1 files changed, 35 insertions, 19 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index f21f4a1d6a1c..941bf82e8961 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -497,41 +497,51 @@ int page_referenced_one(struct page *page, struct vm_area_struct *vma,
         struct mm_struct *mm = vma->vm_mm;
         int referenced = 0;
 
-        /*
-         * Don't want to elevate referenced for mlocked page that gets this far,
-         * in order that it progresses to try_to_unmap and is moved to the
-         * unevictable list.
-         */
-        if (vma->vm_flags & VM_LOCKED) {
-                *mapcount = 0;  /* break early from loop */
-                *vm_flags |= VM_LOCKED;
-                goto out;
-        }
-
-        /* Pretend the page is referenced if the task has the
-           swap token and is in the middle of a page fault. */
-        if (mm != current->mm && has_swap_token(mm) &&
-                        rwsem_is_locked(&mm->mmap_sem))
-                referenced++;
-
         if (unlikely(PageTransHuge(page))) {
                 pmd_t *pmd;
 
                 spin_lock(&mm->page_table_lock);
+                /*
+                 * rmap might return false positives; we must filter
+                 * these out using page_check_address_pmd().
+                 */
                 pmd = page_check_address_pmd(page, mm, address,
                                              PAGE_CHECK_ADDRESS_PMD_FLAG);
-                if (pmd && !pmd_trans_splitting(*pmd) &&
-                    pmdp_clear_flush_young_notify(vma, address, pmd))
+                if (!pmd) {
+                        spin_unlock(&mm->page_table_lock);
+                        goto out;
+                }
+
+                if (vma->vm_flags & VM_LOCKED) {
+                        spin_unlock(&mm->page_table_lock);
+                        *mapcount = 0;  /* break early from loop */
+                        *vm_flags |= VM_LOCKED;
+                        goto out;
+                }
+
+                /* go ahead even if the pmd is pmd_trans_splitting() */
+                if (pmdp_clear_flush_young_notify(vma, address, pmd))
                         referenced++;
                 spin_unlock(&mm->page_table_lock);
         } else {
                 pte_t *pte;
                 spinlock_t *ptl;
 
+                /*
+                 * rmap might return false positives; we must filter
+                 * these out using page_check_address().
+                 */
                 pte = page_check_address(page, mm, address, &ptl, 0);
                 if (!pte)
                         goto out;
 
+                if (vma->vm_flags & VM_LOCKED) {
+                        pte_unmap_unlock(pte, ptl);
+                        *mapcount = 0;  /* break early from loop */
+                        *vm_flags |= VM_LOCKED;
+                        goto out;
+                }
+
                 if (ptep_clear_flush_young_notify(vma, address, pte)) {
                         /*
                          * Don't treat a reference through a sequentially read
@@ -546,6 +556,12 @@ int page_referenced_one(struct page *page, struct vm_area_struct *vma,
                 pte_unmap_unlock(pte, ptl);
         }
 
+        /* Pretend the page is referenced if the task has the
+           swap token and is in the middle of a page fault. */
+        if (mm != current->mm && has_swap_token(mm) &&
+                        rwsem_is_locked(&mm->mmap_sem))
+                referenced++;
+
         (*mapcount)--;
 
         if (referenced)