inference fails.
Otherwise, type inference succeeds.
</p>

<h4 id="Type_unification">Type unification</h4>

<p>
Type inference solves type equations through <i>type unification</i>.
Type unification recursively compares the LHS and RHS types of an
equation, where either or both types may be or contain bound type parameters,
and looks for type arguments for those type parameters such that the LHS

### 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. 

- `readOnly` volumes now support recursive read-only mounts for kernel versions >= 5.12."
   ([#123180](https://github.com/kubernetes/kubernetes/pull/123180), [@AkihiroSuda](https://github.com/AkihiroSuda))
- cri-api: Implemented KEP-3857: Recursive Read-only (RRO) mounts.

- Fixed null `lastTransitionTime` in Pod condition when setting the scheduling gate. ([#122636](https://github.com/kubernetes/kubernetes/pull/122636), [@lianghao208](https://github.com/lianghao208)) [SIG Node and Scheduling]
- Fixed recursive LIST from watch cache returning object matching key. ([#125584](https://github.com/kubernetes/kubernetes/pull/125584), [@serathius](https://github.com/serathius)) [SIG API Machinery and Testing]

SIG Storage is also introducing the following new storage features as alpha in Kubernetes 1.18:
- Windows CSI Support: Enabling containerized CSI node plugins in Windows via new [CSIProxy](https://github.com/kubernetes-csi/csi-proxy)
- Recursive Volume Ownership OnRootMismatch Option: Add a new “OnRootMismatch” policy that can help shorten the mount time for volumes that require ownership change and have many directories and files.

### Other notable announcements

- Deprecated the following kubectl run flags, which are ignored if set: `--cascade`, `--filename`, `--force`, `--grace-period`, `--kustomize`, `--recursive`, `--timeout`, `--wait`. ([#112261](https://github.com/kubernetes/kubernetes/pull/112261), [@brianpursley](https://github.com/brianpursley))

* ✨ Update OpenAPI models, supporting recursive models and extensions. PR [#3628](https://github.com/tiangolo/fastapi/pull/3628) by [@tiangolo](https://github.com/tiangolo).

### Skip Volume Ownership change graduates to GA

The feature to configure volume permission and ownership change policy for Pods moved to GA in 1.23.
This allows users to skip recursive permission changes on mount and speeds up the pod start up time.

### Allow CSI drivers to opt-in to volume ownership and permission change graduates to GA