Return-Path: Received: from fieldses.org ([173.255.197.46]:56486 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbcGEUvf (ORCPT ); Tue, 5 Jul 2016 16:51:35 -0400 Date: Tue, 5 Jul 2016 16:51:30 -0400 From: Bruce Fields To: Marc Eshel Cc: linux-nfs@vger.kernel.org, Tomer Perry Subject: Re: grace period Message-ID: <20160705205130.GA12351@fieldses.org> References: <1465939516-44769-1-git-send-email-trond.myklebust@primarydata.com> <20160701160857.GB20327@fieldses.org> <20160701200742.GA24269@fieldses.org> <20160701210151.GE24269@fieldses.org> <20160702005820.GA27063@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Sat, Jul 02, 2016 at 10:30:11PM -0700, Marc Eshel wrote: > I tried again NFSv3 locks with xfs export. "echo 0 > > /proc/fs/nfsd/threads" releases locks on rhel7.0 but not on rhel7.2 > What else can I show you to find the problem? Sorry, I can't reproduce, though I've only tried a slightly later kernel than that. Could you submit a RHEL bug? --b. > Marc. > > works: > [root@boar11 ~]# uname -a > Linux boar11 3.10.0-123.el7.x86_64 #1 SMP Mon May 5 11:16:57 EDT 2014 > x86_64 x86_64 x86_64 GNU/Linux > [root@boar11 ~]# cat /etc/redhat-release > Red Hat Enterprise Linux Server release 7.0 (Maipo) > > not working: > [root@sonascl21 ~]# uname -a > Linux sonascl21.sonasad.almaden.ibm.com 3.10.0-327.el7.x86_64 #1 SMP Thu > Oct 29 17:29:29 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux > [root@sonascl21 ~]# cat /etc/redhat-release > Red Hat Enterprise Linux Server release 7.2 (Maipo) > [root@sonascl21 ~]# cat /proc/fs/nfsd/threads > 0 > [root@sonascl21 ~]# cat /proc/locks > 1: POSIX ADVISORY WRITE 2346 fd:00:1612092569 0 9999 > > > > From: Bruce Fields > To: Marc Eshel/Almaden/IBM@IBMUS > Cc: linux-nfs@vger.kernel.org, Tomer Perry > Date: 07/01/2016 05:58 PM > Subject: Re: grace period > > > > On Fri, Jul 01, 2016 at 03:42:43PM -0700, Marc Eshel wrote: > > Yes, the locks are requested from another node, what fs are you using, I > > > don't think it should make any difference, but I can try it with the > same > > fs. > > Make sure you are using v3, it does work for v4. > > I tested v3 on upstream.--b. > > > Marc. > > > > > > > > From: Bruce Fields > > To: Marc Eshel/Almaden/IBM@IBMUS > > Cc: linux-nfs@vger.kernel.org, Tomer Perry > > Date: 07/01/2016 02:01 PM > > Subject: Re: grace period > > > > > > > > On Fri, Jul 01, 2016 at 01:46:42PM -0700, Marc Eshel wrote: > > > This is my v3 test that show the lock still there after echo 0 > > > > /proc/fs/nfsd/threads > > > > > > [root@sonascl21 ~]# cat /etc/redhat-release > > > Red Hat Enterprise Linux Server release 7.2 (Maipo) > > > > > > [root@sonascl21 ~]# uname -a > > > Linux sonascl21.sonasad.almaden.ibm.com 3.10.0-327.el7.x86_64 #1 SMP > Thu > > > > > Oct 29 17:29:29 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux > > > > > > [root@sonascl21 ~]# cat /proc/locks | grep 999 > > > 3: POSIX ADVISORY WRITE 2349 00:2a:489486 0 999 > > > > > > [root@sonascl21 ~]# echo 0 > /proc/fs/nfsd/threads > > > [root@sonascl21 ~]# cat /proc/fs/nfsd/threads > > > 0 > > > > > > [root@sonascl21 ~]# cat /proc/locks | grep 999 > > > 3: POSIX ADVISORY WRITE 2349 00:2a:489486 0 999 > > > > Huh, that's not what I see. Are you positive that's the lock on the > > backend filesystem and not the client-side lock (in case you're doing a > > loopback mount?) > > > > --b. > > > > > > > > > > > > > > > > > From: Bruce Fields > > > To: Marc Eshel/Almaden/IBM@IBMUS > > > Cc: linux-nfs@vger.kernel.org > > > Date: 07/01/2016 01:07 PM > > > Subject: Re: grace period > > > > > > > > > > > > On Fri, Jul 01, 2016 at 10:31:55AM -0700, Marc Eshel wrote: > > > > It used to be that sending KILL signal to lockd would free locks and > > > > start > > > > Grace period, and when setting nfsd threads to zero, > > nfsd_last_thread() > > > > calls nfsd_shutdown that called lockd_down that I believe was > causing > > > both > > > > freeing of locks and starting grace period or maybe it was setting > it > > > back > > > > to a value > 0 that started the grace period. > > > > > > OK, apologies, I didn't know (or forgot) that. > > > > > > > Any way starting with the kernels that are in RHEL7.1 and up echo 0 > > > > > > /proc/fs/nfsd/threads doesn't do it anymore, I assume going to > common > > > > grace period for NLM and NFSv4 changed things. > > > > The question is how to do IP fail-over, so when a node fails and the > > > IP > > > is > > > > moving to another node, we need to go into grace period on all the > > nodes > > > > > > > in the cluster so the locks of the failed node are not given to > anyone > > > > > > other than the client that is reclaiming his locks. Restarting NFS > > > server > > > > is to distractive. > > > > > > What's the difference? Just that clients don't have to reestablish > tcp > > > connections? > > > > > > --b. > > > > > > > For NFSv3 KILL signal to lockd still works but for > > > > NFSv4 have no way to do it for v4. > > > > Marc. > > > > > > > > > > > > > > > > From: Bruce Fields > > > > To: Marc Eshel/Almaden/IBM@IBMUS > > > > Cc: linux-nfs@vger.kernel.org > > > > Date: 07/01/2016 09:09 AM > > > > Subject: Re: grace period > > > > > > > > > > > > > > > > On Thu, Jun 30, 2016 at 02:46:19PM -0700, Marc Eshel wrote: > > > > > I see that setting the number of nfsd threads to 0 (echo 0 > > > > > > /proc/fs/nfsd/threads) is not releasing the locks and putting the > > > server > > > > > > > > > in grace mode. > > > > > > > > Writing 0 to /proc/fs/nfsd/threads shuts down knfsd. So it should > > > > certainly drop locks. If that's not happening, there's a bug, but > > we'd > > > > need to know more details (version numbers, etc.) to help. > > > > > > > > That alone has never been enough to start a grace period--you'd have > > > to > > > > start knfsd again to do that. > > > > > > > > > What is the best way to go into grace period, in new version of > the > > > > > kernel, without restarting the nfs server? > > > > > > > > Restarting the nfs server is the only way. That's true on older > > kernels > > > > true, as far as I know. (OK, you can apparently make lockd do > > something > > > > like this with a signal, I don't know if that's used much, and I > doubt > > > > it works outside an NFSv3-only environment.) > > > > > > > > So if you want locks dropped and a new grace period, then you should > > > run > > > > "systemctl restart nfs-server", or your distro's equivalent. > > > > > > > > But you're probably doing something more complicated than that. I'm > > > not > > > > sure I understand the question.... > > > > > > > > --b. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >