This is a note to let you know that I've just added the patch titled
net: sch_generic: fix the missing new qdisc assignment bug
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-sch_generic-fix-the-missing-new-qdisc-assignment-bug.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From linyunsheng@xxxxxxxxxx Tue Nov 17 13:08:29 2020
From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Date: Tue, 3 Nov 2020 11:25:38 +0800
Subject: net: sch_generic: fix the missing new qdisc assignment bug
To: <gregkh@xxxxxxxxxxxxxxxxxxx>, <stable@xxxxxxxxxxxxxxx>
Cc: <vpai@xxxxxxxxxx>, <Joakim.Tjernlund@xxxxxxxxxxxx>, <xiyou.wangcong@xxxxxxxxx>, <johunt@xxxxxxxxxx>, <jhs@xxxxxxxxxxxx>, <jiri@xxxxxxxxxxx>, <davem@xxxxxxxxxxxxx>, <kuba@xxxxxxxxxx>, <netdev@xxxxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <linuxarm@xxxxxxxxxx>, <john.fastabend@xxxxxxxxx>, <eric.dumazet@xxxxxxxxx>, <dsahern@xxxxxxxxx>
Message-ID: <1604373938-211588-1-git-send-email-linyunsheng@xxxxxxxxxx>
When commit 2fb541c862c9 ("net: sch_generic: aviod concurrent reset and
enqueue op for lockless qdisc") is backported to stable kernel, one
assignment is missing, which causes two problems reported by Joakim and
Vishwanath, see [1] and [2].
So add the assignment back to fix it.
1. https://www.spinics.net/lists/netdev/msg693916.html
2. https://www.spinics.net/lists/netdev/msg695131.html
Fixes: 749cc0b0c7f3 ("net: sch_generic: aviod concurrent reset and enqueue op for lockless qdisc")
Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Acked-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Tested-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/sch_generic.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -1127,10 +1127,13 @@ static void dev_deactivate_queue(struct
void *_qdisc_default)
{
struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc);
+ struct Qdisc *qdisc_default = _qdisc_default;
if (qdisc) {
if (!(qdisc->flags & TCQ_F_BUILTIN))
set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
+
+ rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
}
}
Patches currently in stable-queue which might be from linyunsheng@xxxxxxxxxx are
queue-5.4/net-sch_generic-fix-the-missing-new-qdisc-assignment-bug.patch
