Re: Oops when writing to /sys/block/ram0/queue/max_sectors_kb

[Jens Rosenboom <jens.rosenboom@freenet.ag>]

On Tue, Jul 28, 2009 at 09:07:11AM +0200, Jens Axboe wrote:
[...]
> Looks like this will hit nonrot/merge/etc store functions after we
> exposed these sysfs knobs for non-request_fn drivers too. Can you try
> the below? Should fix all of them up.
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 4b45435..a0c340d 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -575,13 +575,6 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
>  		return NULL;
>  	}
>  
> -	/*
> -	 * if caller didn't supply a lock, they get per-queue locking with
> -	 * our embedded lock
> -	 */
> -	if (!lock)
> -		lock = &q->__queue_lock;
> -
>  	q->request_fn		= rfn;
>  	q->prep_rq_fn		= NULL;
>  	q->unplug_fn		= generic_unplug_device;
> diff --git a/block/blk-settings.c b/block/blk-settings.c
> index bd582a7..8a3ea3b 100644
> --- a/block/blk-settings.c
> +++ b/block/blk-settings.c
> @@ -165,6 +165,13 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
>  	blk_set_default_limits(&q->limits);
>  
>  	/*
> +	 * If the caller didn't supply a lock, fall back to our embedded
> +	 * per-queue locks
> +	 */
> +	if (!q->queue_lock)
> +		q->queue_lock = &q->__queue_lock;
> +
> +	/*
>  	 * by default assume old behaviour and bounce for any highmem page
>  	 */
>  	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);

Works for me, no more Oopses.