Re: Crash when unmounting NFS/TCP with -f

[Brice Goglin <Brice.Goglin@ens-lyon.org>]

Bill Davidsen a écrit :
> Brice Goglin wrote:
>
> > Hi Trond,
> >
> > I'm using NFS (v2) over TCP (in a SSH tunnel).
> > Each time the SSH dies before a umount NFS, I have to umount -f
> > and I get a crash (only sysrq works).
> > Actually, the crash occurs a few seconds after umount -f.
> >
> > It seems that killing SSH by hand does _not_ lead to crash.
> > But a long network failure does.
> > I remember seeing this bug several times with all stable releases
> > from 2.6.7 to 2.6.11. I didn't try with earlier versions.
> >
> > I didn't see anything in the logs (after reboot). But I can't be sure
> > there was nothing in dmesg since I didn't get a chance to chvt 1 and
> > see console messages before rebooting (with sysrq).
> >
> > Do you have any idea how to debug this ?
>
>
> No clue, but a question: is this a hard or soft mount? Could you post 
> your ssh and mount commands, munged as needed for security? That might 
> give someone a clue.

The ssh command is just
$ ssh kwad -L 2249:localhost:2049 -L 2248:localhost:870 -N -f
(port is forwarded to 2249 while mountport if forwarded to 2248)

Options is /proc/mounts are
rw,v2,rsize=8192,wsize=8192,hard,tcp,nolock,addr=localhost

I just had another network failure. I ran umount -f from vt1 to see
kernel message. I waited for about 1 minute but didn't get any crash.
So I switched back to X... and got the crash then.
Looks like this crash doesn't want me to see any message...

Brice
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/