[PATCH 2/3] nvme: Sync queues on controller resets

[jianchao.w.wang@oracle.com (jianchao.wang)]

Hi Keith

On 02/13/2018 05:46 AM, Keith Busch wrote:
> On Sun, Feb 11, 2018@09:53:03AM +0800, jianchao.wang wrote:
>> On 02/10/2018 09:55 AM, jianchao.wang wrote:
>>> There could be a circular pattern here. Please consider the following scenario:
>>>
>>> timeout_work context                    reset_work context
>>> nvme_timeout                            nvme_reset_work
>>>   -> nvme_dev_disable                     -> nvme_sync_queues // hold namespace_mutex
>>>     -> nvme_stop_queues                     -> blk_sync_queue
>>>       -> require namespaces_mutex               -> cancel_work_sync(&q->timeout_work)
>>>
>>
>> Looks like we could use rwsem to replace namespaces_mutex.
> 
> Looks like rwsem is queued up for 4.17. I'll send an update based on
> that. I guess this one and 3/3 can wait for 4.17, but 1/3 should still
> go in 4.16.
> 

Would you please queue this patch for next ?
I incurred this issue when NVMe card died with a lot of in-flight requests.

Thanks
Jianchao