Re: [PATCH 4/4] xen-blkfront: atomically update queue limits

[Christoph Hellwig <hch@xxxxxx>]

On Tue, Feb 20, 2024 at 01:35:07PM +0100, Roger Pau Monné wrote:
> On Tue, Feb 20, 2024 at 09:49:35AM +0100, Christoph Hellwig wrote:
> > Pass the initial queue limits to blk_mq_alloc_disk and use the
> > blkif_set_queue_limits API to update the limits on reconnect.
> 
> Allocating queue_limits on the stack might be a bit risky, as I fear
> this struct is likely to grow?

It might grow a little bit, but it's not actually that large, epecially
in a simple probe context that isn't in memory reclaim or similar.

> > Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> 
> Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> 
> Just one addition while you are already modifying a line.
> 
> > ---
> >  drivers/block/xen-blkfront.c | 41 ++++++++++++++++++++----------------
> >  1 file changed, 23 insertions(+), 18 deletions(-)
> > 
> > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
> > index 7664638a0abbfa..b77707ca2c5aa6 100644
> > --- a/drivers/block/xen-blkfront.c
> > +++ b/drivers/block/xen-blkfront.c
> > @@ -941,37 +941,35 @@ static const struct blk_mq_ops blkfront_mq_ops = {
> >     .complete = blkif_complete_rq,
> >  };
> >  
> > -static void blkif_set_queue_limits(struct blkfront_info *info)
> > +static void blkif_set_queue_limits(struct blkfront_info *info,
> 
> While there, could you also constify info?

Sure.