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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>
This commit is contained in:
Eric Dumazet 2009-11-01 19:42:09 +00:00 committed by David S. Miller
parent 685c794405
commit 3710becf8a
1 changed files with 4 additions and 4 deletions
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8
net/core/dev.c
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@ -4315,12 +4315,12 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
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 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
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 = ':';