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hsr: remove unnecessary rcu_read_lock() in hsr module

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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: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Taehee Yoo
2020-02-28 18:01:56 +00:00
committed by David S. Miller
parent 4b793acdca
commit 81390d0c4e
3 changed files with 16 additions and 37 deletions
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23
net/hsr/hsr_device.c
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@@ -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);
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");