From: Aleksa Sarai <asarai@xxxxxxx>
This patch has been added to the v4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit 6c6b5a39c4bf3dbd8cf629c9f5450e983c19dbb9 ]
Several distributions mount the "proper root" as ro during initrd and
then remount it as rw before pivot_root(2). Thus, if a rescan had been
aborted by a previous shutdown, the rescan would never be resumed.
This issue would manifest itself as several btrfs ioctl(2)s causing the
entire machine to hang when btrfs_qgroup_wait_for_completion was hit
(due to the fs_info->qgroup_rescan_running flag being set but the rescan
itself not being resumed). Notably, Docker's btrfs storage driver makes
regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT
(causing this problem to be manifested on boot for some machines).
Cc: <stable@xxxxxxxxxxxxxxx> # v3.11+
Cc: Jeff Mahoney <jeffm@xxxxxxxx>
Fixes: b382a324b60f ("Btrfs: fix qgroup rescan resume on mount")
Signed-off-by: Aleksa Sarai <asarai@xxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
Tested-by: Nikolay Borisov <nborisov@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
fs/btrfs/super.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a40b454aea44..4f6a3afc45f4 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1593,6 +1593,8 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
goto restore;
}
+ btrfs_qgroup_rescan_resume(fs_info);
+
if (!fs_info->uuid_root) {
btrfs_info(fs_info, "creating UUID tree");
ret = btrfs_create_uuid_tree(fs_info);
--
2.11.0