David Miller [off-list ref] writes:

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Thu, 12 Sep 2013 13:06:53 -0700

quoted

David, Eric, do any of you know why we have this netdevice notfier
rebroadcast?

It's been there as long as I can remember, but I don't remember
exactly why we do that.

If I had to guess, it's to handle something that has to retry later
due to a "spin_trylock()" or similar type of situation.

Probably best to not remove it. :)

Since it doesn't completely solve the problem, it isn't worth it to
solve this problem.  Sigh

I have added this bit of code and the moving of references to the
loopback device in dst_ifdown to my hitlist of things to sort out some
day when I have plenty time.

Eric