summaryrefslogtreecommitdiff
path: root/cmds-send.c
diff options
context:
space:
mode:
authorJan Schmidt <list.btrfs@jan-o-sch.net>2012-08-20 13:40:18 +0200
committerJan Schmidt <list.btrfs@jan-o-sch.net>2012-08-20 13:40:18 +0200
commitf99b1f1a631f3dfb8dc9ad03b9a00bdc2a231d31 (patch)
tree89943d439eb92702b0876d12ccd575137ed7618c /cmds-send.c
parent043a63924c9831ac52ce38f0365b9bfd628fb6a3 (diff)
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.c88
1 files changed, 21 insertions, 67 deletions
diff --git a/cmds-send.c b/cmds-send.c
index 8a0c110f..41ea5236 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)