[dm-devel] Re: [PATCH 12/17] bottom-layer barrier support

[Alasdair G Kergon]

On Mon, Apr 20, 2009 at 04:01:11AM -0400, Mikulas Patocka wrote:
> Flush supoprt for dm-delay target.
 
> @@ -281,6 +282,8 @@ static int delay_map(struct dm_target *t
>  		bio->bi_bdev = dc->dev_write->bdev;
>  		bio->bi_sector = dc->start_write +
>  				 (bio->bi_sector - ti->begin);
> +		if (!bio_sectors(bio))
> +			bio->bi_sector = 0;

Why set bio->bi_sector twice on that path?
Should we instead guarantee it's 0 before calling?

>  
>  		return delay_bio(dc, dc->write_delay, bio);
>  	}

Is flushing different - do we really want to delay it?
(I'd have thought not.  But if so, should it be a separate option?)

Alasdair
-- 
agk at redhat.com