Re: [PATCH net-next 22/22] net: sched: act: remove redundant code in act_api

shaozhengchao <shaozhengchao@xxxxxxxxxx> · Tue, 6 Sep 2022 20:20:41 +0800

On 2022/9/2 22:03, Jamal Hadi Salim wrote:
On Fri, Sep 2, 2022 at 7:22 AM Zhengchao Shao <shaozhengchao@xxxxxxxxxx> wrote:

Based on previous patches of this patchset, the walk and lookup hooks in
the tc_action_ops structure are no longer used, and redundant code logic
branches should be removed. tcf_generic_walker() and tcf_idr_search() are
also used only in the act_api.c, change them to static.


All the rest look good.
It is possible to have extra computation for a lookup/walk depending on the
action complexity. That was the point of those APIs; however, we could argue
that if a user shows up with those demands then we'll add them then.
If you want to remove the callbacks, why not do them in the first patch?

cheers,
jamal


Hi jamal:
	Thank you for your reply. I have test patchset v2 with TDC action 
module, and they are all passed. Next, I will add some selftest in other 
patchset.
	I will reserve the walk and lookup interfaces and delete them only when 
they are no longer used.
	
Zhengchao Shao
Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
---
  include/net/act_api.h | 10 ----------
  net/sched/act_api.c   | 42 ++++++++++++------------------------------
  2 files changed, 12 insertions(+), 40 deletions(-)

diff --git a/include/net/act_api.h b/include/net/act_api.h
index a79d6e58519e..ebd84ef06b5b 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -118,15 +118,10 @@ struct tc_action_ops {
                        struct tcf_result *); /* called under RCU BH lock*/
         int     (*dump)(struct sk_buff *, struct tc_action *, int, int);
         void    (*cleanup)(struct tc_action *);
-       int     (*lookup)(struct net *net, struct tc_action **a, u32 index);
         int     (*init)(struct net *net, struct nlattr *nla,
                         struct nlattr *est, struct tc_action **act,
                         struct tcf_proto *tp,
                         u32 flags, struct netlink_ext_ack *extack);
-       int     (*walk)(struct net *, struct sk_buff *,
-                       struct netlink_callback *, int,
-                       const struct tc_action_ops *,
-                       struct netlink_ext_ack *);
         void    (*stats_update)(struct tc_action *, u64, u64, u64, u64, bool);
         size_t  (*get_fill_size)(const struct tc_action *act);
         struct net_device *(*get_dev)(const struct tc_action *a,
@@ -178,11 +173,6 @@ static inline void tc_action_net_exit(struct list_head *net_list,
         rtnl_unlock();
  }

-int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
-                      struct netlink_callback *cb, int type,
-                      const struct tc_action_ops *ops,
-                      struct netlink_ext_ack *extack);
-int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index);
  int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
                    struct tc_action **a, const struct tc_action_ops *ops,
                    int bind, bool cpustats, u32 flags);
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 7063d2004199..2d26aec25e3a 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -636,10 +636,10 @@ static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
         return ret;
  }

-int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
-                      struct netlink_callback *cb, int type,
-                      const struct tc_action_ops *ops,
-                      struct netlink_ext_ack *extack)
+static int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
+                             struct netlink_callback *cb, int type,
+                             const struct tc_action_ops *ops,
+                             struct netlink_ext_ack *extack)
  {
         struct tcf_idrinfo *idrinfo = tn->idrinfo;

@@ -653,9 +653,8 @@ int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
                 return -EINVAL;
         }
  }
-EXPORT_SYMBOL(tcf_generic_walker);

-int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
+static int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
  {
         struct tcf_idrinfo *idrinfo = tn->idrinfo;
         struct tc_action *p;
@@ -674,7 +673,6 @@ int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
         }
         return false;
  }
-EXPORT_SYMBOL(tcf_idr_search);

  static int __tcf_generic_walker(struct net *net, struct sk_buff *skb,
                                 struct netlink_callback *cb, int type,
@@ -945,8 +943,7 @@ int tcf_register_action(struct tc_action_ops *act,
         struct tc_action_ops *a;
         int ret;

-       if (!act->act || !act->dump || !act->init ||
-           (!act->net_id && (!act->walk || !act->lookup)))
+       if (!act->act || !act->dump || !act->init || !act->net_id)
                 return -EINVAL;

         /* We have to register pernet ops before making the action ops visible,
@@ -1658,16 +1655,10 @@ static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
                 goto err_out;
         }
         err = -ENOENT;
-       if (ops->lookup) {
-               if (ops->lookup(net, &a, index) == 0) {
-                       NL_SET_ERR_MSG(extack, "TC action with specified index not found");
-                       goto err_mod;
-               }
-       } else {
-               if (__tcf_idr_search(net, ops, &a, index) == 0) {
-                       NL_SET_ERR_MSG(extack, "TC action with specified index not found");
-                       goto err_mod;
-               }
+
+       if (__tcf_idr_search(net, ops, &a, index) == 0) {
+               NL_SET_ERR_MSG(extack, "TC action with specified index not found");
+               goto err_mod;
         }

         module_put(ops->owner);
@@ -1730,12 +1721,7 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
                 goto out_module_put;
         }

-       if (ops->walk) {
-               err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
-       } else {
-               err = __tcf_generic_walker(net, skb, &dcb, RTM_DELACTION, ops, extack);
-       }
-
+       err = __tcf_generic_walker(net, skb, &dcb, RTM_DELACTION, ops, extack);
         if (err <= 0) {
                 nla_nest_cancel(skb, nest);
                 goto out_module_put;
@@ -2153,11 +2139,7 @@ static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
         if (nest == NULL)
                 goto out_module_put;

-       if (a_o->walk)
-               ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
-       else
-               ret = __tcf_generic_walker(net, skb, cb, RTM_GETACTION, a_o, NULL);
-
+       ret = __tcf_generic_walker(net, skb, cb, RTM_GETACTION, a_o, NULL);
         if (ret < 0)
                 goto out_module_put;

--
2.17.1








