[PATCH] free_swap_and_cache misses

[Hugh Dickins]

free_swap_and_cache() often misses its purpose and leaves freeable page
in swap and cache.  Wrong in mainline 2.4 and 2.5, but looks okay in -aa
(so don't bother to apply this if you're now merging that).

Hugh

--- 2.4.18-pre4/mm/swapfile.c	Sun Dec 23 10:47:32 2001
+++ linux/mm/swapfile.c	Sun Jan 20 23:30:52 2002
@@ -344,7 +344,7 @@
 	if (page) {
 		page_cache_get(page);
 		/* Only cache user (+us), or swap space full? Free it! */
-		if (page_count(page) == 2 || vm_swap_full()) {
+		if (page_count(page) - !!page->buffers == 2 || vm_swap_full()) {
 			delete_from_swap_cache(page);
 			SetPageDirty(page);
 		}