Re: [PATCH] net: openvswitch: introduce common code for flushing flows

[Cong Wang <xiyou.wangcong@gmail.com>]

On Mon, Aug 10, 2020 at 6:14 PM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> To avoid some issues, for example RCU usage warning, we should
> flush the flows under ovs_lock. This patch refactors
> table_instance_destroy and introduces table_instance_flow_flush
> which can be invoked by __dp_destroy or ovs_flow_tbl_flush.
>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Please add a Fixes tag here, I think it is probably your memory leak fix
which introduced this issue. And a Reported-by, to give credits to bug
reporters.

Plus one minor issue below:

> -static void table_instance_destroy(struct flow_table *table,
> -                                  struct table_instance *ti,
> -                                  struct table_instance *ufid_ti,
> -                                  bool deferred)
> +/* Must be called with OVS mutex held. */
> +void table_instance_flow_flush(struct flow_table *table,
> +                              struct table_instance *ti,
> +                              struct table_instance *ufid_ti)
>  {
>         int i;
>
> -       if (!ti)
> -               return;
> -
> -       BUG_ON(!ufid_ti);
>         if (ti->keep_flows)
> -               goto skip_flows;
> +               return;
>
>         for (i = 0; i < ti->n_buckets; i++) {
> -               struct sw_flow *flow;
>                 struct hlist_head *head = &ti->buckets[i];
>                 struct hlist_node *n;
> +               struct sw_flow *flow;

This is at most a coding style change, please do not mix
coding style changes in bug fixes. You can always push coding
style changes separately when net-next is open.

Thanks.