From: Vitaly Kuznetsov <vkuznets@redhat•com>
To: Stephen Hemminger <stephen@networkplumber•org>
Cc: kys@microsoft•com, haiyangz@microsoft•com,
sthemmin@microsoft•com, devel@linuxdriverproject•org,
netdev@vger•kernel.org
Subject: Re: [PATCH net-next 0/1] netvsc: another VF datapath fix
Date: Tue, 08 Aug 2017 17:24:03 +0200 [thread overview]
Message-ID: <87shh29j70.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20170808081506.38bea86c@xeon-e3> (Stephen Hemminger's message of "Tue, 8 Aug 2017 08:15:06 -0700")
Stephen Hemminger <stephen@networkplumber•org> writes:
> On Tue, 08 Aug 2017 16:03:56 +0200
> Vitaly Kuznetsov <vkuznets@redhat•com> wrote:
>
>> Stephen Hemminger <stephen@networkplumber•org> writes:
>>
>> > Previous fix was incomplete.
>> >
>>
>> Not really related to this patch series (which btw fixes my issue,
>> thanks!), but I found one addition issue. Systemd fails to rename VF
>> interface:
>>
>> kernel: mlx4_core 0002:00:02.0 eth2: joined to eth1
>> kernel: hv_netvsc 33b7a6f9-6736-451f-8fce-b382eaa50bee eth1: VF registering: eth2
>> kernel: hv_netvsc 33b7a6f9-6736-451f-8fce-b382eaa50bee eth1: Data path switched to VF: eth2
>> kernel: mlx4_en: eth2: Link Up
>> NetworkManager[750]: <info> [1502200557.0821] device (eth2): link connected
>> NetworkManager[750]: <info> [1502200557.1004] manager: (eth2): new Ethernet device (/org/freedesktop/NetworkManager/Devices/6)
>> systemd-udevd[6942]: Error changing net interface name 'eth2' to 'enP2p0s2': Device or resource busy
>> systemd-udevd[6942]: could not rename interface '6' from 'eth2' to 'enP2p0s2': Device or resource busy
>>
>> With some debug added I figured out what's wrong: __netvsc_vf_setup()
>> does dev_open() which sets IFF_UP flag on the interface. When systemd
>> tries to rename the interface we get into dev_change_name() and this
>> fails with -EBUSY when (dev->flags & IFF_UP).
>>
>> The issue is of less importance as we're not supposed to configure VF
>> interface now. However, we may still want to get a stable name for it.
>>
>> Any idea how this can be fixed?
>
> The problem is Network Manager should ignore the VF device. I don't run NM on these
> interfaces because it causes more issues than it helps (dueling userspace).
>
> The driver needs to have slave track the master interface. Relying on userspace
> to bring interface up leads to all the issues the bonding script had.
>
> One option would be to delay the work of bringing up the slave device to allow
> small window for renaming to run.
Actually, I tried removing 'if (dev->flags & IFF_UP)' check from
dev_change_name() and everything seems to work fine. The history of this
code predates git so I have no idea why it's forbiden to change names of
IFF_UP interfaces... I can send an RFC removing the check to figure out
the truth :-)
--
Vitaly
next prev parent reply other threads:[~2017-08-08 15:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-07 18:29 [PATCH net-next 0/1] netvsc: another VF datapath fix Stephen Hemminger
2017-08-07 18:30 ` [PATCH net-next 1/1] netvsc: make sure and unregister datapath Stephen Hemminger
2017-08-09 1:10 ` David Miller
2017-08-08 14:03 ` [PATCH net-next 0/1] netvsc: another VF datapath fix Vitaly Kuznetsov
2017-08-08 15:15 ` Stephen Hemminger
2017-08-08 15:24 ` Vitaly Kuznetsov [this message]
2017-08-08 15:29 ` Stephen Hemminger
2017-08-08 15:42 ` Vitaly Kuznetsov
2017-08-08 15:53 ` Stephen Hemminger
2017-08-09 9:03 ` Vitaly Kuznetsov
2017-08-09 14:41 ` Stephen Hemminger
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