[systemd-devel] [PATCH] systemd-udevd.service: restore mount propagation

Martin Pitt martin.pitt at ubuntu.com
Tue Jan 27 14:20:18 PST 2015

Hey Lennart,

Lennart Poettering [2015-01-27 22:46 +0100]:
> So I figure the bit that is missing here is the fact that the .device
> units for CD drives and USB card readers don't care for media sense right
> now.

Indeed, I had a similar thought on my evening walk: This works well
for USB sticks and the like, but the /dev/sr0 node for CDs always
stays around after eject. IOW, you get a change event, not a remove
one. This is also why the cleanup in udisks 1.x (probably) didn't
actually work.

> However, I think it would make a ton of sense to change that, and set
> SYSTEMD_READY=0 on all block devices where the media sensing suggests
> that no medium is in it. This would mean that these devices don't show
> up as systemd units until you actually put a medium in it. That would
> be a change of semantics, but I think a useful one. 

That sounds good indeed! I can sit down at qemu tomorrow and simulate
some CD insertions/removals, and come up with an udev rule for this.

Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)

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