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Commit 893f139b authored by Jarno Rajahalme's avatar Jarno Rajahalme Committed by Pravin B Shelar
Browse files

openvswitch: Minimize ovs_flow_cmd_new|set critical sections. 



Signed-off-by: default avatarJarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: default avatarPravin B Shelar <pshelar@nicira.com>
parent 37bdc87b

net/openvswitch/datapath.c

+116 −76
Original line number Diff line number Diff line
@@ -796,8 +796,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) 
{

	struct nlattr **a = info->attrs;

	struct ovs_header *ovs_header = info->userhdr;

	struct sw_flow_key key, masked_key;

	struct sw_flow *flow;

	struct sw_flow *flow, *new_flow;

	struct sw_flow_mask mask;

	struct sk_buff *reply;

	struct datapath *dp;
@@ -805,61 +804,77 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) 
	struct sw_flow_match match;

	int error;



	/* Extract key. */

	/* Must have key and actions. */

	error = -EINVAL;

	if (!a[OVS_FLOW_ATTR_KEY])

		goto error;

	if (!a[OVS_FLOW_ATTR_ACTIONS])

		goto error;



	ovs_match_init(&match, &key, &mask);

	/* Most of the time we need to allocate a new flow, do it before

	 * locking.

	 */

	new_flow = ovs_flow_alloc();

	if (IS_ERR(new_flow)) {

		error = PTR_ERR(new_flow);

		goto error;

	}



	/* Extract key. */

	ovs_match_init(&match, &new_flow->unmasked_key, &mask);

	error = ovs_nla_get_match(&match,

				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);

	if (error)

		goto error;

		goto err_kfree_flow;



	/* Validate actions. */

	error = -EINVAL;

	if (!a[OVS_FLOW_ATTR_ACTIONS])

		goto error;

	ovs_flow_mask_key(&new_flow->key, &new_flow->unmasked_key, &mask);



	/* Validate actions. */

	acts = ovs_nla_alloc_flow_actions(nla_len(a[OVS_FLOW_ATTR_ACTIONS]));

	error = PTR_ERR(acts);

	if (IS_ERR(acts))

		goto error;

		goto err_kfree_flow;



	ovs_flow_mask_key(&masked_key, &key, &mask);

	error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS],

				     &masked_key, 0, &acts);

	error = ovs_nla_copy_actions(a[OVS_FLOW_ATTR_ACTIONS], &new_flow->key,

				     0, &acts);

	if (error) {

		OVS_NLERR("Flow actions may not be safe on all matching packets.\n");

		goto err_kfree;

		goto err_kfree_acts;

	}



	reply = ovs_flow_cmd_alloc_info(acts, info, false);

	if (IS_ERR(reply)) {

		error = PTR_ERR(reply);

		goto err_kfree_acts;

	}



	ovs_lock();

	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);

	if (unlikely(!dp)) {

		error = -ENODEV;

	if (!dp)

		goto err_unlock_ovs;



	/* Check if this is a duplicate flow */

	flow = ovs_flow_tbl_lookup(&dp->table, &key);

	if (!flow) {

		/* Allocate flow. */

		flow = ovs_flow_alloc();

		if (IS_ERR(flow)) {

			error = PTR_ERR(flow);

		goto err_unlock_ovs;

	}



		flow->key = masked_key;

		flow->unmasked_key = key;

		rcu_assign_pointer(flow->sf_acts, acts);

	/* Check if this is a duplicate flow */

	flow = ovs_flow_tbl_lookup(&dp->table, &new_flow->unmasked_key);

	if (likely(!flow)) {

		rcu_assign_pointer(new_flow->sf_acts, acts);



		/* Put flow in bucket. */

		error = ovs_flow_tbl_insert(&dp->table, flow, &mask);

		if (error) {

		error = ovs_flow_tbl_insert(&dp->table, new_flow, &mask);

		if (unlikely(error)) {

			acts = NULL;

			goto err_flow_free;

			goto err_unlock_ovs;

		}



		if (unlikely(reply)) {

			error = ovs_flow_cmd_fill_info(new_flow,

						       ovs_header->dp_ifindex,

						       reply, info->snd_portid,

						       info->snd_seq, 0,

						       OVS_FLOW_CMD_NEW);

			BUG_ON(error < 0);

		}

		ovs_unlock();

	} else {

		struct sw_flow_actions *old_acts;
@@ -869,39 +884,45 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) 
		 * request.  We also accept NLM_F_EXCL in case that bug ever

		 * gets fixed.

		 */

		if (unlikely(info->nlhdr->nlmsg_flags & (NLM_F_CREATE

							 | NLM_F_EXCL))) {

			error = -EEXIST;

		if (info->nlhdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_EXCL))

			goto err_unlock_ovs;



		}

		/* The unmasked key has to be the same for flow updates. */

		if (!ovs_flow_cmp_unmasked_key(flow, &match))

		if (unlikely(!ovs_flow_cmp_unmasked_key(flow, &match))) {

			error = -EEXIST;

			goto err_unlock_ovs;



		}

		/* Update actions. */

		old_acts = ovsl_dereference(flow->sf_acts);

		rcu_assign_pointer(flow->sf_acts, acts);

		ovs_nla_free_flow_actions(old_acts);

	}



	reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,

					info, OVS_FLOW_CMD_NEW, false);

		if (unlikely(reply)) {

			error = ovs_flow_cmd_fill_info(flow,

						       ovs_header->dp_ifindex,

						       reply, info->snd_portid,

						       info->snd_seq, 0,

						       OVS_FLOW_CMD_NEW);

			BUG_ON(error < 0);

		}

		ovs_unlock();



	if (reply) {

		if (!IS_ERR(reply))

			ovs_notify(&dp_flow_genl_family, reply, info);

		else

			netlink_set_err(sock_net(skb->sk)->genl_sock, 0, 0,

					PTR_ERR(reply));

		ovs_nla_free_flow_actions(old_acts);

		ovs_flow_free(new_flow, false);

	}



	if (reply)

		ovs_notify(&dp_flow_genl_family, reply, info);

	return 0;



err_flow_free:

	ovs_flow_free(flow, false);

err_unlock_ovs:

	ovs_unlock();

err_kfree:

	kfree_skb(reply);

err_kfree_acts:

	kfree(acts);

err_kfree_flow:

	ovs_flow_free(new_flow, false);

error:

	return error;

}
@@ -915,7 +936,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info) 
	struct sw_flow_mask mask;

	struct sk_buff *reply = NULL;

	struct datapath *dp;

	struct sw_flow_actions *acts = NULL;

	struct sw_flow_actions *old_acts = NULL, *acts = NULL;

	struct sw_flow_match match;

	int error;
@@ -942,56 +963,75 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info) 
					     &masked_key, 0, &acts);

		if (error) {

			OVS_NLERR("Flow actions may not be safe on all matching packets.\n");

			goto err_kfree;

			goto err_kfree_acts;

		}

	}



	/* Can allocate before locking if have acts. */

	if (acts) {

		reply = ovs_flow_cmd_alloc_info(acts, info, false);

		if (IS_ERR(reply)) {

			error = PTR_ERR(reply);

			goto err_kfree_acts;

		}

	}



	ovs_lock();

	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);

	if (unlikely(!dp)) {

		error = -ENODEV;

	if (!dp)

		goto err_unlock_ovs;



	}

	/* Check that the flow exists. */

	flow = ovs_flow_tbl_lookup(&dp->table, &key);

	if (unlikely(!flow)) {

		error = -ENOENT;

	if (!flow)

		goto err_unlock_ovs;



	}

	/* The unmasked key has to be the same for flow updates. */

	if (unlikely(!ovs_flow_cmp_unmasked_key(flow, &match))) {

		error = -EEXIST;

	if (!ovs_flow_cmp_unmasked_key(flow, &match))

		goto err_unlock_ovs;



	}

	/* Update actions, if present. */

	if (acts) {

		struct sw_flow_actions *old_acts;



	if (likely(acts)) {

		old_acts = ovsl_dereference(flow->sf_acts);

		rcu_assign_pointer(flow->sf_acts, acts);

		ovs_nla_free_flow_actions(old_acts);

	}



		if (unlikely(reply)) {

			error = ovs_flow_cmd_fill_info(flow,

						       ovs_header->dp_ifindex,

						       reply, info->snd_portid,

						       info->snd_seq, 0,

						       OVS_FLOW_CMD_NEW);

			BUG_ON(error < 0);

		}

	} else {

		/* Could not alloc without acts before locking. */

		reply = ovs_flow_cmd_build_info(flow, ovs_header->dp_ifindex,

						info, OVS_FLOW_CMD_NEW, false);

		if (unlikely(IS_ERR(reply))) {

			error = PTR_ERR(reply);

			goto err_unlock_ovs;

		}

	}



	/* Clear stats. */

	if (a[OVS_FLOW_ATTR_CLEAR])

		ovs_flow_stats_clear(flow);

	ovs_unlock();



	if (reply) {

		if (!IS_ERR(reply))

	if (reply)

		ovs_notify(&dp_flow_genl_family, reply, info);

		else

			genl_set_err(&dp_flow_genl_family, sock_net(skb->sk), 0,

				     0, PTR_ERR(reply));

	}

	if (old_acts)

		ovs_nla_free_flow_actions(old_acts);



	return 0;



err_unlock_ovs:

	ovs_unlock();

err_kfree:

	kfree_skb(reply);

err_kfree_acts:

	kfree(acts);

error:

	return error;