xfs_bmap_longest_free_extent
error = xfs_bmap_longest_free_extent(pag, args->tp, blen);
int xfs_bmap_longest_free_extent(struct xfs_perag *pag,
error = xfs_bmap_longest_free_extent(pag, args->tp, longest);
err = xfs_bmap_longest_free_extent(pag, NULL, longest);