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| author | Petr Machata <petrm@mellanox.com> | 2020-01-06 18:01:56 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-12 12:12:08 +0100 |
| commit | a56f6034450677945452a72800dc84354959026e (patch) | |
| tree | abec8180f02b41c77f7ea348274f720ca6fa942c | |
| parent | 841d685ca1154db46d409883a48d15409819a838 (diff) | |
| download | linux-stable-a56f6034450677945452a72800dc84354959026e.tar.gz linux-stable-a56f6034450677945452a72800dc84354959026e.tar.bz2 linux-stable-a56f6034450677945452a72800dc84354959026e.zip | |
net: sch_prio: When ungrafting, replace with FIFO
[ Upstream commit 240ce7f6428ff5188b9eedc066e1e4d645b8635f ]
When a child Qdisc is removed from one of the PRIO Qdisc's bands, it is
replaced unconditionally by a NOOP qdisc. As a result, any traffic hitting
that band gets dropped. That is incorrect--no Qdisc was explicitly added
when PRIO was created, and after removal, none should have to be added
either.
Fix PRIO by first attempting to create a default Qdisc and only falling
back to noop when that fails. This pattern of attempting to create an
invisible FIFO, using NOOP only as a fallback, is also seen in other
Qdiscs.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/sched/sch_prio.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c index c60777351de1..ff6bc7cf6cbd 100644 --- a/net/sched/sch_prio.c +++ b/net/sched/sch_prio.c @@ -244,8 +244,14 @@ static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, struct prio_sched_data *q = qdisc_priv(sch); unsigned long band = arg - 1; - if (new == NULL) - new = &noop_qdisc; + if (!new) { + new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + TC_H_MAKE(sch->handle, arg)); + if (!new) + new = &noop_qdisc; + else + qdisc_hash_add(new, true); + } *old = qdisc_replace(sch, new, &q->queues[band]); return 0; |