btrfs: waiting on qgroup rescan should not always be interruptible
We wait on qgroup rescan completion in three places: file system
shutdown, the quota disable ioctl, and the rescan wait ioctl. If the
user sends a signal while we're waiting, we continue happily along. This
is expected behavior for the rescan wait ioctl. It's racy in the shutdown
path but mostly works due to other unrelated synchronization points.
In the quota disable path, it Oopses the kernel pretty much immediately.
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 3fe295e..13eb6a7 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -995,7 +995,7 @@
goto out;
fs_info->quota_enabled = 0;
fs_info->pending_quota_state = 0;
- btrfs_qgroup_wait_for_completion(fs_info);
+ btrfs_qgroup_wait_for_completion(fs_info, false);
spin_lock(&fs_info->qgroup_lock);
quota_root = fs_info->quota_root;
fs_info->quota_root = NULL;
@@ -2494,7 +2494,8 @@
return 0;
}
-int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info)
+int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info,
+ bool interruptible)
{
int running;
int ret = 0;
@@ -2505,9 +2506,14 @@
spin_unlock(&fs_info->qgroup_lock);
mutex_unlock(&fs_info->qgroup_rescan_lock);
- if (running)
+ if (!running)
+ return 0;
+
+ if (interruptible)
ret = wait_for_completion_interruptible(
&fs_info->qgroup_rescan_completion);
+ else
+ wait_for_completion(&fs_info->qgroup_rescan_completion);
return ret;
}