btrfs: use rb_find() in __btrfs_lookup_delayed_item()

Use the rb-tree helper so we don't open code the search code.

Signed-off-by: Yangtao Li <[e-mail]>
Signed-off-by: Pan Chuang <[e-mail]>
Reviewed-by: David Sterba <[e-mail]>
Signed-off-by: David Sterba <[e-mail]>

fs/btrfs/delayed-inode.c

···
 	return item;
 }
 
+static int delayed_item_index_cmp(const void *key, const struct rb_node *node)
+{
+	const u64 *index = key;
+	const struct btrfs_delayed_item *delayed_item = rb_entry(node,
+						 struct btrfs_delayed_item, rb_node);
+
+	if (delayed_item->index < *index)
+		return 1;
+	else if (delayed_item->index > *index)
+		return -1;
+
+	return 0;
+}
+
 /*
  * Look up the delayed item by key.
  *
···
 				struct rb_root *root,
 				u64 index)
 {
-	struct rb_node *node = root->rb_node;
-	struct btrfs_delayed_item *delayed_item = NULL;
+	struct rb_node *node;
 
-	while (node) {
-		delayed_item = rb_entry(node, struct btrfs_delayed_item,
-					rb_node);
-		if (delayed_item->index < index)
-			node = node->rb_right;
-		else if (delayed_item->index > index)
-			node = node->rb_left;
-		else
-			return delayed_item;
-	}
-
-	return NULL;
+	node = rb_find(&index, root, delayed_item_index_cmp);
+	return rb_entry_safe(node, struct btrfs_delayed_item, rb_node);
 }
 
 static int btrfs_delayed_item_cmp(const struct rb_node *new,
···
 {
 	const struct btrfs_delayed_item *new_item =
 		rb_entry(new, struct btrfs_delayed_item, rb_node);
-	const struct btrfs_delayed_item *exist_item =
-		rb_entry(exist, struct btrfs_delayed_item, rb_node);
 
-	if (new_item->index < exist_item->index)
-		return -1;
-	if (new_item->index > exist_item->index)
-		return 1;
-	return 0;
+	return delayed_item_index_cmp(&new_item->index, exist);
 }
 
 static int __btrfs_add_delayed_item(struct btrfs_delayed_node *delayed_node,