mount: move the MakePrivate to pkg/mount

The logic is unrelated to graphdriver.

Signed-off-by: Vincent Batts <vbatts@redhat.com>

daemon/graphdriver/aufs/aufs.go

@@ -98,7 +98,7 @@ func Init(root string, options []string) (graphdriver.Driver, error) {
 		return nil, err
 	}
 
-	if err := graphdriver.MakePrivate(root); err != nil {
+	if err := mountpk.MakePrivate(root); err != nil {
 		return nil, err
 	}
 

daemon/graphdriver/btrfs/btrfs.go

@@ -40,7 +40,7 @@ func Init(home string, options []string) (graphdriver.Driver, error) {
 		return nil, err
 	}
 
-	if err := graphdriver.MakePrivate(home); err != nil {
+	if err := mount.MakePrivate(home); err != nil {
 		return nil, err
 	}
 

daemon/graphdriver/devmapper/driver.go

@@ -34,7 +34,7 @@ func Init(home string, options []string) (graphdriver.Driver, error) {
 		return nil, err
 	}
 
-	if err := graphdriver.MakePrivate(home); err != nil {
+	if err := mount.MakePrivate(home); err != nil {
 		return nil, err
 	}
 

daemon/graphdriver/driver.go

@@ -7,7 +7,6 @@ import (
 	"path"
 
 	"github.com/docker/docker/pkg/archive"
-	"github.com/docker/docker/pkg/mount"
 )
 
 type FsMagic uint64
@@ -139,18 +138,3 @@ func New(root string, options []string) (driver Driver, err error) {
 	}
 	return nil, fmt.Errorf("No supported storage backend found")
 }
-
-func MakePrivate(mountPoint string) error {
-	mounted, err := mount.Mounted(mountPoint)
-	if err != nil {
-		return err
-	}
-
-	if !mounted {
-		if err := mount.Mount(mountPoint, mountPoint, "none", "bind,rw"); err != nil {
-			return err
-		}
-	}
-
-	return mount.ForceMount("", mountPoint, "none", "private")
-}

pkg/mount/sharedsubtree_linux.go

@@ -0,0 +1,18 @@
+// +build linux
+
+package mount
+
+func MakePrivate(mountPoint string) error {
+	mounted, err := Mounted(mountPoint)
+	if err != nil {
+		return err
+	}
+
+	if !mounted {
+		if err := Mount(mountPoint, mountPoint, "none", "bind,rw"); err != nil {
+			return err
+		}
+	}
+
+	return ForceMount("", mountPoint, "none", "private")
+}