From 6c8d23f78646b20bdbdad476d015b6594ac8ff1c Mon Sep 17 00:00:00 2001 From: "nikolay@redhat.com" Date: Mon, 2 Sep 2013 13:51:38 +0200 Subject: [PATCH] bonding: simplify and fix peer notification This patch aims to remove a use of the bond->lock for mutual exclusion which will later allow easier migration to RCU of the users of this functionality. We use RTNL as a synchronizing mechanism since it's always held when send_peer_notif is set, and when it is decremented from the notifier function. We can also drop some locking, and fix the leakage of the send_peer_notif counter. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index c50679f0a6b6..05e638b8ea25 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -828,7 +828,6 @@ static bool bond_should_notify_peers(struct bonding *bond) test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state)) return false; - bond->send_peer_notif--; return true; } @@ -2259,12 +2258,8 @@ re_arm: read_unlock(&bond->lock); if (should_notify_peers) { - if (!rtnl_trylock()) { - read_lock(&bond->lock); - bond->send_peer_notif++; - read_unlock(&bond->lock); + if (!rtnl_trylock()) return; - } call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev); rtnl_unlock(); } @@ -2876,12 +2871,8 @@ re_arm: read_unlock(&bond->lock); if (should_notify_peers) { - if (!rtnl_trylock()) { - read_lock(&bond->lock); - bond->send_peer_notif++; - read_unlock(&bond->lock); + if (!rtnl_trylock()) return; - } call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev); rtnl_unlock(); } @@ -2916,6 +2907,10 @@ static int bond_master_netdev_event(unsigned long event, case NETDEV_REGISTER: bond_create_proc_entry(event_bond); break; + case NETDEV_NOTIFY_PEERS: + if (event_bond->send_peer_notif) + event_bond->send_peer_notif--; + break; default: break; } @@ -3213,11 +3208,8 @@ static int bond_close(struct net_device *bond_dev) { struct bonding *bond = netdev_priv(bond_dev); - write_lock_bh(&bond->lock); - bond->send_peer_notif = 0; - write_unlock_bh(&bond->lock); - bond_work_cancel_all(bond); + bond->send_peer_notif = 0; if (bond_is_lb(bond)) { /* Must be called only after all * slaves have been released