XBF_SEC_SIZE
lba *= sc->sc_block_size / XBF_SEC_SIZE;
nblk *= sc->sc_block_size / XBF_SEC_SIZE;
capacity = (sc->sc_disk_size * XBF_SEC_SIZE) / sc->sc_block_size - 1;
capacity = (sc->sc_disk_size * XBF_SEC_SIZE) / sc->sc_block_size - 1;