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Date: Sun, 05 May 2002 13:53:41 -0700
From: Andrew Morton <akpm@zip.com.au>
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To: Linus Torvalds <torvalds@transmeta.com>
CC: lkml <linux-kernel@vger.kernel.org>
Subject: [patch 2/10] radix-tree locking fix
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__delete_from_swap_cache modifies the radix tree.  We need to take the
lock for writing.


=====================================

--- 2.5.13/mm/swapfile.c~swap-lock-fix	Sun May  5 13:31:59 2002
+++ 2.5.13-akpm/mm/swapfile.c	Sun May  5 13:31:59 2002
@@ -308,13 +308,13 @@ int remove_exclusive_swap_page(struct pa
 	retval = 0;
 	if (p->swap_map[SWP_OFFSET(entry)] == 1) {
 		/* Recheck the page count with the pagecache lock held.. */
-		read_lock(&swapper_space.page_lock);
+		write_lock(&swapper_space.page_lock);
 		if (page_count(page) - !!PagePrivate(page) == 2) {
 			__delete_from_swap_cache(page);
 			SetPageDirty(page);
 			retval = 1;
 		}
-		read_unlock(&swapper_space.page_lock);
+		write_unlock(&swapper_space.page_lock);
 	}
 	swap_info_put(p);
 


-