This patch makes netpoll work for non-NAPI devices that call
netif_receive_skb. Devices are allowed to call netif_receive_skb
if they are receiving packets in softirq (ie in tasklet).
One side effect of this is that received packets will be looked
at twice for the non-NAPI case, but this is harmless.

Move the locking out of the inline hook and into the internal
function.

Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>


--- a/include/linux/netpoll.h   2007-11-03 11:05:33.000000000 -0700
+++ b/include/linux/netpoll.h   2007-11-03 11:08:36.000000000 -0700
@@ -30,6 +30,9 @@ struct netpoll_info {
        struct delayed_work tx_work;
 };
 
+
+#ifdef CONFIG_NETPOLL
+
 void netpoll_poll(struct netpoll *np);
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
 void netpoll_print_options(const char *prefix, struct netpoll *np);
@@ -38,32 +41,18 @@ int netpoll_setup(struct netpoll *np, st
 int netpoll_trap(void);
 void netpoll_set_trap(int trap);
 void netpoll_cleanup(struct netpoll *np);
-int __netpoll_rx(struct sk_buff *skb);
+bool __netpoll_rx(struct sk_buff *skb);
 
 
-#ifdef CONFIG_NETPOLL
-static inline int netpoll_rx(struct sk_buff *skb)
+/* Hijack incoming packet for use by netpoll.
+ * NB: may be called twice for NAPI case
+ */
+static inline bool netpoll_rx(struct sk_buff *skb)
 {
-       struct netpoll_info *npinfo = skb->dev->npinfo;
-       unsigned long flags;
-       int ret = 0;
-
-       if (!npinfo || !npinfo->rx_np)
-               return 0;
-
-       spin_lock_irqsave(&npinfo->rx_lock, flags);
-       if (__netpoll_rx(skb))
-               ret = 1;
-       spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+       if (unlikely(skb->dev->npinfo))
+               return __netpoll_rx(skb);
 
-       return ret;
-}
-
-static inline int netpoll_receive_skb(struct sk_buff *skb)
-{
-       if (!list_empty(&skb->dev->napi_list))
-               return netpoll_rx(skb);
-       return 0;
+       return false;
 }
 
 static inline void *netpoll_poll_lock(struct napi_struct *napi)
--- a/net/core/dev.c    2007-11-03 11:05:33.000000000 -0700
+++ b/net/core/dev.c    2007-11-03 11:08:36.000000000 -0700
@@ -2020,8 +2020,7 @@ int netif_receive_skb(struct sk_buff *sk
        int ret = NET_RX_DROP;
        __be16 type;
 
-       /* if we've gotten here through NAPI, check netpoll */
-       if (netpoll_receive_skb(skb))
+       if (netpoll_rx(skb))
                return NET_RX_DROP;
 
        if (!skb->tstamp.tv64)
--- a/net/core/netpoll.c        2007-11-03 11:08:23.000000000 -0700
+++ b/net/core/netpoll.c        2007-11-03 11:08:36.000000000 -0700
@@ -458,16 +458,23 @@ static void arp_reply(struct sk_buff *sk
        netpoll_send_skb(np, send_skb);
 }
 
-int __netpoll_rx(struct sk_buff *skb)
+bool __netpoll_rx(struct sk_buff *skb)
 {
        int proto, len, ulen;
        struct iphdr *iph;
        struct udphdr *uh;
        struct netpoll_info *npi = skb->dev->npinfo;
-       struct netpoll *np = npi->rx_np;
+       struct netpoll *np;
+       unsigned long flags;
+
+       if (!npi)
+               return false;
 
+       spin_lock_irqsave(&npi->rx_lock, flags);
+       np = npi->rx_np;
        if (!np)
                goto out;
+
        if (skb->dev->type != ARPHRD_ETHER)
                goto out;
 
@@ -528,20 +535,22 @@ int __netpoll_rx(struct sk_buff *skb)
        np->rx_hook(np, ntohs(uh->source),
                    (char *)(uh+1),
                    ulen - sizeof(struct udphdr));
+       spin_unlock_irqrestore(&npi->rx_lock, flags);
 
        kfree_skb(skb);
-       return 1;
+       return true;
 
 out:
+       spin_unlock_irqrestore(&npi->rx_lock, flags);
        /* If packet received while already in poll then just
         * silently drop.
         */
        if (atomic_read(&trapped)) {
                kfree_skb(skb);
-               return 1;
+               return true;
        }
 
-       return 0;
+       return false;
 }
 
 void netpoll_print_options(const char *name, struct netpoll *np)

-- 
Stephen Hemminger <[EMAIL PROTECTED]>

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