--- src/sys/vfs/hammer/hammer_object.c	2008/01/25 05:49:08	1.24
+++ src/sys/vfs/hammer/hammer_object.c	2008/01/25 10:36:04	1.25
@@ -480,6 +480,8 @@ hammer_ip_sync_data(hammer_transaction_t
 	void *bdata;
 	int error;
 
+	KKASSERT((offset & HAMMER_BUFMASK) == 0);
+	KKASSERT((bytes & HAMMER_BUFMASK) == 0);
 retry:
 	error = hammer_init_cursor_hmp(&cursor, &ip->cache[0], ip->hmp);
 	if (error)