@@ -48,7 +48,7 @@ func Init(home string, options []string) (graphdriver.Driver, error) {

 		home: home,

 	}

-	return graphdriver.NewGenericDriverWrapper(driver), nil

+	return graphdriver.NaiveDiffDriver(driver), nil

 }

 type Driver struct {

@@ -43,7 +43,7 @@ func Init(home string, options []string) (graphdriver.Driver, error) {

 		home:      home,

 	}

-	return graphdriver.NewGenericDriverWrapper(d), nil

+	return graphdriver.NaiveDiffDriver(d), nil

 }

 func (d *Driver) String() string {

@@ -19,17 +19,20 @@ const (

 type InitFunc func(root string, options []string) (Driver, error)

-// GenericDriver defines the basic capabilities of a driver.

-type GenericDriver interface {

+// ProtoDriver defines the basic capabilities of a driver.

+// This interface exists solely to be a minimum set of methods

+// for client code which choose not to implement the entire Driver

+// interface and use the NaiveDiffDriver wrapper constructor.

+//

+// Use of ProtoDriver directly by client code is not recommended.

+type ProtoDriver interface {

 	// String returns a string representation of this driver.

 	String() string

-

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

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

 	Create(id, parent string) error

-	// Remove attepmts to remove the filesystem layer with this id.

+	// Remove attempts to remove the filesystem layer with this id.

 	Remove(id string) error

-

 	// Get returns the mountpoint for the layered filesystem referred

 	// to by this id. You can optionally specify a mountLabel or "".

 	// Returns the absolute path to the mounted layered filesystem.

@@ -40,20 +43,18 @@ type GenericDriver interface {

 	// Exists returns whether a filesystem layer with the specified

 	// ID exists on this driver.

 	Exists(id string) bool

-

 	// Status returns a set of key-value pairs which give low

 	// level diagnostic status about this driver.

 	Status() [][2]string

-

 	// Cleanup performs necessary tasks to release resources

 	// held by the driver, e.g., unmounting all layered filesystems

 	// known to this driver.

 	Cleanup() error

 }

+// Driver is the interface for layered/snapshot file system drivers.

 type Driver interface {

-	GenericDriver

-

+	ProtoDriver

 	// Diff produces an archive of the changes between the specified

 	// layer and its parent layer which may be "".

 	Diff(id, parent string) (archive.Archive, error)

@@ -10,27 +10,30 @@ import (

 	"github.com/docker/docker/utils"

 )

-// GenericDriverWrapper takes a generic Driver and adds the

-// capability of the following methods which it doesn't

-// support on its own:

+// naiveDiffDriver takes a ProtoDriver and adds the

+// capability of the Diffing methods which it may or may not

+// support on its own. See the comment on the exported

+// NaiveDiffDriver function below.

+// Notably, the AUFS driver doesn't need to be wrapped like this.

+type naiveDiffDriver struct {

+	ProtoDriver

+}

+

+// NaiveDiffDriver returns a fully functional driver that wraps the

+// given ProtoDriver and adds the capability of the following methods which

+// it may or may not support on its own:

 //     Diff(id, parent string) (archive.Archive, error)

 //     Changes(id, parent string) ([]archive.Change, error)

 //     ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error)

 //     DiffSize(id, parent string) (bytes int64, err error)

-// Notably, the AUFS driver doesn't need to be wrapped like this.

-type GenericDriverWrapper struct {

-	GenericDriver

-}

-

-// NewGenericDriverWrapper returns a fully functional driver that wraps the given GenericDriver.

-func NewGenericDriverWrapper(driver GenericDriver) Driver {

-	return &GenericDriverWrapper{GenericDriver: driver}

+func NaiveDiffDriver(driver ProtoDriver) Driver {

+	return &naiveDiffDriver{ProtoDriver: driver}

 }

 // Diff produces an archive of the changes between the specified

 // layer and its parent layer which may be "".

-func (gdw *GenericDriverWrapper) Diff(id, parent string) (arch archive.Archive, err error) {

-	driver := gdw.GenericDriver

+func (gdw *naiveDiffDriver) Diff(id, parent string) (arch archive.Archive, err error) {

+	driver := gdw.ProtoDriver

 	layerFs, err := driver.Get(id, "")

 	if err != nil {

@@ -80,8 +83,8 @@ func (gdw *GenericDriverWrapper) Diff(id, parent string) (arch archive.Archive,

 // Changes produces a list of changes between the specified layer

 // and its parent layer. If parent is "", then all changes will be ADD changes.

-func (gdw *GenericDriverWrapper) Changes(id, parent string) ([]archive.Change, error) {

-	driver := gdw.GenericDriver

+func (gdw *naiveDiffDriver) Changes(id, parent string) ([]archive.Change, error) {

+	driver := gdw.ProtoDriver

 	layerFs, err := driver.Get(id, "")

 	if err != nil {

@@ -105,8 +108,8 @@ func (gdw *GenericDriverWrapper) Changes(id, parent string) ([]archive.Change, e

 // ApplyDiff extracts the changeset from the given diff into the

 // layer with the specified id and parent, returning the size of the

 // new layer in bytes.

-func (gdw *GenericDriverWrapper) ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error) {

-	driver := gdw.GenericDriver

+func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error) {

+	driver := gdw.ProtoDriver

 	// Mount the root filesystem so we can apply the diff/layer.

 	layerFs, err := driver.Get(id, "")

@@ -144,8 +147,8 @@ func (gdw *GenericDriverWrapper) ApplyDiff(id, parent string, diff archive.Archi

 // DiffSize calculates the changes between the specified layer

 // and its parent and returns the size in bytes of the changes

 // relative to its base filesystem directory.

-func (gdw *GenericDriverWrapper) DiffSize(id, parent string) (bytes int64, err error) {

-	driver := gdw.GenericDriver

+func (gdw *naiveDiffDriver) DiffSize(id, parent string) (bytes int64, err error) {

+	driver := gdw.ProtoDriver

 	changes, err := gdw.Changes(id, parent)

 	if err != nil {

@@ -19,7 +19,7 @@ func Init(home string, options []string) (graphdriver.Driver, error) {

 	d := &Driver{

 		home: home,

 	}

-	return graphdriver.NewGenericDriverWrapper(d), nil

+	return graphdriver.NaiveDiffDriver(d), nil

 }

 type Driver struct {