ref: f473ac462b3a4464f9ec315c48cee6426dfd5c77
dir: /exportfs/exportsrv.c/
#include <u.h> #include <libc.h> #include <fcall.h> #define Extern extern #include "exportfs.h" char Ebadfid[] = "Bad fid"; char Enotdir[] = "Not a directory"; char Edupfid[] = "Fid already in use"; char Eopen[] = "Fid already opened"; char Exmnt[] = "Cannot .. past mount point"; char Emip[] = "Mount in progress"; char Enopsmt[] = "Out of pseudo mount points"; char Enomem[] = "No memory"; char Eversion[] = "Bad 9P2000 version"; int iounit(int x) { return 8192+IOHDRSZ; } void* emallocz(ulong n) { void *v; v = mallocz(n, 1); if(v == nil) panic("out of memory"); return v; } void Xversion(Fsrpc *t) { Fcall rhdr; if(t->work.msize > messagesize) t->work.msize = messagesize; messagesize = t->work.msize; if(strncmp(t->work.version, "9P2000", 6) != 0){ reply(&t->work, &rhdr, Eversion); return; } rhdr.version = "9P2000"; rhdr.msize = t->work.msize; reply(&t->work, &rhdr, 0); t->busy = 0; } void Xauth(Fsrpc *t) { Fcall rhdr; reply(&t->work, &rhdr, "exportfs: authentication not required"); t->busy = 0; } void Xflush(Fsrpc *t) { Fsrpc *w, *e; Fcall rhdr; e = &Workq[Nr_workbufs]; for(w = Workq; w < e; w++) { if(w->work.tag == t->work.oldtag) { DEBUG(DFD, "\tQ busy %d pid %d can %d\n", w->busy, w->pid, w->canint); if(w->busy && w->pid) { w->flushtag = t->work.tag; DEBUG(DFD, "\tset flushtag %d\n", t->work.tag); // if(w->canint) // postnote(PNPROC, w->pid, "flush"); t->busy = 0; return; } } } reply(&t->work, &rhdr, 0); DEBUG(DFD, "\tflush reply\n"); t->busy = 0; } void Xattach(Fsrpc *t) { Fcall rhdr; Fid *f; f = newfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } if(srvfd >= 0){ /* if(psmpt == 0){ Nomount: reply(&t->work, &rhdr, Enopsmt); t->busy = 0; freefid(t->work.fid); return; } for(i=0; i<Npsmpt; i++) if(psmap[i] == 0) break; if(i >= Npsmpt) goto Nomount; sprint(buf, "%d", i); f->f = file(psmpt, buf); if(f->f == nil) goto Nomount; sprint(buf, "/mnt/exportfs/%d", i); nfd = dup(srvfd, -1); if(amount(nfd, buf, MREPL|MCREATE, t->work.aname) < 0){ errstr(buf, sizeof buf); reply(&t->work, &rhdr, buf); t->busy = 0; freefid(t->work.fid); close(nfd); return; } psmap[i] = 1; f->mid = i; */ }else{ f->f = root; f->f->ref++; } rhdr.qid = f->f->qid; reply(&t->work, &rhdr, 0); t->busy = 0; } Fid* clonefid(Fid *f, int new) { Fid *n; n = newfid(new); if(n == 0) { n = getfid(new); if(n == 0) fatal("inconsistent fids"); if(n->fid >= 0) close(n->fid); freefid(new); n = newfid(new); if(n == 0) fatal("inconsistent fids2"); } n->f = f->f; n->f->ref++; return n; } void Xwalk(Fsrpc *t) { char err[ERRMAX], *e; Fcall rhdr; Fid *f, *nf; File *wf; int i; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } nf = nil; if(t->work.newfid != t->work.fid){ nf = clonefid(f, t->work.newfid); f = nf; } rhdr.nwqid = 0; e = nil; for(i=0; i<t->work.nwname; i++){ if(i == MAXWELEM){ e = "Too many path elements"; break; } if(strcmp(t->work.wname[i], "..") == 0) { if(f->f->parent == nil) { e = Exmnt; break; } wf = f->f->parent; wf->ref++; goto Accept; } wf = file(f->f, t->work.wname[i]); if(wf == 0){ errstr(err, sizeof err); e = err; break; } Accept: freefile(f->f); rhdr.wqid[rhdr.nwqid++] = wf->qid; f->f = wf; continue; } if(nf!=nil && (e!=nil || rhdr.nwqid!=t->work.nwname)) freefid(t->work.newfid); if(rhdr.nwqid > 0) e = nil; reply(&t->work, &rhdr, e); t->busy = 0; } void Xclunk(Fsrpc *t) { Fcall rhdr; Fid *f; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } if(f->fid >= 0) close(f->fid); freefid(t->work.fid); reply(&t->work, &rhdr, 0); t->busy = 0; } void Xstat(Fsrpc *t) { char err[ERRMAX], *path; Fcall rhdr; Fid *f; Dir *d; int s; uchar *statbuf; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } if(f->fid >= 0) d = dirfstat(f->fid); else { path = makepath(f->f, ""); d = dirstat(path); free(path); } if(d == nil) { errstr(err, sizeof err); reply(&t->work, &rhdr, err); t->busy = 0; return; } d->qid.path = f->f->qidt->uniqpath; s = sizeD2M(d); statbuf = emallocz(s); s = convD2M(d, statbuf, s); free(d); rhdr.nstat = s; rhdr.stat = statbuf; reply(&t->work, &rhdr, 0); free(statbuf); t->busy = 0; } static int getiounit(int fd) { int n; n = iounit(fd); if(n > messagesize-IOHDRSZ) n = messagesize-IOHDRSZ; return n; } void Xcreate(Fsrpc *t) { char err[ERRMAX], *path; Fcall rhdr; Fid *f; File *nf; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } path = makepath(f->f, t->work.name); f->fid = create(path, t->work.mode, t->work.perm); free(path); if(f->fid < 0) { errstr(err, sizeof err); reply(&t->work, &rhdr, err); t->busy = 0; return; } nf = file(f->f, t->work.name); if(nf == 0) { errstr(err, sizeof err); reply(&t->work, &rhdr, err); t->busy = 0; return; } f->mode = t->work.mode; freefile(f->f); f->f = nf; rhdr.qid = f->f->qid; rhdr.iounit = getiounit(f->fid); reply(&t->work, &rhdr, 0); t->busy = 0; } void Xremove(Fsrpc *t) { char err[ERRMAX], *path; Fcall rhdr; Fid *f; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } path = makepath(f->f, ""); DEBUG(DFD, "\tremove: %s\n", path); if(remove(path) < 0) { free(path); errstr(err, sizeof err); reply(&t->work, &rhdr, err); t->busy = 0; return; } free(path); f->f->inval = 1; if(f->fid >= 0) close(f->fid); freefid(t->work.fid); reply(&t->work, &rhdr, 0); t->busy = 0; } void Xwstat(Fsrpc *t) { char err[ERRMAX], *path; Fcall rhdr; Fid *f; int s; char *strings; Dir d; f = getfid(t->work.fid); if(f == 0) { reply(&t->work, &rhdr, Ebadfid); t->busy = 0; return; } strings = emallocz(t->work.nstat); /* ample */ if(convM2D(t->work.stat, t->work.nstat, &d, strings) <= BIT16SZ){ rerrstr(err, sizeof err); reply(&t->work, &rhdr, err); t->busy = 0; free(strings); return; } if(f->fid >= 0) s = dirfwstat(f->fid, &d); else { path = makepath(f->f, ""); s = dirwstat(path, &d); free(path); } if(s < 0) { rerrstr(err, sizeof err); reply(&t->work, &rhdr, err); } else { /* wstat may really be rename */ if(strcmp(d.name, f->f->name)!=0 && strcmp(d.name, "")!=0){ free(f->f->name); f->f->name = estrdup(d.name); } reply(&t->work, &rhdr, 0); } free(strings); t->busy = 0; } void slave(Fsrpc *f) { Proc *p; int pid; static int nproc; for(;;) { for(p = Proclist; p; p = p->next) { if(p->busy == 0) { f->pid = p->pid; p->busy = 1; pid = (uintptr)rendezvous((void*)(uintptr)p->pid, f); if(pid != p->pid) fatal("rendezvous sync fail"); return; } } if(++nproc > MAXPROC) fatal("too many procs"); pid = kproc("slave", blockingslave, nil); DEBUG(DFD, "slave pid %d\n", pid); if(pid == -1) fatal("kproc"); p = malloc(sizeof(Proc)); if(p == 0) fatal("out of memory"); p->busy = 0; p->pid = pid; p->next = Proclist; Proclist = p; DEBUG(DFD, "parent %d rendez\n", pid); rendezvous((void*)(uintptr)pid, p); DEBUG(DFD, "parent %d went\n", pid); } } void blockingslave(void *x) { Fsrpc *p; Fcall rhdr; Proc *m; int pid; USED(x); notify(flushaction); pid = getpid(); DEBUG(DFD, "blockingslave %d rendez\n", pid); m = (Proc*)rendezvous((void*)(uintptr)pid, 0); DEBUG(DFD, "blockingslave %d rendez got %p\n", pid, m); for(;;) { p = rendezvous((void*)(uintptr)pid, (void*)(uintptr)pid); if((uintptr)p == ~(uintptr)0) /* Interrupted */ continue; DEBUG(DFD, "\tslave: %d %F b %d p %d\n", pid, &p->work, p->busy, p->pid); if(p->flushtag != NOTAG) goto flushme; switch(p->work.type) { case Tread: slaveread(p); break; case Twrite: slavewrite(p); break; case Topen: slaveopen(p); break; default: reply(&p->work, &rhdr, "exportfs: slave type error"); } if(p->flushtag != NOTAG) { flushme: p->work.type = Tflush; p->work.tag = p->flushtag; reply(&p->work, &rhdr, 0); } p->busy = 0; m->busy = 0; } } int openmount(int sfd) { werrstr("openmount not implemented"); return -1; } void slaveopen(Fsrpc *p) { char err[ERRMAX], *path; Fcall *work, rhdr; Fid *f; Dir *d; work = &p->work; f = getfid(work->fid); if(f == 0) { reply(work, &rhdr, Ebadfid); return; } if(f->fid >= 0) { close(f->fid); f->fid = -1; } path = makepath(f->f, ""); DEBUG(DFD, "\topen: %s %d\n", path, work->mode); p->canint = 1; if(p->flushtag != NOTAG){ free(path); return; } /* There is a race here I ignore because there are no locks */ f->fid = open(path, work->mode); free(path); p->canint = 0; if(f->fid < 0 || (d = dirfstat(f->fid)) == nil) { Error: errstr(err, sizeof err); reply(work, &rhdr, err); return; } f->f->qid = d->qid; free(d); if(f->f->qid.type & QTMOUNT){ /* fork new exportfs for this */ f->fid = openmount(f->fid); if(f->fid < 0) goto Error; } DEBUG(DFD, "\topen: fd %d\n", f->fid); f->mode = work->mode; rhdr.iounit = getiounit(f->fid); rhdr.qid = f->f->qid; reply(work, &rhdr, 0); } void slaveread(Fsrpc *p) { Fid *f; int n, r; Fcall *work, rhdr; char *data, err[ERRMAX]; work = &p->work; f = getfid(work->fid); if(f == 0) { reply(work, &rhdr, Ebadfid); return; } n = (work->count > messagesize-IOHDRSZ) ? messagesize-IOHDRSZ : work->count; p->canint = 1; if(p->flushtag != NOTAG) return; data = malloc(n); if(data == nil) fatal(Enomem); /* can't just call pread, since directories must update the offset */ r = pread(f->fid, data, n, work->offset); p->canint = 0; if(r < 0) { free(data); errstr(err, sizeof err); reply(work, &rhdr, err); return; } DEBUG(DFD, "\tread: fd=%d %d bytes\n", f->fid, r); rhdr.data = data; rhdr.count = r; reply(work, &rhdr, 0); free(data); } void slavewrite(Fsrpc *p) { char err[ERRMAX]; Fcall *work, rhdr; Fid *f; int n; work = &p->work; f = getfid(work->fid); if(f == 0) { reply(work, &rhdr, Ebadfid); return; } n = (work->count > messagesize-IOHDRSZ) ? messagesize-IOHDRSZ : work->count; p->canint = 1; if(p->flushtag != NOTAG) return; n = pwrite(f->fid, work->data, n, work->offset); p->canint = 0; if(n < 0) { errstr(err, sizeof err); reply(work, &rhdr, err); return; } DEBUG(DFD, "\twrite: %d bytes fd=%d\n", n, f->fid); rhdr.count = n; reply(work, &rhdr, 0); } void reopen(Fid *f) { USED(f); fatal("reopen"); } void flushaction(void *a, char *cause) { USED(a); if(strncmp(cause, "sys:", 4) == 0 && !strstr(cause, "pipe")) { fprint(2, "exportsrv: note: %s\n", cause); exits("noted"); } if(strncmp(cause, "kill", 4) == 0) noted(NDFLT); noted(NCONT); }