@@ -194,6 +194,12 @@ func (a *Driver) Exists(id string) bool {

 	return true

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (a *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return a.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create three folders for each id

 // mnt, layers, and diff

 func (a *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

@@ -320,7 +320,7 @@ func TestGetDiff(t *testing.T) {

 	d := newDriver(t)

 	defer os.RemoveAll(tmp)

-	if err := d.Create("1", "", "", nil); err != nil {

+	if err := d.CreateReadWrite("1", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -357,7 +357,7 @@ func TestChanges(t *testing.T) {

 	if err := d.Create("1", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

-	if err := d.Create("2", "1", "", nil); err != nil {

+	if err := d.CreateReadWrite("2", "1", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -403,7 +403,7 @@ func TestChanges(t *testing.T) {

 		t.Fatalf("Change kind should be ChangeAdd got %s", change.Kind)

 	}

-	if err := d.Create("3", "2", "", nil); err != nil {

+	if err := d.CreateReadWrite("3", "2", "", nil); err != nil {

 		t.Fatal(err)

 	}

 	mntPoint, err = d.Get("3", "")

@@ -448,7 +448,7 @@ func TestDiffSize(t *testing.T) {

 	d := newDriver(t)

 	defer os.RemoveAll(tmp)

-	if err := d.Create("1", "", "", nil); err != nil {

+	if err := d.CreateReadWrite("1", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -490,7 +490,7 @@ func TestChildDiffSize(t *testing.T) {

 	defer os.RemoveAll(tmp)

 	defer d.Cleanup()

-	if err := d.Create("1", "", "", nil); err != nil {

+	if err := d.CreateReadWrite("1", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -592,7 +592,7 @@ func TestApplyDiff(t *testing.T) {

 	defer os.RemoveAll(tmp)

 	defer d.Cleanup()

-	if err := d.Create("1", "", "", nil); err != nil {

+	if err := d.CreateReadWrite("1", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -671,7 +671,7 @@ func testMountMoreThan42Layers(t *testing.T, mountPath string) {

 		}

 		current = hash(current)

-		if err := d.Create(current, parent, "", nil); err != nil {

+		if err := d.CreateReadWrite(current, parent, "", nil); err != nil {

 			t.Logf("Current layer %d", i)

 			t.Error(err)

 		}

@@ -241,6 +241,12 @@ func (d *Driver) subvolumesDirID(id string) string {

 	return path.Join(d.subvolumesDir(), id)

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create the filesystem with given id.

 func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

@@ -30,7 +30,7 @@ func TestBtrfsCreateSnap(t *testing.T) {

 func TestBtrfsSubvolDelete(t *testing.T) {

 	d := graphtest.GetDriver(t, "btrfs")

-	if err := d.Create("test", "", "", nil); err != nil {

+	if err := d.CreateReadWrite("test", "", "", nil); err != nil {

 		t.Fatal(err)

 	}

 	defer graphtest.PutDriver(t)

@@ -117,6 +117,12 @@ func (d *Driver) Cleanup() error {

 	return err

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create adds a device with a given id and the parent.

 func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

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

@@ -46,6 +46,9 @@ type InitFunc func(root string, options []string, uidMaps, gidMaps []idtools.IDM

 type ProtoDriver interface {

 	// String returns a string representation of this driver.

 	String() string

+	// CreateReadWrite creates a new, empty filesystem layer that is ready

+	// to be used as the storage for a container.

+	CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error

 	// Create creates a new, empty, filesystem layer with the

 	// specified id and parent and mountLabel. Parent and mountLabel may be "".

 	Create(id, parent, mountLabel string, storageOpt map[string]string) error

@@ -215,7 +215,7 @@ func createBase(t *testing.T, driver graphdriver.Driver, name string) {

 	oldmask := syscall.Umask(0)

 	defer syscall.Umask(oldmask)

-	if err := driver.Create(name, "", "", nil); err != nil {

+	if err := driver.CreateReadWrite(name, "", "", nil); err != nil {

 		t.Fatal(err)

 	}

@@ -220,6 +220,12 @@ func (d *Driver) Cleanup() error {

 	return nil

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create is used to create the upper, lower, and merge directories required for overlay fs for a given id.

 // The parent filesystem is used to configure these directories for the overlay.

 func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) (retErr error) {

@@ -54,6 +54,22 @@ func (d *graphDriverProxy) String() string {

 	return d.name

 }

+func (d *graphDriverProxy) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	args := &graphDriverRequest{

+		ID:         id,

+		Parent:     parent,

+		MountLabel: mountLabel,

+	}

+	var ret graphDriverResponse

+	if err := d.client.Call("GraphDriver.CreateReadWrite", args, &ret); err != nil {

+		return err

+	}

+	if ret.Err != "" {

+		return errors.New(ret.Err)

+	}

+	return nil

+}

+

 func (d *graphDriverProxy) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

 	args := &graphDriverRequest{

 		ID:         id,

@@ -68,6 +68,12 @@ func (d *Driver) Cleanup() error {

 	return nil

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.

 func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

 	if len(storageOpt) != 0 {

@@ -106,8 +106,18 @@ func (d *Driver) Exists(id string) bool {

 	return result

 }

-// Create creates a new layer with the given id.

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.create(id, parent, mountLabel, false, storageOpt)

+}

+

+// Create creates a new read-only layer with the given id.

 func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.create(id, parent, mountLabel, true, storageOpt)

+}

+

+func (d *Driver) create(id, parent, mountLabel string, readOnly bool, storageOpt map[string]string) error {

 	if len(storageOpt) != 0 {

 		return fmt.Errorf("--storage-opt is not supported for windows")

 	}

@@ -124,27 +134,30 @@ func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]str

 	var layerChain []string

-	parentIsInit := strings.HasSuffix(rPId, "-init")

-

-	if !parentIsInit && rPId != "" {

+	if rPId != "" {

 		parentPath, err := hcsshim.GetLayerMountPath(d.info, rPId)

 		if err != nil {

 			return err

 		}

-		layerChain = []string{parentPath}

+		if _, err := os.Stat(filepath.Join(parentPath, "Files")); err == nil {

+			// This is a legitimate parent layer (not the empty "-init" layer),

+			// so include it in the layer chain.

+			layerChain = []string{parentPath}

+		}

 	}

 	layerChain = append(layerChain, parentChain...)

-	if parentIsInit {

-		if len(layerChain) == 0 {

-			return fmt.Errorf("Cannot create a read/write layer without a parent layer.")

-		}

-		if err := hcsshim.CreateSandboxLayer(d.info, id, layerChain[0], layerChain); err != nil {

+	if readOnly {

+		if err := hcsshim.CreateLayer(d.info, id, rPId); err != nil {

 			return err

 		}

 	} else {

-		if err := hcsshim.CreateLayer(d.info, id, rPId); err != nil {

+		var parentPath string

+		if len(layerChain) != 0 {

+			parentPath = layerChain[0]

+		}

+		if err := hcsshim.CreateSandboxLayer(d.info, id, parentPath, layerChain); err != nil {

 			return err

 		}

 	}

@@ -240,6 +240,12 @@ func (d *Driver) mountPath(id string) string {

 	return path.Join(d.options.mountPath, "graph", getMountpoint(id))

 }

+// CreateReadWrite creates a layer that is writable for use as a container

+// file system.

+func (d *Driver) CreateReadWrite(id, parent, mountLabel string, storageOpt map[string]string) error {

+	return d.Create(id, parent, mountLabel, storageOpt)

+}

+

 // Create prepares the dataset and filesystem for the ZFS driver for the given id under the parent.

 func (d *Driver) Create(id string, parent string, mountLabel string, storageOpt map[string]string) error {

 	if len(storageOpt) != 0 {

@@ -67,6 +67,7 @@ func (s *DockerExternalGraphdriverSuite) SetUpSuite(c *check.C) {

 		ID         string `json:",omitempty"`

 		Parent     string `json:",omitempty"`

 		MountLabel string `json:",omitempty"`

+		ReadOnly   bool   `json:",omitempty"`

 	}

 	type graphDriverResponse struct {

@@ -115,6 +116,20 @@ func (s *DockerExternalGraphdriverSuite) SetUpSuite(c *check.C) {

 		respond(w, "{}")

 	})

+	mux.HandleFunc("/GraphDriver.CreateReadWrite", func(w http.ResponseWriter, r *http.Request) {

+		s.ec.creations++

+

+		var req graphDriverRequest

+		if err := decReq(r.Body, &req, w); err != nil {

+			return

+		}

+		if err := driver.CreateReadWrite(req.ID, req.Parent, "", nil); err != nil {

+			respond(w, err)

+			return

+		}

+		respond(w, "{}")

+	})

+

 	mux.HandleFunc("/GraphDriver.Create", func(w http.ResponseWriter, r *http.Request) {

 		s.ec.creations++

@@ -461,7 +461,7 @@ func (ls *layerStore) CreateRWLayer(name string, parent ChainID, mountLabel stri

 		m.initID = pid

 	}

-	if err = ls.driver.Create(m.mountID, pid, "", storageOpt); err != nil {

+	if err = ls.driver.CreateReadWrite(m.mountID, pid, "", storageOpt); err != nil {

 		return nil, err

 	}