If we get to choose, my preference would be to restore the old behavior
because currently existing nvme transports keep their internal ctrl
representation in the tagset->driver_data as they implement
init/exit_request. Bouncing in nvme core would require to change that
and always keep struct nvme_ctrl as the tagset->driver_data and convert
it on every handler...
Everything is doable but it seems like an unneeded hassle to me...
Sorry but I'm not convinced that it would be necessary to change what
tagset->driver_data points at. How about moving blk_mq_reinit_tagset() from
the block layer core to the NVMe core, to rename it and to pass a pointer
to the nvme_ctrl data structure to that function instead of only block layer
information?
That would mean that I need to open-code the tagset iteration in nvme
which does not feel like something a driver should do.
