From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 8AEF26B0012 for ; Wed, 11 May 2011 14:19:19 -0400 (EDT) Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by e8.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p4BHqmZs007552 for ; Wed, 11 May 2011 13:52:48 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p4BIJ2k9115076 for ; Wed, 11 May 2011 14:19:02 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p4BEIngl003936 for ; Wed, 11 May 2011 11:18:51 -0300 Date: Wed, 11 May 2011 11:19:01 -0700 From: "Darrick J. Wong" Subject: Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses Message-ID: <20110511181901.GK20579@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> <20110510125124.GD4402@quack.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110510125124.GD4402@quack.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: 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 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 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. --D -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org