XFS_CNT_BLOCK
agf->agf_cnt_root = cpu_to_be32(XFS_CNT_BLOCK(mp));
.daddr = XFS_AGB_TO_DADDR(mp, id->agno, XFS_CNT_BLOCK(mp)),
#define XFS_IBT_BLOCK(mp) ((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))