Device widget bug

tempmail · August 18, 2024, 11:21am

This is ancient bug, at least for me, both under 4.1 and 4.2.

Namely, when I attach storage device as USB to a qube, it gets lost from the qui-device widget list.

systemctl --user restart qubes-widget@qui-devices.service

won’t bring it back (“Failed to connect to bus: No medium found”)

or

$ systemctl --user restart qubes-widget@qui-devices.service

won’t bring it back (restarts service but to no avail), neither terminating qui-device from GUI task manager works.

It gets back either upon restarting correspondent sys-usb, or upon Qubes restart (which logically implies restarting sys-usb actually).

This is completely annoying for several years, so if anyone knows the solution for dummies, please let me know. If not, can someone place the issue on Github, since I don’t have an account there. Thanks.

apparatus · August 18, 2024, 11:59am

Can you post the service log in dom0?

journalctl --user -u qubes-widget@qui-devices.service

tempmail · August 18, 2024, 12:33pm

I have corrected OP, so now the log as expected shows

Aug 18 08:32:50 dom0 systemd[2386]: Stopping qubes-widget@qui-devices.service - Qubes Widget service…
Aug 18 08:32:50 dom0 systemd[2386]: Stopped qubes-widget@qui-devices.service - Qubes Widget service.
Aug 18 08:32:50 dom0 systemd[2386]: qubes-widget@qui-devices.service: Consumed 2.107s CPU time.
Aug 18 08:32:50 dom0 systemd[2386]: Started qubes-widget@qui-devices.service - Qubes Widget service.

but widget doesn’t reappear the device, anyway.

apparatus · August 18, 2024, 12:39pm

Can you check the journalctl log in dom0 at the time when you attached the device and it disappeared from the list?
Maybe there are some related messages.

Or restart Qubes OS, run this command in dom0:

journalctl -f -n0

And try to attach the USB device to the qube so it’ll disappear and post the resulting log.

tempmail · September 29, 2024, 1:29pm

Well, it happens with the block devices too.

When I attach them as block devices: if I attach whole device, its partitions get lost. If I attach partition, whole device get lost and only that partition remains visible attached and after when detached.

No one else experience this?

I’m using sys-usb minimals based on fedora, regardless of its version.

tempmail · September 29, 2024, 1:43pm

lsblk, however, sees them all in sys-usb, and in destined qube to which they are attachetd to, and partitions can be mounted manually in the latter.

So it has to be something with dom0/widget

apparatus · September 29, 2024, 7:07pm

I’ve tried it myself and I can reproduce it, but it’s not specific to the device widget, CLI tools work the same way.
I couldn’t find a github issue related to this bug so I guess it should be reported on github.

tempmail · September 29, 2024, 7:16pm

Thanks! UInfortunately, I don’t have a github account…

tempmail · September 29, 2024, 7:21pm

I forgot to say that numerous instances of a single error are logged while attaching.

dom0 qubesd[116829]: socket.send() raised exception.

So, it seems it’s something with qubesd…

apparatus · November 9, 2024, 11:27am

I’ve created the issue for this:

github.com/QubesOS/qubes-issues

The hidden block devices due to attachment are not restored after detachment

opened 11:26AM - 09 Nov 24 UTC

apparatius

T: bug P: default

[How to file a helpful issue](https://www.qubes-os.org/doc/issue-tracking/) #…## Qubes OS release R4.2.3 ### Brief summary When block device e.g. /dev/sda has multiple partitions and you attach a single partition e.g. /dev/sda1 to another qube, then block device /dev/sda is removed from the list of block devices available for attachment. And the same is when whole block device e.g. /dev/sda is being attached to another qube, then all partitions of this block device e.g. /dev/sda1 are removed from the list of block devices available for attachment. I guess this is to prevent the attachment of the same device to multiple qubes. The problems that after you detach the attached block device, the block devices removed to prevent the attachment of the same device to multiple qubes won't be available for attachment anymore. If you run `partprobe` in the source qube to refresh the block device info after detachment, then it'll restore the missing block devices in the list of block devices available for attachment. Maybe related: https://github.com/QubesOS/qubes-issues/issues/4692 ### Steps to reproduce In disposable qube disp1234 run these commands: ``` dd if=/dev/zero of=/tmp/tst.img bs=1M count=128 dev=$(sudo losetup -f --show /tmp/tst.img) sudo sgdisk -n 0:0:+64MiB $dev sudo sgdisk -n 0:0: $dev sudo partprobe $dev ``` Check the available block devices in dom0: ``` [user@dom0 ~]$ qvm-block BACKEND:DEVID DESCRIPTION USED BY disp1234:loop0 /tmp/tst.img disp1234:loop0p1 () disp1234:loop0p2 () ``` Attach a single partition of the loop device as block device in dom0 to another disposable qube: ``` qvm-block attach disp4321 disp1234:loop0p1 ``` Check the available block devices in dom0: ``` [user@dom0 ~]$ qvm-block BACKEND:DEVID DESCRIPTION USED BY disp1234:loop0p1 () disp4321 (read-only=no, frontend-dev=xvdi) disp1234:loop0p2 () ``` Detach the block device: ``` qvm-block detach disp4321 disp1234:loop0p1 ``` Check the available block devices in dom0: ### Expected behavior ``` [user@dom0 ~]$ qvm-block BACKEND:DEVID DESCRIPTION USED BY disp1234:loop0 /tmp/tst.img disp1234:loop0p1 () disp1234:loop0p2 () ``` ### Actual behavior ``` [user@dom0 ~]$ qvm-block BACKEND:DEVID DESCRIPTION USED BY disp1234:loop0p1 () disp1234:loop0p2 () ```

tempmail · November 9, 2024, 7:19pm

Thanks. I think complete device widget needs rewrite, or qubesd need major fix. Remember that, UNLIKE this, losetup devices won’t get lost after detachment, hahah