longhorn: [BUG] StorageClass of pv and pvc of a recovered pv should not always be default.

Describe the bug

• I follow this guide to create an encrypted PV: https://longhorn.io/docs/1.2.3/advanced-resources/volume-encryption/
• created a StorageClass longhorn-crypto-global
• then I created a PVC (in namespace “xyz”) that uses this storage class (longhorn-crypto-global) to get an encrypted volume
• then I create a Deployment (in namespace “xyz”) that uses the pvc to create a pv
• then I create a backup to S3 using Longhorn UI
• then I delete the namespace “xyz”
• then I restore the backup
• then I create a pvc of the restored pv and check the “encrypt” checkbox
• but looking at the pv and pvc this is the output:

k get pv -A
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                    STORAGECLASS             REASON   AGE
pvc-250db57b-8c2a-4288-b75a-aae34cc241e8   128Mi      RWO            Delete           Bound    traefik/traefik          longhorn-crypto-global            27h
pvc-2f164f3a-3089-475a-addb-dbb59a9e3fd0   100Mi      RWO            Retain           Bound    db/postgres-pvc          longhorn-static                   7s
pvc-f44fc526-c2e8-499b-a6a1-d67363a33f89   5Gi        RWO            Delete           Bound    monitor/storage-loki-0   longhorn-crypto-global            11h

k get pvc -A
NAMESPACE   NAME             STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS             AGE
xyz          postgres-pvc     Bound    pvc-2f164f3a-3089-475a-addb-dbb59a9e3fd0   100Mi      RWO            longhorn-static          12s
monitor     storage-loki-0   Bound    pvc-f44fc526-c2e8-499b-a6a1-d67363a33f89   5Gi        RWO            longhorn-crypto-global   11h
traefik     traefik          Bound    pvc-250db57b-8c2a-4288-b75a-aae34cc241e8   128Mi      RWO            longhorn-crypto-global   27h

• you see that the recovered pv and pvc has the storage class longhorn-static but both should have longhorn-crypto-global.

My guess is that it uses the default storage class. EDIT: I checked that. If you use the UI to change the default storage class to longhorn-crypto-global then it is set when the pv is recovered from backup. But as I said above - that info should not be taken from the default setting but stored in the backup and taken from there. The problem is that the storage class of the pvc can not be changed (edited) with kubectl edit.

The StorageClass should be stored with the backup nd restored for pv and pvc.

Environment

• Longhorn version: 1.2.3
• Installation method (e.g. Rancher Catalog App/Helm/Kubectl): helm
• Kubernetes distro (e.g. RKE/K3s/EKS/OpenShift) and version: kubeadm
  • Number of management node in the cluster: 1
  • Number of worker node in the cluster: none
• Node config
  • OS type and version: Debian 11.01
  • CPU per node: 8 hyperthreads
  • Memory per node: 32 GB
  • Disk type(e.g. SSD/NVMe): mechanical
  • Network bandwidth between the nodes: none
• Underlying Infrastructure (e.g. on AWS/GCE, EKS/GKE, VMWare/KVM, Baremetal): Baremetal
• Number of Longhorn volumes in the cluster: 3