Bug 1989527

+++ This bug was initially created as a clone of Bug #1989521 +++

Running `rbd info` cmd may return ErrImageNotFound when rbd images are undergoing flattening operation.

Cephcsi uses getImageInfo() at various places listed below.

If it returns false positive ErrImageNotFound in situations where the image is still present(but undergoing flattening), it will leave stale images in ceph cluster.

https://github.com/ceph/ceph-csi/search?q=getImageInfo%28%29

Operations which may leave stale images are create/delete Snapshot, create PVC from data source(PVC or snapshot) &
delete PVC created from another data source.

Note: Task to flatten images is added by cephcsi when we hit snap / imageclonedepth limit.



Steps to Reproduce:
see https://github.com/ceph/ceph-csi/issues/2327


Actual results:
Running getImageInfo() / `rbd info` cmd may return ErrImageNotFound when rbd images are undergoing flattening operation.


Expected results:
Running getImageInfo() / `rbd info` cmd does not return ErrImageNotFound when rbd images are undergoing flattening operation.


Additional info:
see https://github.com/ceph/ceph-csi/issues/2327


root@rook-ceph-tools-7b96766574-wh7sf /]# ceph rbd task add flatten replicapool/tmp
{"sequence": 9, "id": "e2a2df32-3edb-48c4-b538-a41985232e99", "message": "Flattening image replicapool/tmp", "refs": {"action": "flatten", "pool_name": "replicapool", "pool_namespace": "", "image_name": "tmp", "image_id": "41c9e3608f0b"}}
^[[A[root@rook-ceph-tools-7b96766574-wh7sf /]# rbd info replicapool/tmp
rbd image 'tmp':
        size 1 GiB in 256 objects
        order 22 (4 MiB objects)
        snapshot_count: 0
        id: 41c9e3608f0b
        block_name_prefix: rbd_data.41c9e3608f0b
        format: 2
        features: layering, deep-flatten, operations
        op_features: clone-child
        flags: 
        create_timestamp: Tue Jul 27 11:29:40 2021
        access_timestamp: Tue Jul 27 11:29:40 2021
        modify_timestamp: Tue Jul 27 11:29:40 2021
        parent: replicapool/csi-vol-673a80bb-eea1-11eb-80f6-0242ac110006@18f674b3-62f5-4f3c-b248-add99476c0c0
        overlap: 1 GiB
...
[root@rook-ceph-tools-7b96766574-wh7sf /]# rbd info replicapool/tmp
2021-07-27T11:31:04.642+0000 7f0802fef700 -1 librbd::image::OpenRequest: failed to set image snapshot: (2) No such file or directory
2021-07-27T11:31:04.642+0000 7f0802fef700 -1 librbd::image::RefreshParentRequest: failed to open parent image: (2) No such file or directory
2021-07-27T11:31:04.642+0000 7f0802fef700 -1 librbd::image::RefreshRequest: failed to refresh parent image: (2) No such file or directory
2021-07-27T11:31:04.642+0000 7f0802fef700 -1 librbd::image::OpenRequest: failed to refresh image: (2) No such file or directory
rbd: error opening image tmp: (2) No such file or directory
[root@rook-ceph-tools-7b96766574-wh7sf /]# rbd info replicapool/tmp
rbd image 'tmp':
        size 1 GiB in 256 objects
        order 22 (4 MiB objects)
        snapshot_count: 0
        id: 41c9e3608f0b
        block_name_prefix: rbd_data.41c9e3608f0b
        format: 2
        features: layering, deep-flatten
        op_features: 
        flags: 
        create_timestamp: Tue Jul 27 11:29:40 2021
        access_timestamp: Tue Jul 27 11:29:40 2021
        modify_timestamp: Tue Jul 27 11:29:40 2021