diff --git a/README.md b/README.md
index 8e73f811c..923331853 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
 
 ![SeaweedFS Logo](https://raw.githubusercontent.com/chrislusf/seaweedfs/master/note/seaweedfs.png)
 
-<h2 align="center">Supporting SeaweedFS</h2>
+<h2 align="center"><a href="https://www.patreon.com/seaweedfs">Sponsor SeaweedFS via Patreon</a></h2>
 
 SeaweedFS is an independent Apache-licensed open source project with its ongoing development made
 possible entirely thanks to the support of these awesome [backers](https://github.com/chrislusf/seaweedfs/blob/master/backers.md).
@@ -17,8 +17,6 @@ If you'd like to grow SeaweedFS even stronger, please consider joining our
 
 Your support will be really appreciated by me and other supporters!
 
-<h3 align="center"><a href="https://www.patreon.com/seaweedfs">Sponsor SeaweedFS via Patreon</a></h3>
-
 <!--
 <h4 align="center">Platinum</h4>
 
@@ -27,24 +25,12 @@ Your support will be really appreciated by me and other supporters!
     Add your name or icon here
   </a>
 </p>
-
-<h4 align="center">Gold</h4>
-
-<table>
-  <tbody>
-    <tr>
-      <td align="center" valign="middle">
-        <a href="" target="_blank">
-          Add your name or icon here
-        </a>
-      </td>
-    </tr>
-    <tr></tr>
-  </tbody>
-</table>
-
 -->
 
+
+### Gold Sponsors
+![shuguang](https://raw.githubusercontent.com/chrislusf/seaweedfs/master/note/shuguang.png)
+
 ---
 
 
diff --git a/docker/Dockerfile.go_build b/docker/Dockerfile.go_build
index 29b9a85d8..a5f8725e0 100644
--- a/docker/Dockerfile.go_build
+++ b/docker/Dockerfile.go_build
@@ -2,6 +2,8 @@ FROM frolvlad/alpine-glibc as builder
 RUN apk add git go g++
 RUN mkdir -p /go/src/github.com/chrislusf/
 RUN git clone https://github.com/chrislusf/seaweedfs /go/src/github.com/chrislusf/seaweedfs
+ARG branch=${branch:-master}
+RUN cd /go/src/github.com/chrislusf/seaweedfs && git checkout $ARG
 RUN cd /go/src/github.com/chrislusf/seaweedfs/weed \
   && export LDFLAGS="-X github.com/chrislusf/seaweedfs/weed/util.COMMIT=$(git rev-parse --short HEAD)" \
   && go install -ldflags "${LDFLAGS}"
diff --git a/docker/Dockerfile.go_build_large b/docker/Dockerfile.go_build_large
index fa22aeade..c3ea4e606 100644
--- a/docker/Dockerfile.go_build_large
+++ b/docker/Dockerfile.go_build_large
@@ -2,6 +2,8 @@ FROM frolvlad/alpine-glibc as builder
 RUN apk add git go g++
 RUN mkdir -p /go/src/github.com/chrislusf/
 RUN git clone https://github.com/chrislusf/seaweedfs /go/src/github.com/chrislusf/seaweedfs
+ARG branch=${branch:-master}
+RUN cd /go/src/github.com/chrislusf/seaweedfs && git checkout $ARG
 RUN cd /go/src/github.com/chrislusf/seaweedfs/weed \
   && export LDFLAGS="-X github.com/chrislusf/seaweedfs/weed/util.COMMIT=$(git rev-parse --short HEAD)" \
   && go install -tags 5BytesOffset -ldflags "${LDFLAGS}"
diff --git a/note/shuguang.png b/note/shuguang.png
new file mode 100644
index 000000000..54b6d0b6b
Binary files /dev/null and b/note/shuguang.png differ
diff --git a/weed/command/filer_copy.go b/weed/command/filer_copy.go
index cc356de88..1b5f4c849 100644
--- a/weed/command/filer_copy.go
+++ b/weed/command/filer_copy.go
@@ -159,7 +159,7 @@ func runCopy(cmd *Command, args []string) bool {
 		defer close(fileCopyTaskChan)
 		for _, fileOrDir := range fileOrDirs {
 			if err := genFileCopyTask(fileOrDir, urlPath, fileCopyTaskChan); err != nil {
-				fmt.Fprintf(os.Stderr, "gen file list error: %v\n", err)
+				fmt.Fprintf(os.Stderr, "genFileCopyTask : %v\n", err)
 				break
 			}
 		}
@@ -202,7 +202,7 @@ func genFileCopyTask(fileOrDir string, destPath string, fileCopyTaskChan chan Fi
 
 	fi, err := os.Stat(fileOrDir)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Failed to get stat for file %s: %v\n", fileOrDir, err)
+		fmt.Fprintf(os.Stderr, "Error: read file %s: %v\n", fileOrDir, err)
 		return nil
 	}
 
diff --git a/weed/server/filer_server_handlers_write_autochunk.go b/weed/server/filer_server_handlers_write_autochunk.go
index e52e20a8a..0cfbeba47 100644
--- a/weed/server/filer_server_handlers_write_autochunk.go
+++ b/weed/server/filer_server_handlers_write_autochunk.go
@@ -57,7 +57,11 @@ func (fs *FilerServer) autoChunk(ctx context.Context, w http.ResponseWriter, r *
 		reply, md5bytes, err = fs.doPutAutoChunk(ctx, w, r, chunkSize, so)
 	}
 	if err != nil {
-		writeJsonError(w, r, http.StatusInternalServerError, err)
+		if strings.HasPrefix(err.Error(), "read input:") {
+			writeJsonError(w, r, 499, err)
+		} else {
+			writeJsonError(w, r, http.StatusInternalServerError, err)
+		}
 	} else if reply != nil {
 		if len(md5bytes) > 0 {
 			w.Header().Set("Content-MD5", util.Base64Encode(md5bytes))
diff --git a/weed/storage/disk_location.go b/weed/storage/disk_location.go
index 7030900dc..c6619b260 100644
--- a/weed/storage/disk_location.go
+++ b/weed/storage/disk_location.go
@@ -101,12 +101,14 @@ func (l *DiskLocation) loadExistingVolume(fileInfo os.FileInfo, needleMapKind Ne
 	}
 
 	// avoid loading one volume more than once
-	l.volumesLock.RLock()
-	_, found := l.volumes[vid]
-	l.volumesLock.RUnlock()
-	if found {
+	l.volumesLock.Lock()
+	if _, found := l.volumes[vid]; found {
+		l.volumesLock.Unlock()
 		glog.V(1).Infof("loaded volume, %v", vid)
 		return true
+	} else {
+		l.volumes[vid] = nil
+		l.volumesLock.Unlock()
 	}
 
 	// load the volume
@@ -115,7 +117,7 @@ func (l *DiskLocation) loadExistingVolume(fileInfo os.FileInfo, needleMapKind Ne
 		glog.V(0).Infof("new volume %s error %s", volumeName, e)
 		return false
 	}
-
+	
 	l.SetVolume(vid, v)
 
 	size, _, _ := v.FileStat()