After some recent file system woes as well as some past system updates I ran into this error while trying to mount my encrypted home directory:

Enter your login passphrase:
Inserted auth tok with sig [**********************] into the user session keyring
open: Read-only file system
Ecryptfs error locking counter

*SIGH*

Some quick googling yielded the answer, at some point the ecryptfs tools now require /dev/shm mount to function properly. So the following line was added to my /etc/fstab:

tmpfs    /dev/shm   tmpfs   defaults,noexec,nosuid   0   0

After that a quick mount -a and retry to mount my home and all is well again!