1 files changed, 38 insertions, 41 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9850a51a3f19..ed23127a4b02 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3801,58 +3801,55 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 	delayed_refs = &trans->delayed_refs;
 
 	spin_lock(&delayed_refs->lock);
-	if (delayed_refs->num_entries == 0) {
+	if (atomic_read(&delayed_refs->num_entries) == 0) {
 		spin_unlock(&delayed_refs->lock);
 		btrfs_info(root->fs_info, "delayed_refs has NO entry");
 		return ret;
 	}
 
-	while ((node = rb_first(&delayed_refs->root)) != NULL) {
-		struct btrfs_delayed_ref_head *head = NULL;
+	while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
+		struct btrfs_delayed_ref_head *head;
 		bool pin_bytes = false;
 
-		ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
-		atomic_set(&ref->refs, 1);
-		if (btrfs_delayed_ref_is_head(ref)) {
+		head = rb_entry(node, struct btrfs_delayed_ref_head,
+				href_node);
+		if (!mutex_trylock(&head->mutex)) {
+			atomic_inc(&head->node.refs);
+			spin_unlock(&delayed_refs->lock);
 
-			head = btrfs_delayed_node_to_head(ref);
-			if (!mutex_trylock(&head->mutex)) {
-				atomic_inc(&ref->refs);
-				spin_unlock(&delayed_refs->lock);
-
-				/* Need to wait for the delayed ref to run */
-				mutex_lock(&head->mutex);
-				mutex_unlock(&head->mutex);
-				btrfs_put_delayed_ref(ref);
-
-				spin_lock(&delayed_refs->lock);
-				continue;
-			}
-
-			if (head->must_insert_reserved)
-				pin_bytes = true;
-			btrfs_free_delayed_extent_op(head->extent_op);
-			delayed_refs->num_heads--;
-			if (list_empty(&head->cluster))
-				delayed_refs->num_heads_ready--;
-			list_del_init(&head->cluster);
-		}
-
-		ref->in_tree = 0;
-		rb_erase(&ref->rb_node, &delayed_refs->root);
-		if (head)
-			rb_erase(&head->href_node, &delayed_refs->href_root);
-
-		delayed_refs->num_entries--;
-		spin_unlock(&delayed_refs->lock);
-		if (head) {
-			if (pin_bytes)
-				btrfs_pin_extent(root, ref->bytenr,
-						 ref->num_bytes, 1);
+			mutex_lock(&head->mutex);
 			mutex_unlock(&head->mutex);
+			btrfs_put_delayed_ref(&head->node);
+			spin_lock(&delayed_refs->lock);
+			continue;
+		}
+		spin_lock(&head->lock);
+		while ((node = rb_first(&head->ref_root)) != NULL) {
+			ref = rb_entry(node, struct btrfs_delayed_ref_node,
+				       rb_node);
+			ref->in_tree = 0;
+			rb_erase(&ref->rb_node, &head->ref_root);
+			atomic_dec(&delayed_refs->num_entries);
+			btrfs_put_delayed_ref(ref);
+			cond_resched_lock(&head->lock);
 		}
-		btrfs_put_delayed_ref(ref);
+		if (head->must_insert_reserved)
+			pin_bytes = true;
+		btrfs_free_delayed_extent_op(head->extent_op);
+		delayed_refs->num_heads--;
+		if (head->processing == 0)
+			delayed_refs->num_heads_ready--;
+		atomic_dec(&delayed_refs->num_entries);
+		head->node.in_tree = 0;
+		rb_erase(&head->href_node, &delayed_refs->href_root);
+		spin_unlock(&head->lock);
+		spin_unlock(&delayed_refs->lock);
+		mutex_unlock(&head->mutex);
 
+		if (pin_bytes)
+			btrfs_pin_extent(root, head->node.bytenr,
+					 head->node.num_bytes, 1);
+		btrfs_put_delayed_ref(&head->node);
 		cond_resched();
 		spin_lock(&delayed_refs->lock);
 	}