On 20/05/2020 16:09, Horatiu Vultur wrote:
> It is not allow to have the same net bridge port part of multiple MRP
> rings. Therefore add a check if the port is used already in a different
> MRP. In that case return failure.
>
> Fixes: 9a9f26e8f7ea ("bridge: mrp: Connect MRP API with the switchdev API")
> Signed-off-by: Horatiu Vultur <horatiu.vul...@microchip.com>
> ---
> net/bridge/br_mrp.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
> index d7bc09de4c139..a5a3fa59c078a 100644
> --- a/net/bridge/br_mrp.c
> +++ b/net/bridge/br_mrp.c
> @@ -37,6 +37,32 @@ static struct br_mrp *br_mrp_find_id(struct net_bridge
> *br, u32 ring_id)
> return res;
> }
>
> +static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
> +{
> + struct br_mrp *mrp;
> + bool res = true;
> +
> + rcu_read_lock();
Why do you need the rcu_read_lock() here when lockdep_rtnl_is_held() is used?
You should be able to just do rtnl_dereference() below as this is used only
under rtnl.
> + list_for_each_entry_rcu(mrp, &br->mrp_list, list,
> + lockdep_rtnl_is_held()) {
> + struct net_bridge_port *p;
> +
> + p = rcu_dereference(mrp->p_port);
> + if (p && p->dev->ifindex == ifindex) {
> + res = false;
> + break;
> + }
> +
> + p = rcu_dereference(mrp->s_port);
> + if (p && p->dev->ifindex == ifindex) {
> + res = false;
> + break;
> + }
> + }
> + rcu_read_unlock();
> + return res;
> +}
> +
> static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
> struct net_bridge_port *p)
> {
> @@ -255,6 +281,11 @@ int br_mrp_add(struct net_bridge *br, struct
> br_mrp_instance *instance)
> !br_mrp_get_port(br, instance->s_ifindex))
> return -EINVAL;
>
> + /* It is not possible to have the same port part of multiple rings */
> + if (!br_mrp_unique_ifindex(br, instance->p_ifindex) ||
> + !br_mrp_unique_ifindex(br, instance->s_ifindex))
> + return -EINVAL;
> +
> mrp = kzalloc(sizeof(*mrp), GFP_KERNEL);
> if (!mrp)
> return -ENOMEM;
>
