anchor.diff:          apply = x: if isList x then x else lib.strings.splitString "," (builtins.trace "warning: passing a comma-separated string for filesystem options is deprecated; use a list of strings instead. This will become a hard error in 16.09." x);
         });
   
  +    };
  +
  +    config = {
  +      mountPoint = mkDefault name;
  +      device = mkIf (elem config.fsType specialFSTypes) (mkDefault config.fsType);
  +    };
  +
  +  };
  +
  +  fileSystemOpts = { config, ... }: {
  +
  +    options = {
  +
  +      label = mkOption {
  +        default = null;
  +        example = "root-partition";
  +        type = types.nullOr types.str;
  +        description = "Label of the device (if any).";
  +      };
  +
         autoFormat = mkOption {
           default = false;
           type = types.bool;
  
positive.code: 
    specialFSTypes = [ "proc" "sysfs" "tmpfs" "devtmpfs" "devpts" ];
  
    fileSystemOpts = { name, config, ... }: {
  
      options = {
  
  
negative.code:         example = "/dev/sda";
          type = types.nullOr types.str;
          description = "Location of the device.";
        };
  
        fsType = mkOption {
  