net_sched: check cops->tcf_block in tc_bind_tclass()

At least sch_red and sch_tbf don't implement ->tcf_block() while still have a non-zero tc "class". Instead of adding nop implementations to each of such qdisc's, we can just relax the check of cops->tcf_block() in tc_bind_tclass(). They don't support TC filter anyway. Reported-by: [email protected] Cc: Jamal Hadi Salim <[email protected]> Cc: Jiri Pirko <[email protected]> Signed-off-by: Cong Wang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
niw · Sep 10, 2019 · 8b142a0 · 8b142a0
1 parent 94a72b3
commit 8b142a0
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
@@ -1920,6 +1920,8 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
 	cl = cops->find(q, portid);
 	if (!cl)
 		return;
+	if (!cops->tcf_block)
+		return;
 	block = cops->tcf_block(q, cl, NULL);
 	if (!block)
 		return;