XFS_DAENTER_BMAP1B
xfs_calc_buf_res(XFS_DAENTER_BMAP1B(mp, XFS_DATA_FORK) + 1,
(XFS_DAENTER_DBS(mp,w) * XFS_DAENTER_BMAP1B(mp,w))
((mp)->m_dir_geo->fsbcount + XFS_DAENTER_BMAP1B(mp, XFS_DATA_FORK))