From 2698acd6ea4770809af7e65bb8b3250e0a3a807e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 9 Oct 2024 18:44:05 +0000 Subject: [PATCH] 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 Note that after RTNL was dropped, fib_seq_sum() result was possibly outdated anyway.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 Reviewed-by: Kuniyuki Iwashima Reviewed-by: David Ahern Link: https://patch.msgid.link/20241009184405.3752829-6-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/fib_notifier.h | 2 +- net/core/fib_notifier.c | 2 -- net/ipv4/fib_notifier.c | 2 +- net/ipv4/ipmr.c | 2 +- net/ipv6/fib6_notifier.c | 2 +- net/ipv6/ip6mr.c | 2 +- 6 files changed, 5 insertions(+), 7 deletions(-) diff --git a/include/net/fib_notifier.h b/include/net/fib_notifier.h index 6d59221ff05a..48aad6128fea 100644 --- 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 fc96259807b6..5cdca49b1d7c 100644 --- 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 21c85c80de64..b1551c26554b 100644 --- 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 35ed03165184..7a95daeb1946 100644 --- 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 f87ae33e1d01..949b72610df7 100644 --- 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 3f9501fd8c1a..9528e17665fd 100644 --- 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); }