Re: pidfd design

From: Alexey Dobriyan
Date: Wed Mar 20 2019 - 16:39:17 EST


On Wed, Mar 20, 2019 at 01:14:01PM -0700, Daniel Colascione wrote:
> On Wed, Mar 20, 2019 at 1:07 PM Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
> > > What would be your opinion to having a
> > > /proc/<pid>/handle
> > > file instead of having a dirfd.
> >
> > This is even worse than depending on PROC_FS. Just for the dependency
> > pidfd code should be backed out immediately. Forget about /proc.
>
> We already have pidfds, and we've had them since /proc was added ages
> ago.

New pidfd code (or whatever the name) should NOT depend on /proc and
should not interact with VFS at all at any point (other than probably
being a descriptor on a fake filesystem). The reason is that /proc is
full of crap and you don't want to spill that into new and hopefully
properly designed part of new code.