skip only readonly volumes

fix https://github.com/chrislusf/seaweedfs/issues/405

weed/topology/topology_vacuum.go

@@ -86,14 +86,16 @@ func (t *Topology) Vacuum(garbageThreshold string) int {
 		for _, vl := range c.storageType2VolumeLayout.Items() {
 			if vl != nil {
 				volumeLayout := vl.(*VolumeLayout)
-				writableSet := make(map[storage.VolumeId]bool)
-				for _, id := range volumeLayout.writables {
-					writableSet[id] = true
-				}
 				for vid, locationlist := range volumeLayout.vid2location {
-					if _, isWritable := writableSet[vid]; !isWritable {
+
+					vl.accessLock.RLock()
+					isReadOnly, hasValue := volumeLayout.readonlyVolumes[vid]
+					vl.accessLock.RUnlock()
+
+					if hasValue && isReadOnly {
 						continue
 					}
+
 					glog.V(0).Infof("check vacuum on collection:%s volume:%d", c.Name, vid)
 					if batchVacuumVolumeCheck(volumeLayout, vid, locationlist, garbageThreshold) {
 						if batchVacuumVolumeCompact(volumeLayout, vid, locationlist) {

weed/topology/volume_layout.go

@@ -16,6 +16,7 @@ type VolumeLayout struct {
 	ttl              *storage.TTL
 	vid2location     map[storage.VolumeId]*VolumeLocationList
 	writables        []storage.VolumeId        // transient array of writable volume id
+	readonlyVolumes  map[storage.VolumeId]bool // transient set of readonly volumes
 	oversizedVolumes map[storage.VolumeId]bool // set of oversized volumes
 	volumeSizeLimit  uint64
 	accessLock       sync.RWMutex
@@ -27,6 +28,7 @@ func NewVolumeLayout(rp *storage.ReplicaPlacement, ttl *storage.TTL, volumeSizeL
 		ttl:              ttl,
 		vid2location:     make(map[storage.VolumeId]*VolumeLocationList),
 		writables:        *new([]storage.VolumeId),
+		readonlyVolumes:  make(map[storage.VolumeId]bool),
 		oversizedVolumes: make(map[storage.VolumeId]bool),
 		volumeSizeLimit:  volumeSizeLimit,
 	}
@@ -50,11 +52,15 @@ func (vl *VolumeLayout) RegisterVolume(v *storage.VolumeInfo, dn *DataNode) {
 			if v_info.ReadOnly {
 				glog.V(3).Infof("vid %d removed from writable", v.Id)
 				vl.removeFromWritable(v.Id)
+				vl.readonlyVolumes[v.Id] = true
 				return
+			} else {
+				delete(vl.readonlyVolumes, v.Id)
 			}
 		} else {
 			glog.V(3).Infof("vid %d removed from writable", v.Id)
 			vl.removeFromWritable(v.Id)
+			delete(vl.readonlyVolumes, v.Id)
 			return
 		}
 	}