- On compatible systems, a mounter's Unmount implementation is changed to not return an error when the specified target can be detected as not a mount point. On Linux, the behavior of detecting a mount point depends on `umount` command is validated when the mounter is created. Additionally, mount point checks will be skipped in CleanupMountPoint/CleanupMountWithForce if the mounter's Unmount having the changed behavior of not returning error when target is not a...

- Fix: Mount point may become local without calling NodePublishVolume after node rebooting. ([#119923](https://github.com/kubernetes/kubernetes/pull/119923), [@cvvz](https://github.com/cvvz)) [SIG Node and Storage]

* fix mount unmount failure for a Windows pod ([#63272](https://github.com/kubernetes/kubernetes/pull/63272), [@andyzhangx](https://github.com/andyzhangx))
* Fix concurrent map access panic ([#65327](https://github.com/kubernetes/kubernetes/pull/65327), [@dashpole](https://github.com/dashpole))
    * Don't watch .mount cgroups to reduce number of inotify watches

- On compatible systems, a mounter's Unmount implementation is changed to not return an error when the specified target can be detected as not a mount point. On Linux, the behavior of detecting a mount point depends on `umount` command is validated when the mounter is created. Additionally, mount point checks will be skipped in CleanupMountPoint/CleanupMountWithForce if the mounter's Unmount having the changed behavior of not returning error when target is not a...

### Bug or Regression

- Fix: statle smb mount issue when smb file share is deleted and then unmount ([#121851](https://github.com/kubernetes/kubernetes/pull/121851), [@andyzhangx](https://github.com/andyzhangx)) [SIG Storage]

#### Storage

* [stable] Mount options

  * The ability to specify mount options for volumes is moved from beta to stable.

  * A new `MountOptions` field in the `PersistentVolume` spec is available to specify mount options. This field replaces an annotation.

  * A new `MountOptions` field in the `StorageClass` spec allows configuration of mount options for dynamically provisioned volumes.

* Fixes issue where subpath readOnly mounts failed ([#63045](https://github.com/kubernetes/kubernetes/pull/63045), [@msau42](https://github.com/msau42))
* Fix stackdriver metrics for node memory using wrong metric type ([#63535](https://github.co/kubernetes/kubernetes/pull/63535), [@serathius](https://github.com/serathius))

MountPropagation feature is now beta. As a consequence, all volume mounts in containers are now `rslave` on Linux by default. To make this default work in all Linux environments the entire mount tree should be marked as shareable, e.g. via `mount --make-rshared /`. All Linux distributions that use systemd already have the root directory mounted as rshared and hence they need not do anything. In Linux environments without systemd we recommend running `mount --make-rshared /` during boot before docker is started,...

### Non-recursive Volume Ownership (FSGroup) graduates to Beta

By default, the `fsgroup` setting, if specified, recursively updates permissions for every file in a volume on every mount. This can make mount, and pod startup, very slow if the volume has many files. 

- AzureFile and CephFS use the new Mount library that prevents logging of sensitive mount options. ([#88684](https://github.com/kubernetes/kubernetes/pull/88684), [@saad-ali](https://github.com/saad-ali)) [SIG Storage]