---

yaml
---
r: 139472
b: refs/heads/master
c: 1a81af4
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: af4176b49c5ee15a9c9b10720c92456b28e7aac7
+refs/heads/master: 1a81af4d1d9c60d4313309f937a1fc5567205a87

trunk/fs/btrfs/delayed-ref.c

@@ -450,8 +450,12 @@ static noinline int __btrfs_add_delayed_ref(struct btrfs_trans_handle *trans,
 	 * the head node stores the sum of all the mods, so dropping a ref
 	 * should drop the sum in the head node by one.
 	 */
-	if (parent == (u64)-1 && action == BTRFS_DROP_DELAYED_REF)
-		count_mod = -1;
+	if (parent == (u64)-1) {
+		if (action == BTRFS_DROP_DELAYED_REF)
+			count_mod = -1;
+		else if (action == BTRFS_UPDATE_DELAYED_HEAD)
+			count_mod = 0;
+	}
 
 	/*
 	 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
@@ -647,7 +651,7 @@ int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans,
 	 */
 	ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes,
 				      (u64)-1, 0, 0, 0,
-				      BTRFS_ADD_DELAYED_REF, 0);
+				      BTRFS_UPDATE_DELAYED_HEAD, 0);
 	BUG_ON(ret);
 
 	ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes,

trunk/fs/btrfs/delayed-ref.h

@@ -22,6 +22,7 @@
 #define BTRFS_ADD_DELAYED_REF    1 /* add one backref to the tree */
 #define BTRFS_DROP_DELAYED_REF   2 /* delete one backref from the tree */
 #define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */
+#define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */
 
 struct btrfs_delayed_ref_node {
 	struct rb_node rb_node;