Hi Christoph, On Sun, Jul 17, 2022 at 11:38:25PM -0700, Christoph Hellwig wrote: > Hi Ming, > > it seems like ublk uses schedule_work to stop the device, which > includes a del_gendisk. I'm a little fearful this will gets us into > lockdep chains of death once syzbot or Tetsu notice it. ublksrv has two built-in tests(generic/001, generic/002) for covering heavy io with device removal and killing ubq_daemon, not see lockdep warning when running the two tests with lockdep enabled. Could you or Tetsu provide a bit more info about the warning? > > That being said, I don't reall understand the design of > ublk_daemon_monitor_work, which is only used to kick off other > work to start with. If the ubq daemon becomes dead, ublk_daemon_monitor_work will be scheduled for handling the error: abort pending io requests, and start to delete disk. It has to be triggered when del_gendisk() is in-progress for making forward progress. Thanks, Ming
