updateMapMetric: close maps on errors

[ upstream commit 0ffc6c6 ]

create updateMapMetric() function to update the metrics for a single
map. This allows to use defer() to do proper cleanup in case of an error.

Signed-off-by: Kornilios Kourtis <[email protected]>

pkg/observer/observer_stats.go

@@ -47,38 +47,43 @@ func (s *statValue) DeepCopyMapValue() bpf.MapValue {
 	return v
 }
 
-func (k *Observer) startUpdateMapMetrics() {
-	update := func() {
-		for _, m := range sensors.AllMaps {
-			pin := filepath.Join(option.Config.MapDir, m.Name)
-			pinStats := pin + "_stats"
+func updateMapMetric(name string) {
+	pin := filepath.Join(option.Config.MapDir, name)
+	pinStats := pin + "_stats"
 
-			mapLinkStats, err := bpf.OpenMap(pinStats)
-			if err != nil {
-				continue
-			}
-			mapLink, err := bpf.OpenMap(pin)
-			if err != nil {
-				continue
-			}
+	mapLinkStats, err := bpf.OpenMap(pinStats)
+	if err != nil {
+		return
+	}
+	defer mapLinkStats.Close()
+	mapLink, err := bpf.OpenMap(pin)
+	if err != nil {
+		return
+	}
+	defer mapLink.Close()
 
-			zeroKey := &statKey{}
-			value, err := mapLinkStats.Lookup(zeroKey)
-			if err != nil {
-				continue
-			}
+	zeroKey := &statKey{}
+	value, err := mapLinkStats.Lookup(zeroKey)
+	if err != nil {
+		return
+	}
 
-			v, ok := value.DeepCopyMapValue().(*statValue)
-			if !ok {
-				continue
-			}
-			sum := int64(0)
-			for cpu := int(0); cpu < runtime.NumCPU(); cpu++ {
-				sum += v.Value[cpu]
-			}
-			mapmetrics.MapSizeSet(m.Name, int(mapLink.MapInfo.MaxEntries), float64(sum))
-			mapLink.Close()
-			mapLinkStats.Close()
+	v, ok := value.DeepCopyMapValue().(*statValue)
+	if !ok {
+		return
+	}
+
+	sum := int64(0)
+	for cpu := int(0); cpu < runtime.NumCPU(); cpu++ {
+		sum += v.Value[cpu]
+	}
+	mapmetrics.MapSizeSet(name, int(mapLink.MapInfo.MaxEntries), float64(sum))
+}
+
+func (k *Observer) startUpdateMapMetrics() {
+	update := func() {
+		for _, m := range sensors.AllMaps {
+			updateMapMetric(m.Name)
 		}
 	}