如何判断是否使用dbus插入了USB大容量存储设备

Question

我正在制作一个简单的python程序来挂载和卸载闪存驱动器，这样我除了查看列表并选择要挂载的内容外，不必做其他事情。 现在，我有每个设备的对象和属性的列表。 我想知道的是，我应该查看哪些属性来确定设备是否是USB大容量存储设备。 我的第一个直觉是看“可分离”，但是我只插入了一个设备（点燃），但是却得到了两个可分离设备。 我注意到的两个属性是不同的，即/ dev / sdb具有空白的'IdLabel'和'IdUsage'。 这是我现在拥有的代码：

#!/usr/bin/python

import dbus

def get_devices():
  bus = dbus.SystemBus()
  ud_manager_obj = bus.get_object('org.freedesktop.UDisks',
                                  '/org/freedesktop/UDisks')
  ud_manager = dbus.Interface(ud_manager_obj, 'org.freedesktop.UDisks')

  proplist = []

  for device in ud_manager.EnumerateDevices():
    device_obj = bus.get_object('org.freedesktop.UDisks', device)
    device_props = dbus.Interface(device_obj, dbus.PROPERTIES_IFACE)
    proplist.append(device_props.GetAll('org.freedesktop.UDisks.Device'))

  for device_props in proplist:
    print '----------'
    print device_props['IdLabel']
    print device_props['DeviceFile']
    print device_props['IdUsage']
    if device_props['DriveCanDetach']:
      print 'Device is detachable'
    else:
      print 'Device is not detachable'

get_devices()

我正在谈论的两个输出是：

Kindle
/dev/sdb1
filesystem
Device is detachable
----------

/dev/sdb

Device is detachable

udisks的结果--show-info / dev / sdb1

Showing information for /org/freedesktop/UDisks/devices/sdb1
  native-path:                 /sys/devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb3/3-1/3
-1:1.0/host7/target7:0:0/7:0:0:0/block/sdb/sdb1                                           
  device:                      8:17
  device-file:                 /dev/sdb1
    presentation:              /dev/sdb1
    by-id:                     /dev/disk/by-id/usb-Kindle_Internal_Storage_90D42204345600JR
-0:0-part1                                                                                
    by-id:                     /dev/disk/by-uuid/386D-5422
    by-path:                   /dev/disk/by-path/pci-0000:04:00.0-usb-0:1:1.0-scsi-0:0:0:0-
part1                                                                                     
  detected at:                 Sat 04 Jan 2014 03:56:35 PM EST
  system internal:             0
  removable:                   0
  has media:                   1 (detected at Sat 04 Jan 2014 03:56:35 PM EST)
    detects change:            0
    detection by polling:      0
    detection inhibitable:     0
    detection inhibited:       0
  is read only:                0
  is mounted:                  0
  mount paths:             
  mounted by uid:              0
  presentation hide:           0
  presentation nopolicy:       0
  presentation name:           
  presentation icon:           multimedia-player
  automount hint:              
  size:                        1432346624
  block size:                  512
  job underway:                no
  usage:                       filesystem
  type:                        vfat
  version:                     FAT32
  uuid:                        386D-5422
  label:                       Kindle
  partition:
    part of:                   /org/freedesktop/UDisks/devices/sdb
    scheme:                    mbr
    number:                    1
    type:                      0x0b
    flags:                    
    offset:                    8192
    alignment offset:          0
    size:                      1432346624
    label:                     
    uuid:                      

udisks的结果--show-info / dev / sdb

Showing information for /org/freedesktop/UDisks/devices/sdb
  native-path:                 /sys/devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb3/3-1/3
-1:1.0/host7/target7:0:0/7:0:0:0/block/sdb                                                
  device:                      8:16
  device-file:                 /dev/sdb
    presentation:              /dev/sdb
    by-id:                     /dev/disk/by-id/usb-Kindle_Internal_Storage_90D42204345600JR
-0:0                                                                                      
    by-path:                   /dev/disk/by-path/pci-0000:04:00.0-usb-0:1:1.0-scsi-0:0:0:0
  detected at:                 Sat 04 Jan 2014 03:56:34 PM EST
  system internal:             0
  removable:                   1
  has media:                   1 (detected at Sat 04 Jan 2014 03:56:34 PM EST)
    detects change:            1
    detection by polling:      1
    detection inhibitable:     1
    detection inhibited:       0
  is read only:                0
  is mounted:                  0
  mount paths:             
  mounted by uid:              0
  presentation hide:           0
  presentation nopolicy:       0
  presentation name:           
  presentation icon:           multimedia-player
  automount hint:              
  size:                        1432354816
  block size:                  512
  job underway:                no
  usage:                       
  type:                        
  version:                     
  uuid:                        
  label:                       
  partition table:
    scheme:                    mbr
    count:                     1
  drive:
    vendor:                    Kindle
    model:                     Internal Storage
    revision:                  0100
    serial:                    90D42204345600JR
    WWN:                       
    detachable:                1
    can spindown:              0
    rotational media:          Yes, unknown rate
    write-cache:               unknown
    ejectable:                 0
    adapter:                   Unknown
    ports:
    similar devices:
    media:                     
      compat:                 
    interface:                 usb
    if speed:                  480000000 bits/s
    ATA SMART:                 not available

因此，我想知道是否需要检查一个IdLabel和IdUsage是否足以假定某个东西是USB大容量存储设备。

Answer 1

如果您可以使用UDisks2 DBus接口，答案将非常简单:-)首先，似乎UDisks2（可能还有UDisks1，但我尚未安装）仅处理通过USB连接的海量存储设备，而完全忽略了USB -连接的MTP设备和其他类型的USB设备，例如打印机和鼠标。 看一看：

现在我已经连接了6个USB设备：

alex@galene ~ $ /usr/sbin/lsusb | grep -v 'root hub'
Bus 001 Device 004: ID 058f:6362 Alcor Micro Corp. Flash Card Reader/Writer
Bus 001 Device 003: ID 09da:000a A4 Tech Co., Ltd Optical Mouse Opto 510D
Bus 008 Device 090: ID 04e8:6860 Samsung Electronics Co., Ltd GT-I9100 Phone [Galaxy S II], GT-P7500 [Galaxy Tab 10.1]
Bus 008 Device 075: ID 04b8:0007 Seiko Epson Corp. Printer
Bus 009 Device 002: ID 058f:6387 Alcor Micro Corp. Flash Drive
Bus 009 Device 088: ID 1058:1010 Western Digital Technologies, Inc. Elements External HDD

058f：6362是一个“多合一”读卡器，带有当前插入的SD卡。058f：6387和1058：1010分别是真正的USB Mass Storage开发人员，闪存和外部HDD。 04e8：6860是Samsung Galaxy Note1（一种MTP设备），其余是鼠标和打印机。

我也有一个内部SATA驱动器。

这是当前udisksctl status输出（您可能会看到缺少Galaxy Note）：

MODEL                     REVISION  SERIAL               DEVICE
--------------------------------------------------------------------------
Hitachi HDT725040VLA360   V5COA7EA  VFM301R3196R5F       sda     
Generic Flash Disk        8.07      8D0147DF             sdb     
WDC WD1200BEVS-22RST0     04.01G04  WD-WXE108V72690      sdc     
Generic USB CF Reader     1.01      058F312D81B          sde     
Generic USB SM Reader     1.02      058F312D81B          sdf     
Generic USB MS Reader     1.03      058F312D81B          sdg     
Generic USB SD Reader     1.00      058F312D81B          sdd

为了区分可插拔USB大容量存储设备与固定驱动器，可以检查“ ConnectedBus”和“可移动”属性。 请注意，还有另一个属性“ MediaRemovable”，它对应于设备的物理媒体。 这是选择可移动USB Mass Storage设备并打印其“ MediaRemovable”属性的脚本

alex@galene ~ $ cat <<EOF | python -
> import dbus
> bus = dbus.SystemBus()
> ud_manager_obj = bus.get_object('org.freedesktop.UDisks2', '/org/freedesktop/UDisks2')
> om = dbus.Interface(ud_manager_obj, 'org.freedesktop.DBus.ObjectManager')
> for k,v in om.GetManagedObjects().iteritems():
>     drive_info = v.get('org.freedesktop.UDisks2.Drive', {})
>     if drive_info.get('ConnectionBus') == 'usb' and drive_info.get('Removable'):
>         print("Device Path: %s, MediaRemovable: %s" % (k, drive_info['MediaRemovable']))
> block_devices =  [''.join(chr(c) for c in device[dbus.String(u'org.freedesktop.UDisks2.Block')][dbus.String(u'PreferredDev‌​ice')] if chr(c) != '\x00' ) for device in om.GetManagerObjects().values() if dbus.String(u'org.freedesktop.UDisks2.Block') in device]
> EOF
Device Path: /org/freedesktop/UDisks2/drives/Generic_USB_SM_Reader_058F312D81B, MediaRemovable: 1
Device Path: /org/freedesktop/UDisks2/drives/Generic_Flash_Disk_8D0147DF, MediaRemovable: 1
Device Path: /org/freedesktop/UDisks2/drives/Generic_USB_SD_Reader_058F312D81B, MediaRemovable: 1
Device Path: /org/freedesktop/UDisks2/drives/WDC_WD1200BEVS_22RST0_WD_WXE108V72690, MediaRemovable: 0
Device Path: /org/freedesktop/UDisks2/drives/Generic_USB_CF_Reader_058F312D81B, MediaRemovable: 1
Device Path: /org/freedesktop/UDisks2/drives/Generic_USB_MS_Reader_058F312D81B, MediaRemovable: 1

基本上，它可以解决您要解决的问题。 USB-connected storage devices but I haven't seen such. 有传言说，存在 USB连接存储设备，但我还没有看到。