Commit 81390d0c authored by Taehee Yoo's avatar Taehee Yoo Committed by David S. Miller
Browse files

hsr: remove unnecessary rcu_read_lock() in hsr module 



In order to access the port list, the hsr_port_get_hsr() is used.
And this is protected by RTNL and RCU.
The hsr_fill_info(), hsr_check_carrier(), hsr_dev_open() and
hsr_get_max_mtu() are protected by RTNL.
So, rcu_read_lock() in these functions are not necessary.
The hsr_handle_frame() also uses rcu_read_lock() but this function
is called by packet path.
It's already protected by RCU.
So, the rcu_read_lock() in hsr_handle_frame() can be removed.

Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4b793acd

net/hsr/hsr_device.c

+7 −16
Original line number Diff line number Diff line
@@ -57,24 +57,19 @@ static void hsr_set_operstate(struct hsr_port *master, bool has_carrier) 
static bool hsr_check_carrier(struct hsr_port *master)

{

	struct hsr_port *port;

	bool has_carrier;



	has_carrier = false;

	ASSERT_RTNL();



	rcu_read_lock();

	hsr_for_each_port(master->hsr, port)

	hsr_for_each_port(master->hsr, port) {

		if (port->type != HSR_PT_MASTER && is_slave_up(port->dev)) {

			has_carrier = true;

			break;

			netif_carrier_on(master->dev);

			return true;

		}

	}

	rcu_read_unlock();



	if (has_carrier)

		netif_carrier_on(master->dev);

	else

	netif_carrier_off(master->dev);



	return has_carrier;

	return false;

}



static void hsr_check_announce(struct net_device *hsr_dev,
@@ -118,11 +113,9 @@ int hsr_get_max_mtu(struct hsr_priv *hsr) 
	struct hsr_port *port;



	mtu_max = ETH_DATA_LEN;

	rcu_read_lock();

	hsr_for_each_port(hsr, port)

		if (port->type != HSR_PT_MASTER)

			mtu_max = min(port->dev->mtu, mtu_max);

	rcu_read_unlock();



	if (mtu_max < HSR_HLEN)

		return 0;
@@ -157,7 +150,6 @@ static int hsr_dev_open(struct net_device *dev) 
	hsr = netdev_priv(dev);

	designation = '\0';



	rcu_read_lock();

	hsr_for_each_port(hsr, port) {

		if (port->type == HSR_PT_MASTER)

			continue;
@@ -175,7 +167,6 @@ static int hsr_dev_open(struct net_device *dev) 
			netdev_warn(dev, "Slave %c (%s) is not up; please bring it up to get a fully working HSR network\n",

				    designation, port->dev->name);

	}

	rcu_read_unlock();



	if (designation == '\0')

		netdev_warn(dev, "No slave devices configured\n");

net/hsr/hsr_netlink.c

+9 −18
Original line number Diff line number Diff line
@@ -79,29 +79,20 @@ static int hsr_newlink(struct net *src_net, struct net_device *dev, 


static int hsr_fill_info(struct sk_buff *skb, const struct net_device *dev)

{

	struct hsr_priv *hsr;

	struct hsr_priv *hsr = netdev_priv(dev);

	struct hsr_port *port;

	int res;



	hsr = netdev_priv(dev);



	res = 0;



	rcu_read_lock();

	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);

	if (port)

		res = nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex);

	rcu_read_unlock();

	if (res)

	if (port) {

		if (nla_put_u32(skb, IFLA_HSR_SLAVE1, port->dev->ifindex))

			goto nla_put_failure;

	}



	rcu_read_lock();

	port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);

	if (port)

		res = nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex);

	rcu_read_unlock();

	if (res)

	if (port) {

		if (nla_put_u32(skb, IFLA_HSR_SLAVE2, port->dev->ifindex))

			goto nla_put_failure;

	}



	if (nla_put(skb, IFLA_HSR_SUPERVISION_ADDR, ETH_ALEN,

		    hsr->sup_multicast_addr) ||

net/hsr/hsr_slave.c

+0 −3
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb) 
		return RX_HANDLER_PASS;

	}



	rcu_read_lock(); /* hsr->node_db, hsr->ports */

	port = hsr_port_get_rcu(skb->dev);

	if (!port)

		goto finish_pass;
@@ -45,11 +44,9 @@ static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb) 
	hsr_forward_skb(skb, port);



finish_consume:

	rcu_read_unlock(); /* hsr->node_db, hsr->ports */

	return RX_HANDLER_CONSUMED;



finish_pass:

	rcu_read_unlock(); /* hsr->node_db, hsr->ports */

	return RX_HANDLER_PASS;

}

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