libvirt: Revert non-reporting DISK_GB if sharing

Change Iea283322124cb35fc0bc6d25f35548621e8c8c2f went part way toward
implementing proper accounting for sharing providers, but the gaps it
left are untenable - see the associated bug report.

This removes the main functional piece of that change with TODOs to
reinstate it once the broader issues have been resolved.

Change-Id: I245a16315f97d0c2ca69c6ca9727a55a8ceb75ab
Related-Bug: #1784020

nova/tests/functional/libvirt/test_shared_resource_provider.py

@@ -14,6 +14,7 @@
 #    under the License.
 
 import fixtures
+import unittest
 
 from nova.compute import instance_actions
 from nova import conf
@@ -42,6 +43,8 @@ class SharedStorageProviderUsageTestCase(
         nodename = self.compute.manager._get_nodename(None)
         self.host_uuid = self._get_provider_uuid_by_host(nodename)
 
+    # TODO(efried): Bug #1784020
+    @unittest.expectedFailure
     def test_shared_storage_rp_configuration_with_cn_rp(self):
         """Test to check whether compute node and shared storage resource
         provider inventory is configured properly or not.
@@ -114,6 +117,8 @@ class SharedStorageProviderUsageTestCase(
                                    'STORAGE_DISK_SSD'])
         return shared_RP['uuid']
 
+    # TODO(efried): Bug #1784020
+    @unittest.expectedFailure
     def test_rebuild_instance_with_image_traits_on_shared_rp(self):
 
         shared_rp_uuid = self.create_shared_storage_rp()
@@ -175,6 +180,8 @@ class SharedStorageProviderUsageTestCase(
         server = self.api.get_server(server['id'])
         self.assertEqual(rebuild_image_ref, server['image']['id'])
 
+    # TODO(efried): Bug #1784020
+    @unittest.expectedFailure
     def test_rebuild_instance_with_image_traits_on_shared_rp_no_valid_host(
             self):
         shared_rp_uuid = self.create_shared_storage_rp()

nova/tests/unit/virt/libvirt/test_driver.py

@@ -28,6 +28,7 @@ import shutil
 import signal
 import threading
 import time
+import unittest
 
 from castellan import key_manager
 import ddt
@@ -18021,7 +18022,9 @@ class TestUpdateProviderTree(test.NoDBTestCase):
                 return_value=memory_mb)
     @mock.patch('nova.virt.libvirt.driver.LibvirtDriver._get_vcpu_total',
                 return_value=vcpus)
-    def teste_update_provider_tree_for_shared_disk_gb_resource(
+    # TODO(efried): Bug #1784020
+    @unittest.expectedFailure
+    def test_update_provider_tree_for_shared_disk_gb_resource(
         self, mock_vcpu, mock_mem, mock_disk, mock_vgpus):
         """Test to check DISK_GB is reported from shared resource
         provider.

nova/virt/libvirt/driver.py

@@ -6434,14 +6434,16 @@ class LibvirtDriver(driver.ComputeDriver):
         # If a sharing DISK_GB provider exists in the provider tree, then our
         # storage is shared, and we should not report the DISK_GB inventory in
         # the compute node provider.
-        if not provider_tree.has_sharing_provider(
-                rc_fields.ResourceClass.DISK_GB):
-            result[rc_fields.ResourceClass.DISK_GB] = {
-                'total': disk_gb,
-                'min_unit': 1,
-                'max_unit': disk_gb,
-                'step_size': 1,
-            }
+        # TODO(efried): Reinstate non-reporting of shared resource by the
+        # compute RP once the issues from bug #1784020 have been resolved.
+        if provider_tree.has_sharing_provider(rc_fields.ResourceClass.DISK_GB):
+            LOG.debug('Ignoring sharing provider - see bug #1784020')
+        result[rc_fields.ResourceClass.DISK_GB] = {
+            'total': disk_gb,
+            'min_unit': 1,
+            'max_unit': disk_gb,
+            'step_size': 1,
+        }
 
         if vgpus > 0:
             # Only provide VGPU resource classes if the driver supports it.