nvme: subsystem handle not released on hot removal under raid1 configuration and multipath enabled

[Rajashekar, Revanth]

Hi Keith,
Thank you so much for getting back on this :)

On 11/17/2020 7:32 AM, Keith Busch wrote:
> On Mon, Nov 16, 2020 at 04:06:54PM -0800, Rajashekar, Revanth wrote:
>> I guess this is because the md-raid1 driver is still holding a reference to the nvme driver (kref count is 2 in the nvme removal path).
>> Is this a bug in nvme multipath? Because it works fine with multipath off.
>> Please let me know if more information is required :)
> Correct, the md raid is holding a reference. It's not really a bug, but
> others have commented that this behavior isn't necessarily desirable.
>
> I posted an RFC about this issue here:
>
>   http://lists.infradead.org/pipermail/linux-nvme/2020-September/019873.html
The patch suggested in the thread seems to fix the issue.
>
> The discussion evolved a bit since then, but hasn't had much activity
> recently. I'm hoping to get back on that conversation soon.
It's interesting that the thread ended abruptly.  Are there any plans to move forward with this RFC...?

Thanks!
Revanth