test-framework: add null blk

Signed-off-by: Kamil Gierszewski <kamil.gierszewski@huawei.com>

storage_devices/nullblk.py

@@ -0,0 +1,51 @@
+#
+# Copyright(c) 2024 Huawei Technologies Co., Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+from core.test_run import TestRun
+from storage_devices.device import Device
+from test_tools.fs_utils import ls, parse_ls_output
+from test_utils.os_utils import (
+    unload_kernel_module,
+    is_kernel_module_loaded,
+    ModuleRemoveMethod,
+    reload_kernel_module,
+)
+
+
+class NullBlk(Device):
+    _module = "null_blk"
+
+    @classmethod
+    def create(
+        cls, completion_nsec: int = 10000, size_gb: int = 250, nr_devices: int = 1, bs: int = 512
+    ):
+        TestRun.LOGGER.info("Configure null_blk...")
+        params = {
+            "completion_nsec": str(completion_nsec),
+            "gb": str(size_gb),
+            "nr_devices": str(nr_devices),
+            "bs": str(bs),
+        }
+
+        reload_kernel_module(cls._module, params)
+        return cls.list()
+
+    @classmethod
+    def remove_all(cls):
+        if not is_kernel_module_loaded(cls._module):
+            return
+        TestRun.LOGGER.info("Removing null_blk ")
+        unload_kernel_module(module_name=cls._module, unload_method=ModuleRemoveMethod.modprobe)
+
+    @classmethod
+    def list(cls):
+        return [cls(null_blk.full_path) for null_blk in cls._list_devices()]
+
+    @staticmethod
+    def _list_devices():
+        ls_output = ls(f"/dev/nullb*")
+        if "No such file or directory" in ls_output:
+            return []
+        return parse_ls_output(ls_output)

test_tools/fs_utils.py

@@ -100,10 +100,6 @@ def check_if_regular_file_exists(path):
     return TestRun.executor.run(f"test -f \"{path}\"").exit_code == 0
 
 
-def check_if_special_block_exist(path):
-    return TestRun.executor.run(f"test -b \"{path}\"").exit_code == 0
-
-
 def check_if_symlink_exists(path):
     return TestRun.executor.run(f"test -L \"{path}\"").exit_code == 0
 

test_utils/filesystem/symlink.py

@@ -1,6 +1,6 @@
 #
 # Copyright(c) 2019-2021 Intel Corporation
-# Copyright(c) 2023 Huawei Technologies Co., Ltd.
+# Copyright(c) 2023-2024 Huawei Technologies Co., Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
@@ -9,8 +9,7 @@ from test_tools.fs_utils import (
     readlink,
     create_directory,
     check_if_symlink_exists,
-    check_if_directory_exists,
-    check_if_special_block_exist
+    check_if_directory_exists
 )
 from test_utils.filesystem.file import File
 
@@ -77,12 +76,6 @@ class Symlink(File):
                 raise FileExistsError("Existing symlink points to a different target.")
         elif not create:
             raise FileNotFoundError("Requested symlink does not exist.")
-
-        is_special_block = check_if_special_block_exist(link_path)
-        if is_special_block:
-            if not target or readlink(link_path) == readlink(target):
-                return cls(link_path)
-
         is_dir = check_if_directory_exists(link_path)
         if is_dir:
             raise IsADirectoryError(