Re: [PATCH 3/3] bonding: make device count build-time configurable

From: David Miller
Date: Tue Jan 12 2016 - 15:45:56 EST


From: Jay Vosburgh <jay.vosburgh@xxxxxxxxxxxxx>
Date: Tue, 12 Jan 2016 08:34:12 -0800

> Lubomir Rintel <lkundrak@xxxxx> wrote:
>
>>The devices can be created at run-time for quite some time already and the
>>load-time device creation collides with attempts to create the device of
>>the same name:
>>
>> # rmmod bonding
>> # ip link add bond0 type bond
>> RTNETLINK answers: File exists
>>
>>This is pretty much the same situation as was with the block loop devices
>>which was solved by adding a build-time configuration that the
>>distributions could use as they deem fit while keeping the default for
>>compatibility.
>
> I agree this is annoying, but I would expect distros to leave
> this set to 1 (for backwards compatibility with scripts that "modprobe
> bonding" then assume bond0 exists). This leaves the problem in place
> for the vast majority of users.
>
> Is there a reasonable way to resolve this that would actually
> fix things for regular distro kernel users?

Yeah I personally don't like this at all.

This behavior has 2 decades of precedence, it's therefore hard coded
into deep dark nooks and cranies of people's scripts.

Just be content with how things are, and document it better if need
be.