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authorEric Dumazet <edumazet@google.com>2013-12-12 15:41:56 -0800
committerDavid S. Miller <davem@davemloft.net>2013-12-14 01:20:06 -0500
commite57a784d8cae429f5b697fe55abf420181d9ff09 (patch)
tree69c247ac88bc588611f280bf684ae0a707523c63
parent59bcaed5f71f002d39d151ccd387dd0f226e00f2 (diff)
pkt_sched: set root qdisc before change() in attach_default_qdiscs()
After commit 95dc19299f74 ("pkt_sched: give visibility to mq slave qdiscs") we call disc_list_add() while the device qdisc might be the noop_qdisc one. This shows up as duplicates in "tc qdisc show", as all inactive devices point to noop_qdisc. Fix this by setting dev->qdisc to the new qdisc before calling ops->change() in attach_default_qdiscs() Add a WARN_ON_ONCE() to catch any future similar problem. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/sch_api.c5
-rw-r--r--net/sched/sch_generic.c2
2 files changed, 5 insertions, 2 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 547b4a88ae2..c31190e29b9 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -273,8 +273,11 @@ static struct Qdisc *qdisc_match_from_root(struct Qdisc *root, u32 handle)
void qdisc_list_add(struct Qdisc *q)
{
+ struct Qdisc *root = qdisc_dev(q)->qdisc;
+
+ WARN_ON_ONCE(root == &noop_qdisc);
if ((q->parent != TC_H_ROOT) && !(q->flags & TCQ_F_INGRESS))
- list_add_tail(&q->list, &qdisc_dev(q)->qdisc->list);
+ list_add_tail(&q->list, &root->list);
}
EXPORT_SYMBOL(qdisc_list_add);
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 6a91d7d48ad..32bb942d2fa 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -718,8 +718,8 @@ static void attach_default_qdiscs(struct net_device *dev)
} else {
qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
if (qdisc) {
- qdisc->ops->attach(qdisc);
dev->qdisc = qdisc;
+ qdisc->ops->attach(qdisc);
}
}
}