[PATCH 10/17] nvme: switch controller refcounting to use struct device

[Sagi Grimberg]

>>> -	if (!kref_get_unless_zero(&ctrl->ctrl.kref))
>>> -		return -EBUSY;
>>> +	nvme_get_ctrl(&ctrl->ctrl);
>>
>> Given that we take this reference before we are protected with
>> the state change I think this should still be get_unless_zero.
> 
> Because we now refcount the device we must have a reference on it
> when we call the sysfs file for it, and for the fabrics file
> we have an explicit reference already.  So there should not be
> any need to do the unless_zero.

I don't think the fabrics device does not help us to keep the ctrl
allocated until we finish removal.

I do agree that the kobj reference in nvme_dev_open keeps it alive.