mm/page_io: rename swap_iocb fields for clarity

swap_iocb->pages tracks the number of bvec entries (folios), not base
pages.  Rename the array from bvec to bvecs and the counter from pages to
nr_bvecs to accurately reflect their purpose.

Link: https://lore.kernel.org/20260402072650.48811-1-devnexen@gmail.com
Signed-off-by: David Carlier <devnexen@gmail.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: NeilBrown <neil@brown.name>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/page_io.c b/mm/page_io.c
index 70cea9e24d2fd3fd9bd2763d19dc10985497f88c..7ed76592e20d86973026a6b22811cfa6db338886 100644 (file)
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -326,8 +326,8 @@ 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;
+       struct bio_vec          bvecs[SWAP_CLUSTER_MAX];
+       int                     nr_bvecs;
        int                     len;
 };
 static mempool_t *sio_pool;
@@ -348,7 +348,7 @@ int sio_pool_init(void)
 static void sio_write_complete(struct kiocb *iocb, long ret)
 {
        struct swap_iocb *sio = container_of(iocb, struct swap_iocb, iocb);
-       struct page *page = sio->bvec[0].bv_page;
+       struct page *page = sio->bvecs[0].bv_page;
        int p;
 
        if (ret != sio->len) {
@@ -362,15 +362,15 @@ 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++) {
-                       page = sio->bvec[p].bv_page;
+               for (p = 0; p < sio->nr_bvecs; p++) {
+                       page = sio->bvecs[p].bv_page;
                        set_page_dirty(page);
                        ClearPageReclaim(page);
                }
        }
 
-       for (p = 0; p < sio->pages; p++)
-               end_page_writeback(sio->bvec[p].bv_page);
+       for (p = 0; p < sio->nr_bvecs; p++)
+               end_page_writeback(sio->bvecs[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->nr_bvecs = 0;
                sio->len = 0;
        }
-       bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
+       bvec_set_folio(&sio->bvecs[sio->nr_bvecs], folio, folio_size(folio), 0);
        sio->len += folio_size(folio);
-       sio->pages += 1;
-       if (sio->pages == ARRAY_SIZE(sio->bvec) || !swap_plug) {
+       sio->nr_bvecs += 1;
+       if (sio->nr_bvecs == ARRAY_SIZE(sio->bvecs) || !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->bvecs, sio->nr_bvecs, sio->len);
        ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
        if (ret != -EIOCBQUEUED)
                sio_write_complete(&sio->iocb, ret);
@@ -489,8 +489,8 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
        int p;
 
        if (ret == sio->len) {
-               for (p = 0; p < sio->pages; p++) {
-                       struct folio *folio = page_folio(sio->bvec[p].bv_page);
+               for (p = 0; p < sio->nr_bvecs; p++) {
+                       struct folio *folio = page_folio(sio->bvecs[p].bv_page);
 
                        count_mthp_stat(folio_order(folio), MTHP_STAT_SWPIN);
                        count_memcg_folio_events(folio, PSWPIN, folio_nr_pages(folio));
@@ -499,8 +499,8 @@ 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++) {
-                       struct folio *folio = page_folio(sio->bvec[p].bv_page);
+               for (p = 0; p < sio->nr_bvecs; p++) {
+                       struct folio *folio = page_folio(sio->bvecs[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->nr_bvecs = 0;
                sio->len = 0;
        }
-       bvec_set_folio(&sio->bvec[sio->pages], folio, folio_size(folio), 0);
+       bvec_set_folio(&sio->bvecs[sio->nr_bvecs], folio, folio_size(folio), 0);
        sio->len += folio_size(folio);
-       sio->pages += 1;
-       if (sio->pages == ARRAY_SIZE(sio->bvec) || !plug) {
+       sio->nr_bvecs += 1;
+       if (sio->nr_bvecs == ARRAY_SIZE(sio->bvecs) || !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->bvecs, sio->nr_bvecs, sio->len);
        ret = mapping->a_ops->swap_rw(&sio->iocb, &from);
        if (ret != -EIOCBQUEUED)
                sio_read_complete(&sio->iocb, ret);