Fix online PG count change, add a test for it

tests/run_tests.sh

@@ -10,6 +10,8 @@ cd $(dirname $0)
 ./test_change_pg_count.sh
 SCHEME=ec ./test_change_pg_count.sh
 
+./test_change_pg_count_online.sh
+
 ./test_change_pg_size.sh
 
 ./test_create_nomaxid.sh

tests/test_change_pg_count_online.sh

@@ -0,0 +1,61 @@
+#!/bin/bash -ex
+
+OSD_COUNT=${OSD_COUNT:-6}
+PG_COUNT=16
+GLOBAL_CONFIG=',"client_retry_interval":1000'
+
+. `dirname $0`/run_3osds.sh
+
+LD_PRELOAD="build/src/client/libfio_vitastor.so" \
+fio -thread -name=test -ioengine=build/src/client/libfio_vitastor.so -bs=4M -direct=1 -iodepth=1 -fsync=1 -rw=write \
+    -etcd=$ETCD_URL -pool=1 -inode=2 -size=128M
+
+LD_PRELOAD="build/src/client/libfio_vitastor.so" \
+fio -thread -name=test -ioengine=build/src/client/libfio_vitastor.so -bs=4k -direct=1 -iodepth=4 -rw=randrw \
+    -etcd=$ETCD_URL -pool=1 -inode=2 -size=128M -loops=100 -cluster_log_level=3 -runtime=60 &>./testdata/fio.log &
+FIO_PID=$!
+
+try_change()
+{
+    n=$1
+
+    for i in {1..6}; do
+        echo --- Change PG count to $n --- >>testdata/osd$i.log
+    done
+    echo --- Change PG count to $n --- >>testdata/mon.log
+
+    $ETCDCTL put /vitastor/config/pools '{"1":{'$POOLCFG',"pg_size":'$PG_SIZE',"pg_minsize":'$PG_MINSIZE',"pg_count":'$n'}}'
+    echo "Pool 1 (testpool) PG count changed from $PG_COUNT to $n" >> testdata/pgr.log
+    PG_COUNT=$n
+
+    sleep 10
+}
+
+sleep 5
+
+# 16 -> 32
+
+try_change 32
+
+# 32 -> 16
+
+try_change 16
+
+# 16 -> 25
+
+try_change 25
+
+# 25 -> 17
+
+try_change 17
+
+# 17 -> 16
+
+try_change 16
+
+wait $FIO_PID
+
+grep -P 'Pool 1 \(testpool\) PG count changed from \d+ to \d+' testdata/fio.log > testdata/pgc.log
+diff testdata/pgr.log testdata/pgc.log
+
+format_green OK