50mounted-tests prevents os-prober to work with ThinLVM

[Guillaume]

No os-prober entries are added to grub.cfg for alternates systems on ThinLVM, because of an issue with /usr/lib/linux-boot-probes/50mounted-tests.

Updating line 55 from :
    type="$(grub-probe -d "$partition" -t fs)"
to
    type="$(grub-probe -d "$partition" -t fs || echo bad)"
fixes the issue.

Credit is due to mikeaa on bug #1987679.

Tested on Ubuntu 24.04.

[Guillaume (e1msih)]

It indeed also leaves the systems mounted rw on /var/lib/os-prober/mount : (sys2 is the alternate volume group and system)

# lsof /dev/sys2/rootfs
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
grub-moun 65856 root 3r BLK 252,26 0t37912576 1107 /dev/sys2/../dm-26

# ps -ef |grep grub
root 65856 1 0 13:05 ? 00:00:00 grub-mount /dev/mapper/sys2-rootfs /var/lib/os-prober/mount

[Guillaume (e1msih)]

Ubuntu 22.04 is also in need of this fix.

[Guillaume (e1msih)]

Sorry, i misread bug #1987679, i thought it was closed.

[Guillaume (e1msih)]

FYI, this bug concerns Ubuntu 20.04 to 24.04.