Commit 14e3e079 authored by Jeff Garzik's avatar Jeff Garzik Committed by David S. Miller
Browse files

[NET]: split dev_ifsioc() according to locking 



This always bugged me: dev_ioctl() called dev_ifsioc() either inside
read_lock(dev_base_lock) or rtnl_lock(), depending on the ioctl being
executed.

This change moves the ioctls executed inside dev_base_lock to a new
function, dev_ifsioc_locked().  Now the locking context is completely
clear to the reader.

Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cfcabdcc

net/core/dev.c

+58 −30
Original line number Diff line number Diff line
@@ -3083,9 +3083,9 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa) 
}



/*

 *	Perform the SIOCxIFxxx calls.

 *	Perform the SIOCxIFxxx calls, inside read_lock(dev_base_lock)

 */

static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)

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);
@@ -3098,25 +3098,15 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) 
			ifr->ifr_flags = dev_get_flags(dev);

			return 0;



		case SIOCSIFFLAGS:	/* Set interface flags */

			return dev_change_flags(dev, ifr->ifr_flags);



		case SIOCGIFMETRIC:	/* Get the metric on the interface

					   (currently unused) */

			ifr->ifr_metric = 0;

			return 0;



		case SIOCSIFMETRIC:	/* Set the metric on the interface

					   (currently unused) */

			return -EOPNOTSUPP;



		case SIOCGIFMTU:	/* Get the MTU of a device */

			ifr->ifr_mtu = dev->mtu;

			return 0;



		case SIOCSIFMTU:	/* Set the MTU of a device */

			return dev_set_mtu(dev, ifr->ifr_mtu);



		case SIOCGIFHWADDR:

			if (!dev->addr_len)

				memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
@@ -3126,6 +3116,61 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) 
			ifr->ifr_hwaddr.sa_family = dev->type;

			return 0;



		case SIOCGIFSLAVE:

			err = -EINVAL;

			break;



		case SIOCGIFMAP:

			ifr->ifr_map.mem_start = dev->mem_start;

			ifr->ifr_map.mem_end   = dev->mem_end;

			ifr->ifr_map.base_addr = dev->base_addr;

			ifr->ifr_map.irq       = dev->irq;

			ifr->ifr_map.dma       = dev->dma;

			ifr->ifr_map.port      = dev->if_port;

			return 0;



		case SIOCGIFINDEX:

			ifr->ifr_ifindex = dev->ifindex;

			return 0;



		case SIOCGIFTXQLEN:

			ifr->ifr_qlen = dev->tx_queue_len;

			return 0;



		default:

			/* dev_ioctl() should ensure this case

			 * is never reached

			 */

			WARN_ON(1);

			err = -EINVAL;

			break;



	}

	return err;

}



/*

 *	Perform the SIOCxIFxxx calls, inside rtnl_lock()

 */

static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)

{

	int err;

	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);



	if (!dev)

		return -ENODEV;



	switch (cmd) {

		case SIOCSIFFLAGS:	/* Set interface flags */

			return dev_change_flags(dev, ifr->ifr_flags);



		case SIOCSIFMETRIC:	/* Set the metric on the interface

					   (currently unused) */

			return -EOPNOTSUPP;



		case SIOCSIFMTU:	/* Set the MTU of a device */

			return dev_set_mtu(dev, ifr->ifr_mtu);



		case SIOCSIFHWADDR:

			return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
@@ -3137,15 +3182,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) 
			call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);

			return 0;



		case SIOCGIFMAP:

			ifr->ifr_map.mem_start = dev->mem_start;

			ifr->ifr_map.mem_end   = dev->mem_end;

			ifr->ifr_map.base_addr = dev->base_addr;

			ifr->ifr_map.irq       = dev->irq;

			ifr->ifr_map.dma       = dev->dma;

			ifr->ifr_map.port      = dev->if_port;

			return 0;



		case SIOCSIFMAP:

			if (dev->set_config) {

				if (!netif_device_present(dev))
@@ -3172,14 +3208,6 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) 
			return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data,

					     dev->addr_len, 1);



		case SIOCGIFINDEX:

			ifr->ifr_ifindex = dev->ifindex;

			return 0;



		case SIOCGIFTXQLEN:

			ifr->ifr_qlen = dev->tx_queue_len;

			return 0;



		case SIOCSIFTXQLEN:

			if (ifr->ifr_qlen < 0)

				return -EINVAL;
@@ -3290,7 +3318,7 @@ int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg) 
		case SIOCGIFTXQLEN:

			dev_load(net, ifr.ifr_name);

			read_lock(&dev_base_lock);

			ret = dev_ifsioc(net, &ifr, cmd);

			ret = dev_ifsioc_locked(net, &ifr, cmd);

			read_unlock(&dev_base_lock);

			if (!ret) {

				if (colon)