localstore: fix data races on subscriptions

storage/localstore/subscription_pull.go

@@ -201,12 +201,12 @@ func (db *DB) LastPullSubscriptionBinID(bin uint8) (id uint64, err error) {
 // this function should be called.
 func (db *DB) triggerPullSubscriptions(bin uint8) {
 	db.pullTriggersMu.RLock()
+	defer db.pullTriggersMu.RUnlock()
+
 	triggers, ok := db.pullTriggers[bin]
-	db.pullTriggersMu.RUnlock()
 	if !ok {
 		return
 	}
-
 	for _, t := range triggers {
 		select {
 		case t <- struct{}{}:

storage/localstore/subscription_push.go

@@ -150,10 +150,9 @@ func (db *DB) SubscribePush(ctx context.Context) (c <-chan chunk.Chunk, stop fun
 // this function should be called.
 func (db *DB) triggerPushSubscriptions() {
 	db.pushTriggersMu.RLock()
-	triggers := db.pushTriggers
-	db.pushTriggersMu.RUnlock()
+	defer db.pushTriggersMu.RUnlock()
 
-	for _, t := range triggers {
+	for _, t := range db.pushTriggers {
 		select {
 		case t <- struct{}{}:
 		default: