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| author | Justin Maggard <jmaggard10@gmail.com> | 2015-11-04 15:56:16 -0800 |
|---|---|---|
| committer | Filipe Manana <fdmanana@suse.com> | 2015-11-05 10:32:20 +0000 |
| commit | 7343dd61fd1b57c40cc06a5b5b5386df7f73c3ac (patch) | |
| tree | c272af51bf4bba2fd2e1429aa943ad8b78565ea7 /fs/btrfs/disk-io.c | |
| parent | 9c9464cc92668984ebed79e22b5063877a8d97db (diff) | |
| download | lwn-7343dd61fd1b57c40cc06a5b5b5386df7f73c3ac.tar.gz lwn-7343dd61fd1b57c40cc06a5b5b5386df7f73c3ac.zip | |
btrfs: qgroup: exit the rescan worker during umount
I was hitting a consistent NULL pointer dereference during shutdown that
showed the trace running through end_workqueue_bio(). I traced it back to
the endio_meta_workers workqueue being poked after it had already been
destroyed.
Eventually I found that the root cause was a qgroup rescan that was still
in progress while we were stopping all the btrfs workers.
Currently we explicitly pause balance and scrub operations in
close_ctree(), but we do nothing to stop the qgroup rescan. We should
probably be doing the same for qgroup rescan, but that's a much larger
change. This small change is good enough to allow me to unmount without
crashing.
Signed-off-by: Justin Maggard <jmaggard@netgear.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2d4667594681..1eb08393bff0 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3780,6 +3780,9 @@ void close_ctree(struct btrfs_root *root) fs_info->closing = 1; smp_mb(); + /* wait for the qgroup rescan worker to stop */ + btrfs_qgroup_wait_for_completion(fs_info); + /* wait for the uuid_scan task to finish */ down(&fs_info->uuid_tree_rescan_sem); /* avoid complains from lockdep et al., set sem back to initial state */ |