From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:38019 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750970AbeAVMiq (ORCPT ); Mon, 22 Jan 2018 07:38:46 -0500 Subject: Re: [PATCH] btrfs: remove spurious WARN_ON(ref->count) in find_parent_nodes To: Lu Fengqi , enadolski@suse.com Cc: Zygo Blaxell , linux-btrfs@vger.kernel.org References: <20180121190848.7wmps6q5ng6b42ki@hungrycats.org> <20180122033452.GA532@fnst.localdomain> <9151459e-8db2-bdd1-a21e-23d730cb52a4@suse.com> <87ed4d9c-9af4-4425-5a35-b0ccd9305e76@cn.fujitsu.com> From: Nikolay Borisov Message-ID: <377c6852-6617-b4e0-5e69-60a9566bd894@suse.com> Date: Mon, 22 Jan 2018 14:38:42 +0200 MIME-Version: 1.0 In-Reply-To: <87ed4d9c-9af4-4425-5a35-b0ccd9305e76@cn.fujitsu.com> Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 22.01.2018 14:19, Lu Fengqi wrote: > On 01/22/2018 04:46 PM, Nikolay Borisov wrote: >> >> >> On 22.01.2018 05:34, Lu Fengqi wrote: >>> According to my bisect result, The frequency of the warning occurrence >>> increased to the detectable degree after this patch >> >> That sentence implies that even before Ed's patch it was possible to >> trigger those warnings, is that true? Personally I've never seen such >> warnings while executing btrfs/004. How do you configure the filesystem >> for the test runs? >> > > Just only default mount option. > > ➜  xfstests-dev git:(master) for i in $(seq 1 100); do echo $i; if ! > sudo ./check btrfs/004; then break; fi; done > 1 > > FSTYP         -- btrfs > > PLATFORM      -- Linux/x86_64 sarch 4.15.0-rc9 > > MKFS_OPTIONS  -- /dev/vdd1 > > MOUNT_OPTIONS -- /dev/vdd1 /mnt/scratch > > > > > btrfs/004 47s ... 49s > > Ran: btrfs/004 > > Passed all 1 tests > > > > > 2 > > FSTYP         -- btrfs > > PLATFORM      -- Linux/x86_64 sarch 4.15.0-rc9 > > MKFS_OPTIONS  -- /dev/vdd1 > > MOUNT_OPTIONS -- /dev/vdd1 /mnt/scratch > > > > > btrfs/004 49s ... 52s > > _check_dmesg: something found in dmesg (see > /home/luke/workspace/xfstests-dev/results//btrfs/004.dmesg) > > Ran: btrfs/004 > > Failures: btrfs/004 > > Failed 1 of 1 tests > > The probability of this warning appearing is rather low, and I only > encountered 52 warnings when I looped 1008 times btrfs/004 for 20 hours > in 4.15-rc6 (IOW, the probability is nearly 5%). So you want to trigger > warning also need more luck or patience. Thanks but is this before or after the mentioned commit below? > >>> 86d5f9944252 ("btrfs: convert prelimary reference tracking to use >>> rbtrees") >>> is committed. I understand that this does not mean that this patch >>> caused >>> the problem, but maybe Edmund can give us some help, so I added him >>> to the >>> recipient. >> >> > >