when does udev rename network interface ?

Brice Goglin

author

2006-06-29 15:42 UTC #0 lore raw

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

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Andrey Borzenkov

2006-06-29 16:01 UTC #1 lore raw

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Quoted 8 lines · 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.

Quoted 6 lines

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
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Greg KH

2006-06-29 16:56 UTC #2 lore raw

In reply to Brice Goglin

Quoted 16 lines · Andrey Borzenkov

Quoted 8 lines · 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.
Quoted 6 lines
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?

Quoted 7 lines

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

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