From c4e27824666c5f588a2a9e2e4c920967e3be3445 Mon Sep 17 00:00:00 2001
From: Sanjay Tripathi <sanjay.tripathi@citrix.com>
Date: Fri, 19 Jun 2015 15:59:42 +0530
Subject: [PATCH] Recurring snapshot issue post upgrade from 3.0.7 to 4.5

---
 .../cloudstack/storage/snapshot/SnapshotServiceImpl.java     | 5 ++++-
 .../storage/snapshot/XenserverSnapshotStrategy.java          | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/SnapshotServiceImpl.java b/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/SnapshotServiceImpl.java
index 5a8afc68931a..4c76cda9fd61 100644
--- a/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/SnapshotServiceImpl.java
+++ b/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/SnapshotServiceImpl.java
@@ -237,7 +237,10 @@ private DataStore findSnapshotImageStore(SnapshotInfo snapshot) {
             // Note that DataStore information in parentSnapshot is for primary
             // data store here, we need to
             // find the image store where the parent snapshot backup is located
-            SnapshotDataStoreVO parentSnapshotOnBackupStore = _snapshotStoreDao.findBySnapshot(parentSnapshot.getId(), DataStoreRole.Image);
+            SnapshotDataStoreVO parentSnapshotOnBackupStore = null;
+            if (parentSnapshot != null) {
+                parentSnapshotOnBackupStore = _snapshotStoreDao.findBySnapshot(parentSnapshot.getId(), DataStoreRole.Image);
+            }
             if (parentSnapshotOnBackupStore == null) {
                 return dataStoreMgr.getImageStore(snapshot.getDataCenterId());
             }
diff --git a/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/XenserverSnapshotStrategy.java b/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/XenserverSnapshotStrategy.java
index 51f75bd0c330..8ed77df9aaf8 100644
--- a/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/XenserverSnapshotStrategy.java
+++ b/engine/storage/snapshot/src/org/apache/cloudstack/storage/snapshot/XenserverSnapshotStrategy.java
@@ -111,8 +111,9 @@ public SnapshotInfo backupSnapshot(SnapshotInfo snapshot) {
 
         boolean fullBackup = true;
         SnapshotDataStoreVO parentSnapshotOnBackupStore = snapshotStoreDao.findLatestSnapshotForVolume(snapshot.getVolumeId(), DataStoreRole.Image);
+        SnapshotDataStoreVO parentSnapshotOnPrimaryStore = snapshotStoreDao.findLatestSnapshotForVolume(snapshot.getVolumeId(), DataStoreRole.Primary);
         HypervisorType hypervisorType = snapshot.getBaseVolume().getHypervisorType();
-        if (parentSnapshotOnBackupStore != null && hypervisorType == Hypervisor.HypervisorType.XenServer) { // CS does incremental backup only for XenServer
+        if (parentSnapshotOnPrimaryStore != null && parentSnapshotOnBackupStore != null && hypervisorType == Hypervisor.HypervisorType.XenServer) { // CS does incremental backup only for XenServer
 
             // In case of volume migration from one pool to other pool, CS should take full snapshot to avoid any issues with delta chain,
             // to check if this is a migrated volume, compare the current pool id of volume and store_id of oldest snapshot on primary for this volume.