Description of problem:
when you update your systemd from 29 version
to 30, after rebooting, your computer hangs 
with some message about deadlock. 

Version-Release number of selected component (if applicable):
# cat /etc/fedora-release 
Fedora release 16 (Rawhide)
# uname -a
Linux timelock.rtcomm.ru 3.0-0.rc7.git0.1.fc16.i686 #1 SMP Tue Jul 12 13:04:11 UTC 2011 i686 i686 i386 GNU/Linux
#

How reproducible:
just update your systemd{-untis,-sysv}

Steps to Reproduce:
1. yum update
2.
3.
  
Actual results:
system hang after login

Expected results:
system work properly

Additional info:
if you already update your systemd packages, 
you can do the following steps to resurrect your system :
1. boot your computer in single user mode. (in grub you must add 1
at the end of kernel string, press "Enter", press "b")
2. when booting process is done, and you get the shell, you should turn up your network interfaces. systemctl start network.service
3. download old systemd packages 
wget "ftp://ftp.muug.mb.ca/mirror/fedora/linux/development/rawhide/i386/os/Packages/systemd-29-1.fc16.i686.rpm"
wget "ftp://ftp.muug.mb.ca/pub/fedora/linux/development/rawhide/i386/os/Packages/systemd-sysv-29-1.fc16.i686.rpm"
wget "ftp://ftp.muug.mb.ca/pub/fedora/linux/development/rawhide/i386/os/Packages/systemd-units-29-1.fc16.i686.rpm"
4. install old packages 
rpm -Uvh --oldpackage systemd*
5. reboot

Your system should booting as usual

if you need additional information, please let me know.