@@ -106,7 +106,19 @@ func (devices *DeviceSet) loopbackDir() string {

 	return path.Join(devices.root, "devicemapper")

 }

-func (devices *DeviceSet) jsonFile() string {

+func (devices *DeviceSet) metadataDir() string {

+	return path.Join(devices.root, "metadata")

+}

+

+func (devices *DeviceSet) metadataFile(info *DevInfo) string {

+	file := info.Hash

+	if file == "" {

+		file = "base"

+	}

+	return path.Join(devices.metadataDir(), file)

+}

+

+func (devices *DeviceSet) oldMetadataFile() string {

 	return path.Join(devices.loopbackDir(), "json")

 }

@@ -161,14 +173,19 @@ func (devices *DeviceSet) allocateTransactionId() uint64 {

 	return devices.NewTransactionId

 }

-func (devices *DeviceSet) saveMetadata() error {

-	devices.devicesLock.Lock()

-	jsonData, err := json.Marshal(devices.MetaData)

-	devices.devicesLock.Unlock()

+func (devices *DeviceSet) removeMetadata(info *DevInfo) error {

+	if err := osRemoveAll(devices.metadataFile(info)); err != nil {

+		return fmt.Errorf("Error removing metadata file %s: %s", devices.metadataFile(info), err)

+	}

+	return nil

+}

+

+func (devices *DeviceSet) saveMetadata(info *DevInfo) error {

+	jsonData, err := json.Marshal(info)

 	if err != nil {

 		return fmt.Errorf("Error encoding metadata to json: %s", err)

 	}

-	tmpFile, err := ioutil.TempFile(filepath.Dir(devices.jsonFile()), ".json")

+	tmpFile, err := ioutil.TempFile(devices.metadataDir(), ".tmp")

 	if err != nil {

 		return fmt.Errorf("Error creating metadata file: %s", err)

 	}

@@ -186,7 +203,7 @@ func (devices *DeviceSet) saveMetadata() error {

 	if err := tmpFile.Close(); err != nil {

 		return fmt.Errorf("Error closing metadata file %s: %s", tmpFile.Name(), err)

 	}

-	if err := osRename(tmpFile.Name(), devices.jsonFile()); err != nil {

+	if err := osRename(tmpFile.Name(), devices.metadataFile(info)); err != nil {

 		return fmt.Errorf("Error committing metadata file %s: %s", tmpFile.Name(), err)

 	}

@@ -204,7 +221,12 @@ func (devices *DeviceSet) lookupDevice(hash string) (*DevInfo, error) {

 	defer devices.devicesLock.Unlock()

 	info := devices.Devices[hash]

 	if info == nil {

-		return nil, fmt.Errorf("Unknown device %s", hash)

+		info = devices.loadMetadata(hash)

+		if info == nil {

+			return nil, fmt.Errorf("Unknown device %s", hash)

+		}

+

+		devices.Devices[hash] = info

 	}

 	return info, nil

 }

@@ -224,7 +246,7 @@ func (devices *DeviceSet) registerDevice(id int, hash string, size uint64) (*Dev

 	devices.Devices[hash] = info

 	devices.devicesLock.Unlock()

-	if err := devices.saveMetadata(); err != nil {

+	if err := devices.saveMetadata(info); err != nil {

 		// Try to remove unused device

 		devices.devicesLock.Lock()

 		delete(devices.Devices, hash)

@@ -259,9 +281,7 @@ func (devices *DeviceSet) createFilesystem(info *DevInfo) error {

 	return nil

 }

-func (devices *DeviceSet) loadMetaData() error {

-	utils.Debugf("loadMetadata()")

-	defer utils.Debugf("loadMetadata END")

+func (devices *DeviceSet) initMetaData() error {

 	_, _, _, params, err := getStatus(devices.getPoolName())

 	if err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

@@ -274,35 +294,64 @@ func (devices *DeviceSet) loadMetaData() error {

 	}

 	devices.NewTransactionId = devices.TransactionId

-	jsonData, err := ioutil.ReadFile(devices.jsonFile())

+	// Migrate old metadatafile

+

+	jsonData, err := ioutil.ReadFile(devices.oldMetadataFile())

 	if err != nil && !osIsNotExist(err) {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

-	devices.MetaData.Devices = make(map[string]*DevInfo)

 	if jsonData != nil {

-		if err := json.Unmarshal(jsonData, &devices.MetaData); err != nil {

+		m := MetaData{Devices: make(map[string]*DevInfo)}

+

+		if err := json.Unmarshal(jsonData, &m); err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

 			return err

 		}

-	}

-	for hash, d := range devices.Devices {

-		d.Hash = hash

-		d.devices = devices

+		for hash, info := range m.Devices {

+			info.Hash = hash

-		// If the transaction id is larger than the actual one we lost the device due to some crash

-		if d.TransactionId > devices.TransactionId {

-			utils.Debugf("Removing lost device %s with id %d", hash, d.TransactionId)

-			delete(devices.Devices, hash)

+			// If the transaction id is larger than the actual one we lost the device due to some crash

+			if info.TransactionId <= devices.TransactionId {

+				devices.saveMetadata(info)

+			}

+		}

+		if err := osRename(devices.oldMetadataFile(), devices.oldMetadataFile()+".migrated"); err != nil {

+			return err

 		}

+

 	}

+

 	return nil

 }

+func (devices *DeviceSet) loadMetadata(hash string) *DevInfo {

+	info := &DevInfo{Hash: hash, devices: devices}

+

+	jsonData, err := ioutil.ReadFile(devices.metadataFile(info))

+	if err != nil {

+		return nil

+	}

+

+	if err := json.Unmarshal(jsonData, &info); err != nil {

+		return nil

+	}

+

+	fmt.Printf("Loaded metadata %v\n", info)

+

+	// If the transaction id is larger than the actual one we lost the device due to some crash

+	if info.TransactionId > devices.TransactionId {

+		return nil

+	}

+

+	return info

+}

+

 func (devices *DeviceSet) setupBaseImage() error {

 	oldInfo, _ := devices.lookupDevice("")

+	utils.Debugf("oldInfo: %p", oldInfo)

 	if oldInfo != nil && oldInfo.Initialized {

 		return nil

 	}

@@ -349,7 +398,7 @@ func (devices *DeviceSet) setupBaseImage() error {

 	}

 	info.Initialized = true

-	if err = devices.saveMetadata(); err != nil {

+	if err = devices.saveMetadata(info); err != nil {

 		info.Initialized = false

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

@@ -457,29 +506,7 @@ func (devices *DeviceSet) ResizePool(size int64) error {

 func (devices *DeviceSet) initDevmapper(doInit bool) error {

 	logInit(devices)

-	// Make sure the sparse images exist in <root>/devicemapper/data and

-	// <root>/devicemapper/metadata

-

-	hasData := devices.hasImage("data")

-	hasMetadata := devices.hasImage("metadata")

-

-	if !doInit && !hasData {

-		return errors.New("Loopback data file not found")

-	}

-

-	if !doInit && !hasMetadata {

-		return errors.New("Loopback metadata file not found")

-	}

-

-	createdLoopback := !hasData || !hasMetadata

-	data, err := devices.ensureImage("data", DefaultDataLoopbackSize)

-	if err != nil {

-		utils.Debugf("Error device ensureImage (data): %s\n", err)

-		return err

-	}

-	metadata, err := devices.ensureImage("metadata", DefaultMetaDataLoopbackSize)

-	if err != nil {

-		utils.Debugf("Error device ensureImage (metadata): %s\n", err)

+	if err := osMkdirAll(devices.metadataDir(), 0700); err != nil && !osIsExist(err) {

 		return err

 	}

@@ -512,10 +539,38 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {

 	// so we add this badhack to make sure it closes itself

 	setCloseOnExec("/dev/mapper/control")

+	// Make sure the sparse images exist in <root>/devicemapper/data and

+	// <root>/devicemapper/metadata

+

+	createdLoopback := false

+

 	// If the pool doesn't exist, create it

 	if info.Exists == 0 {

 		utils.Debugf("Pool doesn't exist. Creating it.")

+		hasData := devices.hasImage("data")

+		hasMetadata := devices.hasImage("metadata")

+

+		if !doInit && !hasData {

+			return errors.New("Loopback data file not found")

+		}

+

+		if !doInit && !hasMetadata {

+			return errors.New("Loopback metadata file not found")

+		}

+

+		createdLoopback = !hasData || !hasMetadata

+		data, err := devices.ensureImage("data", DefaultDataLoopbackSize)

+		if err != nil {

+			utils.Debugf("Error device ensureImage (data): %s\n", err)

+			return err

+		}

+		metadata, err := devices.ensureImage("metadata", DefaultMetaDataLoopbackSize)

+		if err != nil {

+			utils.Debugf("Error device ensureImage (metadata): %s\n", err)

+			return err

+		}

+

 		dataFile, err := attachLoopDevice(data)

 		if err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

@@ -537,9 +592,9 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {

 	}

 	// If we didn't just create the data or metadata image, we need to

-	// load the metadata from the existing file.

+	// load the transaction id and migrate old metadata

 	if !createdLoopback {

-		if err = devices.loadMetaData(); err != nil {

+		if err = devices.initMetaData(); err != nil {

 			utils.Debugf("\n--->Err: %s\n", err)

 			return err

 		}

@@ -608,14 +663,6 @@ func (devices *DeviceSet) deleteDevice(info *DevInfo) error {

 		}

 	}

-	if info.Initialized {

-		info.Initialized = false

-		if err := devices.saveMetadata(); err != nil {

-			utils.Debugf("Error saving meta data: %s\n", err)

-			return err

-		}

-	}

-

 	if err := deleteDevice(devices.getPoolDevName(), info.DeviceId); err != nil {

 		utils.Debugf("Error deleting device: %s\n", err)

 		return err

@@ -626,11 +673,11 @@ func (devices *DeviceSet) deleteDevice(info *DevInfo) error {

 	delete(devices.Devices, info.Hash)

 	devices.devicesLock.Unlock()

-	if err := devices.saveMetadata(); err != nil {

+	if err := devices.removeMetadata(info); err != nil {

 		devices.devicesLock.Lock()

 		devices.Devices[info.Hash] = info

 		devices.devicesLock.Unlock()

-		utils.Debugf("Error saving meta data: %s\n", err)

+		utils.Debugf("Error removing meta data: %s\n", err)

 		return err

 	}

@@ -873,7 +920,7 @@ func (devices *DeviceSet) MountDevice(hash, path string, mountLabel string) erro

 	info.mountCount = 1

 	info.mountPath = path

-	return devices.setInitialized(info)

+	return nil

 }

 func (devices *DeviceSet) UnmountDevice(hash string) error {

@@ -924,14 +971,6 @@ func (devices *DeviceSet) HasDevice(hash string) bool {

 	return info != nil

 }

-func (devices *DeviceSet) HasInitializedDevice(hash string) bool {

-	devices.Lock()

-	defer devices.Unlock()

-

-	info, _ := devices.lookupDevice(hash)

-	return info != nil && info.Initialized

-}

-

 func (devices *DeviceSet) HasActivatedDevice(hash string) bool {

 	info, _ := devices.lookupDevice(hash)

 	if info == nil {

@@ -948,17 +987,6 @@ func (devices *DeviceSet) HasActivatedDevice(hash string) bool {

 	return devinfo != nil && devinfo.Exists != 0

 }

-func (devices *DeviceSet) setInitialized(info *DevInfo) error {

-	info.Initialized = true

-	if err := devices.saveMetadata(); err != nil {

-		info.Initialized = false

-		utils.Debugf("\n--->Err: %s\n", err)

-		return err

-	}

-

-	return nil

-}

-

 func (devices *DeviceSet) List() []string {

 	devices.Lock()

 	defer devices.Unlock()

@@ -820,10 +820,6 @@ func TestGetReturnsValidDevice(t *testing.T) {

 	if !d.HasActivatedDevice("1") {

 		t.Fatalf("Expected id 1 to be activated")

 	}

-

-	if !d.HasInitializedDevice("1") {

-		t.Fatalf("Expected id 1 to be initialized")

-	}

 }

 func TestDriverGetSize(t *testing.T) {