From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id nAHFCvEA041745 for ; Tue, 17 Nov 2009 09:13:00 -0600 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 5641114E0EEA for ; Tue, 17 Nov 2009 07:13:19 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id IfxH0WPEBpoAjwBI for ; Tue, 17 Nov 2009 07:13:19 -0800 (PST) Date: Tue, 17 Nov 2009 10:13:18 -0500 From: Christoph Hellwig Subject: Re: [PATCH] xfs: copy li_lsn before dropping AIL lock Message-ID: <20091117151318.GA19893@infradead.org> References: <4B01AD54.3030008@houseofnate.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4B01AD54.3030008@houseofnate.net> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: "Nathaniel W. Turner" Cc: xfs@oss.sgi.com On Mon, Nov 16, 2009 at 02:51:48PM -0500, Nathaniel W. Turner wrote: > Access to log items on the AIL is generally protected by m_ail_lock; > this is particularly needed when we're getting or setting the 64-bit > li_lsn on a 32-bit platform. This patch fixes a couple places where we > were accessing the log item after dropping the AIL lock on 32-bit > machines. > > This can result in a partially-zeroed log->l_tail_lsn if > xfs_trans_ail_delete is racing with xfs_trans_ail_update, and in at > least some cases, this can leave the l_tail_lsn with a zero cycle > number, which means xlog_space_left will think the log is full (unless > CONFIG_XFS_DEBUG is set, in which case we'll trip an ASSERT), leading to > processes stuck forever in xlog_grant_log_space. Might this also cause this oops? http://www.kerneloops.org/raw.php?rawid=944396&msgid= It's been shoving up a few times recently. Anyway, the patch looks good to me, but I wonder if we should abstract the li_lsn handling a bit more to avoid easily running into this kind of problems. Reviewed-by: Christoph Hellwig _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs