From patchwork Thu Jun 2 13:10:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 9149955 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A6FE46074E for ; Thu, 2 Jun 2016 13:10:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 960CC26CFB for ; Thu, 2 Jun 2016 13:10:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8A461282EE; Thu, 2 Jun 2016 13:10:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 850BB26CFB for ; Thu, 2 Jun 2016 13:10:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161080AbcFBNKH (ORCPT ); Thu, 2 Jun 2016 09:10:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60839 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161026AbcFBNKE (ORCPT ); Thu, 2 Jun 2016 09:10:04 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EAE7C552F5 for ; Thu, 2 Jun 2016 13:10:02 +0000 (UTC) Received: from bfoster.bfoster (dhcp-41-195.bos.redhat.com [10.18.41.195]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u52DA23a016765 for ; Thu, 2 Jun 2016 09:10:02 -0400 Received: by bfoster.bfoster (Postfix, from userid 1000) id 98D2D1204FE; Thu, 2 Jun 2016 09:10:01 -0400 (EDT) From: Brian Foster To: fstests@vger.kernel.org Subject: [PATCH v2] xfstests: xfs discontiguous multi-block buffer logging test Date: Thu, 2 Jun 2016 09:10:01 -0400 Message-Id: <1464873001-17508-1-git-send-email-bfoster@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 02 Jun 2016 13:10:02 +0000 (UTC) Sender: fstests-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP XFS had a bug in the multi-block buffer logging code that caused a NULL lv panic at log push time due to invalid regions being set in the buffer log format bitmap. This was demonstrated by modifying a multi-block directory buffer in a manner that only logs regions beyond the first FSB-sized mapping of the buffer. To recreate these conditions, this test fragments free space and populates several directories with enough entries to require discontiguous multi-block buffers. To recreate the problem, we remove entries from the tail end of the directory and fsync to flush the log. Note that this test causes a panic on kernels affected by the bug. As such, it is included in the 'dangerous' group. The bug is resolved by kernel commit a3916e528b91 ("xfs: fix broken multi-fsb buffer logging"). Signed-off-by: Brian Foster Reviewed-by: Eryu Guan --- v2: - Added comments and some aesthetic fixups. - Fixed up output file. - Added to quick group. v1: http://thread.gmane.org/gmane.comp.file-systems.fstests/2475 tests/xfs/399 | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ tests/xfs/399.out | 2 + tests/xfs/group | 1 + 3 files changed, 124 insertions(+) create mode 100755 tests/xfs/399 create mode 100644 tests/xfs/399.out diff --git a/tests/xfs/399 b/tests/xfs/399 new file mode 100755 index 0000000..8cea305 --- /dev/null +++ b/tests/xfs/399 @@ -0,0 +1,121 @@ +#! /bin/bash +# FS QA Test No. 399 +# +# Regression test for an XFS multi-block buffer logging bug. +# +# The XFS bug results in a panic when a non-contiguous multi-block buffer is +# mapped and logged in a particular manner, such that only regions beyond the +# first fsb-sized mapping are logged. The crash occurs asynchronous to +# transaction submission, when the associated buffer log item is pushed from the +# CIL (i.e., when the log is subsequently flushed). +# +#----------------------------------------------------------------------- +# Copyright (c) 2016 Red Hat, Inc. All Rights Reserved. +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it would be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write the Free Software Foundation, +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +#----------------------------------------------------------------------- +# + +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() +{ + cd / + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc + +# Modify as appropriate. +_supported_fs xfs +_supported_os Linux + +_require_scratch_nocheck # check complains about single AG fs +_require_xfs_io_command "fpunch" + +rm -f $seqres.full + +# Create a small fs with a large directory block size. We want to fill up the fs +# quickly and then create multi-fsb dirblocks over fragmented free space. +_scratch_mkfs_xfs -d size=20m -n size=64k >> $seqres.full 2>&1 +_scratch_mount + +# Fill a source directory with many largish-named files. 1k uuid-named entries +# sufficiently populates a 64k directory block. +mkdir $SCRATCH_MNT/src +for i in $(seq 0 1023); do + touch $SCRATCH_MNT/src/`uuidgen` +done + +# precreate target dirs while we still have free space for inodes +for i in $(seq 0 3); do + mkdir $SCRATCH_MNT/$i +done + +# consume and fragment free space +$XFS_IO_PROG -xc "resblks 16" $SCRATCH_MNT >> $seqres.full 2>&1 +dd if=/dev/zero of=$SCRATCH_MNT/file bs=4k >> $seqres.full 2>&1 +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/file >> $seqres.full 2>&1 +size=`stat -c %s $SCRATCH_MNT/file` +for i in $(seq 0 8192 $size); do + $XFS_IO_PROG -c "fpunch $i 4k" $SCRATCH_MNT/file >> $seqres.full 2>&1 +done + +# Replicate the src dir several times into fragmented free space. After one or +# two dirs, we should have nothing but non-contiguous directory blocks. +for d in $(seq 0 3); do + for f in `ls -1 $SCRATCH_MNT/src`; do + ln $SCRATCH_MNT/src/$f $SCRATCH_MNT/$d/$f + done +done + +# Fragment the target dirs a bit. Remove a handful of entries from each to +# populate the best free space regions in the directory block headers. We want +# to populate these now so the subsequent unlinks have no reason to log the +# first block of the directory. +for d in $(seq 0 3); do + i=0 + for f in `ls -U $SCRATCH_MNT/$d`; do + if [ $i == 0 ]; then + unlink $SCRATCH_MNT/$d/$f + fi + i=$(((i + 1) % 128)) + done +done + +# remount to flush and ensure subsequent operations allocate a new log item +_scratch_cycle_mount + +# Unlink an entry towards the end of each dir and fsync. The unlink should only +# need to log the latter mappings of the 64k directory block. If the logging bug +# is present, this will crash! +for d in $(seq 0 3); do + f=`ls -U $SCRATCH_MNT/$d | tail -10 | head -n 1` + unlink $SCRATCH_MNT/$d/$f + $XFS_IO_PROG -c fsync $SCRATCH_MNT/$d +done + +echo Silence is golden. + +# success, all done +status=0 +exit diff --git a/tests/xfs/399.out b/tests/xfs/399.out new file mode 100644 index 0000000..01b7175 --- /dev/null +++ b/tests/xfs/399.out @@ -0,0 +1,2 @@ +QA output created by 399 +Silence is golden. diff --git a/tests/xfs/group b/tests/xfs/group index f4c6816..e1bc647 100644 --- a/tests/xfs/group +++ b/tests/xfs/group @@ -285,3 +285,4 @@ 303 auto quick quota 304 auto quick quota 305 auto quota +399 auto dangerous quick