ref: a0a4524bbb03bfa4902c6aa7102d912d403eef6b
dir: /fs.c/
#include <u.h> #include <libc.h> #include <fcall.h> #include <avl.h> #include <bio.h> #include "dat.h" #include "fns.h" int okname(char *name) { int i; if(name[0] == 0) return -1; if(strcmp(name, ".") == 0 || strcmp(name, "..") == 0) return -1; for(i = 0; i < Maxname; i++){ if(name[i] == 0) return 0; if((name[i]&0xff) < 0x20 || name[i] == '/') return -1; } return -1; } static vlong nextqid(void) { vlong q; lock(&fs->qidlk); q = fs->nextqid++; unlock(&fs->qidlk); return q; } static char* fslookup(Fid *f, Key *k, Kvp *kv, char *buf, int nbuf, int lk) { char *e; Blk *b; int h; assert(f->root.bp.addr == -1); if((b = getroot(&fs->root, &h)) == nil) return Efs; if(lk) rlock(f->dent); e = btlookupat(b, h, k, kv, buf, nbuf); if(lk) runlock(f->dent); putblk(b); return e; } static Dent* getdent(vlong root, vlong pqid, Dir *d) { Dent *e; char *ek, *eb; u32int h; int err; h = (ihash(d->qid.path) ^ ihash(root)) % Ndtab; lock(&fs->dtablk); for(e = fs->dtab[h]; e != nil; e = e->next){ if(e->qid.path == d->qid.path && e->rootb == root){ ainc(&e->ref); unlock(&fs->dtablk); return e; } } err = 0; if((e = mallocz(sizeof(Dent), 1)) == nil) return nil; e->ref = 1; e->qid = d->qid; e->rootb = root; e->k = e->buf; e->nk = 9 + strlen(d->name) + 1; ek = e->buf; eb = ek + sizeof(e->buf); ek = pack8(&err, ek, eb, Kent); ek = pack64(&err, ek, eb, pqid); ek = packstr(&err, ek, eb, d->name); e->nk = ek - e->buf; e->next = fs->dtab[h]; fs->dtab[h] = e; unlock(&fs->dtablk); return e; } static void clunkdent(Dent *de) { Dent *e, **pe; u32int h; if(adec(&de->ref) == 0){ h = (ihash(de->qid.path) ^ ihash(de->rootb)) % Ndtab; lock(&fs->dtablk); pe = &fs->dtab[h]; for(e = fs->dtab[h]; e != nil; e = e->next){ if(e == de){ *pe = e->next; unlock(&fs->dtablk); free(de); return; } pe = &e->next; } abort(); } } void showfids(int fd) { int i; Fid *f; lock(&fs->fidtablk); fprint(fd, "fids:---\n"); for(i = 0; i < Nfidtab; i++) for(f = fs->fidtab[i]; f != nil; f = f->next){ rlock(f->dent); fprint(fd, "\tfid[%d]: %d [refs=%ld, k=%K, qid=%Q]\n", i, f->fid, f->dent->ref, &f->dent->Key, f->dent->qid); runlock(f->dent); } unlock(&fs->fidtablk); } Fid* getfid(u32int fid) { u32int h; Fid *f; h = ihash(fid) % Nfidtab; lock(&fs->fidtablk); for(f = fs->fidtab[h]; f != nil; f = f->next) if(f->fid == fid) break; unlock(&fs->fidtablk); ainc(&f->ref); return f; } void putfid(Fid *f) { if(adec(&f->ref) == 0){ clunkdent(f->dent); free(f); } } Fid* dupfid(int new, Fid *f) { Fid *n, *o; u32int h; h = ihash(new) % Nfidtab; if((n = malloc(sizeof(Fid))) == nil) return nil; *n = *f; n->fid = new; n->ref = 2; /* one for dup, one for clunk */ n->mode = -1; n->next = nil; lock(&fs->fidtablk); ainc(&n->dent->ref); for(o = fs->fidtab[h]; o != nil; o = o->next) if(o->fid == new) break; if(o == nil){ n->next = fs->fidtab[h]; fs->fidtab[h] = n; } unlock(&fs->fidtablk); if(o != nil){ werrstr("fid in use: %d == %d", o->fid, new); abort(); free(n); return nil; } return n; } void clunkfid(Fid *fid) { Fid *f, **pf; u32int h; lock(&fs->fidtablk); h = ihash(fid->fid) % Nfidtab; pf = &fs->fidtab[h]; for(f = fs->fidtab[h]; f != nil; f = f->next){ if(f == fid){ assert(adec(&f->ref) != 0); *pf = f->next; break; } pf = &f->next; } unlock(&fs->fidtablk); } void fshangup(int fd, char *fmt, ...) { va_list ap; va_start(ap, fmt); vfprint(2, fmt, ap); va_end(ap); close(fd); abort(); } Fmsg* readmsg(int fd, int max) { char szbuf[4]; int sz; Fmsg *m; if(readn(fd, szbuf, 4) != 4) return nil; sz = GBIT32(szbuf); if(sz > max) return nil; if((m = malloc(sizeof(Fmsg)+sz)) == nil) return nil; if(readn(fd, m->buf+4, sz-4) != sz-4){ werrstr("short read: %r"); free(m); return nil; } m->fd = fd; m->sz = sz; PBIT32(m->buf, sz); return m; } void respond(Fmsg *m, Fcall *r) { uchar buf[Max9p]; int w, n; r->tag = m->tag; dprint("→ %F\n", r); if((n = convS2M(r, buf, sizeof(buf))) == 0) abort(); qlock(m->wrlk); w = write(m->fd, buf, n); qunlock(m->wrlk); if(w != n) fshangup(m->fd, "failed write"); free(m); } void rerror(Fmsg *m, char *fmt, ...) { char buf[128]; va_list ap; Fcall r; va_start(ap, fmt); vsnprint(buf, sizeof(buf), fmt, ap); va_end(ap); r.type = Rerror; r.ename = buf; respond(m, &r); } Chan* mkchan(int size) { Chan *c; if((c = mallocz(sizeof(Chan) + size*sizeof(void*), 1)) == nil) sysfatal("create channel"); c->size = size; c->avail = size; c->count = 0; c->rp = c->args; c->wp = c->args; return c; } Fmsg* chrecv(Chan *c) { void *a; long v; v = c->count; if(v == 0 || cas(&c->count, v, v-1) == 0) semacquire(&c->count, 1); lock(&c->rl); a = *c->rp; if(++c->rp >= &c->args[c->size]) c->rp = c->args; unlock(&c->rl); semrelease(&c->avail, 1); return a; } void chsend(Chan *c, Fmsg *m) { long v; v = c->avail; if(v == 0 || cas(&c->avail, v, v-1) == 0) semacquire(&c->avail, 1); lock(&c->wl); *c->wp = m; if(++c->wp >= &c->args[c->size]) c->wp = c->args; unlock(&c->wl); semrelease(&c->count, 1); } void fsversion(Fmsg *m, int *msz) { Fcall r; memset(&r, 0, sizeof(Fcall)); if(strcmp(m->version, "9P2000") == 0){ if(m->msize < *msz) *msz = m->msize; r.type = Rversion; r.msize = *msz; }else{ r.type = Rversion; r.version = "unknown"; } respond(m, &r); } void fsauth(Fmsg *m) { Fcall r; r.type = Rerror; r.ename = "unimplemented auth"; respond(m, &r); } void fsattach(Fmsg *m, int iounit) { char *p, *ep, buf[Kvmax], kvbuf[Kvmax]; int err; Dent *e; Fcall r; Kvp kv; Key dk; Fid f; Dir d; err = 0; p = buf; ep = buf + sizeof(buf); p = pack8(&err, p, ep, Kent); p = pack64(&err, p, ep, -1ULL); p = packstr(&err, p, ep, ""); dk.k = buf; dk.nk = p - buf; if(btlookup(&fs->root, &dk, &kv, kvbuf, sizeof(kvbuf)) != nil){ rerror(m, Efs); return; } r.type = Rattach; if(kv2dir(&kv, &d) == -1){ rerror(m, Efs); return; } if((e = getdent(-1, -1, &d)) == nil){ rerror(m, Efs); return; } /* * A bit of a hack; we're duping a fid * that doesn't exist, so we'd be off * by one on the refcount. Adjust to * compensate for the dup. */ adec(&e->ref); memset(&f, 0, sizeof(Fid)); f.fid = NOFID; f.qpath = d.qid.path; f.mode = -1; f.root.bp.addr = -1; f.root.bp.hash = -1; f.iounit = iounit; f.dent = e; if(dupfid(m->fid, &f) == nil){ rerror(m, Enomem); return; } r.qid = d.qid; respond(m, &r); return; } void fswalk(Fmsg *m) { char *p, *e, *estr, kbuf[Maxent], kvbuf[Kvmax]; vlong up, prev; int i, err; Fid *o, *f; Dent *dent; Fcall r; Kvp kv; Key k; Dir d; if((o = getfid(m->fid)) == nil){ rerror(m, Efid); return; } if(o->mode != -1){ rerror(m, Einuse); return; } err = 0; estr = nil; up = o->qpath; prev = o->qpath; r.type = Rwalk; for(i = 0; i < m->nwname; i++){ up = prev; p = kbuf; e = p + sizeof(kbuf); p = pack8(&err, p, e, Kent); p = pack64(&err, p, e, up); p = packstr(&err, p, e, m->wname[i]); if(err){ rerror(m, "bad walk: %r"); putfid(o); return; } k.k = kbuf; k.nk = p - kbuf; if((estr = fslookup(o, &k, &kv, kvbuf, sizeof(kvbuf), 0)) != nil){ break; } if(kv2dir(&kv, &d) == -1){ rerror(m, Efs); putfid(o); return; } prev = d.qid.path; r.wqid[i] = d.qid; } r.nwqid = i; if(i == 0 && m->nwname != 0){ rerror(m, estr); putfid(o); return; } f = o; if(m->fid != m->newfid && i == m->nwname){ if((f = dupfid(m->newfid, o)) == nil){ rerror(m, Emem); putfid(o); return; } putfid(o); } if(i > 0){ dent = getdent(f->root.bp.addr, up, &d); if(dent == nil){ if(m->fid != m->newfid) clunkfid(f); rerror(m, Enomem); putfid(f); return; } if(i == m->nwname){ f->qpath = r.wqid[i-1].path; f->dent = dent; } } respond(m, &r); putfid(f); } void fsstat(Fmsg *m) { char *err, buf[STATMAX], kvbuf[Kvmax]; Fcall r; Fid *f; Kvp kv; int n; if((f = getfid(m->fid)) == nil){ rerror(m, "no such fid"); return; } if((err = btlookup(&fs->root, f->dent, &kv, kvbuf, sizeof(kvbuf))) != nil){ rerror(m, err); putfid(f); return; } if((n = kv2statbuf(&kv, buf, sizeof(buf))) == -1){ rerror(m, "stat: %r"); putfid(f); return; } r.type = Rstat; r.stat = (uchar*)buf; r.nstat = n; respond(m, &r); putfid(f); } void fswstat(Fmsg *m) { USED(m); rerror(m, "wstat unimplemented"); } void fsclunk(Fmsg *m) { Fcall r; Fid *f; if((f = getfid(m->fid)) == nil){ rerror(m, "no such fid"); return; } lock(f); if(f->scan != nil){ btdone(f->scan); f->scan = nil; } unlock(f); clunkfid(f); r.type = Rclunk; respond(m, &r); putfid(f); } void fscreate(Fmsg *m) { char buf[Kvmax]; Dent *dent; Fcall r; Msg mb; Fid *f; Dir d; if(okname(m->name) == -1){ rerror(m, Ename); return; } if((f = getfid(m->fid)) == nil){ rerror(m, "no such fid"); return; } if(m->perm & (DMMOUNT|DMAUTH)){ rerror(m, "unknown permission"); return; } d.qid.type = 0; if(m->perm & DMDIR) d.qid.type |= QTDIR; if(m->perm & DMAPPEND) d.qid.type |= QTAPPEND; if(m->perm & DMEXCL) d.qid.type |= QTEXCL; if(m->perm & DMTMP) d.qid.type |= QTTMP; d.qid.path = nextqid(); d.qid.vers = 0; d.mode = m->perm; d.name = m->name; d.atime = nsec(); d.mtime = d.atime; d.length = 0; d.uid = "glenda"; d.gid = "glenda"; d.muid = "glenda"; mb.op = Oinsert; mb.statop = 0; if(dir2kv(f->qpath, &d, &mb, buf, sizeof(buf)) == -1){ rerror(m, Efs); putfid(f); return; } if(btupsert(&fs->root, &mb, 1) == -1){ rerror(m, "%r"); putfid(f); return; } dent = getdent(f->root.bp.addr, f->qpath, &d); if(dent == nil){ if(m->fid != m->newfid) clunkfid(f); rerror(m, Enomem); putfid(f); return; } lock(f); if(f->mode != -1){ unlock(f); clunkdent(dent); rerror(m, Einuse); putfid(f); return; } f->mode = m->mode; f->qpath = d.qid.path; f->dent = dent; wlock(f->dent); // freeb(dent, 0, dent->length); dent->length = 0; wunlock(f->dent); unlock(f); r.type = Rcreate; r.qid = d.qid; r.iounit = f->iounit; respond(m, &r); putfid(f); } void fsremove(Fmsg *m) { Fcall r; Msg mb; Fid *f; if((f = getfid(m->fid)) == nil){ rerror(m, "no such fid"); return; } rlock(f->dent); mb.op = Odelete; mb.k = f->dent->k; mb.nk = f->dent->nk; mb.nv = 0; //showfs("preremove"); if(btupsert(&fs->root, &mb, 1) == -1){ runlock(f->dent); rerror(m, "remove: %r"); putfid(f); return; } runlock(f->dent); clunkfid(f); r.type = Rremove; respond(m, &r); putfid(f); } int fsaccess(Dir*, int) { /* all is permitted */ return 0; } void fsopen(Fmsg *m) { char *e, buf[Kvmax]; Fcall r; Dir d; Fid *f; Kvp kv; if((f = getfid(m->fid)) == nil){ rerror(m, Efid); return; } if((e = fslookup(f, f->dent, &kv, buf, sizeof(buf), 0)) != nil){ rerror(m, e); putfid(f); return; } if(kv2dir(&kv, &d) == -1){ rerror(m, Efs); putfid(f); return; } if(fsaccess(&d, m->mode) == -1){ rerror(m, Eperm); putfid(f); return; } wlock(f->dent); f->dent->length = d.length; wunlock(f->dent); r.type = Ropen; r.qid = d.qid; r.iounit = f->iounit; lock(f); if(f->mode != -1){ rerror(m, Einuse); unlock(f); putfid(f); return; } f->mode = m->mode; // if((f->mode & 0x7) == OEXEC){ // lock(&fs->root.lk); // f->root = fs->root; // refblk(fs->root.bp); // unlock(&fs->root.lk); // } if(f->mode & OTRUNC){ wlock(f->dent); // freeb(f->dent, 0, dent->length); f->dent->length = 0; wunlock(f->dent); } unlock(f); respond(m, &r); putfid(f); } char* fsreaddir(Fmsg *m, Fid *f, Fcall *r) { char pfx[9], *p, *e; int n, ns, done; Tree *t; Scan *s; Dir d; s = f->scan; if(s != nil && s->offset != 0 && s->offset != m->offset) return Edscan; if(s == nil || m->offset == 0){ if((s = mallocz(sizeof(Scan), 1)) == nil) return Enomem; pfx[0] = Kent; PBIT64(pfx+1, f->qpath); t = (f->root.bp.addr != -1) ? &f->root : &fs->root; if((e = btscan(t, s, pfx, sizeof(pfx))) != nil){ free(r->data); btdone(s); return e; } lock(f); if(f->scan != nil) btdone(f->scan); f->scan = s; unlock(f); } if(s->done){ fprint(2, "early done...\n"); r->count = 0; return nil; } p = r->data; n = m->count; if(s->overflow){ kv2dir(&s->kv, &d); if((ns = convD2M(&d, (uchar*)p, n)) <= BIT16SZ) return Edscan; s->overflow = 0; p += ns; n -= ns; } while(1){ if((e = btnext(s, &s->kv, &done)) != nil) return e; if(done) break; kv2dir(&s->kv, &d); if((ns = convD2M(&d, (uchar*)p, n)) <= BIT16SZ){ s->overflow = 1; break; } p += ns; n -= ns; } r->count = p - r->data; return nil; } int readb(Fid *f, char *d, vlong o, vlong n, int sz) { char *e, buf[17], kvbuf[17+32]; vlong fb, fo; Bptr bp; Blk *b; Key k; Kvp kv; if(o >= sz) return 0; fb = o & ~(Blksz-1); fo = o & (Blksz-1); k.k = buf; k.nk = sizeof(buf); k.k[0] = Kdat; PBIT64(k.k+1, f->qpath); PBIT64(k.k+9, fb); e = fslookup(f, &k, &kv, kvbuf, sizeof(kvbuf), 0); if(e != nil && e != Eexist){ werrstr(e); return -1; } bp = unpackbp(kv.v); if((b = getblk(bp, GBraw)) == nil) return -1; if(fo+n > Blksz) n = Blksz-fo; if(b != nil){ memcpy(d, b->buf+fo, n); putblk(b); }else memset(d, 0, n); return n; } char* fsreadfile(Fmsg *m, Fid *f, Fcall *r) { vlong n, c, o; char *p; Dent *e; r->type = Rread; r->count = 0; e = f->dent; rlock(e); if(m->offset > e->length){ runlock(e); return nil; } if((r->data = malloc(m->count)) == nil){ runlock(e); return Enomem; } p = r->data; c = m->count; o = m->offset; if(m->offset + m->count > e->length) c = e->length - m->offset; while(c != 0){ n = readb(f, p, o, c, e->length); if(n == -1){ fprint(2, "read %K [%Q]@%lld+%lld: %r\n", &e->Key, e->qid, o, c); runlock(e); return Efs; } r->count += n; if(n == 0) break; p += n; o += n; c -= n; } runlock(e); return nil; } void fsread(Fmsg *m) { char *e; Fcall r; Fid *f; if((f = getfid(m->fid)) == nil){ rerror(m, Efid); return; } r.type = Rread; r.count = 0; if((r.data = malloc(m->count)) == nil){ rerror(m, Emem); putfid(f); return; } if(f->dent->qid.type & QTDIR) e = fsreaddir(m, f, &r); else e = fsreadfile(m, f, &r); if(e != nil){ rerror(m, e); putfid(f); return; } respond(m, &r); free(r.data); putfid(f); } int writeb(Fid *f, Msg *m, char *s, vlong o, vlong n, vlong sz) { char buf[Kvmax]; vlong fb, fo; Bptr bp; Blk *b, *t; Kvp kv; fb = o & ~(Blksz-1); fo = o & (Blksz-1); m->k[0] = Kdat; PBIT64(m->k+1, f->qpath); PBIT64(m->k+9, fb); b = newblk(Traw); if(b == nil) return -1; if(fb < sz && (fo != 0 || n != Blksz)){ dprint("\tappending to block %B\n", b->bp); if(fslookup(f, m, &kv, buf, sizeof(buf), 0) != nil) return -1; bp = unpackbp(kv.v); if((t = getblk(bp, GBraw)) == nil) return -1; memcpy(b->buf, t->buf, Blksz); freeblk(t); putblk(t); } if(fo+n > Blksz) n = Blksz-fo; memcpy(b->buf+fo, s, n); enqueue(b); bp.gen = fs->nextgen; assert(b->flag & Bfinal); packbp(m->v, &b->bp); putblk(b); return n; } void fswrite(Fmsg *m) { char sbuf[8], offbuf[4][Ptrsz+Offksz], *p; vlong n, o, c; Msg kv[4]; Fcall r; Fid *f; int i; if((f = getfid(m->fid)) == nil){ rerror(m, Efid); return; } if((f->mode&0x7) != OWRITE){ dprint("f->mode: %x\n", f->mode); rerror(m, Einuse); putfid(f); return; } wlock(f->dent); p = m->data; o = m->offset; c = m->count; for(i = 0; i < nelem(kv)-1 && c != 0; i++){ kv[i].op = Oinsert; kv[i].k = offbuf[i]; kv[i].nk = Offksz; kv[i].v = offbuf[i]+Offksz; kv[i].nv = 16; n = writeb(f, &kv[i], p, o, c, f->dent->length); if(n == -1){ // badwrite(f, i); // FIXME: free pages wunlock(f->dent); rerror(m, "%r"); putfid(f); abort(); return; } p += n; o += n; c -= n; } kv[i].op = Owstat; kv[i].statop = 0; kv[i].k = f->dent->k; kv[i].nk = f->dent->nk; kv[i].v = sbuf; kv[i].nv = 0; if(m->offset+m->count > f->dent->length){ kv[i].statop = Owsize; kv[i].nv += 8; PBIT64(kv[i].v, m->offset+m->count); f->dent->length = m->offset+m->count; } if(btupsert(&fs->root, kv, i+1) == -1){ fprint(2, "upsert: %r\n"); putfid(f); abort(); return; } wunlock(f->dent); r.type = Rwrite; r.count = m->count; respond(m, &r); putfid(f); } void runfs(void *pfd) { int fd, msgmax; char err[128]; QLock *wrlk; Fcall r; Fmsg *m; fd = (uintptr)pfd; msgmax = Max9p; if((wrlk = mallocz(sizeof(QLock), 1)) == nil) fshangup(fd, "alloc wrlk: %r"); while(1){ if((m = readmsg(fd, msgmax)) == nil){ fshangup(fd, "truncated message: %r"); return; } if(convM2S(m->buf, m->sz, m) == 0){ fshangup(fd, "invalid message: %r"); return; } /* if(m->type != Tversion && !versioned){ fshangup(fd, "version required"); return; } */ m->wrlk = wrlk; dprint("← %F\n", &m->Fcall); switch(m->type){ /* sync setup */ case Tversion: fsversion(m, &msgmax); break; case Tauth: fsauth(m); break; case Tclunk: fsclunk(m); break; case Topen: fsopen(m); break; case Tattach: fsattach(m, msgmax); break; /* mutators */ case Tflush: chsend(fs->wrchan, m); break; case Tcreate: chsend(fs->wrchan, m); break; case Twrite: chsend(fs->wrchan, m); break; case Twstat: chsend(fs->wrchan, m); break; case Tremove: chsend(fs->wrchan, m); break; /* reads */ case Twalk: chsend(fs->rdchan, m); break; case Tread: chsend(fs->rdchan, m); break; case Tstat: chsend(fs->rdchan, m); break; default: fprint(2, "unknown message %F\n", &m->Fcall); snprint(err, sizeof(err), "unknown message: %F", &m->Fcall); r.type = Rerror; r.ename = err; respond(m, &r); break; } } } void runwrite(void *) { Fmsg *m; while(1){ m = chrecv(fs->wrchan); switch(m->type){ case Tflush: rerror(m, "unimplemented flush"); break; case Tcreate: fscreate(m); break; case Twrite: fswrite(m); break; case Twstat: fswstat(m); break; case Tremove: fsremove(m); break; } } } void runread(void *) { Fmsg *m; while(1){ m = chrecv(fs->rdchan); switch(m->type){ case Twalk: fswalk(m); break; case Tread: fsread(m); break; case Tstat: fsstat(m); break; } } }