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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 8616FC32792 for ; Thu, 3 Oct 2019 11:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5155A21D71 for ; Thu, 3 Oct 2019 11:12:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dMm2ZxL0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729955AbfJCLMu (ORCPT ); Thu, 3 Oct 2019 07:12:50 -0400 Received: from mail-vs1-f65.google.com ([209.85.217.65]:46931 "EHLO mail-vs1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729912AbfJCLMu (ORCPT ); Thu, 3 Oct 2019 07:12:50 -0400 Received: by mail-vs1-f65.google.com with SMTP id z14so1377826vsz.13; Thu, 03 Oct 2019 04:12:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc:content-transfer-encoding; bh=yBDHlcoYRQdJmmXThhd8XlzFxe0grDwuOQ/RnIBDyj4=; b=dMm2ZxL0vi0uHyI3gZ06R5FPeEaymd3GM9TCzNk8jbSMAK3CA0fR/H56BOQdORPXtw 3oIoddQE3VgTh1RqqYkZ/j1xKCElFkT/bPPjnLIbR5pIFbtsBKsme18oiuwP2PttTisg XfbhgVyu6sEWtE14oO6IFsznjMtjhBMnZZNrlsql/ZnZI+/aNdSoDZWV5B8qPM1QDiGt WbrEJhRmdeBJaBFEdwbkZPMJUUbDTP8ZC3i+BJ/PW0oa3f50JvUla8jUrbNtQaH1A+WA oQ2uKRMd5A0BnbcnxkP4syECaxL97xcNCIZMUKBf09jXhWaMjaKJYNfnBFIji4Vt9v30 ny+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc:content-transfer-encoding; bh=yBDHlcoYRQdJmmXThhd8XlzFxe0grDwuOQ/RnIBDyj4=; b=lxtwsbomUENFnUQF4vqfvz3RFYG/XG6FUQYueOCc+K/HDQBBbFsDNaisacMHuTkkkk 9IBBnsE6rgOiWvBWWdlFSkJhMJyotMimp6iJFPvt1EeHL+IRSq46diMuoMJFE6cqxCcq 818kYkv+K7qgf/dY2MQDTR2fVPj+NOHseNOj8SLEuabK1dHD9g3fJepY3kfdzVw0xiB6 0UtoKgN+oeYCSMDlc0EMGtAA0lNUCuz3svYwtop8AhgJs4GP/hSFFKXz0Yn+9OtzJY2J W5u3nhT+TKLF25vg1dgWD/GVAovH9Avgg/XGSEadS3DuPWNnlhrcSiSFfXOLmzv1jImn xNnw== X-Gm-Message-State: APjAAAUcbpTaCqGHpr7lOKIoE6XgJ9xVcgSCfH+I7twOIQg4vomq8dvz Cp8qplqtbKZGvijfYGR6JLfOXLyk+jwHzr+ifqk= X-Google-Smtp-Source: APXvYqzw6XX2a2rcNHe2r6nDiR42wU22xVfEtiY0pzoYqHwW8PrGKBEuuB6d87E0fSkPB08Pt3VNtLUYJ3+XNmb383g= X-Received: by 2002:a67:2d13:: with SMTP id t19mr4067794vst.99.1570101167781; Thu, 03 Oct 2019 04:12:47 -0700 (PDT) MIME-Version: 1.0 References: <20191002184133.21099-1-josef@toxicpanda.com> In-Reply-To: Reply-To: fdmanana@gmail.com From: Filipe Manana Date: Thu, 3 Oct 2019 12:12:36 +0100 Message-ID: Subject: Re: [PATCH][v2] btrfs/194: add a test for multi-subvolume fsyncing To: Josef Bacik Cc: fstests , linux-btrfs , kernel-team@fb.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: fstests-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Thu, Oct 3, 2019 at 11:59 AM Filipe Manana wrote: > > On Wed, Oct 2, 2019 at 7:44 PM Josef Bacik wrote: > > > > I discovered a problem in btrfs where we'd end up pointing at a block w= e > > hadn't written out yet. This is triggered by a race when two different > > files on two different subvolumes fsync. This test exercises this path > > with dm-log-writes, and then replays the log at every FUA to verify the > > file system is still mountable and the log is replayable. > > > > This test is to verify the fix > > > > btrfs: fix incorrect updating of log root tree > > > > actually fixed the problem. > > > > Signed-off-by: Josef Bacik > > Reviewed-by: Filipe Manana > > It's working now. > Confirmed this triggers the bug, and after about 4 hours of this > running with the btrfs patch, it doesn't trigger the bug anymore. > > Thanks! > > > --- > > v1->v2: > > - added the patchname related to this test in the comments and changelo= g. > > - running fio makes it use 400mib of shared memory, so running 50 of th= em is > > impossible on boxes that don't have hundreds of gib of RAM. Fixed th= is to > > just generate a fio config so we can run 1 fio instance with 50 threa= ds which > > makes it not OOM boxes with tiny amounts of RAM. > > - fixed some formatting things that Filipe pointed out. > > > > tests/btrfs/194 | 111 ++++++++++++++++++++++++++++++++++++++++++++ > > tests/btrfs/194.out | 2 + > > tests/btrfs/group | 1 + > > 3 files changed, 114 insertions(+) > > create mode 100755 tests/btrfs/194 > > create mode 100644 tests/btrfs/194.out > > > > diff --git a/tests/btrfs/194 b/tests/btrfs/194 > > new file mode 100755 > > index 00000000..b98064e2 > > --- /dev/null > > +++ b/tests/btrfs/194 > > @@ -0,0 +1,111 @@ > > +#! /bin/bash > > +# SPDX-License-Identifier: GPL-2.0 > > +# Copyright (c) 2019 Facebook. All Rights Reserved. > > +# > > +# FS QA Test 194 > > +# > > +# Test multi subvolume fsync to test a bug where we'd end up pointing = at a block > > +# we haven't written. This was fixed by the patch > > +# > > +# btrfs: fix incorrect updating of log root tree > > +# > > +# Will do log replay and check the filesystem. > > +# > > +seq=3D`basename $0` > > +seqres=3D$RESULT_DIR/$seq > > +echo "QA output created by $seq" > > + > > +here=3D`pwd` > > +tmp=3D/tmp/$$ > > +fio_config=3D$tmp.fio > > +status=3D1 # failure is the default! > > +trap "_cleanup; exit \$status" 0 1 2 3 15 > > + > > +_cleanup() > > +{ > > + cd / > > + _log_writes_cleanup &> /dev/null > > + _dmthin_cleanup > > + rm -f $tmp.* > > +} > > + > > +# get standard environment, filters and checks > > +. ./common/rc > > +. ./common/filter > > +. ./common/dmthin > > +. ./common/dmlogwrites > > + > > +# remove previous $seqres.full before test > > +rm -f $seqres.full > > + > > +# real QA test starts here > > + > > +# Modify as appropriate. > > +_supported_fs generic Btw, only forgot about this. Should be: _supported_fs btrfs Eryu can probably fix that at commit time. Thanks. > > +_supported_os Linux > > + > > +# Use thin device as replay device, which requires $SCRATCH_DEV > > +_require_scratch_nocheck > > +# and we need extra device as log device > > +_require_log_writes > > +_require_dm_target thin-pool > > + > > +cat >$fio_config < > +[global] > > +readwrite=3Dwrite > > +fallocate=3Dnone > > +bs=3D4k > > +fsync=3D1 > > +size=3D128k > > +EOF > > + > > +for i in $(seq 0 49); do > > + echo "[foo$i]" >> $fio_config > > + echo "filename=3D$SCRATCH_MNT/$i/file" >> $fio_config > > +done > > + > > +_require_fio $fio_config > > + > > +cat $fio_config >> $seqres.full > > + > > +# Use a thin device to provide deterministic discard behavior. Discard= s are used > > +# by the log replay tool for fast zeroing to prevent out-of-order repl= ay issues. > > +_test_unmount > > +_dmthin_init $devsize $devsize $csize $lowspace > > +_log_writes_init $DMTHIN_VOL_DEV > > +_log_writes_mkfs >> $seqres.full 2>&1 > > +_log_writes_mark mkfs > > + > > +_log_writes_mount > > + > > +# First create all the subvolumes > > +for i in $(seq 0 49); do > > + $BTRFS_UTIL_PROG subvolume create "$SCRATCH_MNT/$i" > /dev/null > > +done > > + > > +$FIO_PROG $fio_config > /dev/null 2>&1 > > +_log_writes_unmount > > + > > +_log_writes_remove > > +prev=3D$(_log_writes_mark_to_entry_number mkfs) > > +[ -z "$prev" ] && _fail "failed to locate entry mark 'mkfs'" > > +cur=3D$(_log_writes_find_next_fua $prev) > > +[ -z "$cur" ] && _fail "failed to locate next FUA write" > > + > > +while [ ! -z "$cur" ]; do > > + _log_writes_replay_log_range $cur $DMTHIN_VOL_DEV >> $seqres.fu= ll > > + > > + # We need to mount the fs because btrfsck won't bother checking= the log. > > + _dmthin_mount > > + _dmthin_check_fs > > + > > + prev=3D$cur > > + cur=3D$(_log_writes_find_next_fua $(($cur + 1))) > > + [ -z "$cur" ] && break > > +done > > + > > +echo "Silence is golden" > > + > > +# success, all done > > +status=3D0 > > +exit > > diff --git a/tests/btrfs/194.out b/tests/btrfs/194.out > > new file mode 100644 > > index 00000000..7bfd50ff > > --- /dev/null > > +++ b/tests/btrfs/194.out > > @@ -0,0 +1,2 @@ > > +QA output created by 194 > > +Silence is golden > > diff --git a/tests/btrfs/group b/tests/btrfs/group > > index b92cb12c..0d0e1bba 100644 > > --- a/tests/btrfs/group > > +++ b/tests/btrfs/group > > @@ -196,3 +196,4 @@ > > 191 auto quick send dedupe > > 192 auto replay snapshot stress > > 193 auto quick qgroup enospc limit > > +194 auto metadata log volume > > -- > > 2.21.0 > > > > > -- > Filipe David Manana, > > =E2=80=9CWhether you think you can, or you think you can't =E2=80=94 you'= re right.=E2=80=9D --=20 Filipe David Manana, =E2=80=9CWhether you think you can, or you think you can't =E2=80=94 you're= right.=E2=80=9D