Commit 0feb396f authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

rtnetlink: use for_each_netdev_dump() in rtnl_stats_dump() 



Switch rtnl_stats_dump() to use for_each_netdev_dump()
instead of net->dev_index_head[] hash table.

This makes the code much easier to read, and fixes
scalability issues.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240502113748.1622637-3-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 136c2a9a

net/core/rtnetlink.c

+22 −37
Original line number Diff line number Diff line
@@ -5961,19 +5961,17 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh, 
static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct netlink_ext_ack *extack = cb->extack;

	int h, s_h, err, s_idx, s_idxattr, s_prividx;

	struct rtnl_stats_dump_filters filters;

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

	unsigned int flags = NLM_F_MULTI;

	struct if_stats_msg *ifsm;

	struct hlist_head *head;

	struct {

		unsigned long ifindex;

		int idxattr;

		int prividx;

	} *ctx = (void *)cb->ctx;

	struct net_device *dev;

	int idx = 0;



	s_h = cb->args[0];

	s_idx = cb->args[1];

	s_idxattr = cb->args[2];

	s_prividx = cb->args[3];

	int err;



	cb->seq = net->dev_base_seq;
@@ -5992,37 +5990,24 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) 
	if (err)

		return err;



	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {

		idx = 0;

		head = &net->dev_index_head[h];

		hlist_for_each_entry(dev, head, index_hlist) {

			if (idx < s_idx)

				goto cont;

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

		err = rtnl_fill_statsinfo(skb, dev, RTM_NEWSTATS,

					  NETLINK_CB(cb->skb).portid,

					  cb->nlh->nlmsg_seq, 0,

					  flags, &filters,

						  &s_idxattr, &s_prividx,

					  &ctx->idxattr, &ctx->prividx,

					  extack);

		/* If we ran out of room on the first message,

			 * we're in trouble

		 * we're in trouble.

		 */

		WARN_ON((err == -EMSGSIZE) && (skb->len == 0));



		if (err < 0)

				goto out;

			s_prividx = 0;

			s_idxattr = 0;

			break;

		ctx->prividx = 0;

		ctx->idxattr = 0;

		nl_dump_check_consistent(cb, nlmsg_hdr(skb));

cont:

			idx++;

		}

	}

out:

	cb->args[3] = s_prividx;

	cb->args[2] = s_idxattr;

	cb->args[1] = idx;

	cb->args[0] = h;



	return err;

}