WIP

graphdriver/aufs/aufs.go

@@ -95,18 +95,25 @@ func supportsAufs() error {
 	return fmt.Errorf("AUFS was not found in /proc/filesystems")
 }
 
-func (a *AufsDriver) rootPath() string {
+func (a AufsDriver) rootPath() string {
 	return a.root
 }
 
-func (a *AufsDriver) String() string {
+func (AufsDriver) String() string {
 	return "aufs"
 }
 
-func (d *AufsDriver) Status() [][2]string {
+func (AufsDriver) Status() [][2]string {
 	return nil
 }
 
+func (a AufsDriver) Exists(id string) bool {
+	if _, err := os.Lstat(path.Join(a.rootPath(), "diff", id)); err != nil {
+		return false
+	}
+	return true
+}
+
 // Three folders are created for each id
 // mnt, layers, and diff
 func (a *AufsDriver) Create(id, parent string) error {

graphdriver/aufs/migrate.go

@@ -0,0 +1,32 @@
+package aufs
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+func exists(pth string) bool {
+	if _, err := os.Stat(pth); err != nil {
+		return false
+	}
+	return true
+}
+
+func (a *AufsDriver) Migrate(pth string) error {
+	fis, err := ioutil.ReadDir(pth)
+	if err != nil {
+		return err
+	}
+	for _, fi := range fis {
+		if fi.IsDir() && exists(path.Join(pth, fi.Name(), "layer")) && !a.Exists(fi.Name()) {
+			if err := os.Symlink(path.Join(pth, fi.Name(), "layer"), path.Join(a.rootPath(), "diff", fi.Name())); err != nil {
+				return err
+			}
+			if err := a.Create(fi.Name(), ""); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

runtime.go

@@ -8,7 +8,7 @@ import (
 	"github.com/dotcloud/docker/archive"
 	"github.com/dotcloud/docker/graphdb"
 	"github.com/dotcloud/docker/graphdriver"
-	_ "github.com/dotcloud/docker/graphdriver/aufs"
+	"github.com/dotcloud/docker/graphdriver/aufs"
 	_ "github.com/dotcloud/docker/graphdriver/devmapper"
 	_ "github.com/dotcloud/docker/graphdriver/dummy"
 	"github.com/dotcloud/docker/utils"
@@ -629,6 +629,12 @@ func NewRuntimeFromDirectory(config *DaemonConfig) (*Runtime, error) {
 		return nil, err
 	}
 
+	if ad, ok := driver.(*aufs.AufsDriver); ok {
+		if err := ad.Migrate(path.Join(config.Root, "graph")); err != nil {
+			return nil, err
+		}
+	}
+
 	if err := linkLxcStart(config.Root); err != nil {
 		return nil, err
 	}