diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index e2f5be261532..38ee08675468 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2769,6 +2769,8 @@ again:
 		 * contention with the cow code
 		 */
 		if (cow) {
+			bool last_level = (level == (BTRFS_MAX_LEVEL - 1));
+
 			/*
 			 * if we don't really need to cow this block
 			 * then we don't want to set the path blocking,
@@ -2793,9 +2795,13 @@ again:
 			}
 
 			btrfs_set_path_blocking(p);
-			err = btrfs_cow_block(trans, root, b,
-					      p->nodes[level + 1],
-					      p->slots[level + 1], &b);
+			if (last_level)
+				err = btrfs_cow_block(trans, root, b, NULL, 0,
+						      &b);
+			else
+				err = btrfs_cow_block(trans, root, b,
+						      p->nodes[level + 1],
+						      p->slots[level + 1], &b);
 			if (err) {
 				ret = err;
 				goto done;