/* find reloc tree by address of tree root  */
static struct btrfs_root* find_reloc_root(struct reloc_control *rc, u64 bytenr)
/* find reloc tree by address of tree root  */
static struct btrfs_root* find_reloc_root(struct reloc_control *rc, u64 bytenr)
{
	struct rb_node *rb_node;
	struct mapping_node *node;
	struct btrfs_root *root = NULL;
	spin_lock(&rc->reloc_root_tree.lock);
	rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
	if (rb_node) {
		node = rb_entry(rb_node, struct mapping_node, rb_node);
		root = (struct btrfs_root *)node->data;
	}
	spin_unlock(&rc->reloc_root_tree.lock);
	return root;
}