@@ -200,11 +200,8 @@ func (devices *DeviceSet) removeMetadata(info *DevInfo) error {

 	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)

-	}

+// Given json data and file path, write it to disk

+func (devices *DeviceSet) writeMetaFile(jsonData []byte, filePath string) error {

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

 	if err != nil {

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

@@ -223,10 +220,23 @@ func (devices *DeviceSet) saveMetadata(info *DevInfo) error {

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

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

 	}

-	if err := os.Rename(tmpFile.Name(), devices.metadataFile(info)); err != nil {

+	if err := os.Rename(tmpFile.Name(), filePath); err != nil {

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

+	}

+	err = devices.writeMetaFile(jsonData, devices.metadataFile(info))

+	if err != nil {

+		return err

+	}

+

 	if devices.NewTransactionId != devices.TransactionId {

 		if err = setTransactionId(devices.getPoolDevName(), devices.TransactionId, devices.NewTransactionId); err != nil {

 			return fmt.Errorf("Error setting devmapper transition ID: %s", err)