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Commit 93fac7041f082297b93655a0e49f659cd7520e40

Authored by Nick Piggin
Committed by Linus Torvalds
1 parent 9bf9e89c3d
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

[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: Nick Piggin <npiggin@suse.de>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 3 changed files with 24 additions and 6 deletions Side-by-side Diff

Documentation/feature-removal-schedule.txt
Diff comments   View file @ 93fac70
... ... @@ -241,4 +241,16 @@
241 241 Who: Greg Kroah-Hartman <gregkh@suse.de>
242 242  
243 243 ---------------------------
  244 +
  245 +What: find_trylock_page
  246 +When: January 2007
  247 +Why: The interface no longer has any callers left in the kernel. It
  248 + is an odd interface (compared with other find_*_page functions), in
  249 + that it does not take a refcount to the page, only the page lock.
  250 + It should be replaced with find_get_page or find_lock_page if possible.
  251 + This feature removal can be reevaluated if users of the interface
  252 + cannot cleanly use something else.
  253 +Who: Nick Piggin <npiggin@suse.de>
  254 +
  255 +---------------------------
include/linux/pagemap.h
Diff comments   View file @ 93fac70
... ... @@ -72,8 +72,8 @@
72 72 unsigned long index);
73 73 extern struct page * find_lock_page(struct address_space *mapping,
74 74 unsigned long index);
75   -extern struct page * find_trylock_page(struct address_space *mapping,
76   - unsigned long index);
  75 +extern __deprecated_for_modules struct page * find_trylock_page(
  76 + struct address_space *mapping, unsigned long index);
77 77 extern struct page * find_or_create_page(struct address_space *mapping,
78 78 unsigned long index, gfp_t gfp_mask);
79 79 unsigned find_get_pages(struct address_space *mapping, pgoff_t start,
... ... @@ -397,18 +397,24 @@
397 397  
398 398 p = swap_info_get(entry);
399 399 if (p) {
400   - if (swap_entry_free(p, swp_offset(entry)) == 1)
401   - page = find_trylock_page(&swapper_space, entry.val);
  400 + if (swap_entry_free(p, swp_offset(entry)) == 1) {
  401 + page = find_get_page(&swapper_space, entry.val);
  402 + if (page && unlikely(TestSetPageLocked(page))) {
  403 + page_cache_release(page);
  404 + page = NULL;
  405 + }
  406 + }
402 407 spin_unlock(&swap_lock);
403 408 }
404 409 if (page) {
405 410 int one_user;
406 411  
407 412 BUG_ON(PagePrivate(page));
408   - page_cache_get(page);
409 413 one_user = (page_count(page) == 2);
410 414 /* Only cache user (+us), or swap space full? Free it! */
411   - if (!PageWriteback(page) && (one_user || vm_swap_full())) {
  415 + /* Also recheck PageSwapCache after page is locked (above) */
  416 + if (PageSwapCache(page) && !PageWriteback(page) &&
  417 + (one_user || vm_swap_full())) {
412 418 delete_from_swap_cache(page);
413 419 SetPageDirty(page);
414 420 }