[PATCHv3 3/5] nvme: implement I/O Command Sets Command Set support

[Sagi Grimberg]

>> If the controller does not support the CNS value, it may return Invalid
>> Field with DNR set. That error currently gets propogated back to
>> nvme_init_ns_head(), which then abandons the namespace. Just as the code
>> coments say, we had been historically been clearing such errors because
>> we have other ways to identify the namespace, but now we're not clearing
>> that error.
> 
> I don't understand what you are saying Keith.
> 
> My comment was for this block:
> -- 
>      if (!status && nvme_multi_css(ctrl) && !csi_seen) {
>          dev_warn(ctrl->device, "Command set not reported for nsid:%d\n",
>               nsid);
>          status = -EINVAL;
>      }
> -- 
> 
> I was saying that !status doesn't necessarily mean success, but it can
> also mean that its an retry-able error status (due to transport or
> controller). If we see a retry-able error we should still clear the
> status so we don't abandon the namespace.
> 
> This for example would achieve that:

Sorry, meant this:
--
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ba512c45b40f..3187cf768d08 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1130,8 +1130,14 @@ static int nvme_identify_ns_descs(struct 
nvme_ctrl *ctrl, unsigned nsid,
                   * Don't treat an error as fatal, as we potentially 
already
                   * have a NGUID or EUI-64.
                   */
-               if (status > 0 && !(status & NVME_SC_DNR))
+               if (status > 0 && !(status & NVME_SC_DNR)) {
                         status = 0;
+               } else if (status == 0 && nvme_multi_css(ctrl) && 
!csi_seen) {
+                               dev_warn(ctrl->device,
+                                       "Command set not reported for 
nsid:%d\n",
+                                       nsid);
+                               status = -EINVAL;
+               }
                 goto free_data;
         }
--