@@ -249,14 +249,14 @@ func (ta *tarAppender) addTarFile(path, name string) error {

 	}

 	hdr.Name = name

-	nlink, inode, err := setHeaderForSpecialDevice(hdr, ta, name, fi.Sys())

+	inode, err := setHeaderForSpecialDevice(hdr, ta, name, fi.Sys())

 	if err != nil {

 		return err

 	}

-	// if it's a regular file and has more than 1 link,

+	// if it's not a directory and has more than 1 link,

 	// it's hardlinked, so set the type flag accordingly

-	if fi.Mode().IsRegular() && nlink > 1 {

+	if !fi.IsDir() && hasHardlinks(fi) {

 		// a link should have a name that it links too

 		// and that linked name should be first in the tar archive

 		if oldpath, ok := ta.SeenFiles[inode]; ok {

@@ -40,7 +40,7 @@ func chmodTarEntry(perm os.FileMode) os.FileMode {

 	return perm // noop for unix as golang APIs provide perm bits correctly

 }

-func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (nlink uint32, inode uint64, err error) {

+func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (inode uint64, err error) {

 	s, ok := stat.(*syscall.Stat_t)

 	if !ok {

@@ -48,7 +48,6 @@ func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, st

 		return

 	}

-	nlink = uint32(s.Nlink)

 	inode = uint64(s.Ino)

 	// Currently go does not fill in the major/minors

@@ -49,7 +49,7 @@ func chmodTarEntry(perm os.FileMode) os.FileMode {

 	return perm

 }

-func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (nlink uint32, inode uint64, err error) {

+func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (inode uint64, err error) {

 	// do nothing. no notion of Rdev, Inode, Nlink in stat on Windows

 	return

 }

@@ -328,13 +328,29 @@ func ChangesDirs(newDir, oldDir string) ([]Change, error) {

 // ChangesSize calculates the size in bytes of the provided changes, based on newDir.

 func ChangesSize(newDir string, changes []Change) int64 {

-	var size int64

+	var (

+		size int64

+		sf   = make(map[uint64]struct{})

+	)

 	for _, change := range changes {

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

 			file := filepath.Join(newDir, change.Path)

-			fileInfo, _ := os.Lstat(file)

+			fileInfo, err := os.Lstat(file)

+			if err != nil {

+				logrus.Errorf("Can not stat %q: %s", file, err)

+				continue

+			}

+

 			if fileInfo != nil && !fileInfo.IsDir() {

-				size += fileInfo.Size()

+				if hasHardlinks(fileInfo) {

+					inode := getIno(fileInfo)

+					if _, ok := sf[inode]; !ok {

+						size += fileInfo.Size()

+						sf[inode] = struct{}{}

+					}

+				} else {

+					size += fileInfo.Size()

+				}

 			}

 		}

 	}

@@ -434,6 +434,35 @@ func TestApplyLayer(t *testing.T) {

 	}

 }

+func TestChangesSizeWithHardlinks(t *testing.T) {

+	srcDir, err := ioutil.TempDir("", "docker-test-srcDir")

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer os.RemoveAll(srcDir)

+

+	destDir, err := ioutil.TempDir("", "docker-test-destDir")

+	if err != nil {

+		t.Fatal(err)

+	}

+	defer os.RemoveAll(destDir)

+

+	creationSize, err := prepareUntarSourceDirectory(100, destDir, true)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	changes, err := ChangesDirs(destDir, srcDir)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	got := ChangesSize(destDir, changes)

+	if got != int64(creationSize) {

+		t.Errorf("Expected %d bytes of changes, got %d", creationSize, got)

+	}

+}

+

 func TestChangesSizeWithNoChanges(t *testing.T) {

 	size := ChangesSize("/tmp", nil)

 	if size != 0 {

@@ -468,7 +497,7 @@ func TestChangesSize(t *testing.T) {

 	}

 	size := ChangesSize(parentPath, changes)

 	if size != 6 {

-		t.Fatalf("ChangesSizes with only delete changes should be 0, was %d", size)

+		t.Fatalf("Expected 6 bytes of changes, got %d", size)

 	}

 }

@@ -3,6 +3,7 @@

 package archive

 import (

+	"os"

 	"syscall"

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

@@ -25,3 +26,11 @@ func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {

 func (info *FileInfo) isDir() bool {

 	return info.parent == nil || info.stat.Mode()&syscall.S_IFDIR != 0

 }

+

+func getIno(fi os.FileInfo) uint64 {

+	return uint64(fi.Sys().(*syscall.Stat_t).Ino)

+}

+

+func hasHardlinks(fi os.FileInfo) bool {

+	return fi.Sys().(*syscall.Stat_t).Nlink > 1

+}

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

 package archive

 import (

+	"os"

+

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

 )

@@ -18,3 +20,11 @@ func statDifferent(oldStat *system.StatT, newStat *system.StatT) bool {

 func (info *FileInfo) isDir() bool {

 	return info.parent == nil || info.stat.IsDir()

 }

+

+func getIno(fi os.FileInfo) (inode uint64) {

+	return

+}

+

+func hasHardlinks(fi os.FileInfo) bool {

+	return false

+}