mountsPath := filepath.Join(dir, "mounts")
	if err = os.WriteFile(mountsPath, []byte(successCase), 0o666); err != nil {
		t.Fatal(err)
	}
	// Verifies if reading each line worked properly.
	{
		var mounts mountInfos
		mounts, err = readProcMounts(mountsPath)
		if err != nil {
			t.Fatal(err)
		}
		if len(mounts) != 3 {
			t.Fatalf("expected 3 mounts, got %d", len(mounts))
		}

			// At this point if the mount point has a common prefix two conditions can happen.
			// - mount.Path matches exact with `path` means we can proceed no error here.
			// - mount.Path doesn't match (means cross-device mount), should error out.
			if mount.Path != path {
				crossMounts = append(crossMounts, mount)
			}
		}
	}

	mounts.AddExtraHostPathMounts(kubeadmconstants.KubeAPIServer, cfg.APIServer.ExtraVolumes)
	mounts.AddExtraHostPathMounts(kubeadmconstants.KubeControllerManager, cfg.ControllerManager.ExtraVolumes)
	mounts.AddExtraHostPathMounts(kubeadmconstants.KubeScheduler, cfg.Scheduler.ExtraVolumes)

	return mounts
}

// controlPlaneHostPathMounts is a helper struct for handling all the control plane's hostPath mounts in an easy way

		t.Run(rt.name, func(t *testing.T) {
			mounts := getHostPathVolumesForTheControlPlane(rt.cfg)

			// Avoid unit test errors when the flexvolume is mounted
			delete(mounts.volumes[kubeadmconstants.KubeControllerManager], flexvolumeDirVolumeName)
			delete(mounts.volumeMounts[kubeadmconstants.KubeControllerManager], flexvolumeDirVolumeName)
			if !reflect.DeepEqual(mounts.volumes, rt.vol) {
				t.Errorf(

		mountPoints[controller] = util.CgroupRoot
		m := libcontainercgroups.Mount{
			Mountpoint: util.CgroupRoot,
			Root:       util.CgroupRoot,
			Subsystems: []string{controller},
		}
		mounts = append(mounts, m)
	}

	return &CgroupSubsystems{
		Mounts:      mounts,
		MountPoints: mountPoints,
	}, nil
}

	raw, err := os.ReadFile("/proc/mounts")
	if err != nil {
		return err
	}

	if !strings.HasSuffix(kubeletRunDirectory, "/") {
		// trailing "/" is needed to ensure that possibly mounted /var/lib/kubelet is skipped
		kubeletRunDirectory += "/"
	}

	var errList []error
	mounts := strings.Split(string(raw), "\n")
	flagsInt := flagsToInt(flags)
	for _, mount := range mounts {
		m := strings.Split(mount, " ")

			},
			expected: false,
		},
		"extra local mount": {
			mountPath: "/var/lib/kubelet/plugins/kubernetes.io/some-plugin/mounts/volume-XXXX",
			mountRefs: []string{
				"/home/somewhere/var/lib/kubelet/plugins/kubernetes.io/some-plugin/mounts/volume-XXXX",
				"/local/data/kubernetes.io/some-plugin/mounts/volume-XXXX",
				"/mnt/kubelet/plugins/kubernetes.io/some-plugin/mounts/volume-XXXX",

	testContainer = "container0"
	testSubpath   = 1
)

func setupFakeMounter(testMounts []string) *mount.FakeMounter {
	mounts := []mount.MountPoint{}
	for _, mountPoint := range testMounts {
		mounts = append(mounts, mount.MountPoint{Device: "/foo", Path: mountPoint})
	}
	return mount.NewFakeMounter(mounts)
}

func getTestPaths(base string) (string, string) {
	return filepath.Join(base, testVol),

package mountinfo

// mountInfo - This represents a single line in /proc/mounts.
type mountInfo struct {
	Device  string
	Path    string
	FSType  string
	Options []string
	Freq    string
	Pass    string
}

func (m mountInfo) String() string {
	return m.Path
}

// mountInfos - This represents the entire /proc/mounts.

					t.Fatalf("expected error message `%s` but got `%v`", tc.expectedErrMsg, err)
				}
				return
			}

			// otherwise validate the mounts
			if err != nil {
				t.Fatal(err)
			}

			assert.Equal(t, tc.expectedMounts, mounts, "mounts of container %+v", tc.container)
		})
	}
}

func TestMakeBlockVolumes(t *testing.T) {