net_sched: act: clean up tca_action_flush()

We could allocate tc_action on stack in tca_action_flush(),
since it is not large.

Also, we could use create_a() in tcf_action_get_1().

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 30 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 27e4c531ade1..8a5ba5add4bc 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -685,6 +685,20 @@ act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
         return rtnl_unicast(skb, net, portid);
 }
 
+static struct tc_action *create_a(int i)
+{
+        struct tc_action *act;
+
+        act = kzalloc(sizeof(*act), GFP_KERNEL);
+        if (act == NULL) {
+                pr_debug("create_a: failed to alloc!\n");
+                return NULL;
+        }
+        act->order = i;
+        INIT_LIST_HEAD(&act->list);
+        return act;
+}
+
 static struct tc_action *
 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 {
@@ -704,11 +718,10 @@ tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
         index = nla_get_u32(tb[TCA_ACT_INDEX]);
 
         err = -ENOMEM;
-        a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
+        a = create_a(0);
         if (a == NULL)
                 goto err_out;
 
-        INIT_LIST_HEAD(&a->list);
         err = -EINVAL;
         a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
         if (a->ops == NULL) /* could happen in batch of actions */
@@ -738,20 +751,6 @@ static void cleanup_a(struct list_head *actions)
         }
 }
 
-static struct tc_action *create_a(int i)
-{
-        struct tc_action *act;
-
-        act = kzalloc(sizeof(*act), GFP_KERNEL);
-        if (act == NULL) {
-                pr_debug("create_a: failed to alloc!\n");
-                return NULL;
-        }
-        act->order = i;
-        INIT_LIST_HEAD(&act->list);
-        return act;
-}
-
 static int tca_action_flush(struct net *net, struct nlattr *nla,
                             struct nlmsghdr *n, u32 portid)
 {
@@ -763,18 +762,12 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
         struct nlattr *nest;
         struct nlattr *tb[TCA_ACT_MAX + 1];
         struct nlattr *kind;
-        struct tc_action *a = create_a(0);
+        struct tc_action a;
         int err = -ENOMEM;
 
-        if (a == NULL) {
-                pr_debug("tca_action_flush: couldnt create tc_action\n");
-                return err;
-        }
-
         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
         if (!skb) {
                 pr_debug("tca_action_flush: failed skb alloc\n");
-                kfree(a);
                 return err;
         }
 
@@ -786,8 +779,10 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
 
         err = -EINVAL;
         kind = tb[TCA_ACT_KIND];
-        a->ops = tc_lookup_action(kind);
-        if (a->ops == NULL) /*some idjot trying to flush unknown action */
+        memset(&a, 0, sizeof(struct tc_action));
+        INIT_LIST_HEAD(&a.list);
+        a.ops = tc_lookup_action(kind);
+        if (a.ops == NULL) /*some idjot trying to flush unknown action */
                 goto err_out;
 
         nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
@@ -802,7 +797,7 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
         if (nest == NULL)
                 goto out_module_put;
 
-        err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
+        err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
         if (err < 0)
                 goto out_module_put;
         if (err == 0)
@@ -812,8 +807,7 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
 
         nlh->nlmsg_len = skb_tail_pointer(skb) - b;
         nlh->nlmsg_flags |= NLM_F_ROOT;
-        module_put(a->ops->owner);
-        kfree(a);
+        module_put(a.ops->owner);
         err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
                              n->nlmsg_flags & NLM_F_ECHO);
         if (err > 0)
@@ -822,11 +816,10 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
         return err;
 
 out_module_put:
-        module_put(a->ops->owner);
+        module_put(a.ops->owner);
 err_out:
 noflush_out:
         kfree_skb(skb);
-        kfree(a);
         return err;
 }