store: always lookup form master when process write operation

go/operation/lookup.go

@@ -42,7 +42,6 @@ var (
 )
 
 func Lookup(server string, vid string) (ret *LookupResult, err error) {
-	//Maybe we should fetch from master when lookup location for write
 	locations, cache_err := vc.Get(vid)
 	if cache_err != nil {
 		if ret, err = do_lookup(server, vid); err == nil {
@@ -54,6 +53,13 @@ func Lookup(server string, vid string) (ret *LookupResult, err error) {
 	return
 }
 
+func LookupNoCache(server string, vid string) (ret *LookupResult, err error) {
+	if ret, err = do_lookup(server, vid); err == nil {
+		vc.Set(vid, ret.Locations, 10*time.Minute)
+	}
+	return
+}
+
 func do_lookup(server string, vid string) (*LookupResult, error) {
 	values := make(url.Values)
 	values.Add("volumeId", vid)

go/topology/store_replicate.go

@@ -67,7 +67,7 @@ func ReplicatedDelete(masterNode string, store *storage.Store,
 }
 
 func distributedOperation(masterNode string, store *storage.Store, volumeId storage.VolumeId, op func(location operation.Location) bool) bool {
-	if lookupResult, lookupErr := operation.Lookup(masterNode, volumeId.String()); lookupErr == nil {
+	if lookupResult, lookupErr := operation.LookupNoCache(masterNode, volumeId.String()); lookupErr == nil {
 		length := 0
 		selfUrl := (store.Ip + ":" + strconv.Itoa(store.Port))
 		results := make(chan bool)