Btrfs: Release uuid_mutex for shrink during device delete

Device scanning waits on the uuid_mutex, which can result in a very long
wait if dev delete is shrinking the device.

Signed-off-by: Carey Underwood <cwillu@cwillu.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 78b871753cb6..b5c2b6acbf60 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1562,7 +1562,9 @@ int btrfs_rm_device(struct btrfs_root *root, char *device_path)
                 clear_super = true;
         }
 
+        mutex_unlock(&uuid_mutex);
         ret = btrfs_shrink_device(device, 0);
+        mutex_lock(&uuid_mutex);
         if (ret)
                 goto error_undo;