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outdated anyway.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>

diff --git a/include/net/fib_notifier.h b/include/net/fib_notifier.h
index 6d59221..48aad61 100644 (file)
--- a/include/net/fib_notifier.h
+++ b/include/net/fib_notifier.h
@@ -28,7 +28,7 @@ enum fib_event_type {
 struct fib_notifier_ops {
        int family;
        struct list_head list;
-       unsigned int (*fib_seq_read)(struct net *net);
+       unsigned int (*fib_seq_read)(const struct net *net);
        int (*fib_dump)(struct net *net, struct notifier_block *nb,
                        struct netlink_ext_ack *extack);
        struct module *owner;

diff --git a/net/core/fib_notifier.c b/net/core/fib_notifier.c
index fc96259..5cdca49 100644 (file)
--- a/net/core/fib_notifier.c
+++ b/net/core/fib_notifier.c
@@ -43,7 +43,6 @@ static unsigned int fib_seq_sum(struct net *net)
        struct fib_notifier_ops *ops;
        unsigned int fib_seq = 0;
 
-       rtnl_lock();
        rcu_read_lock();
        list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) {
                if (!try_module_get(ops->owner))
@@ -52,7 +51,6 @@ static unsigned int fib_seq_sum(struct net *net)
                module_put(ops->owner);
        }
        rcu_read_unlock();
-       rtnl_unlock();
 
        return fib_seq;
 }

diff --git a/net/ipv4/fib_notifier.c b/net/ipv4/fib_notifier.c
index 21c85c8..b1551c2 100644 (file)
--- a/net/ipv4/fib_notifier.c
+++ b/net/ipv4/fib_notifier.c
@@ -27,7 +27,7 @@ int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
        return call_fib_notifiers(net, event_type, info);
 }
 
-static unsigned int fib4_seq_read(struct net *net)
+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);

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 35ed031..7a95dae 100644 (file)
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -3035,7 +3035,7 @@ static const struct net_protocol pim_protocol = {
 };
 #endif
 
-static unsigned int ipmr_seq_read(struct net *net)
+static unsigned int ipmr_seq_read(const struct net *net)
 {
        return READ_ONCE(net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net);
 }

diff --git a/net/ipv6/fib6_notifier.c b/net/ipv6/fib6_notifier.c
index f87ae33..949b726 100644 (file)
--- a/net/ipv6/fib6_notifier.c
+++ b/net/ipv6/fib6_notifier.c
@@ -22,7 +22,7 @@ int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
        return call_fib_notifiers(net, event_type, info);
 }
 
-static unsigned int fib6_seq_read(struct net *net)
+static unsigned int fib6_seq_read(const struct net *net)
 {
        return fib6_tables_seq_read(net) + fib6_rules_seq_read(net);
 }

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 3f9501f..9528e17 100644 (file)
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -1260,7 +1260,7 @@ static int ip6mr_device_event(struct notifier_block *this,
        return NOTIFY_DONE;
 }
 
-static unsigned int ip6mr_seq_read(struct net *net)
+static unsigned int ip6mr_seq_read(const struct net *net)
 {
        return READ_ONCE(net->ipv6.ipmr_seq) + ip6mr_rules_seq_read(net);
 }