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Commit 93fac704 authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
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[PATCH] mm: schedule find_trylock_page() removal 



find_trylock_page() is an odd interface in that it doesn't take a reference
like the others.  Now that XFS no longer uses it, and its last remaining
caller actually wants an elevated refcount, opencode that callsite and
schedule find_trylock_page() for removal.

Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Acked-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9bf9e89c

Documentation/feature-removal-schedule.txt

+12 −0
Original line number Diff line number Diff line
@@ -241,3 +241,15 @@ Why: The USB subsystem has changed a lot over time, and it has been 
Who:	Greg Kroah-Hartman <gregkh@suse.de>



---------------------------



What:	find_trylock_page

When:	January 2007

Why:	The interface no longer has any callers left in the kernel. It

	is an odd interface (compared with other find_*_page functions), in

	that it does not take a refcount to the page, only the page lock.

	It should be replaced with find_get_page or find_lock_page if possible.

	This feature removal can be reevaluated if users of the interface

	cannot cleanly use something else.

Who:	Nick Piggin <npiggin@suse.de>



---------------------------

include/linux/pagemap.h

+2 −2
Original line number Diff line number Diff line
@@ -72,8 +72,8 @@ extern struct page * find_get_page(struct address_space *mapping, 
				unsigned long index);

extern struct page * find_lock_page(struct address_space *mapping,

				unsigned long index);

extern struct page * find_trylock_page(struct address_space *mapping,

				unsigned long index);

extern __deprecated_for_modules struct page * find_trylock_page(

			struct address_space *mapping, unsigned long index);

extern struct page * find_or_create_page(struct address_space *mapping,

				unsigned long index, gfp_t gfp_mask);

unsigned find_get_pages(struct address_space *mapping, pgoff_t start,

mm/swapfile.c

+10 −4
Original line number Diff line number Diff line
@@ -397,18 +397,24 @@ void free_swap_and_cache(swp_entry_t entry) 


	p = swap_info_get(entry);

	if (p) {

		if (swap_entry_free(p, swp_offset(entry)) == 1)

			page = find_trylock_page(&swapper_space, entry.val);

		if (swap_entry_free(p, swp_offset(entry)) == 1) {

			page = find_get_page(&swapper_space, entry.val);

			if (page && unlikely(TestSetPageLocked(page))) {

				page_cache_release(page);

				page = NULL;

			}

		}

		spin_unlock(&swap_lock);

	}

	if (page) {

		int one_user;



		BUG_ON(PagePrivate(page));

		page_cache_get(page);

		one_user = (page_count(page) == 2);

		/* Only cache user (+us), or swap space full? Free it! */

		if (!PageWriteback(page) && (one_user || vm_swap_full())) {

		/* Also recheck PageSwapCache after page is locked (above) */

		if (PageSwapCache(page) && !PageWriteback(page) &&

					(one_user || vm_swap_full())) {

			delete_from_swap_cache(page);

			SetPageDirty(page);

		}