blob: ef9f104b6a8095079e1ad2d4cc2c6c1585c73ed3 [file] [log] [blame]
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""This is a module to scan /sys/block/ virtual FS, query udev
It provides a list of all removable or USB devices connected to the machine on
which the module is running.
It can be used from command line or from a python script.
To use it as python module it's enough to call the get_all() function.
@see |get_all| documentation for the output format
|get_all()| output is human readable (as oppposite to python's data structures)
import logging, os, re
# this script can be run at command line on DUT (ie /usr/local/autotest
# contains only the client/ subtree), on a normal autotest
# installation/repository or as a python module used on a client-side test.
import common
from autotest_lib.client.common_lib import utils
INFO_PATH = "/sys/block"
UDEV_CMD_FOR_SERIAL_NUMBER = "udevadm info -a -n %s | grep -iE 'ATTRS{" \
"serial}' | head -n 1"
LSUSB_CMD = "lsusb -v | grep -iE '^Device Desc|bcdUSB|iSerial'"
DESC_PATTERN = r'Device Descriptor:'
BCDUSB_PATTERN = r'bcdUSB\s+(\d+\.\d+)'
ISERIAL_PATTERN = r'iSerial\s+\d\s(\S*)'
def read_file(path_to_file, host=None):
"""Reads the file and returns the file content
@param path_to_file: Full path to the file
@param host: DUT object
@return: Returns the content of file
if host:
if not host.path_exists(path_to_file):
raise error.TestError("No such file or directory %s" % path_to_file)
return'cat %s' % path_to_file).stdout.strip()
if not os.path.isfile(path_to_file):
raise error.TestError("No such file or directory %s" % path_to_file)
return utils.read_file(path_to_file)
def system_output(command, host=None, ignore_status=False):
"""Executes command on client
@param host: DUT object
@param command: command to execute
@return: output of command
if host:
return, ignore_status=ignore_status).stdout.strip()
return utils.system_output(command, ignore_status=ignore_status)
def get_udev_info(blockdev, method='udev', host=None):
"""Get information about |blockdev|
@param blockdev: a block device, e.g., /dev/sda1 or /dev/sda
@param method: either 'udev' (default) or 'blkid'
@param host: DUT object
@return a dictionary with two or more of the followig keys:
"ID_BUS", "ID_MODEL": always present
"ID_FS_UUID", "ID_FS_TYPE", "ID_FS_LABEL": present only if those info
are meaningul and present for the queried device
ret = {}
cmd = None
ignore_status = False
if method == "udev":
cmd = "udevadm info --name %s --query=property" % blockdev
elif method == "blkid":
# this script is run as root in a normal autotest run,
# so this works: It doesn't have access to the necessary info
# when run as a non-privileged user
cmd = "blkid -c /dev/null -o udev %s" % blockdev
ignore_status = True
if cmd:
output = system_output(cmd, host, ignore_status=ignore_status)
udev_keys = ("ID_BUS", "ID_MODEL", "ID_FS_UUID", "ID_FS_TYPE",
for line in output.splitlines():
udev_key, udev_val = line.split('=')
if udev_key in udev_keys:
ret[udev_key] = udev_val
return ret
def get_lsusb_info(host=None):
"""Get lsusb info in list format
@param host: DUT object
@return: Returns lsusb output in list format
usb_info_list = []
# Getting the USB type and Serial number info using 'lsusb -v'. Sample
# output is shown in below
# Device Descriptor:
# bcdUSB 2.00
# iSerial 3 131BC7
# bcdUSB 2.00
# Device Descriptor:
# bcdUSB 2.10
# iSerial 3 001A4D5E8634B03169273995
lsusb_output = system_output(LSUSB_CMD, host)
# we are parsing each line and getting the usb info
for line in lsusb_output.splitlines():
desc_matched =, line)
bcdusb_matched =, line)
iserial_matched =, line)
if desc_matched:
usb_info = {}
elif bcdusb_matched:
# bcdUSB may appear multiple time. Drop the remaining.
usb_info['bcdUSB'] =
elif iserial_matched:
usb_info['iSerial'] =
logging.debug('lsusb output is %s', usb_info_list)
return usb_info_list
def get_usbdevice_type_and_serial(device, lsusb_info, host=None):
"""Get USB device type and Serial number
@param device: USB device mount point Example: /dev/sda or /dev/sdb
@param lsusb_info: lsusb info
@param host: DUT object
@return: Returns the information about USB type and the serial number
of the device
# Comparing the lsusb serial number with udev output serial number
# Both serial numbers should be same. Sample udev command output is
# shown in below.
# ATTRS{serial}=="001A4D5E8634B03169273995"
udev_serial_output = system_output(UDEV_CMD_FOR_SERIAL_NUMBER % device,
udev_serial_matched =, udev_serial_output)
if udev_serial_matched:
udev_serial =
logging.debug("udev serial number is %s", udev_serial)
for usb_details in lsusb_info:
if usb_details['iSerial'] == udev_serial:
return usb_details.get('bcdUSB'), udev_serial
return None, None
def get_partition_info(part_path, bus, model, partid=None, fstype=None,
label=None, block_size=0, is_removable=False,
lsusb_info=[], host=None):
"""Return information about a device as a list of dictionaries
Normally a single device described by the passed parameters will match a
single device on the system, and thus a single element list as return
value; although it's possible that a single block device is associated with
several mountpoints, this scenario will lead to a dictionary for each
@param part_path: full partition path under |INFO_PATH|
e.g., /sys/block/sda or /sys/block/sda/sda1
@param bus: bus, e.g., 'usb' or 'ata', according to udev
@param model: device moduel, e.g., according to udev
@param partid: partition id, if present
@param fstype: filesystem type, if present
@param label: filesystem label, if present
@param block_size: filesystem block size
@param is_removable: whether it is a removable device
@param host: DUT object
@param lsusb_info: lsusb info
@return a list of dictionaries contaning each a partition info.
An empty list can be returned if no matching device is found
ret = []
# take the partitioned device name from the /sys/block/ path name
part = part_path.split('/')[-1]
device = "/dev/%s" % part
if not partid:
info = get_udev_info(device, "blkid", host=host)
partid = info.get('ID_FS_UUID', None)
if not fstype:
fstype = info.get('ID_FS_TYPE', None)
if not label:
label = partid
readonly = read_file("%s/ro" % part_path, host)
if not int(readonly):
partition_blocks = read_file("%s/size" % part_path, host)
size = block_size * int(partition_blocks)
stub = {}
stub['device'] = device
stub['bus'] = bus
stub['model'] = model
stub['size'] = size
# look for it among the mounted devices first
mounts = read_file("/proc/mounts", host).splitlines()
seen = False
for line in mounts:
dev, mount, proc_fstype, flags = line.split(' ', 3)
if device == dev:
if 'rw' in flags.split(','):
seen = True # at least one match occurred
# Sorround mountpoint with quotes, to make it parsable in
# case of spaces. Also information retrieved from
# /proc/mount override the udev passed ones (e.g.,
# proc_fstype instead of fstype)
dev = stub.copy()
dev['fs_uuid'] = partid
dev['fstype'] = proc_fstype
dev['is_mounted'] = True
# When USB device is mounted automatically after login a
# non-labelled drive is mounted to:
# '/media/removable/USB Drive'
# Here an octal unicode '\040' is added to the path
# replacing ' ' (space).
# Following '.decode('unicode-escape')' handles the same
dev['mountpoint'] = mount.decode('unicode-escape')
dev['usb_type'], dev['serial'] = \
# If not among mounted devices, it's just attached, print about the
# same information but suggest a place where the user can mount the
# device instead
if not seen:
# we consider it if it's removable and and a partition id
# OR it's on the USB bus or ATA bus.
# Some USB HD do not get announced as removable, but they should be
# showed.
# There are good changes that if it's on a USB bus it's removable
# and thus interesting for us, independently whether it's declared
# removable
if (is_removable and partid) or bus in ['usb', 'ata']:
if not label:
info = get_udev_info(device, 'blkid', host=host)
label = info.get('ID_FS_LABEL', partid)
dev = stub.copy()
dev['fs_uuid'] = partid
dev['fstype'] = fstype
dev['is_mounted'] = False
dev['mountpoint'] = "/media/removable/%s" % label
dev['usb_type'], dev['serial'] = \
return ret
def get_device_info(blockdev, lsusb_info, host=None):
"""Retrieve information about |blockdev|
@see |get_partition_info()| doc for the dictionary format
@param blockdev: a block device name, e.g., "sda".
@param host: DUT object
@param lsusb_info: lsusb info
@return a list of dictionary, with each item representing a found device
ret = []
spath = "%s/%s" % (INFO_PATH, blockdev)
block_size = int(read_file("%s/queue/physical_block_size" % spath,
is_removable = bool(int(read_file("%s/removable" % spath, host)))
info = get_udev_info(blockdev, "udev", host=host)
dev_bus = info['ID_BUS']
dev_model = info['ID_MODEL']
dev_fs = info.get('ID_FS_TYPE', None)
dev_uuid = info.get('ID_FS_UUID', None)
dev_label = info.get('ID_FS_LABEL', dev_uuid)
has_partitions = False
for basename in system_output('ls %s' % spath, host).splitlines():
partition_path = "%s/%s" % (spath, basename)
# we want to check if within |spath| there are subdevices with
# partitions
# e.g., if within /sys/block/sda sda1 and other partition are present
if not re.match("%s[0-9]+" % blockdev, basename):
continue # ignore what is not a subdevice
# |blockdev| has subdevices: get info for them
has_partitions = True
devs = get_partition_info(partition_path, dev_bus, dev_model,
lsusb_info=lsusb_info, host=host)
if not has_partitions:
devs = get_partition_info(spath, dev_bus, dev_model, dev_uuid, dev_fs,
dev_label, block_size=block_size,
lsusb_info=lsusb_info, host=host)
return ret
def get_all(host=None):
"""Return all removable or USB storage devices attached
@param host: DUT object
@return a list of dictionaries, each list element describing a device
ret = []
lsusb_info = get_lsusb_info(host)
for dev in system_output('ls %s' % INFO_PATH, host).splitlines():
# Among block devices we need to filter out what are virtual
if re.match("s[a-z]+", dev):
# for each of them try to obtain some info
ret.extend(get_device_info(dev, lsusb_info, host=host))
return ret
def main():
for device in get_all():
print ("%(device)s %(bus)s %(model)s %(size)d %(fs_uuid)s %(fstype)s "
"%(is_mounted)d %(mountpoint)s %(usb_type)s %(serial)s" %
if __name__ == "__main__":