[PATCH v4 4/5] nvme-rdma: avoid IO error for nvme native multipath

[Sagi Grimberg]

>>>> Why not just call set the status and call nvme_rdma_complete_rq and
>>>> return here?
>>> If the err is ENOMEM or EAGAIN, I am not sure the err must be a
>>> path-related error for all HBA drivers. So reused the error check code.
>>> I think it would be more reasonable to assume any errors returned by HBA
>>> driver as path-related errors.
>>> If you think so, I will modify it in next patch version.
>>
>> Meant to do that only for -EIO. We should absolutely not do any of this
>> for stuff like EINVAL, EOPNOTSUPP, EPERM or any strange error that may
>> return due to a bug or anything like that.
> ok, please review again, thank you.
> ---
>   drivers/nvme/host/rdma.c | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> index b7ce4f221d99..66b697461bd9 100644
> --- a/drivers/nvme/host/rdma.c
> +++ b/drivers/nvme/host/rdma.c
> @@ -2084,8 +2084,13 @@ static blk_status_t nvme_rdma_queue_rq(struct 
> blk_mq_hw_ctx *hctx,
> 
>          err = nvme_rdma_post_send(queue, sqe, req->sge, req->num_sge,
>                          req->mr ? &req->reg_wr.wr : NULL);
> -       if (unlikely(err))
> +       if (unlikely(err)) {
> +               if (err == -EIO) {
> +                       nvme_complete_failed_rq(rq, 
> NVME_SC_HOST_PATH_ERROR);

I was thinking about:
--
         err = nvme_rdma_post_send(queue, sqe, req->sge, req->num_sge,
                         req->mr ? &req->reg_wr.wr : NULL);
         if (unlikely(err)) {
                 if (err == -EIO) {
                         /*
                          * Fail the reuqest so upper layer can failover I/O
                          * if another path is available
                          */
                         req->status = NVME_SC_HOST_PATH_ERROR;
                         nvme_rdma_complete_rq(rq);
                         return BLK_STS_OK;

                 }
                 goto err_unmap;
         }
--