sparc64/142102: FreeBSD 8.0 kernel panics on sparc64 when accessing NFS

[Manuel Tobias Schiller]

The following reply was made to PR sparc64/142102; it has been noted by GNATS.

From: Manuel Tobias Schiller <mala at hinterbergen.de>
To: Marius Strobl <marius at alchemy.franken.de>
Cc: dfr at freebsd.org, FreeBSD-gnats-submit at freebsd.org
Subject: Re: sparc64/142102: FreeBSD 8.0 kernel panics on sparc64 when
 accessing NFS
Date: Wed, 30 Dec 2009 20:32:55 +0100

 On Wed, 30 Dec 2009 17:36:27 +0100
 Marius Strobl <marius at alchemy.franken.de> wrote:
 
 > On Wed, Dec 30, 2009 at 01:25:55AM +0100, Manuel Tobias Schiller wrote:
 > > On Tue, 29 Dec 2009 19:53:58 +0100
 > > Marius Strobl <marius at alchemy.franken.de> wrote:
 > > > Oh, sorry, I had a bug in there, the svc code used a stale
 > > > pointer to the mbuf with this. Could you please re-fetch
 > > > and try again? I can't guarantee that this fixes the hang
 > > > you experienced but at least in theory just re-aligning
 > > > the data can't make the issue with the unaligned access
 > > > any worse. Using the LOM or by breaking into the kernel
 > > > by sending a break you should be able to power-cycle/
 > > > reboot the machine without removing the power cord should
 > > > it hang again though.
 > > > What NFS client and with which mount options are you
 > > > using to trigger is problem?
 > > > 
 > > > Marius
 > > 
 > > I managed to compile and test a kernel with your updated patch, and
 > > things seem to work. I'll try to stress-test it over the night by
 > > copying a few tens of gigabytes over and report back with the results.
 > 
 > Doug,
 > 
 > could you please review the following patch? The problem
 > apparently is that nfsm_srvmtofh_xx() assumes the 4-byte
 > alignment required by XDR so fha_extract_info() has to
 > ensure that the mbuf data is aligned accordingly.
 > http://people.freebsd.org/~marius/fha_extract_info_realign.diff
 > 
 > Thanks,
 > Marius
 
 Marius,
 
 I did a stress-test of the patch by tarring 85 Gigabyte over NFS into a
 pipe, untarring them in a different NFS-mounted directory. I loaded the
 server machine by compiling a kernel in parallel for some time.
 Everything worked perfectly.
 
 Thanks for all your help!
 
 Manuel
 
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