Bug#440676: nfs-kernel-server: Simultaneous transfer on mirrored nfs mounts causes service freezes

["Jeffrey B. Green" <jeff@kikisoso.org>]

Moritz,

Moritz Mühlenhoff wrote:
> severity 440676 important
> thanks
>
> Jeffrey B. Green:
>   
> > > A very similar behaviour can be reproduced with i386 as well (with the
> > > Etch versions of  the Linux kernel and nfs-kernel-server):
> > > We have a setup where a block device is replicated with drbd. On this
> > > device an ext3 partition has been created, which is exported over NFS.
> > > Reading from the NFS share works fairly well, however concurrent writes
> > > to the share lead to lockups. The client processes copying data to the
> > > share are stalling and sometimes the system is locked up requiring a hard
> > > reboot.
> > >
> > > This is reproducable with both NFS over UDP and NFS over TCP.
> > >       
>
>   
> > Actually, the incident is primarily on i386 machines. Sorry about the
> > report being a bit deceptive by submitting from my standard work machine
> > which is a powerpc. The powerpc kernel may not exhibit this behavior.
> >     
>
> Could you please test the attached patch from RHEL5 and report if it resolves
> the problem for you?
>
> Instructions on how to compile a modified kernel can be found at
> http://wiki.debian.org/DebianKernelCustomCompilation
>
> Cheers,
> Moritz
>   

(Resending to document in the bug trail.)

The patch interacts with previous a previous patch. When I explicitly 
patch the kernel source first, and then try to build, I get:

tail make.out
(+) OK        bugfix/2.6.16.30
(+) OK        bugfix/2.6.16.31
(+) OK        bugfix/2.6.16.32
(+) OK        bugfix/2.6.16.33
(+) OK        bugfix/2.6.16.34
(+) OK        bugfix/2.6.16.35
(+) FAIL      bugfix/2.6.16.37
make[1]: *** [debian/stamps/source] Error 1
make[1]: Leaving directory `/home/jeff/linux-2.6-2.6.18.dfsg.1'
make: *** [binary-arch-i386-none-686-real] Error 2

-jeff