sbd_do_write_same_xfer
static void sbd_do_write_same_xfer(struct scsi_task *task, sbd_cmd_t *scmd,
sbd_do_write_same_xfer(task, scmd, NULL, 0);
sbd_do_write_same_xfer(task, scmd, dbuf, dbuf_reusable);
sbd_do_write_same_xfer(task, scmd, dbuf, 0);