BIO_RW_SYNC is a shift-value.

--- diff/drivers/md/dm-io.c	2004-04-06 15:55:06.504396616 +0100
+++ source/drivers/md/dm-io.c	2004-04-06 15:55:32.921380624 +0100
@@ -497,7 +497,7 @@ static void dispatch_io(int rw, unsigned
 	struct dpages old_pages = *dp;
 
 	if (sync)
-		rw |= BIO_RW_SYNC;
+		rw |= (1 << BIO_RW_SYNC);
 
 	/*
 	 * For multiple regions we need to be careful to rewind