not for emptyness
- ext3_stop_delete_thread() must not be called from ->put_super() context,
  because ->put_super() is called with sb being locked. so, that
  routine is called from ->sync_fs() context
- chaos-2.4.18 should drop sb lock before calling ->sync_fs()
- virgin 2.4.20 has no ->sync_fs(), so introduce it by delete-thread patch
- kernel_text_address patch has been added to rh-2.4.22 series