Udisks
Related articles
udisks provides a daemon udisksd, that implements D-Bus interfaces used to query and manipulate storage devices, and a command-line tool udisksctl, used to query and use the daemon.
Contents
Installation
There are two versions of udisks called udisks and udisks2. Development of udisks has ceased in favor of udisks2. [1]
udisksd (udisks2) and udisks-daemon (udisks) are started on-demand by D-Bus, and should not be enabled explicitly (see man udisksd
and man udisks-daemon
). They can be controlled through the command-line with udisksctl and udisks, respectively. See man udisksctl
and man udisks
for more information.
Configuration
Actions a user can perform using udisks are restricted with Policykit. If your session is not activated or present, configure policykit manually. The following file sets common udisks permissions for the storage
group. [2]
/etc/polkit-1/rules.d/50-udisks.rules
polkit.addRule(function(action, subject) { var YES = polkit.Result.YES; var permission = { // only required for udisks1: "org.freedesktop.udisks.filesystem-mount": YES, "org.freedesktop.udisks.filesystem-mount-system-internal": YES, "org.freedesktop.udisks.luks-unlock": YES, "org.freedesktop.udisks.drive-eject": YES, "org.freedesktop.udisks.drive-detach": YES, // only required for udisks2: "org.freedesktop.udisks2.filesystem-mount": YES, "org.freedesktop.udisks2.filesystem-mount-system": YES, "org.freedesktop.udisks2.encrypted-unlock": YES, "org.freedesktop.udisks2.eject-media": YES, "org.freedesktop.udisks2.power-off-drive": YES, // required for udisks2 if using udiskie from another seat (e.g. systemd): "org.freedesktop.udisks2.filesystem-mount-other-seat": YES, "org.freedesktop.udisks2.encrypted-unlock-other-seat": YES, "org.freedesktop.udisks2.eject-media-other-seat": YES, "org.freedesktop.udisks2.power-off-drive-other-seat": YES }; if (subject.isInGroup("storage")) { return permission[action.id]; } });
See [3] for a more restrictive example. Note the org.freedesktop.udisks2.filesystem-*
settings, which are required to start udiskie from a systemd service.
Mount helpers
Automatic mounting of devices is easily achieved with udisks wrappers. See also List of applications#Mount tools and File manager functionality#Mounting.
Devmon
udevil includes devmon, which is compatible to udisks and udisks2. It uses mount helpers with the following priority:
- udevil (SUID)
- pmount (SUID)
- udisks
- udisks2
To mount devices with udisks or udisks2, remove the SUID permission from udevil:
# chmod -s /usr/bin/udevil
inotify
You may use inotify-tools to monitor /dev
, and mount drives when a new block device is created. Stale mount points are automatically removed by udisksd, such that no special action is required on deletion.
#!/bin/bash inotifywait --monitor --event create,delete --format '%e %w%f' /dev | while read event file; do pattern='sd[b-z][1-9]$' if [[ $file =~ $pattern ]]; then case $event in CREATE) echo "Settling..." sleep 1 udisksctl mount --block-device $file --no-user-interaction ;; DELETE) ;; esac fi done
Tips and tricks
Disable hiding of devices (udisks2)
Udisks2 hides certain devices from the user by default. If this is undesired or otherwise problematic, copy /usr/lib/udev/rules.d/80-udisks2.rules
to /etc/udev/rules.d/80-udisks2.rules
and remove the following section in the copy:
# ------------------------------------------------------------------------ # ------------------------------------------------------------------------ # ------------------------------------------------------------------------ # Devices which should not be display in the user interface [...]
Mount to /media (udisks2)
By default, udisks2 mounts removable drives under the ACL controlled directory /run/media/$USER/
. If you wish to mount to /media
instead, use this rule:
/etc/udev/rules.d/99-udisks2.rules
# UDISKS_FILESYSTEM_SHARED # ==1: mount filesystem to a shared directory (/media/VolumeName) # ==0: mount filesystem to a private directory (/run/media/$USER/VolumeName) # See udisks(8) ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{UDISKS_FILESYSTEM_SHARED}="1"
Mount an ISO image
To easily mount ISO images, use the following command:
$ udisksctl loop-setup -r -f image.iso
This will create a loop device and show the ISO image ready to mount. Once unmounted, the loop device will be terminated by udev.
Hide selected partitions
If you wish to prevent certain partitions or drives appearing on the desktop, you can create a udev rule, for example /etc/udev/rules.d/10-local.rules
:
KERNEL=="sda1", ENV{UDISKS_PRESENTATION_HIDE}="1" KERNEL=="sda2", ENV{UDISKS_PRESENTATION_HIDE}="1"
shows all partitions with the exception of sda1
and sda2
on your desktop. Notice if you are using udisks2 the above will not work as UDISKS_PRESENTATION_HIDE
is no longer supported. Instead use UDISKS_IGNORE
as follows:
KERNEL=="sda1", ENV{UDISKS_IGNORE}="1" KERNEL=="sda2", ENV{UDISKS_IGNORE}="1"
Troubleshooting
udisks: Devices do not remain unmounted
udisks remounts devices after a given period, or polls those devices. This can cause unexpected behaviour, for example when formatting drives, sharing them in a virtual machine, power saving, or removing a drive that was not detached with --detach
before.
To disable polling for a given device, for example a CD/DVD device:
# udisks --inhibit-polling /dev/sr0
or for all devices:
# udisks --inhibit-all-polling
See man udisks
for more information.