netdev - [PATCH net-next v6 7/11] bonding: remove unwanted lock for bond enslave and release

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <52AA6ED7.9050702@huawei.com>
Date:	Fri, 13 Dec 2013 10:20:07 +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 v6 7/11] bonding: remove 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.

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_main.c | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bad1bf9..1b1dd01 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1589,11 +1589,9 @@ 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",
@@ -1613,19 +1611,13 @@ 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);
 
@@ -1690,20 +1682,16 @@ 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--;
 
@@ -1721,6 +1709,7 @@ 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,
@@ -1743,8 +1732,11 @@ 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
@@ -1752,9 +1744,7 @@ 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) {
@@ -1765,15 +1755,11 @@ 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)) {
@@ -1788,7 +1774,6 @@ static int __bond_release_one(struct net_device *bond_dev,
 		}
 	}
 
-	write_unlock_bh(&bond->lock);
 	unblock_netpoll_tx();
 	synchronize_rcu();
 
-- 
1.8.0


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html