diff options
Diffstat (limited to 'package/aufs2-util/src/plink.c')
| -rw-r--r-- | package/aufs2-util/src/plink.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/package/aufs2-util/src/plink.c b/package/aufs2-util/src/plink.c new file mode 100644 index 000000000..6ff16c76a --- /dev/null +++ b/package/aufs2-util/src/plink.c @@ -0,0 +1,356 @@ +/* + * Copyright (C) 2005-2009 Junjiro 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 + */ + +#define _FILE_OFFSET_BITS 64 /* ftw.h */ +#define _XOPEN_SOURCE 500 /* ftw.h */ +#define _GNU_SOURCE /* ftw.h */ + +#include <sys/ioctl.h> +#include <sys/resource.h> +#include <sys/time.h> +#include <sys/types.h> +#include <dirent.h> +#include <ftw.h> +#include <mntent.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <linux/aufs_type.h> +#include "au_util.h" + +/* todo: try argz? */ +static struct name_array { + char *o; + int bytes; + + char *cur; + int nname; +} na; + +static struct ino_array { + char *o; + int bytes; + + union { + char *p; + ino_t *cur; + }; + int nino; +} ia; + +static int na_append(char *plink_dir, char *name) +{ + int l, sz; + char *p; + const int cur = na.cur - na.o; + + l = strlen(plink_dir) + strlen(name) + 2; + sz = na.bytes + l; + p = realloc(na.o, sz); + if (!p) + AuFin("realloc"); + + na.o = p; + na.bytes = sz; + na.cur = p + cur; + na.cur += sprintf(na.cur, "%s/%s", plink_dir, name) + 1; + na.nname++; + + return 0; +} + +static int ia_append(ino_t ino) +{ + int sz; + char *p; + const int cur = ia.p - ia.o; + + sz = na.bytes + sizeof(ino_t); + p = realloc(ia.o, sz); + if (!p) + AuFin("realloc"); + + ia.o = p; + ia.bytes = sz; + ia.p = p + cur; + *ia.cur++ = ino; + ia.nino++; + + return 0; +} + +static int build_array(char *plink_dir) +{ + int err; + DIR *dp; + struct dirent *de; + char *p; + ino_t ino; + + err = access(plink_dir, F_OK); + if (err) + return 0; + + err = 0; + dp = opendir(plink_dir); + if (!dp) + AuFin("%s", plink_dir); + while ((de = readdir(dp))) { + if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) + continue; +#if 0 + if (de->d_type == DT_DIR) { + errno = EISDIR; + AuFin(de->d_name); + } +#endif + + err = na_append(plink_dir, de->d_name); + if (err) + break; + + p = strchr(de->d_name, '.'); + if (!p) { + errno = EINVAL; + AuFin("internal error, %s", de->d_name); + } + *p = 0; + errno = 0; + ino = strtoull(de->d_name, NULL, 0); + if (ino == /*ULLONG_MAX*/-1 && errno == ERANGE) + AuFin("internal error, %s", de->d_name); + err = ia_append(ino); + if (err) + break; + } + closedir(dp); + + return err; +} + +static int ia_test(ino_t ino) +{ + int i; + ino_t *p; + + /* todo: hash table */ + ia.p = ia.o; + p = ia.cur; + for (i = 0; i < ia.nino; i++) + if (*p++ == ino) + return 1; + return 0; +} + +/* ---------------------------------------------------------------------- */ + +static int ftw_list(const char *fname, const struct stat *st, int flags, + struct FTW *ftw) +{ + if (!strcmp(fname + ftw->base, AUFS_WH_PLINKDIR)) + return FTW_SKIP_SUBTREE; + if (flags == FTW_D || flags == FTW_DNR) + return FTW_CONTINUE; + + if (ia_test(st->st_ino)) + puts(fname); + + return FTW_CONTINUE; +} + +static int ftw_cpup(const char *fname, const struct stat *st, int flags, + struct FTW *ftw) +{ + int err; + + if (!strcmp(fname + ftw->base, AUFS_WH_PLINKDIR)) + return FTW_SKIP_SUBTREE; + if (flags == FTW_D || flags == FTW_DNR) + return FTW_CONTINUE; + + /* + * do nothing but update something harmless in order to make it copyup + */ + if (ia_test(st->st_ino)) { + Dpri("%s\n", fname); + if (!S_ISLNK(st->st_mode)) + err = chown(fname, -1, -1); + else + err = lchown(fname, -1, -1); + if (err) + AuFin("%s", fname); + } + + return FTW_CONTINUE; +} + +/* ---------------------------------------------------------------------- */ + +static DIR *dp; +void au_plink_maint(char *path) +{ + int err; + + if (path) { + if (dp) { + errno = EINVAL; + AuFin("dp is not NULL"); + } + dp = opendir(path); + if (!dp) + AuFin("%s", path); + + err = ioctl(dirfd(dp), AUFS_CTL_PLINK_MAINT); +#ifndef DEBUG + if (err) + AuFin("AUFS_CTL_PLINK_MAINT"); +#endif + } else { + err = closedir(dp); + if (err) + AuFin("closedir"); + dp = NULL; + } +} + +void au_clean_plink(void) +{ + int err; + + err = ioctl(dirfd(dp), AUFS_CTL_PLINK_CLEAN); +#ifndef DEBUG + if (err) + AuFin("AUFS_CTL_PLINK_CLEAN"); +#endif +} + +static int do_plink(char *cwd, int cmd, int nbr, char *br[]) +{ + int err, i, l; + struct rlimit rlim; + __nftw_func_t func; + char *p; + + err = 0; + switch (cmd) { + case AuPlink_FLUSH: + /*FALLTHROUGH*/ + case AuPlink_CPUP: + func = ftw_cpup; + break; + case AuPlink_LIST: + func = ftw_list; + break; + default: + errno = EINVAL; + AuFin(NULL); + func = NULL; /* never reach here */ + } + + for (i = 0; i < nbr; i++) { + //puts(br[i]); + p = strchr(br[i], '='); + if (strcmp(p + 1, AUFS_BRPERM_RW) + && strcmp(p + 1, AUFS_BRPERM_RWNLWH)) + continue; + + *p = 0; + l = strlen(br[i]); + p = malloc(l + sizeof(AUFS_WH_PLINKDIR) + 2); + if (!p) + AuFin("malloc"); + sprintf(p, "%s/%s", br[i], AUFS_WH_PLINKDIR); + //puts(p); + err = build_array(p); + if (err) + AuFin("build_array"); + free(p); + } + if (!ia.nino) + goto out; + + if (cmd == AuPlink_LIST) { + ia.p = ia.o; + for (i = 0; i < ia.nino; i++) + printf("%llu ", (unsigned long long)*ia.cur++); + putchar('\n'); + } + + err = getrlimit(RLIMIT_NOFILE, &rlim); + if (err) + AuFin("getrlimit"); + nftw(cwd, func, rlim.rlim_cur - 10, + FTW_PHYS | FTW_MOUNT | FTW_ACTIONRETVAL); + /* ignore */ + + if (cmd == AuPlink_FLUSH) { + au_clean_plink(); + + na.cur = na.o; + for (i = 0; i < na.nname; i++) { + Dpri("%s\n", na.cur); + err = unlink(na.cur); + if (err) + AuFin("%s", na.cur); + na.cur += strlen(na.cur) + 1; + } + } + + out: + free(ia.o); + free(na.o); + return err; +} + +int au_plink(char cwd[], int cmd, int begin_maint, int end_maint) +{ + int err, nbr; + struct mntent ent; + char **br; + + if (begin_maint) + au_plink_maint(cwd); + + err = au_proc_getmntent(cwd, &ent); + if (err) + AuFin("no such mount point"); + + if (hasmntopt(&ent, "noplink")) + goto out; /* success */ + +#ifdef DEBUG + //char a[] = "a,b,br:/tmp/br0=rw:/br1=ro"; + char a[] = "a,b,si=1,c"; + ent.mnt_opts = a; +#endif + err = au_br(&br, &nbr, &ent); + //printf("nbr %d\n", nbr); + if (err) + AuFin(NULL); + + err = do_plink(cwd, cmd, nbr, br); + if (err) + AuFin(NULL); + + out: + if (end_maint) + au_plink_maint(NULL); + return err; +} |