wait for master to be aware of the failed volumes

fix https://github.com/chrislusf/seaweedfs/issues/1268

weed/filesys/dirty_page.go

@@ -125,16 +125,18 @@ func (pages *ContinuousDirtyPages) saveExistingLargestPageToStorage() (chunk *fi
 		return nil, false, nil
 	}
 
+	for {
 		chunk, err = pages.saveToStorage(maxList.ToReader(), maxList.Offset(), maxList.Size())
 		if err == nil {
 			hasSavedData = true
 			glog.V(3).Infof("%s saveToStorage [%d,%d) %s", pages.f.fullpath(), maxList.Offset(), maxList.Offset()+maxList.Size(), chunk.FileId)
+			time.Sleep(5 * time.Second)
 		} else {
 			glog.V(0).Infof("%s saveToStorage [%d,%d): %v", pages.f.fullpath(), maxList.Offset(), maxList.Offset()+maxList.Size(), err)
 			return
 		}
+	}
 
-	return
 }
 
 func (pages *ContinuousDirtyPages) saveToStorage(reader io.Reader, offset int64, size int64) (*filer_pb.FileChunk, error) {