tests/generic/085

#! /bin/bash
# FS QA Test No. 085
#
# Exercise fs freeze/unfreeze and mount/umount race, which could lead to
# use-after-free oops.
#
# This commit fixed the issue:
# 1494583 fix get_active_super()/umount() race
#
#-----------------------------------------------------------------------
# Copyright (c) 2015 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.*
	cleanup_dmdev
}

cleanup_dmdev()
{
	# in case it's still suspended and/or mounted
	$DMSETUP_PROG resume $lvdev >/dev/null 2>&1
	$UMOUNT_PROG $lvdev >/dev/null 2>&1

	$DMSETUP_PROG remove $node >>$seqres.full 2>&1
	$DMSETUP_PROG mknodes >/dev/null 2>&1
}

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch
_require_block_device $SCRATCH_DEV
_require_dm_target linear
_require_freeze

setup_dmdev()
{
	table="0 $size_in_sector linear $SCRATCH_DEV 0"
	$DMSETUP_PROG create $node --table "$table" >>$seqres.full 2>&1 && \
	$DMSETUP_PROG mknodes >/dev/null 2>&1
	return $?
}

rm -f $seqres.full
echo "Silence is golden"

size=$((256 * 1024 * 1024))
size_in_sector=$((size / 512))
_scratch_mkfs_sized $size >>$seqres.full 2>&1

node=$seq-test
lvdev=/dev/mapper/$node
setup_dmdev || _fail "setup dm device failed"

# take use of dmsetup suspend to freeze the fs.
# xfs_freeze/fsfreeze cannot be used in this test, because it can possibly
# freeze the root fs of the host when SCRATCH_MNT is not mounted
#
# And the results of the racing commands (suspend/resume, mount/umount) are not
# important, as long as they're racing with each other. So just throw away the
# outputs and ignore the results.
for ((i=0; i<100; i++)); do
	$DMSETUP_PROG suspend $lvdev >/dev/null 2>&1
	$DMSETUP_PROG resume $lvdev >/dev/null 2>&1
done &
pid=$!
for ((i=0; i<100; i++)); do
	$MOUNT_PROG $lvdev $SCRATCH_MNT >/dev/null 2>&1
	$UMOUNT_PROG $lvdev >/dev/null 2>&1
done &
pid="$pid $!"

wait $pid

status=0
exit