From aecc5cefc389735b5327d234e11d1fe505e1c280 Mon Sep 17 00:00:00 2001 From: Jamal Hadi Salim Date: Mon, 19 Sep 2016 19:02:51 -0400 Subject: [PATCH] net sched actions: fix GETing actions 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: 22dc13c837c3 ("net_sched: convert tcf_exts from list to pointer array"), Fixes: 824a7e8863b3 ("net_sched: remove an unnecessary list_del()") Fixes: f07fed82ad79 ("net_sched: remove the leftover cleanup_a()") Acked-by: Cong Wang Signed-off-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- net/sched/act_api.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/net/sched/act_api.c b/net/sched/act_api.c index d0aceb1740b1..c9102172ce3b 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -592,6 +592,17 @@ err_out: return ERR_PTR(err); } +static void cleanup_a(struct list_head *actions, int ovr) +{ + struct tc_action *a; + + if (!ovr) + return; + + list_for_each_entry(a, actions, list) + a->tcfa_refcnt--; +} + int tcf_action_init(struct net *net, struct nlattr *nla, struct nlattr *est, char *name, int ovr, int bind, struct list_head *actions) { @@ -611,8 +622,15 @@ int tcf_action_init(struct net *net, struct nlattr *nla, struct nlattr *est, goto err; } act->order = i; + if (ovr) + act->tcfa_refcnt++; 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: @@ -882,6 +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++; list_add_tail(&act->list, &actions); }