bonding: remvoe unwanted lock for bond enslave and release

PATCH Superseded Ding Tianhong 3 participants 3 messages Nov 8, 2013 – Nov 9, 2013

Subsystems (3)

Networking Network drivers Bonding driver

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Ding Tianhong

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2013-11-08 02:18 UTC #0 lore raw

PATCH v2 9/10 bonding: remvoe unwanted lock for bond enslave and release

The bond_change_active_slave() and bond_select_active_slave() do't need bond lock anymore, so remove the unwanted bond lock for these two functions.

The bond_select_active_slave() will release and acquire curr_slave_lock, so the curr_slave_lock need to protect the function.

In bond enslave and bond release, the bond slave list is also protected by RTNL, so bond lock is no need to exist, remove the lock and clean the functions.

Signed-off-by Ding Tianhong <[email protected]>

---
 drivers/net/bonding/bond_main.c | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

drivers/net/bonding/bond_main.c +6 ~~-21~~

index b48ca55..be163e2 100644
@@ -1579,11 +1579,9 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
 	bond_set_carrier(bond);
 
 	if (USES_PRIMARY(bond->params.mode)) {
-		read_lock(&bond->lock);
 		write_lock_bh(&bond->curr_slave_lock);
 		bond_select_active_slave(bond);
 		write_unlock_bh(&bond->curr_slave_lock);
-		read_unlock(&bond->lock);
 	}
 
 	pr_info("%s: enslaving %s as a%s interface with a%s link.\n",

@@ -1603,19 +1601,13 @@ err_detach:
 		bond_hw_addr_flush(bond_dev, slave_dev);
 
 	vlan_vids_del_by_dev(slave_dev, bond_dev);
-	write_lock_bh(&bond->lock);
 	if (bond->primary_slave == new_slave)
 		bond->primary_slave = NULL;
 	if (bond->curr_active_slave == new_slave) {
-		bond_change_active_slave(bond, NULL);
-		write_unlock_bh(&bond->lock);
-		read_lock(&bond->lock);
 		write_lock_bh(&bond->curr_slave_lock);
+		bond_change_active_slave(bond, NULL);
 		bond_select_active_slave(bond);
 		write_unlock_bh(&bond->curr_slave_lock);
-		read_unlock(&bond->lock);
-	} else {
-		write_unlock_bh(&bond->lock);
 	}
 	slave_disable_netpoll(new_slave);

@@ -1680,20 +1672,16 @@ static int __bond_release_one(struct net_device *bond_dev,
 	}
 
 	block_netpoll_tx();
-	write_lock_bh(&bond->lock);
 
 	slave = bond_get_slave_by_dev(bond, slave_dev);
 	if (!slave) {
 		/* not a slave of this bond */
 		pr_info("%s: %s not enslaved\n",
 			bond_dev->name, slave_dev->name);
-		write_unlock_bh(&bond->lock);
 		unblock_netpoll_tx();
 		return -EINVAL;
 	}
 
-	write_unlock_bh(&bond->lock);
-
 	/* release the slave from its bond */
 	bond->slave_cnt--;

@@ -1711,6 +1699,7 @@ static int __bond_release_one(struct net_device *bond_dev,
 		 */
 		bond_3ad_unbind_slave(slave);
 	}
+	write_unlock_bh(&bond->lock);
 
 	pr_info("%s: releasing %s interface %s\n",
 		bond_dev->name,

@@ -1733,8 +1722,11 @@ static int __bond_release_one(struct net_device *bond_dev,
 	if (bond->primary_slave == slave)
 		bond->primary_slave = NULL;
 
-	if (oldcurrent == slave)
+	if (oldcurrent == slave) {
+		write_lock_bh(&bond->curr_slave_lock);
 		bond_change_active_slave(bond, NULL);
+		write_unlock_bh(&bond->curr_slave_lock);
+	}
 
 	if (bond_is_lb(bond)) {
 		/* Must be called only after the slave has been

@@ -1742,9 +1734,7 @@ static int __bond_release_one(struct net_device *bond_dev,
 		 * has been cleared (if our_slave == old_current),
 		 * but before a new active slave is selected.
 		 */
-		write_unlock_bh(&bond->lock);
 		bond_alb_deinit_slave(bond, slave);
-		write_lock_bh(&bond->lock);
 	}
 
 	if (all) {

@@ -1755,15 +1745,11 @@ static int __bond_release_one(struct net_device *bond_dev,
 		 * is no concern that another slave add/remove event
 		 * will interfere.
 		 */
-		write_unlock_bh(&bond->lock);
-		read_lock(&bond->lock);
 		write_lock_bh(&bond->curr_slave_lock);
 
 		bond_select_active_slave(bond);
 
 		write_unlock_bh(&bond->curr_slave_lock);
-		read_unlock(&bond->lock);
-		write_lock_bh(&bond->lock);
 	}
 
 	if (!bond_has_slaves(bond)) {

@@ -1778,7 +1764,6 @@ static int __bond_release_one(struct net_device *bond_dev,
 		}
 	}
 
-	write_unlock_bh(&bond->lock);
 	unblock_netpoll_tx();
 	synchronize_rcu();

Signature · 1 line

1.8.2.1

Nikolay Aleksandrov

2013-11-08 17:19 UTC #1 lore raw

Quoted 8 lines · Ding Tianhong

The bond_change_active_slave() and bond_select_active_slave() do't need bond lock anymore, so remove the unwanted bond lock for these two functions.
The bond_select_active_slave() will release and acquire curr_slave_lock, so the curr_slave_lock need to protect the function.

Quoted 8 lines

In bond enslave and bond release, the bond slave list is also protected by RTNL, so bond lock is no need to exist, remove the lock and clean the functions.
Suggested-by Jay Vosburgh <[email protected]>
Suggested-by Veaceslav Falico <[email protected]>
Signed-off-by Ding Tianhong <[email protected]>
---

Small nitpick about the subject:
"remvoe" -> "remove"

Ding Tianhong

2013-11-09 14:26 UTC #2 lore raw

Quoted 13 lines · Nikolay Aleksandrov

Quoted 12 lines · Ding Tianhong
The bond_change_active_slave() and bond_select_active_slave() do't need bond lock anymore, so remove the unwanted bond lock for these two functions.
The bond_select_active_slave() will release and acquire curr_slave_lock, so the curr_slave_lock need to protect the function.
In bond enslave and bond release, the bond slave list is also protected by RTNL, so bond lock is no need to exist, remove the lock and clean the functions.

Quoted 6 lines

Quoted 4 lines
Suggested-by Jay Vosburgh <[email protected]>
Suggested-by Veaceslav Falico <[email protected]>
Signed-off-by Ding Tianhong <[email protected]>
---
Small nitpick about the subject:
"remvoe" -> "remove"

:-)

Quoted 6 lines

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