1 files changed, 76 insertions, 5 deletions

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index cb0ba7032609..d25bd224d370 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -26,6 +26,9 @@
  */
 struct anon_vma {
         spinlock_t lock;        /* Serialize access to vma list */
+#ifdef CONFIG_KSM
+        atomic_t ksm_refcount;
+#endif
         /*
          * NOTE: the LSB of the head.next is set by
          * mm_take_all_locks() _after_ taking the above lock. So the
@@ -34,10 +37,58 @@ struct anon_vma {
          * is serialized by a system wide lock only visible to
          * mm_take_all_locks() (mm_all_locks_mutex).
          */
-        struct list_head head;  /* List of private "related" vmas */
+        struct list_head head;  /* Chain of private "related" vmas */
+};
+
+/*
+ * The copy-on-write semantics of fork mean that an anon_vma
+ * can become associated with multiple processes. Furthermore,
+ * each child process will have its own anon_vma, where new
+ * pages for that process are instantiated.
+ *
+ * This structure allows us to find the anon_vmas associated
+ * with a VMA, or the VMAs associated with an anon_vma.
+ * The "same_vma" list contains the anon_vma_chains linking
+ * all the anon_vmas associated with this VMA.
+ * The "same_anon_vma" list contains the anon_vma_chains
+ * which link all the VMAs associated with this anon_vma.
+ */
+struct anon_vma_chain {
+        struct vm_area_struct *vma;
+        struct anon_vma *anon_vma;
+        struct list_head same_vma;   /* locked by mmap_sem & page_table_lock */
+        struct list_head same_anon_vma; /* locked by anon_vma->lock */
 };
 
 #ifdef CONFIG_MMU
+#ifdef CONFIG_KSM
+static inline void ksm_refcount_init(struct anon_vma *anon_vma)
+{
+        atomic_set(&anon_vma->ksm_refcount, 0);
+}
+
+static inline int ksm_refcount(struct anon_vma *anon_vma)
+{
+        return atomic_read(&anon_vma->ksm_refcount);
+}
+#else
+static inline void ksm_refcount_init(struct anon_vma *anon_vma)
+{
+}
+
+static inline int ksm_refcount(struct anon_vma *anon_vma)
+{
+        return 0;
+}
+#endif /* CONFIG_KSM */
+
+static inline struct anon_vma *page_anon_vma(struct page *page)
+{
+        if (((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) !=
+                                            PAGE_MAPPING_ANON)
+                return NULL;
+        return page_rmapping(page);
+}
 
 static inline void anon_vma_lock(struct vm_area_struct *vma)
 {
@@ -58,14 +109,23 @@ static inline void anon_vma_unlock(struct vm_area_struct *vma)
  */
 void anon_vma_init(void);       /* create anon_vma_cachep */
 int  anon_vma_prepare(struct vm_area_struct *);
-void __anon_vma_merge(struct vm_area_struct *, struct vm_area_struct *);
-void anon_vma_unlink(struct vm_area_struct *);
-void anon_vma_link(struct vm_area_struct *);
+void unlink_anon_vmas(struct vm_area_struct *);
+int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
+int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
 void __anon_vma_link(struct vm_area_struct *);
+void anon_vma_free(struct anon_vma *);
+
+static inline void anon_vma_merge(struct vm_area_struct *vma,
+                                  struct vm_area_struct *next)
+{
+        VM_BUG_ON(vma->anon_vma != next->anon_vma);
+        unlink_anon_vmas(next);
+}
 
 /*
  * rmap interfaces called when adding or removing pte of page
  */
+void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
 void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
 void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
 void page_add_file_rmap(struct page *);
@@ -81,6 +141,9 @@ static inline void page_dup_rmap(struct page *page)
  */
 int page_referenced(struct page *, int is_locked,
                         struct mem_cgroup *cnt, unsigned long *vm_flags);
+int page_referenced_one(struct page *, struct vm_area_struct *,
+        unsigned long address, unsigned int *mapcount, unsigned long *vm_flags);
+
 enum ttu_flags {
         TTU_UNMAP = 0,                  /* unmap mode */
         TTU_MIGRATION = 1,              /* migration mode */
@@ -94,6 +157,8 @@ enum ttu_flags {
 #define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
 
 int try_to_unmap(struct page *, enum ttu_flags flags);
+int try_to_unmap_one(struct page *, struct vm_area_struct *,
+                        unsigned long address, enum ttu_flags flags);
 
 /*
  * Called from mm/filemap_xip.c to unmap empty zero page
@@ -127,6 +192,12 @@ struct anon_vma *page_lock_anon_vma(struct page *page);
 void page_unlock_anon_vma(struct anon_vma *anon_vma);
 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 
+/*
+ * Called by migrate.c to remove migration ptes, but might be used more later.
+ */
+int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
+                struct vm_area_struct *, unsigned long, void *), void *arg);
+
 #else   /* !CONFIG_MMU */
 
 #define anon_vma_init()         do {} while (0)
@@ -138,7 +209,7 @@ static inline int page_referenced(struct page *page, int is_locked,
                                   unsigned long *vm_flags)
 {
         *vm_flags = 0;
-        return TestClearPageReferenced(page);
+        return 0;
 }
 
 #define try_to_unmap(page, refs) SWAP_FAIL