Commit 2d20773a authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

mctp: no longer rely on net->dev_index_head[] 



mctp_dump_addrinfo() is one of the last users of
net->dev_index_head[] in the control path.

Switch to for_each_netdev_dump() for better scalability.

Use C99 for mctp_device_rtnl_msg_handlers[] to prepare
future RTNL removal from mctp_dump_addrinfo()

(mdev->addrs is not yet RCU protected)

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Matt Johnston <matt@codeconstruct.com.au>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: default avatarJeremy Kerr <jk@codeconstruct.com.au>
Link: https://patch.msgid.link/20241206223811.1343076-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f9663b7c

net/mctp/device.c

+19 −31
Original line number Diff line number Diff line
@@ -20,8 +20,7 @@ 
#include <net/sock.h>



struct mctp_dump_cb {

	int h;

	int idx;

	unsigned long ifindex;

	size_t a_idx;

};
@@ -115,43 +114,29 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb) 
{

	struct mctp_dump_cb *mcb = (void *)cb->ctx;

	struct net *net = sock_net(skb->sk);

	struct hlist_head *head;

	struct net_device *dev;

	struct ifaddrmsg *hdr;

	struct mctp_dev *mdev;

	int ifindex;

	int idx = 0, rc;

	int ifindex, rc;



	hdr = nlmsg_data(cb->nlh);

	// filter by ifindex if requested

	ifindex = hdr->ifa_index;



	rcu_read_lock();

	for (; mcb->h < NETDEV_HASHENTRIES; mcb->h++, mcb->idx = 0) {

		idx = 0;

		head = &net->dev_index_head[mcb->h];

		hlist_for_each_entry_rcu(dev, head, index_hlist) {

			if (idx >= mcb->idx &&

			    (ifindex == 0 || ifindex == dev->ifindex)) {

	for_each_netdev_dump(net, dev, mcb->ifindex) {

		if (ifindex && ifindex != dev->ifindex)

			continue;

		mdev = __mctp_dev_get(dev);

				if (mdev) {

					rc = mctp_dump_dev_addrinfo(mdev,

								    skb, cb);

		if (!mdev)

			continue;

		rc = mctp_dump_dev_addrinfo(mdev, skb, cb);

		mctp_dev_put(mdev);

					// Error indicates full buffer, this

					// callback will get retried.

		if (rc < 0)

						goto out;

				}

			}

			idx++;

			// reset for next iteration

			break;

		mcb->a_idx = 0;

	}

	}

out:

	rcu_read_unlock();

	mcb->idx = idx;



	return skb->len;

}
@@ -531,9 +516,12 @@ static struct notifier_block mctp_dev_nb = { 
};



static const struct rtnl_msg_handler mctp_device_rtnl_msg_handlers[] = {

	{THIS_MODULE, PF_MCTP, RTM_NEWADDR, mctp_rtm_newaddr, NULL, 0},

	{THIS_MODULE, PF_MCTP, RTM_DELADDR, mctp_rtm_deladdr, NULL, 0},

	{THIS_MODULE, PF_MCTP, RTM_GETADDR, NULL, mctp_dump_addrinfo, 0},

	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_NEWADDR,

	 .doit = mctp_rtm_newaddr},

	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_DELADDR,

	 .doit = mctp_rtm_deladdr},

	{.owner = THIS_MODULE, .protocol = PF_MCTP, .msgtype = RTM_GETADDR,

	 .dumpit = mctp_dump_addrinfo},

};



int __init mctp_device_init(void)