On Tue, Jul 19, 2022 at 08:37:23PM +0800, Ming Lei wrote: > This change will break START_DEV/STOP_DEV, which is supposed to run > multiple cycles after the device is added, especially this way can > help to implement error recovery from userside, such as one ubq_daemon > is crashed/hang, the device can be recovered by sending STOP_DEV/START_DEV > commands again after new ubq_daemon is setup. What is broken in START_DEV/STOP_DEV? Please explain the semantics you want and what doesn't work. FYI, there is nothing in the test suite the complains. And besides the obvious block layer bug that Jens found you seemed to be perfectly happy with the semantics. > So here we do need separated request_queue/disk, and the model is > similar with scsi's, in which disk rebind needs to be supported > and GD_OWNS_QUEUE can't be set. SCSI needs it because it needs the request_queue to probe for what ULP to bind to, and it allows to unbind the ULP. None of that is the case here. And managing the lifetimes separately is a complete mess, so don't do it. Especially not in a virtual driver where you don't have to cater to a long set protocol like SCSI. > > Thanks, > Ming ---end quoted text---
