static Chan* sdattach(char* spec) { Chan *c; char *p; SDev *sdev; int idno, subno; if(*spec == '\0'){ c = devattach(sddevtab.dc, spec); mkqid(&c->qid, QID(0, 0, 0, Qtopdir), 0, QTDIR); return c; } if(spec[0] != 's' || spec[1] != 'd') error(Ebadspec); idno = spec[2]; subno = strtol(&spec[3], &p, 0); if(p == &spec[3]) error(Ebadspec); if((sdev=sdgetdev(idno)) == nil) error(Enonexist); if(sdgetunit(sdev, subno) == nil){ decref(&sdev->r); error(Enonexist); } c = devattach(sddevtab.dc, spec); mkqid(&c->qid, QID(sdev->idno, subno, 0, Qunitdir), 0, QTDIR); c->dev = (sdev->idno << UnitLOG) + subno; decref(&sdev->r); return c; }
static SDunit* sdindex2unit(int index) { SDev *sdev; /* * Associate a unit with a given index into the top-level * device directory. * The device will be probed if it has not already been * successfully accessed. */ for(sdev = sdlist; sdev != nil; sdev = sdev->next){ if(index >= sdev->index && index < sdev->index+sdev->nunit) return sdgetunit(sdev, index-sdev->index); } return nil; }
static int sdgen(Chan* c, char*, Dirtab*, int, int s, Dir* dp) { Qid q; uvlong l; int i, r; SDpart *pp; SDunit *unit; SDev *sdev; switch(TYPE(c->qid)){ case Qtopdir: if(s == DEVDOTDOT){ mkqid(&q, QID(0, 0, 0, Qtopdir), 0, QTDIR); snprint(up->genbuf, sizeof up->genbuf, "#%C", sddevtab.dc); devdir(c, q, up->genbuf, 0, eve, 0555, dp); return 1; } if(s+Qtopbase < Qunitdir) return sd1gen(c, s+Qtopbase, dp); s -= (Qunitdir-Qtopbase); qlock(&devslock); for(i=0; i<nelem(devs); i++){ if(devs[i]){ if(s < devs[i]->nunit) break; s -= devs[i]->nunit; } } if(i == nelem(devs)){ /* Run off the end of the list */ qunlock(&devslock); return -1; } if((sdev = devs[i]) == nil){ qunlock(&devslock); return 0; } incref(&sdev->r); qunlock(&devslock); if((unit = sdev->unit[s]) == nil) if((unit = sdgetunit(sdev, s)) == nil){ decref(&sdev->r); return 0; } mkqid(&q, QID(sdev->idno, s, 0, Qunitdir), 0, QTDIR); if(emptystr(unit->user)) kstrdup(&unit->user, eve); devdir(c, q, unit->name, 0, unit->user, unit->perm, dp); decref(&sdev->r); return 1; case Qunitdir: if(s == DEVDOTDOT){ mkqid(&q, QID(0, 0, 0, Qtopdir), 0, QTDIR); snprint(up->genbuf, sizeof up->genbuf, "#%C", sddevtab.dc); devdir(c, q, up->genbuf, 0, eve, 0555, dp); return 1; } if((sdev = sdgetdev(DEV(c->qid))) == nil){ devdir(c, c->qid, "unavailable", 0, eve, 0, dp); return 1; } unit = sdev->unit[UNIT(c->qid)]; qlock(&unit->ctl); /* * Check for media change. * If one has already been detected, sectors will be zero. * If there is one waiting to be detected, online * will return > 1. * Online is a bit of a large hammer but does the job. */ if(unit->sectors == 0 || (unit->dev->ifc->online && unit->dev->ifc->online(unit) > 1)) sdinitpart(unit); i = s+Qunitbase; if(i < Qpart){ r = sd2gen(c, i, dp); qunlock(&unit->ctl); decref(&sdev->r); return r; } i -= Qpart; if(unit->part == nil || i >= unit->npart){ qunlock(&unit->ctl); decref(&sdev->r); break; } pp = &unit->part[i]; if(!pp->valid){ qunlock(&unit->ctl); decref(&sdev->r); return 0; } l = (pp->end - pp->start) * unit->secsize; mkqid(&q, QID(DEV(c->qid), UNIT(c->qid), i, Qpart), unit->vers+pp->vers, QTFILE); if(emptystr(pp->user)) kstrdup(&pp->user, eve); devdir(c, q, pp->name, l, pp->user, pp->perm, dp); qunlock(&unit->ctl); decref(&sdev->r); return 1; case Qraw: case Qctl: case Qpart: if((sdev = sdgetdev(DEV(c->qid))) == nil){ devdir(c, q, "unavailable", 0, eve, 0, dp); return 1; } unit = sdev->unit[UNIT(c->qid)]; qlock(&unit->ctl); r = sd2gen(c, TYPE(c->qid), dp); qunlock(&unit->ctl); decref(&sdev->r); return r; case Qtopctl: return sd1gen(c, TYPE(c->qid), dp); default: break; } return -1; }