Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932792AbbHYUhW (ORCPT ); Tue, 25 Aug 2015 16:37:22 -0400 Received: from mail-ig0-f178.google.com ([209.85.213.178]:35758 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932609AbbHYUhT (ORCPT ); Tue, 25 Aug 2015 16:37:19 -0400 Subject: Re: [PATCH v2 block/for-linus] writeback: sync_inodes_sb() must write out I_DIRTY_TIME inodes and always call wait_sb_inodes() To: Tejun Heo , Jan Kara References: <20150812101204.GE17933@dhcp-13-216.nay.redhat.com> <20150813004435.GN3902@dastard> <20150813224415.GG4496@mtj.duckdns.org> <20150825181152.GA26785@mtj.duckdns.org> Cc: Eryu Guan , xfs@oss.sgi.com, axboe@fb.com, Dave Chinner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com From: Jens Axboe Message-ID: <55DCD1FD.6070809@kernel.dk> Date: Tue, 25 Aug 2015 14:37:17 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20150825181152.GA26785@mtj.duckdns.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1819 Lines: 46 On 08/25/2015 12:11 PM, Tejun Heo wrote: > e79729123f63 ("writeback: don't issue wb_writeback_work if clean") > updated writeback path to avoid kicking writeback work items if there > are no inodes to be written out; unfortunately, the avoidance logic > was too aggressive and broke sync_inodes_sb(). > > * sync_inodes_sb() must write out I_DIRTY_TIME inodes but I_DIRTY_TIME > inodes dont't contribute to bdi/wb_has_dirty_io() tests and were > being skipped over. > > * inodes are taken off wb->b_dirty/io/more_io lists after writeback > starts on them. sync_inodes_sb() skipping wait_sb_inodes() when > bdi_has_dirty_io() breaks it by making it return while writebacks > are in-flight. > > This patch fixes the breakages by > > * Removing bdi_has_dirty_io() shortcut from bdi_split_work_to_wbs(). > The callers are already testing the condition. > > * Removing bdi_has_dirty_io() shortcut from sync_inodes_sb() so that > it always calls into bdi_split_work_to_wbs() and wait_sb_inodes(). > > * Making bdi_split_work_to_wbs() consider the b_dirty_time list for > WB_SYNC_ALL writebacks. > > Kudos to Eryu, Dave and Jan for tracking down the issue. > > Signed-off-by: Tejun Heo > Fixes: e79729123f63 ("writeback: don't issue wb_writeback_work if clean") > Link: http://lkml.kernel.org/g/20150812101204.GE17933@dhcp-13-216.nay.redhat.com > Reported-and-bisected-by: Eryu Guan > Cc: Dave Chinner > Cc: Jan Kara > Cc: Ted Ts'o Added for 4.2. -- Jens Axboe -- 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/