enhance: [10kcp] Optimize GetLocalDiskSize and segment loader mutex (#38601)

fix of pr: https://github.com/milvus-io/milvus/pull/38599

---------

Signed-off-by: bigsheeper <yihao.dai@zilliz.com>

internal/querynodev2/segments/disk_usage_fetcher.go

@@ -65,14 +65,12 @@ func (d *diskUsageFetcher) Start() {
 	interval := paramtable.Get().QueryNodeCfg.DiskSizeFetchInterval.GetAsDuration(time.Second)
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()
-	go func() {
-		for {
-			select {
-			case <-d.ctx.Done():
-				return
-			case <-ticker.C:
-				d.fetch()
-			}
+	for {
+		select {
+		case <-d.ctx.Done():
+			return
+		case <-ticker.C:
+			d.fetch()
 		}
-	}()
+	}
 }

internal/querynodev2/segments/segment_loader.go

@@ -567,7 +567,7 @@ func NewLoader(
 
 	log.Info("SegmentLoader created", zap.Int("ioPoolSize", ioPoolSize))
 	duf := NewDiskUsageFetcher(ctx)
-	duf.Start()
+	go duf.Start()
 
 	loader := &segmentLoader{
 		manager:                   manager,