[bug report]nvme0: Admin Cmd(0x6), I/O Error (sct 0x0 / sc 0x2) MORE DNR observed during blktests

[Christoph Hellwig]

On Mon, Apr 04, 2022 at 02:30:12PM -0600, Keith Busch wrote:
> > Eg, nvme0: blah blah command set not supported
> 
> The new print in the completion handler is pretty generic. I don't think it can
> readily tell the difference from a harmless error. Maybe pr_err is too high?
> 
> Or maybe since enough people have been concerned about *this* specific
> identify, maybe it should be restricted to 2.0 devices where it's mandatory. I
> was reluctant to do that at first since the initial device I tested was 1.4,
> but it was a prototype and we should be fine without the non-mdts limits
> anyway.

What SCSI does is to add RQF_QUIET to all internal passthrough commands,
and then skips printing the SCSI specific error messages in addition
if that flag is set.

This would be the nvme version of that:

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 7e07dd69262a7..9346cd4cf5820 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -366,7 +366,8 @@ static inline void nvme_end_req(struct request *req)
 {
 	blk_status_t status = nvme_error_status(nvme_req(req)->status);
 
-	if (unlikely(nvme_req(req)->status != NVME_SC_SUCCESS))
+	if (unlikely(nvme_req(req)->status != NVME_SC_SUCCESS &&
+		     !(req->rq_flags & RQF_QUIET)))
 		nvme_log_error(req);
 	nvme_end_req_zoned(req);
 	nvme_trace_bio_complete(req);
@@ -648,6 +649,7 @@ void nvme_init_request(struct request *req, struct nvme_command *cmd)
 	cmd->common.flags &= ~NVME_CMD_SGL_ALL;
 
 	req->cmd_flags |= REQ_FAILFAST_DRIVER;
+	req->rq_flags |= RQF_QUIET;
 	if (req->mq_hctx->type == HCTX_TYPE_POLL)
 		req->cmd_flags |= REQ_POLLED;
 	nvme_clear_nvme_request(req);