This is what happened before this patch (edited for brevity):
dracut-cmdline-ask.service in modules.d/98dracut-systemd, which invokes
dracut-cmdline-ask.sh. This script and systemd-vconsole-setup are
started in parallel for the same console (tty1).
Then dracut-cmdline-ask quits immediately without doing anything (unless
rd.cmdline=ask is given). As this is a bash script and it gets tty as
stdin as specified in its *.service, this triggers the hangup of tty1 at
its exit.
Meanwhile systemd-vconsole-setup continues and tries some ioctls after
that, but they fail because of the hung up tty1.
The usual culprit for starting systemd-vconsole-setup early on is
plymouth-start.service, even if plymouth.enable=0 is set.
A popular (and annoying) symptom of this as reported by users was
the inability use their configured keyboard layout in plymouth when
unlocking their crypted block devices.
Reference: boo#1055834
Basic systemd functionality is in 00systemd now.
Switching root and the initrd.target is in 00systemd-initrd.
Dracut additions to the systemd initrd are in 98dracut-systemd.
Daniel Molkentin