block uploader snapshot implementation

Signed-off-by: Lyndon-Li <lyonghui@vmware.com>

pkg/uploader/provider/block.go

@@ -105,7 +105,7 @@ func (bp *blockProvider) RunBackup(
 	uploaderCfg map[string]string,
 	updater uploader.ProgressUpdater) (string, bool, int64, int64, error) {
 	if updater == nil {
-		return "", false, 0, 0, errors.New("Need to initial backup progress updater first")
+		return "", false, 0, 0, errors.New("backup progress updater is invalid")
 	}
 
 	if path == "" {
@@ -160,6 +160,10 @@ func (bp *blockProvider) RunRestore(
 	volMode uploader.PersistentVolumeMode,
 	uploaderCfg map[string]string,
 	updater uploader.ProgressUpdater) (int64, error) {
+	if updater == nil {
+		return 0, errors.New("restore progress updater is invalid")
+	}
+
 	log := bp.log.WithFields(logrus.Fields{
 		"snapshotID": snapshotID,
 		"volumePath": volumePath,

pkg/uploader/provider/block_test.go

@@ -224,7 +224,7 @@ func TestBlockProviderRunBackup(t *testing.T) {
 			path:           "/dev/sda",
 			updater:        nil,
 			expectError:    true,
-			expectedErrStr: "Need to initial backup progress updater first",
+			expectedErrStr: "backup progress updater is invalid",
 			skipMock:       true,
 		},
 		{
@@ -385,6 +385,12 @@ func TestBlockProviderRunRestore(t *testing.T) {
 		expectedErrStr  string
 		checkCaptures   func(*testing.T, string, string)
 	}{
+		{
+			name:           "nil updater returns error",
+			updater:        nil,
+			expectError:    true,
+			expectedErrStr: "restore progress updater is invalid",
+		},
 		{
 			name:            "success returns size and updates progress",
 			snapshotID:      "snap-001",