diff mbox

[SRU,UTOPIC] Btrfs: send, don't delay dir move if there's a new parent inode

Message ID 1426790098-3207-1-git-send-email-colin.king@canonical.com
State New
Headers show

Commit Message

Colin Ian King March 19, 2015, 6:34 p.m. UTC 
From: Filipe Manana <fdmanana@suse.com>

BugLink: http://bugs.launchpad.net/bugs/1434223

If between two snapshots we rename an existing directory named X to Y and
make it a child (direct or not) of a new inode named X, we were delaying
the move/rename of the former directory unnecessarily, which would result
in attempting to rename the new directory from its orphan name to name X
prematurely.

Minimal reproducer:

    $ mkfs.btrfs -f /dev/vdd
    $ mount /dev/vdd /mnt
    $ mkdir -p /mnt/merlin/RC/OSD/Source

    $ btrfs subvolume snapshot -r /mnt /mnt/mysnap1

    $ mkdir /mnt/OSD
    $ mv /mnt/merlin/RC/OSD /mnt/OSD/OSD-Plane_788
    $ mv /mnt/OSD /mnt/merlin/RC

    $ btrfs subvolume snapshot -r /mnt /mnt/mysnap2

    $ btrfs send /mnt/mysnap1 -f /tmp/1.snap
    $ btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/2.snap

    $ mkfs.btrfs -f /dev/vdc
    $ mount /dev/vdc /mnt2

    $ btrfs receive /mnt2 -f /tmp/1.snap
    $ btrfs receive /mnt2 -f /tmp/2.snap

The second receive (from an incremental send) failed with the following
error message: "rename o261-7-0 -> merlin/RC/OSD failed".
This is a regression introduced in the 3.16 kernel.

A test case for xfstests follows.

Reported-by: Marc Merlin <marc@merlins.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
(cherry pick from upstream commit bf8e8ca6fd4ac6e8edc58b92cffb2ffd51933138)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 fs/btrfs/send.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Seth Forshee March 19, 2015, 7:38 p.m. UTC | #1
Stefan Bader March 20, 2015, 11:01 a.m. UTC | #2 
At least this seems to implement what it claims...
Andy Whitcroft March 20, 2015, 11:28 a.m. UTC | #3 
Applied to utopic.

-apw
diff mbox

Patch

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 7edfc7c..b9c27aa 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -3327,7 +3327,7 @@  static int wait_for_parent_move(struct send_ctx *sctx,
 		if (ret < 0 && ret != -ENOENT) {
 			goto out;
 		} else if (ret == -ENOENT) {
-			ret = 1;
+			ret = 0;
 			break;
 		}