[PATCH 3/3] nvme-multipath: skip failed paths during partition scan

[Sagi Grimberg]

>> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
>> index f03ef983a75f..4113d38606a4 100644
>> --- a/drivers/nvme/host/multipath.c
>> +++ b/drivers/nvme/host/multipath.c
>> @@ -102,6 +102,13 @@ void nvme_failover_req(struct request *req)
>>   		queue_work(nvme_wq, &ns->ctrl->ana_work);
>>   	}
>>   
>> +	/*
>> +	 * Do not use this path during scanning
>> +	 * to avoid deadlocks in device_add_disk()
>> +	 */
>> +	if (mutex_is_locked(&ns->ctrl->scan_lock))
>> +		set_bit(NVME_NS_SCAN_FAILED, &ns->flags);
> Err, no.  mutex_is_locked is never a valid way to detect the calling
> context - obviously someone else could also be holding it.
>

Strongly agree here.