From patchwork Sat Jan 10 10:56:08 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 5604661 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 61BB8C058D for ; Sat, 10 Jan 2015 10:57:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 57C2E20444 for ; Sat, 10 Jan 2015 10:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2DF6C2043C for ; Sat, 10 Jan 2015 10:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752880AbbAJK44 (ORCPT ); Sat, 10 Jan 2015 05:56:56 -0500 Received: from victor.provo.novell.com ([137.65.250.26]:57010 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751156AbbAJK4s (ORCPT ); Sat, 10 Jan 2015 05:56:48 -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); Sat, 10 Jan 2015 03:56:40 -0700 From: Filipe Manana To: fstests@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, Filipe Manana Subject: [PATCH v2] fstests: add generic test for fsync after unlink Date: Sat, 10 Jan 2015 10:56:08 +0000 Message-Id: <1420887368-13825-1-git-send-email-fdmanana@suse.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1420575680-9809-1-git-send-email-fdmanana@suse.com> References: <1420575680-9809-1-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 after fsyncing an inode that got its link count decremented, and the new link count is greater than zero, after the fsync log replay the inode's parent directory metadata became inconsistent - it had a wrong i_size and dangling index entries which prevented the directory from ever being removed (rmdir always failed with -ENOTEMPTY, even if the directory had no more child inodes). The btrfs issue was fixed by the following linux kernel patch: Btrfs: fix directory inconsistency after fsync log replay Signed-off-by: Filipe Manana --- V2: Fixed copyright year, s/2014/2015/. Updated comments to add more details about the issue. tests/generic/039 | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/039.out | 2 + tests/generic/group | 1 + 3 files changed, 115 insertions(+) create mode 100755 tests/generic/039 create mode 100644 tests/generic/039.out diff --git a/tests/generic/039 b/tests/generic/039 new file mode 100755 index 0000000..4997aac --- /dev/null +++ b/tests/generic/039 @@ -0,0 +1,112 @@ +#! /bin/bash +# FS QA Test No. 039 +# +# This test is motivated by an fsync issue discovered in btrfs. +# The issue was that after fsyncing an inode that got its link count +# decremented, and the new link count is greater than zero, after the +# fsync log replay the inode's parent directory metadata became +# inconsistent - it had a wrong i_size and dangling index entries which +# prevented the directory from ever being removed (rmdir always failed +# with -ENOTEMPTY, even if the directory had no more child inodes). +# +# The btrfs issue was fixed by the following linux kernel patch: +# +# Btrfs: fix directory inconsistency after fsync log replay +# +#----------------------------------------------------------------------- +# 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 +} +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 a test file with 2 hard links in the same directory. +mkdir -p $SCRATCH_MNT/a/b +echo "hello world" > $SCRATCH_MNT/a/b/foo +ln $SCRATCH_MNT/a/b/foo $SCRATCH_MNT/a/b/bar + +# Make sure all metadata and data are durably persisted. +sync + +# Now remove one of the hard links and fsync the inode. +rm -f $SCRATCH_MNT/a/b/bar +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a/b/foo + +# Simulate a crash/power loss. This makes sure the next mount +# will see an fsync log and will replay that log. + +_load_flakey_table $FLAKEY_DROP_WRITES +_unmount_flakey + +_load_flakey_table $FLAKEY_ALLOW_WRITES +_mount_flakey + +# Remove the last hard link of the file and attempt to remove its parent +# directory - this failed in btrfs because the fsync log and replay code +# didn't decrement the parent directory's i_size and left dangling directory +# index entries - this made the btrfs rmdir implementation always fail with +# the error -ENOTEMPTY. +# +# The dangling directory index entries were visible to user space, but it was +# impossible to do anything on them (unlink, open, read, write, stat, etc) +# because the inode they pointed to did not exist anymore. +# +# The parent directory's metadata inconsistency (stale index entries) was +# also detected by btrfs' fsck tool, which is run automatically by the fstests +# framework when the test finishes. The error message reported by fsck was: +# +# root 5 inode 259 errors 2001, no inode item, link count wrong +# unresolved ref dir 258 index 3 namelen 3 name bar filetype 1 errors 4, no inode ref +# +rm -f $SCRATCH_MNT/a/b/* +rmdir $SCRATCH_MNT/a/b +rmdir $SCRATCH_MNT/a + +echo "Silence is golden" +status=0 +exit diff --git a/tests/generic/039.out b/tests/generic/039.out new file mode 100644 index 0000000..d4e7ef6 --- /dev/null +++ b/tests/generic/039.out @@ -0,0 +1,2 @@ +QA output created by 039 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index 1e89848..6af5a1a 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -41,6 +41,7 @@ 036 auto aio rw stress 037 metadata auto quick 038 auto stress +039 metadata auto quick 053 acl repair auto quick 062 attr udf auto quick 068 other auto freeze dangerous stress