[patch 18/46] pkt_sched: sch_htb: Fix deadlock in hrtimers triggered by HTB

Greg KH
2009-01-23T01:20:50Z

[-- Attachment #1: pkt_sched-sch_htb-fix-deadlock-in-hrtimers-triggered-by-htb.patch --]
[-- Type: text/plain, Size: 1190 bytes --]

2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Jarek Poplawski <jarkao2@gmail.com>

[ 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>

---
net/sched/sch_htb.c | 1 +
1 file changed, 1 insertion(+)

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