1 files changed, 141 insertions, 140 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 2a80136b23bb..1e0d6b237f44 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -37,36 +37,6 @@
 #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru))
 
 /*
- * Isolate one page from the LRU lists. If successful put it onto
- * the indicated list with elevated page count.
- *
- * Result:
- *  -EBUSY: page not on LRU list
- *  0: page removed from LRU list and added to the specified list.
- */
-int isolate_lru_page(struct page *page, struct list_head *pagelist)
-{
-        int ret = -EBUSY;
-
-        if (PageLRU(page)) {
-                struct zone *zone = page_zone(page);
-
-                spin_lock_irq(&zone->lru_lock);
-                if (PageLRU(page) && get_page_unless_zero(page)) {
-                        ret = 0;
-                        ClearPageLRU(page);
-                        if (PageActive(page))
-                                del_page_from_active_list(zone, page);
-                        else
-                                del_page_from_inactive_list(zone, page);
-                        list_add_tail(&page->lru, pagelist);
-                }
-                spin_unlock_irq(&zone->lru_lock);
-        }
-        return ret;
-}
-
-/*
  * migrate_prep() needs to be called before we start compiling a list of pages
  * to be migrated using isolate_lru_page().
  */
@@ -83,23 +53,9 @@ int migrate_prep(void)
         return 0;
 }
 
-static inline void move_to_lru(struct page *page)
-{
-        if (PageActive(page)) {
-                /*
-                 * lru_cache_add_active checks that
-                 * the PG_active bit is off.
-                 */
-                ClearPageActive(page);
-                lru_cache_add_active(page);
-        } else {
-                lru_cache_add(page);
-        }
-        put_page(page);
-}
-
 /*
- * Add isolated pages on the list back to the LRU.
+ * Add isolated pages on the list back to the LRU under page lock
+ * to avoid leaking evictable pages back onto unevictable list.
  *
  * returns the number of pages put back.
  */
@@ -111,7 +67,7 @@ int putback_lru_pages(struct list_head *l)
 
         list_for_each_entry_safe(page, page2, l, lru) {
                 list_del(&page->lru);
-                move_to_lru(page);
+                putback_lru_page(page);
                 count++;
         }
         return count;
@@ -374,8 +330,6 @@ static int migrate_page_move_mapping(struct address_space *mapping,
         __inc_zone_page_state(newpage, NR_FILE_PAGES);
 
         spin_unlock_irq(&mapping->tree_lock);
-        if (!PageSwapCache(newpage))
-                mem_cgroup_uncharge_cache_page(page);
 
         return 0;
 }
@@ -385,6 +339,8 @@ static int migrate_page_move_mapping(struct address_space *mapping,
  */
 static void migrate_page_copy(struct page *newpage, struct page *page)
 {
+        int anon;
+
         copy_highpage(newpage, page);
 
         if (PageError(page))
@@ -393,8 +349,11 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
                 SetPageReferenced(newpage);
         if (PageUptodate(page))
                 SetPageUptodate(newpage);
-        if (PageActive(page))
+        if (TestClearPageActive(page)) {
+                VM_BUG_ON(PageUnevictable(page));
                 SetPageActive(newpage);
+        } else
+                unevictable_migrate_page(newpage, page);
         if (PageChecked(page))
                 SetPageChecked(newpage);
         if (PageMappedToDisk(page))
@@ -412,14 +371,20 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
                 __set_page_dirty_nobuffers(newpage);
         }
 
+        mlock_migrate_page(newpage, page);
+
 #ifdef CONFIG_SWAP
         ClearPageSwapCache(page);
 #endif
-        ClearPageActive(page);
         ClearPagePrivate(page);
         set_page_private(page, 0);
+        /* page->mapping contains a flag for PageAnon() */
+        anon = PageAnon(page);
         page->mapping = NULL;
 
+        if (!anon) /* This page was removed from radix-tree. */
+                mem_cgroup_uncharge_cache_page(page);
+
         /*
          * If any waiters have accumulated on the new page then
          * wake them up.
@@ -557,15 +522,12 @@ static int writeout(struct address_space *mapping, struct page *page)
         remove_migration_ptes(page, page);
 
         rc = mapping->a_ops->writepage(page, &wbc);
-        if (rc < 0)
-                /* I/O Error writing */
-                return -EIO;
 
         if (rc != AOP_WRITEPAGE_ACTIVATE)
                 /* unlocked. Relock */
                 lock_page(page);
 
-        return -EAGAIN;
+        return (rc < 0) ? -EIO : -EAGAIN;
 }
 
 /*
@@ -594,6 +556,10 @@ static int fallback_migrate_page(struct address_space *mapping,
  *
  * The new page will have replaced the old page if this function
  * is successful.
+ *
+ * Return value:
+ *   < 0 - error code
+ *  == 0 - success
  */
 static int move_to_new_page(struct page *newpage, struct page *page)
 {
@@ -611,6 +577,8 @@ static int move_to_new_page(struct page *newpage, struct page *page)
         /* Prepare mapping for the new page.*/
         newpage->index = page->index;
         newpage->mapping = page->mapping;
+        if (PageSwapBacked(page))
+                SetPageSwapBacked(newpage);
 
         mapping = page_mapping(page);
         if (!mapping)
@@ -654,9 +622,10 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
         if (!newpage)
                 return -ENOMEM;
 
-        if (page_count(page) == 1)
+        if (page_count(page) == 1) {
                 /* page was freed from under us. So we are done. */
                 goto move_newpage;
+        }
 
         charge = mem_cgroup_prepare_migration(page, newpage);
         if (charge == -ENOMEM) {
@@ -730,7 +699,6 @@ rcu_unlock:
                 rcu_read_unlock();
 
 unlock:
-
         unlock_page(page);
 
         if (rc != -EAGAIN) {
@@ -741,17 +709,19 @@ unlock:
                  * restored.
                  */
                 list_del(&page->lru);
-                move_to_lru(page);
+                putback_lru_page(page);
         }
 
 move_newpage:
         if (!charge)
                 mem_cgroup_end_migration(newpage);
+
         /*
          * Move the new page to the LRU. If migration was not successful
          * then this will free the page.
          */
-        move_to_lru(newpage);
+        putback_lru_page(newpage);
+
         if (result) {
                 if (rc)
                         *result = rc;
@@ -858,20 +828,22 @@ static struct page *new_page_node(struct page *p, unsigned long private,
  * Move a set of pages as indicated in the pm array. The addr
  * field must be set to the virtual address of the page to be moved
  * and the node number must contain a valid target node.
+ * The pm array ends with node = MAX_NUMNODES.
  */
-static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm,
-                                int migrate_all)
+static int do_move_page_to_node_array(struct mm_struct *mm,
+                                      struct page_to_node *pm,
+                                      int migrate_all)
 {
         int err;
         struct page_to_node *pp;
         LIST_HEAD(pagelist);
 
+        migrate_prep();
         down_read(&mm->mmap_sem);
 
         /*
          * Build a list of pages to migrate
          */
-        migrate_prep();
         for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
                 struct vm_area_struct *vma;
                 struct page *page;
@@ -914,7 +886,9 @@ static int do_move_pages(struct mm_struct *mm, struct page_to_node *pm,
                                 !migrate_all)
                         goto put_and_set;
 
-                err = isolate_lru_page(page, &pagelist);
+                err = isolate_lru_page(page);
+                if (!err)
+                        list_add_tail(&page->lru, &pagelist);
 put_and_set:
                 /*
                  * Either remove the duplicate refcount from
@@ -926,36 +900,118 @@ set_status:
                 pp->status = err;
         }
 
+        err = 0;
         if (!list_empty(&pagelist))
                 err = migrate_pages(&pagelist, new_page_node,
                                 (unsigned long)pm);
-        else
-                err = -ENOENT;
 
         up_read(&mm->mmap_sem);
         return err;
 }
 
 /*
- * Determine the nodes of a list of pages. The addr in the pm array
- * must have been set to the virtual address of which we want to determine
- * the node number.
+ * Migrate an array of page address onto an array of nodes and fill
+ * the corresponding array of status.
  */
-static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm)
+static int do_pages_move(struct mm_struct *mm, struct task_struct *task,
+                         unsigned long nr_pages,
+                         const void __user * __user *pages,
+                         const int __user *nodes,
+                         int __user *status, int flags)
 {
+        struct page_to_node *pm = NULL;
+        nodemask_t task_nodes;
+        int err = 0;
+        int i;
+
+        task_nodes = cpuset_mems_allowed(task);
+
+        /* Limit nr_pages so that the multiplication may not overflow */
+        if (nr_pages >= ULONG_MAX / sizeof(struct page_to_node) - 1) {
+                err = -E2BIG;
+                goto out;
+        }
+
+        pm = vmalloc((nr_pages + 1) * sizeof(struct page_to_node));
+        if (!pm) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        /*
+         * Get parameters from user space and initialize the pm
+         * array. Return various errors if the user did something wrong.
+         */
+        for (i = 0; i < nr_pages; i++) {
+                const void __user *p;
+
+                err = -EFAULT;
+                if (get_user(p, pages + i))
+                        goto out_pm;
+
+                pm[i].addr = (unsigned long)p;
+                if (nodes) {
+                        int node;
+
+                        if (get_user(node, nodes + i))
+                                goto out_pm;
+
+                        err = -ENODEV;
+                        if (!node_state(node, N_HIGH_MEMORY))
+                                goto out_pm;
+
+                        err = -EACCES;
+                        if (!node_isset(node, task_nodes))
+                                goto out_pm;
+
+                        pm[i].node = node;
+                } else
+                        pm[i].node = 0; /* anything to not match MAX_NUMNODES */
+        }
+        /* End marker */
+        pm[nr_pages].node = MAX_NUMNODES;
+
+        err = do_move_page_to_node_array(mm, pm, flags & MPOL_MF_MOVE_ALL);
+        if (err >= 0)
+                /* Return status information */
+                for (i = 0; i < nr_pages; i++)
+                        if (put_user(pm[i].status, status + i))
+                                err = -EFAULT;
+
+out_pm:
+        vfree(pm);
+out:
+        return err;
+}
+
+/*
+ * Determine the nodes of an array of pages and store it in an array of status.
+ */
+static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
+                         const void __user * __user *pages,
+                         int __user *status)
+{
+        unsigned long i;
+        int err;
+
         down_read(&mm->mmap_sem);
 
-        for ( ; pm->node != MAX_NUMNODES; pm++) {
+        for (i = 0; i < nr_pages; i++) {
+                const void __user *p;
+                unsigned long addr;
                 struct vm_area_struct *vma;
                 struct page *page;
-                int err;
 
                 err = -EFAULT;
-                vma = find_vma(mm, pm->addr);
+                if (get_user(p, pages+i))
+                        goto out;
+                addr = (unsigned long) p;
+
+                vma = find_vma(mm, addr);
                 if (!vma)
                         goto set_status;
 
-                page = follow_page(vma, pm->addr, 0);
+                page = follow_page(vma, addr, 0);
 
                 err = PTR_ERR(page);
                 if (IS_ERR(page))
@@ -968,11 +1024,13 @@ static int do_pages_stat(struct mm_struct *mm, struct page_to_node *pm)
 
                 err = page_to_nid(page);
 set_status:
-                pm->status = err;
+                put_user(err, status+i);
         }
+        err = 0;
 
+out:
         up_read(&mm->mmap_sem);
-        return 0;
+        return err;
 }
 
 /*
@@ -984,12 +1042,9 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
                         const int __user *nodes,
                         int __user *status, int flags)
 {
-        int err = 0;
-        int i;
         struct task_struct *task;
-        nodemask_t task_nodes;
         struct mm_struct *mm;
-        struct page_to_node *pm = NULL;
+        int err;
 
         /* Check flags */
         if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
@@ -1021,75 +1076,21 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
             (current->uid != task->suid) && (current->uid != task->uid) &&
             !capable(CAP_SYS_NICE)) {
                 err = -EPERM;
-                goto out2;
+                goto out;
         }
 
         err = security_task_movememory(task);
         if (err)
-                goto out2;
-
-
-        task_nodes = cpuset_mems_allowed(task);
-
-        /* Limit nr_pages so that the multiplication may not overflow */
-        if (nr_pages >= ULONG_MAX / sizeof(struct page_to_node) - 1) {
-                err = -E2BIG;
-                goto out2;
-        }
-
-        pm = vmalloc((nr_pages + 1) * sizeof(struct page_to_node));
-        if (!pm) {
-                err = -ENOMEM;
-                goto out2;
-        }
-
-        /*
-         * Get parameters from user space and initialize the pm
-         * array. Return various errors if the user did something wrong.
-         */
-        for (i = 0; i < nr_pages; i++) {
-                const void __user *p;
-
-                err = -EFAULT;
-                if (get_user(p, pages + i))
-                        goto out;
-
-                pm[i].addr = (unsigned long)p;
-                if (nodes) {
-                        int node;
-
-                        if (get_user(node, nodes + i))
-                                goto out;
-
-                        err = -ENODEV;
-                        if (!node_state(node, N_HIGH_MEMORY))
-                                goto out;
-
-                        err = -EACCES;
-                        if (!node_isset(node, task_nodes))
-                                goto out;
+                goto out;
 
-                        pm[i].node = node;
-                } else
-                        pm[i].node = 0; /* anything to not match MAX_NUMNODES */
+        if (nodes) {
+                err = do_pages_move(mm, task, nr_pages, pages, nodes, status,
+                                    flags);
+        } else {
+                err = do_pages_stat(mm, nr_pages, pages, status);
         }
-        /* End marker */
-        pm[nr_pages].node = MAX_NUMNODES;
-
-        if (nodes)
-                err = do_move_pages(mm, pm, flags & MPOL_MF_MOVE_ALL);
-        else
-                err = do_pages_stat(mm, pm);
-
-        if (err >= 0)
-                /* Return status information */
-                for (i = 0; i < nr_pages; i++)
-                        if (put_user(pm[i].status, status + i))
-                                err = -EFAULT;
 
 out:
-        vfree(pm);
-out2:
         mmput(mm);
         return err;
 }