From patchwork Fri Feb 13 12:29:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 5824921 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AE0379F37F for ; Fri, 13 Feb 2015 12:30:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A7C6F20265 for ; Fri, 13 Feb 2015 12:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BDB420263 for ; Fri, 13 Feb 2015 12:30:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752665AbbBMMaM (ORCPT ); Fri, 13 Feb 2015 07:30:12 -0500 Received: from victor.provo.novell.com ([137.65.250.26]:39047 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752362AbbBMMaL (ORCPT ); Fri, 13 Feb 2015 07:30:11 -0500 Received: from debian3.lan (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by prv3-mh.provo.novell.com with ESMTP (NOT encrypted); Fri, 13 Feb 2015 05:29:59 -0700 From: Filipe Manana To: fstests@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, Filipe Manana Subject: [PATCH v2] fstests: generic, test fsync after adding hard link differently Date: Fri, 13 Feb 2015 12:29:49 +0000 Message-Id: <1423830589-31546-1-git-send-email-fdmanana@suse.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1423778938-24038-1-git-send-email-fdmanana@suse.com> References: <1423778938-24038-1-git-send-email-fdmanana@suse.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This test is motivated by an fsync issue discovered in btrfs. The issue was that we could lose file data, that was previously fsync'ed successfully, if we end up adding a hard link to our inode and then persist the fsync log later via an fsync of other inode for example. This is similar to my previous test, except that in this test the inode that ends up losing data was created (with some data) in a transaction different from the one we made an fsync. The btrfs issue was fixed by the following linux kernel patch: Btrfs: fix fsync data loss after adding hard link to inode Signed-off-by: Filipe Manana --- V2: Updated two comments with more details about the issue. tests/generic/043 | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/043.out | 17 ++++++++ tests/generic/group | 1 + 3 files changed, 130 insertions(+) create mode 100755 tests/generic/043 create mode 100644 tests/generic/043.out diff --git a/tests/generic/043 b/tests/generic/043 new file mode 100755 index 0000000..9de2469 --- /dev/null +++ b/tests/generic/043 @@ -0,0 +1,112 @@ +#! /bin/bash +# FS QA Test No. 043 +# +# This test is motivated by an fsync issue discovered in btrfs. +# The issue was that we could lose file data, that was previously fsync'ed +# successfully, if we end up adding a hard link to our inode and then persist +# the fsync log later via an fsync of other inode for example. +# +# The btrfs issue was fixed by the following linux kernel patch: +# +# Btrfs: fix fsync data loss after adding hard link to inode +# +#----------------------------------------------------------------------- +# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved. +# Author: Filipe Manana +# +# 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! + +_cleanup() +{ + _cleanup_flakey + rm -f $tmp.* +} +trap "_cleanup; exit \$status" 0 1 2 3 15 + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter +. ./common/dmflakey + +# real QA test starts here +_supported_fs generic +_supported_os Linux +_need_to_be_root +_require_scratch +_require_dm_flakey + +rm -f $seqres.full + +_scratch_mkfs >> $seqres.full 2>&1 +_init_flakey +_mount_flakey + +# Create our test file with some data. +$XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \ + $SCRATCH_MNT/foo | _filter_xfs_io + +# Make sure the file is durably persisted. +sync + +# Append some data to our file, to increase its size. +$XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \ + $SCRATCH_MNT/foo | _filter_xfs_io + +# Fsync the file, so from this point on if a crash/power failure happens, our +# new data is guaranteed to be there next time the fs is mounted. +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo + +# Add one hard link to our file. This made btrfs write into the in memory fsync +# log a special inode with generation 0 and an i_size of 0 too. Note that this +# didn't update the inode in the fsync log on disk. +ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link + +# Now make sure the in memory fsync log is durably persisted. +# Creating and fsync'ing another file will do it. +touch $SCRATCH_MNT/bar +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar + +# As expected, before the crash/power failure, we should be able to read the +# 12Kb of file data. +echo "File content before:" +od -t x1 $SCRATCH_MNT/foo + +# Simulate a crash/power loss. +_load_flakey_table $FLAKEY_DROP_WRITES +_unmount_flakey + +_load_flakey_table $FLAKEY_ALLOW_WRITES +_mount_flakey + +# After mounting the fs again, the fsync log was replayed. +# The btrfs fsync log replay code didn't update the i_size of the persisted +# inode because the inode item in the log had a special generation with a +# value of 0 (and it couldn't know the correct i_size, since that inode item +# had a 0 i_size too). This made the last 4Kb of file data inaccessible and +# effectively lost. +echo "File content after:" +od -t x1 $SCRATCH_MNT/foo + +status=0 +exit diff --git a/tests/generic/043.out b/tests/generic/043.out new file mode 100644 index 0000000..eaf9be5 --- /dev/null +++ b/tests/generic/043.out @@ -0,0 +1,17 @@ +QA output created by 043 +wrote 8192/8192 bytes at offset 0 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +wrote 4096/4096 bytes at offset 8192 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +File content before: +0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa +* +0020000 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc +* +0030000 +File content after: +0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa +* +0020000 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc +* +0030000 diff --git a/tests/generic/group b/tests/generic/group index 001ec80..d686f2f 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -45,6 +45,7 @@ 040 metadata auto quick 041 metadata auto quick 042 metadata auto quick +043 metadata auto quick 053 acl repair auto quick 062 attr udf auto quick 068 other auto freeze dangerous stress