@@ -1382,7 +1382,8 @@ func (container *Container) ExportRw() (archive.Archive, error) {

 	if container.runtime == nil {

 		return nil, fmt.Errorf("Can't load storage driver for unregistered container %s", container.ID)

 	}

-	return container.runtime.driver.Diff(container.ID)

+

+	return container.runtime.Diff(container)

 }

 func (container *Container) Export() (archive.Archive, error) {

@@ -2,7 +2,6 @@ package devmapper

 import (

 	"fmt"

-	"github.com/dotcloud/docker/archive"

 	"github.com/dotcloud/docker/graphdriver"

 	"os"

 	"path"

@@ -57,10 +56,6 @@ func (d *Driver) Get(id string) (string, error) {

 	return mp, nil

 }

-func (d *Driver) Diff(id string) (archive.Archive, error) {

-	return nil, fmt.Errorf("Not implemented")

-}

-

 func (d *Driver) DiffSize(id string) (int64, error) {

 	return -1, fmt.Errorf("Not implemented")

 }

@@ -16,7 +16,6 @@ type Driver interface {

 	Get(id string) (dir string, err error)

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

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

 	Cleanup() error

@@ -26,6 +25,10 @@ type Changer interface {

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

 }

+type Differ interface {

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

+}

+

 var (

 	// All registred drivers

 	drivers map[string]InitFunc

@@ -73,14 +73,6 @@ func (d *Driver) Get(id string) (string, error) {

 	return dir, nil

 }

-func (d *Driver) Diff(id string) (archive.Archive, error) {

-	p, err := d.Get(id)

-	if err != nil {

-		return nil, err

-	}

-	return archive.Tar(p, archive.Uncompressed)

-}

-

 func (d *Driver) DiffSize(id string) (int64, error) {

 	return -1, fmt.Errorf("Not implemented")

 }

@@ -18,6 +18,7 @@ import (

 	"os"

 	"os/exec"

 	"path"

+	"path/filepath"

 	"sort"

 	"strings"

 	"time"

@@ -747,6 +748,37 @@ func (runtime *Runtime) Changes(container *Container) ([]archive.Change, error)

 	return archive.ChangesDirs(cDir, initDir)

 }

+func (runtime *Runtime) Diff(container *Container) (archive.Archive, error) {

+	if differ, ok := runtime.driver.(graphdriver.Differ); ok {

+		return differ.Diff(container.ID)

+	}

+

+	changes, err := runtime.Changes(container)

+	if err != nil {

+		return nil, err

+	}

+

+	cDir, err := runtime.driver.Get(container.ID)

+	if err != nil {

+		return nil, fmt.Errorf("Error getting container rootfs %s from driver %s: %s", container.ID, container.runtime.driver, err)

+	}

+

+	files := make([]string, 0)

+	deletions := make([]string, 0)

+	for _, change := range changes {

+		if change.Kind == archive.ChangeModify || change.Kind == archive.ChangeAdd {

+			files = append(files, change.Path)

+		}

+		if change.Kind == archive.ChangeDelete {

+			base := filepath.Base(change.Path)

+			dir := filepath.Dir(change.Path)

+			deletions = append(deletions, filepath.Join(dir, ".wh."+base))

+		}

+	}

+

+	return archive.TarFilter(cDir, archive.Uncompressed, files, false, deletions)

+}

+

 func linkLxcStart(root string) error {

 	sourcePath, err := exec.LookPath("lxc-start")

 	if err != nil {