diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 55ffcf4..7966acd 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1118,6 +1118,7 @@
 		if (!node)
 			break;
 		bytenr = node->val;
+		cond_resched();
 	}
 
 	ulist_free(tmp);