bonding: add proper __rcu annotation for curr_active_slave
RCU was added to bonding in linux-3.12 but lacked proper sparse annotations.
Using __rcu annotation actually helps to spot all accesses to bond->curr_active_slave
are correctly protected, with LOCKDEP support.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Veaceslav Falico <vfalico@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 76c0dad..de5bd03 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -448,11 +448,13 @@
*/
static void rlb_teach_disabled_mac_on_primary(struct bonding *bond, u8 addr[])
{
- if (!bond->curr_active_slave)
+ struct slave *curr_active = bond_deref_active_protected(bond);
+
+ if (!curr_active)
return;
if (!bond->alb_info.primary_is_promisc) {
- if (!dev_set_promiscuity(bond->curr_active_slave->dev, 1))
+ if (!dev_set_promiscuity(curr_active->dev, 1))
bond->alb_info.primary_is_promisc = 1;
else
bond->alb_info.primary_is_promisc = 0;
@@ -460,7 +462,7 @@
bond->alb_info.rlb_promisc_timeout_counter = 0;
- alb_send_learning_packets(bond->curr_active_slave, addr, true);
+ alb_send_learning_packets(curr_active, addr, true);
}
/* slave being removed should not be active at this point
@@ -509,7 +511,7 @@
write_lock_bh(&bond->curr_slave_lock);
- if (slave != bond->curr_active_slave)
+ if (slave != bond_deref_active_protected(bond))
rlb_teach_disabled_mac_on_primary(bond, slave->dev->dev_addr);
write_unlock_bh(&bond->curr_slave_lock);
@@ -684,7 +686,7 @@
* move the old client to primary (curr_active_slave) so
* that the new client can be assigned to this entry.
*/
- if (bond->curr_active_slave &&
+ if (curr_active_slave &&
client_info->slave != curr_active_slave) {
client_info->slave = curr_active_slave;
rlb_update_client(client_info);
@@ -1221,7 +1223,7 @@
*/
static int alb_handle_addr_collision_on_attach(struct bonding *bond, struct slave *slave)
{
- struct slave *has_bond_addr = bond->curr_active_slave;
+ struct slave *has_bond_addr = rcu_access_pointer(bond->curr_active_slave);
struct slave *tmp_slave1, *free_mac_slave = NULL;
struct list_head *iter;
@@ -1575,7 +1577,7 @@
* use mac of the slave device.
* In RLB mode, we always use strict matches.
*/
- strict_match = (slave != bond->curr_active_slave ||
+ strict_match = (slave != rcu_access_pointer(bond->curr_active_slave) ||
bond_info->rlb_enabled);
alb_send_learning_packets(slave, slave->dev->dev_addr,
strict_match);
@@ -1593,7 +1595,7 @@
bond_for_each_slave_rcu(bond, slave, iter) {
tlb_clear_slave(bond, slave, 1);
- if (slave == bond->curr_active_slave) {
+ if (slave == rcu_access_pointer(bond->curr_active_slave)) {
SLAVE_TLB_INFO(slave).load =
bond_info->unbalanced_load /
BOND_TLB_REBALANCE_INTERVAL;
@@ -1625,7 +1627,8 @@
* because a slave was disabled then
* it can now leave promiscuous mode.
*/
- dev_set_promiscuity(bond->curr_active_slave->dev, -1);
+ dev_set_promiscuity(rtnl_dereference(bond->curr_active_slave)->dev,
+ -1);
bond_info->primary_is_promisc = 0;
rtnl_unlock();
@@ -1742,17 +1745,21 @@
__acquires(&bond->curr_slave_lock)
{
struct slave *swap_slave;
+ struct slave *curr_active;
- if (bond->curr_active_slave == new_slave)
+ curr_active = rcu_dereference_protected(bond->curr_active_slave,
+ !new_slave ||
+ lockdep_is_held(&bond->curr_slave_lock));
+ if (curr_active == new_slave)
return;
- if (bond->curr_active_slave && bond->alb_info.primary_is_promisc) {
- dev_set_promiscuity(bond->curr_active_slave->dev, -1);
+ if (curr_active && bond->alb_info.primary_is_promisc) {
+ dev_set_promiscuity(curr_active->dev, -1);
bond->alb_info.primary_is_promisc = 0;
bond->alb_info.rlb_promisc_timeout_counter = 0;
}
- swap_slave = bond->curr_active_slave;
+ swap_slave = curr_active;
rcu_assign_pointer(bond->curr_active_slave, new_slave);
if (!new_slave || !bond_has_slaves(bond))
@@ -1818,6 +1825,7 @@
{
struct bonding *bond = netdev_priv(bond_dev);
struct sockaddr *sa = addr;
+ struct slave *curr_active;
struct slave *swap_slave;
int res;
@@ -1834,23 +1842,24 @@
* Otherwise we'll need to pass the new address to it and handle
* duplications.
*/
- if (!bond->curr_active_slave)
+ curr_active = rtnl_dereference(bond->curr_active_slave);
+ if (!curr_active)
return 0;
swap_slave = bond_slave_has_mac(bond, bond_dev->dev_addr);
if (swap_slave) {
- alb_swap_mac_addr(swap_slave, bond->curr_active_slave);
- alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
+ alb_swap_mac_addr(swap_slave, curr_active);
+ alb_fasten_mac_swap(bond, swap_slave, curr_active);
} else {
- alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr);
+ alb_set_slave_mac_addr(curr_active, bond_dev->dev_addr);
read_lock(&bond->lock);
- alb_send_learning_packets(bond->curr_active_slave,
+ alb_send_learning_packets(curr_active,
bond_dev->dev_addr, false);
if (bond->alb_info.rlb_enabled) {
/* inform clients mac address has changed */
- rlb_req_update_slave_clients(bond, bond->curr_active_slave);
+ rlb_req_update_slave_clients(bond, curr_active);
}
read_unlock(&bond->lock);
}
