When commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") is backported to stable kernel, one assignment is missing, which causes two problems reported by Joakim and Vishwanath, see [1] and [2].
So add the assignment back to fix it.
1. https://www.spinics.net/lists/netdev/msg693916.html 2. https://www.spinics.net/lists/netdev/msg695131.html
Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc") Signed-off-by: Yunsheng Lin linyunsheng@huawei.com Acked-by: Jakub Kicinski kuba@kernel.org Tested-by: Brian Norris briannorris@chromium.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_generic.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1116,10 +1116,13 @@ static void dev_deactivate_queue(struct void *_qdisc_default) { struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc); + struct Qdisc *qdisc_default = _qdisc_default;
if (qdisc) { if (!(qdisc->flags & TCQ_F_BUILTIN)) set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + + rcu_assign_pointer(dev_queue->qdisc, qdisc_default); } }