write_lock(&os_scsi_tapes_lock);
if (dev >= osst_max_dev || os_scsi_tapes == NULL ||
(STp = os_scsi_tapes[dev]) == NULL || !STp->device) {
write_lock(&os_scsi_tapes_lock);
if (dev >= osst_max_dev || os_scsi_tapes == NULL ||
(STp = os_scsi_tapes[dev]) == NULL || !STp->device) {