Re: [PATCH 7/7] IB/srp: Avoid that mapping failure triggers an infinite loop

[Sagi Grimberg <sagig-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>]

On 03/11/2015 20:56, Bart Van Assche wrote:
> On 11/03/2015 09:44 AM, Sagi Grimberg wrote:
>> Can you spare a few words on this change in the change log?
>>
>>
>>> Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
>>> Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
>>> Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
>>> ---
>>>    drivers/infiniband/ulp/srp/ib_srp.c | 2 ++
>>>    1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
>>> b/drivers/infiniband/ulp/srp/ib_srp.c
>>> index 47c3a72..59d3ff9 100644
>>> --- a/drivers/infiniband/ulp/srp/ib_srp.c
>>> +++ b/drivers/infiniband/ulp/srp/ib_srp.c
>>> @@ -1666,6 +1666,8 @@ map_complete:
>>>
>>>    unmap:
>>>        srp_unmap_data(scmnd, ch, req, true);
>>> +    if (ret == -ENOMEM && req->nmdesc >= target->mr_pool_size)
>>> +        ret = -E2BIG;
>>>        return ret;
>>>    }
>>
>> Why return E2BIG for ENOMEM as well?
>
> Hello Sagi,
>
> The srp_queuecommand() function translates ENOMEM into QUEUE_FULL which
> causes the SCSI mid-layer to retry the command. All other error codes
> are translated into DID_ERROR which causes the SCSI command to fail.

That's what I meant, ENOMEM is transient by nature. Why would you
not want the scsi layer to requeue? I do understand this for the nmdesc
condition but for the ENOMEM?
--
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