[PATCH] remove set_page_count() outside mm/

set_page_count usage outside mm/ is limited to setting the refcount to 1.
Remove set_page_count from outside mm/, and replace those users with
init_page_count() and set_page_refcounted().

This allows more debug checking, and tighter control on how code is allowed
to play around with page->_count.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3d84b7a35e0d..7d8c127daad7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -307,8 +307,6 @@ static inline int get_page_unless_zero(struct page *page)
         return atomic_inc_not_zero(&page->_count);
 }
 
-#define set_page_count(p,v)     atomic_set(&(p)->_count, (v))
-
 extern void FASTCALL(__page_cache_release(struct page *));
 
 static inline int page_count(struct page *page)
@@ -325,6 +323,15 @@ static inline void get_page(struct page *page)
         atomic_inc(&page->_count);
 }
 
+/*
+ * Setup the page count before being freed into the page allocator for
+ * the first time (boot or memory hotplug)
+ */
+static inline void init_page_count(struct page *page)
+{
+        atomic_set(&page->_count, 1);
+}
+
 void put_page(struct page *page);
 
 void split_page(struct page *page, unsigned int order);