Test for IO in d2c after attaching cache

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>

tests/functional/tests/engine/test_d2c.py

@@ -0,0 +1,73 @@
+#
+# Copyright(c) 2024 Huawei Technologies
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+
+import pytest
+
+
+from pyocf.types.cache import Cache
+from pyocf.types.core import Core
+from pyocf.types.data import Data
+from pyocf.types.io import IoDir, Sync
+from pyocf.types.volume import RamVolume
+from pyocf.types.volume_core import CoreVolume
+from pyocf.utils import Size
+
+CORE_SIZE = 4096
+
+
+@pytest.mark.xfail(reason="Data corruption when switching from D2C")
+def test_d2c_io(pyocf_ctx):
+    """
+    Start cache in D2C
+    prepare an IO in D2C
+    attach cache
+    submit and complete an IO in WT
+    submit the D2C IO
+    read data from core
+    verify the data read from core matches with content of the core disk
+    """
+    cache_device = RamVolume(Size.from_MiB(50))
+    core_device = RamVolume(Size(CORE_SIZE))
+
+    cache = Cache(owner=pyocf_ctx)
+    cache.start_cache()
+    core = Core.using_device(core_device)
+    cache.add_core(core)
+
+    queue = cache.get_default_queue()
+    vol = CoreVolume(core)
+    vol.open()
+
+    d2c_io = vol.new_io(queue, 0, CORE_SIZE, IoDir.WRITE, 0, 0)
+    d2c_data = Data(CORE_SIZE)
+    d2c_data.write(b"a" * CORE_SIZE, CORE_SIZE)
+    d2c_io.set_data(d2c_data)
+
+    cache.attach_device(cache_device)
+
+    wt_io = vol.new_io(queue, 0, CORE_SIZE, IoDir.WRITE, 0, 0)
+    wt_data = Data(CORE_SIZE)
+    wt_data.write(b"b" * CORE_SIZE, CORE_SIZE)
+    wt_io.set_data(wt_data)
+
+    wt_completion = Sync(wt_io).submit()
+    assert int(wt_completion.results["err"]) == 0
+    assert cache.get_stats()["req"]["wr_full_misses"]["value"] == 1
+
+    d2c_completion = Sync(d2c_io).submit()
+    assert int(d2c_completion.results["err"]) == 0
+    assert cache.get_stats()["req"]["wr_pt"]["value"] == 1
+
+    read_io = vol.new_io(queue, 0, CORE_SIZE, IoDir.READ, 0, 0)
+    read_data = Data(CORE_SIZE)
+    read_io.set_data(read_data)
+
+    read_completion = Sync(read_io).submit()
+    assert int(read_completion.results["err"]) == 0
+
+    cache.stop()
+
+    assert core_device.md5() == read_data.md5()