I cannot reproduce the bug with the patch; in my failure scenarios, it
seems that completing the request on errors in nvme_rdma_send_done
makes __nvme_submit_sync_cmd to be unblocked. Also, I think this is
safe from the double completions.
However, it seems that nvme_rdma_timeout code is still not free from
the double completion problem. So, it looks promising to me if you
could separate out the nvme_rdma_wr_error handling code as a new