From 3ba08b00e0d8413d79be9cab8ec085ceb6ae6fd6 Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Sat, 3 May 2008 20:46:29 -0700 Subject: [PATCH] sch_htb: remove from event queue in htb_parent_to_leaf() There is lack of removing a class from the event queue while changing from parent to leaf which can cause corruption of this rb tree. This patch fixes a bug introduced by my patch: "sch_htb: turn intermediate classes into leaves" commit: 160d5e10f87b1dc88fd9b84b31b1718e0fd76398. Many thanks to Jan 'yanek' Bortl for finding a way to reproduce this rare bug and narrowing the test case, which made possible proper diagnosing. This patch is recommended for all kernels starting from 2.6.20. Reported-and-tested-by: Jan 'yanek' Bortl Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- net/sched/sch_htb.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 66148cc475..5bc1ed4901 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -1197,12 +1197,16 @@ static inline int htb_parent_last_child(struct htb_class *cl) return 1; } -static void htb_parent_to_leaf(struct htb_class *cl, struct Qdisc *new_q) +static void htb_parent_to_leaf(struct htb_sched *q, struct htb_class *cl, + struct Qdisc *new_q) { struct htb_class *parent = cl->parent; BUG_TRAP(!cl->level && cl->un.leaf.q && !cl->prio_activity); + if (parent->cmode != HTB_CAN_SEND) + htb_safe_rb_erase(&parent->pq_node, q->wait_pq + parent->level); + parent->level = 0; memset(&parent->un.inner, 0, sizeof(parent->un.inner)); INIT_LIST_HEAD(&parent->un.leaf.drop_list); @@ -1300,7 +1304,7 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg) htb_deactivate(q, cl); if (last_child) - htb_parent_to_leaf(cl, new_q); + htb_parent_to_leaf(q, cl, new_q); if (--cl->refcnt == 0) htb_destroy_class(sch, cl); -- 2.39.5