Re: [PATCH net-next v3 2/3] flow_offload: support get tcf block immediately

[Jakub Kicinski <jakub.kicinski@netronome.com>]

On Fri, 26 Jul 2019 21:34:06 +0800, wenxu@ucloud.cn wrote:
> From: wenxu <wenxu@ucloud.cn>
> 
> Because the new flow-indr-block can't get the tcf_block
> directly.
> It provide a callback to find the tcf block immediately
> when the device register and contain a ingress block.
> 
> Signed-off-by: wenxu <wenxu@ucloud.cn>

Please CC people who gave you feedback on your subsequent submissions.

> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
> index 66f89bc..3b2e848 100644
> --- a/include/net/flow_offload.h
> +++ b/include/net/flow_offload.h
> @@ -391,6 +391,10 @@ struct flow_indr_block_dev {
>  	struct flow_block *flow_block;
>  };
>  
> +typedef void flow_indr_get_default_block_t(struct flow_indr_block_dev *indr_dev);
> +
> +void flow_indr_set_default_block_cb(flow_indr_get_default_block_t *cb);
> +
>  struct flow_indr_block_dev *flow_indr_block_dev_lookup(struct net_device *dev);
>  
>  int __flow_indr_block_cb_register(struct net_device *dev, void *cb_priv,
> diff --git a/net/core/flow_offload.c b/net/core/flow_offload.c
> index 9f1ae67..db8469d 100644
> --- a/net/core/flow_offload.c
> +++ b/net/core/flow_offload.c
> @@ -298,6 +298,14 @@ struct flow_indr_block_dev *
>  }
>  EXPORT_SYMBOL(flow_indr_block_dev_lookup);
>  
> +static flow_indr_get_default_block_t *flow_indr_get_default_block;

This static variable which can only be set to the TC's callback really
is not a great API design :/

> +void flow_indr_set_default_block_cb(flow_indr_get_default_block_t *cb)
> +{
> +	flow_indr_get_default_block = cb;
> +}
> +EXPORT_SYMBOL(flow_indr_set_default_block_cb);
> +
>  static struct flow_indr_block_dev *flow_indr_block_dev_get(struct net_device *dev)
>  {
>  	struct flow_indr_block_dev *indr_dev;
> @@ -312,6 +320,10 @@ static struct flow_indr_block_dev *flow_indr_block_dev_get(struct net_device *de
>  
>  	INIT_LIST_HEAD(&indr_dev->cb_list);
>  	indr_dev->dev = dev;
> +
> +	if (flow_indr_get_default_block)
> +		flow_indr_get_default_block(indr_dev);
> +
>  	if (rhashtable_insert_fast(&indr_setup_block_ht, &indr_dev->ht_node,
>  				   flow_indr_setup_block_ht_params)) {
>  		kfree(indr_dev);