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| author | Eric Dumazet <edumazet@google.com> | 2013-12-12 15:41:56 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-12-14 01:20:06 -0500 |
| commit | e57a784d8cae429f5b697fe55abf420181d9ff09 (patch) | |
| tree | 69c247ac88bc588611f280bf684ae0a707523c63 /net/sched/sch_api.c | |
| parent | 59bcaed5f71f002d39d151ccd387dd0f226e00f2 (diff) | |
| download | lwn-e57a784d8cae429f5b697fe55abf420181d9ff09.tar.gz lwn-e57a784d8cae429f5b697fe55abf420181d9ff09.zip | |
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>
Diffstat (limited to 'net/sched/sch_api.c')
| -rw-r--r-- | net/sched/sch_api.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 547b4a88ae2a..c31190e29b90 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); |