blockif_candelete
int blockif_candelete(struct blockif_ctxt *bc);
if (blockif_candelete(p->bctx) && !blockif_is_ro(p->bctx)) {
candelete = blockif_candelete(p->bctx);
nvstore->deallocate = blockif_candelete(nvstore->ctx);
if (blockif_candelete(sc->bc)) {