@@ -39,7 +39,10 @@ import (

 var (

 	ErrAufsNotSupported = fmt.Errorf("AUFS was not found in /proc/filesystems")

-	IncompatibleFSMagic = []int64{0x9123683E /*btrfs*/, 0x61756673 /*AUFS*/}

+	incompatibleFsMagic = []graphdriver.FsMagic{

+		graphdriver.FsMagicBtrfs,

+		graphdriver.FsMagicAufs,

+	}

 )

 func init() {

@@ -67,8 +70,8 @@ func Init(root string) (graphdriver.Driver, error) {

 		return nil, fmt.Errorf("Couldn't stat the root directory: %s", err)

 	}

-	for _, magic := range IncompatibleFSMagic {

-		if int64(buf.Type) == magic {

+	for _, magic := range incompatibleFsMagic {

+		if graphdriver.FsMagic(buf.Type) == magic {

 			return nil, graphdriver.ErrIncompatibleFS

 		}

 	}

@@ -18,10 +18,6 @@ import (

 	"unsafe"

 )

-const (

-	btrfsSuperMagic = 0x9123683E

-)

-

 func init() {

 	graphdriver.Register("btrfs", Init)

 }

@@ -34,7 +30,7 @@ func Init(home string) (graphdriver.Driver, error) {

 		return nil, err

 	}

-	if buf.Type != btrfsSuperMagic {

+	if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicBtrfs {

 		return nil, graphdriver.ErrPrerequisites

 	}

@@ -8,6 +8,13 @@ import (

 	"path"

 )

+type FsMagic uint64

+

+const (

+	FsMagicBtrfs = FsMagic(0x9123683E)

+	FsMagicAufs  = FsMagic(0x61756673)

+)

+

 type InitFunc func(root string) (Driver, error)

 type Driver interface {