Re: [PATCH net-next] net: sched: add checks for tbf classid

On Thu, Dec 20, 2018 at 1:40 AM Cong Wang [off-list ref] wrote:

On Tue, Dec 18, 2018 at 11:08 PM [off-list ref] wrote:

quoted

From: Tonghao Zhang <redacted>

tbf has only one qdisc class. When adding qdisc for it,
we should check the classid, otherwise the parentid:1
classid is available, no matter what classid tc specified.

$ tc qdisc add dev eth1 handle 10: root tbf rate 0.5mbit burst 5kb latency 70ms
$ tc class show dev eth1
class tbf 10:1 parent 10:

$ tc qdisc add dev eth1 parent 10:2 handle 20: pfifo_fast
or
$ tc qdisc add dev eth1 parent 10:0 handle 20: pfifo_fast
$ tc class show dev eth1
class tbf 10:1 parent 10: leaf 20:

I think it is the intended behavior of tbf class.

The parent id such as parent-id:0 is invalid for other qdisc, is
available for tbf. It is confused for administrator.
Should we add that check ?