Re: [PATCH rdma-next v1 1/2] lib/scatterlist: Fix wrong update of orig_nents

[Leon Romanovsky]

On Wed, Jun 30, 2021 at 06:59:11AM +0100, Christoph Hellwig wrote:
> On Tue, Jun 29, 2021 at 11:40:01AM +0300, Leon Romanovsky wrote:
> > 2. Add a new field total_nents to reflect the total number of entries
> >    in the table. This is required for the release flow (sg_free_table).
> >    This filed should be used internally only by scatterlist.
> 
> No, please don't bloat the common structure.

Somehow we need to store that total_nents value and our internal
proposal was to wrap sg_table with another private structure that is
visible in lib/scatterlist.c only.

Something like that:
struct sg_table_private {
  struct sg_table table;
  unsigned int total_nents;
};

But it looks awkward.

> 
> > +	/* The fields below should be used internally only by
> > +	 * scatterlist implementation.
> > +	 */
> 
> And this is not the way kernel comments work.

It is netdev style.

Thanks