Add RPC ControllerGetVolumeStats #598
Description
Is your feature request related to a problem?/Why is this needed
- Many stats can only be accessed by controller.
- For example, controller creates a volume and set quota, and node mount it via NFS. NodeGetVolumeStats can get nothing about this volume.
Describe the solution you'd like in detail
add ControllerGetVolumeStats, controller has more privilege and knows more than node plugin
Describe alternatives you've considered
none
Additional context