Re: [PATCH 1/2] blk-mq: add two interfaces to lock/unlock blk_mq_tags->lock

[yukuai (C)]

On 2021/08/09 0:44, Bart Van Assche wrote:
> On 8/7/21 8:17 PM, Yu Kuai wrote:
> > +void blk_mq_tags_lock(struct blk_mq_tags *tags, unsigned long *flags)
> > +{
> > +	spin_lock_irqsave(&tags->lock, *flags);
> > +}
> > +EXPORT_SYMBOL(blk_mq_tags_lock);
> > +
> > +void blk_mq_tags_unlock(struct blk_mq_tags *tags, unsigned long *flags)
> > +{
> > +	spin_unlock_irqrestore(&tags->lock, *flags);
> > +}
> > +EXPORT_SYMBOL(blk_mq_tags_unlock);
>
> The tag map lock is an implementation detail and hence this lock must
> not be used directly by block drivers. I propose to introduce and export
> a new function to block drivers that does the following:
> * Lock tags->lock.
> * Call blk_mq_tag_to_rq().
> * Check whether the request is in the started state. If so, increment
> its reference count.
> * Unlock tags->lock.

Hi, Bart

Thanks for your advice, will do this in next iteration.

Best regards
Kuai