[PATCH] ifdef blktrace debugging fields

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c773ee5..cfde8b3 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -417,9 +417,9 @@
 	unsigned int		sg_timeout;
 	unsigned int		sg_reserved_size;
 	int			node;
-
+#ifdef CONFIG_BLK_DEV_IO_TRACE
 	struct blk_trace	*blk_trace;
-
+#endif
 	/*
 	 * reserved for flush operations
 	 */