Return an exception if the provider doesn't support shared disks

coriolis/providers/base.py

@@ -22,6 +22,23 @@ class BaseProvider(object, with_metaclass(abc.ABCMeta)):
         """Platform type."""
         raise NotImplementedError("Missing provider platform attribute.")
 
+    @classmethod
+    def supports_shared_disks(cls) -> bool:
+        """Whether this provider supports shared (multi-writer) disks.
+
+        Destination import providers that can attach the same volume to
+        multiple instances (e.g. Libvirt ``<shareable/>``) should override
+        this to return ``True``. Defaults to ``False``.
+
+        In order to coordinate shared disk operations, the conductor will mark
+        one of the instances as owner of the shared disk.
+
+        As such, operations such as disk creation, deletion, resize or
+        data migration should be handled by tasks that are targeting the
+        owner instance.
+        """
+        return False
+
 
 class BaseEndpointProvider(BaseProvider):
 

coriolis/tasks/replica_tasks.py

@@ -1072,6 +1072,16 @@ class ValidateReplicaExecutionDestinationInputsTask(base.TaskRunner):
                 "Replica Import validation for destination platform "
                 "'%s'" % destination_type)
 
+        disks = export_info.get("devices", {}).get("disks") or []
+        if any(d.get("owner") and d.get("owner") != instance
+               for d in disks if d):
+            if not destination_provider.supports_shared_disks():
+                raise exception.NotSupportedOperation(
+                    operation=(
+                        "Destination platform '%s' does not support "
+                        "synchronized transfer of instances that have "
+                        "shared disks" % destination_type))
+
         target_environment = task_info["target_environment"]
         self._validate_provider_replica_import_input(
             destination_provider, ctxt, destination_connection_info,