diff options
author | Jan Schmidt <list.btrfs@jan-o-sch.net> | 2012-08-20 13:40:18 +0200 |
---|---|---|
committer | Jan Schmidt <list.btrfs@jan-o-sch.net> | 2012-08-20 13:40:18 +0200 |
commit | f99b1f1a631f3dfb8dc9ad03b9a00bdc2a231d31 (patch) | |
tree | 89943d439eb92702b0876d12ccd575137ed7618c /cmds-send.c | |
parent | 043a63924c9831ac52ce38f0365b9bfd628fb6a3 (diff) | |
download | btrfs-progs-f99b1f1a631f3dfb8dc9ad03b9a00bdc2a231d31.tar.gz |
Btrfs-progs: replace find_mount_root from send code
find_mount_root had the problem that it tried to conclude from a file system
path to a mount point, taking the fsid as an indicator. This only works if
no two subvolumes (sharing the same btrfs fsid) are mounted in the same
hierarchy.
Now instead, we're parsing /etc/mtab and look for the longest match.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Diffstat (limited to 'cmds-send.c')
-rw-r--r-- | cmds-send.c | 88 |
1 files changed, 21 insertions, 67 deletions
diff --git a/cmds-send.c b/cmds-send.c index 8a0c110..41ea523 100644 --- a/cmds-send.c +++ b/cmds-send.c @@ -28,6 +28,7 @@ #include <sys/types.h> #include <sys/ioctl.h> #include <libgen.h> +#include <mntent.h> #include <uuid/uuid.h> @@ -55,82 +56,35 @@ struct btrfs_send { int find_mount_root(const char *path, char **mount_root) { - int ret; - char *cur; - char fsid[BTRFS_FSID_SIZE]; + FILE *mnttab; int fd; - struct stat st; - char *tmp; - char *dup = NULL; - - struct btrfs_ioctl_fs_info_args args; + struct mntent *ent; + int len; + int longest_matchlen = 0; + char *longest_match = NULL; fd = open(path, O_RDONLY | O_NOATIME); - if (fd < 0) { - ret = -errno; - goto out; - } - - ret = fstat(fd, &st); - if (fd < 0) { - ret = -errno; - goto out; - } - if (!S_ISDIR(st.st_mode)) { - ret = -ENOTDIR; - goto out; - } - - ret = ioctl(fd, BTRFS_IOC_FS_INFO, &args); - if (fd < 0) { - ret = -errno; - goto out; - } - memcpy(fsid, args.fsid, BTRFS_FSID_SIZE); + if (fd < 0) + return -errno; close(fd); - fd = -1; - cur = strdup(path); - - while (1) { - dup = strdup(cur); - tmp = dirname(dup); - - if (!tmp) - break; - fd = open(tmp, O_RDONLY | O_NOATIME); - if (fd < 0) { - ret = -errno; - goto out; + mnttab = fopen("/etc/mtab", "r"); + while ((ent = getmntent(mnttab))) { + len = strlen(ent->mnt_dir); + if (strncmp(ent->mnt_dir, path, len) == 0) { + /* match found */ + if (longest_matchlen < len) { + free(longest_match); + longest_matchlen = len; + longest_match = strdup(ent->mnt_dir); + } } - - ret = ioctl(fd, BTRFS_IOC_FS_INFO, &args); - close(fd); - fd = -1; - if (ret < 0) - break; - if (memcmp(fsid, args.fsid, BTRFS_FSID_SIZE) != 0) - break; - - free(cur); - cur = strdup(tmp); - free(dup); - dup = NULL; - if (strcmp(cur, "/") == 0) - break; - if (strcmp(cur, ".") == 0) - break; } - ret = 0; - *mount_root = realpath(cur, NULL); + *mount_root = realpath(longest_match, NULL); + free(longest_match); -out: - if (dup) - free(dup); - if (fd != -1) - close(fd); - return ret; + return 0; } static int get_root_id(struct btrfs_send *s, const char *path, u64 *root_id) |