@@ -312,7 +312,7 @@ func (a *Driver) applyDiff(id string, diff archive.ArchiveReader) error {

 // DiffSize calculates the changes between the specified id

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

 // relative to its base filesystem directory.

-func (a *Driver) DiffSize(id, parent string) (bytes int64, err error) {

+func (a *Driver) DiffSize(id, parent string) (size int64, err error) {

 	// AUFS doesn't need the parent layer to calculate the diff size.

 	return utils.TreeSize(path.Join(a.rootPath(), "diff", id))

 }

@@ -320,7 +320,7 @@ func (a *Driver) DiffSize(id, parent string) (bytes int64, err error) {

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

+func (a *Driver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error) {

 	// AUFS doesn't need the parent id to apply the diff.

 	if err = a.applyDiff(id, diff); err != nil {

 		return

@@ -63,11 +63,11 @@ type Driver interface {

 	// 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.

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

+	ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error)

 	// DiffSize calculates the changes between the specified id

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

 	// relative to its base filesystem directory.

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

+	DiffSize(id, parent string) (size int64, err error)

 }

 var (

@@ -3,14 +3,12 @@

 package graphdriver

 import (

-	"fmt"

 	"time"

 	log "github.com/Sirupsen/logrus"

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

 	"github.com/docker/docker/pkg/chrootarchive"

 	"github.com/docker/docker/pkg/ioutils"

-	"github.com/docker/docker/utils"

 )

 // naiveDiffDriver takes a ProtoDriver and adds the

@@ -27,8 +25,8 @@ type naiveDiffDriver struct {

 // 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)

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

+//     DiffSize(id, parent string) (size int64, err error)

 func NaiveDiffDriver(driver ProtoDriver) Driver {

 	return &naiveDiffDriver{ProtoDriver: driver}

 }

@@ -111,7 +109,7 @@ func (gdw *naiveDiffDriver) Changes(id, parent string) ([]archive.Change, error)

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

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

 	driver := gdw.ProtoDriver

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

@@ -123,34 +121,18 @@ func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveRea

 	start := time.Now().UTC()

 	log.Debugf("Start untar layer")

-	if err = chrootarchive.ApplyLayer(layerFs, diff); err != nil {

+	if size, err = chrootarchive.ApplyLayer(layerFs, diff); err != nil {

 		return

 	}

 	log.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())

-	if parent == "" {

-		return utils.TreeSize(layerFs)

-	}

-

-	parentFs, err := driver.Get(parent, "")

-	if err != nil {

-		err = fmt.Errorf("Driver %s failed to get image parent %s: %s", driver, parent, err)

-		return

-	}

-	defer driver.Put(parent)

-

-	changes, err := archive.ChangesDirs(layerFs, parentFs)

-	if err != nil {

-		return

-	}

-

-	return archive.ChangesSize(layerFs, changes), nil

+	return

 }

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

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

 	driver := gdw.ProtoDriver

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

@@ -28,7 +28,7 @@ var (

 type ApplyDiffProtoDriver interface {

 	graphdriver.ProtoDriver

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

+	ApplyDiff(id, parent string, diff archive.ArchiveReader) (size int64, err error)

 }

 type naiveDiffDriverWithApply struct {

@@ -309,7 +309,7 @@ func (d *Driver) Put(id string) {

 	delete(d.active, id)

 }

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

+func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader) (size int64, err error) {

 	dir := d.dir(id)

 	if parent == "" {

@@ -347,7 +347,7 @@ func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader)

 		return 0, err

 	}

-	if err := chrootarchive.ApplyLayer(tmpRootDir, diff); err != nil {

+	if size, err = chrootarchive.ApplyLayer(tmpRootDir, diff); err != nil {

 		return 0, err

 	}

@@ -356,12 +356,7 @@ func (d *Driver) ApplyDiff(id string, parent string, diff archive.ArchiveReader)

 		return 0, err

 	}

-	changes, err := archive.ChangesDirs(rootDir, parentRootDir)

-	if err != nil {

-		return 0, err

-	}

-

-	return archive.ChangesSize(rootDir, changes), nil

+	return

 }

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

@@ -286,7 +286,7 @@ func TestApplyLayer(t *testing.T) {

 		t.Fatal(err)

 	}

-	if err := ApplyLayer(src, layerCopy); err != nil {

+	if _, err := ApplyLayer(src, layerCopy); err != nil {

 		t.Fatal(err)

 	}

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

 	"github.com/docker/docker/pkg/system"

 )

-func UnpackLayer(dest string, layer ArchiveReader) error {

+func UnpackLayer(dest string, layer ArchiveReader) (size int64, err error) {

 	tr := tar.NewReader(layer)

 	trBuf := pools.BufioReader32KPool.Get(tr)

 	defer pools.BufioReader32KPool.Put(trBuf)

@@ -33,9 +33,11 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 			break

 		}

 		if err != nil {

-			return err

+			return 0, err

 		}

+		size += hdr.Size

+

 		// Normalize name, for safety and for a simple is-root check

 		hdr.Name = filepath.Clean(hdr.Name)

@@ -48,7 +50,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 			if _, err := os.Lstat(parentPath); err != nil && os.IsNotExist(err) {

 				err = os.MkdirAll(parentPath, 0600)

 				if err != nil {

-					return err

+					return 0, err

 				}

 			}

 		}

@@ -63,12 +65,12 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 				aufsHardlinks[basename] = hdr

 				if aufsTempdir == "" {

 					if aufsTempdir, err = ioutil.TempDir("", "dockerplnk"); err != nil {

-						return err

+						return 0, err

 					}

 					defer os.RemoveAll(aufsTempdir)

 				}

 				if err := createTarFile(filepath.Join(aufsTempdir, basename), dest, hdr, tr, true); err != nil {

-					return err

+					return 0, err

 				}

 			}

 			continue

@@ -77,10 +79,10 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 		path := filepath.Join(dest, hdr.Name)

 		rel, err := filepath.Rel(dest, path)

 		if err != nil {

-			return err

+			return 0, err

 		}

 		if strings.HasPrefix(rel, "..") {

-			return breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))

+			return 0, breakoutError(fmt.Errorf("%q is outside of %q", hdr.Name, dest))

 		}

 		base := filepath.Base(path)

@@ -88,7 +90,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 			originalBase := base[len(".wh."):]

 			originalPath := filepath.Join(filepath.Dir(path), originalBase)

 			if err := os.RemoveAll(originalPath); err != nil {

-				return err

+				return 0, err

 			}

 		} else {

 			// If path exits we almost always just want to remove and replace it.

@@ -98,7 +100,7 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 			if fi, err := os.Lstat(path); err == nil {

 				if !(fi.IsDir() && hdr.Typeflag == tar.TypeDir) {

 					if err := os.RemoveAll(path); err != nil {

-						return err

+						return 0, err

 					}

 				}

 			}

@@ -113,18 +115,18 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 				linkBasename := filepath.Base(hdr.Linkname)

 				srcHdr = aufsHardlinks[linkBasename]

 				if srcHdr == nil {

-					return fmt.Errorf("Invalid aufs hardlink")

+					return 0, fmt.Errorf("Invalid aufs hardlink")

 				}

 				tmpFile, err := os.Open(filepath.Join(aufsTempdir, linkBasename))

 				if err != nil {

-					return err

+					return 0, err

 				}

 				defer tmpFile.Close()

 				srcData = tmpFile

 			}

 			if err := createTarFile(path, dest, srcHdr, srcData, true); err != nil {

-				return err

+				return 0, err

 			}

 			// Directory mtimes must be handled at the end to avoid further

@@ -139,27 +141,29 @@ func UnpackLayer(dest string, layer ArchiveReader) error {

 		path := filepath.Join(dest, hdr.Name)

 		ts := []syscall.Timespec{timeToTimespec(hdr.AccessTime), timeToTimespec(hdr.ModTime)}

 		if err := syscall.UtimesNano(path, ts); err != nil {

-			return err

+			return 0, err

 		}

 	}

-	return nil

+

+	return size, nil

 }

 // ApplyLayer parses a diff in the standard layer format from `layer`, and

-// applies it to the directory `dest`.

-func ApplyLayer(dest string, layer ArchiveReader) error {

+// applies it to the directory `dest`. Returns the size in bytes of the

+// contents of the layer.

+func ApplyLayer(dest string, layer ArchiveReader) (int64, error) {

 	dest = filepath.Clean(dest)

 	// We need to be able to set any perms

 	oldmask, err := system.Umask(0)

 	if err != nil {

-		return err

+		return 0, err

 	}

 	defer system.Umask(oldmask) // ignore err, ErrNotSupportedPlatform

 	layer, err = DecompressStream(layer)

 	if err != nil {

-		return err

+		return 0, err

 	}

 	return UnpackLayer(dest, layer)

 }

@@ -17,7 +17,8 @@ var testUntarFns = map[string]func(string, io.Reader) error{

 		return Untar(r, dest, nil)

 	},

 	"applylayer": func(dest string, r io.Reader) error {

-		return ApplyLayer(dest, ArchiveReader(r))

+		_, err := ApplyLayer(dest, ArchiveReader(r))

+		return err

 	},

 }

@@ -95,7 +95,7 @@ func TestChrootApplyEmptyArchiveFromSlowReader(t *testing.T) {

 		t.Fatal(err)

 	}

 	stream := &slowEmptyTarReader{size: 10240, chunkSize: 1024}

-	if err := ApplyLayer(dest, stream); err != nil {

+	if _, err := ApplyLayer(dest, stream); err != nil {

 		t.Fatal(err)

 	}

 }

@@ -1,6 +1,8 @@

 package chrootarchive

 import (

+	"bytes"

+	"encoding/json"

 	"flag"

 	"fmt"

 	"io"

@@ -14,6 +16,10 @@ import (

 	"github.com/docker/docker/pkg/reexec"

 )

+type applyLayerResponse struct {

+	LayerSize int64 `json:"layerSize"`

+}

+

 func applyLayer() {

 	runtime.LockOSThread()

 	flag.Parse()

@@ -21,6 +27,7 @@ func applyLayer() {

 	if err := chroot(flag.Arg(0)); err != nil {

 		fatal(err)

 	}

+

 	// We need to be able to set any perms

 	oldmask := syscall.Umask(0)

 	defer syscall.Umask(oldmask)

@@ -28,33 +35,53 @@ func applyLayer() {

 	if err != nil {

 		fatal(err)

 	}

+

 	os.Setenv("TMPDIR", tmpDir)

-	err = archive.UnpackLayer("/", os.Stdin)

+	size, err := archive.UnpackLayer("/", os.Stdin)

 	os.RemoveAll(tmpDir)

 	if err != nil {

 		fatal(err)

 	}

-	os.RemoveAll(tmpDir)

+

+	encoder := json.NewEncoder(os.Stdout)

+	if err := encoder.Encode(applyLayerResponse{size}); err != nil {

+		fatal(fmt.Errorf("unable to encode layerSize JSON: %s", err))

+	}

+

+	flush(os.Stdout)

 	flush(os.Stdin)

 	os.Exit(0)

 }

-func ApplyLayer(dest string, layer archive.ArchiveReader) error {

+func ApplyLayer(dest string, layer archive.ArchiveReader) (size int64, err error) {

 	dest = filepath.Clean(dest)

 	decompressed, err := archive.DecompressStream(layer)

 	if err != nil {

-		return err

+		return 0, err

 	}

+

 	defer func() {

 		if c, ok := decompressed.(io.Closer); ok {

 			c.Close()

 		}

 	}()

+

 	cmd := reexec.Command("docker-applyLayer", dest)

 	cmd.Stdin = decompressed

-	out, err := cmd.CombinedOutput()

-	if err != nil {

-		return fmt.Errorf("ApplyLayer %s %s", err, out)

+

+	outBuf, errBuf := new(bytes.Buffer), new(bytes.Buffer)

+	cmd.Stdout, cmd.Stderr = outBuf, errBuf

+

+	if err = cmd.Run(); err != nil {

+		return 0, fmt.Errorf("ApplyLayer %s stdout: %s stderr: %s", err, outBuf, errBuf)

+	}

+

+	// Stdout should be a valid JSON struct representing an applyLayerResponse.

+	response := applyLayerResponse{}

+	decoder := json.NewDecoder(outBuf)

+	if err = decoder.Decode(&response); err != nil {

+		return 0, fmt.Errorf("unable to decode ApplyLayer JSON response: %s", err)

 	}

-	return nil

+

+	return response.LayerSize, nil

 }