Add a test for an idiotic checksum bug

tests/run_tests.sh

@@ -138,6 +138,7 @@ OLD=1 SCHEME=xor ./test_scrub.sh
 OLD=1 PG_SIZE=3 ./test_scrub.sh
 OLD=1 PG_SIZE=6 PG_MINSIZE=4 OSD_COUNT=6 SCHEME=ec ./test_scrub.sh
 OLD=1 SCHEME=ec ./test_scrub.sh
+OLD=1 ./test_partwr_csum.sh
 
 TEST_NAME=old_csum_32k_dmj OLD=1 OSD_ARGS="--data_csum_type crc32c --csum_block_size 32k --inmemory_metadata false --inmemory_journal false" OFFSET_ARGS=$OSD_ARGS ./test_heal.sh
 TEST_NAME=old_csum_32k_dj  OLD=1 OSD_ARGS="--data_csum_type crc32c --csum_block_size 32k --inmemory_journal false" OFFSET_ARGS=$OSD_ARGS ./test_heal.sh

tests/test_partwr_csum.sh

@@ -0,0 +1,18 @@
+#!/bin/bash -ex
+
+OSD_ARGS="--data_csum_type crc32c"
+OFFSET_ARGS=$OSD_ARGS
+GLOBAL_CONFIG=',"client_eio_retry_interval":0'
+. `dirname $0`/run_3osds.sh
+
+$VITASTOR_CLI create -s 32M testimg
+
+$VITASTOR_FIO -bs=4k -blockalign=128k -direct=1 -iodepth=16 -end_fsync=1 -rw=write -image=testimg
+
+$VITASTOR_CLI dd iimg=testimg of=/dev/null
+
+if grep -q 'Checksum mismatch' ./testdata/osd*.log; then
+    format_error Checksum mismatches detected during test
+fi
+
+format_green OK