sr_chunk_in_use
int sr_chunk_in_use(struct sr_softc *, dev_t);
c = sr_chunk_in_use(sc, dev);
status = sr_chunk_in_use(sc, dev);
if (sr_chunk_in_use(sc, dt[i]) != BIOC_SDINVALID) {
c = sr_chunk_in_use(sc, dev);
c = sr_chunk_in_use(sc, dev);
int sr_chunk_in_use(struct sr_softc *, dev_t);