#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2020-2021 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test No. 168
#
# XFS online shrinkfs stress test
#
# This test attempts to shrink unused space as much as possible with
# background fsstress workload. It will decrease the shrink size if
# larger size fails. And totally repeat 2 * TIME_FACTOR times.
#
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1	# failure is the default!
trap "rm -f $tmp.*; exit \$status" 0 1 2 3 15

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

create_scratch()
{
	_scratch_mkfs_xfs $@ | tee -a $seqres.full | \
		_filter_mkfs 2>$tmp.mkfs >/dev/null
	. $tmp.mkfs

	_scratch_mount
	# fix the reserve block pool to a known size so that the enospc
	# calculations work out correctly.
	_scratch_resvblks 1024 > /dev/null 2>&1
}

fill_scratch()
{
	$XFS_IO_PROG -f -c "falloc 0 $1" $SCRATCH_MNT/resvfile
}

stress_scratch()
{
	local procs=3
	local nops=1000
	# -w ensures that the only ops are ones which cause write I/O
	local FSSTRESS_ARGS=`_scale_fsstress_args -d $SCRATCH_MNT -w \
		-p $procs -n $nops $FSSTRESS_AVOID`
	$FSSTRESS_PROG $FSSTRESS_ARGS >> $seqres.full 2>&1
}

# real QA test starts here
_supported_fs xfs
_require_scratch_xfs_shrink
_require_xfs_io_command "falloc"

rm -f $seqres.full
_scratch_mkfs_xfs | tee -a $seqres.full | _filter_mkfs 2>$tmp.mkfs >/dev/null
. $tmp.mkfs	# extract blocksize and data size for scratch device

endsize=`expr 125 \* 1048576`	# stop after shrinking this big
[ `expr $endsize / $dbsize` -lt $dblocks ] || _notrun "Scratch device too small"

nags=2
totalcount=$((2 * TIME_FACTOR))

while [ $totalcount -gt 0 ]; do
	size=`expr 1010 \* 1048576`	# 1010 megabytes initially
	logblks=$(_scratch_find_xfs_min_logblocks -dsize=${size} -dagcount=${nags})

	create_scratch -lsize=${logblks}b -dsize=${size} -dagcount=${nags}

	for i in `seq 125 -1 90`; do
		fillsize=`expr $i \* 1048576`
		out="$(fill_scratch $fillsize 2>&1)"
		echo "$out" | grep -q 'No space left on device' && continue
		test -n "${out}" && echo "$out"
		break
	done

	# shrink in chunks of this size at most
	decsize=`expr  41 \* 1048576 + 1 + $RANDOM \* $RANDOM % 1048576`

	while [ $size -gt $endsize ]; do
		stress_scratch &
		sleep 1

		decb=`expr $decsize / $dbsize`    # in data blocks
		while [ $decb -gt 0 ]; do
			sizeb=`expr $size / $dbsize - $decb`

			$XFS_GROWFS_PROG -D ${sizeb} $SCRATCH_MNT \
				>> $seqres.full 2>&1 && break

			[ $decb -gt 100 ] && decb=`expr $decb + $RANDOM % 10`
			decb=`expr $decb / 2`
		done

		wait
		[ $decb -eq 0 ] && break

		# get latest dblocks
		$XFS_INFO_PROG $SCRATCH_MNT 2>&1 | _filter_mkfs 2>$tmp.growfs >/dev/null
		. $tmp.growfs

		size=`expr $dblocks \* $dbsize`
		_scratch_unmount
		_scratch_xfs_repair -n >> $seqres.full 2>&1 || \
			_fail "xfs_repair failed with shrinking $sizeb"
		_scratch_mount
	done

	_scratch_unmount
	_scratch_xfs_repair -n >> $seqres.full 2>&1 || \
		_fail "xfs_repair failed with shrinking $sizeb"
	totalcount=`expr $totalcount - 1`
done

echo "Silence is golden"
status=0
exit