Tue, Sep 06, 2016 at 05:11:11PM CEST, d...@cumulusnetworks.com wrote:
>On 9/6/16 8:44 AM, Jiri Pirko wrote:
>> Tue, Sep 06, 2016 at 04:32:12PM CEST, d...@cumulusnetworks.com wrote:
>>> On 9/6/16 6:01 AM, Jiri Pirko wrote:
>>>> From: Jiri Pirko <j...@mellanox.com>
>>>>
>>>> This allows to pass information about added/deleted fib entries to
>>>> whoever is interested. This is done in a very similar way as devinet
>>>> notifies address additions/removals.
>>>>
>>>> Signed-off-by: Jiri Pirko <j...@mellanox.com>
>>>> ---
>>>> include/net/ip_fib.h | 19 +++++++++++++++++++
>>>> net/ipv4/fib_trie.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>>>> 2 files changed, 62 insertions(+)
>>>>
>>>
>>> The notifier infrastructure should be generalized for use with IPv4 and
>>> IPv6. While the data will be family based, the infra can be generic.
>>>
>>
>> Yeah, that I thought about as well. Thing is, ipv6 notifier has to be
>> atomic. That is the reason we have:
>> inetaddr_chain and register_inetaddr_notifier (blocking notifier)
>> inet6addr_chain and register_inet6addr_notifier (atomic notifier)
>>
>
>Why is IPv6 atomic? Looking at code paths for adding addresses seems like all
>of the locks are dropped before the notifier is called and adding and deleting
>ipv6 addresses does not show a hit with this WARN_ON:
Maybe historic reasons. Would be good to unite the notifiers then. I'll
look at it.
>
>
>diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
>index bfa941fc1165..4f9f964d95e5 100644
>--- a/net/ipv6/addrconf_core.c
>+++ b/net/ipv6/addrconf_core.c
>@@ -103,6 +103,7 @@ EXPORT_SYMBOL(unregister_inet6addr_notifier);
>
> int inet6addr_notifier_call_chain(unsigned long val, void *v)
> {
>+WARN_ON(in_atomic());
> return atomic_notifier_call_chain(&inet6addr_chain, val, v);
> }
> EXPORT_SYMBOL(inet6addr_notifier_call_chain);
