Commit d02e3b38 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

netdev: don't hold rtnl_lock over nl queue info get when possible 



Netdev queue dump accesses: NAPI, memory providers, XSk pointers.
All three are "ops protected" now, switch to the op compat locking.
rtnl lock does not have to be taken for "ops locked" devices.

Reviewed-by: default avatarJoe Damato <jdamato@fastly.com>
Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250408195956.412733-5-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4ec9031c

net/core/netdev-genl.c

+7 −11
Original line number Diff line number Diff line
@@ -481,18 +481,15 @@ int netdev_nl_queue_get_doit(struct sk_buff *skb, struct genl_info *info) 
	if (!rsp)

		return -ENOMEM;



	rtnl_lock();



	netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex);

	netdev = netdev_get_by_index_lock_ops_compat(genl_info_net(info),

						     ifindex);

	if (netdev) {

		err = netdev_nl_queue_fill(rsp, netdev, q_id, q_type, info);

		netdev_unlock(netdev);

		netdev_unlock_ops_compat(netdev);

	} else {

		err = -ENODEV;

	}



	rtnl_unlock();



	if (err)

		goto err_free_msg;
@@ -541,17 +538,17 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) 
	if (info->attrs[NETDEV_A_QUEUE_IFINDEX])

		ifindex = nla_get_u32(info->attrs[NETDEV_A_QUEUE_IFINDEX]);



	rtnl_lock();

	if (ifindex) {

		netdev = netdev_get_by_index_lock(net, ifindex);

		netdev = netdev_get_by_index_lock_ops_compat(net, ifindex);

		if (netdev) {

			err = netdev_nl_queue_dump_one(netdev, skb, info, ctx);

			netdev_unlock(netdev);

			netdev_unlock_ops_compat(netdev);

		} else {

			err = -ENODEV;

		}

	} else {

		for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) {

		for_each_netdev_lock_ops_compat_scoped(net, netdev,

						       ctx->ifindex) {

			err = netdev_nl_queue_dump_one(netdev, skb, info, ctx);

			if (err < 0)

				break;
@@ -559,7 +556,6 @@ int netdev_nl_queue_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) 
			ctx->txq_idx = 0;

		}

	}

	rtnl_unlock();



	return err;

}