Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756638Ab1ELJnD (ORCPT ); Thu, 12 May 2011 05:43:03 -0400 Received: from cantor.suse.de ([195.135.220.2]:51304 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754476Ab1ELJnA (ORCPT ); Thu, 12 May 2011 05:43:00 -0400 Date: Thu, 12 May 2011 11:42:55 +0200 From: Jan Kara To: "Darrick J. Wong" Cc: Jan Kara , Theodore Tso , Alexander Viro , OGAWA Hirofumi , Jens Axboe , "Martin K. Petersen" , Jeff Layton , Dave Chinner , linux-kernel , Dave Hansen , Christoph Hellwig , linux-mm@kvack.org, Chris Mason , Joel Becker , linux-scsi , linux-fsdevel , linux-ext4@vger.kernel.org, Mingming Cao Subject: Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses Message-ID: <20110512094255.GA4690@quack.suse.cz> References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> <20110510125124.GD4402@quack.suse.cz> <20110511181901.GK20579@tux1.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110511181901.GK20579@tux1.beaverton.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2042 Lines: 37 On Wed 11-05-11 11:19:01, Darrick J. Wong wrote: > On Tue, May 10, 2011 at 02:51:24PM +0200, Jan Kara wrote: > > On Mon 09-05-11 16:03:18, Darrick J. Wong wrote: > > > I am still chasing down what exactly is broken in ext3. data=writeback mode > > > passes with no failures. data=ordered, however, does not pass; my current > > > suspicion is that jbd is calling submit_bh on data buffers but doesn't call > > > page_mkclean to kick the userspace programs off the page before writing it. > > Yes, ext3 in data=ordered mode writes pages from > > journal_commit_transaction() via submit_bh() without clearing page dirty > > bits thus page_mkclean() is not called for these pages. Frankly, do you > > really want to bother with adding support for ext2 and ext3? People can use > > ext4 as a fs driver when they want to start using blk-integrity support. > > Especially ext2 patch looks really painful and just from a quick look I can > > see code e.g. in fs/ext2/namei.c which isn't handled by your patch yet. > > Yeah, I agree that ext2 is ugly and ext3/jbd might be more painful. Are there > any other code that wants stable pages that's already running with ext3? In > this months-long discussion I've heard that encryption and raid also like > stable pages during writes. Have those users been broken this whole time, or > have they been stabilizing pages themselves? I believe part of them has been broken (e.g. raid) and part of them do copy-out so they were OK. > I suppose we can cross the "ext3 fails horribly on DIF" bridge when someone > complains about it. Possibly we could try to steer them to btrfs. Well, btrfs might be a bit too advantageous for production servers but ext4 would be definitely viable for them. Honza -- Jan Kara SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/