swap: rework map_swap_page() again

Seems that page_io.c doesn't really need to know that page_private(page)
is the swp_entry 'val'.  Rework map_swap_page() to do what its name says
and map a page to a page offset in the swap space.

The only other caller of map_swap_page() is internal to mm/swapfile.c and
it does want to map a swap entry to the 'sector'.  So rename
map_swap_page() to map_swap_entry(), make it 'static' and and implement
map_swap_page() as a wrapper around that.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 3 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index afeed89a0a5d..a19af956ee1b 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -26,9 +26,7 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
 
         bio = bio_alloc(gfp_flags, 1);
         if (bio) {
-                swp_entry_t entry;
-                entry.val = page_private(page);
-                bio->bi_sector = map_swap_page(entry, &bio->bi_bdev);
+                bio->bi_sector = map_swap_page(page, &bio->bi_bdev);
                 bio->bi_sector <<= PAGE_SHIFT - 9;
                 bio->bi_io_vec[0].bv_page = page;
                 bio->bi_io_vec[0].bv_len = PAGE_SIZE;