nvme reservation commands during controller reset

[Christoph Hellwig]

On Fri, Aug 14, 2020 at 11:29:57AM -0700, Sagi Grimberg wrote:
> 
> > Amit,
> > 
> > can you try the branch below?  Pretty much hot off the press, but I
> > think this should address your problem:
> > 
> > http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/nvme-pr-fix
> 
> I like the approach, but I think we'll need a bit more path awareness
> like we check for available paths if we requeue or fail..

If there is no available path, nvme_find_path will fail and thus we'll
error it.  This is the same mechanism as used by
nvme_ns_head_submit_bio.