static void
rread(Fcall* f)
{
ulong n, rn, nn, delta;
Dir d;
Fid* fp;
if (!isfdir(f, &fp))
return;
if (f->count == 0)
goto done;
cleannames();
for (n = nn = 0; n < f->count; n += rn){
rn = convM2D((uchar*)f->data + n, f->count - n, &d, statbuf);
if (rn <= BIT16SZ)
break;
d.name = importname(d.name);
//dprint("⇒ %D\n", &d);
nn += convD2M(&d, (uchar*)dirbuf + nn, sizeof(dirbuf) - nn);
}
delta = nn - n;
setaux(fp, getaux(fp) + delta);
f->count = nn;
f->data = dirbuf;
done:
closefid(fp);
}
void
closereq(Req *r)
{
int i;
if(r == nil)
return;
if(chatty9p > 1)
fprint(2, "closereq %p %d\n", r, r->ref.ref);
if(decref(&r->ref) == 0){
if(r->fid)
closefid(r->fid);
if(r->newfid)
closefid(r->newfid);
if(r->afid)
closefid(r->afid);
if(r->oldreq)
closereq(r->oldreq);
for(i=0; i<r->nflush; i++)
respond(r->flush[i], nil);
free(r->flush);
switch(r->ifcall.type){
case Tstat:
free(r->ofcall.stat);
free(r->d.name);
free(r->d.uid);
free(r->d.gid);
free(r->d.muid);
break;
}
if(r->pool->destroy)
r->pool->destroy(r);
free(r->buf);
free(r->rbuf);
free(r);
}
}
void
closereq(Req *r)
{
if(r == nil)
return;
if(chatty9p > 1)
fprint(2, "closereq %p %ld\n", r, r->ref.ref);
if(decref(&r->ref) == 0) {
if(r->fid)
closefid(r->fid);
if(r->newfid)
closefid(r->newfid);
if(r->afid)
closefid(r->afid);
if(r->oldreq)
closereq(r->oldreq);
if(r->nflush)
fprint(2, "closereq: flushes remaining\n");
free(r->flush);
switch(r->ifcall.type) {
case Tstat:
free(r->ofcall.stat);
free(r->d.name);
free(r->d.uid);
free(r->d.gid);
free(r->d.muid);
break;
}
if(r->pool->destroy)
r->pool->destroy(r);
free(r->buf);
free(r->rbuf);
free(r);
}
}
static int
isfdir(Fcall* f, Fid **fpp)
{
Fid* fp;
int r;
fp = lookupfid(fidpool, f->fid);
if (fp == nil)
return 0;
r = (fp->qid.type&QTDIR);
if (r)
*fpp = fp;
else
closefid(fp);
return r;
}
// Dir read is tricky.
// We have to change the user supplied offset to match the sizes
// seen by the server. Sizes seen by client are greater than those
// seen by server since the change from ' ' to '␣' adds 2 bytes.
static void
tread(Fcall* f)
{
Fid* fp;
fp = nil;
if (!isfdir(f, &fp))
return;
f->count /= 3; // sizes will grow upon return.
if (fp == nil)
sysfatal("can't find fid\n");
if (f->offset == 0)
setaux(fp, 0);
f->offset -= getaux(fp); // cumulative size delta
closefid(fp);
}
static void
rwalk(Req *r, char *error)
{
if(error || r->ofcall.nwqid < r->ifcall.nwname){
if(r->ifcall.fid != r->ifcall.newfid && r->newfid)
closefid(removefid(r->srv->fpool, r->newfid->fid));
if (r->ofcall.nwqid==0){
if(error==nil && r->ifcall.nwname!=0)
r->error = Enotfound;
}else
r->error = nil; /* No error on partial walks */
}else{
if(r->ofcall.nwqid == 0){
/* Just a clone */
r->newfid->qid = r->fid->qid;
}else{
/* if file trees are in use, filewalk took care of the rest */
r->newfid->qid = r->ofcall.wqid[r->ofcall.nwqid-1];
}
}
}
static void
service(int cfd, int sfd, int dfd)
{
Fcall f;
int r;
Fid* fp;
fidpool = allocfidpool(nop);
for(;;){
fp = nil;
r = getfcall(cfd, &f);
if (r <= 0){
fprint(dfd, "trfs: getfcall %r\n");
break;
}
if(verbose)
fprint(dfd , "c→s %F\n", &f);
switch(f.type){
case Tclunk:
case Tremove:
// BUG in lib9p? removefid leaks fid.
// is that what it should do?
fp = lookupfid(fidpool, f.fid);
if (fp != nil){
removefid(fidpool, f.fid);
closefid(fp);
closefid(fp);
fp = nil;
}
break;
case Tcreate:
tcreate(&f);
// and also...
case Topen:
fp = allocfid(fidpool, f.fid);
fp->aux = 0;
break;
case Tread:
tread(&f);
break;
case Twalk:
twalk(&f);
break;
case Twstat:
twstat(&f);
break;
}
if(verbose && debug)
fprint(dfd , "c→s %F\n", &f);
if (putfcall(sfd, &f) < 0)
fprint(dfd , "can't putfcall: %r\n");
r = getfcall(sfd, &f);
if (r <= 0){
fprint(dfd, "trfs: 2nd getfcall %r\n");
break;
}
if (verbose)
fprint(dfd, "c←s %F\n", &f);
switch(f.type){
case Ropen:
case Rcreate:
fp->qid = f.qid;
break;
case Rread:
rread(&f);
break;
case Rstat:
rstat(&f);
break;
}
if(verbose && debug)
fprint(dfd , "c←s %F\n", &f);
if (putfcall(cfd, &f) < 0)
fprint(dfd , "can't 2n dputfcall: %r\n");
if (fp != nil)
closefid(fp);
}
}
void
respond(Req *r, char *error)
{
int i, m, n;
char errbuf[ERRMAX];
Srv *srv;
srv = r->srv;
assert(srv != nil);
if(r->responded){
assert(r->pool);
goto free;
}
assert(r->responded == 0);
r->error = error;
switch(r->ifcall.type){
default:
assert(0);
/*
* Flush is special. If the handler says so, we return
* without further processing. Respond will be called
* again once it is safe.
*/
case Tflush:
if(rflush(r, error)<0)
return;
break;
case Tversion: rversion(r, error); break;
case Tauth: rauth(r, error); break;
case Tattach: rattach(r, error); break;
case Twalk: rwalk(r, error); break;
case Topen: ropen(r, error); break;
case Tcreate: rcreate(r, error); break;
case Tread: rread(r, error); break;
case Twrite: rwrite(r, error); break;
case Tclunk: rclunk(r, error); break;
case Tremove: rremove(r, error, errbuf); break;
case Tstat: rstat(r, error); break;
case Twstat: rwstat(r, error); break;
}
r->ofcall.tag = r->ifcall.tag;
r->ofcall.type = r->ifcall.type+1;
if(r->error)
setfcallerror(&r->ofcall, r->error);
if(chatty9p)
fprint(2, "-%d-> %F\n", srv->outfd, &r->ofcall);
qlock(&srv->wlock);
n = convS2M(&r->ofcall, srv->wbuf, srv->msize);
if(n <= 0){
fprint(2, "n = %d %F\n", n, &r->ofcall);
abort();
}
assert(n > 2);
/*
* There is a race here - we must remove the entry before
* the write, so that if the client is very fast and reuses the
* tag, the read loop won't think it is still in use.
*
* By removing the entry before the write, we open up a
* race with incoming Tflush messages. Specifically, an
* incoming Tflush might not see r even though it has not
* yet been responded to. It would then send an Rflush
* immediately, potentially before we do the write. This can't
* happen because we already old srv->wlock, so nothing
* is going out on the wire before this write.
*/
if(r->pool) /* not a fake */
closereq(removereq(r->pool, r->ifcall.tag));
qlock(&r->lk);
r->responded = 1;
if(r->pool)
if(r->ref.ref == 1+r->nflush)
if(r->fid){
/*
* There are no references other than in our r->flush array,
* so no one else should be accessing r concurrently.
* Close the fid now, before responding to the message.
*
* If the client is behaving (there are no outstanding T-messages
* that reference r->fid) and the message is a Tclunk or Tremove,
* then this closefid will call destroyfid.
*
* This means destroyfid can't piddle around
* indefinitely (we're holding srv->wlock!), but it provides
* for tighter semantics as to when destroyfid is called.
*
* LANL has observed cases where waiting until after the write
* can delay a closefid on a Twrite for many 9P transactions,
* so that a handful of transactions can happen including a Tclunk
* and a Topen, and the original fid will still not be destroyed.
*/
closefid(r->fid);
r->fid = nil;
}
qunlock(&r->lk);
m = write(srv->outfd, srv->wbuf, n);
if(m != n)
sysfatal("lib9p srv: write %d returned %d on fd %d: %r", n, m, srv->outfd);
qunlock(&srv->wlock);
free:
qlock(&r->lk); /* no one will add flushes now */
for(i=0; i<r->nflush; i++){
r->flush[i]->oldreq = nil; /* so it doesn't try to lock us! */
respond(r->flush[i], nil);
}
free(r->flush);
r->flush = nil;
r->nflush = 0;
qunlock(&r->lk);
if(r->pool)
closereq(r);
else
free(r);
}
static void
rattach(Req *r, char *error)
{
if(error && r->fid)
closefid(removefid(r->srv->fpool, r->fid->fid));
}
