bonding: fix set_multicast_list locking
This patch eliminates a problem (reported by lockdep) in the
bond_set_multicast_list function. It first reduces the locking on
bond->lock to a simple read_lock, and second, adds netif_tx locking
around the bonding mc_list manipulations that occur outside of the
set_multicast_list function.
The original problem was related to IPv6 addrconf activity.
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 2766855..65c7eba 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1464,10 +1464,12 @@
dev_set_allmulti(slave_dev, 1);
}
+ netif_tx_lock_bh(bond_dev);
/* upload master's mc_list to new slave */
for (dmi = bond_dev->mc_list; dmi; dmi = dmi->next) {
dev_mc_add (slave_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
}
+ netif_tx_unlock_bh(bond_dev);
}
if (bond->params.mode == BOND_MODE_8023AD) {
@@ -1821,7 +1823,9 @@
}
/* flush master's mc_list from slave */
+ netif_tx_lock_bh(bond_dev);
bond_mc_list_flush(bond_dev, slave_dev);
+ netif_tx_unlock_bh(bond_dev);
}
netdev_set_master(slave_dev, NULL);
@@ -1942,7 +1946,9 @@
}
/* flush master's mc_list from slave */
+ netif_tx_lock_bh(bond_dev);
bond_mc_list_flush(bond_dev, slave_dev);
+ netif_tx_unlock_bh(bond_dev);
}
netdev_set_master(slave_dev, NULL);
@@ -3937,8 +3943,6 @@
struct bonding *bond = bond_dev->priv;
struct dev_mc_list *dmi;
- write_lock_bh(&bond->lock);
-
/*
* Do promisc before checking multicast_mode
*/
@@ -3959,6 +3963,8 @@
bond_set_allmulti(bond, -1);
}
+ read_lock(&bond->lock);
+
bond->flags = bond_dev->flags;
/* looking for addresses to add to slaves' mc list */
@@ -3979,7 +3985,7 @@
bond_mc_list_destroy(bond);
bond_mc_list_copy(bond_dev->mc_list, bond, GFP_ATOMIC);
- write_unlock_bh(&bond->lock);
+ read_unlock(&bond->lock);
}
/*
@@ -4526,7 +4532,9 @@
struct net_device *bond_dev = bond->dev;
bond_work_cancel_all(bond);
+ netif_tx_lock_bh(bond_dev);
bond_mc_list_destroy(bond);
+ netif_tx_unlock_bh(bond_dev);
/* Release the bonded slaves */
bond_release_all(bond_dev);
bond_deinit(bond_dev);