Re: [PATCH v4] mm/page_io: rename swap_iocb->pages to swap_iocb->bvecs

[David CARLIER <devnexen@gmail.com>]

please ignore this one, I resent after. Cheers.

On Thu, 2 Apr 2026 at 07:12, David Carlier <devnexen@gmail.com> wrote:
>
> swap_iocb->pages tracks the number of bvec entries (folios), not base
> pages. Rename it to bvecs to accurately reflect its purpose.
>
> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---
> v4: renamed swap_iocb->pages to ->bvecs (Willy)
> v3: use sio->len for PSWPIN accounting
> v2: convert sio_write_complete() to folio APIs
>  mm/page_io.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/mm/page_io.c b/mm/page_io.c
> index 1389cd57ca88..e524cb821d04 100644
> --- a/mm/page_io.c
> +++ b/mm/page_io.c
> @@ -327,7 +327,7 @@ static void bio_associate_blkg_from_page(struct bio *bio, struct folio *folio)
>  struct swap_iocb {
>         struct kiocb            iocb;
>         struct bio_vec          bvec[SWAP_CLUSTER_MAX];
> -       int                     pages;
> +       int                     bvecs;
>         int                     len;
>  };
>  static mempool_t *sio_pool;
> @@ -362,14 +362,14 @@ static void sio_write_complete(struct kiocb *iocb, long ret)
>                  */
>                 pr_err_ratelimited("Write error %ld on dio swapfile (%llu)\n",
>                                    ret, swap_dev_pos(page_swap_entry(page)));
> -               for (p = 0; p < sio->pages; p++) {
> +               for (p = 0; p < sio->bvecs; p++) {
>                         page = sio->bvec[p].bv_page;
>                         set_page_dirty(page);
>                         ClearPageReclaim(page);
>                 }
>         }
>
> -       for (p = 0; p < sio->pages; p++)
> +       for (p = 0; p < sio->bvecs; p++)
>                 end_page_writeback(sio->bvec[p].bv_page);
>
>         mempool_free(sio, sio_pool);
> @@ -397,13 +397,13 @@ static void swap_writepage_fs(struct folio *folio, struct swap_iocb **swap_plug)
>                 init_sync_kiocb(&sio->iocb, swap_file);
>                 sio->iocb.ki_complete = sio_write_complete;
>                 sio->iocb.ki_pos = pos;
> -               sio->pages = 0;
> +               sio->bvecs = 0;
>                 sio->len = 0;
>         }
> -       bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
> +       bvec_set_folio(&sio->bvec[sio->bvecs], folio, folio_size(folio), 0);
>         sio->len += folio_size(folio);
> -       sio->pages += 1;
> -       if (sio->pages == ARRAY_SIZE(sio->bvec) || !swap_plug) {
> +       sio->bvecs += 1;
> +       if (sio->bvecs == ARRAY_SIZE(sio->bvec) || !swap_plug) {
>                 swap_write_unplug(sio);
>                 sio = NULL;
>         }
> @@ -477,7 +477,7 @@ void swap_write_unplug(struct swap_iocb *sio)
>         struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
>         int ret;
>
> -       iov_iter_bvec(&from, ITER_SOURCE, sio->bvec, sio->pages, sio->len);
> +       iov_iter_bvec(&from, ITER_SOURCE, sio->bvec, sio->bvecs, sio->len);
>         ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
>         if (ret != -EIOCBQUEUED)
>                 sio_write_complete(&sio->iocb, ret);
> @@ -489,7 +489,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
>         int p;
>
>         if (ret == sio->len) {
> -               for (p = 0; p < sio->pages; p++) {
> +               for (p = 0; p < sio->bvecs; p++) {
>                         struct folio *folio = page_folio(sio->bvec[p].bv_page);
>
>                         count_mthp_stat(folio_order(folio), MTHP_STAT_SWPIN);
> @@ -499,7 +499,7 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
>                 }
>                 count_vm_events(PSWPIN, sio->len >> PAGE_SHIFT);
>         } else {
> -               for (p = 0; p < sio->pages; p++) {
> +               for (p = 0; p < sio->bvecs; p++) {
>                         struct folio *folio = page_folio(sio->bvec[p].bv_page);
>
>                         folio_unlock(folio);
> @@ -559,13 +559,13 @@ static void swap_read_folio_fs(struct folio *folio, struct swap_iocb **plug)
>                 init_sync_kiocb(&sio->iocb, sis->swap_file);
>                 sio->iocb.ki_pos = pos;
>                 sio->iocb.ki_complete = sio_read_complete;
> -               sio->pages = 0;
> +               sio->bvecs = 0;
>                 sio->len = 0;
>         }
> -       bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
> +       bvec_set_folio(&sio->bvec[sio->bvecs], folio, folio_size(folio), 0);
>         sio->len += folio_size(folio);
> -       sio->pages += 1;
> -       if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) {
> +       sio->bvecs += 1;
> +       if (sio->bvecs == ARRAY_SIZE(sio->bvec) || !plug) {
>                 swap_read_unplug(sio);
>                 sio = NULL;
>         }
> @@ -666,7 +666,7 @@ void __swap_read_unplug(struct swap_iocb *sio)
>         struct address_space *mapping = sio->iocb.ki_filp->f_mapping;
>         int ret;
>
> -       iov_iter_bvec(&from, ITER_DEST, sio->bvec, sio->pages, sio->len);
> +       iov_iter_bvec(&from, ITER_DEST, sio->bvec, sio->bvecs, sio->len);
>         ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
>         if (ret != -EIOCBQUEUED)
>                 sio_read_complete(&sio->iocb, ret);
> --
> 2.53.0
>