Re: [PATCH V2] vlan:return error when real dev is enslaved

On 11/16/2011 03:19 AM, Nicolas de Pesloüan wrote:

Le 15/11/2011 13:44, Weiping Pan a écrit :

quoted

Qinhuibin reported a kernel panic when he do some operation about vlan.
https://lkml.org/lkml/2011/11/6/218

The operation is as below:
ifconfig eth2 up
modprobe bonding
modprobe 8021q
ifconfig bond0 up
ifenslave bond0 eth2
vconfig add eth2 3300
vconfig add bond0 33
vconfig rem eth2.3300

the panic stack is as below:
[<ffffffffa002f1c9>] panic_event+0x49/0x70 [ipmi_msghandler]
[<ffffffff80378917>] notifier_call_chain+0x37/0x70
[<ffffffff80372122>] panic+0xa2/0x195
[<ffffffff80376ed8>] oops_end+0xd8/0x140
[<ffffffff8001bea7>] no_context+0xf7/0x280
[<ffffffff8001c1a5>] __bad_area_nosemaphore+0x175/0x250
[<ffffffff80376318>] page_fault+0x28/0x30
[<ffffffffa039dabd>] igb_vlan_rx_kill_vid+0x4d/0x100 [igb]
[<ffffffffa044045f>] bond_vlan_rx_kill_vid+0x9f/0x290 [bonding]
[<ffffffffa047e636>] unregister_vlan_dev+0x136/0x180 [8021q]
[<ffffffffa047ed20>] vlan_ioctl_handler+0x170/0x3f0 [8021q]
[<ffffffff802c1d3f>] sock_ioctl+0x21f/0x280
[<ffffffff800e6d7f>] vfs_ioctl+0x2f/0xb0
[<ffffffff800e726b>] do_vfs_ioctl+0x3cb/0x5a0
[<ffffffff800e74e1>] sys_ioctl+0xa1/0xb0
[<ffffffff80007388>] system_call_fastpath+0x16/0x1b
[<00007f108a2b8bd7>] 0x7f108a2b8bd7
And the nic is as below:
[root@localhost ~]# ethtool -i eth2
driver: igb
version: 3.0.6-k2
firmware-version: 1.2-1
bus-info: 0000:04:00.0
kernel version：
2.6.32.12-0.7 also happen in 2.6.32-131

For kernel 2.6.32, the reason of this bug is that when we do "vconfig add bond0 33",
adapter->vlgrp is overwritten in igb_vlan_rx_register. So when we do "vconfig rem
eth2.3300", it can't find the correct vlgrp.

And this bug is avoided by vlan cleanup patchset from Jiri Pirko
[off-list ref], especially commit b2cb09b1a772(igb: do vlan cleanup).

But it is not a correct operation to creat a vlan interface on eth2
when it have been enslaved by bond0, so this patch is to return error
when the real dev is already enslaved.

Why isn't this setup correct?

Compare to bridge, where ebtables allow for some sort of sharing of the physical interface between bridge and vlan.

I think bonding should behave the same way instead of denying this setup.

    Nicolas.

Hi, Nicolas,

After some investigation I agree with you that this setup is correct,
since we can  "switchport trunk allowed vlan 2-3" on the switch.

I can confirm that both bonding and bridge support this kind of setup.

bond0.2                                        br0.2
      |                                                |
  eth0 ----- eth0.3                          eth0 -----eth0.3

Both works fine(git commit 06236ac3726f1),  so please discard this patch.

thanks
Weiping Pan