Move vol_db_empty to NFS driver

Check for vol_db_empty is needed only for NFS-based drivers. That's why
I moved these checks out from volume manager.

Change-Id: I11d29948b9850734278bf66b790ffb214f8e4872

cinder/tests/unit/volume/drivers/test_quobyte.py

@@ -46,6 +46,9 @@ class FakeDb(object):
         """Mock this if you want results from it."""
         return []
 
+    def volume_get_all(self, *a, **kw):
+        return []
+
 
 class QuobyteDriverTestCase(test.TestCase):
     """Test case for Quobyte driver."""

cinder/tests/unit/windows/test_smbfs.py

@@ -53,12 +53,15 @@ class WindowsSmbFsTestCase(test.TestCase):
                                      _FAKE_VOLUME_NAME)
     _FAKE_SHARE_OPTS = '-o username=Administrator,password=12345'
 
+    @mock.patch.object(remotefs.RemoteFSDriver,
+                       '_check_if_volume_db_is_empty')
     @mock.patch.object(smbfs, 'utilsfactory')
     @mock.patch.object(smbfs, 'remotefs_brick')
-    def setUp(self, mock_remotefs, mock_utilsfactory):
+    def setUp(self, mock_remotefs, mock_utilsfactory, mock_is_empty):
         super(WindowsSmbFsTestCase, self).setUp()
 
         self.context = context.get_admin_context()
+        mock_is_empty.return_value = None
 
         self._FAKE_SMBFS_CONFIG = mock.MagicMock(
             smbfs_oversub_ratio = 2,

cinder/volume/drivers/remotefs.py

@@ -29,6 +29,7 @@ from oslo_utils import units
 import six
 
 from cinder import compute
+from cinder import context
 from cinder import coordination
 from cinder import db
 from cinder import exception
@@ -148,7 +149,7 @@ class RemoteFSDriver(driver.BaseVD):
         self.shares = {}
         self._mounted_shares = []
         self._execute_as_root = True
-        self._is_voldb_empty_at_startup = kwargs.pop('is_vol_db_empty', None)
+        self._is_voldb_empty_at_startup = self._check_if_volume_db_is_empty()
         self._supports_encryption = False
 
         # We let the drivers inheriting this specify
@@ -159,6 +160,32 @@ class RemoteFSDriver(driver.BaseVD):
             self.configuration.append_config_values(nas_opts)
             self.configuration.append_config_values(volume_opts)
 
+    def _set_voldb_empty_at_startup_indicator(self, ctxt):
+        """Determine if the Cinder volume DB is empty.
+
+        A check of the volume DB is done to determine whether it is empty or
+        not at this point.
+
+        :param ctxt: our working context
+        """
+        if not self.db:
+            return False
+        vol_entries = self.db.volume_get_all(ctxt, None, 1, filters=None)
+
+        if len(vol_entries) == 0:
+            LOG.info("Determined volume DB was empty at startup.")
+            return True
+        else:
+            LOG.info("Determined volume DB was not empty at startup.")
+            return False
+
+    def _check_if_volume_db_is_empty(self):
+        vol_db_empty = self._set_voldb_empty_at_startup_indicator(
+            context.get_admin_context())
+        LOG.debug("Cinder Volume DB check: vol_db_empty=%s", vol_db_empty)
+
+        return vol_db_empty
+
     def check_for_setup_error(self):
         """Just to override parent behavior."""
         pass

cinder/volume/manager.py

@@ -216,10 +216,6 @@ class VolumeManager(manager.CleanableManager,
                         "configuration to the new path.", volume_driver)
             volume_driver = MAPPING[volume_driver]
 
-        vol_db_empty = self._set_voldb_empty_at_startup_indicator(
-            context.get_admin_context())
-        LOG.debug("Cinder Volume DB check: vol_db_empty=%s", vol_db_empty)
-
         # We pass the current setting for service.active_backend_id to
         # the driver on init, in case there was a restart or something
         curr_active_backend_id = None
@@ -251,7 +247,6 @@ class VolumeManager(manager.CleanableManager,
             db=self.db,
             host=self.host,
             cluster_name=self.cluster,
-            is_vol_db_empty=vol_db_empty,
             active_backend_id=curr_active_backend_id)
 
         if self.cluster and not self.driver.SUPPORTS_ACTIVE_ACTIVE:
@@ -341,23 +336,6 @@ class VolumeManager(manager.CleanableManager,
         self.stats['pools'][pool]['allocated_capacity_gb'] = pool_sum
         self.stats['allocated_capacity_gb'] += volume['size']
 
-    def _set_voldb_empty_at_startup_indicator(self, ctxt):
-        """Determine if the Cinder volume DB is empty.
-
-        A check of the volume DB is done to determine whether it is empty or
-        not at this point.
-
-        :param ctxt: our working context
-        """
-        vol_entries = self.db.volume_get_all(ctxt, None, 1, filters=None)
-
-        if len(vol_entries) == 0:
-            LOG.info("Determined volume DB was empty at startup.")
-            return True
-        else:
-            LOG.info("Determined volume DB was not empty at startup.")
-            return False
-
     def _sync_provider_info(self, ctxt, volumes, snapshots):
         # NOTE(jdg): For now this just updates provider_id, we can add more
         # items to the update if they're relevant but we need to be safe in