Created attachment 695460 [details]
blkid output before and after util-linux update

Description of problem:
After installing available updates for F18 the system would only boot to emergency mode. The reason was that for just one of my ext4 partitions, the UUID apparently no longer got detected (nowhere to be found under /dev/disk/by-uuid for example).
I ran "yum downgrade libblkid libuuid libmount util-linux", and afterwards the UUID got detected again and all worked well. Mounting via device name instead of UUID works too of course.
fsck -f finds nothing to complain about so I assume the partition is healthy.

Version-Release number of selected component (if applicable):
not working: libuuid-2.22.2-3.fc18.x86_64 libblkid-2.22.2-3.fc18.x86_64 libmount-2.22.2-3.fc18.x86_64 util-linux-2.22.2-3.fc18.x86_64
working: libuuid-2.22.1-2.1.fc18.x86_64 libblkid-2.22.1-2.1.fc18.x86_64 libmount-2.22.1-2.1.fc18.x86_64 util-linux-2.22.1-2.1.fc18.x86_64

How reproducible:
I have no idea. I have 10 partitions on 4 drives and only a single one is affected. Also there's nothing fancy about my setup, no LVM or anything, just boring old primary partitions.

Steps to Reproduce:
1. install util-linux-2.22.2-3.fc18.x86_64
2. reboot
3. nothing in /dev/disk/by-uuid or by-label points to the partition device /dev/sda1 anymore
4. downgrade to util-linux-2.22.1-2.1.fc18.x86_64
5. /dev/disk/by-uuid and by-label populated with links to /dev/sda1
  
Actual results:
One ext4 partition cannot be mounted by UUID or label. System no longer boots.

Expected results:
All ext4 partitions mountable by UUID or label.

Additional info: