mongoose validator error async issue

shop_controller.js

exports.create = function*(){

	var body = this.request.body,
	name = body.name,
	type = body.shop_type,
	context = body.context;

/*
	this.checkBody("name").notEmpty("请输入商户名称");
	this.checkBody("shop_type").notEmpty("请输入原料名");
	this.checkBody("context").notEmpty("请输入口味描述");
	
	if(this.errors){
		return this.body = {retcode:1 , message:'请输入完整信息'};
	}
*/

	var checkShop = yield Shop.model.findOne({name:name}).exec();
	if(checkShop != null){
		return this.body = {retcode:1,message:'已存在相同的商户'}
	}

	var shopData = {};

	shopData.name = name;
	shopData.type = type;
	shopData.context = context;


	
	try{
		var newShop = new Shop.model(shopData);
		yield newShop.save(function(err){
			if(err) {
				return this.body = {retcode: 1, message: err.errors};
			} else {
				return this.body = {retcode: 0}		
			}
			
		});		
	} catch(ex) {
		
	}
	
	
	/*
	var result = yield (function(newShop){		
					return function(fn){newShop.save(fn)};
			})(newShop);

	
	return this.body = {retcode:0}
	*/
	return this.body = {retcode: 0}
}