add vers mountoptions and fix comments

pkg/volume/azure_file/azure_util.go

@@ -27,10 +27,12 @@ import (
 )
 
 const (
-	fileModeName    = "file_mode"
-	dirModeName     = "dir_mode"
-	defaultFileMode = "700"
-	defaultDirMode  = "700"
+	fileMode        = "file_mode"
+	dirMode         = "dir_mode"
+	vers            = "vers"
+	defaultFileMode = "0700"
+	defaultDirMode  = "0700"
+	defaultVers     = "3.0"
 )
 
 // Abstract interface to azure file operations.
@@ -93,28 +95,35 @@ func (s *azureSvc) SetAzureCredentials(host volume.VolumeHost, nameSpace, accoun
 	return secretName, err
 }
 
-// check whether mountOptions contains file_mode and dir_mode, if not, append default mode
+// check whether mountOptions contain file_mode and dir_mode, if not, append default mode
 func appendDefaultMountOptions(mountOptions []string) []string {
 	fileModeFlag := false
 	dirModeFlag := false
+	versFlag := false
 
 	for _, mountOption := range mountOptions {
-		if strings.HasPrefix(mountOption, fileModeName) {
+		if strings.HasPrefix(mountOption, fileMode) {
 			fileModeFlag = true
 		}
-		if strings.HasPrefix(mountOption, dirModeName) {
+		if strings.HasPrefix(mountOption, dirMode) {
 			dirModeFlag = true
 		}
+		if strings.HasPrefix(mountOption, vers) {
+			versFlag = true
+		}
 	}
 
 	allMountOptions := mountOptions
 	if !fileModeFlag {
-		allMountOptions = append(allMountOptions, fmt.Sprintf("%s=%s", fileModeName, defaultFileMode))
+		allMountOptions = append(allMountOptions, fmt.Sprintf("%s=%s", fileMode, defaultFileMode))
 	}
 
 	if !dirModeFlag {
-		allMountOptions = append(allMountOptions, fmt.Sprintf("%s=%s", dirModeName, defaultDirMode))
+		allMountOptions = append(allMountOptions, fmt.Sprintf("%s=%s", dirMode, defaultDirMode))
 	}
 
+	if !versFlag {
+		allMountOptions = append(allMountOptions, fmt.Sprintf("%s=%s", vers, defaultVers))
+	}
 	return allMountOptions
 }