* Increase allowed lag for ssh key sync loop in tunneler to allow for one failure ([#60068](https://github.com/kubernetes/kubernetes/pull/60068), [@wojtek-t](https://github.com/wojtek-t))

- Added scheduler preemption support for pods using `ReadWriteOncePod` PVCs ([#114051](https://github.com/kubernetes/kubernetes/pull/114051),...

### Other (Cleanup or Flake)

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and time to read the headers of incoming requests ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Node]

* Changed ext3/ext4 volume creation to not reserve any portion of the volume for the root user. When creating ext3/ext4 volume, mkfs defaults to reserving 5% of the volume for the super-user (root). This patch changes the mkfs to pass -m0 to disable this setting.
([#64102](https://github.com/kubernetes/kubernetes/pull/64102), [@atombender](https://github.com/atombender))

 - `kubeadm`: a separate "super-admin.conf" file is now deployed. The User in `admin.conf` is now bound to a new RBAC Group `kubeadm:cluster-admins` that has `cluster-admin` `ClusterRole` access. The User in `super-admin.conf` is now bound to the `system:masters` built-in super-powers / break-glass Group that can bypass RBAC. Before this change, the default `admin.conf` was bound to `system:masters`...

    - `apiserver_flowcontrol_lower_limit_seats`: Configured lower bound on number of execution seats available to each priority level
    - `apiserver_flowcontrol_upper_limit_seats`: Configured upper bound on number of execution seats available to each priority level

     2. Be allowed to bind the referenced role, either by already having all of the permissions contained in the referenced role, or by having the "bind" permission on the referenced role.
* The `--authorization-rbac-super-user` flag (alpha in 1.5) is deprecated; the `system:masters` group has privileged access ([#38121](https://github.com/kubernetes/kubernetes/pull/38121), [@deads2k](https://github.com/deads2k))

- XFS-filesystems are now force-formatted (option `-f`) in order to avoid problems being formatted due to detection of magic super-blocks. This aligns with the behaviour of formatting of ext3/4 filesystems. ([#104923](https://github.com/kubernetes/kubernetes/pull/104923), [@davidkarlsen](https://github.com/davidkarlsen))

* The init-container (pod.beta.kubernetes.io/init-containers) annotations used to accept capitalized field names that could be accidentally generated by the k8s.io/kubernetes/pkg/api package. Using an upper case field name will now return an error and all users should use the versioned API types from `pkg/api/v1` when serializing from Golang.

## Action Required Before Upgrading

### Other (Cleanup or Flake)

- Kube-apiserver: sets an upper-bound on the lifetime of idle keep-alive connections and time to read the headers of incoming requests ([#103958](https://github.com/kubernetes/kubernetes/pull/103958), [@liggitt](https://github.com/liggitt)) [SIG API Machinery and Node]