X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Frmap.c;h=450f5241b5a525282ae7eb150fe322423b01e570;hb=570bc1c2e5ccdb408081e77507a385dc7ebed7fa;hp=9827409eb7c7ea4026e27b34fdaceacd909cabc3;hpb=2089a0d38bc9c2cdd084207ebf7082b18cf4bf58;p=linux-2.6

diff --git a/mm/rmap.c b/mm/rmap.c
index 9827409eb7..450f5241b5 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -34,9 +34,8 @@
  *       anon_vma->lock
  *         mm->page_table_lock
  *           zone->lru_lock (in mark_page_accessed)
- *           swap_list_lock (in swap_free etc's swap_info_get)
+ *           swap_lock (in swap_duplicate, swap_info_get)
  *             mmlist_lock (in mmput, drain_mmlist and others)
- *             swap_device_lock (in swap_duplicate, swap_info_get)
  *             mapping->private_lock (in __set_page_dirty_buffers)
  *             inode_lock (in set_page_dirty's __mark_inode_dirty)
  *               sb_lock (within inode_lock in fs/fs-writeback.c)
@@ -247,8 +246,8 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
  *
  * On success returns with mapped pte and locked mm->page_table_lock.
  */
-static pte_t *page_check_address(struct page *page, struct mm_struct *mm,
-					unsigned long address)
+pte_t *page_check_address(struct page *page, struct mm_struct *mm,
+			  unsigned long address)
 {
 	pgd_t *pgd;
 	pud_t *pud;
@@ -290,8 +289,6 @@ static int page_referenced_one(struct page *page,
 	pte_t *pte;
 	int referenced = 0;
 
-	if (!get_mm_counter(mm, rss))
-		goto out;
 	address = vma_address(page, vma);
 	if (address == -EFAULT)
 		goto out;
@@ -442,22 +439,19 @@ int page_referenced(struct page *page, int is_locked, int ignore_token)
 void page_add_anon_rmap(struct page *page,
 	struct vm_area_struct *vma, unsigned long address)
 {
-	struct anon_vma *anon_vma = vma->anon_vma;
-	pgoff_t index;
-
 	BUG_ON(PageReserved(page));
-	BUG_ON(!anon_vma);
 
 	inc_mm_counter(vma->vm_mm, anon_rss);
 
-	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
-	index = (address - vma->vm_start) >> PAGE_SHIFT;
-	index += vma->vm_pgoff;
-	index >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;
-
 	if (atomic_inc_and_test(&page->_mapcount)) {
-		page->index = index;
+		struct anon_vma *anon_vma = vma->anon_vma;
+
+		BUG_ON(!anon_vma);
+		anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
 		page->mapping = (struct address_space *) anon_vma;
+
+		page->index = linear_page_index(vma, address);
+
 		inc_page_state(nr_mapped);
 	}
 	/* else checking page index and mapping is racy */
@@ -518,8 +512,6 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
 	pte_t pteval;
 	int ret = SWAP_AGAIN;
 
-	if (!get_mm_counter(mm, rss))
-		goto out;
 	address = vma_address(page, vma);
 	if (address == -EFAULT)
 		goto out;
@@ -532,6 +524,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
 	 * If the page is mlock()d, we cannot swap it out.
 	 * If it's recently referenced (perhaps page_referenced
 	 * skipped over this mm) then we should reactivate it.
+	 *
+	 * Pages belonging to VM_RESERVED regions should not happen here.
 	 */
 	if ((vma->vm_flags & (VM_LOCKED|VM_RESERVED)) ||
 			ptep_clear_flush_young(vma, address, pte)) {
@@ -539,27 +533,6 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
 		goto out_unmap;
 	}
 
-	/*
-	 * Don't pull an anonymous page out from under get_user_pages.
-	 * GUP carefully breaks COW and raises page count (while holding
-	 * page_table_lock, as we have here) to make sure that the page
-	 * cannot be freed.  If we unmap that page here, a user write
-	 * access to the virtual address will bring back the page, but
-	 * its raised count will (ironically) be taken to mean it's not
-	 * an exclusive swap page, do_wp_page will replace it by a copy
-	 * page, and the user never get to see the data GUP was holding
-	 * the original page for.
-	 *
-	 * This test is also useful for when swapoff (unuse_process) has
-	 * to drop page lock: its reference to the page stops existing
-	 * ptes from being unmapped, so swapoff can make progress.
-	 */
-	if (PageSwapCache(page) &&
-	    page_count(page) != page_mapcount(page) + 2) {
-		ret = SWAP_FAIL;
-		goto out_unmap;
-	}
-
 	/* Nuke the page table entry. */
 	flush_cache_page(vma, address, page_to_pfn(page));
 	pteval = ptep_clear_flush(vma, address, pte);
@@ -788,8 +761,7 @@ static int try_to_unmap_file(struct page *page)
 			if (vma->vm_flags & (VM_LOCKED|VM_RESERVED))
 				continue;
 			cursor = (unsigned long) vma->vm_private_data;
-			while (get_mm_counter(vma->vm_mm, rss) &&
-				cursor < max_nl_cursor &&
+			while ( cursor < max_nl_cursor &&
 				cursor < vma->vm_end - vma->vm_start) {
 				try_to_unmap_cluster(cursor, &mapcount, vma);
 				cursor += CLUSTER_SIZE;