xfs_inobt_ptr_t
return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
((xfs_inobt_ptr_t *) \
((index) - 1) * sizeof(xfs_inobt_ptr_t)))
XFS_CHECK_STRUCT_SIZE(xfs_inobt_ptr_t, 4);