- Flex volume plugins now support expandvolume (to increase underlying volume capacity) and expanfs (resize filesystem) commands that Flex plugin authors can implement to support expanding in use Flex PersistentVolumes ([#67851](https://github.com/kubernetes/kubernetes/pull/67851), [@aniket-s-kulkarni](https://github.com/aniket-s-kulkarni))

a2 := [2]byte(s)         // a2[0] == s[0]
a4 := [4]byte(s)         // panics: len([4]byte) > len(s)

s0 := (*[0]byte)(s)      // s0 != nil
s1 := (*[1]byte)(s[1:])  // &s1[0] == &s[1]
s2 := (*[2]byte)(s)      // &s2[0] == &s[0]
s4 := (*[4]byte)(s)      // panics: len([4]byte) > len(s)

var t []string
t0 := [0]string(t)       // ok for nil slice t

pkg syscall (netbsd-arm64), type RawSockaddrDatalink struct, Data [12]int8
pkg syscall (netbsd-arm64), type RawSockaddrDatalink struct, Family uint8
pkg syscall (netbsd-arm64), type RawSockaddrDatalink struct, Index uint16
pkg syscall (netbsd-arm64), type RawSockaddrDatalink struct, Len uint8
pkg syscall (netbsd-arm64), type RawSockaddrDatalink struct, Nlen uint8

- Fixed a race condition that could result in erroneous volume unmounts for flex volume plugins during kubelet restart. ([#127669](https://github.com/kubernetes/kubernetes/pull/127669), [@olyazavr](https://github.com/olyazavr))

  * You can now set `VolumeMount.Propagation` to `Bidirectional` to enable a particular mount for a container to propagate itself to the host or other containers.

* [alpha] Improve Flex volume deployment

  * Flex volume driver deployment is simplified in the following ways:

    * New driver files can now be automatically discovered and initialized without requiring a kubelet or controller-manager restart.

pkg syscall (darwin-arm64), type RawSockaddrDatalink struct, Nlen uint8
pkg syscall (darwin-arm64), type RawSockaddrDatalink struct, Slen uint8
pkg syscall (darwin-arm64), type RawSockaddrDatalink struct, Type uint8
pkg syscall (darwin-arm64), type RawSockaddrInet4 struct, Family uint8
pkg syscall (darwin-arm64), type RawSockaddrInet4 struct, Len uint8

- Kubeadm: always mount the kube-controller-manager hostPath volume that is given by the `--flex-volume-plugin-dir` flag. ([#84468](https://github.com/kubernetes/kubernetes/pull/84468), [@neolit123](https://github.com/neolit123))

- Fix controller-manager crashes when flex plugin is removed from flex plugin directory ([#65536](https://github.com/kubernetes/kubernetes/pull/65536), [@gnufied](https://github.com/gnufied))

* HostAliases is now parsed with `hostAliases` json keys to be in line with the feature's name. ([#47512](https://github.com/kubernetes/kubernetes/pull/47512), [@rickypai](https://github.com/rickypai))

  * If you depend on the old behavior of volumes binding to existing pool of PersistentVolume objects then modify the StorageClass object and set `storageclass.beta.kubernetes.io/is-default-class` to `false`.