Date: Fri, 1 Oct 2010 19:11:44 -0400
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Nix <nix@esperi.org.uk>
Cc: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: persistent, quasi-random -ESTALE at mount time
Message-ID: <20101001231144.GB12203@fieldses.org>
References: <87mxra6duq.fsf@spindle.srvr.nix>
 <20100922155235.GE15560@fieldses.org>
 <8762xwqijb.fsf@spindle.srvr.nix>
 <20101001220018.GE1472@fieldses.org>
 <87zkux5ye1.fsf@spindle.srvr.nix>
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In-Reply-To: <87zkux5ye1.fsf@spindle.srvr.nix>
Sender: linux-nfs-owner@vger.kernel.org
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On Fri, Oct 01, 2010 at 11:41:42PM +0100, Nix wrote:
> On 1 Oct 2010, J. Bruce Fields spake thusly:
> 
> > On Thu, Sep 23, 2010 at 10:03:36PM +0100, Nix wrote:
> >> I'll say.
> >
> > Sorry for the slow response; have you figured out anything more?
> 
> Not yet. I try not to reboot the server except at weekends... I'll
> try to hook things up with a more rebootable machine as an NFS
> server (perhaps via qemu) so I can look into this without so much
> disruption.
> 
> >> I flipped RPC debug on and rebooted the client next. The server said:
> >> 
> >> Sep 23 21:33:15 spindle warning: [  127.385537] RPC:       Want update, refage=120, age=0
> >> Sep 23 21:33:15 spindle warning: [  127.536779] RPC:       Want update, refage=120, age=0
> >> [repeated 40 times]
> >> 
> >> When it connected, the server said
> >> 
> >> Sep 23 21:34:23 spindle warning: [  195.696257] RPC:       Want update, refage=120, age=68
> > ...
> >> Sep 23 21:34:38 spindle warning: [  210.766205] RPC:       Want update, refage=120, age=83
> >> 
> >> Now, the rpc/*/content files had grown again, and even the -ESTALEd
> >> filesystems, like /home/.spindle.srvr.nix, are represented once more:
> >
> > I'm a little confused.  Are you saying that in this case the client did
> > get ESTALE's?
> 
> Yes. Bizarre, isn't it? -ESTALE, but here the filesystems are! Note that
> if you try to reboot again, you still get -ESTALE: only restarting
> rpc.mountd seems to fix it.
> 
> >> I restarted rpc.mountd and the client, so it mounted correctly. Here's a
> >
> > And then here the problems was cleared and you didn't see any more of
> > them?
> 
> Yes, until the server got rebooted again.
> 
> I mean, yes, we can work around it by killing rpc.mountd and restarting
> it as soon as the server has booted, but, well, yuck, no thanks, too
> much of a kludge. I'll have a concentrated hunt for the bug soon (once I
> can reproduce it without rebooting the single largest machine I have
> root on!)

OK, thanks for the persistence, and apologies that I can't think of
anything off the top of my head (and haven't had the time to try and
look more closely).  I'll look forward to anything more you can figure
out....

--b.