- Reverted the previous fix for portforward cleanup because it introduced a kubelet regression which can lead into segmentation faults. ([#102587](https://github.com/kubernetes/kubernetes/pull/102587), [@saschagrunert](https://github.com/saschagrunert)) [SIG API Machinery and Node]

### Other (Cleanup or Flake)

- Fixed attaching volumes after detach errors. Now volumes that failed to detach are not treated as attached, Kubernetes will make sure they are fully attached before they can be used by pods. ([#120595](https://github.com/kubernetes/kubernetes/pull/120595), [@jsafrane](https://github.com/jsafrane)) [SIG Apps and Storage]

- Fixed attaching volumes after detach errors. Now volumes that failed to detach are not treated as attached, Kubernetes will make sure they are fully attached before they can be used by pods. ([#120595](https://github.com/kubernetes/kubernetes/pull/120595), [@jsafrane](https://github.com/jsafrane)) [SIG Apps and Storage]

* Check if container memory stats are available before accessing it ([#77656](https://github.com/kubernetes/kubernetes/pull/77656), [@yastij](https://github.com/yastij))
* Fixes segmentation fault issue with Protobuf library when log entries are deeply nested. ([#77224](https://github.com/kubernetes/kubernetes/pull/77224), [@qingling128](https://github.com/qingling128))

 the apps/v1beta1 API in this release, but you should start planning for code
 that does not depend on mutable selectors.

 - Extended Resources are fully-qualified resource names outside the
 `kubernetes.io` domain. Extended Resource quantities must be integers.
 You can specify any resource name of the form `[aaa.]my-domain.bbb/ccc`

- Finalizer Protection for Service LoadBalancers is now in GA (enabled by default). This feature ensures the Service resource is not fully deleted until the correlating load balancer resources are deleted. ([#85023](https://github.com/kubernetes/kubernetes/pull/85023), [@MrHohn](https://github.com/MrHohn))

## Changelog since v1.18.19

## Changes by Kind

### Bug or Regression

- Reverted the previous fix for portforward cleanup because it introduced a kubelet regression which can lead into segmentation faults. ([#102838](https://github.com/kubernetes/kubernetes/pull/102838), [@saschagrunert](https://github.com/saschagrunert)) [SIG API Machinery and Node]

## Dependencies

### Added
_Nothing has changed._

* kube-apiserver: the `Priority` admission plugin is now enabled by default when using `--enable-admission-plugins`. If using `--admission-control` to fully specify the set of admission plugins, the `Priority` admission plugin should be added if using the `PodPriority` feature, which is enabled by default in 1.11. ([#65739](https://github.com/kubernetes/kubernetes/pull/65739), [@liggitt](https://github.com/liggitt))...

* fix smb unmount issue on Windows ([#75087](https://github.com/kubernetes/kubernetes/pull/75087), [@andyzhangx](https://github.com/andyzhangx))
* Fixes segmentation fault issue with Protobuf library when log entries are deeply nested. ([#77224](https://github.com/kubernetes/kubernetes/pull/77224), [@qingling128](https://github.com/qingling128))

  * When deleting an object with `kubectl delete ... --grace-period=0`, the client will
    begin a graceful deletion and wait until the resource is fully deleted.  To force
    deletion immediately, use the `--force` flag. This prevents users from accidentally
    allowing two Stateful Set pods to share the same persistent volume which could lead to data