blk_mq_reinit_tagset during NVMEoF port toggling

[Israel Rukshin]

On 8/28/2017 10:40 AM, Sagi Grimberg wrote:
>> Hi guys,
>
> Hi Max, CCing linux-nvme.
Hi Sagi,
>
>> we have encountered a bug during our port toggling test with MP using 
>> NVMEoF over RDMA (1 IO queue repro it quickly).
>> We have been receiving local protection errors dumps after failing 
>> back to the port that became active again (it's not the 
>> retransmission issue we fixed in the past). After debugging it we saw 
>> that the requests have been doing a reinit process (dereg_mr/alloc_mr).
>> But somehow the req->mr->need_inval is still true in the beginning of 
>> nvme_rdma_queue_rq function. This shouldn't happen since we should 
>> have perform the dereg_mr/alloc_mr in the reinit func and set it to 
>> false.
>> We don't see this issue in kernel older than 4.11 so before bisecting:
>
> Which code base is this max?
The code base is kernel 4.13.0-rc3.
>
> is commit 842594c8775b585c58459e044708c0335b6aa6b7 applied?
Yes.
>
> if so, maybe it is possible that not all requests are being 
> reinitialized.
> Can you reproduce with the following applied:
We reproduced this issue with similar prints and we didn't see them.
blk_mq_reinit_tagset() went over all the the static requests.

Thanks,
Israel.