* When a pod is deleted, the controller waits for the volume to be safely unmounted by kubelet. It does this by waiting for the volume to no longer be present in the nodes Node.Status.VolumesInUse list. If the volume is not safely unmounted by kubelet within a pre-configured duration (3 minutes in Kubernetes v1.3),...

### Other notable changes

* Fix issue in reconstruct volume data when kubelet restarts ([#36616](https://github.com/kubernetes/kubernetes/pull/36616), [@jingxu97](https://github.com/jingxu97))
* Add sync state loop in master's volume reconciler ([#34859](https://github.com/kubernetes/kubernetes/pull/34859), [@jingxu97](https://github.com/jingxu97))

      - [Bug fixes](#bug-fixes-1)
    - [kube-controller-manager](#kube-controller-manager)
    - [kube-dns](#kube-dns)
    - [kube-proxy](#kube-proxy)
    - [Scheduler](#scheduler)
    - [Volume Plugins](#volume-plugins)
      - [Azure Disk](#azure-disk)
      - [GlusterFS](#glusterfs)
      - [Photon](#photon)
      - [rbd](#rbd)
      - [vSphere](#vsphere-1)

  * Don't try to attach volume to new node if it is already attached to another node and the volume does not support multi-attach. ([#45346](https://github.com/kubernetes/kubernetes/pull/45346), [@codablock](https://github.com/codablock))

New alpha features include:
* Online volume resizing will increase the filesystem size of a resized volume without requiring a Pod restart.

    - [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)

        </codeSegment>
      </codeSegments>
    </class>
    <class locationTracker="locations">
      <name>InputLocation</name>
      <version>4.0.0/4.0.99</version>
      <fields>
        <!-- line, column and source fields are auto-generated by Modello -->
      </fields>
      <codeSegments>
        <codeSegment>
          <version>4.0.0+</version>
          <code>
            <![CDATA[

	// Volume operations.
	MakeVol(ctx context.Context, volume string) (err error)
	MakeVolBulk(ctx context.Context, volumes ...string) (err error)
	ListVols(ctx context.Context) (vols []VolInfo, err error)
	StatVol(ctx context.Context, volume string) (vol VolInfo, err error)
	DeleteVol(ctx context.Context, volume string, forceDelete bool) (err error)

- Kubelet: Fix the volume manager didn't check the device mount state in the actual state of the world before marking the volume as detached. It may cause a pod to be stuck in the Terminating state due to the above issue when it was deleted. ([#129063](https://github.com/kubernetes/kubernetes/pull/129063), [@carlory](https...

### CVE-2021-25741: Symlink Exchange Can Allow Host Filesystem Access

A security issue was discovered in Kubernetes where a user may be able to
create a container with subpath volume mounts to access files &
directories outside of the volume, including on the host filesystem.

**Affected Versions**:
  - kubelet v1.22.0 - v1.22.1
  - kubelet v1.21.0 - v1.21.4
  - kubelet v1.20.0 - v1.20.10
  - kubelet <= v1.19.14