linstor: Only set allow-two-primaries if resource is already in use

For live migrate we need the allow-two-primaries option,
but we don't know exactly if we are called for a migration operation.
Now also check if at least any of the resources is in use somewhere and
only then set the option.

plugins/storage/volume/linstor/src/main/java/com/cloud/hypervisor/kvm/storage/LinstorStorageAdaptor.java

@@ -285,15 +285,17 @@ public boolean connectPhysicalDisk(String volumePath, KVMStoragePool pool, Map<S
 
         try
         {
-            // allow 2 primaries for live migration, should be removed by disconnect on the other end
-            ResourceDefinitionModify rdm = new ResourceDefinitionModify();
-            Properties props = new Properties();
-            props.put("DrbdOptions/Net/allow-two-primaries", "yes");
-            rdm.setOverrideProps(props);
-            ApiCallRcList answers = api.resourceDefinitionModify(rscName, rdm);
-            if (answers.hasError()) {
-                s_logger.error("Unable to set 'allow-two-primaries' on " + rscName);
-                // do not fail here as adding allow-two-primaries property is only a problem while live migrating
+            if (LinstorUtil.isResourceInUse(api, rscName)) {
+                // allow 2 primaries for live migration, should be removed by disconnect on the other end
+                ResourceDefinitionModify rdm = new ResourceDefinitionModify();
+                Properties props = new Properties();
+                props.put("DrbdOptions/Net/allow-two-primaries", "yes");
+                rdm.setOverrideProps(props);
+                ApiCallRcList answers = api.resourceDefinitionModify(rscName, rdm);
+                if (answers.hasError()) {
+                    s_logger.error("Unable to set 'allow-two-primaries' on " + rscName);
+                    // do not fail here as adding allow-two-primaries property is only a problem while live migrating
+                }
             }
         } catch (ApiException apiEx) {
             s_logger.error(apiEx);

plugins/storage/volume/linstor/src/main/java/org/apache/cloudstack/storage/datastore/util/LinstorUtil.java

@@ -23,6 +23,7 @@
 import com.linbit.linstor.api.model.ApiCallRc;
 import com.linbit.linstor.api.model.ApiCallRcList;
 import com.linbit.linstor.api.model.ProviderKind;
+import com.linbit.linstor.api.model.Resource;
 import com.linbit.linstor.api.model.ResourceGroup;
 import com.linbit.linstor.api.model.StoragePool;
 
@@ -90,4 +91,17 @@ public static long getCapacityBytes(String linstorUrl, String rscGroupName) {
             throw new CloudRuntimeException(apiEx);
         }
     }
+
+    /**
+     * Check if any resource of the given name is InUse on any host.
+     *
+     * @param api developer api object to use
+     * @param rscName resource name to check in use state.
+     * @return True if a resource found that is in use(primary) state, else false.
+     * @throws ApiException forwards api errors
+     */
+    public static boolean isResourceInUse(DevelopersApi api, String rscName) throws ApiException {
+        List<Resource> rscs = api.resourceList(rscName, null, null);
+        return rscs.stream().anyMatch(rsc -> rsc.getState() != null ? rsc.getState().isInUse() : false);
+    }
 }