[systemd-devel] Why does initrd-parse-etc.service re-start initrd-fs.target?

[Andrei Borzenkov]

05.12.2019 17:31, Colin Walters пишет:
> See https://github.com/coreos/ignition-dracut/pull/140
> 
> Basically, we do a lot of nontrivial stuff in the initramfs (Ignition) and this was re-starting some of our units, which I found surprising.
> 
> The behavior seems to have come from https://github.com/systemd/systemd/commit/7d89ce303fb59743a4392eeb3110c00f100172ca

It was there much earlier, just that it restarted local-fs.target then.

> 
> Now, I understand the goal of having systemd re-load its configuration, but why do we need to start the initrd-fs.target unit again?  Can't we assume that the mount points set up for the root are still active?

After real root is mounted daemon-reload re-runs fstab generator which
parses real root /etc/fstab and may pull mount points from it.
Restarting initrd-fs.target will propagate start request to its (newly
created) dependent mount units. Otherwise there is no obvious way to
start them (without explicitly starting each).