[PATCH 1/5] nvme-core: Make nvme_init/uninit_ctrl setup/teardown symmetric

[keith.busch@intel.com (Keith Busch)]

On Wed, Oct 18, 2017@06:29:40PM +0300, Sagi Grimberg wrote:
> 
> > > From: Roy Shterman <roys at lightbitslabs.com>
> > > 
> > > Its strange to have some of the cleanup for nvme_init_ctrl in
> > > nvme_free_ctrl. This cause us to have some magic ctrl refcount
> > > handling in controller initialization error paths.
> > > 
> > > Make the init/uninit symmetric so we can have a sane and
> > > maintainable error sequences.
> > 
> > It's not magic. It's just preventing name reuse when some management
> > code retains an open handle after the device was removed.
> 
> management code as in nvme-cli?
> 
> > Otherwise
> > you're going to get naming clashes when you bring up a new device with
> > the same name from reusing the still in-use instance.
> 
> Can userspace keep an open-handle after device_destroy() was invoked?
> 
> Can you explain how would I see naming clashes? I'm not sure I
> understand what you are referring to.

Hm, I'm not hitting duplicate name issues anymore. I can't be bothered
to bisect when that started working, but I think the dev_t lifetime
fixes has something to do with it.

Anyway, simpler is certainly preferred. This is looking okay so far,
and I'll try a few more things to see if I can break it.