Description of problem (please be detailed as possible and provide log
snippests):
If RBD provisioner leader pod is deleted when a thick PVC provision is progressing, the resulting volume will not be thick provisioned.
This was tested with a 20 GiB PVC. The PVC reached Bound state. But the used size of the rbd image is 984 MiB. This 984 MiB used size could be the thick provisioned size before deleting the csi-rbdplugin-provisioner leader pod. Provisioned size is 20GiB.


Test case error showing the du output of the image and describe output of PV:

E       AssertionError: PVC pvc-test-f854452cb4a64712beb2ce4a0ffd691 is not thick provisioned. Rbd image csi-vol-74a77a0a-b7c1-11eb-9543-0a580a830148 expected used size: 20GiB. Actual used size 984MiB.
E          Rbd du out: NAME                                         PROVISIONED USED csi-vol-74a77a0a-b7c1-11eb-9543-0a580a830148      20 GiB 984 MiB
E          PV describe :
E          Name:            pvc-487fb831-03b5-4bc6-8f67-72b5eee94a7c
E         Labels:          <none>
E         Annotations:     pv.kubernetes.io/provisioned-by: openshift-storage.rbd.csi.ceph.com
E         Finalizers:      [kubernetes.io/pv-protection]
E         StorageClass:    ocs-storagecluster-ceph-rbd-thick
E         Status:          Bound
E         Claim:           namespace-test-d57cab19c5f14cd5a75ae33eb/pvc-test-f854452cb4a64712beb2ce4a0ffd691
E         Reclaim Policy:  Delete
E         Access Modes:    RWO
E         VolumeMode:      Filesystem
E         Capacity:        20Gi
E         Node Affinity:   <none>
E         Message:         
E         Source:
E             Type:              CSI (a Container Storage Interface (CSI) volume source)
E             Driver:            openshift-storage.rbd.csi.ceph.com
E             FSType:            ext4
E             VolumeHandle:      0001-0011-openshift-storage-0000000000000001-74a77a0a-b7c1-11eb-9543-0a580a830148
E             ReadOnly:          false
E             VolumeAttributes:      clusterID=openshift-storage
E                                    csi.storage.k8s.io/pv/name=pvc-487fb831-03b5-4bc6-8f67-72b5eee94a7c
E                                    csi.storage.k8s.io/pvc/name=pvc-test-f854452cb4a64712beb2ce4a0ffd691
E                                    csi.storage.k8s.io/pvc/namespace=namespace-test-d57cab19c5f14cd5a75ae33eb
E                                    imageFeatures=layering
E                                    imageFormat=2
E                                    imageName=csi-vol-74a77a0a-b7c1-11eb-9543-0a580a830148
E                                    journalPool=ocs-storagecluster-cephblockpool
E                                    pool=ocs-storagecluster-cephblockpool
E                                    storage.kubernetes.io/csiProvisionerIdentity=1621299316893-8081-openshift-storage.rbd.csi.ceph.com
E                                    thickProvision=true
E         Events:                <none>
E         
E       assert '984MiB' == '20GiB'
E         - 984MiB
E         + 20GiB

tests/manage/pv_services/test_delete_provisioner_pod_while_thick_provisioning.py:90: AssertionError


Test case:
tests/manage/pv_services/test_delete_provisioner_pod_while_thick_provisioning.py::TestDeleteProvisionerPodWhileThickProvisioning::test_delete_provisioner_pod_while_thick_provisioning

ocs-ci PR: https://github.com/red-hat-storage/ocs-ci/pull/4300


OCS and OCP must-gather logs : 
http://magna002.ceph.redhat.com/ocsci-jenkins/openshift-clusters/jijoy-17may/jijoy-17may_20210517T110547/logs/failed_testcase_ocs_logs_1621332632/test_delete_provisioner_pod_while_thick_provisioning_ocs_logs/


Test case logs: http://magna002.ceph.redhat.com/ocsci-jenkins/openshift-clusters/jijoy-17may/jijoy-17may_20210517T110547/logs/ocs-ci-logs-1621332632/by_outcome/failed/tests/manage/pv_services/test_delete_provisioner_pod_while_thick_provisioning.py/TestDeleteProvisionerPodWhileThickProvisioning/test_delete_provisioner_pod_while_thick_provisioning


===========================================================================

Version of all relevant components (if applicable):
OCS 4.8.0-394.ci
OCP 4.8.0-0.nightly-2021-05-15-141455
Ceph 14.2.11-147.el8cp (1f54d52f20d93c1b91f1ec6af4c67a4b81402800) nautilus (stable)

rook_csi_provisioner	ose-csi-external-provisioner@sha256:0d1cab421c433c213d37043dd0dbaa6a2942ccf1d21d35afc32e35ce8216ddec


Does this issue impact your ability to continue to work with the product
(please explain in detail what is the user impact)?
Yes, the volume will not be thick provisioned.

Is there any workaround available to the best of your knowledge?
No

Rate from 1 - 5 the complexity of the scenario you performed that caused this
bug (1 - very simple, 5 - very complex)?
2

Can this issue reproducible?
Yes

Can this issue reproduce from the UI?
Yes

If this is a regression, please provide more details to justify this:
RBD thick provisioning is a new feature in OCS 4.8

=======================================================================

Steps to Reproduce:
1. Start creating a PVC of size 20GiB. Use "ocs-storagecluster-ceph-rbd-thick" storage class in which thick provision is enabled.
2. When step 1 is progressing, delete the csi-rbdplugin-provisioner leader pod.
3. Wait for the new csi-rbdplugin-provisioner pod to spin up.
4. Wait for the PVC to reach Bound state and check the used size of the corresponding rbd image.
Command:
rbd du -p ocs-storagecluster-cephblockpool csi-vol-74a77a0a-b7c1-11eb-9543-0a580a830148

where "ocs-storagecluster-cephblockpool" is the pool name and "csi-vol-74a77a0a-b7c1-11eb-9543-0a580a830148" is the image name


OR

Run the ocs-ci test case
tests/manage/pv_services/test_delete_provisioner_pod_while_thick_provisioning.py::TestDeleteProvisionerPodWhileThickProvisioning::test_delete_provisioner_pod_while_thick_provisioning

====================================================================

Actual results:
The used size of the rbd image is not equal to the provisioned size.

Expected results:
The used size of the rbd image should be equal to the provisioned size.

Additional info: