Presence of ROM device raises _ped.DiskException

[codefiles]

The list of devices returned by parted.getAllDevices() is iterated over and each device is passed to parted.Disk(). If that raises an 'unrecognised disk label' DiskLabelException then the device is passed to parted.freshDisk(). ROM devices are inlcuded in the list of devices returned by parted.getAllDevices() and will cause both of these to raise an exception.

archinstall/archinstall/lib/disk/device_handler.py

Lines 47 to 52 in 5276d95

	for device in getAllDevices():
	try:
	disk = Disk(device)
	except DiskLabelException as err:
	if 'unrecognised disk label' in getattr(error, 'message', str(err)):
	disk = freshDisk(device, PartitionTable.GPT.value)

Proposed fix

Do not initialize parted.Disk or parted.freshDisk with ROM devices. Use get_lsblk_info() to get the type of a device and skip the device if the type is 'rom'. See the commit codefiles@08b963f for an implementation of this fix.

Traceback

Traceback (most recent call last):
  File "/home/scripttest/archinstall/archinstall/lib/disk/device_handler.py", line 49, in load_devices
    disk = Disk(device)
           ^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/parted/decorators.py", line 42, in new
    ret = fn(*args, **kwds)
          ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/parted/disk.py", line 52, in __init__
    self.__disk = _ped.Disk(device.getPedDevice())
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
_ped.DiskLabelException: /dev/sr0: unrecognised disk label

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/scripttest/archinstall/.venv/bin/archinstall", line 5, in <module>
    from archinstall import run_as_a_module
  File "/home/scripttest/archinstall/archinstall/__init__.py", line 8, in <module>
    from .lib import disk
  File "/home/scripttest/archinstall/archinstall/lib/disk/__init__.py", line 1, in <module>
    from .device_handler import device_handler, disk_layouts
  File "/home/scripttest/archinstall/archinstall/lib/disk/device_handler.py", line 603, in <module>
    device_handler = DeviceHandler()
                     ^^^^^^^^^^^^^^^
  File "/home/scripttest/archinstall/archinstall/lib/disk/device_handler.py", line 38, in __init__
    self.load_devices()
  File "/home/scripttest/archinstall/archinstall/lib/disk/device_handler.py", line 52, in load_devices
    disk = freshDisk(device, PartitionTable.GPT.value)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/parted/decorators.py", line 42, in new
    ret = fn(*args, **kwds)
          ^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/site-packages/parted/__init__.py", line 546, in freshDisk
    peddisk = disk_new_fresh(device.getPedDevice(), ty)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
_ped.DiskException: device is too small for GPT

Device information

• lsblk -o NAME,PATH,TYPE /dev/sr0

  NAME PATH     TYPE
  sr0  /dev/sr0 rom
  

• pyparted

  import parted
  
  device = parted.getDevice('/dev/sr0')
  print(device)
  print(parted.devices[device.type])

  Output

  parted.Device instance --
    model: QEMU QEMU DVD-ROM  path: /dev/sr0  type: 1
    sectorSize: 2048  physicalSectorSize:  2048
    length: 1  openCount: 0  readOnly: False
    externalMode: False  dirty: False  bootDirty: False
    host: 1  did: 0  busy: False
    hardwareGeometry: (0, 255, 5)  biosGeometry: (0, 255, 5)
    PedDevice: <_ped.Device object at 0x7f7652da5040>
  scsi
  

[codefiles]

If my proposed fix is agreed upon I will submit a pull request.

[svartkanin]

I'll have to have a look at this a bit more

[codefiles]

@Torxed, this should be addressed before a release is made.

[Torxed]

I agree. I personally think it's a small and clean implementation.
Any suggestions @svartkanin? three lines of code could be easy to change later on if we decide to go another route?

[svartkanin]

@Torxed @codefiles yes absolutely go ahead with the patch

[codefiles]

Relevant pyparted issue: dcantrell/pyparted#102

[Torxed]

Will be interesting to see pyparted's response.
But for us your method will do more than fine for this release:

if get_lsblk_info(device.path).type == 'rom':
	continue