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Message-ID: <52A2D233.6090905@huawei.com>
Date: Sat, 7 Dec 2013 15:45:55 +0800
From: Ding Tianhong <dingtianhong@...wei.com>
To: Jay Vosburgh <fubar@...ibm.com>,
Andy Gospodarek <andy@...yhouse.net>,
"David S. Miller" <davem@...emloft.net>,
Nikolay Aleksandrov <nikolay@...hat.com>,
Veaceslav Falico <vfalico@...hat.com>,
Netdev <netdev@...r.kernel.org>
Subject: [PATCH net-next v4 7/11] bonding: rebuild the lock use for bond_3ad_state_machine_handler()
The bond_3ad_state_machine_handler() use the bond lock to protect
the bond slave list and slave port, so as the before patch said,
I remove bond lock and replace with RCU.
There was a lot of function need RCU protect, I have two choice
to make the function in RCU-safe, (1) create new similar functions
and make the bond slave list in RCU. (2) modify the existed functions
and make them in read-side critical section, because the RCU
read-side critical sections may be nested.
I choose (2) because it is no need to create more similar functions.
The nots in the function is still too old, clean up the nots.
Suggested-by: Nikolay Aleksandrov <nikolay@...hat.com>
Suggested-by: Jay Vosburgh <fubar@...ibm.com>
Suggested-by: Veaceslav Falico <vfalico@...hat.com>
Signed-off-by: Ding Tianhong <dingtianhong@...wei.com>
---
drivers/net/bonding/bond_3ad.c | 53 ++++++++++++++++++++++++------------------
1 file changed, 31 insertions(+), 22 deletions(-)
diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 187b1b7..d935da5 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -147,11 +147,12 @@ static inline struct aggregator *__get_first_agg(struct port *port)
struct bonding *bond = __get_bond_by_port(port);
struct slave *first_slave;
- // If there's no bond for this port, or bond has no slaves
+ /* If there's no bond for this port, or bond has no slaves */
if (bond == NULL)
return NULL;
- first_slave = bond_first_slave(bond);
-
+ rcu_read_lock();
+ first_slave = bond_first_slave_rcu(bond);
+ rcu_read_unlock();
return first_slave ? &(SLAVE_AD_INFO(first_slave).aggregator) : NULL;
}
@@ -702,9 +703,13 @@ static struct aggregator *__get_active_agg(struct aggregator *aggregator)
struct list_head *iter;
struct slave *slave;
- bond_for_each_slave(bond, slave, iter)
- if (SLAVE_AD_INFO(slave).aggregator.is_active)
+ rcu_read_lock();
+ bond_for_each_slave_rcu(bond, slave, iter)
+ if (SLAVE_AD_INFO(slave).aggregator.is_active) {
+ rcu_read_unlock();
return &(SLAVE_AD_INFO(slave).aggregator);
+ }
+ rcu_read_unlock();
return NULL;
}
@@ -1471,7 +1476,8 @@ static void ad_agg_selection_logic(struct aggregator *agg)
active = __get_active_agg(agg);
best = (active && agg_device_up(active)) ? active : NULL;
- bond_for_each_slave(bond, slave, iter) {
+ rcu_read_lock();
+ bond_for_each_slave_rcu(bond, slave, iter) {
agg = &(SLAVE_AD_INFO(slave).aggregator);
agg->is_active = 0;
@@ -1505,7 +1511,7 @@ static void ad_agg_selection_logic(struct aggregator *agg)
active->is_active = 1;
}
- // if there is new best aggregator, activate it
+ /* if there is new best aggregator, activate it */
if (best) {
pr_debug("best Agg=%d; P=%d; a k=%d; p k=%d; Ind=%d; Act=%d\n",
best->aggregator_identifier, best->num_of_ports,
@@ -1516,7 +1522,7 @@ static void ad_agg_selection_logic(struct aggregator *agg)
best->lag_ports, best->slave,
best->slave ? best->slave->dev->name : "NULL");
- bond_for_each_slave(bond, slave, iter) {
+ bond_for_each_slave_rcu(bond, slave, iter) {
agg = &(SLAVE_AD_INFO(slave).aggregator);
pr_debug("Agg=%d; P=%d; a k=%d; p k=%d; Ind=%d; Act=%d\n",
@@ -1526,10 +1532,10 @@ static void ad_agg_selection_logic(struct aggregator *agg)
agg->is_individual, agg->is_active);
}
- // check if any partner replys
+ /* check if any partner replys */
if (best->is_individual) {
pr_warning("%s: Warning: No 802.3ad response from the link partner for any adapters in the bond\n",
- best->slave ? best->slave->bond->dev->name : "NULL");
+ best->slave ? best->slave->bond->dev->name : "NULL");
}
best->is_active = 1;
@@ -1541,7 +1547,7 @@ static void ad_agg_selection_logic(struct aggregator *agg)
best->partner_oper_aggregator_key,
best->is_individual, best->is_active);
- // disable the ports that were related to the former active_aggregator
+ /* disable the ports that were related to the former active_aggregator */
if (active) {
for (port = active->lag_ports; port;
port = port->next_port_in_aggregator) {
@@ -1565,6 +1571,8 @@ static void ad_agg_selection_logic(struct aggregator *agg)
}
}
+ rcu_read_unlock();
+
bond_3ad_set_carrier(bond);
}
@@ -2068,18 +2076,18 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
struct slave *slave;
struct port *port;
- read_lock(&bond->lock);
+ rcu_read_lock();
- //check if there are any slaves
+ /* check if there are any slaves */
if (!bond_has_slaves(bond))
goto re_arm;
- // check if agg_select_timer timer after initialize is timed out
+ /* check if agg_select_timer timer after initialize is timed out */
if (BOND_AD_INFO(bond).agg_select_timer && !(--BOND_AD_INFO(bond).agg_select_timer)) {
- slave = bond_first_slave(bond);
+ slave = bond_first_slave_rcu(bond);
port = slave ? &(SLAVE_AD_INFO(slave).port) : NULL;
- // select the active aggregator for the bond
+ /* select the active aggregator for the bond */
if (port) {
if (!port->slave) {
pr_warning("%s: Warning: bond's first port is uninitialized\n",
@@ -2093,8 +2101,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
bond_3ad_set_carrier(bond);
}
- // for each port run the state machines
- bond_for_each_slave(bond, slave, iter) {
+ /* for each port run the state machines */
+ bond_for_each_slave_rcu(bond, slave, iter) {
port = &(SLAVE_AD_INFO(slave).port);
if (!port->slave) {
pr_warning("%s: Warning: Found an uninitialized port\n",
@@ -2114,7 +2122,7 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
ad_mux_machine(port);
ad_tx_machine(port);
- // turn off the BEGIN bit, since we already handled it
+ /* turn off the BEGIN bit, since we already handled it */
if (port->sm_vars & AD_PORT_BEGIN)
port->sm_vars &= ~AD_PORT_BEGIN;
@@ -2122,9 +2130,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work)
}
re_arm:
+ rcu_read_unlock();
queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks);
-
- read_unlock(&bond->lock);
}
/**
@@ -2303,7 +2310,9 @@ int bond_3ad_set_carrier(struct bonding *bond)
struct aggregator *active;
struct slave *first_slave;
- first_slave = bond_first_slave(bond);
+ rcu_read_lock();
+ first_slave = bond_first_slave_rcu(bond);
+ rcu_read_unlock();
if (!first_slave)
return 0;
active = __get_active_agg(&(SLAVE_AD_INFO(first_slave).aggregator));
--
1.8.2.1
--
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