From 803ca3c9589ce11d1799ded47bce25c58f179d85 Mon Sep 17 00:00:00 2001
From: Konstantin Lebedev <9497591+kmlebedev@users.noreply.github.com>
Date: Thu, 1 Sep 2022 21:01:47 +0500
Subject: [PATCH] avoid data race on
 doSubscribeToOneFiler/ma.filer.UniqueFilerEpoch (#3566)

https://github.com/seaweedfs/seaweedfs/issues/3565
---
 weed/filer/meta_aggregator.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/weed/filer/meta_aggregator.go b/weed/filer/meta_aggregator.go
index d384c2c38..fbc163442 100644
--- a/weed/filer/meta_aggregator.go
+++ b/weed/filer/meta_aggregator.go
@@ -9,6 +9,7 @@ import (
 	"io"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"google.golang.org/grpc"
@@ -194,13 +195,13 @@ func (ma *MetaAggregator) doSubscribeToOneFiler(f *Filer, self pb.ServerAddress,
 	err = pb.WithFilerClient(true, peer, ma.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error {
 		ctx, cancel := context.WithCancel(context.Background())
 		defer cancel()
-		ma.filer.UniqueFilerEpoch++
+		atomic.AddInt32(&ma.filer.UniqueFilerEpoch, 1)
 		stream, err := client.SubscribeLocalMetadata(ctx, &filer_pb.SubscribeMetadataRequest{
 			ClientName:  "filer:" + string(self),
 			PathPrefix:  "/",
 			SinceNs:     lastTsNs,
 			ClientId:    ma.filer.UniqueFilerId,
-			ClientEpoch: ma.filer.UniqueFilerEpoch,
+			ClientEpoch: atomic.LoadInt32(&ma.filer.UniqueFilerEpoch),
 		})
 		if err != nil {
 			return fmt.Errorf("subscribe: %v", err)