Re: [PATCH v2 16/51] block: bounce: avoid direct access to bvec table

Ming Lei
2017-06-27T07:35:20Z

On Mon, Jun 26, 2017 at 11:12:11PM -0700, Matthew Wilcox wrote:
> On Mon, Jun 26, 2017 at 08:09:59PM +0800, Ming Lei wrote:
> > bio_for_each_segment_all(bvec, bio, i) {
> > - org_vec = bio_orig->bi_io_vec + i + start;
> > -
> > - if (bvec->bv_page == org_vec->bv_page)
> > - continue;
> > + orig_vec = bio_iter_iovec(bio_orig, orig_iter);
> > + if (bvec->bv_page == orig_vec.bv_page)
> > + goto next;
> >
> > dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
> > mempool_free(bvec->bv_page, pool);
> > + next:
> > + bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len);
> > }
> >
>
> I think this might be written more clearly as:
>
> bio_for_each_segment_all(bvec, bio, i) {
> orig_vec = bio_iter_iovec(bio_orig, orig_iter);
> if (bvec->bv_page != orig_vec.bv_page) {
> dec_zone_page_state(bvec->bv_page, NR_BOUNCE);
> mempool_free(bvec->bv_page, pool);
> }
> bio_advance_iter(bio_orig, &orig_iter, orig_vec.bv_len);
> }
>
> What do you think?

Yeah, looks the above code is more clean, will do it in V3.

thanks,
Ming