[PATCH] Fix: writing to the swap space

Ah.  That's some left-over code.  Reads will be OK, but writes will be
unexpectedly asynchronous.  Nothing in the kernel uses that function for
writes so it didn't show up.

mm/page_io.c

@@ -117,9 +117,6 @@ void rw_swap_page_nolock(int rw, swp_entry_t entry, char *buf)
 	page->mapping = &swapper_space;
 	if (!rw_swap_page_base(rw, entry, page))
 		unlock_page(page);
-	if (rw == WRITE)
-		wait_on_page_writeback(page);
-	else
 	wait_on_page_locked(page);
 	page->mapping = NULL;
 }