Hi Greg:

Thanks for replying. Here goes my response:

> -----Original Message-----
> From: Greg Banks [mailto:[EMAIL PROTECTED]
> Sent: Wednesday, January 30, 2008 6:37 PM
> To: Anirban Sinha
> Cc: [email protected]
> Subject: Re: kernel exports table flushes out on running exportfs -a
> over mips
> 
> On Wed, Jan 30, 2008 at 05:34:13PM -0800, Anirban Sinha wrote:
> > Hi:
> >
> > I am seeing an unusual problem on running nfs server on mips. Over
> Intel
> > this does not happen. When I run exportfs -a on the server when the
> > clients have already mounted their nfs filesystem, the kernel
exports
> > table as can be seen from /proc/fs/nfs/exports gets completely
> flushed
> > out. We (me and one another colleague) have done some digging
(mostly
> > looking into nfsutils codebase) and it looks like a kernel side
> issue.
> > We had also asked folks in the linux-mips mailing list, but
> apparently
> > no one has any clue. I am just hoping that those who are more
> familiar
> > with the user level and kernel side of nfs might me something more
to
> > chew on. If you can give any suggestions that will be really useful.
> If
> > you think the information I provided is not enough, I can give you
> any
> > other information you need in this regard.
> 
> Does the MIPS box have the /proc/fs/nfsd/ filesystem mounted?

Ahh, I see what you mean. Yes, it is mounted, both /proc/fs/nfsd and
/proc/fs/nfs. However, I can see from the code that check_new_cache()
checks for a file "filehandle" which does not exist in that location. To
be dead sure, I instrumented the code to insert a perror and it returns
"no such file or directory". The new_cache flag remains 0. Is this some
sort of kernel bug? 


> Perhaps you could try
> 
> 1) running exportfs under strace.  I suggest
>    strace -o /tmp/s.log -s 1024 exportfs ...

Strace does not work in our environment as it has not been properly
ported to mips.

> 2) AND enabling kernel debug messages
>    rpcdebug -m nfsd -s export
>    rpcdebug -m rpc -s cache

I attach the dmesg output after enabling those flags. Zeugma-x-y are the
clients to this server. Not sure if it means anything suspicious. 

Ani


> 
> 
> --
> Greg Banks, R&D Software Engineer, SGI Australian Software Group.
> The cake is *not* a lie.
> I don't speak for SGI.

Attachment: nfs-dmesg.log
Description: nfs-dmesg.log

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