Fixed subpath in containerized kubelet.

pkg/util/mount/mount.go

@@ -251,14 +251,9 @@ func GetDeviceNameFromMount(mounter Interface, mountPath string) (string, int, e
 // It is more extensive than IsLikelyNotMountPoint
 // and it detects bind mounts in linux
 func IsNotMountPoint(mounter Interface, file string) (bool, error) {
-	// Resolve any symlinks in file, kernel would do the same and use the resolved path in /proc/mounts
-	resolvedFile, err := mounter.EvalHostSymlinks(file)
-	if err != nil {
-		return true, err
-	}
 	// IsLikelyNotMountPoint provides a quick check
 	// to determine whether file IS A mountpoint
-	notMnt, notMntErr := mounter.IsLikelyNotMountPoint(resolvedFile)
+	notMnt, notMntErr := mounter.IsLikelyNotMountPoint(file)
 	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.
@@ -272,6 +267,13 @@ func IsNotMountPoint(mounter Interface, file string) (bool, error) {
 	if notMnt == false {
 		return notMnt, nil
 	}
+
+	// Resolve any symlinks in file, kernel would do the same and use the resolved path in /proc/mounts
+	resolvedFile, err := mounter.EvalHostSymlinks(file)
+	if err != nil {
+		return true, err
+	}
+
 	// check all mountpoints since IsLikelyNotMountPoint
 	// is not reliable for some mountpoint types
 	mountPoints, mountPointsErr := mounter.List()

pkg/util/mount/nsenter_mount.go

@@ -166,15 +166,22 @@ func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
 		glog.V(5).Infof("findmnt: directory %s does not exist", file)
 		return true, err
 	}
+
+	// Resolve any symlinks in file, kernel would do the same and use the resolved path in /proc/mounts
+	resolvedFile, err := n.EvalHostSymlinks(file)
+	if err != nil {
+		return true, err
+	}
+
 	// Add --first-only option: since we are testing for the absence of a mountpoint, it is sufficient to get only
 	// the first of multiple possible mountpoints using --first-only.
 	// Also add fstype output to make sure that the output of target file will give the full path
 	// TODO: Need more refactoring for this function. Track the solution with issue #26996
-	args := []string{"-o", "target,fstype", "--noheadings", "--first-only", "--target", file}
+	args := []string{"-o", "target,fstype", "--noheadings", "--first-only", "--target", resolvedFile}
 	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: %s %v", file, out, err)
+		glog.V(2).Infof("Failed findmnt command for path %s: %s %v", resolvedFile, 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.
@@ -185,13 +192,13 @@ func (n *NsenterMounter) IsLikelyNotMountPoint(file string) (bool, error) {
 		return false, err
 	}
 
-	glog.V(5).Infof("IsLikelyNotMountPoint findmnt output for path %s: %v:", file, mountTarget)
+	glog.V(5).Infof("IsLikelyNotMountPoint findmnt output for path %s: %v:", resolvedFile, mountTarget)
 
-	if mountTarget == file {
-		glog.V(5).Infof("IsLikelyNotMountPoint: %s is a mount point", file)
+	if mountTarget == resolvedFile {
+		glog.V(5).Infof("IsLikelyNotMountPoint: %s is a mount point", resolvedFile)
 		return false, nil
 	}
-	glog.V(5).Infof("IsLikelyNotMountPoint: %s is not a mount point", file)
+	glog.V(5).Infof("IsLikelyNotMountPoint: %s is not a mount point", resolvedFile)
 	return true, nil
 }