#! /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"

_scratch_mkfs >>$seqres.full 2>&1
_dmerror_init

# 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