Re: [GIT PULL] vfs pidfd

From: Linus Torvalds
Date: Mon Mar 11 2024 - 16:05:34 EST


On Fri, 8 Mar 2024 at 02:14, Christian Brauner <brauner@xxxxxxxxxx> wrote:
>
> * Move pidfds from the anonymous inode infrastructure to a tiny
> pseudo filesystem. This will unblock further work that we weren't able
> to do simply because of the very justified limitations of anonymous
> inodes. Moving pidfds to a tiny pseudo filesystem allows for statx on
> pidfds to become useful for the first time. They can now be compared
> by inode number which are unique for the system lifetime.

So I obviously pulled this already, but I did have one question - we
don't make nsfs conditional, and I'm not convinced we should make
pidfs conditional either.

I think (and *hope*) all the semantic annoyances got sorted out, and I
don't think there are any realistic size advantages to not enabling
CONFIG_FS_PID.

Is there some fundamental reason for that config entry to exist?

Linus