Make do_swap_page redo the fault

do_swap_page currently retries locally after successfully locking
a swap entry that is used for page migration. Change that to
redo the complete fault in order to be able to directly switch from
migration entry to a valid pte for an anonymous page.

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

Index: linux-2.6.16-mm2/mm/memory.c
===================================================================
--- linux-2.6.16-mm2.orig/mm/memory.c	2006-03-30 21:21:06.000000000 -0800
+++ linux-2.6.16-mm2/mm/memory.c	2006-03-30 22:55:34.000000000 -0800
@@ -1879,7 +1879,6 @@ static int do_swap_page(struct mm_struct
 		goto out;
 
 	entry = pte_to_swp_entry(orig_pte);
-again:
 	page = lookup_swap_cache(entry);
 	if (!page) {
  		swapin_readahead(entry, address, vma);
@@ -1906,8 +1905,7 @@ again:
 	if (!PageSwapCache(page)) {
 		/* Page migration has occured */
 		unlock_page(page);
-		page_cache_release(page);
-		goto again;
+		goto out;
 	}
 
 	/*