Re: [PATCH 3/6] IB/srp: Fail SCSI commands silently

[Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>]

On 02/27/14 06:48, David Dillow wrote:
> I don't see where the block level is printing messages about the failed
> requests -- but maybe I'm missing it. I see scsi_done() ->
> blk_complete_request() -> blk_done_softirq() -> scsi_softirq_done() ->
> scsi_finish_command() -> scsi_io_completion()
> 
> I'm not seeing where the errored block requests would be printed before
> scsi_io_completion(), which is where we were talking about setting the
> REQ_QUIET flag above.
> 
> What messages are you talking about -- even better if you can point to
> where they come from -- but mainly which ones; I'm happy to track them
> down myself. It's been a while since I've done a deep dive on this code,
> so my apologies if it should be obvious to me...

Hello Dave,

I think the call chain is as follows: scsi_io_completion() ->
scsi_end_request() -> blk_end_request() -> blk_end_bidi_request() ->
blk_update_bidi_request() -> blk_update_request(). That last function
prints an error message for failed requests if REQ_QUIET has not been
set. So this means that it's possible to set the REQ_QUIET flag from the
SCSI mid-layer before the block layer checks that flag.

> I agree it is the most expedient approach to solve Sebastian's immediate
> problem, but I'd rather the solution be generic to the SCSI mid-layer so
> it will be useful for others beyond SRP.

It would be great if this would be solved in a more generic way. But
please keep in mind that this is not just Sebastian's problem - other
users have reported this before.

Bart.

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html