-extern int guestfs___for_each_disk (guestfs_h *g, virDomainPtr dom, int (*)(guestfs_h *g, const char *filename, const char *format, void *data), void *data);
+extern int guestfs___for_each_disk (guestfs_h *g, virDomainPtr dom, int (*)(guestfs_h *g, const char *filename, const char *format, int readonly, void *data), void *data);