[PATCH] block: always set partition number to '0' in blk_partition_remap()

[hare@suse.de (Hannes Reinecke)]

On Wed, 6 Jun 2018 08:26:56 -0600
Jens Axboe <axboe@kernel.dk> wrote:

> On 6/6/18 8:22 AM, Hannes Reinecke wrote:
> > blk_partition_remap() will only clear bi_partno if an actual
> > remapping has happened. But flush request et al don't have an
> > actual size, so the remapping doesn't happen and bi_partno is never
> > cleared. So for stacked devices blk_partition_remap() will be
> > called on each level. If (as is the case for native nvme
> > multipathing) one of the lower-level devices do _not_support
> > partitioning a spurious I/O error is generated.  
> 
> Just move it down, we're now clearing it for both cases.
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 3f56be15f17e..cf0ee764b908 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -2220,10 +2220,10 @@ static inline int blk_partition_remap(struct
> bio *bio) if (bio_check_eod(bio, part_nr_sects_read(p)))
>  			goto out;
>  		bio->bi_iter.bi_sector += p->start_sect;
> -		bio->bi_partno = 0;
>  		trace_block_bio_remap(bio->bi_disk->queue, bio,
> part_devt(p), bio->bi_iter.bi_sector - p->start_sect);
>  	}
> +	bio->bi_partno = 0;
>  	ret = 0;
>  out:
>  	rcu_read_unlock();
> 

Okay, will be resending.

Cheers,

Hannes