Unfortunately that just gets me a helpful "Journaling could not be enabled". I guess something got messed up when I was writing to the volume from Linux.
enableJournal device
Enable journaling on an HFS+ volume. This works whether or not
the volume is currently mounted (the volume is temporarily
mounted if necessary). Ownership of the affected disk is
required.
disableJournal [force] device
Disable journaling on an HFS+ volume. This normally works
whether or not the volume is currently mounted (the volume is
temporarily mounted if necessary). If the force option is speci-
fied, then journaling is disabled directly on disk; in this case,
the volume must not be mounted. Ownership of the affected disk
is required.
moveJournal external | internal [journalDevice] device
external will create a 512MB Apple_Journal partition out of
journalDevice and an HFS+ partition will be created out of the
remaining space if available; journalDevice must be a partition,
not a whole-disk. The journal for device will then be moved
externally onto the newly created Apple_Journal partition.
internal will move the journal for device back locally.
I don't know if it can work on the mounted root filesystem so you may want to try that from the recovery partition.
