#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2017 Red Hat Inc.  All Rights Reserved.
#
# FS QA Test 418
#
# Test pagecache invalidation in buffer/direct write/read combination.
#
# Fork N children, each child writes to and reads from its own region of the
# same test file, and check if what it reads is what it writes. The test region
# is determined by N * blksz. Write and read operation can be either direct or
# buffered.
#
# Regression test for commit c771c14baa33 ("iomap: invalidate page caches
# should be after iomap_dio_complete() in direct write")
#
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

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

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_test
_require_odirect
_require_block_device $TEST_DEV
_require_test_program "dio-invalidate-cache"
_require_test_program "feature"

diotest=$here/src/dio-invalidate-cache
testfile=$TEST_DIR/$seq-diotest
sectorsize=`blockdev --getss $TEST_DEV`
pagesize=`$here/src/feature -s`

# test case array, test different write/read combinations
# -r: use direct read
# -w: use direct write
# -t: truncate file to final size before test, i.e. write to hole
# -p: fallocate whole file before test, i.e. write to allocated but unwritten extents
# -F: fulfill whole file before test, i.e. write to allocated & written extents
t_cases=(
	"-w"
	"-wt"
	"-wp"
	"-wF"
	"-r"
	"-rt"
	"-rp"
	"-rF"
	"-rw"
	"-rwt"
	"-rwp"
	"-rwF"
)

runtest()
{
	local i=0
	local tc=""
	local loop=$1
	shift

	for tc in ${t_cases[*]}; do
		echo "diotest $tc $*" >> $seqres.full
		i=0
		while [ $i -lt $loop ]; do
			$diotest $tc $* -f $testfile
			if [ $? -ne 0 ]; then
				echo "diotest $tc $* failed at loop $i" | \
					tee -a $seqres.full
				break
			fi
			let i=i+1
		done
	done
}

while [ $sectorsize -le $((pagesize * 2)) ]; do
	# reproducer for the original bug
	runtest $((10 * LOAD_FACTOR)) -b $sectorsize -n 3 -i 1
	# try more processes and iterations
	runtest $((5 * LOAD_FACTOR))  -b $sectorsize -n 8 -i 4
	sectorsize=$((sectorsize * 2))
done
echo "Silence is golden"

# success, all done
status=0
exit