From 38e6bc185d9544dfad1774b3f8902a0b061aea25 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:38 +0000 Subject: [PATCH] netpoll: make __netpoll_cleanup non-block Like the previous patch, slave_disable_netpoll() and __netpoll_cleanup() may be called with read_lock() held too, so we should make them non-block, by moving the cleanup and kfree() to call_rcu_bh() callbacks. Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 4 +--- include/linux/netpoll.h | 3 +++ net/8021q/vlan_dev.c | 6 +---- net/bridge/br_device.c | 6 +---- net/core/netpoll.c | 42 +++++++++++++++++++++++++-------- 5 files changed, 38 insertions(+), 23 deletions(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 8697136e27c0..e42891683e3b 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1257,9 +1257,7 @@ static inline void slave_disable_netpoll(struct slave *slave) return; slave->np = NULL; - synchronize_rcu_bh(); - __netpoll_cleanup(np); - kfree(np); + __netpoll_free_rcu(np); } static inline bool slave_dev_support_netpoll(struct net_device *slave_dev) { diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index bf2d51eec0f3..907812efb4d9 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -23,6 +23,7 @@ struct netpoll { u8 remote_mac[ETH_ALEN]; struct list_head rx; /* rx_np list element */ + struct rcu_head rcu; }; struct netpoll_info { @@ -38,6 +39,7 @@ struct netpoll_info { struct delayed_work tx_work; struct netpoll *netpoll; + struct rcu_head rcu; }; void netpoll_send_udp(struct netpoll *np, const char *msg, int len); @@ -48,6 +50,7 @@ int netpoll_setup(struct netpoll *np); int netpoll_trap(void); void netpoll_set_trap(int trap); void __netpoll_cleanup(struct netpoll *np); +void __netpoll_free_rcu(struct netpoll *np); void netpoll_cleanup(struct netpoll *np); int __netpoll_rx(struct sk_buff *skb); void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb, diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index ee4ae0944cef..b65623f90660 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -704,11 +704,7 @@ static void vlan_dev_netpoll_cleanup(struct net_device *dev) info->netpoll = NULL; - /* Wait for transmitting packets to finish before freeing. */ - synchronize_rcu_bh(); - - __netpoll_cleanup(netpoll); - kfree(netpoll); + __netpoll_free_rcu(netpoll); } #endif /* CONFIG_NET_POLL_CONTROLLER */ diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index ed0e0f9dc788..f41ba4048c9a 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -267,11 +267,7 @@ void br_netpoll_disable(struct net_bridge_port *p) p->np = NULL; - /* Wait for transmitting packets to finish before freeing. */ - synchronize_rcu_bh(); - - __netpoll_cleanup(np); - kfree(np); + __netpoll_free_rcu(np); } #endif diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 37cc854774a4..dc17f1db1479 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -878,6 +878,24 @@ static int __init netpoll_init(void) } core_initcall(netpoll_init); +static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) +{ + struct netpoll_info *npinfo = + container_of(rcu_head, struct netpoll_info, rcu); + + skb_queue_purge(&npinfo->arp_tx); + skb_queue_purge(&npinfo->txq); + + /* we can't call cancel_delayed_work_sync here, as we are in softirq */ + cancel_delayed_work(&npinfo->tx_work); + + /* clean after last, unfinished work */ + __skb_queue_purge(&npinfo->txq); + /* now cancel it again */ + cancel_delayed_work(&npinfo->tx_work); + kfree(npinfo); +} + void __netpoll_cleanup(struct netpoll *np) { struct netpoll_info *npinfo; @@ -903,20 +921,24 @@ void __netpoll_cleanup(struct netpoll *np) ops->ndo_netpoll_cleanup(np->dev); RCU_INIT_POINTER(np->dev->npinfo, NULL); + call_rcu_bh(&npinfo->rcu, rcu_cleanup_netpoll_info); + } +} +EXPORT_SYMBOL_GPL(__netpoll_cleanup); - /* avoid racing with NAPI reading npinfo */ - synchronize_rcu_bh(); +static void rcu_cleanup_netpoll(struct rcu_head *rcu_head) +{ + struct netpoll *np = container_of(rcu_head, struct netpoll, rcu); - skb_queue_purge(&npinfo->arp_tx); - skb_queue_purge(&npinfo->txq); - cancel_delayed_work_sync(&npinfo->tx_work); + __netpoll_cleanup(np); + kfree(np); +} - /* clean after last, unfinished work */ - __skb_queue_purge(&npinfo->txq); - kfree(npinfo); - } +void __netpoll_free_rcu(struct netpoll *np) +{ + call_rcu_bh(&np->rcu, rcu_cleanup_netpoll); } -EXPORT_SYMBOL_GPL(__netpoll_cleanup); +EXPORT_SYMBOL_GPL(__netpoll_free_rcu); void netpoll_cleanup(struct netpoll *np) { -- 2.20.1