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

[Sagi Grimberg]

>> 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.

We could do that. But it feels like trying to go head over heals just to
keep a change titled:

"blk-mq: Make blk_mq_reinit_tagset() calls easier to read"

Which I'm not exactly sure I share the motivation. Also, I kinda liked
the symmetry of init/exit/reinit_request calling convention.

But, if you absolutely think its necessary to keep the change, we can
add an "all tags" iterator and use that to implement reinit_request in
nvme.

Christoph? Jens? verdict before we go forward here?