On Fri, Oct 27, 2017 at 06:53:16PM +0200, Greg KH wrote: > On Fri, Oct 27, 2017 at 05:20:48PM +0200, Anisse Astier wrote: > > Hi, > > > > Would it be possible to backport upstream commit > > ca4c8a3a800039c2681d609c5b7491c1bd17c0a7 into 4.9 ? > > > > From: Miklos Szeredi <mszeredi@xxxxxxxxxx> > > ovl: treat special files like a regular fs > > > > No sense in opening special files on the underlying layers, they work just > > as well if opened on the overlay. > > > > Side effect is that it's no longer possible to connect one side of a pipe > > opened on overlayfs with the other side opened on the underlying layer. > > > > > > Before this it's impossible to do in-kernel resolution of a device file, > > for example to mount or use dmsetup. > > So, this adds a new feature, and does not fix a bug, right? :) That's correct. I thought earlier version behaved this way, after some testing it seems they did not. > > > Miklos, you say this might cause a behaviour change in a very > > particular case; but did it cause an issue upstream since it was merged > > in 4.10 ? > > > > I also wish this was fixed in 4.1, so I did a tentative backport below. > > What do you think Sasha, Miklos ? > > What is preventing you from using a newer kernel like 4.13 if you rely > on this new feature? Nothing fancy here, that's what you get when using lots of non-upstream code from a vendor. Regards, Anisse