net_sched: convert tc_action_ops to use struct list_head

We don't need to maintain our own singly linked list code.

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>

2 files changed, 10 insertions, 12 deletions

diff --git a/include/net/act_api.h b/include/net/act_api.h
index 22418d1a8396..77d5d8156efc 100644
--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -85,7 +85,7 @@ struct tc_action {
 
 #define TCA_CAP_NONE 0
 struct tc_action_ops {
-        struct tc_action_ops *next;
+        struct list_head head;
         struct tcf_hashinfo *hinfo;
         char    kind[IFNAMSIZ];
         __u32   type; /* TBD to match kind */
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index dc457c957656..8114fef308d9 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -255,12 +255,12 @@ void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
 }
 EXPORT_SYMBOL(tcf_hash_insert);
 
-static struct tc_action_ops *act_base = NULL;
+static LIST_HEAD(act_base);
 static DEFINE_RWLOCK(act_mod_lock);
 
 int tcf_register_action(struct tc_action_ops *act)
 {
-        struct tc_action_ops *a, **ap;
+        struct tc_action_ops *a;
 
         /* Must supply act, dump, cleanup and init */
         if (!act->act || !act->dump || !act->cleanup || !act->init)
@@ -273,14 +273,13 @@ int tcf_register_action(struct tc_action_ops *act)
                 act->walk = tcf_generic_walker;
 
         write_lock(&act_mod_lock);
-        for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
+        list_for_each_entry(a, &act_base, head) {
                 if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
                         write_unlock(&act_mod_lock);
                         return -EEXIST;
                 }
         }
-        act->next = NULL;
-        *ap = act;
+        list_add_tail(&act->head, &act_base);
         write_unlock(&act_mod_lock);
         return 0;
 }
@@ -288,16 +287,15 @@ EXPORT_SYMBOL(tcf_register_action);
 
 int tcf_unregister_action(struct tc_action_ops *act)
 {
-        struct tc_action_ops *a, **ap;
+        struct tc_action_ops *a;
         int err = -ENOENT;
 
         write_lock(&act_mod_lock);
-        for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
+        list_for_each_entry(a, &act_base, head)
                 if (a == act)
                         break;
         if (a) {
-                *ap = a->next;
-                a->next = NULL;
+                list_del(&act->head);
                 err = 0;
         }
         write_unlock(&act_mod_lock);
@@ -312,7 +310,7 @@ static struct tc_action_ops *tc_lookup_action_n(char *kind)
 
         if (kind) {
                 read_lock(&act_mod_lock);
-                for (a = act_base; a; a = a->next) {
+                list_for_each_entry(a, &act_base, head) {
                         if (strcmp(kind, a->kind) == 0) {
                                 if (!try_module_get(a->owner)) {
                                         read_unlock(&act_mod_lock);
@@ -333,7 +331,7 @@ static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
 
         if (kind) {
                 read_lock(&act_mod_lock);
-                for (a = act_base; a; a = a->next) {
+                list_for_each_entry(a, &act_base, head) {
                         if (nla_strcmp(kind, a->kind) == 0) {
                                 if (!try_module_get(a->owner)) {
                                         read_unlock(&act_mod_lock);