Fix set_page_count() macro to handle complex arguments.
Signed-off-by: Avishay Traeger <atraeger@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
  */
 #define get_page_testone(p)    atomic_inc_and_test(&(p)->_count)
 
-#define set_page_count(p,v)    atomic_set(&(p)->_count, v - 1)
+#define set_page_count(p,v)    atomic_set(&(p)->_count, (v) - 1)
 #define __put_page(p)          atomic_dec(&(p)->_count)
 
 extern void FASTCALL(__page_cache_release(struct page *));