loopback.py 文件源码

def loopback_devices():
    '''
    Parse through 'losetup -a' output to determine currently mapped
    loopback devices. Output is expected to look like:

        /dev/loop0: [0807]:961814 (/tmp/my.img)

    :returns: dict: a dict mapping {loopback_dev: backing_file}
    '''
    loopbacks = {}
    cmd = ['losetup', '-a']
    devs = [d.strip().split(' ') for d in
            check_output(cmd).splitlines() if d != '']
    for dev, _, f in devs:
        loopbacks[dev.replace(':', '')] = re.search('\((\S+)\)', f).groups()[0]
    return loopbacks