From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=FAKE_REPLY_C, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C812C11D00 for ; Thu, 20 Feb 2020 21:46:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69CD4206F4 for ; Thu, 20 Feb 2020 21:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729111AbgBTVq5 (ORCPT ); Thu, 20 Feb 2020 16:46:57 -0500 Received: from magic.merlins.org ([209.81.13.136]:50240 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729052AbgBTVq5 (ORCPT ); Thu, 20 Feb 2020 16:46:57 -0500 Received: from [207.164.22.11] (port=44083 helo=saruman.merlins.org) by mail1.merlins.org with esmtpsa (Cipher TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.92 #3) id 1j4tel-00034a-NB by authid with srv_auth_plain; Thu, 20 Feb 2020 13:46:51 -0800 Received: from merlin by saruman.merlins.org with local (Exim 4.80) (envelope-from ) id 1j4tej-0007xY-QD; Thu, 20 Feb 2020 13:46:49 -0800 Date: Thu, 20 Feb 2020 13:46:49 -0800 From: Marc MERLIN To: dsterba@suse.cz, Martin Steigerwald , Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com, Roman Mamedov Subject: Re: [PATCH] btrfs: do not zero f_bavail if we have available space Message-ID: <20200220214649.GD26873@merlins.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2656316.bop9uDDU3N@merkaba> <20200219225051.39ca1082@natsu> <20200219153652.GA26873@merlins.org> X-Sysadmin: BOFH X-URL: http://marc.merlins.org/ User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-No-Run: Yes X-Broken-Reverse-DNS: no host name for IP address 207.164.22.11 X-SA-Exim-Connect-IP: 207.164.22.11 X-SA-Exim-Mail-From: marc@merlins.org Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Well, turns out this was a more serious bug than we thought. With dm-thin overcommit, it causes this: [1324107.675334] BTRFS info (device dm-13): forced readonly [1324107.692909] BTRFS warning (device dm-13): Skipping commit of aborted transaction. [1324107.717141] BTRFS: error (device dm-13) in cleanup_transaction:1828: errno=-5 IO failure [1324107.743298] BTRFS info (device dm-13): delayed_refs has NO entry [1324107.817671] device-mapper: thin: 252:9: switching pool to write mode [1324108.662095] BTRFS error (device dm-13): bad tree block start, want 9050645626880 have 0 [1324108.694286] BTRFS error (device dm-13): bad tree block start, want 9050645626880 have 0 In other words, this broke my filesystem. I didn't try to see if it's damaged or just read-only, but obviously, this isn't good. New kernel should stop this from happening hopefully. VG/dm details if you care: VG Name vgds2 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 88 VG Access read/write VG Status resizable MAX LV 0 Cur LV 8 Open LV 7 Max PV 0 Cur PV 1 Act PV 1 VG Size 14.55 TiB PE Size 4.00 MiB Total PE 3815316 Alloc PE / Size 3801146 / 14.50 TiB Free PE / Size 14170 / 55.35 GiB VG UUID pc1cTH-kFo7-g0Kz-dELp-j51s-1yOO-v20WIV --- Logical volume --- LV Name thinpool2 VG Name vgds2 LV UUID rxJCsT-ImNv-ibvM-zOS0-Xzqv-O8AU-1STUH9 LV Write Access read/write LV Creation host, time gargamel.svh.merlins.org, 2018-07-26 08:42:51 -0700 LV Pool metadata thinpool2_tmeta LV Pool data thinpool2_tdata LV Status available # open 8 LV Size 14.50 TiB Allocated pool data 99.99% Allocated metadata 59.88% Current LE 3801088 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 252:9 LV Path /dev/vgds2/ubuntu LV Name ubuntu VG Name vgds2 LV UUID y42AA8-5zfq-Vbmr-TNo9-g7rn-UbGf-KOnFrf LV Write Access read/write LV Creation host, time gargamel.svh.merlins.org, 2018-07-26 23:22:18 -0700 LV Pool name thinpool2 LV Status available # open 1 LV Size 14.00 TiB Mapped size 60.26% Current LE 3670016 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 252:13 -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Home page: http://marc.merlins.org/ | PGP 7F55D5F27AAF9D08