Re: [patch net-next v6 06/11] net: sched: use block index as a handle instead of qdisc when block is shared

Sun, Jan 07, 2018 at 02:11:19PM CET, jhs@mojatatu.com wrote:

On 18-01-06 03:43 PM, Jiri Pirko wrote:

quoted

quoted

@@ -886,8 +887,13 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,

	tcm->tcm_family = AF_UNSPEC;
	tcm->tcm__pad1 = 0;
	tcm->tcm__pad2 = 0;
-	tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
-	tcm->tcm_parent = parent;
+	if (q) {
+		tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
+		tcm->tcm_parent = parent;
+	} else {
+		tcm->tcm_ifindex = 0; /* block index is stored in parent */
+		tcm->tcm_parent = block->index;
+	}

Please guys, please look at this reuse (also on clt side). I would like
you to double-check this reuse of existing API for balock_index carrying
purpose. I believe it's UAPI safe. But please, check it out carefully.

Should not break any ABI/UAPI AFAIK. Maybe go for a negative ifindex
(not sure if zero means something speacial to someone).

Like -1 means parent is block_index?

Why would 0 mean something special? Could you point to a code that
suggests it?

cheers,
jamal