I can see that I have space on the volume group, so as to extend the logical volume where root / filesystem is mounted.
I know that after extending the logical volume, the btrfs filesystem needs to be updated, or resized to the new size I have never extended this kind of filesystem.
Do you know what are the steps to do this?
After resizing the logical volume with lvextend
I think this command would make increase the filesystem:
btrfs filesystem resize SIZE /mnt