[PATCH] nvme-rdma: fix crash for no IO queues

[Hannes Reinecke]

On 2/24/21 6:59 AM, Chao Leng wrote:
> 
> 
> On 2021/2/24 7:21, Keith Busch wrote:
>> On Tue, Feb 23, 2021 at 03:26:02PM +0800, Chao Leng wrote:
>>> A crash happens when set feature(NVME_FEAT_NUM_QUEUES) timeout in nvme
>>> over rdma(roce) reconnection, the reason is use the queue which is not
>>> alloced.
>>>
>>> If it is not discovery and no io queues, the connection should fail.
>>
>> If you're getting a timeout, we need to quit initialization. Hannes
>> attempted making that status visible for fabrics here:
>>
>>    
>> http://lists.infradead.org/pipermail/linux-nvme/2021-January/022353.html
> I know the patch. It can not solve the scenario: target may be an
> attacker or the target behavior is incorrect.
> If target return 0 io queues or return other error code, the crash will
> still happen. We should not allow this to happen.
I'm fully with you that we shouldn't crash, but at the same time a value 
of '0' for the number of I/O queues is considered valid.
So we should fix the code to handle this scenario, and not disallowing 
zero I/O queues.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare at suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer