Re: [PATCH V11 12/19] block: allow bio_for_each_segment_all() to iterate over multi-page bvec

[Christoph Hellwig]

> +/* used for chunk_for_each_segment */
> +static inline void bvec_next_segment(const struct bio_vec *bvec,
> +				     struct bvec_iter_all *iter_all)

FYI, chunk_for_each_segment doesn't exist anymore, this is
bvec_for_each_segment now.  Not sure the comment helps much, though.

> +{
> +	struct bio_vec *bv = &iter_all->bv;
> +
> +	if (bv->bv_page) {
> +		bv->bv_page += 1;

I think this needs to use nth_page() given that with discontigmem
page structures might not be allocated contigously.