Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760163Ab0FQO3H (ORCPT ); Thu, 17 Jun 2010 10:29:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58107 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755136Ab0FQO3E (ORCPT ); Thu, 17 Jun 2010 10:29:04 -0400 Date: Thu, 17 Jun 2010 10:30:43 -0400 From: Jeff Layton To: Chris Vine Cc: "J. Bruce Fields" , Linux Kernel Mailing List Subject: Re: nfsd hang and kernel bug in 2.6.35-rc3 Message-ID: <20100617103043.16298e9e@corrin.poochiereds.net> In-Reply-To: <20100617113815.7e15d070@boulder.homenet> References: <20100615175034.1e015fbc@boulder.homenet> <20100616153603.GH10223@fieldses.org> <20100616123532.569efeb9@tlielax.poochiereds.net> <20100616220824.4e886552@boulder.homenet> <20100616204415.49285875@corrin.poochiereds.net> <20100617113815.7e15d070@boulder.homenet> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3137 Lines: 71 On Thu, 17 Jun 2010 11:38:15 +0100 Chris Vine wrote: > On Wed, 16 Jun 2010 20:44:15 -0400 > Jeff Layton wrote: > [snip] > > I stand corrected then. That's pretty close to the nfsd that I've been > > testing. I pulled down the nfsd init script and the only thing that > > looks substantially different is that it sends signals to nfsd to shut > > it down rather than just running "rpc.nfsd 0". That should work fine, > > however. > > > > Still I think the problem is basically something like what I've > > described. You ended up somehow with sockets on the sv_permsocks list > > that didn't hold lockd references. The way I described is one way that > > could occur. Another seems to be __write_ports_addxprt (which I think > > is clearly broken in light of this)... > > > > The root cause of this however is likely to be related to this > > problem: > > > > > Jun 15 16:07:18 laptop kernel: svc: failed to register lockdv3 RPC > > > service (errno 110). Jun 15 16:07:18 laptop kernel: lockd_up: > > > makesock failed, error=-110 > > > > ...which means that the kernel couldn't talk to portmap or rpcbind. > > Maybe it wasn't up at the time? Or a problem with firewalling? > > My initial reaction was "of course it is up" but your mention of > portmap sent me investigating with interesting results. I was going > to say "of course its is up" because the standard start-up script for > nfsd (rc.nfsd) checks whether rpc.portmap and rpc.statd are running, if > not starts them, and then starts exportfs, rpc.rquotad, rpc.nfsd and > rpc.mountd. > > However, if I start portmap and statd early on so they do not rely on > the nfsd start-up script, then nfsd starts fine, so it seems to be a > timing thing notwithstanding that they are all started (at user level) > sequentially and in the same thread/process. > > The timing problem does not arise on kernel-2.6.34 and earlier. Nor > does it arise on my pentium uniprocessor machine with kernel 2.6.35-rc3, > so it could well be core/thread related. It looks as if something in > the kernel has changed on that in 2.6.35 which provokes the kernel bug > report if timing is wrong. (If timing is wrong and if this is a user > tools rather than a kernel deficiency, and I express no view on that, > then I suppose it probably needs to be handled more gracefully in the > kernel.) > > Chris > > The timing may help tickle the other bugs in nfsd startup/shutdown. I've just sent another couple of patches to Bruce (and cc'ed you) that I suspect may help this. With those, it should always be the case that a nfsd sv_permsocks entry holds a lockd reference. It would be good if you could test the stack of patches in the nfsd-error branch of my kernel.org git tree: http://git.kernel.org/?p=linux/kernel/git/jlayton/linux.git;a=summary Thanks, -- Jeff Layton -- 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/