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authorLee Schermerhorn <Lee.Schermerhorn@hp.com>2009-12-14 20:58:49 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 11:53:16 -0500
commitd4906e1aa516cc965292b43b5a26122dd4344e7e (patch)
tree78c19149282e93200d90f380a40f1e1192354936 /mm/swapfile.c
parent7509765a29cfb1a4c506c09b304aaf3b4111c653 (diff)
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.c20
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 @@
38static bool swap_count_continued(struct swap_info_struct *, pgoff_t, 38static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
39 unsigned char); 39 unsigned char);
40static void free_swap_count_continuations(struct swap_info_struct *); 40static void free_swap_count_continuations(struct swap_info_struct *);
41static sector_t map_swap_entry(swp_entry_t, struct block_device**);
41 42
42static DEFINE_SPINLOCK(swap_lock); 43static DEFINE_SPINLOCK(swap_lock);
43static unsigned int nr_swapfiles; 44static unsigned int nr_swapfiles;
@@ -782,7 +783,7 @@ sector_t swapdev_block(int type, pgoff_t offset)
782 return 0; 783 return 0;
783 if (!(swap_info[type]->flags & SWP_WRITEOK)) 784 if (!(swap_info[type]->flags & SWP_WRITEOK))
784 return 0; 785 return 0;
785 return map_swap_page(swp_entry(type, offset), &bdev); 786 return map_swap_entry(swp_entry(type, offset), &bdev);
786} 787}
787 788
788/* 789/*
@@ -1249,10 +1250,11 @@ static void drain_mmlist(void)
1249 1250
1250/* 1251/*
1251 * Use this swapdev's extent info to locate the (PAGE_SIZE) block which 1252 * Use this swapdev's extent info to locate the (PAGE_SIZE) block which
1252 * corresponds to page offset `offset'. Note that the type of this function 1253 * corresponds to page offset for the specified swap entry.
1253 * is sector_t, but it returns page offset into the bdev, not sector offset. 1254 * Note that the type of this function is sector_t, but it returns page offset
1255 * into the bdev, not sector offset.
1254 */ 1256 */
1255sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev) 1257static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev)
1256{ 1258{
1257 struct swap_info_struct *sis; 1259 struct swap_info_struct *sis;
1258 struct swap_extent *start_se; 1260 struct swap_extent *start_se;
@@ -1281,6 +1283,16 @@ sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev)
1281} 1283}
1282 1284
1283/* 1285/*
1286 * Returns the page offset into bdev for the specified page's swap entry.
1287 */
1288sector_t map_swap_page(struct page *page, struct block_device **bdev)
1289{
1290 swp_entry_t entry;
1291 entry.val = page_private(page);
1292 return map_swap_entry(entry, bdev);
1293}
1294
1295/*
1284 * Free all of a swapdev's extent information 1296 * Free all of a swapdev's extent information
1285 */ 1297 */
1286static void destroy_swap_extents(struct swap_info_struct *sis) 1298static void destroy_swap_extents(struct swap_info_struct *sis)