Flip SELinuxMountReadWriteOncePod to Beta

And enable all e2e tests by default. They're still behind
`[Feature:SELinux]` tag to ensure the underlying OS supports SELinux.

pkg/apis/storage/fuzzer/fuzzer.go

@@ -96,6 +96,10 @@ var Funcs = func(codecs runtimeserializer.CodecFactory) []interface{} {
 					storage.VolumeLifecyclePersistent,
 				}
 			}
+			if obj.Spec.SELinuxMount == nil {
+				obj.Spec.SELinuxMount = new(bool)
+				*(obj.Spec.SELinuxMount) = false
+			}
 		},
 	}
 }

pkg/features/kube_features.go

@@ -858,6 +858,7 @@ const (
 	// owner: @jsafrane
 	// kep: https://kep.k8s.io/1710
 	// alpha: v1.25
+	// beta: v1.27
 	// Speed up container startup by mounting volumes with the correct SELinux label
 	// instead of changing each file on the volumes recursively.
 	// Initial implementation focused on ReadWriteOncePod volumes.
@@ -1098,7 +1099,7 @@ var defaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureS
 
 	NodeInclusionPolicyInPodTopologySpread: {Default: true, PreRelease: featuregate.Beta},
 
-	SELinuxMountReadWriteOncePod: {Default: false, PreRelease: featuregate.Alpha},
+	SELinuxMountReadWriteOncePod: {Default: true, PreRelease: featuregate.Beta},
 
 	InPlacePodVerticalScaling: {Default: false, PreRelease: featuregate.Alpha},
 

pkg/volume/util/hostutil/fake_hostutil.go

@@ -120,5 +120,6 @@ func (hu *FakeHostUtil) GetMode(pathname string) (os.FileMode, error) {
 // GetSELinuxMountContext returns value of -o context=XYZ mount option on
 // given mount point.
 func (hu *FakeHostUtil) GetSELinuxMountContext(pathname string) (string, error) {
-	return "", errors.New("not implemented")
+	// This pretends the OS does not support SELinux.
+	return "", nil
 }