Creating an encrypted directory using ecryptfs - cannot umount

[John Magolske <listmail@b79.net>]

I'm trying to create an encrypted directory using ecryptfs such that I
can switch it between being encrypted to non-encrypted at will. I did:

  # aptitude install ecryptfs-utils
  # modprobe ecryptfs
  # mkdir encrypted-directory
  # chmod 700 encrypted-directory
  # mount -t ecryptfs encrypted-directory encrypted-directory
  Passphrase:

At this point I made up and entered a passphrase, then followed the
steps, selecting the defaults (with the exceptions of choosing the
twofish cipher and 32 key bytes). There was this message:

  WARNING: Based on the contents of [/root/.ecryptfs/sig-cache.txt],
  it looks like you have never mounted with this key
  before. This could mean that you have typed your
  passphrase wrong.
  Would you like to proceed with the mount (yes/no)? : yes
  Would you like to append sig [****************] to
  [/root/.ecryptfs/sig-cache.txt]
  in order to avoid this warning in the future (yes/no)? : yes
  Successfully appended new sig to user sig cache file
  Mounted eCryptfs

Then I cd'd into ~/encrypted-directory (as non-root) and created some
files there. But when I try to umount, I'm getting this:

  # umount encrypted-directory
  /sbin/umount.ecryptfs: symbol lookup error: /sbin/umount.ecryptfs: undefined symbol: ecryptfs_remove_auth_tok_from_keyring
  /sbin/umount.ecryptfs: symbol lookup error: /sbin/umount.ecryptfs: undefined symbol: ecryptfs_remove_auth_tok_from_keyring

  # umount ecryptfs encrypted-directory
  Could not unlink the key(s) from your keying. Please use `keyctl unlink` if you wish to remove the key(s).
  Proceeding with umount.
  umount: ecryptfs: not found
  /sbin/umount.ecryptfs: symbol lookup error: /sbin/umount.ecryptfs: undefined symbol: ecryptfs_remove_auth_tok_from_keyring
  /sbin/umount.ecryptfs: symbol lookup error: /sbin/umount.ecryptfs: undefined symbol: ecryptfs_remove_auth_tok_from_keyring

What else should I be doing?

TIA for any help,

John

-- 
John Magolske
http://B79.net/contact