Description of problem:

Systemd fails to mount most cgroups (/sys/fs/cgroup/devices, /sys/fs/cgroup/memory, ...) after upgrade from F27 to F28. This seems to be the case only when the systemd dracut module is not present, which happens for example if the crypt-gpg dracut module is used.

Most likely this is caused by the following bug:
https://github.com/systemd/systemd/issues/7901

Should be fixed by:
https://github.com/systemd/systemd/pull/8595


Version-Release number of selected component (if applicable):

systemd-238-7.fc28.1


How reproducible:
Always


Steps to Reproduce:
1. Create a file /etc/dracut.conf.d/10-no-systemd.conf with the content 'omit_dracutmodules+=" systemd "'.
2. Rebuild initramfs with dracut -f.
3. Reboot and check /proc/mounts.


Actual results:

# cat /proc/mounts | grep cgroup
tmpfs /sys/fs/cgroup tmpfs ro,seclabel,nosuid,nodev,noexec,mode=755 0 0
cgroup2 /sys/fs/cgroup/unified cgroup2 rw,seclabel,nosuid,nodev,noexec,relatime,nsdelegate 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,seclabel,nosuid,nodev,noexec,relatime,xattr,name=systemd 0 0


Expected results:

Cgroups for devices, memory, etc. should be present in /sys/fs/cgroup/devices, /sys/fs/cgroup/memory, etc.


Additional info:

This bug prevents docker from working. The bug is not present in F27.
Could be related to https://bugzilla.redhat.com/show_bug.cgi?id=1574649.