From patchwork Tue Mar 9 04:40:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 12124015 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=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 158A8C433DB for ; Tue, 9 Mar 2021 04:41:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE6AF65290 for ; Tue, 9 Mar 2021 04:41:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229992AbhCIElO (ORCPT ); Mon, 8 Mar 2021 23:41:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:33082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbhCIEkx (ORCPT ); Mon, 8 Mar 2021 23:40:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 61C9365275; Tue, 9 Mar 2021 04:40:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615264853; bh=O/8xPqrlVA31AQ13Ug1211UcQ/I3PFRPbN+ktCU8lnA=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=X5sjV4Owp9wNDaWj3wvaU+5sJP1ReNw7zHNjErAla/dyulNZsVXUy8fvIimRV4gsJ 0dGoEdovTS5K3dzc+F8NGxNGySjnrbcIlZgYbYO3TjTfl5X+zT9Fpc3sQTo5doD314 kJz2hSvU2fG8E8AaGq0mVw7B5dewvv+GBKYBPNq76/8KJi2eibGD5yaIA4Mroyn/eF U5lqA/c/ld3I3rEcuXdiCA19nyx3V8Ll3YVoHoTqmPbFuVyni1nSNdNmwrwSTD3zCK XFn/DNuvCKJ3GAlQzJY1wP/gDqcIW4XpPVGKHPS9uA9vZyzbIRshf+LwySPcnJ5MIv LtvmWeibSkVcA== Subject: [PATCH 09/10] generic: test a deadlock in xfs_rename when whiteing out files From: "Darrick J. Wong" To: djwong@kernel.org, guaneryu@gmail.com Cc: wenli xie , linux-xfs@vger.kernel.org, fstests@vger.kernel.org, guan@eryu.me Date: Mon, 08 Mar 2021 20:40:53 -0800 Message-ID: <161526485320.1214319.14486851135232825638.stgit@magnolia> In-Reply-To: <161526480371.1214319.3263690953532787783.stgit@magnolia> References: <161526480371.1214319.3263690953532787783.stgit@magnolia> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Darrick J. Wong wenli xie reported a buffer cache deadlock when an overlayfs is mounted atop xfs and overlayfs tries to replace a single-nlink file with a whiteout file. This test reproduces that deadlock. Reported-by: wenli xie Signed-off-by: Darrick J. Wong --- tests/generic/1300 | 109 ++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/1300.out | 2 + tests/generic/group | 1 3 files changed, 112 insertions(+) create mode 100755 tests/generic/1300 create mode 100644 tests/generic/1300.out diff --git a/tests/generic/1300 b/tests/generic/1300 new file mode 100755 index 00000000..10df44e3 --- /dev/null +++ b/tests/generic/1300 @@ -0,0 +1,109 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0-or-later +# Copyright (c) 2021 Oracle. All Rights Reserved. +# +# FS QA Test No. 1300 +# +# Reproducer for a deadlock in xfs_rename reported by Wenli Xie. +# +# When overlayfs is running on top of xfs and the user unlinks a file in the +# overlay, overlayfs will create a whiteout inode and ask us to "rename" the +# whiteout file atop the one being unlinked. If the file being unlinked loses +# its one nlink, we then have to put the inode on the unlinked list. +# +# This requires us to grab the AGI buffer of the whiteout inode to take it +# off the unlinked list (which is where whiteouts are created) and to grab +# the AGI buffer of the file being deleted. If the whiteout was created in +# a higher numbered AG than the file being deleted, we'll lock the AGIs in +# the wrong order and deadlock. +# +# Note that this test doesn't do anything xfs-specific so it's a generic test. +# This is a regression test for commit 6da1b4b1ab36 ("xfs: fix an ABBA deadlock +# in xfs_rename"). + +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" + +here=`pwd` +tmp=/tmp/$$ +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + stop_workers + cd / + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc + +# real QA test starts here +_supported_fs generic +_require_scratch +test "$FSTYP" = "overlay" && _notrun "Test does not apply to overlayfs." + +modprobe -q overlay +grep -q overlay /proc/filesystems || _notrun "Test requires overlayfs." + +rm -f $seqres.full + +_scratch_mkfs >> $seqres.full +_scratch_mount + +mkdir $SCRATCH_MNT/lowerdir +mkdir $SCRATCH_MNT/lowerdir1 +mkdir $SCRATCH_MNT/lowerdir/etc +mkdir $SCRATCH_MNT/workers +echo salts > $SCRATCH_MNT/lowerdir/etc/access.conf +touch $SCRATCH_MNT/running + +stop_workers() { + test -e $SCRATCH_MNT/running || return + rm -f $SCRATCH_MNT/running + + while [ "$(ls $SCRATCH_MNT/workers/ | wc -l)" -gt 0 ]; do + wait + done +} + +worker() { + local tag="$1" + local mergedir="$SCRATCH_MNT/merged$tag" + local l="lowerdir=$SCRATCH_MNT/lowerdir:$SCRATCH_MNT/lowerdir1" + local u="upperdir=$SCRATCH_MNT/upperdir$tag" + local w="workdir=$SCRATCH_MNT/workdir$tag" + local i="index=off,nfs_export=off" + + touch $SCRATCH_MNT/workers/$tag + while test -e $SCRATCH_MNT/running; do + rm -rf $SCRATCH_MNT/merged$tag + rm -rf $SCRATCH_MNT/upperdir$tag + rm -rf $SCRATCH_MNT/workdir$tag + mkdir $SCRATCH_MNT/merged$tag + mkdir $SCRATCH_MNT/workdir$tag + mkdir $SCRATCH_MNT/upperdir$tag + + mount -t overlay overlay -o "$l,$u,$w,$i" $mergedir + mv $mergedir/etc/access.conf $mergedir/etc/access.conf.bak + touch $mergedir/etc/access.conf + mv $mergedir/etc/access.conf $mergedir/etc/access.conf.bak + touch $mergedir/etc/access.conf + umount $mergedir + done + rm -f $SCRATCH_MNT/workers/$tag +} + +for i in $(seq 0 $((4 + LOAD_FACTOR)) ); do + worker $i & +done + +sleep $((30 * TIME_FACTOR)) +stop_workers + +echo Silence is golden. +# success, all done +status=0 +exit diff --git a/tests/generic/1300.out b/tests/generic/1300.out new file mode 100644 index 00000000..5805d30d --- /dev/null +++ b/tests/generic/1300.out @@ -0,0 +1,2 @@ +QA output created by 1300 +Silence is golden. diff --git a/tests/generic/group b/tests/generic/group index 778aa8c4..2233a59d 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -631,3 +631,4 @@ 947 auto quick rw clone 948 auto quick rw copy_range 949 auto quick rw dedupe clone +1300 auto rw overlay