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=-16.2 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=unavailable 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 772B4C433E6 for ; Mon, 15 Mar 2021 16:54:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4542B64F37 for ; Mon, 15 Mar 2021 16:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230201AbhCOQy0 (ORCPT ); Mon, 15 Mar 2021 12:54:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:57424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230034AbhCOQyT (ORCPT ); Mon, 15 Mar 2021 12:54:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EAB5F64F33; Mon, 15 Mar 2021 16:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1615827259; bh=M9IzYyDIuGqykFZa8hLqMh1LVAvUJ7CNfg4HcifHTsM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Xby26mFKJiwfarGLna122EgO6CLc6y+D/lPAiZ3+6X/n8sJlrgjNYP6ki7vF5K6RG 6toEat0LdO9wQa93gt48XmwncV+ny2vuGwqQARrqkJ6N7fUPAuwW2qXB0mKE/HnYVi 7lFOzCkLFLrpcKCme8DtGOCyH4kK4t/awRBxKe0qTnECojSsLVx///8sQE/wbi4L2i seXc8mAWGDWoeMNDKZY5p9OqRxBUZdfHmNDeRD3iW4YzRtL3NisKR5eIK7g3i44ToX Zp3j/TNY5xyChAWDprqKWTYbdX3ceSK+8TZXHesvNLUe9l9ibXVAHxi4QCUbmL33qH aBWYD2xlrk8cw== Date: Mon, 15 Mar 2021 09:54:18 -0700 From: "Darrick J. Wong" To: Eryu Guan Cc: guaneryu@gmail.com, wenli xie , linux-xfs@vger.kernel.org, fstests@vger.kernel.org Subject: Re: [PATCH 09/10] generic: test a deadlock in xfs_rename when whiteing out files Message-ID: <20210315165418.GB22097@magnolia> References: <161526480371.1214319.3263690953532787783.stgit@magnolia> <161526485320.1214319.14486851135232825638.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Mar 15, 2021 at 02:06:35AM +0800, Eryu Guan wrote: > On Mon, Mar 08, 2021 at 08:40:53PM -0800, Darrick J. Wong wrote: > > 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." > > We have _require_ext2() and _require_tmpfs(), I think it's time to > refactor them into a new _require_filesystem() helper? Yeah, I'll refactor them into a new _require_extra_fs helper. > > + > > +rm -f $seqres.full > > + > > +_scratch_mkfs >> $seqres.full > > +_scratch_mount > > Also, doing overlay mount requires the underlying to export d_type, > perhaps we should do '_supports_filetype $SCRATCH_MNT' here, otherwise > filesystems like nfs would fail the test. Oh! Thank you for pointing that out. > > > + > > +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 > > Also add 'rename' group? Done. --D > Thanks, > Eryu