Merge pull request #486 from katlapinka/trim-eviction

Add test verifying if trim request does not cause eviction on CAS device

test/functional/tests/io/trim/test_trim_eviction.py

@@ -0,0 +1,88 @@
+#
+# Copyright(c) 2020 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+
+import os
+import pytest
+from api.cas import casadm
+from api.cas.cache_config import CacheMode, CacheLineSize, CleaningPolicy
+from core.test_run import TestRun
+from storage_devices.disk import DiskTypeSet, DiskType, DiskTypeLowerThan
+from test_tools import fs_utils
+from test_tools.ddrescue import Ddrescue
+from test_tools.disk_utils import Filesystem
+from test_utils import os_utils
+from test_utils.os_utils import Udev
+from test_utils.size import Size, Unit
+
+
+@pytest.mark.require_disk("cache", DiskTypeSet([DiskType.optane, DiskType.nand, DiskType.sata]))
+@pytest.mark.require_disk("core", DiskTypeLowerThan("cache"))
+@pytest.mark.parametrizex("cache_mode", CacheMode)
+@pytest.mark.parametrizex("cache_line_size", CacheLineSize)
+@pytest.mark.parametrizex("filesystem", [Filesystem.ext4, Filesystem.xfs])
+@pytest.mark.parametrizex("cleaning", [CleaningPolicy.alru, CleaningPolicy.nop])
+def test_trim_eviction(cache_mode, cache_line_size, filesystem, cleaning):
+    """
+        title: Test verifying if trim requests do not cause eviction on CAS device.
+        description: |
+          When trim requests enabled and files are being added and removed from CAS device,
+          there is no eviction (no reads from cache).
+        pass_criteria:
+          - Reads from cache device are the same before and after removing test file.
+    """
+    mount_point = "/mnt"
+    test_file_path = os.path.join(mount_point, "test_file")
+
+    with TestRun.step("Prepare devices."):
+        cache_disk = TestRun.disks['cache']
+        cache_disk.create_partitions([Size(1, Unit.GibiByte)])
+        cache_dev = cache_disk.partitions[0]
+
+        core_disk = TestRun.disks['core']
+        core_disk.create_partitions([Size(1, Unit.GibiByte)])
+        core_dev = core_disk.partitions[0]
+
+    with TestRun.step("Start cache on device supporting trim and add core."):
+        cache = casadm.start_cache(cache_dev, cache_mode, cache_line_size)
+        cache.set_cleaning_policy(cleaning)
+        Udev.disable()
+        core = cache.add_core(core_dev)
+
+    with TestRun.step("Create filesystem on CAS device and mount it."):
+        core.create_filesystem(filesystem)
+        core.mount(mount_point, ["discard"])
+
+    with TestRun.step("Create random file using ddrescue."):
+        test_file = fs_utils.create_random_test_file(test_file_path, core_dev.size * 0.9)
+        create_file_with_ddrescue(core_dev, test_file)
+
+    with TestRun.step("Remove file and create a new one."):
+        cache_iostats_before = cache_dev.get_io_stats()
+        test_file.remove()
+        os_utils.sync()
+        os_utils.drop_caches()
+        create_file_with_ddrescue(core_dev, test_file)
+
+    with TestRun.step("Check using iostat that reads from cache did not occur."):
+        cache_iostats_after = cache_dev.get_io_stats()
+        reads_before = cache_iostats_before.sectors_read
+        reads_after = cache_iostats_after.sectors_read
+
+        if reads_after != reads_before:
+            TestRun.fail(f"Number of reads from cache before and after removing test file "
+                         f"differs. Reads before: {reads_before}, reads after: {reads_after}.")
+        else:
+            TestRun.LOGGER.info(
+                "Number of reads from cache before and after removing test file is the same.")
+
+
+def create_file_with_ddrescue(core_dev, test_file):
+    ddrescue = Ddrescue() \
+        .block_size(Size(1, Unit.Blocks4096)) \
+        .size(core_dev.size * 0.9) \
+        .synchronous() \
+        .source("/dev/urandom") \
+        .destination(test_file.full_path)
+    ddrescue.run()