<div class="block js-block-obj" data-info="{ b 10, s: 1 }"></div>console.log( $('.js-block-obj').data('info') );
$( ".js-block-obj" ).data( "info", { b: 100, s: 0 } );
console.log( $('.js-block-obj').data('info') ); 
  
  <div class="block js-block-obj" data-info="{ b: 10, s: 1 }"></div>
            
    ...
    
    $.fn.jsonData = function(name) {
        var data = this.data(name);
        if (typeof data === "string") {
            data = JSON.parse(data);
            this.data(name, data);
        }
        return data;
    };
    ...
    console.log( $('.js-block-obj').jsonData('info') );
    $( ".js-block-obj" ).data( "info", { b: 100, s: 0 } );
    console.log( $('.js-block-obj').jsonData('info') );