Re: [RFC PATCH v7 03/19] Export 2 func for device to assign/deassign new strucure

2010-06-05 Thread Eric Dumazet
Le samedi 05 juin 2010 à 18:14 +0800, xiaohui@intel.com a écrit :
> From: Xin Xiaohui 
> 
> Signed-off-by: Xin Xiaohui 
> Signed-off-by: Zhao Yu 
> Reviewed-by: Jeff Dike 
> ---
>  include/linux/netdevice.h |3 +++
>  net/core/dev.c|   28 
>  2 files changed, 31 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index bae725c..efb575a 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -1592,6 +1592,9 @@ extern gro_result_t napi_frags_finish(struct 
> napi_struct *napi,
> gro_result_t ret);
>  extern struct sk_buff *  napi_frags_skb(struct napi_struct *napi);
>  extern gro_result_t  napi_gro_frags(struct napi_struct *napi);
> +extern int netdev_mp_port_attach(struct net_device *dev,
> +  struct mpassthru_port *port);
> +extern void netdev_mp_port_detach(struct net_device *dev);
>  
>  static inline void napi_free_frags(struct napi_struct *napi)
>  {
> diff --git a/net/core/dev.c b/net/core/dev.c
> index f769098..ecbb6b1 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2469,6 +2469,34 @@ void netif_nit_deliver(struct sk_buff *skb)
>   rcu_read_unlock();
>  }
>  
> +/* Export two functions to assign/de-assign mp_port pointer
> + * to a net device.
> + */
> +
> +int netdev_mp_port_attach(struct net_device *dev,
> + struct mpassthru_port *port)
> +{
> + /* locked by mp_mutex */
> + if (rcu_dereference(dev->mp_port))
> + return -EBUSY;
> +

Please... this is bogus...

Try with following config settings :

CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
CONFIG_PROVE_RCU_REPEATEDLY=y




> + rcu_assign_pointer(dev->mp_port, port);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(netdev_mp_port_attach);
> +
> +void netdev_mp_port_detach(struct net_device *dev)
> +{
> + /* locked by mp_mutex */
> + if (!rcu_dereference(dev->mp_port))
> + return;

same problem here

> +
> + rcu_assign_pointer(dev->mp_port, NULL);
> + synchronize_rcu();
> +}
> +EXPORT_SYMBOL(netdev_mp_port_detach);
> +
>  /**
>   *   netif_receive_skb - process receive buffer from network
>   *   @skb: buffer to process


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[RFC PATCH v7 03/19] Export 2 func for device to assign/deassign new strucure

2010-06-05 Thread xiaohui . xin
From: Xin Xiaohui 

Signed-off-by: Xin Xiaohui 
Signed-off-by: Zhao Yu 
Reviewed-by: Jeff Dike 
---
 include/linux/netdevice.h |3 +++
 net/core/dev.c|   28 
 2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index bae725c..efb575a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1592,6 +1592,9 @@ extern gro_result_t   napi_frags_finish(struct 
napi_struct *napi,
  gro_result_t ret);
 extern struct sk_buff *napi_frags_skb(struct napi_struct *napi);
 extern gro_result_tnapi_gro_frags(struct napi_struct *napi);
+extern int netdev_mp_port_attach(struct net_device *dev,
+struct mpassthru_port *port);
+extern void netdev_mp_port_detach(struct net_device *dev);
 
 static inline void napi_free_frags(struct napi_struct *napi)
 {
diff --git a/net/core/dev.c b/net/core/dev.c
index f769098..ecbb6b1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2469,6 +2469,34 @@ void netif_nit_deliver(struct sk_buff *skb)
rcu_read_unlock();
 }
 
+/* Export two functions to assign/de-assign mp_port pointer
+ * to a net device.
+ */
+
+int netdev_mp_port_attach(struct net_device *dev,
+   struct mpassthru_port *port)
+{
+   /* locked by mp_mutex */
+   if (rcu_dereference(dev->mp_port))
+   return -EBUSY;
+
+   rcu_assign_pointer(dev->mp_port, port);
+
+   return 0;
+}
+EXPORT_SYMBOL(netdev_mp_port_attach);
+
+void netdev_mp_port_detach(struct net_device *dev)
+{
+   /* locked by mp_mutex */
+   if (!rcu_dereference(dev->mp_port))
+   return;
+
+   rcu_assign_pointer(dev->mp_port, NULL);
+   synchronize_rcu();
+}
+EXPORT_SYMBOL(netdev_mp_port_detach);
+
 /**
  * netif_receive_skb - process receive buffer from network
  * @skb: buffer to process
-- 
1.5.4.4

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