@@ -57,10 +57,6 @@ func (ml *mockLayer) DiffSize() (size int64, err error) {

 	return 0, nil

 }

-func (ml *mockLayer) OS() string {

-	return ml.os

-}

-

 func (ml *mockLayer) Metadata() (map[string]string, error) {

 	return make(map[string]string), nil

 }

@@ -158,10 +154,6 @@ func (ls *mockLayerStore) DriverName() string {

 	return "mock"

 }

-func (ls *mockLayerStore) OS() string {

-	return runtime.GOOS

-}

-

 type mockDownloadDescriptor struct {

 	currentDownloads *int32

 	id               string

@@ -224,6 +224,13 @@ func (is *store) Delete(id ID) ([]layer.Metadata, error) {

 	if imageMeta == nil {

 		return nil, fmt.Errorf("unrecognized image ID %s", id.String())

 	}

+	img, err := is.Get(id)

+	if err != nil {

+		return nil, fmt.Errorf("unrecognized image %s, %v", id.String(), err)

+	}

+	if !system.IsOSSupported(img.OperatingSystem()) {

+		return nil, fmt.Errorf("unsupported image operating system %q", img.OperatingSystem())

+	}

 	for id := range imageMeta.children {

 		is.fs.DeleteMetadata(id.Digest(), "parent")

 	}

@@ -238,7 +245,7 @@ func (is *store) Delete(id ID) ([]layer.Metadata, error) {

 	is.fs.Delete(id.Digest())

 	if imageMeta.layer != nil {

-		return is.lss[imageMeta.layer.OS()].Release(imageMeta.layer)

+		return is.lss[img.OperatingSystem()].Release(imageMeta.layer)

 	}

 	return nil, nil

 }

@@ -43,10 +43,6 @@ func (el *emptyLayer) Parent() Layer {

 	return nil

 }

-func (el *emptyLayer) OS() string {

-	return ""

-}

-

 func (el *emptyLayer) Size() (size int64, err error) {

 	return 0, nil

 }

@@ -100,9 +100,6 @@ type Layer interface {

 	// Parent returns the next layer in the layer chain.

 	Parent() Layer

-	// OS returns the operating system of the layer

-	OS() string

-

 	// Size returns the size of the entire layer chain. The size

 	// is calculated from the total size of all files in the layers.

 	Size() (int64, error)

@@ -148,9 +145,6 @@ type RWLayer interface {

 	// Metadata returns the low level metadata for the mutable layer

 	Metadata() (map[string]string, error)

-

-	// OS returns the operating system of the writable layer

-	OS() string

 }

 // Metadata holds information about a

@@ -199,7 +193,6 @@ type Store interface {

 	Cleanup() error

 	DriverStatus() [][2]string

 	DriverName() string

-	OS() string

 }

 // DescribableStore represents a layer store capable of storing

@@ -725,10 +725,6 @@ func (ls *layerStore) DriverName() string {

 	return ls.driver.String()

 }

-func (ls *layerStore) OS() string {

-	return ls.os

-}

-

 type naiveDiffPathDriver struct {

 	graphdriver.Driver

 }

@@ -46,10 +46,6 @@ func (ml *mountedLayer) Parent() Layer {

 	return nil

 }

-func (ml *mountedLayer) OS() string {

-	return ml.layerStore.os

-}

-

 func (ml *mountedLayer) Size() (int64, error) {

 	return ml.layerStore.driver.DiffSize(ml.mountID, ml.cacheParent())

 }

@@ -69,10 +69,6 @@ func (rl *roLayer) Parent() Layer {

 	return rl.parent

 }

-func (rl *roLayer) OS() string {

-	return rl.layerStore.os

-}

-

 func (rl *roLayer) Size() (size int64, err error) {

 	if rl.parent != nil {

 		size, err = rl.parent.Size()

@@ -432,10 +432,6 @@ func (l *mockLayer) DiffSize() (int64, error) {

 	return 0, nil

 }

-func (l *mockLayer) OS() string {

-	return ""

-}

-

 func (l *mockLayer) Metadata() (map[string]string, error) {

 	return nil, nil

 }