Merge pull request #1371 from adrianreber/master

checkpoint: check if system supports pre-dumping

libcontainer/container_linux.go

@@ -535,6 +535,56 @@ func (c *linuxContainer) NotifyMemoryPressure(level PressureLevel) (<-chan struc
 	return notifyMemoryPressure(c.cgroupManager.GetPaths(), level)
 }
 
+var criuFeatures *criurpc.CriuFeatures
+
+func (c *linuxContainer) checkCriuFeatures(criuOpts *CriuOpts, rpcOpts *criurpc.CriuOpts, criuFeat *criurpc.CriuFeatures) error {
+
+	var t criurpc.CriuReqType
+	t = criurpc.CriuReqType_FEATURE_CHECK
+
+	if err := c.checkCriuVersion("1.8"); err != nil {
+		// Feature checking was introduced with CRIU 1.8.
+		// Ignore the feature check if an older CRIU version is used
+		// and just act as before.
+		// As all automated PR testing is done using CRIU 1.7 this
+		// code will not be tested by automated PR testing.
+		return nil
+	}
+
+	// make sure the features we are looking for are really not from
+	// some previous check
+	criuFeatures = nil
+
+	req := &criurpc.CriuReq{
+		Type: &t,
+		// Theoretically this should not be necessary but CRIU
+		// segfaults if Opts is empty.
+		// Fixed in CRIU  2.12
+		Opts:     rpcOpts,
+		Features: criuFeat,
+	}
+
+	err := c.criuSwrk(nil, req, criuOpts, false)
+	if err != nil {
+		logrus.Debugf("%s", err)
+		return fmt.Errorf("CRIU feature check failed")
+	}
+
+	logrus.Debugf("Feature check says: %s", criuFeatures)
+	missingFeatures := false
+
+	if *criuFeat.MemTrack && !*criuFeatures.MemTrack {
+		missingFeatures = true
+		logrus.Debugf("CRIU does not support MemTrack")
+	}
+
+	if missingFeatures {
+		return fmt.Errorf("CRIU is missing features")
+	}
+
+	return nil
+}
+
 // checkCriuVersion checks Criu version greater than or equal to minVersion
 func (c *linuxContainer) checkCriuVersion(minVersion string) error {
 	var x, y, z, versionReq int
@@ -717,6 +767,14 @@ func (c *linuxContainer) Checkpoint(criuOpts *CriuOpts) error {
 
 	var t criurpc.CriuReqType
 	if criuOpts.PreDump {
+		feat := criurpc.CriuFeatures{
+			MemTrack: proto.Bool(true),
+		}
+
+		if err := c.checkCriuFeatures(criuOpts, &rpcOpts, &feat); err != nil {
+			return err
+		}
+
 		t = criurpc.CriuReqType_PRE_DUMP
 	} else {
 		t = criurpc.CriuReqType_DUMP
@@ -1018,16 +1076,21 @@ func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *
 	}
 
 	logrus.Debugf("Using CRIU in %s mode", req.GetType().String())
-	val := reflect.ValueOf(req.GetOpts())
+	// In the case of criurpc.CriuReqType_FEATURE_CHECK req.GetOpts()
-	v := reflect.Indirect(val)
+	// should be empty. For older CRIU versions it still will be
-	for i := 0; i < v.NumField(); i++ {
+	// available but empty.
-		st := v.Type()
+	if req.GetType() != criurpc.CriuReqType_FEATURE_CHECK {
-		name := st.Field(i).Name
+		val := reflect.ValueOf(req.GetOpts())
-		if strings.HasPrefix(name, "XXX_") {
+		v := reflect.Indirect(val)
-			continue
+		for i := 0; i < v.NumField(); i++ {
+			st := v.Type()
+			name := st.Field(i).Name
+			if strings.HasPrefix(name, "XXX_") {
+				continue
+			}
+			value := val.MethodByName("Get" + name).Call([]reflect.Value{})
+			logrus.Debugf("CRIU option %s with value %v", name, value[0])
 		}
-		value := val.MethodByName("Get" + name).Call([]reflect.Value{})
-		logrus.Debugf("CRIU option %s with value %v", name, value[0])
 	}
 	data, err := proto.Marshal(req)
 	if err != nil {
@@ -1063,6 +1126,10 @@ func (c *linuxContainer) criuSwrk(process *Process, req *criurpc.CriuReq, opts *
 
 		t := resp.GetType()
 		switch {
+		case t == criurpc.CriuReqType_FEATURE_CHECK:
+			logrus.Debugf("Feature check says: %s", resp)
+			criuFeatures = resp.GetFeatures()
+			break
 		case t == criurpc.CriuReqType_NOTIFY:
 			if err := c.criuNotifications(resp, process, opts, extFds); err != nil {
 				return err