[systemd-devel] [PATCH] unit: When stopping due to BindsTo=, log which unit caused it

[Lennart Poettering]

On Thu, 26.02.15 16:50, Martin Pitt (martin.pitt at ubuntu.com) wrote:

> IMHO it would be prudent to skip adding the BindsTo= if at the time of
> creating the .mount unit the backing .device unit doesn't actually
> exist. In that case it's a mount which isn't managed by systemd, and
> we shouldn't touch it. We mostly want this BindsTo= for mounts where
> the .device units *do* exist, so that when they go away we can clean
> up the mount (mostly for hotpluggable devices and removable media).
> I'll have a deeper look ASAP.

I ran into this myself the other day, and Kay, Daniel and I spent a
lot of time to come up with a scheme how to deal with the race... And
I think we have a nice scheme now and I started implementing it.

The idea is that .device units will gain a third state: currently they
are either "dead" or "plugged", and the new state will be
"tentative". It is entered when a device is referenced in
/proc/self/mountinfo or /proc/swap, even though it has not yet shown
up via udev.

This new state has will not result in BindsTo= getting active.

Lennart

-- 
Lennart Poettering, Red Hat