#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2021 Western Digital Corporation.  All Rights Reserved.
#
# FS QA Test 237
#
# Test that zone autoreclaim works as expected, that is: if the dirty
# threshold is exceeded the data gets relocated to new block group and the
# old block group gets deleted. On block group deletion, the underlying device
# zone also needs to be reset.
#
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 btrfs
_require_scratch
_require_btrfs_command inspect-internal dump-tree
_require_btrfs_command filesystem sync
_require_command "$BLKZONE_PROG" blkzone
_require_zoned_device "$SCRATCH_DEV"

get_data_bg()
{
	$BTRFS_UTIL_PROG inspect-internal dump-tree -t CHUNK $SCRATCH_DEV |\
		grep -A 1 "CHUNK_ITEM" | grep -B 1 "type DATA" |\
		grep -Eo "CHUNK_ITEM [[:digit:]]+" | cut -d ' ' -f 2
}

zonesize=$(cat /sys/block/$(_short_dev $SCRATCH_DEV)/queue/chunk_sectors)
zonesize=$((zonesize << 9))

_scratch_mkfs >/dev/null 2>&1
_scratch_mount -o commit=1 # 1s commit time to speed up test

uuid=$(findmnt -n -o UUID "$SCRATCH_MNT")
reclaim_threshold=75
echo $reclaim_threshold > /sys/fs/btrfs/"$uuid"/bg_reclaim_threshold
fill_percent=$((reclaim_threshold + 2))
rest_percent=$((90 - fill_percent)) # make sure we're not creating a new BG
fill_size=$((zonesize * fill_percent / 100))
rest=$((zonesize * rest_percent / 100))

# step 1, fill FS over $fillsize
$XFS_IO_PROG -fc "pwrite 0 $fill_size" $SCRATCH_MNT/$seq.test1 >> $seqres.full
$XFS_IO_PROG -fc "pwrite 0 $rest" $SCRATCH_MNT/$seq.test2 >> $seqres.full
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT

zones_before=$($BLKZONE_PROG report $SCRATCH_DEV | grep -v -e em -e nw | wc -l)
echo "Before reclaim: $zones_before zones open" >> $seqres.full
old_data_zone=$(get_data_bg)
old_data_zone=$((old_data_zone >> 9))
printf "Old data zone 0x%x\n" $old_data_zone >> $seqres.full

# step 2, delete the 1st $fill_size sized file to trigger reclaim
rm $SCRATCH_MNT/$seq.test1
$BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT
sleep 2 # 1 transaction commit for 'rm' and 1 for balance

# check that we don't have more zones open than before
zones_after=$($BLKZONE_PROG report $SCRATCH_DEV | grep -v -e em -e nw | wc -l)
echo "After reclaim: $zones_after zones open" >> $seqres.full

# Check that old data zone was reset
old_wptr=$($BLKZONE_PROG report -o $old_data_zone -c 1 $SCRATCH_DEV |\
	grep -Eo "wptr 0x[[:xdigit:]]+" | cut -d ' ' -f 2)
if [ "$old_wptr" != "0x000000" ]; then
	_fail "Old wptr still at $old_wptr"
fi

new_data_zone=$(get_data_bg)
new_data_zone=$((new_data_zone >> 9))
printf "New data zone 0x%x\n" $new_data_zone >> $seqres.full

# Check that data was really relocated to a different zone
if [ $old_data_zone -eq $new_data_zone ]; then
	echo "New zone same as old zone"
fi

# success, all done
echo "Silence is golden"
status=0
exit