Re: [PATCH net-next v2 3/6] net: dcb: add new rewrite table

Petr Machata
2023-01-18T11:43:18Z

Daniel Machon <daniel.machon@microchip.com> writes:

> diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
> index cb5319c6afe6..54af3ee03491 100644
> --- a/net/dcb/dcbnl.c
> +++ b/net/dcb/dcbnl.c
> @@ -178,6 +178,7 @@ static const struct nla_policy dcbnl_featcfg_nest[DCB_FEATCFG_ATTR_MAX + 1] = {
> };
>
> static LIST_HEAD(dcb_app_list);
> +static LIST_HEAD(dcb_rewr_list);
> static DEFINE_SPINLOCK(dcb_lock);
>
> static enum ieee_attrs_app dcbnl_app_attr_type_get(u8 selector)
> @@ -1138,7 +1139,7 @@ static int dcbnl_app_table_setdel(struct nlattr *attr,
> static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
> {
> const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops;
> - struct nlattr *ieee, *app;
> + struct nlattr *ieee, *app, *rewr;
> struct dcb_app_type *itr;
> int dcbx;
> int err;
> @@ -1241,6 +1242,26 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
> spin_unlock_bh(&dcb_lock);
> nla_nest_end(skb, app);
>
> + rewr = nla_nest_start_noflag(skb, DCB_ATTR_DCB_REWR_TABLE);
> + if (!rewr)
> + return -EMSGSIZE;

This being new code, don't use _noflag please.

> +
> + spin_lock_bh(&dcb_lock);
> + list_for_each_entry(itr, &dcb_rewr_list, list) {
> + if (itr->ifindex == netdev->ifindex) {
> + enum ieee_attrs_app type =
> + dcbnl_app_attr_type_get(itr->app.selector);
> + err = nla_put(skb, type, sizeof(itr->app), &itr->app);
> + if (err) {
> + spin_unlock_bh(&dcb_lock);

This should cancel the nest started above.

I wonder if it would be cleaner in a separate function, so that there
can be a dedicated clean-up block to goto.

> + return -EMSGSIZE;
> + }
> + }
> + }
> +
> + spin_unlock_bh(&dcb_lock);
> + nla_nest_end(skb, rewr);
> +
> if (ops->dcbnl_getapptrust) {
> err = dcbnl_getapptrust(netdev, skb);
> if (err)