Esempio n. 1
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def ReleaseBdevPartitionMapping(loop_dev_path):
    """Release allocated dm devices and loopback devices.

  @type loop_dev_path: string
  @param loop_dev_path: path of loopback device returned by
  L{CreateBdevPartitionMapping}

  """
    result = utils_process.RunCmd(["kpartx", "-d", loop_dev_path])
    if result.failed:
        raise errors.CommandError(
            "Failed to release partition mapping of %s: %s" %
            (loop_dev_path, result.output))

    # The invocation of udevadm settle was added here because users had issues
    # with the loopback device still being busy after kpartx / earlier commands
    # did their work.
    result = utils_process.RunCmd(["udevadm", "settle"])
    if result.failed:
        raise errors.CommandError("Waiting on udev failed: %s" % result.output)

    result = utils_process.RunCmd(["losetup", "-d", loop_dev_path])
    if result.failed:
        raise errors.CommandError("Failed to detach %s: %s" %
                                  (loop_dev_path, result.output))
Esempio n. 2
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def CreateBdevPartitionMapping(image_path):
    """Create dm device for each partition of disk image.

  This operation will allocate a loopback and a device-mapper device to map
  partitions.
  You must call L{ReleaseBdevPartitionMapping} to clean up resources allocated
  by this function call.

  @type image_path: string
  @param image_path: path of multi-partition disk image
  @rtype: tuple(string, list(string)) or NoneType
  @return: returns the tuple(loopback_device, list(device_mapper_files)) if
    image_path is a multi-partition disk image. otherwise, returns None.

  """
    # Unfortunately, there are two different losetup commands in this world.
    # One has the '-s' switch and the other has the '--show' switch to provide the
    # same functionality.
    result = utils_process.RunCmd(["losetup", "-f", "-s", image_path])
    if result.failed and "invalid option -- 's'" in result.stderr:
        result = utils_process.RunCmd(["losetup", "-f", "--show", image_path])
    if result.failed:
        raise errors.CommandError("Failed to setup loop device for %s: %s" %
                                  (image_path, result.output))
    loop_dev_path = result.stdout.strip()
    logging.debug("Loop dev %s allocated for %s", loop_dev_path, image_path)

    result = utils_process.RunCmd(["kpartx", "-a", "-v", loop_dev_path])
    if result.failed:
        # Just try to cleanup allocated loop device
        utils_process.RunCmd(["losetup", "-d", loop_dev_path])
        raise errors.CommandError(
            "Failed to add partition mapping for %s: %s" %
            (image_path, result.output))
    dm_devs = [x.split(" ") for x in result.stdout.split("\n") if x]
    if dm_devs:
        dm_dev_paths = [
            utils_io.PathJoin("/dev/mapper", x[2]) for x in dm_devs
        ]
        return (loop_dev_path, dm_dev_paths)
    else:
        # image_path is not a multi partition disk image, no need to use
        # device-mapper.
        logging.debug("Release loop dev %s allocated for %s", loop_dev_path,
                      image_path)
        ReleaseBdevPartitionMapping(loop_dev_path)
        return None
Esempio n. 3
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def ReleaseBdevPartitionMapping(loop_dev_path):
    """Release allocated dm devices and loopback devices.

  @type loop_dev_path: string
  @param loop_dev_path: path of loopback device returned by
  L{CreateBdevPartitionMapping}

  """
    result = utils_process.RunCmd(["kpartx", "-d", loop_dev_path])
    if result.failed:
        raise errors.CommandError(
            "Failed to release partition mapping of %s: %s" %
            (loop_dev_path, result.output))

    result = utils_process.RunCmd(["losetup", "-d", loop_dev_path])
    if result.failed:
        raise errors.CommandError("Failed to detach %s: %s" %
                                  (loop_dev_path, result.output))