[4.2.y-ckt stable] Patch "net_sched: make qdisc_tree_decrease_qlen() work for non mq" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net_sched: make qdisc_tree_decrease_qlen() work for non mq

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 63a64263130bed7a146663744275e5291a0ff7ab Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet at google.com>
Date: Tue, 15 Dec 2015 09:43:12 -0800
Subject: net_sched: make qdisc_tree_decrease_qlen() work for non mq

[ Upstream commit 225734de70cd0a9e0b978f3583a4a87939271d5e ]

Stas Nichiporovich reported a regression in his HFSC qdisc setup
on a non multi queue device.

It turns out I mistakenly added a TCQ_F_NOPARENT flag on all qdisc
allocated in qdisc_create() for non multi queue devices, which was
rather buggy. I was clearly mislead by the TCQ_F_ONETXQUEUE that is
also set here for no good reason, since it only matters for the root
qdisc.

Fixes: 4eaf3b84f288 ("net_sched: fix qdisc_tree_decrease_qlen() races")
Reported-by: Stas Nichiporovich <stasn77 at gmail.com>
Tested-by: Stas Nichiporovich <stasn77 at gmail.com>
Signed-off-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/sched/sch_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 1a0aa2a..ae795fd 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -950,7 +950,7 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
 		}
 		lockdep_set_class(qdisc_lock(sch), &qdisc_tx_lock);
 		if (!netif_is_multiqueue(dev))
-			sch->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
+			sch->flags |= TCQ_F_ONETXQUEUE;
 	}

 	sch->handle = handle;
--
1.9.1