#! /bin/bash
# FS QA Test 464
#
# Run delalloc writes & append writes & non-data-integrity syncs concurrently
# to test the race between block map change vs writeback.
#
#-----------------------------------------------------------------------
# Copyright (c) 2017 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

MAXFILES=200
BLOCK_SZ=65536

LOOP_CNT=10
LOOP_TIME=5
PROC_CNT=16

stop=$tmp.stop

# get a random file to work on
getfile()
{
	echo $SCRATCH_MNT/$((RANDOM % MAXFILES))
}

# delalloc write a relative big file to get enough dirty pages to be written
# back, and XFS needs big enough file to trigger speculative preallocations, so
# freeing these eofblocks could change the extent record
do_write()
{
	local blockcount=$((RANDOM % 100))
	local filesize=$((blockcount * BLOCK_SZ))
	$XFS_IO_PROG -ftc "pwrite -b $BLOCK_SZ 0 $filesize" `getfile` \
		>/dev/null 2>&1
}

# append another dirty page to the file, the writeback might pick it up too if
# the file is already under writeback
do_append()
{
	echo "test string" >> `getfile`
}

# issue WB_SYNC_NONE writeback with the '-w' option of sync_range xfs_io
# command, so that the last dirty page from append write can be picked up in
# this writeback cycle. This is not mandatory but could help reproduce XFS
# corruption more easily.
do_writeback()
{
	$XFS_IO_PROG -c "sync_range -w 0 0" `getfile` >/dev/null 2>&1
}

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

# real QA test starts here
_supported_fs generic
_supported_os Linux
# do fsck after each iteration in test
_require_scratch_nocheck
_require_xfs_io_command "sync_range"

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

# loop for $LOOP_CNT iterations, and each iteration starts $PROC_CNT processes
# for each operation and runs for $LOOP_TIME seconds, and check filesystem
# consistency after each iteration
for i in `seq 1 $LOOP_CNT`; do
	rm -f $stop
	for j in `seq 1 $PROC_CNT`; do
		while [ ! -e $stop ]; do
			do_write
		done &

		while [ ! -e $stop ]; do
			do_append
		done &

		while [ ! -e $stop ]; do
			do_writeback
		done &
	done
	sleep $LOOP_TIME
	touch $stop
	wait

	_scratch_unmount
	# test exits here if fs is inconsistent
	_check_scratch_fs
	_scratch_mount
done

echo "Silence is golden"

# success, all done
status=0
exit