tests/generic/462

#! /bin/bash
# FS QA Test 462
#
# This is a regression test for kernel commit
#  ef947b2 x86, mm: fix gup_pte_range() vs DAX mappings
# created by Jeffrey Moyer <jmoyer@redhat.com>
#
# This is reproducible only when testing on pmem device
# which is configured in "memory mode", not in "raw mode".
#
#-----------------------------------------------------------------------
# Copyright (c) 2017 Red Hat.  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 -rf $tmp.*
}

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

# remove previous $seqres.full before test
rm -f $seqres.full

# Modify as appropriate.
_supported_fs generic
_supported_os Linux
_require_test
_require_scratch_dax
_require_test_program "t_mmap_write_ro"
# running by unpriviliged user is not necessary to reproduce
# this bug, just trying to test more.
_require_user

# real QA test starts here

_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o dax"

# remount TEST_DEV wo/ dax
export TEST_FS_MOUNT_OPTS=""
_test_cycle_mount

# prepare a 4k read-only DAX file, save its md5sum
$XFS_IO_PROG -f -c "pwrite -S 0xFF 0 4096" \
	$SCRATCH_MNT/readonlyfile >> $seqres.full 2>&1
chmod 0644  $SCRATCH_MNT/readonlyfile
md5_1="$(_md5_checksum $SCRATCH_MNT/readonlyfile)"

# prepare another 4k non-DAX file
$XFS_IO_PROG -f -c "pwrite -S 0x00 0 4096" \
	$TEST_DIR/${seq}.file >> $seqres.full 2>&1

# allow qa_user access
chown $qa_user $TEST_DIR/${seq}.file

# run test programme, read another file writing into
# the read-only file with mmap, which should fail.
_user_do "src/t_mmap_write_ro $TEST_DIR/${seq}.file \
	$SCRATCH_MNT/readonlyfile"

# read-only file should not get updated, md5sum again.
md5_2="$(_md5_checksum $SCRATCH_MNT/readonlyfile)"

[ "$md5_1" != "$md5_2" ] && echo "read only file changed"

# success, all done
status=0
exit