ref: 1281b234e893b2306dbfef442144b75873f2365c
parent: 9c40e15ba8ae000f73c23d89143d6c44b75220fd
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Thu Feb 20 20:02:32 EST 2014
exportfs: reverting previous changes getting strange tag mismatches on some machines. needs to be debugged. until then, reverting the change.
--- a/sys/src/cmd/exportfs/exportfs.c
+++ b/sys/src/cmd/exportfs/exportfs.c
@@ -460,8 +460,8 @@
fatal(Enomem);
n = convS2M(t, data, messagesize);
if(write(netfd, data, n)!=n){- /* not fatal, might have got a note due to flush */
- fprint(2, "exportfs: short write in reply: %r\n");
+ syslog(0, "exportfs", "short write: %r");
+ fatal("mount write");}
free(data);
}
@@ -570,6 +570,8 @@
unlock(&sbufalloc);
w = emallocz(sizeof(*w) + messagesize);
}
+ w->pid = 0;
+ w->canint = 0;
w->flushtag = NOTAG;
return w;
}
@@ -577,6 +579,8 @@
void
putsbuf(Fsrpc *w)
{+ w->pid = 0;
+ w->canint = 0;
w->flushtag = NOTAG;
lock(&sbufalloc);
w->next = sbufalloc.free;
--- a/sys/src/cmd/exportfs/exportfs.h
+++ b/sys/src/cmd/exportfs/exportfs.h
@@ -15,6 +15,8 @@
struct Fsrpc
{Fsrpc *next; /* freelist */
+ uintptr pid; /* Pid of slave process executing the rpc */
+ int canint; /* Interrupt gate */
int flushtag; /* Tag on which to reply to flush */
Fcall work; /* Plan 9 incoming Fcall */
uchar buf[]; /* Data buffer */
@@ -51,10 +53,9 @@
struct Proc
{- Lock;
+ uintptr pid;
Fsrpc *busy;
Proc *next;
- int pid;
};
struct Qidtab
@@ -69,6 +70,7 @@
enum
{+ MAXPROC = 50,
FHASHSIZE = 64,
Fidchunk = 1000,
Npsmpt = 32,
@@ -126,7 +128,7 @@
void slaveopen(Fsrpc*);
void slaveread(Fsrpc*);
void slavewrite(Fsrpc*);
-void blockingslave(Proc*);
+void blockingslave(void);
void reopen(Fid *f);
void noteproc(int, char*);
void flushaction(void*, char*);
--- a/sys/src/cmd/exportfs/exportsrv.c
+++ b/sys/src/cmd/exportfs/exportsrv.c
@@ -64,20 +64,14 @@
for(m = Proclist; m; m = m->next){w = m->busy;
- if(w == nil || w->work.tag != t->work.oldtag)
- continue;
-
- lock(m);
- w = m->busy;
- if(w != nil && w->work.tag == t->work.oldtag) {+ if(w != 0 && w->pid == m->pid && w->work.tag == t->work.oldtag) {w->flushtag = t->work.tag;
DEBUG(DFD, "\tset flushtag %d\n", t->work.tag);
- postnote(PNPROC, m->pid, "flush");
- unlock(m);
+ if(w->canint)
+ postnote(PNPROC, w->pid, "flush");
putsbuf(t);
return;
}
- unlock(m);
}
reply(&t->work, &rhdr, 0);
@@ -465,10 +459,10 @@
void
slave(Fsrpc *f)
{- static int nproc;
- Proc *p, **l;
+ Proc *p;
+ uintptr pid;
Fcall rhdr;
- int pid;
+ static int nproc;
if(readonly){ switch(f->work.type){@@ -485,41 +479,30 @@
}
}
for(;;) {- for(l = &Proclist; (p = *l) != nil; l = &p->next) {- if(p->busy != nil)
- continue;
-
- p->busy = f;
- while(rendezvous(p, f) == (void*)~0)
- ;
-
- /* swept a slave proc */
- if(f == nil){- *l = p->next;
- free(p);
- nproc--;
- break;
- }
- f = nil;
-
- /*
- * as long as the number of slave procs
- * is small, dont bother sweeping.
- */
- if(nproc < 16)
- break;
+ for(p = Proclist; p; p = p->next) {+ if(p->busy == 0) {+ f->pid = p->pid;
+ p->busy = f;
+ do {+ pid = (uintptr)rendezvous((void*)p->pid, f);
+ }
+ while(pid == ~0); /* Interrupted */
+ if(pid != p->pid)
+ fatal("rendezvous sync fail");+ return;
+ }
}
- if(f == nil)
- return;
- p = emallocz(sizeof(Proc));
- pid = rfork(RFPROC|RFMEM|RFNOWAIT);
- switch(pid) {- case -1:
+ if(nproc >= MAXPROC){reply(&f->work, &rhdr, Enoprocs);
putsbuf(f);
- free(p);
return;
+ }
+ nproc++;
+ pid = rfork(RFPROC|RFMEM);
+ switch(pid) {+ case -1:
+ fatal("rfork");case 0:
if (local[0] != '\0')
@@ -528,34 +511,44 @@
local, remote);
else
procsetname("%s -> %s", local, remote);- blockingslave(p);
- _exits(0);
+ blockingslave();
+ fatal("slave");default:
+ p = emallocz(sizeof(Proc));
+ p->busy = 0;
p->pid = pid;
p->next = Proclist;
Proclist = p;
- nproc++;
+ while(rendezvous((void*)pid, p) == (void*)~0)
+ ;
}
}
}
void
-blockingslave(Proc *m)
+blockingslave(void)
{Fsrpc *p;
Fcall rhdr;
+ Proc *m;
+ uintptr pid;
notify(flushaction);
+ pid = getpid();
+
+ do {+ m = rendezvous((void*)pid, 0);
+ }
+ while(m == (void*)~0); /* Interrupted */
+
for(;;) {- p = rendezvous(m, nil);
- if(p == (void*)~0) /* Interrupted */
+ p = rendezvous((void*)pid, (void*)pid);
+ if(p == (void*)~0) /* Interrupted */
continue;
- if(p == nil) /* Swept */
- break;
- DEBUG(DFD, "\tslave: %d %F\n", m->pid, &p->work);
+ DEBUG(DFD, "\tslave: %p %F p %p\n", pid, &p->work, p->pid);
if(p->flushtag != NOTAG)
goto flushme;
@@ -575,17 +568,13 @@
default:
reply(&p->work, &rhdr, "exportfs: slave type error");
}
-flushme:
- lock(m);
- m->busy = nil;
- unlock(m);
-
- /* no more flushes can come in now */
if(p->flushtag != NOTAG) {+flushme:
p->work.type = Tflush;
p->work.tag = p->flushtag;
reply(&p->work, &rhdr, 0);
}
+ m->busy = 0;
putsbuf(p);
}
}
@@ -665,8 +654,16 @@
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);
@@ -706,6 +703,9 @@
}
n = (work->count > messagesize-IOHDRSZ) ? messagesize-IOHDRSZ : work->count;
+ p->canint = 1;
+ if(p->flushtag != NOTAG)
+ return;
data = malloc(n);
if(data == 0) {reply(work, &rhdr, Enomem);
@@ -717,6 +717,7 @@
r = preaddir(f, (uchar*)data, n, work->offset);
else
r = pread(f->fid, data, n, work->offset);
+ p->canint = 0;
if(r < 0) {free(data);
errstr(err, sizeof err);
@@ -723,6 +724,7 @@
reply(work, &rhdr, err);
return;
}
+
DEBUG(DFD, "\tread: fd=%d %d bytes\n", f->fid, r);
rhdr.data = data;
@@ -748,7 +750,11 @@
}
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);