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authorVlad Buslov <vladbu@mellanox.com>2018-07-05 17:24:23 +0300
committerDavid S. Miller <davem@davemloft.net>2018-07-08 06:42:28 +0300
commiteec94fdb04806790c7b7e6ea347820064cc6d467 (patch)
treec89619835d2251871fb2b3cd59de939bef9e49af /net/sched/act_api.c
parentb233504033dbd65740e59681820ccfd0a2a8ec53 (diff)
downloadlinux-eec94fdb04806790c7b7e6ea347820064cc6d467.tar.xz
net: sched: use rcu for action cookie update
Implement functions to atomically update and free action cookie using rcu mechanism. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/act_api.c')
-rw-r--r--net/sched/act_api.c44
1 files changed, 30 insertions, 14 deletions
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 3f4cf930f809..02670c7489e3 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -55,6 +55,24 @@ static void tcf_action_goto_chain_exec(const struct tc_action *a,
res->goto_tp = rcu_dereference_bh(chain->filter_chain);
}
+static void tcf_free_cookie_rcu(struct rcu_head *p)
+{
+ struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
+
+ kfree(cookie->data);
+ kfree(cookie);
+}
+
+static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
+ struct tc_cookie *new_cookie)
+{
+ struct tc_cookie *old;
+
+ old = xchg(old_cookie, new_cookie);
+ if (old)
+ call_rcu(&old->rcu, tcf_free_cookie_rcu);
+}
+
/* XXX: For standalone actions, we don't need a RCU grace period either, because
* actions are always connected to filters and filters are already destroyed in
* RCU callbacks, so after a RCU grace period actions are already disconnected
@@ -65,10 +83,7 @@ static void free_tcf(struct tc_action *p)
free_percpu(p->cpu_bstats);
free_percpu(p->cpu_qstats);
- if (p->act_cookie) {
- kfree(p->act_cookie->data);
- kfree(p->act_cookie);
- }
+ tcf_set_action_cookie(&p->act_cookie, NULL);
if (p->goto_chain)
tcf_action_goto_chain_fini(p);
@@ -567,16 +582,22 @@ tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
int err = -EINVAL;
unsigned char *b = skb_tail_pointer(skb);
struct nlattr *nest;
+ struct tc_cookie *cookie;
if (nla_put_string(skb, TCA_KIND, a->ops->kind))
goto nla_put_failure;
if (tcf_action_copy_stats(skb, a, 0))
goto nla_put_failure;
- if (a->act_cookie) {
- if (nla_put(skb, TCA_ACT_COOKIE, a->act_cookie->len,
- a->act_cookie->data))
+
+ rcu_read_lock();
+ cookie = rcu_dereference(a->act_cookie);
+ if (cookie) {
+ if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
+ rcu_read_unlock();
goto nla_put_failure;
+ }
}
+ rcu_read_unlock();
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
@@ -719,13 +740,8 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
if (err < 0)
goto err_mod;
- if (name == NULL && tb[TCA_ACT_COOKIE]) {
- if (a->act_cookie) {
- kfree(a->act_cookie->data);
- kfree(a->act_cookie);
- }
- a->act_cookie = cookie;
- }
+ if (!name && tb[TCA_ACT_COOKIE])
+ tcf_set_action_cookie(&a->act_cookie, cookie);
/* module count goes up only when brand new policy is created
* if it exists and is only bound to in a_o->init() then