Comment 2 for bug 1410852

I have the same problem.

Network config:
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lxc.network.type=vlan
lxc.network.link=eth0
lxc.network.name=eth1
lxc.network.vlan.id = 3575
lxc.network.flags=up
--------------

From stack trace:
----------------
[63371.593308] WARNING: CPU: 6 PID: 10623 at /build/buildd/linux-lts-trusty-3.13.0/fs/sysfs/dir.c:486 sysfs_warn_dup+0x91/0xb0()
[63371.593310] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:06.0/0000:03:00.0/0000:04:00.0/net/eth0/upper_vlan3575'
---------------

It seems to be a problem with the kernel. This is the kernel version on this host:
# uname -r
3.13.0-32-generic

I have another host with the same lxc version. But with a different kernel that doesn't have this problem:
# uname -r
3.5.0-39-generic