[PATCH] mark address_space_operations const

Same as with already do with the file operations: keep them in .rodata and
prevents people from doing runtime patching.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index f23bb64..e999472 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2598,7 +2598,7 @@
 	unsigned offset = from & (PAGE_CACHE_SIZE-1);
 	unsigned to;
 	struct page *page;
-	struct address_space_operations *a_ops = mapping->a_ops;
+	const struct address_space_operations *a_ops = mapping->a_ops;
 	char *kaddr;
 	int ret = 0;