On 12/16/2015 07:16 PM, Jason Gunthorpe wrote:
> On Wed, Dec 16, 2015 at 11:26:39AM +0100, Michael Wang wrote:
[snip]
>>
>> I've rechecked the ib_init_ah_from_path() again, and found it
>> still set IB_AH_GRH when the GID cache missing, but with:
>
> How do you mean?
>
> ah_attr->ah_flags = IB_AH_GRH;
> ah_attr->grh.dgid = rec->dgid;
>
> ret = ib_find_cached_gid(device, &rec->sgid, ndev, &port_num,
> &gid_index);
> if (ret) {
> if (ndev)
> dev_put(ndev);
> return ret;
> }
>
> If find_cached_gid fails then ib_init_ah_from_path also fails.
>
> Is there a case where ib_find_cached_gid can succeed but not return
> good data?
Just for the GRH header, ib_find_cached_gid() will failed but the flag
and dgid will be correct, and others are all 0 including hop limit, but
may be just coincidence...
As long as hop_limit > 1 means the pkg do have to pass through a router
to other subnet, the fix make sense :-)
Regards,
Michael Wang
>
> I agree it would read nicer if the ah_flags and gr.dgid was moved
> after the ib_find_cached_gid
>
>> BTW, cma_sidr_rep_handler() also call ib_init_ah_from_path() with out
>> a check on return.
>
> That sounds like a problem.
>
> Jason
>
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