Don't rely on drivers for diff and export

archive/changes.go

@@ -206,3 +206,25 @@ func ChangesDirs(newDir, oldDir string) ([]Change, error) {
 	}
 	return changes, nil
 }
+
+
+func ExportChanges(root, rw string) (Archive, error) {
+        changes, err := ChangesDirs(root, rw)
+        if err != nil {
+                return nil, err
+        }
+        files := make([]string, 0)
+        deletions := make([]string, 0)
+        for _, change := range changes {
+                if change.Kind == ChangeModify || change.Kind == ChangeAdd {
+                        files = append(files, change.Path)
+                }
+                if change.Kind == ChangeDelete {
+                        base := filepath.Base(change.Path)
+                        dir := filepath.Dir(change.Path)
+                        deletions = append(deletions, filepath.Join(dir, ".wh."+base))
+                }
+        }
+        return TarFilter(root, Uncompressed, files, false, deletions)
+}
+

container.go

@@ -1363,10 +1363,17 @@ func (container *Container) Resize(h, w int) error {
 }
 
 func (container *Container) ExportRw() (archive.Archive, error) {
+	if err := container.EnsureMounted(); err != nil {
+		return nil, err
+	}
 	if container.runtime == nil {
 		return nil, fmt.Errorf("Can't load storage driver for unregistered container %s", container.ID)
 	}
-	return container.runtime.driver.Diff(container.ID)
+	imgDir, err := container.runtime.driver.Get(container.Image)
+	if err != nil {
+		return nil, err
+	}
+	return archive.ExportChanges(container.RootfsPath(), imgDir)
 }
 
 func (container *Container) Export() (archive.Archive, error) {

runtime.go

@@ -733,7 +733,15 @@ func (runtime *Runtime) Unmount(container *Container) error {
 }
 
 func (runtime *Runtime) Changes(container *Container) ([]archive.Change, error) {
-	return runtime.driver.Changes(container.ID)
+	cDir, err := runtime.driver.Get(container.ID)
+	if err != nil {
+		return nil, fmt.Errorf("Error getting container rootfs %s from driver %s: %s", container.ID, container.runtime.driver, err)
+	}
+	initDir, err := runtime.driver.Get(container.ID + "-init")
+	if err != nil {
+		return nil, fmt.Errorf("Error getting container init rootfs %s from driver %s: %s", container.ID, container.runtime.driver, err)
+	}
+	return archive.ChangesDirs(cDir, initDir)
 }
 
 func linkLxcStart(root string) error {