*: set errcheck exclude func

.golangci.yml

@@ -198,6 +198,14 @@ linters-settings:
         severity: warning
         disabled: false
         exclude: [""]
+  errcheck:
+    exclude-functions:
+      - (*github.com/unrolled/render.Render).JSON
+      - (*github.com/unrolled/render.Render).Data
+      - (*github.com/unrolled/render.Render).Text
+      - (net/http.ResponseWriter).Write
+      - github.com/pingcap/log.Sync
+      - (github.com/tikv/pd/pkg/ratelimit.Runner).RunTask
 issues:
   exclude-rules:
     - path: (_test\.go|pkg/mock/.*\.go|tests/.*\.go)
@@ -207,6 +215,3 @@ issues:
     - path: (pd-analysis|pd-api-bench|pd-backup|pd-ctl|pd-heartbeat-bench|pd-recover|pd-simulator|pd-tso-bench|pd-ut|regions-dump|stores-dump)
       linters:
         - errcheck
-    - path: (pkg/schedule/schedulers/split_bucket.go|server/api/.*\.go|pkg/schedule/schedulers/balance_leader.go)
-      linters:
-        - errcheck

cmd/pd-server/main.go

@@ -235,9 +235,7 @@ func start(cmd *cobra.Command, args []string, services ...string) {
 		log.Fatal("initialize logger error", errs.ZapError(err))
 	}
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
+	defer log.Sync()
 	memory.InitMemoryHook()
 	if len(services) != 0 {
 		versioninfo.Log(server.APIServiceMode)
@@ -301,6 +299,6 @@ func start(cmd *cobra.Command, args []string, services ...string) {
 }
 
 func exit(code int) {
-	_ = log.Sync()
+	log.Sync()
 	os.Exit(code)
 }

pkg/autoscaling/handler.go

@@ -41,22 +41,22 @@ func NewHTTPHandler(svr *server.Server, rd *render.Render) *HTTPHandler {
 func (h *HTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	rc := h.svr.GetRaftCluster()
 	if rc == nil {
-		_ = h.rd.JSON(w, http.StatusInternalServerError, errs.ErrNotBootstrapped.FastGenByArgs().Error())
+		h.rd.JSON(w, http.StatusInternalServerError, errs.ErrNotBootstrapped.FastGenByArgs().Error())
 		return
 	}
 	data, err := io.ReadAll(r.Body)
 	r.Body.Close()
 	if err != nil {
-		_ = h.rd.JSON(w, http.StatusInternalServerError, err.Error())
+		h.rd.JSON(w, http.StatusInternalServerError, err.Error())
 		return
 	}
 
 	strategy := Strategy{}
 	if err := json.Unmarshal(data, &strategy); err != nil {
-		_ = h.rd.JSON(w, http.StatusBadRequest, err.Error())
+		h.rd.JSON(w, http.StatusBadRequest, err.Error())
 		return
 	}
 
 	plan := calculate(rc, h.svr.GetPDServerConfig(), &strategy)
-	_ = h.rd.JSON(w, http.StatusOK, plan)
+	h.rd.JSON(w, http.StatusOK, plan)
 }

pkg/core/region.go

@@ -747,7 +747,7 @@ func GenerateRegionGuideFunc(enableLog bool) RegionGuideFunc {
 		regionID := region.GetID()
 		if logRunner != nil {
 			debug = func(msg string, fields ...zap.Field) {
-				_ = logRunner.RunTask(
+				logRunner.RunTask(
 					regionID,
 					"DebugLog",
 					func() {
@@ -756,7 +756,7 @@ func GenerateRegionGuideFunc(enableLog bool) RegionGuideFunc {
 				)
 			}
 			info = func(msg string, fields ...zap.Field) {
-				_ = logRunner.RunTask(
+				logRunner.RunTask(
 					regionID,
 					"InfoLog",
 					func() {

pkg/mcs/metastorage/server/grpc_service.go

@@ -47,7 +47,7 @@ type dummyRestService struct{}
 
 func (dummyRestService) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
 	w.WriteHeader(http.StatusNotImplemented)
-	_, _ = w.Write([]byte("not implemented"))
+	w.Write([]byte("not implemented"))
 }
 
 // Service is the gRPC service for meta storage.

pkg/mcs/resourcemanager/server/grpc_service.go

@@ -49,7 +49,7 @@ type dummyRestService struct{}
 
 func (dummyRestService) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
 	w.WriteHeader(http.StatusNotImplemented)
-	_, _ = w.Write([]byte("not implemented"))
+	w.Write([]byte("not implemented"))
 }
 
 // Service is the gRPC service for resource manager.

pkg/mcs/resourcemanager/server/server.go

@@ -397,10 +397,7 @@ func CreateServerWrapper(cmd *cobra.Command, args []string) {
 		log.Fatal("initialize logger error", errs.ZapError(err))
 	}
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
-
+	log.Sync()
 	versioninfo.Log(serviceName)
 	log.Info("resource manager config", zap.Reflect("config", cfg))
 

pkg/mcs/resourcemanager/server/testutil.go

@@ -32,9 +32,7 @@ func NewTestServer(ctx context.Context, re *require.Assertions, cfg *Config) (*S
 	re.NoError(err)
 	log.ReplaceGlobals(cfg.Logger, cfg.LogProps)
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
+	log.Sync()
 
 	s := CreateServer(ctx, cfg)
 	if err = s.Run(); err != nil {

pkg/mcs/scheduling/server/cluster.go

@@ -624,7 +624,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 		// Due to some config changes need to update the region stats as well,
 		// so we do some extra checks here.
 		if hasRegionStats && c.regionStats.RegionStatsNeedUpdate(region) {
-			_ = ctx.TaskRunner.RunTask(
+			ctx.TaskRunner.RunTask(
 				regionID,
 				ratelimit.ObserveRegionStatsAsync,
 				func() {
@@ -636,7 +636,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 		}
 		// region is not updated to the subtree.
 		if origin.GetRef() < 2 {
-			_ = ctx.TaskRunner.RunTask(
+			ctx.TaskRunner.RunTask(
 				regionID,
 				ratelimit.UpdateSubTree,
 				func() {
@@ -660,7 +660,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 			tracer.OnSaveCacheFinished()
 			return err
 		}
-		_ = ctx.TaskRunner.RunTask(
+		ctx.TaskRunner.RunTask(
 			regionID,
 			ratelimit.UpdateSubTree,
 			func() {
@@ -669,7 +669,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 			ratelimit.WithRetained(retained),
 		)
 		tracer.OnUpdateSubTreeFinished()
-		_ = ctx.TaskRunner.RunTask(
+		ctx.TaskRunner.RunTask(
 			regionID,
 			ratelimit.HandleOverlaps,
 			func() {
@@ -679,7 +679,7 @@ func (c *Cluster) processRegionHeartbeat(ctx *core.MetaProcessContext, region *c
 	}
 	tracer.OnSaveCacheFinished()
 	// handle region stats
-	_ = ctx.TaskRunner.RunTask(
+	ctx.TaskRunner.RunTask(
 		regionID,
 		ratelimit.CollectRegionStatsAsync,
 		func() {

pkg/mcs/scheduling/server/grpc_service.go

@@ -53,7 +53,7 @@ type dummyRestService struct{}
 
 func (dummyRestService) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
 	w.WriteHeader(http.StatusNotImplemented)
-	_, _ = w.Write([]byte("not implemented"))
+	w.Write([]byte("not implemented"))
 }
 
 // ConfigProvider is used to get scheduling config from the given

pkg/mcs/scheduling/server/server.go

@@ -596,9 +596,7 @@ func CreateServerWrapper(cmd *cobra.Command, args []string) {
 		log.Fatal("initialize logger error", errs.ZapError(err))
 	}
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
+	log.Sync()
 
 	versioninfo.Log(serviceName)
 	log.Info("scheduling service config", zap.Reflect("config", cfg))

pkg/mcs/scheduling/server/testutil.go

@@ -33,10 +33,7 @@ func NewTestServer(ctx context.Context, re *require.Assertions, cfg *config.Conf
 	re.NoError(err)
 	log.ReplaceGlobals(cfg.Logger, cfg.LogProps)
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
-
+	log.Sync()
 	s := CreateServer(ctx, cfg)
 	if err = s.Run(); err != nil {
 		return nil, nil, err

pkg/mcs/tso/server/grpc_service.go

@@ -49,7 +49,7 @@ type dummyRestService struct{}
 
 func (dummyRestService) ServeHTTP(w http.ResponseWriter, _ *http.Request) {
 	w.WriteHeader(http.StatusNotImplemented)
-	_, _ = w.Write([]byte("not implemented"))
+	w.Write([]byte("not implemented"))
 }
 
 // ConfigProvider is used to get tso config from the given

pkg/mcs/tso/server/server.go

@@ -468,9 +468,7 @@ func CreateServerWrapper(cmd *cobra.Command, args []string) {
 		log.Fatal("initialize logger error", errs.ZapError(err))
 	}
 	// Flushing any buffered log entries
-	defer func() {
-		_ = log.Sync()
-	}()
+	log.Sync()
 
 	versioninfo.Log(serviceName)
 	log.Info("TSO service config", zap.Reflect("config", cfg))

pkg/mcs/utils/util.go

@@ -324,6 +324,6 @@ func StopGRPCServer(s server) {
 
 // Exit exits the program with the given code.
 func Exit(code int) {
-	_ = log.Sync()
+	log.Sync()
 	os.Exit(code)
 }

pkg/schedule/schedulers/balance_leader.go

@@ -86,10 +86,14 @@ func (conf *balanceLeaderSchedulerConfig) Update(data []byte) (int, any) {
 	newConfig, _ := json.Marshal(conf)
 	if !bytes.Equal(oldConfig, newConfig) {
 		if !conf.validateLocked() {
-			json.Unmarshal(oldConfig, conf)
+			if err := json.Unmarshal(oldConfig, conf); err != nil {
+				return http.StatusInternalServerError, err.Error()
+			}
 			return http.StatusBadRequest, "invalid batch size which should be an integer between 1 and 10"
 		}
-		conf.persistLocked()
+		if err := conf.persistLocked(); err != nil {
+			log.Warn("failed to save balance-leader-scheduler config", errs.ZapError(err))
+		}
 		log.Info("balance-leader-scheduler config is updated", zap.ByteString("old", oldConfig), zap.ByteString("new", newConfig))
 		return http.StatusOK, "Config is updated."
 	}
@@ -161,12 +165,12 @@ func (handler *balanceLeaderHandler) UpdateConfig(w http.ResponseWriter, r *http
 	data, _ := io.ReadAll(r.Body)
 	r.Body.Close()
 	httpCode, v := handler.config.Update(data)
-	_ = handler.rd.JSON(w, httpCode, v)
+	handler.rd.JSON(w, httpCode, v)
 }
 
 func (handler *balanceLeaderHandler) ListConfig(w http.ResponseWriter, _ *http.Request) {
 	conf := handler.config.Clone()
-	_ = handler.rd.JSON(w, http.StatusOK, conf)
+	handler.rd.JSON(w, http.StatusOK, conf)
 }
 
 type balanceLeaderScheduler struct {

pkg/schedule/schedulers/balance_witness.go

@@ -151,12 +151,12 @@ func (handler *balanceWitnessHandler) UpdateConfig(w http.ResponseWriter, r *htt
 	data, _ := io.ReadAll(r.Body)
 	r.Body.Close()
 	httpCode, v := handler.config.Update(data)
-	_ = handler.rd.JSON(w, httpCode, v)
+	handler.rd.JSON(w, httpCode, v)
 }
 
 func (handler *balanceWitnessHandler) ListConfig(w http.ResponseWriter, _ *http.Request) {
 	conf := handler.config.Clone()
-	_ = handler.rd.JSON(w, http.StatusOK, conf)
+	handler.rd.JSON(w, http.StatusOK, conf)
 }
 
 type balanceWitnessScheduler struct {

pkg/schedule/schedulers/evict_leader.go

@@ -373,7 +373,7 @@ func (handler *evictLeaderHandler) UpdateConfig(w http.ResponseWriter, r *http.R
 		if _, exists = handler.config.StoreIDWithRanges[id]; !exists {
 			if err := handler.config.cluster.PauseLeaderTransfer(id); err != nil {
 				handler.config.RUnlock()
-				_ = handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
+				handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
 				return
 			}
 		}
@@ -390,28 +390,28 @@ func (handler *evictLeaderHandler) UpdateConfig(w http.ResponseWriter, r *http.R
 
 	err := handler.config.BuildWithArgs(args)
 	if err != nil {
-		_ = handler.rd.JSON(w, http.StatusBadRequest, err.Error())
+		handler.rd.JSON(w, http.StatusBadRequest, err.Error())
 		return
 	}
 	err = handler.config.Persist()
 	if err != nil {
 		handler.config.removeStore(id)
-		_ = handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
+		handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
 		return
 	}
-	_ = handler.rd.JSON(w, http.StatusOK, "The scheduler has been applied to the store.")
+	handler.rd.JSON(w, http.StatusOK, "The scheduler has been applied to the store.")
 }
 
 func (handler *evictLeaderHandler) ListConfig(w http.ResponseWriter, _ *http.Request) {
 	conf := handler.config.Clone()
-	_ = handler.rd.JSON(w, http.StatusOK, conf)
+	handler.rd.JSON(w, http.StatusOK, conf)
 }
 
 func (handler *evictLeaderHandler) DeleteConfig(w http.ResponseWriter, r *http.Request) {
 	idStr := mux.Vars(r)["store_id"]
 	id, err := strconv.ParseUint(idStr, 10, 64)
 	if err != nil {
-		_ = handler.rd.JSON(w, http.StatusBadRequest, err.Error())
+		handler.rd.JSON(w, http.StatusBadRequest, err.Error())
 		return
 	}
 
@@ -422,26 +422,26 @@ func (handler *evictLeaderHandler) DeleteConfig(w http.ResponseWriter, r *http.R
 		err = handler.config.Persist()
 		if err != nil {
 			handler.config.resetStore(id, keyRanges)
-			_ = handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
+			handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
 			return
 		}
 		if last {
 			if err := handler.config.removeSchedulerCb(EvictLeaderName); err != nil {
 				if errors.ErrorEqual(err, errs.ErrSchedulerNotFound.FastGenByArgs()) {
-					_ = handler.rd.JSON(w, http.StatusNotFound, err.Error())
+					handler.rd.JSON(w, http.StatusNotFound, err.Error())
 				} else {
 					handler.config.resetStore(id, keyRanges)
-					_ = handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
+					handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
 				}
 				return
 			}
 			resp = lastStoreDeleteInfo
 		}
-		_ = handler.rd.JSON(w, http.StatusOK, resp)
+		handler.rd.JSON(w, http.StatusOK, resp)
 		return
 	}
 
-	_ = handler.rd.JSON(w, http.StatusNotFound, errs.ErrScheduleConfigNotExist.FastGenByArgs().Error())
+	handler.rd.JSON(w, http.StatusNotFound, errs.ErrScheduleConfigNotExist.FastGenByArgs().Error())
 }
 
 func newEvictLeaderHandler(config *evictLeaderSchedulerConfig) http.Handler {

pkg/schedule/schedulers/evict_slow_store.go

@@ -160,7 +160,7 @@ func (handler *evictSlowStoreHandler) UpdateConfig(w http.ResponseWriter, r *htt
 	}
 	recoveryDurationGapFloat, ok := input["recovery-duration"].(float64)
 	if !ok {
-		_ = handler.rd.JSON(w, http.StatusInternalServerError, errors.New("invalid argument for 'recovery-duration'").Error())
+		handler.rd.JSON(w, http.StatusInternalServerError, errors.New("invalid argument for 'recovery-duration'").Error())
 		return
 	}
 	handler.config.Lock()
@@ -169,17 +169,17 @@ func (handler *evictSlowStoreHandler) UpdateConfig(w http.ResponseWriter, r *htt
 	recoveryDurationGap := uint64(recoveryDurationGapFloat)
 	handler.config.RecoveryDurationGap = recoveryDurationGap
 	if err := handler.config.persistLocked(); err != nil {
-		_ = handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
+		handler.rd.JSON(w, http.StatusInternalServerError, err.Error())
 		handler.config.RecoveryDurationGap = prevRecoveryDurationGap
 		return
 	}
 	log.Info("evict-slow-store-scheduler update 'recovery-duration' - unit: s", zap.Uint64("prev", prevRecoveryDurationGap), zap.Uint64("cur", recoveryDurationGap))
-	_ = handler.rd.JSON(w, http.StatusOK, "Config updated.")
+	handler.rd.JSON(w, http.StatusOK, "Config updated.")
 }
 
 func (handler *evictSlowStoreHandler) ListConfig(w http.ResponseWriter, _ *http.Request) {
 	conf := handler.config.Clone()
-	_ = handler.rd.JSON(w, http.StatusOK, conf)
+	handler.rd.JSON(w, http.StatusOK, conf)
 }
 
 type evictSlowStoreScheduler struct {