I've got another example of bind mounts resulting in confusing (incorrect) information in the mount command with Btrfs. In this case, it's Docker using bind mounts.
Full raw version (expires in 7 days) https://paste.fedoraproject.org/paste/r8tr-3nuvoycwxf0bPUrmA/raw Relevant portion: mount shows: /dev/mmcblk0p3 on /var/lib/docker/containers type btrfs (rw,noatime,seclabel,compress-force=zstd,ssd,space_cache=v2,subvolid=265,subvol=/root/var/lib/docker/containers) /dev/mmcblk0p3 on /var/lib/docker/btrfs type btrfs (rw,noatime,seclabel,compress-force=zstd,ssd,space_cache=v2,subvolid=265,subvol=/root/var/lib/docker/btrfs) And from the detail fpaste, you can see there is no such subvolume docker/btrfs or docker/containers - and subvolid=265 is actually for rootfs. Anyway, mortals will be confused by this behavior. -- Chris Murphy