prevents error using freed slice in pool

pkg/ingester/ingester.go

@@ -289,6 +289,8 @@ func (i *Ingester) Push(ctx old_ctx.Context, req *client.WriteRequest) (*client.
 		return i.v2Push(ctx, req)
 	}
 
+	defer client.ReuseSlice(req.Timeseries)
+
 	userID, err := user.ExtractOrgID(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("no user id")
@@ -311,7 +313,6 @@ func (i *Ingester) Push(ctx old_ctx.Context, req *client.WriteRequest) (*client.
 			return nil, wrapWithUser(err, userID)
 		}
 	}
-	client.ReuseSlice(req.Timeseries)
 
 	if lastPartialErr != nil {
 		return &client.WriteResponse{}, lastPartialErr.WrapWithUser(userID).WrappedError()

pkg/ingester/ingester_v2.go

@@ -82,6 +82,8 @@ func NewV2(cfg Config, clientConfig client.Config, limits *validation.Overrides,
 func (i *Ingester) v2Push(ctx old_ctx.Context, req *client.WriteRequest) (*client.WriteResponse, error) {
 	var lastPartialErr error
 
+	defer client.ReuseSlice(req.Timeseries)
+
 	userID, err := user.ExtractOrgID(ctx)
 	if err != nil {
 		return nil, fmt.Errorf("no user id")
@@ -157,8 +159,6 @@ func (i *Ingester) v2Push(ctx old_ctx.Context, req *client.WriteRequest) (*clien
 	i.metrics.ingestedSamples.Add(float64(succeededSamplesCount))
 	i.metrics.ingestedSamplesFail.Add(float64(failedSamplesCount))
 
-	client.ReuseSlice(req.Timeseries)
-
 	if lastPartialErr != nil {
 		return &client.WriteResponse{}, httpgrpc.Errorf(http.StatusBadRequest, wrapWithUser(lastPartialErr, userID).Error())
 	}