* Because some plugins mount volume on sub-directory of volume path, we need to distinguish between volume path and mount path to fix issue in reconstruction. ([#74653](https://github.com/kubernetes/kubernetes/pull/74653), [@cofyc](https://github.com/cofyc))

    - [IPv4/IPv6 run](#ipv4ipv6-run)
    - [go1.15.5](#go1155)
    - [CSI Volume Snapshot graduates to General Availability](#csi-volume-snapshot-graduates-to-general-availability)
    - [Non-recursive Volume Ownership (FSGroup) graduates to Beta](#non-recursive-volume-ownership-fsgroup-graduates-to-beta)
    - [CSIDriver policy for FSGroup graduates to Beta](#csidriver-policy-for-fsgroup-graduates-to-beta)

### General ephemeral volumes

wittrock))

* The strategicmerge patchMergeKey for VolumeMounts was changed from "name" to "mountPath".  This was necessary because the name field refers to the name of the Volume, and is not a unique key for the VolumeMount.  Multiple VolumeMounts will have the same Volume name if mounting the same volume more than once.  The "mountPath" is verified to be unique and can act as the mergekey.  ([#35071](https://github.com/kubernetes/kubernetes/pull/35071), [@pwittrock](https://github.com/pwittrock))...

the in-tree storage drivers indicate support for the `MetricsProvider` interface, but fail to configure this for BlockMode volumes. With a recent change, `Kubelet` will call `GetMetrics()` for BlockMode volumes, and the in-tree drivers that miss the support cause a Go panic. Now the in-tree storage drivers that support BlockMode volumes, will return the Capacity of the volume in the `GetMetrics()` call. ([#101587](https://github.com/kubernetes/kubernetes/pull/101587), [@nixpanic](https://github.com/nixpanic))...

    - [Generic Ephemeral Volume feature graduates to GA](#generic-ephemeral-volume-feature-graduates-to-ga)
    - [Skip Volume Ownership change graduates to GA](#skip-volume-ownership-change-graduates-to-ga)
    - [Allow CSI drivers to opt-in to volume ownership and permission change graduates to GA](#allow-csi-drivers-to-opt-in-to-volume-ownership-and-permission-change-graduates-to-ga)

### Promoted CSI Ephemeral Volume to Stable

- For raw block CSI volumes on Kubernetes, kubelet was incorrectly calling CSI NodeStageVolume for every single "map" (i.e. raw block "mount") operation for a volume already attached to the node. This PR ensures it is only called once per volume per node. ([#112403](https://github.com/kubernetes/kubernetes/pull/112403), [@akankshakumari393](https://github.com/akankshakumari393)) [SIG...

- **Volume Extension**: There are quite a few enhancements in this release that pertain to volumes and volume modifications. Volume resizing support in CSI specs is moving to beta which allows for any CSI spec volume plugin to be resizable.

### Additional Notable Feature Updates

    * see https://kubernetes.io/docs/user-guide/persistent-volumes/#class-1 for details.
* Reduce verbosity of volume reconciler when attaching volumes ([#36900](https://github.com/kubernetes/kubernetes/pull/36900), [@codablock](https://github.com/codablock))