diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f619c3c..79ec933 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3696,6 +3696,7 @@ int btrfs_block_rsv_add(struct btrfs_trans_handle *trans,
 {
 	int ret;
 
+	WARN_ON(block_rsv == root->orphan_block_rsv);
 	if (num_bytes == 0)
 		return 0;