#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2022 Western Digital Corporation.  All Rights Reserved.
#
# FS QA Test No. 273
#
# Test that an active zone is properly reclaimed to allow the further
# allocations, even if the active zones are mostly filled.
#
. ./common/preamble
_begin_fstest auto quick snapshot zone

# Override the default cleanup function.
_cleanup()
{
	cd /

	# kill commands in stress_data_bgs_2
	[ -n "$pid1" ] && kill $pid1
	[ -n "$pid2" ] && kill $pid2
	wait
}

. ./common/zoned

_supported_fs btrfs
_fixed_by_kernel_commit 2ce543f47843 \
	"btrfs: zoned: wait until zone is finished when allocation didn't progress"
# which is further fixed by
_fixed_by_kernel_commit d5b81ced74af \
	"btrfs: zoned: fix API misuse of zone finish waiting"
_require_zoned_device "$SCRATCH_DEV"
_require_limited_active_zones "$SCRATCH_DEV"

_require_command "$BLKZONE_PROG" blkzone
_require_btrfs_command inspect-internal dump-tree

# This test requires specific data space usage, skip if we have compression
# enabled.
_require_no_compress

max_active=$(cat $(_sysfs_dev ${SCRATCH_DEV})/queue/max_active_zones)

# Fill the zones leaving the last 1MB
fill_active_zones() {
	# Asuumes we have the same capacity between zones.
	local capacity=$(_zone_capacity 0)
	local fill_size=$((capacity - 1024 * 1024))

	for x in $(seq ${max_active}); do
		dd if=/dev/zero of=${SCRATCH_MNT}/fill$(printf "%02d" $x) \
			bs=${fill_size} count=1 oflag=direct 2>/dev/null
		$BTRFS_UTIL_PROG filesystem sync ${SCRATCH_MNT}

		local nactive=$($BLKZONE_PROG report ${SCRATCH_DEV} | grep oi | wc -l)
		if [[ ${nactive} == ${max_active} ]]; then
			break
		fi
	done

	echo "max active zones: ${max_active}" >> $seqres.full
	$BLKZONE_PROG report ${SCRATCH_DEV} | grep oi | cat -n >> $seqres.full
}

workout() {
	local func="$1"

	_scratch_mkfs >/dev/null 2>&1
	_scratch_mount

	fill_active_zones
	eval "$func" || _fail "${func} failed"

	_scratch_unmount
	_check_btrfs_filesystem ${SCRATCH_DEV}
}

stress_data_bgs() {
	# This dd fails with ENOSPC, which should not :(
	dd if=/dev/zero of=${SCRATCH_MNT}/large bs=64M count=1 oflag=sync \
		>>$seqres.full 2>&1
}

stress_data_bgs_2() {
	# This dd fails with ENOSPC, which should not :(
	dd if=/dev/zero of=${SCRATCH_MNT}/large bs=64M count=10 conv=fsync \
		>>$seqres.full 2>&1 &
	pid1=$!

	dd if=/dev/zero of=${SCRATCH_MNT}/large2 bs=64M count=10 conv=fsync \
		>>$seqres.full 2>&1 &
	pid2=$!

	wait $pid1; local ret1=$?; unset pid1
	wait $pid2; local ret2=$?; unset pid2

	if [ $ret1 -ne 0 -o $ret2 -ne 0 ]; then
		return 1
	fi
	return 0
}

get_meta_bgs() {
	$BTRFS_UTIL_PROG inspect-internal dump-tree -t EXTENT ${SCRATCH_DEV} |
		grep BLOCK_GROUP -A 1 |grep -B1 'METADATA|' |
		grep -oP '\(\d+ BLOCK_GROUP_ITEM \d+\)'
}

# This test case does not return the result because
# _btrfs will call _fail() in the error case anyway.
stress_metadata_bgs() {
	local metabgs=$(get_meta_bgs)
	local count=0

	while : ; do
		_btrfs subvolume snapshot ${SCRATCH_MNT} ${SCRATCH_MNT}/snap$i
		_btrfs filesystem sync ${SCRATCH_MNT}
		cur_metabgs=$(get_meta_bgs)
		if [[ "${cur_metabgs}" != "${metabgs}" ]]; then
			break
		fi
		i=$((i + 1))
	done
}

WORKS=(
	stress_data_bgs
	stress_data_bgs_2
	stress_metadata_bgs
)

for work in "${WORKS[@]}"; do
	workout "${work}"
done

echo "Silence is golden"

# success, all done
status=0
exit