,
++	Opt_wbr_copyup, Opt_wbr_create,
++	Opt_refrof, Opt_norefrof,
++	Opt_verbose, Opt_noverbose,
++	Opt_sum, Opt_nosum, Opt_wsum,
++	Opt_tail, Opt_ignore, Opt_ignore_silent, Opt_err
++};
++
++static match_table_t options = {
++	{Opt_br, "br=%s"},
++	{Opt_br, "br:%s"},
++
++	{Opt_add, "add=%d:%s"},
++	{Opt_add, "add:%d:%s"},
++	{Opt_add, "ins=%d:%s"},
++	{Opt_add, "ins:%d:%s"},
++	{Opt_append, "append=%s"},
++	{Opt_append, "append:%s"},
++	{Opt_prepend, "prepend=%s"},
++	{Opt_prepend, "prepend:%s"},
++
++	{Opt_del, "del=%s"},
++	{Opt_del, "del:%s"},
++	/* {Opt_idel, "idel:%d"}, */
++	{Opt_mod, "mod=%s"},
++	{Opt_mod, "mod:%s"},
++	/* {Opt_imod, "imod:%d:%s"}, */
++
++	{Opt_dirwh, "dirwh=%d"},
++
++	{Opt_xino, "xino=%s"},
++	{Opt_noxino, "noxino"},
++	{Opt_trunc_xino, "trunc_xino"},
++	{Opt_trunc_xino_v, "trunc_xino_v=%d:%d"},
++	{Opt_notrunc_xino, "notrunc_xino"},
++	{Opt_trunc_xino_path, "trunc_xino=%s"},
++	{Opt_itrunc_xino, "itrunc_xino=%d"},
++	/* {Opt_zxino, "zxino=%s"}, */
++	{Opt_trunc_xib, "trunc_xib"},
++	{Opt_notrunc_xib, "notrunc_xib"},
++
++#ifdef CONFIG_PROC_FS
++	{Opt_plink, "plink"},
++#else
++	{Opt_ignore_silent, "plink"},
++#endif
++
++	{Opt_noplink, "noplink"},
++
++#ifdef CONFIG_AUFS_DEBUG
++	{Opt_list_plink, "list_plink"},
++#endif
++
++	{Opt_udba, "udba=%s"},
++
++	{Opt_dio, "dio"},
++	{Opt_nodio, "nodio"},
++
++	{Opt_diropq_a, "diropq=always"},
++	{Opt_diropq_a, "diropq=a"},
++	{Opt_diropq_w, "diropq=whiteouted"},
++	{Opt_diropq_w, "diropq=w"},
++
++	{Opt_warn_perm, "warn_perm"},
++	{Opt_nowarn_perm, "nowarn_perm"},
++
++	/* keep them temporary */
++	{Opt_ignore_silent, "coo=%s"},
++	{Opt_ignore_silent, "nodlgt"},
++	{Opt_ignore_silent, "nodirperm1"},
++	{Opt_ignore_silent, "clean_plink"},
++
++#ifdef CONFIG_AUFS_SHWH
++	{Opt_shwh, "shwh"},
++#endif
++	{Opt_noshwh, "noshwh"},
++
++	{Opt_rendir, "rendir=%d"},
++
++	{Opt_refrof, "refrof"},
++	{Opt_norefrof, "norefrof"},
++
++	{Opt_verbose, "verbose"},
++	{Opt_verbose, "v"},
++	{Opt_noverbose, "noverbose"},
++	{Opt_noverbose, "quiet"},
++	{Opt_noverbose, "q"},
++	{Opt_noverbose, "silent"},
++
++	{Opt_sum, "sum"},
++	{Opt_nosum, "nosum"},
++	{Opt_wsum, "wsum"},
++
++	{Opt_rdcache, "rdcache=%d"},
++	{Opt_rdblk, "rdblk=%d"},
++	{Opt_rdblk_def, "rdblk=def"},
++	{Opt_rdhash, "rdhash=%d"},
++	{Opt_rdhash_def, "rdhash=def"},
++
++	{Opt_wbr_create, "create=%s"},
++	{Opt_wbr_create, "create_policy=%s"},
++	{Opt_wbr_copyup, "cpup=%s"},
++	{Opt_wbr_copyup, "copyup=%s"},
++	{Opt_wbr_copyup, "copyup_policy=%s"},
++
++	/* internal use for the scripts */
++	{Opt_ignore_silent, "si=%s"},
++
++	{Opt_br, "dirs=%s"},
++	{Opt_ignore, "debug=%d"},
++	{Opt_ignore, "delete=whiteout"},
++	{Opt_ignore, "delete=all"},
++	{Opt_ignore, "imap=%s"},
++
++	/* temporary workaround, due to old mount(8)? */
++	{Opt_ignore_silent, "relatime"},
++
++	{Opt_err, NULL}
++};
++
++/* ---------------------------------------------------------------------- */
++
++static const char *au_parser_pattern(int val, struct match_token *token)
++{
++	while (token->pattern) {
++		if (token->token == val)
++			return token->pattern;
++		token++;
++	}
++	BUG();
++	return "??";
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t brperms = {
++	{AuBrPerm_RO, AUFS_BRPERM_RO},
++	{AuBrPerm_RR, AUFS_BRPERM_RR},
++	{AuBrPerm_RW, AUFS_BRPERM_RW},
++
++	{AuBrPerm_ROWH, AUFS_BRPERM_ROWH},
++	{AuBrPerm_RRWH, AUFS_BRPERM_RRWH},
++	{AuBrPerm_RWNoLinkWH, AUFS_BRPERM_RWNLWH},
++
++	{AuBrPerm_ROWH, "nfsro"},
++	{AuBrPerm_RO, NULL}
++};
++
++static int noinline_for_stack br_perm_val(char *perm)
++{
++	int val;
++	substring_t args[MAX_OPT_ARGS];
++
++	val = match_token(perm, brperms, args);
++	return val;
++}
++
++const char *au_optstr_br_perm(int brperm)
++{
++	return au_parser_pattern(brperm, (void *)brperms);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t udbalevel = {
++	{AuOpt_UDBA_REVAL, "reval"},
++	{AuOpt_UDBA_NONE, "none"},
++#ifdef CONFIG_AUFS_HNOTIFY
++	{AuOpt_UDBA_HNOTIFY, "notify"}, /* abstraction */
++#ifdef CONFIG_AUFS_HFSNOTIFY
++	{AuOpt_UDBA_HNOTIFY, "fsnotify"},
++#endif
++#endif
++	{-1, NULL}
++};
++
++static int noinline_for_stack udba_val(char *str)
++{
++	substring_t args[MAX_OPT_ARGS];
++
++	return match_token(str, udbalevel, args);
++}
++
++const char *au_optstr_udba(int udba)
++{
++	return au_parser_pattern(udba, (void *)udbalevel);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t au_wbr_create_policy = {
++	{AuWbrCreate_TDP, "tdp"},
++	{AuWbrCreate_TDP, "top-down-parent"},
++	{AuWbrCreate_RR, "rr"},
++	{AuWbrCreate_RR, "round-robin"},
++	{AuWbrCreate_MFS, "mfs"},
++	{AuWbrCreate_MFS, "most-free-space"},
++	{AuWbrCreate_MFSV, "mfs:%d"},
++	{AuWbrCreate_MFSV, "most-free-space:%d"},
++
++	{AuWbrCreate_MFSRR, "mfsrr:%d"},
++	{AuWbrCreate_MFSRRV, "mfsrr:%d:%d"},
++	{AuWbrCreate_PMFS, "pmfs"},
++	{AuWbrCreate_PMFSV, "pmfs:%d"},
++
++	{-1, NULL}
++};
++
++/*
++ * cf. linux/lib/parser.c and cmdline.c
++ * gave up calling memparse() since it uses simple_strtoull() instead of
++ * strict_...().
++ */
++static int noinline_for_stack
++au_match_ull(substring_t *s, unsigned long long *result)
++{
++	int err;
++	unsigned int len;
++	char a[32];
++
++	err = -ERANGE;
++	len = s->to - s->from;
++	if (len + 1 <= sizeof(a)) {
++		memcpy(a, s->from, len);
++		a[len] = '\0';
++		err = strict_strtoull(a, 0, result);
++	}
++	return err;
++}
++
++static int au_wbr_mfs_wmark(substring_t *arg, char *str,
++			    struct au_opt_wbr_create *create)
++{
++	int err;
++	unsigned long long ull;
++
++	err = 0;
++	if (!au_match_ull(arg, &ull))
++		create->mfsrr_watermark = ull;
++	else {
++		pr_err("bad integer in %s\n", str);
++		err = -EINVAL;
++	}
++
++	return err;
++}
++
++static int au_wbr_mfs_sec(substring_t *arg, char *str,
++			  struct au_opt_wbr_create *create)
++{
++	int n, err;
++
++	err = 0;
++	if (!match_int(arg, &n) && 0 <= n && n <= AUFS_MFS_MAX_SEC)
++		create->mfs_second = n;
++	else {
++		pr_err("bad integer in %s\n", str);
++		err = -EINVAL;
++	}
++
++	return err;
++}
++
++static int noinline_for_stack
++au_wbr_create_val(char *str, struct au_opt_wbr_create *create)
++{
++	int err, e;
++	substring_t args[MAX_OPT_ARGS];
++
++	err = match_token(str, au_wbr_create_policy, args);
++	create->wbr_create = err;
++	switch (err) {
++	case AuWbrCreate_MFSRRV:
++		e = au_wbr_mfs_wmark(&args[0], str, create);
++		if (!e)
++			e = au_wbr_mfs_sec(&args[1], str, create);
++		if (unlikely(e))
++			err = e;
++		break;
++	case AuWbrCreate_MFSRR:
++		e = au_wbr_mfs_wmark(&args[0], str, create);
++		if (unlikely(e)) {
++			err = e;
++			break;
++		}
++		/*FALLTHROUGH*/
++	case AuWbrCreate_MFS:
++	case AuWbrCreate_PMFS:
++		create->mfs_second = AUFS_MFS_DEF_SEC;
++		break;
++	case AuWbrCreate_MFSV:
++	case AuWbrCreate_PMFSV:
++		e = au_wbr_mfs_sec(&args[0], str, create);
++		if (unlikely(e))
++			err = e;
++		break;
++	}
++
++	return err;
++}
++
++const char *au_optstr_wbr_create(int wbr_create)
++{
++	return au_parser_pattern(wbr_create, (void *)au_wbr_create_policy);
++}
++
++static match_table_t au_wbr_copyup_policy = {
++	{AuWbrCopyup_TDP, "tdp"},
++	{AuWbrCopyup_TDP, "top-down-parent"},
++	{AuWbrCopyup_BUP, "bup"},
++	{AuWbrCopyup_BUP, "bottom-up-parent"},
++	{AuWbrCopyup_BU, "bu"},
++	{AuWbrCopyup_BU, "bottom-up"},
++	{-1, NULL}
++};
++
++static int noinline_for_stack au_wbr_copyup_val(char *str)
++{
++	substring_t args[MAX_OPT_ARGS];
++
++	return match_token(str, au_wbr_copyup_policy, args);
++}
++
++const char *au_optstr_wbr_copyup(int wbr_copyup)
++{
++	return au_parser_pattern(wbr_copyup, (void *)au_wbr_copyup_policy);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static const int lkup_dirflags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
++
++static void dump_opts(struct au_opts *opts)
++{
++#ifdef CONFIG_AUFS_DEBUG
++	/* reduce stack space */
++	union {
++		struct au_opt_add *add;
++		struct au_opt_del *del;
++		struct au_opt_mod *mod;
++		struct au_opt_xino *xino;
++		struct au_opt_xino_itrunc *xino_itrunc;
++		struct au_opt_wbr_create *create;
++	} u;
++	struct au_opt *opt;
++
++	opt = opts->opt;
++	while (opt->type != Opt_tail) {
++		switch (opt->type) {
++		case Opt_add:
++			u.add = &opt->add;
++			AuDbg("add {b%d, %s, 0x%x, %p}\n",
++				  u.add->bindex, u.add->pathname, u.add->perm,
++				  u.add->path.dentry);
++			break;
++		case Opt_del:
++		case Opt_idel:
++			u.del = &opt->del;
++			AuDbg("del {%s, %p}\n",
++			      u.del->pathname, u.del->h_path.dentry);
++			break;
++		case Opt_mod:
++		case Opt_imod:
++			u.mod = &opt->mod;
++			AuDbg("mod {%s, 0x%x, %p}\n",
++				  u.mod->path, u.mod->perm, u.mod->h_root);
++			break;
++		case Opt_append:
++			u.add = &opt->add;
++			AuDbg("append {b%d, %s, 0x%x, %p}\n",
++				  u.add->bindex, u.add->pathname, u.add->perm,
++				  u.add->path.dentry);
++			break;
++		case Opt_prepend:
++			u.add = &opt->add;
++			AuDbg("prepend {b%d, %s, 0x%x, %p}\n",
++				  u.add->bindex, u.add->pathname, u.add->perm,
++				  u.add->path.dentry);
++			break;
++		case Opt_dirwh:
++			AuDbg("dirwh %d\n", opt->dirwh);
++			break;
++		case Opt_rdcache:
++			AuDbg("rdcache %d\n", opt->rdcache);
++			break;
++		case Opt_rdblk:
++			AuDbg("rdblk %u\n", opt->rdblk);
++			break;
++		case Opt_rdblk_def:
++			AuDbg("rdblk_def\n");
++			break;
++		case Opt_rdhash:
++			AuDbg("rdhash %u\n", opt->rdhash);
++			break;
++		case Opt_rdhash_def:
++			AuDbg("rdhash_def\n");
++			break;
++		case Opt_xino:
++			u.xino = &opt->xino;
++			AuDbg("xino {%s %.*s}\n",
++				  u.xino->path,
++				  AuDLNPair(u.xino->file->f_dentry));
++			break;
++		case Opt_trunc_xino:
++			AuLabel(trunc_xino);
++			break;
++		case Opt_notrunc_xino:
++			AuLabel(notrunc_xino);
++			break;
++		case Opt_trunc_xino_path:
++		case Opt_itrunc_xino:
++			u.xino_itrunc = &opt->xino_itrunc;
++			AuDbg("trunc_xino %d\n", u.xino_itrunc->bindex);
++			break;
++
++		case Opt_noxino:
++			AuLabel(noxino);
++			break;
++		case Opt_trunc_xib:
++			AuLabel(trunc_xib);
++			break;
++		case Opt_notrunc_xib:
++			AuLabel(notrunc_xib);
++			break;
++		case Opt_shwh:
++			AuLabel(shwh);
++			break;
++		case Opt_noshwh:
++			AuLabel(noshwh);
++			break;
++		case Opt_plink:
++			AuLabel(plink);
++			break;
++		case Opt_noplink:
++			AuLabel(noplink);
++			break;
++		case Opt_list_plink:
++			AuLabel(list_plink);
++			break;
++		case Opt_udba:
++			AuDbg("udba %d, %s\n",
++				  opt->udba, au_optstr_udba(opt->udba));
++			break;
++		case Opt_dio:
++			AuLabel(dio);
++			break;
++		case Opt_nodio:
++			AuLabel(nodio);
++			break;
++		case Opt_diropq_a:
++			AuLabel(diropq_a);
++			break;
++		case Opt_diropq_w:
++			AuLabel(diropq_w);
++			break;
++		case Opt_warn_perm:
++			AuLabel(warn_perm);
++			break;
++		case Opt_nowarn_perm:
++			AuLabel(nowarn_perm);
++			break;
++		case Opt_refrof:
++			AuLabel(refrof);
++			break;
++		case Opt_norefrof:
++			AuLabel(norefrof);
++			break;
++		case Opt_verbose:
++			AuLabel(verbose);
++			break;
++		case Opt_noverbose:
++			AuLabel(noverbose);
++			break;
++		case Opt_sum:
++			AuLabel(sum);
++			break;
++		case Opt_nosum:
++			AuLabel(nosum);
++			break;
++		case Opt_wsum:
++			AuLabel(wsum);
++			break;
++		case Opt_wbr_create:
++			u.create = &opt->wbr_create;
++			AuDbg("create %d, %s\n", u.create->wbr_create,
++				  au_optstr_wbr_create(u.create->wbr_create));
++			switch (u.create->wbr_create) {
++			case AuWbrCreate_MFSV:
++			case AuWbrCreate_PMFSV:
++				AuDbg("%d sec\n", u.create->mfs_second);
++				break;
++			case AuWbrCreate_MFSRR:
++				AuDbg("%llu watermark\n",
++					  u.create->mfsrr_watermark);
++				break;
++			case AuWbrCreate_MFSRRV:
++				AuDbg("%llu watermark, %d sec\n",
++					  u.create->mfsrr_watermark,
++					  u.create->mfs_second);
++				break;
++			}
++			break;
++		case Opt_wbr_copyup:
++			AuDbg("copyup %d, %s\n", opt->wbr_copyup,
++				  au_optstr_wbr_copyup(opt->wbr_copyup));
++			break;
++		default:
++			BUG();
++		}
++		opt++;
++	}
++#endif
++}
++
++void au_opts_free(struct au_opts *opts)
++{
++	struct au_opt *opt;
++
++	opt = opts->opt;
++	while (opt->type != Opt_tail) {
++		switch (opt->type) {
++		case Opt_add:
++		case Opt_append:
++		case Opt_prepend:
++			path_put(&opt->add.path);
++			break;
++		case Opt_del:
++		case Opt_idel:
++			path_put(&opt->del.h_path);
++			break;
++		case Opt_mod:
++		case Opt_imod:
++			dput(opt->mod.h_root);
++			break;
++		case Opt_xino:
++			fput(opt->xino.file);
++			break;
++		}
++		opt++;
++	}
++}
++
++static int opt_add(struct au_opt *opt, char *opt_str, unsigned long sb_flags,
++		   aufs_bindex_t bindex)
++{
++	int err;
++	struct au_opt_add *add = &opt->add;
++	char *p;
++
++	add->bindex = bindex;
++	add->perm = AuBrPerm_Last;
++	add->pathname = opt_str;
++	p = strchr(opt_str, '=');
++	if (p) {
++		*p++ = 0;
++		if (*p)
++			add->perm = br_perm_val(p);
++	}
++
++	err = vfsub_kern_path(add->pathname, lkup_dirflags, &add->path);
++	if (!err) {
++		if (!p) {
++			add->perm = AuBrPerm_RO;
++			if (au_test_fs_rr(add->path.dentry->d_sb))
++				add->perm = AuBrPerm_RR;
++			else if (!bindex && !(sb_flags & MS_RDONLY))
++				add->perm = AuBrPerm_RW;
++		}
++		opt->type = Opt_add;
++		goto out;
++	}
++	pr_err("lookup failed %s (%d)\n", add->pathname, err);
++	err = -EINVAL;
++
++out:
++	return err;
++}
++
++static int au_opts_parse_del(struct au_opt_del *del, substring_t args[])
++{
++	int err;
++
++	del->pathname = args[0].from;
++	AuDbg("del path %s\n", del->pathname);
++
++	err = vfsub_kern_path(del->pathname, lkup_dirflags, &del->h_path);
++	if (unlikely(err))
++		pr_err("lookup failed %s (%d)\n", del->pathname, err);
++
++	return err;
++}
++
++#if 0 /* reserved for future use */
++static int au_opts_parse_idel(struct super_block *sb, aufs_bindex_t bindex,
++			      struct au_opt_del *del, substring_t args[])
++{
++	int err;
++	struct dentry *root;
++
++	err = -EINVAL;
++	root = sb->s_root;
++	aufs_read_lock(root, AuLock_FLUSH);
++	if (bindex < 0 || au_sbend(sb) < bindex) {
++		pr_err("out of bounds, %d\n", bindex);
++		goto out;
++	}
++
++	err = 0;
++	del->h_path.dentry = dget(au_h_dptr(root, bindex));
++	del->h_path.mnt = mntget(au_sbr_mnt(sb, bindex));
++
++out:
++	aufs_read_unlock(root, !AuLock_IR);
++	return err;
++}
++#endif
++
++static int noinline_for_stack
++au_opts_parse_mod(struct au_opt_mod *mod, substring_t args[])
++{
++	int err;
++	struct path path;
++	char *p;
++
++	err = -EINVAL;
++	mod->path = args[0].from;
++	p = strchr(mod->path, '=');
++	if (unlikely(!p)) {
++		pr_err("no permssion %s\n", args[0].from);
++		goto out;
++	}
++
++	*p++ = 0;
++	err = vfsub_kern_path(mod->path, lkup_dirflags, &path);
++	if (unlikely(err)) {
++		pr_err("lookup failed %s (%d)\n", mod->path, err);
++		goto out;
++	}
++
++	mod->perm = br_perm_val(p);
++	AuDbg("mod path %s, perm 0x%x, %s\n", mod->path, mod->perm, p);
++	mod->h_root = dget(path.dentry);
++	path_put(&path);
++
++out:
++	return err;
++}
++
++#if 0 /* reserved for future use */
++static int au_opts_parse_imod(struct super_block *sb, aufs_bindex_t bindex,
++			      struct au_opt_mod *mod, substring_t args[])
++{
++	int err;
++	struct dentry *root;
++
++	err = -EINVAL;
++	root = sb->s_root;
++	aufs_read_lock(root, AuLock_FLUSH);
++	if (bindex < 0 || au_sbend(sb) < bindex) {
++		pr_err("out of bounds, %d\n", bindex);
++		goto out;
++	}
++
++	err = 0;
++	mod->perm = br_perm_val(args[1].from);
++	AuDbg("mod path %s, perm 0x%x, %s\n",
++	      mod->path, mod->perm, args[1].from);
++	mod->h_root = dget(au_h_dptr(root, bindex));
++
++out:
++	aufs_read_unlock(root, !AuLock_IR);
++	return err;
++}
++#endif
++
++static int au_opts_parse_xino(struct super_block *sb, struct au_opt_xino *xino,
++			      substring_t args[])
++{
++	int err;
++	struct file *file;
++
++	file = au_xino_create(sb, args[0].from, /*silent*/0);
++	err = PTR_ERR(file);
++	if (IS_ERR(file))
++		goto out;
++
++	err = -EINVAL;
++	if (unlikely(file->f_dentry->d_sb == sb)) {
++		fput(file);
++		pr_err("%s must be outside\n", args[0].from);
++		goto out;
++	}
++
++	err = 0;
++	xino->file = file;
++	xino->path = args[0].from;
++
++out:
++	return err;
++}
++
++static int noinline_for_stack
++au_opts_parse_xino_itrunc_path(struct super_block *sb,
++			       struct au_opt_xino_itrunc *xino_itrunc,
++			       substring_t args[])
++{
++	int err;
++	aufs_bindex_t bend, bindex;
++	struct path path;
++	struct dentry *root;
++
++	err = vfsub_kern_path(args[0].from, lkup_dirflags, &path);
++	if (unlikely(err)) {
++		pr_err("lookup failed %s (%d)\n", args[0].from, err);
++		goto out;
++	}
++
++	xino_itrunc->bindex = -1;
++	root = sb->s_root;
++	aufs_read_lock(root, AuLock_FLUSH);
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++) {
++		if (au_h_dptr(root, bindex) == path.dentry) {
++			xino_itrunc->bindex = bindex;
++			break;
++		}
++	}
++	aufs_read_unlock(root, !AuLock_IR);
++	path_put(&path);
++
++	if (unlikely(xino_itrunc->bindex < 0)) {
++		pr_err("no such branch %s\n", args[0].from);
++		err = -EINVAL;
++	}
++
++out:
++	return err;
++}
++
++/* called without aufs lock */
++int au_opts_parse(struct super_block *sb, char *str, struct au_opts *opts)
++{
++	int err, n, token;
++	aufs_bindex_t bindex;
++	unsigned char skipped;
++	struct dentry *root;
++	struct au_opt *opt, *opt_tail;
++	char *opt_str;
++	/* reduce the stack space */
++	union {
++		struct au_opt_xino_itrunc *xino_itrunc;
++		struct au_opt_wbr_create *create;
++	} u;
++	struct {
++		substring_t args[MAX_OPT_ARGS];
++	} *a;
++
++	err = -ENOMEM;
++	a = kmalloc(sizeof(*a), GFP_NOFS);
++	if (unlikely(!a))
++		goto out;
++
++	root = sb->s_root;
++	err = 0;
++	bindex = 0;
++	opt = opts->opt;
++	opt_tail = opt + opts->max_opt - 1;
++	opt->type = Opt_tail;
++	while (!err && (opt_str = strsep(&str, ",")) && *opt_str) {
++		err = -EINVAL;
++		skipped = 0;
++		token = match_token(opt_str, options, a->args);
++		switch (token) {
++		case Opt_br:
++			err = 0;
++			while (!err && (opt_str = strsep(&a->args[0].from, ":"))
++			       && *opt_str) {
++				err = opt_add(opt, opt_str, opts->sb_flags,
++					      bindex++);
++				if (unlikely(!err && ++opt > opt_tail)) {
++					err = -E2BIG;
++					break;
++				}
++				opt->type = Opt_tail;
++				skipped = 1;
++			}
++			break;
++		case Opt_add:
++			if (unlikely(match_int(&a->args[0], &n))) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			bindex = n;
++			err = opt_add(opt, a->args[1].from, opts->sb_flags,
++				      bindex);
++			if (!err)
++				opt->type = token;
++			break;
++		case Opt_append:
++			err = opt_add(opt, a->args[0].from, opts->sb_flags,
++				      /*dummy bindex*/1);
++			if (!err)
++				opt->type = token;
++			break;
++		case Opt_prepend:
++			err = opt_add(opt, a->args[0].from, opts->sb_flags,
++				      /*bindex*/0);
++			if (!err)
++				opt->type = token;
++			break;
++		case Opt_del:
++			err = au_opts_parse_del(&opt->del, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++#if 0 /* reserved for future use */
++		case Opt_idel:
++			del->pathname = "(indexed)";
++			if (unlikely(match_int(&args[0], &n))) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			err = au_opts_parse_idel(sb, n, &opt->del, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++#endif
++		case Opt_mod:
++			err = au_opts_parse_mod(&opt->mod, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++#ifdef IMOD /* reserved for future use */
++		case Opt_imod:
++			u.mod->path = "(indexed)";
++			if (unlikely(match_int(&a->args[0], &n))) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			err = au_opts_parse_imod(sb, n, &opt->mod, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++#endif
++		case Opt_xino:
++			err = au_opts_parse_xino(sb, &opt->xino, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++
++		case Opt_trunc_xino_path:
++			err = au_opts_parse_xino_itrunc_path
++				(sb, &opt->xino_itrunc, a->args);
++			if (!err)
++				opt->type = token;
++			break;
++
++		case Opt_itrunc_xino:
++			u.xino_itrunc = &opt->xino_itrunc;
++			if (unlikely(match_int(&a->args[0], &n))) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			u.xino_itrunc->bindex = n;
++			aufs_read_lock(root, AuLock_FLUSH);
++			if (n < 0 || au_sbend(sb) < n) {
++				pr_err("out of bounds, %d\n", n);
++				aufs_read_unlock(root, !AuLock_IR);
++				break;
++			}
++			aufs_read_unlock(root, !AuLock_IR);
++			err = 0;
++			opt->type = token;
++			break;
++
++		case Opt_dirwh:
++			if (unlikely(match_int(&a->args[0], &opt->dirwh)))
++				break;
++			err = 0;
++			opt->type = token;
++			break;
++
++		case Opt_rdcache:
++			if (unlikely(match_int(&a->args[0], &n))) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			if (unlikely(n > AUFS_RDCACHE_MAX)) {
++				pr_err("rdcache must be smaller than %d\n",
++				       AUFS_RDCACHE_MAX);
++				break;
++			}
++			opt->rdcache = n;
++			err = 0;
++			opt->type = token;
++			break;
++		case Opt_rdblk:
++			if (unlikely(match_int(&a->args[0], &n)
++				     || n < 0
++				     || n > KMALLOC_MAX_SIZE)) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			if (unlikely(n && n < NAME_MAX)) {
++				pr_err("rdblk must be larger than %d\n",
++				       NAME_MAX);
++				break;
++			}
++			opt->rdblk = n;
++			err = 0;
++			opt->type = token;
++			break;
++		case Opt_rdhash:
++			if (unlikely(match_int(&a->args[0], &n)
++				     || n < 0
++				     || n * sizeof(struct hlist_head)
++				     > KMALLOC_MAX_SIZE)) {
++				pr_err("bad integer in %s\n", opt_str);
++				break;
++			}
++			opt->rdhash = n;
++			err = 0;
++			opt->type = token;
++			break;
++
++		case Opt_trunc_xino:
++		case Opt_notrunc_xino:
++		case Opt_noxino:
++		case Opt_trunc_xib:
++		case Opt_notrunc_xib:
++		case Opt_shwh:
++		case Opt_noshwh:
++		case Opt_plink:
++		case Opt_noplink:
++		case Opt_list_plink:
++		case Opt_dio:
++		case Opt_nodio:
++		case Opt_diropq_a:
++		case Opt_diropq_w:
++		case Opt_warn_perm:
++		case Opt_nowarn_perm:
++		case Opt_refrof:
++		case Opt_norefrof:
++		case Opt_verbose:
++		case Opt_noverbose:
++		case Opt_sum:
++		case Opt_nosum:
++		case Opt_wsum:
++		case Opt_rdblk_def:
++		case Opt_rdhash_def:
++			err = 0;
++			opt->type = token;
++			break;
++
++		case Opt_udba:
++			opt->udba = udba_val(a->args[0].from);
++			if (opt->udba >= 0) {
++				err = 0;
++				opt->type = token;
++			} else
++				pr_err("wrong value, %s\n", opt_str);
++			break;
++
++		case Opt_wbr_create:
++			u.create = &opt->wbr_create;
++			u.create->wbr_create
++				= au_wbr_create_val(a->args[0].from, u.create);
++			if (u.create->wbr_create >= 0) {
++				err = 0;
++				opt->type = token;
++			} else
++				pr_err("wrong value, %s\n", opt_str);
++			break;
++		case Opt_wbr_copyup:
++			opt->wbr_copyup = au_wbr_copyup_val(a->args[0].from);
++			if (opt->wbr_copyup >= 0) {
++				err = 0;
++				opt->type = token;
++			} else
++				pr_err("wrong value, %s\n", opt_str);
++			break;
++
++		case Opt_ignore:
++			pr_warning("ignored %s\n", opt_str);
++			/*FALLTHROUGH*/
++		case Opt_ignore_silent:
++			skipped = 1;
++			err = 0;
++			break;
++		case Opt_err:
++			pr_err("unknown option %s\n", opt_str);
++			break;
++		}
++
++		if (!err && !skipped) {
++			if (unlikely(++opt > opt_tail)) {
++				err = -E2BIG;
++				opt--;
++				opt->type = Opt_tail;
++				break;
++			}
++			opt->type = Opt_tail;
++		}
++	}
++
++	kfree(a);
++	dump_opts(opts);
++	if (unlikely(err))
++		au_opts_free(opts);
++
++out:
++	return err;
++}
++
++static int au_opt_wbr_create(struct super_block *sb,
++			     struct au_opt_wbr_create *create)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	err = 1; /* handled */
++	sbinfo = au_sbi(sb);
++	if (sbinfo->si_wbr_create_ops->fin) {
++		err = sbinfo->si_wbr_create_ops->fin(sb);
++		if (!err)
++			err = 1;
++	}
++
++	sbinfo->si_wbr_create = create->wbr_create;
++	sbinfo->si_wbr_create_ops = au_wbr_create_ops + create->wbr_create;
++	switch (create->wbr_create) {
++	case AuWbrCreate_MFSRRV:
++	case AuWbrCreate_MFSRR:
++		sbinfo->si_wbr_mfs.mfsrr_watermark = create->mfsrr_watermark;
++		/*FALLTHROUGH*/
++	case AuWbrCreate_MFS:
++	case AuWbrCreate_MFSV:
++	case AuWbrCreate_PMFS:
++	case AuWbrCreate_PMFSV:
++		sbinfo->si_wbr_mfs.mfs_expire
++			= msecs_to_jiffies(create->mfs_second * MSEC_PER_SEC);
++		break;
++	}
++
++	if (sbinfo->si_wbr_create_ops->init)
++		sbinfo->si_wbr_create_ops->init(sb); /* ignore */
++
++	return err;
++}
++
++/*
++ * returns,
++ * plus: processed without an error
++ * zero: unprocessed
++ */
++static int au_opt_simple(struct super_block *sb, struct au_opt *opt,
++			 struct au_opts *opts)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	err = 1; /* handled */
++	sbinfo = au_sbi(sb);
++	switch (opt->type) {
++	case Opt_udba:
++		sbinfo->si_mntflags &= ~AuOptMask_UDBA;
++		sbinfo->si_mntflags |= opt->udba;
++		opts->given_udba |= opt->udba;
++		break;
++
++	case Opt_plink:
++		au_opt_set(sbinfo->si_mntflags, PLINK);
++		break;
++	case Opt_noplink:
++		if (au_opt_test(sbinfo->si_mntflags, PLINK))
++			au_plink_put(sb, /*verbose*/1);
++		au_opt_clr(sbinfo->si_mntflags, PLINK);
++		break;
++	case Opt_list_plink:
++		if (au_opt_test(sbinfo->si_mntflags, PLINK))
++			au_plink_list(sb);
++		break;
++
++	case Opt_dio:
++		au_opt_set(sbinfo->si_mntflags, DIO);
++		au_fset_opts(opts->flags, REFRESH_DYAOP);
++		break;
++	case Opt_nodio:
++		au_opt_clr(sbinfo->si_mntflags, DIO);
++		au_fset_opts(opts->flags, REFRESH_DYAOP);
++		break;
++
++	case Opt_diropq_a:
++		au_opt_set(sbinfo->si_mntflags, ALWAYS_DIROPQ);
++		break;
++	case Opt_diropq_w:
++		au_opt_clr(sbinfo->si_mntflags, ALWAYS_DIROPQ);
++		break;
++
++	case Opt_warn_perm:
++		au_opt_set(sbinfo->si_mntflags, WARN_PERM);
++		break;
++	case Opt_nowarn_perm:
++		au_opt_clr(sbinfo->si_mntflags, WARN_PERM);
++		break;
++
++	case Opt_refrof:
++		au_opt_set(sbinfo->si_mntflags, REFROF);
++		break;
++	case Opt_norefrof:
++		au_opt_clr(sbinfo->si_mntflags, REFROF);
++		break;
++
++	case Opt_verbose:
++		au_opt_set(sbinfo->si_mntflags, VERBOSE);
++		break;
++	case Opt_noverbose:
++		au_opt_clr(sbinfo->si_mntflags, VERBOSE);
++		break;
++
++	case Opt_sum:
++		au_opt_set(sbinfo->si_mntflags, SUM);
++		break;
++	case Opt_wsum:
++		au_opt_clr(sbinfo->si_mntflags, SUM);
++		au_opt_set(sbinfo->si_mntflags, SUM_W);
++	case Opt_nosum:
++		au_opt_clr(sbinfo->si_mntflags, SUM);
++		au_opt_clr(sbinfo->si_mntflags, SUM_W);
++		break;
++
++	case Opt_wbr_create:
++		err = au_opt_wbr_create(sb, &opt->wbr_create);
++		break;
++	case Opt_wbr_copyup:
++		sbinfo->si_wbr_copyup = opt->wbr_copyup;
++		sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + opt->wbr_copyup;
++		break;
++
++	case Opt_dirwh:
++		sbinfo->si_dirwh = opt->dirwh;
++		break;
++
++	case Opt_rdcache:
++		sbinfo->si_rdcache
++			= msecs_to_jiffies(opt->rdcache * MSEC_PER_SEC);
++		break;
++	case Opt_rdblk:
++		sbinfo->si_rdblk = opt->rdblk;
++		break;
++	case Opt_rdblk_def:
++		sbinfo->si_rdblk = AUFS_RDBLK_DEF;
++		break;
++	case Opt_rdhash:
++		sbinfo->si_rdhash = opt->rdhash;
++		break;
++	case Opt_rdhash_def:
++		sbinfo->si_rdhash = AUFS_RDHASH_DEF;
++		break;
++
++	case Opt_shwh:
++		au_opt_set(sbinfo->si_mntflags, SHWH);
++		break;
++	case Opt_noshwh:
++		au_opt_clr(sbinfo->si_mntflags, SHWH);
++		break;
++
++	case Opt_trunc_xino:
++		au_opt_set(sbinfo->si_mntflags, TRUNC_XINO);
++		break;
++	case Opt_notrunc_xino:
++		au_opt_clr(sbinfo->si_mntflags, TRUNC_XINO);
++		break;
++
++	case Opt_trunc_xino_path:
++	case Opt_itrunc_xino:
++		err = au_xino_trunc(sb, opt->xino_itrunc.bindex);
++		if (!err)
++			err = 1;
++		break;
++
++	case Opt_trunc_xib:
++		au_fset_opts(opts->flags, TRUNC_XIB);
++		break;
++	case Opt_notrunc_xib:
++		au_fclr_opts(opts->flags, TRUNC_XIB);
++		break;
++
++	default:
++		err = 0;
++		break;
++	}
++
++	return err;
++}
++
++/*
++ * returns tri-state.
++ * plus: processed without an error
++ * zero: unprocessed
++ * minus: error
++ */
++static int au_opt_br(struct super_block *sb, struct au_opt *opt,
++		     struct au_opts *opts)
++{
++	int err, do_refresh;
++
++	err = 0;
++	switch (opt->type) {
++	case Opt_append:
++		opt->add.bindex = au_sbend(sb) + 1;
++		if (opt->add.bindex < 0)
++			opt->add.bindex = 0;
++		goto add;
++	case Opt_prepend:
++		opt->add.bindex = 0;
++	add:
++	case Opt_add:
++		err = au_br_add(sb, &opt->add,
++				au_ftest_opts(opts->flags, REMOUNT));
++		if (!err) {
++			err = 1;
++			au_fset_opts(opts->flags, REFRESH);
++		}
++		break;
++
++	case Opt_del:
++	case Opt_idel:
++		err = au_br_del(sb, &opt->del,
++				au_ftest_opts(opts->flags, REMOUNT));
++		if (!err) {
++			err = 1;
++			au_fset_opts(opts->flags, TRUNC_XIB);
++			au_fset_opts(opts->flags, REFRESH);
++		}
++		break;
++
++	case Opt_mod:
++	case Opt_imod:
++		err = au_br_mod(sb, &opt->mod,
++				au_ftest_opts(opts->flags, REMOUNT),
++				&do_refresh);
++		if (!err) {
++			err = 1;
++			if (do_refresh)
++				au_fset_opts(opts->flags, REFRESH);
++		}
++		break;
++	}
++
++	return err;
++}
++
++static int au_opt_xino(struct super_block *sb, struct au_opt *opt,
++		       struct au_opt_xino **opt_xino,
++		       struct au_opts *opts)
++{
++	int err;
++	aufs_bindex_t bend, bindex;
++	struct dentry *root, *parent, *h_root;
++
++	err = 0;
++	switch (opt->type) {
++	case Opt_xino:
++		err = au_xino_set(sb, &opt->xino,
++				  !!au_ftest_opts(opts->flags, REMOUNT));
++		if (unlikely(err))
++			break;
++
++		*opt_xino = &opt->xino;
++		au_xino_brid_set(sb, -1);
++
++		/* safe d_parent access */
++		parent = opt->xino.file->f_dentry->d_parent;
++		root = sb->s_root;
++		bend = au_sbend(sb);
++		for (bindex = 0; bindex <= bend; bindex++) {
++			h_root = au_h_dptr(root, bindex);
++			if (h_root == parent) {
++				au_xino_brid_set(sb, au_sbr_id(sb, bindex));
++				break;
++			}
++		}
++		break;
++
++	case Opt_noxino:
++		au_xino_clr(sb);
++		au_xino_brid_set(sb, -1);
++		*opt_xino = (void *)-1;
++		break;
++	}
++
++	return err;
++}
++
++int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
++		   unsigned int pending)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	unsigned char do_plink, skip, do_free;
++	struct au_branch *br;
++	struct au_wbr *wbr;
++	struct dentry *root;
++	struct inode *dir, *h_dir;
++	struct au_sbinfo *sbinfo;
++	struct au_hinode *hdir;
++
++	SiMustAnyLock(sb);
++
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!(sbinfo->si_mntflags & AuOptMask_UDBA));
++
++	if (!(sb_flags & MS_RDONLY)) {
++		if (unlikely(!au_br_writable(au_sbr_perm(sb, 0))))
++			pr_warning("first branch should be rw\n");
++		if (unlikely(au_opt_test(sbinfo->si_mntflags, SHWH)))
++			pr_warning("shwh should be used with ro\n");
++	}
++
++	if (au_opt_test((sbinfo->si_mntflags | pending), UDBA_HNOTIFY)
++	    && !au_opt_test(sbinfo->si_mntflags, XINO))
++		pr_warning("udba=*notify requires xino\n");
++
++	err = 0;
++	root = sb->s_root;
++	dir = root->d_inode;
++	do_plink = !!au_opt_test(sbinfo->si_mntflags, PLINK);
++	bend = au_sbend(sb);
++	for (bindex = 0; !err && bindex <= bend; bindex++) {
++		skip = 0;
++		h_dir = au_h_iptr(dir, bindex);
++		br = au_sbr(sb, bindex);
++		do_free = 0;
++
++		wbr = br->br_wbr;
++		if (wbr)
++			wbr_wh_read_lock(wbr);
++
++		switch (br->br_perm) {
++		case AuBrPerm_RO:
++		case AuBrPerm_ROWH:
++		case AuBrPerm_RR:
++		case AuBrPerm_RRWH:
++			do_free = !!wbr;
++			skip = (!wbr
++				|| (!wbr->wbr_whbase
++				    && !wbr->wbr_plink
++				    && !wbr->wbr_orph));
++			break;
++
++		case AuBrPerm_RWNoLinkWH:
++			/* skip = (!br->br_whbase && !br->br_orph); */
++			skip = (!wbr || !wbr->wbr_whbase);
++			if (skip && wbr) {
++				if (do_plink)
++					skip = !!wbr->wbr_plink;
++				else
++					skip = !wbr->wbr_plink;
++			}
++			break;
++
++		case AuBrPerm_RW:
++			/* skip = (br->br_whbase && br->br_ohph); */
++			skip = (wbr && wbr->wbr_whbase);
++			if (skip) {
++				if (do_plink)
++					skip = !!wbr->wbr_plink;
++				else
++					skip = !wbr->wbr_plink;
++			}
++			break;
++
++		default:
++			BUG();
++		}
++		if (wbr)
++			wbr_wh_read_unlock(wbr);
++
++		if (skip)
++			continue;
++
++		hdir = au_hi(dir, bindex);
++		au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++		if (wbr)
++			wbr_wh_write_lock(wbr);
++		err = au_wh_init(au_h_dptr(root, bindex), br, sb);
++		if (wbr)
++			wbr_wh_write_unlock(wbr);
++		au_hn_imtx_unlock(hdir);
++
++		if (!err && do_free) {
++			kfree(wbr);
++			br->br_wbr = NULL;
++		}
++	}
++
++	return err;
++}
++
++int au_opts_mount(struct super_block *sb, struct au_opts *opts)
++{
++	int err;
++	unsigned int tmp;
++	aufs_bindex_t bindex, bend;
++	struct au_opt *opt;
++	struct au_opt_xino *opt_xino, xino;
++	struct au_sbinfo *sbinfo;
++	struct au_branch *br;
++
++	SiMustWriteLock(sb);
++
++	err = 0;
++	opt_xino = NULL;
++	opt = opts->opt;
++	while (err >= 0 && opt->type != Opt_tail)
++		err = au_opt_simple(sb, opt++, opts);
++	if (err > 0)
++		err = 0;
++	else if (unlikely(err < 0))
++		goto out;
++
++	/* disable xino and udba temporary */
++	sbinfo = au_sbi(sb);
++	tmp = sbinfo->si_mntflags;
++	au_opt_clr(sbinfo->si_mntflags, XINO);
++	au_opt_set_udba(sbinfo->si_mntflags, UDBA_REVAL);
++
++	opt = opts->opt;
++	while (err >= 0 && opt->type != Opt_tail)
++		err = au_opt_br(sb, opt++, opts);
++	if (err > 0)
++		err = 0;
++	else if (unlikely(err < 0))
++		goto out;
++
++	bend = au_sbend(sb);
++	if (unlikely(bend < 0)) {
++		err = -EINVAL;
++		pr_err("no branches\n");
++		goto out;
++	}
++
++	if (au_opt_test(tmp, XINO))
++		au_opt_set(sbinfo->si_mntflags, XINO);
++	opt = opts->opt;
++	while (!err && opt->type != Opt_tail)
++		err = au_opt_xino(sb, opt++, &opt_xino, opts);
++	if (unlikely(err))
++		goto out;
++
++	err = au_opts_verify(sb, sb->s_flags, tmp);
++	if (unlikely(err))
++		goto out;
++
++	/* restore xino */
++	if (au_opt_test(tmp, XINO) && !opt_xino) {
++		xino.file = au_xino_def(sb);
++		err = PTR_ERR(xino.file);
++		if (IS_ERR(xino.file))
++			goto out;
++
++		err = au_xino_set(sb, &xino, /*remount*/0);
++		fput(xino.file);
++		if (unlikely(err))
++			goto out;
++	}
++
++	/* restore udba */
++	tmp &= AuOptMask_UDBA;
++	sbinfo->si_mntflags &= ~AuOptMask_UDBA;
++	sbinfo->si_mntflags |= tmp;
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		err = au_hnotify_reset_br(tmp, br, br->br_perm);
++		if (unlikely(err))
++			AuIOErr("hnotify failed on br %d, %d, ignored\n",
++				bindex, err);
++		/* go on even if err */
++	}
++	if (au_opt_test(tmp, UDBA_HNOTIFY)) {
++		struct inode *dir = sb->s_root->d_inode;
++		au_hn_reset(dir, au_hi_flags(dir, /*isdir*/1) & ~AuHi_XINO);
++	}
++
++out:
++	return err;
++}
++
++int au_opts_remount(struct super_block *sb, struct au_opts *opts)
++{
++	int err, rerr;
++	struct inode *dir;
++	struct au_opt_xino *opt_xino;
++	struct au_opt *opt;
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	dir = sb->s_root->d_inode;
++	sbinfo = au_sbi(sb);
++	err = 0;
++	opt_xino = NULL;
++	opt = opts->opt;
++	while (err >= 0 && opt->type != Opt_tail) {
++		err = au_opt_simple(sb, opt, opts);
++		if (!err)
++			err = au_opt_br(sb, opt, opts);
++		if (!err)
++			err = au_opt_xino(sb, opt, &opt_xino, opts);
++		opt++;
++	}
++	if (err > 0)
++		err = 0;
++	AuTraceErr(err);
++	/* go on even err */
++
++	rerr = au_opts_verify(sb, opts->sb_flags, /*pending*/0);
++	if (unlikely(rerr && !err))
++		err = rerr;
++
++	if (au_ftest_opts(opts->flags, TRUNC_XIB)) {
++		rerr = au_xib_trunc(sb);
++		if (unlikely(rerr && !err))
++			err = rerr;
++	}
++
++	/* will be handled by the caller */
++	if (!au_ftest_opts(opts->flags, REFRESH)
++	    && (opts->given_udba || au_opt_test(sbinfo->si_mntflags, XINO)))
++		au_fset_opts(opts->flags, REFRESH);
++
++	AuDbg("status 0x%x\n", opts->flags);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++unsigned int au_opt_udba(struct super_block *sb)
++{
++	return au_mntflags(sb) & AuOptMask_UDBA;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/opts.h linux-2.6.36/fs/aufs/opts.h
+--- linux-2.6.36.orig/fs/aufs/opts.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/opts.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,210 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * mount options/flags
++ */
++
++#ifndef __AUFS_OPTS_H__
++#define __AUFS_OPTS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/path.h>
++#include <linux/aufs_type.h>
++
++struct file;
++struct super_block;
++
++/* ---------------------------------------------------------------------- */
++
++/* mount flags */
++#define AuOpt_XINO		1		/* external inode number bitmap
++						   and translation table */
++#define AuOpt_TRUNC_XINO	(1 << 1)	/* truncate xino files */
++#define AuOpt_UDBA_NONE		(1 << 2)	/* users direct branch access */
++#define AuOpt_UDBA_REVAL	(1 << 3)
++#define AuOpt_UDBA_HNOTIFY	(1 << 4)
++#define AuOpt_SHWH		(1 << 5)	/* show whiteout */
++#define AuOpt_PLINK		(1 << 6)	/* pseudo-link */
++#define AuOpt_DIRPERM1		(1 << 7)	/* unimplemented */
++#define AuOpt_REFROF		(1 << 8)	/* unimplemented */
++#define AuOpt_ALWAYS_DIROPQ	(1 << 9)	/* policy to creating diropq */
++#define AuOpt_SUM		(1 << 10)	/* summation for statfs(2) */
++#define AuOpt_SUM_W		(1 << 11)	/* unimplemented */
++#define AuOpt_WARN_PERM		(1 << 12)	/* warn when add-branch */
++#define AuOpt_VERBOSE		(1 << 13)	/* busy inode when del-branch */
++#define AuOpt_DIO		(1 << 14)	/* direct io */
++
++#ifndef CONFIG_AUFS_HNOTIFY
++#undef AuOpt_UDBA_HNOTIFY
++#define AuOpt_UDBA_HNOTIFY	0
++#endif
++#ifndef CONFIG_AUFS_SHWH
++#undef AuOpt_SHWH
++#define AuOpt_SHWH		0
++#endif
++
++#define AuOpt_Def	(AuOpt_XINO \
++			 | AuOpt_UDBA_REVAL \
++			 | AuOpt_PLINK \
++			 /* | AuOpt_DIRPERM1 */ \
++			 | AuOpt_WARN_PERM)
++#define AuOptMask_UDBA	(AuOpt_UDBA_NONE \
++			 | AuOpt_UDBA_REVAL \
++			 | AuOpt_UDBA_HNOTIFY)
++
++#define au_opt_test(flags, name)	(flags & AuOpt_##name)
++#define au_opt_set(flags, name) do { \
++	BUILD_BUG_ON(AuOpt_##name & AuOptMask_UDBA); \
++	((flags) |= AuOpt_##name); \
++} while (0)
++#define au_opt_set_udba(flags, name) do { \
++	(flags) &= ~AuOptMask_UDBA; \
++	((flags) |= AuOpt_##name); \
++} while (0)
++#define au_opt_clr(flags, name) do { \
++	((flags) &= ~AuOpt_##name); \
++} while (0)
++
++static inline unsigned int au_opts_plink(unsigned int mntflags)
++{
++#ifdef CONFIG_PROC_FS
++	return mntflags;
++#else
++	return mntflags & ~AuOpt_PLINK;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* policies to select one among multiple writable branches */
++enum {
++	AuWbrCreate_TDP,	/* top down parent */
++	AuWbrCreate_RR,		/* round robin */
++	AuWbrCreate_MFS,	/* most free space */
++	AuWbrCreate_MFSV,	/* mfs with seconds */
++	AuWbrCreate_MFSRR,	/* mfs then rr */
++	AuWbrCreate_MFSRRV,	/* mfs then rr with seconds */
++	AuWbrCreate_PMFS,	/* parent and mfs */
++	AuWbrCreate_PMFSV,	/* parent and mfs with seconds */
++
++	AuWbrCreate_Def = AuWbrCreate_TDP
++};
++
++enum {
++	AuWbrCopyup_TDP,	/* top down parent */
++	AuWbrCopyup_BUP,	/* bottom up parent */
++	AuWbrCopyup_BU,		/* bottom up */
++
++	AuWbrCopyup_Def = AuWbrCopyup_TDP
++};
++
++/* ---------------------------------------------------------------------- */
++
++struct au_opt_add {
++	aufs_bindex_t	bindex;
++	char		*pathname;
++	int		perm;
++	struct path	path;
++};
++
++struct au_opt_del {
++	char		*pathname;
++	struct path	h_path;
++};
++
++struct au_opt_mod {
++	char		*path;
++	int		perm;
++	struct dentry	*h_root;
++};
++
++struct au_opt_xino {
++	char		*path;
++	struct file	*file;
++};
++
++struct au_opt_xino_itrunc {
++	aufs_bindex_t	bindex;
++};
++
++struct au_opt_wbr_create {
++	int			wbr_create;
++	int			mfs_second;
++	unsigned long long	mfsrr_watermark;
++};
++
++struct au_opt {
++	int type;
++	union {
++		struct au_opt_xino	xino;
++		struct au_opt_xino_itrunc xino_itrunc;
++		struct au_opt_add	add;
++		struct au_opt_del	del;
++		struct au_opt_mod	mod;
++		int			dirwh;
++		int			rdcache;
++		unsigned int		rdblk;
++		unsigned int		rdhash;
++		int			udba;
++		struct au_opt_wbr_create wbr_create;
++		int			wbr_copyup;
++	};
++};
++
++/* opts flags */
++#define AuOpts_REMOUNT		1
++#define AuOpts_REFRESH		(1 << 1)
++#define AuOpts_TRUNC_XIB	(1 << 2)
++#define AuOpts_REFRESH_DYAOP	(1 << 3)
++#define au_ftest_opts(flags, name)	((flags) & AuOpts_##name)
++#define au_fset_opts(flags, name) \
++	do { (flags) |= AuOpts_##name; } while (0)
++#define au_fclr_opts(flags, name) \
++	do { (flags) &= ~AuOpts_##name; } while (0)
++
++struct au_opts {
++	struct au_opt	*opt;
++	int		max_opt;
++
++	unsigned int	given_udba;
++	unsigned int	flags;
++	unsigned long	sb_flags;
++};
++
++/* ---------------------------------------------------------------------- */
++
++const char *au_optstr_br_perm(int brperm);
++const char *au_optstr_udba(int udba);
++const char *au_optstr_wbr_copyup(int wbr_copyup);
++const char *au_optstr_wbr_create(int wbr_create);
++
++void au_opts_free(struct au_opts *opts);
++int au_opts_parse(struct super_block *sb, char *str, struct au_opts *opts);
++int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
++		   unsigned int pending);
++int au_opts_mount(struct super_block *sb, struct au_opts *opts);
++int au_opts_remount(struct super_block *sb, struct au_opts *opts);
++
++unsigned int au_opt_udba(struct super_block *sb);
++
++/* ---------------------------------------------------------------------- */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_OPTS_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/plink.c linux-2.6.36/fs/aufs/plink.c
+--- linux-2.6.36.orig/fs/aufs/plink.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/plink.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,515 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * pseudo-link
++ */
++
++#include "aufs.h"
++
++/*
++ * the pseudo-link maintenance mode.
++ * during a user process maintains the pseudo-links,
++ * prohibit adding a new plink and branch manipulation.
++ *
++ * Flags
++ * NOPLM:
++ *	For entry functions which will handle plink, and i_mutex is already held
++ *	in VFS.
++ *	They cannot wait and should return an error at once.
++ *	Callers has to check the error.
++ * NOPLMW:
++ *	For entry functions which will handle plink, but i_mutex is not held
++ *	in VFS.
++ *	They can wait the plink maintenance mode to finish.
++ *
++ * They behave like F_SETLK and F_SETLKW.
++ * If the caller never handle plink, then both flags are unnecessary.
++ */
++
++int au_plink_maint(struct super_block *sb, int flags)
++{
++	int err;
++	pid_t pid, ppid;
++	struct au_sbinfo *sbi;
++
++	SiMustAnyLock(sb);
++
++	err = 0;
++	if (!au_opt_test(au_mntflags(sb), PLINK))
++		goto out;
++
++	sbi = au_sbi(sb);
++	pid = sbi->si_plink_maint_pid;
++	if (!pid || pid == current->pid)
++		goto out;
++
++	/* todo: it highly depends upon /sbin/mount.aufs */
++	rcu_read_lock();
++	ppid = task_pid_vnr(rcu_dereference(current->real_parent));
++	rcu_read_unlock();
++	if (pid == ppid)
++		goto out;
++
++	if (au_ftest_lock(flags, NOPLMW)) {
++		/* if there is no i_mutex lock in VFS, we don't need to wait */
++		/* AuDebugOn(!lockdep_depth(current)); */
++		while (sbi->si_plink_maint_pid) {
++			si_read_unlock(sb);
++			/* gave up wake_up_bit() */
++			wait_event(sbi->si_plink_wq, !sbi->si_plink_maint_pid);
++
++			if (au_ftest_lock(flags, FLUSH))
++				au_nwt_flush(&sbi->si_nowait);
++			si_noflush_read_lock(sb);
++		}
++	} else if (au_ftest_lock(flags, NOPLM)) {
++		AuDbg("ppid %d, pid %d\n", ppid, pid);
++		err = -EAGAIN;
++	}
++
++out:
++	return err;
++}
++
++void au_plink_maint_leave(struct au_sbinfo *sbinfo)
++{
++	spin_lock(&sbinfo->si_plink_maint_lock);
++	sbinfo->si_plink_maint_pid = 0;
++	spin_unlock(&sbinfo->si_plink_maint_lock);
++	wake_up_all(&sbinfo->si_plink_wq);
++}
++
++int au_plink_maint_enter(struct super_block *sb)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	/* make sure i am the only one in this fs */
++	si_write_lock(sb, AuLock_FLUSH);
++	if (au_opt_test(au_mntflags(sb), PLINK)) {
++		spin_lock(&sbinfo->si_plink_maint_lock);
++		if (!sbinfo->si_plink_maint_pid)
++			sbinfo->si_plink_maint_pid = current->pid;
++		else
++			err = -EBUSY;
++		spin_unlock(&sbinfo->si_plink_maint_lock);
++	}
++	si_write_unlock(sb);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct pseudo_link {
++	union {
++		struct list_head list;
++		struct rcu_head rcu;
++	};
++	struct inode *inode;
++};
++
++#ifdef CONFIG_AUFS_DEBUG
++void au_plink_list(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++	struct list_head *plink_list;
++	struct pseudo_link *plink;
++
++	SiMustAnyLock(sb);
++
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
++
++	plink_list = &sbinfo->si_plink.head;
++	rcu_read_lock();
++	list_for_each_entry_rcu(plink, plink_list, list)
++		AuDbg("%lu\n", plink->inode->i_ino);
++	rcu_read_unlock();
++}
++#endif
++
++/* is the inode pseudo-linked? */
++int au_plink_test(struct inode *inode)
++{
++	int found;
++	struct au_sbinfo *sbinfo;
++	struct list_head *plink_list;
++	struct pseudo_link *plink;
++
++	sbinfo = au_sbi(inode->i_sb);
++	AuRwMustAnyLock(&sbinfo->si_rwsem);
++	AuDebugOn(!au_opt_test(au_mntflags(inode->i_sb), PLINK));
++	AuDebugOn(au_plink_maint(inode->i_sb, AuLock_NOPLM));
++
++	found = 0;
++	plink_list = &sbinfo->si_plink.head;
++	rcu_read_lock();
++	list_for_each_entry_rcu(plink, plink_list, list)
++		if (plink->inode == inode) {
++			found = 1;
++			break;
++		}
++	rcu_read_unlock();
++	return found;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * generate a name for plink.
++ * the file will be stored under AUFS_WH_PLINKDIR.
++ */
++/* 20 is max digits length of ulong 64 */
++#define PLINK_NAME_LEN	((20 + 1) * 2)
++
++static int plink_name(char *name, int len, struct inode *inode,
++		      aufs_bindex_t bindex)
++{
++	int rlen;
++	struct inode *h_inode;
++
++	h_inode = au_h_iptr(inode, bindex);
++	rlen = snprintf(name, len, "%lu.%lu", inode->i_ino, h_inode->i_ino);
++	return rlen;
++}
++
++struct au_do_plink_lkup_args {
++	struct dentry **errp;
++	struct qstr *tgtname;
++	struct dentry *h_parent;
++	struct au_branch *br;
++};
++
++static struct dentry *au_do_plink_lkup(struct qstr *tgtname,
++				       struct dentry *h_parent,
++				       struct au_branch *br)
++{
++	struct dentry *h_dentry;
++	struct mutex *h_mtx;
++
++	h_mtx = &h_parent->d_inode->i_mutex;
++	mutex_lock_nested(h_mtx, AuLsc_I_CHILD2);
++	h_dentry = au_lkup_one(tgtname, h_parent, br, /*nd*/NULL);
++	mutex_unlock(h_mtx);
++	return h_dentry;
++}
++
++static void au_call_do_plink_lkup(void *args)
++{
++	struct au_do_plink_lkup_args *a = args;
++	*a->errp = au_do_plink_lkup(a->tgtname, a->h_parent, a->br);
++}
++
++/* lookup the plink-ed @inode under the branch at @bindex */
++struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex)
++{
++	struct dentry *h_dentry, *h_parent;
++	struct au_branch *br;
++	struct inode *h_dir;
++	int wkq_err;
++	char a[PLINK_NAME_LEN];
++	struct qstr tgtname = {
++		.name	= a
++	};
++
++	AuDebugOn(au_plink_maint(inode->i_sb, AuLock_NOPLM));
++
++	br = au_sbr(inode->i_sb, bindex);
++	h_parent = br->br_wbr->wbr_plink;
++	h_dir = h_parent->d_inode;
++	tgtname.len = plink_name(a, sizeof(a), inode, bindex);
++
++	if (current_fsuid()) {
++		struct au_do_plink_lkup_args args = {
++			.errp		= &h_dentry,
++			.tgtname	= &tgtname,
++			.h_parent	= h_parent,
++			.br		= br
++		};
++
++		wkq_err = au_wkq_wait(au_call_do_plink_lkup, &args);
++		if (unlikely(wkq_err))
++			h_dentry = ERR_PTR(wkq_err);
++	} else
++		h_dentry = au_do_plink_lkup(&tgtname, h_parent, br);
++
++	return h_dentry;
++}
++
++/* create a pseudo-link */
++static int do_whplink(struct qstr *tgt, struct dentry *h_parent,
++		      struct dentry *h_dentry, struct au_branch *br)
++{
++	int err;
++	struct path h_path = {
++		.mnt = br->br_mnt
++	};
++	struct inode *h_dir;
++
++	h_dir = h_parent->d_inode;
++	mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_CHILD2);
++again:
++	h_path.dentry = au_lkup_one(tgt, h_parent, br, /*nd*/NULL);
++	err = PTR_ERR(h_path.dentry);
++	if (IS_ERR(h_path.dentry))
++		goto out;
++
++	err = 0;
++	/* wh.plink dir is not monitored */
++	/* todo: is it really safe? */
++	if (h_path.dentry->d_inode
++	    && h_path.dentry->d_inode != h_dentry->d_inode) {
++		err = vfsub_unlink(h_dir, &h_path, /*force*/0);
++		dput(h_path.dentry);
++		h_path.dentry = NULL;
++		if (!err)
++			goto again;
++	}
++	if (!err && !h_path.dentry->d_inode)
++		err = vfsub_link(h_dentry, h_dir, &h_path);
++	dput(h_path.dentry);
++
++out:
++	mutex_unlock(&h_dir->i_mutex);
++	return err;
++}
++
++struct do_whplink_args {
++	int *errp;
++	struct qstr *tgt;
++	struct dentry *h_parent;
++	struct dentry *h_dentry;
++	struct au_branch *br;
++};
++
++static void call_do_whplink(void *args)
++{
++	struct do_whplink_args *a = args;
++	*a->errp = do_whplink(a->tgt, a->h_parent, a->h_dentry, a->br);
++}
++
++static int whplink(struct dentry *h_dentry, struct inode *inode,
++		   aufs_bindex_t bindex, struct au_branch *br)
++{
++	int err, wkq_err;
++	struct au_wbr *wbr;
++	struct dentry *h_parent;
++	struct inode *h_dir;
++	char a[PLINK_NAME_LEN];
++	struct qstr tgtname = {
++		.name = a
++	};
++
++	wbr = au_sbr(inode->i_sb, bindex)->br_wbr;
++	h_parent = wbr->wbr_plink;
++	h_dir = h_parent->d_inode;
++	tgtname.len = plink_name(a, sizeof(a), inode, bindex);
++
++	/* always superio. */
++	if (current_fsuid()) {
++		struct do_whplink_args args = {
++			.errp		= &err,
++			.tgt		= &tgtname,
++			.h_parent	= h_parent,
++			.h_dentry	= h_dentry,
++			.br		= br
++		};
++		wkq_err = au_wkq_wait(call_do_whplink, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	} else
++		err = do_whplink(&tgtname, h_parent, h_dentry, br);
++
++	return err;
++}
++
++/* free a single plink */
++static void do_put_plink(struct pseudo_link *plink, int do_del)
++{
++	if (do_del)
++		list_del(&plink->list);
++	iput(plink->inode);
++	kfree(plink);
++}
++
++static void do_put_plink_rcu(struct rcu_head *rcu)
++{
++	struct pseudo_link *plink;
++
++	plink = container_of(rcu, struct pseudo_link, rcu);
++	iput(plink->inode);
++	kfree(plink);
++}
++
++/*
++ * create a new pseudo-link for @h_dentry on @bindex.
++ * the linked inode is held in aufs @inode.
++ */
++void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
++		     struct dentry *h_dentry)
++{
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++	struct list_head *plink_list;
++	struct pseudo_link *plink, *tmp;
++	int found, err, cnt;
++
++	sb = inode->i_sb;
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
++
++	cnt = 0;
++	found = 0;
++	plink_list = &sbinfo->si_plink.head;
++	rcu_read_lock();
++	list_for_each_entry_rcu(plink, plink_list, list) {
++		cnt++;
++		if (plink->inode == inode) {
++			found = 1;
++			break;
++		}
++	}
++	rcu_read_unlock();
++	if (found)
++		return;
++
++	tmp = kmalloc(sizeof(*plink), GFP_NOFS);
++	if (tmp)
++		tmp->inode = au_igrab(inode);
++	else {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	spin_lock(&sbinfo->si_plink.spin);
++	list_for_each_entry(plink, plink_list, list) {
++		if (plink->inode == inode) {
++			found = 1;
++			break;
++		}
++	}
++	if (!found)
++		list_add_rcu(&tmp->list, plink_list);
++	spin_unlock(&sbinfo->si_plink.spin);
++	if (!found) {
++		cnt++;
++		WARN_ONCE(cnt > AUFS_PLINK_WARN,
++			  "unexpectedly many pseudo links, %d\n", cnt);
++		err = whplink(h_dentry, inode, bindex, au_sbr(sb, bindex));
++	} else {
++		do_put_plink(tmp, 0);
++		return;
++	}
++
++out:
++	if (unlikely(err)) {
++		pr_warning("err %d, damaged pseudo link.\n", err);
++		if (tmp) {
++			au_spl_del_rcu(&tmp->list, &sbinfo->si_plink);
++			call_rcu(&tmp->rcu, do_put_plink_rcu);
++		}
++	}
++}
++
++/* free all plinks */
++void au_plink_put(struct super_block *sb, int verbose)
++{
++	struct au_sbinfo *sbinfo;
++	struct list_head *plink_list;
++	struct pseudo_link *plink, *tmp;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
++
++	plink_list = &sbinfo->si_plink.head;
++	/* no spin_lock since sbinfo is write-locked */
++	WARN(verbose && !list_empty(plink_list), "pseudo-link is not flushed");
++	list_for_each_entry_safe(plink, tmp, plink_list, list)
++		do_put_plink(plink, 0);
++	INIT_LIST_HEAD(plink_list);
++}
++
++void au_plink_clean(struct super_block *sb, int verbose)
++{
++	struct dentry *root;
++
++	root = sb->s_root;
++	aufs_write_lock(root);
++	if (au_opt_test(au_mntflags(sb), PLINK))
++		au_plink_put(sb, verbose);
++	aufs_write_unlock(root);
++}
++
++/* free the plinks on a branch specified by @br_id */
++void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id)
++{
++	struct au_sbinfo *sbinfo;
++	struct list_head *plink_list;
++	struct pseudo_link *plink, *tmp;
++	struct inode *inode;
++	aufs_bindex_t bstart, bend, bindex;
++	unsigned char do_put;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++	AuDebugOn(au_plink_maint(sb, AuLock_NOPLM));
++
++	plink_list = &sbinfo->si_plink.head;
++	/* no spin_lock since sbinfo is write-locked */
++	list_for_each_entry_safe(plink, tmp, plink_list, list) {
++		do_put = 0;
++		inode = au_igrab(plink->inode);
++		ii_write_lock_child(inode);
++		bstart = au_ibstart(inode);
++		bend = au_ibend(inode);
++		if (bstart >= 0) {
++			for (bindex = bstart; bindex <= bend; bindex++) {
++				if (!au_h_iptr(inode, bindex)
++				    || au_ii_br_id(inode, bindex) != br_id)
++					continue;
++				au_set_h_iptr(inode, bindex, NULL, 0);
++				do_put = 1;
++				break;
++			}
++		} else
++			do_put_plink(plink, 1);
++
++		if (do_put) {
++			for (bindex = bstart; bindex <= bend; bindex++)
++				if (au_h_iptr(inode, bindex)) {
++					do_put = 0;
++					break;
++				}
++			if (do_put)
++				do_put_plink(plink, 1);
++		}
++		ii_write_unlock(inode);
++		iput(inode);
++	}
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/poll.c linux-2.6.36/fs/aufs/poll.c
+--- linux-2.6.36.orig/fs/aufs/poll.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/poll.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,56 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * poll operation
++ * There is only one filesystem which implements ->poll operation, currently.
++ */
++
++#include "aufs.h"
++
++unsigned int aufs_poll(struct file *file, poll_table *wait)
++{
++	unsigned int mask;
++	int err;
++	struct file *h_file;
++	struct dentry *dentry;
++	struct super_block *sb;
++
++	/* We should pretend an error happened. */
++	mask = POLLERR /* | POLLIN | POLLOUT */;
++	dentry = file->f_dentry;
++	sb = dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLMW);
++	err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++	if (unlikely(err))
++		goto out;
++
++	/* it is not an error if h_file has no operation */
++	mask = DEFAULT_POLLMASK;
++	h_file = au_hf_top(file);
++	if (h_file->f_op && h_file->f_op->poll)
++		mask = h_file->f_op->poll(h_file, wait);
++
++	di_read_unlock(dentry, AuLock_IR);
++	fi_read_unlock(file);
++
++out:
++	si_read_unlock(sb);
++	AuTraceErr((int)mask);
++	return mask;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/procfs.c linux-2.6.36/fs/aufs/procfs.c
+--- linux-2.6.36.orig/fs/aufs/procfs.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/procfs.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,169 @@
++/*
++ * Copyright (C) 2010-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * procfs interfaces
++ */
++
++#include <linux/proc_fs.h>
++#include "aufs.h"
++
++static int au_procfs_plm_release(struct inode *inode, struct file *file)
++{
++	struct au_sbinfo *sbinfo;
++
++	sbinfo = file->private_data;
++	if (sbinfo) {
++		au_plink_maint_leave(sbinfo);
++		kobject_put(&sbinfo->si_kobj);
++	}
++
++	return 0;
++}
++
++static void au_procfs_plm_write_clean(struct file *file)
++{
++	struct au_sbinfo *sbinfo;
++
++	sbinfo = file->private_data;
++	if (sbinfo)
++		au_plink_clean(sbinfo->si_sb, /*verbose*/0);
++}
++
++static int au_procfs_plm_write_si(struct file *file, unsigned long id)
++{
++	int err;
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++
++	err = -EBUSY;
++	if (unlikely(file->private_data))
++		goto out;
++
++	sb = NULL;
++	spin_lock(&au_sbilist.spin);
++	list_for_each_entry(sbinfo, &au_sbilist.head, si_list)
++		if (id == sysaufs_si_id(sbinfo)) {
++			kobject_get(&sbinfo->si_kobj);
++			sb = sbinfo->si_sb;
++			break;
++		}
++	spin_unlock(&au_sbilist.spin);
++
++	err = -EINVAL;
++	if (unlikely(!sb))
++		goto out;
++
++	err = au_plink_maint_enter(sb);
++	if (!err)
++		/* keep kobject_get() */
++		file->private_data = sbinfo;
++	else
++		kobject_put(&sbinfo->si_kobj);
++out:
++	return err;
++}
++
++/*
++ * Accept a valid "si=xxxx" only.
++ * Once it is accepted successfully, accept "clean" too.
++ */
++static ssize_t au_procfs_plm_write(struct file *file, const char __user *ubuf,
++				   size_t count, loff_t *ppos)
++{
++	ssize_t err;
++	unsigned long id;
++	/* last newline is allowed */
++	char buf[3 + sizeof(unsigned long) * 2 + 1];
++
++	err = -EACCES;
++	if (unlikely(!capable(CAP_SYS_ADMIN)))
++		goto out;
++
++	err = -EINVAL;
++	if (unlikely(count > sizeof(buf)))
++		goto out;
++
++	err = copy_from_user(buf, ubuf, count);
++	if (unlikely(err)) {
++		err = -EFAULT;
++		goto out;
++	}
++	buf[count] = 0;
++
++	err = -EINVAL;
++	if (!strcmp("clean", buf)) {
++		au_procfs_plm_write_clean(file);
++		goto out_success;
++	} else if (unlikely(strncmp("si=", buf, 3)))
++		goto out;
++
++	err = strict_strtoul(buf + 3, 16, &id);
++	if (unlikely(err))
++		goto out;
++
++	err = au_procfs_plm_write_si(file, id);
++	if (unlikely(err))
++		goto out;
++
++out_success:
++	err = count; /* success */
++out:
++	return err;
++}
++
++static const struct file_operations au_procfs_plm_fop = {
++	.write		= au_procfs_plm_write,
++	.release	= au_procfs_plm_release,
++	.owner		= THIS_MODULE
++};
++
++/* ---------------------------------------------------------------------- */
++
++static struct proc_dir_entry *au_procfs_dir;
++
++void au_procfs_fin(void)
++{
++	remove_proc_entry(AUFS_PLINK_MAINT_NAME, au_procfs_dir);
++	remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
++}
++
++int __init au_procfs_init(void)
++{
++	int err;
++	struct proc_dir_entry *entry;
++
++	err = -ENOMEM;
++	au_procfs_dir = proc_mkdir(AUFS_PLINK_MAINT_DIR, NULL);
++	if (unlikely(!au_procfs_dir))
++		goto out;
++
++	entry = proc_create(AUFS_PLINK_MAINT_NAME, S_IFREG | S_IWUSR,
++			    au_procfs_dir, &au_procfs_plm_fop);
++	if (unlikely(!entry))
++		goto out_dir;
++
++	err = 0;
++	goto out; /* success */
++
++
++out_dir:
++	remove_proc_entry(AUFS_PLINK_MAINT_DIR, NULL);
++out:
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/rdu.c linux-2.6.36/fs/aufs/rdu.c
+--- linux-2.6.36.orig/fs/aufs/rdu.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/rdu.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,383 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * readdir in userspace.
++ */
++
++#include <linux/compat.h>
++#include <linux/fs_stack.h>
++#include <linux/security.h>
++#include <linux/uaccess.h>
++#include <linux/aufs_type.h>
++#include "aufs.h"
++
++/* bits for struct aufs_rdu.flags */
++#define	AuRdu_CALLED	1
++#define	AuRdu_CONT	(1 << 1)
++#define	AuRdu_FULL	(1 << 2)
++#define au_ftest_rdu(flags, name)	((flags) & AuRdu_##name)
++#define au_fset_rdu(flags, name) \
++	do { (flags) |= AuRdu_##name; } while (0)
++#define au_fclr_rdu(flags, name) \
++	do { (flags) &= ~AuRdu_##name; } while (0)
++
++struct au_rdu_arg {
++	struct aufs_rdu			*rdu;
++	union au_rdu_ent_ul		ent;
++	unsigned long			end;
++
++	struct super_block		*sb;
++	int				err;
++};
++
++static int au_rdu_fill(void *__arg, const char *name, int nlen,
++		       loff_t offset, u64 h_ino, unsigned int d_type)
++{
++	int err, len;
++	struct au_rdu_arg *arg = __arg;
++	struct aufs_rdu *rdu = arg->rdu;
++	struct au_rdu_ent ent;
++
++	err = 0;
++	arg->err = 0;
++	au_fset_rdu(rdu->cookie.flags, CALLED);
++	len = au_rdu_len(nlen);
++	if (arg->ent.ul + len  < arg->end) {
++		ent.ino = h_ino;
++		ent.bindex = rdu->cookie.bindex;
++		ent.type = d_type;
++		ent.nlen = nlen;
++		if (unlikely(nlen > AUFS_MAX_NAMELEN))
++			ent.type = DT_UNKNOWN;
++
++		err = -EFAULT;
++		if (copy_to_user(arg->ent.e, &ent, sizeof(ent)))
++			goto out;
++		if (copy_to_user(arg->ent.e->name, name, nlen))
++			goto out;
++		/* the terminating NULL */
++		if (__put_user(0, arg->ent.e->name + nlen))
++			goto out;
++		err = 0;
++		/* AuDbg("%p, %.*s\n", arg->ent.p, nlen, name); */
++		arg->ent.ul += len;
++		rdu->rent++;
++	} else {
++		err = -EFAULT;
++		au_fset_rdu(rdu->cookie.flags, FULL);
++		rdu->full = 1;
++		rdu->tail = arg->ent;
++	}
++
++out:
++	/* AuTraceErr(err); */
++	return err;
++}
++
++static int au_rdu_do(struct file *h_file, struct au_rdu_arg *arg)
++{
++	int err;
++	loff_t offset;
++	struct au_rdu_cookie *cookie = &arg->rdu->cookie;
++
++	offset = vfsub_llseek(h_file, cookie->h_pos, SEEK_SET);
++	err = offset;
++	if (unlikely(offset != cookie->h_pos))
++		goto out;
++
++	err = 0;
++	do {
++		arg->err = 0;
++		au_fclr_rdu(cookie->flags, CALLED);
++		/* smp_mb(); */
++		err = vfsub_readdir(h_file, au_rdu_fill, arg);
++		if (err >= 0)
++			err = arg->err;
++	} while (!err
++		 && au_ftest_rdu(cookie->flags, CALLED)
++		 && !au_ftest_rdu(cookie->flags, FULL));
++	cookie->h_pos = h_file->f_pos;
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static int au_rdu(struct file *file, struct aufs_rdu *rdu)
++{
++	int err;
++	aufs_bindex_t bend;
++	struct au_rdu_arg arg;
++	struct dentry *dentry;
++	struct inode *inode;
++	struct file *h_file;
++	struct au_rdu_cookie *cookie = &rdu->cookie;
++
++	err = !access_ok(VERIFY_WRITE, rdu->ent.e, rdu->sz);
++	if (unlikely(err)) {
++		err = -EFAULT;
++		AuTraceErr(err);
++		goto out;
++	}
++	rdu->rent = 0;
++	rdu->tail = rdu->ent;
++	rdu->full = 0;
++	arg.rdu = rdu;
++	arg.ent = rdu->ent;
++	arg.end = arg.ent.ul;
++	arg.end += rdu->sz;
++
++	err = -ENOTDIR;
++	if (unlikely(!file->f_op || !file->f_op->readdir))
++		goto out;
++
++	err = security_file_permission(file, MAY_READ);
++	AuTraceErr(err);
++	if (unlikely(err))
++		goto out;
++
++	dentry = file->f_dentry;
++	inode = dentry->d_inode;
++#if 1
++	mutex_lock(&inode->i_mutex);
++#else
++	err = mutex_lock_killable(&inode->i_mutex);
++	AuTraceErr(err);
++	if (unlikely(err))
++		goto out;
++#endif
++
++	arg.sb = inode->i_sb;
++	err = si_read_lock(arg.sb, AuLock_FLUSH | AuLock_NOPLM);
++	if (unlikely(err))
++		goto out_mtx;
++	err = au_alive_dir(dentry);
++	if (unlikely(err))
++		goto out_si;
++	/* todo: reval? */
++	fi_read_lock(file);
++
++	err = -EAGAIN;
++	if (unlikely(au_ftest_rdu(cookie->flags, CONT)
++		     && cookie->generation != au_figen(file)))
++		goto out_unlock;
++
++	err = 0;
++	if (!rdu->blk) {
++		rdu->blk = au_sbi(arg.sb)->si_rdblk;
++		if (!rdu->blk)
++			rdu->blk = au_dir_size(file, /*dentry*/NULL);
++	}
++	bend = au_fbstart(file);
++	if (cookie->bindex < bend)
++		cookie->bindex = bend;
++	bend = au_fbend_dir(file);
++	/* AuDbg("b%d, b%d\n", cookie->bindex, bend); */
++	for (; !err && cookie->bindex <= bend;
++	     cookie->bindex++, cookie->h_pos = 0) {
++		h_file = au_hf_dir(file, cookie->bindex);
++		if (!h_file)
++			continue;
++
++		au_fclr_rdu(cookie->flags, FULL);
++		err = au_rdu_do(h_file, &arg);
++		AuTraceErr(err);
++		if (unlikely(au_ftest_rdu(cookie->flags, FULL) || err))
++			break;
++	}
++	AuDbg("rent %llu\n", rdu->rent);
++
++	if (!err && !au_ftest_rdu(cookie->flags, CONT)) {
++		rdu->shwh = !!au_opt_test(au_sbi(arg.sb)->si_mntflags, SHWH);
++		au_fset_rdu(cookie->flags, CONT);
++		cookie->generation = au_figen(file);
++	}
++
++	ii_read_lock_child(inode);
++	fsstack_copy_attr_atime(inode, au_h_iptr(inode, au_ibstart(inode)));
++	ii_read_unlock(inode);
++
++out_unlock:
++	fi_read_unlock(file);
++out_si:
++	si_read_unlock(arg.sb);
++out_mtx:
++	mutex_unlock(&inode->i_mutex);
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++static int au_rdu_ino(struct file *file, struct aufs_rdu *rdu)
++{
++	int err;
++	ino_t ino;
++	unsigned long long nent;
++	union au_rdu_ent_ul *u;
++	struct au_rdu_ent ent;
++	struct super_block *sb;
++
++	err = 0;
++	nent = rdu->nent;
++	u = &rdu->ent;
++	sb = file->f_dentry->d_sb;
++	si_read_lock(sb, AuLock_FLUSH);
++	while (nent-- > 0) {
++		err = copy_from_user(&ent, u->e, sizeof(ent));
++		if (!err)
++			err = !access_ok(VERIFY_WRITE, &u->e->ino, sizeof(ino));
++		if (unlikely(err)) {
++			err = -EFAULT;
++			AuTraceErr(err);
++			break;
++		}
++
++		/* AuDbg("b%d, i%llu\n", ent.bindex, ent.ino); */
++		if (!ent.wh)
++			err = au_ino(sb, ent.bindex, ent.ino, ent.type, &ino);
++		else
++			err = au_wh_ino(sb, ent.bindex, ent.ino, ent.type,
++					&ino);
++		if (unlikely(err)) {
++			AuTraceErr(err);
++			break;
++		}
++
++		err = __put_user(ino, &u->e->ino);
++		if (unlikely(err)) {
++			err = -EFAULT;
++			AuTraceErr(err);
++			break;
++		}
++		u->ul += au_rdu_len(ent.nlen);
++	}
++	si_read_unlock(sb);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_rdu_verify(struct aufs_rdu *rdu)
++{
++	AuDbg("rdu{%llu, %p, %u | %u | %llu, %u, %u | "
++	      "%llu, b%d, 0x%x, g%u}\n",
++	      rdu->sz, rdu->ent.e, rdu->verify[AufsCtlRduV_SZ],
++	      rdu->blk,
++	      rdu->rent, rdu->shwh, rdu->full,
++	      rdu->cookie.h_pos, rdu->cookie.bindex, rdu->cookie.flags,
++	      rdu->cookie.generation);
++
++	if (rdu->verify[AufsCtlRduV_SZ] == sizeof(*rdu))
++		return 0;
++
++	AuDbg("%u:%u\n",
++	      rdu->verify[AufsCtlRduV_SZ], (unsigned int)sizeof(*rdu));
++	return -EINVAL;
++}
++
++long au_rdu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	long err, e;
++	struct aufs_rdu rdu;
++	void __user *p = (void __user *)arg;
++
++	err = copy_from_user(&rdu, p, sizeof(rdu));
++	if (unlikely(err)) {
++		err = -EFAULT;
++		AuTraceErr(err);
++		goto out;
++	}
++	err = au_rdu_verify(&rdu);
++	if (unlikely(err))
++		goto out;
++
++	switch (cmd) {
++	case AUFS_CTL_RDU:
++		err = au_rdu(file, &rdu);
++		if (unlikely(err))
++			break;
++
++		e = copy_to_user(p, &rdu, sizeof(rdu));
++		if (unlikely(e)) {
++			err = -EFAULT;
++			AuTraceErr(err);
++		}
++		break;
++	case AUFS_CTL_RDU_INO:
++		err = au_rdu_ino(file, &rdu);
++		break;
++
++	default:
++		/* err = -ENOTTY; */
++		err = -EINVAL;
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++#ifdef CONFIG_COMPAT
++long au_rdu_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	long err, e;
++	struct aufs_rdu rdu;
++	void __user *p = compat_ptr(arg);
++
++	/* todo: get_user()? */
++	err = copy_from_user(&rdu, p, sizeof(rdu));
++	if (unlikely(err)) {
++		err = -EFAULT;
++		AuTraceErr(err);
++		goto out;
++	}
++	rdu.ent.e = compat_ptr(rdu.ent.ul);
++	err = au_rdu_verify(&rdu);
++	if (unlikely(err))
++		goto out;
++
++	switch (cmd) {
++	case AUFS_CTL_RDU:
++		err = au_rdu(file, &rdu);
++		if (unlikely(err))
++			break;
++
++		rdu.ent.ul = ptr_to_compat(rdu.ent.e);
++		rdu.tail.ul = ptr_to_compat(rdu.tail.e);
++		e = copy_to_user(p, &rdu, sizeof(rdu));
++		if (unlikely(e)) {
++			err = -EFAULT;
++			AuTraceErr(err);
++		}
++		break;
++	case AUFS_CTL_RDU_INO:
++		err = au_rdu_ino(file, &rdu);
++		break;
++
++	default:
++		/* err = -ENOTTY; */
++		err = -EINVAL;
++	}
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++#endif
+diff -Nur linux-2.6.36.orig/fs/aufs/rwsem.h linux-2.6.36/fs/aufs/rwsem.h
+--- linux-2.6.36.orig/fs/aufs/rwsem.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/rwsem.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,189 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * simple read-write semaphore wrappers
++ */
++
++#ifndef __AUFS_RWSEM_H__
++#define __AUFS_RWSEM_H__
++
++#ifdef __KERNEL__
++
++#include <linux/rwsem.h>
++#include "debug.h"
++
++struct au_rwsem {
++	struct rw_semaphore	rwsem;
++#ifdef CONFIG_AUFS_DEBUG
++	/* just for debugging, not almighty counter */
++	atomic_t		rcnt, wcnt;
++#endif
++};
++
++#ifdef CONFIG_AUFS_DEBUG
++#define AuDbgCntInit(rw) do { \
++	atomic_set(&(rw)->rcnt, 0); \
++	atomic_set(&(rw)->wcnt, 0); \
++	smp_mb(); /* atomic set */ \
++} while (0)
++
++#define AuDbgRcntInc(rw)	atomic_inc(&(rw)->rcnt)
++#define AuDbgRcntDec(rw)	WARN_ON(atomic_dec_return(&(rw)->rcnt) < 0)
++#define AuDbgWcntInc(rw)	atomic_inc(&(rw)->wcnt)
++#define AuDbgWcntDec(rw)	WARN_ON(atomic_dec_return(&(rw)->wcnt) < 0)
++#else
++#define AuDbgCntInit(rw)	do {} while (0)
++#define AuDbgRcntInc(rw)	do {} while (0)
++#define AuDbgRcntDec(rw)	do {} while (0)
++#define AuDbgWcntInc(rw)	do {} while (0)
++#define AuDbgWcntDec(rw)	do {} while (0)
++#endif /* CONFIG_AUFS_DEBUG */
++
++/* to debug easier, do not make them inlined functions */
++#define AuRwMustNoWaiters(rw)	AuDebugOn(!list_empty(&(rw)->rwsem.wait_list))
++/* rwsem_is_locked() is unusable */
++#define AuRwMustReadLock(rw)	AuDebugOn(atomic_read(&(rw)->rcnt) <= 0)
++#define AuRwMustWriteLock(rw)	AuDebugOn(atomic_read(&(rw)->wcnt) <= 0)
++#define AuRwMustAnyLock(rw)	AuDebugOn(atomic_read(&(rw)->rcnt) <= 0 \
++					&& atomic_read(&(rw)->wcnt) <= 0)
++#define AuRwDestroy(rw)		AuDebugOn(atomic_read(&(rw)->rcnt) \
++					|| atomic_read(&(rw)->wcnt))
++
++#define au_rw_class(rw, key)	lockdep_set_class(&(rw)->rwsem, key)
++
++static inline void au_rw_init(struct au_rwsem *rw)
++{
++	AuDbgCntInit(rw);
++	init_rwsem(&rw->rwsem);
++}
++
++static inline void au_rw_init_wlock(struct au_rwsem *rw)
++{
++	au_rw_init(rw);
++	down_write(&rw->rwsem);
++	AuDbgWcntInc(rw);
++}
++
++static inline void au_rw_init_wlock_nested(struct au_rwsem *rw,
++					   unsigned int lsc)
++{
++	au_rw_init(rw);
++	down_write_nested(&rw->rwsem, lsc);
++	AuDbgWcntInc(rw);
++}
++
++static inline void au_rw_read_lock(struct au_rwsem *rw)
++{
++	down_read(&rw->rwsem);
++	AuDbgRcntInc(rw);
++}
++
++static inline void au_rw_read_lock_nested(struct au_rwsem *rw, unsigned int lsc)
++{
++	down_read_nested(&rw->rwsem, lsc);
++	AuDbgRcntInc(rw);
++}
++
++static inline void au_rw_read_unlock(struct au_rwsem *rw)
++{
++	AuRwMustReadLock(rw);
++	AuDbgRcntDec(rw);
++	up_read(&rw->rwsem);
++}
++
++static inline void au_rw_dgrade_lock(struct au_rwsem *rw)
++{
++	AuRwMustWriteLock(rw);
++	AuDbgRcntInc(rw);
++	AuDbgWcntDec(rw);
++	downgrade_write(&rw->rwsem);
++}
++
++static inline void au_rw_write_lock(struct au_rwsem *rw)
++{
++	down_write(&rw->rwsem);
++	AuDbgWcntInc(rw);
++}
++
++static inline void au_rw_write_lock_nested(struct au_rwsem *rw,
++					   unsigned int lsc)
++{
++	down_write_nested(&rw->rwsem, lsc);
++	AuDbgWcntInc(rw);
++}
++
++static inline void au_rw_write_unlock(struct au_rwsem *rw)
++{
++	AuRwMustWriteLock(rw);
++	AuDbgWcntDec(rw);
++	up_write(&rw->rwsem);
++}
++
++/* why is not _nested version defined */
++static inline int au_rw_read_trylock(struct au_rwsem *rw)
++{
++	int ret = down_read_trylock(&rw->rwsem);
++	if (ret)
++		AuDbgRcntInc(rw);
++	return ret;
++}
++
++static inline int au_rw_write_trylock(struct au_rwsem *rw)
++{
++	int ret = down_write_trylock(&rw->rwsem);
++	if (ret)
++		AuDbgWcntInc(rw);
++	return ret;
++}
++
++#undef AuDbgCntInit
++#undef AuDbgRcntInc
++#undef AuDbgRcntDec
++#undef AuDbgWcntInc
++#undef AuDbgWcntDec
++
++#define AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
++static inline void prefix##_read_lock(param) \
++{ au_rw_read_lock(rwsem); } \
++static inline void prefix##_write_lock(param) \
++{ au_rw_write_lock(rwsem); } \
++static inline int prefix##_read_trylock(param) \
++{ return au_rw_read_trylock(rwsem); } \
++static inline int prefix##_write_trylock(param) \
++{ return au_rw_write_trylock(rwsem); }
++/* why is not _nested version defined */
++/* static inline void prefix##_read_trylock_nested(param, lsc)
++{ au_rw_read_trylock_nested(rwsem, lsc)); }
++static inline void prefix##_write_trylock_nestd(param, lsc)
++{ au_rw_write_trylock_nested(rwsem, lsc); } */
++
++#define AuSimpleUnlockRwsemFuncs(prefix, param, rwsem) \
++static inline void prefix##_read_unlock(param) \
++{ au_rw_read_unlock(rwsem); } \
++static inline void prefix##_write_unlock(param) \
++{ au_rw_write_unlock(rwsem); } \
++static inline void prefix##_downgrade_lock(param) \
++{ au_rw_dgrade_lock(rwsem); }
++
++#define AuSimpleRwsemFuncs(prefix, param, rwsem) \
++	AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
++	AuSimpleUnlockRwsemFuncs(prefix, param, rwsem)
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_RWSEM_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/sbinfo.c linux-2.6.36/fs/aufs/sbinfo.c
+--- linux-2.6.36.orig/fs/aufs/sbinfo.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/sbinfo.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,345 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * superblock private data
++ */
++
++#include <linux/jiffies.h>
++#include "aufs.h"
++
++/*
++ * they are necessary regardless sysfs is disabled.
++ */
++void au_si_free(struct kobject *kobj)
++{
++	struct au_sbinfo *sbinfo;
++	char *locked __maybe_unused; /* debug only */
++
++	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
++	AuDebugOn(!list_empty(&sbinfo->si_plink.head));
++	AuDebugOn(atomic_read(&sbinfo->si_nowait.nw_len));
++
++	au_rw_write_lock(&sbinfo->si_rwsem);
++	au_br_free(sbinfo);
++	au_rw_write_unlock(&sbinfo->si_rwsem);
++
++	AuDebugOn(radix_tree_gang_lookup
++		  (&sbinfo->au_si_pid.tree, (void **)&locked,
++		   /*first_index*/PID_MAX_DEFAULT - 1,
++		   /*max_items*/sizeof(locked)/sizeof(*locked)));
++
++	kfree(sbinfo->si_branch);
++	kfree(sbinfo->au_si_pid.bitmap);
++	mutex_destroy(&sbinfo->si_xib_mtx);
++	AuRwDestroy(&sbinfo->si_rwsem);
++
++	kfree(sbinfo);
++}
++
++int au_si_alloc(struct super_block *sb)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++	static struct lock_class_key aufs_si;
++
++	err = -ENOMEM;
++	sbinfo = kzalloc(sizeof(*sbinfo), GFP_NOFS);
++	if (unlikely(!sbinfo))
++		goto out;
++
++	BUILD_BUG_ON(sizeof(unsigned long) !=
++		     sizeof(*sbinfo->au_si_pid.bitmap));
++	sbinfo->au_si_pid.bitmap = kcalloc(BITS_TO_LONGS(PID_MAX_DEFAULT),
++					sizeof(*sbinfo->au_si_pid.bitmap),
++					GFP_NOFS);
++	if (unlikely(!sbinfo->au_si_pid.bitmap))
++		goto out_sbinfo;
++
++	/* will be reallocated separately */
++	sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_NOFS);
++	if (unlikely(!sbinfo->si_branch))
++		goto out_pidmap;
++
++	err = sysaufs_si_init(sbinfo);
++	if (unlikely(err))
++		goto out_br;
++
++	au_nwt_init(&sbinfo->si_nowait);
++	au_rw_init_wlock(&sbinfo->si_rwsem);
++	au_rw_class(&sbinfo->si_rwsem, &aufs_si);
++	spin_lock_init(&sbinfo->au_si_pid.tree_lock);
++	INIT_RADIX_TREE(&sbinfo->au_si_pid.tree, GFP_ATOMIC | __GFP_NOFAIL);
++
++	atomic_long_set(&sbinfo->si_ninodes, 0);
++	atomic_long_set(&sbinfo->si_nfiles, 0);
++
++	sbinfo->si_bend = -1;
++
++	sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
++	sbinfo->si_wbr_create = AuWbrCreate_Def;
++	sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + sbinfo->si_wbr_copyup;
++	sbinfo->si_wbr_create_ops = au_wbr_create_ops + sbinfo->si_wbr_create;
++
++	sbinfo->si_mntflags = au_opts_plink(AuOpt_Def);
++
++	mutex_init(&sbinfo->si_xib_mtx);
++	sbinfo->si_xino_brid = -1;
++	/* leave si_xib_last_pindex and si_xib_next_bit */
++
++	sbinfo->si_rdcache = msecs_to_jiffies(AUFS_RDCACHE_DEF * MSEC_PER_SEC);
++	sbinfo->si_rdblk = AUFS_RDBLK_DEF;
++	sbinfo->si_rdhash = AUFS_RDHASH_DEF;
++	sbinfo->si_dirwh = AUFS_DIRWH_DEF;
++
++	au_spl_init(&sbinfo->si_plink);
++	init_waitqueue_head(&sbinfo->si_plink_wq);
++	spin_lock_init(&sbinfo->si_plink_maint_lock);
++
++	/* leave other members for sysaufs and si_mnt. */
++	sbinfo->si_sb = sb;
++	sb->s_fs_info = sbinfo;
++	si_pid_set(sb);
++	au_debug_sbinfo_init(sbinfo);
++	return 0; /* success */
++
++out_br:
++	kfree(sbinfo->si_branch);
++out_pidmap:
++	kfree(sbinfo->au_si_pid.bitmap);
++out_sbinfo:
++	kfree(sbinfo);
++out:
++	return err;
++}
++
++int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr)
++{
++	int err, sz;
++	struct au_branch **brp;
++
++	AuRwMustWriteLock(&sbinfo->si_rwsem);
++
++	err = -ENOMEM;
++	sz = sizeof(*brp) * (sbinfo->si_bend + 1);
++	if (unlikely(!sz))
++		sz = sizeof(*brp);
++	brp = au_kzrealloc(sbinfo->si_branch, sz, sizeof(*brp) * nbr, GFP_NOFS);
++	if (brp) {
++		sbinfo->si_branch = brp;
++		err = 0;
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++unsigned int au_sigen_inc(struct super_block *sb)
++{
++	unsigned int gen;
++
++	SiMustWriteLock(sb);
++
++	gen = ++au_sbi(sb)->si_generation;
++	au_update_digen(sb->s_root);
++	au_update_iigen(sb->s_root->d_inode);
++	sb->s_root->d_inode->i_version++;
++	return gen;
++}
++
++aufs_bindex_t au_new_br_id(struct super_block *sb)
++{
++	aufs_bindex_t br_id;
++	int i;
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	for (i = 0; i <= AUFS_BRANCH_MAX; i++) {
++		br_id = ++sbinfo->si_last_br_id;
++		AuDebugOn(br_id < 0);
++		if (br_id && au_br_index(sb, br_id) < 0)
++			return br_id;
++	}
++
++	return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* it is ok that new 'nwt' tasks are appended while we are sleeping */
++int si_read_lock(struct super_block *sb, int flags)
++{
++	int err;
++
++	err = 0;
++	if (au_ftest_lock(flags, FLUSH))
++		au_nwt_flush(&au_sbi(sb)->si_nowait);
++
++	si_noflush_read_lock(sb);
++	err = au_plink_maint(sb, flags);
++	if (unlikely(err))
++		si_read_unlock(sb);
++
++	return err;
++}
++
++int si_write_lock(struct super_block *sb, int flags)
++{
++	int err;
++
++	if (au_ftest_lock(flags, FLUSH))
++		au_nwt_flush(&au_sbi(sb)->si_nowait);
++
++	si_noflush_write_lock(sb);
++	err = au_plink_maint(sb, flags);
++	if (unlikely(err))
++		si_write_unlock(sb);
++
++	return err;
++}
++
++/* dentry and super_block lock. call at entry point */
++int aufs_read_lock(struct dentry *dentry, int flags)
++{
++	int err;
++	struct super_block *sb;
++
++	sb = dentry->d_sb;
++	err = si_read_lock(sb, flags);
++	if (unlikely(err))
++		goto out;
++
++	if (au_ftest_lock(flags, DW))
++		di_write_lock_child(dentry);
++	else
++		di_read_lock_child(dentry, flags);
++
++	if (au_ftest_lock(flags, GEN)) {
++		err = au_digen_test(dentry, au_sigen(sb));
++		AuDebugOn(!err && au_dbrange_test(dentry));
++		if (unlikely(err))
++			aufs_read_unlock(dentry, flags);
++	}
++
++out:
++	return err;
++}
++
++void aufs_read_unlock(struct dentry *dentry, int flags)
++{
++	if (au_ftest_lock(flags, DW))
++		di_write_unlock(dentry);
++	else
++		di_read_unlock(dentry, flags);
++	si_read_unlock(dentry->d_sb);
++}
++
++void aufs_write_lock(struct dentry *dentry)
++{
++	si_write_lock(dentry->d_sb, AuLock_FLUSH | AuLock_NOPLMW);
++	di_write_lock_child(dentry);
++}
++
++void aufs_write_unlock(struct dentry *dentry)
++{
++	di_write_unlock(dentry);
++	si_write_unlock(dentry->d_sb);
++}
++
++int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
++{
++	int err;
++	unsigned int sigen;
++	struct super_block *sb;
++
++	sb = d1->d_sb;
++	err = si_read_lock(sb, flags);
++	if (unlikely(err))
++		goto out;
++
++	di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
++
++	if (au_ftest_lock(flags, GEN)) {
++		sigen = au_sigen(sb);
++		err = au_digen_test(d1, sigen);
++		AuDebugOn(!err && au_dbrange_test(d1));
++		if (!err) {
++			err = au_digen_test(d2, sigen);
++			AuDebugOn(!err && au_dbrange_test(d2));
++		}
++		if (unlikely(err))
++			aufs_read_and_write_unlock2(d1, d2);
++	}
++
++out:
++	return err;
++}
++
++void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
++{
++	di_write_unlock2(d1, d2);
++	si_read_unlock(d1->d_sb);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int si_pid_test_slow(struct super_block *sb)
++{
++	void *p;
++
++	rcu_read_lock();
++	p = radix_tree_lookup(&au_sbi(sb)->au_si_pid.tree, current->pid);
++	rcu_read_unlock();
++
++	return (long)p;
++}
++
++void si_pid_set_slow(struct super_block *sb)
++{
++	int err;
++	struct au_sbinfo *sbinfo;
++
++	AuDebugOn(si_pid_test_slow(sb));
++
++	sbinfo = au_sbi(sb);
++	err = radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
++	AuDebugOn(err);
++	spin_lock(&sbinfo->au_si_pid.tree_lock);
++	err = radix_tree_insert(&sbinfo->au_si_pid.tree, current->pid,
++				(void *)1);
++	spin_unlock(&sbinfo->au_si_pid.tree_lock);
++	AuDebugOn(err);
++	radix_tree_preload_end();
++}
++
++void si_pid_clr_slow(struct super_block *sb)
++{
++	void *p;
++	struct au_sbinfo *sbinfo;
++
++	AuDebugOn(!si_pid_test_slow(sb));
++
++	sbinfo = au_sbi(sb);
++	spin_lock(&sbinfo->au_si_pid.tree_lock);
++	p = radix_tree_delete(&sbinfo->au_si_pid.tree, current->pid);
++	spin_unlock(&sbinfo->au_si_pid.tree_lock);
++	AuDebugOn(1 != (long)p);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/spl.h linux-2.6.36/fs/aufs/spl.h
+--- linux-2.6.36.orig/fs/aufs/spl.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/spl.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,66 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * simple list protected by a spinlock
++ */
++
++#ifndef __AUFS_SPL_H__
++#define __AUFS_SPL_H__
++
++#ifdef __KERNEL__
++
++#include <linux/spinlock.h>
++#include <linux/list.h>
++#include <linux/rculist.h>
++
++struct au_splhead {
++	spinlock_t		spin;
++	struct list_head	head;
++};
++
++static inline void au_spl_init(struct au_splhead *spl)
++{
++	spin_lock_init(&spl->spin);
++	INIT_LIST_HEAD(&spl->head);
++}
++
++static inline void au_spl_add(struct list_head *list, struct au_splhead *spl)
++{
++	spin_lock(&spl->spin);
++	list_add(list, &spl->head);
++	spin_unlock(&spl->spin);
++}
++
++static inline void au_spl_del(struct list_head *list, struct au_splhead *spl)
++{
++	spin_lock(&spl->spin);
++	list_del(list);
++	spin_unlock(&spl->spin);
++}
++
++static inline void au_spl_del_rcu(struct list_head *list,
++				  struct au_splhead *spl)
++{
++	spin_lock(&spl->spin);
++	list_del_rcu(list);
++	spin_unlock(&spl->spin);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_SPL_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/super.c linux-2.6.36/fs/aufs/super.c
+--- linux-2.6.36.orig/fs/aufs/super.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/super.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,913 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * mount and super_block operations
++ */
++
++#include <linux/buffer_head.h>
++#include <linux/jiffies.h>
++#include <linux/module.h>
++#include <linux/seq_file.h>
++#include <linux/statfs.h>
++#include <linux/vmalloc.h>
++#include <linux/writeback.h>
++#include "aufs.h"
++
++/*
++ * super_operations
++ */
++static struct inode *aufs_alloc_inode(struct super_block *sb __maybe_unused)
++{
++	struct au_icntnr *c;
++
++	c = au_cache_alloc_icntnr();
++	if (c) {
++		au_icntnr_init(c);
++		c->vfs_inode.i_version = 1; /* sigen(sb); */
++		c->iinfo.ii_hinode = NULL;
++		return &c->vfs_inode;
++	}
++	return NULL;
++}
++
++static void aufs_destroy_inode(struct inode *inode)
++{
++	au_iinfo_fin(inode);
++	au_cache_free_icntnr(container_of(inode, struct au_icntnr, vfs_inode));
++}
++
++struct inode *au_iget_locked(struct super_block *sb, ino_t ino)
++{
++	struct inode *inode;
++	int err;
++
++	inode = iget_locked(sb, ino);
++	if (unlikely(!inode)) {
++		inode = ERR_PTR(-ENOMEM);
++		goto out;
++	}
++	if (!(inode->i_state & I_NEW))
++		goto out;
++
++	err = au_xigen_new(inode);
++	if (!err)
++		err = au_iinfo_init(inode);
++	if (!err)
++		inode->i_version++;
++	else {
++		iget_failed(inode);
++		inode = ERR_PTR(err);
++	}
++
++out:
++	/* never return NULL */
++	AuDebugOn(!inode);
++	AuTraceErrPtr(inode);
++	return inode;
++}
++
++/* lock free root dinfo */
++static int au_show_brs(struct seq_file *seq, struct super_block *sb)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	struct path path;
++	struct au_hdentry *hdp;
++	struct au_branch *br;
++
++	err = 0;
++	bend = au_sbend(sb);
++	hdp = au_di(sb->s_root)->di_hdentry;
++	for (bindex = 0; !err && bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		path.mnt = br->br_mnt;
++		path.dentry = hdp[bindex].hd_dentry;
++		err = au_seq_path(seq, &path);
++		if (err > 0)
++			err = seq_printf(seq, "=%s",
++					 au_optstr_br_perm(br->br_perm));
++		if (!err && bindex != bend)
++			err = seq_putc(seq, ':');
++	}
++
++	return err;
++}
++
++static void au_show_wbr_create(struct seq_file *m, int v,
++			       struct au_sbinfo *sbinfo)
++{
++	const char *pat;
++
++	AuRwMustAnyLock(&sbinfo->si_rwsem);
++
++	seq_printf(m, ",create=");
++	pat = au_optstr_wbr_create(v);
++	switch (v) {
++	case AuWbrCreate_TDP:
++	case AuWbrCreate_RR:
++	case AuWbrCreate_MFS:
++	case AuWbrCreate_PMFS:
++		seq_printf(m, pat);
++		break;
++	case AuWbrCreate_MFSV:
++		seq_printf(m, /*pat*/"mfs:%lu",
++			   jiffies_to_msecs(sbinfo->si_wbr_mfs.mfs_expire)
++			   / MSEC_PER_SEC);
++		break;
++	case AuWbrCreate_PMFSV:
++		seq_printf(m, /*pat*/"pmfs:%lu",
++			   jiffies_to_msecs(sbinfo->si_wbr_mfs.mfs_expire)
++			   / MSEC_PER_SEC);
++		break;
++	case AuWbrCreate_MFSRR:
++		seq_printf(m, /*pat*/"mfsrr:%llu",
++			   sbinfo->si_wbr_mfs.mfsrr_watermark);
++		break;
++	case AuWbrCreate_MFSRRV:
++		seq_printf(m, /*pat*/"mfsrr:%llu:%lu",
++			   sbinfo->si_wbr_mfs.mfsrr_watermark,
++			   jiffies_to_msecs(sbinfo->si_wbr_mfs.mfs_expire)
++			   / MSEC_PER_SEC);
++		break;
++	}
++}
++
++static int au_show_xino(struct seq_file *seq, struct vfsmount *mnt)
++{
++#ifdef CONFIG_SYSFS
++	return 0;
++#else
++	int err;
++	const int len = sizeof(AUFS_XINO_FNAME) - 1;
++	aufs_bindex_t bindex, brid;
++	struct super_block *sb;
++	struct qstr *name;
++	struct file *f;
++	struct dentry *d, *h_root;
++	struct au_hdentry *hdp;
++
++	AuRwMustAnyLock(&sbinfo->si_rwsem);
++
++	err = 0;
++	sb = mnt->mnt_sb;
++	f = au_sbi(sb)->si_xib;
++	if (!f)
++		goto out;
++
++	/* stop printing the default xino path on the first writable branch */
++	h_root = NULL;
++	brid = au_xino_brid(sb);
++	if (brid >= 0) {
++		bindex = au_br_index(sb, brid);
++		hdp = au_di(sb->s_root)->di_hdentry;
++		h_root = hdp[0 + bindex].hd_dentry;
++	}
++	d = f->f_dentry;
++	name = &d->d_name;
++	/* safe ->d_parent because the file is unlinked */
++	if (d->d_parent == h_root
++	    && name->len == len
++	    && !memcmp(name->name, AUFS_XINO_FNAME, len))
++		goto out;
++
++	seq_puts(seq, ",xino=");
++	err = au_xino_path(seq, f);
++
++out:
++	return err;
++#endif
++}
++
++/* seq_file will re-call me in case of too long string */
++static int aufs_show_options(struct seq_file *m, struct vfsmount *mnt)
++{
++	int err;
++	unsigned int mnt_flags, v;
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++
++#define AuBool(name, str) do { \
++	v = au_opt_test(mnt_flags, name); \
++	if (v != au_opt_test(AuOpt_Def, name)) \
++		seq_printf(m, ",%s" #str, v ? "" : "no"); \
++} while (0)
++
++#define AuStr(name, str) do { \
++	v = mnt_flags & AuOptMask_##name; \
++	if (v != (AuOpt_Def & AuOptMask_##name)) \
++		seq_printf(m, "," #str "=%s", au_optstr_##str(v)); \
++} while (0)
++
++#define AuUInt(name, str, val) do { \
++	if (val != AUFS_##name##_DEF) \
++		seq_printf(m, "," #str "=%u", val); \
++} while (0)
++
++	/* lock free root dinfo */
++	sb = mnt->mnt_sb;
++	si_noflush_read_lock(sb);
++	sbinfo = au_sbi(sb);
++	seq_printf(m, ",si=%lx", sysaufs_si_id(sbinfo));
++
++	mnt_flags = au_mntflags(sb);
++	if (au_opt_test(mnt_flags, XINO)) {
++		err = au_show_xino(m, mnt);
++		if (unlikely(err))
++			goto out;
++	} else
++		seq_puts(m, ",noxino");
++
++	AuBool(TRUNC_XINO, trunc_xino);
++	AuStr(UDBA, udba);
++	AuBool(SHWH, shwh);
++	AuBool(PLINK, plink);
++	AuBool(DIO, dio);
++	/* AuBool(DIRPERM1, dirperm1); */
++	/* AuBool(REFROF, refrof); */
++
++	v = sbinfo->si_wbr_create;
++	if (v != AuWbrCreate_Def)
++		au_show_wbr_create(m, v, sbinfo);
++
++	v = sbinfo->si_wbr_copyup;
++	if (v != AuWbrCopyup_Def)
++		seq_printf(m, ",cpup=%s", au_optstr_wbr_copyup(v));
++
++	v = au_opt_test(mnt_flags, ALWAYS_DIROPQ);
++	if (v != au_opt_test(AuOpt_Def, ALWAYS_DIROPQ))
++		seq_printf(m, ",diropq=%c", v ? 'a' : 'w');
++
++	AuUInt(DIRWH, dirwh, sbinfo->si_dirwh);
++
++	v = jiffies_to_msecs(sbinfo->si_rdcache) / MSEC_PER_SEC;
++	AuUInt(RDCACHE, rdcache, v);
++
++	AuUInt(RDBLK, rdblk, sbinfo->si_rdblk);
++	AuUInt(RDHASH, rdhash, sbinfo->si_rdhash);
++
++	AuBool(SUM, sum);
++	/* AuBool(SUM_W, wsum); */
++	AuBool(WARN_PERM, warn_perm);
++	AuBool(VERBOSE, verbose);
++
++out:
++	/* be sure to print "br:" last */
++	if (!sysaufs_brs) {
++		seq_puts(m, ",br:");
++		au_show_brs(m, sb);
++	}
++	si_read_unlock(sb);
++	return 0;
++
++#undef AuBool
++#undef AuStr
++#undef AuUInt
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* sum mode which returns the summation for statfs(2) */
++
++static u64 au_add_till_max(u64 a, u64 b)
++{
++	u64 old;
++
++	old = a;
++	a += b;
++	if (old < a)
++		return a;
++	return ULLONG_MAX;
++}
++
++static int au_statfs_sum(struct super_block *sb, struct kstatfs *buf)
++{
++	int err;
++	u64 blocks, bfree, bavail, files, ffree;
++	aufs_bindex_t bend, bindex, i;
++	unsigned char shared;
++	struct path h_path;
++	struct super_block *h_sb;
++
++	blocks = 0;
++	bfree = 0;
++	bavail = 0;
++	files = 0;
++	ffree = 0;
++
++	err = 0;
++	bend = au_sbend(sb);
++	for (bindex = bend; bindex >= 0; bindex--) {
++		h_path.mnt = au_sbr_mnt(sb, bindex);
++		h_sb = h_path.mnt->mnt_sb;
++		shared = 0;
++		for (i = bindex + 1; !shared && i <= bend; i++)
++			shared = (au_sbr_sb(sb, i) == h_sb);
++		if (shared)
++			continue;
++
++		/* sb->s_root for NFS is unreliable */
++		h_path.dentry = h_path.mnt->mnt_root;
++		err = vfs_statfs(&h_path, buf);
++		if (unlikely(err))
++			goto out;
++
++		blocks = au_add_till_max(blocks, buf->f_blocks);
++		bfree = au_add_till_max(bfree, buf->f_bfree);
++		bavail = au_add_till_max(bavail, buf->f_bavail);
++		files = au_add_till_max(files, buf->f_files);
++		ffree = au_add_till_max(ffree, buf->f_ffree);
++	}
++
++	buf->f_blocks = blocks;
++	buf->f_bfree = bfree;
++	buf->f_bavail = bavail;
++	buf->f_files = files;
++	buf->f_ffree = ffree;
++
++out:
++	return err;
++}
++
++static int aufs_statfs(struct dentry *dentry, struct kstatfs *buf)
++{
++	int err;
++	struct path h_path;
++	struct super_block *sb;
++
++	/* lock free root dinfo */
++	sb = dentry->d_sb;
++	si_noflush_read_lock(sb);
++	if (!au_opt_test(au_mntflags(sb), SUM)) {
++		/* sb->s_root for NFS is unreliable */
++		h_path.mnt = au_sbr_mnt(sb, 0);
++		h_path.dentry = h_path.mnt->mnt_root;
++		err = vfs_statfs(&h_path, buf);
++	} else
++		err = au_statfs_sum(sb, buf);
++	si_read_unlock(sb);
++
++	if (!err) {
++		buf->f_type = AUFS_SUPER_MAGIC;
++		buf->f_namelen = AUFS_MAX_NAMELEN;
++		memset(&buf->f_fsid, 0, sizeof(buf->f_fsid));
++	}
++	/* buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1; */
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* final actions when unmounting a file system */
++static void aufs_put_super(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++
++	sbinfo = au_sbi(sb);
++	if (!sbinfo)
++		return;
++
++	dbgaufs_si_fin(sbinfo);
++	kobject_put(&sbinfo->si_kobj);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_array_free(void *array)
++{
++	if (array) {
++		if (!is_vmalloc_addr(array))
++			kfree(array);
++		else
++			vfree(array);
++	}
++}
++
++void *au_array_alloc(unsigned long long *hint, au_arraycb_t cb, void *arg)
++{
++	void *array;
++	unsigned long long n;
++
++	array = NULL;
++	n = 0;
++	if (!*hint)
++		goto out;
++
++	if (*hint > ULLONG_MAX / sizeof(array)) {
++		array = ERR_PTR(-EMFILE);
++		pr_err("hint %llu\n", *hint);
++		goto out;
++	}
++
++	array = kmalloc(sizeof(array) * *hint, GFP_NOFS);
++	if (unlikely(!array))
++		array = vmalloc(sizeof(array) * *hint);
++	if (unlikely(!array)) {
++		array = ERR_PTR(-ENOMEM);
++		goto out;
++	}
++
++	n = cb(array, *hint, arg);
++	AuDebugOn(n > *hint);
++
++out:
++	*hint = n;
++	return array;
++}
++
++static unsigned long long au_iarray_cb(void *a,
++				       unsigned long long max __maybe_unused,
++				       void *arg)
++{
++	unsigned long long n;
++	struct inode **p, *inode;
++	struct list_head *head;
++
++	n = 0;
++	p = a;
++	head = arg;
++	spin_lock(&inode_lock);
++	list_for_each_entry(inode, head, i_sb_list) {
++		if (!is_bad_inode(inode)
++		    && au_ii(inode)->ii_bstart >= 0) {
++			au_igrab(inode);
++			*p++ = inode;
++			n++;
++			AuDebugOn(n > max);
++		}
++	}
++	spin_unlock(&inode_lock);
++
++	return n;
++}
++
++struct inode **au_iarray_alloc(struct super_block *sb, unsigned long long *max)
++{
++	*max = atomic_long_read(&au_sbi(sb)->si_ninodes);
++	return au_array_alloc(max, au_iarray_cb, &sb->s_inodes);
++}
++
++void au_iarray_free(struct inode **a, unsigned long long max)
++{
++	unsigned long long ull;
++
++	for (ull = 0; ull < max; ull++)
++		iput(a[ull]);
++	au_array_free(a);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * refresh dentry and inode at remount time.
++ */
++/* todo: consolidate with simple_reval_dpath() and au_reval_for_attr() */
++static int au_do_refresh(struct dentry *dentry, unsigned int dir_flags,
++		      struct dentry *parent)
++{
++	int err;
++
++	di_write_lock_child(dentry);
++	di_read_lock_parent(parent, AuLock_IR);
++	err = au_refresh_dentry(dentry, parent);
++	if (!err && dir_flags)
++		au_hn_reset(dentry->d_inode, dir_flags);
++	di_read_unlock(parent, AuLock_IR);
++	di_write_unlock(dentry);
++
++	return err;
++}
++
++static int au_do_refresh_d(struct dentry *dentry, unsigned int sigen,
++			   struct au_sbinfo *sbinfo,
++			   const unsigned int dir_flags)
++{
++	int err;
++	struct dentry *parent;
++	struct inode *inode;
++
++	err = 0;
++	parent = dget_parent(dentry);
++	if (!au_digen_test(parent, sigen) && au_digen_test(dentry, sigen)) {
++		inode = dentry->d_inode;
++		if (inode) {
++			if (!S_ISDIR(inode->i_mode))
++				err = au_do_refresh(dentry, /*dir_flags*/0,
++						 parent);
++			else {
++				err = au_do_refresh(dentry, dir_flags, parent);
++				if (unlikely(err))
++					au_fset_si(sbinfo, FAILED_REFRESH_DIR);
++			}
++		} else
++			err = au_do_refresh(dentry, /*dir_flags*/0, parent);
++		AuDbgDentry(dentry);
++	}
++	dput(parent);
++
++	AuTraceErr(err);
++	return err;
++}
++
++static int au_refresh_d(struct super_block *sb)
++{
++	int err, i, j, ndentry, e;
++	unsigned int sigen;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry **dentries, *d;
++	struct au_sbinfo *sbinfo;
++	struct dentry *root = sb->s_root;
++	const unsigned int dir_flags = au_hi_flags(root->d_inode, /*isdir*/1);
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	err = au_dcsub_pages(&dpages, root, NULL, NULL);
++	if (unlikely(err))
++		goto out_dpages;
++
++	sigen = au_sigen(sb);
++	sbinfo = au_sbi(sb);
++	for (i = 0; i < dpages.ndpage; i++) {
++		dpage = dpages.dpages + i;
++		dentries = dpage->dentries;
++		ndentry = dpage->ndentry;
++		for (j = 0; j < ndentry; j++) {
++			d = dentries[j];
++			e = au_do_refresh_d(d, sigen, sbinfo, dir_flags);
++			if (unlikely(e && !err))
++				err = e;
++			/* go on even err */
++		}
++	}
++
++out_dpages:
++	au_dpages_free(&dpages);
++out:
++	return err;
++}
++
++static int au_refresh_i(struct super_block *sb)
++{
++	int err, e;
++	unsigned int sigen;
++	unsigned long long max, ull;
++	struct inode *inode, **array;
++
++	array = au_iarray_alloc(sb, &max);
++	err = PTR_ERR(array);
++	if (IS_ERR(array))
++		goto out;
++
++	err = 0;
++	sigen = au_sigen(sb);
++	for (ull = 0; ull < max; ull++) {
++		inode = array[ull];
++		if (au_iigen(inode) != sigen) {
++			ii_write_lock_child(inode);
++			e = au_refresh_hinode_self(inode);
++			ii_write_unlock(inode);
++			if (unlikely(e)) {
++				pr_err("error %d, i%lu\n", e, inode->i_ino);
++				if (!err)
++					err = e;
++				/* go on even if err */
++			}
++		}
++	}
++
++	au_iarray_free(array, max);
++
++out:
++	return err;
++}
++
++static void au_remount_refresh(struct super_block *sb)
++{
++	int err, e;
++	unsigned int udba;
++	aufs_bindex_t bindex, bend;
++	struct dentry *root;
++	struct inode *inode;
++	struct au_branch *br;
++
++	au_sigen_inc(sb);
++	au_fclr_si(au_sbi(sb), FAILED_REFRESH_DIR);
++
++	root = sb->s_root;
++	DiMustNoWaiters(root);
++	inode = root->d_inode;
++	IiMustNoWaiters(inode);
++
++	udba = au_opt_udba(sb);
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		err = au_hnotify_reset_br(udba, br, br->br_perm);
++		if (unlikely(err))
++			AuIOErr("hnotify failed on br %d, %d, ignored\n",
++				bindex, err);
++		/* go on even if err */
++	}
++	au_hn_reset(inode, au_hi_flags(inode, /*isdir*/1));
++
++	di_write_unlock(root);
++	err = au_refresh_d(sb);
++	e = au_refresh_i(sb);
++	if (unlikely(e && !err))
++		err = e;
++	/* aufs_write_lock() calls ..._child() */
++	di_write_lock_child(root);
++
++	au_cpup_attr_all(inode, /*force*/1);
++
++	if (unlikely(err))
++		AuIOErr("refresh failed, ignored, %d\n", err);
++}
++
++/* stop extra interpretation of errno in mount(8), and strange error messages */
++static int cvt_err(int err)
++{
++	AuTraceErr(err);
++
++	switch (err) {
++	case -ENOENT:
++	case -ENOTDIR:
++	case -EEXIST:
++	case -EIO:
++		err = -EINVAL;
++	}
++	return err;
++}
++
++static int aufs_remount_fs(struct super_block *sb, int *flags, char *data)
++{
++	int err, do_dx;
++	unsigned int mntflags;
++	struct au_opts opts;
++	struct dentry *root;
++	struct inode *inode;
++	struct au_sbinfo *sbinfo;
++
++	err = 0;
++	root = sb->s_root;
++	if (!data || !*data) {
++		err = si_write_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++		if (!err) {
++			di_write_lock_child(root);
++			err = au_opts_verify(sb, *flags, /*pending*/0);
++			aufs_write_unlock(root);
++		}
++		goto out;
++	}
++
++	err = -ENOMEM;
++	memset(&opts, 0, sizeof(opts));
++	opts.opt = (void *)__get_free_page(GFP_NOFS);
++	if (unlikely(!opts.opt))
++		goto out;
++	opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
++	opts.flags = AuOpts_REMOUNT;
++	opts.sb_flags = *flags;
++
++	/* parse it before aufs lock */
++	err = au_opts_parse(sb, data, &opts);
++	if (unlikely(err))
++		goto out_opts;
++
++	sbinfo = au_sbi(sb);
++	inode = root->d_inode;
++	mutex_lock(&inode->i_mutex);
++	err = si_write_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
++	if (unlikely(err))
++		goto out_mtx;
++	di_write_lock_child(root);
++
++	/* au_opts_remount() may return an error */
++	err = au_opts_remount(sb, &opts);
++	au_opts_free(&opts);
++
++	if (au_ftest_opts(opts.flags, REFRESH))
++		au_remount_refresh(sb);
++
++	if (au_ftest_opts(opts.flags, REFRESH_DYAOP)) {
++		mntflags = au_mntflags(sb);
++		do_dx = !!au_opt_test(mntflags, DIO);
++		au_dy_arefresh(do_dx);
++	}
++
++	aufs_write_unlock(root);
++
++out_mtx:
++	mutex_unlock(&inode->i_mutex);
++out_opts:
++	free_page((unsigned long)opts.opt);
++out:
++	err = cvt_err(err);
++	AuTraceErr(err);
++	return err;
++}
++
++static const struct super_operations aufs_sop = {
++	.alloc_inode	= aufs_alloc_inode,
++	.destroy_inode	= aufs_destroy_inode,
++	/* always deleting, no clearing */
++	.drop_inode	= generic_delete_inode,
++	.show_options	= aufs_show_options,
++	.statfs		= aufs_statfs,
++	.put_super	= aufs_put_super,
++	.remount_fs	= aufs_remount_fs
++};
++
++/* ---------------------------------------------------------------------- */
++
++static int alloc_root(struct super_block *sb)
++{
++	int err;
++	struct inode *inode;
++	struct dentry *root;
++
++	err = -ENOMEM;
++	inode = au_iget_locked(sb, AUFS_ROOT_INO);
++	err = PTR_ERR(inode);
++	if (IS_ERR(inode))
++		goto out;
++
++	inode->i_op = &aufs_dir_iop;
++	inode->i_fop = &aufs_dir_fop;
++	inode->i_mode = S_IFDIR;
++	inode->i_nlink = 2;
++	unlock_new_inode(inode);
++
++	root = d_alloc_root(inode);
++	if (unlikely(!root))
++		goto out_iput;
++	err = PTR_ERR(root);
++	if (IS_ERR(root))
++		goto out_iput;
++
++	err = au_di_init(root);
++	if (!err) {
++		sb->s_root = root;
++		return 0; /* success */
++	}
++	dput(root);
++	goto out; /* do not iput */
++
++out_iput:
++	iget_failed(inode);
++out:
++	return err;
++
++}
++
++static int aufs_fill_super(struct super_block *sb, void *raw_data,
++			   int silent __maybe_unused)
++{
++	int err;
++	struct au_opts opts;
++	struct dentry *root;
++	struct inode *inode;
++	char *arg = raw_data;
++
++	if (unlikely(!arg || !*arg)) {
++		err = -EINVAL;
++		pr_err("no arg\n");
++		goto out;
++	}
++
++	err = -ENOMEM;
++	memset(&opts, 0, sizeof(opts));
++	opts.opt = (void *)__get_free_page(GFP_NOFS);
++	if (unlikely(!opts.opt))
++		goto out;
++	opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
++	opts.sb_flags = sb->s_flags;
++
++	err = au_si_alloc(sb);
++	if (unlikely(err))
++		goto out_opts;
++
++	/* all timestamps always follow the ones on the branch */
++	sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
++	sb->s_op = &aufs_sop;
++	sb->s_magic = AUFS_SUPER_MAGIC;
++	sb->s_maxbytes = 0;
++	au_export_init(sb);
++
++	err = alloc_root(sb);
++	if (unlikely(err)) {
++		si_write_unlock(sb);
++		goto out_info;
++	}
++	root = sb->s_root;
++	inode = root->d_inode;
++
++	/*
++	 * actually we can parse options regardless aufs lock here.
++	 * but at remount time, parsing must be done before aufs lock.
++	 * so we follow the same rule.
++	 */
++	ii_write_lock_parent(inode);
++	aufs_write_unlock(root);
++	err = au_opts_parse(sb, arg, &opts);
++	if (unlikely(err))
++		goto out_root;
++
++	/* lock vfs_inode first, then aufs. */
++	mutex_lock(&inode->i_mutex);
++	aufs_write_lock(root);
++	err = au_opts_mount(sb, &opts);
++	au_opts_free(&opts);
++	aufs_write_unlock(root);
++	mutex_unlock(&inode->i_mutex);
++	if (!err)
++		goto out_opts; /* success */
++
++out_root:
++	dput(root);
++	sb->s_root = NULL;
++out_info:
++	kobject_put(&au_sbi(sb)->si_kobj);
++	sb->s_fs_info = NULL;
++out_opts:
++	free_page((unsigned long)opts.opt);
++out:
++	AuTraceErr(err);
++	err = cvt_err(err);
++	AuTraceErr(err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_get_sb(struct file_system_type *fs_type, int flags,
++		       const char *dev_name __maybe_unused, void *raw_data,
++		       struct vfsmount *mnt)
++{
++	int err;
++	struct super_block *sb;
++
++	/* all timestamps always follow the ones on the branch */
++	/* mnt->mnt_flags |= MNT_NOATIME | MNT_NODIRATIME; */
++	err = get_sb_nodev(fs_type, flags, raw_data, aufs_fill_super, mnt);
++	if (!err) {
++		sb = mnt->mnt_sb;
++		si_write_lock(sb, !AuLock_FLUSH);
++		sysaufs_brs_add(sb, 0);
++		si_write_unlock(sb);
++		au_sbilist_add(sb);
++	}
++	return err;
++}
++
++static void aufs_kill_sb(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++
++	sbinfo = au_sbi(sb);
++	if (sbinfo) {
++		au_sbilist_del(sb);
++		aufs_write_lock(sb->s_root);
++		if (sbinfo->si_wbr_create_ops->fin)
++			sbinfo->si_wbr_create_ops->fin(sb);
++		if (au_opt_test(sbinfo->si_mntflags, UDBA_HNOTIFY)) {
++			au_opt_set_udba(sbinfo->si_mntflags, UDBA_NONE);
++			au_remount_refresh(sb);
++		}
++		if (au_opt_test(sbinfo->si_mntflags, PLINK))
++			au_plink_put(sb, /*verbose*/1);
++		au_xino_clr(sb);
++		aufs_write_unlock(sb->s_root);
++		au_nwt_flush(&sbinfo->si_nowait);
++	}
++	generic_shutdown_super(sb);
++}
++
++struct file_system_type aufs_fs_type = {
++	.name		= AUFS_FSTYPE,
++	.fs_flags	=
++		FS_RENAME_DOES_D_MOVE	/* a race between rename and others */
++		| FS_REVAL_DOT,		/* for NFS branch and udba */
++	.get_sb		= aufs_get_sb,
++	.kill_sb	= aufs_kill_sb,
++	/* no need to __module_get() and module_put(). */
++	.owner		= THIS_MODULE,
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/super.h linux-2.6.36/fs/aufs/super.h
+--- linux-2.6.36.orig/fs/aufs/super.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/super.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,527 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * super_block operations
++ */
++
++#ifndef __AUFS_SUPER_H__
++#define __AUFS_SUPER_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++#include "spl.h"
++#include "wkq.h"
++
++typedef ssize_t (*au_readf_t)(struct file *, char __user *, size_t, loff_t *);
++typedef ssize_t (*au_writef_t)(struct file *, const char __user *, size_t,
++			       loff_t *);
++
++/* policies to select one among multiple writable branches */
++struct au_wbr_copyup_operations {
++	int (*copyup)(struct dentry *dentry);
++};
++
++struct au_wbr_create_operations {
++	int (*create)(struct dentry *dentry, int isdir);
++	int (*init)(struct super_block *sb);
++	int (*fin)(struct super_block *sb);
++};
++
++struct au_wbr_mfs {
++	struct mutex	mfs_lock; /* protect this structure */
++	unsigned long	mfs_jiffy;
++	unsigned long	mfs_expire;
++	aufs_bindex_t	mfs_bindex;
++
++	unsigned long long	mfsrr_bytes;
++	unsigned long long	mfsrr_watermark;
++};
++
++struct au_branch;
++struct au_sbinfo {
++	/* nowait tasks in the system-wide workqueue */
++	struct au_nowait_tasks	si_nowait;
++
++	/*
++	 * tried sb->s_umount, but failed due to the dependecy between i_mutex.
++	 * rwsem for au_sbinfo is necessary.
++	 */
++	struct au_rwsem		si_rwsem;
++
++	/* prevent recursive locking in deleting inode */
++	struct {
++		unsigned long		*bitmap;
++		spinlock_t		tree_lock;
++		struct radix_tree_root	tree;
++	} au_si_pid;
++
++	/*
++	 * dirty approach to protect sb->sb_inodes and ->s_files from remount.
++	 */
++	atomic_long_t		si_ninodes, si_nfiles;
++
++	/* branch management */
++	unsigned int		si_generation;
++
++	/* see above flags */
++	unsigned char		au_si_status;
++
++	aufs_bindex_t		si_bend;
++
++	/* dirty trick to keep br_id plus */
++	unsigned int		si_last_br_id :
++				sizeof(aufs_bindex_t) * BITS_PER_BYTE - 1;
++	struct au_branch	**si_branch;
++
++	/* policy to select a writable branch */
++	unsigned char		si_wbr_copyup;
++	unsigned char		si_wbr_create;
++	struct au_wbr_copyup_operations *si_wbr_copyup_ops;
++	struct au_wbr_create_operations *si_wbr_create_ops;
++
++	/* round robin */
++	atomic_t		si_wbr_rr_next;
++
++	/* most free space */
++	struct au_wbr_mfs	si_wbr_mfs;
++
++	/* mount flags */
++	/* include/asm-ia64/siginfo.h defines a macro named si_flags */
++	unsigned int		si_mntflags;
++
++	/* external inode number (bitmap and translation table) */
++	au_readf_t		si_xread;
++	au_writef_t		si_xwrite;
++	struct file		*si_xib;
++	struct mutex		si_xib_mtx; /* protect xib members */
++	unsigned long		*si_xib_buf;
++	unsigned long		si_xib_last_pindex;
++	int			si_xib_next_bit;
++	aufs_bindex_t		si_xino_brid;
++	/* reserved for future use */
++	/* unsigned long long	si_xib_limit; */	/* Max xib file size */
++
++#ifdef CONFIG_AUFS_EXPORT
++	/* i_generation */
++	struct file		*si_xigen;
++	atomic_t		si_xigen_next;
++#endif
++
++	/* vdir parameters */
++	unsigned long		si_rdcache;	/* max cache time in jiffies */
++	unsigned int		si_rdblk;	/* deblk size */
++	unsigned int		si_rdhash;	/* hash size */
++
++	/*
++	 * If the number of whiteouts are larger than si_dirwh, leave all of
++	 * them after au_whtmp_ren to reduce the cost of rmdir(2).
++	 * future fsck.aufs or kernel thread will remove them later.
++	 * Otherwise, remove all whiteouts and the dir in rmdir(2).
++	 */
++	unsigned int		si_dirwh;
++
++	/*
++	 * rename(2) a directory with all children.
++	 */
++	/* reserved for future use */
++	/* int			si_rendir; */
++
++	/* pseudo_link list */
++	struct au_splhead	si_plink;
++	wait_queue_head_t	si_plink_wq;
++	spinlock_t		si_plink_maint_lock;
++	pid_t			si_plink_maint_pid;
++
++	/*
++	 * sysfs and lifetime management.
++	 * this is not a small structure and it may be a waste of memory in case
++	 * of sysfs is disabled, particulary when many aufs-es are mounted.
++	 * but using sysfs is majority.
++	 */
++	struct kobject		si_kobj;
++#ifdef CONFIG_DEBUG_FS
++	struct dentry		 *si_dbgaufs, *si_dbgaufs_xib;
++#ifdef CONFIG_AUFS_EXPORT
++	struct dentry		 *si_dbgaufs_xigen;
++#endif
++#endif
++
++#ifdef CONFIG_AUFS_SBILIST
++	struct list_head	si_list;
++#endif
++
++	/* dirty, necessary for unmounting, sysfs and sysrq */
++	struct super_block	*si_sb;
++};
++
++/* sbinfo status flags */
++/*
++ * set true when refresh_dirs() failed at remount time.
++ * then try refreshing dirs at access time again.
++ * if it is false, refreshing dirs at access time is unnecesary
++ */
++#define AuSi_FAILED_REFRESH_DIR	1
++static inline unsigned char au_do_ftest_si(struct au_sbinfo *sbi,
++					   unsigned int flag)
++{
++	AuRwMustAnyLock(&sbi->si_rwsem);
++	return sbi->au_si_status & flag;
++}
++#define au_ftest_si(sbinfo, name)	au_do_ftest_si(sbinfo, AuSi_##name)
++#define au_fset_si(sbinfo, name) do { \
++	AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
++	(sbinfo)->au_si_status |= AuSi_##name; \
++} while (0)
++#define au_fclr_si(sbinfo, name) do { \
++	AuRwMustWriteLock(&(sbinfo)->si_rwsem); \
++	(sbinfo)->au_si_status &= ~AuSi_##name; \
++} while (0)
++
++/* ---------------------------------------------------------------------- */
++
++/* policy to select one among writable branches */
++#define AuWbrCopyup(sbinfo, ...) \
++	((sbinfo)->si_wbr_copyup_ops->copyup(__VA_ARGS__))
++#define AuWbrCreate(sbinfo, ...) \
++	((sbinfo)->si_wbr_create_ops->create(__VA_ARGS__))
++
++/* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
++#define AuLock_DW		1		/* write-lock dentry */
++#define AuLock_IR		(1 << 1)	/* read-lock inode */
++#define AuLock_IW		(1 << 2)	/* write-lock inode */
++#define AuLock_FLUSH		(1 << 3)	/* wait for 'nowait' tasks */
++#define AuLock_DIR		(1 << 4)	/* target is a dir */
++#define AuLock_NOPLM		(1 << 5)	/* return err in plm mode */
++#define AuLock_NOPLMW		(1 << 6)	/* wait for plm mode ends */
++#define AuLock_GEN		(1 << 7)	/* test digen/iigen */
++#define au_ftest_lock(flags, name)	((flags) & AuLock_##name)
++#define au_fset_lock(flags, name) \
++	do { (flags) |= AuLock_##name; } while (0)
++#define au_fclr_lock(flags, name) \
++	do { (flags) &= ~AuLock_##name; } while (0)
++
++/* ---------------------------------------------------------------------- */
++
++/* super.c */
++extern struct file_system_type aufs_fs_type;
++struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
++typedef unsigned long long (*au_arraycb_t)(void *array, unsigned long long max,
++					   void *arg);
++void au_array_free(void *array);
++void *au_array_alloc(unsigned long long *hint, au_arraycb_t cb, void *arg);
++struct inode **au_iarray_alloc(struct super_block *sb, unsigned long long *max);
++void au_iarray_free(struct inode **a, unsigned long long max);
++
++/* sbinfo.c */
++void au_si_free(struct kobject *kobj);
++int au_si_alloc(struct super_block *sb);
++int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr);
++
++unsigned int au_sigen_inc(struct super_block *sb);
++aufs_bindex_t au_new_br_id(struct super_block *sb);
++
++int si_read_lock(struct super_block *sb, int flags);
++int si_write_lock(struct super_block *sb, int flags);
++int aufs_read_lock(struct dentry *dentry, int flags);
++void aufs_read_unlock(struct dentry *dentry, int flags);
++void aufs_write_lock(struct dentry *dentry);
++void aufs_write_unlock(struct dentry *dentry);
++int aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags);
++void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
++
++int si_pid_test_slow(struct super_block *sb);
++void si_pid_set_slow(struct super_block *sb);
++void si_pid_clr_slow(struct super_block *sb);
++
++/* wbr_policy.c */
++extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
++extern struct au_wbr_create_operations au_wbr_create_ops[];
++int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_sbinfo *au_sbi(struct super_block *sb)
++{
++	return sb->s_fs_info;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_EXPORT
++void au_export_init(struct super_block *sb);
++
++static inline int au_test_nfsd(void)
++{
++	struct task_struct *tsk = current;
++
++	return (tsk->flags & PF_KTHREAD)
++		&& !strcmp(tsk->comm, "nfsd");
++}
++
++void au_xigen_inc(struct inode *inode);
++int au_xigen_new(struct inode *inode);
++int au_xigen_set(struct super_block *sb, struct file *base);
++void au_xigen_clr(struct super_block *sb);
++
++static inline int au_busy_or_stale(void)
++{
++	if (!au_test_nfsd())
++		return -EBUSY;
++	return -ESTALE;
++}
++#else
++AuStubVoid(au_export_init, struct super_block *sb)
++AuStubInt0(au_test_nfsd, void)
++AuStubVoid(au_xigen_inc, struct inode *inode)
++AuStubInt0(au_xigen_new, struct inode *inode)
++AuStubInt0(au_xigen_set, struct super_block *sb, struct file *base)
++AuStubVoid(au_xigen_clr, struct super_block *sb)
++static inline int au_busy_or_stale(void)
++{
++	return -EBUSY;
++}
++#endif /* CONFIG_AUFS_EXPORT */
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_SBILIST
++/* module.c */
++extern struct au_splhead au_sbilist;
++
++static inline void au_sbilist_init(void)
++{
++	au_spl_init(&au_sbilist);
++}
++
++static inline void au_sbilist_add(struct super_block *sb)
++{
++	au_spl_add(&au_sbi(sb)->si_list, &au_sbilist);
++}
++
++static inline void au_sbilist_del(struct super_block *sb)
++{
++	au_spl_del(&au_sbi(sb)->si_list, &au_sbilist);
++}
++#else
++AuStubVoid(au_sbilist_init, void)
++AuStubVoid(au_sbilist_add, struct super_block*)
++AuStubVoid(au_sbilist_del, struct super_block*)
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static inline void dbgaufs_si_null(struct au_sbinfo *sbinfo)
++{
++	/*
++	 * This function is a dynamic '__init' fucntion actually,
++	 * so the tiny check for si_rwsem is unnecessary.
++	 */
++	/* AuRwMustWriteLock(&sbinfo->si_rwsem); */
++#ifdef CONFIG_DEBUG_FS
++	sbinfo->si_dbgaufs = NULL;
++	sbinfo->si_dbgaufs_xib = NULL;
++#ifdef CONFIG_AUFS_EXPORT
++	sbinfo->si_dbgaufs_xigen = NULL;
++#endif
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline pid_t si_pid_bit(void)
++{
++	/* the origin of pid is 1, but the bitmap's is 0 */
++	return current->pid - 1;
++}
++
++static inline int si_pid_test(struct super_block *sb)
++{
++	pid_t bit = si_pid_bit();
++	if (bit < PID_MAX_DEFAULT)
++		return test_bit(bit, au_sbi(sb)->au_si_pid.bitmap);
++	else
++		return si_pid_test_slow(sb);
++}
++
++static inline void si_pid_set(struct super_block *sb)
++{
++	pid_t bit = si_pid_bit();
++	if (bit < PID_MAX_DEFAULT) {
++		AuDebugOn(test_bit(bit, au_sbi(sb)->au_si_pid.bitmap));
++		set_bit(bit, au_sbi(sb)->au_si_pid.bitmap);
++		/* smp_mb(); */
++	} else
++		si_pid_set_slow(sb);
++}
++
++static inline void si_pid_clr(struct super_block *sb)
++{
++	pid_t bit = si_pid_bit();
++	if (bit < PID_MAX_DEFAULT) {
++		AuDebugOn(!test_bit(bit, au_sbi(sb)->au_si_pid.bitmap));
++		clear_bit(bit, au_sbi(sb)->au_si_pid.bitmap);
++		/* smp_mb(); */
++	} else
++		si_pid_clr_slow(sb);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* lock superblock. mainly for entry point functions */
++/*
++ * __si_read_lock, __si_write_lock,
++ * __si_read_unlock, __si_write_unlock, __si_downgrade_lock
++ */
++AuSimpleRwsemFuncs(__si, struct super_block *sb, &au_sbi(sb)->si_rwsem);
++
++#define SiMustNoWaiters(sb)	AuRwMustNoWaiters(&au_sbi(sb)->si_rwsem)
++#define SiMustAnyLock(sb)	AuRwMustAnyLock(&au_sbi(sb)->si_rwsem)
++#define SiMustWriteLock(sb)	AuRwMustWriteLock(&au_sbi(sb)->si_rwsem)
++
++static inline void si_noflush_read_lock(struct super_block *sb)
++{
++	__si_read_lock(sb);
++	si_pid_set(sb);
++}
++
++static inline int si_noflush_read_trylock(struct super_block *sb)
++{
++	int locked = __si_read_trylock(sb);
++	if (locked)
++		si_pid_set(sb);
++	return locked;
++}
++
++static inline void si_noflush_write_lock(struct super_block *sb)
++{
++	__si_write_lock(sb);
++	si_pid_set(sb);
++}
++
++static inline int si_noflush_write_trylock(struct super_block *sb)
++{
++	int locked = __si_write_trylock(sb);
++	if (locked)
++		si_pid_set(sb);
++	return locked;
++}
++
++#if 0 /* unused */
++static inline int si_read_trylock(struct super_block *sb, int flags)
++{
++	if (au_ftest_lock(flags, FLUSH))
++		au_nwt_flush(&au_sbi(sb)->si_nowait);
++	return si_noflush_read_trylock(sb);
++}
++#endif
++
++static inline void si_read_unlock(struct super_block *sb)
++{
++	si_pid_clr(sb);
++	__si_read_unlock(sb);
++}
++
++#if 0 /* unused */
++static inline int si_write_trylock(struct super_block *sb, int flags)
++{
++	if (au_ftest_lock(flags, FLUSH))
++		au_nwt_flush(&au_sbi(sb)->si_nowait);
++	return si_noflush_write_trylock(sb);
++}
++#endif
++
++static inline void si_write_unlock(struct super_block *sb)
++{
++	si_pid_clr(sb);
++	__si_write_unlock(sb);
++}
++
++#if 0 /* unused */
++static inline void si_downgrade_lock(struct super_block *sb)
++{
++	__si_downgrade_lock(sb);
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static inline aufs_bindex_t au_sbend(struct super_block *sb)
++{
++	SiMustAnyLock(sb);
++	return au_sbi(sb)->si_bend;
++}
++
++static inline unsigned int au_mntflags(struct super_block *sb)
++{
++	SiMustAnyLock(sb);
++	return au_sbi(sb)->si_mntflags;
++}
++
++static inline unsigned int au_sigen(struct super_block *sb)
++{
++	SiMustAnyLock(sb);
++	return au_sbi(sb)->si_generation;
++}
++
++static inline void au_ninodes_inc(struct super_block *sb)
++{
++	atomic_long_inc(&au_sbi(sb)->si_ninodes);
++}
++
++static inline void au_ninodes_dec(struct super_block *sb)
++{
++	AuDebugOn(!atomic_long_read(&au_sbi(sb)->si_ninodes));
++	atomic_long_dec(&au_sbi(sb)->si_ninodes);
++}
++
++static inline void au_nfiles_inc(struct super_block *sb)
++{
++	atomic_long_inc(&au_sbi(sb)->si_nfiles);
++}
++
++static inline void au_nfiles_dec(struct super_block *sb)
++{
++	AuDebugOn(!atomic_long_read(&au_sbi(sb)->si_nfiles));
++	atomic_long_dec(&au_sbi(sb)->si_nfiles);
++}
++
++static inline struct au_branch *au_sbr(struct super_block *sb,
++				       aufs_bindex_t bindex)
++{
++	SiMustAnyLock(sb);
++	return au_sbi(sb)->si_branch[0 + bindex];
++}
++
++static inline void au_xino_brid_set(struct super_block *sb, aufs_bindex_t brid)
++{
++	SiMustWriteLock(sb);
++	au_sbi(sb)->si_xino_brid = brid;
++}
++
++static inline aufs_bindex_t au_xino_brid(struct super_block *sb)
++{
++	SiMustAnyLock(sb);
++	return au_sbi(sb)->si_xino_brid;
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_SUPER_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/sysaufs.c linux-2.6.36/fs/aufs/sysaufs.c
+--- linux-2.6.36.orig/fs/aufs/sysaufs.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/sysaufs.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,107 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sysfs interface and lifetime management
++ * they are necessary regardless sysfs is disabled.
++ */
++
++#include <linux/fs.h>
++#include <linux/random.h>
++#include <linux/sysfs.h>
++#include "aufs.h"
++
++unsigned long sysaufs_si_mask;
++struct kset *sysaufs_kset;
++
++#define AuSiAttr(_name) { \
++	.attr   = { .name = __stringify(_name), .mode = 0444 },	\
++	.show   = sysaufs_si_##_name,				\
++}
++
++static struct sysaufs_si_attr sysaufs_si_attr_xi_path = AuSiAttr(xi_path);
++struct attribute *sysaufs_si_attrs[] = {
++	&sysaufs_si_attr_xi_path.attr,
++	NULL,
++};
++
++static const struct sysfs_ops au_sbi_ops = {
++	.show   = sysaufs_si_show
++};
++
++static struct kobj_type au_sbi_ktype = {
++	.release	= au_si_free,
++	.sysfs_ops	= &au_sbi_ops,
++	.default_attrs	= sysaufs_si_attrs
++};
++
++/* ---------------------------------------------------------------------- */
++
++int sysaufs_si_init(struct au_sbinfo *sbinfo)
++{
++	int err;
++
++	sbinfo->si_kobj.kset = sysaufs_kset;
++	/* cf. sysaufs_name() */
++	err = kobject_init_and_add
++		(&sbinfo->si_kobj, &au_sbi_ktype, /*&sysaufs_kset->kobj*/NULL,
++		 SysaufsSiNamePrefix "%lx", sysaufs_si_id(sbinfo));
++
++	dbgaufs_si_null(sbinfo);
++	if (!err) {
++		err = dbgaufs_si_init(sbinfo);
++		if (unlikely(err))
++			kobject_put(&sbinfo->si_kobj);
++	}
++	return err;
++}
++
++void sysaufs_fin(void)
++{
++	dbgaufs_fin();
++	sysfs_remove_group(&sysaufs_kset->kobj, sysaufs_attr_group);
++	kset_unregister(sysaufs_kset);
++}
++
++int __init sysaufs_init(void)
++{
++	int err;
++
++	do {
++		get_random_bytes(&sysaufs_si_mask, sizeof(sysaufs_si_mask));
++	} while (!sysaufs_si_mask);
++
++	err = -EINVAL;
++	sysaufs_kset = kset_create_and_add(AUFS_NAME, NULL, fs_kobj);
++	if (unlikely(!sysaufs_kset))
++		goto out;
++	err = PTR_ERR(sysaufs_kset);
++	if (IS_ERR(sysaufs_kset))
++		goto out;
++	err = sysfs_create_group(&sysaufs_kset->kobj, sysaufs_attr_group);
++	if (unlikely(err)) {
++		kset_unregister(sysaufs_kset);
++		goto out;
++	}
++
++	err = dbgaufs_init();
++	if (unlikely(err))
++		sysaufs_fin();
++out:
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/sysaufs.h linux-2.6.36/fs/aufs/sysaufs.h
+--- linux-2.6.36.orig/fs/aufs/sysaufs.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/sysaufs.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,105 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sysfs interface and mount lifetime management
++ */
++
++#ifndef __SYSAUFS_H__
++#define __SYSAUFS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/sysfs.h>
++#include <linux/aufs_type.h>
++#include "module.h"
++
++struct super_block;
++struct au_sbinfo;
++
++struct sysaufs_si_attr {
++	struct attribute attr;
++	int (*show)(struct seq_file *seq, struct super_block *sb);
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* sysaufs.c */
++extern unsigned long sysaufs_si_mask;
++extern struct kset *sysaufs_kset;
++extern struct attribute *sysaufs_si_attrs[];
++int sysaufs_si_init(struct au_sbinfo *sbinfo);
++int __init sysaufs_init(void);
++void sysaufs_fin(void);
++
++/* ---------------------------------------------------------------------- */
++
++/* some people doesn't like to show a pointer in kernel */
++static inline unsigned long sysaufs_si_id(struct au_sbinfo *sbinfo)
++{
++	return sysaufs_si_mask ^ (unsigned long)sbinfo;
++}
++
++#define SysaufsSiNamePrefix	"si_"
++#define SysaufsSiNameLen	(sizeof(SysaufsSiNamePrefix) + 16)
++static inline void sysaufs_name(struct au_sbinfo *sbinfo, char *name)
++{
++	snprintf(name, SysaufsSiNameLen, SysaufsSiNamePrefix "%lx",
++		 sysaufs_si_id(sbinfo));
++}
++
++struct au_branch;
++#ifdef CONFIG_SYSFS
++/* sysfs.c */
++extern struct attribute_group *sysaufs_attr_group;
++
++int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb);
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++			 char *buf);
++
++void sysaufs_br_init(struct au_branch *br);
++void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
++void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
++
++#define sysaufs_brs_init()	do {} while (0)
++
++#else
++#define sysaufs_attr_group	NULL
++
++AuStubInt0(sysaufs_si_xi_path, struct seq_file *seq, struct super_block *sb)
++
++static inline
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++			 char *buf)
++{
++	return 0;
++}
++
++AuStubVoid(sysaufs_br_init, struct au_branch *br)
++AuStubVoid(sysaufs_brs_add, struct super_block *sb, aufs_bindex_t bindex)
++AuStubVoid(sysaufs_brs_del, struct super_block *sb, aufs_bindex_t bindex)
++
++static inline void sysaufs_brs_init(void)
++{
++	sysaufs_brs = 0;
++}
++
++#endif /* CONFIG_SYSFS */
++
++#endif /* __KERNEL__ */
++#endif /* __SYSAUFS_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/sysfs.c linux-2.6.36/fs/aufs/sysfs.c
+--- linux-2.6.36.orig/fs/aufs/sysfs.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/sysfs.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,250 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sysfs interface
++ */
++
++#include <linux/fs.h>
++#include <linux/module.h>
++#include <linux/seq_file.h>
++#include <linux/sysfs.h>
++#include "aufs.h"
++
++#ifdef CONFIG_AUFS_FS_MODULE
++/* this entry violates the "one line per file" policy of sysfs */
++static ssize_t config_show(struct kobject *kobj, struct kobj_attribute *attr,
++			   char *buf)
++{
++	ssize_t err;
++	static char *conf =
++/* this file is generated at compiling */
++#include "conf.str"
++		;
++
++	err = snprintf(buf, PAGE_SIZE, conf);
++	if (unlikely(err >= PAGE_SIZE))
++		err = -EFBIG;
++	return err;
++}
++
++static struct kobj_attribute au_config_attr = __ATTR_RO(config);
++#endif
++
++static struct attribute *au_attr[] = {
++#ifdef CONFIG_AUFS_FS_MODULE
++	&au_config_attr.attr,
++#endif
++	NULL,	/* need to NULL terminate the list of attributes */
++};
++
++static struct attribute_group sysaufs_attr_group_body = {
++	.attrs = au_attr
++};
++
++struct attribute_group *sysaufs_attr_group = &sysaufs_attr_group_body;
++
++/* ---------------------------------------------------------------------- */
++
++int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb)
++{
++	int err;
++
++	SiMustAnyLock(sb);
++
++	err = 0;
++	if (au_opt_test(au_mntflags(sb), XINO)) {
++		err = au_xino_path(seq, au_sbi(sb)->si_xib);
++		seq_putc(seq, '\n');
++	}
++	return err;
++}
++
++/*
++ * the lifetime of branch is independent from the entry under sysfs.
++ * sysfs handles the lifetime of the entry, and never call ->show() after it is
++ * unlinked.
++ */
++static int sysaufs_si_br(struct seq_file *seq, struct super_block *sb,
++			 aufs_bindex_t bindex)
++{
++	struct path path;
++	struct dentry *root;
++	struct au_branch *br;
++
++	AuDbg("b%d\n", bindex);
++
++	root = sb->s_root;
++	di_read_lock_parent(root, !AuLock_IR);
++	br = au_sbr(sb, bindex);
++	path.mnt = br->br_mnt;
++	path.dentry = au_h_dptr(root, bindex);
++	au_seq_path(seq, &path);
++	di_read_unlock(root, !AuLock_IR);
++	seq_printf(seq, "=%s\n", au_optstr_br_perm(br->br_perm));
++	return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct seq_file *au_seq(char *p, ssize_t len)
++{
++	struct seq_file *seq;
++
++	seq = kzalloc(sizeof(*seq), GFP_NOFS);
++	if (seq) {
++		/* mutex_init(&seq.lock); */
++		seq->buf = p;
++		seq->size = len;
++		return seq; /* success */
++	}
++
++	seq = ERR_PTR(-ENOMEM);
++	return seq;
++}
++
++#define SysaufsBr_PREFIX "br"
++
++/* todo: file size may exceed PAGE_SIZE */
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++			char *buf)
++{
++	ssize_t err;
++	long l;
++	aufs_bindex_t bend;
++	struct au_sbinfo *sbinfo;
++	struct super_block *sb;
++	struct seq_file *seq;
++	char *name;
++	struct attribute **cattr;
++
++	sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
++	sb = sbinfo->si_sb;
++
++	/*
++	 * prevent a race condition between sysfs and aufs.
++	 * for instance, sysfs_file_read() calls sysfs_get_active_two() which
++	 * prohibits maintaining the sysfs entries.
++	 * hew we acquire read lock after sysfs_get_active_two().
++	 * on the other hand, the remount process may maintain the sysfs/aufs
++	 * entries after acquiring write lock.
++	 * it can cause a deadlock.
++	 * simply we gave up processing read here.
++	 */
++	err = -EBUSY;
++	if (unlikely(!si_noflush_read_trylock(sb)))
++		goto out;
++
++	seq = au_seq(buf, PAGE_SIZE);
++	err = PTR_ERR(seq);
++	if (IS_ERR(seq))
++		goto out_unlock;
++
++	name = (void *)attr->name;
++	cattr = sysaufs_si_attrs;
++	while (*cattr) {
++		if (!strcmp(name, (*cattr)->name)) {
++			err = container_of(*cattr, struct sysaufs_si_attr, attr)
++				->show(seq, sb);
++			goto out_seq;
++		}
++		cattr++;
++	}
++
++	bend = au_sbend(sb);
++	if (!strncmp(name, SysaufsBr_PREFIX, sizeof(SysaufsBr_PREFIX) - 1)) {
++		name += sizeof(SysaufsBr_PREFIX) - 1;
++		err = strict_strtol(name, 10, &l);
++		if (!err) {
++			if (l <= bend)
++				err = sysaufs_si_br(seq, sb, (aufs_bindex_t)l);
++			else
++				err = -ENOENT;
++		}
++		goto out_seq;
++	}
++	BUG();
++
++out_seq:
++	if (!err) {
++		err = seq->count;
++		/* sysfs limit */
++		if (unlikely(err == PAGE_SIZE))
++			err = -EFBIG;
++	}
++	kfree(seq);
++out_unlock:
++	si_read_unlock(sb);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void sysaufs_br_init(struct au_branch *br)
++{
++	struct attribute *attr = &br->br_attr;
++
++	sysfs_attr_init(attr);
++	attr->name = br->br_name;
++	attr->mode = S_IRUGO;
++}
++
++void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++	struct au_branch *br;
++	struct kobject *kobj;
++	aufs_bindex_t bend;
++
++	dbgaufs_brs_del(sb, bindex);
++
++	if (!sysaufs_brs)
++		return;
++
++	kobj = &au_sbi(sb)->si_kobj;
++	bend = au_sbend(sb);
++	for (; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		sysfs_remove_file(kobj, &br->br_attr);
++	}
++}
++
++void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++	int err;
++	aufs_bindex_t bend;
++	struct kobject *kobj;
++	struct au_branch *br;
++
++	dbgaufs_brs_add(sb, bindex);
++
++	if (!sysaufs_brs)
++		return;
++
++	kobj = &au_sbi(sb)->si_kobj;
++	bend = au_sbend(sb);
++	for (; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		snprintf(br->br_name, sizeof(br->br_name), SysaufsBr_PREFIX
++			 "%d", bindex);
++		err = sysfs_create_file(kobj, &br->br_attr);
++		if (unlikely(err))
++			pr_warning("failed %s under sysfs(%d)\n",
++				   br->br_name, err);
++	}
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/sysrq.c linux-2.6.36/fs/aufs/sysrq.c
+--- linux-2.6.36.orig/fs/aufs/sysrq.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/sysrq.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,148 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * magic sysrq hanlder
++ */
++
++#include <linux/fs.h>
++#include <linux/module.h>
++#include <linux/moduleparam.h>
++/* #include <linux/sysrq.h> */
++#include <linux/writeback.h>
++#include "aufs.h"
++
++/* ---------------------------------------------------------------------- */
++
++static void sysrq_sb(struct super_block *sb)
++{
++	char *plevel;
++	struct au_sbinfo *sbinfo;
++	struct file *file;
++
++	plevel = au_plevel;
++	au_plevel = KERN_WARNING;
++
++	sbinfo = au_sbi(sb);
++	/* since we define pr_fmt, call printk directly */
++	printk(KERN_WARNING "si=%lx\n", sysaufs_si_id(sbinfo));
++	printk(KERN_WARNING AUFS_NAME ": superblock\n");
++	au_dpri_sb(sb);
++
++#if 0
++	printk(KERN_WARNING AUFS_NAME ": root dentry\n");
++	au_dpri_dentry(sb->s_root);
++	printk(KERN_WARNING AUFS_NAME ": root inode\n");
++	au_dpri_inode(sb->s_root->d_inode);
++#endif
++
++#if 0
++	do {
++		int err, i, j, ndentry;
++		struct au_dcsub_pages dpages;
++		struct au_dpage *dpage;
++
++		err = au_dpages_init(&dpages, GFP_ATOMIC);
++		if (unlikely(err))
++			break;
++		err = au_dcsub_pages(&dpages, sb->s_root, NULL, NULL);
++		if (!err)
++			for (i = 0; i < dpages.ndpage; i++) {
++				dpage = dpages.dpages + i;
++				ndentry = dpage->ndentry;
++				for (j = 0; j < ndentry; j++)
++					au_dpri_dentry(dpage->dentries[j]);
++			}
++		au_dpages_free(&dpages);
++	} while (0);
++#endif
++
++#if 1
++	{
++		struct inode *i;
++		printk(KERN_WARNING AUFS_NAME ": isolated inode\n");
++		spin_lock(&inode_lock);
++		list_for_each_entry(i, &sb->s_inodes, i_sb_list)
++			if (1 || list_empty(&i->i_dentry))
++				au_dpri_inode(i);
++		spin_unlock(&inode_lock);
++	}
++#endif
++	printk(KERN_WARNING AUFS_NAME ": files\n");
++	lg_global_lock(files_lglock);
++	do_file_list_for_each_entry(sb, file) {
++		umode_t mode;
++		mode = file->f_dentry->d_inode->i_mode;
++		if (!special_file(mode) || au_special_file(mode))
++			au_dpri_file(file);
++	} while_file_list_for_each_entry;
++	lg_global_unlock(files_lglock);
++	printk(KERN_WARNING AUFS_NAME ": done\n");
++
++	au_plevel = plevel;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* module parameter */
++static char *aufs_sysrq_key = "a";
++module_param_named(sysrq, aufs_sysrq_key, charp, S_IRUGO);
++MODULE_PARM_DESC(sysrq, "MagicSysRq key for " AUFS_NAME);
++
++static void au_sysrq(int key __maybe_unused)
++{
++	struct au_sbinfo *sbinfo;
++
++	lockdep_off();
++	spin_lock(&au_sbilist.spin);
++	list_for_each_entry(sbinfo, &au_sbilist.head, si_list)
++		sysrq_sb(sbinfo->si_sb);
++	spin_unlock(&au_sbilist.spin);
++	lockdep_on();
++}
++
++static struct sysrq_key_op au_sysrq_op = {
++	.handler	= au_sysrq,
++	.help_msg	= "Aufs",
++	.action_msg	= "Aufs",
++	.enable_mask	= SYSRQ_ENABLE_DUMP
++};
++
++/* ---------------------------------------------------------------------- */
++
++int __init au_sysrq_init(void)
++{
++	int err;
++	char key;
++
++	err = -1;
++	key = *aufs_sysrq_key;
++	if ('a' <= key && key <= 'z')
++		err = register_sysrq_key(key, &au_sysrq_op);
++	if (unlikely(err))
++		pr_err("err %d, sysrq=%c\n", err, key);
++	return err;
++}
++
++void au_sysrq_fin(void)
++{
++	int err;
++	err = unregister_sysrq_key(*aufs_sysrq_key, &au_sysrq_op);
++	if (unlikely(err))
++		pr_err("err %d (ignored)\n", err);
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/vdir.c linux-2.6.36/fs/aufs/vdir.c
+--- linux-2.6.36.orig/fs/aufs/vdir.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/vdir.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,886 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * virtual or vertical directory
++ */
++
++#include <linux/hash.h>
++#include "aufs.h"
++
++static unsigned int calc_size(int nlen)
++{
++	return ALIGN(sizeof(struct au_vdir_de) + nlen, sizeof(ino_t));
++}
++
++static int set_deblk_end(union au_vdir_deblk_p *p,
++			 union au_vdir_deblk_p *deblk_end)
++{
++	if (calc_size(0) <= deblk_end->deblk - p->deblk) {
++		p->de->de_str.len = 0;
++		/* smp_mb(); */
++		return 0;
++	}
++	return -1; /* error */
++}
++
++/* returns true or false */
++static int is_deblk_end(union au_vdir_deblk_p *p,
++			union au_vdir_deblk_p *deblk_end)
++{
++	if (calc_size(0) <= deblk_end->deblk - p->deblk)
++		return !p->de->de_str.len;
++	return 1;
++}
++
++static unsigned char *last_deblk(struct au_vdir *vdir)
++{
++	return vdir->vd_deblk[vdir->vd_nblk - 1];
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* estimate the apropriate size for name hash table */
++unsigned int au_rdhash_est(loff_t sz)
++{
++	unsigned int n;
++
++	n = UINT_MAX;
++	sz >>= 10;
++	if (sz < n)
++		n = sz;
++	if (sz < AUFS_RDHASH_DEF)
++		n = AUFS_RDHASH_DEF;
++	/* pr_info("n %u\n", n); */
++	return n;
++}
++
++/*
++ * the allocated memory has to be freed by
++ * au_nhash_wh_free() or au_nhash_de_free().
++ */
++int au_nhash_alloc(struct au_nhash *nhash, unsigned int num_hash, gfp_t gfp)
++{
++	struct hlist_head *head;
++	unsigned int u;
++
++	head = kmalloc(sizeof(*nhash->nh_head) * num_hash, gfp);
++	if (head) {
++		nhash->nh_num = num_hash;
++		nhash->nh_head = head;
++		for (u = 0; u < num_hash; u++)
++			INIT_HLIST_HEAD(head++);
++		return 0; /* success */
++	}
++
++	return -ENOMEM;
++}
++
++static void nhash_count(struct hlist_head *head)
++{
++#if 0
++	unsigned long n;
++	struct hlist_node *pos;
++
++	n = 0;
++	hlist_for_each(pos, head)
++		n++;
++	pr_info("%lu\n", n);
++#endif
++}
++
++static void au_nhash_wh_do_free(struct hlist_head *head)
++{
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos, *node;
++
++	hlist_for_each_entry_safe(tpos, pos, node, head, wh_hash) {
++		/* hlist_del(pos); */
++		kfree(tpos);
++	}
++}
++
++static void au_nhash_de_do_free(struct hlist_head *head)
++{
++	struct au_vdir_dehstr *tpos;
++	struct hlist_node *pos, *node;
++
++	hlist_for_each_entry_safe(tpos, pos, node, head, hash) {
++		/* hlist_del(pos); */
++		au_cache_free_vdir_dehstr(tpos);
++	}
++}
++
++static void au_nhash_do_free(struct au_nhash *nhash,
++			     void (*free)(struct hlist_head *head))
++{
++	unsigned int n;
++	struct hlist_head *head;
++
++	n = nhash->nh_num;
++	if (!n)
++		return;
++
++	head = nhash->nh_head;
++	while (n-- > 0) {
++		nhash_count(head);
++		free(head++);
++	}
++	kfree(nhash->nh_head);
++}
++
++void au_nhash_wh_free(struct au_nhash *whlist)
++{
++	au_nhash_do_free(whlist, au_nhash_wh_do_free);
++}
++
++static void au_nhash_de_free(struct au_nhash *delist)
++{
++	au_nhash_do_free(delist, au_nhash_de_do_free);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
++			    int limit)
++{
++	int num;
++	unsigned int u, n;
++	struct hlist_head *head;
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos;
++
++	num = 0;
++	n = whlist->nh_num;
++	head = whlist->nh_head;
++	for (u = 0; u < n; u++, head++)
++		hlist_for_each_entry(tpos, pos, head, wh_hash)
++			if (tpos->wh_bindex == btgt && ++num > limit)
++				return 1;
++	return 0;
++}
++
++static struct hlist_head *au_name_hash(struct au_nhash *nhash,
++				       unsigned char *name,
++				       unsigned int len)
++{
++	unsigned int v;
++	/* const unsigned int magic_bit = 12; */
++
++	AuDebugOn(!nhash->nh_num || !nhash->nh_head);
++
++	v = 0;
++	while (len--)
++		v += *name++;
++	/* v = hash_long(v, magic_bit); */
++	v %= nhash->nh_num;
++	return nhash->nh_head + v;
++}
++
++static int au_nhash_test_name(struct au_vdir_destr *str, const char *name,
++			      int nlen)
++{
++	return str->len == nlen && !memcmp(str->name, name, nlen);
++}
++
++/* returns found or not */
++int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int nlen)
++{
++	struct hlist_head *head;
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos;
++	struct au_vdir_destr *str;
++
++	head = au_name_hash(whlist, name, nlen);
++	hlist_for_each_entry(tpos, pos, head, wh_hash) {
++		str = &tpos->wh_str;
++		AuDbg("%.*s\n", str->len, str->name);
++		if (au_nhash_test_name(str, name, nlen))
++			return 1;
++	}
++	return 0;
++}
++
++/* returns found(true) or not */
++static int test_known(struct au_nhash *delist, char *name, int nlen)
++{
++	struct hlist_head *head;
++	struct au_vdir_dehstr *tpos;
++	struct hlist_node *pos;
++	struct au_vdir_destr *str;
++
++	head = au_name_hash(delist, name, nlen);
++	hlist_for_each_entry(tpos, pos, head, hash) {
++		str = tpos->str;
++		AuDbg("%.*s\n", str->len, str->name);
++		if (au_nhash_test_name(str, name, nlen))
++			return 1;
++	}
++	return 0;
++}
++
++static void au_shwh_init_wh(struct au_vdir_wh *wh, ino_t ino,
++			    unsigned char d_type)
++{
++#ifdef CONFIG_AUFS_SHWH
++	wh->wh_ino = ino;
++	wh->wh_type = d_type;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_nhash_append_wh(struct au_nhash *whlist, char *name, int nlen, ino_t ino,
++		       unsigned int d_type, aufs_bindex_t bindex,
++		       unsigned char shwh)
++{
++	int err;
++	struct au_vdir_destr *str;
++	struct au_vdir_wh *wh;
++
++	AuDbg("%.*s\n", nlen, name);
++	AuDebugOn(!whlist->nh_num || !whlist->nh_head);
++
++	err = -ENOMEM;
++	wh = kmalloc(sizeof(*wh) + nlen, GFP_NOFS);
++	if (unlikely(!wh))
++		goto out;
++
++	err = 0;
++	wh->wh_bindex = bindex;
++	if (shwh)
++		au_shwh_init_wh(wh, ino, d_type);
++	str = &wh->wh_str;
++	str->len = nlen;
++	memcpy(str->name, name, nlen);
++	hlist_add_head(&wh->wh_hash, au_name_hash(whlist, name, nlen));
++	/* smp_mb(); */
++
++out:
++	return err;
++}
++
++static int append_deblk(struct au_vdir *vdir)
++{
++	int err;
++	unsigned long ul;
++	const unsigned int deblk_sz = vdir->vd_deblk_sz;
++	union au_vdir_deblk_p p, deblk_end;
++	unsigned char **o;
++
++	err = -ENOMEM;
++	o = krealloc(vdir->vd_deblk, sizeof(*o) * (vdir->vd_nblk + 1),
++		     GFP_NOFS);
++	if (unlikely(!o))
++		goto out;
++
++	vdir->vd_deblk = o;
++	p.deblk = kmalloc(deblk_sz, GFP_NOFS);
++	if (p.deblk) {
++		ul = vdir->vd_nblk++;
++		vdir->vd_deblk[ul] = p.deblk;
++		vdir->vd_last.ul = ul;
++		vdir->vd_last.p.deblk = p.deblk;
++		deblk_end.deblk = p.deblk + deblk_sz;
++		err = set_deblk_end(&p, &deblk_end);
++	}
++
++out:
++	return err;
++}
++
++static int append_de(struct au_vdir *vdir, char *name, int nlen, ino_t ino,
++		     unsigned int d_type, struct au_nhash *delist)
++{
++	int err;
++	unsigned int sz;
++	const unsigned int deblk_sz = vdir->vd_deblk_sz;
++	union au_vdir_deblk_p p, *room, deblk_end;
++	struct au_vdir_dehstr *dehstr;
++
++	p.deblk = last_deblk(vdir);
++	deblk_end.deblk = p.deblk + deblk_sz;
++	room = &vdir->vd_last.p;
++	AuDebugOn(room->deblk < p.deblk || deblk_end.deblk <= room->deblk
++		  || !is_deblk_end(room, &deblk_end));
++
++	sz = calc_size(nlen);
++	if (unlikely(sz > deblk_end.deblk - room->deblk)) {
++		err = append_deblk(vdir);
++		if (unlikely(err))
++			goto out;
++
++		p.deblk = last_deblk(vdir);
++		deblk_end.deblk = p.deblk + deblk_sz;
++		/* smp_mb(); */
++		AuDebugOn(room->deblk != p.deblk);
++	}
++
++	err = -ENOMEM;
++	dehstr = au_cache_alloc_vdir_dehstr();
++	if (unlikely(!dehstr))
++		goto out;
++
++	dehstr->str = &room->de->de_str;
++	hlist_add_head(&dehstr->hash, au_name_hash(delist, name, nlen));
++	room->de->de_ino = ino;
++	room->de->de_type = d_type;
++	room->de->de_str.len = nlen;
++	memcpy(room->de->de_str.name, name, nlen);
++
++	err = 0;
++	room->deblk += sz;
++	if (unlikely(set_deblk_end(room, &deblk_end)))
++		err = append_deblk(vdir);
++	/* smp_mb(); */
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_vdir_free(struct au_vdir *vdir)
++{
++	unsigned char **deblk;
++
++	deblk = vdir->vd_deblk;
++	while (vdir->vd_nblk--)
++		kfree(*deblk++);
++	kfree(vdir->vd_deblk);
++	au_cache_free_vdir(vdir);
++}
++
++static struct au_vdir *alloc_vdir(struct file *file)
++{
++	struct au_vdir *vdir;
++	struct super_block *sb;
++	int err;
++
++	sb = file->f_dentry->d_sb;
++	SiMustAnyLock(sb);
++
++	err = -ENOMEM;
++	vdir = au_cache_alloc_vdir();
++	if (unlikely(!vdir))
++		goto out;
++
++	vdir->vd_deblk = kzalloc(sizeof(*vdir->vd_deblk), GFP_NOFS);
++	if (unlikely(!vdir->vd_deblk))
++		goto out_free;
++
++	vdir->vd_deblk_sz = au_sbi(sb)->si_rdblk;
++	if (!vdir->vd_deblk_sz) {
++		/* estimate the apropriate size for deblk */
++		vdir->vd_deblk_sz = au_dir_size(file, /*dentry*/NULL);
++		/* pr_info("vd_deblk_sz %u\n", vdir->vd_deblk_sz); */
++	}
++	vdir->vd_nblk = 0;
++	vdir->vd_version = 0;
++	vdir->vd_jiffy = 0;
++	err = append_deblk(vdir);
++	if (!err)
++		return vdir; /* success */
++
++	kfree(vdir->vd_deblk);
++
++out_free:
++	au_cache_free_vdir(vdir);
++out:
++	vdir = ERR_PTR(err);
++	return vdir;
++}
++
++static int reinit_vdir(struct au_vdir *vdir)
++{
++	int err;
++	union au_vdir_deblk_p p, deblk_end;
++
++	while (vdir->vd_nblk > 1) {
++		kfree(vdir->vd_deblk[vdir->vd_nblk - 1]);
++		/* vdir->vd_deblk[vdir->vd_nblk - 1] = NULL; */
++		vdir->vd_nblk--;
++	}
++	p.deblk = vdir->vd_deblk[0];
++	deblk_end.deblk = p.deblk + vdir->vd_deblk_sz;
++	err = set_deblk_end(&p, &deblk_end);
++	/* keep vd_dblk_sz */
++	vdir->vd_last.ul = 0;
++	vdir->vd_last.p.deblk = vdir->vd_deblk[0];
++	vdir->vd_version = 0;
++	vdir->vd_jiffy = 0;
++	/* smp_mb(); */
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#define AuFillVdir_CALLED	1
++#define AuFillVdir_WHABLE	(1 << 1)
++#define AuFillVdir_SHWH		(1 << 2)
++#define au_ftest_fillvdir(flags, name)	((flags) & AuFillVdir_##name)
++#define au_fset_fillvdir(flags, name) \
++	do { (flags) |= AuFillVdir_##name; } while (0)
++#define au_fclr_fillvdir(flags, name) \
++	do { (flags) &= ~AuFillVdir_##name; } while (0)
++
++#ifndef CONFIG_AUFS_SHWH
++#undef AuFillVdir_SHWH
++#define AuFillVdir_SHWH		0
++#endif
++
++struct fillvdir_arg {
++	struct file		*file;
++	struct au_vdir		*vdir;
++	struct au_nhash		delist;
++	struct au_nhash		whlist;
++	aufs_bindex_t		bindex;
++	unsigned int		flags;
++	int			err;
++};
++
++static int fillvdir(void *__arg, const char *__name, int nlen,
++		    loff_t offset __maybe_unused, u64 h_ino,
++		    unsigned int d_type)
++{
++	struct fillvdir_arg *arg = __arg;
++	char *name = (void *)__name;
++	struct super_block *sb;
++	ino_t ino;
++	const unsigned char shwh = !!au_ftest_fillvdir(arg->flags, SHWH);
++
++	arg->err = 0;
++	sb = arg->file->f_dentry->d_sb;
++	au_fset_fillvdir(arg->flags, CALLED);
++	/* smp_mb(); */
++	if (nlen <= AUFS_WH_PFX_LEN
++	    || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++		if (test_known(&arg->delist, name, nlen)
++		    || au_nhash_test_known_wh(&arg->whlist, name, nlen))
++			goto out; /* already exists or whiteouted */
++
++		sb = arg->file->f_dentry->d_sb;
++		arg->err = au_ino(sb, arg->bindex, h_ino, d_type, &ino);
++		if (!arg->err) {
++			if (unlikely(nlen > AUFS_MAX_NAMELEN))
++				d_type = DT_UNKNOWN;
++			arg->err = append_de(arg->vdir, name, nlen, ino,
++					     d_type, &arg->delist);
++		}
++	} else if (au_ftest_fillvdir(arg->flags, WHABLE)) {
++		name += AUFS_WH_PFX_LEN;
++		nlen -= AUFS_WH_PFX_LEN;
++		if (au_nhash_test_known_wh(&arg->whlist, name, nlen))
++			goto out; /* already whiteouted */
++
++		if (shwh)
++			arg->err = au_wh_ino(sb, arg->bindex, h_ino, d_type,
++					     &ino);
++		if (!arg->err) {
++			if (nlen <= AUFS_MAX_NAMELEN + AUFS_WH_PFX_LEN)
++				d_type = DT_UNKNOWN;
++			arg->err = au_nhash_append_wh
++				(&arg->whlist, name, nlen, ino, d_type,
++				 arg->bindex, shwh);
++		}
++	}
++
++out:
++	if (!arg->err)
++		arg->vdir->vd_jiffy = jiffies;
++	/* smp_mb(); */
++	AuTraceErr(arg->err);
++	return arg->err;
++}
++
++static int au_handle_shwh(struct super_block *sb, struct au_vdir *vdir,
++			  struct au_nhash *whlist, struct au_nhash *delist)
++{
++#ifdef CONFIG_AUFS_SHWH
++	int err;
++	unsigned int nh, u;
++	struct hlist_head *head;
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos, *n;
++	char *p, *o;
++	struct au_vdir_destr *destr;
++
++	AuDebugOn(!au_opt_test(au_mntflags(sb), SHWH));
++
++	err = -ENOMEM;
++	o = p = __getname_gfp(GFP_NOFS);
++	if (unlikely(!p))
++		goto out;
++
++	err = 0;
++	nh = whlist->nh_num;
++	memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
++	p += AUFS_WH_PFX_LEN;
++	for (u = 0; u < nh; u++) {
++		head = whlist->nh_head + u;
++		hlist_for_each_entry_safe(tpos, pos, n, head, wh_hash) {
++			destr = &tpos->wh_str;
++			memcpy(p, destr->name, destr->len);
++			err = append_de(vdir, o, destr->len + AUFS_WH_PFX_LEN,
++					tpos->wh_ino, tpos->wh_type, delist);
++			if (unlikely(err))
++				break;
++		}
++	}
++
++	__putname(o);
++
++out:
++	AuTraceErr(err);
++	return err;
++#else
++	return 0;
++#endif
++}
++
++static int au_do_read_vdir(struct fillvdir_arg *arg)
++{
++	int err;
++	unsigned int rdhash;
++	loff_t offset;
++	aufs_bindex_t bend, bindex, bstart;
++	unsigned char shwh;
++	struct file *hf, *file;
++	struct super_block *sb;
++
++	file = arg->file;
++	sb = file->f_dentry->d_sb;
++	SiMustAnyLock(sb);
++
++	rdhash = au_sbi(sb)->si_rdhash;
++	if (!rdhash)
++		rdhash = au_rdhash_est(au_dir_size(file, /*dentry*/NULL));
++	err = au_nhash_alloc(&arg->delist, rdhash, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	err = au_nhash_alloc(&arg->whlist, rdhash, GFP_NOFS);
++	if (unlikely(err))
++		goto out_delist;
++
++	err = 0;
++	arg->flags = 0;
++	shwh = 0;
++	if (au_opt_test(au_mntflags(sb), SHWH)) {
++		shwh = 1;
++		au_fset_fillvdir(arg->flags, SHWH);
++	}
++	bstart = au_fbstart(file);
++	bend = au_fbend_dir(file);
++	for (bindex = bstart; !err && bindex <= bend; bindex++) {
++		hf = au_hf_dir(file, bindex);
++		if (!hf)
++			continue;
++
++		offset = vfsub_llseek(hf, 0, SEEK_SET);
++		err = offset;
++		if (unlikely(offset))
++			break;
++
++		arg->bindex = bindex;
++		au_fclr_fillvdir(arg->flags, WHABLE);
++		if (shwh
++		    || (bindex != bend
++			&& au_br_whable(au_sbr_perm(sb, bindex))))
++			au_fset_fillvdir(arg->flags, WHABLE);
++		do {
++			arg->err = 0;
++			au_fclr_fillvdir(arg->flags, CALLED);
++			/* smp_mb(); */
++			err = vfsub_readdir(hf, fillvdir, arg);
++			if (err >= 0)
++				err = arg->err;
++		} while (!err && au_ftest_fillvdir(arg->flags, CALLED));
++	}
++
++	if (!err && shwh)
++		err = au_handle_shwh(sb, arg->vdir, &arg->whlist, &arg->delist);
++
++	au_nhash_wh_free(&arg->whlist);
++
++out_delist:
++	au_nhash_de_free(&arg->delist);
++out:
++	return err;
++}
++
++static int read_vdir(struct file *file, int may_read)
++{
++	int err;
++	unsigned long expire;
++	unsigned char do_read;
++	struct fillvdir_arg arg;
++	struct inode *inode;
++	struct au_vdir *vdir, *allocated;
++
++	err = 0;
++	inode = file->f_dentry->d_inode;
++	IMustLock(inode);
++	SiMustAnyLock(inode->i_sb);
++
++	allocated = NULL;
++	do_read = 0;
++	expire = au_sbi(inode->i_sb)->si_rdcache;
++	vdir = au_ivdir(inode);
++	if (!vdir) {
++		do_read = 1;
++		vdir = alloc_vdir(file);
++		err = PTR_ERR(vdir);
++		if (IS_ERR(vdir))
++			goto out;
++		err = 0;
++		allocated = vdir;
++	} else if (may_read
++		   && (inode->i_version != vdir->vd_version
++		       || time_after(jiffies, vdir->vd_jiffy + expire))) {
++		do_read = 1;
++		err = reinit_vdir(vdir);
++		if (unlikely(err))
++			goto out;
++	}
++
++	if (!do_read)
++		return 0; /* success */
++
++	arg.file = file;
++	arg.vdir = vdir;
++	err = au_do_read_vdir(&arg);
++	if (!err) {
++		/* file->f_pos = 0; */
++		vdir->vd_version = inode->i_version;
++		vdir->vd_last.ul = 0;
++		vdir->vd_last.p.deblk = vdir->vd_deblk[0];
++		if (allocated)
++			au_set_ivdir(inode, allocated);
++	} else if (allocated)
++		au_vdir_free(allocated);
++
++out:
++	return err;
++}
++
++static int copy_vdir(struct au_vdir *tgt, struct au_vdir *src)
++{
++	int err, rerr;
++	unsigned long ul, n;
++	const unsigned int deblk_sz = src->vd_deblk_sz;
++
++	AuDebugOn(tgt->vd_nblk != 1);
++
++	err = -ENOMEM;
++	if (tgt->vd_nblk < src->vd_nblk) {
++		unsigned char **p;
++
++		p = krealloc(tgt->vd_deblk, sizeof(*p) * src->vd_nblk,
++			     GFP_NOFS);
++		if (unlikely(!p))
++			goto out;
++		tgt->vd_deblk = p;
++	}
++
++	if (tgt->vd_deblk_sz != deblk_sz) {
++		unsigned char *p;
++
++		tgt->vd_deblk_sz = deblk_sz;
++		p = krealloc(tgt->vd_deblk[0], deblk_sz, GFP_NOFS);
++		if (unlikely(!p))
++			goto out;
++		tgt->vd_deblk[0] = p;
++	}
++	memcpy(tgt->vd_deblk[0], src->vd_deblk[0], deblk_sz);
++	tgt->vd_version = src->vd_version;
++	tgt->vd_jiffy = src->vd_jiffy;
++
++	n = src->vd_nblk;
++	for (ul = 1; ul < n; ul++) {
++		tgt->vd_deblk[ul] = kmemdup(src->vd_deblk[ul], deblk_sz,
++					    GFP_NOFS);
++		if (unlikely(!tgt->vd_deblk[ul]))
++			goto out;
++		tgt->vd_nblk++;
++	}
++	tgt->vd_nblk = n;
++	tgt->vd_last.ul = tgt->vd_last.ul;
++	tgt->vd_last.p.deblk = tgt->vd_deblk[tgt->vd_last.ul];
++	tgt->vd_last.p.deblk += src->vd_last.p.deblk
++		- src->vd_deblk[src->vd_last.ul];
++	/* smp_mb(); */
++	return 0; /* success */
++
++out:
++	rerr = reinit_vdir(tgt);
++	BUG_ON(rerr);
++	return err;
++}
++
++int au_vdir_init(struct file *file)
++{
++	int err;
++	struct inode *inode;
++	struct au_vdir *vdir_cache, *allocated;
++
++	err = read_vdir(file, !file->f_pos);
++	if (unlikely(err))
++		goto out;
++
++	allocated = NULL;
++	vdir_cache = au_fvdir_cache(file);
++	if (!vdir_cache) {
++		vdir_cache = alloc_vdir(file);
++		err = PTR_ERR(vdir_cache);
++		if (IS_ERR(vdir_cache))
++			goto out;
++		allocated = vdir_cache;
++	} else if (!file->f_pos && vdir_cache->vd_version != file->f_version) {
++		err = reinit_vdir(vdir_cache);
++		if (unlikely(err))
++			goto out;
++	} else
++		return 0; /* success */
++
++	inode = file->f_dentry->d_inode;
++	err = copy_vdir(vdir_cache, au_ivdir(inode));
++	if (!err) {
++		file->f_version = inode->i_version;
++		if (allocated)
++			au_set_fvdir_cache(file, allocated);
++	} else if (allocated)
++		au_vdir_free(allocated);
++
++out:
++	return err;
++}
++
++static loff_t calc_offset(struct au_vdir *vdir)
++{
++	loff_t offset;
++	union au_vdir_deblk_p p;
++
++	p.deblk = vdir->vd_deblk[vdir->vd_last.ul];
++	offset = vdir->vd_last.p.deblk - p.deblk;
++	offset += vdir->vd_deblk_sz * vdir->vd_last.ul;
++	return offset;
++}
++
++/* returns true or false */
++static int seek_vdir(struct file *file)
++{
++	int valid;
++	unsigned int deblk_sz;
++	unsigned long ul, n;
++	loff_t offset;
++	union au_vdir_deblk_p p, deblk_end;
++	struct au_vdir *vdir_cache;
++
++	valid = 1;
++	vdir_cache = au_fvdir_cache(file);
++	offset = calc_offset(vdir_cache);
++	AuDbg("offset %lld\n", offset);
++	if (file->f_pos == offset)
++		goto out;
++
++	vdir_cache->vd_last.ul = 0;
++	vdir_cache->vd_last.p.deblk = vdir_cache->vd_deblk[0];
++	if (!file->f_pos)
++		goto out;
++
++	valid = 0;
++	deblk_sz = vdir_cache->vd_deblk_sz;
++	ul = div64_u64(file->f_pos, deblk_sz);
++	AuDbg("ul %lu\n", ul);
++	if (ul >= vdir_cache->vd_nblk)
++		goto out;
++
++	n = vdir_cache->vd_nblk;
++	for (; ul < n; ul++) {
++		p.deblk = vdir_cache->vd_deblk[ul];
++		deblk_end.deblk = p.deblk + deblk_sz;
++		offset = ul;
++		offset *= deblk_sz;
++		while (!is_deblk_end(&p, &deblk_end) && offset < file->f_pos) {
++			unsigned int l;
++
++			l = calc_size(p.de->de_str.len);
++			offset += l;
++			p.deblk += l;
++		}
++		if (!is_deblk_end(&p, &deblk_end)) {
++			valid = 1;
++			vdir_cache->vd_last.ul = ul;
++			vdir_cache->vd_last.p = p;
++			break;
++		}
++	}
++
++out:
++	/* smp_mb(); */
++	AuTraceErr(!valid);
++	return valid;
++}
++
++int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir)
++{
++	int err;
++	unsigned int l, deblk_sz;
++	union au_vdir_deblk_p deblk_end;
++	struct au_vdir *vdir_cache;
++	struct au_vdir_de *de;
++
++	vdir_cache = au_fvdir_cache(file);
++	if (!seek_vdir(file))
++		return 0;
++
++	deblk_sz = vdir_cache->vd_deblk_sz;
++	while (1) {
++		deblk_end.deblk = vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
++		deblk_end.deblk += deblk_sz;
++		while (!is_deblk_end(&vdir_cache->vd_last.p, &deblk_end)) {
++			de = vdir_cache->vd_last.p.de;
++			AuDbg("%.*s, off%lld, i%lu, dt%d\n",
++			      de->de_str.len, de->de_str.name, file->f_pos,
++			      (unsigned long)de->de_ino, de->de_type);
++			err = filldir(dirent, de->de_str.name, de->de_str.len,
++				      file->f_pos, de->de_ino, de->de_type);
++			if (unlikely(err)) {
++				AuTraceErr(err);
++				/* todo: ignore the error caused by udba? */
++				/* return err; */
++				return 0;
++			}
++
++			l = calc_size(de->de_str.len);
++			vdir_cache->vd_last.p.deblk += l;
++			file->f_pos += l;
++		}
++		if (vdir_cache->vd_last.ul < vdir_cache->vd_nblk - 1) {
++			vdir_cache->vd_last.ul++;
++			vdir_cache->vd_last.p.deblk
++				= vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
++			file->f_pos = deblk_sz * vdir_cache->vd_last.ul;
++			continue;
++		}
++		break;
++	}
++
++	/* smp_mb(); */
++	return 0;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/vfsub.c linux-2.6.36/fs/aufs/vfsub.c
+--- linux-2.6.36.orig/fs/aufs/vfsub.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/vfsub.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,790 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sub-routines for VFS
++ */
++
++#include <linux/file.h>
++#include <linux/ima.h>
++#include <linux/namei.h>
++#include <linux/security.h>
++#include <linux/splice.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++int vfsub_update_h_iattr(struct path *h_path, int *did)
++{
++	int err;
++	struct kstat st;
++	struct super_block *h_sb;
++
++	/* for remote fs, leave work for its getattr or d_revalidate */
++	/* for bad i_attr fs, handle them in aufs_getattr() */
++	/* still some fs may acquire i_mutex. we need to skip them */
++	err = 0;
++	if (!did)
++		did = &err;
++	h_sb = h_path->dentry->d_sb;
++	*did = (!au_test_fs_remote(h_sb) && au_test_fs_refresh_iattr(h_sb));
++	if (*did)
++		err = vfs_getattr(h_path->mnt, h_path->dentry, &st);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_conv_oflags(int flags)
++{
++	int mask = 0;
++
++#ifdef CONFIG_IMA
++	fmode_t fmode;
++
++	/* mask = MAY_OPEN; */
++	fmode = OPEN_FMODE(flags);
++	if (fmode & FMODE_READ)
++		mask |= MAY_READ;
++	if ((fmode & FMODE_WRITE)
++	    || (flags & O_TRUNC))
++		mask |= MAY_WRITE;
++	/*
++	 * if (flags & O_APPEND)
++	 *	mask |= MAY_APPEND;
++	 */
++	if (flags & vfsub_fmode_to_uint(FMODE_EXEC))
++		mask |= MAY_EXEC;
++
++	AuDbg("flags 0x%x, mask 0x%x\n", flags, mask);
++#endif
++
++	return mask;
++}
++
++struct file *vfsub_dentry_open(struct path *path, int flags)
++{
++	struct file *file;
++	int err;
++
++	path_get(path);
++	file = dentry_open(path->dentry, path->mnt,
++			   flags /* | vfsub_fmode_to_uint(FMODE_NONOTIFY) */,
++			   current_cred());
++	if (IS_ERR(file))
++		goto out;
++
++	err = ima_file_check(file, au_conv_oflags(flags));
++	if (unlikely(err)) {
++		fput(file);
++		file = ERR_PTR(err);
++	}
++out:
++	return file;
++}
++
++struct file *vfsub_filp_open(const char *path, int oflags, int mode)
++{
++	struct file *file;
++
++	file = filp_open(path,
++			 oflags /* | vfsub_fmode_to_uint(FMODE_NONOTIFY) */,
++			 mode);
++	if (IS_ERR(file))
++		goto out;
++	vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++
++out:
++	return file;
++}
++
++int vfsub_kern_path(const char *name, unsigned int flags, struct path *path)
++{
++	int err;
++
++	err = kern_path(name, flags, path);
++	if (!err && path->dentry->d_inode)
++		vfsub_update_h_iattr(path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
++				    int len)
++{
++	struct path path = {
++		.mnt = NULL
++	};
++
++	/* VFS checks it too, but by WARN_ON_ONCE() */
++	IMustLock(parent->d_inode);
++
++	path.dentry = lookup_one_len(name, parent, len);
++	if (IS_ERR(path.dentry))
++		goto out;
++	if (path.dentry->d_inode)
++		vfsub_update_h_iattr(&path, /*did*/NULL); /*ignore*/
++
++out:
++	AuTraceErrPtr(path.dentry);
++	return path.dentry;
++}
++
++struct dentry *vfsub_lookup_hash(struct nameidata *nd)
++{
++	struct path path = {
++		.mnt = nd->path.mnt
++	};
++
++	IMustLock(nd->path.dentry->d_inode);
++
++	path.dentry = lookup_hash(nd);
++	if (IS_ERR(path.dentry))
++		goto out;
++	if (path.dentry->d_inode)
++		vfsub_update_h_iattr(&path, /*did*/NULL); /*ignore*/
++
++out:
++	AuTraceErrPtr(path.dentry);
++	return path.dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *vfsub_lock_rename(struct dentry *d1, struct au_hinode *hdir1,
++				 struct dentry *d2, struct au_hinode *hdir2)
++{
++	struct dentry *d;
++
++	d = lock_rename(d1, d2);
++	au_hn_suspend(hdir1);
++	if (hdir1 != hdir2)
++		au_hn_suspend(hdir2);
++
++	return d;
++}
++
++void vfsub_unlock_rename(struct dentry *d1, struct au_hinode *hdir1,
++			 struct dentry *d2, struct au_hinode *hdir2)
++{
++	au_hn_resume(hdir1);
++	if (hdir1 != hdir2)
++		au_hn_resume(hdir2);
++	unlock_rename(d1, d2);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int vfsub_create(struct inode *dir, struct path *path, int mode)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_mknod(path, d, mode, 0);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	if (au_test_fs_null_nd(dir->i_sb))
++		err = vfs_create(dir, path->dentry, mode, NULL);
++	else {
++		struct nameidata h_nd;
++
++		memset(&h_nd, 0, sizeof(h_nd));
++		h_nd.flags = LOOKUP_CREATE;
++		h_nd.intent.open.flags = O_CREAT
++			| vfsub_fmode_to_uint(FMODE_READ);
++		h_nd.intent.open.create_mode = mode;
++		h_nd.path.dentry = path->dentry->d_parent;
++		h_nd.path.mnt = path->mnt;
++		path_get(&h_nd.path);
++		err = vfs_create(dir, path->dentry, mode, &h_nd);
++		path_put(&h_nd.path);
++	}
++
++	if (!err) {
++		struct path tmp = *path;
++		int did;
++
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = path->dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++int vfsub_symlink(struct inode *dir, struct path *path, const char *symname)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_symlink(path, d, symname);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_symlink(dir, path->dentry, symname);
++	if (!err) {
++		struct path tmp = *path;
++		int did;
++
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = path->dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++int vfsub_mknod(struct inode *dir, struct path *path, int mode, dev_t dev)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_mknod(path, d, mode, dev);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_mknod(dir, path->dentry, mode, dev);
++	if (!err) {
++		struct path tmp = *path;
++		int did;
++
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = path->dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++static int au_test_nlink(struct inode *inode)
++{
++	const unsigned int link_max = UINT_MAX >> 1; /* rough margin */
++
++	if (!au_test_fs_no_limit_nlink(inode->i_sb)
++	    || inode->i_nlink < link_max)
++		return 0;
++	return -EMLINK;
++}
++
++int vfsub_link(struct dentry *src_dentry, struct inode *dir, struct path *path)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	err = au_test_nlink(src_dentry->d_inode);
++	if (unlikely(err))
++		return err;
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_link(src_dentry, path, d);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_link(src_dentry, dir, path->dentry);
++	if (!err) {
++		struct path tmp = *path;
++		int did;
++
++		/* fuse has different memory inode for the same inumber */
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = path->dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++			tmp.dentry = src_dentry;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
++		 struct inode *dir, struct path *path)
++{
++	int err;
++	struct path tmp = {
++		.mnt	= path->mnt
++	};
++	struct dentry *d;
++
++	IMustLock(dir);
++	IMustLock(src_dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	tmp.dentry = src_dentry->d_parent;
++	err = security_path_rename(&tmp, src_dentry, path, d);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_rename(src_dir, src_dentry, dir, path->dentry);
++	if (!err) {
++		int did;
++
++		tmp.dentry = d->d_parent;
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = src_dentry;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++			tmp.dentry = src_dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++int vfsub_mkdir(struct inode *dir, struct path *path, int mode)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_mkdir(path, d, mode);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_mkdir(dir, path->dentry, mode);
++	if (!err) {
++		struct path tmp = *path;
++		int did;
++
++		vfsub_update_h_iattr(&tmp, &did);
++		if (did) {
++			tmp.dentry = path->dentry->d_parent;
++			vfsub_update_h_iattr(&tmp, /*did*/NULL);
++		}
++		/*ignore*/
++	}
++
++out:
++	return err;
++}
++
++int vfsub_rmdir(struct inode *dir, struct path *path)
++{
++	int err;
++	struct dentry *d;
++
++	IMustLock(dir);
++
++	d = path->dentry;
++	path->dentry = d->d_parent;
++	err = security_path_rmdir(path, d);
++	path->dentry = d;
++	if (unlikely(err))
++		goto out;
++
++	err = vfs_rmdir(dir, path->dentry);
++	if (!err) {
++		struct path tmp = {
++			.dentry	= path->dentry->d_parent,
++			.mnt	= path->mnt
++		};
++
++		vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
++	}
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
++		     loff_t *ppos)
++{
++	ssize_t err;
++
++	err = vfs_read(file, ubuf, count, ppos);
++	if (err >= 0)
++		vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++/* todo: kernel_read()? */
++ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count,
++		     loff_t *ppos)
++{
++	ssize_t err;
++	mm_segment_t oldfs;
++	union {
++		void *k;
++		char __user *u;
++	} buf;
++
++	buf.k = kbuf;
++	oldfs = get_fs();
++	set_fs(KERNEL_DS);
++	err = vfsub_read_u(file, buf.u, count, ppos);
++	set_fs(oldfs);
++	return err;
++}
++
++ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
++		      loff_t *ppos)
++{
++	ssize_t err;
++
++	err = vfs_write(file, ubuf, count, ppos);
++	if (err >= 0)
++		vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos)
++{
++	ssize_t err;
++	mm_segment_t oldfs;
++	union {
++		void *k;
++		const char __user *u;
++	} buf;
++
++	buf.k = kbuf;
++	oldfs = get_fs();
++	set_fs(KERNEL_DS);
++	err = vfsub_write_u(file, buf.u, count, ppos);
++	set_fs(oldfs);
++	return err;
++}
++
++int vfsub_flush(struct file *file, fl_owner_t id)
++{
++	int err;
++
++	err = 0;
++	if (file->f_op && file->f_op->flush) {
++		err = file->f_op->flush(file, id);
++		if (!err)
++			vfsub_update_h_iattr(&file->f_path, /*did*/NULL);
++		/*ignore*/
++	}
++	return err;
++}
++
++int vfsub_readdir(struct file *file, filldir_t filldir, void *arg)
++{
++	int err;
++
++	err = vfs_readdir(file, filldir, arg);
++	if (err >= 0)
++		vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++long vfsub_splice_to(struct file *in, loff_t *ppos,
++		     struct pipe_inode_info *pipe, size_t len,
++		     unsigned int flags)
++{
++	long err;
++
++	err = do_splice_to(in, ppos, pipe, len, flags);
++	file_accessed(in);
++	if (err >= 0)
++		vfsub_update_h_iattr(&in->f_path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
++		       loff_t *ppos, size_t len, unsigned int flags)
++{
++	long err;
++
++	err = do_splice_from(pipe, out, ppos, len, flags);
++	if (err >= 0)
++		vfsub_update_h_iattr(&out->f_path, /*did*/NULL); /*ignore*/
++	return err;
++}
++
++/* cf. open.c:do_sys_truncate() and do_sys_ftruncate() */
++int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
++		struct file *h_file)
++{
++	int err;
++	struct inode *h_inode;
++
++	h_inode = h_path->dentry->d_inode;
++	if (!h_file) {
++		err = mnt_want_write(h_path->mnt);
++		if (err)
++			goto out;
++		err = inode_permission(h_inode, MAY_WRITE);
++		if (err)
++			goto out_mnt;
++		err = get_write_access(h_inode);
++		if (err)
++			goto out_mnt;
++		err = break_lease(h_inode, O_WRONLY);
++		if (err)
++			goto out_inode;
++	}
++
++	err = locks_verify_truncate(h_inode, h_file, length);
++	if (!err)
++		err = security_path_truncate(h_path);
++	if (!err)
++		err = do_truncate(h_path->dentry, length, attr, h_file);
++
++out_inode:
++	if (!h_file)
++		put_write_access(h_inode);
++out_mnt:
++	if (!h_file)
++		mnt_drop_write(h_path->mnt);
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_vfsub_mkdir_args {
++	int *errp;
++	struct inode *dir;
++	struct path *path;
++	int mode;
++};
++
++static void au_call_vfsub_mkdir(void *args)
++{
++	struct au_vfsub_mkdir_args *a = args;
++	*a->errp = vfsub_mkdir(a->dir, a->path, a->mode);
++}
++
++int vfsub_sio_mkdir(struct inode *dir, struct path *path, int mode)
++{
++	int err, do_sio, wkq_err;
++
++	do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
++	if (!do_sio)
++		err = vfsub_mkdir(dir, path, mode);
++	else {
++		struct au_vfsub_mkdir_args args = {
++			.errp	= &err,
++			.dir	= dir,
++			.path	= path,
++			.mode	= mode
++		};
++		wkq_err = au_wkq_wait(au_call_vfsub_mkdir, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	return err;
++}
++
++struct au_vfsub_rmdir_args {
++	int *errp;
++	struct inode *dir;
++	struct path *path;
++};
++
++static void au_call_vfsub_rmdir(void *args)
++{
++	struct au_vfsub_rmdir_args *a = args;
++	*a->errp = vfsub_rmdir(a->dir, a->path);
++}
++
++int vfsub_sio_rmdir(struct inode *dir, struct path *path)
++{
++	int err, do_sio, wkq_err;
++
++	do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
++	if (!do_sio)
++		err = vfsub_rmdir(dir, path);
++	else {
++		struct au_vfsub_rmdir_args args = {
++			.errp	= &err,
++			.dir	= dir,
++			.path	= path
++		};
++		wkq_err = au_wkq_wait(au_call_vfsub_rmdir, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct notify_change_args {
++	int *errp;
++	struct path *path;
++	struct iattr *ia;
++};
++
++static void call_notify_change(void *args)
++{
++	struct notify_change_args *a = args;
++	struct inode *h_inode;
++
++	h_inode = a->path->dentry->d_inode;
++	IMustLock(h_inode);
++
++	*a->errp = -EPERM;
++	if (!IS_IMMUTABLE(h_inode) && !IS_APPEND(h_inode)) {
++		*a->errp = notify_change(a->path->dentry, a->ia);
++		if (!*a->errp)
++			vfsub_update_h_iattr(a->path, /*did*/NULL); /*ignore*/
++	}
++	AuTraceErr(*a->errp);
++}
++
++int vfsub_notify_change(struct path *path, struct iattr *ia)
++{
++	int err;
++	struct notify_change_args args = {
++		.errp	= &err,
++		.path	= path,
++		.ia	= ia
++	};
++
++	call_notify_change(&args);
++
++	return err;
++}
++
++int vfsub_sio_notify_change(struct path *path, struct iattr *ia)
++{
++	int err, wkq_err;
++	struct notify_change_args args = {
++		.errp	= &err,
++		.path	= path,
++		.ia	= ia
++	};
++
++	wkq_err = au_wkq_wait(call_notify_change, &args);
++	if (unlikely(wkq_err))
++		err = wkq_err;
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct unlink_args {
++	int *errp;
++	struct inode *dir;
++	struct path *path;
++};
++
++static void call_unlink(void *args)
++{
++	struct unlink_args *a = args;
++	struct dentry *d = a->path->dentry;
++	struct inode *h_inode;
++	const int stop_sillyrename = (au_test_nfs(d->d_sb)
++				      && atomic_read(&d->d_count) == 1);
++
++	IMustLock(a->dir);
++
++	a->path->dentry = d->d_parent;
++	*a->errp = security_path_unlink(a->path, d);
++	a->path->dentry = d;
++	if (unlikely(*a->errp))
++		return;
++
++	if (!stop_sillyrename)
++		dget(d);
++	h_inode = d->d_inode;
++	if (h_inode)
++		atomic_inc(&h_inode->i_count);
++
++	*a->errp = vfs_unlink(a->dir, d);
++	if (!*a->errp) {
++		struct path tmp = {
++			.dentry = d->d_parent,
++			.mnt	= a->path->mnt
++		};
++		vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
++	}
++
++	if (!stop_sillyrename)
++		dput(d);
++	if (h_inode)
++		iput(h_inode);
++
++	AuTraceErr(*a->errp);
++}
++
++/*
++ * @dir: must be locked.
++ * @dentry: target dentry.
++ */
++int vfsub_unlink(struct inode *dir, struct path *path, int force)
++{
++	int err;
++	struct unlink_args args = {
++		.errp	= &err,
++		.dir	= dir,
++		.path	= path
++	};
++
++	if (!force)
++		call_unlink(&args);
++	else {
++		int wkq_err;
++
++		wkq_err = au_wkq_wait(call_unlink, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/vfsub.h linux-2.6.36/fs/aufs/vfsub.h
+--- linux-2.6.36.orig/fs/aufs/vfsub.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/vfsub.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,226 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * sub-routines for VFS
++ */
++
++#ifndef __AUFS_VFSUB_H__
++#define __AUFS_VFSUB_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/lglock.h>
++#include "debug.h"
++
++/* copied from linux/fs/internal.h */
++DECLARE_BRLOCK(vfsmount_lock);
++extern void file_sb_list_del(struct file *f);
++
++/* copied from linux/fs/file_table.c */
++DECLARE_LGLOCK(files_lglock);
++#ifdef CONFIG_SMP
++/*
++ * These macros iterate all files on all CPUs for a given superblock.
++ * files_lglock must be held globally.
++ */
++#define do_file_list_for_each_entry(__sb, __file)		\
++{								\
++	int i;							\
++	for_each_possible_cpu(i) {				\
++		struct list_head *list;				\
++		list = per_cpu_ptr((__sb)->s_files, i);		\
++		list_for_each_entry((__file), list, f_u.fu_list)
++
++#define while_file_list_for_each_entry				\
++	}							\
++}
++
++#else
++
++#define do_file_list_for_each_entry(__sb, __file)		\
++{								\
++	struct list_head *list;					\
++	list = &(sb)->s_files;					\
++	list_for_each_entry((__file), list, f_u.fu_list)
++
++#define while_file_list_for_each_entry				\
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for lower inode */
++/* default MAX_LOCKDEP_SUBCLASSES(8) is not enough */
++/* reduce? gave up. */
++enum {
++	AuLsc_I_Begin = I_MUTEX_QUOTA, /* 4 */
++	AuLsc_I_PARENT,		/* lower inode, parent first */
++	AuLsc_I_PARENT2,	/* copyup dirs */
++	AuLsc_I_PARENT3,	/* copyup wh */
++	AuLsc_I_CHILD,
++	AuLsc_I_CHILD2,
++	AuLsc_I_End
++};
++
++/* to debug easier, do not make them inlined functions */
++#define MtxMustLock(mtx)	AuDebugOn(!mutex_is_locked(mtx))
++#define IMustLock(i)		MtxMustLock(&(i)->i_mutex)
++
++/* ---------------------------------------------------------------------- */
++
++static inline void vfsub_drop_nlink(struct inode *inode)
++{
++	AuDebugOn(!inode->i_nlink);
++	drop_nlink(inode);
++}
++
++static inline void vfsub_dead_dir(struct inode *inode)
++{
++	AuDebugOn(!S_ISDIR(inode->i_mode));
++	inode->i_flags |= S_DEAD;
++	clear_nlink(inode);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int vfsub_update_h_iattr(struct path *h_path, int *did);
++struct file *vfsub_dentry_open(struct path *path, int flags);
++struct file *vfsub_filp_open(const char *path, int oflags, int mode);
++int vfsub_kern_path(const char *name, unsigned int flags, struct path *path);
++struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
++				    int len);
++struct dentry *vfsub_lookup_hash(struct nameidata *nd);
++
++/* ---------------------------------------------------------------------- */
++
++struct au_hinode;
++struct dentry *vfsub_lock_rename(struct dentry *d1, struct au_hinode *hdir1,
++				 struct dentry *d2, struct au_hinode *hdir2);
++void vfsub_unlock_rename(struct dentry *d1, struct au_hinode *hdir1,
++			 struct dentry *d2, struct au_hinode *hdir2);
++
++int vfsub_create(struct inode *dir, struct path *path, int mode);
++int vfsub_symlink(struct inode *dir, struct path *path,
++		  const char *symname);
++int vfsub_mknod(struct inode *dir, struct path *path, int mode, dev_t dev);
++int vfsub_link(struct dentry *src_dentry, struct inode *dir,
++	       struct path *path);
++int vfsub_rename(struct inode *src_hdir, struct dentry *src_dentry,
++		 struct inode *hdir, struct path *path);
++int vfsub_mkdir(struct inode *dir, struct path *path, int mode);
++int vfsub_rmdir(struct inode *dir, struct path *path);
++
++/* ---------------------------------------------------------------------- */
++
++ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
++		     loff_t *ppos);
++ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count,
++			loff_t *ppos);
++ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
++		      loff_t *ppos);
++ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count,
++		      loff_t *ppos);
++int vfsub_flush(struct file *file, fl_owner_t id);
++int vfsub_readdir(struct file *file, filldir_t filldir, void *arg);
++
++static inline unsigned int vfsub_file_flags(struct file *file)
++{
++	unsigned int flags;
++
++	spin_lock(&file->f_lock);
++	flags = file->f_flags;
++	spin_unlock(&file->f_lock);
++
++	return flags;
++}
++
++static inline void vfsub_file_accessed(struct file *h_file)
++{
++	file_accessed(h_file);
++	vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL); /*ignore*/
++}
++
++static inline void vfsub_touch_atime(struct vfsmount *h_mnt,
++				     struct dentry *h_dentry)
++{
++	struct path h_path = {
++		.dentry	= h_dentry,
++		.mnt	= h_mnt
++	};
++	touch_atime(h_mnt, h_dentry);
++	vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++}
++
++long vfsub_splice_to(struct file *in, loff_t *ppos,
++		     struct pipe_inode_info *pipe, size_t len,
++		     unsigned int flags);
++long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
++		       loff_t *ppos, size_t len, unsigned int flags);
++int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
++		struct file *h_file);
++
++/* ---------------------------------------------------------------------- */
++
++static inline loff_t vfsub_llseek(struct file *file, loff_t offset, int origin)
++{
++	loff_t err;
++
++	err = vfs_llseek(file, offset, origin);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* dirty workaround for strict type of fmode_t */
++union vfsub_fmu {
++	fmode_t fm;
++	unsigned int ui;
++};
++
++static inline unsigned int vfsub_fmode_to_uint(fmode_t fm)
++{
++	union vfsub_fmu u = {
++		.fm = fm
++	};
++
++	BUILD_BUG_ON(sizeof(u.fm) != sizeof(u.ui));
++
++	return u.ui;
++}
++
++static inline fmode_t vfsub_uint_to_fmode(unsigned int ui)
++{
++	union vfsub_fmu u = {
++		.ui = ui
++	};
++
++	return u.fm;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int vfsub_sio_mkdir(struct inode *dir, struct path *path, int mode);
++int vfsub_sio_rmdir(struct inode *dir, struct path *path);
++int vfsub_sio_notify_change(struct path *path, struct iattr *ia);
++int vfsub_notify_change(struct path *path, struct iattr *ia);
++int vfsub_unlink(struct inode *dir, struct path *path, int force);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_VFSUB_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/wbr_policy.c linux-2.6.36/fs/aufs/wbr_policy.c
+--- linux-2.6.36.orig/fs/aufs/wbr_policy.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/wbr_policy.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,700 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * policies for selecting one among multiple writable branches
++ */
++
++#include <linux/statfs.h>
++#include "aufs.h"
++
++/* subset of cpup_attr() */
++static noinline_for_stack
++int au_cpdown_attr(struct path *h_path, struct dentry *h_src)
++{
++	int err, sbits;
++	struct iattr ia;
++	struct inode *h_isrc;
++
++	h_isrc = h_src->d_inode;
++	ia.ia_valid = ATTR_FORCE | ATTR_MODE | ATTR_UID | ATTR_GID;
++	ia.ia_mode = h_isrc->i_mode;
++	ia.ia_uid = h_isrc->i_uid;
++	ia.ia_gid = h_isrc->i_gid;
++	sbits = !!(ia.ia_mode & (S_ISUID | S_ISGID));
++	au_cpup_attr_flags(h_path->dentry->d_inode, h_isrc);
++	err = vfsub_sio_notify_change(h_path, &ia);
++
++	/* is this nfs only? */
++	if (!err && sbits && au_test_nfs(h_path->dentry->d_sb)) {
++		ia.ia_valid = ATTR_FORCE | ATTR_MODE;
++		ia.ia_mode = h_isrc->i_mode;
++		err = vfsub_sio_notify_change(h_path, &ia);
++	}
++
++	return err;
++}
++
++#define AuCpdown_PARENT_OPQ	1
++#define AuCpdown_WHED		(1 << 1)
++#define AuCpdown_MADE_DIR	(1 << 2)
++#define AuCpdown_DIROPQ		(1 << 3)
++#define au_ftest_cpdown(flags, name)	((flags) & AuCpdown_##name)
++#define au_fset_cpdown(flags, name) \
++	do { (flags) |= AuCpdown_##name; } while (0)
++#define au_fclr_cpdown(flags, name) \
++	do { (flags) &= ~AuCpdown_##name; } while (0)
++
++struct au_cpdown_dir_args {
++	struct dentry *parent;
++	unsigned int flags;
++};
++
++static int au_cpdown_dir_opq(struct dentry *dentry, aufs_bindex_t bdst,
++			     struct au_cpdown_dir_args *a)
++{
++	int err;
++	struct dentry *opq_dentry;
++
++	opq_dentry = au_diropq_create(dentry, bdst);
++	err = PTR_ERR(opq_dentry);
++	if (IS_ERR(opq_dentry))
++		goto out;
++	dput(opq_dentry);
++	au_fset_cpdown(a->flags, DIROPQ);
++
++out:
++	return err;
++}
++
++static int au_cpdown_dir_wh(struct dentry *dentry, struct dentry *h_parent,
++			    struct inode *dir, aufs_bindex_t bdst)
++{
++	int err;
++	struct path h_path;
++	struct au_branch *br;
++
++	br = au_sbr(dentry->d_sb, bdst);
++	h_path.dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
++	err = PTR_ERR(h_path.dentry);
++	if (IS_ERR(h_path.dentry))
++		goto out;
++
++	err = 0;
++	if (h_path.dentry->d_inode) {
++		h_path.mnt = br->br_mnt;
++		err = au_wh_unlink_dentry(au_h_iptr(dir, bdst), &h_path,
++					  dentry);
++	}
++	dput(h_path.dentry);
++
++out:
++	return err;
++}
++
++static int au_cpdown_dir(struct dentry *dentry, aufs_bindex_t bdst,
++			 struct dentry *h_parent, void *arg)
++{
++	int err, rerr;
++	aufs_bindex_t bopq, bstart;
++	struct path h_path;
++	struct dentry *parent;
++	struct inode *h_dir, *h_inode, *inode, *dir;
++	struct au_cpdown_dir_args *args = arg;
++
++	bstart = au_dbstart(dentry);
++	/* dentry is di-locked */
++	parent = dget_parent(dentry);
++	dir = parent->d_inode;
++	h_dir = h_parent->d_inode;
++	AuDebugOn(h_dir != au_h_iptr(dir, bdst));
++	IMustLock(h_dir);
++
++	err = au_lkup_neg(dentry, bdst);
++	if (unlikely(err < 0))
++		goto out;
++	h_path.dentry = au_h_dptr(dentry, bdst);
++	h_path.mnt = au_sbr_mnt(dentry->d_sb, bdst);
++	err = vfsub_sio_mkdir(au_h_iptr(dir, bdst), &h_path,
++			      S_IRWXU | S_IRUGO | S_IXUGO);
++	if (unlikely(err))
++		goto out_put;
++	au_fset_cpdown(args->flags, MADE_DIR);
++
++	bopq = au_dbdiropq(dentry);
++	au_fclr_cpdown(args->flags, WHED);
++	au_fclr_cpdown(args->flags, DIROPQ);
++	if (au_dbwh(dentry) == bdst)
++		au_fset_cpdown(args->flags, WHED);
++	if (!au_ftest_cpdown(args->flags, PARENT_OPQ) && bopq <= bdst)
++		au_fset_cpdown(args->flags, PARENT_OPQ);
++	h_inode = h_path.dentry->d_inode;
++	mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++	if (au_ftest_cpdown(args->flags, WHED)) {
++		err = au_cpdown_dir_opq(dentry, bdst, args);
++		if (unlikely(err)) {
++			mutex_unlock(&h_inode->i_mutex);
++			goto out_dir;
++		}
++	}
++
++	err = au_cpdown_attr(&h_path, au_h_dptr(dentry, bstart));
++	mutex_unlock(&h_inode->i_mutex);
++	if (unlikely(err))
++		goto out_opq;
++
++	if (au_ftest_cpdown(args->flags, WHED)) {
++		err = au_cpdown_dir_wh(dentry, h_parent, dir, bdst);
++		if (unlikely(err))
++			goto out_opq;
++	}
++
++	inode = dentry->d_inode;
++	if (au_ibend(inode) < bdst)
++		au_set_ibend(inode, bdst);
++	au_set_h_iptr(inode, bdst, au_igrab(h_inode),
++		      au_hi_flags(inode, /*isdir*/1));
++	goto out; /* success */
++
++	/* revert */
++out_opq:
++	if (au_ftest_cpdown(args->flags, DIROPQ)) {
++		mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++		rerr = au_diropq_remove(dentry, bdst);
++		mutex_unlock(&h_inode->i_mutex);
++		if (unlikely(rerr)) {
++			AuIOErr("failed removing diropq for %.*s b%d (%d)\n",
++				AuDLNPair(dentry), bdst, rerr);
++			err = -EIO;
++			goto out;
++		}
++	}
++out_dir:
++	if (au_ftest_cpdown(args->flags, MADE_DIR)) {
++		rerr = vfsub_sio_rmdir(au_h_iptr(dir, bdst), &h_path);
++		if (unlikely(rerr)) {
++			AuIOErr("failed removing %.*s b%d (%d)\n",
++				AuDLNPair(dentry), bdst, rerr);
++			err = -EIO;
++		}
++	}
++out_put:
++	au_set_h_dptr(dentry, bdst, NULL);
++	if (au_dbend(dentry) == bdst)
++		au_update_dbend(dentry);
++out:
++	dput(parent);
++	return err;
++}
++
++int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++	int err;
++	struct au_cpdown_dir_args args = {
++		.parent	= dget_parent(dentry),
++		.flags	= 0
++	};
++
++	err = au_cp_dirs(dentry, bdst, au_cpdown_dir, &args);
++	dput(args.parent);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* policies for create */
++
++static int au_wbr_nonopq(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	int err, i, j, ndentry;
++	aufs_bindex_t bopq;
++	struct au_dcsub_pages dpages;
++	struct au_dpage *dpage;
++	struct dentry **dentries, *parent, *d;
++
++	err = au_dpages_init(&dpages, GFP_NOFS);
++	if (unlikely(err))
++		goto out;
++	parent = dget_parent(dentry);
++	err = au_dcsub_pages_rev_aufs(&dpages, parent, /*do_include*/0);
++	if (unlikely(err))
++		goto out_free;
++
++	err = bindex;
++	for (i = 0; i < dpages.ndpage; i++) {
++		dpage = dpages.dpages + i;
++		dentries = dpage->dentries;
++		ndentry = dpage->ndentry;
++		for (j = 0; j < ndentry; j++) {
++			d = dentries[j];
++			di_read_lock_parent2(d, !AuLock_IR);
++			bopq = au_dbdiropq(d);
++			di_read_unlock(d, !AuLock_IR);
++			if (bopq >= 0 && bopq < err)
++				err = bopq;
++		}
++	}
++
++out_free:
++	dput(parent);
++	au_dpages_free(&dpages);
++out:
++	return err;
++}
++
++static int au_wbr_bu(struct super_block *sb, aufs_bindex_t bindex)
++{
++	for (; bindex >= 0; bindex--)
++		if (!au_br_rdonly(au_sbr(sb, bindex)))
++			return bindex;
++	return -EROFS;
++}
++
++/* top down parent */
++static int au_wbr_create_tdp(struct dentry *dentry, int isdir __maybe_unused)
++{
++	int err;
++	aufs_bindex_t bstart, bindex;
++	struct super_block *sb;
++	struct dentry *parent, *h_parent;
++
++	sb = dentry->d_sb;
++	bstart = au_dbstart(dentry);
++	err = bstart;
++	if (!au_br_rdonly(au_sbr(sb, bstart)))
++		goto out;
++
++	err = -EROFS;
++	parent = dget_parent(dentry);
++	for (bindex = au_dbstart(parent); bindex < bstart; bindex++) {
++		h_parent = au_h_dptr(parent, bindex);
++		if (!h_parent || !h_parent->d_inode)
++			continue;
++
++		if (!au_br_rdonly(au_sbr(sb, bindex))) {
++			err = bindex;
++			break;
++		}
++	}
++	dput(parent);
++
++	/* bottom up here */
++	if (unlikely(err < 0)) {
++		err = au_wbr_bu(sb, bstart - 1);
++		if (err >= 0)
++			err = au_wbr_nonopq(dentry, err);
++	}
++
++out:
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* an exception for the policy other than tdp */
++static int au_wbr_create_exp(struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bwh, bdiropq;
++	struct dentry *parent;
++
++	err = -1;
++	bwh = au_dbwh(dentry);
++	parent = dget_parent(dentry);
++	bdiropq = au_dbdiropq(parent);
++	if (bwh >= 0) {
++		if (bdiropq >= 0)
++			err = min(bdiropq, bwh);
++		else
++			err = bwh;
++		AuDbg("%d\n", err);
++	} else if (bdiropq >= 0) {
++		err = bdiropq;
++		AuDbg("%d\n", err);
++	}
++	dput(parent);
++
++	if (err >= 0)
++		err = au_wbr_nonopq(dentry, err);
++
++	if (err >= 0 && au_br_rdonly(au_sbr(dentry->d_sb, err)))
++		err = -1;
++
++	AuDbg("%d\n", err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* round robin */
++static int au_wbr_create_init_rr(struct super_block *sb)
++{
++	int err;
++
++	err = au_wbr_bu(sb, au_sbend(sb));
++	atomic_set(&au_sbi(sb)->si_wbr_rr_next, -err); /* less important */
++	/* smp_mb(); */
++
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++static int au_wbr_create_rr(struct dentry *dentry, int isdir)
++{
++	int err, nbr;
++	unsigned int u;
++	aufs_bindex_t bindex, bend;
++	struct super_block *sb;
++	atomic_t *next;
++
++	err = au_wbr_create_exp(dentry);
++	if (err >= 0)
++		goto out;
++
++	sb = dentry->d_sb;
++	next = &au_sbi(sb)->si_wbr_rr_next;
++	bend = au_sbend(sb);
++	nbr = bend + 1;
++	for (bindex = 0; bindex <= bend; bindex++) {
++		if (!isdir) {
++			err = atomic_dec_return(next) + 1;
++			/* modulo for 0 is meaningless */
++			if (unlikely(!err))
++				err = atomic_dec_return(next) + 1;
++		} else
++			err = atomic_read(next);
++		AuDbg("%d\n", err);
++		u = err;
++		err = u % nbr;
++		AuDbg("%d\n", err);
++		if (!au_br_rdonly(au_sbr(sb, err)))
++			break;
++		err = -EROFS;
++	}
++
++	if (err >= 0)
++		err = au_wbr_nonopq(dentry, err);
++
++out:
++	AuDbg("%d\n", err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* most free space */
++static void au_mfs(struct dentry *dentry)
++{
++	struct super_block *sb;
++	struct au_branch *br;
++	struct au_wbr_mfs *mfs;
++	aufs_bindex_t bindex, bend;
++	int err;
++	unsigned long long b, bavail;
++	struct path h_path;
++	/* reduce the stack usage */
++	struct kstatfs *st;
++
++	st = kmalloc(sizeof(*st), GFP_NOFS);
++	if (unlikely(!st)) {
++		AuWarn1("failed updating mfs(%d), ignored\n", -ENOMEM);
++		return;
++	}
++
++	bavail = 0;
++	sb = dentry->d_sb;
++	mfs = &au_sbi(sb)->si_wbr_mfs;
++	MtxMustLock(&mfs->mfs_lock);
++	mfs->mfs_bindex = -EROFS;
++	mfs->mfsrr_bytes = 0;
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		if (au_br_rdonly(br))
++			continue;
++
++		/* sb->s_root for NFS is unreliable */
++		h_path.mnt = br->br_mnt;
++		h_path.dentry = h_path.mnt->mnt_root;
++		err = vfs_statfs(&h_path, st);
++		if (unlikely(err)) {
++			AuWarn1("failed statfs, b%d, %d\n", bindex, err);
++			continue;
++		}
++
++		/* when the available size is equal, select the lower one */
++		BUILD_BUG_ON(sizeof(b) < sizeof(st->f_bavail)
++			     || sizeof(b) < sizeof(st->f_bsize));
++		b = st->f_bavail * st->f_bsize;
++		br->br_wbr->wbr_bytes = b;
++		if (b >= bavail) {
++			bavail = b;
++			mfs->mfs_bindex = bindex;
++			mfs->mfs_jiffy = jiffies;
++		}
++	}
++
++	mfs->mfsrr_bytes = bavail;
++	AuDbg("b%d\n", mfs->mfs_bindex);
++	kfree(st);
++}
++
++static int au_wbr_create_mfs(struct dentry *dentry, int isdir __maybe_unused)
++{
++	int err;
++	struct super_block *sb;
++	struct au_wbr_mfs *mfs;
++
++	err = au_wbr_create_exp(dentry);
++	if (err >= 0)
++		goto out;
++
++	sb = dentry->d_sb;
++	mfs = &au_sbi(sb)->si_wbr_mfs;
++	mutex_lock(&mfs->mfs_lock);
++	if (time_after(jiffies, mfs->mfs_jiffy + mfs->mfs_expire)
++	    || mfs->mfs_bindex < 0
++	    || au_br_rdonly(au_sbr(sb, mfs->mfs_bindex)))
++		au_mfs(dentry);
++	mutex_unlock(&mfs->mfs_lock);
++	err = mfs->mfs_bindex;
++
++	if (err >= 0)
++		err = au_wbr_nonopq(dentry, err);
++
++out:
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++static int au_wbr_create_init_mfs(struct super_block *sb)
++{
++	struct au_wbr_mfs *mfs;
++
++	mfs = &au_sbi(sb)->si_wbr_mfs;
++	mutex_init(&mfs->mfs_lock);
++	mfs->mfs_jiffy = 0;
++	mfs->mfs_bindex = -EROFS;
++
++	return 0;
++}
++
++static int au_wbr_create_fin_mfs(struct super_block *sb __maybe_unused)
++{
++	mutex_destroy(&au_sbi(sb)->si_wbr_mfs.mfs_lock);
++	return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* most free space and then round robin */
++static int au_wbr_create_mfsrr(struct dentry *dentry, int isdir)
++{
++	int err;
++	struct au_wbr_mfs *mfs;
++
++	err = au_wbr_create_mfs(dentry, isdir);
++	if (err >= 0) {
++		mfs = &au_sbi(dentry->d_sb)->si_wbr_mfs;
++		mutex_lock(&mfs->mfs_lock);
++		if (mfs->mfsrr_bytes < mfs->mfsrr_watermark)
++			err = au_wbr_create_rr(dentry, isdir);
++		mutex_unlock(&mfs->mfs_lock);
++	}
++
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++static int au_wbr_create_init_mfsrr(struct super_block *sb)
++{
++	int err;
++
++	au_wbr_create_init_mfs(sb); /* ignore */
++	err = au_wbr_create_init_rr(sb);
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* top down parent and most free space */
++static int au_wbr_create_pmfs(struct dentry *dentry, int isdir)
++{
++	int err, e2;
++	unsigned long long b;
++	aufs_bindex_t bindex, bstart, bend;
++	struct super_block *sb;
++	struct dentry *parent, *h_parent;
++	struct au_branch *br;
++
++	err = au_wbr_create_tdp(dentry, isdir);
++	if (unlikely(err < 0))
++		goto out;
++	parent = dget_parent(dentry);
++	bstart = au_dbstart(parent);
++	bend = au_dbtaildir(parent);
++	if (bstart == bend)
++		goto out_parent; /* success */
++
++	e2 = au_wbr_create_mfs(dentry, isdir);
++	if (e2 < 0)
++		goto out_parent; /* success */
++
++	/* when the available size is equal, select upper one */
++	sb = dentry->d_sb;
++	br = au_sbr(sb, err);
++	b = br->br_wbr->wbr_bytes;
++	AuDbg("b%d, %llu\n", err, b);
++
++	for (bindex = bstart; bindex <= bend; bindex++) {
++		h_parent = au_h_dptr(parent, bindex);
++		if (!h_parent || !h_parent->d_inode)
++			continue;
++
++		br = au_sbr(sb, bindex);
++		if (!au_br_rdonly(br) && br->br_wbr->wbr_bytes > b) {
++			b = br->br_wbr->wbr_bytes;
++			err = bindex;
++			AuDbg("b%d, %llu\n", err, b);
++		}
++	}
++
++	if (err >= 0)
++		err = au_wbr_nonopq(dentry, err);
++
++out_parent:
++	dput(parent);
++out:
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* policies for copyup */
++
++/* top down parent */
++static int au_wbr_copyup_tdp(struct dentry *dentry)
++{
++	return au_wbr_create_tdp(dentry, /*isdir, anything is ok*/0);
++}
++
++/* bottom up parent */
++static int au_wbr_copyup_bup(struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bindex, bstart;
++	struct dentry *parent, *h_parent;
++	struct super_block *sb;
++
++	err = -EROFS;
++	sb = dentry->d_sb;
++	parent = dget_parent(dentry);
++	bstart = au_dbstart(parent);
++	for (bindex = au_dbstart(dentry); bindex >= bstart; bindex--) {
++		h_parent = au_h_dptr(parent, bindex);
++		if (!h_parent || !h_parent->d_inode)
++			continue;
++
++		if (!au_br_rdonly(au_sbr(sb, bindex))) {
++			err = bindex;
++			break;
++		}
++	}
++	dput(parent);
++
++	/* bottom up here */
++	if (unlikely(err < 0))
++		err = au_wbr_bu(sb, bstart - 1);
++
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++/* bottom up */
++static int au_wbr_copyup_bu(struct dentry *dentry)
++{
++	int err;
++	aufs_bindex_t bstart;
++
++	bstart = au_dbstart(dentry);
++	err = au_wbr_bu(dentry->d_sb, bstart);
++	AuDbg("b%d\n", err);
++	if (err > bstart)
++		err = au_wbr_nonopq(dentry, err);
++
++	AuDbg("b%d\n", err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_wbr_copyup_operations au_wbr_copyup_ops[] = {
++	[AuWbrCopyup_TDP] = {
++		.copyup	= au_wbr_copyup_tdp
++	},
++	[AuWbrCopyup_BUP] = {
++		.copyup	= au_wbr_copyup_bup
++	},
++	[AuWbrCopyup_BU] = {
++		.copyup	= au_wbr_copyup_bu
++	}
++};
++
++struct au_wbr_create_operations au_wbr_create_ops[] = {
++	[AuWbrCreate_TDP] = {
++		.create	= au_wbr_create_tdp
++	},
++	[AuWbrCreate_RR] = {
++		.create	= au_wbr_create_rr,
++		.init	= au_wbr_create_init_rr
++	},
++	[AuWbrCreate_MFS] = {
++		.create	= au_wbr_create_mfs,
++		.init	= au_wbr_create_init_mfs,
++		.fin	= au_wbr_create_fin_mfs
++	},
++	[AuWbrCreate_MFSV] = {
++		.create	= au_wbr_create_mfs,
++		.init	= au_wbr_create_init_mfs,
++		.fin	= au_wbr_create_fin_mfs
++	},
++	[AuWbrCreate_MFSRR] = {
++		.create	= au_wbr_create_mfsrr,
++		.init	= au_wbr_create_init_mfsrr,
++		.fin	= au_wbr_create_fin_mfs
++	},
++	[AuWbrCreate_MFSRRV] = {
++		.create	= au_wbr_create_mfsrr,
++		.init	= au_wbr_create_init_mfsrr,
++		.fin	= au_wbr_create_fin_mfs
++	},
++	[AuWbrCreate_PMFS] = {
++		.create	= au_wbr_create_pmfs,
++		.init	= au_wbr_create_init_mfs,
++		.fin	= au_wbr_create_fin_mfs
++	},
++	[AuWbrCreate_PMFSV] = {
++		.create	= au_wbr_create_pmfs,
++		.init	= au_wbr_create_init_mfs,
++		.fin	= au_wbr_create_fin_mfs
++	}
++};
+diff -Nur linux-2.6.36.orig/fs/aufs/whout.c linux-2.6.36/fs/aufs/whout.c
+--- linux-2.6.36.orig/fs/aufs/whout.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/whout.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1062 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * whiteout for logical deletion and opaque directory
++ */
++
++#include <linux/fs.h>
++#include "aufs.h"
++
++#define WH_MASK			S_IRUGO
++
++/*
++ * If a directory contains this file, then it is opaque.  We start with the
++ * .wh. flag so that it is blocked by lookup.
++ */
++static struct qstr diropq_name = {
++	.name = AUFS_WH_DIROPQ,
++	.len = sizeof(AUFS_WH_DIROPQ) - 1
++};
++
++/*
++ * generate whiteout name, which is NOT terminated by NULL.
++ * @name: original d_name.name
++ * @len: original d_name.len
++ * @wh: whiteout qstr
++ * returns zero when succeeds, otherwise error.
++ * succeeded value as wh->name should be freed by kfree().
++ */
++int au_wh_name_alloc(struct qstr *wh, const struct qstr *name)
++{
++	char *p;
++
++	if (unlikely(name->len > PATH_MAX - AUFS_WH_PFX_LEN))
++		return -ENAMETOOLONG;
++
++	wh->len = name->len + AUFS_WH_PFX_LEN;
++	p = kmalloc(wh->len, GFP_NOFS);
++	wh->name = p;
++	if (p) {
++		memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
++		memcpy(p + AUFS_WH_PFX_LEN, name->name, name->len);
++		/* smp_mb(); */
++		return 0;
++	}
++	return -ENOMEM;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * test if the @wh_name exists under @h_parent.
++ * @try_sio specifies the necessary of super-io.
++ */
++int au_wh_test(struct dentry *h_parent, struct qstr *wh_name,
++	       struct au_branch *br, int try_sio)
++{
++	int err;
++	struct dentry *wh_dentry;
++
++	if (!try_sio)
++		wh_dentry = au_lkup_one(wh_name, h_parent, br, /*nd*/NULL);
++	else
++		wh_dentry = au_sio_lkup_one(wh_name, h_parent, br);
++	err = PTR_ERR(wh_dentry);
++	if (IS_ERR(wh_dentry))
++		goto out;
++
++	err = 0;
++	if (!wh_dentry->d_inode)
++		goto out_wh; /* success */
++
++	err = 1;
++	if (S_ISREG(wh_dentry->d_inode->i_mode))
++		goto out_wh; /* success */
++
++	err = -EIO;
++	AuIOErr("%.*s Invalid whiteout entry type 0%o.\n",
++		AuDLNPair(wh_dentry), wh_dentry->d_inode->i_mode);
++
++out_wh:
++	dput(wh_dentry);
++out:
++	return err;
++}
++
++/*
++ * test if the @h_dentry sets opaque or not.
++ */
++int au_diropq_test(struct dentry *h_dentry, struct au_branch *br)
++{
++	int err;
++	struct inode *h_dir;
++
++	h_dir = h_dentry->d_inode;
++	err = au_wh_test(h_dentry, &diropq_name, br,
++			 au_test_h_perm_sio(h_dir, MAY_EXEC));
++	return err;
++}
++
++/*
++ * returns a negative dentry whose name is unique and temporary.
++ */
++struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct au_branch *br,
++			     struct qstr *prefix)
++{
++	struct dentry *dentry;
++	int i;
++	char defname[NAME_MAX - AUFS_MAX_NAMELEN + DNAME_INLINE_LEN_MIN + 1],
++		*name, *p;
++	/* strict atomic_t is unnecessary here */
++	static unsigned short cnt;
++	struct qstr qs;
++
++	BUILD_BUG_ON(sizeof(cnt) * 2 > AUFS_WH_TMP_LEN);
++
++	name = defname;
++	qs.len = sizeof(defname) - DNAME_INLINE_LEN_MIN + prefix->len - 1;
++	if (unlikely(prefix->len > DNAME_INLINE_LEN_MIN)) {
++		dentry = ERR_PTR(-ENAMETOOLONG);
++		if (unlikely(qs.len > NAME_MAX))
++			goto out;
++		dentry = ERR_PTR(-ENOMEM);
++		name = kmalloc(qs.len + 1, GFP_NOFS);
++		if (unlikely(!name))
++			goto out;
++	}
++
++	/* doubly whiteout-ed */
++	memcpy(name, AUFS_WH_PFX AUFS_WH_PFX, AUFS_WH_PFX_LEN * 2);
++	p = name + AUFS_WH_PFX_LEN * 2;
++	memcpy(p, prefix->name, prefix->len);
++	p += prefix->len;
++	*p++ = '.';
++	AuDebugOn(name + qs.len + 1 - p <= AUFS_WH_TMP_LEN);
++
++	qs.name = name;
++	for (i = 0; i < 3; i++) {
++		sprintf(p, "%.*x", AUFS_WH_TMP_LEN, cnt++);
++		dentry = au_sio_lkup_one(&qs, h_parent, br);
++		if (IS_ERR(dentry) || !dentry->d_inode)
++			goto out_name;
++		dput(dentry);
++	}
++	/* pr_warning("could not get random name\n"); */
++	dentry = ERR_PTR(-EEXIST);
++	AuDbg("%.*s\n", AuLNPair(&qs));
++	BUG();
++
++out_name:
++	if (name != defname)
++		kfree(name);
++out:
++	AuTraceErrPtr(dentry);
++	return dentry;
++}
++
++/*
++ * rename the @h_dentry on @br to the whiteouted temporary name.
++ */
++int au_whtmp_ren(struct dentry *h_dentry, struct au_branch *br)
++{
++	int err;
++	struct path h_path = {
++		.mnt = br->br_mnt
++	};
++	struct inode *h_dir;
++	struct dentry *h_parent;
++
++	h_parent = h_dentry->d_parent; /* dir inode is locked */
++	h_dir = h_parent->d_inode;
++	IMustLock(h_dir);
++
++	h_path.dentry = au_whtmp_lkup(h_parent, br, &h_dentry->d_name);
++	err = PTR_ERR(h_path.dentry);
++	if (IS_ERR(h_path.dentry))
++		goto out;
++
++	/* under the same dir, no need to lock_rename() */
++	err = vfsub_rename(h_dir, h_dentry, h_dir, &h_path);
++	AuTraceErr(err);
++	dput(h_path.dentry);
++
++out:
++	AuTraceErr(err);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * functions for removing a whiteout
++ */
++
++static int do_unlink_wh(struct inode *h_dir, struct path *h_path)
++{
++	int force;
++
++	/*
++	 * forces superio when the dir has a sticky bit.
++	 * this may be a violation of unix fs semantics.
++	 */
++	force = (h_dir->i_mode & S_ISVTX)
++		&& h_path->dentry->d_inode->i_uid != current_fsuid();
++	return vfsub_unlink(h_dir, h_path, force);
++}
++
++int au_wh_unlink_dentry(struct inode *h_dir, struct path *h_path,
++			struct dentry *dentry)
++{
++	int err;
++
++	err = do_unlink_wh(h_dir, h_path);
++	if (!err && dentry)
++		au_set_dbwh(dentry, -1);
++
++	return err;
++}
++
++static int unlink_wh_name(struct dentry *h_parent, struct qstr *wh,
++			  struct au_branch *br)
++{
++	int err;
++	struct path h_path = {
++		.mnt = br->br_mnt
++	};
++
++	err = 0;
++	h_path.dentry = au_lkup_one(wh, h_parent, br, /*nd*/NULL);
++	if (IS_ERR(h_path.dentry))
++		err = PTR_ERR(h_path.dentry);
++	else {
++		if (h_path.dentry->d_inode
++		    && S_ISREG(h_path.dentry->d_inode->i_mode))
++			err = do_unlink_wh(h_parent->d_inode, &h_path);
++		dput(h_path.dentry);
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * initialize/clean whiteout for a branch
++ */
++
++static void au_wh_clean(struct inode *h_dir, struct path *whpath,
++			const int isdir)
++{
++	int err;
++
++	if (!whpath->dentry->d_inode)
++		return;
++
++	err = mnt_want_write(whpath->mnt);
++	if (!err) {
++		if (isdir)
++			err = vfsub_rmdir(h_dir, whpath);
++		else
++			err = vfsub_unlink(h_dir, whpath, /*force*/0);
++		mnt_drop_write(whpath->mnt);
++	}
++	if (unlikely(err))
++		pr_warning("failed removing %.*s (%d), ignored.\n",
++			   AuDLNPair(whpath->dentry), err);
++}
++
++static int test_linkable(struct dentry *h_root)
++{
++	struct inode *h_dir = h_root->d_inode;
++
++	if (h_dir->i_op->link)
++		return 0;
++
++	pr_err("%.*s (%s) doesn't support link(2), use noplink and rw+nolwh\n",
++	       AuDLNPair(h_root), au_sbtype(h_root->d_sb));
++	return -ENOSYS;
++}
++
++/* todo: should this mkdir be done in /sbin/mount.aufs helper? */
++static int au_whdir(struct inode *h_dir, struct path *path)
++{
++	int err;
++
++	err = -EEXIST;
++	if (!path->dentry->d_inode) {
++		int mode = S_IRWXU;
++
++		if (au_test_nfs(path->dentry->d_sb))
++			mode |= S_IXUGO;
++		err = mnt_want_write(path->mnt);
++		if (!err) {
++			err = vfsub_mkdir(h_dir, path, mode);
++			mnt_drop_write(path->mnt);
++		}
++	} else if (S_ISDIR(path->dentry->d_inode->i_mode))
++		err = 0;
++	else
++		pr_err("unknown %.*s exists\n", AuDLNPair(path->dentry));
++
++	return err;
++}
++
++struct au_wh_base {
++	const struct qstr *name;
++	struct dentry *dentry;
++};
++
++static void au_wh_init_ro(struct inode *h_dir, struct au_wh_base base[],
++			  struct path *h_path)
++{
++	h_path->dentry = base[AuBrWh_BASE].dentry;
++	au_wh_clean(h_dir, h_path, /*isdir*/0);
++	h_path->dentry = base[AuBrWh_PLINK].dentry;
++	au_wh_clean(h_dir, h_path, /*isdir*/1);
++	h_path->dentry = base[AuBrWh_ORPH].dentry;
++	au_wh_clean(h_dir, h_path, /*isdir*/1);
++}
++
++/*
++ * returns tri-state,
++ * minus: error, caller should print the mesage
++ * zero: succuess
++ * plus: error, caller should NOT print the mesage
++ */
++static int au_wh_init_rw_nolink(struct dentry *h_root, struct au_wbr *wbr,
++				int do_plink, struct au_wh_base base[],
++				struct path *h_path)
++{
++	int err;
++	struct inode *h_dir;
++
++	h_dir = h_root->d_inode;
++	h_path->dentry = base[AuBrWh_BASE].dentry;
++	au_wh_clean(h_dir, h_path, /*isdir*/0);
++	h_path->dentry = base[AuBrWh_PLINK].dentry;
++	if (do_plink) {
++		err = test_linkable(h_root);
++		if (unlikely(err)) {
++			err = 1;
++			goto out;
++		}
++
++		err = au_whdir(h_dir, h_path);
++		if (unlikely(err))
++			goto out;
++		wbr->wbr_plink = dget(base[AuBrWh_PLINK].dentry);
++	} else
++		au_wh_clean(h_dir, h_path, /*isdir*/1);
++	h_path->dentry = base[AuBrWh_ORPH].dentry;
++	err = au_whdir(h_dir, h_path);
++	if (unlikely(err))
++		goto out;
++	wbr->wbr_orph = dget(base[AuBrWh_ORPH].dentry);
++
++out:
++	return err;
++}
++
++/*
++ * for the moment, aufs supports the branch filesystem which does not support
++ * link(2). testing on FAT which does not support i_op->setattr() fully either,
++ * copyup failed. finally, such filesystem will not be used as the writable
++ * branch.
++ *
++ * returns tri-state, see above.
++ */
++static int au_wh_init_rw(struct dentry *h_root, struct au_wbr *wbr,
++			 int do_plink, struct au_wh_base base[],
++			 struct path *h_path)
++{
++	int err;
++	struct inode *h_dir;
++
++	WbrWhMustWriteLock(wbr);
++
++	err = test_linkable(h_root);
++	if (unlikely(err)) {
++		err = 1;
++		goto out;
++	}
++
++	/*
++	 * todo: should this create be done in /sbin/mount.aufs helper?
++	 */
++	err = -EEXIST;
++	h_dir = h_root->d_inode;
++	if (!base[AuBrWh_BASE].dentry->d_inode) {
++		err = mnt_want_write(h_path->mnt);
++		if (!err) {
++			h_path->dentry = base[AuBrWh_BASE].dentry;
++			err = vfsub_create(h_dir, h_path, WH_MASK);
++			mnt_drop_write(h_path->mnt);
++		}
++	} else if (S_ISREG(base[AuBrWh_BASE].dentry->d_inode->i_mode))
++		err = 0;
++	else
++		pr_err("unknown %.*s/%.*s exists\n",
++		       AuDLNPair(h_root), AuDLNPair(base[AuBrWh_BASE].dentry));
++	if (unlikely(err))
++		goto out;
++
++	h_path->dentry = base[AuBrWh_PLINK].dentry;
++	if (do_plink) {
++		err = au_whdir(h_dir, h_path);
++		if (unlikely(err))
++			goto out;
++		wbr->wbr_plink = dget(base[AuBrWh_PLINK].dentry);
++	} else
++		au_wh_clean(h_dir, h_path, /*isdir*/1);
++	wbr->wbr_whbase = dget(base[AuBrWh_BASE].dentry);
++
++	h_path->dentry = base[AuBrWh_ORPH].dentry;
++	err = au_whdir(h_dir, h_path);
++	if (unlikely(err))
++		goto out;
++	wbr->wbr_orph = dget(base[AuBrWh_ORPH].dentry);
++
++out:
++	return err;
++}
++
++/*
++ * initialize the whiteout base file/dir for @br.
++ */
++int au_wh_init(struct dentry *h_root, struct au_branch *br,
++	       struct super_block *sb)
++{
++	int err, i;
++	const unsigned char do_plink
++		= !!au_opt_test(au_mntflags(sb), PLINK);
++	struct path path = {
++		.mnt = br->br_mnt
++	};
++	struct inode *h_dir;
++	struct au_wbr *wbr = br->br_wbr;
++	static const struct qstr base_name[] = {
++		[AuBrWh_BASE] = {
++			.name	= AUFS_BASE_NAME,
++			.len	= sizeof(AUFS_BASE_NAME) - 1
++		},
++		[AuBrWh_PLINK] = {
++			.name	= AUFS_PLINKDIR_NAME,
++			.len	= sizeof(AUFS_PLINKDIR_NAME) - 1
++		},
++		[AuBrWh_ORPH] = {
++			.name	= AUFS_ORPHDIR_NAME,
++			.len	= sizeof(AUFS_ORPHDIR_NAME) - 1
++		}
++	};
++	struct au_wh_base base[] = {
++		[AuBrWh_BASE] = {
++			.name	= base_name + AuBrWh_BASE,
++			.dentry	= NULL
++		},
++		[AuBrWh_PLINK] = {
++			.name	= base_name + AuBrWh_PLINK,
++			.dentry	= NULL
++		},
++		[AuBrWh_ORPH] = {
++			.name	= base_name + AuBrWh_ORPH,
++			.dentry	= NULL
++		}
++	};
++
++	if (wbr)
++		WbrWhMustWriteLock(wbr);
++
++	for (i = 0; i < AuBrWh_Last; i++) {
++		/* doubly whiteouted */
++		struct dentry *d;
++
++		d = au_wh_lkup(h_root, (void *)base[i].name, br);
++		err = PTR_ERR(d);
++		if (IS_ERR(d))
++			goto out;
++
++		base[i].dentry = d;
++		AuDebugOn(wbr
++			  && wbr->wbr_wh[i]
++			  && wbr->wbr_wh[i] != base[i].dentry);
++	}
++
++	if (wbr)
++		for (i = 0; i < AuBrWh_Last; i++) {
++			dput(wbr->wbr_wh[i]);
++			wbr->wbr_wh[i] = NULL;
++		}
++
++	err = 0;
++	switch (br->br_perm) {
++	case AuBrPerm_RO:
++	case AuBrPerm_ROWH:
++	case AuBrPerm_RR:
++	case AuBrPerm_RRWH:
++		h_dir = h_root->d_inode;
++		au_wh_init_ro(h_dir, base, &path);
++		break;
++
++	case AuBrPerm_RWNoLinkWH:
++		err = au_wh_init_rw_nolink(h_root, wbr, do_plink, base, &path);
++		if (err > 0)
++			goto out;
++		else if (err)
++			goto out_err;
++		break;
++
++	case AuBrPerm_RW:
++		err = au_wh_init_rw(h_root, wbr, do_plink, base, &path);
++		if (err > 0)
++			goto out;
++		else if (err)
++			goto out_err;
++		break;
++
++	default:
++		BUG();
++	}
++	goto out; /* success */
++
++out_err:
++	pr_err("an error(%d) on the writable branch %.*s(%s)\n",
++	       err, AuDLNPair(h_root), au_sbtype(h_root->d_sb));
++out:
++	for (i = 0; i < AuBrWh_Last; i++)
++		dput(base[i].dentry);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * whiteouts are all hard-linked usually.
++ * when its link count reaches a ceiling, we create a new whiteout base
++ * asynchronously.
++ */
++
++struct reinit_br_wh {
++	struct super_block *sb;
++	struct au_branch *br;
++};
++
++static void reinit_br_wh(void *arg)
++{
++	int err;
++	aufs_bindex_t bindex;
++	struct path h_path;
++	struct reinit_br_wh *a = arg;
++	struct au_wbr *wbr;
++	struct inode *dir;
++	struct dentry *h_root;
++	struct au_hinode *hdir;
++
++	err = 0;
++	wbr = a->br->br_wbr;
++	/* big aufs lock */
++	si_noflush_write_lock(a->sb);
++	if (!au_br_writable(a->br->br_perm))
++		goto out;
++	bindex = au_br_index(a->sb, a->br->br_id);
++	if (unlikely(bindex < 0))
++		goto out;
++
++	di_read_lock_parent(a->sb->s_root, AuLock_IR);
++	dir = a->sb->s_root->d_inode;
++	hdir = au_hi(dir, bindex);
++	h_root = au_h_dptr(a->sb->s_root, bindex);
++
++	au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++	wbr_wh_write_lock(wbr);
++	err = au_h_verify(wbr->wbr_whbase, au_opt_udba(a->sb), hdir->hi_inode,
++			  h_root, a->br);
++	if (!err) {
++		err = mnt_want_write(a->br->br_mnt);
++		if (!err) {
++			h_path.dentry = wbr->wbr_whbase;
++			h_path.mnt = a->br->br_mnt;
++			err = vfsub_unlink(hdir->hi_inode, &h_path, /*force*/0);
++			mnt_drop_write(a->br->br_mnt);
++		}
++	} else {
++		pr_warning("%.*s is moved, ignored\n",
++			   AuDLNPair(wbr->wbr_whbase));
++		err = 0;
++	}
++	dput(wbr->wbr_whbase);
++	wbr->wbr_whbase = NULL;
++	if (!err)
++		err = au_wh_init(h_root, a->br, a->sb);
++	wbr_wh_write_unlock(wbr);
++	au_hn_imtx_unlock(hdir);
++	di_read_unlock(a->sb->s_root, AuLock_IR);
++
++out:
++	if (wbr)
++		atomic_dec(&wbr->wbr_wh_running);
++	atomic_dec(&a->br->br_count);
++	si_write_unlock(a->sb);
++	au_nwt_done(&au_sbi(a->sb)->si_nowait);
++	kfree(arg);
++	if (unlikely(err))
++		AuIOErr("err %d\n", err);
++}
++
++static void kick_reinit_br_wh(struct super_block *sb, struct au_branch *br)
++{
++	int do_dec, wkq_err;
++	struct reinit_br_wh *arg;
++
++	do_dec = 1;
++	if (atomic_inc_return(&br->br_wbr->wbr_wh_running) != 1)
++		goto out;
++
++	/* ignore ENOMEM */
++	arg = kmalloc(sizeof(*arg), GFP_NOFS);
++	if (arg) {
++		/*
++		 * dec(wh_running), kfree(arg) and dec(br_count)
++		 * in reinit function
++		 */
++		arg->sb = sb;
++		arg->br = br;
++		atomic_inc(&br->br_count);
++		wkq_err = au_wkq_nowait(reinit_br_wh, arg, sb);
++		if (unlikely(wkq_err)) {
++			atomic_dec(&br->br_wbr->wbr_wh_running);
++			atomic_dec(&br->br_count);
++			kfree(arg);
++		}
++		do_dec = 0;
++	}
++
++out:
++	if (do_dec)
++		atomic_dec(&br->br_wbr->wbr_wh_running);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create the whiteout @wh.
++ */
++static int link_or_create_wh(struct super_block *sb, aufs_bindex_t bindex,
++			     struct dentry *wh)
++{
++	int err;
++	struct path h_path = {
++		.dentry = wh
++	};
++	struct au_branch *br;
++	struct au_wbr *wbr;
++	struct dentry *h_parent;
++	struct inode *h_dir;
++
++	h_parent = wh->d_parent; /* dir inode is locked */
++	h_dir = h_parent->d_inode;
++	IMustLock(h_dir);
++
++	br = au_sbr(sb, bindex);
++	h_path.mnt = br->br_mnt;
++	wbr = br->br_wbr;
++	wbr_wh_read_lock(wbr);
++	if (wbr->wbr_whbase) {
++		err = vfsub_link(wbr->wbr_whbase, h_dir, &h_path);
++		if (!err || err != -EMLINK)
++			goto out;
++
++		/* link count full. re-initialize br_whbase. */
++		kick_reinit_br_wh(sb, br);
++	}
++
++	/* return this error in this context */
++	err = vfsub_create(h_dir, &h_path, WH_MASK);
++
++out:
++	wbr_wh_read_unlock(wbr);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create or remove the diropq.
++ */
++static struct dentry *do_diropq(struct dentry *dentry, aufs_bindex_t bindex,
++				unsigned int flags)
++{
++	struct dentry *opq_dentry, *h_dentry;
++	struct super_block *sb;
++	struct au_branch *br;
++	int err;
++
++	sb = dentry->d_sb;
++	br = au_sbr(sb, bindex);
++	h_dentry = au_h_dptr(dentry, bindex);
++	opq_dentry = au_lkup_one(&diropq_name, h_dentry, br, /*nd*/NULL);
++	if (IS_ERR(opq_dentry))
++		goto out;
++
++	if (au_ftest_diropq(flags, CREATE)) {
++		err = link_or_create_wh(sb, bindex, opq_dentry);
++		if (!err) {
++			au_set_dbdiropq(dentry, bindex);
++			goto out; /* success */
++		}
++	} else {
++		struct path tmp = {
++			.dentry = opq_dentry,
++			.mnt	= br->br_mnt
++		};
++		err = do_unlink_wh(au_h_iptr(dentry->d_inode, bindex), &tmp);
++		if (!err)
++			au_set_dbdiropq(dentry, -1);
++	}
++	dput(opq_dentry);
++	opq_dentry = ERR_PTR(err);
++
++out:
++	return opq_dentry;
++}
++
++struct do_diropq_args {
++	struct dentry **errp;
++	struct dentry *dentry;
++	aufs_bindex_t bindex;
++	unsigned int flags;
++};
++
++static void call_do_diropq(void *args)
++{
++	struct do_diropq_args *a = args;
++	*a->errp = do_diropq(a->dentry, a->bindex, a->flags);
++}
++
++struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
++			     unsigned int flags)
++{
++	struct dentry *diropq, *h_dentry;
++
++	h_dentry = au_h_dptr(dentry, bindex);
++	if (!au_test_h_perm_sio(h_dentry->d_inode, MAY_EXEC | MAY_WRITE))
++		diropq = do_diropq(dentry, bindex, flags);
++	else {
++		int wkq_err;
++		struct do_diropq_args args = {
++			.errp		= &diropq,
++			.dentry		= dentry,
++			.bindex		= bindex,
++			.flags		= flags
++		};
++
++		wkq_err = au_wkq_wait(call_do_diropq, &args);
++		if (unlikely(wkq_err))
++			diropq = ERR_PTR(wkq_err);
++	}
++
++	return diropq;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * lookup whiteout dentry.
++ * @h_parent: lower parent dentry which must exist and be locked
++ * @base_name: name of dentry which will be whiteouted
++ * returns dentry for whiteout.
++ */
++struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
++			  struct au_branch *br)
++{
++	int err;
++	struct qstr wh_name;
++	struct dentry *wh_dentry;
++
++	err = au_wh_name_alloc(&wh_name, base_name);
++	wh_dentry = ERR_PTR(err);
++	if (!err) {
++		wh_dentry = au_lkup_one(&wh_name, h_parent, br, /*nd*/NULL);
++		kfree(wh_name.name);
++	}
++	return wh_dentry;
++}
++
++/*
++ * link/create a whiteout for @dentry on @bindex.
++ */
++struct dentry *au_wh_create(struct dentry *dentry, aufs_bindex_t bindex,
++			    struct dentry *h_parent)
++{
++	struct dentry *wh_dentry;
++	struct super_block *sb;
++	int err;
++
++	sb = dentry->d_sb;
++	wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, au_sbr(sb, bindex));
++	if (!IS_ERR(wh_dentry) && !wh_dentry->d_inode) {
++		err = link_or_create_wh(sb, bindex, wh_dentry);
++		if (!err)
++			au_set_dbwh(dentry, bindex);
++		else {
++			dput(wh_dentry);
++			wh_dentry = ERR_PTR(err);
++		}
++	}
++
++	return wh_dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* Delete all whiteouts in this directory on branch bindex. */
++static int del_wh_children(struct dentry *h_dentry, struct au_nhash *whlist,
++			   aufs_bindex_t bindex, struct au_branch *br)
++{
++	int err;
++	unsigned long ul, n;
++	struct qstr wh_name;
++	char *p;
++	struct hlist_head *head;
++	struct au_vdir_wh *tpos;
++	struct hlist_node *pos;
++	struct au_vdir_destr *str;
++
++	err = -ENOMEM;
++	p = __getname_gfp(GFP_NOFS);
++	wh_name.name = p;
++	if (unlikely(!wh_name.name))
++		goto out;
++
++	err = 0;
++	memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
++	p += AUFS_WH_PFX_LEN;
++	n = whlist->nh_num;
++	head = whlist->nh_head;
++	for (ul = 0; !err && ul < n; ul++, head++) {
++		hlist_for_each_entry(tpos, pos, head, wh_hash) {
++			if (tpos->wh_bindex != bindex)
++				continue;
++
++			str = &tpos->wh_str;
++			if (str->len + AUFS_WH_PFX_LEN <= PATH_MAX) {
++				memcpy(p, str->name, str->len);
++				wh_name.len = AUFS_WH_PFX_LEN + str->len;
++				err = unlink_wh_name(h_dentry, &wh_name, br);
++				if (!err)
++					continue;
++				break;
++			}
++			AuIOErr("whiteout name too long %.*s\n",
++				str->len, str->name);
++			err = -EIO;
++			break;
++		}
++	}
++	__putname(wh_name.name);
++
++out:
++	return err;
++}
++
++struct del_wh_children_args {
++	int *errp;
++	struct dentry *h_dentry;
++	struct au_nhash *whlist;
++	aufs_bindex_t bindex;
++	struct au_branch *br;
++};
++
++static void call_del_wh_children(void *args)
++{
++	struct del_wh_children_args *a = args;
++	*a->errp = del_wh_children(a->h_dentry, a->whlist, a->bindex, a->br);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_whtmp_rmdir *au_whtmp_rmdir_alloc(struct super_block *sb, gfp_t gfp)
++{
++	struct au_whtmp_rmdir *whtmp;
++	int err;
++	unsigned int rdhash;
++
++	SiMustAnyLock(sb);
++
++	whtmp = kmalloc(sizeof(*whtmp), gfp);
++	if (unlikely(!whtmp)) {
++		whtmp = ERR_PTR(-ENOMEM);
++		goto out;
++	}
++
++	whtmp->dir = NULL;
++	whtmp->br = NULL;
++	whtmp->wh_dentry = NULL;
++	/* no estimation for dir size */
++	rdhash = au_sbi(sb)->si_rdhash;
++	if (!rdhash)
++		rdhash = AUFS_RDHASH_DEF;
++	err = au_nhash_alloc(&whtmp->whlist, rdhash, gfp);
++	if (unlikely(err)) {
++		kfree(whtmp);
++		whtmp = ERR_PTR(err);
++	}
++
++out:
++	return whtmp;
++}
++
++void au_whtmp_rmdir_free(struct au_whtmp_rmdir *whtmp)
++{
++	if (whtmp->br)
++		atomic_dec(&whtmp->br->br_count);
++	dput(whtmp->wh_dentry);
++	iput(whtmp->dir);
++	au_nhash_wh_free(&whtmp->whlist);
++	kfree(whtmp);
++}
++
++/*
++ * rmdir the whiteouted temporary named dir @h_dentry.
++ * @whlist: whiteouted children.
++ */
++int au_whtmp_rmdir(struct inode *dir, aufs_bindex_t bindex,
++		   struct dentry *wh_dentry, struct au_nhash *whlist)
++{
++	int err;
++	struct path h_tmp;
++	struct inode *wh_inode, *h_dir;
++	struct au_branch *br;
++
++	h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
++	IMustLock(h_dir);
++
++	br = au_sbr(dir->i_sb, bindex);
++	wh_inode = wh_dentry->d_inode;
++	mutex_lock_nested(&wh_inode->i_mutex, AuLsc_I_CHILD);
++
++	/*
++	 * someone else might change some whiteouts while we were sleeping.
++	 * it means this whlist may have an obsoleted entry.
++	 */
++	if (!au_test_h_perm_sio(wh_inode, MAY_EXEC | MAY_WRITE))
++		err = del_wh_children(wh_dentry, whlist, bindex, br);
++	else {
++		int wkq_err;
++		struct del_wh_children_args args = {
++			.errp		= &err,
++			.h_dentry	= wh_dentry,
++			.whlist		= whlist,
++			.bindex		= bindex,
++			.br		= br
++		};
++
++		wkq_err = au_wkq_wait(call_del_wh_children, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++	mutex_unlock(&wh_inode->i_mutex);
++
++	if (!err) {
++		h_tmp.dentry = wh_dentry;
++		h_tmp.mnt = br->br_mnt;
++		err = vfsub_rmdir(h_dir, &h_tmp);
++	}
++
++	if (!err) {
++		if (au_ibstart(dir) == bindex) {
++			/* todo: dir->i_mutex is necessary */
++			au_cpup_attr_timesizes(dir);
++			vfsub_drop_nlink(dir);
++		}
++		return 0; /* success */
++	}
++
++	pr_warning("failed removing %.*s(%d), ignored\n",
++		   AuDLNPair(wh_dentry), err);
++	return err;
++}
++
++static void call_rmdir_whtmp(void *args)
++{
++	int err;
++	aufs_bindex_t bindex;
++	struct au_whtmp_rmdir *a = args;
++	struct super_block *sb;
++	struct dentry *h_parent;
++	struct inode *h_dir;
++	struct au_hinode *hdir;
++
++	/* rmdir by nfsd may cause deadlock with this i_mutex */
++	/* mutex_lock(&a->dir->i_mutex); */
++	err = -EROFS;
++	sb = a->dir->i_sb;
++	si_read_lock(sb, !AuLock_FLUSH);
++	if (!au_br_writable(a->br->br_perm))
++		goto out;
++	bindex = au_br_index(sb, a->br->br_id);
++	if (unlikely(bindex < 0))
++		goto out;
++
++	err = -EIO;
++	ii_write_lock_parent(a->dir);
++	h_parent = dget_parent(a->wh_dentry);
++	h_dir = h_parent->d_inode;
++	hdir = au_hi(a->dir, bindex);
++	au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++	err = au_h_verify(a->wh_dentry, au_opt_udba(sb), h_dir, h_parent,
++			  a->br);
++	if (!err) {
++		err = mnt_want_write(a->br->br_mnt);
++		if (!err) {
++			err = au_whtmp_rmdir(a->dir, bindex, a->wh_dentry,
++					     &a->whlist);
++			mnt_drop_write(a->br->br_mnt);
++		}
++	}
++	au_hn_imtx_unlock(hdir);
++	dput(h_parent);
++	ii_write_unlock(a->dir);
++
++out:
++	/* mutex_unlock(&a->dir->i_mutex); */
++	au_whtmp_rmdir_free(a);
++	si_read_unlock(sb);
++	au_nwt_done(&au_sbi(sb)->si_nowait);
++	if (unlikely(err))
++		AuIOErr("err %d\n", err);
++}
++
++void au_whtmp_kick_rmdir(struct inode *dir, aufs_bindex_t bindex,
++			 struct dentry *wh_dentry, struct au_whtmp_rmdir *args)
++{
++	int wkq_err;
++	struct super_block *sb;
++
++	IMustLock(dir);
++
++	/* all post-process will be done in do_rmdir_whtmp(). */
++	sb = dir->i_sb;
++	args->dir = au_igrab(dir);
++	args->br = au_sbr(sb, bindex);
++	atomic_inc(&args->br->br_count);
++	args->wh_dentry = dget(wh_dentry);
++	wkq_err = au_wkq_nowait(call_rmdir_whtmp, args, sb);
++	if (unlikely(wkq_err)) {
++		pr_warning("rmdir error %.*s (%d), ignored\n",
++			   AuDLNPair(wh_dentry), wkq_err);
++		au_whtmp_rmdir_free(args);
++	}
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/whout.h linux-2.6.36/fs/aufs/whout.h
+--- linux-2.6.36.orig/fs/aufs/whout.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/whout.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,89 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * whiteout for logical deletion and opaque directory
++ */
++
++#ifndef __AUFS_WHOUT_H__
++#define __AUFS_WHOUT_H__
++
++#ifdef __KERNEL__
++
++#include <linux/aufs_type.h>
++#include "dir.h"
++
++/* whout.c */
++int au_wh_name_alloc(struct qstr *wh, const struct qstr *name);
++struct au_branch;
++int au_wh_test(struct dentry *h_parent, struct qstr *wh_name,
++	       struct au_branch *br, int try_sio);
++int au_diropq_test(struct dentry *h_dentry, struct au_branch *br);
++struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct au_branch *br,
++			     struct qstr *prefix);
++int au_whtmp_ren(struct dentry *h_dentry, struct au_branch *br);
++int au_wh_unlink_dentry(struct inode *h_dir, struct path *h_path,
++			struct dentry *dentry);
++int au_wh_init(struct dentry *h_parent, struct au_branch *br,
++	       struct super_block *sb);
++
++/* diropq flags */
++#define AuDiropq_CREATE	1
++#define au_ftest_diropq(flags, name)	((flags) & AuDiropq_##name)
++#define au_fset_diropq(flags, name) \
++	do { (flags) |= AuDiropq_##name; } while (0)
++#define au_fclr_diropq(flags, name) \
++	do { (flags) &= ~AuDiropq_##name; } while (0)
++
++struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
++			     unsigned int flags);
++struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
++			  struct au_branch *br);
++struct dentry *au_wh_create(struct dentry *dentry, aufs_bindex_t bindex,
++			    struct dentry *h_parent);
++
++/* real rmdir for the whiteout-ed dir */
++struct au_whtmp_rmdir {
++	struct inode *dir;
++	struct au_branch *br;
++	struct dentry *wh_dentry;
++	struct au_nhash whlist;
++};
++
++struct au_whtmp_rmdir *au_whtmp_rmdir_alloc(struct super_block *sb, gfp_t gfp);
++void au_whtmp_rmdir_free(struct au_whtmp_rmdir *whtmp);
++int au_whtmp_rmdir(struct inode *dir, aufs_bindex_t bindex,
++		   struct dentry *wh_dentry, struct au_nhash *whlist);
++void au_whtmp_kick_rmdir(struct inode *dir, aufs_bindex_t bindex,
++			 struct dentry *wh_dentry, struct au_whtmp_rmdir *args);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct dentry *au_diropq_create(struct dentry *dentry,
++					      aufs_bindex_t bindex)
++{
++	return au_diropq_sio(dentry, bindex, AuDiropq_CREATE);
++}
++
++static inline int au_diropq_remove(struct dentry *dentry, aufs_bindex_t bindex)
++{
++	return PTR_ERR(au_diropq_sio(dentry, bindex, !AuDiropq_CREATE));
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_WHOUT_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/wkq.c linux-2.6.36/fs/aufs/wkq.c
+--- linux-2.6.36.orig/fs/aufs/wkq.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/wkq.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,236 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * workqueue for asynchronous/super-io operations
++ * todo: try new dredential scheme
++ */
++
++#include <linux/module.h>
++#include "aufs.h"
++
++/* internal workqueue named AUFS_WKQ_NAME and AUFS_WKQ_PRE_NAME */
++enum {
++	AuWkq_INORMAL,
++	AuWkq_IPRE
++};
++
++static struct {
++	char *name;
++	struct workqueue_struct *wkq;
++} au_wkq[] = {
++	[AuWkq_INORMAL] = {
++		.name = AUFS_WKQ_NAME
++	},
++	[AuWkq_IPRE] = {
++		.name = AUFS_WKQ_PRE_NAME
++	}
++};
++
++struct au_wkinfo {
++	struct work_struct wk;
++	struct kobject *kobj;
++
++	unsigned int flags; /* see wkq.h */
++
++	au_wkq_func_t func;
++	void *args;
++
++	struct completion *comp;
++};
++
++/* ---------------------------------------------------------------------- */
++
++static void wkq_func(struct work_struct *wk)
++{
++	struct au_wkinfo *wkinfo = container_of(wk, struct au_wkinfo, wk);
++
++	AuDebugOn(current_fsuid());
++	AuDebugOn(rlimit(RLIMIT_FSIZE) != RLIM_INFINITY);
++
++	wkinfo->func(wkinfo->args);
++	if (au_ftest_wkq(wkinfo->flags, WAIT))
++		complete(wkinfo->comp);
++	else {
++		kobject_put(wkinfo->kobj);
++		module_put(THIS_MODULE);
++		kfree(wkinfo);
++	}
++}
++
++/*
++ * Since struct completion is large, try allocating it dynamically.
++ */
++#if defined(CONFIG_4KSTACKS) || defined(AuTest4KSTACKS)
++#define AuWkqCompDeclare(name)	struct completion *comp = NULL
++
++static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
++{
++	*comp = kmalloc(sizeof(**comp), GFP_NOFS);
++	if (*comp) {
++		init_completion(*comp);
++		wkinfo->comp = *comp;
++		return 0;
++	}
++	return -ENOMEM;
++}
++
++static void au_wkq_comp_free(struct completion *comp)
++{
++	kfree(comp);
++}
++
++#else
++
++/* no braces */
++#define AuWkqCompDeclare(name) \
++	DECLARE_COMPLETION_ONSTACK(_ ## name); \
++	struct completion *comp = &_ ## name
++
++static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
++{
++	wkinfo->comp = *comp;
++	return 0;
++}
++
++static void au_wkq_comp_free(struct completion *comp __maybe_unused)
++{
++	/* empty */
++}
++#endif /* 4KSTACKS */
++
++static void au_wkq_run(struct au_wkinfo *wkinfo, unsigned int flags)
++{
++	struct workqueue_struct *wkq;
++
++	au_dbg_verify_kthread();
++	if (flags & AuWkq_WAIT) {
++		INIT_WORK_ON_STACK(&wkinfo->wk, wkq_func);
++		wkq = au_wkq[AuWkq_INORMAL].wkq;
++		if (flags & AuWkq_PRE)
++			wkq = au_wkq[AuWkq_IPRE].wkq;
++		queue_work(wkq, &wkinfo->wk);
++	} else {
++		INIT_WORK(&wkinfo->wk, wkq_func);
++		schedule_work(&wkinfo->wk);
++	}
++}
++
++/*
++ * Be careful. It is easy to make deadlock happen.
++ * processA: lock, wkq and wait
++ * processB: wkq and wait, lock in wkq
++ * --> deadlock
++ */
++int au_wkq_do_wait(unsigned int flags, au_wkq_func_t func, void *args)
++{
++	int err;
++	AuWkqCompDeclare(comp);
++	struct au_wkinfo wkinfo = {
++		.flags	= flags,
++		.func	= func,
++		.args	= args
++	};
++
++	err = au_wkq_comp_alloc(&wkinfo, &comp);
++	if (!err) {
++		au_wkq_run(&wkinfo, flags);
++		/* no timeout, no interrupt */
++		wait_for_completion(wkinfo.comp);
++		au_wkq_comp_free(comp);
++		destroy_work_on_stack(&wkinfo.wk);
++	}
++
++	return err;
++
++}
++
++/*
++ * Note: dget/dput() in func for aufs dentries are not supported. It will be a
++ * problem in a concurrent umounting.
++ */
++int au_wkq_nowait(au_wkq_func_t func, void *args, struct super_block *sb)
++{
++	int err;
++	struct au_wkinfo *wkinfo;
++
++	atomic_inc(&au_sbi(sb)->si_nowait.nw_len);
++
++	/*
++	 * wkq_func() must free this wkinfo.
++	 * it highly depends upon the implementation of workqueue.
++	 */
++	err = 0;
++	wkinfo = kmalloc(sizeof(*wkinfo), GFP_NOFS);
++	if (wkinfo) {
++		wkinfo->kobj = &au_sbi(sb)->si_kobj;
++		wkinfo->flags = !AuWkq_WAIT;
++		wkinfo->func = func;
++		wkinfo->args = args;
++		wkinfo->comp = NULL;
++		kobject_get(wkinfo->kobj);
++		__module_get(THIS_MODULE);
++
++		au_wkq_run(wkinfo, !AuWkq_WAIT);
++	} else {
++		err = -ENOMEM;
++		au_nwt_done(&au_sbi(sb)->si_nowait);
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_nwt_init(struct au_nowait_tasks *nwt)
++{
++	atomic_set(&nwt->nw_len, 0);
++	/* smp_mb(); */ /* atomic_set */
++	init_waitqueue_head(&nwt->nw_wq);
++}
++
++void au_wkq_fin(void)
++{
++	int i;
++
++	for (i = 0; i < ARRAY_SIZE(au_wkq); i++)
++		if (au_wkq[i].wkq)
++			destroy_workqueue(au_wkq[i].wkq);
++}
++
++int __init au_wkq_init(void)
++{
++	int err, i;
++
++	err = 0;
++	for (i = 0; !err && i < ARRAY_SIZE(au_wkq); i++) {
++		BUILD_BUG_ON(!WQ_RESCUER);
++		au_wkq[i].wkq = alloc_workqueue(au_wkq[i].name, !WQ_RESCUER,
++						WQ_DFL_ACTIVE);
++		if (IS_ERR(au_wkq[i].wkq))
++			err = PTR_ERR(au_wkq[i].wkq);
++		else if (!au_wkq[i].wkq)
++			err = -ENOMEM;
++		if (unlikely(err))
++			au_wkq[i].wkq = NULL;
++	}
++	if (unlikely(err))
++		au_wkq_fin();
++
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/aufs/wkq.h linux-2.6.36/fs/aufs/wkq.h
+--- linux-2.6.36.orig/fs/aufs/wkq.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/wkq.h	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,90 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * workqueue for asynchronous/super-io operations
++ * todo: try new credentials management scheme
++ */
++
++#ifndef __AUFS_WKQ_H__
++#define __AUFS_WKQ_H__
++
++#ifdef __KERNEL__
++
++#include <linux/sched.h>
++#include <linux/wait.h>
++#include <linux/aufs_type.h>
++
++struct super_block;
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * in the next operation, wait for the 'nowait' tasks in system-wide workqueue
++ */
++struct au_nowait_tasks {
++	atomic_t		nw_len;
++	wait_queue_head_t	nw_wq;
++};
++
++/* ---------------------------------------------------------------------- */
++
++typedef void (*au_wkq_func_t)(void *args);
++
++/* wkq flags */
++#define AuWkq_WAIT	1
++#define AuWkq_PRE	(1 << 1)
++#define au_ftest_wkq(flags, name)	((flags) & AuWkq_##name)
++#define au_fset_wkq(flags, name) \
++	do { (flags) |= AuWkq_##name; } while (0)
++#define au_fclr_wkq(flags, name) \
++	do { (flags) &= ~AuWkq_##name; } while (0)
++
++/* wkq.c */
++int au_wkq_do_wait(unsigned int flags, au_wkq_func_t func, void *args);
++int au_wkq_nowait(au_wkq_func_t func, void *args, struct super_block *sb);
++void au_nwt_init(struct au_nowait_tasks *nwt);
++int __init au_wkq_init(void);
++void au_wkq_fin(void);
++
++/* ---------------------------------------------------------------------- */
++
++static inline int au_wkq_wait_pre(au_wkq_func_t func, void *args)
++{
++	return au_wkq_do_wait(AuWkq_WAIT | AuWkq_PRE, func, args);
++}
++
++static inline int au_wkq_wait(au_wkq_func_t func, void *args)
++{
++	return au_wkq_do_wait(AuWkq_WAIT, func, args);
++}
++
++static inline void au_nwt_done(struct au_nowait_tasks *nwt)
++{
++	if (atomic_dec_and_test(&nwt->nw_len))
++		wake_up_all(&nwt->nw_wq);
++}
++
++static inline int au_nwt_flush(struct au_nowait_tasks *nwt)
++{
++	wait_event(nwt->nw_wq, !atomic_read(&nwt->nw_len));
++	return 0;
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_WKQ_H__ */
+diff -Nur linux-2.6.36.orig/fs/aufs/xino.c linux-2.6.36/fs/aufs/xino.c
+--- linux-2.6.36.orig/fs/aufs/xino.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/aufs/xino.c	2011-01-10 19:24:41.000000000 +0100
+@@ -0,0 +1,1265 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++/*
++ * external inode number translation table and bitmap
++ */
++
++#include <linux/file.h>
++#include <linux/seq_file.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++ssize_t xino_fread(au_readf_t func, struct file *file, void *kbuf, size_t size,
++		   loff_t *pos)
++{
++	ssize_t err;
++	mm_segment_t oldfs;
++	union {
++		void *k;
++		char __user *u;
++	} buf;
++
++	buf.k = kbuf;
++	oldfs = get_fs();
++	set_fs(KERNEL_DS);
++	do {
++		/* todo: signal_pending? */
++		err = func(file, buf.u, size, pos);
++	} while (err == -EAGAIN || err == -EINTR);
++	set_fs(oldfs);
++
++#if 0 /* reserved for future use */
++	if (err > 0)
++		fsnotify_access(file->f_dentry);
++#endif
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static ssize_t do_xino_fwrite(au_writef_t func, struct file *file, void *kbuf,
++			      size_t size, loff_t *pos)
++{
++	ssize_t err;
++	mm_segment_t oldfs;
++	union {
++		void *k;
++		const char __user *u;
++	} buf;
++
++	buf.k = kbuf;
++	oldfs = get_fs();
++	set_fs(KERNEL_DS);
++	do {
++		/* todo: signal_pending? */
++		err = func(file, buf.u, size, pos);
++	} while (err == -EAGAIN || err == -EINTR);
++	set_fs(oldfs);
++
++#if 0 /* reserved for future use */
++	if (err > 0)
++		fsnotify_modify(file->f_dentry);
++#endif
++
++	return err;
++}
++
++struct do_xino_fwrite_args {
++	ssize_t *errp;
++	au_writef_t func;
++	struct file *file;
++	void *buf;
++	size_t size;
++	loff_t *pos;
++};
++
++static void call_do_xino_fwrite(void *args)
++{
++	struct do_xino_fwrite_args *a = args;
++	*a->errp = do_xino_fwrite(a->func, a->file, a->buf, a->size, a->pos);
++}
++
++ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
++		    loff_t *pos)
++{
++	ssize_t err;
++
++	/* todo: signal block and no wkq? */
++	if (rlimit(RLIMIT_FSIZE) == RLIM_INFINITY) {
++		lockdep_off();
++		err = do_xino_fwrite(func, file, buf, size, pos);
++		lockdep_on();
++	} else {
++		/*
++		 * it breaks RLIMIT_FSIZE and normal user's limit,
++		 * users should care about quota and real 'filesystem full.'
++		 */
++		int wkq_err;
++		struct do_xino_fwrite_args args = {
++			.errp	= &err,
++			.func	= func,
++			.file	= file,
++			.buf	= buf,
++			.size	= size,
++			.pos	= pos
++		};
++
++		wkq_err = au_wkq_wait(call_do_xino_fwrite, &args);
++		if (unlikely(wkq_err))
++			err = wkq_err;
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create a new xinofile at the same place/path as @base_file.
++ */
++struct file *au_xino_create2(struct file *base_file, struct file *copy_src)
++{
++	struct file *file;
++	struct dentry *base, *parent;
++	struct inode *dir;
++	struct qstr *name;
++	struct path path;
++	int err;
++
++	base = base_file->f_dentry;
++	parent = base->d_parent; /* dir inode is locked */
++	dir = parent->d_inode;
++	IMustLock(dir);
++
++	file = ERR_PTR(-EINVAL);
++	name = &base->d_name;
++	path.dentry = vfsub_lookup_one_len(name->name, parent, name->len);
++	if (IS_ERR(path.dentry)) {
++		file = (void *)path.dentry;
++		pr_err("%.*s lookup err %ld\n",
++		       AuLNPair(name), PTR_ERR(path.dentry));
++		goto out;
++	}
++
++	/* no need to mnt_want_write() since we call dentry_open() later */
++	err = vfs_create(dir, path.dentry, S_IRUGO | S_IWUGO, NULL);
++	if (unlikely(err)) {
++		file = ERR_PTR(err);
++		pr_err("%.*s create err %d\n", AuLNPair(name), err);
++		goto out_dput;
++	}
++
++	path.mnt = base_file->f_vfsmnt;
++	file = vfsub_dentry_open(&path,
++				 O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE
++				 /* | FMODE_NONOTIFY */);
++	if (IS_ERR(file)) {
++		pr_err("%.*s open err %ld\n", AuLNPair(name), PTR_ERR(file));
++		goto out_dput;
++	}
++
++	err = vfsub_unlink(dir, &file->f_path, /*force*/0);
++	if (unlikely(err)) {
++		pr_err("%.*s unlink err %d\n", AuLNPair(name), err);
++		goto out_fput;
++	}
++
++	if (copy_src) {
++		/* no one can touch copy_src xino */
++		err = au_copy_file(file, copy_src,
++				   i_size_read(copy_src->f_dentry->d_inode));
++		if (unlikely(err)) {
++			pr_err("%.*s copy err %d\n", AuLNPair(name), err);
++			goto out_fput;
++		}
++	}
++	goto out_dput; /* success */
++
++out_fput:
++	fput(file);
++	file = ERR_PTR(err);
++out_dput:
++	dput(path.dentry);
++out:
++	return file;
++}
++
++struct au_xino_lock_dir {
++	struct au_hinode *hdir;
++	struct dentry *parent;
++	struct mutex *mtx;
++};
++
++static void au_xino_lock_dir(struct super_block *sb, struct file *xino,
++			     struct au_xino_lock_dir *ldir)
++{
++	aufs_bindex_t brid, bindex;
++
++	ldir->hdir = NULL;
++	bindex = -1;
++	brid = au_xino_brid(sb);
++	if (brid >= 0)
++		bindex = au_br_index(sb, brid);
++	if (bindex >= 0) {
++		ldir->hdir = au_hi(sb->s_root->d_inode, bindex);
++		au_hn_imtx_lock_nested(ldir->hdir, AuLsc_I_PARENT);
++	} else {
++		ldir->parent = dget_parent(xino->f_dentry);
++		ldir->mtx = &ldir->parent->d_inode->i_mutex;
++		mutex_lock_nested(ldir->mtx, AuLsc_I_PARENT);
++	}
++}
++
++static void au_xino_unlock_dir(struct au_xino_lock_dir *ldir)
++{
++	if (ldir->hdir)
++		au_hn_imtx_unlock(ldir->hdir);
++	else {
++		mutex_unlock(ldir->mtx);
++		dput(ldir->parent);
++	}
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* trucate xino files asynchronously */
++
++int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex)
++{
++	int err;
++	aufs_bindex_t bi, bend;
++	struct au_branch *br;
++	struct file *new_xino, *file;
++	struct super_block *h_sb;
++	struct au_xino_lock_dir ldir;
++
++	err = -EINVAL;
++	bend = au_sbend(sb);
++	if (unlikely(bindex < 0 || bend < bindex))
++		goto out;
++	br = au_sbr(sb, bindex);
++	file = br->br_xino.xi_file;
++	if (!file)
++		goto out;
++
++	au_xino_lock_dir(sb, file, &ldir);
++	/* mnt_want_write() is unnecessary here */
++	new_xino = au_xino_create2(file, file);
++	au_xino_unlock_dir(&ldir);
++	err = PTR_ERR(new_xino);
++	if (IS_ERR(new_xino))
++		goto out;
++	err = 0;
++	fput(file);
++	br->br_xino.xi_file = new_xino;
++
++	h_sb = br->br_mnt->mnt_sb;
++	for (bi = 0; bi <= bend; bi++) {
++		if (unlikely(bi == bindex))
++			continue;
++		br = au_sbr(sb, bi);
++		if (br->br_mnt->mnt_sb != h_sb)
++			continue;
++
++		fput(br->br_xino.xi_file);
++		br->br_xino.xi_file = new_xino;
++		get_file(new_xino);
++	}
++
++out:
++	return err;
++}
++
++struct xino_do_trunc_args {
++	struct super_block *sb;
++	struct au_branch *br;
++};
++
++static void xino_do_trunc(void *_args)
++{
++	struct xino_do_trunc_args *args = _args;
++	struct super_block *sb;
++	struct au_branch *br;
++	struct inode *dir;
++	int err;
++	aufs_bindex_t bindex;
++
++	err = 0;
++	sb = args->sb;
++	dir = sb->s_root->d_inode;
++	br = args->br;
++
++	si_noflush_write_lock(sb);
++	ii_read_lock_parent(dir);
++	bindex = au_br_index(sb, br->br_id);
++	err = au_xino_trunc(sb, bindex);
++	if (!err
++	    && br->br_xino.xi_file->f_dentry->d_inode->i_blocks
++	    >= br->br_xino_upper)
++		br->br_xino_upper += AUFS_XINO_TRUNC_STEP;
++
++	ii_read_unlock(dir);
++	if (unlikely(err))
++		pr_warning("err b%d, (%d)\n", bindex, err);
++	atomic_dec(&br->br_xino_running);
++	atomic_dec(&br->br_count);
++	si_write_unlock(sb);
++	au_nwt_done(&au_sbi(sb)->si_nowait);
++	kfree(args);
++}
++
++static void xino_try_trunc(struct super_block *sb, struct au_branch *br)
++{
++	struct xino_do_trunc_args *args;
++	int wkq_err;
++
++	if (br->br_xino.xi_file->f_dentry->d_inode->i_blocks
++	    < br->br_xino_upper)
++		return;
++
++	if (atomic_inc_return(&br->br_xino_running) > 1)
++		goto out;
++
++	/* lock and kfree() will be called in trunc_xino() */
++	args = kmalloc(sizeof(*args), GFP_NOFS);
++	if (unlikely(!args)) {
++		AuErr1("no memory\n");
++		goto out_args;
++	}
++
++	atomic_inc(&br->br_count);
++	args->sb = sb;
++	args->br = br;
++	wkq_err = au_wkq_nowait(xino_do_trunc, args, sb);
++	if (!wkq_err)
++		return; /* success */
++
++	pr_err("wkq %d\n", wkq_err);
++	atomic_dec(&br->br_count);
++
++out_args:
++	kfree(args);
++out:
++	atomic_dec(&br->br_xino_running);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_xino_do_write(au_writef_t write, struct file *file,
++			    ino_t h_ino, ino_t ino)
++{
++	loff_t pos;
++	ssize_t sz;
++
++	pos = h_ino;
++	if (unlikely(au_loff_max / sizeof(ino) - 1 < pos)) {
++		AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
++		return -EFBIG;
++	}
++	pos *= sizeof(ino);
++	sz = xino_fwrite(write, file, &ino, sizeof(ino), &pos);
++	if (sz == sizeof(ino))
++		return 0; /* success */
++
++	AuIOErr("write failed (%zd)\n", sz);
++	return -EIO;
++}
++
++/*
++ * write @ino to the xinofile for the specified branch{@sb, @bindex}
++ * at the position of @h_ino.
++ * even if @ino is zero, it is written to the xinofile and means no entry.
++ * if the size of the xino file on a specific filesystem exceeds the watermark,
++ * try truncating it.
++ */
++int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++		  ino_t ino)
++{
++	int err;
++	unsigned int mnt_flags;
++	struct au_branch *br;
++
++	BUILD_BUG_ON(sizeof(long long) != sizeof(au_loff_max)
++		     || ((loff_t)-1) > 0);
++	SiMustAnyLock(sb);
++
++	mnt_flags = au_mntflags(sb);
++	if (!au_opt_test(mnt_flags, XINO))
++		return 0;
++
++	br = au_sbr(sb, bindex);
++	err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
++			       h_ino, ino);
++	if (!err) {
++		if (au_opt_test(mnt_flags, TRUNC_XINO)
++		    && au_test_fs_trunc_xino(br->br_mnt->mnt_sb))
++			xino_try_trunc(sb, br);
++		return 0; /* success */
++	}
++
++	AuIOErr("write failed (%d)\n", err);
++	return -EIO;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* aufs inode number bitmap */
++
++static const int page_bits = (int)PAGE_SIZE * BITS_PER_BYTE;
++static ino_t xib_calc_ino(unsigned long pindex, int bit)
++{
++	ino_t ino;
++
++	AuDebugOn(bit < 0 || page_bits <= bit);
++	ino = AUFS_FIRST_INO + pindex * page_bits + bit;
++	return ino;
++}
++
++static void xib_calc_bit(ino_t ino, unsigned long *pindex, int *bit)
++{
++	AuDebugOn(ino < AUFS_FIRST_INO);
++	ino -= AUFS_FIRST_INO;
++	*pindex = ino / page_bits;
++	*bit = ino % page_bits;
++}
++
++static int xib_pindex(struct super_block *sb, unsigned long pindex)
++{
++	int err;
++	loff_t pos;
++	ssize_t sz;
++	struct au_sbinfo *sbinfo;
++	struct file *xib;
++	unsigned long *p;
++
++	sbinfo = au_sbi(sb);
++	MtxMustLock(&sbinfo->si_xib_mtx);
++	AuDebugOn(pindex > ULONG_MAX / PAGE_SIZE
++		  || !au_opt_test(sbinfo->si_mntflags, XINO));
++
++	if (pindex == sbinfo->si_xib_last_pindex)
++		return 0;
++
++	xib = sbinfo->si_xib;
++	p = sbinfo->si_xib_buf;
++	pos = sbinfo->si_xib_last_pindex;
++	pos *= PAGE_SIZE;
++	sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
++	if (unlikely(sz != PAGE_SIZE))
++		goto out;
++
++	pos = pindex;
++	pos *= PAGE_SIZE;
++	if (i_size_read(xib->f_dentry->d_inode) >= pos + PAGE_SIZE)
++		sz = xino_fread(sbinfo->si_xread, xib, p, PAGE_SIZE, &pos);
++	else {
++		memset(p, 0, PAGE_SIZE);
++		sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
++	}
++	if (sz == PAGE_SIZE) {
++		sbinfo->si_xib_last_pindex = pindex;
++		return 0; /* success */
++	}
++
++out:
++	AuIOErr1("write failed (%zd)\n", sz);
++	err = sz;
++	if (sz >= 0)
++		err = -EIO;
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void au_xib_clear_bit(struct inode *inode)
++{
++	int err, bit;
++	unsigned long pindex;
++	struct super_block *sb;
++	struct au_sbinfo *sbinfo;
++
++	AuDebugOn(inode->i_nlink);
++
++	sb = inode->i_sb;
++	xib_calc_bit(inode->i_ino, &pindex, &bit);
++	AuDebugOn(page_bits <= bit);
++	sbinfo = au_sbi(sb);
++	mutex_lock(&sbinfo->si_xib_mtx);
++	err = xib_pindex(sb, pindex);
++	if (!err) {
++		clear_bit(bit, sbinfo->si_xib_buf);
++		sbinfo->si_xib_next_bit = bit;
++	}
++	mutex_unlock(&sbinfo->si_xib_mtx);
++}
++
++/* for s_op->delete_inode() */
++void au_xino_delete_inode(struct inode *inode, const int unlinked)
++{
++	int err;
++	unsigned int mnt_flags;
++	aufs_bindex_t bindex, bend, bi;
++	unsigned char try_trunc;
++	struct au_iinfo *iinfo;
++	struct super_block *sb;
++	struct au_hinode *hi;
++	struct inode *h_inode;
++	struct au_branch *br;
++	au_writef_t xwrite;
++
++	sb = inode->i_sb;
++	mnt_flags = au_mntflags(sb);
++	if (!au_opt_test(mnt_flags, XINO)
++	    || inode->i_ino == AUFS_ROOT_INO)
++		return;
++
++	if (unlinked) {
++		au_xigen_inc(inode);
++		au_xib_clear_bit(inode);
++	}
++
++	iinfo = au_ii(inode);
++	if (!iinfo)
++		return;
++
++	bindex = iinfo->ii_bstart;
++	if (bindex < 0)
++		return;
++
++	xwrite = au_sbi(sb)->si_xwrite;
++	try_trunc = !!au_opt_test(mnt_flags, TRUNC_XINO);
++	hi = iinfo->ii_hinode + bindex;
++	bend = iinfo->ii_bend;
++	for (; bindex <= bend; bindex++, hi++) {
++		h_inode = hi->hi_inode;
++		if (!h_inode
++		    || (!unlinked && h_inode->i_nlink))
++			continue;
++
++		/* inode may not be revalidated */
++		bi = au_br_index(sb, hi->hi_id);
++		if (bi < 0)
++			continue;
++
++		br = au_sbr(sb, bi);
++		err = au_xino_do_write(xwrite, br->br_xino.xi_file,
++				       h_inode->i_ino, /*ino*/0);
++		if (!err && try_trunc
++		    && au_test_fs_trunc_xino(br->br_mnt->mnt_sb))
++			xino_try_trunc(sb, br);
++	}
++}
++
++/* get an unused inode number from bitmap */
++ino_t au_xino_new_ino(struct super_block *sb)
++{
++	ino_t ino;
++	unsigned long *p, pindex, ul, pend;
++	struct au_sbinfo *sbinfo;
++	struct file *file;
++	int free_bit, err;
++
++	if (!au_opt_test(au_mntflags(sb), XINO))
++		return iunique(sb, AUFS_FIRST_INO);
++
++	sbinfo = au_sbi(sb);
++	mutex_lock(&sbinfo->si_xib_mtx);
++	p = sbinfo->si_xib_buf;
++	free_bit = sbinfo->si_xib_next_bit;
++	if (free_bit < page_bits && !test_bit(free_bit, p))
++		goto out; /* success */
++	free_bit = find_first_zero_bit(p, page_bits);
++	if (free_bit < page_bits)
++		goto out; /* success */
++
++	pindex = sbinfo->si_xib_last_pindex;
++	for (ul = pindex - 1; ul < ULONG_MAX; ul--) {
++		err = xib_pindex(sb, ul);
++		if (unlikely(err))
++			goto out_err;
++		free_bit = find_first_zero_bit(p, page_bits);
++		if (free_bit < page_bits)
++			goto out; /* success */
++	}
++
++	file = sbinfo->si_xib;
++	pend = i_size_read(file->f_dentry->d_inode) / PAGE_SIZE;
++	for (ul = pindex + 1; ul <= pend; ul++) {
++		err = xib_pindex(sb, ul);
++		if (unlikely(err))
++			goto out_err;
++		free_bit = find_first_zero_bit(p, page_bits);
++		if (free_bit < page_bits)
++			goto out; /* success */
++	}
++	BUG();
++
++out:
++	set_bit(free_bit, p);
++	sbinfo->si_xib_next_bit = free_bit + 1;
++	pindex = sbinfo->si_xib_last_pindex;
++	mutex_unlock(&sbinfo->si_xib_mtx);
++	ino = xib_calc_ino(pindex, free_bit);
++	AuDbg("i%lu\n", (unsigned long)ino);
++	return ino;
++out_err:
++	mutex_unlock(&sbinfo->si_xib_mtx);
++	AuDbg("i0\n");
++	return 0;
++}
++
++/*
++ * read @ino from xinofile for the specified branch{@sb, @bindex}
++ * at the position of @h_ino.
++ * if @ino does not exist and @do_new is true, get new one.
++ */
++int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++		 ino_t *ino)
++{
++	int err;
++	ssize_t sz;
++	loff_t pos;
++	struct file *file;
++	struct au_sbinfo *sbinfo;
++
++	*ino = 0;
++	if (!au_opt_test(au_mntflags(sb), XINO))
++		return 0; /* no xino */
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	pos = h_ino;
++	if (unlikely(au_loff_max / sizeof(*ino) - 1 < pos)) {
++		AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
++		return -EFBIG;
++	}
++	pos *= sizeof(*ino);
++
++	file = au_sbr(sb, bindex)->br_xino.xi_file;
++	if (i_size_read(file->f_dentry->d_inode) < pos + sizeof(*ino))
++		return 0; /* no ino */
++
++	sz = xino_fread(sbinfo->si_xread, file, ino, sizeof(*ino), &pos);
++	if (sz == sizeof(*ino))
++		return 0; /* success */
++
++	err = sz;
++	if (unlikely(sz >= 0)) {
++		err = -EIO;
++		AuIOErr("xino read error (%zd)\n", sz);
++	}
++
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* create and set a new xino file */
++
++struct file *au_xino_create(struct super_block *sb, char *fname, int silent)
++{
++	struct file *file;
++	struct dentry *h_parent, *d;
++	struct inode *h_dir;
++	int err;
++
++	/*
++	 * at mount-time, and the xino file is the default path,
++	 * hnotify is disabled so we have no notify events to ignore.
++	 * when a user specified the xino, we cannot get au_hdir to be ignored.
++	 */
++	file = vfsub_filp_open(fname, O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE
++			       /* | FMODE_NONOTIFY */,
++			       S_IRUGO | S_IWUGO);
++	if (IS_ERR(file)) {
++		if (!silent)
++			pr_err("open %s(%ld)\n", fname, PTR_ERR(file));
++		return file;
++	}
++
++	/* keep file count */
++	h_parent = dget_parent(file->f_dentry);
++	h_dir = h_parent->d_inode;
++	mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++	/* mnt_want_write() is unnecessary here */
++	err = vfsub_unlink(h_dir, &file->f_path, /*force*/0);
++	mutex_unlock(&h_dir->i_mutex);
++	dput(h_parent);
++	if (unlikely(err)) {
++		if (!silent)
++			pr_err("unlink %s(%d)\n", fname, err);
++		goto out;
++	}
++
++	err = -EINVAL;
++	d = file->f_dentry;
++	if (unlikely(sb == d->d_sb)) {
++		if (!silent)
++			pr_err("%s must be outside\n", fname);
++		goto out;
++	}
++	if (unlikely(au_test_fs_bad_xino(d->d_sb))) {
++		if (!silent)
++			pr_err("xino doesn't support %s(%s)\n",
++			       fname, au_sbtype(d->d_sb));
++		goto out;
++	}
++	return file; /* success */
++
++out:
++	fput(file);
++	file = ERR_PTR(err);
++	return file;
++}
++
++/*
++ * find another branch who is on the same filesystem of the specified
++ * branch{@btgt}. search until @bend.
++ */
++static int is_sb_shared(struct super_block *sb, aufs_bindex_t btgt,
++			aufs_bindex_t bend)
++{
++	aufs_bindex_t bindex;
++	struct super_block *tgt_sb = au_sbr_sb(sb, btgt);
++
++	for (bindex = 0; bindex < btgt; bindex++)
++		if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
++			return bindex;
++	for (bindex++; bindex <= bend; bindex++)
++		if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
++			return bindex;
++	return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * initialize the xinofile for the specified branch @br
++ * at the place/path where @base_file indicates.
++ * test whether another branch is on the same filesystem or not,
++ * if @do_test is true.
++ */
++int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t h_ino,
++	       struct file *base_file, int do_test)
++{
++	int err;
++	ino_t ino;
++	aufs_bindex_t bend, bindex;
++	struct au_branch *shared_br, *b;
++	struct file *file;
++	struct super_block *tgt_sb;
++
++	shared_br = NULL;
++	bend = au_sbend(sb);
++	if (do_test) {
++		tgt_sb = br->br_mnt->mnt_sb;
++		for (bindex = 0; bindex <= bend; bindex++) {
++			b = au_sbr(sb, bindex);
++			if (tgt_sb == b->br_mnt->mnt_sb) {
++				shared_br = b;
++				break;
++			}
++		}
++	}
++
++	if (!shared_br || !shared_br->br_xino.xi_file) {
++		struct au_xino_lock_dir ldir;
++
++		au_xino_lock_dir(sb, base_file, &ldir);
++		/* mnt_want_write() is unnecessary here */
++		file = au_xino_create2(base_file, NULL);
++		au_xino_unlock_dir(&ldir);
++		err = PTR_ERR(file);
++		if (IS_ERR(file))
++			goto out;
++		br->br_xino.xi_file = file;
++	} else {
++		br->br_xino.xi_file = shared_br->br_xino.xi_file;
++		get_file(br->br_xino.xi_file);
++	}
++
++	ino = AUFS_ROOT_INO;
++	err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
++			       h_ino, ino);
++	if (unlikely(err)) {
++		fput(br->br_xino.xi_file);
++		br->br_xino.xi_file = NULL;
++	}
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* trucate a xino bitmap file */
++
++/* todo: slow */
++static int do_xib_restore(struct super_block *sb, struct file *file, void *page)
++{
++	int err, bit;
++	ssize_t sz;
++	unsigned long pindex;
++	loff_t pos, pend;
++	struct au_sbinfo *sbinfo;
++	au_readf_t func;
++	ino_t *ino;
++	unsigned long *p;
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	MtxMustLock(&sbinfo->si_xib_mtx);
++	p = sbinfo->si_xib_buf;
++	func = sbinfo->si_xread;
++	pend = i_size_read(file->f_dentry->d_inode);
++	pos = 0;
++	while (pos < pend) {
++		sz = xino_fread(func, file, page, PAGE_SIZE, &pos);
++		err = sz;
++		if (unlikely(sz <= 0))
++			goto out;
++
++		err = 0;
++		for (ino = page; sz > 0; ino++, sz -= sizeof(ino)) {
++			if (unlikely(*ino < AUFS_FIRST_INO))
++				continue;
++
++			xib_calc_bit(*ino, &pindex, &bit);
++			AuDebugOn(page_bits <= bit);
++			err = xib_pindex(sb, pindex);
++			if (!err)
++				set_bit(bit, p);
++			else
++				goto out;
++		}
++	}
++
++out:
++	return err;
++}
++
++static int xib_restore(struct super_block *sb)
++{
++	int err;
++	aufs_bindex_t bindex, bend;
++	void *page;
++
++	err = -ENOMEM;
++	page = (void *)__get_free_page(GFP_NOFS);
++	if (unlikely(!page))
++		goto out;
++
++	err = 0;
++	bend = au_sbend(sb);
++	for (bindex = 0; !err && bindex <= bend; bindex++)
++		if (!bindex || is_sb_shared(sb, bindex, bindex - 1) < 0)
++			err = do_xib_restore
++				(sb, au_sbr(sb, bindex)->br_xino.xi_file, page);
++		else
++			AuDbg("b%d\n", bindex);
++	free_page((unsigned long)page);
++
++out:
++	return err;
++}
++
++int au_xib_trunc(struct super_block *sb)
++{
++	int err;
++	ssize_t sz;
++	loff_t pos;
++	struct au_xino_lock_dir ldir;
++	struct au_sbinfo *sbinfo;
++	unsigned long *p;
++	struct file *file;
++
++	SiMustWriteLock(sb);
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	if (!au_opt_test(sbinfo->si_mntflags, XINO))
++		goto out;
++
++	file = sbinfo->si_xib;
++	if (i_size_read(file->f_dentry->d_inode) <= PAGE_SIZE)
++		goto out;
++
++	au_xino_lock_dir(sb, file, &ldir);
++	/* mnt_want_write() is unnecessary here */
++	file = au_xino_create2(sbinfo->si_xib, NULL);
++	au_xino_unlock_dir(&ldir);
++	err = PTR_ERR(file);
++	if (IS_ERR(file))
++		goto out;
++	fput(sbinfo->si_xib);
++	sbinfo->si_xib = file;
++
++	p = sbinfo->si_xib_buf;
++	memset(p, 0, PAGE_SIZE);
++	pos = 0;
++	sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xib, p, PAGE_SIZE, &pos);
++	if (unlikely(sz != PAGE_SIZE)) {
++		err = sz;
++		AuIOErr("err %d\n", err);
++		if (sz >= 0)
++			err = -EIO;
++		goto out;
++	}
++
++	mutex_lock(&sbinfo->si_xib_mtx);
++	/* mnt_want_write() is unnecessary here */
++	err = xib_restore(sb);
++	mutex_unlock(&sbinfo->si_xib_mtx);
++
++out:
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * xino mount option handlers
++ */
++static au_readf_t find_readf(struct file *h_file)
++{
++	const struct file_operations *fop = h_file->f_op;
++
++	if (fop) {
++		if (fop->read)
++			return fop->read;
++		if (fop->aio_read)
++			return do_sync_read;
++	}
++	return ERR_PTR(-ENOSYS);
++}
++
++static au_writef_t find_writef(struct file *h_file)
++{
++	const struct file_operations *fop = h_file->f_op;
++
++	if (fop) {
++		if (fop->write)
++			return fop->write;
++		if (fop->aio_write)
++			return do_sync_write;
++	}
++	return ERR_PTR(-ENOSYS);
++}
++
++/* xino bitmap */
++static void xino_clear_xib(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	sbinfo->si_xread = NULL;
++	sbinfo->si_xwrite = NULL;
++	if (sbinfo->si_xib)
++		fput(sbinfo->si_xib);
++	sbinfo->si_xib = NULL;
++	free_page((unsigned long)sbinfo->si_xib_buf);
++	sbinfo->si_xib_buf = NULL;
++}
++
++static int au_xino_set_xib(struct super_block *sb, struct file *base)
++{
++	int err;
++	loff_t pos;
++	struct au_sbinfo *sbinfo;
++	struct file *file;
++
++	SiMustWriteLock(sb);
++
++	sbinfo = au_sbi(sb);
++	file = au_xino_create2(base, sbinfo->si_xib);
++	err = PTR_ERR(file);
++	if (IS_ERR(file))
++		goto out;
++	if (sbinfo->si_xib)
++		fput(sbinfo->si_xib);
++	sbinfo->si_xib = file;
++	sbinfo->si_xread = find_readf(file);
++	sbinfo->si_xwrite = find_writef(file);
++
++	err = -ENOMEM;
++	if (!sbinfo->si_xib_buf)
++		sbinfo->si_xib_buf = (void *)get_zeroed_page(GFP_NOFS);
++	if (unlikely(!sbinfo->si_xib_buf))
++		goto out_unset;
++
++	sbinfo->si_xib_last_pindex = 0;
++	sbinfo->si_xib_next_bit = 0;
++	if (i_size_read(file->f_dentry->d_inode) < PAGE_SIZE) {
++		pos = 0;
++		err = xino_fwrite(sbinfo->si_xwrite, file, sbinfo->si_xib_buf,
++				  PAGE_SIZE, &pos);
++		if (unlikely(err != PAGE_SIZE))
++			goto out_free;
++	}
++	err = 0;
++	goto out; /* success */
++
++out_free:
++	free_page((unsigned long)sbinfo->si_xib_buf);
++	sbinfo->si_xib_buf = NULL;
++	if (err >= 0)
++		err = -EIO;
++out_unset:
++	fput(sbinfo->si_xib);
++	sbinfo->si_xib = NULL;
++	sbinfo->si_xread = NULL;
++	sbinfo->si_xwrite = NULL;
++out:
++	return err;
++}
++
++/* xino for each branch */
++static void xino_clear_br(struct super_block *sb)
++{
++	aufs_bindex_t bindex, bend;
++	struct au_branch *br;
++
++	bend = au_sbend(sb);
++	for (bindex = 0; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		if (!br || !br->br_xino.xi_file)
++			continue;
++
++		fput(br->br_xino.xi_file);
++		br->br_xino.xi_file = NULL;
++	}
++}
++
++static int au_xino_set_br(struct super_block *sb, struct file *base)
++{
++	int err;
++	ino_t ino;
++	aufs_bindex_t bindex, bend, bshared;
++	struct {
++		struct file *old, *new;
++	} *fpair, *p;
++	struct au_branch *br;
++	struct inode *inode;
++	au_writef_t writef;
++
++	SiMustWriteLock(sb);
++
++	err = -ENOMEM;
++	bend = au_sbend(sb);
++	fpair = kcalloc(bend + 1, sizeof(*fpair), GFP_NOFS);
++	if (unlikely(!fpair))
++		goto out;
++
++	inode = sb->s_root->d_inode;
++	ino = AUFS_ROOT_INO;
++	writef = au_sbi(sb)->si_xwrite;
++	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
++		br = au_sbr(sb, bindex);
++		bshared = is_sb_shared(sb, bindex, bindex - 1);
++		if (bshared >= 0) {
++			/* shared xino */
++			*p = fpair[bshared];
++			get_file(p->new);
++		}
++
++		if (!p->new) {
++			/* new xino */
++			p->old = br->br_xino.xi_file;
++			p->new = au_xino_create2(base, br->br_xino.xi_file);
++			err = PTR_ERR(p->new);
++			if (IS_ERR(p->new)) {
++				p->new = NULL;
++				goto out_pair;
++			}
++		}
++
++		err = au_xino_do_write(writef, p->new,
++				       au_h_iptr(inode, bindex)->i_ino, ino);
++		if (unlikely(err))
++			goto out_pair;
++	}
++
++	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
++		br = au_sbr(sb, bindex);
++		if (br->br_xino.xi_file)
++			fput(br->br_xino.xi_file);
++		get_file(p->new);
++		br->br_xino.xi_file = p->new;
++	}
++
++out_pair:
++	for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++)
++		if (p->new)
++			fput(p->new);
++		else
++			break;
++	kfree(fpair);
++out:
++	return err;
++}
++
++void au_xino_clr(struct super_block *sb)
++{
++	struct au_sbinfo *sbinfo;
++
++	au_xigen_clr(sb);
++	xino_clear_xib(sb);
++	xino_clear_br(sb);
++	sbinfo = au_sbi(sb);
++	/* lvalue, do not call au_mntflags() */
++	au_opt_clr(sbinfo->si_mntflags, XINO);
++}
++
++int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount)
++{
++	int err, skip;
++	struct dentry *parent, *cur_parent;
++	struct qstr *dname, *cur_name;
++	struct file *cur_xino;
++	struct inode *dir;
++	struct au_sbinfo *sbinfo;
++
++	SiMustWriteLock(sb);
++
++	err = 0;
++	sbinfo = au_sbi(sb);
++	parent = dget_parent(xino->file->f_dentry);
++	if (remount) {
++		skip = 0;
++		dname = &xino->file->f_dentry->d_name;
++		cur_xino = sbinfo->si_xib;
++		if (cur_xino) {
++			cur_parent = dget_parent(cur_xino->f_dentry);
++			cur_name = &cur_xino->f_dentry->d_name;
++			skip = (cur_parent == parent
++				&& dname->len == cur_name->len
++				&& !memcmp(dname->name, cur_name->name,
++					   dname->len));
++			dput(cur_parent);
++		}
++		if (skip)
++			goto out;
++	}
++
++	au_opt_set(sbinfo->si_mntflags, XINO);
++	dir = parent->d_inode;
++	mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
++	/* mnt_want_write() is unnecessary here */
++	err = au_xino_set_xib(sb, xino->file);
++	if (!err)
++		err = au_xigen_set(sb, xino->file);
++	if (!err)
++		err = au_xino_set_br(sb, xino->file);
++	mutex_unlock(&dir->i_mutex);
++	if (!err)
++		goto out; /* success */
++
++	/* reset all */
++	AuIOErr("failed creating xino(%d).\n", err);
++
++out:
++	dput(parent);
++	return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create a xinofile at the default place/path.
++ */
++struct file *au_xino_def(struct super_block *sb)
++{
++	struct file *file;
++	char *page, *p;
++	struct au_branch *br;
++	struct super_block *h_sb;
++	struct path path;
++	aufs_bindex_t bend, bindex, bwr;
++
++	br = NULL;
++	bend = au_sbend(sb);
++	bwr = -1;
++	for (bindex = 0; bindex <= bend; bindex++) {
++		br = au_sbr(sb, bindex);
++		if (au_br_writable(br->br_perm)
++		    && !au_test_fs_bad_xino(br->br_mnt->mnt_sb)) {
++			bwr = bindex;
++			break;
++		}
++	}
++
++	if (bwr >= 0) {
++		file = ERR_PTR(-ENOMEM);
++		page = __getname_gfp(GFP_NOFS);
++		if (unlikely(!page))
++			goto out;
++		path.mnt = br->br_mnt;
++		path.dentry = au_h_dptr(sb->s_root, bwr);
++		p = d_path(&path, page, PATH_MAX - sizeof(AUFS_XINO_FNAME));
++		file = (void *)p;
++		if (!IS_ERR(p)) {
++			strcat(p, "/" AUFS_XINO_FNAME);
++			AuDbg("%s\n", p);
++			file = au_xino_create(sb, p, /*silent*/0);
++			if (!IS_ERR(file))
++				au_xino_brid_set(sb, br->br_id);
++		}
++		__putname(page);
++	} else {
++		file = au_xino_create(sb, AUFS_XINO_DEFPATH, /*silent*/0);
++		if (IS_ERR(file))
++			goto out;
++		h_sb = file->f_dentry->d_sb;
++		if (unlikely(au_test_fs_bad_xino(h_sb))) {
++			pr_err("xino doesn't support %s(%s)\n",
++			       AUFS_XINO_DEFPATH, au_sbtype(h_sb));
++			fput(file);
++			file = ERR_PTR(-EINVAL);
++		}
++		if (!IS_ERR(file))
++			au_xino_brid_set(sb, -1);
++	}
++
++out:
++	return file;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_xino_path(struct seq_file *seq, struct file *file)
++{
++	int err;
++
++	err = au_seq_path(seq, &file->f_path);
++	if (unlikely(err < 0))
++		goto out;
++
++	err = 0;
++#define Deleted "\\040(deleted)"
++	seq->count -= sizeof(Deleted) - 1;
++	AuDebugOn(memcmp(seq->buf + seq->count, Deleted,
++			 sizeof(Deleted) - 1));
++#undef Deleted
++
++out:
++	return err;
++}
+diff -Nur linux-2.6.36.orig/fs/file_table.c linux-2.6.36/fs/file_table.c
+--- linux-2.6.36.orig/fs/file_table.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/file_table.c	2011-01-10 19:52:38.000000000 +0100
+@@ -394,6 +394,8 @@
+ 	}
+ }
+ 
++EXPORT_SYMBOL(file_sb_list_del);
++
+ #ifdef CONFIG_SMP
+ 
+ /*
+diff -Nur linux-2.6.36.orig/fs/inode.c linux-2.6.36/fs/inode.c
+--- linux-2.6.36.orig/fs/inode.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/inode.c	2011-01-10 19:52:38.000000000 +0100
+@@ -83,6 +83,7 @@
+  * the i_state of an inode while it is in use..
+  */
+ DEFINE_SPINLOCK(inode_lock);
++EXPORT_SYMBOL(inode_lock);
+ 
+ /*
+  * iprune_sem provides exclusion between the kswapd or try_to_free_pages
+diff -Nur linux-2.6.36.orig/fs/namei.c linux-2.6.36/fs/namei.c
+--- linux-2.6.36.orig/fs/namei.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/namei.c	2011-01-10 19:52:38.000000000 +0100
+@@ -347,6 +347,7 @@
+ 
+ 	return 0;
+ }
++EXPORT_SYMBOL(deny_write_access);
+ 
+ /**
+  * path_get - get a reference to a path
+@@ -1159,7 +1160,7 @@
+  * needs parent already locked. Doesn't follow mounts.
+  * SMP-safe.
+  */
+-static struct dentry *lookup_hash(struct nameidata *nd)
++struct dentry *lookup_hash(struct nameidata *nd)
+ {
+ 	int err;
+ 
+@@ -1168,8 +1169,9 @@
+ 		return ERR_PTR(err);
+ 	return __lookup_hash(&nd->last, nd->path.dentry, nd);
+ }
++EXPORT_SYMBOL(lookup_hash);
+ 
+-static int __lookup_one_len(const char *name, struct qstr *this,
++int __lookup_one_len(const char *name, struct qstr *this,
+ 		struct dentry *base, int len)
+ {
+ 	unsigned long hash;
+@@ -1190,6 +1192,7 @@
+ 	this->hash = end_name_hash(hash);
+ 	return 0;
+ }
++EXPORT_SYMBOL(__lookup_one_len);
+ 
+ /**
+  * lookup_one_len - filesystem helper to lookup single pathname component
+diff -Nur linux-2.6.36.orig/fs/namei.c.orig linux-2.6.36/fs/namei.c.orig
+--- linux-2.6.36.orig/fs/namei.c.orig	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/namei.c.orig	2011-01-10 19:52:38.000000000 +0100
+@@ -0,0 +1,2921 @@
++/*
++ *  linux/fs/namei.c
++ *
++ *  Copyright (C) 1991, 1992  Linus Torvalds
++ */
++
++/*
++ * Some corrections by tytso.
++ */
++
++/* [Feb 1997 T. Schoebel-Theuer] Complete rewrite of the pathname
++ * lookup logic.
++ */
++/* [Feb-Apr 2000, AV] Rewrite to the new namespace architecture.
++ */
++
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/slab.h>
++#include <linux/fs.h>
++#include <linux/namei.h>
++#include <linux/pagemap.h>
++#include <linux/fsnotify.h>
++#include <linux/personality.h>
++#include <linux/security.h>
++#include <linux/ima.h>
++#include <linux/syscalls.h>
++#include <linux/mount.h>
++#include <linux/audit.h>
++#include <linux/capability.h>
++#include <linux/file.h>
++#include <linux/fcntl.h>
++#include <linux/device_cgroup.h>
++#include <linux/fs_struct.h>
++#include <asm/uaccess.h>
++
++#include "internal.h"
++
++/* [Feb-1997 T. Schoebel-Theuer]
++ * Fundamental changes in the pathname lookup mechanisms (namei)
++ * were necessary because of omirr.  The reason is that omirr needs
++ * to know the _real_ pathname, not the user-supplied one, in case
++ * of symlinks (and also when transname replacements occur).
++ *
++ * The new code replaces the old recursive symlink resolution with
++ * an iterative one (in case of non-nested symlink chains).  It does
++ * this with calls to <fs>_follow_link().
++ * As a side effect, dir_namei(), _namei() and follow_link() are now 
++ * replaced with a single function lookup_dentry() that can handle all 
++ * the special cases of the former code.
++ *
++ * With the new dcache, the pathname is stored at each inode, at least as
++ * long as the refcount of the inode is positive.  As a side effect, the
++ * size of the dcache depends on the inode cache and thus is dynamic.
++ *
++ * [29-Apr-1998 C. Scott Ananian] Updated above description of symlink
++ * resolution to correspond with current state of the code.
++ *
++ * Note that the symlink resolution is not *completely* iterative.
++ * There is still a significant amount of tail- and mid- recursion in
++ * the algorithm.  Also, note that <fs>_readlink() is not used in
++ * lookup_dentry(): lookup_dentry() on the result of <fs>_readlink()
++ * may return different results than <fs>_follow_link().  Many virtual
++ * filesystems (including /proc) exhibit this behavior.
++ */
++
++/* [24-Feb-97 T. Schoebel-Theuer] Side effects caused by new implementation:
++ * New symlink semantics: when open() is called with flags O_CREAT | O_EXCL
++ * and the name already exists in form of a symlink, try to create the new
++ * name indicated by the symlink. The old code always complained that the
++ * name already exists, due to not following the symlink even if its target
++ * is nonexistent.  The new semantics affects also mknod() and link() when
++ * the name is a symlink pointing to a non-existant name.
++ *
++ * I don't know which semantics is the right one, since I have no access
++ * to standards. But I found by trial that HP-UX 9.0 has the full "new"
++ * semantics implemented, while SunOS 4.1.1 and Solaris (SunOS 5.4) have the
++ * "old" one. Personally, I think the new semantics is much more logical.
++ * Note that "ln old new" where "new" is a symlink pointing to a non-existing
++ * file does succeed in both HP-UX and SunOs, but not in Solaris
++ * and in the old Linux semantics.
++ */
++
++/* [16-Dec-97 Kevin Buhr] For security reasons, we change some symlink
++ * semantics.  See the comments in "open_namei" and "do_link" below.
++ *
++ * [10-Sep-98 Alan Modra] Another symlink change.
++ */
++
++/* [Feb-Apr 2000 AV] Complete rewrite. Rules for symlinks:
++ *	inside the path - always follow.
++ *	in the last component in creation/removal/renaming - never follow.
++ *	if LOOKUP_FOLLOW passed - follow.
++ *	if the pathname has trailing slashes - follow.
++ *	otherwise - don't follow.
++ * (applied in that order).
++ *
++ * [Jun 2000 AV] Inconsistent behaviour of open() in case if flags==O_CREAT
++ * restored for 2.4. This is the last surviving part of old 4.2BSD bug.
++ * During the 2.4 we need to fix the userland stuff depending on it -
++ * hopefully we will be able to get rid of that wart in 2.5. So far only
++ * XEmacs seems to be relying on it...
++ */
++/*
++ * [Sep 2001 AV] Single-semaphore locking scheme (kudos to David Holland)
++ * implemented.  Let's see if raised priority of ->s_vfs_rename_mutex gives
++ * any extra contention...
++ */
++
++/* In order to reduce some races, while at the same time doing additional
++ * checking and hopefully speeding things up, we copy filenames to the
++ * kernel data space before using them..
++ *
++ * POSIX.1 2.4: an empty pathname is invalid (ENOENT).
++ * PATH_MAX includes the nul terminator --RR.
++ */
++static int do_getname(const char __user *filename, char *page)
++{
++	int retval;
++	unsigned long len = PATH_MAX;
++
++	if (!segment_eq(get_fs(), KERNEL_DS)) {
++		if ((unsigned long) filename >= TASK_SIZE)
++			return -EFAULT;
++		if (TASK_SIZE - (unsigned long) filename < PATH_MAX)
++			len = TASK_SIZE - (unsigned long) filename;
++	}
++
++	retval = strncpy_from_user(page, filename, len);
++	if (retval > 0) {
++		if (retval < len)
++			return 0;
++		return -ENAMETOOLONG;
++	} else if (!retval)
++		retval = -ENOENT;
++	return retval;
++}
++
++char * getname(const char __user * filename)
++{
++	char *tmp, *result;
++
++	result = ERR_PTR(-ENOMEM);
++	tmp = __getname();
++	if (tmp)  {
++		int retval = do_getname(filename, tmp);
++
++		result = tmp;
++		if (retval < 0) {
++			__putname(tmp);
++			result = ERR_PTR(retval);
++		}
++	}
++	audit_getname(result);
++	return result;
++}
++
++#ifdef CONFIG_AUDITSYSCALL
++void putname(const char *name)
++{
++	if (unlikely(!audit_dummy_context()))
++		audit_putname(name);
++	else
++		__putname(name);
++}
++EXPORT_SYMBOL(putname);
++#endif
++
++/*
++ * This does basic POSIX ACL permission checking
++ */
++static int acl_permission_check(struct inode *inode, int mask,
++		int (*check_acl)(struct inode *inode, int mask))
++{
++	umode_t			mode = inode->i_mode;
++
++	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
++
++	if (current_fsuid() == inode->i_uid)
++		mode >>= 6;
++	else {
++		if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
++			int error = check_acl(inode, mask);
++			if (error != -EAGAIN)
++				return error;
++		}
++
++		if (in_group_p(inode->i_gid))
++			mode >>= 3;
++	}
++
++	/*
++	 * If the DACs are ok we don't need any capability check.
++	 */
++	if ((mask & ~mode) == 0)
++		return 0;
++	return -EACCES;
++}
++
++/**
++ * generic_permission  -  check for access rights on a Posix-like filesystem
++ * @inode:	inode to check access rights for
++ * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
++ * @check_acl:	optional callback to check for Posix ACLs
++ *
++ * Used to check for read/write/execute permissions on a file.
++ * We use "fsuid" for this, letting us set arbitrary permissions
++ * for filesystem access without changing the "normal" uids which
++ * are used for other things..
++ */
++int generic_permission(struct inode *inode, int mask,
++		int (*check_acl)(struct inode *inode, int mask))
++{
++	int ret;
++
++	/*
++	 * Do the basic POSIX ACL permission checks.
++	 */
++	ret = acl_permission_check(inode, mask, check_acl);
++	if (ret != -EACCES)
++		return ret;
++
++	/*
++	 * Read/write DACs are always overridable.
++	 * Executable DACs are overridable if at least one exec bit is set.
++	 */
++	if (!(mask & MAY_EXEC) || execute_ok(inode))
++		if (capable(CAP_DAC_OVERRIDE))
++			return 0;
++
++	/*
++	 * Searching includes executable on directories, else just read.
++	 */
++	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
++	if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
++		if (capable(CAP_DAC_READ_SEARCH))
++			return 0;
++
++	return -EACCES;
++}
++
++/**
++ * inode_permission  -  check for access rights to a given inode
++ * @inode:	inode to check permission on
++ * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
++ *
++ * Used to check for read/write/execute permissions on an inode.
++ * We use "fsuid" for this, letting us set arbitrary permissions
++ * for filesystem access without changing the "normal" uids which
++ * are used for other things.
++ */
++int inode_permission(struct inode *inode, int mask)
++{
++	int retval;
++
++	if (mask & MAY_WRITE) {
++		umode_t mode = inode->i_mode;
++
++		/*
++		 * Nobody gets write access to a read-only fs.
++		 */
++		if (IS_RDONLY(inode) &&
++		    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
++			return -EROFS;
++
++		/*
++		 * Nobody gets write access to an immutable file.
++		 */
++		if (IS_IMMUTABLE(inode))
++			return -EACCES;
++	}
++
++	if (inode->i_op->permission)
++		retval = inode->i_op->permission(inode, mask);
++	else
++		retval = generic_permission(inode, mask, inode->i_op->check_acl);
++
++	if (retval)
++		return retval;
++
++	retval = devcgroup_inode_permission(inode, mask);
++	if (retval)
++		return retval;
++
++	return security_inode_permission(inode, mask);
++}
++
++/**
++ * file_permission  -  check for additional access rights to a given file
++ * @file:	file to check access rights for
++ * @mask:	right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
++ *
++ * Used to check for read/write/execute permissions on an already opened
++ * file.
++ *
++ * Note:
++ *	Do not use this function in new code.  All access checks should
++ *	be done using inode_permission().
++ */
++int file_permission(struct file *file, int mask)
++{
++	return inode_permission(file->f_path.dentry->d_inode, mask);
++}
++
++/*
++ * get_write_access() gets write permission for a file.
++ * put_write_access() releases this write permission.
++ * This is used for regular files.
++ * We cannot support write (and maybe mmap read-write shared) accesses and
++ * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
++ * can have the following values:
++ * 0: no writers, no VM_DENYWRITE mappings
++ * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
++ * > 0: (i_writecount) users are writing to the file.
++ *
++ * Normally we operate on that counter with atomic_{inc,dec} and it's safe
++ * except for the cases where we don't hold i_writecount yet. Then we need to
++ * use {get,deny}_write_access() - these functions check the sign and refuse
++ * to do the change if sign is wrong. Exclusion between them is provided by
++ * the inode->i_lock spinlock.
++ */
++
++int get_write_access(struct inode * inode)
++{
++	spin_lock(&inode->i_lock);
++	if (atomic_read(&inode->i_writecount) < 0) {
++		spin_unlock(&inode->i_lock);
++		return -ETXTBSY;
++	}
++	atomic_inc(&inode->i_writecount);
++	spin_unlock(&inode->i_lock);
++
++	return 0;
++}
++
++int deny_write_access(struct file * file)
++{
++	struct inode *inode = file->f_path.dentry->d_inode;
++
++	spin_lock(&inode->i_lock);
++	if (atomic_read(&inode->i_writecount) > 0) {
++		spin_unlock(&inode->i_lock);
++		return -ETXTBSY;
++	}
++	atomic_dec(&inode->i_writecount);
++	spin_unlock(&inode->i_lock);
++
++	return 0;
++}
++EXPORT_SYMBOL(deny_write_access);
++
++/**
++ * path_get - get a reference to a path
++ * @path: path to get the reference to
++ *
++ * Given a path increment the reference count to the dentry and the vfsmount.
++ */
++void path_get(struct path *path)
++{
++	mntget(path->mnt);
++	dget(path->dentry);
++}
++EXPORT_SYMBOL(path_get);
++
++/**
++ * path_put - put a reference to a path
++ * @path: path to put the reference to
++ *
++ * Given a path decrement the reference count to the dentry and the vfsmount.
++ */
++void path_put(struct path *path)
++{
++	dput(path->dentry);
++	mntput(path->mnt);
++}
++EXPORT_SYMBOL(path_put);
++
++/**
++ * release_open_intent - free up open intent resources
++ * @nd: pointer to nameidata
++ */
++void release_open_intent(struct nameidata *nd)
++{
++	if (nd->intent.open.file->f_path.dentry == NULL)
++		put_filp(nd->intent.open.file);
++	else
++		fput(nd->intent.open.file);
++}
++
++static inline struct dentry *
++do_revalidate(struct dentry *dentry, struct nameidata *nd)
++{
++	int status = dentry->d_op->d_revalidate(dentry, nd);
++	if (unlikely(status <= 0)) {
++		/*
++		 * The dentry failed validation.
++		 * If d_revalidate returned 0 attempt to invalidate
++		 * the dentry otherwise d_revalidate is asking us
++		 * to return a fail status.
++		 */
++		if (!status) {
++			if (!d_invalidate(dentry)) {
++				dput(dentry);
++				dentry = NULL;
++			}
++		} else {
++			dput(dentry);
++			dentry = ERR_PTR(status);
++		}
++	}
++	return dentry;
++}
++
++/*
++ * force_reval_path - force revalidation of a dentry
++ *
++ * In some situations the path walking code will trust dentries without
++ * revalidating them. This causes problems for filesystems that depend on
++ * d_revalidate to handle file opens (e.g. NFSv4). When FS_REVAL_DOT is set
++ * (which indicates that it's possible for the dentry to go stale), force
++ * a d_revalidate call before proceeding.
++ *
++ * Returns 0 if the revalidation was successful. If the revalidation fails,
++ * either return the error returned by d_revalidate or -ESTALE if the
++ * revalidation it just returned 0. If d_revalidate returns 0, we attempt to
++ * invalidate the dentry. It's up to the caller to handle putting references
++ * to the path if necessary.
++ */
++static int
++force_reval_path(struct path *path, struct nameidata *nd)
++{
++	int status;
++	struct dentry *dentry = path->dentry;
++
++	/*
++	 * only check on filesystems where it's possible for the dentry to
++	 * become stale. It's assumed that if this flag is set then the
++	 * d_revalidate op will also be defined.
++	 */
++	if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT))
++		return 0;
++
++	status = dentry->d_op->d_revalidate(dentry, nd);
++	if (status > 0)
++		return 0;
++
++	if (!status) {
++		d_invalidate(dentry);
++		status = -ESTALE;
++	}
++	return status;
++}
++
++/*
++ * Short-cut version of permission(), for calling on directories
++ * during pathname resolution.  Combines parts of permission()
++ * and generic_permission(), and tests ONLY for MAY_EXEC permission.
++ *
++ * If appropriate, check DAC only.  If not appropriate, or
++ * short-cut DAC fails, then call ->permission() to do more
++ * complete permission check.
++ */
++static int exec_permission(struct inode *inode)
++{
++	int ret;
++
++	if (inode->i_op->permission) {
++		ret = inode->i_op->permission(inode, MAY_EXEC);
++		if (!ret)
++			goto ok;
++		return ret;
++	}
++	ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl);
++	if (!ret)
++		goto ok;
++
++	if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
++		goto ok;
++
++	return ret;
++ok:
++	return security_inode_permission(inode, MAY_EXEC);
++}
++
++static __always_inline void set_root(struct nameidata *nd)
++{
++	if (!nd->root.mnt)
++		get_fs_root(current->fs, &nd->root);
++}
++
++static int link_path_walk(const char *, struct nameidata *);
++
++static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link)
++{
++	if (IS_ERR(link))
++		goto fail;
++
++	if (*link == '/') {
++		set_root(nd);
++		path_put(&nd->path);
++		nd->path = nd->root;
++		path_get(&nd->root);
++	}
++
++	return link_path_walk(link, nd);
++fail:
++	path_put(&nd->path);
++	return PTR_ERR(link);
++}
++
++static void path_put_conditional(struct path *path, struct nameidata *nd)
++{
++	dput(path->dentry);
++	if (path->mnt != nd->path.mnt)
++		mntput(path->mnt);
++}
++
++static inline void path_to_nameidata(struct path *path, struct nameidata *nd)
++{
++	dput(nd->path.dentry);
++	if (nd->path.mnt != path->mnt) {
++		mntput(nd->path.mnt);
++		nd->path.mnt = path->mnt;
++	}
++	nd->path.dentry = path->dentry;
++}
++
++static __always_inline int
++__do_follow_link(struct path *path, struct nameidata *nd, void **p)
++{
++	int error;
++	struct dentry *dentry = path->dentry;
++
++	touch_atime(path->mnt, dentry);
++	nd_set_link(nd, NULL);
++
++	if (path->mnt != nd->path.mnt) {
++		path_to_nameidata(path, nd);
++		dget(dentry);
++	}
++	mntget(path->mnt);
++	nd->last_type = LAST_BIND;
++	*p = dentry->d_inode->i_op->follow_link(dentry, nd);
++	error = PTR_ERR(*p);
++	if (!IS_ERR(*p)) {
++		char *s = nd_get_link(nd);
++		error = 0;
++		if (s)
++			error = __vfs_follow_link(nd, s);
++		else if (nd->last_type == LAST_BIND) {
++			error = force_reval_path(&nd->path, nd);
++			if (error)
++				path_put(&nd->path);
++		}
++	}
++	return error;
++}
++
++/*
++ * This limits recursive symlink follows to 8, while
++ * limiting consecutive symlinks to 40.
++ *
++ * Without that kind of total limit, nasty chains of consecutive
++ * symlinks can cause almost arbitrarily long lookups. 
++ */
++static inline int do_follow_link(struct path *path, struct nameidata *nd)
++{
++	void *cookie;
++	int err = -ELOOP;
++	if (current->link_count >= MAX_NESTED_LINKS)
++		goto loop;
++	if (current->total_link_count >= 40)
++		goto loop;
++	BUG_ON(nd->depth >= MAX_NESTED_LINKS);
++	cond_resched();
++	err = security_inode_follow_link(path->dentry, nd);
++	if (err)
++		goto loop;
++	current->link_count++;
++	current->total_link_count++;
++	nd->depth++;
++	err = __do_follow_link(path, nd, &cookie);
++	if (!IS_ERR(cookie) && path->dentry->d_inode->i_op->put_link)
++		path->dentry->d_inode->i_op->put_link(path->dentry, nd, cookie);
++	path_put(path);
++	current->link_count--;
++	nd->depth--;
++	return err;
++loop:
++	path_put_conditional(path, nd);
++	path_put(&nd->path);
++	return err;
++}
++
++int follow_up(struct path *path)
++{
++	struct vfsmount *parent;
++	struct dentry *mountpoint;
++
++	br_read_lock(vfsmount_lock);
++	parent = path->mnt->mnt_parent;
++	if (parent == path->mnt) {
++		br_read_unlock(vfsmount_lock);
++		return 0;
++	}
++	mntget(parent);
++	mountpoint = dget(path->mnt->mnt_mountpoint);
++	br_read_unlock(vfsmount_lock);
++	dput(path->dentry);
++	path->dentry = mountpoint;
++	mntput(path->mnt);
++	path->mnt = parent;
++	return 1;
++}
++
++/* no need for dcache_lock, as serialization is taken care in
++ * namespace.c
++ */
++static int __follow_mount(struct path *path)
++{
++	int res = 0;
++	while (d_mountpoint(path->dentry)) {
++		struct vfsmount *mounted = lookup_mnt(path);
++		if (!mounted)
++			break;
++		dput(path->dentry);
++		if (res)
++			mntput(path->mnt);
++		path->mnt = mounted;
++		path->dentry = dget(mounted->mnt_root);
++		res = 1;
++	}
++	return res;
++}
++
++static void follow_mount(struct path *path)
++{
++	while (d_mountpoint(path->dentry)) {
++		struct vfsmount *mounted = lookup_mnt(path);
++		if (!mounted)
++			break;
++		dput(path->dentry);
++		mntput(path->mnt);
++		path->mnt = mounted;
++		path->dentry = dget(mounted->mnt_root);
++	}
++}
++
++/* no need for dcache_lock, as serialization is taken care in
++ * namespace.c
++ */
++int follow_down(struct path *path)
++{
++	struct vfsmount *mounted;
++
++	mounted = lookup_mnt(path);
++	if (mounted) {
++		dput(path->dentry);
++		mntput(path->mnt);
++		path->mnt = mounted;
++		path->dentry = dget(mounted->mnt_root);
++		return 1;
++	}
++	return 0;
++}
++
++static __always_inline void follow_dotdot(struct nameidata *nd)
++{
++	set_root(nd);
++
++	while(1) {
++		struct dentry *old = nd->path.dentry;
++
++		if (nd->path.dentry == nd->root.dentry &&
++		    nd->path.mnt == nd->root.mnt) {
++			break;
++		}
++		if (nd->path.dentry != nd->path.mnt->mnt_root) {
++			/* rare case of legitimate dget_parent()... */
++			nd->path.dentry = dget_parent(nd->path.dentry);
++			dput(old);
++			break;
++		}
++		if (!follow_up(&nd->path))
++			break;
++	}
++	follow_mount(&nd->path);
++}
++
++/*
++ * Allocate a dentry with name and parent, and perform a parent
++ * directory ->lookup on it. Returns the new dentry, or ERR_PTR
++ * on error. parent->d_inode->i_mutex must be held. d_lookup must
++ * have verified that no child exists while under i_mutex.
++ */
++static struct dentry *d_alloc_and_lookup(struct dentry *parent,
++				struct qstr *name, struct nameidata *nd)
++{
++	struct inode *inode = parent->d_inode;
++	struct dentry *dentry;
++	struct dentry *old;
++
++	/* Don't create child dentry for a dead directory. */
++	if (unlikely(IS_DEADDIR(inode)))
++		return ERR_PTR(-ENOENT);
++
++	dentry = d_alloc(parent, name);
++	if (unlikely(!dentry))
++		return ERR_PTR(-ENOMEM);
++
++	old = inode->i_op->lookup(inode, dentry, nd);
++	if (unlikely(old)) {
++		dput(dentry);
++		dentry = old;
++	}
++	return dentry;
++}
++
++/*
++ *  It's more convoluted than I'd like it to be, but... it's still fairly
++ *  small and for now I'd prefer to have fast path as straight as possible.
++ *  It _is_ time-critical.
++ */
++static int do_lookup(struct nameidata *nd, struct qstr *name,
++		     struct path *path)
++{
++	struct vfsmount *mnt = nd->path.mnt;
++	struct dentry *dentry, *parent;
++	struct inode *dir;
++	/*
++	 * See if the low-level filesystem might want
++	 * to use its own hash..
++	 */
++	if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) {
++		int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name);
++		if (err < 0)
++			return err;
++	}
++
++	/*
++	 * Rename seqlock is not required here because in the off chance
++	 * of a false negative due to a concurrent rename, we're going to
++	 * do the non-racy lookup, below.
++	 */
++	dentry = __d_lookup(nd->path.dentry, name);
++	if (!dentry)
++		goto need_lookup;
++found:
++	if (dentry->d_op && dentry->d_op->d_revalidate)
++		goto need_revalidate;
++done:
++	path->mnt = mnt;
++	path->dentry = dentry;
++	__follow_mount(path);
++	return 0;
++
++need_lookup:
++	parent = nd->path.dentry;
++	dir = parent->d_inode;
++
++	mutex_lock(&dir->i_mutex);
++	/*
++	 * First re-do the cached lookup just in case it was created
++	 * while we waited for the directory semaphore, or the first
++	 * lookup failed due to an unrelated rename.
++	 *
++	 * This could use version numbering or similar to avoid unnecessary
++	 * cache lookups, but then we'd have to do the first lookup in the
++	 * non-racy way. However in the common case here, everything should
++	 * be hot in cache, so would it be a big win?
++	 */
++	dentry = d_lookup(parent, name);
++	if (likely(!dentry)) {
++		dentry = d_alloc_and_lookup(parent, name, nd);
++		mutex_unlock(&dir->i_mutex);
++		if (IS_ERR(dentry))
++			goto fail;
++		goto done;
++	}
++	/*
++	 * Uhhuh! Nasty case: the cache was re-populated while
++	 * we waited on the semaphore. Need to revalidate.
++	 */
++	mutex_unlock(&dir->i_mutex);
++	goto found;
++
++need_revalidate:
++	dentry = do_revalidate(dentry, nd);
++	if (!dentry)
++		goto need_lookup;
++	if (IS_ERR(dentry))
++		goto fail;
++	goto done;
++
++fail:
++	return PTR_ERR(dentry);
++}
++
++/*
++ * This is a temporary kludge to deal with "automount" symlinks; proper
++ * solution is to trigger them on follow_mount(), so that do_lookup()
++ * would DTRT.  To be killed before 2.6.34-final.
++ */
++static inline int follow_on_final(struct inode *inode, unsigned lookup_flags)
++{
++	return inode && unlikely(inode->i_op->follow_link) &&
++		((lookup_flags & LOOKUP_FOLLOW) || S_ISDIR(inode->i_mode));
++}
++
++/*
++ * Name resolution.
++ * This is the basic name resolution function, turning a pathname into
++ * the final dentry. We expect 'base' to be positive and a directory.
++ *
++ * Returns 0 and nd will have valid dentry and mnt on success.
++ * Returns error and drops reference to input namei data on failure.
++ */
++static int link_path_walk(const char *name, struct nameidata *nd)
++{
++	struct path next;
++	struct inode *inode;
++	int err;
++	unsigned int lookup_flags = nd->flags;
++	
++	while (*name=='/')
++		name++;
++	if (!*name)
++		goto return_reval;
++
++	inode = nd->path.dentry->d_inode;
++	if (nd->depth)
++		lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE);
++
++	/* At this point we know we have a real path component. */
++	for(;;) {
++		unsigned long hash;
++		struct qstr this;
++		unsigned int c;
++
++		nd->flags |= LOOKUP_CONTINUE;
++		err = exec_permission(inode);
++ 		if (err)
++			break;
++
++		this.name = name;
++		c = *(const unsigned char *)name;
++
++		hash = init_name_hash();
++		do {
++			name++;
++			hash = partial_name_hash(c, hash);
++			c = *(const unsigned char *)name;
++		} while (c && (c != '/'));
++		this.len = name - (const char *) this.name;
++		this.hash = end_name_hash(hash);
++
++		/* remove trailing slashes? */
++		if (!c)
++			goto last_component;
++		while (*++name == '/');
++		if (!*name)
++			goto last_with_slashes;
++
++		/*
++		 * "." and ".." are special - ".." especially so because it has
++		 * to be able to know about the current root directory and
++		 * parent relationships.
++		 */
++		if (this.name[0] == '.') switch (this.len) {
++			default:
++				break;
++			case 2:	
++				if (this.name[1] != '.')
++					break;
++				follow_dotdot(nd);
++				inode = nd->path.dentry->d_inode;
++				/* fallthrough */
++			case 1:
++				continue;
++		}
++		/* This does the actual lookups.. */
++		err = do_lookup(nd, &this, &next);
++		if (err)
++			break;
++
++		err = -ENOENT;
++		inode = next.dentry->d_inode;
++		if (!inode)
++			goto out_dput;
++
++		if (inode->i_op->follow_link) {
++			err = do_follow_link(&next, nd);
++			if (err)
++				goto return_err;
++			err = -ENOENT;
++			inode = nd->path.dentry->d_inode;
++			if (!inode)
++				break;
++		} else
++			path_to_nameidata(&next, nd);
++		err = -ENOTDIR; 
++		if (!inode->i_op->lookup)
++			break;
++		continue;
++		/* here ends the main loop */
++
++last_with_slashes:
++		lookup_flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
++last_component:
++		/* Clear LOOKUP_CONTINUE iff it was previously unset */
++		nd->flags &= lookup_flags | ~LOOKUP_CONTINUE;
++		if (lookup_flags & LOOKUP_PARENT)
++			goto lookup_parent;
++		if (this.name[0] == '.') switch (this.len) {
++			default:
++				break;
++			case 2:	
++				if (this.name[1] != '.')
++					break;
++				follow_dotdot(nd);
++				inode = nd->path.dentry->d_inode;
++				/* fallthrough */
++			case 1:
++				goto return_reval;
++		}
++		err = do_lookup(nd, &this, &next);
++		if (err)
++			break;
++		inode = next.dentry->d_inode;
++		if (follow_on_final(inode, lookup_flags)) {
++			err = do_follow_link(&next, nd);
++			if (err)
++				goto return_err;
++			inode = nd->path.dentry->d_inode;
++		} else
++			path_to_nameidata(&next, nd);
++		err = -ENOENT;
++		if (!inode)
++			break;
++		if (lookup_flags & LOOKUP_DIRECTORY) {
++			err = -ENOTDIR; 
++			if (!inode->i_op->lookup)
++				break;
++		}
++		goto return_base;
++lookup_parent:
++		nd->last = this;
++		nd->last_type = LAST_NORM;
++		if (this.name[0] != '.')
++			goto return_base;
++		if (this.len == 1)
++			nd->last_type = LAST_DOT;
++		else if (this.len == 2 && this.name[1] == '.')
++			nd->last_type = LAST_DOTDOT;
++		else
++			goto return_base;
++return_reval:
++		/*
++		 * We bypassed the ordinary revalidation routines.
++		 * We may need to check the cached dentry for staleness.
++		 */
++		if (nd->path.dentry && nd->path.dentry->d_sb &&
++		    (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) {
++			err = -ESTALE;
++			/* Note: we do not d_invalidate() */
++			if (!nd->path.dentry->d_op->d_revalidate(
++					nd->path.dentry, nd))
++				break;
++		}
++return_base:
++		return 0;
++out_dput:
++		path_put_conditional(&next, nd);
++		break;
++	}
++	path_put(&nd->path);
++return_err:
++	return err;
++}
++
++static int path_walk(const char *name, struct nameidata *nd)
++{
++	struct path save = nd->path;
++	int result;
++
++	current->total_link_count = 0;
++
++	/* make sure the stuff we saved doesn't go away */
++	path_get(&save);
++
++	result = link_path_walk(name, nd);
++	if (result == -ESTALE) {
++		/* nd->path had been dropped */
++		current->total_link_count = 0;
++		nd->path = save;
++		path_get(&nd->path);
++		nd->flags |= LOOKUP_REVAL;
++		result = link_path_walk(name, nd);
++	}
++
++	path_put(&save);
++
++	return result;
++}
++
++static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd)
++{
++	int retval = 0;
++	int fput_needed;
++	struct file *file;
++
++	nd->last_type = LAST_ROOT; /* if there are only slashes... */
++	nd->flags = flags;
++	nd->depth = 0;
++	nd->root.mnt = NULL;
++
++	if (*name=='/') {
++		set_root(nd);
++		nd->path = nd->root;
++		path_get(&nd->root);
++	} else if (dfd == AT_FDCWD) {
++		get_fs_pwd(current->fs, &nd->path);
++	} else {
++		struct dentry *dentry;
++
++		file = fget_light(dfd, &fput_needed);
++		retval = -EBADF;
++		if (!file)
++			goto out_fail;
++
++		dentry = file->f_path.dentry;
++
++		retval = -ENOTDIR;
++		if (!S_ISDIR(dentry->d_inode->i_mode))
++			goto fput_fail;
++
++		retval = file_permission(file, MAY_EXEC);
++		if (retval)
++			goto fput_fail;
++
++		nd->path = file->f_path;
++		path_get(&file->f_path);
++
++		fput_light(file, fput_needed);
++	}
++	return 0;
++
++fput_fail:
++	fput_light(file, fput_needed);
++out_fail:
++	return retval;
++}
++
++/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
++static int do_path_lookup(int dfd, const char *name,
++				unsigned int flags, struct nameidata *nd)
++{
++	int retval = path_init(dfd, name, flags, nd);
++	if (!retval)
++		retval = path_walk(name, nd);
++	if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
++				nd->path.dentry->d_inode))
++		audit_inode(name, nd->path.dentry);
++	if (nd->root.mnt) {
++		path_put(&nd->root);
++		nd->root.mnt = NULL;
++	}
++	return retval;
++}
++
++int path_lookup(const char *name, unsigned int flags,
++			struct nameidata *nd)
++{
++	return do_path_lookup(AT_FDCWD, name, flags, nd);
++}
++
++int kern_path(const char *name, unsigned int flags, struct path *path)
++{
++	struct nameidata nd;
++	int res = do_path_lookup(AT_FDCWD, name, flags, &nd);
++	if (!res)
++		*path = nd.path;
++	return res;
++}
++
++/**
++ * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
++ * @dentry:  pointer to dentry of the base directory
++ * @mnt: pointer to vfs mount of the base directory
++ * @name: pointer to file name
++ * @flags: lookup flags
++ * @nd: pointer to nameidata
++ */
++int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
++		    const char *name, unsigned int flags,
++		    struct nameidata *nd)
++{
++	int retval;
++
++	/* same as do_path_lookup */
++	nd->last_type = LAST_ROOT;
++	nd->flags = flags;
++	nd->depth = 0;
++
++	nd->path.dentry = dentry;
++	nd->path.mnt = mnt;
++	path_get(&nd->path);
++	nd->root = nd->path;
++	path_get(&nd->root);
++
++	retval = path_walk(name, nd);
++	if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry &&
++				nd->path.dentry->d_inode))
++		audit_inode(name, nd->path.dentry);
++
++	path_put(&nd->root);
++	nd->root.mnt = NULL;
++
++	return retval;
++}
++
++static struct dentry *__lookup_hash(struct qstr *name,
++		struct dentry *base, struct nameidata *nd)
++{
++	struct dentry *dentry;
++	struct inode *inode;
++	int err;
++
++	inode = base->d_inode;
++
++	/*
++	 * See if the low-level filesystem might want
++	 * to use its own hash..
++	 */
++	if (base->d_op && base->d_op->d_hash) {
++		err = base->d_op->d_hash(base, name);
++		dentry = ERR_PTR(err);
++		if (err < 0)
++			goto out;
++	}
++
++	/*
++	 * Don't bother with __d_lookup: callers are for creat as
++	 * well as unlink, so a lot of the time it would cost
++	 * a double lookup.
++	 */
++	dentry = d_lookup(base, name);
++
++	if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
++		dentry = do_revalidate(dentry, nd);
++
++	if (!dentry)
++		dentry = d_alloc_and_lookup(base, name, nd);
++out:
++	return dentry;
++}
++
++/*
++ * Restricted form of lookup. Doesn't follow links, single-component only,
++ * needs parent already locked. Doesn't follow mounts.
++ * SMP-safe.
++ */
++static struct dentry *lookup_hash(struct nameidata *nd)
++{
++	int err;
++
++	err = exec_permission(nd->path.dentry->d_inode);
++	if (err)
++		return ERR_PTR(err);
++	return __lookup_hash(&nd->last, nd->path.dentry, nd);
++}
++EXPORT_SYMBOL(lookup_hash);
++
++static int __lookup_one_len(const char *name, struct qstr *this,
++		struct dentry *base, int len)
++{
++	unsigned long hash;
++	unsigned int c;
++
++	this->name = name;
++	this->len = len;
++	if (!len)
++		return -EACCES;
++
++	hash = init_name_hash();
++	while (len--) {
++		c = *(const unsigned char *)name++;
++		if (c == '/' || c == '\0')
++			return -EACCES;
++		hash = partial_name_hash(c, hash);
++	}
++	this->hash = end_name_hash(hash);
++	return 0;
++}
++EXPORT_SYMBOL(__lookup_one_len);
++
++/**
++ * lookup_one_len - filesystem helper to lookup single pathname component
++ * @name:	pathname component to lookup
++ * @base:	base directory to lookup from
++ * @len:	maximum length @len should be interpreted to
++ *
++ * Note that this routine is purely a helper for filesystem usage and should
++ * not be called by generic code.  Also note that by using this function the
++ * nameidata argument is passed to the filesystem methods and a filesystem
++ * using this helper needs to be prepared for that.
++ */
++struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
++{
++	int err;
++	struct qstr this;
++
++	WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex));
++
++	err = __lookup_one_len(name, &this, base, len);
++	if (err)
++		return ERR_PTR(err);
++
++	err = exec_permission(base->d_inode);
++	if (err)
++		return ERR_PTR(err);
++	return __lookup_hash(&this, base, NULL);
++}
++
++int user_path_at(int dfd, const char __user *name, unsigned flags,
++		 struct path *path)
++{
++	struct nameidata nd;
++	char *tmp = getname(name);
++	int err = PTR_ERR(tmp);
++	if (!IS_ERR(tmp)) {
++
++		BUG_ON(flags & LOOKUP_PARENT);
++
++		err = do_path_lookup(dfd, tmp, flags, &nd);
++		putname(tmp);
++		if (!err)
++			*path = nd.path;
++	}
++	return err;
++}
++
++static int user_path_parent(int dfd, const char __user *path,
++			struct nameidata *nd, char **name)
++{
++	char *s = getname(path);
++	int error;
++
++	if (IS_ERR(s))
++		return PTR_ERR(s);
++
++	error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd);
++	if (error)
++		putname(s);
++	else
++		*name = s;
++
++	return error;
++}
++
++/*
++ * It's inline, so penalty for filesystems that don't use sticky bit is
++ * minimal.
++ */
++static inline int check_sticky(struct inode *dir, struct inode *inode)
++{
++	uid_t fsuid = current_fsuid();
++
++	if (!(dir->i_mode & S_ISVTX))
++		return 0;
++	if (inode->i_uid == fsuid)
++		return 0;
++	if (dir->i_uid == fsuid)
++		return 0;
++	return !capable(CAP_FOWNER);
++}
++
++/*
++ *	Check whether we can remove a link victim from directory dir, check
++ *  whether the type of victim is right.
++ *  1. We can't do it if dir is read-only (done in permission())
++ *  2. We should have write and exec permissions on dir
++ *  3. We can't remove anything from append-only dir
++ *  4. We can't do anything with immutable dir (done in permission())
++ *  5. If the sticky bit on dir is set we should either
++ *	a. be owner of dir, or
++ *	b. be owner of victim, or
++ *	c. have CAP_FOWNER capability
++ *  6. If the victim is append-only or immutable we can't do antyhing with
++ *     links pointing to it.
++ *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
++ *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
++ *  9. We can't remove a root or mountpoint.
++ * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
++ *     nfs_async_unlink().
++ */
++static int may_delete(struct inode *dir,struct dentry *victim,int isdir)
++{
++	int error;
++
++	if (!victim->d_inode)
++		return -ENOENT;
++
++	BUG_ON(victim->d_parent->d_inode != dir);
++	audit_inode_child(victim, dir);
++
++	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
++	if (error)
++		return error;
++	if (IS_APPEND(dir))
++		return -EPERM;
++	if (check_sticky(dir, victim->d_inode)||IS_APPEND(victim->d_inode)||
++	    IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
++		return -EPERM;
++	if (isdir) {
++		if (!S_ISDIR(victim->d_inode->i_mode))
++			return -ENOTDIR;
++		if (IS_ROOT(victim))
++			return -EBUSY;
++	} else if (S_ISDIR(victim->d_inode->i_mode))
++		return -EISDIR;
++	if (IS_DEADDIR(dir))
++		return -ENOENT;
++	if (victim->d_flags & DCACHE_NFSFS_RENAMED)
++		return -EBUSY;
++	return 0;
++}
++
++/*	Check whether we can create an object with dentry child in directory
++ *  dir.
++ *  1. We can't do it if child already exists (open has special treatment for
++ *     this case, but since we are inlined it's OK)
++ *  2. We can't do it if dir is read-only (done in permission())
++ *  3. We should have write and exec permissions on dir
++ *  4. We can't do it if dir is immutable (done in permission())
++ */
++static inline int may_create(struct inode *dir, struct dentry *child)
++{
++	if (child->d_inode)
++		return -EEXIST;
++	if (IS_DEADDIR(dir))
++		return -ENOENT;
++	return inode_permission(dir, MAY_WRITE | MAY_EXEC);
++}
++
++/*
++ * p1 and p2 should be directories on the same fs.
++ */
++struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
++{
++	struct dentry *p;
++
++	if (p1 == p2) {
++		mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
++		return NULL;
++	}
++
++	mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
++
++	p = d_ancestor(p2, p1);
++	if (p) {
++		mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
++		mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
++		return p;
++	}
++
++	p = d_ancestor(p1, p2);
++	if (p) {
++		mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
++		mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
++		return p;
++	}
++
++	mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
++	mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
++	return NULL;
++}
++
++void unlock_rename(struct dentry *p1, struct dentry *p2)
++{
++	mutex_unlock(&p1->d_inode->i_mutex);
++	if (p1 != p2) {
++		mutex_unlock(&p2->d_inode->i_mutex);
++		mutex_unlock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
++	}
++}
++
++int vfs_create(struct inode *dir, struct dentry *dentry, int mode,
++		struct nameidata *nd)
++{
++	int error = may_create(dir, dentry);
++
++	if (error)
++		return error;
++
++	if (!dir->i_op->create)
++		return -EACCES;	/* shouldn't it be ENOSYS? */
++	mode &= S_IALLUGO;
++	mode |= S_IFREG;
++	error = security_inode_create(dir, dentry, mode);
++	if (error)
++		return error;
++	error = dir->i_op->create(dir, dentry, mode, nd);
++	if (!error)
++		fsnotify_create(dir, dentry);
++	return error;
++}
++
++int may_open(struct path *path, int acc_mode, int flag)
++{
++	struct dentry *dentry = path->dentry;
++	struct inode *inode = dentry->d_inode;
++	int error;
++
++	if (!inode)
++		return -ENOENT;
++
++	switch (inode->i_mode & S_IFMT) {
++	case S_IFLNK:
++		return -ELOOP;
++	case S_IFDIR:
++		if (acc_mode & MAY_WRITE)
++			return -EISDIR;
++		break;
++	case S_IFBLK:
++	case S_IFCHR:
++		if (path->mnt->mnt_flags & MNT_NODEV)
++			return -EACCES;
++		/*FALLTHRU*/
++	case S_IFIFO:
++	case S_IFSOCK:
++		flag &= ~O_TRUNC;
++		break;
++	}
++
++	error = inode_permission(inode, acc_mode);
++	if (error)
++		return error;
++
++	/*
++	 * An append-only file must be opened in append mode for writing.
++	 */
++	if (IS_APPEND(inode)) {
++		if  ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND))
++			return -EPERM;
++		if (flag & O_TRUNC)
++			return -EPERM;
++	}
++
++	/* O_NOATIME can only be set by the owner or superuser */
++	if (flag & O_NOATIME && !is_owner_or_cap(inode))
++		return -EPERM;
++
++	/*
++	 * Ensure there are no outstanding leases on the file.
++	 */
++	return break_lease(inode, flag);
++}
++
++static int handle_truncate(struct path *path)
++{
++	struct inode *inode = path->dentry->d_inode;
++	int error = get_write_access(inode);
++	if (error)
++		return error;
++	/*
++	 * Refuse to truncate files with mandatory locks held on them.
++	 */
++	error = locks_verify_locked(inode);
++	if (!error)
++		error = security_path_truncate(path);
++	if (!error) {
++		error = do_truncate(path->dentry, 0,
++				    ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
++				    NULL);
++	}
++	put_write_access(inode);
++	return error;
++}
++
++/*
++ * Be careful about ever adding any more callers of this
++ * function.  Its flags must be in the namei format, not
++ * what get passed to sys_open().
++ */
++static int __open_namei_create(struct nameidata *nd, struct path *path,
++				int open_flag, int mode)
++{
++	int error;
++	struct dentry *dir = nd->path.dentry;
++
++	if (!IS_POSIXACL(dir->d_inode))
++		mode &= ~current_umask();
++	error = security_path_mknod(&nd->path, path->dentry, mode, 0);
++	if (error)
++		goto out_unlock;
++	error = vfs_create(dir->d_inode, path->dentry, mode, nd);
++out_unlock:
++	mutex_unlock(&dir->d_inode->i_mutex);
++	dput(nd->path.dentry);
++	nd->path.dentry = path->dentry;
++	if (error)
++		return error;
++	/* Don't check for write permission, don't truncate */
++	return may_open(&nd->path, 0, open_flag & ~O_TRUNC);
++}
++
++/*
++ * Note that while the flag value (low two bits) for sys_open means:
++ *	00 - read-only
++ *	01 - write-only
++ *	10 - read-write
++ *	11 - special
++ * it is changed into
++ *	00 - no permissions needed
++ *	01 - read-permission
++ *	10 - write-permission
++ *	11 - read-write
++ * for the internal routines (ie open_namei()/follow_link() etc)
++ * This is more logical, and also allows the 00 "no perm needed"
++ * to be used for symlinks (where the permissions are checked
++ * later).
++ *
++*/
++static inline int open_to_namei_flags(int flag)
++{
++	if ((flag+1) & O_ACCMODE)
++		flag++;
++	return flag;
++}
++
++static int open_will_truncate(int flag, struct inode *inode)
++{
++	/*
++	 * We'll never write to the fs underlying
++	 * a device file.
++	 */
++	if (special_file(inode->i_mode))
++		return 0;
++	return (flag & O_TRUNC);
++}
++
++static struct file *finish_open(struct nameidata *nd,
++				int open_flag, int acc_mode)
++{
++	struct file *filp;
++	int will_truncate;
++	int error;
++
++	will_truncate = open_will_truncate(open_flag, nd->path.dentry->d_inode);
++	if (will_truncate) {
++		error = mnt_want_write(nd->path.mnt);
++		if (error)
++			goto exit;
++	}
++	error = may_open(&nd->path, acc_mode, open_flag);
++	if (error) {
++		if (will_truncate)
++			mnt_drop_write(nd->path.mnt);
++		goto exit;
++	}
++	filp = nameidata_to_filp(nd);
++	if (!IS_ERR(filp)) {
++		error = ima_file_check(filp, acc_mode);
++		if (error) {
++			fput(filp);
++			filp = ERR_PTR(error);
++		}
++	}
++	if (!IS_ERR(filp)) {
++		if (will_truncate) {
++			error = handle_truncate(&nd->path);
++			if (error) {
++				fput(filp);
++				filp = ERR_PTR(error);
++			}
++		}
++	}
++	/*
++	 * It is now safe to drop the mnt write
++	 * because the filp has had a write taken
++	 * on its behalf.
++	 */
++	if (will_truncate)
++		mnt_drop_write(nd->path.mnt);
++	return filp;
++
++exit:
++	if (!IS_ERR(nd->intent.open.file))
++		release_open_intent(nd);
++	path_put(&nd->path);
++	return ERR_PTR(error);
++}
++
++static struct file *do_last(struct nameidata *nd, struct path *path,
++			    int open_flag, int acc_mode,
++			    int mode, const char *pathname)
++{
++	struct dentry *dir = nd->path.dentry;
++	struct file *filp;
++	int error = -EISDIR;
++
++	switch (nd->last_type) {
++	case LAST_DOTDOT:
++		follow_dotdot(nd);
++		dir = nd->path.dentry;
++	case LAST_DOT:
++		if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) {
++			if (!dir->d_op->d_revalidate(dir, nd)) {
++				error = -ESTALE;
++				goto exit;
++			}
++		}
++		/* fallthrough */
++	case LAST_ROOT:
++		if (open_flag & O_CREAT)
++			goto exit;
++		/* fallthrough */
++	case LAST_BIND:
++		audit_inode(pathname, dir);
++		goto ok;
++	}
++
++	/* trailing slashes? */
++	if (nd->last.name[nd->last.len]) {
++		if (open_flag & O_CREAT)
++			goto exit;
++		nd->flags |= LOOKUP_DIRECTORY | LOOKUP_FOLLOW;
++	}
++
++	/* just plain open? */
++	if (!(open_flag & O_CREAT)) {
++		error = do_lookup(nd, &nd->last, path);
++		if (error)
++			goto exit;
++		error = -ENOENT;
++		if (!path->dentry->d_inode)
++			goto exit_dput;
++		if (path->dentry->d_inode->i_op->follow_link)
++			return NULL;
++		error = -ENOTDIR;
++		if (nd->flags & LOOKUP_DIRECTORY) {
++			if (!path->dentry->d_inode->i_op->lookup)
++				goto exit_dput;
++		}
++		path_to_nameidata(path, nd);
++		audit_inode(pathname, nd->path.dentry);
++		goto ok;
++	}
++
++	/* OK, it's O_CREAT */
++	mutex_lock(&dir->d_inode->i_mutex);
++
++	path->dentry = lookup_hash(nd);
++	path->mnt = nd->path.mnt;
++
++	error = PTR_ERR(path->dentry);
++	if (IS_ERR(path->dentry)) {
++		mutex_unlock(&dir->d_inode->i_mutex);
++		goto exit;
++	}
++
++	if (IS_ERR(nd->intent.open.file)) {
++		error = PTR_ERR(nd->intent.open.file);
++		goto exit_mutex_unlock;
++	}
++
++	/* Negative dentry, just create the file */
++	if (!path->dentry->d_inode) {
++		/*
++		 * This write is needed to ensure that a
++		 * ro->rw transition does not occur between
++		 * the time when the file is created and when
++		 * a permanent write count is taken through
++		 * the 'struct file' in nameidata_to_filp().
++		 */
++		error = mnt_want_write(nd->path.mnt);
++		if (error)
++			goto exit_mutex_unlock;
++		error = __open_namei_create(nd, path, open_flag, mode);
++		if (error) {
++			mnt_drop_write(nd->path.mnt);
++			goto exit;
++		}
++		filp = nameidata_to_filp(nd);
++		mnt_drop_write(nd->path.mnt);
++		if (!IS_ERR(filp)) {
++			error = ima_file_check(filp, acc_mode);
++			if (error) {
++				fput(filp);
++				filp = ERR_PTR(error);
++			}
++		}
++		return filp;
++	}
++
++	/*
++	 * It already exists.
++	 */
++	mutex_unlock(&dir->d_inode->i_mutex);
++	audit_inode(pathname, path->dentry);
++
++	error = -EEXIST;
++	if (open_flag & O_EXCL)
++		goto exit_dput;
++
++	if (__follow_mount(path)) {
++		error = -ELOOP;
++		if (open_flag & O_NOFOLLOW)
++			goto exit_dput;
++	}
++
++	error = -ENOENT;
++	if (!path->dentry->d_inode)
++		goto exit_dput;
++
++	if (path->dentry->d_inode->i_op->follow_link)
++		return NULL;
++
++	path_to_nameidata(path, nd);
++	error = -EISDIR;
++	if (S_ISDIR(path->dentry->d_inode->i_mode))
++		goto exit;
++ok:
++	filp = finish_open(nd, open_flag, acc_mode);
++	return filp;
++
++exit_mutex_unlock:
++	mutex_unlock(&dir->d_inode->i_mutex);
++exit_dput:
++	path_put_conditional(path, nd);
++exit:
++	if (!IS_ERR(nd->intent.open.file))
++		release_open_intent(nd);
++	path_put(&nd->path);
++	return ERR_PTR(error);
++}
++
++/*
++ * Note that the low bits of the passed in "open_flag"
++ * are not the same as in the local variable "flag". See
++ * open_to_namei_flags() for more details.
++ */
++struct file *do_filp_open(int dfd, const char *pathname,
++		int open_flag, int mode, int acc_mode)
++{
++	struct file *filp;
++	struct nameidata nd;
++	int error;
++	struct path path;
++	int count = 0;
++	int flag = open_to_namei_flags(open_flag);
++	int force_reval = 0;
++
++	if (!(open_flag & O_CREAT))
++		mode = 0;
++
++	/*
++	 * O_SYNC is implemented as __O_SYNC|O_DSYNC.  As many places only
++	 * check for O_DSYNC if the need any syncing at all we enforce it's
++	 * always set instead of having to deal with possibly weird behaviour
++	 * for malicious applications setting only __O_SYNC.
++	 */
++	if (open_flag & __O_SYNC)
++		open_flag |= O_DSYNC;
++
++	if (!acc_mode)
++		acc_mode = MAY_OPEN | ACC_MODE(open_flag);
++
++	/* O_TRUNC implies we need access checks for write permissions */
++	if (open_flag & O_TRUNC)
++		acc_mode |= MAY_WRITE;
++
++	/* Allow the LSM permission hook to distinguish append 
++	   access from general write access. */
++	if (open_flag & O_APPEND)
++		acc_mode |= MAY_APPEND;
++
++	/* find the parent */
++reval:
++	error = path_init(dfd, pathname, LOOKUP_PARENT, &nd);
++	if (error)
++		return ERR_PTR(error);
++	if (force_reval)
++		nd.flags |= LOOKUP_REVAL;
++
++	current->total_link_count = 0;
++	error = link_path_walk(pathname, &nd);
++	if (error) {
++		filp = ERR_PTR(error);
++		goto out;
++	}
++	if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT))
++		audit_inode(pathname, nd.path.dentry);
++
++	/*
++	 * We have the parent and last component.
++	 */
++
++	error = -ENFILE;
++	filp = get_empty_filp();
++	if (filp == NULL)
++		goto exit_parent;
++	nd.intent.open.file = filp;
++	filp->f_flags = open_flag;
++	nd.intent.open.flags = flag;
++	nd.intent.open.create_mode = mode;
++	nd.flags &= ~LOOKUP_PARENT;
++	nd.flags |= LOOKUP_OPEN;
++	if (open_flag & O_CREAT) {
++		nd.flags |= LOOKUP_CREATE;
++		if (open_flag & O_EXCL)
++			nd.flags |= LOOKUP_EXCL;
++	}
++	if (open_flag & O_DIRECTORY)
++		nd.flags |= LOOKUP_DIRECTORY;
++	if (!(open_flag & O_NOFOLLOW))
++		nd.flags |= LOOKUP_FOLLOW;
++	filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
++	while (unlikely(!filp)) { /* trailing symlink */
++		struct path holder;
++		struct inode *inode = path.dentry->d_inode;
++		void *cookie;
++		error = -ELOOP;
++		/* S_ISDIR part is a temporary automount kludge */
++		if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(inode->i_mode))
++			goto exit_dput;
++		if (count++ == 32)
++			goto exit_dput;
++		/*
++		 * This is subtle. Instead of calling do_follow_link() we do
++		 * the thing by hands. The reason is that this way we have zero
++		 * link_count and path_walk() (called from ->follow_link)
++		 * honoring LOOKUP_PARENT.  After that we have the parent and
++		 * last component, i.e. we are in the same situation as after
++		 * the first path_walk().  Well, almost - if the last component
++		 * is normal we get its copy stored in nd->last.name and we will
++		 * have to putname() it when we are done. Procfs-like symlinks
++		 * just set LAST_BIND.
++		 */
++		nd.flags |= LOOKUP_PARENT;
++		error = security_inode_follow_link(path.dentry, &nd);
++		if (error)
++			goto exit_dput;
++		error = __do_follow_link(&path, &nd, &cookie);
++		if (unlikely(error)) {
++			/* nd.path had been dropped */
++			if (!IS_ERR(cookie) && inode->i_op->put_link)
++				inode->i_op->put_link(path.dentry, &nd, cookie);
++			path_put(&path);
++			release_open_intent(&nd);
++			filp = ERR_PTR(error);
++			goto out;
++		}
++		holder = path;
++		nd.flags &= ~LOOKUP_PARENT;
++		filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname);
++		if (inode->i_op->put_link)
++			inode->i_op->put_link(holder.dentry, &nd, cookie);
++		path_put(&holder);
++	}
++out:
++	if (nd.root.mnt)
++		path_put(&nd.root);
++	if (filp == ERR_PTR(-ESTALE) && !force_reval) {
++		force_reval = 1;
++		goto reval;
++	}
++	return filp;
++
++exit_dput:
++	path_put_conditional(&path, &nd);
++	if (!IS_ERR(nd.intent.open.file))
++		release_open_intent(&nd);
++exit_parent:
++	path_put(&nd.path);
++	filp = ERR_PTR(error);
++	goto out;
++}
++
++/**
++ * filp_open - open file and return file pointer
++ *
++ * @filename:	path to open
++ * @flags:	open flags as per the open(2) second argument
++ * @mode:	mode for the new file if O_CREAT is set, else ignored
++ *
++ * This is the helper to open a file from kernelspace if you really
++ * have to.  But in generally you should not do this, so please move
++ * along, nothing to see here..
++ */
++struct file *filp_open(const char *filename, int flags, int mode)
++{
++	return do_filp_open(AT_FDCWD, filename, flags, mode, 0);
++}
++EXPORT_SYMBOL(filp_open);
++
++/**
++ * lookup_create - lookup a dentry, creating it if it doesn't exist
++ * @nd: nameidata info
++ * @is_dir: directory flag
++ *
++ * Simple function to lookup and return a dentry and create it
++ * if it doesn't exist.  Is SMP-safe.
++ *
++ * Returns with nd->path.dentry->d_inode->i_mutex locked.
++ */
++struct dentry *lookup_create(struct nameidata *nd, int is_dir)
++{
++	struct dentry *dentry = ERR_PTR(-EEXIST);
++
++	mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
++	/*
++	 * Yucky last component or no last component at all?
++	 * (foo/., foo/.., /////)
++	 */
++	if (nd->last_type != LAST_NORM)
++		goto fail;
++	nd->flags &= ~LOOKUP_PARENT;
++	nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
++	nd->intent.open.flags = O_EXCL;
++
++	/*
++	 * Do the final lookup.
++	 */
++	dentry = lookup_hash(nd);
++	if (IS_ERR(dentry))
++		goto fail;
++
++	if (dentry->d_inode)
++		goto eexist;
++	/*
++	 * Special case - lookup gave negative, but... we had foo/bar/
++	 * From the vfs_mknod() POV we just have a negative dentry -
++	 * all is fine. Let's be bastards - you had / on the end, you've
++	 * been asking for (non-existent) directory. -ENOENT for you.
++	 */
++	if (unlikely(!is_dir && nd->last.name[nd->last.len])) {
++		dput(dentry);
++		dentry = ERR_PTR(-ENOENT);
++	}
++	return dentry;
++eexist:
++	dput(dentry);
++	dentry = ERR_PTR(-EEXIST);
++fail:
++	return dentry;
++}
++EXPORT_SYMBOL_GPL(lookup_create);
++
++int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
++{
++	int error = may_create(dir, dentry);
++
++	if (error)
++		return error;
++
++	if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
++		return -EPERM;
++
++	if (!dir->i_op->mknod)
++		return -EPERM;
++
++	error = devcgroup_inode_mknod(mode, dev);
++	if (error)
++		return error;
++
++	error = security_inode_mknod(dir, dentry, mode, dev);
++	if (error)
++		return error;
++
++	error = dir->i_op->mknod(dir, dentry, mode, dev);
++	if (!error)
++		fsnotify_create(dir, dentry);
++	return error;
++}
++
++static int may_mknod(mode_t mode)
++{
++	switch (mode & S_IFMT) {
++	case S_IFREG:
++	case S_IFCHR:
++	case S_IFBLK:
++	case S_IFIFO:
++	case S_IFSOCK:
++	case 0: /* zero mode translates to S_IFREG */
++		return 0;
++	case S_IFDIR:
++		return -EPERM;
++	default:
++		return -EINVAL;
++	}
++}
++
++SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode,
++		unsigned, dev)
++{
++	int error;
++	char *tmp;
++	struct dentry *dentry;
++	struct nameidata nd;
++
++	if (S_ISDIR(mode))
++		return -EPERM;
++
++	error = user_path_parent(dfd, filename, &nd, &tmp);
++	if (error)
++		return error;
++
++	dentry = lookup_create(&nd, 0);
++	if (IS_ERR(dentry)) {
++		error = PTR_ERR(dentry);
++		goto out_unlock;
++	}
++	if (!IS_POSIXACL(nd.path.dentry->d_inode))
++		mode &= ~current_umask();
++	error = may_mknod(mode);
++	if (error)
++		goto out_dput;
++	error = mnt_want_write(nd.path.mnt);
++	if (error)
++		goto out_dput;
++	error = security_path_mknod(&nd.path, dentry, mode, dev);
++	if (error)
++		goto out_drop_write;
++	switch (mode & S_IFMT) {
++		case 0: case S_IFREG:
++			error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd);
++			break;
++		case S_IFCHR: case S_IFBLK:
++			error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,
++					new_decode_dev(dev));
++			break;
++		case S_IFIFO: case S_IFSOCK:
++			error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0);
++			break;
++	}
++out_drop_write:
++	mnt_drop_write(nd.path.mnt);
++out_dput:
++	dput(dentry);
++out_unlock:
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++	path_put(&nd.path);
++	putname(tmp);
++
++	return error;
++}
++
++SYSCALL_DEFINE3(mknod, const char __user *, filename, int, mode, unsigned, dev)
++{
++	return sys_mknodat(AT_FDCWD, filename, mode, dev);
++}
++
++int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
++{
++	int error = may_create(dir, dentry);
++
++	if (error)
++		return error;
++
++	if (!dir->i_op->mkdir)
++		return -EPERM;
++
++	mode &= (S_IRWXUGO|S_ISVTX);
++	error = security_inode_mkdir(dir, dentry, mode);
++	if (error)
++		return error;
++
++	error = dir->i_op->mkdir(dir, dentry, mode);
++	if (!error)
++		fsnotify_mkdir(dir, dentry);
++	return error;
++}
++
++SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode)
++{
++	int error = 0;
++	char * tmp;
++	struct dentry *dentry;
++	struct nameidata nd;
++
++	error = user_path_parent(dfd, pathname, &nd, &tmp);
++	if (error)
++		goto out_err;
++
++	dentry = lookup_create(&nd, 1);
++	error = PTR_ERR(dentry);
++	if (IS_ERR(dentry))
++		goto out_unlock;
++
++	if (!IS_POSIXACL(nd.path.dentry->d_inode))
++		mode &= ~current_umask();
++	error = mnt_want_write(nd.path.mnt);
++	if (error)
++		goto out_dput;
++	error = security_path_mkdir(&nd.path, dentry, mode);
++	if (error)
++		goto out_drop_write;
++	error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode);
++out_drop_write:
++	mnt_drop_write(nd.path.mnt);
++out_dput:
++	dput(dentry);
++out_unlock:
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++	path_put(&nd.path);
++	putname(tmp);
++out_err:
++	return error;
++}
++
++SYSCALL_DEFINE2(mkdir, const char __user *, pathname, int, mode)
++{
++	return sys_mkdirat(AT_FDCWD, pathname, mode);
++}
++
++/*
++ * We try to drop the dentry early: we should have
++ * a usage count of 2 if we're the only user of this
++ * dentry, and if that is true (possibly after pruning
++ * the dcache), then we drop the dentry now.
++ *
++ * A low-level filesystem can, if it choses, legally
++ * do a
++ *
++ *	if (!d_unhashed(dentry))
++ *		return -EBUSY;
++ *
++ * if it cannot handle the case of removing a directory
++ * that is still in use by something else..
++ */
++void dentry_unhash(struct dentry *dentry)
++{
++	dget(dentry);
++	shrink_dcache_parent(dentry);
++	spin_lock(&dcache_lock);
++	spin_lock(&dentry->d_lock);
++	if (atomic_read(&dentry->d_count) == 2)
++		__d_drop(dentry);
++	spin_unlock(&dentry->d_lock);
++	spin_unlock(&dcache_lock);
++}
++
++int vfs_rmdir(struct inode *dir, struct dentry *dentry)
++{
++	int error = may_delete(dir, dentry, 1);
++
++	if (error)
++		return error;
++
++	if (!dir->i_op->rmdir)
++		return -EPERM;
++
++	mutex_lock(&dentry->d_inode->i_mutex);
++	dentry_unhash(dentry);
++	if (d_mountpoint(dentry))
++		error = -EBUSY;
++	else {
++		error = security_inode_rmdir(dir, dentry);
++		if (!error) {
++			error = dir->i_op->rmdir(dir, dentry);
++			if (!error) {
++				dentry->d_inode->i_flags |= S_DEAD;
++				dont_mount(dentry);
++			}
++		}
++	}
++	mutex_unlock(&dentry->d_inode->i_mutex);
++	if (!error) {
++		d_delete(dentry);
++	}
++	dput(dentry);
++
++	return error;
++}
++
++static long do_rmdir(int dfd, const char __user *pathname)
++{
++	int error = 0;
++	char * name;
++	struct dentry *dentry;
++	struct nameidata nd;
++
++	error = user_path_parent(dfd, pathname, &nd, &name);
++	if (error)
++		return error;
++
++	switch(nd.last_type) {
++	case LAST_DOTDOT:
++		error = -ENOTEMPTY;
++		goto exit1;
++	case LAST_DOT:
++		error = -EINVAL;
++		goto exit1;
++	case LAST_ROOT:
++		error = -EBUSY;
++		goto exit1;
++	}
++
++	nd.flags &= ~LOOKUP_PARENT;
++
++	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
++	dentry = lookup_hash(&nd);
++	error = PTR_ERR(dentry);
++	if (IS_ERR(dentry))
++		goto exit2;
++	error = mnt_want_write(nd.path.mnt);
++	if (error)
++		goto exit3;
++	error = security_path_rmdir(&nd.path, dentry);
++	if (error)
++		goto exit4;
++	error = vfs_rmdir(nd.path.dentry->d_inode, dentry);
++exit4:
++	mnt_drop_write(nd.path.mnt);
++exit3:
++	dput(dentry);
++exit2:
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++exit1:
++	path_put(&nd.path);
++	putname(name);
++	return error;
++}
++
++SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
++{
++	return do_rmdir(AT_FDCWD, pathname);
++}
++
++int vfs_unlink(struct inode *dir, struct dentry *dentry)
++{
++	int error = may_delete(dir, dentry, 0);
++
++	if (error)
++		return error;
++
++	if (!dir->i_op->unlink)
++		return -EPERM;
++
++	mutex_lock(&dentry->d_inode->i_mutex);
++	if (d_mountpoint(dentry))
++		error = -EBUSY;
++	else {
++		error = security_inode_unlink(dir, dentry);
++		if (!error) {
++			error = dir->i_op->unlink(dir, dentry);
++			if (!error)
++				dont_mount(dentry);
++		}
++	}
++	mutex_unlock(&dentry->d_inode->i_mutex);
++
++	/* We don't d_delete() NFS sillyrenamed files--they still exist. */
++	if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
++		fsnotify_link_count(dentry->d_inode);
++		d_delete(dentry);
++	}
++
++	return error;
++}
++
++/*
++ * Make sure that the actual truncation of the file will occur outside its
++ * directory's i_mutex.  Truncate can take a long time if there is a lot of
++ * writeout happening, and we don't want to prevent access to the directory
++ * while waiting on the I/O.
++ */
++static long do_unlinkat(int dfd, const char __user *pathname)
++{
++	int error;
++	char *name;
++	struct dentry *dentry;
++	struct nameidata nd;
++	struct inode *inode = NULL;
++
++	error = user_path_parent(dfd, pathname, &nd, &name);
++	if (error)
++		return error;
++
++	error = -EISDIR;
++	if (nd.last_type != LAST_NORM)
++		goto exit1;
++
++	nd.flags &= ~LOOKUP_PARENT;
++
++	mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
++	dentry = lookup_hash(&nd);
++	error = PTR_ERR(dentry);
++	if (!IS_ERR(dentry)) {
++		/* Why not before? Because we want correct error value */
++		if (nd.last.name[nd.last.len])
++			goto slashes;
++		inode = dentry->d_inode;
++		if (inode)
++			atomic_inc(&inode->i_count);
++		error = mnt_want_write(nd.path.mnt);
++		if (error)
++			goto exit2;
++		error = security_path_unlink(&nd.path, dentry);
++		if (error)
++			goto exit3;
++		error = vfs_unlink(nd.path.dentry->d_inode, dentry);
++exit3:
++		mnt_drop_write(nd.path.mnt);
++	exit2:
++		dput(dentry);
++	}
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++	if (inode)
++		iput(inode);	/* truncate the inode here */
++exit1:
++	path_put(&nd.path);
++	putname(name);
++	return error;
++
++slashes:
++	error = !dentry->d_inode ? -ENOENT :
++		S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
++	goto exit2;
++}
++
++SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag)
++{
++	if ((flag & ~AT_REMOVEDIR) != 0)
++		return -EINVAL;
++
++	if (flag & AT_REMOVEDIR)
++		return do_rmdir(dfd, pathname);
++
++	return do_unlinkat(dfd, pathname);
++}
++
++SYSCALL_DEFINE1(unlink, const char __user *, pathname)
++{
++	return do_unlinkat(AT_FDCWD, pathname);
++}
++
++int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
++{
++	int error = may_create(dir, dentry);
++
++	if (error)
++		return error;
++
++	if (!dir->i_op->symlink)
++		return -EPERM;
++
++	error = security_inode_symlink(dir, dentry, oldname);
++	if (error)
++		return error;
++
++	error = dir->i_op->symlink(dir, dentry, oldname);
++	if (!error)
++		fsnotify_create(dir, dentry);
++	return error;
++}
++
++SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
++		int, newdfd, const char __user *, newname)
++{
++	int error;
++	char *from;
++	char *to;
++	struct dentry *dentry;
++	struct nameidata nd;
++
++	from = getname(oldname);
++	if (IS_ERR(from))
++		return PTR_ERR(from);
++
++	error = user_path_parent(newdfd, newname, &nd, &to);
++	if (error)
++		goto out_putname;
++
++	dentry = lookup_create(&nd, 0);
++	error = PTR_ERR(dentry);
++	if (IS_ERR(dentry))
++		goto out_unlock;
++
++	error = mnt_want_write(nd.path.mnt);
++	if (error)
++		goto out_dput;
++	error = security_path_symlink(&nd.path, dentry, from);
++	if (error)
++		goto out_drop_write;
++	error = vfs_symlink(nd.path.dentry->d_inode, dentry, from);
++out_drop_write:
++	mnt_drop_write(nd.path.mnt);
++out_dput:
++	dput(dentry);
++out_unlock:
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++	path_put(&nd.path);
++	putname(to);
++out_putname:
++	putname(from);
++	return error;
++}
++
++SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
++{
++	return sys_symlinkat(oldname, AT_FDCWD, newname);
++}
++
++int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
++{
++	struct inode *inode = old_dentry->d_inode;
++	int error;
++
++	if (!inode)
++		return -ENOENT;
++
++	error = may_create(dir, new_dentry);
++	if (error)
++		return error;
++
++	if (dir->i_sb != inode->i_sb)
++		return -EXDEV;
++
++	/*
++	 * A link to an append-only or immutable file cannot be created.
++	 */
++	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
++		return -EPERM;
++	if (!dir->i_op->link)
++		return -EPERM;
++	if (S_ISDIR(inode->i_mode))
++		return -EPERM;
++
++	error = security_inode_link(old_dentry, dir, new_dentry);
++	if (error)
++		return error;
++
++	mutex_lock(&inode->i_mutex);
++	error = dir->i_op->link(old_dentry, dir, new_dentry);
++	mutex_unlock(&inode->i_mutex);
++	if (!error)
++		fsnotify_link(dir, inode, new_dentry);
++	return error;
++}
++
++/*
++ * Hardlinks are often used in delicate situations.  We avoid
++ * security-related surprises by not following symlinks on the
++ * newname.  --KAB
++ *
++ * We don't follow them on the oldname either to be compatible
++ * with linux 2.0, and to avoid hard-linking to directories
++ * and other special files.  --ADM
++ */
++SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
++		int, newdfd, const char __user *, newname, int, flags)
++{
++	struct dentry *new_dentry;
++	struct nameidata nd;
++	struct path old_path;
++	int error;
++	char *to;
++
++	if ((flags & ~AT_SYMLINK_FOLLOW) != 0)
++		return -EINVAL;
++
++	error = user_path_at(olddfd, oldname,
++			     flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0,
++			     &old_path);
++	if (error)
++		return error;
++
++	error = user_path_parent(newdfd, newname, &nd, &to);
++	if (error)
++		goto out;
++	error = -EXDEV;
++	if (old_path.mnt != nd.path.mnt)
++		goto out_release;
++	new_dentry = lookup_create(&nd, 0);
++	error = PTR_ERR(new_dentry);
++	if (IS_ERR(new_dentry))
++		goto out_unlock;
++	error = mnt_want_write(nd.path.mnt);
++	if (error)
++		goto out_dput;
++	error = security_path_link(old_path.dentry, &nd.path, new_dentry);
++	if (error)
++		goto out_drop_write;
++	error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry);
++out_drop_write:
++	mnt_drop_write(nd.path.mnt);
++out_dput:
++	dput(new_dentry);
++out_unlock:
++	mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
++out_release:
++	path_put(&nd.path);
++	putname(to);
++out:
++	path_put(&old_path);
++
++	return error;
++}
++
++SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname)
++{
++	return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
++}
++
++/*
++ * The worst of all namespace operations - renaming directory. "Perverted"
++ * doesn't even start to describe it. Somebody in UCB had a heck of a trip...
++ * Problems:
++ *	a) we can get into loop creation. Check is done in is_subdir().
++ *	b) race potential - two innocent renames can create a loop together.
++ *	   That's where 4.4 screws up. Current fix: serialization on
++ *	   sb->s_vfs_rename_mutex. We might be more accurate, but that's another
++ *	   story.
++ *	c) we have to lock _three_ objects - parents and victim (if it exists).
++ *	   And that - after we got ->i_mutex on parents (until then we don't know
++ *	   whether the target exists).  Solution: try to be smart with locking
++ *	   order for inodes.  We rely on the fact that tree topology may change
++ *	   only under ->s_vfs_rename_mutex _and_ that parent of the object we
++ *	   move will be locked.  Thus we can rank directories by the tree
++ *	   (ancestors first) and rank all non-directories after them.
++ *	   That works since everybody except rename does "lock parent, lookup,
++ *	   lock child" and rename is under ->s_vfs_rename_mutex.
++ *	   HOWEVER, it relies on the assumption that any object with ->lookup()
++ *	   has no more than 1 dentry.  If "hybrid" objects will ever appear,
++ *	   we'd better make sure that there's no link(2) for them.
++ *	d) some filesystems don't support opened-but-unlinked directories,
++ *	   either because of layout or because they are not ready to deal with
++ *	   all cases correctly. The latter will be fixed (taking this sort of
++ *	   stuff into VFS), but the former is not going away. Solution: the same
++ *	   trick as in rmdir().
++ *	e) conversion from fhandle to dentry may come in the wrong moment - when
++ *	   we are removing the target. Solution: we will have to grab ->i_mutex
++ *	   in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on
++ *	   ->i_mutex on parents, which works but leads to some truly excessive
++ *	   locking].
++ */
++static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry,
++			  struct inode *new_dir, struct dentry *new_dentry)
++{
++	int error = 0;
++	struct inode *target;
++
++	/*
++	 * If we are going to change the parent - check write permissions,
++	 * we'll need to flip '..'.
++	 */
++	if (new_dir != old_dir) {
++		error = inode_permission(old_dentry->d_inode, MAY_WRITE);
++		if (error)
++			return error;
++	}
++
++	error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
++	if (error)
++		return error;
++
++	target = new_dentry->d_inode;
++	if (target)
++		mutex_lock(&target->i_mutex);
++	if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
++		error = -EBUSY;
++	else {
++		if (target)
++			dentry_unhash(new_dentry);
++		error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
++	}
++	if (target) {
++		if (!error) {
++			target->i_flags |= S_DEAD;
++			dont_mount(new_dentry);
++		}
++		mutex_unlock(&target->i_mutex);
++		if (d_unhashed(new_dentry))
++			d_rehash(new_dentry);
++		dput(new_dentry);
++	}
++	if (!error)
++		if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
++			d_move(old_dentry,new_dentry);
++	return error;
++}
++
++static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
++			    struct inode *new_dir, struct dentry *new_dentry)
++{
++	struct inode *target;
++	int error;
++
++	error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
++	if (error)
++		return error;
++
++	dget(new_dentry);
++	target = new_dentry->d_inode;
++	if (target)
++		mutex_lock(&target->i_mutex);
++	if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
++		error = -EBUSY;
++	else
++		error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
++	if (!error) {
++		if (target)
++			dont_mount(new_dentry);
++		if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
++			d_move(old_dentry, new_dentry);
++	}
++	if (target)
++		mutex_unlock(&target->i_mutex);
++	dput(new_dentry);
++	return error;
++}
++
++int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
++	       struct inode *new_dir, struct dentry *new_dentry)
++{
++	int error;
++	int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
++	const unsigned char *old_name;
++
++	if (old_dentry->d_inode == new_dentry->d_inode)
++ 		return 0;
++ 
++	error = may_delete(old_dir, old_dentry, is_dir);
++	if (error)
++		return error;
++
++	if (!new_dentry->d_inode)
++		error = may_create(new_dir, new_dentry);
++	else
++		error = may_delete(new_dir, new_dentry, is_dir);
++	if (error)
++		return error;
++
++	if (!old_dir->i_op->rename)
++		return -EPERM;
++
++	old_name = fsnotify_oldname_init(old_dentry->d_name.name);
++
++	if (is_dir)
++		error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
++	else
++		error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
++	if (!error)
++		fsnotify_move(old_dir, new_dir, old_name, is_dir,
++			      new_dentry->d_inode, old_dentry);
++	fsnotify_oldname_free(old_name);
++
++	return error;
++}
++
++SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
++		int, newdfd, const char __user *, newname)
++{
++	struct dentry *old_dir, *new_dir;
++	struct dentry *old_dentry, *new_dentry;
++	struct dentry *trap;
++	struct nameidata oldnd, newnd;
++	char *from;
++	char *to;
++	int error;
++
++	error = user_path_parent(olddfd, oldname, &oldnd, &from);
++	if (error)
++		goto exit;
++
++	error = user_path_parent(newdfd, newname, &newnd, &to);
++	if (error)
++		goto exit1;
++
++	error = -EXDEV;
++	if (oldnd.path.mnt != newnd.path.mnt)
++		goto exit2;
++
++	old_dir = oldnd.path.dentry;
++	error = -EBUSY;
++	if (oldnd.last_type != LAST_NORM)
++		goto exit2;
++
++	new_dir = newnd.path.dentry;
++	if (newnd.last_type != LAST_NORM)
++		goto exit2;
++
++	oldnd.flags &= ~LOOKUP_PARENT;
++	newnd.flags &= ~LOOKUP_PARENT;
++	newnd.flags |= LOOKUP_RENAME_TARGET;
++
++	trap = lock_rename(new_dir, old_dir);
++
++	old_dentry = lookup_hash(&oldnd);
++	error = PTR_ERR(old_dentry);
++	if (IS_ERR(old_dentry))
++		goto exit3;
++	/* source must exist */
++	error = -ENOENT;
++	if (!old_dentry->d_inode)
++		goto exit4;
++	/* unless the source is a directory trailing slashes give -ENOTDIR */
++	if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
++		error = -ENOTDIR;
++		if (oldnd.last.name[oldnd.last.len])
++			goto exit4;
++		if (newnd.last.name[newnd.last.len])
++			goto exit4;
++	}
++	/* source should not be ancestor of target */
++	error = -EINVAL;
++	if (old_dentry == trap)
++		goto exit4;
++	new_dentry = lookup_hash(&newnd);
++	error = PTR_ERR(new_dentry);
++	if (IS_ERR(new_dentry))
++		goto exit4;
++	/* target should not be an ancestor of source */
++	error = -ENOTEMPTY;
++	if (new_dentry == trap)
++		goto exit5;
++
++	error = mnt_want_write(oldnd.path.mnt);
++	if (error)
++		goto exit5;
++	error = security_path_rename(&oldnd.path, old_dentry,
++				     &newnd.path, new_dentry);
++	if (error)
++		goto exit6;
++	error = vfs_rename(old_dir->d_inode, old_dentry,
++				   new_dir->d_inode, new_dentry);
++exit6:
++	mnt_drop_write(oldnd.path.mnt);
++exit5:
++	dput(new_dentry);
++exit4:
++	dput(old_dentry);
++exit3:
++	unlock_rename(new_dir, old_dir);
++exit2:
++	path_put(&newnd.path);
++	putname(to);
++exit1:
++	path_put(&oldnd.path);
++	putname(from);
++exit:
++	return error;
++}
++
++SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname)
++{
++	return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname);
++}
++
++int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link)
++{
++	int len;
++
++	len = PTR_ERR(link);
++	if (IS_ERR(link))
++		goto out;
++
++	len = strlen(link);
++	if (len > (unsigned) buflen)
++		len = buflen;
++	if (copy_to_user(buffer, link, len))
++		len = -EFAULT;
++out:
++	return len;
++}
++
++/*
++ * A helper for ->readlink().  This should be used *ONLY* for symlinks that
++ * have ->follow_link() touching nd only in nd_set_link().  Using (or not
++ * using) it for any given inode is up to filesystem.
++ */
++int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
++{
++	struct nameidata nd;
++	void *cookie;
++	int res;
++
++	nd.depth = 0;
++	cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
++	if (IS_ERR(cookie))
++		return PTR_ERR(cookie);
++
++	res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd));
++	if (dentry->d_inode->i_op->put_link)
++		dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
++	return res;
++}
++
++int vfs_follow_link(struct nameidata *nd, const char *link)
++{
++	return __vfs_follow_link(nd, link);
++}
++
++/* get the link contents into pagecache */
++static char *page_getlink(struct dentry * dentry, struct page **ppage)
++{
++	char *kaddr;
++	struct page *page;
++	struct address_space *mapping = dentry->d_inode->i_mapping;
++	page = read_mapping_page(mapping, 0, NULL);
++	if (IS_ERR(page))
++		return (char*)page;
++	*ppage = page;
++	kaddr = kmap(page);
++	nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
++	return kaddr;
++}
++
++int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
++{
++	struct page *page = NULL;
++	char *s = page_getlink(dentry, &page);
++	int res = vfs_readlink(dentry,buffer,buflen,s);
++	if (page) {
++		kunmap(page);
++		page_cache_release(page);
++	}
++	return res;
++}
++
++void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
++{
++	struct page *page = NULL;
++	nd_set_link(nd, page_getlink(dentry, &page));
++	return page;
++}
++
++void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
++{
++	struct page *page = cookie;
++
++	if (page) {
++		kunmap(page);
++		page_cache_release(page);
++	}
++}
++
++/*
++ * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS
++ */
++int __page_symlink(struct inode *inode, const char *symname, int len, int nofs)
++{
++	struct address_space *mapping = inode->i_mapping;
++	struct page *page;
++	void *fsdata;
++	int err;
++	char *kaddr;
++	unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE;
++	if (nofs)
++		flags |= AOP_FLAG_NOFS;
++
++retry:
++	err = pagecache_write_begin(NULL, mapping, 0, len-1,
++				flags, &page, &fsdata);
++	if (err)
++		goto fail;
++
++	kaddr = kmap_atomic(page, KM_USER0);
++	memcpy(kaddr, symname, len-1);
++	kunmap_atomic(kaddr, KM_USER0);
++
++	err = pagecache_write_end(NULL, mapping, 0, len-1, len-1,
++							page, fsdata);
++	if (err < 0)
++		goto fail;
++	if (err < len-1)
++		goto retry;
++
++	mark_inode_dirty(inode);
++	return 0;
++fail:
++	return err;
++}
++
++int page_symlink(struct inode *inode, const char *symname, int len)
++{
++	return __page_symlink(inode, symname, len,
++			!(mapping_gfp_mask(inode->i_mapping) & __GFP_FS));
++}
++
++const struct inode_operations page_symlink_inode_operations = {
++	.readlink	= generic_readlink,
++	.follow_link	= page_follow_link_light,
++	.put_link	= page_put_link,
++};
++
++EXPORT_SYMBOL(user_path_at);
++EXPORT_SYMBOL(follow_down);
++EXPORT_SYMBOL(follow_up);
++EXPORT_SYMBOL(get_write_access); /* binfmt_aout */
++EXPORT_SYMBOL(getname);
++EXPORT_SYMBOL(lock_rename);
++EXPORT_SYMBOL(lookup_one_len);
++EXPORT_SYMBOL(page_follow_link_light);
++EXPORT_SYMBOL(page_put_link);
++EXPORT_SYMBOL(page_readlink);
++EXPORT_SYMBOL(__page_symlink);
++EXPORT_SYMBOL(page_symlink);
++EXPORT_SYMBOL(page_symlink_inode_operations);
++EXPORT_SYMBOL(path_lookup);
++EXPORT_SYMBOL(kern_path);
++EXPORT_SYMBOL(vfs_path_lookup);
++EXPORT_SYMBOL(inode_permission);
++EXPORT_SYMBOL(file_permission);
++EXPORT_SYMBOL(unlock_rename);
++EXPORT_SYMBOL(vfs_create);
++EXPORT_SYMBOL(vfs_follow_link);
++EXPORT_SYMBOL(vfs_link);
++EXPORT_SYMBOL(vfs_mkdir);
++EXPORT_SYMBOL(vfs_mknod);
++EXPORT_SYMBOL(generic_permission);
++EXPORT_SYMBOL(vfs_readlink);
++EXPORT_SYMBOL(vfs_rename);
++EXPORT_SYMBOL(vfs_rmdir);
++EXPORT_SYMBOL(vfs_symlink);
++EXPORT_SYMBOL(vfs_unlink);
++EXPORT_SYMBOL(dentry_unhash);
++EXPORT_SYMBOL(generic_readlink);
+diff -Nur linux-2.6.36.orig/fs/namespace.c linux-2.6.36/fs/namespace.c
+--- linux-2.6.36.orig/fs/namespace.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/namespace.c	2011-01-10 19:52:38.000000000 +0100
+@@ -1322,6 +1322,7 @@
+ 	}
+ 	return 0;
+ }
++EXPORT_SYMBOL(iterate_mounts);
+ 
+ static void cleanup_group_ids(struct vfsmount *mnt, struct vfsmount *end)
+ {
+diff -Nur linux-2.6.36.orig/fs/notify/group.c linux-2.6.36/fs/notify/group.c
+--- linux-2.6.36.orig/fs/notify/group.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/notify/group.c	2011-01-10 19:52:38.000000000 +0100
+@@ -22,6 +22,7 @@
+ #include <linux/srcu.h>
+ #include <linux/rculist.h>
+ #include <linux/wait.h>
++#include <linux/module.h>
+ 
+ #include <linux/fsnotify_backend.h>
+ #include "fsnotify.h"
+@@ -70,6 +71,7 @@
+ 	if (atomic_dec_and_test(&group->refcnt))
+ 		fsnotify_destroy_group(group);
+ }
++EXPORT_SYMBOL(fsnotify_put_group);
+ 
+ /*
+  * Create a new fsnotify_group and hold a reference for the group returned.
+@@ -102,3 +104,4 @@
+ 
+ 	return group;
+ }
++EXPORT_SYMBOL(fsnotify_alloc_group);
+diff -Nur linux-2.6.36.orig/fs/notify/mark.c linux-2.6.36/fs/notify/mark.c
+--- linux-2.6.36.orig/fs/notify/mark.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/notify/mark.c	2011-01-10 19:52:38.000000000 +0100
+@@ -113,6 +113,7 @@
+ 	if (atomic_dec_and_test(&mark->refcnt))
+ 		mark->free_mark(mark);
+ }
++EXPORT_SYMBOL(fsnotify_put_mark);
+ 
+ /*
+  * Any time a mark is getting freed we end up here.
+@@ -190,6 +191,7 @@
+ 	if (unlikely(atomic_dec_and_test(&group->num_marks)))
+ 		fsnotify_final_destroy_group(group);
+ }
++EXPORT_SYMBOL(fsnotify_destroy_mark);
+ 
+ void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
+ {
+@@ -277,6 +279,7 @@
+ 
+ 	return ret;
+ }
++EXPORT_SYMBOL(fsnotify_add_mark);
+ 
+ /*
+  * clear any marks in a group in which mark->flags & flags is true
+@@ -332,6 +335,7 @@
+ 	atomic_set(&mark->refcnt, 1);
+ 	mark->free_mark = free_mark;
+ }
++EXPORT_SYMBOL(fsnotify_init_mark);
+ 
+ static int fsnotify_mark_destroy(void *ignored)
+ {
+diff -Nur linux-2.6.36.orig/fs/open.c linux-2.6.36/fs/open.c
+--- linux-2.6.36.orig/fs/open.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/open.c	2011-01-10 19:52:38.000000000 +0100
+@@ -60,6 +60,7 @@
+ 	mutex_unlock(&dentry->d_inode->i_mutex);
+ 	return ret;
+ }
++EXPORT_SYMBOL(do_truncate);
+ 
+ static long do_sys_truncate(const char __user *pathname, loff_t length)
+ {
+diff -Nur linux-2.6.36.orig/fs/splice.c linux-2.6.36/fs/splice.c
+--- linux-2.6.36.orig/fs/splice.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/fs/splice.c	2011-01-10 19:52:38.000000000 +0100
+@@ -1092,8 +1092,8 @@
+ /*
+  * Attempt to initiate a splice from pipe to file.
+  */
+-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+-			   loff_t *ppos, size_t len, unsigned int flags)
++long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
++		    loff_t *ppos, size_t len, unsigned int flags)
+ {
+ 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
+ 				loff_t *, size_t, unsigned int);
+@@ -1116,13 +1116,14 @@
+ 
+ 	return splice_write(pipe, out, ppos, len, flags);
+ }
++EXPORT_SYMBOL(do_splice_from);
+ 
+ /*
+  * Attempt to initiate a splice from a file to a pipe.
+  */
+-static long do_splice_to(struct file *in, loff_t *ppos,
+-			 struct pipe_inode_info *pipe, size_t len,
+-			 unsigned int flags)
++long do_splice_to(struct file *in, loff_t *ppos,
++		  struct pipe_inode_info *pipe, size_t len,
++		  unsigned int flags)
+ {
+ 	ssize_t (*splice_read)(struct file *, loff_t *,
+ 			       struct pipe_inode_info *, size_t, unsigned int);
+@@ -1142,6 +1143,7 @@
+ 
+ 	return splice_read(in, ppos, pipe, len, flags);
+ }
++EXPORT_SYMBOL(do_splice_to);
+ 
+ /**
+  * splice_direct_to_actor - splices data directly between two non-pipes
+diff -Nur linux-2.6.36.orig/fs/splice.c.orig linux-2.6.36/fs/splice.c.orig
+--- linux-2.6.36.orig/fs/splice.c.orig	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/fs/splice.c.orig	2011-01-10 19:52:38.000000000 +0100
+@@ -0,0 +1,2076 @@
++/*
++ * "splice": joining two ropes together by interweaving their strands.
++ *
++ * This is the "extended pipe" functionality, where a pipe is used as
++ * an arbitrary in-memory buffer. Think of a pipe as a small kernel
++ * buffer that you can use to transfer data from one end to the other.
++ *
++ * The traditional unix read/write is extended with a "splice()" operation
++ * that transfers data buffers to or from a pipe buffer.
++ *
++ * Named by Larry McVoy, original implementation from Linus, extended by
++ * Jens to support splicing to files, network, direct splicing, etc and
++ * fixing lots of bugs.
++ *
++ * Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk>
++ * Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org>
++ * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu>
++ *
++ */
++#include <linux/fs.h>
++#include <linux/file.h>
++#include <linux/pagemap.h>
++#include <linux/splice.h>
++#include <linux/memcontrol.h>
++#include <linux/mm_inline.h>
++#include <linux/swap.h>
++#include <linux/writeback.h>
++#include <linux/buffer_head.h>
++#include <linux/module.h>
++#include <linux/syscalls.h>
++#include <linux/uio.h>
++#include <linux/security.h>
++#include <linux/gfp.h>
++
++/*
++ * Attempt to steal a page from a pipe buffer. This should perhaps go into
++ * a vm helper function, it's already simplified quite a bit by the
++ * addition of remove_mapping(). If success is returned, the caller may
++ * attempt to reuse this page for another destination.
++ */
++static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
++				     struct pipe_buffer *buf)
++{
++	struct page *page = buf->page;
++	struct address_space *mapping;
++
++	lock_page(page);
++
++	mapping = page_mapping(page);
++	if (mapping) {
++		WARN_ON(!PageUptodate(page));
++
++		/*
++		 * At least for ext2 with nobh option, we need to wait on
++		 * writeback completing on this page, since we'll remove it
++		 * from the pagecache.  Otherwise truncate wont wait on the
++		 * page, allowing the disk blocks to be reused by someone else
++		 * before we actually wrote our data to them. fs corruption
++		 * ensues.
++		 */
++		wait_on_page_writeback(page);
++
++		if (page_has_private(page) &&
++		    !try_to_release_page(page, GFP_KERNEL))
++			goto out_unlock;
++
++		/*
++		 * If we succeeded in removing the mapping, set LRU flag
++		 * and return good.
++		 */
++		if (remove_mapping(mapping, page)) {
++			buf->flags |= PIPE_BUF_FLAG_LRU;
++			return 0;
++		}
++	}
++
++	/*
++	 * Raced with truncate or failed to remove page from current
++	 * address space, unlock and return failure.
++	 */
++out_unlock:
++	unlock_page(page);
++	return 1;
++}
++
++static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
++					struct pipe_buffer *buf)
++{
++	page_cache_release(buf->page);
++	buf->flags &= ~PIPE_BUF_FLAG_LRU;
++}
++
++/*
++ * Check whether the contents of buf is OK to access. Since the content
++ * is a page cache page, IO may be in flight.
++ */
++static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe,
++				       struct pipe_buffer *buf)
++{
++	struct page *page = buf->page;
++	int err;
++
++	if (!PageUptodate(page)) {
++		lock_page(page);
++
++		/*
++		 * Page got truncated/unhashed. This will cause a 0-byte
++		 * splice, if this is the first page.
++		 */
++		if (!page->mapping) {
++			err = -ENODATA;
++			goto error;
++		}
++
++		/*
++		 * Uh oh, read-error from disk.
++		 */
++		if (!PageUptodate(page)) {
++			err = -EIO;
++			goto error;
++		}
++
++		/*
++		 * Page is ok afterall, we are done.
++		 */
++		unlock_page(page);
++	}
++
++	return 0;
++error:
++	unlock_page(page);
++	return err;
++}
++
++static const struct pipe_buf_operations page_cache_pipe_buf_ops = {
++	.can_merge = 0,
++	.map = generic_pipe_buf_map,
++	.unmap = generic_pipe_buf_unmap,
++	.confirm = page_cache_pipe_buf_confirm,
++	.release = page_cache_pipe_buf_release,
++	.steal = page_cache_pipe_buf_steal,
++	.get = generic_pipe_buf_get,
++};
++
++static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
++				    struct pipe_buffer *buf)
++{
++	if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
++		return 1;
++
++	buf->flags |= PIPE_BUF_FLAG_LRU;
++	return generic_pipe_buf_steal(pipe, buf);
++}
++
++static const struct pipe_buf_operations user_page_pipe_buf_ops = {
++	.can_merge = 0,
++	.map = generic_pipe_buf_map,
++	.unmap = generic_pipe_buf_unmap,
++	.confirm = generic_pipe_buf_confirm,
++	.release = page_cache_pipe_buf_release,
++	.steal = user_page_pipe_buf_steal,
++	.get = generic_pipe_buf_get,
++};
++
++/**
++ * splice_to_pipe - fill passed data into a pipe
++ * @pipe:	pipe to fill
++ * @spd:	data to fill
++ *
++ * Description:
++ *    @spd contains a map of pages and len/offset tuples, along with
++ *    the struct pipe_buf_operations associated with these pages. This
++ *    function will link that data to the pipe.
++ *
++ */
++ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
++		       struct splice_pipe_desc *spd)
++{
++	unsigned int spd_pages = spd->nr_pages;
++	int ret, do_wakeup, page_nr;
++
++	ret = 0;
++	do_wakeup = 0;
++	page_nr = 0;
++
++	pipe_lock(pipe);
++
++	for (;;) {
++		if (!pipe->readers) {
++			send_sig(SIGPIPE, current, 0);
++			if (!ret)
++				ret = -EPIPE;
++			break;
++		}
++
++		if (pipe->nrbufs < pipe->buffers) {
++			int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
++			struct pipe_buffer *buf = pipe->bufs + newbuf;
++
++			buf->page = spd->pages[page_nr];
++			buf->offset = spd->partial[page_nr].offset;
++			buf->len = spd->partial[page_nr].len;
++			buf->private = spd->partial[page_nr].private;
++			buf->ops = spd->ops;
++			if (spd->flags & SPLICE_F_GIFT)
++				buf->flags |= PIPE_BUF_FLAG_GIFT;
++
++			pipe->nrbufs++;
++			page_nr++;
++			ret += buf->len;
++
++			if (pipe->inode)
++				do_wakeup = 1;
++
++			if (!--spd->nr_pages)
++				break;
++			if (pipe->nrbufs < pipe->buffers)
++				continue;
++
++			break;
++		}
++
++		if (spd->flags & SPLICE_F_NONBLOCK) {
++			if (!ret)
++				ret = -EAGAIN;
++			break;
++		}
++
++		if (signal_pending(current)) {
++			if (!ret)
++				ret = -ERESTARTSYS;
++			break;
++		}
++
++		if (do_wakeup) {
++			smp_mb();
++			if (waitqueue_active(&pipe->wait))
++				wake_up_interruptible_sync(&pipe->wait);
++			kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
++			do_wakeup = 0;
++		}
++
++		pipe->waiting_writers++;
++		pipe_wait(pipe);
++		pipe->waiting_writers--;
++	}
++
++	pipe_unlock(pipe);
++
++	if (do_wakeup) {
++		smp_mb();
++		if (waitqueue_active(&pipe->wait))
++			wake_up_interruptible(&pipe->wait);
++		kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
++	}
++
++	while (page_nr < spd_pages)
++		spd->spd_release(spd, page_nr++);
++
++	return ret;
++}
++
++static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
++{
++	page_cache_release(spd->pages[i]);
++}
++
++/*
++ * Check if we need to grow the arrays holding pages and partial page
++ * descriptions.
++ */
++int splice_grow_spd(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
++{
++	if (pipe->buffers <= PIPE_DEF_BUFFERS)
++		return 0;
++
++	spd->pages = kmalloc(pipe->buffers * sizeof(struct page *), GFP_KERNEL);
++	spd->partial = kmalloc(pipe->buffers * sizeof(struct partial_page), GFP_KERNEL);
++
++	if (spd->pages && spd->partial)
++		return 0;
++
++	kfree(spd->pages);
++	kfree(spd->partial);
++	return -ENOMEM;
++}
++
++void splice_shrink_spd(struct pipe_inode_info *pipe,
++		       struct splice_pipe_desc *spd)
++{
++	if (pipe->buffers <= PIPE_DEF_BUFFERS)
++		return;
++
++	kfree(spd->pages);
++	kfree(spd->partial);
++}
++
++static int
++__generic_file_splice_read(struct file *in, loff_t *ppos,
++			   struct pipe_inode_info *pipe, size_t len,
++			   unsigned int flags)
++{
++	struct address_space *mapping = in->f_mapping;
++	unsigned int loff, nr_pages, req_pages;
++	struct page *pages[PIPE_DEF_BUFFERS];
++	struct partial_page partial[PIPE_DEF_BUFFERS];
++	struct page *page;
++	pgoff_t index, end_index;
++	loff_t isize;
++	int error, page_nr;
++	struct splice_pipe_desc spd = {
++		.pages = pages,
++		.partial = partial,
++		.flags = flags,
++		.ops = &page_cache_pipe_buf_ops,
++		.spd_release = spd_release_page,
++	};
++
++	if (splice_grow_spd(pipe, &spd))
++		return -ENOMEM;
++
++	index = *ppos >> PAGE_CACHE_SHIFT;
++	loff = *ppos & ~PAGE_CACHE_MASK;
++	req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
++	nr_pages = min(req_pages, pipe->buffers);
++
++	/*
++	 * Lookup the (hopefully) full range of pages we need.
++	 */
++	spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages);
++	index += spd.nr_pages;
++
++	/*
++	 * If find_get_pages_contig() returned fewer pages than we needed,
++	 * readahead/allocate the rest and fill in the holes.
++	 */
++	if (spd.nr_pages < nr_pages)
++		page_cache_sync_readahead(mapping, &in->f_ra, in,
++				index, req_pages - spd.nr_pages);
++
++	error = 0;
++	while (spd.nr_pages < nr_pages) {
++		/*
++		 * Page could be there, find_get_pages_contig() breaks on
++		 * the first hole.
++		 */
++		page = find_get_page(mapping, index);
++		if (!page) {
++			/*
++			 * page didn't exist, allocate one.
++			 */
++			page = page_cache_alloc_cold(mapping);
++			if (!page)
++				break;
++
++			error = add_to_page_cache_lru(page, mapping, index,
++						GFP_KERNEL);
++			if (unlikely(error)) {
++				page_cache_release(page);
++				if (error == -EEXIST)
++					continue;
++				break;
++			}
++			/*
++			 * add_to_page_cache() locks the page, unlock it
++			 * to avoid convoluting the logic below even more.
++			 */
++			unlock_page(page);
++		}
++
++		spd.pages[spd.nr_pages++] = page;
++		index++;
++	}
++
++	/*
++	 * Now loop over the map and see if we need to start IO on any
++	 * pages, fill in the partial map, etc.
++	 */
++	index = *ppos >> PAGE_CACHE_SHIFT;
++	nr_pages = spd.nr_pages;
++	spd.nr_pages = 0;
++	for (page_nr = 0; page_nr < nr_pages; page_nr++) {
++		unsigned int this_len;
++
++		if (!len)
++			break;
++
++		/*
++		 * this_len is the max we'll use from this page
++		 */
++		this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
++		page = spd.pages[page_nr];
++
++		if (PageReadahead(page))
++			page_cache_async_readahead(mapping, &in->f_ra, in,
++					page, index, req_pages - page_nr);
++
++		/*
++		 * If the page isn't uptodate, we may need to start io on it
++		 */
++		if (!PageUptodate(page)) {
++			lock_page(page);
++
++			/*
++			 * Page was truncated, or invalidated by the
++			 * filesystem.  Redo the find/create, but this time the
++			 * page is kept locked, so there's no chance of another
++			 * race with truncate/invalidate.
++			 */
++			if (!page->mapping) {
++				unlock_page(page);
++				page = find_or_create_page(mapping, index,
++						mapping_gfp_mask(mapping));
++
++				if (!page) {
++					error = -ENOMEM;
++					break;
++				}
++				page_cache_release(spd.pages[page_nr]);
++				spd.pages[page_nr] = page;
++			}
++			/*
++			 * page was already under io and is now done, great
++			 */
++			if (PageUptodate(page)) {
++				unlock_page(page);
++				goto fill_it;
++			}
++
++			/*
++			 * need to read in the page
++			 */
++			error = mapping->a_ops->readpage(in, page);
++			if (unlikely(error)) {
++				/*
++				 * We really should re-lookup the page here,
++				 * but it complicates things a lot. Instead
++				 * lets just do what we already stored, and
++				 * we'll get it the next time we are called.
++				 */
++				if (error == AOP_TRUNCATED_PAGE)
++					error = 0;
++
++				break;
++			}
++		}
++fill_it:
++		/*
++		 * i_size must be checked after PageUptodate.
++		 */
++		isize = i_size_read(mapping->host);
++		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
++		if (unlikely(!isize || index > end_index))
++			break;
++
++		/*
++		 * if this is the last page, see if we need to shrink
++		 * the length and stop
++		 */
++		if (end_index == index) {
++			unsigned int plen;
++
++			/*
++			 * max good bytes in this page
++			 */
++			plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
++			if (plen <= loff)
++				break;
++
++			/*
++			 * force quit after adding this page
++			 */
++			this_len = min(this_len, plen - loff);
++			len = this_len;
++		}
++
++		spd.partial[page_nr].offset = loff;
++		spd.partial[page_nr].len = this_len;
++		len -= this_len;
++		loff = 0;
++		spd.nr_pages++;
++		index++;
++	}
++
++	/*
++	 * Release any pages at the end, if we quit early. 'page_nr' is how far
++	 * we got, 'nr_pages' is how many pages are in the map.
++	 */
++	while (page_nr < nr_pages)
++		page_cache_release(spd.pages[page_nr++]);
++	in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
++
++	if (spd.nr_pages)
++		error = splice_to_pipe(pipe, &spd);
++
++	splice_shrink_spd(pipe, &spd);
++	return error;
++}
++
++/**
++ * generic_file_splice_read - splice data from file to a pipe
++ * @in:		file to splice from
++ * @ppos:	position in @in
++ * @pipe:	pipe to splice to
++ * @len:	number of bytes to splice
++ * @flags:	splice modifier flags
++ *
++ * Description:
++ *    Will read pages from given file and fill them into a pipe. Can be
++ *    used as long as the address_space operations for the source implements
++ *    a readpage() hook.
++ *
++ */
++ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
++				 struct pipe_inode_info *pipe, size_t len,
++				 unsigned int flags)
++{
++	loff_t isize, left;
++	int ret;
++
++	isize = i_size_read(in->f_mapping->host);
++	if (unlikely(*ppos >= isize))
++		return 0;
++
++	left = isize - *ppos;
++	if (unlikely(left < len))
++		len = left;
++
++	ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
++	if (ret > 0) {
++		*ppos += ret;
++		file_accessed(in);
++	}
++
++	return ret;
++}
++EXPORT_SYMBOL(generic_file_splice_read);
++
++static const struct pipe_buf_operations default_pipe_buf_ops = {
++	.can_merge = 0,
++	.map = generic_pipe_buf_map,
++	.unmap = generic_pipe_buf_unmap,
++	.confirm = generic_pipe_buf_confirm,
++	.release = generic_pipe_buf_release,
++	.steal = generic_pipe_buf_steal,
++	.get = generic_pipe_buf_get,
++};
++
++static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
++			    unsigned long vlen, loff_t offset)
++{
++	mm_segment_t old_fs;
++	loff_t pos = offset;
++	ssize_t res;
++
++	old_fs = get_fs();
++	set_fs(get_ds());
++	/* The cast to a user pointer is valid due to the set_fs() */
++	res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
++	set_fs(old_fs);
++
++	return res;
++}
++
++static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
++			    loff_t pos)
++{
++	mm_segment_t old_fs;
++	ssize_t res;
++
++	old_fs = get_fs();
++	set_fs(get_ds());
++	/* The cast to a user pointer is valid due to the set_fs() */
++	res = vfs_write(file, (const char __user *)buf, count, &pos);
++	set_fs(old_fs);
++
++	return res;
++}
++
++ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
++				 struct pipe_inode_info *pipe, size_t len,
++				 unsigned int flags)
++{
++	unsigned int nr_pages;
++	unsigned int nr_freed;
++	size_t offset;
++	struct page *pages[PIPE_DEF_BUFFERS];
++	struct partial_page partial[PIPE_DEF_BUFFERS];
++	struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
++	ssize_t res;
++	size_t this_len;
++	int error;
++	int i;
++	struct splice_pipe_desc spd = {
++		.pages = pages,
++		.partial = partial,
++		.flags = flags,
++		.ops = &default_pipe_buf_ops,
++		.spd_release = spd_release_page,
++	};
++
++	if (splice_grow_spd(pipe, &spd))
++		return -ENOMEM;
++
++	res = -ENOMEM;
++	vec = __vec;
++	if (pipe->buffers > PIPE_DEF_BUFFERS) {
++		vec = kmalloc(pipe->buffers * sizeof(struct iovec), GFP_KERNEL);
++		if (!vec)
++			goto shrink_ret;
++	}
++
++	offset = *ppos & ~PAGE_CACHE_MASK;
++	nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
++
++	for (i = 0; i < nr_pages && i < pipe->buffers && len; i++) {
++		struct page *page;
++
++		page = alloc_page(GFP_USER);
++		error = -ENOMEM;
++		if (!page)
++			goto err;
++
++		this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset);
++		vec[i].iov_base = (void __user *) page_address(page);
++		vec[i].iov_len = this_len;
++		spd.pages[i] = page;
++		spd.nr_pages++;
++		len -= this_len;
++		offset = 0;
++	}
++
++	res = kernel_readv(in, vec, spd.nr_pages, *ppos);
++	if (res < 0) {
++		error = res;
++		goto err;
++	}
++
++	error = 0;
++	if (!res)
++		goto err;
++
++	nr_freed = 0;
++	for (i = 0; i < spd.nr_pages; i++) {
++		this_len = min_t(size_t, vec[i].iov_len, res);
++		spd.partial[i].offset = 0;
++		spd.partial[i].len = this_len;
++		if (!this_len) {
++			__free_page(spd.pages[i]);
++			spd.pages[i] = NULL;
++			nr_freed++;
++		}
++		res -= this_len;
++	}
++	spd.nr_pages -= nr_freed;
++
++	res = splice_to_pipe(pipe, &spd);
++	if (res > 0)
++		*ppos += res;
++
++shrink_ret:
++	if (vec != __vec)
++		kfree(vec);
++	splice_shrink_spd(pipe, &spd);
++	return res;
++
++err:
++	for (i = 0; i < spd.nr_pages; i++)
++		__free_page(spd.pages[i]);
++
++	res = error;
++	goto shrink_ret;
++}
++EXPORT_SYMBOL(default_file_splice_read);
++
++/*
++ * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
++ * using sendpage(). Return the number of bytes sent.
++ */
++static int pipe_to_sendpage(struct pipe_inode_info *pipe,
++			    struct pipe_buffer *buf, struct splice_desc *sd)
++{
++	struct file *file = sd->u.file;
++	loff_t pos = sd->pos;
++	int ret, more;
++
++	ret = buf->ops->confirm(pipe, buf);
++	if (!ret) {
++		more = (sd->flags & SPLICE_F_MORE) || sd->len < sd->total_len;
++		if (file->f_op && file->f_op->sendpage)
++			ret = file->f_op->sendpage(file, buf->page, buf->offset,
++						   sd->len, &pos, more);
++		else
++			ret = -EINVAL;
++	}
++
++	return ret;
++}
++
++/*
++ * This is a little more tricky than the file -> pipe splicing. There are
++ * basically three cases:
++ *
++ *	- Destination page already exists in the address space and there
++ *	  are users of it. For that case we have no other option that
++ *	  copying the data. Tough luck.
++ *	- Destination page already exists in the address space, but there
++ *	  are no users of it. Make sure it's uptodate, then drop it. Fall
++ *	  through to last case.
++ *	- Destination page does not exist, we can add the pipe page to
++ *	  the page cache and avoid the copy.
++ *
++ * If asked to move pages to the output file (SPLICE_F_MOVE is set in
++ * sd->flags), we attempt to migrate pages from the pipe to the output
++ * file address space page cache. This is possible if no one else has
++ * the pipe page referenced outside of the pipe and page cache. If
++ * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create
++ * a new page in the output file page cache and fill/dirty that.
++ */
++int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
++		 struct splice_desc *sd)
++{
++	struct file *file = sd->u.file;
++	struct address_space *mapping = file->f_mapping;
++	unsigned int offset, this_len;
++	struct page *page;
++	void *fsdata;
++	int ret;
++
++	/*
++	 * make sure the data in this buffer is uptodate
++	 */
++	ret = buf->ops->confirm(pipe, buf);
++	if (unlikely(ret))
++		return ret;
++
++	offset = sd->pos & ~PAGE_CACHE_MASK;
++
++	this_len = sd->len;
++	if (this_len + offset > PAGE_CACHE_SIZE)
++		this_len = PAGE_CACHE_SIZE - offset;
++
++	ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
++				AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
++	if (unlikely(ret))
++		goto out;
++
++	if (buf->page != page) {
++		/*
++		 * Careful, ->map() uses KM_USER0!
++		 */
++		char *src = buf->ops->map(pipe, buf, 1);
++		char *dst = kmap_atomic(page, KM_USER1);
++
++		memcpy(dst + offset, src + buf->offset, this_len);
++		flush_dcache_page(page);
++		kunmap_atomic(dst, KM_USER1);
++		buf->ops->unmap(pipe, buf, src);
++	}
++	ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
++				page, fsdata);
++out:
++	return ret;
++}
++EXPORT_SYMBOL(pipe_to_file);
++
++static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
++{
++	smp_mb();
++	if (waitqueue_active(&pipe->wait))
++		wake_up_interruptible(&pipe->wait);
++	kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
++}
++
++/**
++ * splice_from_pipe_feed - feed available data from a pipe to a file
++ * @pipe:	pipe to splice from
++ * @sd:		information to @actor
++ * @actor:	handler that splices the data
++ *
++ * Description:
++ *    This function loops over the pipe and calls @actor to do the
++ *    actual moving of a single struct pipe_buffer to the desired
++ *    destination.  It returns when there's no more buffers left in
++ *    the pipe or if the requested number of bytes (@sd->total_len)
++ *    have been copied.  It returns a positive number (one) if the
++ *    pipe needs to be filled with more data, zero if the required
++ *    number of bytes have been copied and -errno on error.
++ *
++ *    This, together with splice_from_pipe_{begin,end,next}, may be
++ *    used to implement the functionality of __splice_from_pipe() when
++ *    locking is required around copying the pipe buffers to the
++ *    destination.
++ */
++int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
++			  splice_actor *actor)
++{
++	int ret;
++
++	while (pipe->nrbufs) {
++		struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
++		const struct pipe_buf_operations *ops = buf->ops;
++
++		sd->len = buf->len;
++		if (sd->len > sd->total_len)
++			sd->len = sd->total_len;
++
++		ret = actor(pipe, buf, sd);
++		if (ret <= 0) {
++			if (ret == -ENODATA)
++				ret = 0;
++			return ret;
++		}
++		buf->offset += ret;
++		buf->len -= ret;
++
++		sd->num_spliced += ret;
++		sd->len -= ret;
++		sd->pos += ret;
++		sd->total_len -= ret;
++
++		if (!buf->len) {
++			buf->ops = NULL;
++			ops->release(pipe, buf);
++			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
++			pipe->nrbufs--;
++			if (pipe->inode)
++				sd->need_wakeup = true;
++		}
++
++		if (!sd->total_len)
++			return 0;
++	}
++
++	return 1;
++}
++EXPORT_SYMBOL(splice_from_pipe_feed);
++
++/**
++ * splice_from_pipe_next - wait for some data to splice from
++ * @pipe:	pipe to splice from
++ * @sd:		information about the splice operation
++ *
++ * Description:
++ *    This function will wait for some data and return a positive
++ *    value (one) if pipe buffers are available.  It will return zero
++ *    or -errno if no more data needs to be spliced.
++ */
++int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
++{
++	while (!pipe->nrbufs) {
++		if (!pipe->writers)
++			return 0;
++
++		if (!pipe->waiting_writers && sd->num_spliced)
++			return 0;
++
++		if (sd->flags & SPLICE_F_NONBLOCK)
++			return -EAGAIN;
++
++		if (signal_pending(current))
++			return -ERESTARTSYS;
++
++		if (sd->need_wakeup) {
++			wakeup_pipe_writers(pipe);
++			sd->need_wakeup = false;
++		}
++
++		pipe_wait(pipe);
++	}
++
++	return 1;
++}
++EXPORT_SYMBOL(splice_from_pipe_next);
++
++/**
++ * splice_from_pipe_begin - start splicing from pipe
++ * @sd:		information about the splice operation
++ *
++ * Description:
++ *    This function should be called before a loop containing
++ *    splice_from_pipe_next() and splice_from_pipe_feed() to
++ *    initialize the necessary fields of @sd.
++ */
++void splice_from_pipe_begin(struct splice_desc *sd)
++{
++	sd->num_spliced = 0;
++	sd->need_wakeup = false;
++}
++EXPORT_SYMBOL(splice_from_pipe_begin);
++
++/**
++ * splice_from_pipe_end - finish splicing from pipe
++ * @pipe:	pipe to splice from
++ * @sd:		information about the splice operation
++ *
++ * Description:
++ *    This function will wake up pipe writers if necessary.  It should
++ *    be called after a loop containing splice_from_pipe_next() and
++ *    splice_from_pipe_feed().
++ */
++void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
++{
++	if (sd->need_wakeup)
++		wakeup_pipe_writers(pipe);
++}
++EXPORT_SYMBOL(splice_from_pipe_end);
++
++/**
++ * __splice_from_pipe - splice data from a pipe to given actor
++ * @pipe:	pipe to splice from
++ * @sd:		information to @actor
++ * @actor:	handler that splices the data
++ *
++ * Description:
++ *    This function does little more than loop over the pipe and call
++ *    @actor to do the actual moving of a single struct pipe_buffer to
++ *    the desired destination. See pipe_to_file, pipe_to_sendpage, or
++ *    pipe_to_user.
++ *
++ */
++ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
++			   splice_actor *actor)
++{
++	int ret;
++
++	splice_from_pipe_begin(sd);
++	do {
++		ret = splice_from_pipe_next(pipe, sd);
++		if (ret > 0)
++			ret = splice_from_pipe_feed(pipe, sd, actor);
++	} while (ret > 0);
++	splice_from_pipe_end(pipe, sd);
++
++	return sd->num_spliced ? sd->num_spliced : ret;
++}
++EXPORT_SYMBOL(__splice_from_pipe);
++
++/**
++ * splice_from_pipe - splice data from a pipe to a file
++ * @pipe:	pipe to splice from
++ * @out:	file to splice to
++ * @ppos:	position in @out
++ * @len:	how many bytes to splice
++ * @flags:	splice modifier flags
++ * @actor:	handler that splices the data
++ *
++ * Description:
++ *    See __splice_from_pipe. This function locks the pipe inode,
++ *    otherwise it's identical to __splice_from_pipe().
++ *
++ */
++ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
++			 loff_t *ppos, size_t len, unsigned int flags,
++			 splice_actor *actor)
++{
++	ssize_t ret;
++	struct splice_desc sd = {
++		.total_len = len,
++		.flags = flags,
++		.pos = *ppos,
++		.u.file = out,
++	};
++
++	pipe_lock(pipe);
++	ret = __splice_from_pipe(pipe, &sd, actor);
++	pipe_unlock(pipe);
++
++	return ret;
++}
++
++/**
++ * generic_file_splice_write - splice data from a pipe to a file
++ * @pipe:	pipe info
++ * @out:	file to write to
++ * @ppos:	position in @out
++ * @len:	number of bytes to splice
++ * @flags:	splice modifier flags
++ *
++ * Description:
++ *    Will either move or copy pages (determined by @flags options) from
++ *    the given pipe inode to the given file.
++ *
++ */
++ssize_t
++generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
++			  loff_t *ppos, size_t len, unsigned int flags)
++{
++	struct address_space *mapping = out->f_mapping;
++	struct inode *inode = mapping->host;
++	struct splice_desc sd = {
++		.total_len = len,
++		.flags = flags,
++		.pos = *ppos,
++		.u.file = out,
++	};
++	ssize_t ret;
++
++	pipe_lock(pipe);
++
++	splice_from_pipe_begin(&sd);
++	do {
++		ret = splice_from_pipe_next(pipe, &sd);
++		if (ret <= 0)
++			break;
++
++		mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
++		ret = file_remove_suid(out);
++		if (!ret) {
++			file_update_time(out);
++			ret = splice_from_pipe_feed(pipe, &sd, pipe_to_file);
++		}
++		mutex_unlock(&inode->i_mutex);
++	} while (ret > 0);
++	splice_from_pipe_end(pipe, &sd);
++
++	pipe_unlock(pipe);
++
++	if (sd.num_spliced)
++		ret = sd.num_spliced;
++
++	if (ret > 0) {
++		unsigned long nr_pages;
++		int err;
++
++		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
++
++		err = generic_write_sync(out, *ppos, ret);
++		if (err)
++			ret = err;
++		else
++			*ppos += ret;
++		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
++	}
++
++	return ret;
++}
++
++EXPORT_SYMBOL(generic_file_splice_write);
++
++static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
++			  struct splice_desc *sd)
++{
++	int ret;
++	void *data;
++
++	ret = buf->ops->confirm(pipe, buf);
++	if (ret)
++		return ret;
++
++	data = buf->ops->map(pipe, buf, 0);
++	ret = kernel_write(sd->u.file, data + buf->offset, sd->len, sd->pos);
++	buf->ops->unmap(pipe, buf, data);
++
++	return ret;
++}
++
++static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
++					 struct file *out, loff_t *ppos,
++					 size_t len, unsigned int flags)
++{
++	ssize_t ret;
++
++	ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
++	if (ret > 0)
++		*ppos += ret;
++
++	return ret;
++}
++
++/**
++ * generic_splice_sendpage - splice data from a pipe to a socket
++ * @pipe:	pipe to splice from
++ * @out:	socket to write to
++ * @ppos:	position in @out
++ * @len:	number of bytes to splice
++ * @flags:	splice modifier flags
++ *
++ * Description:
++ *    Will send @len bytes from the pipe to a network socket. No data copying
++ *    is involved.
++ *
++ */
++ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
++				loff_t *ppos, size_t len, unsigned int flags)
++{
++	return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
++}
++
++EXPORT_SYMBOL(generic_splice_sendpage);
++
++/*
++ * Attempt to initiate a splice from pipe to file.
++ */
++static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
++			   loff_t *ppos, size_t len, unsigned int flags)
++{
++	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
++				loff_t *, size_t, unsigned int);
++	int ret;
++
++	if (unlikely(!(out->f_mode & FMODE_WRITE)))
++		return -EBADF;
++
++	if (unlikely(out->f_flags & O_APPEND))
++		return -EINVAL;
++
++	ret = rw_verify_area(WRITE, out, ppos, len);
++	if (unlikely(ret < 0))
++		return ret;
++
++	if (out->f_op && out->f_op->splice_write)
++		splice_write = out->f_op->splice_write;
++	else
++		splice_write = default_file_splice_write;
++
++	return splice_write(pipe, out, ppos, len, flags);
++}
++EXPORT_SYMBOL(do_splice_from);
++
++/*
++ * Attempt to initiate a splice from a file to a pipe.
++ */
++static long do_splice_to(struct file *in, loff_t *ppos,
++			 struct pipe_inode_info *pipe, size_t len,
++			 unsigned int flags)
++{
++	ssize_t (*splice_read)(struct file *, loff_t *,
++			       struct pipe_inode_info *, size_t, unsigned int);
++	int ret;
++
++	if (unlikely(!(in->f_mode & FMODE_READ)))
++		return -EBADF;
++
++	ret = rw_verify_area(READ, in, ppos, len);
++	if (unlikely(ret < 0))
++		return ret;
++
++	if (in->f_op && in->f_op->splice_read)
++		splice_read = in->f_op->splice_read;
++	else
++		splice_read = default_file_splice_read;
++
++	return splice_read(in, ppos, pipe, len, flags);
++}
++EXPORT_SYMBOL(do_splice_to);
++
++/**
++ * splice_direct_to_actor - splices data directly between two non-pipes
++ * @in:		file to splice from
++ * @sd:		actor information on where to splice to
++ * @actor:	handles the data splicing
++ *
++ * Description:
++ *    This is a special case helper to splice directly between two
++ *    points, without requiring an explicit pipe. Internally an allocated
++ *    pipe is cached in the process, and reused during the lifetime of
++ *    that process.
++ *
++ */
++ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
++			       splice_direct_actor *actor)
++{
++	struct pipe_inode_info *pipe;
++	long ret, bytes;
++	umode_t i_mode;
++	size_t len;
++	int i, flags;
++
++	/*
++	 * We require the input being a regular file, as we don't want to
++	 * randomly drop data for eg socket -> socket splicing. Use the
++	 * piped splicing for that!
++	 */
++	i_mode = in->f_path.dentry->d_inode->i_mode;
++	if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode)))
++		return -EINVAL;
++
++	/*
++	 * neither in nor out is a pipe, setup an internal pipe attached to
++	 * 'out' and transfer the wanted data from 'in' to 'out' through that
++	 */
++	pipe = current->splice_pipe;
++	if (unlikely(!pipe)) {
++		pipe = alloc_pipe_info(NULL);
++		if (!pipe)
++			return -ENOMEM;
++
++		/*
++		 * We don't have an immediate reader, but we'll read the stuff
++		 * out of the pipe right after the splice_to_pipe(). So set
++		 * PIPE_READERS appropriately.
++		 */
++		pipe->readers = 1;
++
++		current->splice_pipe = pipe;
++	}
++
++	/*
++	 * Do the splice.
++	 */
++	ret = 0;
++	bytes = 0;
++	len = sd->total_len;
++	flags = sd->flags;
++
++	/*
++	 * Don't block on output, we have to drain the direct pipe.
++	 */
++	sd->flags &= ~SPLICE_F_NONBLOCK;
++
++	while (len) {
++		size_t read_len;
++		loff_t pos = sd->pos, prev_pos = pos;
++
++		ret = do_splice_to(in, &pos, pipe, len, flags);
++		if (unlikely(ret <= 0))
++			goto out_release;
++
++		read_len = ret;
++		sd->total_len = read_len;
++
++		/*
++		 * NOTE: nonblocking mode only applies to the input. We
++		 * must not do the output in nonblocking mode as then we
++		 * could get stuck data in the internal pipe:
++		 */
++		ret = actor(pipe, sd);
++		if (unlikely(ret <= 0)) {
++			sd->pos = prev_pos;
++			goto out_release;
++		}
++
++		bytes += ret;
++		len -= ret;
++		sd->pos = pos;
++
++		if (ret < read_len) {
++			sd->pos = prev_pos + ret;
++			goto out_release;
++		}
++	}
++
++done:
++	pipe->nrbufs = pipe->curbuf = 0;
++	file_accessed(in);
++	return bytes;
++
++out_release:
++	/*
++	 * If we did an incomplete transfer we must release
++	 * the pipe buffers in question:
++	 */
++	for (i = 0; i < pipe->buffers; i++) {
++		struct pipe_buffer *buf = pipe->bufs + i;
++
++		if (buf->ops) {
++			buf->ops->release(pipe, buf);
++			buf->ops = NULL;
++		}
++	}
++
++	if (!bytes)
++		bytes = ret;
++
++	goto done;
++}
++EXPORT_SYMBOL(splice_direct_to_actor);
++
++static int direct_splice_actor(struct pipe_inode_info *pipe,
++			       struct splice_desc *sd)
++{
++	struct file *file = sd->u.file;
++
++	return do_splice_from(pipe, file, &file->f_pos, sd->total_len,
++			      sd->flags);
++}
++
++/**
++ * do_splice_direct - splices data directly between two files
++ * @in:		file to splice from
++ * @ppos:	input file offset
++ * @out:	file to splice to
++ * @len:	number of bytes to splice
++ * @flags:	splice modifier flags
++ *
++ * Description:
++ *    For use by do_sendfile(). splice can easily emulate sendfile, but
++ *    doing it in the application would incur an extra system call
++ *    (splice in + splice out, as compared to just sendfile()). So this helper
++ *    can splice directly through a process-private pipe.
++ *
++ */
++long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
++		      size_t len, unsigned int flags)
++{
++	struct splice_desc sd = {
++		.len		= len,
++		.total_len	= len,
++		.flags		= flags,
++		.pos		= *ppos,
++		.u.file		= out,
++	};
++	long ret;
++
++	ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
++	if (ret > 0)
++		*ppos = sd.pos;
++
++	return ret;
++}
++
++static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
++			       struct pipe_inode_info *opipe,
++			       size_t len, unsigned int flags);
++/*
++ * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same
++ * location, so checking ->i_pipe is not enough to verify that this is a
++ * pipe.
++ */
++static inline struct pipe_inode_info *pipe_info(struct inode *inode)
++{
++	if (S_ISFIFO(inode->i_mode))
++		return inode->i_pipe;
++
++	return NULL;
++}
++
++/*
++ * Determine where to splice to/from.
++ */
++static long do_splice(struct file *in, loff_t __user *off_in,
++		      struct file *out, loff_t __user *off_out,
++		      size_t len, unsigned int flags)
++{
++	struct pipe_inode_info *ipipe;
++	struct pipe_inode_info *opipe;
++	loff_t offset, *off;
++	long ret;
++
++	ipipe = pipe_info(in->f_path.dentry->d_inode);
++	opipe = pipe_info(out->f_path.dentry->d_inode);
++
++	if (ipipe && opipe) {
++		if (off_in || off_out)
++			return -ESPIPE;
++
++		if (!(in->f_mode & FMODE_READ))
++			return -EBADF;
++
++		if (!(out->f_mode & FMODE_WRITE))
++			return -EBADF;
++
++		/* Splicing to self would be fun, but... */
++		if (ipipe == opipe)
++			return -EINVAL;
++
++		return splice_pipe_to_pipe(ipipe, opipe, len, flags);
++	}
++
++	if (ipipe) {
++		if (off_in)
++			return -ESPIPE;
++		if (off_out) {
++			if (!(out->f_mode & FMODE_PWRITE))
++				return -EINVAL;
++			if (copy_from_user(&offset, off_out, sizeof(loff_t)))
++				return -EFAULT;
++			off = &offset;
++		} else
++			off = &out->f_pos;
++
++		ret = do_splice_from(ipipe, out, off, len, flags);
++
++		if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
++			ret = -EFAULT;
++
++		return ret;
++	}
++
++	if (opipe) {
++		if (off_out)
++			return -ESPIPE;
++		if (off_in) {
++			if (!(in->f_mode & FMODE_PREAD))
++				return -EINVAL;
++			if (copy_from_user(&offset, off_in, sizeof(loff_t)))
++				return -EFAULT;
++			off = &offset;
++		} else
++			off = &in->f_pos;
++
++		ret = do_splice_to(in, off, opipe, len, flags);
++
++		if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
++			ret = -EFAULT;
++
++		return ret;
++	}
++
++	return -EINVAL;
++}
++
++/*
++ * Map an iov into an array of pages and offset/length tupples. With the
++ * partial_page structure, we can map several non-contiguous ranges into
++ * our ones pages[] map instead of splitting that operation into pieces.
++ * Could easily be exported as a generic helper for other users, in which
++ * case one would probably want to add a 'max_nr_pages' parameter as well.
++ */
++static int get_iovec_page_array(const struct iovec __user *iov,
++				unsigned int nr_vecs, struct page **pages,
++				struct partial_page *partial, int aligned,
++				unsigned int pipe_buffers)
++{
++	int buffers = 0, error = 0;
++
++	while (nr_vecs) {
++		unsigned long off, npages;
++		struct iovec entry;
++		void __user *base;
++		size_t len;
++		int i;
++
++		error = -EFAULT;
++		if (copy_from_user(&entry, iov, sizeof(entry)))
++			break;
++
++		base = entry.iov_base;
++		len = entry.iov_len;
++
++		/*
++		 * Sanity check this iovec. 0 read succeeds.
++		 */
++		error = 0;
++		if (unlikely(!len))
++			break;
++		error = -EFAULT;
++		if (!access_ok(VERIFY_READ, base, len))
++			break;
++
++		/*
++		 * Get this base offset and number of pages, then map
++		 * in the user pages.
++		 */
++		off = (unsigned long) base & ~PAGE_MASK;
++
++		/*
++		 * If asked for alignment, the offset must be zero and the
++		 * length a multiple of the PAGE_SIZE.
++		 */
++		error = -EINVAL;
++		if (aligned && (off || len & ~PAGE_MASK))
++			break;
++
++		npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
++		if (npages > pipe_buffers - buffers)
++			npages = pipe_buffers - buffers;
++
++		error = get_user_pages_fast((unsigned long)base, npages,
++					0, &pages[buffers]);
++
++		if (unlikely(error <= 0))
++			break;
++
++		/*
++		 * Fill this contiguous range into the partial page map.
++		 */
++		for (i = 0; i < error; i++) {
++			const int plen = min_t(size_t, len, PAGE_SIZE - off);
++
++			partial[buffers].offset = off;
++			partial[buffers].len = plen;
++
++			off = 0;
++			len -= plen;
++			buffers++;
++		}
++
++		/*
++		 * We didn't complete this iov, stop here since it probably
++		 * means we have to move some of this into a pipe to
++		 * be able to continue.
++		 */
++		if (len)
++			break;
++
++		/*
++		 * Don't continue if we mapped fewer pages than we asked for,
++		 * or if we mapped the max number of pages that we have
++		 * room for.
++		 */
++		if (error < npages || buffers == pipe_buffers)
++			break;
++
++		nr_vecs--;
++		iov++;
++	}
++
++	if (buffers)
++		return buffers;
++
++	return error;
++}
++
++static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
++			struct splice_desc *sd)
++{
++	char *src;
++	int ret;
++
++	ret = buf->ops->confirm(pipe, buf);
++	if (unlikely(ret))
++		return ret;
++
++	/*
++	 * See if we can use the atomic maps, by prefaulting in the
++	 * pages and doing an atomic copy
++	 */
++	if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) {
++		src = buf->ops->map(pipe, buf, 1);
++		ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset,
++							sd->len);
++		buf->ops->unmap(pipe, buf, src);
++		if (!ret) {
++			ret = sd->len;
++			goto out;
++		}
++	}
++
++	/*
++	 * No dice, use slow non-atomic map and copy
++ 	 */
++	src = buf->ops->map(pipe, buf, 0);
++
++	ret = sd->len;
++	if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len))
++		ret = -EFAULT;
++
++	buf->ops->unmap(pipe, buf, src);
++out:
++	if (ret > 0)
++		sd->u.userptr += ret;
++	return ret;
++}
++
++/*
++ * For lack of a better implementation, implement vmsplice() to userspace
++ * as a simple copy of the pipes pages to the user iov.
++ */
++static long vmsplice_to_user(struct file *file, const struct iovec __user *iov,
++			     unsigned long nr_segs, unsigned int flags)
++{
++	struct pipe_inode_info *pipe;
++	struct splice_desc sd;
++	ssize_t size;
++	int error;
++	long ret;
++
++	pipe = pipe_info(file->f_path.dentry->d_inode);
++	if (!pipe)
++		return -EBADF;
++
++	pipe_lock(pipe);
++
++	error = ret = 0;
++	while (nr_segs) {
++		void __user *base;
++		size_t len;
++
++		/*
++		 * Get user address base and length for this iovec.
++		 */
++		error = get_user(base, &iov->iov_base);
++		if (unlikely(error))
++			break;
++		error = get_user(len, &iov->iov_len);
++		if (unlikely(error))
++			break;
++
++		/*
++		 * Sanity check this iovec. 0 read succeeds.
++		 */
++		if (unlikely(!len))
++			break;
++		if (unlikely(!base)) {
++			error = -EFAULT;
++			break;
++		}
++
++		if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
++			error = -EFAULT;
++			break;
++		}
++
++		sd.len = 0;
++		sd.total_len = len;
++		sd.flags = flags;
++		sd.u.userptr = base;
++		sd.pos = 0;
++
++		size = __splice_from_pipe(pipe, &sd, pipe_to_user);
++		if (size < 0) {
++			if (!ret)
++				ret = size;
++
++			break;
++		}
++
++		ret += size;
++
++		if (size < len)
++			break;
++
++		nr_segs--;
++		iov++;
++	}
++
++	pipe_unlock(pipe);
++
++	if (!ret)
++		ret = error;
++
++	return ret;
++}
++
++/*
++ * vmsplice splices a user address range into a pipe. It can be thought of
++ * as splice-from-memory, where the regular splice is splice-from-file (or
++ * to file). In both cases the output is a pipe, naturally.
++ */
++static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
++			     unsigned long nr_segs, unsigned int flags)
++{
++	struct pipe_inode_info *pipe;
++	struct page *pages[PIPE_DEF_BUFFERS];
++	struct partial_page partial[PIPE_DEF_BUFFERS];
++	struct splice_pipe_desc spd = {
++		.pages = pages,
++		.partial = partial,
++		.flags = flags,
++		.ops = &user_page_pipe_buf_ops,
++		.spd_release = spd_release_page,
++	};
++	long ret;
++
++	pipe = pipe_info(file->f_path.dentry->d_inode);
++	if (!pipe)
++		return -EBADF;
++
++	if (splice_grow_spd(pipe, &spd))
++		return -ENOMEM;
++
++	spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
++					    spd.partial, flags & SPLICE_F_GIFT,
++					    pipe->buffers);
++	if (spd.nr_pages <= 0)
++		ret = spd.nr_pages;
++	else
++		ret = splice_to_pipe(pipe, &spd);
++
++	splice_shrink_spd(pipe, &spd);
++	return ret;
++}
++
++/*
++ * Note that vmsplice only really supports true splicing _from_ user memory
++ * to a pipe, not the other way around. Splicing from user memory is a simple
++ * operation that can be supported without any funky alignment restrictions
++ * or nasty vm tricks. We simply map in the user memory and fill them into
++ * a pipe. The reverse isn't quite as easy, though. There are two possible
++ * solutions for that:
++ *
++ *	- memcpy() the data internally, at which point we might as well just
++ *	  do a regular read() on the buffer anyway.
++ *	- Lots of nasty vm tricks, that are neither fast nor flexible (it
++ *	  has restriction limitations on both ends of the pipe).
++ *
++ * Currently we punt and implement it as a normal copy, see pipe_to_user().
++ *
++ */
++SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov,
++		unsigned long, nr_segs, unsigned int, flags)
++{
++	struct file *file;
++	long error;
++	int fput;
++
++	if (unlikely(nr_segs > UIO_MAXIOV))
++		return -EINVAL;
++	else if (unlikely(!nr_segs))
++		return 0;
++
++	error = -EBADF;
++	file = fget_light(fd, &fput);
++	if (file) {
++		if (file->f_mode & FMODE_WRITE)
++			error = vmsplice_to_pipe(file, iov, nr_segs, flags);
++		else if (file->f_mode & FMODE_READ)
++			error = vmsplice_to_user(file, iov, nr_segs, flags);
++
++		fput_light(file, fput);
++	}
++
++	return error;
++}
++
++SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in,
++		int, fd_out, loff_t __user *, off_out,
++		size_t, len, unsigned int, flags)
++{
++	long error;
++	struct file *in, *out;
++	int fput_in, fput_out;
++
++	if (unlikely(!len))
++		return 0;
++
++	error = -EBADF;
++	in = fget_light(fd_in, &fput_in);
++	if (in) {
++		if (in->f_mode & FMODE_READ) {
++			out = fget_light(fd_out, &fput_out);
++			if (out) {
++				if (out->f_mode & FMODE_WRITE)
++					error = do_splice(in, off_in,
++							  out, off_out,
++							  len, flags);
++				fput_light(out, fput_out);
++			}
++		}
++
++		fput_light(in, fput_in);
++	}
++
++	return error;
++}
++
++/*
++ * Make sure there's data to read. Wait for input if we can, otherwise
++ * return an appropriate error.
++ */
++static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
++{
++	int ret;
++
++	/*
++	 * Check ->nrbufs without the inode lock first. This function
++	 * is speculative anyways, so missing one is ok.
++	 */
++	if (pipe->nrbufs)
++		return 0;
++
++	ret = 0;
++	pipe_lock(pipe);
++
++	while (!pipe->nrbufs) {
++		if (signal_pending(current)) {
++			ret = -ERESTARTSYS;
++			break;
++		}
++		if (!pipe->writers)
++			break;
++		if (!pipe->waiting_writers) {
++			if (flags & SPLICE_F_NONBLOCK) {
++				ret = -EAGAIN;
++				break;
++			}
++		}
++		pipe_wait(pipe);
++	}
++
++	pipe_unlock(pipe);
++	return ret;
++}
++
++/*
++ * Make sure there's writeable room. Wait for room if we can, otherwise
++ * return an appropriate error.
++ */
++static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
++{
++	int ret;
++
++	/*
++	 * Check ->nrbufs without the inode lock first. This function
++	 * is speculative anyways, so missing one is ok.
++	 */
++	if (pipe->nrbufs < pipe->buffers)
++		return 0;
++
++	ret = 0;
++	pipe_lock(pipe);
++
++	while (pipe->nrbufs >= pipe->buffers) {
++		if (!pipe->readers) {
++			send_sig(SIGPIPE, current, 0);
++			ret = -EPIPE;
++			break;
++		}
++		if (flags & SPLICE_F_NONBLOCK) {
++			ret = -EAGAIN;
++			break;
++		}
++		if (signal_pending(current)) {
++			ret = -ERESTARTSYS;
++			break;
++		}
++		pipe->waiting_writers++;
++		pipe_wait(pipe);
++		pipe->waiting_writers--;
++	}
++
++	pipe_unlock(pipe);
++	return ret;
++}
++
++/*
++ * Splice contents of ipipe to opipe.
++ */
++static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
++			       struct pipe_inode_info *opipe,
++			       size_t len, unsigned int flags)
++{
++	struct pipe_buffer *ibuf, *obuf;
++	int ret = 0, nbuf;
++	bool input_wakeup = false;
++
++
++retry:
++	ret = ipipe_prep(ipipe, flags);
++	if (ret)
++		return ret;
++
++	ret = opipe_prep(opipe, flags);
++	if (ret)
++		return ret;
++
++	/*
++	 * Potential ABBA deadlock, work around it by ordering lock
++	 * grabbing by pipe info address. Otherwise two different processes
++	 * could deadlock (one doing tee from A -> B, the other from B -> A).
++	 */
++	pipe_double_lock(ipipe, opipe);
++
++	do {
++		if (!opipe->readers) {
++			send_sig(SIGPIPE, current, 0);
++			if (!ret)
++				ret = -EPIPE;
++			break;
++		}
++
++		if (!ipipe->nrbufs && !ipipe->writers)
++			break;
++
++		/*
++		 * Cannot make any progress, because either the input
++		 * pipe is empty or the output pipe is full.
++		 */
++		if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
++			/* Already processed some buffers, break */
++			if (ret)
++				break;
++
++			if (flags & SPLICE_F_NONBLOCK) {
++				ret = -EAGAIN;
++				break;
++			}
++
++			/*
++			 * We raced with another reader/writer and haven't
++			 * managed to process any buffers.  A zero return
++			 * value means EOF, so retry instead.
++			 */
++			pipe_unlock(ipipe);
++			pipe_unlock(opipe);
++			goto retry;
++		}
++
++		ibuf = ipipe->bufs + ipipe->curbuf;
++		nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
++		obuf = opipe->bufs + nbuf;
++
++		if (len >= ibuf->len) {
++			/*
++			 * Simply move the whole buffer from ipipe to opipe
++			 */
++			*obuf = *ibuf;
++			ibuf->ops = NULL;
++			opipe->nrbufs++;
++			ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
++			ipipe->nrbufs--;
++			input_wakeup = true;
++		} else {
++			/*
++			 * Get a reference to this pipe buffer,
++			 * so we can copy the contents over.
++			 */
++			ibuf->ops->get(ipipe, ibuf);
++			*obuf = *ibuf;
++
++			/*
++			 * Don't inherit the gift flag, we need to
++			 * prevent multiple steals of this page.
++			 */
++			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
++
++			obuf->len = len;
++			opipe->nrbufs++;
++			ibuf->offset += obuf->len;
++			ibuf->len -= obuf->len;
++		}
++		ret += obuf->len;
++		len -= obuf->len;
++	} while (len);
++
++	pipe_unlock(ipipe);
++	pipe_unlock(opipe);
++
++	/*
++	 * If we put data in the output pipe, wakeup any potential readers.
++	 */
++	if (ret > 0) {
++		smp_mb();
++		if (waitqueue_active(&opipe->wait))
++			wake_up_interruptible(&opipe->wait);
++		kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN);
++	}
++	if (input_wakeup)
++		wakeup_pipe_writers(ipipe);
++
++	return ret;
++}
++
++/*
++ * Link contents of ipipe to opipe.
++ */
++static int link_pipe(struct pipe_inode_info *ipipe,
++		     struct pipe_inode_info *opipe,
++		     size_t len, unsigned int flags)
++{
++	struct pipe_buffer *ibuf, *obuf;
++	int ret = 0, i = 0, nbuf;
++
++	/*
++	 * Potential ABBA deadlock, work around it by ordering lock
++	 * grabbing by pipe info address. Otherwise two different processes
++	 * could deadlock (one doing tee from A -> B, the other from B -> A).
++	 */
++	pipe_double_lock(ipipe, opipe);
++
++	do {
++		if (!opipe->readers) {
++			send_sig(SIGPIPE, current, 0);
++			if (!ret)
++				ret = -EPIPE;
++			break;
++		}
++
++		/*
++		 * If we have iterated all input buffers or ran out of
++		 * output room, break.
++		 */
++		if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
++			break;
++
++		ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
++		nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
++
++		/*
++		 * Get a reference to this pipe buffer,
++		 * so we can copy the contents over.
++		 */
++		ibuf->ops->get(ipipe, ibuf);
++
++		obuf = opipe->bufs + nbuf;
++		*obuf = *ibuf;
++
++		/*
++		 * Don't inherit the gift flag, we need to
++		 * prevent multiple steals of this page.
++		 */
++		obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
++
++		if (obuf->len > len)
++			obuf->len = len;
++
++		opipe->nrbufs++;
++		ret += obuf->len;
++		len -= obuf->len;
++		i++;
++	} while (len);
++
++	/*
++	 * return EAGAIN if we have the potential of some data in the
++	 * future, otherwise just return 0
++	 */
++	if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK))
++		ret = -EAGAIN;
++
++	pipe_unlock(ipipe);
++	pipe_unlock(opipe);
++
++	/*
++	 * If we put data in the output pipe, wakeup any potential readers.
++	 */
++	if (ret > 0) {
++		smp_mb();
++		if (waitqueue_active(&opipe->wait))
++			wake_up_interruptible(&opipe->wait);
++		kill_fasync(&opipe->fasync_readers, SIGIO, POLL_IN);
++	}
++
++	return ret;
++}
++
++/*
++ * This is a tee(1) implementation that works on pipes. It doesn't copy
++ * any data, it simply references the 'in' pages on the 'out' pipe.
++ * The 'flags' used are the SPLICE_F_* variants, currently the only
++ * applicable one is SPLICE_F_NONBLOCK.
++ */
++static long do_tee(struct file *in, struct file *out, size_t len,
++		   unsigned int flags)
++{
++	struct pipe_inode_info *ipipe = pipe_info(in->f_path.dentry->d_inode);
++	struct pipe_inode_info *opipe = pipe_info(out->f_path.dentry->d_inode);
++	int ret = -EINVAL;
++
++	/*
++	 * Duplicate the contents of ipipe to opipe without actually
++	 * copying the data.
++	 */
++	if (ipipe && opipe && ipipe != opipe) {
++		/*
++		 * Keep going, unless we encounter an error. The ipipe/opipe
++		 * ordering doesn't really matter.
++		 */
++		ret = ipipe_prep(ipipe, flags);
++		if (!ret) {
++			ret = opipe_prep(opipe, flags);
++			if (!ret)
++				ret = link_pipe(ipipe, opipe, len, flags);
++		}
++	}
++
++	return ret;
++}
++
++SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
++{
++	struct file *in;
++	int error, fput_in;
++
++	if (unlikely(!len))
++		return 0;
++
++	error = -EBADF;
++	in = fget_light(fdin, &fput_in);
++	if (in) {
++		if (in->f_mode & FMODE_READ) {
++			int fput_out;
++			struct file *out = fget_light(fdout, &fput_out);
++
++			if (out) {
++				if (out->f_mode & FMODE_WRITE)
++					error = do_tee(in, out, len, flags);
++				fput_light(out, fput_out);
++			}
++		}
++ 		fput_light(in, fput_in);
++ 	}
++
++	return error;
++}
+diff -Nur linux-2.6.36.orig/security/commoncap.c linux-2.6.36/security/commoncap.c
+--- linux-2.6.36.orig/security/commoncap.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/security/commoncap.c	2011-01-10 19:52:38.000000000 +0100
+@@ -951,3 +951,4 @@
+ 	}
+ 	return ret;
+ }
++EXPORT_SYMBOL(cap_file_mmap);
+diff -Nur linux-2.6.36.orig/security/device_cgroup.c linux-2.6.36/security/device_cgroup.c
+--- linux-2.6.36.orig/security/device_cgroup.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/security/device_cgroup.c	2011-01-10 19:52:38.000000000 +0100
+@@ -515,6 +515,7 @@
+ 
+ 	return -EPERM;
+ }
++EXPORT_SYMBOL(devcgroup_inode_permission);
+ 
+ int devcgroup_inode_mknod(int mode, dev_t dev)
+ {
+diff -Nur linux-2.6.36.orig/security/security.c linux-2.6.36/security/security.c
+--- linux-2.6.36.orig/security/security.c	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/security/security.c	2011-01-10 19:52:38.000000000 +0100
+@@ -376,6 +376,7 @@
+ 		return 0;
+ 	return security_ops->path_mkdir(dir, dentry, mode);
+ }
++EXPORT_SYMBOL(security_path_mkdir);
+ 
+ int security_path_rmdir(struct path *dir, struct dentry *dentry)
+ {
+@@ -383,6 +384,7 @@
+ 		return 0;
+ 	return security_ops->path_rmdir(dir, dentry);
+ }
++EXPORT_SYMBOL(security_path_rmdir);
+ 
+ int security_path_unlink(struct path *dir, struct dentry *dentry)
+ {
+@@ -390,6 +392,7 @@
+ 		return 0;
+ 	return security_ops->path_unlink(dir, dentry);
+ }
++EXPORT_SYMBOL(security_path_unlink);
+ 
+ int security_path_symlink(struct path *dir, struct dentry *dentry,
+ 			  const char *old_name)
+@@ -398,6 +401,7 @@
+ 		return 0;
+ 	return security_ops->path_symlink(dir, dentry, old_name);
+ }
++EXPORT_SYMBOL(security_path_symlink);
+ 
+ int security_path_link(struct dentry *old_dentry, struct path *new_dir,
+ 		       struct dentry *new_dentry)
+@@ -406,6 +410,7 @@
+ 		return 0;
+ 	return security_ops->path_link(old_dentry, new_dir, new_dentry);
+ }
++EXPORT_SYMBOL(security_path_link);
+ 
+ int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
+ 			 struct path *new_dir, struct dentry *new_dentry)
+@@ -416,6 +421,7 @@
+ 	return security_ops->path_rename(old_dir, old_dentry, new_dir,
+ 					 new_dentry);
+ }
++EXPORT_SYMBOL(security_path_rename);
+ 
+ int security_path_truncate(struct path *path)
+ {
+@@ -423,6 +429,7 @@
+ 		return 0;
+ 	return security_ops->path_truncate(path);
+ }
++EXPORT_SYMBOL(security_path_truncate);
+ 
+ int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
+ 			mode_t mode)
+@@ -431,6 +438,7 @@
+ 		return 0;
+ 	return security_ops->path_chmod(dentry, mnt, mode);
+ }
++EXPORT_SYMBOL(security_path_chmod);
+ 
+ int security_path_chown(struct path *path, uid_t uid, gid_t gid)
+ {
+@@ -438,6 +446,7 @@
+ 		return 0;
+ 	return security_ops->path_chown(path, uid, gid);
+ }
++EXPORT_SYMBOL(security_path_chown);
+ 
+ int security_path_chroot(struct path *path)
+ {
+@@ -514,6 +523,7 @@
+ 		return 0;
+ 	return security_ops->inode_readlink(dentry);
+ }
++EXPORT_SYMBOL(security_inode_readlink);
+ 
+ int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd)
+ {
+@@ -528,6 +538,7 @@
+ 		return 0;
+ 	return security_ops->inode_permission(inode, mask);
+ }
++EXPORT_SYMBOL(security_inode_permission);
+ 
+ int security_inode_setattr(struct dentry *dentry, struct iattr *attr)
+ {
+@@ -627,6 +638,7 @@
+ 
+ 	return fsnotify_perm(file, mask);
+ }
++EXPORT_SYMBOL(security_file_permission);
+ 
+ int security_file_alloc(struct file *file)
+ {
+@@ -654,6 +666,7 @@
+ 		return ret;
+ 	return ima_file_mmap(file, prot);
+ }
++EXPORT_SYMBOL(security_file_mmap);
+ 
+ int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
+ 			    unsigned long prot)
diff --git a/toolchain/kernel-headers/patches/2.6.36/aufs2.patch b/toolchain/kernel-headers/patches/2.6.36/aufs2.patch
new file mode 100644
index 000000000..eafbe6814
--- /dev/null
+++ b/toolchain/kernel-headers/patches/2.6.36/aufs2.patch
@@ -0,0 +1,240 @@
+diff -Nur linux-2.6.36.orig/include/linux/Kbuild linux-2.6.36/include/linux/Kbuild
+--- linux-2.6.36.orig/include/linux/Kbuild	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/include/linux/Kbuild	2011-01-10 19:52:38.000000000 +0100
+@@ -60,6 +60,7 @@
+ header-y += atmsap.h
+ header-y += atmsvc.h
+ header-y += audit.h
++header-y += aufs_type.h
+ header-y += auto_fs.h
+ header-y += auto_fs4.h
+ header-y += auxvec.h
+diff -Nur linux-2.6.36.orig/include/linux/aufs_type.h linux-2.6.36/include/linux/aufs_type.h
+--- linux-2.6.36.orig/include/linux/aufs_type.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.36/include/linux/aufs_type.h	2011-01-10 19:54:22.000000000 +0100
+@@ -0,0 +1,197 @@
++/*
++ * Copyright (C) 2005-2011 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++ * GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
++ */
++
++#ifndef __AUFS_TYPE_H__
++#define __AUFS_TYPE_H__
++
++#include <linux/ioctl.h>
++#include <linux/kernel.h>
++#include <linux/limits.h>
++#include <linux/types.h>
++
++#define AUFS_VERSION	"2.1-standalone.tree-36-20110110"
++
++/* todo? move this to linux-2.6.19/include/magic.h */
++#define AUFS_SUPER_MAGIC	('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_BRANCH_MAX_127
++typedef __s8 aufs_bindex_t;
++#define AUFS_BRANCH_MAX 127
++#else
++typedef __s16 aufs_bindex_t;
++#ifdef CONFIG_AUFS_BRANCH_MAX_511
++#define AUFS_BRANCH_MAX 511
++#elif defined(CONFIG_AUFS_BRANCH_MAX_1023)
++#define AUFS_BRANCH_MAX 1023
++#elif defined(CONFIG_AUFS_BRANCH_MAX_32767)
++#define AUFS_BRANCH_MAX 32767
++#endif
++#endif
++
++#ifdef __KERNEL__
++#ifndef AUFS_BRANCH_MAX
++#error unknown CONFIG_AUFS_BRANCH_MAX value
++#endif
++#endif /* __KERNEL__ */
++
++/* ---------------------------------------------------------------------- */
++
++#define AUFS_NAME		"aufs"
++#define AUFS_FSTYPE		AUFS_NAME
++
++#define AUFS_ROOT_INO		2
++#define AUFS_FIRST_INO		11
++
++#define AUFS_WH_PFX		".wh."
++#define AUFS_WH_PFX_LEN		((int)sizeof(AUFS_WH_PFX) - 1)
++#define AUFS_WH_TMP_LEN		4
++/* a limit for rmdir/rename a dir */
++#define AUFS_MAX_NAMELEN	(NAME_MAX \
++				- AUFS_WH_PFX_LEN * 2	/* doubly whiteouted */\
++				- 1			/* dot */\
++				- AUFS_WH_TMP_LEN)	/* hex */
++#define AUFS_XINO_FNAME		"." AUFS_NAME ".xino"
++#define AUFS_XINO_DEFPATH	"/tmp/" AUFS_XINO_FNAME
++#define AUFS_XINO_TRUNC_INIT	64 /* blocks */
++#define AUFS_XINO_TRUNC_STEP	4  /* blocks */
++#define AUFS_DIRWH_DEF		3
++#define AUFS_RDCACHE_DEF	10 /* seconds */
++#define AUFS_RDCACHE_MAX	3600 /* seconds */
++#define AUFS_RDBLK_DEF		512 /* bytes */
++#define AUFS_RDHASH_DEF		32
++#define AUFS_WKQ_NAME		AUFS_NAME "d"
++#define AUFS_WKQ_PRE_NAME	AUFS_WKQ_NAME "_pre"
++#define AUFS_MFS_DEF_SEC	30 /* seconds */
++#define AUFS_MFS_MAX_SEC	3600 /* seconds */
++#define AUFS_PLINK_WARN		100 /* number of plinks */
++
++/* pseudo-link maintenace under /proc */
++#define AUFS_PLINK_MAINT_NAME	"plink_maint"
++#define AUFS_PLINK_MAINT_DIR	"fs/" AUFS_NAME
++#define AUFS_PLINK_MAINT_PATH	AUFS_PLINK_MAINT_DIR "/" AUFS_PLINK_MAINT_NAME
++
++#define AUFS_DIROPQ_NAME	AUFS_WH_PFX ".opq" /* whiteouted doubly */
++#define AUFS_WH_DIROPQ		AUFS_WH_PFX AUFS_DIROPQ_NAME
++
++#define AUFS_BASE_NAME		AUFS_WH_PFX AUFS_NAME
++#define AUFS_PLINKDIR_NAME	AUFS_WH_PFX "plnk"
++#define AUFS_ORPHDIR_NAME	AUFS_WH_PFX "orph"
++
++/* doubly whiteouted */
++#define AUFS_WH_BASE		AUFS_WH_PFX AUFS_BASE_NAME
++#define AUFS_WH_PLINKDIR	AUFS_WH_PFX AUFS_PLINKDIR_NAME
++#define AUFS_WH_ORPHDIR		AUFS_WH_PFX AUFS_ORPHDIR_NAME
++
++/* branch permission */
++#define AUFS_BRPERM_RW		"rw"
++#define AUFS_BRPERM_RO		"ro"
++#define AUFS_BRPERM_RR		"rr"
++#define AUFS_BRPERM_WH		"wh"
++#define AUFS_BRPERM_NLWH	"nolwh"
++#define AUFS_BRPERM_ROWH	AUFS_BRPERM_RO "+" AUFS_BRPERM_WH
++#define AUFS_BRPERM_RRWH	AUFS_BRPERM_RR "+" AUFS_BRPERM_WH
++#define AUFS_BRPERM_RWNLWH	AUFS_BRPERM_RW "+" AUFS_BRPERM_NLWH
++
++/* ---------------------------------------------------------------------- */
++
++/* ioctl */
++enum {
++	/* readdir in userspace */
++	AuCtl_RDU,
++	AuCtl_RDU_INO,
++
++	/* pathconf wrapper */
++	AuCtl_WBR_FD
++};
++
++/* borrowed from linux/include/linux/kernel.h */
++#ifndef ALIGN
++#define ALIGN(x, a)		__ALIGN_MASK(x, (typeof(x))(a)-1)
++#define __ALIGN_MASK(x, mask)	(((x)+(mask))&~(mask))
++#endif
++
++/* borrowed from linux/include/linux/compiler-gcc3.h */
++#ifndef __aligned
++#define __aligned(x)			__attribute__((aligned(x)))
++#define __packed			__attribute__((packed))
++#endif
++
++struct au_rdu_cookie {
++	__u64		h_pos;
++	__s16		bindex;
++	__u8		flags;
++	__u8		pad;
++	__u32		generation;
++} __aligned(8);
++
++struct au_rdu_ent {
++	__u64		ino;
++	__s16		bindex;
++	__u8		type;
++	__u8		nlen;
++	__u8		wh;
++	char		name[0];
++} __aligned(8);
++
++static inline int au_rdu_len(int nlen)
++{
++	/* include the terminating NULL */
++	return ALIGN(sizeof(struct au_rdu_ent) + nlen + 1,
++		     sizeof(__u64));
++}
++
++union au_rdu_ent_ul {
++	struct au_rdu_ent __user	*e;
++	__u64				ul;
++};
++
++enum {
++	AufsCtlRduV_SZ,
++	AufsCtlRduV_End
++};
++
++struct aufs_rdu {
++	/* input */
++	union {
++		__u64		sz;	/* AuCtl_RDU */
++		__u64		nent;	/* AuCtl_RDU_INO */
++	};
++	union au_rdu_ent_ul	ent;
++	__u16			verify[AufsCtlRduV_End];
++
++	/* input/output */
++	__u32			blk;
++
++	/* output */
++	union au_rdu_ent_ul	tail;
++	/* number of entries which were added in a single call */
++	__u64			rent;
++	__u8			full;
++	__u8			shwh;
++
++	struct au_rdu_cookie	cookie;
++} __aligned(8);
++
++#define AuCtlType		'A'
++#define AUFS_CTL_RDU		_IOWR(AuCtlType, AuCtl_RDU, struct aufs_rdu)
++#define AUFS_CTL_RDU_INO	_IOWR(AuCtlType, AuCtl_RDU_INO, struct aufs_rdu)
++#define AUFS_CTL_WBR_FD		_IO(AuCtlType, AuCtl_WBR_FD)
++
++#endif /* __AUFS_TYPE_H__ */
+diff -Nur linux-2.6.36.orig/include/linux/namei.h linux-2.6.36/include/linux/namei.h
+--- linux-2.6.36.orig/include/linux/namei.h	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/include/linux/namei.h	2011-01-10 19:52:38.000000000 +0100
+@@ -73,6 +73,9 @@
+ extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
+ 		int (*open)(struct inode *, struct file *));
+ 
++extern struct dentry *lookup_hash(struct nameidata *nd);
++extern int __lookup_one_len(const char *name, struct qstr *this,
++			    struct dentry *base, int len);
+ extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
+ 
+ extern int follow_down(struct path *);
+diff -Nur linux-2.6.36.orig/include/linux/splice.h linux-2.6.36/include/linux/splice.h
+--- linux-2.6.36.orig/include/linux/splice.h	2010-10-20 22:30:22.000000000 +0200
++++ linux-2.6.36/include/linux/splice.h	2011-01-10 19:52:38.000000000 +0100
+@@ -89,4 +89,10 @@
+ extern void splice_shrink_spd(struct pipe_inode_info *,
+ 				struct splice_pipe_desc *);
+ 
++extern long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
++			   loff_t *ppos, size_t len, unsigned int flags);
++extern long do_splice_to(struct file *in, loff_t *ppos,
++			 struct pipe_inode_info *pipe, size_t len,
++			 unsigned int flags);
++
+ #endif
+