[PATCH] sunrpc: cache_register can use wrong module reference

[linux-2.6] / net / core / netpoll.c

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index a119696d55212d3821718f54593a0600fd1acde4..a1a9a7abff50981c1e26fdcca3d2b7b2fa315d59 100644 (file)
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -33,6 +33,7 @@
 #define MAX_UDP_CHUNK 1460
 #define MAX_SKBS 32
 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
+#define MAX_RETRIES 20000
 
 static DEFINE_SPINLOCK(skb_list_lock);
 static int nr_skbs;
@@ -130,19 +131,20 @@ static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
  */
 static void poll_napi(struct netpoll *np)
 {
+       struct netpoll_info *npinfo = np->dev->npinfo;
        int budget = 16;
 
        if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
-           np->poll_owner != smp_processor_id() &&
-           spin_trylock(&np->poll_lock)) {
-               np->rx_flags |= NETPOLL_RX_DROP;
+           npinfo->poll_owner != smp_processor_id() &&
+           spin_trylock(&npinfo->poll_lock)) {
+               npinfo->rx_flags |= NETPOLL_RX_DROP;
                atomic_inc(&trapped);
 
                np->dev->poll(np->dev, &budget);
 
                atomic_dec(&trapped);
-               np->rx_flags &= ~NETPOLL_RX_DROP;
-               spin_unlock(&np->poll_lock);
+               npinfo->rx_flags &= ~NETPOLL_RX_DROP;
+               spin_unlock(&npinfo->poll_lock);
        }
 }
 
@@ -245,16 +247,18 @@ repeat:
 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 {
        int status;
+       struct netpoll_info *npinfo;
 
-repeat:
-       if(!np || !np->dev || !netif_running(np->dev)) {
+       if (!np || !np->dev || !netif_running(np->dev)) {
                __kfree_skb(skb);
                return;
        }
 
+       npinfo = np->dev->npinfo;
+
        /* avoid recursion */
-       if(np->poll_owner == smp_processor_id() ||
-          np->dev->xmit_lock_owner == smp_processor_id()) {
+       if (npinfo->poll_owner == smp_processor_id() ||
+           np->dev->xmit_lock_owner == smp_processor_id()) {
                if (np->drop)
                        np->drop(skb);
                else
@@ -262,30 +266,37 @@ repeat:
                return;
        }
 
-       spin_lock(&np->dev->xmit_lock);
-       np->dev->xmit_lock_owner = smp_processor_id();
+       do {
+               npinfo->tries--;
+               spin_lock(&np->dev->xmit_lock);
+               np->dev->xmit_lock_owner = smp_processor_id();
 
-       /*
-        * network drivers do not expect to be called if the queue is
-        * stopped.
-        */
-       if (netif_queue_stopped(np->dev)) {
+               /*
+                * network drivers do not expect to be called if the queue is
+                * stopped.
+                */
+               if (netif_queue_stopped(np->dev)) {
+                       np->dev->xmit_lock_owner = -1;
+                       spin_unlock(&np->dev->xmit_lock);
+                       netpoll_poll(np);
+                       udelay(50);
+                       continue;
+               }
+
+               status = np->dev->hard_start_xmit(skb, np->dev);
                np->dev->xmit_lock_owner = -1;
                spin_unlock(&np->dev->xmit_lock);
 
-               netpoll_poll(np);
-               goto repeat;
-       }
-
-       status = np->dev->hard_start_xmit(skb, np->dev);
-       np->dev->xmit_lock_owner = -1;
-       spin_unlock(&np->dev->xmit_lock);
+               /* success */
+               if(!status) {
+                       npinfo->tries = MAX_RETRIES; /* reset */
+                       return;
+               }
 
-       /* transmit busy */
-       if(status) {
+               /* transmit busy */
                netpoll_poll(np);
-               goto repeat;
-       }
+               udelay(50);
+       } while (npinfo->tries > 0);
 }
 
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
@@ -341,14 +352,18 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
 
 static void arp_reply(struct sk_buff *skb)
 {
+       struct netpoll_info *npinfo = skb->dev->npinfo;
        struct arphdr *arp;
        unsigned char *arp_ptr;
        int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
        u32 sip, tip;
        struct sk_buff *send_skb;
-       struct netpoll *np = skb->dev->np;
+       struct netpoll *np = NULL;
 
-       if (!np) return;
+       if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
+               np = npinfo->rx_np;
+       if (!np)
+               return;
 
        /* No arp on this interface */
        if (skb->dev->flags & IFF_NOARP)
@@ -429,9 +444,9 @@ int __netpoll_rx(struct sk_buff *skb)
        int proto, len, ulen;
        struct iphdr *iph;
        struct udphdr *uh;
-       struct netpoll *np = skb->dev->np;
+       struct netpoll *np = skb->dev->npinfo->rx_np;
 
-       if (!np->rx_hook)
+       if (!np)
                goto out;
        if (skb->dev->type != ARPHRD_ETHER)
                goto out;
@@ -611,9 +626,8 @@ int netpoll_setup(struct netpoll *np)
 {
        struct net_device *ndev = NULL;
        struct in_device *in_dev;
-
-       np->poll_lock = SPIN_LOCK_UNLOCKED;
-       np->poll_owner = -1;
+       struct netpoll_info *npinfo;
+       unsigned long flags;
 
        if (np->dev_name)
                ndev = dev_get_by_name(np->dev_name);
@@ -624,7 +638,19 @@ int netpoll_setup(struct netpoll *np)
        }
 
        np->dev = ndev;
-       ndev->np = np;
+       if (!ndev->npinfo) {
+               npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
+               if (!npinfo)
+                       goto release;
+
+               npinfo->rx_flags = 0;
+               npinfo->rx_np = NULL;
+               npinfo->poll_lock = SPIN_LOCK_UNLOCKED;
+               npinfo->poll_owner = -1;
+               npinfo->tries = MAX_RETRIES;
+               npinfo->rx_lock = SPIN_LOCK_UNLOCKED;
+       } else
+               npinfo = ndev->npinfo;
 
        if (!ndev->poll_controller) {
                printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
@@ -692,13 +718,27 @@ int netpoll_setup(struct netpoll *np)
                       np->name, HIPQUAD(np->local_ip));
        }
 
-       if(np->rx_hook)
-               np->rx_flags = NETPOLL_RX_ENABLED;
+       if (np->rx_hook) {
+               spin_lock_irqsave(&npinfo->rx_lock, flags);
+               npinfo->rx_flags |= NETPOLL_RX_ENABLED;
+               npinfo->rx_np = np;
+               spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+       }
+
+       /* fill up the skb queue */
+       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();
 
        return 0;
 
  release:
-       ndev->np = NULL;
+       if (!ndev->npinfo)
+               kfree(npinfo);
        np->dev = NULL;
        dev_put(ndev);
        return -1;
@@ -706,9 +746,20 @@ int netpoll_setup(struct netpoll *np)
 
 void netpoll_cleanup(struct netpoll *np)
 {
-       if (np->dev)
-               np->dev->np = NULL;
-       dev_put(np->dev);
+       struct netpoll_info *npinfo;
+       unsigned long flags;
+
+       if (np->dev) {
+               npinfo = np->dev->npinfo;
+               if (npinfo && npinfo->rx_np == np) {
+                       spin_lock_irqsave(&npinfo->rx_lock, flags);
+                       npinfo->rx_np = NULL;
+                       npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
+                       spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+               }
+               dev_put(np->dev);
+       }
+
        np->dev = NULL;
 }