@@ -20,6 +20,6 @@ func (daemon *Daemon) tarCopyOptions(container *container.Container, noOverwrite

 	return &archive.TarOptions{

 		NoOverwriteDirNonDir: noOverwriteDirNonDir,

-		ChownOpts:            idtools.IDPair{UID: user.Uid, GID: user.Gid},

+		ChownOpts:            &idtools.IDPair{UID: user.Uid, GID: user.Gid},

 	}, nil

 }

@@ -4,6 +4,8 @@ package devmapper

 import (

 	"fmt"

+	"os"

+	"syscall"

 	"testing"

 	"time"

@@ -17,11 +19,51 @@ func init() {

 	defaultMetaDataLoopbackSize = 200 * 1024 * 1024

 	defaultBaseFsSize = 300 * 1024 * 1024

 	defaultUdevSyncOverride = true

-	if err := graphtest.InitLoopbacks(); err != nil {

+	if err := initLoopbacks(); err != nil {

 		panic(err)

 	}

 }

+// initLoopbacks ensures that the loopback devices are properly created within

+// the system running the device mapper tests.

+func initLoopbacks() error {

+	statT, err := getBaseLoopStats()

+	if err != nil {

+		return err

+	}

+	// create at least 8 loopback files, ya, that is a good number

+	for i := 0; i < 8; i++ {

+		loopPath := fmt.Sprintf("/dev/loop%d", i)

+		// only create new loopback files if they don't exist

+		if _, err := os.Stat(loopPath); err != nil {

+			if mkerr := syscall.Mknod(loopPath,

+				uint32(statT.Mode|syscall.S_IFBLK), int((7<<8)|(i&0xff)|((i&0xfff00)<<12))); mkerr != nil {

+				return mkerr

+			}

+			os.Chown(loopPath, int(statT.Uid), int(statT.Gid))

+		}

+	}

+	return nil

+}

+

+// getBaseLoopStats inspects /dev/loop0 to collect uid,gid, and mode for the

+// loop0 device on the system.  If it does not exist we assume 0,0,0660 for the

+// stat data

+func getBaseLoopStats() (*syscall.Stat_t, error) {

+	loop0, err := os.Stat("/dev/loop0")

+	if err != nil {

+		if os.IsNotExist(err) {

+			return &syscall.Stat_t{

+				Uid:  0,

+				Gid:  0,

+				Mode: 0660,

+			}, nil

+		}

+		return nil, err

+	}

+	return loop0.Sys().(*syscall.Stat_t), nil

+}

+

 // This avoids creating a new driver for each test if all tests are run

 // Make sure to put new tests between TestDevmapperSetup and TestDevmapperTeardown

 func TestDevmapperSetup(t *testing.T) {

@@ -16,6 +16,8 @@ import (

 	"github.com/docker/docker/daemon/graphdriver"

 	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/go-units"

+	"github.com/stretchr/testify/assert"

+	"github.com/stretchr/testify/require"

 )

 var (

@@ -33,14 +35,9 @@ type Driver struct {

 func newDriver(t testing.TB, name string, options []string) *Driver {

 	root, err := ioutil.TempDir("", "docker-graphtest-")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if err := os.MkdirAll(root, 0755); err != nil {

-		t.Fatal(err)

-	}

+	require.NoError(t, err)

+	require.NoError(t, os.MkdirAll(root, 0755))

 	d, err := graphdriver.GetDriver(name, nil, graphdriver.Options{DriverOptions: options, Root: root})

 	if err != nil {

 		t.Logf("graphdriver: %v\n", err)

@@ -86,14 +83,11 @@ func DriverTestCreateEmpty(t testing.TB, drivername string, driverOptions ...str

 	driver := GetDriver(t, drivername, driverOptions...)

 	defer PutDriver(t)

-	if err := driver.Create("empty", "", nil); err != nil {

-		t.Fatal(err)

-	}

+	err := driver.Create("empty", "", nil)

+	require.NoError(t, err)

 	defer func() {

-		if err := driver.Remove("empty"); err != nil {

-			t.Fatal(err)

-		}

+		require.NoError(t, driver.Remove("empty"))

 	}()

 	if !driver.Exists("empty") {

@@ -101,21 +95,14 @@ func DriverTestCreateEmpty(t testing.TB, drivername string, driverOptions ...str

 	}

 	dir, err := driver.Get("empty", "")

-	if err != nil {

-		t.Fatal(err)

-	}

+	require.NoError(t, err)

 	verifyFile(t, dir, 0755|os.ModeDir, 0, 0)

 	// Verify that the directory is empty

 	fis, err := readDir(dir)

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if len(fis) != 0 {

-		t.Fatal("New directory not empty")

-	}

+	require.NoError(t, err)

+	assert.Len(t, fis, 0)

 	driver.Put("empty")

 }

@@ -127,9 +114,7 @@ func DriverTestCreateBase(t testing.TB, drivername string, driverOptions ...stri

 	createBase(t, driver, "Base")

 	defer func() {

-		if err := driver.Remove("Base"); err != nil {

-			t.Fatal(err)

-		}

+		require.NoError(t, driver.Remove("Base"))

 	}()

 	verifyBase(t, driver, "Base")

 }

@@ -140,21 +125,14 @@ func DriverTestCreateSnap(t testing.TB, drivername string, driverOptions ...stri

 	defer PutDriver(t)

 	createBase(t, driver, "Base")

-

 	defer func() {

-		if err := driver.Remove("Base"); err != nil {

-			t.Fatal(err)

-		}

+		require.NoError(t, driver.Remove("Base"))

 	}()

-	if err := driver.Create("Snap", "Base", nil); err != nil {

-		t.Fatal(err)

-	}

-

+	err := driver.Create("Snap", "Base", nil)

+	require.NoError(t, err)

 	defer func() {

-		if err := driver.Remove("Snap"); err != nil {

-			t.Fatal(err)

-		}

+		require.NoError(t, driver.Remove("Snap"))

 	}()

 	verifyBase(t, driver, "Snap")

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

 package graphtest

 import (

-	"fmt"

 	"io/ioutil"

 	"os"

 	"path"

@@ -11,81 +10,24 @@ import (

 	"testing"

 	"github.com/docker/docker/daemon/graphdriver"

+	"github.com/stretchr/testify/assert"

+	"github.com/stretchr/testify/require"

 )

-// InitLoopbacks ensures that the loopback devices are properly created within

-// the system running the device mapper tests.

-func InitLoopbacks() error {

-	statT, err := getBaseLoopStats()

-	if err != nil {

-		return err

-	}

-	// create at least 8 loopback files, ya, that is a good number

-	for i := 0; i < 8; i++ {

-		loopPath := fmt.Sprintf("/dev/loop%d", i)

-		// only create new loopback files if they don't exist

-		if _, err := os.Stat(loopPath); err != nil {

-			if mkerr := syscall.Mknod(loopPath,

-				uint32(statT.Mode|syscall.S_IFBLK), int((7<<8)|(i&0xff)|((i&0xfff00)<<12))); mkerr != nil {

-				return mkerr

-			}

-			os.Chown(loopPath, int(statT.Uid), int(statT.Gid))

-		}

-	}

-	return nil

-}

-

-// getBaseLoopStats inspects /dev/loop0 to collect uid,gid, and mode for the

-// loop0 device on the system.  If it does not exist we assume 0,0,0660 for the

-// stat data

-func getBaseLoopStats() (*syscall.Stat_t, error) {

-	loop0, err := os.Stat("/dev/loop0")

-	if err != nil {

-		if os.IsNotExist(err) {

-			return &syscall.Stat_t{

-				Uid:  0,

-				Gid:  0,

-				Mode: 0660,

-			}, nil

-		}

-		return nil, err

-	}

-	return loop0.Sys().(*syscall.Stat_t), nil

-}

-

 func verifyFile(t testing.TB, path string, mode os.FileMode, uid, gid uint32) {

 	fi, err := os.Stat(path)

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if fi.Mode()&os.ModeType != mode&os.ModeType {

-		t.Fatalf("Expected %s type 0x%x, got 0x%x", path, mode&os.ModeType, fi.Mode()&os.ModeType)

-	}

+	require.NoError(t, err)

-	if fi.Mode()&os.ModePerm != mode&os.ModePerm {

-		t.Fatalf("Expected %s mode %o, got %o", path, mode&os.ModePerm, fi.Mode()&os.ModePerm)

-	}

-

-	if fi.Mode()&os.ModeSticky != mode&os.ModeSticky {

-		t.Fatalf("Expected %s sticky 0x%x, got 0x%x", path, mode&os.ModeSticky, fi.Mode()&os.ModeSticky)

-	}

-

-	if fi.Mode()&os.ModeSetuid != mode&os.ModeSetuid {

-		t.Fatalf("Expected %s setuid 0x%x, got 0x%x", path, mode&os.ModeSetuid, fi.Mode()&os.ModeSetuid)

-	}

-

-	if fi.Mode()&os.ModeSetgid != mode&os.ModeSetgid {

-		t.Fatalf("Expected %s setgid 0x%x, got 0x%x", path, mode&os.ModeSetgid, fi.Mode()&os.ModeSetgid)

-	}

+	actual := fi.Mode()

+	assert.Equal(t, mode&os.ModeType, actual&os.ModeType, path)

+	assert.Equal(t, mode&os.ModePerm, actual&os.ModePerm, path)

+	assert.Equal(t, mode&os.ModeSticky, actual&os.ModeSticky, path)

+	assert.Equal(t, mode&os.ModeSetuid, actual&os.ModeSetuid, path)

+	assert.Equal(t, mode&os.ModeSetgid, actual&os.ModeSetgid, path)

 	if stat, ok := fi.Sys().(*syscall.Stat_t); ok {

-		if stat.Uid != uid {

-			t.Fatalf("%s no owned by uid %d", path, uid)

-		}

-		if stat.Gid != gid {

-			t.Fatalf("%s not owned by gid %d", path, gid)

-		}

+		assert.Equal(t, uid, stat.Uid, path)

+		assert.Equal(t, gid, stat.Gid, path)

 	}

 }

@@ -94,35 +36,25 @@ func createBase(t testing.TB, driver graphdriver.Driver, name string) {

 	oldmask := syscall.Umask(0)

 	defer syscall.Umask(oldmask)

-	if err := driver.CreateReadWrite(name, "", nil); err != nil {

-		t.Fatal(err)

-	}

+	err := driver.CreateReadWrite(name, "", nil)

+	require.NoError(t, err)

 	dir, err := driver.Get(name, "")

-	if err != nil {

-		t.Fatal(err)

-	}

+	require.NoError(t, err)

 	defer driver.Put(name)

 	subdir := path.Join(dir, "a subdir")

-	if err := os.Mkdir(subdir, 0705|os.ModeSticky); err != nil {

-		t.Fatal(err)

-	}

-	if err := os.Chown(subdir, 1, 2); err != nil {

-		t.Fatal(err)

-	}

+	require.NoError(t, os.Mkdir(subdir, 0705|os.ModeSticky))

+	require.NoError(t, os.Chown(subdir, 1, 2))

 	file := path.Join(dir, "a file")

-	if err := ioutil.WriteFile(file, []byte("Some data"), 0222|os.ModeSetuid); err != nil {

-		t.Fatal(err)

-	}

+	err = ioutil.WriteFile(file, []byte("Some data"), 0222|os.ModeSetuid)

+	require.NoError(t, err)

 }

 func verifyBase(t testing.TB, driver graphdriver.Driver, name string) {

 	dir, err := driver.Get(name, "")

-	if err != nil {

-		t.Fatal(err)

-	}

+	require.NoError(t, err)

 	defer driver.Put(name)

 	subdir := path.Join(dir, "a subdir")

@@ -131,13 +63,7 @@ func verifyBase(t testing.TB, driver graphdriver.Driver, name string) {

 	file := path.Join(dir, "a file")

 	verifyFile(t, file, 0222|os.ModeSetuid, 0, 0)

-	fis, err := readDir(dir)

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if len(fis) != 2 {

-		t.Fatal("Unexpected files in base image")

-	}

-

+	files, err := readDir(dir)

+	require.NoError(t, err)

+	assert.Len(t, files, 2)

 }

@@ -9,7 +9,6 @@ import (

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

 	"github.com/docker/docker/pkg/idtools"

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

-

 	"github.com/opencontainers/selinux/go-selinux/label"

 )

@@ -26,15 +25,14 @@ func init() {

 // This sets the home directory for the driver and returns NaiveDiffDriver.

 func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {

 	d := &Driver{

-		home:    home,

-		uidMaps: uidMaps,

-		gidMaps: gidMaps,

+		home:       home,

+		idMappings: idtools.NewIDMappingsFromMaps(uidMaps, gidMaps),

 	}

-	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)

+	rootIDs, err := d.idMappings.RootPair()

 	if err != nil {

 		return nil, err

 	}

-	if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {

+	if err := idtools.MkdirAllAndChown(home, 0700, rootIDs); err != nil {

 		return nil, err

 	}

 	return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil

@@ -45,9 +43,8 @@ func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap

 // In order to support layering, files are copied from the parent layer into the new layer. There is no copy-on-write support.

 // Driver must be wrapped in NaiveDiffDriver to be used as a graphdriver.Driver

 type Driver struct {

-	home    string

-	uidMaps []idtools.IDMap

-	gidMaps []idtools.IDMap

+	home       string

+	idMappings *idtools.IDMappings

 }

 func (d *Driver) String() string {

@@ -82,14 +79,14 @@ func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {

 	}

 	dir := d.dir(id)

-	rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)

+	rootIDs, err := d.idMappings.RootPair()

 	if err != nil {

 		return err

 	}

-	if err := idtools.MkdirAllAs(filepath.Dir(dir), 0700, rootUID, rootGID); err != nil {

+	if err := idtools.MkdirAllAndChown(filepath.Dir(dir), 0700, rootIDs); err != nil {

 		return err

 	}

-	if err := idtools.MkdirAs(dir, 0755, rootUID, rootGID); err != nil {

+	if err := idtools.MkdirAndChown(dir, 0755, rootIDs); err != nil {

 		return err

 	}

 	labelOpts := []string{"level:s0"}

@@ -103,10 +100,7 @@ func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {

 	if err != nil {

 		return fmt.Errorf("%s: %s", parent, err)

 	}

-	if err := CopyWithTar(parentDir, dir); err != nil {

-		return err

-	}

-	return nil

+	return CopyWithTar(parentDir, dir)

 }

 func (d *Driver) dir(id string) string {

@@ -39,7 +39,7 @@ type (

 		NoLchown         bool

 		UIDMaps          []idtools.IDMap

 		GIDMaps          []idtools.IDMap

-		ChownOpts        idtools.IDPair

+		ChownOpts        *idtools.IDPair

 		IncludeSourceDir bool

 		// WhiteoutFormat is the expected on disk format for whiteout files.

 		// This format will be converted to the standard format on pack

@@ -920,7 +920,7 @@ loop:

 			}

 		}

-		if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown, &options.ChownOpts, options.InUserNS); err != nil {

+		if err := createTarFile(path, dest, hdr, trBuf, !options.NoLchown, options.ChownOpts, options.InUserNS); err != nil {

 			return err

 		}