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| author | Lee Schermerhorn <Lee.Schermerhorn@hp.com> | 2009-12-14 17:58:49 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-15 08:53:16 -0800 |
| commit | d4906e1aa516cc965292b43b5a26122dd4344e7e (patch) | |
| tree | 78c19149282e93200d90f380a40f1e1192354936 /mm/swapfile.c | |
| parent | 7509765a29cfb1a4c506c09b304aaf3b4111c653 (diff) | |
| download | lwn-d4906e1aa516cc965292b43b5a26122dd4344e7e.tar.gz lwn-d4906e1aa516cc965292b43b5a26122dd4344e7e.zip | |
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>
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 58bec6600167..d5eb2e85600b 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) |