IPS_BLKSIZE
command_struct->lba = bio->bio_offset / IPS_BLKSIZE;
length = (length + IPS_BLKSIZE - 1)/IPS_BLKSIZE;
bio->bio_offset / IPS_BLKSIZE,
info.d_media_blksize = IPS_BLKSIZE; /* mandatory */
command_struct->lba = off / IPS_BLKSIZE;
length = (length + IPS_BLKSIZE - 1) / IPS_BLKSIZE;