Hi Jan,
thanks for the patch! Sending works. But i got some trouble on the
receiving side.
Here's my complete test-setup:
I have two btrfs partitions:
mount | grep btrfs:
/dev/loop0 on /mnt/TEST_ROOT type btrfs
(rw,relatime,compress=lzo,space_cache) # default-subvolume
/dev/loop0 on /mnt/TEST_ROOT/root_volid0 type btrfs
(rw,relatime,compress=lzo,space_cache) # subvolid= 0
/dev/loop1 on /mnt/TEST_ROOT/backup_volid0 type btrfs
(rw,relatime,compress=lzo,space_cache)
With the patch this works now:
btrfs subvolume snapshot -r /mnt/TEST_ROOT/root_volid0/root/
/mnt/TEST_ROOT/root_volid0/root_snap
btrfs send /mnt/TEST_ROOT/root_volid0/root_snap > root_snap_send
But when i try to receive it on the /mnt/TEST_ROOT/backup_volid0 btrfs
partition i get:
btrfs receive -f root_snap_send /mnt/TEST_ROOT/backup_volid0/
ERROR: utimes failed. Bad file descriptor
i also tried "cat root_snap_send | btrfs receive
/mnt/TEST_ROOT/backup_volid0". But the result is the same.
What's interesting is that there is actually a subvolume "root_snap"
created in "backup_volid0", but it's empty.
I'm on linux-3.6-rc2 and btrfs-progs from git.
If further Information is needed, just tell me.
Regards,
Robert
On 20.08.2012 13:57, Jan Schmidt wrote:
Hi Robert,
i made a quick patch, can you please give it a try? Can be applied with
"git am --scissors".
Thanks,
-Jan
-- >8 --
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@xxxxxxxxxxxxx>
---
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)
--
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