First, make sure that you have hfsprogs installed. Example installation command:

sudo apt-get install hfsprogs

Next, mount or remount the HFS+ drive; commands need to be as follows:

sudo mount -t hfsplus -o force,rw /dev/sdXY /media/mntpoint

or

sudo mount -t hfsplus -o remount,force,rw /mount/point

Finally, if the drive was improperly unmounted or has otherwise become partially corrupted run fsck.hfsplus … as such:

sudo fsck.hfsplus -f /dev/sdXY