Re: [PATCH 5/9] block: introduce blk_drain_queue()

[Ming Lei <ming.lei@redhat.com>]

On Thu, Aug 31, 2017 at 10:34:49PM +0000, Bart Van Assche wrote:
> On Fri, 2017-09-01 at 01:27 +0800, Ming Lei wrote:
> > So that we can support legacy version of freezing queue,
> > which is required by safe SCSI quiescing.
> > 
> > Signed-off-by: Ming Lei <ming.lei@redhat.com>
> > ---
> >  block/blk-core.c       | 16 ++++++++++++++++
> >  include/linux/blkdev.h |  1 +
> >  2 files changed, 17 insertions(+)
> > 
> > diff --git a/block/blk-core.c b/block/blk-core.c
> > index d579501f24ba..636452f151ea 100644
> > --- a/block/blk-core.c
> > +++ b/block/blk-core.c
> > @@ -530,6 +530,22 @@ static void __blk_drain_queue(struct request_queue *q, bool drain_all)
> >  }
> >  
> >  /**
> > + * blk_drain_queue - drain requests from request_queue
> > + * @q: queue to drain
> > + *
> > + * Drain requests from @q.  All pending requests are drained.
> > + * The caller is responsible for ensuring that no new requests
> > + * which need to be drained are queued.
> > + */
> > +void blk_drain_queue(struct request_queue *q)
> > +{
> > +	spin_lock_irq(q->queue_lock);
> > +	__blk_drain_queue(q, true);
> > +	spin_unlock_irq(q->queue_lock);
> > +}
> > +EXPORT_SYMBOL(blk_drain_queue);
> 
> Hello Ming,
> 
> Please drop this patch. As far as I can see this patch series introduces only
> one call to blk_drain_queue(), namely in blk_freeze_queue_wait() in patch 6.
> My proposal is to inline the body of blk_drain_queue() in blk_freeze_queue_wait()
> instead of reintroducing blk_drain_queue() (see also commit 807592a4fafb;
> "block: Let blk_drain_queue() caller obtain the queue lock").

Looks good, will do it in V2.

-- 
Ming