From 90a6ec85351b31449c2c6b5406b5396ac96f191d Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 29 Nov 2017 16:07:51 -0800 Subject: [PATCH] act_sample: get rid of tcf_sample_cleanup_rcu() Similar to commit d7fb60b9cafb ("net_sched: get rid of tcfa_rcu"), TC actions don't need to respect RCU grace period, because it is either just detached from tc filter (standalone case) or it is removed together with tc filter (bound case) in which case RCU grace period is already respected at filter layer. Fixes: 5c5670fae430 ("net/sched: Introduce sample tc action") Reported-by: Eric Dumazet Cc: Jamal Hadi Salim Cc: Jiri Pirko Cc: Yotam Gigi Signed-off-by: Cong Wang Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/tc_act/tc_sample.h | 1 - net/sched/act_sample.c | 16 ++++------------ 2 files changed, 4 insertions(+), 13 deletions(-) diff --git a/include/net/tc_act/tc_sample.h b/include/net/tc_act/tc_sample.h index 524cee4f4c81..01dbfea32672 100644 --- a/include/net/tc_act/tc_sample.h +++ b/include/net/tc_act/tc_sample.h @@ -14,7 +14,6 @@ struct tcf_sample { struct psample_group __rcu *psample_group; u32 psample_group_num; struct list_head tcfm_list; - struct rcu_head rcu; }; #define to_sample(a) ((struct tcf_sample *)a) diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c index 8b5abcd2f32f..9438969290a6 100644 --- a/net/sched/act_sample.c +++ b/net/sched/act_sample.c @@ -96,21 +96,14 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla, return ret; } -static void tcf_sample_cleanup_rcu(struct rcu_head *rcu) -{ - struct tcf_sample *s = container_of(rcu, struct tcf_sample, rcu); - struct psample_group *psample_group; - - psample_group = rcu_dereference_protected(s->psample_group, 1); - RCU_INIT_POINTER(s->psample_group, NULL); - psample_group_put(psample_group); -} - static void tcf_sample_cleanup(struct tc_action *a, int bind) { struct tcf_sample *s = to_sample(a); + struct psample_group *psample_group; - call_rcu(&s->rcu, tcf_sample_cleanup_rcu); + psample_group = rtnl_dereference(s->psample_group); + RCU_INIT_POINTER(s->psample_group, NULL); + psample_group_put(psample_group); } static bool tcf_sample_dev_ok_push(struct net_device *dev) @@ -264,7 +257,6 @@ static int __init sample_init_module(void) static void __exit sample_cleanup_module(void) { - rcu_barrier(); tcf_unregister_action(&act_sample_ops, &sample_net_ops); }