On 09/21/2017 08:29 PM, Tyrel Datwyler wrote:
> On 09/21/2017 08:13 AM, Brian King wrote:
>> On 09/21/2017 05:02 AM, Hannes Reinecke wrote:
>>> Hi Brian,
>>>
>>> I was looking at the ibmvfc code (trying to hook up libfc), and have
>>> found this definition:
>>>
>>> struct ibmvfc_fcp_rsp_info {
>>> __be16 reserved;
>>> u8 rsp_code;
>>> u8 reserved2[4];
>>> }__attribute__((packed, aligned (2)));
>>>
>>> in comparison, libfc has this:
>>>
>>> struct fcp_resp_rsp_info {
>>> __u8 _fr_resvd[3]; /* reserved */
>>> __u8 rsp_code; /* Response Info Code */
>>> __u8 _fr_resvd2[4]; /* reserved */
>>> };
>>>
>>> So both look _nearly_ identical, except the missing byte at the start.
>>> It might be inserted due to some compile alignment magic, but I'd rather
>>> not rely on this.
>>> Could you clarify if the two structures really are different, or if this
>>> is a simple oversight?
>>
>> Looks like a bug to me. We should probably just have ibmvfc use the
>> libfc definition.
>
> Yes, after looking at the FC spec we most definitely have it defined wrong, and I'm pretty
> certain that we aren't getting saved by any compiler magic.
>
>>
>> Tyrel - can you do this conversion and run a bit of regression testing?
>> Looking at the possible values of rsp_code, the most likely place where
>> this might cause us some issues is in TMF handling. I'm a little
>> worried this could result in a potential double completion in error
>> handling in some rare cases.... Tyrel - are you aware of any issues
>> like that, which this might explain?
>
> I certainly can. I recollect something like a double completion issue, but its been so
> long I can't remember if we were seeing it in the vfc driver or the vscsi driver. Anyhow,
> I do feel like from what I recall it seems like rsp_code is always zero in reported error
> messages.
>
Sure it would, given that the ibmvfc driver would always use the
reserved bytes as rsp_code :-)
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
