CLOUDSTACK-3264: [ZWPS]NPE while finding storage pools for migration

Description:

    Filter primary storage pools based on zonewide/clusterwide configuration
    when considering pools to list for storage migration of volumes.

engine/storage/src/org/apache/cloudstack/storage/allocator/AbstractStoragePoolAllocator.java

@@ -145,6 +145,9 @@ public abstract class AbstractStoragePoolAllocator extends AdapterBase implement
 
     protected List<StoragePool> reOrder(List<StoragePool> pools,
             VirtualMachineProfile<? extends VirtualMachine> vmProfile, DeploymentPlan plan) {
+        if (pools == null) {
+            return null;
+        }
         Account account = null;
         if (vmProfile.getVirtualMachine() != null) {
             account = vmProfile.getOwner();

engine/storage/src/org/apache/cloudstack/storage/allocator/ClusterScopeStoragePoolAllocator.java

@@ -59,6 +59,9 @@ public class ClusterScopeStoragePoolAllocator extends AbstractStoragePoolAllocat
         Long podId = plan.getPodId();
         Long clusterId = plan.getClusterId();
 
+		if (clusterId == null) {
+			return null;
+		}
         if (dskCh.getTags() != null && dskCh.getTags().length != 0) {
             s_logger.debug("Looking for pools in dc: " + dcId + "  pod:" + podId + "  cluster:" + clusterId
                     + " having tags:" + Arrays.toString(dskCh.getTags()));

engine/storage/src/org/apache/cloudstack/storage/allocator/LocalStoragePoolAllocator.java

@@ -96,6 +96,9 @@ public class LocalStoragePoolAllocator extends AbstractStoragePoolAllocator {
                 }
             }
         } else {
+            if (plan.getClusterId() == null) {
+                return null;
+            }
             List<StoragePoolVO> availablePools = _storagePoolDao.findLocalStoragePoolsByTags(plan.getDataCenterId(),
                     plan.getPodId(), plan.getClusterId(), dskCh.getTags());
             for (StoragePoolVO pool : availablePools) {

plugins/storage-allocators/random/src/org/apache/cloudstack/storage/allocator/RandomStoragePoolAllocator.java

@@ -46,6 +46,11 @@ public class RandomStoragePoolAllocator extends AbstractStoragePoolAllocator {
         long dcId = plan.getDataCenterId();
         Long podId = plan.getPodId();
         Long clusterId = plan.getClusterId();
+
+		if (clusterId == null) {
+			return null;
+		}
+
         s_logger.debug("Looking for pools in dc: " + dcId + "  pod:" + podId + "  cluster:" + clusterId);
         List<StoragePoolVO> pools = _storagePoolDao.listBy(dcId, podId, clusterId, ScopeType.CLUSTER);
         if (pools.size() == 0) {

server/src/com/cloud/server/ManagementServerImpl.java

@@ -1258,8 +1258,14 @@ public class ManagementServerImpl extends ManagerBase implements ManagementServe
 
             // Get all the pools available. Only shared pools are considered because only a volume on a shared pools
             // can be live migrated while the virtual machine stays on the same host.
-            List<StoragePoolVO> storagePools = _poolDao.findPoolsByTags(volume.getDataCenterId(),
+            List<StoragePoolVO> storagePools = null;
-                    volume.getPodId(), srcVolumePool.getClusterId(), null);
+
+            if (srcVolumePool.getClusterId() == null) {
+                storagePools = _poolDao.findZoneWideStoragePoolsByTags(volume.getDataCenterId(), null);
+            } else {
+                storagePools = _poolDao.findPoolsByTags(volume.getDataCenterId(), volume.getPodId(), srcVolumePool.getClusterId(), null);
+            }
+
             storagePools.remove(srcVolumePool);
             for (StoragePoolVO pool : storagePools) {
                 if (pool.isShared()) {