From: "J. Bruce Fields" Subject: Re: [NLM] 2.6.27.14 breakage when grace period expires Date: Wed, 11 Feb 2009 15:35:55 -0500 Message-ID: <20090211203555.GC27686@fieldses.org> References: <20090211112318.GA29133@janus> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Linux NFS mailing list To: Frank van Maarseveen Return-path: Received: from mail.fieldses.org ([141.211.133.115]:42354 "EHLO pickle.fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753890AbZBKUfw (ORCPT ); Wed, 11 Feb 2009 15:35:52 -0500 In-Reply-To: <20090211112318.GA29133@janus> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Feb 11, 2009 at 12:23:18PM +0100, Frank van Maarseveen wrote: > I'm sorry to inform you but... it seems that there is a similar problem > in the NLM subsystem as reported previously but this time it is triggered > when the grace time expires after a reboot. > > Client and server run 2.6.27.14 + previous fix, NFSv3. > > On the client there are three shells running: > > while :; do lck -w /mnt/foo 2; done > > The "lck" program is the same as posted before and it obtains an exclusive > write lock then waits 2 seconds in above invocation (there's probably an > "fcntl" command equivalent). After an orderly server reboot + grace time How are you rebooting the server? --b. > expiration one of above command loops reports: > > lck: fcntl: No locks available > > and all three get stuck. After ^C-ing all "lck" loops the server still > shows an entry in /proc/locks which causes the file to be locked > indefinately. Maybe two loops are sufficient to reproduce the issue or > maybe you need more, I don't know. > > Interestingly, during the grace time at least one of the "lck" processes > should have re-obtained the lock but it didn't show up in /proc/locks > on the server. > > Interestingly (#2), after removing the file on the server (i.e. no > sillyrename) the now free inode is still locked according to /proc/locks. > Even stopping/starting /etc/init.d/nfs-kernel-server plus "echo > 3 >/proc/sys/vm/drop_caches" did not remove the lock (it did re-enter > grace). > > -- > Frank > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html