1 files changed, 36 insertions, 8 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 5da31c12101c..709742be02f0 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -32,6 +32,34 @@ static inline void mapping_set_error(struct address_space *mapping, int error)
         }
 }
 
+#ifdef CONFIG_UNEVICTABLE_LRU
+#define AS_UNEVICTABLE  (__GFP_BITS_SHIFT + 2)  /* e.g., ramdisk, SHM_LOCK */
+
+static inline void mapping_set_unevictable(struct address_space *mapping)
+{
+        set_bit(AS_UNEVICTABLE, &mapping->flags);
+}
+
+static inline void mapping_clear_unevictable(struct address_space *mapping)
+{
+        clear_bit(AS_UNEVICTABLE, &mapping->flags);
+}
+
+static inline int mapping_unevictable(struct address_space *mapping)
+{
+        if (likely(mapping))
+                return test_bit(AS_UNEVICTABLE, &mapping->flags);
+        return !!mapping;
+}
+#else
+static inline void mapping_set_unevictable(struct address_space *mapping) { }
+static inline void mapping_clear_unevictable(struct address_space *mapping) { }
+static inline int mapping_unevictable(struct address_space *mapping)
+{
+        return 0;
+}
+#endif
+
 static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
 {
         return (__force gfp_t)mapping->flags & __GFP_BITS_MASK;
@@ -271,19 +299,19 @@ extern int __lock_page_killable(struct page *page);
 extern void __lock_page_nosync(struct page *page);
 extern void unlock_page(struct page *page);
 
-static inline void set_page_locked(struct page *page)
+static inline void __set_page_locked(struct page *page)
 {
-        set_bit(PG_locked, &page->flags);
+        __set_bit(PG_locked, &page->flags);
 }
 
-static inline void clear_page_locked(struct page *page)
+static inline void __clear_page_locked(struct page *page)
 {
-        clear_bit(PG_locked, &page->flags);
+        __clear_bit(PG_locked, &page->flags);
 }
 
 static inline int trylock_page(struct page *page)
 {
-        return !test_and_set_bit(PG_locked, &page->flags);
+        return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
 }
 
 /*
@@ -410,17 +438,17 @@ extern void __remove_from_page_cache(struct page *page);
 
 /*
  * Like add_to_page_cache_locked, but used to add newly allocated pages:
- * the page is new, so we can just run set_page_locked() against it.
+ * the page is new, so we can just run __set_page_locked() against it.
  */
 static inline int add_to_page_cache(struct page *page,
                 struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
 {
         int error;
 
-        set_page_locked(page);
+        __set_page_locked(page);
         error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
         if (unlikely(error))
-                clear_page_locked(page);
+                __clear_page_locked(page);
         return error;
 }