diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 78d7d2458..6a8b919be 100755
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3193,6 +3193,7 @@ again:
 			 * alignment and size).
 			 */
 			ret = -EUCLEAN;
+			mutex_unlock(&fs_info->delete_unused_bgs_mutex);
 			goto error;
 		}