UnionFS: how to transfer overlay / uppercase changes to base / lowerdir filesystem?

Suppose you have the following scenario on Linux:

• Ext4 data partition set read-only: data_ro
  
  
• Overlay section: data_overlay
  
  
• Two of them are merged into UnionW: mount -t overlayfs -o lowerdir=data_ro,upperdir=data_overlay overlayfs data
  
  

At some point in time, you need to save the changes from data_overlay

to data_ro

(obviously, the data_ro

R / W would be restarted in this case, and then the R / O would be reinstalled back).

How can I save changes to overlay / upperdir in base / lowerdir filesystem?

Is it compatible with going from overlay to base FS like the following sequence of commands?

umount data
mount -o remount,rw data_ro
mv -rf data_overlay data_ro
mount -o remount,ro data_ro
mount -t overlayfs -o lowerdir=data_ro,upperdir=data_overlay overlayfs data