rebase: update kubernetes to v1.20.0

updated kubernetes packages to latest
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/mount-utils/mount_helper_common.go

@@ -0,0 +1,103 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package mount
+
+import (
+	"fmt"
+	"os"
+
+	"k8s.io/klog/v2"
+)
+
+// CleanupMountPoint unmounts the given path and deletes the remaining directory
+// if successful. If extensiveMountPointCheck is true IsNotMountPoint will be
+// called instead of IsLikelyNotMountPoint. IsNotMountPoint is more expensive
+// but properly handles bind mounts within the same fs.
+func CleanupMountPoint(mountPath string, mounter Interface, extensiveMountPointCheck bool) error {
+	pathExists, pathErr := PathExists(mountPath)
+	if !pathExists {
+		klog.Warningf("Warning: Unmount skipped because path does not exist: %v", mountPath)
+		return nil
+	}
+	corruptedMnt := IsCorruptedMnt(pathErr)
+	if pathErr != nil && !corruptedMnt {
+		return fmt.Errorf("Error checking path: %v", pathErr)
+	}
+	return doCleanupMountPoint(mountPath, mounter, extensiveMountPointCheck, corruptedMnt)
+}
+
+// doCleanupMountPoint unmounts the given path and
+// deletes the remaining directory if successful.
+// if extensiveMountPointCheck is true
+// IsNotMountPoint will be called instead of IsLikelyNotMountPoint.
+// IsNotMountPoint is more expensive but properly handles bind mounts within the same fs.
+// if corruptedMnt is true, it means that the mountPath is a corrupted mountpoint, and the mount point check
+// will be skipped
+func doCleanupMountPoint(mountPath string, mounter Interface, extensiveMountPointCheck bool, corruptedMnt bool) error {
+	var notMnt bool
+	var err error
+	if !corruptedMnt {
+		if extensiveMountPointCheck {
+			notMnt, err = IsNotMountPoint(mounter, mountPath)
+		} else {
+			notMnt, err = mounter.IsLikelyNotMountPoint(mountPath)
+		}
+
+		if err != nil {
+			return err
+		}
+
+		if notMnt {
+			klog.Warningf("Warning: %q is not a mountpoint, deleting", mountPath)
+			return os.Remove(mountPath)
+		}
+	}
+
+	// Unmount the mount path
+	klog.V(4).Infof("%q is a mountpoint, unmounting", mountPath)
+	if err := mounter.Unmount(mountPath); err != nil {
+		return err
+	}
+
+	if extensiveMountPointCheck {
+		notMnt, err = IsNotMountPoint(mounter, mountPath)
+	} else {
+		notMnt, err = mounter.IsLikelyNotMountPoint(mountPath)
+	}
+	if err != nil {
+		return err
+	}
+	if notMnt {
+		klog.V(4).Infof("%q is unmounted, deleting the directory", mountPath)
+		return os.Remove(mountPath)
+	}
+	return fmt.Errorf("Failed to unmount path %v", mountPath)
+}
+
+// PathExists returns true if the specified path exists.
+// TODO: clean this up to use pkg/util/file/FileExists
+func PathExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	} else if os.IsNotExist(err) {
+		return false, nil
+	} else if IsCorruptedMnt(err) {
+		return true, err
+	}
+	return false, err
+}