ipv4: fib: Convert fib_net_exit_batch() to ->exit_rtnl().

Currently, IPv4 routes are flushed in ->exit_batch() after
all devices are unregistered.

Unlike IPv6, IPv4 routes are not added from the fast path,
so we can flush routes before default_device_exit_batch().

Let's call ip_fib_net_exit() from ->exit_rtnl() to save
one RTNL locking dance.

ip_fib_net_exit() must use list_del_rcu() for fib_table
for the fast path on dying dev.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260612063225.455191-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kuniyuki Iwashima
2026-06-12 06:32:08 +00:00
committed by Jakub Kicinski
parent 5a7fef12d9
commit 759923cf03

View File

@@ -1607,7 +1607,7 @@ static void ip_fib_net_exit(struct net *net)
struct fib_table *tb;
hlist_for_each_entry_safe(tb, tmp, head, tb_hlist) {
hlist_del(&tb->tb_hlist);
hlist_del_rcu(&tb->tb_hlist);
fib_table_flush(net, tb, true);
fib_free_table(tb);
}
@@ -1663,29 +1663,24 @@ static void __net_exit fib_net_pre_exit(struct net *net)
nl_fib_lookup_exit(net);
}
static void __net_exit fib_net_exit_batch(struct list_head *net_list)
static void __net_exit fib_net_exit_rtnl(struct net *net,
struct list_head *dev_kill_list)
{
struct net *net;
ip_fib_net_exit(net);
}
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
__rtnl_net_lock(net);
ip_fib_net_exit(net);
__rtnl_net_unlock(net);
}
rtnl_unlock();
list_for_each_entry(net, net_list, exit_list) {
kfree(net->ipv4.fib_table_hash);
fib4_notifier_exit(net);
fib4_semantics_exit(net);
}
static void __net_exit fib_net_exit(struct net *net)
{
kfree(net->ipv4.fib_table_hash);
fib4_notifier_exit(net);
fib4_semantics_exit(net);
}
static struct pernet_operations fib_net_ops = {
.init = fib_net_init,
.pre_exit = fib_net_pre_exit,
.exit_batch = fib_net_exit_batch,
.exit_rtnl = fib_net_exit_rtnl,
.exit = fib_net_exit,
};
static const struct rtnl_msg_handler fib_rtnl_msg_handlers[] __initconst = {