pkt_sched: Fix qdisc_watchdog() vs. dev_deactivate() race

dev_deactivate() can skip rescheduling of a qdisc by qdisc_watchdog()
or other timer calling netif_schedule() after dev_queue_deactivate().
We prevent this checking aliveness before scheduling the timer. Since
during deactivation the root qdisc is available only as qdisc_sleeping
additional accessor qdisc_root_sleeping() is created.

With feedback from Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jarek Poplawski
2008-08-21 05:11:14 -07:00
committed by David S. Miller
parent 5e739d1752
commit 2540e0511e
3 changed files with 13 additions and 0 deletions

View File

@@ -521,6 +521,10 @@ static void cbq_ovl_delay(struct cbq_class *cl)
struct cbq_sched_data *q = qdisc_priv(cl->qdisc);
psched_tdiff_t delay = cl->undertime - q->now;
if (test_bit(__QDISC_STATE_DEACTIVATED,
&qdisc_root_sleeping(cl->qdisc)->state))
return;
if (!cl->delayed) {
psched_time_t sched = q->now;
ktime_t expires;