On 2/26/18 3:28 PM, Wei Wang wrote:
>> @@ -213,11 +234,6 @@ static inline void rt6_set_expires(struct rt6_info *rt,
>> unsigned long expires)
>>
>> static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
>> {
>> - struct rt6_info *rt;
>> -
>> - for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); rt = rt->from);
>> - if (rt && rt != rt0)
>> - rt0->dst.expires = rt->dst.expires;
>
> I was wondering if we need to retain the above logic. It makes sure
> dst.expires gets synced to its "parent" route. But it might be hard
> because after your change, we can no longer use rt->from to refer to
> the "parent".
As I understand it, the FIB entries are cloned into pcpu, uncached and
exception routes. We should never have an rt6_info that ever points back
more than 1 level -- ie., the dst rt6_info points to a from representing
the original FIB entry.
After my change 'from' will still point to the FIB entry as a fib6_info
which has its own expires.
When I looked this code I was really confused. At best, the for loop
above sets rt0->dst.expires to some value based on the 'from' but then
the very next line calls dst_set_expires with the passed in timeout value.
>
>> dst_set_expires(&rt0->dst, timeout);
>> rt0->rt6i_flags |= RTF_EXPIRES;
>> }
