1 files changed, 45 insertions, 62 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 1963e26931..882a85826b 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -103,7 +103,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
                 spin_lock(&mm->page_table_lock);
                 if (likely(!vma->anon_vma)) {
                         vma->anon_vma = anon_vma;
-                        list_add(&vma->anon_vma_node, &anon_vma->head);
+                        list_add_tail(&vma->anon_vma_node, &anon_vma->head);
                         allocated = NULL;
                 }
                 spin_unlock(&mm->page_table_lock);
@@ -127,7 +127,7 @@ void __anon_vma_link(struct vm_area_struct *vma)
         struct anon_vma *anon_vma = vma->anon_vma;
 
         if (anon_vma) {
-                list_add(&vma->anon_vma_node, &anon_vma->head);
+                list_add_tail(&vma->anon_vma_node, &anon_vma->head);
                 validate_anon_vma(vma);
         }
 }
@@ -138,7 +138,7 @@ void anon_vma_link(struct vm_area_struct *vma)
 
         if (anon_vma) {
                 spin_lock(&anon_vma->lock);
-                list_add(&vma->anon_vma_node, &anon_vma->head);
+                list_add_tail(&vma->anon_vma_node, &anon_vma->head);
                 validate_anon_vma(vma);
                 spin_unlock(&anon_vma->lock);
         }
@@ -205,44 +205,6 @@ out:
         return anon_vma;
 }
 
-#ifdef CONFIG_MIGRATION
-/*
- * Remove an anonymous page from swap replacing the swap pte's
- * through real pte's pointing to valid pages and then releasing
- * the page from the swap cache.
- *
- * 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 (!PageSwapCache(page))
-                return;
-
-        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);
-#endif
-
 /*
  * At what user virtual address is page expected in vma?
  */
@@ -578,7 +540,7 @@ void page_remove_rmap(struct page *page)
  * repeatedly from either try_to_unmap_anon or try_to_unmap_file.
  */
 static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
-                                int ignore_refs)
+                                int migration)
 {
         struct mm_struct *mm = vma->vm_mm;
         unsigned long address;
@@ -602,7 +564,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
          */
         if ((vma->vm_flags & VM_LOCKED) ||
                         (ptep_clear_flush_young(vma, address, pte)
-                                && !ignore_refs)) {
+                                && !migration)) {
                 ret = SWAP_FAIL;
                 goto out_unmap;
         }
@@ -620,24 +582,45 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 
         if (PageAnon(page)) {
                 swp_entry_t entry = { .val = page_private(page) };
-                /*
-                 * Store the swap location in the pte.
-                 * See handle_pte_fault() ...
-                 */
-                BUG_ON(!PageSwapCache(page));
-                swap_duplicate(entry);
-                if (list_empty(&mm->mmlist)) {
-                        spin_lock(&mmlist_lock);
-                        if (list_empty(&mm->mmlist))
-                                list_add(&mm->mmlist, &init_mm.mmlist);
-                        spin_unlock(&mmlist_lock);
+
+                if (PageSwapCache(page)) {
+                        /*
+                         * Store the swap location in the pte.
+                         * See handle_pte_fault() ...
+                         */
+                        swap_duplicate(entry);
+                        if (list_empty(&mm->mmlist)) {
+                                spin_lock(&mmlist_lock);
+                                if (list_empty(&mm->mmlist))
+                                        list_add(&mm->mmlist, &init_mm.mmlist);
+                                spin_unlock(&mmlist_lock);
+                        }
+                        dec_mm_counter(mm, anon_rss);
+#ifdef CONFIG_MIGRATION
+                } else {
+                        /*
+                         * Store the pfn of the page in a special migration
+                         * pte. do_swap_page() will wait until the migration
+                         * pte is removed and then restart fault handling.
+                         */
+                        BUG_ON(!migration);
+                        entry = make_migration_entry(page, pte_write(pteval));
+#endif
                 }
                 set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
                 BUG_ON(pte_file(*pte));
-                dec_mm_counter(mm, anon_rss);
         } else
+#ifdef CONFIG_MIGRATION
+        if (migration) {
+                /* Establish migration entry for a file page */
+                swp_entry_t entry;
+                entry = make_migration_entry(page, pte_write(pteval));
+                set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
+        } else
+#endif
                 dec_mm_counter(mm, file_rss);
 
+
         page_remove_rmap(page);
         page_cache_release(page);
 
@@ -736,7 +719,7 @@ static void try_to_unmap_cluster(unsigned long cursor,
         pte_unmap_unlock(pte - 1, ptl);
 }
 
-static int try_to_unmap_anon(struct page *page, int ignore_refs)
+static int try_to_unmap_anon(struct page *page, int migration)
 {
         struct anon_vma *anon_vma;
         struct vm_area_struct *vma;
@@ -747,7 +730,7 @@ static int try_to_unmap_anon(struct page *page, int ignore_refs)
                 return ret;
 
         list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
-                ret = try_to_unmap_one(page, vma, ignore_refs);
+                ret = try_to_unmap_one(page, vma, migration);
                 if (ret == SWAP_FAIL || !page_mapped(page))
                         break;
         }
@@ -764,7 +747,7 @@ static int try_to_unmap_anon(struct page *page, int ignore_refs)
  *
  * This function is only called from try_to_unmap for object-based pages.
  */
-static int try_to_unmap_file(struct page *page, int ignore_refs)
+static int try_to_unmap_file(struct page *page, int migration)
 {
         struct address_space *mapping = page->mapping;
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -778,7 +761,7 @@ static int try_to_unmap_file(struct page *page, int ignore_refs)
 
         spin_lock(&mapping->i_mmap_lock);
         vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
-                ret = try_to_unmap_one(page, vma, ignore_refs);
+                ret = try_to_unmap_one(page, vma, migration);
                 if (ret == SWAP_FAIL || !page_mapped(page))
                         goto out;
         }
@@ -863,16 +846,16 @@ out:
  * SWAP_AGAIN   - we missed a mapping, try again later
  * SWAP_FAIL    - the page is unswappable
  */
-int try_to_unmap(struct page *page, int ignore_refs)
+int try_to_unmap(struct page *page, int migration)
 {
         int ret;
 
         BUG_ON(!PageLocked(page));
 
         if (PageAnon(page))
-                ret = try_to_unmap_anon(page, ignore_refs);
+                ret = try_to_unmap_anon(page, migration);
         else
-                ret = try_to_unmap_file(page, ignore_refs);
+                ret = try_to_unmap_file(page, migration);
 
         if (!page_mapped(page))
                 ret = SWAP_SUCCESS;