Resets during user commands leads to hung task and controller stuck in connecting

[Sagi Grimberg]

>>> I'm (again) seeing a hung task when doing resets and formats simultaneously.
>>> Controller state is left in 'connecting'
>>>
>>> Using nvme.git/nvme-6.2 as of 'nvme: implement the DEAC bit for the Write Zeroes command',
>>> but I have also repro'd with Christoph's latest reset/probe-split set
>>>
>>>
>>> ctrl="nvme0"
>>> nsid=1
>>> pci="/sys/block/${ctrl}n${nsid}/device/"
>>> echo 30 > /proc/sys/kernel/hung_task_timeout_secs
>>> while true; do
>>>           nvme format -f /dev/${ctrl}n${nsid} &
>>
>> How long to it take the format to complete?
> Well it's pretty immediate but I'm under the impression that the
> nvme_dev_disable path leads to CC_EN disabling, interrupting any formats
> 
>>
>>>           echo 1 > $pci/reset_controller &
>>> done
>>
>> What happens if you set io_timeout to 20 instead of 30? (given
>> that you bound hung tasks at 30 seconds...
> It occurs with the standard 120s task timeout too
> Also there's no I/O occurring at the moment; just admin work
> 
> I added a blktests for this:
> http://lists.infradead.org/pipermail/linux-nvme/2022-November/036475.html

Keith?

Is this related to bc8fb906b0ff ("nvme: handle effects after freeing the 
request") ?