Merge pull request #1298 from song-zhang/master

add fsync option for benchmark

weed/operation/submit.go

@@ -27,6 +27,7 @@ type FilePart struct {
 	Ttl         string
 	Server      string //this comes from assign result
 	Fid         string //this comes from assign result, but customizable
+	Fsync       bool      
 }
 
 type SubmitResult struct {
@@ -116,6 +117,9 @@ func (fi FilePart) Upload(maxMB int, master string, usePublicUrl bool, jwt secur
 	if fi.ModTime != 0 {
 		fileUrl += "?ts=" + strconv.Itoa(int(fi.ModTime))
 	}
+	if fi.Fsync {
+		fileUrl += "?fsync=true"
+	}
 	if closer, ok := fi.Reader.(io.Closer); ok {
 		defer closer.Close()
 	}