Update go dependencies

vendor/k8s.io/kubernetes/pkg/util/mount/BUILD

@@ -1,10 +1,4 @@
-package(default_visibility = ["//visibility:public"])
-
-load(
-    "@io_bazel_rules_go//go:def.bzl",
-    "go_library",
-    "go_test",
-)
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -72,6 +66,7 @@ go_library(
         "//conditions:default": [],
     }),
     importpath = "k8s.io/kubernetes/pkg/util/mount",
+    visibility = ["//visibility:public"],
     deps = [
         "//vendor/github.com/golang/glog:go_default_library",
         "//vendor/k8s.io/utils/exec:go_default_library",
@@ -102,10 +97,17 @@ go_test(
         "//conditions:default": [],
     }),
     embed = [":go_default_library"],
-    importpath = "k8s.io/kubernetes/pkg/util/mount",
     deps = [
         "//vendor/k8s.io/utils/exec/testing:go_default_library",
-    ],
+    ] + select({
+        "@io_bazel_rules_go//go/platform:linux": [
+            "//vendor/github.com/golang/glog:go_default_library",
+        ],
+        "@io_bazel_rules_go//go/platform:windows": [
+            "//vendor/github.com/stretchr/testify/assert:go_default_library",
+        ],
+        "//conditions:default": [],
+    }),
 )
 
 filegroup(
@@ -119,4 +121,5 @@ filegroup(
     name = "all-srcs",
     srcs = [":package-srcs"],
     tags = ["automanaged"],
+    visibility = ["//visibility:public"],
 )

vendor/k8s.io/kubernetes/pkg/util/mount/OWNERS

@@ -1,7 +1,10 @@
 reviewers:
   - jingxu97
   - saad-ali
+  - jsafrane
+  - msau42
 approvers:
   - jingxu97
   - saad-ali
+  - jsafrane
 

vendor/k8s.io/kubernetes/pkg/util/mount/exec_mount.go

@@ -20,6 +20,7 @@ package mount
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/golang/glog"
 )
@@ -56,7 +57,7 @@ func (m *execMounter) Mount(source string, target string, fstype string, options
 	return m.doExecMount(source, target, fstype, options)
 }
 
-// doExecMount calls exec(mount <waht> <where>) using given exec interface.
+// doExecMount calls exec(mount <what> <where>) using given exec interface.
 func (m *execMounter) doExecMount(source, target, fstype string, options []string) error {
 	glog.V(5).Infof("Exec Mounting %s %s %s %v", source, target, fstype, options)
 	mountArgs := makeMountArgs(source, target, fstype, options)
@@ -138,3 +139,15 @@ func (m *execMounter) MakeDir(pathname string) error {
 func (m *execMounter) ExistsPath(pathname string) bool {
 	return m.wrappedMounter.ExistsPath(pathname)
 }
+
+func (m *execMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return m.wrappedMounter.PrepareSafeSubpath(subPath)
+}
+
+func (m *execMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return m.wrappedMounter.CleanSubPaths(podDir, volumeName)
+}
+
+func (m *execMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return m.wrappedMounter.SafeMakeDir(pathname, base, perm)
+}

vendor/k8s.io/kubernetes/pkg/util/mount/exec_mount_test.go

@@ -20,6 +20,7 @@ package mount
 
 import (
 	"fmt"
+	"os"
 	"reflect"
 	"strings"
 	"testing"
@@ -151,3 +152,14 @@ func (fm *fakeMounter) ExistsPath(pathname string) bool {
 func (fm *fakeMounter) GetFileType(pathname string) (FileType, error) {
 	return FileTypeFile, nil
 }
+func (fm *fakeMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return subPath.Path, nil, nil
+}
+
+func (fm *fakeMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}
+
+func (fm *fakeMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/exec_mount_unsupported.go

@@ -20,6 +20,7 @@ package mount
 
 import (
 	"errors"
+	"os"
 )
 
 type execMounter struct{}
@@ -85,3 +86,15 @@ func (mounter *execMounter) MakeFile(pathname string) error {
 func (mounter *execMounter) ExistsPath(pathname string) bool {
 	return true
 }
+
+func (mounter *execMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return subPath.Path, nil, nil
+}
+
+func (mounter *execMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}
+
+func (mounter *execMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/fake.go

@@ -197,3 +197,14 @@ func (f *FakeMounter) MakeFile(pathname string) error {
 func (f *FakeMounter) ExistsPath(pathname string) bool {
 	return false
 }
+
+func (f *FakeMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return subPath.Path, nil, nil
+}
+
+func (f *FakeMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}
+func (mounter *FakeMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount.go

@@ -19,7 +19,10 @@ limitations under the License.
 package mount
 
 import (
+	"os"
 	"path/filepath"
+	"strings"
+	"syscall"
 )
 
 type FileType string
@@ -81,9 +84,45 @@ type Interface interface {
 	// MakeDir creates a new directory.
 	// Will operate in the host mount namespace if kubelet is running in a container
 	MakeDir(pathname string) error
+	// SafeMakeDir makes sure that the created directory does not escape given
+	// base directory mis-using symlinks. The directory is created in the same
+	// mount namespace as where kubelet is running. Note that the function makes
+	// sure that it creates the directory somewhere under the base, nothing
+	// else. E.g. if the directory already exists, it may exists outside of the
+	// base due to symlinks.
+	SafeMakeDir(pathname string, base string, perm os.FileMode) error
 	// ExistsPath checks whether the path exists.
 	// Will operate in the host mount namespace if kubelet is running in a container
 	ExistsPath(pathname string) bool
+	// CleanSubPaths removes any bind-mounts created by PrepareSafeSubpath in given
+	// pod volume directory.
+	CleanSubPaths(podDir string, volumeName string) error
+	// PrepareSafeSubpath does everything that's necessary to prepare a subPath
+	// that's 1) inside given volumePath and 2) immutable after this call.
+	//
+	// newHostPath - location of prepared subPath. It should be used instead of
+	// hostName when running the container.
+	// cleanupAction - action to run when the container is running or it failed to start.
+	//
+	// CleanupAction must be called immediately after the container with given
+	// subpath starts. On the other hand, Interface.CleanSubPaths must be called
+	// when the pod finishes.
+	PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error)
+}
+
+type Subpath struct {
+	// index of the VolumeMount for this container
+	VolumeMountIndex int
+	// Full path to the subpath directory on the host
+	Path string
+	// name of the volume that is a valid directory name.
+	VolumeName string
+	// Full path to the volume path
+	VolumePath string
+	// Path to the pod's directory, including pod UID
+	PodDir string
+	// Name of the container
+	ContainerName string
 }
 
 // Exec executes command where mount utilities are. This can be either the host,
@@ -124,12 +163,6 @@ type SafeFormatAndMount struct {
 // disk is already formatted or it is being mounted as read-only, it
 // will be mounted without formatting.
 func (mounter *SafeFormatAndMount) FormatAndMount(source string, target string, fstype string, options []string) error {
-	// Don't attempt to format if mounting as readonly. Go straight to mounting.
-	for _, option := range options {
-		if option == "ro" {
-			return mounter.Interface.Mount(source, target, fstype, options)
-		}
-	}
 	return mounter.formatAndMount(source, target, fstype, options)
 }
 
@@ -199,6 +232,13 @@ func GetDeviceNameFromMount(mounter Interface, mountPath string) (string, int, e
 	return device, refCount, nil
 }
 
+func isNotDirErr(err error) bool {
+	if e, ok := err.(*os.PathError); ok && e.Err == syscall.ENOTDIR {
+		return true
+	}
+	return false
+}
+
 // IsNotMountPoint determines if a directory is a mountpoint.
 // It should return ErrNotExist when the directory does not exist.
 // This method uses the List() of all mountpoints
@@ -208,7 +248,13 @@ func IsNotMountPoint(mounter Interface, file string) (bool, error) {
 	// IsLikelyNotMountPoint provides a quick check
 	// to determine whether file IS A mountpoint
 	notMnt, notMntErr := mounter.IsLikelyNotMountPoint(file)
-	if notMntErr != nil {
+	if notMntErr != nil && os.IsPermission(notMntErr) {
+		// We were not allowed to do the simple stat() check, e.g. on NFS with
+		// root_squash. Fall back to /proc/mounts check below.
+		notMnt = true
+		notMntErr = nil
+	}
+	if notMntErr != nil && isNotDirErr(notMntErr) {
 		return notMnt, notMntErr
 	}
 	// identified as mountpoint, so return this fact
@@ -254,3 +300,40 @@ func isBind(options []string) (bool, []string) {
 
 	return bind, bindRemountOpts
 }
+
+// TODO: this is a workaround for the unmount device issue caused by gci mounter.
+// In GCI cluster, if gci mounter is used for mounting, the container started by mounter
+// script will cause additional mounts created in the container. Since these mounts are
+// irrelevant to the original mounts, they should be not considered when checking the
+// mount references. Current solution is to filter out those mount paths that contain
+// the string of original mount path.
+// Plan to work on better approach to solve this issue.
+
+func HasMountRefs(mountPath string, mountRefs []string) bool {
+	count := 0
+	for _, ref := range mountRefs {
+		if !strings.Contains(ref, mountPath) {
+			count = count + 1
+		}
+	}
+	return count > 0
+}
+
+// pathWithinBase checks if give path is within given base directory.
+func pathWithinBase(fullPath, basePath string) bool {
+	rel, err := filepath.Rel(basePath, fullPath)
+	if err != nil {
+		return false
+	}
+	if startsWithBackstep(rel) {
+		// Needed to escape the base path
+		return false
+	}
+	return true
+}
+
+// startsWithBackstep checks if the given path starts with a backstep segment
+func startsWithBackstep(rel string) bool {
+	// normalize to / and check for ../
+	return rel == ".." || strings.HasPrefix(filepath.ToSlash(rel), "../")
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount_linux.go

@@ -19,7 +19,9 @@ limitations under the License.
 package mount
 
 import (
+	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
@@ -48,6 +50,13 @@ const (
 	fsckErrorsCorrected = 1
 	// 'fsck' found errors but exited without correcting them
 	fsckErrorsUncorrected = 4
+
+	// place for subpath mounts
+	containerSubPathDirectoryName = "volume-subpaths"
+	// syscall.Openat flags used to traverse directories not following symlinks
+	nofollowFlags = unix.O_RDONLY | unix.O_NOFOLLOW
+	// flags for getting file descriptor without following the symlink
+	openFDFlags = unix.O_NOFOLLOW | unix.O_PATH
 )
 
 // Mounter provides the default implementation of mount.Interface
@@ -69,7 +78,7 @@ func New(mounterPath string) Interface {
 }
 
 // Mount mounts source to target as fstype with given options. 'source' and 'fstype' must
-// be an emtpy string in case it's not required, e.g. for remount, or for auto filesystem
+// be an empty string in case it's not required, e.g. for remount, or for auto filesystem
 // type, where kernel handles fstype for you. The mount 'options' is a list of options,
 // currently come from mount(8), e.g. "ro", "remount", "bind", etc. If no more option is
 // required, call Mount with an empty string list or nil.
@@ -265,7 +274,7 @@ func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	if err != nil {
 		return true, err
 	}
-	rootStat, err := os.Lstat(file + "/..")
+	rootStat, err := os.Lstat(filepath.Dir(strings.TrimSuffix(file, "/")))
 	if err != nil {
 		return true, err
 	}
@@ -313,7 +322,7 @@ func exclusiveOpenFailsOnDevice(pathname string) (bool, error) {
 	}
 
 	if !isDevice {
-		glog.Errorf("Path %q is not refering to a device.", pathname)
+		glog.Errorf("Path %q is not referring to a device.", pathname)
 		return false, nil
 	}
 	fd, errno := unix.Open(pathname, unix.O_RDONLY|unix.O_EXCL, 0)
@@ -431,7 +440,7 @@ func (mounter *Mounter) GetFileType(pathname string) (FileType, error) {
 	case syscall.S_IFBLK:
 		return FileTypeBlockDev, nil
 	case syscall.S_IFCHR:
-		return FileTypeBlockDev, nil
+		return FileTypeCharDev, nil
 	case syscall.S_IFDIR:
 		return FileTypeDirectory, nil
 	case syscall.S_IFREG:
@@ -472,23 +481,33 @@ func (mounter *Mounter) ExistsPath(pathname string) bool {
 
 // formatAndMount uses unix utils to format and mount the given disk
 func (mounter *SafeFormatAndMount) formatAndMount(source string, target string, fstype string, options []string) error {
+	readOnly := false
+	for _, option := range options {
+		if option == "ro" {
+			readOnly = true
+			break
+		}
+	}
+
 	options = append(options, "defaults")
 
-	// Run fsck on the disk to fix repairable issues
-	glog.V(4).Infof("Checking for issues with fsck on disk: %s", source)
-	args := []string{"-a", source}
-	out, err := mounter.Exec.Run("fsck", args...)
-	if err != nil {
-		ee, isExitError := err.(utilexec.ExitError)
-		switch {
-		case err == utilexec.ErrExecutableNotFound:
-			glog.Warningf("'fsck' not found on system; continuing mount without running 'fsck'.")
-		case isExitError && ee.ExitStatus() == fsckErrorsCorrected:
-			glog.Infof("Device %s has errors which were corrected by fsck.", source)
-		case isExitError && ee.ExitStatus() == fsckErrorsUncorrected:
-			return fmt.Errorf("'fsck' found errors on device %s but could not correct them: %s.", source, string(out))
-		case isExitError && ee.ExitStatus() > fsckErrorsUncorrected:
-			glog.Infof("`fsck` error %s", string(out))
+	if !readOnly {
+		// Run fsck on the disk to fix repairable issues, only do this for volumes requested as rw.
+		glog.V(4).Infof("Checking for issues with fsck on disk: %s", source)
+		args := []string{"-a", source}
+		out, err := mounter.Exec.Run("fsck", args...)
+		if err != nil {
+			ee, isExitError := err.(utilexec.ExitError)
+			switch {
+			case err == utilexec.ErrExecutableNotFound:
+				glog.Warningf("'fsck' not found on system; continuing mount without running 'fsck'.")
+			case isExitError && ee.ExitStatus() == fsckErrorsCorrected:
+				glog.Infof("Device %s has errors which were corrected by fsck.", source)
+			case isExitError && ee.ExitStatus() == fsckErrorsUncorrected:
+				return fmt.Errorf("'fsck' found errors on device %s but could not correct them: %s.", source, string(out))
+			case isExitError && ee.ExitStatus() > fsckErrorsUncorrected:
+				glog.Infof("`fsck` error %s", string(out))
+			}
 		}
 	}
 
@@ -503,8 +522,13 @@ func (mounter *SafeFormatAndMount) formatAndMount(source string, target string,
 			return err
 		}
 		if existingFormat == "" {
+			if readOnly {
+				// Don't attempt to format if mounting as readonly, return an error to reflect this.
+				return errors.New("failed to mount unformatted volume as read only")
+			}
+
 			// Disk is unformatted so format it.
-			args = []string{source}
+			args := []string{source}
 			// Use 'ext4' as the default
 			if len(fstype) == 0 {
 				fstype = "ext4"
@@ -536,36 +560,57 @@ func (mounter *SafeFormatAndMount) formatAndMount(source string, target string,
 	return mountErr
 }
 
-// GetDiskFormat uses 'lsblk' to see if the given disk is unformated
+// GetDiskFormat uses 'blkid' to see if the given disk is unformated
 func (mounter *SafeFormatAndMount) GetDiskFormat(disk string) (string, error) {
-	args := []string{"-n", "-o", "FSTYPE", disk}
-	glog.V(4).Infof("Attempting to determine if disk %q is formatted using lsblk with args: (%v)", disk, args)
-	dataOut, err := mounter.Exec.Run("lsblk", args...)
+	args := []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", disk}
+	glog.V(4).Infof("Attempting to determine if disk %q is formatted using blkid with args: (%v)", disk, args)
+	dataOut, err := mounter.Exec.Run("blkid", args...)
 	output := string(dataOut)
-	glog.V(4).Infof("Output: %q", output)
+	glog.V(4).Infof("Output: %q, err: %v", output, err)
 
 	if err != nil {
+		if exit, ok := err.(utilexec.ExitError); ok {
+			if exit.ExitStatus() == 2 {
+				// Disk device is unformatted.
+				// For `blkid`, if the specified token (TYPE/PTTYPE, etc) was
+				// not found, or no (specified) devices could be identified, an
+				// exit code of 2 is returned.
+				return "", nil
+			}
+		}
 		glog.Errorf("Could not determine if disk %q is formatted (%v)", disk, err)
 		return "", err
 	}
 
-	// Split lsblk output into lines. Unformatted devices should contain only
-	// "\n". Beware of "\n\n", that's a device with one empty partition.
-	output = strings.TrimSuffix(output, "\n") // Avoid last empty line
+	var fstype, pttype string
+
 	lines := strings.Split(output, "\n")
-	if lines[0] != "" {
-		// The device is formatted
-		return lines[0], nil
+	for _, l := range lines {
+		if len(l) <= 0 {
+			// Ignore empty line.
+			continue
+		}
+		cs := strings.Split(l, "=")
+		if len(cs) != 2 {
+			return "", fmt.Errorf("blkid returns invalid output: %s", output)
+		}
+		// TYPE is filesystem type, and PTTYPE is partition table type, according
+		// to https://www.kernel.org/pub/linux/utils/util-linux/v2.21/libblkid-docs/.
+		if cs[0] == "TYPE" {
+			fstype = cs[1]
+		} else if cs[0] == "PTTYPE" {
+			pttype = cs[1]
+		}
 	}
 
-	if len(lines) == 1 {
-		// The device is unformatted and has no dependent devices
-		return "", nil
+	if len(pttype) > 0 {
+		glog.V(4).Infof("Disk %s detected partition table type: %s", pttype)
+		// Returns a special non-empty string as filesystem type, then kubelet
+		// will not format it.
+		return "unknown data, probably partitions", nil
 	}
 
-	// The device has dependent devices, most probably partitions (LVM, LUKS
-	// and MD RAID are reported as FSTYPE and caught above).
-	return "unknown data, probably partitions", nil
+	return fstype, nil
 }
 
 // isShared returns true, if given path is on a mount point that has shared
@@ -599,6 +644,7 @@ func isShared(path string, filename string) (bool, error) {
 }
 
 type mountInfo struct {
+	// Path of the mount point
 	mountPoint string
 	// list of "optional parameters", mount propagation is one of them
 	optional []string
@@ -618,6 +664,7 @@ func parseMountInfo(filename string) ([]mountInfo, error) {
 			// the last split() item is empty string following the last \n
 			continue
 		}
+		// See `man proc` for authoritative description of format of the file.
 		fields := strings.Fields(line)
 		if len(fields) < 7 {
 			return nil, fmt.Errorf("wrong number of fields in (expected %d, got %d): %s", 8, len(fields), line)
@@ -626,6 +673,7 @@ func parseMountInfo(filename string) ([]mountInfo, error) {
 			mountPoint: fields[4],
 			optional:   []string{},
 		}
+		// All fields until "-" are "optional fields".
 		for i := 6; i < len(fields) && fields[i] != "-"; i++ {
 			info.optional = append(info.optional, fields[i])
 		}
@@ -661,3 +709,464 @@ func doMakeRShared(path string, mountInfoFilename string) error {
 
 	return nil
 }
+
+func (mounter *Mounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	newHostPath, err = doBindSubPath(mounter, subPath, os.Getpid())
+	// There is no action when the container starts. Bind-mount will be cleaned
+	// when container stops by CleanSubPaths.
+	cleanupAction = nil
+	return newHostPath, cleanupAction, err
+}
+
+// This implementation is shared between Linux and NsEnterMounter
+// kubeletPid is PID of kubelet in the PID namespace where bind-mount is done,
+// i.e. pid on the *host* if kubelet runs in a container.
+func doBindSubPath(mounter Interface, subpath Subpath, kubeletPid int) (hostPath string, err error) {
+	// Check early for symlink. This is just a pre-check to avoid bind-mount
+	// before the final check.
+	evalSubPath, err := filepath.EvalSymlinks(subpath.Path)
+	if err != nil {
+		return "", fmt.Errorf("evalSymlinks %q failed: %v", subpath.Path, err)
+	}
+	glog.V(5).Infof("doBindSubPath %q, full subpath %q for volumepath %q", subpath.Path, evalSubPath, subpath.VolumePath)
+
+	evalSubPath = filepath.Clean(evalSubPath)
+	if !pathWithinBase(evalSubPath, subpath.VolumePath) {
+		return "", fmt.Errorf("subpath %q not within volume path %q", evalSubPath, subpath.VolumePath)
+	}
+
+	// Prepare directory for bind mounts
+	// containerName is DNS label, i.e. safe as a directory name.
+	bindDir := filepath.Join(subpath.PodDir, containerSubPathDirectoryName, subpath.VolumeName, subpath.ContainerName)
+	err = os.MkdirAll(bindDir, 0750)
+	if err != nil && !os.IsExist(err) {
+		return "", fmt.Errorf("error creating directory %s: %s", bindDir, err)
+	}
+	bindPathTarget := filepath.Join(bindDir, strconv.Itoa(subpath.VolumeMountIndex))
+
+	success := false
+	defer func() {
+		// Cleanup subpath on error
+		if !success {
+			glog.V(4).Infof("doBindSubPath() failed for %q, cleaning up subpath", bindPathTarget)
+			if cleanErr := cleanSubPath(mounter, subpath); cleanErr != nil {
+				glog.Errorf("Failed to clean subpath %q: %v", bindPathTarget, cleanErr)
+			}
+		}
+	}()
+
+	// Check it's not already bind-mounted
+	notMount, err := IsNotMountPoint(mounter, bindPathTarget)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return "", fmt.Errorf("error checking path %s for mount: %s", bindPathTarget, err)
+		}
+		// Ignore ErrorNotExist: the file/directory will be created below if it does not exist yet.
+		notMount = true
+	}
+	if !notMount {
+		// It's already mounted
+		glog.V(5).Infof("Skipping bind-mounting subpath %s: already mounted", bindPathTarget)
+		success = true
+		return bindPathTarget, nil
+	}
+
+	// Create target of the bind mount. A directory for directories, empty file
+	// for everything else.
+	t, err := os.Lstat(subpath.Path)
+	if err != nil {
+		return "", fmt.Errorf("lstat %s failed: %s", subpath.Path, err)
+	}
+	if t.Mode()&os.ModeDir > 0 {
+		if err = os.Mkdir(bindPathTarget, 0750); err != nil && !os.IsExist(err) {
+			return "", fmt.Errorf("error creating directory %s: %s", bindPathTarget, err)
+		}
+	} else {
+		// "/bin/touch <bindDir>".
+		// A file is enough for all possible targets (symlink, device, pipe,
+		// socket, ...), bind-mounting them into a file correctly changes type
+		// of the target file.
+		if err = ioutil.WriteFile(bindPathTarget, []byte{}, 0640); err != nil {
+			return "", fmt.Errorf("error creating file %s: %s", bindPathTarget, err)
+		}
+	}
+
+	// Safe open subpath and get the fd
+	fd, err := doSafeOpen(evalSubPath, subpath.VolumePath)
+	if err != nil {
+		return "", fmt.Errorf("error opening subpath %v: %v", evalSubPath, err)
+	}
+	defer syscall.Close(fd)
+
+	mountSource := fmt.Sprintf("/proc/%d/fd/%v", kubeletPid, fd)
+
+	// Do the bind mount
+	glog.V(5).Infof("bind mounting %q at %q", mountSource, bindPathTarget)
+	if err = mounter.Mount(mountSource, bindPathTarget, "" /*fstype*/, []string{"bind"}); err != nil {
+		return "", fmt.Errorf("error mounting %s: %s", subpath.Path, err)
+	}
+
+	success = true
+	glog.V(3).Infof("Bound SubPath %s into %s", subpath.Path, bindPathTarget)
+	return bindPathTarget, nil
+}
+
+func (mounter *Mounter) CleanSubPaths(podDir string, volumeName string) error {
+	return doCleanSubPaths(mounter, podDir, volumeName)
+}
+
+// This implementation is shared between Linux and NsEnterMounter
+func doCleanSubPaths(mounter Interface, podDir string, volumeName string) error {
+	// scan /var/lib/kubelet/pods/<uid>/volume-subpaths/<volume>/*
+	subPathDir := filepath.Join(podDir, containerSubPathDirectoryName, volumeName)
+	glog.V(4).Infof("Cleaning up subpath mounts for %s", subPathDir)
+
+	containerDirs, err := ioutil.ReadDir(subPathDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return fmt.Errorf("error reading %s: %s", subPathDir, err)
+	}
+
+	for _, containerDir := range containerDirs {
+		if !containerDir.IsDir() {
+			glog.V(4).Infof("Container file is not a directory: %s", containerDir.Name())
+			continue
+		}
+		glog.V(4).Infof("Cleaning up subpath mounts for container %s", containerDir.Name())
+
+		// scan /var/lib/kubelet/pods/<uid>/volume-subpaths/<volume>/<container name>/*
+		fullContainerDirPath := filepath.Join(subPathDir, containerDir.Name())
+		subPaths, err := ioutil.ReadDir(fullContainerDirPath)
+		if err != nil {
+			return fmt.Errorf("error reading %s: %s", fullContainerDirPath, err)
+		}
+		for _, subPath := range subPaths {
+			if err = doCleanSubPath(mounter, fullContainerDirPath, subPath.Name()); err != nil {
+				return err
+			}
+		}
+		// Whole container has been processed, remove its directory.
+		if err := os.Remove(fullContainerDirPath); err != nil {
+			return fmt.Errorf("error deleting %s: %s", fullContainerDirPath, err)
+		}
+		glog.V(5).Infof("Removed %s", fullContainerDirPath)
+	}
+	// Whole pod volume subpaths have been cleaned up, remove its subpath directory.
+	if err := os.Remove(subPathDir); err != nil {
+		return fmt.Errorf("error deleting %s: %s", subPathDir, err)
+	}
+	glog.V(5).Infof("Removed %s", subPathDir)
+
+	// Remove entire subpath directory if it's the last one
+	podSubPathDir := filepath.Join(podDir, containerSubPathDirectoryName)
+	if err := os.Remove(podSubPathDir); err != nil && !os.IsExist(err) {
+		return fmt.Errorf("error deleting %s: %s", podSubPathDir, err)
+	}
+	glog.V(5).Infof("Removed %s", podSubPathDir)
+	return nil
+}
+
+// doCleanSubPath tears down the single subpath bind mount
+func doCleanSubPath(mounter Interface, fullContainerDirPath, subPathIndex string) error {
+	// process /var/lib/kubelet/pods/<uid>/volume-subpaths/<volume>/<container name>/<subPathName>
+	glog.V(4).Infof("Cleaning up subpath mounts for subpath %v", subPathIndex)
+	fullSubPath := filepath.Join(fullContainerDirPath, subPathIndex)
+	notMnt, err := IsNotMountPoint(mounter, fullSubPath)
+	if err != nil {
+		return fmt.Errorf("error checking %s for mount: %s", fullSubPath, err)
+	}
+	// Unmount it
+	if !notMnt {
+		if err = mounter.Unmount(fullSubPath); err != nil {
+			return fmt.Errorf("error unmounting %s: %s", fullSubPath, err)
+		}
+		glog.V(5).Infof("Unmounted %s", fullSubPath)
+	}
+	// Remove it *non*-recursively, just in case there were some hiccups.
+	if err = os.Remove(fullSubPath); err != nil {
+		return fmt.Errorf("error deleting %s: %s", fullSubPath, err)
+	}
+	glog.V(5).Infof("Removed %s", fullSubPath)
+	return nil
+}
+
+// cleanSubPath will teardown the subpath bind mount and any remove any directories if empty
+func cleanSubPath(mounter Interface, subpath Subpath) error {
+	containerDir := filepath.Join(subpath.PodDir, containerSubPathDirectoryName, subpath.VolumeName, subpath.ContainerName)
+
+	// Clean subdir bindmount
+	if err := doCleanSubPath(mounter, containerDir, strconv.Itoa(subpath.VolumeMountIndex)); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+
+	// Recusively remove directories if empty
+	if err := removeEmptyDirs(subpath.PodDir, containerDir); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// removeEmptyDirs works backwards from endDir to baseDir and removes each directory
+// if it is empty.  It stops once it encounters a directory that has content
+func removeEmptyDirs(baseDir, endDir string) error {
+	if !pathWithinBase(endDir, baseDir) {
+		return fmt.Errorf("endDir %q is not within baseDir %q", endDir, baseDir)
+	}
+
+	for curDir := endDir; curDir != baseDir; curDir = filepath.Dir(curDir) {
+		s, err := os.Stat(curDir)
+		if err != nil {
+			if os.IsNotExist(err) {
+				glog.V(5).Infof("curDir %q doesn't exist, skipping", curDir)
+				continue
+			}
+			return fmt.Errorf("error stat %q: %v", curDir, err)
+		}
+		if !s.IsDir() {
+			return fmt.Errorf("path %q not a directory", curDir)
+		}
+
+		err = os.Remove(curDir)
+		if os.IsExist(err) {
+			glog.V(5).Infof("Directory %q not empty, not removing", curDir)
+			break
+		} else if err != nil {
+			return fmt.Errorf("error removing directory %q: %v", curDir, err)
+		}
+		glog.V(5).Infof("Removed directory %q", curDir)
+	}
+	return nil
+}
+
+func (mounter *Mounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return doSafeMakeDir(pathname, base, perm)
+}
+
+// This implementation is shared between Linux and NsEnterMounter
+func doSafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	glog.V(4).Infof("Creating directory %q within base %q", pathname, base)
+
+	if !pathWithinBase(pathname, base) {
+		return fmt.Errorf("path %s is outside of allowed base %s", pathname, base)
+	}
+
+	// Quick check if the directory already exists
+	s, err := os.Stat(pathname)
+	if err == nil {
+		// Path exists
+		if s.IsDir() {
+			// The directory already exists. It can be outside of the parent,
+			// but there is no race-proof check.
+			glog.V(4).Infof("Directory %s already exists", pathname)
+			return nil
+		}
+		return &os.PathError{Op: "mkdir", Path: pathname, Err: syscall.ENOTDIR}
+	}
+
+	// Find all existing directories
+	existingPath, toCreate, err := findExistingPrefix(base, pathname)
+	if err != nil {
+		return fmt.Errorf("error opening directory %s: %s", pathname, err)
+	}
+	// Ensure the existing directory is inside allowed base
+	fullExistingPath, err := filepath.EvalSymlinks(existingPath)
+	if err != nil {
+		return fmt.Errorf("error opening directory %s: %s", existingPath, err)
+	}
+	if !pathWithinBase(fullExistingPath, base) {
+		return fmt.Errorf("path %s is outside of allowed base %s", fullExistingPath, err)
+	}
+
+	glog.V(4).Infof("%q already exists, %q to create", fullExistingPath, filepath.Join(toCreate...))
+	parentFD, err := doSafeOpen(fullExistingPath, base)
+	if err != nil {
+		return fmt.Errorf("cannot open directory %s: %s", existingPath, err)
+	}
+	childFD := -1
+	defer func() {
+		if parentFD != -1 {
+			if err = syscall.Close(parentFD); err != nil {
+				glog.V(4).Infof("Closing FD %v failed for safemkdir(%v): %v", parentFD, pathname, err)
+			}
+		}
+		if childFD != -1 {
+			if err = syscall.Close(childFD); err != nil {
+				glog.V(4).Infof("Closing FD %v failed for safemkdir(%v): %v", childFD, pathname, err)
+			}
+		}
+	}()
+
+	currentPath := fullExistingPath
+	// create the directories one by one, making sure nobody can change
+	// created directory into symlink.
+	for _, dir := range toCreate {
+		currentPath = filepath.Join(currentPath, dir)
+		glog.V(4).Infof("Creating %s", dir)
+		err = syscall.Mkdirat(parentFD, currentPath, uint32(perm))
+		if err != nil {
+			return fmt.Errorf("cannot create directory %s: %s", currentPath, err)
+		}
+		// Dive into the created directory
+		childFD, err := syscall.Openat(parentFD, dir, nofollowFlags, 0)
+		if err != nil {
+			return fmt.Errorf("cannot open %s: %s", currentPath, err)
+		}
+		// We can be sure that childFD is safe to use. It could be changed
+		// by user after Mkdirat() and before Openat(), however:
+		// - it could not be changed to symlink - we use nofollowFlags
+		// - it could be changed to a file (or device, pipe, socket, ...)
+		//   but either subsequent Mkdirat() fails or we mount this file
+		//   to user's container. Security is no violated in both cases
+		//   and user either gets error or the file that it can already access.
+
+		if err = syscall.Close(parentFD); err != nil {
+			glog.V(4).Infof("Closing FD %v failed for safemkdir(%v): %v", parentFD, pathname, err)
+		}
+		parentFD = childFD
+		childFD = -1
+	}
+
+	// Everything was created. mkdirat(..., perm) above was affected by current
+	// umask and we must apply the right permissions to the last directory
+	// (that's the one that will be available to the container as subpath)
+	// so user can read/write it. This is the behavior of previous code.
+	// TODO: chmod all created directories, not just the last one.
+	// parentFD is the last created directory.
+
+	// Translate perm (os.FileMode) to uint32 that fchmod() expects
+	kernelPerm := uint32(perm & os.ModePerm)
+	if perm&os.ModeSetgid > 0 {
+		kernelPerm |= syscall.S_ISGID
+	}
+	if perm&os.ModeSetuid > 0 {
+		kernelPerm |= syscall.S_ISUID
+	}
+	if perm&os.ModeSticky > 0 {
+		kernelPerm |= syscall.S_ISVTX
+	}
+	if err = syscall.Fchmod(parentFD, kernelPerm); err != nil {
+		return fmt.Errorf("chmod %q failed: %s", currentPath, err)
+	}
+	return nil
+}
+
+// findExistingPrefix finds prefix of pathname that exists. In addition, it
+// returns list of remaining directories that don't exist yet.
+func findExistingPrefix(base, pathname string) (string, []string, error) {
+	rel, err := filepath.Rel(base, pathname)
+	if err != nil {
+		return base, nil, err
+	}
+	dirs := strings.Split(rel, string(filepath.Separator))
+
+	// Do OpenAt in a loop to find the first non-existing dir. Resolve symlinks.
+	// This should be faster than looping through all dirs and calling os.Stat()
+	// on each of them, as the symlinks are resolved only once with OpenAt().
+	currentPath := base
+	fd, err := syscall.Open(currentPath, syscall.O_RDONLY, 0)
+	if err != nil {
+		return pathname, nil, fmt.Errorf("error opening %s: %s", currentPath, err)
+	}
+	defer func() {
+		if err = syscall.Close(fd); err != nil {
+			glog.V(4).Infof("Closing FD %v failed for findExistingPrefix(%v): %v", fd, pathname, err)
+		}
+	}()
+	for i, dir := range dirs {
+		// Using O_PATH here will prevent hangs in case user replaces directory with
+		// fifo
+		childFD, err := syscall.Openat(fd, dir, unix.O_PATH, 0)
+		if err != nil {
+			if os.IsNotExist(err) {
+				return currentPath, dirs[i:], nil
+			}
+			return base, nil, err
+		}
+		if err = syscall.Close(fd); err != nil {
+			glog.V(4).Infof("Closing FD %v failed for findExistingPrefix(%v): %v", fd, pathname, err)
+		}
+		fd = childFD
+		currentPath = filepath.Join(currentPath, dir)
+	}
+	return pathname, []string{}, nil
+}
+
+// This implementation is shared between Linux and NsEnterMounter
+// Open path and return its fd.
+// Symlinks are disallowed (pathname must already resolve symlinks),
+// and the path must be within the base directory.
+func doSafeOpen(pathname string, base string) (int, error) {
+	// Calculate segments to follow
+	subpath, err := filepath.Rel(base, pathname)
+	if err != nil {
+		return -1, err
+	}
+	segments := strings.Split(subpath, string(filepath.Separator))
+
+	// Assumption: base is the only directory that we have under control.
+	// Base dir is not allowed to be a symlink.
+	parentFD, err := syscall.Open(base, nofollowFlags, 0)
+	if err != nil {
+		return -1, fmt.Errorf("cannot open directory %s: %s", base, err)
+	}
+	defer func() {
+		if parentFD != -1 {
+			if err = syscall.Close(parentFD); err != nil {
+				glog.V(4).Infof("Closing FD %v failed for safeopen(%v): %v", parentFD, pathname, err)
+			}
+		}
+	}()
+
+	childFD := -1
+	defer func() {
+		if childFD != -1 {
+			if err = syscall.Close(childFD); err != nil {
+				glog.V(4).Infof("Closing FD %v failed for safeopen(%v): %v", childFD, pathname, err)
+			}
+		}
+	}()
+
+	currentPath := base
+
+	// Follow the segments one by one using openat() to make
+	// sure the user cannot change already existing directories into symlinks.
+	for _, seg := range segments {
+		currentPath = filepath.Join(currentPath, seg)
+		if !pathWithinBase(currentPath, base) {
+			return -1, fmt.Errorf("path %s is outside of allowed base %s", currentPath, base)
+		}
+
+		glog.V(5).Infof("Opening path %s", currentPath)
+		childFD, err = syscall.Openat(parentFD, seg, openFDFlags, 0)
+		if err != nil {
+			return -1, fmt.Errorf("cannot open %s: %s", currentPath, err)
+		}
+
+		var deviceStat unix.Stat_t
+		err := unix.Fstat(childFD, &deviceStat)
+		if err != nil {
+			return -1, fmt.Errorf("Error running fstat on %s with %v", currentPath, err)
+		}
+		fileFmt := deviceStat.Mode & syscall.S_IFMT
+		if fileFmt == syscall.S_IFLNK {
+			return -1, fmt.Errorf("Unexpected symlink found %s", currentPath)
+		}
+
+		// Close parentFD
+		if err = syscall.Close(parentFD); err != nil {
+			return -1, fmt.Errorf("closing fd for %q failed: %v", filepath.Dir(currentPath), err)
+		}
+		// Set child to new parent
+		parentFD = childFD
+		childFD = -1
+	}
+
+	// We made it to the end, return this fd, don't close it
+	finalFD := parentFD
+	parentFD = -1
+
+	return finalFD, nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount_unsupported.go

@@ -20,6 +20,7 @@ package mount
 
 import (
 	"errors"
+	"os"
 )
 
 type Mounter struct {
@@ -108,3 +109,15 @@ func (mounter *Mounter) MakeFile(pathname string) error {
 func (mounter *Mounter) ExistsPath(pathname string) bool {
 	return true
 }
+
+func (mounter *Mounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return subPath.Path, nil, nil
+}
+
+func (mounter *Mounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}
+
+func (mounter *Mounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount_windows.go

@@ -89,10 +89,7 @@ func (mounter *Mounter) Mount(source string, target string, fstype string, optio
 		cmdLine += fmt.Sprintf(";New-SmbGlobalMapping -RemotePath %s -Credential $Credential", source)
 
 		if output, err := exec.Command("powershell", "/c", cmdLine).CombinedOutput(); err != nil {
-			// we don't return error here, even though New-SmbGlobalMapping failed, we still make it successful,
-			// will return error when Windows 2016 RS3 is ready on azure
-			glog.Errorf("azureMount: SmbGlobalMapping failed: %v, only SMB mount is supported now, output: %q", err, string(output))
-			return os.MkdirAll(target, 0755)
+			return fmt.Errorf("azureMount: SmbGlobalMapping failed: %v, only SMB mount is supported now, output: %q", err, string(output))
 		}
 	}
 
@@ -263,6 +260,123 @@ func (mounter *Mounter) ExistsPath(pathname string) bool {
 	return true
 }
 
+// check whether hostPath is within volume path
+// this func will lock all intermediate subpath directories, need to close handle outside of this func after container started
+func lockAndCheckSubPath(volumePath, hostPath string) ([]uintptr, error) {
+	if len(volumePath) == 0 || len(hostPath) == 0 {
+		return []uintptr{}, nil
+	}
+
+	finalSubPath, err := filepath.EvalSymlinks(hostPath)
+	if err != nil {
+		return []uintptr{}, fmt.Errorf("cannot read link %s: %s", hostPath, err)
+	}
+	finalVolumePath, err := filepath.EvalSymlinks(volumePath)
+	if err != nil {
+		return []uintptr{}, fmt.Errorf("cannot read link %s: %s", volumePath, err)
+	}
+
+	return lockAndCheckSubPathWithoutSymlink(finalVolumePath, finalSubPath)
+}
+
+// lock all intermediate subPath directories and check they are all within volumePath
+// volumePath & subPath should not contain any symlink, otherwise it will return error
+func lockAndCheckSubPathWithoutSymlink(volumePath, subPath string) ([]uintptr, error) {
+	if len(volumePath) == 0 || len(subPath) == 0 {
+		return []uintptr{}, nil
+	}
+
+	// get relative path to volumePath
+	relSubPath, err := filepath.Rel(volumePath, subPath)
+	if err != nil {
+		return []uintptr{}, fmt.Errorf("Rel(%s, %s) error: %v", volumePath, subPath, err)
+	}
+	if startsWithBackstep(relSubPath) {
+		return []uintptr{}, fmt.Errorf("SubPath %q not within volume path %q", subPath, volumePath)
+	}
+
+	if relSubPath == "." {
+		// volumePath and subPath are equal
+		return []uintptr{}, nil
+	}
+
+	fileHandles := []uintptr{}
+	var errorResult error
+
+	currentFullPath := volumePath
+	dirs := strings.Split(relSubPath, string(os.PathSeparator))
+	for _, dir := range dirs {
+		// lock intermediate subPath directory first
+		currentFullPath = filepath.Join(currentFullPath, dir)
+		handle, err := lockPath(currentFullPath)
+		if err != nil {
+			errorResult = fmt.Errorf("cannot lock path %s: %s", currentFullPath, err)
+			break
+		}
+		fileHandles = append(fileHandles, handle)
+
+		// make sure intermediate subPath directory does not contain symlink any more
+		stat, err := os.Lstat(currentFullPath)
+		if err != nil {
+			errorResult = fmt.Errorf("Lstat(%q) error: %v", currentFullPath, err)
+			break
+		}
+		if stat.Mode()&os.ModeSymlink != 0 {
+			errorResult = fmt.Errorf("subpath %q is an unexpected symlink after EvalSymlinks", currentFullPath)
+			break
+		}
+
+		if !pathWithinBase(currentFullPath, volumePath) {
+			errorResult = fmt.Errorf("SubPath %q not within volume path %q", currentFullPath, volumePath)
+			break
+		}
+	}
+
+	return fileHandles, errorResult
+}
+
+// unlockPath unlock directories
+func unlockPath(fileHandles []uintptr) {
+	if fileHandles != nil {
+		for _, handle := range fileHandles {
+			syscall.CloseHandle(syscall.Handle(handle))
+		}
+	}
+}
+
+// lockPath locks a directory or symlink, return handle, exec "syscall.CloseHandle(handle)" to unlock the path
+func lockPath(path string) (uintptr, error) {
+	if len(path) == 0 {
+		return uintptr(syscall.InvalidHandle), syscall.ERROR_FILE_NOT_FOUND
+	}
+	pathp, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return uintptr(syscall.InvalidHandle), err
+	}
+	access := uint32(syscall.GENERIC_READ)
+	sharemode := uint32(syscall.FILE_SHARE_READ)
+	createmode := uint32(syscall.OPEN_EXISTING)
+	flags := uint32(syscall.FILE_FLAG_BACKUP_SEMANTICS | syscall.FILE_FLAG_OPEN_REPARSE_POINT)
+	fd, err := syscall.CreateFile(pathp, access, sharemode, nil, createmode, flags, 0)
+	return uintptr(fd), err
+}
+
+// Lock all directories in subPath and check they're not symlinks.
+func (mounter *Mounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	handles, err := lockAndCheckSubPath(subPath.VolumePath, subPath.Path)
+
+	// Unlock the directories when the container starts
+	cleanupAction = func() {
+		unlockPath(handles)
+	}
+	return subPath.Path, cleanupAction, err
+}
+
+// No bind-mounts for subpaths are necessary on Windows
+func (mounter *Mounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}
+
 func (mounter *SafeFormatAndMount) formatAndMount(source string, target string, fstype string, options []string) error {
 	// Try to mount the disk
 	glog.V(4).Infof("Attempting to formatAndMount disk: %s %s %s", fstype, source, target)
@@ -347,3 +461,120 @@ func getAllParentLinks(path string) ([]string, error) {
 
 	return links, nil
 }
+
+// SafeMakeDir makes sure that the created directory does not escape given base directory mis-using symlinks.
+func (mounter *Mounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return doSafeMakeDir(pathname, base, perm)
+}
+
+func doSafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	glog.V(4).Infof("Creating directory %q within base %q", pathname, base)
+
+	if !pathWithinBase(pathname, base) {
+		return fmt.Errorf("path %s is outside of allowed base %s", pathname, base)
+	}
+
+	// Quick check if the directory already exists
+	s, err := os.Stat(pathname)
+	if err == nil {
+		// Path exists
+		if s.IsDir() {
+			// The directory already exists. It can be outside of the parent,
+			// but there is no race-proof check.
+			glog.V(4).Infof("Directory %s already exists", pathname)
+			return nil
+		}
+		return &os.PathError{Op: "mkdir", Path: pathname, Err: syscall.ENOTDIR}
+	}
+
+	// Find all existing directories
+	existingPath, toCreate, err := findExistingPrefix(base, pathname)
+	if err != nil {
+		return fmt.Errorf("error opening directory %s: %s", pathname, err)
+	}
+	if len(toCreate) == 0 {
+		return nil
+	}
+
+	// Ensure the existing directory is inside allowed base
+	fullExistingPath, err := filepath.EvalSymlinks(existingPath)
+	if err != nil {
+		return fmt.Errorf("error opening existing directory %s: %s", existingPath, err)
+	}
+	fullBasePath, err := filepath.EvalSymlinks(base)
+	if err != nil {
+		return fmt.Errorf("cannot read link %s: %s", base, err)
+	}
+	if !pathWithinBase(fullExistingPath, fullBasePath) {
+		return fmt.Errorf("path %s is outside of allowed base %s", fullExistingPath, err)
+	}
+
+	// lock all intermediate directories from fullBasePath to fullExistingPath (top to bottom)
+	fileHandles, err := lockAndCheckSubPathWithoutSymlink(fullBasePath, fullExistingPath)
+	defer unlockPath(fileHandles)
+	if err != nil {
+		return err
+	}
+
+	glog.V(4).Infof("%q already exists, %q to create", fullExistingPath, filepath.Join(toCreate...))
+	currentPath := fullExistingPath
+	// create the directories one by one, making sure nobody can change
+	// created directory into symlink by lock that directory immediately
+	for _, dir := range toCreate {
+		currentPath = filepath.Join(currentPath, dir)
+		glog.V(4).Infof("Creating %s", dir)
+		if err := os.Mkdir(currentPath, perm); err != nil {
+			return fmt.Errorf("cannot create directory %s: %s", currentPath, err)
+		}
+		handle, err := lockPath(currentPath)
+		if err != nil {
+			return fmt.Errorf("cannot lock path %s: %s", currentPath, err)
+		}
+		defer syscall.CloseHandle(syscall.Handle(handle))
+		// make sure newly created directory does not contain symlink after lock
+		stat, err := os.Lstat(currentPath)
+		if err != nil {
+			return fmt.Errorf("Lstat(%q) error: %v", currentPath, err)
+		}
+		if stat.Mode()&os.ModeSymlink != 0 {
+			return fmt.Errorf("subpath %q is an unexpected symlink after Mkdir", currentPath)
+		}
+	}
+
+	return nil
+}
+
+// findExistingPrefix finds prefix of pathname that exists. In addition, it
+// returns list of remaining directories that don't exist yet.
+func findExistingPrefix(base, pathname string) (string, []string, error) {
+	rel, err := filepath.Rel(base, pathname)
+	if err != nil {
+		return base, nil, err
+	}
+
+	if startsWithBackstep(rel) {
+		return base, nil, fmt.Errorf("pathname(%s) is not within base(%s)", pathname, base)
+	}
+
+	if rel == "." {
+		// base and pathname are equal
+		return pathname, []string{}, nil
+	}
+
+	dirs := strings.Split(rel, string(filepath.Separator))
+
+	parent := base
+	currentPath := base
+	for i, dir := range dirs {
+		parent = currentPath
+		currentPath = filepath.Join(parent, dir)
+		if _, err := os.Lstat(currentPath); err != nil {
+			if os.IsNotExist(err) {
+				return parent, dirs[i:], nil
+			}
+			return base, nil, err
+		}
+	}
+
+	return pathname, []string{}, nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/mount_windows_test.go

@@ -20,8 +20,12 @@ package mount
 
 import (
 	"fmt"
+	"os"
 	"os/exec"
+	"path/filepath"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestNormalizeWindowsPath(t *testing.T) {
@@ -132,3 +136,418 @@ func TestGetMountRefs(t *testing.T) {
 		}
 	}
 }
+
+func TestDoSafeMakeDir(t *testing.T) {
+	const testingVolumePath = `c:\tmp\DoSafeMakeDirTest`
+	os.MkdirAll(testingVolumePath, 0755)
+	defer os.RemoveAll(testingVolumePath)
+
+	tests := []struct {
+		volumePath    string
+		subPath       string
+		expectError   bool
+		symlinkTarget string
+	}{
+		{
+			volumePath:    testingVolumePath,
+			subPath:       ``,
+			expectError:   true,
+			symlinkTarget: "",
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `x`),
+			expectError:   false,
+			symlinkTarget: "",
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `a\b\c\d`),
+			expectError:   false,
+			symlinkTarget: "",
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `symlink`),
+			expectError:   false,
+			symlinkTarget: `c:\tmp`,
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `symlink\c\d`),
+			expectError:   true,
+			symlinkTarget: "",
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `symlink\y926`),
+			expectError:   true,
+			symlinkTarget: "",
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `a\b\symlink`),
+			expectError:   false,
+			symlinkTarget: `c:\tmp`,
+		},
+		{
+			volumePath:    testingVolumePath,
+			subPath:       filepath.Join(testingVolumePath, `a\x\symlink`),
+			expectError:   false,
+			symlinkTarget: filepath.Join(testingVolumePath, `a`),
+		},
+	}
+
+	for _, test := range tests {
+		if len(test.volumePath) > 0 && len(test.subPath) > 0 && len(test.symlinkTarget) > 0 {
+			// make all parent sub directories
+			if parent := filepath.Dir(test.subPath); parent != "." {
+				os.MkdirAll(parent, 0755)
+			}
+
+			// make last element as symlink
+			linkPath := test.subPath
+			if _, err := os.Stat(linkPath); err != nil && os.IsNotExist(err) {
+				if err := makeLink(linkPath, test.symlinkTarget); err != nil {
+					t.Fatalf("unexpected error: %v", fmt.Errorf("mklink link(%q) target(%q) error: %q", linkPath, test.symlinkTarget, err))
+				}
+			}
+		}
+
+		err := doSafeMakeDir(test.subPath, test.volumePath, os.FileMode(0755))
+		if test.expectError {
+			assert.NotNil(t, err, "Expect error during doSafeMakeDir(%s, %s)", test.subPath, test.volumePath)
+			continue
+		}
+		assert.Nil(t, err, "Expect no error during doSafeMakeDir(%s, %s)", test.subPath, test.volumePath)
+		if _, err := os.Stat(test.subPath); os.IsNotExist(err) {
+			t.Errorf("subPath should exists after doSafeMakeDir(%s, %s)", test.subPath, test.volumePath)
+		}
+	}
+}
+
+func TestLockAndCheckSubPath(t *testing.T) {
+	const testingVolumePath = `c:\tmp\LockAndCheckSubPathTest`
+
+	tests := []struct {
+		volumePath          string
+		subPath             string
+		expectedHandleCount int
+		expectError         bool
+		symlinkTarget       string
+	}{
+		{
+			volumePath:          `c:\`,
+			subPath:             ``,
+			expectedHandleCount: 0,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          ``,
+			subPath:             `a`,
+			expectedHandleCount: 0,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a`),
+			expectedHandleCount: 1,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\d`),
+			expectedHandleCount: 4,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `symlink`),
+			expectedHandleCount: 0,
+			expectError:         true,
+			symlinkTarget:       `c:\tmp`,
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\symlink`),
+			expectedHandleCount: 0,
+			expectError:         true,
+			symlinkTarget:       `c:\tmp`,
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\d\symlink`),
+			expectedHandleCount: 2,
+			expectError:         false,
+			symlinkTarget:       filepath.Join(testingVolumePath, `a\b`),
+		},
+	}
+
+	for _, test := range tests {
+		if len(test.volumePath) > 0 && len(test.subPath) > 0 {
+			os.MkdirAll(test.volumePath, 0755)
+			if len(test.symlinkTarget) == 0 {
+				// make all intermediate sub directories
+				os.MkdirAll(test.subPath, 0755)
+			} else {
+				// make all parent sub directories
+				if parent := filepath.Dir(test.subPath); parent != "." {
+					os.MkdirAll(parent, 0755)
+				}
+
+				// make last element as symlink
+				linkPath := test.subPath
+				if _, err := os.Stat(linkPath); err != nil && os.IsNotExist(err) {
+					if err := makeLink(linkPath, test.symlinkTarget); err != nil {
+						t.Fatalf("unexpected error: %v", fmt.Errorf("mklink link(%q) target(%q) error: %q", linkPath, test.symlinkTarget, err))
+					}
+				}
+			}
+		}
+
+		fileHandles, err := lockAndCheckSubPath(test.volumePath, test.subPath)
+		unlockPath(fileHandles)
+		assert.Equal(t, test.expectedHandleCount, len(fileHandles))
+		if test.expectError {
+			assert.NotNil(t, err, "Expect error during LockAndCheckSubPath(%s, %s)", test.volumePath, test.subPath)
+			continue
+		}
+		assert.Nil(t, err, "Expect no error during LockAndCheckSubPath(%s, %s)", test.volumePath, test.subPath)
+	}
+
+	// remove dir will happen after closing all file handles
+	assert.Nil(t, os.RemoveAll(testingVolumePath), "Expect no error during remove dir %s", testingVolumePath)
+}
+
+func TestLockAndCheckSubPathWithoutSymlink(t *testing.T) {
+	const testingVolumePath = `c:\tmp\LockAndCheckSubPathWithoutSymlinkTest`
+
+	tests := []struct {
+		volumePath          string
+		subPath             string
+		expectedHandleCount int
+		expectError         bool
+		symlinkTarget       string
+	}{
+		{
+			volumePath:          `c:\`,
+			subPath:             ``,
+			expectedHandleCount: 0,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          ``,
+			subPath:             `a`,
+			expectedHandleCount: 0,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a`),
+			expectedHandleCount: 1,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\d`),
+			expectedHandleCount: 4,
+			expectError:         false,
+			symlinkTarget:       "",
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `symlink`),
+			expectedHandleCount: 1,
+			expectError:         true,
+			symlinkTarget:       `c:\tmp`,
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\symlink`),
+			expectedHandleCount: 4,
+			expectError:         true,
+			symlinkTarget:       `c:\tmp`,
+		},
+		{
+			volumePath:          testingVolumePath,
+			subPath:             filepath.Join(testingVolumePath, `a\b\c\d\symlink`),
+			expectedHandleCount: 5,
+			expectError:         true,
+			symlinkTarget:       filepath.Join(testingVolumePath, `a\b`),
+		},
+	}
+
+	for _, test := range tests {
+		if len(test.volumePath) > 0 && len(test.subPath) > 0 {
+			os.MkdirAll(test.volumePath, 0755)
+			if len(test.symlinkTarget) == 0 {
+				// make all intermediate sub directories
+				os.MkdirAll(test.subPath, 0755)
+			} else {
+				// make all parent sub directories
+				if parent := filepath.Dir(test.subPath); parent != "." {
+					os.MkdirAll(parent, 0755)
+				}
+
+				// make last element as symlink
+				linkPath := test.subPath
+				if _, err := os.Stat(linkPath); err != nil && os.IsNotExist(err) {
+					if err := makeLink(linkPath, test.symlinkTarget); err != nil {
+						t.Fatalf("unexpected error: %v", fmt.Errorf("mklink link(%q) target(%q) error: %q", linkPath, test.symlinkTarget, err))
+					}
+				}
+			}
+		}
+
+		fileHandles, err := lockAndCheckSubPathWithoutSymlink(test.volumePath, test.subPath)
+		unlockPath(fileHandles)
+		assert.Equal(t, test.expectedHandleCount, len(fileHandles))
+		if test.expectError {
+			assert.NotNil(t, err, "Expect error during LockAndCheckSubPath(%s, %s)", test.volumePath, test.subPath)
+			continue
+		}
+		assert.Nil(t, err, "Expect no error during LockAndCheckSubPath(%s, %s)", test.volumePath, test.subPath)
+	}
+
+	// remove dir will happen after closing all file handles
+	assert.Nil(t, os.RemoveAll(testingVolumePath), "Expect no error during remove dir %s", testingVolumePath)
+}
+
+func TestFindExistingPrefix(t *testing.T) {
+	const testingVolumePath = `c:\tmp\FindExistingPrefixTest`
+
+	tests := []struct {
+		base                    string
+		pathname                string
+		expectError             bool
+		expectedExistingPath    string
+		expectedToCreateDirs    []string
+		createSubPathBeforeTest bool
+	}{
+		{
+			base:                    `c:\tmp\a`,
+			pathname:                `c:\tmp\b`,
+			expectError:             true,
+			expectedExistingPath:    "",
+			expectedToCreateDirs:    []string{},
+			createSubPathBeforeTest: false,
+		},
+		{
+			base:                    ``,
+			pathname:                `c:\tmp\b`,
+			expectError:             true,
+			expectedExistingPath:    "",
+			expectedToCreateDirs:    []string{},
+			createSubPathBeforeTest: false,
+		},
+		{
+			base:                    `c:\tmp\a`,
+			pathname:                `d:\tmp\b`,
+			expectError:             true,
+			expectedExistingPath:    "",
+			expectedToCreateDirs:    []string{},
+			createSubPathBeforeTest: false,
+		},
+		{
+			base:                    testingVolumePath,
+			pathname:                testingVolumePath,
+			expectError:             false,
+			expectedExistingPath:    testingVolumePath,
+			expectedToCreateDirs:    []string{},
+			createSubPathBeforeTest: false,
+		},
+		{
+			base:                    testingVolumePath,
+			pathname:                filepath.Join(testingVolumePath, `a\b`),
+			expectError:             false,
+			expectedExistingPath:    filepath.Join(testingVolumePath, `a\b`),
+			expectedToCreateDirs:    []string{},
+			createSubPathBeforeTest: true,
+		},
+		{
+			base:                    testingVolumePath,
+			pathname:                filepath.Join(testingVolumePath, `a\b\c\`),
+			expectError:             false,
+			expectedExistingPath:    filepath.Join(testingVolumePath, `a\b`),
+			expectedToCreateDirs:    []string{`c`},
+			createSubPathBeforeTest: false,
+		},
+		{
+			base:                    testingVolumePath,
+			pathname:                filepath.Join(testingVolumePath, `a\b\c\d`),
+			expectError:             false,
+			expectedExistingPath:    filepath.Join(testingVolumePath, `a\b`),
+			expectedToCreateDirs:    []string{`c`, `d`},
+			createSubPathBeforeTest: false,
+		},
+	}
+
+	for _, test := range tests {
+		if test.createSubPathBeforeTest {
+			os.MkdirAll(test.pathname, 0755)
+		}
+
+		existingPath, toCreate, err := findExistingPrefix(test.base, test.pathname)
+		if test.expectError {
+			assert.NotNil(t, err, "Expect error during findExistingPrefix(%s, %s)", test.base, test.pathname)
+			continue
+		}
+		assert.Nil(t, err, "Expect no error during findExistingPrefix(%s, %s)", test.base, test.pathname)
+
+		assert.Equal(t, test.expectedExistingPath, existingPath, "Expect result not equal with findExistingPrefix(%s, %s) return: %q, expected: %q",
+			test.base, test.pathname, existingPath, test.expectedExistingPath)
+
+		assert.Equal(t, test.expectedToCreateDirs, toCreate, "Expect result not equal with findExistingPrefix(%s, %s) return: %q, expected: %q",
+			test.base, test.pathname, toCreate, test.expectedToCreateDirs)
+
+	}
+	// remove dir will happen after closing all file handles
+	assert.Nil(t, os.RemoveAll(testingVolumePath), "Expect no error during remove dir %s", testingVolumePath)
+}
+
+func TestPathWithinBase(t *testing.T) {
+	tests := []struct {
+		fullPath       string
+		basePath       string
+		expectedResult bool
+	}{
+		{
+			fullPath:       `c:\tmp\a\b\c`,
+			basePath:       `c:\tmp`,
+			expectedResult: true,
+		},
+		{
+			fullPath:       `c:\tmp1`,
+			basePath:       `c:\tmp2`,
+			expectedResult: false,
+		},
+		{
+			fullPath:       `c:\tmp`,
+			basePath:       `c:\tmp`,
+			expectedResult: true,
+		},
+		{
+			fullPath:       `c:\tmp`,
+			basePath:       `c:\tmp\a\b\c`,
+			expectedResult: false,
+		},
+		{
+			fullPath:       `c:\kubelet\pods\uuid\volumes\kubernetes.io~configmap\config\..timestamp\file.txt`,
+			basePath:       `c:\kubelet\pods\uuid\volumes\kubernetes.io~configmap\config`,
+			expectedResult: true,
+		},
+	}
+
+	for _, test := range tests {
+		result := pathWithinBase(test.fullPath, test.basePath)
+		assert.Equal(t, result, test.expectedResult, "Expect result not equal with pathWithinBase(%s, %s) return: %q, expected: %q",
+			test.fullPath, test.basePath, result, test.expectedResult)
+	}
+}

vendor/k8s.io/kubernetes/pkg/util/mount/nsenter_mount.go

@@ -22,9 +22,12 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/golang/glog"
+	utilio "k8s.io/kubernetes/pkg/util/io"
 	"k8s.io/kubernetes/pkg/util/nsenter"
 )
 
@@ -33,6 +36,13 @@ const (
 	hostProcMountsPath = "/rootfs/proc/1/mounts"
 	// hostProcMountinfoPath is the default mount info path for rootfs
 	hostProcMountinfoPath = "/rootfs/proc/1/mountinfo"
+	// hostProcSelfStatusPath is the default path to /proc/self/status on the host
+	hostProcSelfStatusPath = "/rootfs/proc/self/status"
+)
+
+var (
+	// pidRegExp matches "Pid:	<pid>" in /proc/self/status
+	pidRegExp = regexp.MustCompile(`\nPid:\t([0-9]*)\n`)
 )
 
 // Currently, all docker containers receive their own mount namespaces.
@@ -165,7 +175,7 @@ func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	glog.V(5).Infof("nsenter findmnt args: %v", args)
 	out, err := n.ne.Exec("findmnt", args).CombinedOutput()
 	if err != nil {
-		glog.V(2).Infof("Failed findmnt command for path %s: %v", file, err)
+		glog.V(2).Infof("Failed findmnt command for path %s: %s %v", file, out, err)
 		// Different operating systems behave differently for paths which are not mount points.
 		// On older versions (e.g. 2.20.1) we'd get error, on newer ones (e.g. 2.26.2) we'd get "/".
 		// It's safer to assume that it's not a mount point.
@@ -270,3 +280,41 @@ func (mounter *NsenterMounter) ExistsPath(pathname string) bool {
 	}
 	return false
 }
+
+func (mounter *NsenterMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return doCleanSubPaths(mounter, podDir, volumeName)
+}
+
+// getPidOnHost returns kubelet's pid in the host pid namespace
+func (mounter *NsenterMounter) getPidOnHost(procStatusPath string) (int, error) {
+	// Get the PID from /rootfs/proc/self/status
+	statusBytes, err := utilio.ConsistentRead(procStatusPath, maxListTries)
+	if err != nil {
+		return 0, fmt.Errorf("error reading %s: %s", procStatusPath, err)
+	}
+	matches := pidRegExp.FindSubmatch(statusBytes)
+	if len(matches) < 2 {
+		return 0, fmt.Errorf("cannot parse %s: no Pid:", procStatusPath)
+	}
+	return strconv.Atoi(string(matches[1]))
+}
+
+func (mounter *NsenterMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	hostPid, err := mounter.getPidOnHost(hostProcSelfStatusPath)
+	if err != nil {
+		return "", nil, err
+	}
+	glog.V(4).Infof("Kubelet's PID on the host is %d", hostPid)
+
+	// Bind-mount the subpath to avoid using symlinks in subpaths.
+	newHostPath, err = doBindSubPath(mounter, subPath, hostPid)
+
+	// There is no action when the container starts. Bind-mount will be cleaned
+	// when container stops by CleanSubPaths.
+	cleanupAction = nil
+	return newHostPath, cleanupAction, err
+}
+
+func (mounter *NsenterMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return doSafeMakeDir(pathname, base, perm)
+}

vendor/k8s.io/kubernetes/pkg/util/mount/nsenter_mount_test.go

@@ -18,7 +18,13 @@ limitations under the License.
 
 package mount
 
-import "testing"
+import (
+	"io/ioutil"
+	"os"
+	"path"
+	"strconv"
+	"testing"
+)
 
 func TestParseFindMnt(t *testing.T) {
 	tests := []struct {
@@ -65,3 +71,121 @@ func TestParseFindMnt(t *testing.T) {
 		}
 	}
 }
+
+func TestGetPidOnHost(t *testing.T) {
+	tempDir, err := ioutil.TempDir("", "get_pid_on_host_tests")
+	if err != nil {
+		t.Fatalf(err.Error())
+	}
+	defer os.RemoveAll(tempDir)
+
+	tests := []struct {
+		name        string
+		procFile    string
+		expectedPid int
+		expectError bool
+	}{
+		{
+			name: "valid status file",
+			procFile: `Name:	cat
+Umask:	0002
+State:	R (running)
+Tgid:	15041
+Ngid:	0
+Pid:	15041
+PPid:	22699
+TracerPid:	0
+Uid:	1000	1000	1000	1000
+Gid:	1000	1000	1000	1000
+FDSize:	256
+Groups:	10 135 156 157 158 973 984 1000 1001
+NStgid:	15041
+NSpid:	15041
+NSpgid:	15041
+NSsid:	22699
+VmPeak:	  115016 kB
+VmSize:	  115016 kB
+VmLck:	       0 kB
+VmPin:	       0 kB
+VmHWM:	     816 kB
+VmRSS:	     816 kB
+RssAnon:	      64 kB
+RssFile:	     752 kB
+RssShmem:	       0 kB
+VmData:	     312 kB
+VmStk:	     136 kB
+VmExe:	      32 kB
+VmLib:	    2060 kB
+VmPTE:	      44 kB
+VmPMD:	      12 kB
+VmSwap:	       0 kB
+HugetlbPages:	       0 kB
+Threads:	1
+SigQ:	2/60752
+SigPnd:	0000000000000000
+ShdPnd:	0000000000000000
+SigBlk:	0000000000000000
+SigIgn:	0000000000000000
+SigCgt:	0000000000000000
+CapInh:	0000000000000000
+CapPrm:	0000000000000000
+CapEff:	0000000000000000
+CapBnd:	0000003fffffffff
+CapAmb:	0000000000000000
+NoNewPrivs:	0
+Seccomp:	0
+Cpus_allowed:	ff
+Cpus_allowed_list:	0-7
+Mems_allowed:	00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000001
+Mems_allowed_list:	0
+voluntary_ctxt_switches:	0
+nonvoluntary_ctxt_switches:	0
+`,
+			expectedPid: 15041,
+		},
+		{
+			name: "no Pid:",
+			procFile: `Name:	cat
+Umask:	0002
+State:	R (running)
+Tgid:	15041
+Ngid:	0
+PPid:	22699
+`,
+			expectedPid: 0,
+			expectError: true,
+		},
+		{
+			name: "invalid Pid:",
+			procFile: `Name:	cat
+Umask:	0002
+State:	R (running)
+Tgid:	15041
+Ngid:	0
+Pid:	invalid
+PPid:	22699
+`,
+			expectedPid: 0,
+			expectError: true,
+		},
+	}
+
+	for i, test := range tests {
+		filename := path.Join(tempDir, strconv.Itoa(i))
+		err := ioutil.WriteFile(filename, []byte(test.procFile), 0666)
+		if err != nil {
+			t.Fatalf(err.Error())
+		}
+		mounter := NsenterMounter{}
+		pid, err := mounter.getPidOnHost(filename)
+		if err != nil && !test.expectError {
+			t.Errorf("Test %q: unexpected error: %s", test.name, err)
+		}
+		if err == nil && test.expectError {
+			t.Errorf("Test %q: expected error, got none", test.name)
+		}
+		if pid != test.expectedPid {
+			t.Errorf("Test %q: expected pid %d, got %d", test.name, test.expectedPid, pid)
+		}
+	}
+}

vendor/k8s.io/kubernetes/pkg/util/mount/nsenter_mount_unsupported.go

@@ -20,6 +20,7 @@ package mount
 
 import (
 	"errors"
+	"os"
 )
 
 type NsenterMounter struct{}
@@ -85,3 +86,15 @@ func (*NsenterMounter) MakeFile(pathname string) error {
 func (*NsenterMounter) ExistsPath(pathname string) bool {
 	return true
 }
+
+func (*NsenterMounter) SafeMakeDir(pathname string, base string, perm os.FileMode) error {
+	return nil
+}
+
+func (*NsenterMounter) PrepareSafeSubpath(subPath Subpath) (newHostPath string, cleanupAction func(), err error) {
+	return subPath.Path, nil, nil
+}
+
+func (*NsenterMounter) CleanSubPaths(podDir string, volumeName string) error {
+	return nil
+}

vendor/k8s.io/kubernetes/pkg/util/mount/safe_format_and_mount_test.go

@@ -100,55 +100,55 @@ func TestSafeFormatAndMount(t *testing.T) {
 			},
 		},
 		{
-			description: "Test that 'lsblk' is called and fails",
+			description: "Test that 'blkid' is called and fails",
 			fstype:      "ext4",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'")},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "ext4\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "DEVNAME=/dev/foo\nTYPE=ext4\n", nil},
 			},
 			expectedError: fmt.Errorf("unknown filesystem type '(null)'"),
 		},
 		{
-			description: "Test that 'lsblk' is called and confirms unformatted disk, format fails",
+			description: "Test that 'blkid' is called and confirms unformatted disk, format fails",
 			fstype:      "ext4",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'")},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 2}},
 				{"mkfs.ext4", []string{"-F", "/dev/foo"}, "", fmt.Errorf("formatting failed")},
 			},
 			expectedError: fmt.Errorf("formatting failed"),
 		},
 		{
-			description: "Test that 'lsblk' is called and confirms unformatted disk, format passes, second mount fails",
+			description: "Test that 'blkid' is called and confirms unformatted disk, format passes, second mount fails",
 			fstype:      "ext4",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'"), fmt.Errorf("Still cannot mount")},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 2}},
 				{"mkfs.ext4", []string{"-F", "/dev/foo"}, "", nil},
 			},
 			expectedError: fmt.Errorf("Still cannot mount"),
 		},
 		{
-			description: "Test that 'lsblk' is called and confirms unformatted disk, format passes, second mount passes",
+			description: "Test that 'blkid' is called and confirms unformatted disk, format passes, second mount passes",
 			fstype:      "ext4",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'"), nil},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 2}},
 				{"mkfs.ext4", []string{"-F", "/dev/foo"}, "", nil},
 			},
 			expectedError: nil,
 		},
 		{
-			description: "Test that 'lsblk' is called and confirms unformatted disk, format passes, second mount passes with ext3",
+			description: "Test that 'blkid' is called and confirms unformatted disk, format passes, second mount passes with ext3",
 			fstype:      "ext3",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'"), nil},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 2}},
 				{"mkfs.ext3", []string{"-F", "/dev/foo"}, "", nil},
 			},
 			expectedError: nil,
@@ -159,30 +159,31 @@ func TestSafeFormatAndMount(t *testing.T) {
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'"), nil},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 2}},
 				{"mkfs.xfs", []string{"/dev/foo"}, "", nil},
 			},
 			expectedError: nil,
 		},
 		{
-			description: "Test that 'lsblk' is called and reports ext4 partition",
+			description: "Test that 'blkid' is called and reports ext4 partition",
 			fstype:      "ext3",
 			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'")},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\next4\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "DEVNAME=/dev/foo\nPTTYPE=dos\n", nil},
 			},
 			expectedError: fmt.Errorf("failed to mount the volume as \"ext3\", it already contains unknown data, probably partitions. Mount error: unknown filesystem type '(null)'"),
 		},
 		{
-			description: "Test that 'lsblk' is called and reports empty partition",
-			fstype:      "ext3",
-			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'")},
+			description: "Test that 'blkid' is called but has some usage or other errors (an exit code of 4 is returned)",
+			fstype:      "xfs",
+			mountErrs:   []error{fmt.Errorf("unknown filesystem type '(null)'"), nil},
 			execScripts: []ExecArgs{
 				{"fsck", []string{"-a", "/dev/foo"}, "", nil},
-				{"lsblk", []string{"-n", "-o", "FSTYPE", "/dev/foo"}, "\n\n", nil},
+				{"blkid", []string{"-p", "-s", "TYPE", "-s", "PTTYPE", "-o", "export", "/dev/foo"}, "", &fakeexec.FakeExitError{Status: 4}},
+				{"mkfs.xfs", []string{"/dev/foo"}, "", nil},
 			},
-			expectedError: fmt.Errorf("failed to mount the volume as \"ext3\", it already contains unknown data, probably partitions. Mount error: unknown filesystem type '(null)'"),
+			expectedError: fmt.Errorf("exit 4"),
 		},
 	}