[PATCH v2 2/2] btrfs: add test for zone auto reclaim

[Johannes Thumshirn <johannes.thumshirn@wdc.com>]

Add a test for the patch titled "btrfs: zoned: automatically reclaim
zones".

This test creates a two file on a newly created FS in a way that when we
delete the first one, an auto reclaim process will be triggered by the FS.

After the reclaim process, it verifies that the data was moved to another
zone and old zone was successfully reset.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 common/config       |   1 +
 tests/btrfs/236     | 103 ++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/236.out |   2 +
 tests/btrfs/group   |   1 +
 4 files changed, 107 insertions(+)
 create mode 100755 tests/btrfs/236
 create mode 100644 tests/btrfs/236.out

diff --git a/common/config b/common/config
index a47e462c7792..1a26934985dd 100644
--- a/common/config
+++ b/common/config
@@ -226,6 +226,7 @@ export FSVERITY_PROG="$(type -P fsverity)"
 export OPENSSL_PROG="$(type -P openssl)"
 export ACCTON_PROG="$(type -P accton)"
 export E2IMAGE_PROG="$(type -P e2image)"
+export BLKZONE_PROG="$(type -P blkzone)"
 
 # use 'udevadm settle' or 'udevsettle' to wait for lv to be settled.
 # newer systems have udevadm command but older systems like RHEL5 don't.
diff --git a/tests/btrfs/236 b/tests/btrfs/236
new file mode 100755
index 000000000000..3be74196ec5d
--- /dev/null
+++ b/tests/btrfs/236
@@ -0,0 +1,103 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Western Digital Corporation.  All Rights Reserved.
+#
+# FS QA Test 236
+#
+# Test that zone autoreclaim works as expected, that is: if the dirty
+# threashold 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=5 # 5s 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 -fdc "pwrite -W 0 $fill_size" $SCRATCH_MNT/$seq.test1 >> $seqres.full
+$XFS_IO_PROG -fdc "pwrite -W 0 $rest" $SCRATCH_MNT/$seq.test2 >> $seqres.full
+sleep 5 # need to make sure the transaction got committed
+
+zones_before=$($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 $SCRATCH_MNT
+sleep 10 # 1 transaction commit for 'rm' and one for balance
+
+# check that we don't have more zones open than before
+zones_after=$($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
+	_fail "New zone same as old zone"
+fi
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/btrfs/236.out b/tests/btrfs/236.out
new file mode 100644
index 000000000000..b6b6e0cad9a7
--- /dev/null
+++ b/tests/btrfs/236.out
@@ -0,0 +1,2 @@
+QA output created by 236
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 331dd432fac3..62c9c761e974 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -238,3 +238,4 @@
 233 auto quick subvolume
 234 auto quick compress rw
 235 auto quick send
+236 auto quick balance
-- 
2.31.1