Re: new sysfs layout and ethernet device names

["Kay Sievers" <kay.sievers@vrfy.org>]

On 3/20/07, Bill Nottingham <notting@redhat.com> wrote:
> I was fiddling with the 'new' (no CONFIG_SYSFS_DEPRECATED) layout
> and ethernet device names, and noticed that the new layout effectively
> restricts the availability of certain device names.
>
> By making a directory for the ethernet device name in the parent
> device, you no longer can use any name that is used in sysfs for
> the parent device type - for PCI devices this would be 'resource0',
> 'power', 'enable', etc. For USB, it would be a different set
> of names that are no longer available.

Yeah, we heard, people want to name their network interfaces "irq". :)

> If you *do* try to use one of these names, the rename will succeed...
> partway. The link in /sys/class/net is renamed, the directory is
> not (as it obviously can't rename on top of whatever is already there.)
> Various networking tools then break in assorted ways due to the
> naming disconnect.
>
> Going back to the deprecated layout makes these names available again -
> it's possible (although not necessarily likely) that the new layout
> will break someone's device configuration if they upgrade kernels,
> even if the rest of their tools are updated for the new layout.

There will be a directory at the bus-device with the name of the
class, that glues together the bus-devices and the class-devices in
the unified tree:
  http://git.kernel.org/?p=linux/kernel/git/gregkh/patches.git;a=blob;f=driver/driver-core-fix-namespace-issue-with-devices-assigned-to-classes.patch;hb=HEAD

So the network-interface(s) will be in their own directory "net",
below the bus-device, and don't conflict with the existing attributes.

Thanks,
Kay