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Commit ad202074 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

netlink: Use rhashtable walk interface in diag dump 



This patch converts the diag dumping code to use the rhashtable
walk code instead of going through rhashtable by hand.  The lock
nl_table_lock is now only taken while we process the multicast
list as it's not needed for the rhashtable walk.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 39ec406d

net/netlink/diag.c

+73 −30
Original line number Diff line number Diff line
@@ -63,29 +63,53 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, 
static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,

				int protocol, int s_num)

{

	struct rhashtable_iter *hti = (void *)cb->args[2];

	struct netlink_table *tbl = &nl_table[protocol];

	struct rhashtable *ht = &tbl->hash;

	const struct bucket_table *htbl = rht_dereference_rcu(ht->tbl, ht);

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

	struct netlink_diag_req *req;

	struct netlink_sock *nlsk;

	struct sock *sk;

	int ret = 0, num = 0, i;

	int num = 2;

	int ret = 0;



	req = nlmsg_data(cb->nlh);



	for (i = 0; i < htbl->size; i++) {

		struct rhash_head *pos;

	if (s_num > 1)

		goto mc_list;



	num--;



	if (!hti) {

		hti = kmalloc(sizeof(*hti), GFP_KERNEL);

		if (!hti)

			return -ENOMEM;



		cb->args[2] = (long)hti;

	}



	if (!s_num)

		rhashtable_walk_enter(&tbl->hash, hti);



	ret = rhashtable_walk_start(hti);

	if (ret == -EAGAIN)

		ret = 0;

	if (ret)

		goto stop;



	while ((nlsk = rhashtable_walk_next(hti))) {

		if (IS_ERR(nlsk)) {

			ret = PTR_ERR(nlsk);

			if (ret == -EAGAIN) {

				ret = 0;

				continue;

			}

			break;

		}



		rht_for_each_entry_rcu(nlsk, pos, htbl, i, node) {

		sk = (struct sock *)nlsk;



		if (!net_eq(sock_net(sk), net))

			continue;

			if (num < s_num) {

				num++;

				continue;

			}



		if (sk_diag_fill(sk, skb, req,

				 NETLINK_CB(cb->skb).portid,
@@ -93,13 +117,21 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
				 NLM_F_MULTI,

				 sock_i_ino(sk)) < 0) {

			ret = 1;

				goto done;

			break;

		}

	}



stop:

	rhashtable_walk_stop(hti);

	if (ret)

		goto done;



	rhashtable_walk_exit(hti);

	cb->args[2] = 0;

	num++;

		}

	}



mc_list:

	read_lock(&nl_table_lock);

	sk_for_each_bound(sk, &tbl->mc_list) {

		if (sk_hashed(sk))

			continue;
@@ -116,13 +148,14 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 
				 NLM_F_MULTI,

				 sock_i_ino(sk)) < 0) {

			ret = 1;

			goto done;

			break;

		}

		num++;

	}

	read_unlock(&nl_table_lock);



done:

	cb->args[0] = num;

	cb->args[1] = protocol;



	return ret;

}
@@ -131,20 +164,20 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) 
{

	struct netlink_diag_req *req;

	int s_num = cb->args[0];

	int err = 0;



	req = nlmsg_data(cb->nlh);



	rcu_read_lock();

	read_lock(&nl_table_lock);



	if (req->sdiag_protocol == NDIAG_PROTO_ALL) {

		int i;



		for (i = cb->args[1]; i < MAX_LINKS; i++) {

			if (__netlink_diag_dump(skb, cb, i, s_num))

			err = __netlink_diag_dump(skb, cb, i, s_num);

			if (err)

				break;

			s_num = 0;

		}

		cb->args[1] = i;

	} else {

		if (req->sdiag_protocol >= MAX_LINKS) {

			read_unlock(&nl_table_lock);
@@ -152,13 +185,22 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) 
			return -ENOENT;

		}



		__netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);

		err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);

	}



	read_unlock(&nl_table_lock);

	rcu_read_unlock();

	return err < 0 ? err : skb->len;

}



	return skb->len;

static int netlink_diag_dump_done(struct netlink_callback *cb)

{

	struct rhashtable_iter *hti = (void *)cb->args[2];



	if (cb->args[0] == 1)

		rhashtable_walk_exit(hti);



	kfree(hti);



	return 0;

}



static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
@@ -172,6 +214,7 @@ static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h) 
	if (h->nlmsg_flags & NLM_F_DUMP) {

		struct netlink_dump_control c = {

			.dump = netlink_diag_dump,

			.done = netlink_diag_dump_done,

		};

		return netlink_dump_start(net->diag_nlsk, skb, h, &c);

	} else