Re: [PATCH v6 net 2/3] ipv6: Don't remove permanent routes with exceptions from tb6_gc_hlist.

[David Ahern <dsahern@kernel.org>]

On 3/20/26 1:23 AM, Kuniyuki Iwashima wrote:
> The cited commit mechanically put fib6_remove_gc_list()
> just after every fib6_clean_expires() call.
> 
> When a temporary route is promoted to a permanent route,
> there may already be exception routes tied to it.
> 
> If fib6_remove_gc_list() removes the route from tb6_gc_hlist,
> such exception routes will no longer be aged.
> 
> Let's replace fib6_remove_gc_list() with a new helper
> fib6_may_remove_gc_list() and use fib6_age_exceptions() there.
> 
> Note that net->ipv6 is only compiled when CONFIG_IPV6 is
> enabled, so fib6_{add,remove,may_remove}_gc_list() are guarded.
> 
> Fixes: 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
> ---
> v6: Call fib6_age_exceptions() under RCU
> v4: s/,/;/ for fib6_gc_args initialisation
> v3: Use IS_ENABLED()
> v2: Fix build failure when CONFIG_IPV6=n (no net->ipv6 definition)
> 
> squash
> ---
>  include/net/ip6_fib.h | 21 ++++++++++++++++++++-
>  net/ipv6/addrconf.c   |  4 ++--
>  net/ipv6/ip6_fib.c    |  6 +++---
>  net/ipv6/route.c      |  2 +-
>  4 files changed, 26 insertions(+), 7 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>