1 files changed, 13 insertions, 8 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index df2c41c2a9a2..67f0e20b101f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -212,25 +212,33 @@ out:
  * through real pte's pointing to valid pages and then releasing
  * the page from the swap cache.
  *
- * Must hold page lock on page.
+ * Must hold page lock on page and mmap_sem of one vma that contains
+ * the page.
  */
 void remove_from_swap(struct page *page)
 {
         struct anon_vma *anon_vma;
         struct vm_area_struct *vma;
+        unsigned long mapping;
 
-        if (!PageAnon(page) || !PageSwapCache(page))
+        if (!PageSwapCache(page))
                 return;
 
-        anon_vma = page_lock_anon_vma(page);
-        if (!anon_vma)
+        mapping = (unsigned long)page->mapping;
+
+        if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
                 return;
 
+        /*
+         * We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
+         */
+        anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
+        spin_lock(&anon_vma->lock);
+
         list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
                 remove_vma_swap(vma, page);
 
         spin_unlock(&anon_vma->lock);
-
         delete_from_swap_cache(page);
 }
 EXPORT_SYMBOL(remove_from_swap);
@@ -529,9 +537,6 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-        BUG_ON(PageAnon(page));
-        BUG_ON(!pfn_valid(page_to_pfn(page)));
-
         if (atomic_inc_and_test(&page->_mapcount))
                 __inc_page_state(nr_mapped);
 }