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Commit f7a2ba5a authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

ila: Fix use of rhashtable walk in ila_xlat.c 



Perform better EAGAIN handling, handle case where ila_dump_info
fails and we missed objects in the dump, and add a skip index
to skip over ila entires in a list on a rhashtable node that have
already been visited (by a previous call to ila_nl_dump).

Signed-off-by: default avatarTom Herbert <tom@quantonium.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6d268910

net/ipv6/ila/ila_xlat.c

+54 −16
Original line number Diff line number Diff line
@@ -475,24 +475,31 @@ static int ila_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info) 


struct ila_dump_iter {

	struct rhashtable_iter rhiter;

	int skip;

};



static int ila_nl_dump_start(struct netlink_callback *cb)

{

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

	struct ila_net *ilan = net_generic(net, ila_net_id);

	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];

	struct ila_dump_iter *iter;

	int ret;



	if (!iter) {

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

	if (!iter)

		return -ENOMEM;



		cb->args[0] = (long)iter;

	ret = rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter,

				   GFP_KERNEL);

	if (ret) {

		kfree(iter);

		return ret;

	}



	return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter,

				    GFP_KERNEL);

	iter->skip = 0;

	cb->args[0] = (long)iter;



	return ret;

}



static int ila_nl_dump_done(struct netlink_callback *cb)
@@ -510,20 +517,45 @@ static int ila_nl_dump(struct sk_buff *skb, struct netlink_callback *cb) 
{

	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];

	struct rhashtable_iter *rhiter = &iter->rhiter;

	int skip = iter->skip;

	struct ila_map *ila;

	int ret;



	rhashtable_walk_start(rhiter);



	for (;;) {

		ila = rhashtable_walk_next(rhiter);

	/* Get first entry */

	ila = rhashtable_walk_peek(rhiter);



	if (ila && !IS_ERR(ila) && skip) {

		/* Skip over visited entries */



		while (ila && skip) {

			/* Skip over any ila entries in this list that we

			 * have already dumped.

			 */

			ila = rcu_access_pointer(ila->next);

			skip--;

		}

	}



	skip = 0;



	for (;;) {

		if (IS_ERR(ila)) {

			if (PTR_ERR(ila) == -EAGAIN)

				continue;

			ret = PTR_ERR(ila);

			goto done;

			if (ret == -EAGAIN) {

				/* Table has changed and iter has reset. Return

				 * -EAGAIN to the application even if we have

				 * written data to the skb. The application

				 * needs to deal with this.

				 */



				goto out_ret;

			} else {

				break;

			}

		} else if (!ila) {

			ret = 0;

			break;

		}
@@ -532,15 +564,21 @@ static int ila_nl_dump(struct sk_buff *skb, struct netlink_callback *cb) 
					     cb->nlh->nlmsg_seq, NLM_F_MULTI,

					     skb, ILA_CMD_GET);

			if (ret)

				goto done;

				goto out;



			skip++;

			ila = rcu_access_pointer(ila->next);

		}



		skip = 0;

		ila = rhashtable_walk_next(rhiter);

	}



	ret = skb->len;

out:

	iter->skip = skip;

	ret = (skb->len ? : ret);



done:

out_ret:

	rhashtable_walk_stop(rhiter);

	return ret;

}