From b69d7d443ae8428b3c55cb910177f3554ee25c18 Mon Sep 17 00:00:00 2001
From: anthony <anthony@cloud.com>
Date: Tue, 12 Oct 2010 16:53:56 -0700
Subject: [PATCH] bug 6516: didn't consider it last snapshot is deleted but the
 new snapshot is empty

status 6516: resolved fixed
---
 .../executor/CreateSnapshotExecutor.java      | 16 +++++++----
 .../storage/snapshot/SnapshotManagerImpl.java | 28 +++++++++++++++----
 2 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/server/src/com/cloud/async/executor/CreateSnapshotExecutor.java b/server/src/com/cloud/async/executor/CreateSnapshotExecutor.java
index d32aada79e4..4fa8b75d26b 100644
--- a/server/src/com/cloud/async/executor/CreateSnapshotExecutor.java
+++ b/server/src/com/cloud/async/executor/CreateSnapshotExecutor.java
@@ -68,17 +68,21 @@ public class CreateSnapshotExecutor extends BaseAsyncJobExecutor {
             
 	    	try {
 	    	    SnapshotVO snapshot = snapshotManager.createSnapshot(userId, param.getVolumeId(), param.getPolicyIds());
-
-		    	if (snapshot != null && snapshot.getStatus() == Snapshot.Status.CreatedOnPrimary) {
+	    	    Snapshot.Status status = snapshot.getStatus();
+		    	if (snapshot != null && ( status == Snapshot.Status.CreatedOnPrimary 
+		    	        || status == Snapshot.Status.BackedUp) ) {
 				    snapshotId = snapshot.getId();
-				    asyncMgr.updateAsyncJobStatus(jobId, BaseCmd.PROGRESS_INSTANCE_CREATED, snapshotId);
-				    backedUp = snapshotManager.backupSnapshotToSecondaryStorage(userId, snapshot);
+				    if( status == Snapshot.Status.CreatedOnPrimary ) {
+    				    asyncMgr.updateAsyncJobStatus(jobId, BaseCmd.PROGRESS_INSTANCE_CREATED, snapshotId);
+    				    backedUp = snapshotManager.backupSnapshotToSecondaryStorage(userId, snapshot);
+				    } else {
+				        backedUp = true;
+				    }
 				    if (backedUp) {
 				        result = AsyncJobResult.STATUS_SUCCEEDED;
 				        errorCode = 0; // Success
 				        resultObject = composeResultObject(snapshot);
-				    }
-				    else {
+				    } else {
 				        // More specific error
 				        resultObject = "Created snapshot: " + snapshotId + " on primary but failed to backup on secondary";
 				    }
diff --git a/server/src/com/cloud/storage/snapshot/SnapshotManagerImpl.java b/server/src/com/cloud/storage/snapshot/SnapshotManagerImpl.java
index 4e9eb137894..fb1078bb3f7 100644
--- a/server/src/com/cloud/storage/snapshot/SnapshotManagerImpl.java
+++ b/server/src/com/cloud/storage/snapshot/SnapshotManagerImpl.java
@@ -387,12 +387,19 @@ public class SnapshotManagerImpl implements SnapshotManager {
             if ((answer != null) && answer.getResult()) {
                 // The snapshot was successfully created
                 if (preSnapshotPath != null && preSnapshotPath == answer.getSnapshotPath()) {
-                    // empty snapshot
-                    s_logger.debug("CreateSnapshot: this is empty snapshot, remove it ");
-                    // delete from the snapshots table
-                    _snapshotDao.delete(id);
-                    throw new CloudRuntimeException(
+
+                    if( preSnapshotVO.getRemoved() != null ) {
+                        String backupPath = preSnapshotVO.getBackupSnapshotId();
+                        _snapshotDao.delete(preId);
+                        createdSnapshot = updateDBOnCreateDuplicate(id, answer.getSnapshotPath(), backupPath);  
+                    } else {
+                        // empty snapshot
+                        s_logger.debug("CreateSnapshot: this is empty snapshot, remove it ");
+                        // delete from the snapshots table
+                        _snapshotDao.delete(id);
+                        throw new CloudRuntimeException(
                             " There is no change since last snapshot, please use last snapshot " + preSnapshotPath);
+                    }
 
                 } else {
                     createdSnapshot = updateDBOnCreate(id, answer.getSnapshotPath());
@@ -436,6 +443,17 @@ public class SnapshotManagerImpl implements SnapshotManager {
         return createdSnapshot;
     }
     
+    private SnapshotVO updateDBOnCreateDuplicate(Long id, String snapshotPath, String backUpSnapshotPath) {
+        SnapshotVO createdSnapshot = _snapshotDao.findById(id);
+        Long volumeId = createdSnapshot.getVolumeId();
+        createdSnapshot.setPath(snapshotPath);
+        createdSnapshot.setBackupSnapshotId(backUpSnapshotPath);
+        createdSnapshot.setStatus(Snapshot.Status.BackedUp);
+        createdSnapshot.setPrevSnapshotId(_snapshotDao.getLastSnapshot(volumeId, id));
+        _snapshotDao.update(id, createdSnapshot);
+        return createdSnapshot;
+    }
+    
     @Override
     @DB
     @SuppressWarnings("fallthrough")