Unmount a Device Without Knowing Where It's Mounted

[Gerowen]

I've written a python script to fill a need at work. We have to wipe hard drives using specific methods and requirements (wiping it multiple times over), and it was easier for me to script it, but I happened upon a question, more for myself. In order for the device to get wiped, it cannot be mounted. So let's say that I tell the script to wipe /dev/sdc , which should kill the whole drive. However, let's say /dev/sdc1 is a partition that is mounted, but there's no way I can predict what it is mounted as. Is it possible to detect where the device is mounted to, if it is, or a way to force unmount it without knowing where it's mounted?

It's too easy for me to just unmount it, but I'm going for modularity here. I want the rest of my guys in the shop to be able to double click the icon, enter the device ID, and let it go, without having to worry about unmounting things manually.

Edit: Here is the source code.

#!/usr/bin/env python
#Killdisk 11.10.6 - October 6th 2011
#Author: Marcus Dean Adams (marcusdean.adams@gmail.com)
#Licensed under version 3 of the GNU General Public License
#A copy of the GNU GPL should be included with this software.
#If it is not, you can view the latest version at
#http://www.gnu.org/licenses/gpl.html

#Imports functions
import os
import sys
import time

#Checks that the user is running a Linux/Unix system
if os.name!="posix":
    print "This program is designed to run only on Unix like"
    print "operating systems."
    print ""
    raw_input("Press Enter to exit...")
    sys.exit("Exiting...")

#Welcome message
print ""
print "KillDisk 11.10.6"
print ""
print "This program will erase any file, disk or partition you specify."
print "At any time you can press Ctrl+C to cancel the program."
print "If you do so before a wipe operation has begun, no changes"
print "will have been made to the drive."
print ""
print "If you experience any problems with this software, feel free to e-mail me:"
print "Marcus Dean Adams (marcusdean.adams@gmail.com)"
print ""
raw_input("Press Enter to continue...")
print ""

#Prompts for the type of wipe to be executed, and sets variables accordingly.
print "What type of wipe would you like to perform? "
print ""
print "1) Overwrite all sectors with zeros (Faster, less secure)"
print "2) Overwrite all sectors with random data (Slower, more secure)"
print ""
style=raw_input("Enter a number: ")
if style=="1":
    wipe="dd if=/dev/zero of="
elif style=="2":
    wipe="dd if=/dev/urandom of="
else:
    print "Invalid input, exiting program to avoid unwanted"
    print "damage to data."
    print ""
    raw_input("Press Enter to exit...")
    sys.exit("Exiting...")

#Displays partitions on all disks.
print ""
print "Displaying partition tables of all drives in 3 seconds..."
time.sleep(3)
os.system("su-to-root -c 'fdisk -l'")
print ""
print "Please choose a device to kill.  Remember if you want to"
print "wipe the whole drive and not just a partition, you can"
print "remove the number appended.  Example /dev/sdc1 becomes /dev/sdc ."
print ""
device=raw_input("Enter device: ")
print ""
count=input("How many times would you like to wipe the device? ")
print ""
print "Writing changes to disk.  All data on %s will be lost."%(device)
print ""
raw_input("Press Enter to continue, or Ctrl+C to exit: ")
print ""
lap=1
for i in range(count):
    print "Processing wipe count %s of %s..."%(lap, count)
    os.system((wipe + "%s")%(device))
    lap=lap+1
print ""
"Done!"

exit

[kjordan2001]

You don't need to specify where it's mounted, the umount command can take either a directory where it's mounted or the device itself. If you want to confirm it by saying where it's currently mounted, you can just use the mount command without any arguments and that will give a list of device to directory (as well as its filesystem type and mount options). If you want to unmount any partitions, you can use fdisk -l and get any sub-devices from there and unmount all those.

[Kami-]

^ What he said...