Fix deadlock

msgbus.go

@@ -334,7 +334,7 @@ func (mb *MessageBus) readLog(f fs.FileInfo) error {
 		return fmt.Errorf("error opening log %s: %w", f, err)
 	}
 
-	t := mb.NewTopic(filepath.Base(f.Name()))
+	t := mb.newTopic(filepath.Base(f.Name()))
 	t.Created = f.ModTime()
 
 	index, err := l.LastIndex()
@@ -399,11 +399,7 @@ func (mb *MessageBus) Metrics() *Metrics {
 	return mb.metrics
 }
 
-// NewTopic ...
-func (mb *MessageBus) NewTopic(topic string) *Topic {
-	mb.Lock()
-	defer mb.Unlock()
-
+func (mb *MessageBus) newTopic(topic string) *Topic {
 	t, ok := mb.topics[topic]
 	if !ok {
 		t = &Topic{Name: topic, Created: time.Now()}
@@ -415,6 +411,14 @@ func (mb *MessageBus) NewTopic(topic string) *Topic {
 	return t
 }
 
+// NewTopic ...
+func (mb *MessageBus) NewTopic(topic string) *Topic {
+	mb.Lock()
+	defer mb.Unlock()
+
+	return mb.newTopic(topic)
+}
+
 // NewMessage ...
 func (mb *MessageBus) NewMessage(topic *Topic, payload []byte) Message {
 	defer func() {