Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753692Ab1EPTAR (ORCPT ); Mon, 16 May 2011 15:00:17 -0400 Received: from cantor.suse.de ([195.135.220.2]:37436 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751204Ab1EPTAP (ORCPT ); Mon, 16 May 2011 15:00:15 -0400 Date: Mon, 16 May 2011 20:59:47 +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: <20110516185947.GK5344@quack.suse.cz> References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> <20110510125124.GD4402@quack.suse.cz> <20110511181901.GK20579@tux1.beaverton.ibm.com> <20110512094255.GA4690@quack.suse.cz> <20110516184927.GM20579@tux1.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110516184927.GM20579@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: 2611 Lines: 47 On Mon 16-05-11 11:49:27, Darrick J. Wong wrote: > On Thu, May 12, 2011 at 11:42:55AM +0200, Jan Kara wrote: > > 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. > > A future step might be to undo all these homegrown copy-outs? Sure but I'm not the right one to tell you where these are ;). > > > 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. > > Are there any distros that are going straight from ext3 to btrfs? Most distros currently offer users a choice of xfs, ext3, ext4, btrfs with ext4 being the default. I'm not sure if that's what you are asking about... 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/