Created attachment 1788466 [details]
Logs

Description of problem:

There is a NullPointerException on engine log when trying to remove the disks which were earlier uploaded to the engine NFS storage type with usage of transfer_url.
The attempt to delete disks is done AFTER taking the checksums of the uploaded disks. So the reason for the NPE might be that.
This NPE wasnt seen when deleting the disks uploaded with proxy_url,
This NPE Was seen also when deleting the disks (with proxy) on a block storage type (ISCSI).

Although NPE on the engine log, the actual disks removal is finished successfully, and there is no sign of a failure on the engine UI as well.

Marking this as a regression, because this NPE wasnt seen earlier. Although this is a regression bug, I am marking it as 'medium' because this doesnt look like it affects the disk upload or removal of the disks.
However, this could affect some other areas that we are not yet aware of. And also the NPE shouldn't be there if all works fine.

Version-Release number of selected component (if applicable):
rhv-4.4.6-10

How reproducible:
100%

Steps to Reproduce:
1. Starting parallel upload of disks ['/root/upload/qcow2_v2_rhel74_ovirt42_guest_disk_1G.qcow2', '/root/upload/qcow2_v3_cow_sparse_disk_1G.qcow2', '/root/upload/test_raw_to_delete.raw', '/root/upload/1G_Fedora-Workstation-Live-x86_64-25-1.3.iso']
2. Check image checksums for local images: ['qcow2_v2_rhel74_ovirt42_guest_disk_1G.qcow2', 'qcow2_v3_cow_sparse_disk_1G.qcow2', 'test_raw_to_delete.raw', '1G_Fedora-Workstation-Live-x86_64-25-1.3.iso']
3. Check disk checksums for the uploaded disks: ['qcow2_v2_rhel74_ovirt42_guest_disk_1G.qcow2', 'qcow2_v3_cow_sparse_disk_1G.qcow2', 'test_raw_to_delete.raw', '1G_Fedora-Workstation-Live-x86_64-25-1.3.iso']


Actual results:
NPE

2021-06-01 13:42:58,077+03 INFO  [org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-1) [a74c219e-622e-45a0-b05c-c80437802c13] Exception in invoking callback of command TransferDiskImage (922f35a5-a542-4c79-9a0e-0be0d920f84d): NullPointerException: 
2021-06-01 13:42:58,077+03 ERROR [org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-1) [a74c219e-622e-45a0-b05c-c80437802c13] Error invoking callback method 'doPolling' for 'ACTIVE' command '922f35a5-a542-4c79-9a0e-0be0d920f84d'
2021-06-01 13:42:58,077+03 ERROR [org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-1) [a74c219e-622e-45a0-b05c-c80437802c13] Exception: java.lang.NullPointerException
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand.getImageAlias(TransferDiskImageCommand.java:326)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand.getTransferDescription(TransferDiskImageCommand.java:1401)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand.handleFinishedSuccess(TransferDiskImageCommand.java:904)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand.executeStateHandler(TransferDiskImageCommand.java:535)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferDiskImageCommand.proceedCommandExecution(TransferDiskImageCommand.java:492)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.storage.disk.image.TransferImageCommandCallback.doPolling(TransferImageCommandCallback.java:21)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller.invokeCallbackMethodsImpl(CommandCallbacksPoller.java:175)
        at deployment.engine.ear.bll.jar//org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller.invokeCallbackMethods(CommandCallbacksPoller.java:109)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
        at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305)
        at org.glassfish.javax.enterprise.concurrent.0.redhat-1//org.glassfish.enterprise.concurrent.internal.ManagedScheduledThreadPoolExecutor$ManagedScheduledFutureTask.access$201(ManagedScheduledThreadPoolExecutor.java:383)
        at org.glassfish.javax.enterprise.concurrent.0.redhat-1//org.glassfish.enterprise.concurrent.internal.ManagedScheduledThreadPoolExecutor$ManagedScheduledFutureTask.run(ManagedScheduledThreadPoolExecutor.java:534)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:829)
        at org.glassfish.javax.enterprise.concurrent.0.redhat-1//org.glassfish.enterprise.concurrent.ManagedThreadFactoryImpl$ManagedThread.run(ManagedThreadFactoryImpl.java:250)




Expected results:
Shouldnt be NPE

Additional info:
Attaching engine + vdsm + daemon logs from all involved.