Hello,
we have the same behavior.

What happened:
All data of the PVCs of a namespace are deleted with the configuration
subdir=${pvc.metadata.namespace}/${pvc.metadata.name} when deleting a PVC from the namespace.

What you expected to happen:
the deleted PVC is deleted without deleting all data of the other PVCs in the namespace

How to reproduce it:
Create a default storage class with subDir=${pvc.metadata.namespace}/${pvc.metadata.name}
Create 2 PVCs in the namespace
Delete one of the two PVCs and the entire folder of the namespace will be deleted.

Environment:
CSI Driver version: 4.10
Kubernetes version: v1.31.4
OS (e.g. from /etc/os-release): Red Hat Enterprise Linux 9.3 (Plow)
Kernel (e.g. uname -a): 5.14.0-362.8.1.el9_3.x86_64

Same of this.
Deleting a pvc under a namespace causes the namespace folder to be deleted.
It's a very horrible phenomenon.

(base) root@g-controller:~/sanXian/yamls# helm get values -n storage-system csi-driver-nfs
USER-SUPPLIED VALUES:
controller:
  replicas: 1
  runOnControlPlane: true
externalSnapshotter:
  customResourceDefinitions:
    enabled: false
  enabled: true
image:
  csiProvisioner:
    repository: 100.64.254.1/sig-storage/csi-provisioner
  csiResizer:
    repository: 100.64.254.1/sig-storage/csi-resizer
  csiSnapshotter:
    repository: 100.64.254.1/sig-storage/csi-snapshotter
  externalSnapshotter:
    repository: 100.64.254.1/sig-storage/snapshot-controller
  livenessProbe:
    repository: 100.64.254.1/sig-storage/livenessprobe
  nfs:
    repository: 100.64.254.1/sig-storage/nfsplugin
  nodeDriverRegistrar:
    repository: 100.64.254.1/sig-storage/csi-node-driver-registrar
storageClass:
  annotations:
    storageclass.kubernetes.io/is-default-class: "false"
  create: "true"
  name: nfs-k8s-storage-system
  parameters:
    server: 10.233.34.184
    share: /exports
    subDir: ${pvc.metadata.namespace}/${pv.metadata.name}--${pvc.metadata.name}
  reclaimPolicy: Delete
(base) root@g-controller:~/sanXian/yamls# helm list -n storage-system
NAME          	NAMESPACE     	REVISION	UPDATED                                	STATUS  	CHART                 	APP VERSION
csi-driver-nfs	storage-system	1       	2025-02-20 21:02:20.589728127 +0800 CST	deployed	csi-driver-nfs-v4.10.0	v4.10.0

Similar Issues: #763

this is for solving this issue: #763, quite opposite requirement to cleanup empty parents when deleting PV

working on a PR to only delete root folder of subDir when OnDelete: DeleteRootSubDir since there is data loss concern: #876

I am trying to understand what happened.

According to @adelmoradian:
What you expected to happen: This is arguably caused by bad config since something like subDir=${pvc.metadata.namespace}/${pvc.metadata.name}/ would prevent the issue. But still, would be nice to have this highlighted in the docs at least.
which seems that delete a pvc under ${pvc.metadata.namespace}/${pvc.metadata.name} would not delete the parent if there are other pvcs.

but according to @UnknownAtoms and @san3Xian , delete one pvc inside a multi pvc namespace would delete all PVCs. ( directory ${pvc.metadata.namespace}/)

@andyzhangx Was this a bug in the implementation? The parent should only be deleted if all children directories are empty.

@andyzhangx concerning #876 , wouldn ´t be safer to traverse the parent's tree checking for files before using removeAll() or use Remove() that only delete empty dirs afaik ?