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>
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 84d25f2..b1d2cfe 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -193,6 +193,11 @@
return qdisc->dev_queue->qdisc;
}
+static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
+{
+ return qdisc->dev_queue->qdisc_sleeping;
+}
+
/* The qdisc root lock is a mechanism by which to top level
* of a qdisc tree can be locked from any qdisc node in the
* forest. This allows changing the configuration of some