Extend tcmu dev_config to support optional device ID

Signed-off-by: Xun Chen <xunchen@hust.edu.cn>

Author: Xun Chen

cmd/overlaybd-attacher/main.go

@@ -59,6 +59,11 @@ func main() {
 						Usage:   "Enable verbose logging",
 						Aliases: []string{"v"},
 					},
+					&cli.BoolFlag{
+						Name:  "with-devid",
+						Usage: "Include devid in dev_config",
+						Value: false,
+					},
 				},
 				Action: attachAction,
 			},
@@ -96,6 +101,7 @@ func attachAction(c *cli.Context) error {
 	tenant := -1
 	configPath := c.String("config")
 	retryCount := 5
+	withDevID := c.Bool("with-devid")
 
 	if _, err := os.Stat(configPath); err != nil {
 		return fmt.Errorf("config file does not exist: %s: %w", configPath, err)
@@ -128,9 +134,9 @@ func attachAction(c *cli.Context) error {
 	}
 
 	ctx := context.Background()
-	params := snapshot.NewAttachDeviceParams(id, tenant, absConfigPath, resultFile)
+	params := snapshot.NewAttachDeviceParams(id, tenant, absConfigPath, resultFile, withDevID)
 
-	logrus.Infof("attaching device: id=%s, tenant=%d, config=%s, resultFile=%s", id, tenant, absConfigPath, resultFile)
+	logrus.Infof("attaching device: id=%s, tenant=%d, config=%s, resultFile=%s, withDevID=%t", id, tenant, absConfigPath, resultFile, withDevID)
 
 	var devName string
 	var lastErr error

pkg/snapshot/storage.go

@@ -78,14 +78,16 @@ type AttachDeviceParams struct {
 
 	configPath string // config.v1.json
 	resultFile string // init-debug.log
+	withDevID  bool
 }
 
-func NewAttachDeviceParams(id string, tenant int, configPath string, resultFile string) *AttachDeviceParams {
+func NewAttachDeviceParams(id string, tenant int, configPath string, resultFile string, withDevID bool) *AttachDeviceParams {
 	return &AttachDeviceParams{
 		id:         id,
 		tenant:     tenant,
 		configPath: configPath,
 		resultFile: resultFile,
+		withDevID:  withDevID,
 	}
 }
 
@@ -299,8 +301,14 @@ func AttachDevice(ctx context.Context, params *AttachDeviceParams) (devName stri
 		}
 	}()
 
-	if err = os.WriteFile(path.Join(targetPath, "control"), ([]byte)(fmt.Sprintf("dev_config=overlaybd/%s", configPath)), 0666); err != nil {
-		return devName, fmt.Errorf("failed to write target dev_config for %s: dev_config=overlaybd/%s: %w", targetPath, configPath, err)
+	if params.withDevID {
+		if err = os.WriteFile(path.Join(targetPath, "control"), ([]byte)(fmt.Sprintf("dev_config=overlaybd/%s;%s", configPath, snID)), 0666); err != nil {
+			return devName, fmt.Errorf("failed to write target dev_config for %s: dev_config=overlaybd/%s;%s: %w", targetPath, configPath, snID, err)
+		}
+	} else {
+		if err = os.WriteFile(path.Join(targetPath, "control"), ([]byte)(fmt.Sprintf("dev_config=overlaybd/%s", configPath)), 0666); err != nil {
+			return devName, fmt.Errorf("failed to write target dev_config for %s: dev_config=overlaybd/%s: %w", targetPath, configPath, err)
+		}
 	}
 
 	err = os.WriteFile(path.Join(targetPath, "control"), ([]byte)(fmt.Sprintf("max_data_area_mb=%d", obdMaxDataAreaMB)), 0666)
@@ -455,6 +463,7 @@ func (o *snapshotter) attachAndMountBlockDevice(ctx context.Context, snID string
 			o.tenant,
 			configPath,
 			o.overlaybdInitDebuglogPath(snID),
+			false,
 		),
 	)
 	if err != nil {

script/config.json

@@ -6,5 +6,8 @@
     "runtimeType": "containerd",
     "logReportCaller": false,
     "autoRemoveDev": false,
-    "mirrorRegistry": []
+    "mirrorRegistry": [],
+    "experimental": {
+        "enable": true
+    }
 }