Update to 3.4-final.

[linux-flexiantxendom0-3.2.10.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index 4c98630..2189af4 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -37,16 +37,53 @@ static inline void __put_page(struct page *page)
        atomic_dec(&page->_count);
 }
 
-extern unsigned long highest_memmap_pfn;
+static inline void __get_page_tail_foll(struct page *page,
+                                       bool get_page_head)
+{
+       /*
+        * If we're getting a tail page, the elevated page->_count is
+        * required only in the head page and we will elevate the head
+        * page->_count and tail page->_mapcount.
+        *
+        * We elevate page_tail->_mapcount for tail pages to force
+        * page_tail->_count to be zero at all times to avoid getting
+        * false positives from get_page_unless_zero() with
+        * speculative page access (like in
+        * page_cache_get_speculative()) on tail pages.
+        */
+       VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0);
+       VM_BUG_ON(atomic_read(&page->_count) != 0);
+       VM_BUG_ON(page_mapcount(page) < 0);
+       if (get_page_head)
+               atomic_inc(&page->first_page->_count);
+       atomic_inc(&page->_mapcount);
+}
 
-#ifdef CONFIG_SMP
-extern int putback_active_lru_page(struct zone *zone, struct page *page);
-#else
-static inline int putback_active_lru_page(struct zone *zone, struct page *page)
+/*
+ * This is meant to be called as the FOLL_GET operation of
+ * follow_page() and it must be called while holding the proper PT
+ * lock while the pte (or pmd_trans_huge) is still mapping the page.
+ */
+static inline void get_page_foll(struct page *page)
 {
-       return 0;
+       if (unlikely(PageTail(page)))
+               /*
+                * This is safe only because
+                * __split_huge_page_refcount() can't run under
+                * get_page_foll() because we hold the proper PT lock.
+                */
+               __get_page_tail_foll(page, true);
+       else {
+               /*
+                * Getting a normal page or the head of a compound page
+                * requires to already have an elevated page->_count.
+                */
+               VM_BUG_ON(atomic_read(&page->_count) <= 0);
+               atomic_inc(&page->_count);
+       }
 }
-#endif
+
+extern unsigned long highest_memmap_pfn;
 
 /*
  * in mm/vmscan.c:
@@ -75,6 +112,10 @@ static inline unsigned long page_order(struct page *page)
        return page_private(page);
 }
 
+/* mm/util.c */
+void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
+               struct vm_area_struct *prev, struct rb_node *rb_parent);
+
 #ifdef CONFIG_MMU
 extern long mlock_vma_pages_range(struct vm_area_struct *vma,
                        unsigned long start, unsigned long end);
@@ -171,7 +212,7 @@ static inline struct page *mem_map_offset(struct page *base, int offset)
 }
 
 /*
- * Iterator over all subpages withing the maximally aligned gigantic
+ * Iterator over all subpages within the maximally aligned gigantic
  * page 'base'.  Handle any discontiguity in the mem_map.
  */
 static inline struct page *mem_map_next(struct page *iter,
@@ -254,11 +295,6 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 }
 #endif /* CONFIG_SPARSEMEM */
 
-int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                    unsigned long start, int len, unsigned int foll_flags,
-                    struct page **pages, struct vm_area_struct **vmas,
-                    int *nonblocking);
-
 #define ZONE_RECLAIM_NOSCAN    -2
 #define ZONE_RECLAIM_FULL      -1
 #define ZONE_RECLAIM_SOME      0