netdev - A net device refcnt leak problem

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Date:	Fri, 19 Feb 2016 13:17:59 +0800
From:	Yang Yingliang <yangyingliang@...wei.com>
To:	<netdev@...r.kernel.org>
CC:	<davem@...emloft.net>, <eric.dumazet@...il.com>,
	<rui.xiang@...wei.com>
Subject: A net device refcnt leak problem

Hi,

I got a tap device refcnt leak message when I was detaching the device
and it's deadloop for waiting the usage count decrease to 0.

The log is:
unregister_netdevice: waiting for pae_tap0 to become free. Usage count = 1

Unfortunately, it happened only once unit now, I cannot reproduce this.
My kernel version is 3.10 LTS.

The attachment is value of struct net_device, tun_struct and
tun_file while the leak is occurred.

Does anyone have any thoughts or if there is a patch could fix this ?

Thanks,
Yang

View attachment "val of struct net_device tun_struct and tun_file" of type "text/plain" (29075 bytes)