@@ -35,12 +35,6 @@ type DevInfo struct {

 	mountCount int    `json:"-"`

 	mountPath  string `json:"-"`

-	// A floating mount means one reference is not owned and

-	// will be stolen by the next mount. This allows us to

-	// avoid unmounting directly after creation before the

-	// first get (since we need to mount to set up the device

-	// a bit first).

-	floating bool `json:"-"`

 	// The global DeviceSet lock guarantees that we serialize all

 	// the calls to libdevmapper (which is not threadsafe), but we

@@ -94,14 +88,6 @@ type DevStatus struct {

 	HighestMappedSector uint64

 }

-type UnmountMode int

-

-const (

-	UnmountRegular UnmountMode = iota

-	UnmountFloat

-	UnmountSink

-)

-

 func getDevName(name string) string {

 	return "/dev/mapper/" + name

 }

@@ -876,12 +862,7 @@ func (devices *DeviceSet) MountDevice(hash, path string, mountLabel string) erro

 			return fmt.Errorf("Trying to mount devmapper device in multple places (%s, %s)", info.mountPath, path)

 		}

-		if info.floating {

-			// Steal floating ref

-			info.floating = false

-		} else {

-			info.mountCount++

-		}

+		info.mountCount++

 		return nil

 	}

@@ -903,13 +884,12 @@ func (devices *DeviceSet) MountDevice(hash, path string, mountLabel string) erro

 	info.mountCount = 1

 	info.mountPath = path

-	info.floating = false

 	return devices.setInitialized(info)

 }

-func (devices *DeviceSet) UnmountDevice(hash string, mode UnmountMode) error {

-	utils.Debugf("[devmapper] UnmountDevice(hash=%s, mode=%d)", hash, mode)

+func (devices *DeviceSet) UnmountDevice(hash string) error {

+	utils.Debugf("[devmapper] UnmountDevice(hash=%s)", hash)

 	defer utils.Debugf("[devmapper] UnmountDevice END")

 	info, err := devices.lookupDevice(hash)

@@ -923,24 +903,6 @@ func (devices *DeviceSet) UnmountDevice(hash string, mode UnmountMode) error {

 	devices.Lock()

 	defer devices.Unlock()

-	if mode == UnmountFloat {

-		if info.floating {

-			return fmt.Errorf("UnmountDevice: can't float floating reference %s\n", hash)

-		}

-

-		// Leave this reference floating

-		info.floating = true

-		return nil

-	}

-

-	if mode == UnmountSink {

-		if !info.floating {

-			// Someone already sunk this

-			return nil

-		}

-		// Otherwise, treat this as a regular unmount

-	}

-

 	if info.mountCount == 0 {

 		return fmt.Errorf("UnmountDevice: device not-mounted id %s\n", hash)

 	}

@@ -64,26 +64,6 @@ func (d *Driver) Create(id, parent string, mountLabel string) error {

 	if err := d.DeviceSet.AddDevice(id, parent); err != nil {

 		return err

 	}

-	mp := path.Join(d.home, "mnt", id)

-	if err := d.mount(id, mp); err != nil {

-		return err

-	}

-

-	if err := osMkdirAll(path.Join(mp, "rootfs"), 0755); err != nil && !osIsExist(err) {

-		return err

-	}

-

-	// Create an "id" file with the container/image id in it to help reconscruct this in case

-	// of later problems

-	if err := ioutil.WriteFile(path.Join(mp, "id"), []byte(id), 0600); err != nil {

-		return err

-	}

-

-	// We float this reference so that the next Get call can

-	// steal it, so we don't have to unmount

-	if err := d.DeviceSet.UnmountDevice(id, UnmountFloat); err != nil {

-		return err

-	}

 	return nil

 }

@@ -96,10 +76,6 @@ func (d *Driver) Remove(id string) error {

 		return nil

 	}

-	// Sink the float from create in case no Get() call was made

-	if err := d.DeviceSet.UnmountDevice(id, UnmountSink); err != nil {

-		return err

-	}

 	// This assumes the device has been properly Get/Put:ed and thus is unmounted

 	if err := d.DeviceSet.DeleteDevice(id); err != nil {

 		return err

@@ -115,28 +91,42 @@ func (d *Driver) Remove(id string) error {

 func (d *Driver) Get(id string) (string, error) {

 	mp := path.Join(d.home, "mnt", id)

-	if err := d.mount(id, mp); err != nil {

+

+	// Create the target directories if they don't exist

+	if err := osMkdirAll(mp, 0755); err != nil && !osIsExist(err) {

 		return "", err

 	}

-	return path.Join(mp, "rootfs"), nil

-}

+	// Mount the device

+	if err := d.DeviceSet.MountDevice(id, mp, ""); err != nil {

+		return "", err

+	}

-func (d *Driver) Put(id string) {

-	if err := d.DeviceSet.UnmountDevice(id, UnmountRegular); err != nil {

-		utils.Errorf("Warning: error unmounting device %s: %s\n", id, err)

+	rootFs := path.Join(mp, "rootfs")

+	if err := osMkdirAll(rootFs, 0755); err != nil && !osIsExist(err) {

+		d.DeviceSet.UnmountDevice(id)

+		return "", err

 	}

+

+	idFile := path.Join(mp, "id")

+	if _, err := osStat(idFile); err != nil && osIsNotExist(err) {

+		// Create an "id" file with the container/image id in it to help reconscruct this in case

+		// of later problems

+		if err := ioutil.WriteFile(idFile, []byte(id), 0600); err != nil {

+			d.DeviceSet.UnmountDevice(id)

+			return "", err

+		}

+	}

+

+	return rootFs, nil

 }

-func (d *Driver) mount(id, mountPoint string) error {

-	// Create the target directories if they don't exist

-	if err := osMkdirAll(mountPoint, 0755); err != nil && !osIsExist(err) {

-		return err

+func (d *Driver) Put(id string) {

+	if err := d.DeviceSet.UnmountDevice(id); err != nil {

+		utils.Errorf("Warning: error unmounting device %s: %s\n", id, err)

 	}

-	// Mount the device

-	return d.DeviceSet.MountDevice(id, mountPoint, "")

 }

 func (d *Driver) Exists(id string) bool {

-	return d.Devices[id] != nil

+	return d.DeviceSet.HasDevice(id)

 }

@@ -500,15 +500,10 @@ func TestDriverCreate(t *testing.T) {

 		calls.Assert(t,

 			"DmTaskCreate",

 			"DmTaskGetInfo",

-			"sysMount",

 			"DmTaskRun",

-			"DmTaskSetTarget",

 			"DmTaskSetSector",

-			"DmTaskSetCookie",

-			"DmUdevWait",

 			"DmTaskSetName",

 			"DmTaskSetMessage",

-			"DmTaskSetAddNode",

 		)

 	}()

@@ -619,15 +614,10 @@ func TestDriverRemove(t *testing.T) {

 		calls.Assert(t,

 			"DmTaskCreate",

 			"DmTaskGetInfo",

-			"sysMount",

 			"DmTaskRun",

-			"DmTaskSetTarget",

 			"DmTaskSetSector",

-			"DmTaskSetCookie",

-			"DmUdevWait",

 			"DmTaskSetName",

 			"DmTaskSetMessage",

-			"DmTaskSetAddNode",

 		)

 		Mounted = func(mnt string) (bool, error) {

@@ -650,7 +640,6 @@ func TestDriverRemove(t *testing.T) {

 			"DmTaskSetTarget",

 			"DmTaskSetAddNode",

 			"DmUdevWait",

-			"sysUnmount",

 		)

 	}()

 	runtime.GC()