net: fib_rules: Add fib_rules_ops.lock.

We will no longer hold RTNL for RTM_NEWRULE and RMT_DELRULE
except for the first IPv4 RTM_NEWRULE.

Let's add per-fib_rules_ops mutex inside RTNL.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260629181226.1929658-6-kuniyu@google.com
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima
2026-06-29 18:10:57 +00:00
committed by Paolo Abeni
parent 763a943710
commit 8e133ba99c
2 changed files with 19 additions and 2 deletions

View File

@@ -98,6 +98,7 @@ struct fib_rules_ops {
struct list_head rules_list;
struct module *owner;
struct net *fro_net;
struct mutex lock;
struct rcu_head rcu;
};

View File

@@ -172,6 +172,7 @@ fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&ops->rules_list);
mutex_init(&ops->lock);
ops->fro_net = net;
err = __fib_rules_register(ops);
@@ -392,6 +393,7 @@ static int call_fib_rule_notifiers(struct net *net,
};
ASSERT_RTNL_NET(net);
lockdep_assert_held(&ops->lock);
/* Paired with READ_ONCE() in fib_rules_seq() */
WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1);
@@ -910,6 +912,7 @@ int fib_newrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
if (!rtnl_held)
rtnl_net_lock(net);
mutex_lock(&ops->lock);
err = fib_nl2rule_rtnl(rule, ops, tb, extack);
if (err)
@@ -978,6 +981,7 @@ int fib_newrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
fib_rule_get(rule);
mutex_unlock(&ops->lock);
if (!rtnl_held)
rtnl_net_unlock(net);
@@ -988,6 +992,7 @@ int fib_newrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
return 0;
errout_free:
mutex_unlock(&ops->lock);
if (!rtnl_held)
rtnl_net_unlock(net);
kfree(rule);
@@ -1039,6 +1044,7 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
if (!rtnl_held)
rtnl_net_lock(net);
mutex_lock(&ops->lock);
err = fib_nl2rule_rtnl(nlrule, ops, tb, extack);
if (err)
@@ -1093,6 +1099,7 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, NULL);
mutex_unlock(&ops->lock);
if (!rtnl_held)
rtnl_net_unlock(net);
@@ -1104,6 +1111,7 @@ int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
return 0;
errout_free:
mutex_unlock(&ops->lock);
if (!rtnl_held)
rtnl_net_unlock(net);
kfree(nlrule);
@@ -1403,20 +1411,28 @@ static int fib_rules_event(struct notifier_block *this, unsigned long event,
switch (event) {
case NETDEV_REGISTER:
list_for_each_entry(ops, &net->rules_ops, list)
list_for_each_entry(ops, &net->rules_ops, list) {
mutex_lock(&ops->lock);
attach_rules(&ops->rules_list, dev);
mutex_unlock(&ops->lock);
}
break;
case NETDEV_CHANGENAME:
list_for_each_entry(ops, &net->rules_ops, list) {
mutex_lock(&ops->lock);
detach_rules(&ops->rules_list, dev);
attach_rules(&ops->rules_list, dev);
mutex_unlock(&ops->lock);
}
break;
case NETDEV_UNREGISTER:
list_for_each_entry(ops, &net->rules_ops, list)
list_for_each_entry(ops, &net->rules_ops, list) {
mutex_lock(&ops->lock);
detach_rules(&ops->rules_list, dev);
mutex_unlock(&ops->lock);
}
break;
}