@@ -289,7 +289,8 @@ func (daemon *Daemon) getSize(container *container.Container) (int64, int64) {

 	sizeRw, err = container.RWLayer.Size()

 	if err != nil {

-		logrus.Errorf("Driver %s couldn't return diff size of container %s: %s", daemon.driver, container.ID, err)

+		logrus.Errorf("Driver %s couldn't return diff size of container %s: %s",

+			daemon.GraphDriverName(), container.ID, err)

 		// FIXME: GetSize should return an error. Not changing it now in case

 		// there is a side-effect.

 		sizeRw = -1

@@ -30,7 +30,6 @@ import (

 	"github.com/docker/docker/daemon/exec"

 	"github.com/docker/docker/daemon/execdriver"

 	"github.com/docker/docker/daemon/execdriver/execdrivers"

-	"github.com/docker/docker/daemon/graphdriver"

 	_ "github.com/docker/docker/daemon/graphdriver/vfs" // register vfs

 	"github.com/docker/docker/daemon/logger"

 	"github.com/docker/docker/daemon/network"

@@ -146,7 +145,6 @@ type Daemon struct {

 	idIndex                   *truncindex.TruncIndex

 	configStore               *Config

 	containerGraphDB          *graphdb.Database

-	driver                    graphdriver.Driver

 	execDriver                execdriver.Driver

 	statsCollector            *statsCollector

 	defaultLogConfig          containertypes.LogConfig

@@ -297,7 +295,7 @@ func (daemon *Daemon) restore() error {

 	var (

 		debug         = os.Getenv("DEBUG") != ""

-		currentDriver = daemon.driver.String()

+		currentDriver = daemon.GraphDriverName()

 		containers    = make(map[string]*cr)

 	)

@@ -520,7 +518,7 @@ func (daemon *Daemon) newContainer(name string, config *containertypes.Config, i

 	base.ImageID = imgID

 	base.NetworkSettings = &network.Settings{IsAnonymousEndpoint: noExplicitName}

 	base.Name = name

-	base.Driver = daemon.driver.String()

+	base.Driver = daemon.GraphDriverName()

 	return base, err

 }

@@ -703,20 +701,9 @@ func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemo

 	}

 	os.Setenv("TMPDIR", realTmp)

-	// Set the default driver

-	graphdriver.DefaultDriver = config.GraphDriver

-

-	// Load storage driver

-	driver, err := graphdriver.New(config.Root, config.GraphOptions, uidMaps, gidMaps)

-	if err != nil {

-		return nil, fmt.Errorf("error initializing graphdriver: %v", err)

-	}

-	logrus.Debugf("Using graph driver %s", driver)

-

 	d := &Daemon{}

-	d.driver = driver

-

-	// Ensure the graph driver is shutdown at a later point

+	// Ensure the daemon is properly shutdown if there is a failure during

+	// initialization

 	defer func() {

 		if err != nil {

 			if err := d.Shutdown(); err != nil {

@@ -733,25 +720,32 @@ func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemo

 	}

 	logrus.Debugf("Using default logging driver %s", config.LogConfig.Type)

-	// Configure and validate the kernels security support

-	if err := configureKernelSecuritySupport(config, d.driver.String()); err != nil {

-		return nil, err

-	}

-

 	daemonRepo := filepath.Join(config.Root, "containers")

-

 	if err := idtools.MkdirAllAs(daemonRepo, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {

 		return nil, err

 	}

-	imageRoot := filepath.Join(config.Root, "image", d.driver.String())

-	fms, err := layer.NewFSMetadataStore(filepath.Join(imageRoot, "layerdb"))

+	driverName := os.Getenv("DOCKER_DRIVER")

+	if driverName == "" {

+		driverName = config.GraphDriver

+	}

+	d.layerStore, err = layer.NewStoreFromOptions(layer.StoreOptions{

+		StorePath:                 config.Root,

+		MetadataStorePathTemplate: filepath.Join(config.Root, "image", "%s"),

+		GraphDriver:               driverName,

+		GraphDriverOptions:        config.GraphOptions,

+		UIDMaps:                   uidMaps,

+		GIDMaps:                   gidMaps,

+	})

 	if err != nil {

 		return nil, err

 	}

-	d.layerStore, err = layer.NewStore(fms, d.driver)

-	if err != nil {

+	graphDriver := d.layerStore.DriverName()

+	imageRoot := filepath.Join(config.Root, "image", graphDriver)

+

+	// Configure and validate the kernels security support

+	if err := configureKernelSecuritySupport(config, graphDriver); err != nil {

 		return nil, err

 	}

@@ -797,11 +791,11 @@ func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemo

 		return nil, fmt.Errorf("Couldn't create Tag store repositories: %s", err)

 	}

-	if err := restoreCustomImage(d.driver, d.imageStore, d.layerStore, referenceStore); err != nil {

+	if err := restoreCustomImage(d.imageStore, d.layerStore, referenceStore); err != nil {

 		return nil, fmt.Errorf("Couldn't restore custom images: %s", err)

 	}

-	if err := v1.Migrate(config.Root, d.driver.String(), d.layerStore, d.imageStore, referenceStore, distributionMetadataStore); err != nil {

+	if err := v1.Migrate(config.Root, graphDriver, d.layerStore, d.imageStore, referenceStore, distributionMetadataStore); err != nil {

 		return nil, err

 	}

@@ -953,9 +947,9 @@ func (daemon *Daemon) Shutdown() error {

 		}

 	}

-	if daemon.driver != nil {

-		if err := daemon.driver.Cleanup(); err != nil {

-			logrus.Errorf("Error during graph storage driver.Cleanup(): %v", err)

+	if daemon.layerStore != nil {

+		if err := daemon.layerStore.Cleanup(); err != nil {

+			logrus.Errorf("Error during layer Store.Cleanup(): %v", err)

 		}

 	}

@@ -982,7 +976,7 @@ func (daemon *Daemon) Mount(container *container.Container) error {

 		if container.BaseFS != "" && runtime.GOOS != "windows" {

 			daemon.Unmount(container)

 			return fmt.Errorf("Error: driver %s is returning inconsistent paths for container %s ('%s' then '%s')",

-				daemon.driver, container.ID, container.BaseFS, dir)

+				daemon.GraphDriverName(), container.ID, container.BaseFS, dir)

 		}

 	}

 	container.BaseFS = dir // TODO: combine these fields

@@ -1193,7 +1187,7 @@ func (daemon *Daemon) LookupImage(name string) (*types.ImageInspect, error) {

 		VirtualSize:     size, // TODO: field unused, deprecate

 	}

-	imageInspect.GraphDriver.Name = daemon.driver.String()

+	imageInspect.GraphDriver.Name = daemon.GraphDriverName()

 	imageInspect.GraphDriver.Data = layerMetadata

@@ -1322,10 +1316,9 @@ func (daemon *Daemon) GetImage(refOrID string) (*image.Image, error) {

 	return daemon.imageStore.Get(imgID)

 }

-// GraphDriver returns the currently used driver for processing

-// container layers.

-func (daemon *Daemon) GraphDriver() graphdriver.Driver {

-	return daemon.driver

+// GraphDriverName returns the name of the graph driver used by the layer.Store

+func (daemon *Daemon) GraphDriverName() string {

+	return daemon.layerStore.DriverName()

 }

 // ExecutionDriver returns the currently used driver for creating and

@@ -15,7 +15,6 @@ import (

 	pblkiodev "github.com/docker/docker/api/types/blkiodev"

 	containertypes "github.com/docker/docker/api/types/container"

 	"github.com/docker/docker/container"

-	"github.com/docker/docker/daemon/graphdriver"

 	derr "github.com/docker/docker/errors"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/layer"

@@ -728,7 +727,7 @@ func (daemon *Daemon) conditionalUnmountOnCleanup(container *container.Container

 	daemon.Unmount(container)

 }

-func restoreCustomImage(driver graphdriver.Driver, is image.Store, ls layer.Store, rs reference.Store) error {

+func restoreCustomImage(is image.Store, ls layer.Store, rs reference.Store) error {

 	// Unix has no custom images to register

 	return nil

 }

@@ -156,67 +156,78 @@ func (daemon *Daemon) conditionalUnmountOnCleanup(container *container.Container

 	}

 }

-func restoreCustomImage(driver graphdriver.Driver, is image.Store, ls layer.Store, rs reference.Store) error {

-	if wd, ok := driver.(*windows.Driver); ok {

-		imageInfos, err := wd.GetCustomImageInfos()

+func restoreCustomImage(is image.Store, ls layer.Store, rs reference.Store) error {

+	type graphDriverStore interface {

+		GraphDriver() graphdriver.Driver

+	}

+

+	gds, ok := ls.(graphDriverStore)

+	if !ok {

+		return nil

+	}

+

+	driver := gds.GraphDriver()

+	wd, ok := driver.(*windows.Driver)

+	if !ok {

+		return nil

+	}

+

+	imageInfos, err := wd.GetCustomImageInfos()

+	if err != nil {

+		return err

+	}

+

+	// Convert imageData to valid image configuration

+	for i := range imageInfos {

+		name := strings.ToLower(imageInfos[i].Name)

+

+		type registrar interface {

+			RegisterDiffID(graphID string, size int64) (layer.Layer, error)

+		}

+		r, ok := ls.(registrar)

+		if !ok {

+			return errors.New("Layerstore doesn't support RegisterDiffID")

+		}

+		if _, err := r.RegisterDiffID(imageInfos[i].ID, imageInfos[i].Size); err != nil {

+			return err

+		}

+		// layer is intentionally not released

+

+		rootFS := image.NewRootFS()

+		rootFS.BaseLayer = filepath.Base(imageInfos[i].Path)

+

+		// Create history for base layer

+		config, err := json.Marshal(&image.Image{

+			V1Image: image.V1Image{

+				DockerVersion: dockerversion.Version,

+				Architecture:  runtime.GOARCH,

+				OS:            runtime.GOOS,

+				Created:       imageInfos[i].CreatedTime,

+			},

+			RootFS:  rootFS,

+			History: []image.History{},

+		})

+

+		named, err := reference.ParseNamed(name)

 		if err != nil {

 			return err

 		}

-		// Convert imageData to valid image configuration

-		for i := range imageInfos {

-			name := strings.ToLower(imageInfos[i].Name)

-

-			type registrar interface {

-				RegisterDiffID(graphID string, size int64) (layer.Layer, error)

-			}

-			r, ok := ls.(registrar)

-			if !ok {

-				return errors.New("Layerstore doesn't support RegisterDiffID")

-			}

-			if _, err := r.RegisterDiffID(imageInfos[i].ID, imageInfos[i].Size); err != nil {

-				return err

-			}

-			// layer is intentionally not released

-

-			rootFS := image.NewRootFS()

-			rootFS.BaseLayer = filepath.Base(imageInfos[i].Path)

-

-			// Create history for base layer

-			config, err := json.Marshal(&image.Image{

-				V1Image: image.V1Image{

-					DockerVersion: dockerversion.Version,

-					Architecture:  runtime.GOARCH,

-					OS:            runtime.GOOS,

-					Created:       imageInfos[i].CreatedTime,

-				},

-				RootFS:  rootFS,

-				History: []image.History{},

-			})

-

-			named, err := reference.ParseNamed(name)

-			if err != nil {

-				return err

-			}

-

-			ref, err := reference.WithTag(named, imageInfos[i].Version)

-			if err != nil {

-				return err

-			}

-

-			id, err := is.Create(config)

-			if err != nil {

-				return err

-			}

-

-			if err := rs.AddTag(ref, id, true); err != nil {

-				return err

-			}

-

-			logrus.Debugf("Registered base layer %s as %s", ref, id)

+		ref, err := reference.WithTag(named, imageInfos[i].Version)

+		if err != nil {

+			return err

 		}

-	}

+		id, err := is.Create(config)

+		if err != nil {

+			return err

+		}

+

+		if err := rs.AddTag(ref, id, true); err != nil {

+			return err

+		}

+		logrus.Debugf("Registered base layer %s as %s", ref, id)

+	}

 	return nil

 }

@@ -133,7 +133,7 @@ func (daemon *Daemon) cleanupContainer(container *container.Container, forceRemo

 	metadata, err := daemon.layerStore.ReleaseRWLayer(container.RWLayer)

 	layer.LogReleaseMetadata(metadata)

 	if err != nil && err != layer.ErrMountDoesNotExist {

-		return derr.ErrorCodeRmDriverFS.WithArgs(daemon.driver, container.ID, err)

+		return derr.ErrorCodeRmDriverFS.WithArgs(daemon.GraphDriverName(), container.ID, err)

 	}

 	if err = daemon.execDriver.Clean(container.ID); err != nil {

@@ -22,8 +22,6 @@ const (

 )

 var (

-	// DefaultDriver if a storage driver is not specified.

-	DefaultDriver string

 	// All registered drivers

 	drivers map[string]InitFunc

@@ -130,12 +128,10 @@ func getBuiltinDriver(name, home string, options []string, uidMaps, gidMaps []id

 }

 // New creates the driver and initializes it at the specified root.

-func New(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (driver Driver, err error) {

-	for _, name := range []string{os.Getenv("DOCKER_DRIVER"), DefaultDriver} {

-		if name != "" {

-			logrus.Debugf("[graphdriver] trying provided driver %q", name) // so the logs show specified driver

-			return GetDriver(name, root, options, uidMaps, gidMaps)

-		}

+func New(root string, name string, options []string, uidMaps, gidMaps []idtools.IDMap) (driver Driver, err error) {

+	if name != "" {

+		logrus.Debugf("[graphdriver] trying provided driver %q", name) // so the logs show specified driver

+		return GetDriver(name, root, options, uidMaps, gidMaps)

 	}

 	// Guess for prior driver

@@ -58,8 +58,8 @@ func (daemon *Daemon) SystemInfo() (*types.Info, error) {

 		ID:                 daemon.ID,

 		Containers:         len(daemon.List()),

 		Images:             len(daemon.imageStore.Map()),

-		Driver:             daemon.GraphDriver().String(),

-		DriverStatus:       daemon.GraphDriver().Status(),

+		Driver:             daemon.GraphDriverName(),

+		DriverStatus:       daemon.layerStore.DriverStatus(),

 		Plugins:            daemon.showPluginsInfo(),

 		IPv4Forwarding:     !sysInfo.IPv4ForwardingDisabled,

 		BridgeNfIptables:   !sysInfo.BridgeNfCallIptablesDisabled,

@@ -128,6 +128,18 @@ func (ls *mockLayerStore) ReleaseRWLayer(layer.RWLayer) ([]layer.Metadata, error

 }

+func (ls *mockLayerStore) Cleanup() error {

+	return nil

+}

+

+func (ls *mockLayerStore) DriverStatus() [][2]string {

+	return [][2]string{}

+}

+

+func (ls *mockLayerStore) DriverName() string {

+	return "mock"

+}

+

 type mockDownloadDescriptor struct {

 	currentDownloads *int32

 	id               string

@@ -240,7 +240,7 @@ func (cli *DaemonCli) CmdDaemon(args ...string) error {

 		"version":     dockerversion.Version,

 		"commit":      dockerversion.GitCommit,

 		"execdriver":  d.ExecutionDriver().Name(),

-		"graphdriver": d.GraphDriver().String(),

+		"graphdriver": d.GraphDriverName(),

 	}).Info("Docker daemon")

 	api.InitRouters(d)

@@ -170,6 +170,10 @@ type Store interface {

 	CreateRWLayer(id string, parent ChainID, mountLabel string, initFunc MountInit) (RWLayer, error)

 	GetRWLayer(id string) (RWLayer, error)

 	ReleaseRWLayer(RWLayer) ([]Metadata, error)

+

+	Cleanup() error

+	DriverStatus() [][2]string

+	DriverName() string

 }

 // MetadataTransaction represents functions for setting layer metadata

@@ -11,6 +11,7 @@ import (

 	"github.com/docker/distribution/digest"

 	"github.com/docker/docker/daemon/graphdriver"

 	"github.com/docker/docker/pkg/archive"

+	"github.com/docker/docker/pkg/idtools"

 	"github.com/docker/docker/pkg/stringid"

 	"github.com/vbatts/tar-split/tar/asm"

 	"github.com/vbatts/tar-split/tar/storage"

@@ -34,11 +35,41 @@ type layerStore struct {

 	mountL sync.Mutex

 }

-// NewStore creates a new Store instance using

-// the provided metadata store and graph driver.

-// The metadata store will be used to restore

+// StoreOptions are the options used to create a new Store instance

+type StoreOptions struct {

+	StorePath                 string

+	MetadataStorePathTemplate string

+	GraphDriver               string

+	GraphDriverOptions        []string

+	UIDMaps                   []idtools.IDMap

+	GIDMaps                   []idtools.IDMap

+}

+

+// NewStoreFromOptions creates a new Store instance

+func NewStoreFromOptions(options StoreOptions) (Store, error) {

+	driver, err := graphdriver.New(

+		options.StorePath,

+		options.GraphDriver,

+		options.GraphDriverOptions,

+		options.UIDMaps,

+		options.GIDMaps)

+	if err != nil {

+		return nil, fmt.Errorf("error initializing graphdriver: %v", err)

+	}

+	logrus.Debugf("Using graph driver %s", driver)

+

+	fms, err := NewFSMetadataStore(fmt.Sprintf(options.MetadataStorePathTemplate, driver))

+	if err != nil {

+		return nil, err

+	}

+

+	return NewStoreFromGraphDriver(fms, driver)

+}

+

+// NewStoreFromGraphDriver creates a new Store instance using the provided

+// metadata store and graph driver. The metadata store will be used to restore

 // the Store.

-func NewStore(store MetadataStore, driver graphdriver.Driver) (Store, error) {

+func NewStoreFromGraphDriver(store MetadataStore, driver graphdriver.Driver) (Store, error) {

 	ls := &layerStore{

 		store:    store,

 		driver:   driver,

@@ -581,6 +612,18 @@ func (ls *layerStore) assembleTar(graphID string, metadata io.ReadCloser, size *

 	return pR, nil

 }

+func (ls *layerStore) Cleanup() error {

+	return ls.driver.Cleanup()

+}

+

+func (ls *layerStore) DriverStatus() [][2]string {

+	return ls.driver.Status()

+}

+

+func (ls *layerStore) DriverName() string {

+	return ls.driver.String()

+}

+

 type naiveDiffPathDriver struct {

 	graphdriver.Driver

 }

@@ -67,7 +67,7 @@ func newTestStore(t *testing.T) (Store, func()) {

 	if err != nil {

 		t.Fatal(err)

 	}

-	ls, err := NewStore(fms, graph)

+	ls, err := NewStoreFromGraphDriver(fms, graph)

 	if err != nil {

 		t.Fatal(err)

 	}

@@ -398,7 +398,7 @@ func TestStoreRestore(t *testing.T) {

 	assertActivityCount(t, m, 0)

-	ls2, err := NewStore(ls.(*layerStore).store, ls.(*layerStore).driver)

+	ls2, err := NewStoreFromGraphDriver(ls.(*layerStore).store, ls.(*layerStore).driver)

 	if err != nil {

 		t.Fatal(err)

 	}

@@ -6,6 +6,7 @@ import (

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/distribution/digest"

+	"github.com/docker/docker/daemon/graphdriver"

 )

 // GetLayerPath returns the path to a layer

@@ -94,3 +95,7 @@ func (ls *layerStore) mountID(name string) string {

 	// windows has issues if container ID doesn't match mount ID

 	return name

 }

+

+func (ls *layerStore) GraphDriver() graphdriver.Driver {

+	return ls.driver

+}

@@ -89,7 +89,7 @@ func TestLayerMigration(t *testing.T) {

 	if err != nil {

 		t.Fatal(err)

 	}

-	ls, err := NewStore(fms, graph)

+	ls, err := NewStoreFromGraphDriver(fms, graph)

 	if err != nil {

 		t.Fatal(err)

 	}

@@ -205,7 +205,7 @@ func TestLayerMigrationNoTarsplit(t *testing.T) {

 	if err != nil {

 		t.Fatal(err)

 	}

-	ls, err := NewStore(fms, graph)

+	ls, err := NewStoreFromGraphDriver(fms, graph)

 	if err != nil {

 		t.Fatal(err)

 	}