Chagnes done to the rootfs do not redirect to the overlay set in fstab

Question

The fstab is a link to the next fstabB file:

    # <file system> <mount pt> <type> <options> <dump> <pass>
    /dev/root       /          ext2   ro,noauto 0       1
    proc            /proc      proc   defaults  0       0
    /dev/mmcblk0p10 /data      ext4   defaults  0       0
    overlay         /          overlay
    lowerdir=/,upperdir=/data/rfs_overlay,workdir=/data/rfs_overlay_work 0 0

the overlay does not take effect using the fstab and the mount command output does no contain any overlay line.

I tried changing the fstab line to :

    # <file system> <mount pt>         <type>  <options> <dump> <pass>
    overlay         /data/rfs_overlay  overlay
    lowerdir=/,upperdir=/data/rfs_overlay_upper,workdir=/data/rfs_overlay_work 0 0

Then, I get that line from the mount command :

    overlay on /data/rfs_overlay type overlay
    (rw,relatime,lowerdir=/,upperdir=/data/rfs_overlay_upper,workdir=/data/rfs_overlay_work)

However, when i try to create test.txt file in the rootfs I get the folowing resopnse:

    touch test.txt
    touch: test.txt: Read-only file system

It is to be noticed that if I change the rootfs to rw and than create the file on the rootfs, the file is created both in the roofs and in the overlay:

    mount -o remount,rw /
    touch test.txt
    find / -name test.txt
    /data/rfs_overlay/root/test.txt /root/test.txt

I tried the following links with no success: