when does udev rename network interface ?

when does udev rename network interface ?

[Brice Goglin]

Hi,

In our myri10ge ethernet driver, we print the interface name with
netdev->name at the end of the myri10ge_probe routine. When the user
wrote a rule to rename the interface, it looks like udev does the
renaming after the end of the probe routine, which means we are printing
the original netdev->name instead of the final one that udev sets.

I thought that udev would be called during register_netdev (which we
call in the probe routine). But, it seems it is actually called later.
Is there any way to wait until udev is actually called? or to force it
to rename before the end of the probe routine so that we can end the
driver initialization by printing the final name of the interface?

Thank you
Brice Goglin


Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid\x120709&bid&3057&dat\x121642
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: when does udev rename network interface ?

[Andrey Borzenkov]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Thursday 29 June 2006 19:42, Brice Goglin wrote:
> Hi,
>
> In our myri10ge ethernet driver, we print the interface name with
> netdev->name at the end of the myri10ge_probe routine. When the user
> wrote a rule to rename the interface, it looks like udev does the
> renaming after the end of the probe routine, which means we are printing
> the original netdev->name instead of the final one that udev sets.
>
> I thought that udev would be called during register_netdev (which we
> call in the probe routine). But, it seems it is actually called later.
> Is there any way to wait until udev is actually called? or to force it
> to rename before the end of the probe routine so that we can end the
> driver initialization by printing the final name of the interface?
>

udev is not called (in the sense of synchronous procedure call). 
register_netdev just sends notification about new interface; udev 
asynchronously processes this notification.

I am not aware of any way to wait for udev action completion. The only 
solution in your case seems to be long enough timeout (say several seconds) 
before printing interface name.

- -andrey
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)

iD8DBQFEo/lVR6LMutpd94wRAn1dAKCJwVwyuH2Uw//Pp8GvI5oDTg/UWwCguCoO
XFTtsYHa+pZ+QuvKBgk5dP0=XMql
-----END PGP SIGNATURE-----

Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid\x120709&bid&3057&dat\x121642
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: when does udev rename network interface ?

[Greg KH]

On Thu, Jun 29, 2006 at 08:01:15PM +0400, Andrey Borzenkov wrote:
> On Thursday 29 June 2006 19:42, Brice Goglin wrote:
> > Hi,
> >
> > In our myri10ge ethernet driver, we print the interface name with
> > netdev->name at the end of the myri10ge_probe routine. When the user
> > wrote a rule to rename the interface, it looks like udev does the
> > renaming after the end of the probe routine, which means we are printing
> > the original netdev->name instead of the final one that udev sets.
> >
> > I thought that udev would be called during register_netdev (which we
> > call in the probe routine). But, it seems it is actually called later.
> > Is there any way to wait until udev is actually called? or to force it
> > to rename before the end of the probe routine so that we can end the
> > driver initialization by printing the final name of the interface?
> >
> 
> udev is not called (in the sense of synchronous procedure call). 
> register_netdev just sends notification about new interface; udev 
> asynchronously processes this notification.
> 
> I am not aware of any way to wait for udev action completion. The only 
> solution in your case seems to be long enough timeout (say several seconds) 
> before printing interface name.

And even then, it's a pretty foolish thing to do, as the inteface can be
renamed at any point in time.

In short, don't worry about it, if userspace renames your device,
there's nothing you can do about it, just accept it as what the user
wanted to do.

thanks,

greg k-h

Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid\x120709&bid&3057&dat\x121642
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel