From: Eric Sandeen Subject: Re: [PATCH 2/2] ext2: Add blk_issue_flush() to syncing paths Date: Wed, 14 Jan 2009 11:47:28 -0600 Message-ID: <496E2530.4080205@redhat.com> References: <1231945948-23676-1-git-send-email-jack@suse.cz> <1231945948-23676-2-git-send-email-jack@suse.cz> <496E2276.8050309@redhat.com> <20090114174023.GK19950@duck.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org, Andrew Morton , linux-kernel@vger.kernel.org, pavel@suse.cz To: Jan Kara Return-path: Received: from mx2.redhat.com ([66.187.237.31]:49446 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751311AbZANRrw (ORCPT ); Wed, 14 Jan 2009 12:47:52 -0500 In-Reply-To: <20090114174023.GK19950@duck.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: Jan Kara wrote: > On Wed 14-01-09 11:35:50, Eric Sandeen wrote: >> Jan Kara wrote: >>> To be really safe that the data hit the platter, we should also flush drive's >>> writeback caches on fsync and for O_SYNC files or O_DIRSYNC inodes. >> Seems sane, but aren't we getting really divergent behavior here between >> ext2, ext3, and ext4 w.r.t. drive cache flushing for sync paths? > Well, but ext3/4 should do a barrier on a transaction commit (if the user > really cares about data integrity) and hence it implicitely does the same. > > Honza Sorry, just now catching up with that other thread, which addresses this topic. :) But yes, this seems correct... (OTOH, I thought SuSE was carrying a patch which did add this blkdev_flush to sync for ext3...) -Eric