XFS_DIR3_DATA_CRC_OFF
xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);
!xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
!xfs_buf_verify_cksum(bp, XFS_DIR3_DATA_CRC_OFF))
xfs_buf_update_cksum(bp, XFS_DIR3_DATA_CRC_OFF);