btrfs_remove_block_group_free_space
ret = btrfs_remove_block_group_free_space(trans, block_group);
int btrfs_remove_block_group_free_space(struct btrfs_trans_handle *trans,
ret = btrfs_remove_block_group_free_space(trans, bg);
ret = btrfs_remove_block_group_free_space(&trans, cache);