From: Eryu Guan Subject: [PATCH v2] generic: test I/O on dm error device Date: Tue, 15 Mar 2016 16:12:14 +0800 Message-ID: <1458029534-17578-1-git-send-email-eguan@redhat.com> References: <1457710822-30532-2-git-send-email-eguan@redhat.com> Cc: linux-ext4@vger.kernel.org, Eryu Guan To: fstests@vger.kernel.org Return-path: In-Reply-To: <1457710822-30532-2-git-send-email-eguan@redhat.com> Sender: fstests-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org This is a test that performs simple I/O on dm error device, which returns EIO on all I/O request. This is motivated by an ext4 bug that crashes kernel on error path when trying to update atime. Following kernel patch should fix the issue ext4: fix NULL pointer dereference in ext4_mark_inode_dirty() Signed-off-by: Eryu Guan --- v2: - use SCRATCH_DEV directly instead of loop device and call blockdev --flushbufs $SCRATCH_DEV before drop caches (suggested by Dave) tests/generic/338 | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/338.out | 2 ++ tests/generic/group | 1 + 3 files changed, 83 insertions(+) create mode 100755 tests/generic/338 create mode 100644 tests/generic/338.out diff --git a/tests/generic/338 b/tests/generic/338 new file mode 100755 index 0000000..235549a --- /dev/null +++ b/tests/generic/338 @@ -0,0 +1,80 @@ +#! /bin/bash +# FS QA Test 338 +# +# Test I/O on dm error device. +# +# Motivated by an ext4 bug that crashes kernel on error path when trying to +# update atime. +# +#----------------------------------------------------------------------- +# 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.* + _dmerror_cleanup +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter +. ./common/dmerror + +# remove previous $seqres.full before test +rm -f $seqres.full + +# real QA test starts here +_supported_fs generic +_supported_os Linux +_require_scratch +_require_dm_target error +# If SCRATCH_DEV is not a valid block device, FSTYP cannot be mkfs'ed either +_require_block_device $SCRATCH_DEV + +echo "Silence is golden" + +_dmerror_init +_mkfs_dev $DMERROR_DEV + +# Use strictatime mount option here to force atime updates, which could help +# trigger the NULL pointer dereference on ext4 more easily +_dmerror_mount "-o strictatime" +_dmerror_load_error_table + +# flush dmerror block device buffers and drop all caches, force reading from +# error device +blockdev --flushbufs $DMERROR_DEV +echo 3 > /proc/sys/vm/drop_caches + +# do some test I/O +ls -l $SCRATCH_MNT >>$seqres.full 2>&1 +$XFS_IO_PROG -fc "pwrite 0 1M" $SCRATCH_MNT/testfile >>$seqres.full 2>&1 + +# no panic no hang, success, all done +status=0 +exit diff --git a/tests/generic/338.out b/tests/generic/338.out new file mode 100644 index 0000000..3482cf4 --- /dev/null +++ b/tests/generic/338.out @@ -0,0 +1,2 @@ +QA output created by 338 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index 727648c..8818827 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -340,3 +340,4 @@ 335 auto quick metadata 336 auto quick metadata 337 auto quick metadata +338 auto quick rw -- 1.8.3.1