[PATCH v3 4/8] blk-mp: introduce blk_mq_hctx_map_queues

[Greg Kroah-Hartman]

On Tue, Nov 12, 2024 at 04:33:09PM +0100, Daniel Wagner wrote:
> On Tue, Nov 12, 2024 at 02:58:43PM +0100, Greg Kroah-Hartman wrote:
> > > +void blk_mq_hctx_map_queues(struct blk_mq_queue_map *qmap,
> > > +			    struct device *dev, unsigned int offset)
> > > +
> > > +{
> > > +	const struct cpumask *mask;
> > > +	unsigned int queue, cpu;
> > > +
> > > +	if (!dev->bus->irq_get_affinity)
> > > +		goto fallback;
> > 
> > I think this is better than hard-coding it, but are you sure that the
> > bus will always be bound to the device here so that you have a valid
> > bus-> pointer?
> 
> No, I just assumed the bus pointer is always valid. If it is possible to
> have a device without a bus, than I'll better extend the condition to
> 
> 	if (!dev->bus || !dev->bus->irq_get_affinity)
>         	goto fallback;

I don't know if it's possible as I don't know what codepaths are calling
this, it was hard to unwind.  But you should check "just to be safe" :)

thanks,

greg k-h