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authorJarek Poplawski <jarkao2@gmail.com>2008-08-21 05:11:14 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-21 05:11:14 -0700
commit2540e0511ea17e25831be543cdf9381e6209950d (patch)
tree31c505b9957d82125cd7e779d83da0d389f9d336 /net
parentsctp: fix potential panics in the SCTP-AUTH API. (diff)
downloadlinux-dev-2540e0511ea17e25831be543cdf9381e6209950d.tar.xz
linux-dev-2540e0511ea17e25831be543cdf9381e6209950d.zip
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>
Diffstat (limited to 'net')
-rw-r--r--net/sched/sch_api.c4
-rw-r--r--net/sched/sch_cbq.c4
2 files changed, 8 insertions, 0 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index ef0efeca6352..45f442d7de47 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -444,6 +444,10 @@ void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires)
{
ktime_t time;
+ if (test_bit(__QDISC_STATE_DEACTIVATED,
+ &qdisc_root_sleeping(wd->qdisc)->state))
+ return;
+
wd->qdisc->flags |= TCQ_F_THROTTLED;
time = ktime_set(0, 0);
time = ktime_add_ns(time, PSCHED_US2NS(expires));
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 47ef492c4ff4..8fa90d68ec6d 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -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;