#! /bin/bash
# FS QA Test No. 042
#
# Test stale data exposure via writeback using various file allocation
# modification commands. The presumption is that such commands result in partial
# writeback and can convert a delayed allocation extent, that might be larger
# than the ranged affected by fallocate, to a normal extent. If the fs happens
# to crash sometime between when the extent modification is logged and writeback
# occurs for dirty pages within the extent but outside of the fallocated range,
# stale data exposure can occur.
#
#-----------------------------------------------------------------------
# Copyright (c) 2014 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.*
}

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

# real QA test starts here
rm -f $seqres.full

_crashtest()
{
	cmd=$1
	img=$SCRATCH_MNT/$seq.img
	mnt=$SCRATCH_MNT/$seq.mnt
	file=$mnt/file

	# Create an fs on a small, initialized image. The pattern is written to
	# the image to detect stale data exposure.
	$XFS_IO_PROG -f -c "truncate 0" -c "pwrite 0 25M" $img \
		>> $seqres.full 2>&1
	_mkfs_dev $img >> $seqres.full 2>&1

	mkdir -p $mnt
	_mount $img $mnt

	echo $cmd

	# write, run the test command and shutdown the fs
	$XFS_IO_PROG -f -c "pwrite -S 1 0 64k" -c "$cmd 60k 4k" $file | \
		_filter_xfs_io
	./src/godown -f $mnt

	$UMOUNT_PROG $mnt
	_mount $img $mnt

	# we generally expect a zero-sized file (this should be silent)
	hexdump $file

	$UMOUNT_PROG $mnt
}

# Modify as appropriate.
_supported_fs generic
_supported_os Linux
_require_scratch
_require_scratch_shutdown
_require_xfs_io_command "falloc"
_require_xfs_io_command "fpunch"
_require_xfs_io_command "fzero"

_scratch_mkfs >/dev/null 2>&1
_scratch_mount

_crashtest "falloc -k"
_crashtest "fpunch"
_crashtest "fzero -k"

status=0
exit
