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authorHugh Dickins <hugh@veritas.com>2008-02-04 22:28:50 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:15 -0800
commit73b1262fa43a778b1e154deea632cdef5009d6a1 (patch)
tree409f14e78e23cd999e8c3d1e0945f0fa9b67048f /mm/swap_state.c
parentf000944d03a5b74ab3c92b2fcdf0e944cc898065 (diff)
tmpfs: move swap swizzling into shmem
move_to_swap_cache and move_from_swap_cache functions (which swizzle a page between tmpfs page cache and swap cache, to avoid page copying) are only used by shmem.c; and our subsequent fix for unionfs needs different treatments in the two instances of move_from_swap_cache. Move them from swap_state.c into their callsites shmem_writepage, shmem_unuse_inode and shmem_getpage, making add_to_swap_cache externally visible. shmem.c likes to say set_page_dirty where swap_state.c liked to say SetPageDirty: respect that diversity, which __set_page_dirty_no_writeback makes moot (and implies we should lose that "shift page from clean_pages to dirty_pages list" comment: it's on neither). Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/swap_state.c')
-rw-r--r--mm/swap_state.c35
1 files changed, 1 insertions, 34 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c
index c75eda2c9cc5..65b81c92738f 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -67,8 +67,7 @@ void show_swap_cache_info(void)
* add_to_swap_cache resembles add_to_page_cache on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
-static int add_to_swap_cache(struct page *page, swp_entry_t entry,
- gfp_t gfp_mask)
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
{
int error;
@@ -183,38 +182,6 @@ void delete_from_swap_cache(struct page *page)
page_cache_release(page);
}
-/*
- * Strange swizzling function only for use by shmem_writepage
- */
-int move_to_swap_cache(struct page *page, swp_entry_t entry)
-{
- int err = add_to_swap_cache(page, entry, GFP_ATOMIC);
- if (!err) {
- remove_from_page_cache(page);
- page_cache_release(page); /* pagecache ref */
- if (!swap_duplicate(entry))
- BUG();
- SetPageDirty(page);
- }
- return err;
-}
-
-/*
- * Strange swizzling function for shmem_getpage (and shmem_unuse)
- */
-int move_from_swap_cache(struct page *page, unsigned long index,
- struct address_space *mapping)
-{
- int err = add_to_page_cache(page, mapping, index, GFP_ATOMIC);
- if (!err) {
- delete_from_swap_cache(page);
- /* shift page from clean_pages to dirty_pages list */
- ClearPageDirty(page);
- set_page_dirty(page);
- }
- return err;
-}
-
/*
* If we are the only user, then try to free up the swap cache.
*