[GIT PULL] nvme update for Linux 4.14, take 2

[Bart Van Assche]

On Wed, 2017-08-30 at 19:47 +0300, Sagi Grimberg wrote:
> > > 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.

How about renaming blk_mq_reinit_tagset() into blk_mq_tagset_iter() and
to make the argument list of blk_mq_tagset_iter() more similar to that of
blk_mq_queue_tag_busy_iter() such that callers of blk_mq_tagset_iter()
can pass a pointer to any structure through the @priv argument? That would
make this function more general and maybe also more useful to other block
drivers.

Bart.