fixing possible race.

src/dbnode/storage/bootstrap/bootstrapper/commitlog/source.go

@@ -114,7 +114,6 @@ type readSeriesBlocksWorker struct {
 }
 
 func (w *readSeriesBlocksWorker) readSeriesBlocks() error {
-	defer close(w.dataCh)
 	for {
 		id, tags, data, expectedChecksum, err := w.reader.Read()
 		if err != nil && !errors.Is(err, io.EOF) {
@@ -940,12 +939,23 @@ func (s *commitLogSource) bootstrapShardBlockSnapshot(
 	}
 
 	go func() {
-		if workerErr = worker.readSeriesBlocks(); workerErr != nil {
-			s.log.Error("series read blocks error", zap.Error(workerErr))
+		if err := worker.readSeriesBlocks(); err != nil {
+			s.log.Error("series read blocks error", zap.Error(err))
+			workerErr = err
 		}
+		close(worker.dataCh)
 	}()
 
-	for seriesBlock := range worker.dataCh {
+	if err := s.loadBlocks(worker.dataCh, writeType); err != nil {
+		close(worker.dataCh)
+		return err
+	}
+
+	return workerErr
+}
+
+func (s *commitLogSource) loadBlocks(dataCh <-chan seriesBlock, writeType series.WriteType) error {
+	for seriesBlock := range dataCh {
 		// Load into series.
 		seriesRef, err := seriesBlock.resolver.SeriesRef()
 		if err != nil {
@@ -956,8 +966,7 @@ func (s *commitLogSource) bootstrapShardBlockSnapshot(
 			return err
 		}
 	}
-
-	return workerErr
+	return nil
 }
 
 func (s *commitLogSource) mostRecentSnapshotByBlockShard(

src/dbnode/storage/bootstrap/types.go

@@ -279,7 +279,7 @@ type NamespaceDataAccumulator interface {
 
 // CheckoutSeriesResult is the result of a checkout series operation.
 type CheckoutSeriesResult struct {
-	// Resolver is the series for the checkout operation.
+	// Resolver is the series read write ref resolver.
 	Resolver SeriesRefResolver
 	// Shard is the shard for the series.
 	Shard uint32