Check for FLUSH and FUA signals sent to multilevel cache in lazy-write modes

Add test for checking for logs of requests insyslog from OpenCAS
when SCSI_DEBUG module is base-level core device in multilevel cache.

Signed-off-by: Slawomir Jankowski <slawomir.jankowski@intel.com>

test/functional/tests/lazy_writes/test_lazy_writes_signals.py

@@ -218,6 +218,117 @@ def test_flush_signal_cache(cache_mode):
         cache.stop()
 
 
+@pytest.mark.require_plugin("scsi_debug_fua_signals", dev_size_mb="2048", opts="1")
+@pytest.mark.parametrize("cache_mode", CacheMode.with_traits(CacheModeTrait.LazyWrites))
+@pytest.mark.require_disk("cache", DiskTypeSet([DiskType.optane, DiskType.nand]))
+def test_flush_signal_multilevel_cache(cache_mode):
+    """
+        title: Test for FLUSH and FUA signals sent to multilevel cache in modes with lazy writes.
+        description: |
+          Test if OpenCAS transmits FLUSH and FUA signals with multilevel cache in lazy-write modes.
+        pass_criteria:
+          - FLUSH requests should be passed by multilevel cache to core device.
+          - FUA requests should be passed by multilevel cache to core device.
+    """
+    with TestRun.step("Set mark in syslog to not read entries existing before the test."):
+        Logs._read_syslog(Logs.last_read_line)
+
+    with TestRun.step("Prepare devices for multilevel cache."):
+        cache_dev = TestRun.disks['cache']
+        cache_dev.create_partitions([Size(1, Unit.GibiByte)] * 2)
+        cache_part1 = cache_dev.partitions[0]
+        cache_part2 = cache_dev.partitions[1]
+        core_dev = TestRun.scsi_debug_devices[0]
+
+    with TestRun.step("Start the first cache and add the SCSI device as a core."):
+        cache1 = casadm.start_cache(cache_part1, cache_mode)
+        core1 = cache1.add_core(core_dev)
+
+    with TestRun.step("Start the second cache and add the 1st exported object as core."):
+        cache2 = casadm.start_cache(cache_part2, cache_mode)
+        core2 = cache2.add_core(core1)
+
+    with TestRun.step("Create xfs filesystem on the 2nd exported object and mount it."):
+        core2.create_filesystem(Filesystem.xfs)
+        if core2.is_mounted():
+            core2.unmount()
+        core2.mount(mount_point)
+
+    with TestRun.step("Turn off cleaning policy on both caches."):
+        cache1.set_cleaning_policy(CleaningPolicy.nop)
+        cache2.set_cleaning_policy(CleaningPolicy.nop)
+
+    with TestRun.step("Create temporary file on the 2nd exported object."):
+        tmp_file = create_random_test_file(f"{mount_point}/tmp.file", Size(512, Unit.MebiByte))
+        os_utils.sync()
+
+    with TestRun.step("Flush both caches."):
+        cache2.flush_cache()
+        cache1.flush_cache()
+        os_utils.sync()
+
+    with TestRun.step(f"Check {syslog_path} for flush and FUA requests and delete temporary file."):
+        Logs.check_syslog_for_signals()
+        tmp_file.remove(True)
+
+    with TestRun.step("Create temporary file on the 2nd exported object."):
+        tmp_file = create_random_test_file(f"{mount_point}/tmp.file", Size(512, Unit.MebiByte))
+        os_utils.sync()
+
+    with TestRun.step("Flush both cores."):
+        core2.flush_core()
+        core1.flush_core()
+        os_utils.sync()
+
+    with TestRun.step(f"Check {syslog_path} for flush request and delete temporary file."):
+        Logs.check_syslog_for_signals()
+        tmp_file.remove(True)
+
+    with TestRun.step("Turn on alru cleaning policy and set policy params on both caches."):
+        cache1.set_cleaning_policy(CleaningPolicy.alru)
+        cache1.set_params_alru(FlushParametersAlru(
+            Time(milliseconds=5000), 10000, Time(seconds=10), Time(seconds=10))
+        )
+        cache2.set_cleaning_policy(CleaningPolicy.alru)
+        cache2.set_params_alru(FlushParametersAlru(
+            Time(milliseconds=5000), 10000, Time(seconds=10), Time(seconds=10))
+        )
+
+    with TestRun.step("Create big temporary file on the 2nd exported object."):
+        tmp_file = create_random_test_file(f"{mount_point}/tmp.file", Size(3, Unit.GibiByte))
+        os_utils.sync()
+
+    with TestRun.step("Wait for automatic flush from alru cleaning policy and check log."):
+        wait_time = (
+            int(cache2.get_flush_parameters_alru().staleness_time.total_seconds())
+            + int(cache2.get_flush_parameters_alru().activity_threshold.total_seconds())
+            + int(cache2.get_flush_parameters_alru().wake_up_time.total_seconds())
+            + 5
+        )
+        sleep(wait_time)
+
+    with TestRun.step(f"Check {syslog_path} for flush and FUA requests and delete temporary file."):
+        Logs.check_syslog_for_signals()
+        tmp_file.remove(True)
+
+    with TestRun.step("Create temporary file on the 2nd exported object."):
+        create_random_test_file(f"{mount_point}/tmp.file", Size(512, Unit.MebiByte))
+        os_utils.sync()
+
+    with TestRun.step("Unmount the 2nd exported object and remove cores from caches."):
+        core2.unmount()
+        core2.remove_core()
+        core1.remove_core()
+        os_utils.sync()
+
+    with TestRun.step(f"Check {syslog_path} for flush request."):
+        Logs.check_syslog_for_signals()
+
+    with TestRun.step("Stop both caches."):
+        cache2.stop()
+        cache1.stop()
+
+
 class Logs:
     last_read_line = 1
     FLUSH = re.compile(r"scsi_debug:[\s\S]*cmd 35")