diff options
author | Lee Schermerhorn <Lee.Schermerhorn@hp.com> | 2009-12-15 01:58:49 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 16:53:16 (GMT) |
commit | d4906e1aa516cc965292b43b5a26122dd4344e7e (patch) | |
tree | 78c19149282e93200d90f380a40f1e1192354936 | |
parent | 7509765a29cfb1a4c506c09b304aaf3b4111c653 (diff) | |
download | linux-d4906e1aa516cc965292b43b5a26122dd4344e7e.tar.xz |
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>
-rw-r--r-- | include/linux/swap.h | 2 | ||||
-rw-r--r-- | mm/page_io.c | 4 | ||||
-rw-r--r-- | mm/swapfile.c | 20 |
3 files changed, 18 insertions, 8 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index 9f0ca32..a2602a8 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -325,7 +325,7 @@ extern void swapcache_free(swp_entry_t, struct page *page); extern int free_swap_and_cache(swp_entry_t); extern int swap_type_of(dev_t, sector_t, struct block_device **); extern unsigned int count_swap_pages(int, int); -extern sector_t map_swap_page(swp_entry_t, struct block_device **); +extern sector_t map_swap_page(struct page *, struct block_device **); extern sector_t swapdev_block(int, pgoff_t); extern int reuse_swap_page(struct page *); extern int try_to_free_swap(struct page *); diff --git a/mm/page_io.c b/mm/page_io.c index afeed89..a19af95 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; diff --git a/mm/swapfile.c b/mm/swapfile.c index 58bec66..d5eb2e8 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -38,6 +38,7 @@ static bool swap_count_continued(struct swap_info_struct *, pgoff_t, unsigned char); static void free_swap_count_continuations(struct swap_info_struct *); +static sector_t map_swap_entry(swp_entry_t, struct block_device**); static DEFINE_SPINLOCK(swap_lock); static unsigned int nr_swapfiles; @@ -782,7 +783,7 @@ sector_t swapdev_block(int type, pgoff_t offset) return 0; if (!(swap_info[type]->flags & SWP_WRITEOK)) return 0; - return map_swap_page(swp_entry(type, offset), &bdev); + return map_swap_entry(swp_entry(type, offset), &bdev); } /* @@ -1249,10 +1250,11 @@ static void drain_mmlist(void) /* * Use this swapdev's extent info to locate the (PAGE_SIZE) block which - * corresponds to page offset `offset'. Note that the type of this function - * is sector_t, but it returns page offset into the bdev, not sector offset. + * corresponds to page offset for the specified swap entry. + * Note that the type of this function is sector_t, but it returns page offset + * into the bdev, not sector offset. */ -sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev) +static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev) { struct swap_info_struct *sis; struct swap_extent *start_se; @@ -1281,6 +1283,16 @@ sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev) } /* + * Returns the page offset into bdev for the specified page's swap entry. + */ +sector_t map_swap_page(struct page *page, struct block_device **bdev) +{ + swp_entry_t entry; + entry.val = page_private(page); + return map_swap_entry(entry, bdev); +} + +/* * Free all of a swapdev's extent information */ static void destroy_swap_extents(struct swap_info_struct *sis) |