ipv4: convert fib_num_tclassid_users to atomic_t
Before commit faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
changes to net->ipv4.fib_num_tclassid_users were protected by RTNL.
After the change, this is no longer the case, as free_fib_info_rcu()
runs after rcu grace period, without rtnl being held.
Fixes: faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index ab5348e..3417ba2 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -438,7 +438,7 @@
#ifdef CONFIG_IP_ROUTE_CLASSID
static inline int fib_num_tclassid_users(struct net *net)
{
- return net->ipv4.fib_num_tclassid_users;
+ return atomic_read(&net->ipv4.fib_num_tclassid_users);
}
#else
static inline int fib_num_tclassid_users(struct net *net)
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 2f65701..6c5b2ef 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -65,7 +65,7 @@
bool fib_has_custom_local_routes;
bool fib_offload_disabled;
#ifdef CONFIG_IP_ROUTE_CLASSID
- int fib_num_tclassid_users;
+ atomic_t fib_num_tclassid_users;
#endif
struct hlist_head *fib_table_hash;
struct sock *fibnl;
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 9fe13e4..4d61ddd8 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1582,7 +1582,7 @@
int error;
#ifdef CONFIG_IP_ROUTE_CLASSID
- net->ipv4.fib_num_tclassid_users = 0;
+ atomic_set(&net->ipv4.fib_num_tclassid_users, 0);
#endif
error = ip_fib_net_init(net);
if (error < 0)
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 364ad34..d279cb8 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -264,7 +264,7 @@
if (tb[FRA_FLOW]) {
rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
if (rule4->tclassid)
- net->ipv4.fib_num_tclassid_users++;
+ atomic_inc(&net->ipv4.fib_num_tclassid_users);
}
#endif
@@ -296,7 +296,7 @@
#ifdef CONFIG_IP_ROUTE_CLASSID
if (((struct fib4_rule *)rule)->tclassid)
- net->ipv4.fib_num_tclassid_users--;
+ atomic_dec(&net->ipv4.fib_num_tclassid_users);
#endif
net->ipv4.fib_has_custom_rules = true;
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 3364cb9..fde7797 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -220,7 +220,7 @@
{
#ifdef CONFIG_IP_ROUTE_CLASSID
if (fib_nh->nh_tclassid)
- net->ipv4.fib_num_tclassid_users--;
+ atomic_dec(&net->ipv4.fib_num_tclassid_users);
#endif
fib_nh_common_release(&fib_nh->nh_common);
}
@@ -632,7 +632,7 @@
#ifdef CONFIG_IP_ROUTE_CLASSID
nh->nh_tclassid = cfg->fc_flow;
if (nh->nh_tclassid)
- net->ipv4.fib_num_tclassid_users++;
+ atomic_inc(&net->ipv4.fib_num_tclassid_users);
#endif
#ifdef CONFIG_IP_ROUTE_MULTIPATH
nh->fib_nh_weight = nh_weight;
