1 files changed, 13 insertions, 6 deletions

diff --git a/mm/memory.c b/mm/memory.c
index dd7d7fc5ed60..65962534b4ed 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1467,11 +1467,21 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 goto gotten;
 
         /*
-         * Only catch write-faults on shared writable pages, read-only
-         * shared pages can get COWed by get_user_pages(.write=1, .force=1).
+         * Take out anonymous pages first, anonymous shared vmas are
+         * not dirty accountable.
          */
-        if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
+        if (PageAnon(old_page)) {
+                if (!TestSetPageLocked(old_page)) {
+                        reuse = can_share_swap_page(old_page);
+                        unlock_page(old_page);
+                }
+        } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
                                         (VM_WRITE|VM_SHARED))) {
+                /*
+                 * Only catch write-faults on shared writable pages,
+                 * read-only shared pages can get COWed by
+                 * get_user_pages(.write=1, .force=1).
+                 */
                 if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
                         /*
                          * Notify the address space that the page is about to
@@ -1503,9 +1513,6 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 dirty_page = old_page;
                 get_page(dirty_page);
                 reuse = 1;
-        } else if (PageAnon(old_page) && !TestSetPageLocked(old_page)) {
-                reuse = can_share_swap_page(old_page);
-                unlock_page(old_page);
         }
 
         if (reuse) {