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/pci0000:00/0000:00:15.0/usb2/2-4/2-4:1.0/host3/target3:0:0/3:0:0:0/block/sdb': KERNEL=="sdb" SUBSYSTEM=="block" DRIVER=="" ATTR{alignment_offset}=="0" ATTR{capability}=="50" ATTR{discard_alignment}=="0" ATTR{events}=="" ATTR{events_async}=="" ATTR{events_poll_msecs}=="-1" ATTR{ext_range}=="256" ATTR{hidden}=="0" ATTR{inflight}==" 0 0" ATTR{range}=="16" ATTR{removable}=="0" ATTR{ro}=="0" ATTR{size}=="7814037167" ATTR{stat}==" 379 200 11527 1824 1 0 8 40 0 220 1864" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2/2-4/2-4:1.0/host3/target3:0:0/3:0:0:0': KERNELS=="3:0:0:0" SUBSYSTEMS=="scsi" DRIVERS=="sd" ATTRS{blacklist}=="" 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}=="0x1bb" ATTRS{ioerr_cnt}=="0x8" ATTRS{iorequest_cnt}=="0x1bb" ATTRS{model}=="Expansion " ATTRS{queue_depth}=="30" ATTRS{queue_type}=="simple" ATTRS{rev}=="9300" ATTRS{scsi_level}=="7" ATTRS{state}=="running" ATTRS{timeout}=="30" ATTRS{type}=="0" ATTRS{vendor}=="Seagate " ATTRS{vpd_pg80}=="" ATTRS{vpd_pg83}=="" ATTRS{wwid}=="naa.5000000000000001" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2/2-4/2-4:1.0/host3/target3:0:0': KERNELS=="target3:0:0" SUBSYSTEMS=="scsi" DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2/2-4/2-4:1.0/host3': KERNELS=="host3" SUBSYSTEMS=="scsi" DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2/2-4/2-4:1.0': KERNELS=="2-4:1.0" SUBSYSTEMS=="usb" DRIVERS=="uas" ATTRS{authorized}=="1" ATTRS{bAlternateSetting}==" 1" ATTRS{bInterfaceClass}=="08" ATTRS{bInterfaceNumber}=="00" ATTRS{bInterfaceProtocol}=="62" ATTRS{bInterfaceSubClass}=="06" ATTRS{bNumEndpoints}=="04" ATTRS{supports_autosuspend}=="0" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2/2-4': KERNELS=="2-4" 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}=="9" ATTRS{bMaxPower}=="144mA" ATTRS{bNumConfigurations}=="1" ATTRS{bNumInterfaces}==" 1" ATTRS{bcdDevice}=="0000" ATTRS{bmAttributes}=="80" ATTRS{busnum}=="2" ATTRS{configuration}=="" ATTRS{devnum}=="3" ATTRS{devpath}=="4" ATTRS{idProduct}=="2322" ATTRS{idVendor}=="0bc2" ATTRS{ltm_capable}=="no" ATTRS{manufacturer}=="Seagate" ATTRS{maxchild}=="0" ATTRS{product}=="Expansion" ATTRS{quirks}=="0x0" ATTRS{removable}=="removable" ATTRS{serial}=="NZ0E3577" ATTRS{speed}=="5000" ATTRS{urbnum}=="1308" ATTRS{version}==" 3.00" looking at parent device '/devices/pci0000:00/0000:00:15.0/usb2': KERNELS=="usb2" SUBSYSTEMS=="usb" DRIVERS=="usb" ATTRS{authorized}=="1" ATTRS{authorized_default}=="1" ATTRS{avoid_reset_quirk}=="0" ATTRS{bConfigurationValue}=="1" ATTRS{bDeviceClass}=="09" ATTRS{bDeviceProtocol}=="03" ATTRS{bDeviceSubClass}=="00" ATTRS{bMaxPacketSize0}=="9" ATTRS{bMaxPower}=="0mA" ATTRS{bNumConfigurations}=="1" ATTRS{bNumInterfaces}==" 1" ATTRS{bcdDevice}=="0417" ATTRS{bmAttributes}=="e0" ATTRS{busnum}=="2" ATTRS{configuration}=="" ATTRS{devnum}=="1" ATTRS{devpath}=="0" ATTRS{idProduct}=="0003" ATTRS{idVendor}=="1d6b" ATTRS{interface_authorized_default}=="1" ATTRS{ltm_capable}=="yes" ATTRS{manufacturer}=="Linux 4.17.2-041702-generic xhci-hcd" ATTRS{maxchild}=="7" ATTRS{product}=="xHCI Host Controller" ATTRS{quirks}=="0x0" ATTRS{removable}=="unknown" ATTRS{serial}=="0000:00:15.0" ATTRS{speed}=="5000" ATTRS{urbnum}=="59" ATTRS{version}==" 3.00" looking at parent device '/devices/pci0000:00/0000:00:15.0': KERNELS=="0000:00:15.0" SUBSYSTEMS=="pci" DRIVERS=="xhci_hcd" ATTRS{ari_enabled}=="0" ATTRS{broken_parity_status}=="0" ATTRS{class}=="0x0c0330" ATTRS{consistent_dma_mask_bits}=="64" ATTRS{d3cold_allowed}=="1" ATTRS{dbc}=="disabled" ATTRS{device}=="0x31a8" ATTRS{dma_mask_bits}=="64" ATTRS{driver_override}=="(null)" ATTRS{enable}=="1" ATTRS{index}=="6" ATTRS{irq}=="123" ATTRS{label}=="Onboard - Other" ATTRS{local_cpulist}=="0-3" ATTRS{local_cpus}=="f" ATTRS{msi_bus}=="1" ATTRS{numa_node}=="-1" ATTRS{revision}=="0x03" ATTRS{subsystem_device}=="0x2072" ATTRS{subsystem_vendor}=="0x8086" ATTRS{vendor}=="0x8086" looking at parent device '/devices/pci0000:00': KERNELS=="pci0000:00" SUBSYSTEMS=="" DRIVERS==""