Do not free the page in swap_page()

Do not free the page in swap_page() to allow the page to be managed by
the caller of migrate_page().

If the page count dropped to 1 then rely on the next loop in migrate_pages()
to deal with the page of freeing it directly.

Some whitespace cleanup.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.15-rc1-mm2/mm/vmscan.c
===================================================================
--- linux-2.6.15-rc1-mm2.orig/mm/vmscan.c	2005-11-18 09:47:15.000000000 -0800
+++ linux-2.6.15-rc1-mm2/mm/vmscan.c	2005-11-18 10:04:05.000000000 -0800
@@ -627,41 +627,32 @@ static int swap_page(struct page *page)
 		case PAGE_KEEP:
 		case PAGE_ACTIVATE:
 			goto unlock_retry;
+
 		case PAGE_SUCCESS:
 			goto retry;
+
 		case PAGE_CLEAN:
 			; /* try to free the page below */
 		}
 	}
 
 	if (PagePrivate(page)) {
-		if (!try_to_release_page(page, GFP_KERNEL))
+		if (!try_to_release_page(page, GFP_KERNEL) ||
+		    (!mapping && page_count(page) == 1))
 			goto unlock_retry;
-		if (!mapping && page_count(page) == 1)
-			goto free_it;
 	}
 
-	if (!remove_mapping(mapping, page))
-		goto unlock_retry;		/* truncate got there first */
-
-free_it:
-	/*
-	 * We may free pages that were taken off the active list
-	 * by isolate_lru_page. However, free_hot_cold_page will check
-	 * if the active bit is set. So clear it.
-	 */
-	ClearPageActive(page);
-
-	list_del(&page->lru);
-	unlock_page(page);
-	put_page(page);
- 	return 0;
+	if (remove_mapping(mapping, page)) {
+		/* Success */
+		unlock_page(page);
+		return 0;
+	}
 
 unlock_retry:
 	unlock_page(page);
 
 retry:
-       return 1;
+	return 1;
 }
 /*
  * migrate_pages