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author | Vlad Buslov <vladbu@mellanox.com> | 2018-07-05 17:24:23 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-07-08 12:42:28 +0900 |
commit | eec94fdb04806790c7b7e6ea347820064cc6d467 (patch) | |
tree | c89619835d2251871fb2b3cd59de939bef9e49af /net/sched/act_api.c | |
parent | b233504033dbd65740e59681820ccfd0a2a8ec53 (diff) | |
download | linux-stable-eec94fdb04806790c7b7e6ea347820064cc6d467.tar.gz linux-stable-eec94fdb04806790c7b7e6ea347820064cc6d467.tar.bz2 linux-stable-eec94fdb04806790c7b7e6ea347820064cc6d467.zip |
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.c | 44 |
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 |