On 9/8/20 3:10 AM, Ido Schimmel wrote:
> From: Ido Schimmel <ido...@nvidia.com>
>
> The notification is emitted after all the validation checks were
> performed, but before the new configuration (i.e., 'struct nh_info') is
> pointed at by the old shell (i.e., 'struct nexthop'). This prevents the
> need to perform rollback in case the notification is vetoed.
>
> The next patch will also emit a replace notification for all the nexthop
> groups in which the nexthop is used.
>
> Signed-off-by: Ido Schimmel <ido...@nvidia.com>
> ---
> net/ipv4/nexthop.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
> index a60a519a5462..b8a4abc00146 100644
> --- a/net/ipv4/nexthop.c
> +++ b/net/ipv4/nexthop.c
> @@ -1099,12 +1099,22 @@ static int replace_nexthop_single(struct net *net,
> struct nexthop *old,
> struct netlink_ext_ack *extack)
> {
> struct nh_info *oldi, *newi;
> + int err;
>
> if (new->is_group) {
> NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a
> nexthop group.");
> return -EINVAL;
> }
>
> + err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack);
> + if (err)
> + return err;
> +
> + /* Hardware flags were set on 'old' as 'new' is not in the red-black
> + * tree. Therefore, inherit the flags from 'old' to 'new'.
> + */
> + new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP);
Will that always be true? ie., has h/w seen 'new' and offloaded it yet?
vs the notifier telling hardware about the change, it does its thing and
sets the flags. But I guess that creates a race between the offload and
the new data being available.
> +
> oldi = rtnl_dereference(old->nh_info);
> newi = rtnl_dereference(new->nh_info);
>
>
