[PATCH] nvme-multipath: set nr_zones for zoned namespaces

[Keith Busch]

On Sun, Feb 07, 2021 at 11:06:36PM +0000, Damien Le Moal wrote:
> On 2021/02/06 4:50, Keith Busch wrote:
> > The bio based drivers only require the request_queue's nr_zones is set,
> > so set this field in the head if the namespace path is zoned.
> > 
> > Reported-by: Minwoo Im <minwoo.im.dev at gmail.com>
> > Cc: Damien Le Moal <damien.lemoal at wdc.com>
> > Signed-off-by: Keith Busch <kbusch at kernel.org>
> 
> Shouldn't this have a Fixes tag ?

Probably yes, since this omission does go back to the initial inclusion:

Fixes: 240e6ee272c07 ("nvme: support for zoned namespaces")
 
> > ---
> >  drivers/nvme/host/multipath.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> > index 1427c9555cef..a1d476e1ac02 100644
> > --- a/drivers/nvme/host/multipath.c
> > +++ b/drivers/nvme/host/multipath.c
> > @@ -677,6 +677,10 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
> >  	if (blk_queue_stable_writes(ns->queue) && ns->head->disk)
> >  		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES,
> >  				   ns->head->disk->queue);
> > +#ifdef CONFIG_BLK_DEV_ZONED
> > +	if (blk_queue_is_zoned(ns->queue) && ns->head->disk)
> > +		ns->head->disk->queue->nr_zones = ns->queue->nr_zones;
> > +#endif
> 
> Is the zone model set already ? I have not checked...

That's a good question, and we should be safe with the zone namespace's
zone settings set at this point: nvme_mpath_add_disk() is invoked after
nvme_update_ns_info().