Re: [PATCH] block: don't use for-inside-for in bio_for_each_segment_all

[Ming Lei <tom.leiming@gmail.com>]

On Sun, Apr 7, 2019 at 3:58 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Sun, Apr 07, 2019 at 03:54:16PM +0800, Ming Lei wrote:
> > > OK, will move index check into mp_bvec_advance.
> >
> > oops, I recall the above line, because:
> >
> > 1) the index check expression is quite straight-forward
> >
> > 2) it has been in my todo list to re-use bvec_advance() to re-write
> > iterate_bvec()
> > given bvec_advance() is much light-weight than for_each_bvec(). If we
> > move the index check into bvec_advance(), the helper has to be moved
> > to bio.h, then we can't use that for iterate_bvec().
>
> You can always create a tiny wrapper around bvec_advance() that sits
> in bio.h.  Which in general is much better style than complex
> expressions inside of loops inside of macros..

OK, fair enough.


Thanks,
Ming Lei