net: RCU locking for simple ioctl()
All ioctls() implemented by dev_ifsioc_locked() :
SIOCGIFFLAGS, SIOCGIFMETRIC, SIOCGIFMTU, SIOCGIFHWADDR,
SIOCGIFSLAVE, SIOCGIFMAP, SIOCGIFINDEX & SIOCGIFTXQLEN
can use RCU lock instead of dev_base_lock rwlock
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 3c40d54..76a1502 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4315,12 +4315,12 @@
EXPORT_SYMBOL(dev_set_mac_address);
/*
- * Perform the SIOCxIFxxx calls, inside read_lock(dev_base_lock)
+ * Perform the SIOCxIFxxx calls, inside rcu_read_lock()
*/
static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
{
int err;
- struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
+ struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
if (!dev)
return -ENODEV;
@@ -4552,9 +4552,9 @@
case SIOCGIFINDEX:
case SIOCGIFTXQLEN:
dev_load(net, ifr.ifr_name);
- read_lock(&dev_base_lock);
+ rcu_read_lock();
ret = dev_ifsioc_locked(net, &ifr, cmd);
- read_unlock(&dev_base_lock);
+ rcu_read_unlock();
if (!ret) {
if (colon)
*colon = ':';
