From: Jarek Poplawski <jarkao2@gmail.com>
Date: Tue, 20 Jan 2009 22:06:26 +0000 (-0800)
Subject: pkt_sched: sch_htb: Fix deadlock in hrtimers triggered by HTB
X-Git-Tag: v2.6.28.2~29
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e46032840eae03a502638049468edc1167345c9c;p=karo-tx-linux.git

pkt_sched: sch_htb: Fix deadlock in hrtimers triggered by HTB

[ Upstream commit: none

  This is a quick fix for -stable purposes.  Upstream fixes these
  problems via a large set of invasive hrtimer changes.  ]

Most probably there is a (still unproven) race in hrtimers (before
2.6.29 kernels), which causes a corruption of hrtimers rbtree. This
patch doesn't fix it, but should let HTB avoid triggering the bug.

Reported-by: Denys Fedoryschenko <denys@visp.net.lb>
Reported-by: Badalian Vyacheslav <slavon@bigtelecom.ru>
Reported-by: Chris Caputo <ccaputo@alt.net>
Tested-by: Badalian Vyacheslav <slavon@bigtelecom.ru>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index d14f02056ae6..d2943a4864fa 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -924,6 +924,7 @@ static struct sk_buff *htb_dequeue(struct Qdisc *sch)
 		}
 	}
 	sch->qstats.overlimits++;
+	qdisc_watchdog_cancel(&q->watchdog);
 	qdisc_watchdog_schedule(&q->watchdog, next_event);
 fin:
 	return skb;