__add_block_group_free_space
ret = __add_block_group_free_space(trans, block_group, NULL);
static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
ret = __add_block_group_free_space(trans, block_group, path);
ret = __add_block_group_free_space(trans, block_group, path);