st_unmount
st_unmount(st, EJECT, DOREWIND);
void st_unmount(struct st_softc *, int, int);
st_unmount(st, NOEJECT, DOREWIND);
st_unmount(st, NOEJECT, DOREWIND);
st_unmount(st, NOEJECT, NOREWIND);
st_unmount(st, EJECT, DOREWIND);
st_unmount(st, EJECT, NOREWIND);