diff options
| -rw-r--r-- | include/linux/netpoll.h | 13 | ||||
| -rw-r--r-- | net/core/netpoll.c | 20 |
2 files changed, 20 insertions, 13 deletions
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index e9e231215865..95c9f7e16776 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -57,12 +57,15 @@ void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb); #ifdef CONFIG_NETPOLL static inline bool netpoll_rx(struct sk_buff *skb) { - struct netpoll_info *npinfo = skb->dev->npinfo; + struct netpoll_info *npinfo; unsigned long flags; bool ret = false; + rcu_read_lock_bh(); + npinfo = rcu_dereference(skb->dev->npinfo); + if (!npinfo || (list_empty(&npinfo->rx_np) && !npinfo->rx_flags)) - return false; + goto out; spin_lock_irqsave(&npinfo->rx_lock, flags); /* check rx_flags again with the lock held */ @@ -70,12 +73,14 @@ static inline bool netpoll_rx(struct sk_buff *skb) ret = true; spin_unlock_irqrestore(&npinfo->rx_lock, flags); +out: + rcu_read_unlock_bh(); return ret; } static inline int netpoll_rx_on(struct sk_buff *skb) { - struct netpoll_info *npinfo = skb->dev->npinfo; + struct netpoll_info *npinfo = rcu_dereference(skb->dev->npinfo); return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags); } @@ -91,7 +96,6 @@ static inline void *netpoll_poll_lock(struct napi_struct *napi) { struct net_device *dev = napi->dev; - rcu_read_lock(); /* deal with race on ->npinfo */ if (dev && dev->npinfo) { spin_lock(&napi->poll_lock); napi->poll_owner = smp_processor_id(); @@ -108,7 +112,6 @@ static inline void netpoll_poll_unlock(void *have) napi->poll_owner = -1; spin_unlock(&napi->poll_lock); } - rcu_read_unlock(); } #else diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 19ff66079f76..e9ab4f0c454c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -261,6 +261,7 @@ void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) unsigned long tries; struct net_device *dev = np->dev; const struct net_device_ops *ops = dev->netdev_ops; + /* It is up to the caller to keep npinfo alive. */ struct netpoll_info *npinfo = np->dev->npinfo; if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { @@ -810,10 +811,7 @@ int netpoll_setup(struct netpoll *np) refill_skbs(); /* last thing to do is link it to the net device structure */ - ndev->npinfo = npinfo; - - /* avoid racing with NAPI reading npinfo */ - synchronize_rcu(); + rcu_assign_pointer(ndev->npinfo, npinfo); return 0; @@ -857,6 +855,16 @@ void netpoll_cleanup(struct netpoll *np) if (atomic_dec_and_test(&npinfo->refcnt)) { const struct net_device_ops *ops; + + ops = np->dev->netdev_ops; + if (ops->ndo_netpoll_cleanup) + ops->ndo_netpoll_cleanup(np->dev); + + rcu_assign_pointer(np->dev->npinfo, NULL); + + /* avoid racing with NAPI reading npinfo */ + synchronize_rcu_bh(); + skb_queue_purge(&npinfo->arp_tx); skb_queue_purge(&npinfo->txq); cancel_rearming_delayed_work(&npinfo->tx_work); @@ -864,10 +872,6 @@ void netpoll_cleanup(struct netpoll *np) /* clean after last, unfinished work */ __skb_queue_purge(&npinfo->txq); kfree(npinfo); - ops = np->dev->netdev_ops; - if (ops->ndo_netpoll_cleanup) - ops->ndo_netpoll_cleanup(np->dev); - np->dev->npinfo = NULL; } } |