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#include        "all.h"
#include        "9p1.h"

/*
 * buggery to give false qid for
 * the top 2 levels of the dump fs
 */
void
mkqid(Qid* qid, Dentry *d, int buggery)
{
        int c;

        if(buggery && d->qid.path == QPROOT && (d->qid.path & QPDIR)){
                c = d->name[0];
                if(c >= '0' && c <= '9'){
                        qid->path = 3;
                        qid->vers = d->qid.version;
                        qid->type = QTDIR;

                        c = (c-'0')*10 + (d->name[1]-'0');
                        if(c >= 1 && c <= 12)
                                qid->path = 4;
                        return;
                }
        }

        mkqid9p2(qid, &d->qid, d->mode);
}

int
mkqidcmp(Qid* qid, Dentry *d)
{
        Qid tmp;

        mkqid(&tmp, d, 1);
        if(qid->path==tmp.path && (qid->type&QTDIR)==(tmp.type&QTDIR))
                return 0;
        return Eqid;
}

void
f_nop(Chan *cp, Oldfcall *in, Oldfcall *ou)
{

        USED(in);
        USED(ou);
        if(CHAT(cp))
                print("c_nop %d\n", cp->chan);
}

void
f_flush(Chan *cp, Oldfcall *in, Oldfcall *ou)
{

        USED(in);
        USED(ou);
        if(CHAT(cp))
                print("c_flush %d\n", cp->chan);
        runlock(&cp->reflock);
        wlock(&cp->reflock);
        wunlock(&cp->reflock);
        rlock(&cp->reflock);
}

void
f_session(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        if(CHAT(cp))
                print("c_session %d\n", cp->chan);

        memmove(cp->rchal, in->chal, sizeof(cp->rchal));
        if(wstatallow || cp == cons.srvchan){
                memset(ou->chal, 0, sizeof(ou->chal));
                memset(ou->authid, 0, sizeof(ou->authid));
        }else{
                mkchallenge(cp);
                memmove(ou->chal, cp->chal, sizeof(ou->chal));
                memmove(ou->authid, nvr.authid, sizeof(ou->authid));
        }
        sprint(ou->authdom, "%s.%s", service, nvr.authdom);
        fileinit(cp);
}

void
f_attach(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p;
        Dentry *d;
        File *f;
        int u;
        Filsys *fs;
        long raddr;

        if(CHAT(cp)) {
                print("c_attach %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" uid = %s\n", in->uname);
                print(" arg = %s\n", in->aname);
        }

        ou->qid = QID9P1(0,0);
        ou->fid = in->fid;
        if(!in->aname[0])       /* default */
                strncpy(in->aname, filesys[0].name, sizeof(in->aname));
        p = 0;
        f = filep(cp, in->fid, 1);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        u = -1;
        if(cp != cons.chan){
                if(authorize(cp, in, ou) == 0 || strcmp(in->uname, "adm") == 0){
                        ou->err = Eauth;
                        goto out;
                }
                u = strtouid(in->uname);
                if(u < 0){
                        ou->err = Ebadu;
                        goto out;
                }
        }

        fs = fsstr(in->aname);
        if(fs == 0) {
                ou->err = Ebadspc;
                goto out;
        }
        raddr = getraddr(fs->dev);
        p = getbuf(fs->dev, raddr, Bread);
        d = getdir(p, 0);
        if(!d || checktag(p, Tdir, QPROOT) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        f->uid = u;
        if(iaccess(f, d, DREAD)) {
                ou->err = Eaccess;
                goto out;
        }
        accessdir(p, d, FREAD);
        mkqid(&f->qid, d, 1);
        f->fs = fs;
        f->addr = raddr;
        f->slot = 0;
        f->open = 0;
        freewp(f->wpath);
        f->wpath = 0;

        mkqid9p1(&ou->qid, &f->qid);

out:
        if(p)
                putbuf(p);
        if(f) {
                qunlock(f);
                if(ou->err)
                        freefp(f);
        }
}

void
f_clone(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        File *f1, *f2;
        int fid, fid1;

        if(CHAT(cp)) {
                print("c_clone %d\n", cp->chan);
                print(" old fid = %d\n", in->fid);
                print(" new fid = %d\n", in->newfid);
        }

        fid = in->fid;
        fid1 = in->newfid;

        f1 = 0;
        f2 = 0;
        if(fid < fid1) {
                f1 = filep(cp, fid, 0);
                f2 = filep(cp, fid1, 1);
        } else
        if(fid1 < fid) {
                f2 = filep(cp, fid1, 1);
                f1 = filep(cp, fid, 0);
        }
        if(!f1 || !f2) {
                ou->err = Efid;
                goto out;
        }


        f2->fs = f1->fs;
        f2->addr = f1->addr;
        f2->open = f1->open & ~FREMOV;
        f2->uid = f1->uid;
        f2->slot = f1->slot;
        f2->qid = f1->qid;

        freewp(f2->wpath);
        f2->wpath = getwp(f1->wpath);

out:
        ou->fid = fid;
        if(f1)
                qunlock(f1);
        if(f2)
                qunlock(f2);
}

void
f_walk(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p, *p1;
        Dentry *d, *d1;
        File *f;
        Wpath *w, *ow;
        int slot;
        long addr;

        if(CHAT(cp)) {
                print("c_walk %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" name = %s\n", in->name);
        }

        ou->fid = in->fid;
        ou->qid = QID9P1(0,0);
        p = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(!(d->mode & DDIR)) {
                ou->err = Edir1;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        if(cp != cons.chan && iaccess(f, d, DEXEC)) {
                ou->err = Eaccess;
                goto out;
        }
        accessdir(p, d, FREAD);
        if(strcmp(in->name, ".") == 0)
                goto setdot;
        if(strcmp(in->name, "..") == 0) {
                if(f->wpath == 0)
                        goto setdot;
                putbuf(p);
                p = 0;
                addr = f->wpath->addr;
                slot = f->wpath->slot;
                p1 = getbuf(f->fs->dev, addr, Bread);
                d1 = getdir(p1, slot);
                if(!d1 || checktag(p1, Tdir, QPNONE) || !(d1->mode & DALLOC)) {
                        if(p1)
                                putbuf(p1);
                        ou->err = Ephase;
                        goto out;
                }
                ow = f->wpath;
                f->wpath = ow->up;
                putwp(ow);
                goto found;
        }
        for(addr=0;; addr++) {
                p1 = dnodebuf(p, d, addr, 0);
                if(!p1 || checktag(p1, Tdir, d->qid.path) ) {
                        if(p1)
                                putbuf(p1);
                        ou->err = Eentry;
                        goto out;
                }
                for(slot=0; slot<DIRPERBUF; slot++) {
                        d1 = getdir(p1, slot);
                        if(!(d1->mode & DALLOC))
                                continue;
                        if(strncmp(in->name, d1->name, sizeof(in->name)))
                                continue;
                        /*
                         * update walk path
                         */
                        w = newwp();
                        if(!w) {
                                ou->err = Ewalk;
                                putbuf(p1);
                                goto out;
                        }
                        w->addr = f->addr;
                        w->slot = f->slot;
                        w->up = f->wpath;
                        f->wpath = w;
                        slot += DIRPERBUF*addr;
                        goto found;
                }
                putbuf(p1);
        }

found:
        f->addr = p1->addr;
        mkqid(&f->qid, d1, 1);
        putbuf(p1);
        f->slot = slot;

setdot:
        mkqid9p1(&ou->qid, &f->qid);
        f->open = 0;

out:
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
}

void
f_clunk(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        File *f;
        Tlock *t;
        long tim;

        if(CHAT(cp)) {
                print("c_clunk %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
        }

        f = filep(cp, in->fid, 0);
        if(!f) {
                print("%p\n", f);
                ou->err = Efid;
                goto out;
        }
        if(t = f->tlock) {
                tim = time(0);
                if(t->time < tim || t->file != f)
                        ou->err = Ebroken;
                t->time = 0;    /* free the lock */
                f->tlock = 0;
        }
        if(f->open & FREMOV)
                ou->err = doremove(f, 0);
        f->open = 0;
        freewp(f->wpath);
        freefp(f);

out:
        if(f)
                qunlock(f);
        ou->fid = in->fid;
}

void
f_clwalk(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        int er, fid;

        if(CHAT(cp))
                print("c_clwalk macro\n");

        f_clone(cp, in, ou);            /* sets tag, fid */
        if(ou->err)
                return;
        fid = in->fid;
        in->fid = in->newfid;
        f_walk(cp, in, ou);             /* sets tag, fid, qid */
        er = ou->err;
        if(er == Eentry) {
                /*
                 * if error is "no entry"
                 * return non error and fid
                 */
                ou->err = 0;
                f_clunk(cp, in, ou);    /* sets tag, fid */
                ou->err = 0;
                ou->fid = fid;
                if(CHAT(cp)) 
                        print(" error: %s\n", errstring[er]);
                return;
        }
        if(er) {
                /*
                 * if any other error
                 * return an error
                 */
                ou->err = 0;
                f_clunk(cp, in, ou);    /* sets tag, fid */
                ou->err = er;
                return;
        }
        /*
         * non error
         * return newfid
         */
}

void
f_open(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p;
        Dentry *d;
        File *f;
        Tlock *t;
        Qid qid;
        int ro, fmod;

        if(CHAT(cp)) {
                print("c_open %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" mode = %o\n", in->mode);
        }

        p = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }

        /*
         * if remove on close, check access here
         */
        ro = isro(f->fs->dev) || (cp != cons.chan && writegroup && !ingroup(f->uid, writegroup));
        if(in->mode & MRCLOSE) {
                if(ro) {
                        ou->err = Eronly;
                        goto out;
                }
                /*
                 * check on parent directory of file to be deleted
                 */
                if(f->wpath == 0 || f->wpath->addr == f->addr) {
                        ou->err = Ephase;
                        goto out;
                }
                p = getbuf(f->fs->dev, f->wpath->addr, Bread);
                d = getdir(p, f->wpath->slot);
                if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                        ou->err = Ephase;
                        goto out;
                }
                if(iaccess(f, d, DWRITE)) {
                        ou->err = Eaccess;
                        goto out;
                }
                putbuf(p);
        }
        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        mkqid(&qid, d, 1);
        switch(in->mode & 7) {

        case MREAD:
                if(iaccess(f, d, DREAD) && !writeallow)
                        goto badaccess;
                fmod = FREAD;
                break;

        case MWRITE:
                if((d->mode & DDIR) ||
                   (iaccess(f, d, DWRITE) && !writeallow))
                        goto badaccess;
                if(ro) {
                        ou->err = Eronly;
                        goto out;
                }
                fmod = FWRITE;
                break;

        case MBOTH:
                if((d->mode & DDIR) ||
                   (iaccess(f, d, DREAD) && !writeallow) ||
                   (iaccess(f, d, DWRITE) && !writeallow))
                        goto badaccess;
                if(ro) {
                        ou->err = Eronly;
                        goto out;
                }
                fmod = FREAD+FWRITE;
                break;

        case MEXEC:
                if((d->mode & DDIR) ||
                   iaccess(f, d, DEXEC))
                        goto badaccess;
                fmod = FREAD;
                break;

        default:
                ou->err = Emode;
                goto out;
        }
        if(in->mode & MTRUNC) {
                if((d->mode & DDIR) ||
                   (iaccess(f, d, DWRITE) && !writeallow))
                        goto badaccess;
                if(ro) {
                        ou->err = Eronly;
                        goto out;
                }
        }
        t = 0;
        if(d->mode & DLOCK) {
                t = tlocked(p, d);
                if(t == 0) {
                        ou->err = Elocked;
                        goto out;
                }
                t->file = f;
        }
        if(in->mode & MRCLOSE)
                fmod |= FREMOV;
        f->open = fmod;
        if(in->mode & MTRUNC)
                if(!(d->mode & DAPND))
                        dtrunc(p, d);
        f->tlock = t;
        f->lastra = 0;
        mkqid9p1(&ou->qid, &qid);
        goto out;

badaccess:
        ou->err = Eaccess;
        f->open = 0;

out:
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
}

void
f_create(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p, *p1;
        Dentry *d, *d1;
        File *f;
        int slot, slot1, fmod;
        long addr, addr1, path;
        Qid qid;
        Tlock *t;
        Wpath *w;

        if(CHAT(cp)) {
                print("c_create %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" name = %s\n", in->name);
                print(" perm = %lx+%lo\n", (in->perm>>28)&0xf,
                                in->perm&0777);
                print(" mode = %d\n", in->mode);
        }

        p = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        if(isro(f->fs->dev) || (cp != cons.chan && writegroup && !ingroup(f->uid, writegroup))) {
                ou->err = Eronly;
                goto out;
        }

        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        if(!(d->mode & DDIR)) {
                ou->err = Edir2;
                goto out;
        }
        if(cp != cons.chan && iaccess(f, d, DWRITE) && !writeallow) {
                ou->err = Eaccess;
                goto out;
        }
        accessdir(p, d, FREAD);
        if(!strncmp(in->name, ".", sizeof(in->name)) ||
           !strncmp(in->name, "..", sizeof(in->name))) {
                ou->err = Edot;
                goto out;
        }
        if(checkname(in->name)) {
                ou->err = Ename;
                goto out;
        }
        addr1 = 0;
        slot1 = 0;      /* set */
        for(addr=0;; addr++) {
                p1 = dnodebuf(p, d, addr, 0);
                if(!p1) {
                        if(addr1)
                                break;
                        p1 = dnodebuf(p, d, addr, Tdir);
                }
                if(p1 == 0) {
                        ou->err = Efull;
                        goto out;
                }
                if(checktag(p1, Tdir, d->qid.path)) {
                        putbuf(p1);
                        goto phase;
                }
                for(slot=0; slot<DIRPERBUF; slot++) {
                        d1 = getdir(p1, slot);
                        if(!(d1->mode & DALLOC)) {
                                if(!addr1) {
                                        addr1 = p1->addr;
                                        slot1 = slot + addr*DIRPERBUF;
                                }
                                continue;
                        }
                        if(!strncmp(in->name, d1->name, sizeof(in->name))) {
                                putbuf(p1);
                                ou->err = Eexist;
                                goto out;
                        }
                }
                putbuf(p1);
        }
        switch(in->mode & 7) {
        case MEXEC:
        case MREAD:             /* seems only useful to make directories */
                fmod = FREAD;
                break;

        case MWRITE:
                fmod = FWRITE;
                break;

        case MBOTH:
                fmod = FREAD+FWRITE;
                break;

        default:
                ou->err = Emode;
                goto out;
        }
        if(in->perm & PDIR)
                if((in->mode & MTRUNC) || (in->perm & PAPND) || (fmod & FWRITE))
                        goto badaccess;
        /*
         * do it
         */
        path = qidpathgen(&f->fs->dev);
        p1 = getbuf(f->fs->dev, addr1, Bread|Bimm|Bmod);
        d1 = getdir(p1, slot1);
        if(!d1 || checktag(p1, Tdir, d->qid.path)) {
                if(p1)
                        putbuf(p1);
                goto phase;
        }
        if(d1->mode & DALLOC) {
                putbuf(p1);
                goto phase;
        }

        strncpy(d1->name, in->name, sizeof(in->name));
        /*
         * bogus argument passing -- see console.c
         */
        if(cp == cons.chan) {
                d1->uid = cons.uid;
                d1->gid = cons.gid;
        } else {
                d1->uid = f->uid;
                d1->gid = d->gid;
                in->perm &= d->mode | ~0666;
                if(in->perm & PDIR)
                        in->perm &= d->mode | ~0777;
        }
        d1->qid.path = path;
        d1->qid.version = 0;
        d1->mode = DALLOC | (in->perm & 0777);
        if(in->perm & PDIR) {
                d1->mode |= DDIR;
                d1->qid.path |= QPDIR;
        }
        if(in->perm & PAPND)
                d1->mode |= DAPND;
        t = 0;
        if(in->perm & PLOCK) {
                d1->mode |= DLOCK;
                t = tlocked(p1, d1);
        }
        accessdir(p1, d1, FWRITE);
        mkqid(&qid, d1, 0);
        putbuf(p1);
        accessdir(p, d, FWRITE);

        /*
         * do a walk to new directory entry
         */
        w = newwp();
        if(!w) {
                ou->err = Ewalk;
                goto out;
        }
        w->addr = f->addr;
        w->slot = f->slot;
        w->up = f->wpath;
        f->wpath = w;
        f->qid = qid;
        f->tlock = t;
        f->lastra = 0;
        if(in->mode & MRCLOSE)
                fmod |= FREMOV;
        f->open = fmod;
        f->addr = addr1;
        f->slot = slot1;
        if(t)
                t->file = f;
        mkqid9p1(&ou->qid, &qid);
        goto out;

badaccess:
        ou->err = Eaccess;
        goto out;

phase:
        ou->err = Ephase;

out:
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
}

void
f_read(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p, *p1;
        File *f;
        Dentry *d, *d1;
        Tlock *t;
        long addr, offset, tim;
        int nread, count, n, o, slot;

        if(CHAT(cp)) {
                print("c_read %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" offset = %ld\n", in->offset);
                print(" count = %ld\n", in->count);
        }

        p = 0;
        count = in->count;
        offset = in->offset;
        nread = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        if(!(f->open & FREAD)) {
                ou->err = Eopen;
                goto out;
        }
        if(count < 0 || count > MAXDAT) {
                ou->err = Ecount;
                goto out;
        }
        if(offset < 0) {
                ou->err = Eoffset;
                goto out;
        }
        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        if(t = f->tlock) {
                tim = time(0);
                if(t->time < tim || t->file != f) {
                        ou->err = Ebroken;
                        goto out;
                }
                /* renew the lock */
                t->time = tim + TLOCK;
        }
        accessdir(p, d, FREAD);
        if(d->mode & DDIR) {
                addr = 0;
                goto dread;
        }
        if(offset+count > d->size)
                count = d->size - offset;
        while(count > 0) {
                addr = offset / BUFSIZE;
                if(addr == f->lastra+1)
                        dbufread(p, d, addr+1);
                f->lastra = addr;
                o = offset % BUFSIZE;
                n = BUFSIZE - o;
                if(n > count)
                        n = count;
                p1 = dnodebuf(p, d, addr, 0);
                if(p1) {
                        if(checktag(p1, Tfile, QPNONE)) {
                                ou->err = Ephase;
                                putbuf(p1);
                                goto out;
                        }
                        memmove(ou->data+nread, p1->iobuf+o, n);
                        putbuf(p1);
                } else
                        memset(ou->data+nread, 0, n);
                count -= n;
                nread += n;
                offset += n;
        }
        goto out;

dread:
        p1 = dnodebuf(p, d, addr, 0);
        if(!p1)
                goto out;
        if(checktag(p1, Tdir, QPNONE)) {
                ou->err = Ephase;
                putbuf(p1);
                goto out;
        }
        n = DIRREC;
        for(slot=0; slot<DIRPERBUF; slot++) {
                d1 = getdir(p1, slot);
                if(!(d1->mode & DALLOC))
                        continue;
                if(offset >= n) {
                        offset -= n;
                        continue;
                }
                if(count < n) {
                        putbuf(p1);
                        goto out;
                }
                if(convD2M9p1(d1, ou->data+nread) != n)
                        print("dirread convD2M\n");
                nread += n;
                count -= n;
        }
        putbuf(p1);
        addr++;
        goto dread;

out:
        count = in->count - nread;
        if(count > 0)
                memset(ou->data+nread, 0, count);
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
        ou->count = nread;
        if(CHAT(cp))
                print(" nread = %d\n", nread);
}

void
f_write(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p, *p1;
        Dentry *d;
        File *f;
        Tlock *t;
        long offset, addr, tim;
        int count, nwrite, o, n;

        if(CHAT(cp)) {
                print("c_write %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
                print(" offset = %ld\n", in->offset);
                print(" count = %ld\n", in->count);
        }

        offset = in->offset;
        count = in->count;
        nwrite = 0;
        p = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        if(!(f->open & FWRITE)) {
                ou->err = Eopen;
                goto out;
        }
        if(isro(f->fs->dev) || (cp != cons.chan && writegroup && !ingroup(f->uid, writegroup))) {
                ou->err = Eronly;
                goto out;
        }
        if(count < 0 || count > MAXDAT) {
                ou->err = Ecount;
                goto out;
        }
        if(offset < 0) {
                ou->err = Eoffset;
                goto out;
        }
        p = getbuf(f->fs->dev, f->addr, Bread|Bmod);
        d = getdir(p, f->slot);
        if(!d || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        if(t = f->tlock) {
                tim = time(0);
                if(t->time < tim || t->file != f) {
                        ou->err = Ebroken;
                        goto out;
                }
                /* renew the lock */
                t->time = tim + TLOCK;
        }
        accessdir(p, d, FWRITE);
        if(d->mode & DAPND)
                offset = d->size;
        if(offset+count > d->size)
                d->size = offset+count;
        while(count > 0) {
                addr = offset / BUFSIZE;
                o = offset % BUFSIZE;
                n = BUFSIZE - o;
                if(n > count)
                        n = count;
                p1 = dnodebuf(p, d, addr, Tfile);
                if(p1 == 0) {
                        ou->err = Efull;
                        goto out;
                }
                if(checktag(p1, Tfile, d->qid.path)) {
                        putbuf(p1);
                        ou->err = Ephase;
                        goto out;
                }
                memmove(p1->iobuf+o, in->data+nwrite, n);
                p1->flags |= Bmod;
                putbuf(p1);
                count -= n;
                nwrite += n;
                offset += n;
        }
        if(CHAT(cp))
                print(" nwrite = %d\n", nwrite);

out:
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
        ou->count = nwrite;
}

int
doremove(File *f, int iscon)
{
        Iobuf *p, *p1;
        Dentry *d, *d1;
        long addr;
        int slot, err;

        p = 0;
        p1 = 0;
        if(isro(f->fs->dev) || (f->cp != cons.chan && writegroup && !ingroup(f->uid, writegroup))) {
                err = Eronly;
                goto out;
        }
        /*
         * check on parent directory of file to be deleted
         */
        if(f->wpath == 0 || f->wpath->addr == f->addr) {
                err = Ephase;
                goto out;
        }
        p1 = getbuf(f->fs->dev, f->wpath->addr, Bread);
        d1 = getdir(p1, f->wpath->slot);
        if(!d1 || checktag(p1, Tdir, QPNONE) || !(d1->mode & DALLOC)) {
                err = Ephase;
                goto out;
        }
        if(!iscon && iaccess(f, d1, DWRITE)) {
                err = Eaccess;
                goto out;
        }
        accessdir(p1, d1, FWRITE);
        putbuf(p1);
        p1 = 0;

        /*
         * check on file to be deleted
         */
        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                err = Ealloc;
                goto out;
        }
        if(err = mkqidcmp(&f->qid, d))
                goto out;

        /*
         * if deleting a directory, make sure it is empty
         */
        if((d->mode & DDIR))
        for(addr=0;; addr++) {
                p1 = dnodebuf(p, d, addr, 0);
                if(!p1)
                        break;
                if(checktag(p1, Tdir, d->qid.path)) {
                        err = Ephase;
                        goto out;
                }
                for(slot=0; slot<DIRPERBUF; slot++) {
                        d1 = getdir(p1, slot);
                        if(!(d1->mode & DALLOC))
                                continue;
                        err = Eempty;
                        goto out;
                }
                putbuf(p1);
        }

        /*
         * do it
         */
        dtrunc(p, d);
        memset(d, 0, sizeof(Dentry));
        settag(p, Tdir, QPNONE);

out:
        if(p1)
                putbuf(p1);
        if(p)
                putbuf(p);
        return err;
}

void
f_remove(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        File *f;

        if(CHAT(cp)) {
                print("c_remove %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
        }

        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        ou->err = doremove(f, cp==cons.chan);

out:
        ou->fid = in->fid;
        if(f)
                qunlock(f);
}

void
f_stat(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p;
        Dentry *d;
        File *f;

        if(CHAT(cp)) {
                print("c_stat %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
        }

        p = 0;
        memset(ou->stat, 0, sizeof(ou->stat));
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;
        if(d->qid.path == QPROOT)       /* stat of root gives time */
                d->atime = time(0);
        if(convD2M9p1(d, ou->stat) != DIRREC)
                print("stat convD2M\n");

out:
        if(p)
                putbuf(p);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
}

void
f_wstat(Chan *cp, Oldfcall *in, Oldfcall *ou)
{
        Iobuf *p, *p1;
        Dentry *d, *d1, xd;
        File *f;
        int slot;
        long addr;

        if(CHAT(cp)) {
                print("c_wstat %d\n", cp->chan);
                print(" fid = %d\n", in->fid);
        }

        p = 0;
        p1 = 0;
        d1 = 0;
        f = filep(cp, in->fid, 0);
        if(!f) {
                ou->err = Efid;
                goto out;
        }
        if(isro(f->fs->dev) || (cp != cons.chan && writegroup && !ingroup(f->uid, writegroup))) {
                ou->err = Eronly;
                goto out;
        }

        /*
         * first get parent
         */
        if(f->wpath) {
                p1 = getbuf(f->fs->dev, f->wpath->addr, Bread);
                d1 = getdir(p1, f->wpath->slot);
                if(!d1 || checktag(p1, Tdir, QPNONE) || !(d1->mode & DALLOC)) {
                        ou->err = Ephase;
                        goto out;
                }
        }

        p = getbuf(f->fs->dev, f->addr, Bread);
        d = getdir(p, f->slot);
        if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                ou->err = Ealloc;
                goto out;
        }
        if(ou->err = mkqidcmp(&f->qid, d))
                goto out;

        convM2D9p1(in->stat, &xd);
        if(CHAT(cp)) {
                print(" d.name = %s\n", xd.name);
                print(" d.uid  = %d\n", xd.uid);
                print(" d.gid  = %d\n", xd.gid);
                print(" d.mode = %.4x\n", xd.mode);
        }

        /*
         * if chown,
         * must be god
         */
        while(xd.uid != d->uid) {
                if(wstatallow)                  /* set to allow chown during boot */
                        break;
                ou->err = Enotu;
                goto out;
        }

        /*
         * if chgroup,
         * must be either
         *      a) owner and in new group
         *      b) leader of both groups
         */
        while(xd.gid != d->gid) {
                if(wstatallow || writeallow)            /* set to allow chgrp during boot */
                        break;
                if(d->uid == f->uid && ingroup(f->uid, xd.gid))
                        break;
                if(leadgroup(f->uid, xd.gid))
                        if(leadgroup(f->uid, d->gid))
                                break;
                ou->err = Enotg;
                goto out;
        }

        /*
         * if rename,
         * must have write permission in parent
         */
        if(xd.name[0] == 0)
                strncpy(xd.name, d->name, sizeof(xd.name));
        while(strncmp(d->name, xd.name, sizeof(d->name)) != 0) {
                if(checkname(xd.name)) {
                        ou->err = Ename;
                        goto out;
                }

                if(strcmp(xd.name, ".") == 0 || strcmp(xd.name, "..") == 0) {
                        ou->err = Ename;
                        goto out;
                }

                /*
                 * drop entry to prevent lock, then
                 * check that destination name is unique,
                 */
                putbuf(p);
                for(addr=0;; addr++) {
                        p = dnodebuf(p1, d1, addr, 0);
                        if(!p)
                                break;
                        if(checktag(p, Tdir, d1->qid.path)) {
                                putbuf(p);
                                continue;
                        }
                        for(slot=0; slot<DIRPERBUF; slot++) {
                                d = getdir(p, slot);
                                if(!(d->mode & DALLOC))
                                        continue;
                                if(!strncmp(xd.name, d->name, sizeof(xd.name))) {
                                        ou->err = Eexist;
                                        goto out;
                                }
                        }
                        putbuf(p);
                }

                /*
                 * reacquire entry
                 */
                p = getbuf(f->fs->dev, f->addr, Bread);
                d = getdir(p, f->slot);
                if(!d || checktag(p, Tdir, QPNONE) || !(d->mode & DALLOC)) {
                        ou->err = Ephase;
                        goto out;
                }

                if(wstatallow || writeallow) /* set to allow rename during boot */
                        break;
                if(!d1 || iaccess(f, d1, DWRITE)) {
                        ou->err = Eaccess;
                        goto out;
                }
                break;
        }

        /*
         * if mode/time, either
         *      a) owner
         *      b) leader of either group
         */
        while(d->mtime != xd.mtime ||
             ((d->mode^xd.mode) & (DAPND|DLOCK|0777))) {
                if(wstatallow)                  /* set to allow chmod during boot */
                        break;
                if(d->uid == f->uid)
                        break;
                if(leadgroup(f->uid, xd.gid))
                        break;
                if(leadgroup(f->uid, d->gid))
                        break;
                ou->err = Enotu;
                goto out;
        }
        d->mtime = xd.mtime;
        d->uid = xd.uid;
        d->gid = xd.gid;
        d->mode = (xd.mode & (DAPND|DLOCK|0777)) | (d->mode & (DALLOC|DDIR));

        strncpy(d->name, xd.name, sizeof(d->name));
        if(wstatallow) {
                p->flags |= Bmod;
                if(xd.atime)
                        d->atime = xd.atime;
                if(xd.mtime)
                        d->mtime = xd.mtime;
        } else
                accessdir(p, d, FWSTAT);

out:
        if(p)
                putbuf(p);
        if(p1)
                putbuf(p1);
        if(f)
                qunlock(f);
        ou->fid = in->fid;
}

void
(*call9p1[MAXSYSCALL])(Chan*, Oldfcall*, Oldfcall*) =
{
        [Tnop9p1]               f_nop,
        [Tosession9p1]  f_session,
        [Tsession9p1]   f_session,
        [Tflush9p1]     f_flush,
        [Toattach9p1]   f_attach,
        [Tattach9p1]    f_attach,
        [Tclone9p1]     f_clone,
        [Twalk9p1]              f_walk,
        [Topen9p1]              f_open,
        [Tcreate9p1]    f_create,
        [Tread9p1]              f_read,
        [Twrite9p1]     f_write,
        [Tclunk9p1]     f_clunk,
        [Tremove9p1]    f_remove,
        [Tstat9p1]              f_stat,
        [Twstat9p1]     f_wstat,
        [Tclwalk9p1]    f_clwalk,
};

static void
send(Chan *c, uchar *buf, int n)
{
        int fd, m;

        fd = c->chan;
        m = write(fd, buf, n);
        if(m == n)
                return;
        panic("write failed");
}

void
error9p1(Chan *c, uchar *buf)
{
        buf[0] = Rnop9p1;
        buf[1] = ~0;
        buf[2] = ~0;

        send(c, buf, 3);
}

void
serve9p1(Chan *chan, uchar *ib, int nib)
{
        int n, t;
        uchar inbuf[MAXMSG+MAXDAT], outbuf[MAXMSG+MAXDAT];
        Oldfcall fi, fo;

        for(;;){
                if(nib){
                        memmove(inbuf, ib, nib);
                        n = nib;
                        nib = 0;
                }else
                        n = read(chan->chan, inbuf, sizeof inbuf);
                if(chat)
                        print("read msg %d\n", n);
                if(n == 0 && (chan == cons.srvchan || chan == cons.chan))
                        continue;
                if(n <= 0)
                        return;
                if(convM2S9p1(inbuf, &fi, n) != n){
                        error9p1(chan, outbuf);
                        continue;
                }

                t = fi.type;
                if(t < 0 || t >= MAXSYSCALL || (t&1) || !call9p1[t]) {
                        print("9p1: bad message type\n");
                        error9p1(chan, outbuf);
                        continue;
                }

                if(CHAT(chan))
                        print("9p1: fi %O\n", &fi);

                /*
                 * set up reply message
                 */
                fo.err = 0;
                if(t == Tread9p1)
                        fo.data = (char*)outbuf + 8;
        
                /*
                 * call the file system
                 */
                cons.work.count++;
                cons.rate.count += n;

                /*
                 * call the file system
                 */
                rlock(&mainlock);
                rlock(&chan->reflock);
        
                (*call9p1[t])(chan, &fi, &fo);
        
                runlock(&chan->reflock);
                runlock(&mainlock);
        
                fo.type = t+1;
                fo.tag = fi.tag;
        
                if(chat)
                        print("9p1: fo %O\n", &fo);

                if(fo.err) {
                        strcpy(fo.ename, errstring[fo.err]);
                        if(CHAT(cp))
                                print(" error: %s\n", fo.ename);
                        fo.type = Terror9p1+1;
                }
        
                n = convS2M9p1(&fo, outbuf);
                if(n == 0) {
                        print("9p1: bad S2M conversion\n");
                        error9p1(chan, outbuf);
                        continue;
                }

                cons.rate.count += n;
                send(chan, outbuf, n);
        }
}