On Mon, Sep 12, 2016 at 3:21 AM, Jamal Hadi Salim <j...@mojatatu.com> wrote:
> From: Jamal Hadi Salim <j...@mojatatu.com>
>
> With the batch changes that translated transient actions into
> a temporary list we lost in the translation 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"),
> 824a7e8863b3 ("net_sched: remove an unnecessary list_del()")
> f07fed82ad79 ("net_sched: remove the leftover cleanup_a()")
>
> Signed-off-by: Jamal Hadi Salim <j...@mojatatu.com>
> ---
> 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..63b8167 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, *tmp;
> +
> + list_for_each_entry_safe(a, tmp, actions, list) {
No need the safe version.
> + if (ovr)
> + a->tcfa_refcnt-=1;
How about tcfa_bindcnt?
I hate to point out coding style issue, but since you need to update
the patch anyway, please add two spaces surround '-='.
I think checkpatch.pl should be able to catch this.
> + }
> +}
> +
> 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)
Need to check this boolean? It looks like we need this for !ovr case too?
> + act->tcfa_refcnt+=1;
Ditto for coding style.
> 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;
Ditto.
> list_add_tail(&act->list, &actions);
> }
>
Thanks.
