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

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

On Tue, Jul 28 2009, Jens Rosenboom wrote:
> 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.

Thanks for confirming, I've queued it up for next 2.6.31-rc pull
request.

-- 
Jens Axboe