Allow Pure drivers to handle detach with no host

Apparently force-detach is ok with no connector
object passed in. This changes the driver to assume
that no connector means just detach the volume from
anything its attached to.

I updated the base driver to document this quirk
too.

This should only ever happen with force detach and
"old" style connections, which means multi-attach
shouldn't be in the picture so this is kind of
safe... probably..

Change-Id: Ia0710d66bdbc85afffdb6e4f22f3ce6ca642ec75
Closes-Bug: #1696215

cinder/interface/volume_driver.py

@@ -206,7 +206,8 @@ class VolumeDriverCore(base.CinderInterface):
 
         :param volume: The volume to remove.
         :param connector: The Dictionary containing information about the
-                          connection.
+                          connection. This is optional when doing a
+                          force-detach and can be None.
         """
 
     def detach_volume(self, context, volume, attachment=None):

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

@@ -967,6 +967,27 @@ class PureBaseVolumeDriverTestCase(PureBaseSharedDriverTestCase):
             'Host cannot be deleted due to existing connections.'
         )
 
+    def test_terminate_connection_no_connector_with_host(self):
+        # Show the volume having a connection
+        self.array.list_volume_private_connections.return_value = \
+            [VOLUME_CONNECTIONS[0]]
+
+        self.driver.terminate_connection(VOLUME, None)
+        self.array.disconnect_host.assert_called_with(
+            VOLUME_CONNECTIONS[0]["host"],
+            VOLUME_CONNECTIONS[0]["name"]
+        )
+
+    def test_terminate_connection_no_connector_no_host(self):
+        vol = fake_volume.fake_volume_obj(None, name=VOLUME["name"])
+
+        # Show the volume having a connection
+        self.array.list_volume_private_connections.return_value = []
+
+        # Make sure
+        self.driver.terminate_connection(vol, None)
+        self.array.disconnect_host.assert_not_called()
+
     def test_extend_volume(self):
         vol_name = VOLUME["name"] + "-cinder"
         self.driver.extend_volume(VOLUME, 3)

cinder/volume/driver.py

@@ -1361,7 +1361,12 @@ class BaseVD(object):
 
     @abc.abstractmethod
     def terminate_connection(self, volume, connector, **kwargs):
-        """Disallow connection from connector."""
+        """Disallow connection from connector.
+
+        :param volume: The volume to be disconnected.
+        :param connector: A dictionary describing the connection with details
+                          about the initiator. Can be None.
+        """
         return
 
     def terminate_connection_snapshot(self, snapshot, connector, **kwargs):
@@ -2095,7 +2100,12 @@ class VolumeDriver(ManageableVD, CloneableImageVD, ManageableSnapshotsVD,
         """Allow connection from connector for a snapshot."""
 
     def terminate_connection(self, volume, connector, **kwargs):
-        """Disallow connection from connector"""
+        """Disallow connection from connector
+
+        :param volume: The volume to be disconnected.
+        :param connector: A dictionary describing the connection with details
+                          about the initiator. Can be None.
+        """
 
     def terminate_connection_snapshot(self, snapshot, connector, **kwargs):
         """Disallow connection from connector for a snapshot."""

cinder/volume/drivers/pure.py

@@ -428,17 +428,33 @@ class PureBaseVolumeDriver(san.SanDriver):
         raise NotImplementedError
 
     def _disconnect(self, array, volume, connector, **kwargs):
-        vol_name = self._get_vol_name(volume)
-        host = self._get_host(array, connector)
-        if host:
-            host_name = host["name"]
-            result = self._disconnect_host(array, host_name, vol_name)
-        else:
-            LOG.error("Unable to disconnect host from volume, could not "
-                      "determine Purity host")
-            result = False
+        """Disconnect the volume from the host described by the connector.
 
-        return result
+        If no connector is specified it will remove *all* attachments for
+        the volume.
+
+        Returns True if it was the hosts last connection.
+        """
+        vol_name = self._get_vol_name(volume)
+        if connector is None:
+            # If no connector was provided it is a force-detach, remove all
+            # host connections for the volume
+            LOG.warning("Removing ALL host connections for volume %s",
+                        vol_name)
+            connections = array.list_volume_private_connections(vol_name)
+            for connection in connections:
+                self._disconnect_host(array, connection['host'], vol_name)
+            return False
+        else:
+            # Normal case with a specific initiator to detach it from
+            host = self._get_host(array, connector)
+            if host:
+                host_name = host["name"]
+                return self._disconnect_host(array, host_name, vol_name)
+            else:
+                LOG.error("Unable to disconnect host from volume, could not "
+                          "determine Purity host")
+                return False
 
     @pure_driver_debug_trace
     def terminate_connection(self, volume, connector, **kwargs):