diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 27 | ||||
| -rw-r--r-- | net/core/netpoll.c | 40 |
2 files changed, 66 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index e04bfdc..2b275a7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1266,6 +1266,14 @@ static int __dev_open(struct net_device *dev) if (!netif_device_present(dev)) return -ENODEV; + /* Block netpoll from trying to do any rx path servicing. + * If we don't do this there is a chance ndo_poll_controller + * or ndo_poll may be running while we open the device + */ + ret = netpoll_rx_disable(dev); + if (ret) + return ret; + ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev); ret = notifier_to_errno(ret); if (ret) @@ -1279,6 +1287,8 @@ static int __dev_open(struct net_device *dev) if (!ret && ops->ndo_open) ret = ops->ndo_open(dev); + netpoll_rx_enable(dev); + if (ret) clear_bit(__LINK_STATE_START, &dev->state); else { @@ -1370,9 +1380,16 @@ static int __dev_close(struct net_device *dev) int retval; LIST_HEAD(single); + /* Temporarily disable netpoll until the interface is down */ + retval = netpoll_rx_disable(dev); + if (retval) + return retval; + list_add(&dev->unreg_list, &single); retval = __dev_close_many(&single); list_del(&single); + + netpoll_rx_enable(dev); return retval; } @@ -1408,14 +1425,22 @@ static int dev_close_many(struct list_head *head) */ int dev_close(struct net_device *dev) { + int ret = 0; if (dev->flags & IFF_UP) { LIST_HEAD(single); + /* Block netpoll rx while the interface is going down */ + ret = netpoll_rx_disable(dev); + if (ret) + return ret; + list_add(&dev->unreg_list, &single); dev_close_many(&single); list_del(&single); + + netpoll_rx_enable(dev); } - return 0; + return ret; } EXPORT_SYMBOL(dev_close); diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 331ccb9..edcd9ad 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -47,6 +47,8 @@ static struct sk_buff_head skb_pool; static atomic_t trapped; +static struct srcu_struct netpoll_srcu; + #define USEC_PER_POLL 50 #define NETPOLL_RX_ENABLED 1 #define NETPOLL_RX_DROP 2 @@ -199,6 +201,13 @@ static void netpoll_poll_dev(struct net_device *dev) const struct net_device_ops *ops; struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); + /* Don't do any rx activity if the dev_lock mutex is held + * the dev_open/close paths use this to block netpoll activity + * while changing device state + */ + if (!mutex_trylock(&dev->npinfo->dev_lock)) + return; + if (!dev || !netif_running(dev)) return; @@ -211,6 +220,8 @@ static void netpoll_poll_dev(struct net_device *dev) poll_napi(dev); + mutex_unlock(&dev->npinfo->dev_lock); + if (dev->flags & IFF_SLAVE) { if (ni) { struct net_device *bond_dev; @@ -231,6 +242,31 @@ static void netpoll_poll_dev(struct net_device *dev) zap_completion_queue(); } +int netpoll_rx_disable(struct net_device *dev) +{ + struct netpoll_info *ni; + int idx; + might_sleep(); + idx = srcu_read_lock(&netpoll_srcu); + ni = srcu_dereference(dev->npinfo, &netpoll_srcu); + if (ni) + mutex_lock(&ni->dev_lock); + srcu_read_unlock(&netpoll_srcu, idx); + return 0; +} +EXPORT_SYMBOL(netpoll_rx_disable); + +void netpoll_rx_enable(struct net_device *dev) +{ + struct netpoll_info *ni; + rcu_read_lock(); + ni = rcu_dereference(dev->npinfo); + if (ni) + mutex_unlock(&ni->dev_lock); + rcu_read_unlock(); +} +EXPORT_SYMBOL(netpoll_rx_enable); + static void refill_skbs(void) { struct sk_buff *skb; @@ -1004,6 +1040,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp) INIT_LIST_HEAD(&npinfo->rx_np); spin_lock_init(&npinfo->rx_lock); + mutex_init(&npinfo->dev_lock); skb_queue_head_init(&npinfo->neigh_tx); skb_queue_head_init(&npinfo->txq); INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); @@ -1169,6 +1206,7 @@ EXPORT_SYMBOL(netpoll_setup); static int __init netpoll_init(void) { skb_queue_head_init(&skb_pool); + init_srcu_struct(&netpoll_srcu); return 0; } core_initcall(netpoll_init); @@ -1208,6 +1246,8 @@ void __netpoll_cleanup(struct netpoll *np) spin_unlock_irqrestore(&npinfo->rx_lock, flags); } + synchronize_srcu(&netpoll_srcu); + if (atomic_dec_and_test(&npinfo->refcnt)) { const struct net_device_ops *ops; |