worker(dm): fix deadlock (#5427)

close #5089
pingcap · May 16, 2022 · 4a99270 · 4a99270
1 parent 76e95e2
commit 4a99270
Showing 1 changed file with 11 additions and 6 deletions.
diff --git a/dm/dm/worker/source_worker.go b/dm/dm/worker/source_worker.go
@@ -183,7 +183,7 @@ func (w *SourceWorker) Start() {
 					continue
 				}
 			}
-			if err2 := w.updateSourceStatus(w.ctx); err2 != nil {
+			if err2 := w.updateSourceStatus(w.ctx, true); err2 != nil {
 				if terror.ErrNoMasterStatus.Equal(err2) {
 					w.l.Warn("This source's bin_log is OFF, so it only supports full_mode.", zap.String("sourceID", w.cfg.SourceID), zap.Error(err2))
 				} else {
@@ -248,11 +248,16 @@ func (w *SourceWorker) Stop(graceful bool) {
 }
 
 // updateSourceStatus updates w.sourceStatus.
-func (w *SourceWorker) updateSourceStatus(ctx context.Context) error {
+func (w *SourceWorker) updateSourceStatus(ctx context.Context, needLock bool) error {
+	var cfg *config.SourceConfig
+	if needLock {
+		w.RLock()
+		cfg = w.cfg
+		w.RUnlock()
+	} else {
+		cfg = w.cfg
+	}
 	w.sourceDBMu.Lock()
-	w.RLock()
-	cfg := w.cfg
-	w.RUnlock()
 	if w.sourceDB == nil {
 		var err error
 		w.sourceDB, err = conn.DefaultDBProvider.Apply(&cfg.DecryptPassword().From)
@@ -669,7 +674,7 @@ func (w *SourceWorker) QueryStatus(ctx context.Context, name string) ([]*pb.SubT
 		relayStatus  *pb.RelayStatus
 	)
 
-	if err := w.updateSourceStatus(ctx); err != nil {
+	if err := w.updateSourceStatus(ctx, false); err != nil {
 		if terror.ErrNoMasterStatus.Equal(err) {
 			w.l.Warn("This source's bin_log is OFF, so it only supports full_mode.", zap.String("sourceID", w.cfg.SourceID), zap.Error(err))
 		} else {