I've searched high and low, and can't figure this one out. I have a older Olympus Camera (2001 or so). When I plug in the USB connection, I get the following log output:

$ dmesg | grep sd
[20047.625076] sd 21:0:0:0: Attached scsi generic sg7 type 0
[20047.627922] sd 21:0:0:0: [sdg] Attached SCSI removable disk

Secondly, the drive is not mounted in the FS, but when I run gphoto2 I get the following error:

$ gphoto2 --list-config

*** Error ***              
An error occurred in the io-library ('Could not lock the device'): Camera is already in use.
*** Error (-60: 'Could not lock the device') ***       

What command will unmount the drive. For example in Nautilus, I can right click and select "Safely Remove Device". After doing that, the /dev/sg7 and /dev/sdg devices are removed.

The output of gphoto2 is then:

# gphoto2 --list-config
/Camera Configuration/Picture Settings/resolution                              
/Camera Configuration/Picture Settings/shutter
/Camera Configuration/Picture Settings/aperture
/Camera Configuration/Picture Settings/color
/Camera Configuration/Picture Settings/flash
/Camera Configuration/Picture Settings/whitebalance
/Camera Configuration/Picture Settings/focus-mode
/Camera Configuration/Picture Settings/focus-pos
/Camera Configuration/Picture Settings/exp
/Camera Configuration/Picture Settings/exp-meter
/Camera Configuration/Picture Settings/zoom
/Camera Configuration/Picture Settings/dzoom
/Camera Configuration/Picture Settings/iso
/Camera Configuration/Camera Settings/date-time
/Camera Configuration/Camera Settings/lcd-mode
/Camera Configuration/Camera Settings/lcd-brightness
/Camera Configuration/Camera Settings/lcd-auto-shutoff
/Camera Configuration/Camera Settings/camera-power-save
/Camera Configuration/Camera Settings/host-power-save
/Camera Configuration/Camera Settings/timefmt

Some things I've tried already are sdparm and sg3_utils, however I am unfamiliar with them, so it's possible I just didn't find the right command.

Update 1:

# mount | grep sdg
# mount | grep sg7
# umount /dev/sg7
umount: /dev/sg7: not mounted
# umount /dev/sdg
umount: /dev/sdg: not mounted
# gphoto2 --list-config

*** Error ***              
An error occurred in the io-library ('Could not lock the device'): Camera is already in use.
*** Error (-60: 'Could not lock the device') ***