TAPE_MINORS_PER_DEV
device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
minor += TAPE_MINORS_PER_DEV;
if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
if (*pos >= 256 / TAPE_MINORS_PER_DEV)