一般ユーザーが断続的なブロックに書き込むことを許可する

現在、私はハードドライブからディスクイメージを頻繁にコピーしています。通常はUSB経由で接続されます。

通常、ブロックデバイスは通常のユーザが書くことができないため、すべての操作をrootとして実行します。いつか私が/dev/sda本当に欲しい人に手紙を書くミスを犯すのではないかと心配です/dev/sds。

GNU / Linuxに「書き込み禁止」を指示する方法はありますか/dev/sda？または、グループのユーザーがすべてのUSBブロックデバイスに書き込むことを許可する方法はありますかusbwriters？

保護したいブロックデバイスを簡単に一覧表示できます。ただし、書きたいデバイスは通常USB一時接続を使用しているため、リストできません。

以下は、デバイスの1つのudev出力です。

# /sbin/udevadm info -a -p $(/sbin/udevadm info -q path -n /dev/sdn)

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/host16/target16:0:0/16:0:0:1/block/sdn':
    KERNEL=="sdn"
    SUBSYSTEM=="block"
    DRIVER==""
    ATTR{alignment_offset}=="0"
    ATTR{capability}=="d1"
    ATTR{discard_alignment}=="0"
    ATTR{events}=="media_change"
    ATTR{events_async}==""
    ATTR{events_poll_msecs}=="-1"
    ATTR{ext_range}=="256"
    ATTR{hidden}=="0"
    ATTR{inflight}=="       0        0"
    ATTR{range}=="16"
    ATTR{removable}=="1"
    ATTR{ro}=="0"
    ATTR{size}=="13563904"
    ATTR{stat}=="      77        0     4168      224        0        0        0        0        0      140      224"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/host16/target16:0:0/16:0:0:1':
    KERNELS=="16:0:0:1"
    SUBSYSTEMS=="scsi"
    DRIVERS=="sd"
    ATTRS{blacklist}=="FORCELUN"
    ATTRS{device_blocked}=="0"
    ATTRS{device_busy}=="0"
    ATTRS{dh_state}=="detached"
    ATTRS{eh_timeout}=="10"
    ATTRS{evt_capacity_change_reported}=="0"
    ATTRS{evt_inquiry_change_reported}=="0"
    ATTRS{evt_lun_change_reported}=="0"
    ATTRS{evt_media_change}=="0"
    ATTRS{evt_mode_parameter_change_reported}=="0"
    ATTRS{evt_soft_threshold_reached}=="0"
    ATTRS{inquiry}==""
    ATTRS{iocounterbits}=="32"
    ATTRS{iodone_cnt}=="0x81"
    ATTRS{ioerr_cnt}=="0x1"
    ATTRS{iorequest_cnt}=="0x81"
    ATTRS{max_sectors}=="240"
    ATTRS{model}=="USB Flash Disk  "
    ATTRS{queue_depth}=="1"
    ATTRS{queue_type}=="none"
    ATTRS{rev}=="1100"
    ATTRS{scsi_level}=="5"
    ATTRS{state}=="running"
    ATTRS{timeout}=="30"
    ATTRS{type}=="0"
    ATTRS{vendor}=="General "

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/host16/target16:0:0':
    KERNELS=="target16:0:0"
    SUBSYSTEMS=="scsi"
    DRIVERS==""

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0/host16':
    KERNELS=="host16"
    SUBSYSTEMS=="scsi"
    DRIVERS==""

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1:1.0':
    KERNELS=="3-1:1.0"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb-storage"
    ATTRS{authorized}=="1"
    ATTRS{bAlternateSetting}==" 0"
    ATTRS{bInterfaceClass}=="08"
    ATTRS{bInterfaceNumber}=="00"
    ATTRS{bInterfaceProtocol}=="50"
    ATTRS{bInterfaceSubClass}=="06"
    ATTRS{bNumEndpoints}=="02"
    ATTRS{supports_autosuspend}=="1"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3/3-1':
    KERNELS=="3-1"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="00"
    ATTRS{bDeviceProtocol}=="00"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="300mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bcdDevice}=="1100"
    ATTRS{bmAttributes}=="80"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="29"
    ATTRS{devpath}=="1"
    ATTRS{idProduct}=="1000"
    ATTRS{idVendor}=="090c"
    ATTRS{ltm_capable}=="no"
    ATTRS{manufacturer}=="General"
    ATTRS{maxchild}=="0"
    ATTRS{product}=="USB Flash Disk"
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="removable"
    ATTRS{serial}=="FBK1611110100145"
    ATTRS{speed}=="480"
    ATTRS{urbnum}=="981"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/pci0000:00/0000:00:14.0/usb3':
    KERNELS=="usb3"
    SUBSYSTEMS=="usb"
    DRIVERS=="usb"
    ATTRS{authorized}=="1"
    ATTRS{authorized_default}=="1"
    ATTRS{avoid_reset_quirk}=="0"
    ATTRS{bConfigurationValue}=="1"
    ATTRS{bDeviceClass}=="09"
    ATTRS{bDeviceProtocol}=="01"
    ATTRS{bDeviceSubClass}=="00"
    ATTRS{bMaxPacketSize0}=="64"
    ATTRS{bMaxPower}=="0mA"
    ATTRS{bNumConfigurations}=="1"
    ATTRS{bNumInterfaces}==" 1"
    ATTRS{bcdDevice}=="0415"
    ATTRS{bmAttributes}=="e0"
    ATTRS{busnum}=="3"
    ATTRS{configuration}==""
    ATTRS{devnum}=="1"
    ATTRS{devpath}=="0"
    ATTRS{idProduct}=="0002"
    ATTRS{idVendor}=="1d6b"
    ATTRS{interface_authorized_default}=="1"
    ATTRS{ltm_capable}=="no"
    ATTRS{manufacturer}=="Linux 4.15.0-96-generic xhci-hcd"
    ATTRS{maxchild}=="4"
    ATTRS{product}=="xHCI Host Controller"
    ATTRS{quirks}=="0x0"
    ATTRS{removable}=="unknown"
    ATTRS{serial}=="0000:00:14.0"
    ATTRS{speed}=="480"
    ATTRS{urbnum}=="918"
    ATTRS{version}==" 2.00"

  looking at parent device '/devices/pci0000:00/0000:00:14.0':
    KERNELS=="0000:00:14.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="xhci_hcd"
    ATTRS{broken_parity_status}=="0"
    ATTRS{class}=="0x0c0330"
    ATTRS{consistent_dma_mask_bits}=="64"
    ATTRS{d3cold_allowed}=="1"
    ATTRS{device}=="0x1e31"
    ATTRS{dma_mask_bits}=="64"
    ATTRS{driver_override}=="(null)"
    ATTRS{enable}=="1"
    ATTRS{irq}=="24"
    ATTRS{local_cpulist}=="0-7"
    ATTRS{local_cpus}=="ff"
    ATTRS{msi_bus}=="1"
    ATTRS{numa_node}=="-1"
    ATTRS{revision}=="0x04"
    ATTRS{subsystem_device}=="0x0686"
    ATTRS{subsystem_vendor}=="0x1025"
    ATTRS{vendor}=="0x8086"

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""