[systemd-devel] Two conditional mount units for the same mount point

[Jan Kundrát]

I would like to mount one of two partitions to a common mount point based 
on an option passed on the kernel's command line. I tried to implement this 
with two cfg-A.mount and cfg-B.mount units with an appropriate 
ConditionKernelCommandLine=... stanzas, but this did not work because a 
.mount unit apparently needs to have a name which exactly matches its 
mountpoint. I don't know how I can have two units with a different content 
sharing the same unit name, though.

Here's my cfg-A.mount, the other one was very similar:

> [Unit]
> Description=Persistent configuration: slot A
> ConditionKernelCommandLine=rauc.slot=A
> DefaultDependencies=no
> Conflicts=umount.target
> Before=local-fs.target umount.target
> After=swap.target
>
> [Mount]
> What=/dev/mmcblk0p2
> Where=/cfg
> Type=auto
> Options=relatime,nosuid,nodev

In the end, I kinda-solved this by a custom oneshot service which simply 
calls `mount` explicitly, but that's probably not a very systemd-ish 
solution.

How should I solve this elegantly?

With kind regards,
Jan