Re: [PATCH] scsi: libsas: fix length error in sas_smp_handler()

[Jason Yan <yanaijie@huawei.com>]

On 2017/12/7 17:27, John Garry wrote:
> On 07/12/2017 01:41, Jason Yan wrote:
>> Can anybody review this patch? Our test of SG_IO all failed because of
>> this bug.
>>
>> On 2017/12/5 17:39, Jason Yan wrote:
>>> The bsg_job_done() requires the length of payload received, but we give
>>> it the untransferred residual.
>>>
>>> Fixes: 651a01364994 ("scsi: scsi_transport_sas: switch to bsg-lib for
>>> SMP")
>>> Reported-and-tested-by: chenqilin <chenqilin2@huawei.com>
>>> Signed-off-by: Jason Yan <yanaijie@huawei.com>
>>> CC: Christoph Hellwig <hch@lst.de>
>>> ---
>>>   drivers/scsi/libsas/sas_expander.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/scsi/libsas/sas_expander.c
>>> b/drivers/scsi/libsas/sas_expander.c
>>> index 50cb0f3..8323dc1 100644
>>> --- a/drivers/scsi/libsas/sas_expander.c
>>> +++ b/drivers/scsi/libsas/sas_expander.c
>>> @@ -2177,9 +2177,9 @@ void sas_smp_handler(struct bsg_job *job, struct
>>> Scsi_Host *shost,
>>>
>>>       ret = smp_execute_task_sg(dev, job->request_payload.sg_list,
>>>               job->reply_payload.sg_list);
>>> -    if (ret > 0) {
>>> +    if (ret >= 0) {
>>>           /* positive number is the untransferred residual */
>>> -        reslen = ret;
>>> +        reslen = job->reply_payload.payload_len - ret;
>
> Hi Jason,
>
> If we really want the length of the payload received, then should you
> change the reslen variable name? The name implies "residual length",
> which is not really what it is holding according to your change.
>
> Thanks,
> John
>

Thanks a lot. I will correct it.

Jason

>>>           ret = 0;
>>>       }
>>>
>>>
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