From e8a83e10d7dfe5d0841062780769b30f65417e15 Mon Sep 17 00:00:00 2001
From: Jarek Poplawski <jarkao2@gmail.com>
Date: Sun, 7 Sep 2008 18:41:21 -0700
Subject: [PATCH] pkt_sched: Fix qdisc state in net_tx_action()

net_tx_action() can skip __QDISC_STATE_SCHED bit clearing while qdisc
is neither ran nor rescheduled, which may cause endless loop in
dev_deactivate().

Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Tested-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/core/dev.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 60c51f7658..e719ed2931 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1991,8 +1991,13 @@ static void net_tx_action(struct softirq_action *h)
 				spin_unlock(root_lock);
 			} else {
 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
-					      &q->state))
+					      &q->state)) {
 					__netif_reschedule(q);
+				} else {
+					smp_mb__before_clear_bit();
+					clear_bit(__QDISC_STATE_SCHED,
+						  &q->state);
+				}
 			}
 		}
 	}
-- 
2.39.5