On Mon, Nov 06, 2023 at 02:05:45PM +0100, Christian Brauner wrote: > > > I think spending time engaging this claim isn't worth it. This is just > > > easily falsifiable via a simple grep for btrfs in systemd, lxc, runc, > > > util-linux. > > > > Myabe you need to get our of your little bubble. There is plenty of > > Unnecessary personal comment, let alone that I'm not in any specific > bubble just because I'm trying to be aware of what is currently going on > in userspace. Maybe you're just taking it to personal? A place where systemd, lxc, runc, and util-linux are "all software" is a very much a bubble as you won't find much userspace that stays more uptodate with particular quirks of modern Linux features. > Whatever you do here: vfsmounts or any other solution will force changes > in userspace on a larger scale and changes to the filesystem itself. If > you accommodate tar then you are fscking over other parts of userspace > which are equally important. There is no free lunch. It works for everything that knows that Linux mountpoint as exposed in /proc/mounts and proc/self/mountinfo corresponds to the posix definition of a mount point, and that one used on basically every other unix system. It might not work as-is for software that actually particularly knows how to manage btrfs subvolumes, but those are, by defintion, not the problem anyway. It's thinkgs like backup tools that run into random ino_t duplicates. That's an example we had in the past, and I would be absolutely not be surprised if there is more than more of those hiding right now.
