diff options
| 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 | |
| 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')
| -rw-r--r-- | fs/btrfs/disk-io.c | 3 | ||||
| -rw-r--r-- | fs/btrfs/qgroup.c | 9 |
2 files changed, 9 insertions, 3 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 */ diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 46476c226395..75c0249702df 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2286,7 +2286,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work) goto out; err = 0; - while (!err) { + while (!err && !btrfs_fs_closing(fs_info)) { trans = btrfs_start_transaction(fs_info->fs_root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); @@ -2307,7 +2307,8 @@ out: btrfs_free_path(path); mutex_lock(&fs_info->qgroup_rescan_lock); - fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; + if (!btrfs_fs_closing(fs_info)) + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; if (err > 0 && fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) { @@ -2336,7 +2337,9 @@ out: } btrfs_end_transaction(trans, fs_info->quota_root); - if (err >= 0) { + if (btrfs_fs_closing(fs_info)) { + btrfs_info(fs_info, "qgroup scan paused"); + } else if (err >= 0) { btrfs_info(fs_info, "qgroup scan completed%s", err > 0 ? " (inconsistency flag cleared)" : ""); } else { |