Re: [PATCH] xc: deal with xen/evtchn and xen/gntdev device names

[Jeremy Fitzhardinge <jeremy@goop.org>]

On 06/03/2010 01:31 AM, Ian Campbell wrote:
> On Wed, 2010-06-02 at 17:09 +0100, Jeremy Fitzhardinge wrote:
>   
>> On 06/02/2010 02:29 AM, Ian Campbell wrote:
>>     
>>> On Tue, 2010-06-01 at 17:35 +0100, Jeremy Fitzhardinge wrote:
>>> I don't think we need a flag day. It seems like we already ship a udev
>>> rule (in tools/hotplug/Linux/xen-backend.rules) which correctly
>>> created /dev/xen/evtchn with the current kernel and which is apparently
>>> unnecessary (but harmless) with the proposed kernel change.
>>>   
>>>       
>> My main concern is that an old libxc will screw anyone with new kernel
>> and udev.
>>     
> Is it any more likely to screw them with a new kernel than with an old
> one?
>   

Yeah, because libxc's rummage around in sysfs will actually work.  If we
rename the devices to be correct, it won't find them and it just ends up
deleting the old device and either failing to create a new one, or
creating it with a bogus major/minor.

> If so I think that's an argument for propagating the removal of this
> functionality into stable trees sooner rather than later rather than
> papering over the craziness for even longer.
>   

Yep.

    J