[systemd-devel] dev-root.device is not active, results in an umount spree

[Dimitri John Ledkov]

I am booting without initramfs, using a plan9 filesystem as rootfs in a kvm.

Thus my /proc/cmdline has:
root=/dev/root rootflags=rw,trans=virtio,version=9p2000.L rootfstype=9p

# mount
/dev/root on / type 9p
(rw,relatime,sync,dirsync,rw,trans=virtio,version=9p2000.L)

Yet, dev-root.device is dead:
# systemctl status dev-root.device
● dev-root.device
   Loaded: loaded
   Active: inactive (dead)

This is very bad. As a harmless action like following:

# mount --bind /opt /opt

Results in opt.mount unit to be generated which BindsTo
dev-root.device, which is inactive, thus systemd tries to stop that
unit straight away, and umount fails and is retried infinitely...
effectively DoSing init.

What am I missing and/or how can I force make dev-root.device to be
considered active?

I am planning to locally patch mount_add_device_links to skip if what
is "/dev/root", to avoid a call to unit_add_node_link... But I'm not
sure if this is the right thing to do or not.

-- 
Regards,

Dimitri.
Pura Vida!

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