[master] refactor HasGrowRequest to atomic bool (#5782)

refactor HasGrowRequest to atomit bool

weed/topology/volume_layout.go

@@ -106,7 +106,7 @@ func (v *volumesBinaryState) copyState(list *VolumeLocationList) copyState {
 
 // mapping from volume to its locations, inverted from server to volume
 type VolumeLayout struct {
-	growRequestCount int32
+	growRequest      atomic.Bool
 	rp               *super_block.ReplicaPlacement
 	ttl              *needle.TTL
 	diskType         types.DiskType
@@ -345,13 +345,13 @@ func (vl *VolumeLayout) PickForWrite(count uint64, option *VolumeGrowOption) (vi
 }
 
 func (vl *VolumeLayout) HasGrowRequest() bool {
-	return atomic.LoadInt32(&vl.growRequestCount) > 0
+	return vl.growRequest.Load()
 }
 func (vl *VolumeLayout) AddGrowRequest() {
-	atomic.AddInt32(&vl.growRequestCount, 1)
+	vl.growRequest.Store(true)
 }
 func (vl *VolumeLayout) DoneGrowRequest() {
-	atomic.AddInt32(&vl.growRequestCount, -1)
+	vl.growRequest.Store(false)
 }
 
 func (vl *VolumeLayout) ShouldGrowVolumes(option *VolumeGrowOption) bool {