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+/*
+ * Mach Operating System
+ * Copyright (c) 1993 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
+ * School of Computer Science
+ * Carnegie Mellon University
+ * Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+/*
+ * HISTORY
+ * $Log: ufs.c,v $
+ * Revision 1.1.1.2 2007/08/16 07:04:23 vorlon
+ * Import upstream "release" 1.0pre20040408 to CVS to facilitate rebasing
+ * against the current upstream work and avoid copying patches one-by-one.
+ *
+ * Revision 1.2 2003/11/08 00:03:36 wgwoods
+ * Reverted changes from 0.10, merged doc changes
+ *
+ * Revision 1.1.1.1.2.1 2003/03/21 23:32:23 wgwoods
+ * Warning cleanups
+ *
+ * Revision 1.1.1.1 2001/10/08 23:03:52 wgwoods
+ * initial import of CVS source from alphalinux.org, plus a couple bugfixes
+ *
+ * Revision 1.1.1.1 2000/05/03 03:58:22 dhd
+ * Initial import (from 0.7 release)
+ *
+ * Revision 2.2 93/02/05 08:01:36 danner
+ * Adapted for alpha.
+ * [93/02/04 af]
+ *
+ */
+/*
+ * File: ufs.c
+ * Author: David Golub, Carnegie Mellon University
+ * Date: 12/90
+ *
+ * Stand-alone file reading package.
+ *
+ * Modified for use by Linux/Alpha by David Mosberger
+ * (davidm@cs.arizona.edu)
+ */
+#include <linux/kernel.h>
+#include <asm/stat.h>
+
+#include "aboot.h"
+#include "bootfs.h"
+#include "cons.h"
+#include "disklabel.h"
+#include "ufs.h"
+#include "utils.h"
+#include "string.h"
+
+#define MAX_OPEN_FILES 1
+
+extern struct bootfs ufs;
+
+static long dev;
+static long partition_offset;
+static struct fs *fs;
+static struct file {
+ int inuse;
+ struct icommon i_ic; /* copy of on-disk inode */
+ int f_nindir[NIADDR+1];
+ /* number of blocks mapped by
+ indirect block at level i */
+ void *f_blk[NIADDR]; /* buffer for indir block at level i */
+ long f_blksize[NIADDR];
+ /* size of buffer */
+ __kernel_daddr_t f_blkno[NIADDR];
+ /* disk address of block in buffer */
+ void *f_buf; /* buffer for data block */
+ long f_buf_size; /* size of data block */
+ __kernel_daddr_t f_buf_blkno; /* block number of data block */
+} inode_table[MAX_OPEN_FILES];
+
+
+static int read_inode(__kernel_ino_t inumber, struct file *fp)
+{
+ __kernel_daddr_t disk_block;
+ long offset;
+ struct dinode *dp;
+ int level;
+
+ disk_block = itod(fs, inumber);
+
+ offset = fsbtodb(fs, disk_block) * DEV_BSIZE + partition_offset;
+ if (cons_read(dev, fp->f_buf, fs->fs_bsize, offset) != fs->fs_bsize) {
+ printf("ufs_read_inode: read error\n");
+ return 1;
+ }
+ dp = (struct dinode *)fp->f_buf;
+ dp += itoo(fs, inumber);
+ fp->i_ic = dp->di_ic;
+ /*
+ * Clear out the old buffers
+ */
+ for (level = 0; level < NIADDR; level++) {
+ if (fp->f_blk[level]) {
+ free(fp->f_blk[level]);
+ fp->f_blk[level] = 0;
+ }
+ fp->f_blkno[level] = -1;
+ }
+ return 0;
+}
+
+
+/*
+ * Given an offset in a file, find the disk block number that
+ * contains that block.
+ */
+static __kernel_daddr_t block_map(struct file *fp, __kernel_daddr_t file_block)
+{
+ __kernel_daddr_t ind_block_num, *ind_p;
+ int level, idx;
+ long offset;
+ /*
+ * Index structure of an inode:
+ *
+ * i_db[0..NDADDR-1] hold block numbers for blocks
+ * 0..NDADDR-1
+ *
+ * i_ib[0] index block 0 is the single indirect
+ * block
+ * holds block numbers for blocks
+ * NDADDR .. NDADDR + NINDIR(fs)-1
+ *
+ * i_ib[1] index block 1 is the double indirect
+ * block
+ * holds block numbers for INDEX blocks
+ * for blocks
+ * NDADDR + NINDIR(fs) ..
+ * NDADDR + NINDIR(fs) + NINDIR(fs)**2 - 1
+ *
+ * i_ib[2] index block 2 is the triple indirect
+ * block
+ * holds block numbers for double-indirect
+ * blocks for blocks
+ * NDADDR + NINDIR(fs) + NINDIR(fs)**2 ..
+ * NDADDR + NINDIR(fs) + NINDIR(fs)**2
+ * + NINDIR(fs)**3 - 1
+ */
+ if (file_block < NDADDR) {
+ /* Direct block. */
+ return fp->i_db[file_block];
+ }
+
+ file_block -= NDADDR;
+
+ /*
+ * nindir[0] = NINDIR
+ * nindir[1] = NINDIR**2
+ * nindir[2] = NINDIR**3
+ * etc
+ */
+ for (level = 0; level < NIADDR; level++) {
+ if (file_block < fp->f_nindir[level])
+ break;
+ file_block -= fp->f_nindir[level];
+ }
+ if (level == NIADDR) {
+ printf("ufs_block_map: block number too high\n");
+ return -1;
+ }
+
+ ind_block_num = fp->i_ib[level];
+
+ for (; level >= 0; level--) {
+ if (ind_block_num == 0) {
+ return 0;
+ }
+
+ if (fp->f_blkno[level] != ind_block_num) {
+ if (fp->f_blk[level]) {
+ free(fp->f_blk[level]);
+ }
+
+ offset = fsbtodb(fs, ind_block_num) * DEV_BSIZE
+ + partition_offset;
+ fp->f_blk[level] = malloc(fs->fs_bsize);
+ if (cons_read(dev, fp->f_blk[level], fs->fs_bsize,
+ offset)
+ != fs->fs_bsize)
+ {
+ printf("ufs_block_map: read error\n");
+ return -1;
+ }
+ fp->f_blkno[level] = ind_block_num;
+ }
+
+ ind_p = (__kernel_daddr_t *)fp->f_blk[level];
+
+ if (level > 0) {
+ idx = file_block / fp->f_nindir[level-1];
+ file_block %= fp->f_nindir[level-1];
+ } else {
+ idx = file_block;
+ }
+ ind_block_num = ind_p[idx];
+ }
+ return ind_block_num;
+}
+
+
+static int breadi(struct file *fp, long blkno, long nblks, char *buffer)
+{
+ long block_size, offset, tot_bytes, nbytes, ncontig;
+ __kernel_daddr_t disk_block;
+
+ tot_bytes = 0;
+ while (nblks) {
+ /*
+ * Contiguous reads are a lot faster, so we try to group
+ * as many blocks as possible:
+ */
+ ncontig = 0; /* # of *fragments* that are contiguous */
+ nbytes = 0;
+ disk_block = block_map(fp, blkno);
+ do {
+ block_size = blksize(fs, fp, blkno);
+ nbytes += block_size;
+ ncontig += numfrags(fs, block_size);
+ ++blkno; --nblks;
+ } while (nblks &&
+ block_map(fp, blkno) == disk_block + ncontig);
+
+ if (!disk_block) {
+ /* it's a hole... */
+ memset(buffer, 0, nbytes);
+ } else {
+ offset = fsbtodb(fs, disk_block) * DEV_BSIZE
+ + partition_offset;
+ if (cons_read(dev, buffer, nbytes, offset) != nbytes) {
+ printf("ufs_breadi: read error\n");
+ return -1;
+ }
+ }
+ buffer += nbytes;
+ tot_bytes += nbytes;
+ }
+ return tot_bytes;
+}
+
+
+/*
+ * Search a directory for a name and return its
+ * i_number.
+ */
+static int search_dir(const char *name, struct file *fp, __kernel_ino_t *inumber_p)
+{
+ long offset, blockoffset;
+ struct direct *dp;
+ int len;
+
+ len = strlen(name);
+
+ offset = 0;
+ while (offset < fp->i_size) {
+ blockoffset = 0;
+ if (breadi(fp, offset / fs->fs_bsize, 1, fp->f_buf) < 0) {
+ return -1;
+ }
+ while (blockoffset < fs->fs_bsize) {
+ dp = (struct direct *)((char*)fp->f_buf + blockoffset);
+ if (dp->d_ino) {
+ if (dp->d_namlen == len
+ && strcmp(name, dp->d_name) == 0)
+ {
+ /* found entry */
+ *inumber_p = dp->d_ino;
+ return 0;
+ }
+ }
+ blockoffset += dp->d_reclen;
+ }
+ offset += fs->fs_bsize;
+ }
+ return -1;
+}
+
+
+/*
+ * Initialize a BSD FFS partition starting at offset P_OFFSET; this is
+ * sort-of the same idea as "mounting" it. Read in the relevant
+ * control structures and make them available to the user. Returns 0
+ * if successful, -1 on failure.
+ */
+static int ufs_mount(long cons_dev, long p_offset, long quiet)
+{
+ static char buf[SBSIZE]; /* minimize frame size */
+ long rc;
+
+ memset(&inode_table, 0, sizeof(inode_table));
+
+ dev = cons_dev;
+ partition_offset = p_offset;
+
+ rc = cons_read(dev, buf, SBSIZE, SBLOCK*DEV_BSIZE + partition_offset);
+ if (rc != SBSIZE)
+ {
+ printf("ufs_mount: superblock read failed (retval=%ld)\n", rc);
+ return -1;
+ }
+
+ fs = (struct fs *)buf;
+ if (fs->fs_magic != FS_MAGIC ||
+ fs->fs_bsize > MAXBSIZE ||
+ fs->fs_bsize < (int) sizeof(struct fs))
+ {
+ if (!quiet) {
+ printf("ufs_mount: invalid superblock "
+ "(magic=%x, bsize=%d)\n",
+ fs->fs_magic, fs->fs_bsize);
+ }
+ return -1;
+ }
+ ufs.blocksize = fs->fs_bsize;
+
+ /* don't read cylinder groups - we aren't modifying anything */
+ return 0;
+}
+
+
+static int ufs_open(const char *path)
+{
+ char *cp = 0, *component;
+ int fd;
+ __kernel_ino_t inumber, parent_inumber;
+ int nlinks = 0;
+ struct file *fp;
+ static char namebuf[MAXPATHLEN+1];
+
+ if (!path || !*path) {
+ return -1;
+ }
+
+ for (fd = 0; inode_table[fd].inuse; ++fd) {
+ if (fd >= MAX_OPEN_FILES) {
+ return -1;
+ }
+ }
+ fp = &inode_table[fd];
+ fp->f_buf_size = fs->fs_bsize;
+ fp->f_buf = malloc(fp->f_buf_size);
+
+ /* copy name into buffer to allow modifying it: */
+ memcpy(namebuf, path, (unsigned)(strlen(path) + 1));
+
+ inumber = (__kernel_ino_t) ROOTINO;
+ if (read_inode(inumber, fp) < 0) {
+ return -1;
+ }
+
+ component = strtok(namebuf, "/");
+ while (component) {
+ /* verify that current node is a directory: */
+ if ((fp->i_mode & IFMT) != IFDIR) {
+ return -1;
+ }
+ /*
+ * Look up component in current directory.
+ * Save directory inumber in case we find a
+ * symbolic link.
+ */
+ parent_inumber = inumber;
+ if (search_dir(component, fp, &inumber))
+ return -1;
+
+ /* open next component: */
+ if (read_inode(inumber, fp))
+ return -1;
+
+ /* check for symbolic link: */
+ if ((fp->i_mode & IFMT) == IFLNK) {
+ int link_len = fp->i_size;
+ int len;
+
+ len = strlen(cp) + 1;
+
+ if (link_len + len >= MAXPATHLEN - 1) {
+ return -1;
+ }
+
+ if (++nlinks > MAXSYMLINKS) {
+ return FS_SYMLINK_LOOP;
+ }
+ memcpy(&namebuf[link_len], cp, len);
+#ifdef IC_FASTLINK
+ if ((fp->i_flags & IC_FASTLINK) != 0) {
+ memcpy(namebuf, fp->i_symlink, link_len);
+ } else
+#endif /* IC_FASTLINK */
+ {
+ /* read file for symbolic link: */
+ long rc, offset;
+ __kernel_daddr_t disk_block;
+
+ disk_block = block_map(fp, (__kernel_daddr_t)0);
+ offset = fsbtodb(fs, disk_block) * DEV_BSIZE
+ + partition_offset;
+ rc = cons_read(dev, namebuf, sizeof(namebuf),
+ offset);
+ if (rc != sizeof(namebuf)) {
+ return -1;
+ }
+ }
+ /*
+ * If relative pathname, restart at parent directory.
+ * If absolute pathname, restart at root.
+ */
+ cp = namebuf;
+ if (*cp != '/') {
+ inumber = parent_inumber;
+ } else
+ inumber = (__kernel_ino_t)ROOTINO;
+
+ if (read_inode(inumber, fp))
+ return -1;
+ }
+ component = strtok(NULL, "/");
+ }
+ /* calculate indirect block levels: */
+ {
+ register int mult;
+ register int level;
+
+ mult = 1;
+ for (level = 0; level < NIADDR; level++) {
+ mult *= NINDIR(fs);
+ fp->f_nindir[level] = mult;
+ }
+ }
+ return fd;
+}
+
+
+static int ufs_bread(int fd, long blkno, long nblks, char *buffer)
+{
+ struct file *fp;
+
+ fp = &inode_table[fd];
+ return breadi(fp, blkno, nblks, buffer);
+}
+
+
+static void ufs_close(int fd)
+{
+ inode_table[fd].inuse = 0;
+}
+
+static const char *
+ufs_readdir(int fd, int rewind)
+{
+ return NULL;
+}
+
+static int
+ufs_fstat(int fd, struct stat* buf)
+{
+ return -1;
+}
+
+struct bootfs ufs = {
+ FS_BSDFFS, 0,
+ ufs_mount,
+ ufs_open, ufs_bread, ufs_close, ufs_readdir, ufs_fstat
+};
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