volume: skip the proxy lookup error when the inbound request is gone

weed/server/volume_server_handlers_read.go

@@ -67,6 +67,9 @@ func (vs *VolumeServer) proxyReqToTargetServer(w http.ResponseWriter, r *http.Re
 	}
 	lookupResult, err := operation.LookupVolumeIdWithContext(r.Context(), vs.GetMaster, vs.grpcDialOption, volumeId.String())
 	if err != nil && vs.ReadMode == "proxy" {
+		if r.Context().Err() != nil {
+			return
+		}
 		glog.V(0).InfofCtx(r.Context(), "lookup error: %v %s", err, r.URL.Path)
 		InternalError(w, r, nil)
 		return

weed/server/volume_server_handlers_read_test.go

@@ -355,6 +355,18 @@ func TestProxyReqToTargetServerCancelsUpstreamBodyReadWithInboundRequest(t *test
 }
 
 func TestProxyReqToTargetServerDistinguishesLookupFailureFromNoLocation(t *testing.T) {
+	t.Run("cancelled request skips the lookup error response", func(t *testing.T) {
+		const volumeID = "849300107"
+		vs := newProxyTestVolumeServer(t, volumeID, nil, nil)
+		ctx, cancel := context.WithCancel(context.Background())
+		cancel()
+		w := httptest.NewRecorder()
+		vs.proxyReqToTargetServer(w, httptest.NewRequest(http.MethodGet, "/"+volumeID+",abcdef", nil).WithContext(ctx))
+		if w.Code != http.StatusOK {
+			t.Errorf("status %d, want no response written for a cancelled request", w.Code)
+		}
+	})
+
 	t.Run("master lookup failure is internal error", func(t *testing.T) {
 		const volumeID = "849300103"
 		vs := newProxyTestVolumeServer(t, volumeID, nil, status.Error(codes.Unavailable, "master unavailable"))