Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754201Ab3ITI2O (ORCPT ); Fri, 20 Sep 2013 04:28:14 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58289 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754112Ab3ITI2L (ORCPT ); Fri, 20 Sep 2013 04:28:11 -0400 Date: Fri, 20 Sep 2013 09:28:07 +0100 From: Mel Gorman To: "Darrick J. Wong" Cc: Kent Overstreet , Andrew Morton , Jens Axboe , Jan Kara , Hannes Reinecke , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: Fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored Message-ID: <20130920082807.GW22421@suse.de> References: <20130920030602.GC4565@birch.djwong.org> <20130920080637.GV22421@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20130920080637.GV22421@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1373 Lines: 35 On Fri, Sep 20, 2013 at 09:06:37AM +0100, Mel Gorman wrote: > On Thu, Sep 19, 2013 at 08:06:02PM -0700, Darrick J. Wong wrote: > > The "force" parameter in __blk_queue_bounce was being ignored, which means that > > stable page snapshots are not always happening (on ext3). This of course > > leads to DIF disks reporting checksum errors, so fix this regression. > > > > The regression was introduced in commit 6bc454d1 (bounce: Refactor > > __blk_queue_bounce to not use bi_io_vec) > > > > Reported-by: Mel Gorman > > Signed-off-by: Darrick J. Wong > > I have no means of testing it but it looks right and thanks for checking > DIF disks. > > Acked-by: Mel Gorman > That said the two checks are now redundant. They could just be deleted and depend entirely on the following check within the loop if (page_to_pfn(page) <= queue_bounce_pfn(q) && !force) continue; with an update to the comment explaining that the check is for pages below the bounce pfn or for bios that require stable writes -- Mel Gorman SUSE Labs -- 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/