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From: Neil Brown <neilb@suse.de>
To: "John Stoffel" <john@stoffel.org>
Date: Thu, 2 Aug 2007 13:43:34 +1000
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Cc: Tejun Heo <teheo@suse.de>, Avi Kivity <avi@argo.co.il>,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH 000 of 35] Refactor block layer to improve support for
 stacked devices.
In-Reply-To: message from John Stoffel on Wednesday August 1
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On Wednesday August 1, john@stoffel.org wrote:
> 
> In any case, why does something so complicated need to be a macro, why
> not a function instead?

There needs to be a macro so you can put a statement after it to be
executed "for each ..."
But you are right that it doesn't all need to be in the one macro.

The idea of something like

#define bio_for_each_segment_offset(bv, bio, _i, offset, _size) \
	for (bio_iterator_init(bio, &_i, &bv, offset, _size);	\
	     i.remaining > 0 ;					\
	     bio_next(bio, &_i, &bv))
	
with bio_iterator_init and bio_next being (inline?) functions is a
very good one.  I'll see what works.

Thanks,
NeilBrown