Added cache mode change in pyocf and basic test

tests/functional/pyocf/types/cache.py

@@ -160,6 +160,11 @@ class Cache:
         if status:
             raise OcfError("Error setting management queue", status)
 
+    def change_cache_mode(self, cache_mode: CacheMode):
+        self.get_and_write_lock()
+        self.owner.lib.ocf_mngt_cache_set_mode(self.cache_handle, cache_mode)
+        self.put_and_write_unlock()
+
     def configure_device(
         self, device, force=False, perform_test=False, cache_line_size=None
     ):

tests/functional/tests/management/test_change_mode.py

@@ -0,0 +1,29 @@
+#
+# Copyright(c) 2019 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+
+import pytest
+
+from pyocf.types.cache import Cache, CacheMode
+from pyocf.types.volume import Volume
+from pyocf.utils import Size as S
+from pyocf.types.shared import CacheLineSize
+
+
+@pytest.mark.parametrize("from_cm", CacheMode)
+@pytest.mark.parametrize("to_cm", CacheMode)
+@pytest.mark.parametrize("cls", CacheLineSize)
+def test_change_cache_mode(pyocf_ctx, from_cm, to_cm, cls):
+    # Start cache device
+    cache_device = Volume(S.from_MiB(100))
+    cache = Cache.start_on_device(cache_device, cache_mode=from_cm, cache_line_size=cls)
+
+    # Check if started with correct cache mode
+    stats = cache.get_stats()
+    assert stats["conf"]["cache_mode"] == from_cm
+
+    # Change cache mode and check if stats are as expected
+    cache.change_cache_mode(to_cm)
+    stats_after = cache.get_stats()
+    assert stats_after["conf"]["cache_mode"] == to_cm