From: Jan Kara Subject: Re: [PATCH 1/5] jbd: strictly check for write errors on data buffers Date: Wed, 4 Jun 2008 12:19:25 +0200 Message-ID: <20080604101925.GB16572@duck.suse.cz> References: <4843CE15.6080506@hitachi.com> <4843CEED.9080002@hitachi.com> <20080603153050.fb99ac8a.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Hidehiro Kawai , sct@redhat.com, adilger@sun.com, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, jack@suse.cz, jbacik@redhat.com, cmm@us.ibm.com, tytso@mit.edu, yumiko.sugita.yf@hitachi.com, satoshi.oshima.fk@hitachi.com To: Andrew Morton Return-path: Received: from styx.suse.cz ([82.119.242.94]:53035 "EHLO mail.suse.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758770AbYFDKT0 (ORCPT ); Wed, 4 Jun 2008 06:19:26 -0400 Content-Disposition: inline In-Reply-To: <20080603153050.fb99ac8a.akpm@linux-foundation.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue 03-06-08 15:30:50, Andrew Morton wrote: > On Mon, 02 Jun 2008 19:43:57 +0900 > Hidehiro Kawai wrote: > > > > > In ordered mode, we should abort journaling when an I/O error has > > occurred on a file data buffer in the committing transaction. > > Why should we do that? I see two reasons: 1) If fs below us is returning IO errors, we don't really know how severe it is so it's safest to stop accepting writes. Also user notices the problem early this way. I agree that with the growing size of disks and thus probability of seeing IO error, we should probably think of something cleverer than this but aborting seems better than just doing nothing. 2) If the IO error is just transient (i.e., link to NAS is disconnected for a while), we would silently break ordering mode guarantees (user could be able to see old / uninitialized data). Honza PS: Changed Andreas's address in the email to the new one... -- Jan Kara SUSE Labs, CR