@@ -3,15 +3,16 @@ package archive

 import (

 	"bytes"

 	"fmt"

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

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

-	"github.com/dotcloud/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"

 	"io"

 	"os"

 	"path/filepath"

 	"strings"

 	"syscall"

 	"time"

+

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

+	"github.com/dotcloud/docker/utils"

+	"github.com/dotcloud/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"

 )

 type ChangeType int

@@ -293,13 +294,23 @@ func collectFileInfo(sourceDir string) (*FileInfo, error) {

 // Compare two directories and generate an array of Change objects describing the changes

 func ChangesDirs(newDir, oldDir string) ([]Change, error) {

-	oldRoot, err := collectFileInfo(oldDir)

-	if err != nil {

-		return nil, err

-	}

-	newRoot, err := collectFileInfo(newDir)

-	if err != nil {

-		return nil, err

+	var (

+		oldRoot, newRoot *FileInfo

+		err1, err2       error

+		errs             = make(chan error, 2)

+	)

+	go func() {

+		oldRoot, err1 = collectFileInfo(oldDir)

+		errs <- err1

+	}()

+	go func() {

+		newRoot, err2 = collectFileInfo(newDir)

+		errs <- err2

+	}()

+	for i := 0; i < 2; i++ {

+		if err := <-errs; err != nil {

+			return nil, err

+		}

 	}

 	return newRoot.Changes(oldRoot), nil