Commit 0f7787b4 authored Oct 16, 2017 by Jesus Sanchez-Palencia Committed by Jeff Kirsher Oct 27, 2017

net/sched: Add select_queue() class_ops for mqprio

When replacing a child qdisc from mqprio, tc_modify_qdisc() must fetch
the netdev_queue pointer that the current child qdisc is associated
with before creating the new qdisc.

Currently, when using mqprio as root qdisc, the kernel will end up
getting the queue #0 pointer from the mqprio (root qdisc), which leaves
any new child qdisc with a possibly wrong netdev_queue pointer.

Implementing the Qdisc_class_ops select_queue() on mqprio fixes this
issue and avoid an inconsistent state when child qdiscs are replaced.

Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Tested-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

parent ce8a75f6

net/sched/sch_mqprio.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -575,6 +575,12 @@ static void mqprio_walk(struct Qdisc sch, struct qdisc_walker arg)
		}
		}

		static struct netdev_queue mqprio_select_queue(struct Qdisc sch,
		struct tcmsg *tcm)
		{
		return mqprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
		}

		static const struct Qdisc_class_ops mqprio_class_ops = {
		.graft = mqprio_graft,
		.leaf = mqprio_leaf,
		@@ -582,6 +588,7 @@ static const struct Qdisc_class_ops mqprio_class_ops = {
		.walk = mqprio_walk,
		.dump = mqprio_dump_class,
		.dump_stats = mqprio_dump_class_stats,
		.select_queue = mqprio_select_queue,
		};

		static struct Qdisc_ops mqprio_qdisc_ops __read_mostly = {