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 pBKLLAln184016 for ; Tue, 20 Dec 2011 15:21:11 -0600 Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id u6lvj3Tf5532XPOb for ; Tue, 20 Dec 2011 13:21:07 -0800 (PST) Date: Wed, 21 Dec 2011 08:21:06 +1100 From: Dave Chinner Subject: Re: [PATCH 2/2 v2] xfs: log all dirty inodes in xfs_fs_sync_fs Message-ID: <20111220212106.GY23662@dastard> References: <20111218154936.GA17626@infradead.org> <20111218155015.GC17626@infradead.org> <20111220200841.GA2788@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111220200841.GA2788@infradead.org> 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: Christoph Hellwig Cc: Paul Anderson , Sean Thomas Caron , xfs@oss.sgi.com On Tue, Dec 20, 2011 at 03:08:41PM -0500, Christoph Hellwig wrote: > Since Linux 2.6.36 the writeback code has introduces various measures for > live lock prevention during sync(). Unfortunately some of these are > actively harmful for the XFS model, where the inode gets marked dirty for > metadata from the data I/O handler. > > The older_than_this checks that are now more strictly enforced since > > writeback: avoid livelocking WB_SYNC_ALL writeback > > by only calling into __writeback_inodes_sb and thus only sampling the > current cut off time once. But on a slow enough devices the previous > asynchronous sync pass might not have fully completed yet, and thus XFS > might mark metadata dirty only after that sampling of the cut off time for > the blocking pass already happened. I have not myself reproduced this > myself on a real system, but by introducing artificial delay into the > XFS I/O completion workqueues it can be reproduced easily. > > Fix this by iterating over all XFS inodes in ->sync_fs and log all that > are dirty. This might log inode that only got redirtied after the > previous pass, but given how cheap delayed logging of inodes is it > isn't a major concern for performance. > > Signed-off-by: Christoph Hellwig Looks OK now. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs