PIng @DaanHoogland can you review this please? I'll run some tests.

Though I would like to see how this situation is reproduced, the code is fine and sensible.

LGTM

I have the same concern with Daan. How to reproduce this issue ?
Check my env

mysql> select * from volumes where volume_type is null or provisioning_type is null or state is null;
Empty set (0.00 sec)

@DaanHoogland , @ustcweizhou
This issue is reproduced when the volume associated vm instance has null or invalid state (vm_state in volume_view). The code changes would guard this situation since it should not block volume listing.

mysql> SELECT id, name, volume_type, state, vm_state FROM cloud.volume_view where vm_state is null;
+----+----------------------+-------------+----------+----------+
| id | name | volume_type | state | vm_state |
+----+----------------------+-------------+----------+----------+
| 57 | ROOT-57 | ROOT | Expunged | NULL |
| 69 | mytestvolume | DATADISK | Ready | NULL |
| 71 | DATA-69 | DATADISK | Expunged | NULL |
| 73 | DATA-70 | DATADISK | Expunged | NULL |
| 78 | testvolcreated | DATADISK | Ready | NULL |
| 81 | test2volume | DATADISK | Destroy | NULL |
| 83 | testvol07 | DATADISK | Ready | NULL |
| 87 | testattachvolcreated | DATADISK | Ready | NULL |
+----+----------------------+-------------+----------+----------+
8 rows in set (0.00 sec)

@sureshanaparti How do we force such a situation to occur?
It seems to me that should be guarded on input and alerted on on output instead of silently filtered.

@sureshanaparti

mysql> SELECT id, name, volume_type, state, vm_state FROM cloud.volume_view where vm_state is null and vm_id is not null;
Empty set (0.00 sec)

even in vm_instance

mysql> select * from vm_instance where state is null;
Empty set (0.00 sec)

@ustcweizhou , Same with my result set as well.
mysql> select * from vm_instance where state is null;
Empty set (0.00 sec)

mysql> SELECT id, name, volume_type, state, vm_state FROM cloud.volume_view where vm_state is null and vm_id is not null;
Empty set (0.00 sec)

The volumes, in Ready state and are not attached to any VM have their vm_state has null and querying such volumes may result in NPE. These changes are only to safe guard.

@sureshanaparti
I do not get NPE when listVolumes.

please notice the code:
long instanceId = volume.getVmId();
if (instanceId > 0 && volume.getState() != Volume.State.Destroy) {
...

if the volume is not attached, this judgment returns false.

@ustcweizhou , Yes. I agree. In case on instance id, vm_state is not null.

LGTM

Merging as it has 2LGTMs