Merge branch 'bonding_rcu'
Eric Dumazet says:
====================
bonding: rcu cleanups
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 & cond->current_arp_slave
are correctly protected, with full sparse & LOCKDEP support.
Lets clean the code.
====================
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);
}
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 46dcb7b..6d3b8db 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -498,11 +498,11 @@
int err = 0;
if (bond_uses_primary(bond)) {
+ struct slave *curr_active = bond_deref_active_protected(bond);
+
/* write lock already acquired */
- if (bond->curr_active_slave) {
- err = dev_set_promiscuity(bond->curr_active_slave->dev,
- inc);
- }
+ if (curr_active)
+ err = dev_set_promiscuity(curr_active->dev, inc);
} else {
struct slave *slave;
@@ -524,11 +524,11 @@
int err = 0;
if (bond_uses_primary(bond)) {
+ struct slave *curr_active = bond_deref_active_protected(bond);
+
/* write lock already acquired */
- if (bond->curr_active_slave) {
- err = dev_set_allmulti(bond->curr_active_slave->dev,
- inc);
- }
+ if (curr_active)
+ err = dev_set_allmulti(curr_active->dev, inc);
} else {
struct slave *slave;
@@ -713,7 +713,7 @@
static bool bond_should_change_active(struct bonding *bond)
{
struct slave *prim = bond->primary_slave;
- struct slave *curr = bond->curr_active_slave;
+ struct slave *curr = bond_deref_active_protected(bond);
if (!prim || !curr || curr->link != BOND_LINK_UP)
return true;
@@ -792,7 +792,11 @@
*/
void bond_change_active_slave(struct bonding *bond, struct slave *new_active)
{
- struct slave *old_active = bond->curr_active_slave;
+ struct slave *old_active;
+
+ old_active = rcu_dereference_protected(bond->curr_active_slave,
+ !new_active ||
+ lockdep_is_held(&bond->curr_slave_lock));
if (old_active == new_active)
return;
@@ -900,7 +904,7 @@
int rv;
best_slave = bond_find_best_slave(bond);
- if (best_slave != bond->curr_active_slave) {
+ if (best_slave != bond_deref_active_protected(bond)) {
bond_change_active_slave(bond, best_slave);
rv = bond_set_carrier(bond);
if (!rv)
@@ -1531,7 +1535,8 @@
* anyway (it holds no special properties of the bond device),
* so we can change it without calling change_active_interface()
*/
- if (!bond->curr_active_slave && new_slave->link == BOND_LINK_UP)
+ if (!rcu_access_pointer(bond->curr_active_slave) &&
+ new_slave->link == BOND_LINK_UP)
rcu_assign_pointer(bond->curr_active_slave, new_slave);
break;
@@ -1602,7 +1607,7 @@
vlan_vids_del_by_dev(slave_dev, bond_dev);
if (bond->primary_slave == new_slave)
bond->primary_slave = NULL;
- if (bond->curr_active_slave == new_slave) {
+ if (rcu_access_pointer(bond->curr_active_slave) == new_slave) {
block_netpoll_tx();
write_lock_bh(&bond->curr_slave_lock);
bond_change_active_slave(bond, NULL);
@@ -1704,9 +1709,9 @@
bond_is_active_slave(slave) ? "active" : "backup",
slave_dev->name);
- oldcurrent = bond->curr_active_slave;
+ oldcurrent = rcu_access_pointer(bond->curr_active_slave);
- bond->current_arp_slave = NULL;
+ RCU_INIT_POINTER(bond->current_arp_slave, NULL);
if (!all && (!bond->params.fail_over_mac ||
BOND_MODE(bond) != BOND_MODE_ACTIVEBACKUP)) {
@@ -1878,7 +1883,7 @@
/*-------------------------------- Monitoring -------------------------------*/
-
+/* called with rcu_read_lock() */
static int bond_miimon_inspect(struct bonding *bond)
{
int link_state, commit = 0;
@@ -1886,7 +1891,7 @@
struct slave *slave;
bool ignore_updelay;
- ignore_updelay = !bond->curr_active_slave ? true : false;
+ ignore_updelay = !rcu_dereference(bond->curr_active_slave);
bond_for_each_slave_rcu(bond, slave, iter) {
slave->new_link = BOND_LINK_NOCHANGE;
@@ -2046,7 +2051,7 @@
bond_alb_handle_link_change(bond, slave,
BOND_LINK_DOWN);
- if (slave == bond->curr_active_slave)
+ if (slave == rcu_access_pointer(bond->curr_active_slave))
goto do_failover;
continue;
@@ -2416,7 +2421,7 @@
rcu_read_lock();
- oldcurrent = ACCESS_ONCE(bond->curr_active_slave);
+ oldcurrent = rcu_dereference(bond->curr_active_slave);
/* see if any of the previous devices are up now (i.e. they have
* xmt and rcv traffic). the curr_active_slave does not come into
* the picture unless it is null. also, slave->last_link_up is not
@@ -2564,7 +2569,7 @@
* before being taken out
*/
if (!bond_is_active_slave(slave) &&
- !bond->current_arp_slave &&
+ !rcu_access_pointer(bond->current_arp_slave) &&
!bond_time_in_interval(bond, last_rx, 3)) {
slave->new_link = BOND_LINK_DOWN;
commit++;
@@ -2607,21 +2612,24 @@
case BOND_LINK_UP:
trans_start = dev_trans_start(slave->dev);
- if (bond->curr_active_slave != slave ||
- (!bond->curr_active_slave &&
+ if (rtnl_dereference(bond->curr_active_slave) != slave ||
+ (!rtnl_dereference(bond->curr_active_slave) &&
bond_time_in_interval(bond, trans_start, 1))) {
+ struct slave *current_arp_slave;
+
+ current_arp_slave = rtnl_dereference(bond->current_arp_slave);
slave->link = BOND_LINK_UP;
- if (bond->current_arp_slave) {
+ if (current_arp_slave) {
bond_set_slave_inactive_flags(
- bond->current_arp_slave,
+ current_arp_slave,
BOND_SLAVE_NOTIFY_NOW);
- bond->current_arp_slave = NULL;
+ RCU_INIT_POINTER(bond->current_arp_slave, NULL);
}
pr_info("%s: link status definitely up for interface %s\n",
bond->dev->name, slave->dev->name);
- if (!bond->curr_active_slave ||
+ if (!rtnl_dereference(bond->curr_active_slave) ||
(slave == bond->primary_slave))
goto do_failover;
@@ -2640,8 +2648,8 @@
pr_info("%s: link status definitely down for interface %s, disabling it\n",
bond->dev->name, slave->dev->name);
- if (slave == bond->curr_active_slave) {
- bond->current_arp_slave = NULL;
+ if (slave == rtnl_dereference(bond->curr_active_slave)) {
+ RCU_INIT_POINTER(bond->current_arp_slave, NULL);
goto do_failover;
}
@@ -3097,8 +3105,8 @@
if (bond_has_slaves(bond)) {
read_lock(&bond->curr_slave_lock);
bond_for_each_slave(bond, slave, iter) {
- if (bond_uses_primary(bond)
- && (slave != bond->curr_active_slave)) {
+ if (bond_uses_primary(bond) &&
+ slave != rcu_access_pointer(bond->curr_active_slave)) {
bond_set_slave_inactive_flags(slave,
BOND_SLAVE_NOTIFY_NOW);
} else {
diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 5ab3c18..4d97e23 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -398,20 +398,31 @@
0;
}
+static int bond_option_active_slave_get_ifindex(struct bonding *bond)
+{
+ const struct net_device *slave;
+ int ifindex;
+
+ rcu_read_lock();
+ slave = bond_option_active_slave_get_rcu(bond);
+ ifindex = slave ? slave->ifindex : 0;
+ rcu_read_unlock();
+ return ifindex;
+}
+
static int bond_fill_info(struct sk_buff *skb,
const struct net_device *bond_dev)
{
struct bonding *bond = netdev_priv(bond_dev);
- struct net_device *slave_dev = bond_option_active_slave_get(bond);
- struct nlattr *targets;
unsigned int packets_per_slave;
- int i, targets_added;
+ int ifindex, i, targets_added;
+ struct nlattr *targets;
if (nla_put_u8(skb, IFLA_BOND_MODE, BOND_MODE(bond)))
goto nla_put_failure;
- if (slave_dev &&
- nla_put_u32(skb, IFLA_BOND_ACTIVE_SLAVE, slave_dev->ifindex))
+ ifindex = bond_option_active_slave_get_ifindex(bond);
+ if (ifindex && nla_put_u32(skb, IFLA_BOND_ACTIVE_SLAVE, ifindex))
goto nla_put_failure;
if (nla_put_u32(skb, IFLA_BOND_MIIMON, bond->params.miimon))
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 540e016..f908e65 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -704,11 +704,6 @@
return __bond_option_active_slave_get(bond, slave);
}
-struct net_device *bond_option_active_slave_get(struct bonding *bond)
-{
- return __bond_option_active_slave_get(bond, bond->curr_active_slave);
-}
-
static int bond_option_active_slave_set(struct bonding *bond,
const struct bond_opt_value *newval)
{
@@ -748,7 +743,7 @@
RCU_INIT_POINTER(bond->curr_active_slave, NULL);
bond_select_active_slave(bond);
} else {
- struct slave *old_active = bond->curr_active_slave;
+ struct slave *old_active = bond_deref_active_protected(bond);
struct slave *new_active = bond_slave_get_rtnl(slave_dev);
BUG_ON(!new_active);
diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index daed52f..98db8ed 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -492,8 +492,9 @@
char *buf)
{
struct bonding *bond = to_bond(d);
+ bool active = !!rcu_access_pointer(bond->curr_active_slave);
- return sprintf(buf, "%s\n", bond->curr_active_slave ? "up" : "down");
+ return sprintf(buf, "%s\n", active ? "up" : "down");
}
static DEVICE_ATTR(mii_status, S_IRUGO, bonding_show_mii_status, NULL);
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 0b4d9cd..b2e548e 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -194,8 +194,8 @@
*/
struct bonding {
struct net_device *dev; /* first - useful for panic debug */
- struct slave *curr_active_slave;
- struct slave *current_arp_slave;
+ struct slave __rcu *curr_active_slave;
+ struct slave __rcu *current_arp_slave;
struct slave *primary_slave;
bool force_primary;
s32 slave_cnt; /* never change this value outside the attach/detach wrappers */
@@ -232,6 +232,10 @@
#define bond_slave_get_rtnl(dev) \
((struct slave *) rtnl_dereference(dev->rx_handler_data))
+#define bond_deref_active_protected(bond) \
+ rcu_dereference_protected(bond->curr_active_slave, \
+ lockdep_is_held(&bond->curr_slave_lock))
+
struct bond_vlan_tag {
__be16 vlan_proto;
unsigned short vlan_id;
@@ -514,7 +518,6 @@
int bond_netlink_init(void);
void bond_netlink_fini(void);
struct net_device *bond_option_active_slave_get_rcu(struct bonding *bond);
-struct net_device *bond_option_active_slave_get(struct bonding *bond);
const char *bond_slave_link_status(s8 link);
bool bond_verify_device_path(struct net_device *start_dev,
struct net_device *end_dev,