Growfs fails on Debian 11 with btrfs

[remyzandwijk]

The script loc-05-grow-rootsfs fails on a vanilla install of Debian 11 with btrfs. /var/log/messages:

Dec 7 11:38:27 debian-BASE one-contextd[1178]: Script loc-05-grow-rootfs output: GROWFS: No such mountpoint: /

The root filesystem in /proc/mounts looks like this:

root@debian-BASE:~# grep btrfs /proc/mounts
/dev/vda1 / btrfs rw,relatime,space_cache,subvolid=256,subvol=/@rootfs 0 0

Note the subvol=/@rootfs part.

The script fails due to this block of code:

MOUNT_LINE=$(\
        if [ -e /proc/mounts ] ; then \
            cat /proc/mounts ; \
        else \
            cat /etc/mtab ; \
        fi | awk -v grow_fs="${_FS}" '
            {if (($0 !~ /rootfs/) && ($2 == grow_fs)) print $1, $3;}
        ')

MOUNT_LINE is empty due to the fact that lines containing 'rootfs' are filtered out, causing the partition which holds the rootfs cannot be found.

No patch attached since I am not sure why the rootfs lines are being filtered out.