nvme tcp receive errors

[Sagi Grimberg]

>>>>> Hey Keith,
>>>>>
>>>>> Did this resolve the issues?
>>>>
>>>> We're unfortunately still observing data digest issues even with this.
>>>> Most of the testing has shifted to the r2t error, so I don't have any
>>>> additional details on the data digest problem.
>>>
>>> I've looked again at the code, and I'm not convinced that the patch
>>> is needed at all anymore, I'm now surprised that it actually changed
>>> anything (disregarding data digest).
>>>
>>> The driver does not track the received bytes by definition, it relies
>>> on the controller to send it a completion, or set the success flag in
>>> the _last_ c2hdata pdu. Does your target set
>>> NVME_TCP_F_DATA_SUCCESS on any of the c2hdata pdus?
>>
>> Perhaps you can also run this patch instead?
> 
> Thanks, will give this a shot.

Still would be beneficial to look at the traces and check if
the success flag happens to be set. If this flag is set, the
driver _will_ complete the request without checking the bytes
received thus far (similar to how pci and rdma don't and can't
check dma byte count).