btrfs: add test for zone auto reclaim

Add a test for commit 18bb8bbf13c1 ("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>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

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.

tests/btrfs/237

@@ -0,0 +1,103 @@
+#! /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

tests/btrfs/237.out

@@ -0,0 +1,2 @@
+QA output created by 237
+Silence is golden

tests/btrfs/group

@@ -239,3 +239,4 @@
 234 auto quick compress rw
 235 auto quick send
 236 auto quick log
+237 auto quick zone balance