def device_name_is_disk(device_name,
devicetree=None,
refresh_udev_cache=False):
"""Report if the given device name corresponds to a disk device.
Check if the device name is a disk device or not. This function uses
the provided Blivet devicetree for the checking and Blivet udev module
if no devicetree is provided.
Please note that the udev based check uses an internal cache that is generated
when this function is first called in the udev checking mode. This basically
means that udev devices added later will not be taken into account.
If this is a problem for your usecase then use the refresh_udev_cache option
to force a refresh of the udev cache.
:param str device_name: name of the device to check
:param devicetree: device tree to look up devices in (optional)
:type devicetree: :class:`blivet.DeviceTree`
:param bool refresh_udev_cache: governs if the udev device cache should be refreshed
:returns: True if the device name corresponds to a disk, False if not
:rtype: bool
"""
if devicetree is None:
global udev_device_dict_cache
if device_name:
if udev_device_dict_cache is None or refresh_udev_cache:
# Lazy load the udev dick that contains the {device_name : udev_device,..,}
# mappings. The operation could be quite costly due to udev_settle() calls,
# so we cache it in this non-elegant way.
# An unfortunate side effect of this is that udev devices that show up after
# this function is called for the first time will not be taken into account.
udev_device_dict_cache = dict()
for d in udev.get_devices():
# Add the device name to the cache.
udev_device_dict_cache[udev.device_get_name(d)] = d
# If the device is md, add the md name as well.
if udev.device_is_md(d) and udev.device_get_md_name(d):
udev_device_dict_cache[udev.device_get_md_name(d)] = d
udev_device = udev_device_dict_cache.get(device_name)
return udev_device and udev.device_is_disk(udev_device)
else:
return False
else:
device = devicetree.get_device_by_name(device_name)
return device and device.is_disk
def device_name_is_disk(device_name, devicetree=None, refresh_udev_cache=False):
"""Report if the given device name corresponds to a disk device.
Check if the device name is a disk device or not. This function uses
the provided Blivet devicetree for the checking and Blivet udev module
if no devicetree is provided.
Please note that the udev based check uses an internal cache that is generated
when this function is first called in the udev checking mode. This basically
means that udev devices added later will not be taken into account.
If this is a problem for your usecase then use the refresh_udev_cache option
to force a refresh of the udev cache.
:param str device_name: name of the device to check
:param devicetree: device tree to look up devices in (optional)
:type devicetree: :class:`blivet.DeviceTree`
:param bool refresh_udev_cache: governs if the udev device cache should be refreshed
:returns: True if the device name corresponds to a disk, False if not
:rtype: bool
"""
if devicetree is None:
global udev_device_dict_cache
if device_name:
if udev_device_dict_cache is None or refresh_udev_cache:
# Lazy load the udev dick that contains the {device_name : udev_device,..,}
# mappings. The operation could be quite costly due to udev_settle() calls,
# so we cache it in this non-elegant way.
# An unfortunate side effect of this is that udev devices that show up after
# this function is called for the first time will not be taken into account.
udev_device_dict_cache = dict()
for d in udev.get_devices():
# Add the device name to the cache.
udev_device_dict_cache[udev.device_get_name(d)] = d
# If the device is md, add the md name as well.
if udev.device_is_md(d) and udev.device_get_md_name(d):
udev_device_dict_cache[udev.device_get_md_name(d)] = d
udev_device = udev_device_dict_cache.get(device_name)
return udev_device and udev.device_is_disk(udev_device)
else:
return False
else:
device = devicetree.get_device_by_name(device_name)
return device and device.is_disk
