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

[Ming Lei]

On Thu, Nov 22, 2018 at 12:03:15PM +0100, Christoph Hellwig wrote:
> > +/* 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.

OK, will remove the comment.

> 
> > +{
> > +   struct bio_vec *bv = _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.

Good catch!

Thanks,
Ming

Re: [Cluster-devel] [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 = _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.

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

[Christoph Hellwig]

On Wed, Nov 21, 2018 at 11:23:20AM +0800, Ming Lei wrote:
> This patch introduces one extra iterator variable to 
> bio_for_each_segment_all(),
> then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.
> 
> Given it is just one mechannical & simple change on all 
> bio_for_each_segment_all()
> users, this patch does tree-wide change in one single patch, so that we can
> avoid to use a temporary helper for this conversion.
> 
> Signed-off-by: Ming Lei 

Looks good,

Reviewed-by: Christoph Hellwig