Re: [PATCH net-next v6 5/6] flow_offload: support get multi-subsystem block

wenxu
2019-08-06T23:37:15Z

在 2019/8/7 0:10, Pablo Neira Ayuso 写道:
> On Sun, Aug 04, 2019 at 09:24:00PM +0800, wenxu@ucloud.cn wrote:
>> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
>> index 8f1a7b8..6022dd0 100644
>> --- a/include/net/flow_offload.h
>> +++ b/include/net/flow_offload.h
> [...]
>> @@ -282,6 +282,8 @@ int flow_block_cb_setup_simple(struct flow_block_offload *f,
>> }
>> EXPORT_SYMBOL(flow_block_cb_setup_simple);
>>
>> +static LIST_HEAD(block_ing_cb_list);
>> +
>> static struct rhashtable indr_setup_block_ht;
>>
>> struct flow_indr_block_cb {
>> @@ -295,7 +297,6 @@ struct flow_indr_block_dev {
>> struct rhash_head ht_node;
>> struct net_device *dev;
>> unsigned int refcnt;
>> - flow_indr_block_ing_cmd_t *block_ing_cmd_cb;
>> struct list_head cb_list;
>> };
>>
>> @@ -389,6 +390,22 @@ static void flow_indr_block_cb_del(struct flow_indr_block_cb *indr_block_cb)
>> kfree(indr_block_cb);
>> }
>>
>> +static void flow_block_ing_cmd(struct net_device *dev,
>> + flow_indr_block_bind_cb_t *cb,
>> + void *cb_priv,
>> + enum flow_block_command command)
>> +{
>> + struct flow_indr_block_ing_entry *entry;
>> +
>> + rcu_read_lock();
>> +
> unnecessary empty line.
>
>> + list_for_each_entry_rcu(entry, &block_ing_cb_list, list) {
>> + entry->cb(dev, cb, cb_priv, command);
>> + }
>> +
>> + rcu_read_unlock();
> OK, there's rcu_read_lock here...
>
>> +}
>> +
>> int __flow_indr_block_cb_register(struct net_device *dev, void *cb_priv,
>> flow_indr_block_bind_cb_t *cb,
>> void *cb_ident)
>> @@ -406,10 +423,8 @@ int __flow_indr_block_cb_register(struct net_device *dev, void *cb_priv,
>> if (err)
>> goto err_dev_put;
>>
>> - if (indr_dev->block_ing_cmd_cb)
>> - indr_dev->block_ing_cmd_cb(dev, indr_block_cb->cb,
>> - indr_block_cb->cb_priv,
>> - FLOW_BLOCK_BIND);
>> + flow_block_ing_cmd(dev, indr_block_cb->cb, indr_block_cb->cb_priv,
>> + FLOW_BLOCK_BIND);
>>
>> return 0;
>>
>> @@ -448,10 +463,8 @@ void __flow_indr_block_cb_unregister(struct net_device *dev,
>> if (!indr_block_cb)
>> return;
>>
>> - if (indr_dev->block_ing_cmd_cb)
>> - indr_dev->block_ing_cmd_cb(dev, indr_block_cb->cb,
>> - indr_block_cb->cb_priv,
>> - FLOW_BLOCK_UNBIND);
>> + flow_block_ing_cmd(dev, indr_block_cb->cb, indr_block_cb->cb_priv,
>> + FLOW_BLOCK_UNBIND);
>>
>> flow_indr_block_cb_del(indr_block_cb);
>> flow_indr_block_dev_put(indr_dev);
>> @@ -469,7 +482,6 @@ void flow_indr_block_cb_unregister(struct net_device *dev,
>> EXPORT_SYMBOL_GPL(flow_indr_block_cb_unregister);
>>
>> void flow_indr_block_call(struct net_device *dev,
>> - flow_indr_block_ing_cmd_t cb,
>> struct flow_block_offload *bo,
>> enum flow_block_command command)
>> {
>> @@ -480,15 +492,24 @@ void flow_indr_block_call(struct net_device *dev,
>> if (!indr_dev)
>> return;
>>
>> - indr_dev->block_ing_cmd_cb = command == FLOW_BLOCK_BIND
>> - ? cb : NULL;
>> -
>> list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list)
>> indr_block_cb->cb(dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK,
>> bo);
>> }
>> EXPORT_SYMBOL_GPL(flow_indr_block_call);
>>
>> +void flow_indr_add_block_ing_cb(struct flow_indr_block_ing_entry *entry)
>> +{
> ... but registration does not protect the list with a mutex.
>
>> + list_add_tail_rcu(&entry->list, &block_ing_cb_list);
>> +}
>> +EXPORT_SYMBOL_GPL(flow_indr_add_block_ing_cb);

flow_indr_add_block_ing_cb called from tc and nft in different order.
subsys_initcall(tc_filter_init) and nf_tables_module_init
It will be called at the same time?

And any nft need flow_indr_del_block_ing_cb. It also does nedd the lock?