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net: RCU locking for simple ioctl()

PATCH Applied Eric Dumazet 2 participants 2 messages Nov 2, 2009

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Networking Network drivers
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Eric Dumazet

author
#0 lore raw

PATCH 1/1 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 <[email protected]>
---
 net/core/dev.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)
net/core/dev.c +4 -4
index f54d8b8..c0f27ad 100644
@@ -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 = ':';
maintainer Applied
#1 lore raw

From: Eric Dumazet <[email protected]>
Date: Mon, 02 Nov 2009 06:42:09 +0100

Quoted 6 lines

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 <[email protected]>

Applied.