SD_SYSBLOCKS2BYTES
resid = SD_SYSBLOCKS2BYTES(
first_byte = SD_SYSBLOCKS2BYTES((offset_t)xp->xb_blkno);
shadow_start = SD_SYSBLOCKS2BYTES((offset_t)xp->xb_blkno);
part_off = SD_SYSBLOCKS2BYTES(part_off_sysblks);
part_len = SD_SYSBLOCKS2BYTES(part_len_sysblks);
first_byte = SD_SYSBLOCKS2BYTES(start_block);
(SD_SYSBLOCKS2BYTES(sysblk) - SD_TGTBLOCKS2BYTES(un, tgtblk))