Merge "Fix race in check and access of /dev/disk/by-path/"

os_brick/initiator/host_driver.py

@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import errno
 import os
 
 
@@ -20,10 +21,15 @@ class HostDriver(object):
 
     def get_all_block_devices(self):
         """Get the list of all block devices seen in /dev/disk/by-path/."""
-        files = []
         dir = "/dev/disk/by-path/"
-        if os.path.isdir(dir):
+        try:
             files = os.listdir(dir)
+        except OSError as e:
+            if e.errno == errno.ENOENT:
+                files = []
+            else:
+                raise
+
         devices = []
         for file in files:
             devices.append(dir + file)

os_brick/tests/initiator/test_connector.py

@@ -193,22 +193,6 @@ class ConnectorTestCase(base.TestCase):
             self.assertFalse(self.connector.check_valid_device('/dev'))
 
 
-class HostDriverTestCase(base.TestCase):
-
-    def setUp(self):
-        super(HostDriverTestCase, self).setUp()
-        self.devlist = ['device1', 'device2']
-        mock.patch.object(os.path, 'isdir', return_value=True).start()
-        mock.patch.object(os, 'listdir', return_value=self.devlist).start()
-        self.addCleanup(mock.patch.stopall)
-
-    def test_host_driver(self):
-        expected = ['/dev/disk/by-path/' + dev for dev in self.devlist]
-        driver = host_driver.HostDriver()
-        actual = driver.get_all_block_devices()
-        self.assertEqual(expected, actual)
-
-
 class ISCSIConnectorTestCase(ConnectorTestCase):
 
     def setUp(self):

os_brick/tests/initiator/test_host_driver.py

@@ -0,0 +1,47 @@
+# Copyright (c) 2015 Scality
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import errno
+
+import mock
+
+from os_brick.initiator import host_driver
+from os_brick.tests import base
+
+
+class HostDriverTestCase(base.TestCase):
+
+    def test_get_all_block_devices(self):
+        fake_dev = ['device1', 'device2']
+        expected = ['/dev/disk/by-path/' + dev for dev in fake_dev]
+
+        driver = host_driver.HostDriver()
+        with mock.patch('os.listdir', return_value=fake_dev):
+            actual = driver.get_all_block_devices()
+
+        self.assertEqual(expected, actual)
+
+    def test_get_all_block_devices_when_oserror_is_enoent(self):
+        driver = host_driver.HostDriver()
+        oserror = OSError(errno.ENOENT, "")
+        with mock.patch('os.listdir', side_effect=oserror):
+            block_devices = driver.get_all_block_devices()
+
+        self.assertEqual([], block_devices)
+
+    def test_get_all_block_devices_when_oserror_is_not_enoent(self):
+        driver = host_driver.HostDriver()
+        oserror = OSError(errno.ENOMEM, "")
+        with mock.patch('os.listdir', side_effect=oserror):
+            self.assertRaises(OSError, driver.get_all_block_devices)