Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753532Ab1CKSvd (ORCPT ); Fri, 11 Mar 2011 13:51:33 -0500 Received: from e33.co.us.ibm.com ([32.97.110.151]:49241 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752955Ab1CKSvb (ORCPT ); Fri, 11 Mar 2011 13:51:31 -0500 Date: Fri, 11 Mar 2011 10:51:18 -0800 From: "Darrick J. Wong" To: Chris Mason Cc: Dave Chinner , Jan Kara , Joel Becker , "Martin K. Petersen" , Jens Axboe , linux-kernel , linux-fsdevel , Mingming Cao , linux-scsi Subject: Re: [RFC] block integrity: Fix write after checksum calculation problem Message-ID: <20110311185118.GB1110@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com References: <20110223202446.GG4020@noexit> <1298493173-sup-8301@think> <20110224164758.GH23042@quack.suse.cz> <1298566775-sup-730@think> <20110224182732.GV27190@tux1.beaverton.ibm.com> <1298897186-sup-9394@think> <20110304210724.GF27190@tux1.beaverton.ibm.com> <20110308045626.GD1956@dastard> <20110310235722.GA1110@tux1.beaverton.ibm.com> <1299860233-sup-4443@think> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1299860233-sup-4443@think> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2589 Lines: 48 On Fri, Mar 11, 2011 at 11:34:05AM -0500, Chris Mason wrote: > Excerpts from Darrick J. Wong's message of 2011-03-10 18:57:22 -0500: > > On Tue, Mar 08, 2011 at 03:56:26PM +1100, Dave Chinner wrote: > > > > > On Fri, Mar 04, 2011 at 01:07:24PM -0800, Darrick J. Wong wrote: > > > > On Mon, Feb 28, 2011 at 07:54:05AM -0500, Chris Mason wrote: > > > > > Excerpts from Darrick J. Wong's message of 2011-02-24 13:27:32 -0500: > > > > > > On Thu, Feb 24, 2011 at 12:37:53PM -0500, Chris Mason wrote: > > > > > > > Excerpts from Jan Kara's message of 2011-02-24 11:47:58 -0500: > > > > > > > > On Wed 23-02-11 15:35:11, Chris Mason wrote: > > > > > > > > > Excerpts from Joel Becker's message of 2011-02-23 15:24:47 -0500: > > > > > > > > > > On Tue, Feb 22, 2011 at 11:45:44AM -0500, Martin K. Petersen wrote: > > > > > > > > > > > Also, DIX is only the tip of the iceberg. Many other impending > > > > > > > > > > > technologies feature checksums and require pages to be stable during I/O > > > > > > > > > > > due to checksumming, encryption and so on. > > > > > > > > > > > > > > > > > > > > > > The VM is already trying to do the right thing. We just need the > > > > > > > > > > > relevant filesystems to catch up. > > > > > > > > > > > > > > > > > > > > ocfs2 handles stable metadata for its checksums when feeding > > > > > > > > > > things to the journal. If we're doing pagecache-based I/O, is the > > > > > > > > > > pagecache going to help here for data? > > > > > > > > > > > > > > > > > > Data is much easier than metadata. All you really need is to wait on > > > > > > > > > writeback in file_write, wait on writeback in page_mkwrite, and make > > > > Hrm... I've been looking for a file_write in ext4; was the aio_write function > > pointer what you had in mind here? > > Your change to grab_cache_page_write_begin looks good to me, at least > for ext4. For ext3 you have to actually go in and wait for each of the > buffer heads in the page, since ext3 (and reiserfs) will write the buffer heads > directly without using writepage. Heh, I hadn't really given much thought to ext2/3 yet. I'm still trying to figure out what causes the occasional ext4 failures. :) > Have you confirmed by looking at the block mapping that your crc errors > are from data blocks? Yes, debugfs confirms that they are data blocks. --D -- 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/