2 files changed, 8 insertions, 3 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 759fa247ced8..cbf7dc8ae3ec 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/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,
diff --git a/fs/btrfs/delayed-ref.h b/fs/btrfs/delayed-ref.h
index 57153fcc347b..3bec2ff0b15c 100644
--- a/fs/btrfs/delayed-ref.h
+++ b/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;