Phonet: put protocols array under RCU
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index 8d3a55b..ed65da2 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -35,7 +35,6 @@
/* Transport protocol registration */
static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
-static DEFINE_SPINLOCK(proto_tab_lock);
static struct phonet_protocol *phonet_proto_get(int protocol)
{
@@ -44,11 +43,11 @@
if (protocol >= PHONET_NPROTO)
return NULL;
- spin_lock(&proto_tab_lock);
+ rcu_read_lock();
pp = proto_tab[protocol];
if (pp && !try_module_get(pp->prot->owner))
pp = NULL;
- spin_unlock(&proto_tab_lock);
+ rcu_read_unlock();
return pp;
}
@@ -439,6 +438,8 @@
.func = phonet_rcv,
};
+static DEFINE_MUTEX(proto_tab_lock);
+
int __init_or_module phonet_proto_register(int protocol,
struct phonet_protocol *pp)
{
@@ -451,12 +452,12 @@
if (err)
return err;
- spin_lock(&proto_tab_lock);
+ mutex_lock(&proto_tab_lock);
if (proto_tab[protocol])
err = -EBUSY;
else
- proto_tab[protocol] = pp;
- spin_unlock(&proto_tab_lock);
+ rcu_assign_pointer(proto_tab[protocol], pp);
+ mutex_unlock(&proto_tab_lock);
return err;
}
@@ -464,10 +465,11 @@
void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
{
- spin_lock(&proto_tab_lock);
+ mutex_lock(&proto_tab_lock);
BUG_ON(proto_tab[protocol] != pp);
- proto_tab[protocol] = NULL;
- spin_unlock(&proto_tab_lock);
+ rcu_assign_pointer(proto_tab[protocol], NULL);
+ mutex_unlock(&proto_tab_lock);
+ synchronize_rcu();
proto_unregister(pp->prot);
}
EXPORT_SYMBOL(phonet_proto_unregister);