From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [Patch net 11/15] net_sched: remove RCU callbacks in route filter Date: Mon, 23 Oct 2017 15:03:00 -0700 Message-ID: <20171023220304.2268-12-xiyou.wangcong@gmail.com> References: <20171023220304.2268-1-xiyou.wangcong@gmail.com> Cc: paulmck@linux.vnet.ibm.com, jhs@mojatatu.com, john.fastabend@gmail.com, Chris Mi , Cong Wang , Daniel Borkmann , Jiri Pirko To: netdev@vger.kernel.org Return-path: Received: from mail-pf0-f196.google.com ([209.85.192.196]:50903 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751623AbdJWWDp (ORCPT ); Mon, 23 Oct 2017 18:03:45 -0400 Received: by mail-pf0-f196.google.com with SMTP id b6so18105008pfh.7 for ; Mon, 23 Oct 2017 15:03:45 -0700 (PDT) In-Reply-To: <20171023220304.2268-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Replace call_rcu() with synchronize_rcu(). Similarly, route4_destroy() is special here, because it deletes all elements from a hashtable, we definitely don't want to wait for each element, however we can unpublish the whole hashtable from upper layer first, so that after one grace period, the whole hashtable is safe to remove too. Reported-by: Chris Mi Cc: Daniel Borkmann Cc: Jiri Pirko Cc: John Fastabend Cc: Jamal Hadi Salim Cc: "Paul E. McKenney" Signed-off-by: Cong Wang --- net/sched/cls_route.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c index 9ddde65915d2..b9b77baac1d2 100644 --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -38,7 +38,6 @@ struct route4_fastmap { struct route4_head { struct route4_fastmap fastmap[16]; struct route4_bucket __rcu *table[256 + 1]; - struct rcu_head rcu; }; struct route4_bucket { @@ -57,7 +56,6 @@ struct route4_filter { u32 handle; struct route4_bucket *bkt; struct tcf_proto *tp; - struct rcu_head rcu; }; #define ROUTE4_FAILURE ((struct route4_filter *)(-1L)) @@ -254,10 +252,8 @@ static int route4_init(struct tcf_proto *tp) return 0; } -static void route4_delete_filter(struct rcu_head *head) +static void route4_delete_filter(struct route4_filter *f) { - struct route4_filter *f = container_of(head, struct route4_filter, rcu); - tcf_exts_destroy(&f->exts); kfree(f); } @@ -270,6 +266,9 @@ static void route4_destroy(struct tcf_proto *tp) if (head == NULL) return; + RCU_INIT_POINTER(tp->root, NULL); + synchronize_rcu(); + for (h1 = 0; h1 <= 256; h1++) { struct route4_bucket *b; @@ -284,14 +283,14 @@ static void route4_destroy(struct tcf_proto *tp) next = rtnl_dereference(f->next); RCU_INIT_POINTER(b->ht[h2], next); tcf_unbind_filter(tp, &f->res); - call_rcu(&f->rcu, route4_delete_filter); + route4_delete_filter(f); } } RCU_INIT_POINTER(head->table[h1], NULL); - kfree_rcu(b, rcu); + kfree(b); } } - kfree_rcu(head, rcu); + kfree(head); } static int route4_delete(struct tcf_proto *tp, void *arg, bool *last) @@ -325,7 +324,8 @@ static int route4_delete(struct tcf_proto *tp, void *arg, bool *last) /* Delete it */ tcf_unbind_filter(tp, &f->res); - call_rcu(&f->rcu, route4_delete_filter); + synchronize_rcu(); + route4_delete_filter(f); /* Strip RTNL protected tree */ for (i = 0; i <= 32; i++) { @@ -528,7 +528,8 @@ static int route4_change(struct net *net, struct sk_buff *in_skb, *arg = f; if (fold) { tcf_unbind_filter(tp, &fold->res); - call_rcu(&fold->rcu, route4_delete_filter); + synchronize_rcu(); + route4_delete_filter(fold); } return 0; -- 2.13.0