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

[Alasdair G Kergon]

On Mon, Apr 27, 2009 at 07:09:32PM -0400, Mikulas Patocka wrote:
> The code is correct as it is.
 
I don't see that.

> The difference is the zero-barrier flush request --- it should have 
> bi_sector always 0.

But I'm asking at what point that is defined?
0 before calling the target's map function?
In which case it is wrong to perform:
	bio->bi_sector = dc->start_write + (bio->bi_sector - ti->begin);

Or if it's not set to zero until the
	bio->bi_sector = 0 
line, then what does it hold on entry to the function and what does that
mean?

Alasdair
-- 
agk at redhat.com