Commit 6da7a0f9 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'dev-covnert-dev_change_name-to-per-netns-rtnl' 

Kuniyuki Iwashima says:

====================
dev: Covnert dev_change_name() to per-netns RTNL.

Patch 1 adds a missing netdev_rename_lock in dev_change_name()
and Patch 2 removes unnecessary devnet_rename_sem there.

Patch 3 replaces RTNL with rtnl_net_lock() in dev_ifsioc(),
and now dev_change_name() is always called under per-netns RTNL.

Given it's close to -rc8 and Patch 1 touches the trivial unlikely
path, can Patch 1 go into net-next ?  Otherwise I'll post Patch 2 & 3
separately in the next cycle.
====================

Link: https://patch.msgid.link/20250115095545.52709-1-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 8d20dcda be94cfdb

net/core/dev.c

+6 −19
Original line number Diff line number Diff line
@@ -181,8 +181,6 @@ static DEFINE_SPINLOCK(napi_hash_lock); 
static unsigned int napi_gen_id = NR_CPUS;

static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);



static DECLARE_RWSEM(devnet_rename_sem);



static inline void dev_base_seq_inc(struct net *net)

{

	unsigned int val = net->dev_base_seq + 1;
@@ -1350,23 +1348,16 @@ static int dev_get_valid_name(struct net *net, struct net_device *dev, 
 */

int dev_change_name(struct net_device *dev, const char *newname)

{

	struct net *net = dev_net(dev);

	unsigned char old_assign_type;

	char oldname[IFNAMSIZ];

	int err = 0;

	int ret;

	struct net *net;



	ASSERT_RTNL();

	BUG_ON(!dev_net(dev));



	net = dev_net(dev);



	down_write(&devnet_rename_sem);

	ASSERT_RTNL_NET(net);



	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {

		up_write(&devnet_rename_sem);

	if (!strncmp(newname, dev->name, IFNAMSIZ))

		return 0;

	}



	memcpy(oldname, dev->name, IFNAMSIZ);
@@ -1374,10 +1365,8 @@ int dev_change_name(struct net_device *dev, const char *newname) 
	err = dev_get_valid_name(net, dev, newname);

	write_sequnlock_bh(&netdev_rename_lock);



	if (err < 0) {

		up_write(&devnet_rename_sem);

	if (err < 0)

		return err;

	}



	if (oldname[0] && !strchr(oldname, '%'))

		netdev_info(dev, "renamed from %s%s\n", oldname,
@@ -1389,14 +1378,13 @@ int dev_change_name(struct net_device *dev, const char *newname) 
rollback:

	ret = device_rename(&dev->dev, dev->name);

	if (ret) {

		write_seqlock_bh(&netdev_rename_lock);

		memcpy(dev->name, oldname, IFNAMSIZ);

		write_sequnlock_bh(&netdev_rename_lock);

		WRITE_ONCE(dev->name_assign_type, old_assign_type);

		up_write(&devnet_rename_sem);

		return ret;

	}



	up_write(&devnet_rename_sem);



	netdev_adjacent_rename_links(dev, oldname);



	netdev_name_node_del(dev->name_node);
@@ -1412,7 +1400,6 @@ int dev_change_name(struct net_device *dev, const char *newname) 
		/* err >= 0 after dev_alloc_name() or stores the first errno */

		if (err >= 0) {

			err = ret;

			down_write(&devnet_rename_sem);

			write_seqlock_bh(&netdev_rename_lock);

			memcpy(dev->name, oldname, IFNAMSIZ);

			write_sequnlock_bh(&netdev_rename_lock);

net/core/dev_ioctl.c

+17 −9
Original line number Diff line number Diff line
@@ -543,7 +543,7 @@ static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs) 
}



/*

 *	Perform the SIOCxIFxxx calls, inside rtnl_lock()

 *	Perform the SIOCxIFxxx calls, inside rtnl_net_lock()

 */

static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,

		      unsigned int cmd)
@@ -620,11 +620,14 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, 
			return -ENODEV;

		if (!netif_is_bridge_master(dev))

			return -EOPNOTSUPP;



		netdev_hold(dev, &dev_tracker, GFP_KERNEL);

		rtnl_unlock();

		rtnl_net_unlock(net);



		err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);



		netdev_put(dev, &dev_tracker);

		rtnl_lock();

		rtnl_net_lock(net);

		return err;



	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
@@ -770,9 +773,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
		dev_load(net, ifr->ifr_name);

		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))

			return -EPERM;

		rtnl_lock();



		rtnl_net_lock(net);

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

		rtnl_unlock();

		rtnl_net_unlock(net);



		if (colon)

			*colon = ':';

		return ret;
@@ -816,9 +821,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
	case SIOCBONDSLAVEINFOQUERY:

	case SIOCBONDINFOQUERY:

		dev_load(net, ifr->ifr_name);

		rtnl_lock();



		rtnl_net_lock(net);

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

		rtnl_unlock();

		rtnl_net_unlock(net);



		if (need_copyout)

			*need_copyout = false;

		return ret;
@@ -841,9 +848,10 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
		    (cmd >= SIOCDEVPRIVATE &&

		     cmd <= SIOCDEVPRIVATE + 15)) {

			dev_load(net, ifr->ifr_name);

			rtnl_lock();



			rtnl_net_lock(net);

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

			rtnl_unlock();

			rtnl_net_unlock(net);

			return ret;

		}

		return -ENOTTY;

net/core/rtnl_net_debug.c

+3 −12
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 
	case NETDEV_CHANGEADDR:

	case NETDEV_PRE_CHANGEADDR:

	case NETDEV_GOING_DOWN:

	case NETDEV_CHANGENAME:

	case NETDEV_FEAT_CHANGE:

	case NETDEV_BONDING_FAILOVER:

	case NETDEV_PRE_UP:
@@ -60,18 +59,10 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 
		ASSERT_RTNL();

		break;



	/* Once an event fully supports RTNL_NET, move it here

	 * and remove "if (0)" below.

	 *

	 * case NETDEV_XXX:

	 *	ASSERT_RTNL_NET(net);

	 *	break;

	 */

	}



	/* Just to avoid unused-variable error for dev and net. */

	if (0)

	case NETDEV_CHANGENAME:

		ASSERT_RTNL_NET(net);

		break;

	}



	return NOTIFY_DONE;

}