[PATCHv2 2/2] nvme: Complete all stuck requests

[Sagi Grimberg]

>>> OK, I think we can get it for fabrics too, need to figure out how to
>>> handle it there too.
>>>
>>> Do you have a reproducer?
>>
>> To repro, I have to run a buffered writer workload then put the system into S3.
>>
>> This fio job seems to reproduce for me:
>>
>>   fio --name=global --filename=/dev/nvme0n1 --bsrange=4k-128k --rw=randwrite --ioengine=libaio --iodepth=8 --numjobs=8 --name=foobar
>>
>> I use rtcwake to test suspend/resume:
>>
>>   rtcwake -m mem -s 10
>>
>> Without the patch we'll get stuck after "Disabling non-boot CPUs ..."
>> when blk-mq waits to freeze some entered queues after nvme was disabled.
>
> I'm observing the same thing when hibernating during mdraid resync on
> nvme - it hangs in blk_mq_freeze_queue_wait() after "Disabling non-boot
> CPUs ...". This patch did not help but when I put nvme_wait_freeze()
> right after nvme_start_freeze() it appeared to be working.

Interesting. did the nvme device succeeded to shutdown at all?

> Maybe the
> difference here is that requests are submitted from a non-freezable
> kernel thread (md sync_thread)?

Don't think its related...