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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 @@
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)