linux-stable/net/ipv4/fib_notifier.c
Eric Dumazet 2698acd6ea net: do not acquire rtnl in fib_seq_sum()
After we made sure no fib_seq_read() handlers needs RTNL anymore,
we can remove RTNL from fib_seq_sum().

Note that after RTNL was dropped, fib_seq_sum() result was possibly
outdated anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241009184405.3752829-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-11 15:35:05 -07:00

73 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/rtnetlink.h>
#include <linux/notifier.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/fib_notifier.h>
#include <net/ip_fib.h>
int call_fib4_notifier(struct notifier_block *nb,
enum fib_event_type event_type,
struct fib_notifier_info *info)
{
info->family = AF_INET;
return call_fib_notifier(nb, event_type, info);
}
int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
struct fib_notifier_info *info)
{
ASSERT_RTNL();
info->family = AF_INET;
/* Paired with READ_ONCE() in fib4_seq_read() */
WRITE_ONCE(net->ipv4.fib_seq, net->ipv4.fib_seq + 1);
return call_fib_notifiers(net, event_type, info);
}
static unsigned int fib4_seq_read(const struct net *net)
{
/* Paired with WRITE_ONCE() in call_fib4_notifiers() */
return READ_ONCE(net->ipv4.fib_seq) + fib4_rules_seq_read(net);
}
static int fib4_dump(struct net *net, struct notifier_block *nb,
struct netlink_ext_ack *extack)
{
int err;
err = fib4_rules_dump(net, nb, extack);
if (err)
return err;
return fib_notify(net, nb, extack);
}
static const struct fib_notifier_ops fib4_notifier_ops_template = {
.family = AF_INET,
.fib_seq_read = fib4_seq_read,
.fib_dump = fib4_dump,
.owner = THIS_MODULE,
};
int __net_init fib4_notifier_init(struct net *net)
{
struct fib_notifier_ops *ops;
net->ipv4.fib_seq = 0;
ops = fib_notifier_ops_register(&fib4_notifier_ops_template, net);
if (IS_ERR(ops))
return PTR_ERR(ops);
net->ipv4.notifier_ops = ops;
return 0;
}
void __net_exit fib4_notifier_exit(struct net *net)
{
fib_notifier_ops_unregister(net->ipv4.notifier_ops);
}