From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Subject: [PATCH v3 net 1/1] net sched actions: fix GETing actions Date: Mon, 12 Sep 2016 19:07:38 -0400 Message-ID: <1473721658-6034-1-git-send-email-jhs@emojatatu.com> Cc: netdev@vger.kernel.org, xiyou.wangcong@gmail.com, Jamal Hadi Salim To: davem@davemloft.net Return-path: Received: from mail-oi0-f67.google.com ([209.85.218.67]:33071 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbcILXHr (ORCPT ); Mon, 12 Sep 2016 19:07:47 -0400 Received: by mail-oi0-f67.google.com with SMTP id y2so20437915oie.0 for ; Mon, 12 Sep 2016 16:07:47 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Jamal Hadi Salim With the batch changes that translated transient actions into a temporary list lost in the translation was the fact that tcf_action_destroy() will eventually delete the action from the permanent location if the refcount is zero. Example of what broke: ...add a gact action to drop sudo $TC actions add action drop index 10 ...now retrieve it, looks good sudo $TC actions get action gact index 10 ...retrieve it again and find it is gone! sudo $TC actions get action gact index 10 Fixes: commit 22dc13c837c3 ("net_sched: convert tcf_exts from list to pointer array"), commit 824a7e8863b3 ("net_sched: remove an unnecessary list_del()") commit f07fed82ad79 ("net_sched: remove the leftover cleanup_a()") Signed-off-by: Jamal Hadi Salim --- net/sched/act_api.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index d09d068..50720b1 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -592,6 +592,16 @@ err_out: return ERR_PTR(err); } +static void cleanup_a(struct list_head *actions, int ovr) +{ + struct tc_action *a; + + list_for_each_entry(a, actions, list) { + if (ovr) + a->tcfa_refcnt -= 1; + } +} + int tcf_action_init(struct net *net, struct nlattr *nla, struct nlattr *est, char *name, int ovr, int bind, struct list_head *actions) @@ -612,8 +622,15 @@ int tcf_action_init(struct net *net, struct nlattr *nla, goto err; } act->order = i; + if (ovr) + act->tcfa_refcnt += 1; list_add_tail(&act->list, actions); } + + /* Remove the temp refcnt which was necessary to protect against + * destroying an existing action which was being replaced + */ + cleanup_a(actions, ovr); return 0; err: @@ -883,6 +900,8 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n, goto err; } act->order = i; + if (event == RTM_GETACTION) + act->tcfa_refcnt += 1; list_add_tail(&act->list, &actions); } -- 1.9.1