Package: os-prober
Version: 1.78
Severity: normal
Issue:
Currently Debian os-prober support only btrfs root-filesystem on the root of
the btrfs, i.e., ID 5 (FS_TREE). This makes auto generated grub.cfg to miss
Linux install to btrfs for some Ubuntu and Suse since they put root-system
under @ subvolume.
Existing patch in other distro:
Ubuntu ships patched os-prober 1.77 to address its subvolume use (@ as root-
filesystem) with hardcoded path and very rudamental check for /lib directory.
--------
diff -pruN 1.77/linux-boot-probes/common/50mounted-tests 1.77ubuntu1/linux-
boot-probes/common/50mounted-tests
--- 1.77/linux-boot-probes/common/50mounted-tests 2018-08-10
19:23:18.000000000 +0000
+++ 1.77ubuntu1/linux-boot-probes/common/50mounted-tests 2020-11-02
11:12:51.000000000 +0000
@@ -54,6 +54,19 @@ if type grub-mount >/dev/null 2>&1 && \
mounted=1
type="$(grub-probe -d "$partition" -t fs)"
[ "$type" ] || type=fuseblk
+
+ case "$type" in
+ btrfs)
+ if [ -x "$tmpmnt/@/lib" ] && \
+ ! mount --bind "$tmpmnt/@" "$tmpmnt"; then
+ warn "failed to mount btrfs subvolume @ on
$partition"
+ if ! umount $tmpmnt; then
+ warn "failed to umount $tmpmnt"
+ fi
+ mounted=
+ fi
+ ;;
+ esac
fi
if [ "$mounted" ]; then
------
Discussion:
Since we should offer the choice for the subbvolume name, this hardcoding "@"
here is not elegant. We should get it as:
-----
RSUBVOL=$(btrfs subvolume get-default $tmpmnt |cut -d' ' -f 9)
-----
Proposed fix:
So updated patch should be more like
---
+ case "$type" in
+ btrfs)
+ RSUBVOL=$(btrfs subvolume get-default $tmpmnt |cut -d'
' -f 9)
+ if [ -n "$RSUBVOL" ] && [ -x "$tmpmnt/$RSUBVOL/lib" ]
&& \
+ ! mount --bind "$tmpmnt/$RSUBVOL" "$tmpmnt"; then
+ warn "failed to mount btrfs subvolume $RSUBVOL
on $partition"
+ if ! umount $tmpmnt; then
+ warn "failed to umount $tmpmnt"
+ fi
+ mounted=
+ fi
+ ;;
+ esac
---
This is much simpler patch than ones discussed in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=688336
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=699189
Since we expect any sane person set-default to the root-filesystem.
You could add fall-back with "elif" to use Ubuntu specific hardcoded subvolume
name.
This should make Debian friendly to older Ubuntu with btrfs.
What do you think?
Osamu
-- System Information:
Debian Release: bullseye/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Kernel: Linux 5.10.0-3-amd64 (SMP w/12 CPU threads)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8),
LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages os-prober depends on:
ii grub-common 2.04-15
ii libc6 2.31-9
os-prober recommends no packages.
os-prober suggests no packages.
-- no debconf information
