volume: detect max volume count changes based on disk usage

fix https://github.com/chrislusf/seaweedfs/issues/1594

weed/server/volume_grpc_client_to_master.go

@@ -203,6 +203,7 @@ func (vs *VolumeServer) doHeartbeat(masterNode, masterGrpcAddress string, grpcDi
 			}
 		case <-volumeTickChan:
 			glog.V(4).Infof("volume server %s:%d heartbeat", vs.store.Ip, vs.store.Port)
+			vs.store.MaybeAdjustVolumeMax()
 			if err = stream.Send(vs.store.CollectHeartbeat()); err != nil {
 				glog.V(0).Infof("Volume Server Failed to talk with master %s: %v", masterNode, err)
 				return "", err

weed/storage/disk_location.go

@@ -17,11 +17,12 @@ import (
 )
 
 type DiskLocation struct {
-	Directory           string
-	MaxVolumeCount      int
-	MinFreeSpacePercent float32
-	volumes             map[needle.VolumeId]*Volume
-	volumesLock         sync.RWMutex
+	Directory              string
+	MaxVolumeCount         int
+	OriginalMaxVolumeCount int
+	MinFreeSpacePercent    float32
+	volumes                map[needle.VolumeId]*Volume
+	volumesLock            sync.RWMutex
 
 	// erasure coding
 	ecVolumes     map[needle.VolumeId]*erasure_coding.EcVolume
@@ -31,7 +32,7 @@ type DiskLocation struct {
 }
 
 func NewDiskLocation(dir string, maxVolumeCount int, minFreeSpacePercent float32) *DiskLocation {
-	location := &DiskLocation{Directory: dir, MaxVolumeCount: maxVolumeCount, MinFreeSpacePercent: minFreeSpacePercent}
+	location := &DiskLocation{Directory: dir, MaxVolumeCount: maxVolumeCount, OriginalMaxVolumeCount: maxVolumeCount, MinFreeSpacePercent: minFreeSpacePercent}
 	location.volumes = make(map[needle.VolumeId]*Volume)
 	location.ecVolumes = make(map[needle.VolumeId]*erasure_coding.EcVolume)
 	go location.CheckDiskSpace()

weed/storage/store.go

@@ -461,7 +461,8 @@ func (s *Store) GetVolumeSizeLimit() uint64 {
 func (s *Store) MaybeAdjustVolumeMax() (hasChanges bool) {
 	volumeSizeLimit := s.GetVolumeSizeLimit()
 	for _, diskLocation := range s.Locations {
-		if diskLocation.MaxVolumeCount == 0 {
+		if diskLocation.OriginalMaxVolumeCount == 0 {
+			currentMaxVolumeCount := diskLocation.MaxVolumeCount
 			diskStatus := stats.NewDiskStatus(diskLocation.Directory)
 			unusedSpace := diskLocation.UnUsedSpace(volumeSizeLimit)
 			unclaimedSpaces := int64(diskStatus.Free) - int64(unusedSpace)
@@ -473,7 +474,7 @@ func (s *Store) MaybeAdjustVolumeMax() (hasChanges bool) {
 			diskLocation.MaxVolumeCount = maxVolumeCount
 			glog.V(0).Infof("disk %s max %d unclaimedSpace:%dMB, unused:%dMB volumeSizeLimit:%dMB",
 				diskLocation.Directory, maxVolumeCount, unclaimedSpaces/1024/1024, unusedSpace/1024/1024, volumeSizeLimit/1024/1024)
-			hasChanges = true
+			hasChanges = hasChanges || currentMaxVolumeCount != diskLocation.MaxVolumeCount
 		}
 	}
 	return