swap_info: private to swapfile.c
The swap_info_struct is mostly private to mm/swapfile.c, with only
one other in-tree user: get_swap_bio(). Adjust its interface to
map_swap_page(), so that we can then remove get_swap_info_struct().
But there is a popular user out-of-tree, TuxOnIce: so leave the
declaration of swap_info_struct in linux/swap.h.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Nigel Cunningham <ncunningham@crca.org.au>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 9c590ee..f83f1c6 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1283,12 +1283,22 @@
/*
* Use this swapdev's extent info to locate the (PAGE_SIZE) block which
- * corresponds to page offset `offset'.
+ * 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.
*/
-sector_t map_swap_page(struct swap_info_struct *sis, pgoff_t offset)
+sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev)
{
- struct swap_extent *se = sis->curr_swap_extent;
- struct swap_extent *start_se = se;
+ struct swap_info_struct *sis;
+ struct swap_extent *start_se;
+ struct swap_extent *se;
+ pgoff_t offset;
+
+ sis = swap_info + swp_type(entry);
+ *bdev = sis->bdev;
+
+ offset = swp_offset(entry);
+ start_se = sis->curr_swap_extent;
+ se = start_se;
for ( ; ; ) {
struct list_head *lh;
@@ -1314,12 +1324,14 @@
sector_t swapdev_block(int swap_type, pgoff_t offset)
{
struct swap_info_struct *sis;
+ struct block_device *bdev;
if (swap_type >= nr_swapfiles)
return 0;
sis = swap_info + swap_type;
- return (sis->flags & SWP_WRITEOK) ? map_swap_page(sis, offset) : 0;
+ return (sis->flags & SWP_WRITEOK) ?
+ map_swap_page(swp_entry(swap_type, offset), &bdev) : 0;
}
#endif /* CONFIG_HIBERNATION */
@@ -2159,13 +2171,6 @@
return __swap_duplicate(entry, SWAP_CACHE);
}
-
-struct swap_info_struct *
-get_swap_info_struct(unsigned type)
-{
- return &swap_info[type];
-}
-
/*
* swap_lock prevents swap_map being freed. Don't grab an extra
* reference on the swaphandle, it doesn't matter if it becomes unused.