[PATCH 3/7] vfs: Add a mount-notification facility

[Jann Horn]

On Wed, May 29, 2019 at 1:04 AM David Howells <dhowells at redhat.com> wrote:
> Jann Horn <jannh at google.com> wrote:
> > It might make sense to redesign this stuff so that watches don't hold
> > references on the object being watched.
>
> I explicitly made it hold a reference so that if you place a watch on an
> automounted mount it stops it from expiring.
>
> Further, if I create a watch on something, *should* it be unmountable, just as
> if I had a file open there or had chdir'd into there?

I don't really know. I guess it depends on how it's being used? If
someone decides to e.g. make a file browser that installs watches for
a bunch of mountpoints for some fancy sidebar showing the device
mounts on the system, or something like that, that probably shouldn't
inhibit unmounting... I don't know if that's a realistic use case.