[Devel] [PATCH] fix of BUG_ON in drop_buffers

[Mishin Dmitry]

Patch from Dmitry (dim@):
 - fixed race in pagevec_strip
   Bug #56040
   Bug #55235

-- 
Thanks,
Dmitry.
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--- ./mm/swap.c.bh	2005-12-13 15:25:05.000000000 +0300
+++ ./mm/swap.c	2005-12-13 15:26:51.000000000 +0300
@@ -351,7 +351,9 @@ void pagevec_strip(struct pagevec *pvec)
 		struct page *page = pvec->pages[i];
 
 		if (PagePrivate(page) && !TestSetPageLocked(page)) {
-			try_to_release_page(page, 0);
+			/* need to recheck after lock */
+			if (page_has_buffers(page))
+				try_to_release_page(page, 0);
 			unlock_page(page);
 		}
 	}