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

[Alasdair G Kergon]

On Mon, Apr 27, 2009 at 10:48:37PM +0100, Alasdair G Kergon wrote:
> 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_sector = dc->start_write +
> >  				 (bio->bi_sector - ti->begin);

In fact, does bi_sector have a meaningful value within
the context of a specific target any more when processing
a barrier flush, or is it a bug if a target attempts to access it?
(For example, it could be set to ti->begin or 0.)

I think the situation deserves defining in a comment.

(Maybe we will remove "- ti->begin" from all the mapping functions one day.
Not mixed in with this patch set though.)

Alasdair
-- 
agk at redhat.com