From 10ad7967cdfa2f19cd8f34ce53c3ff267055d771 Mon Sep 17 00:00:00 2001
From: Abhisar Sinha <63767682+abh1sar@users.noreply.github.com>
Date: Sat, 14 Mar 2026 20:09:25 +0530
Subject: [PATCH] bug fixes

---
 .../backup/StartNBDServerCommand.java           |  8 +++++++-
 .../META-INF/db/schema-42100to42200.sql         |  1 -
 ...ibvirtCreateImageTransferCommandWrapper.java |  2 +-
 .../LibvirtStartBackupCommandWrapper.java       |  4 ++--
 .../LibvirtStartNBDServerCommandWrapper.java    |  3 ++-
 .../LibvirtStopNBDServerCommandWrapper.java     | 16 ++--------------
 .../backup/IncrementalBackupServiceImpl.java    | 17 +++++++++--------
 7 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/core/src/main/java/org/apache/cloudstack/backup/StartNBDServerCommand.java b/core/src/main/java/org/apache/cloudstack/backup/StartNBDServerCommand.java
index 47dd2b4a6df..67a858af7f0 100644
--- a/core/src/main/java/org/apache/cloudstack/backup/StartNBDServerCommand.java
+++ b/core/src/main/java/org/apache/cloudstack/backup/StartNBDServerCommand.java
@@ -25,16 +25,18 @@ public class StartNBDServerCommand extends Command {
     private String volumePath;
     private String socket;
     private String direction;
+    private String fromCheckpointId;
 
     public StartNBDServerCommand() {
     }
 
-    protected StartNBDServerCommand(String transferId, String exportName, String volumePath, String socket, String direction) {
+    protected StartNBDServerCommand(String transferId, String exportName, String volumePath, String socket, String direction, String fromCheckpointId) {
         this.transferId = transferId;
         this.socket = socket;
         this.exportName = exportName;
         this.volumePath = volumePath;
         this.direction = direction;
+        this.fromCheckpointId = fromCheckpointId;
     }
 
     public String getExportName() {
@@ -61,4 +63,8 @@ public class StartNBDServerCommand extends Command {
     public String getDirection() {
         return direction;
     }
+
+    public String getFromCheckpointId() {
+        return fromCheckpointId;
+    }
 }
diff --git a/engine/schema/src/main/resources/META-INF/db/schema-42100to42200.sql b/engine/schema/src/main/resources/META-INF/db/schema-42100to42200.sql
index 044f7475324..fbb2fd079f9 100644
--- a/engine/schema/src/main/resources/META-INF/db/schema-42100to42200.sql
+++ b/engine/schema/src/main/resources/META-INF/db/schema-42100to42200.sql
@@ -18,7 +18,6 @@
 --;
 -- Schema upgrade from 4.21.0.0 to 4.22.0.0
 --;
-not supported for download
 
 -- health check status as enum
 CALL `cloud`.`IDEMPOTENT_CHANGE_COLUMN`('router_health_check', 'check_result', 'check_result', 'varchar(16) NOT NULL COMMENT "check executions result: SUCCESS, FAILURE, WARNING, UNKNOWN"');
diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateImageTransferCommandWrapper.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateImageTransferCommandWrapper.java
index d3eca1aeb23..db0918f5c07 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateImageTransferCommandWrapper.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtCreateImageTransferCommandWrapper.java
@@ -134,7 +134,7 @@ public class LibvirtCreateImageTransferCommandWrapper extends CommandWrapper<Cre
             payload.put("export", exportName);
             String checkpointId = cmd.getCheckpointId();
             if (checkpointId != null) {
-                payload.put("export_bitmap", exportName + "-" + checkpointId.substring(0, 4));
+                payload.put("export_bitmap", cmd.getCheckpointId());
             }
         }
 
diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartBackupCommandWrapper.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartBackupCommandWrapper.java
index 4c0087cccef..04416559c57 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartBackupCommandWrapper.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartBackupCommandWrapper.java
@@ -88,8 +88,8 @@ public class LibvirtStartBackupCommandWrapper extends CommandWrapper<StartBackup
             script.add(backupCmd);
             String result = script.execute();
 
-//            backupXmlFile.delete();
-//            checkpointXmlFile.delete();
+            backupXmlFile.delete();
+            checkpointXmlFile.delete();
 
             if (result != null) {
                 return new StartBackupAnswer(cmd, false, "Backup begin failed: " + result);
diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
index 263e5f1cae5..fb532fd2a9a 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStartNBDServerCommandWrapper.java
@@ -69,10 +69,11 @@ public class LibvirtStartNBDServerCommandWrapper extends CommandWrapper<StartNBD
 
         String socketName = "/tmp/imagetransfer/" + socket + ".sock";
         String systemdRunCmd = String.format(
-                "systemd-run --unit=%s --property=Restart=no qemu-nbd --export-name %s --socket %s --persistent %s %s",
+                "systemd-run --unit=%s --property=Restart=no qemu-nbd --export-name %s --socket %s --persistent %s %s %s",
                 unitName,
                 exportName,
                 socketName,
+                cmd.getFromCheckpointId() != null ? "-B " + cmd.getFromCheckpointId() : "",
                 cmd.getDirection().equals("download") ? "--read-only" : "",
                 volumePath
         );
diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStopNBDServerCommandWrapper.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStopNBDServerCommandWrapper.java
index a2de9b56d03..57c7ebb706b 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStopNBDServerCommandWrapper.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/wrapper/LibvirtStopNBDServerCommandWrapper.java
@@ -38,7 +38,8 @@ public class LibvirtStopNBDServerCommandWrapper extends CommandWrapper<StopNBDSe
         resetScript.execute();
     }
 
-    private Answer handleUpload(StopNBDServerCommand cmd) {
+    @Override
+    public Answer execute(StopNBDServerCommand cmd, LibvirtComputingResource resource) {
         try {
             String unitName = "qemu-nbd-" + cmd.getTransferId().hashCode();
 
@@ -68,17 +69,4 @@ public class LibvirtStopNBDServerCommandWrapper extends CommandWrapper<StopNBDSe
             return new Answer(cmd, false, "Error finalizing image transfer: " + e.getMessage());
         }
     }
-
-    private Answer handleDownload(StopNBDServerCommand cmd) {
-        return new Answer(cmd, true, "Image transfer finalized");
-    }
-
-    @Override
-    public Answer execute(StopNBDServerCommand cmd, LibvirtComputingResource resource) {
-        if (cmd.getDirection().equals("download")) {
-            return handleDownload(cmd);
-        } else {
-            return handleUpload(cmd);
-        }
-    }
 }
diff --git a/server/src/main/java/org/apache/cloudstack/backup/IncrementalBackupServiceImpl.java b/server/src/main/java/org/apache/cloudstack/backup/IncrementalBackupServiceImpl.java
index 855a9cfcb5b..dd4dc756595 100644
--- a/server/src/main/java/org/apache/cloudstack/backup/IncrementalBackupServiceImpl.java
+++ b/server/src/main/java/org/apache/cloudstack/backup/IncrementalBackupServiceImpl.java
@@ -337,7 +337,7 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
         VMInstanceVO vm = vmInstanceDao.findById(backup.getVmId());
         if (vm.getState() == State.Stopped) {
             String volumePath = getVolumePathForFileBasedBackend(volume);
-            startNBDServer(transferId, direction, backup.getHostId(), volume.getUuid(), volumePath);
+            startNBDServer(transferId, direction, backup.getHostId(), volume.getUuid(), volumePath, vm.getActiveCheckpointId());
             socket = transferId;
         }
 
@@ -393,7 +393,7 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
         return hosts.get(0);
     }
 
-    private void startNBDServer(String transferId, String direction, Long hostId, String exportName, String volumePath) {
+    private void startNBDServer(String transferId, String direction, Long hostId, String exportName, String volumePath, String checkpointId) {
         StartNBDServerAnswer nbdServerAnswer;
         if (hostId == null) {
             throw new CloudRuntimeException("Host cannot be determined for starting NBD server");
@@ -407,7 +407,8 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
                 exportName,
                 volumePath,
                 transferId,
-                direction
+                direction,
+                checkpointId
         );
         try {
             nbdServerAnswer = (StartNBDServerAnswer) agentManager.send(hostId, nbdServerCmd);
@@ -457,7 +458,7 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
                     volumePath);
 
         } else {
-            startNBDServer(transferId, direction, host.getId(), volume.getUuid(), volumePath);
+            startNBDServer(transferId, direction, host.getId(), volume.getUuid(), volumePath, null);
             imageTransfer = new ImageTransferVO(
                     transferId,
                     null,
@@ -486,7 +487,7 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
 
         if (!transferAnswer.getResult()) {
             if (!backend.equals(ImageTransfer.Backend.file)) {
-                stopNbdServer(imageTransfer);
+                stopNBDServer(imageTransfer);
             }
             throw new CloudRuntimeException("Failed to create image transfer: " + transferAnswer.getDetails());
         }
@@ -578,14 +579,14 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
 
         VMInstanceVO vm = vmInstanceDao.findById(backup.getVmId());
         if (vm.getState() == State.Stopped) {
-            boolean stopNbdServerResult = stopNbdServer(imageTransfer);
+            boolean stopNbdServerResult = stopNBDServer(imageTransfer);
             if (!stopNbdServerResult) {
                 throw new CloudRuntimeException("Failed to stop the nbd server");
             }
         }
     }
 
-    private boolean stopNbdServer(ImageTransferVO imageTransfer) {
+    private boolean stopNBDServer(ImageTransferVO imageTransfer) {
         String transferId = imageTransfer.getUuid();
         String direction = imageTransfer.getDirection().toString();
         StopNBDServerCommand stopNbdServerCommand = new StopNBDServerCommand(transferId, direction);
@@ -602,7 +603,7 @@ public class IncrementalBackupServiceImpl extends ManagerBase implements Increme
     private void finalizeUploadImageTransfer(ImageTransferVO imageTransfer) {
         String transferId = imageTransfer.getUuid();
 
-        boolean stopNbdServerResult = stopNbdServer(imageTransfer);
+        boolean stopNbdServerResult = stopNBDServer(imageTransfer);
         if (!stopNbdServerResult) {
             throw new CloudRuntimeException("Failed to stop the nbd server");
         }