Re: [PATCH V2] blkio: Fix blkio crash during rq stat update

[Jens Axboe <jens.axboe@oracle.com>]

On Wed, Apr 21 2010, Vivek Goyal wrote:
> @@ -1001,6 +1002,11 @@ static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create)
>  	return cfqg;
>  }
>  
> +static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) {
> +	atomic_inc(&cfqg->ref);
> +	return cfqg;
> +}
> +

Sorry to keep harping on this - style is still wrong, and:

> @@ -3560,6 +3574,9 @@ new_queue:
>  
>  	rq->elevator_private = cic;
>  	rq->elevator_private2 = cfqq;
> +	rq->elevator_private3 = cfqq->cfqg;
> +	/* rq reference on cfqg */
> +	cfq_ref_get_cfqg(RQ_CFQG(rq));
>  	return 0;

should be

        /* hold a reference to the cfqg */
        rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg);

-- 
Jens Axboe