[Unity] Add `force detach` support

Add support to force detach a volume from all hosts on Unity.

Closes-bug: #1741831
Change-Id: I5f0f3d474b00f3c1f742c1bfa6877911415c32f9
(cherry picked from commit b44721dfac)
(cherry picked from commit 25d76990d0)

cinder/tests/unit/volume/drivers/dell_emc/unity/fake_exception.py

@@ -54,6 +54,14 @@ class DetachIsCalled(Exception):
     pass
 
 
+class DetachAllIsCalled(Exception):
+    pass
+
+
+class DetachFromIsCalled(Exception):
+    pass
+
+
 class LunDeleteIsCalled(Exception):
     pass
 

cinder/tests/unit/volume/drivers/dell_emc/unity/test_adapter.py

@@ -129,6 +129,12 @@ class MockClient(object):
         if host.name == 'host1' and lun_or_snap.get_id() in error_ids:
             raise ex.DetachIsCalled()
 
+    @staticmethod
+    def detach_all(lun):
+        error_ids = ['lun_44']
+        if lun.get_id() in error_ids:
+            raise ex.DetachAllIsCalled()
+
     @staticmethod
     def get_iscsi_target_info(allowed_ports=None):
         return [{'portal': '1.2.3.4:1234', 'iqn': 'iqn.1-1.com.e:c.a.a0'},
@@ -187,6 +193,13 @@ class MockLookupService(object):
         }
 
 
+class MockOSResource(mock.Mock):
+    def __init__(self, *args, **kwargs):
+        super(MockOSResource, self).__init__(*args, **kwargs)
+        if 'name' in kwargs:
+            self.name = kwargs['name']
+
+
 def mock_adapter(driver_clz):
     ret = driver_clz()
     ret._client = MockClient()
@@ -382,6 +395,13 @@ class CommonAdapterTest(unittest.TestCase):
 
         self.assertRaises(ex.DetachIsCalled, f)
 
+    def test_terminate_connection_force_detach(self):
+        def f():
+            volume = MockOSResource(provider_location='id^lun_44', id='id_44')
+            self.adapter.terminate_connection(volume, None)
+
+        self.assertRaises(ex.DetachAllIsCalled, f)
+
     def test_terminate_connection_snapshot(self):
         def f():
             connector = {'host': 'host1'}

cinder/tests/unit/volume/drivers/dell_emc/unity/test_client.py

@@ -100,6 +100,11 @@ class MockResource(object):
         if lun_or_snap.name == 'detach_failure':
             raise ex.DetachIsCalled()
 
+    @staticmethod
+    def detach_from(host):
+        if host is None:
+            raise ex.DetachFromIsCalled()
+
     def get_hlu(self, lun):
         return self.alu_hlu_map.get(lun.get_id(), None)
 
@@ -405,6 +410,13 @@ class ClientTest(unittest.TestCase):
 
         self.assertRaises(ex.DetachIsCalled, f)
 
+    def test_detach_all(self):
+        def f():
+            lun = MockResource('lun_44')
+            self.client.detach_all(lun)
+
+        self.assertRaises(ex.DetachFromIsCalled, f)
+
     @mock.patch.object(coordination.Coordinator, 'get_lock')
     def test_create_host(self, fake):
         self.assertEqual('host2', self.client.create_host('host2').name)

cinder/volume/drivers/dell_emc/unity/adapter.py

@@ -223,8 +223,12 @@ class CommonAdapter(object):
 
     @cinder_utils.trace
     def _terminate_connection(self, lun_or_snap, connector):
-        host = self.client.create_host(connector['host'])
-        self.client.detach(host, lun_or_snap)
+        is_force_detach = connector is None
+        if is_force_detach:
+            self.client.detach_all(lun_or_snap)
+        else:
+            host = self.client.create_host(connector['host'])
+            self.client.detach(host, lun_or_snap)
 
     @cinder_utils.trace
     def terminate_connection(self, volume, connector):

cinder/volume/drivers/dell_emc/unity/client.py

@@ -239,6 +239,15 @@ class UnityClient(object):
         lun_or_snap.update()
         host.detach(lun_or_snap)
 
+    @staticmethod
+    def detach_all(lun):
+        """Detaches a `UnityLun` from all hosts.
+
+        :param lun: `UnityLun` object
+        """
+        lun.update()
+        lun.detach_from(host=None)
+
     def get_ethernet_ports(self):
         return self.system.get_ethernet_port()
 

cinder/volume/drivers/dell_emc/unity/driver.py

@@ -53,9 +53,11 @@ class UnityDriver(driver.ManageableVD,
         1.0.2 - Fixes bug 1775518 to make sure driver succeed to initialize
                 even though the value of unity_io_ports and
                 unity_storage_pool_names are empty
+        1.0.3 - Fixed bug 1741831: corrected support to force detach a volume
+                from all its attached hosts.
     """
 
-    VERSION = '01.00.02'
+    VERSION = '01.00.03'
     VENDOR = 'Dell EMC'
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = "EMC_UNITY_CI"

releasenotes/notes/unity-force-detach-7c89e72105f9de61.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Corrected support to force detach a volume from all hosts on Unity.