[feature request] Moving files or directory trees between subvolumes

[kode54]

You told me this was already sort of possible with reflinks, but that they become indirect references. The objective would be to un-indirect them?

Basically, to be able to reorganize the structure of a bcachefs volume and move files or directory trees out of one subvolume and into another, to save the effort of having to completely reformat and migrate contents to dodge what was likely a bad choice of subvol structure.

I currently have:

/ /root /home /srv /var/cache /var/log /var/tmp

I would likely be migrating to something that merges everything outside of the /var subvolumes, keeping just those ones so I'm not putting that crap into snapshots. Which also made me realize I also have snapshot trees of /, /root, /home, and /srv as well, though / and /home are the only ones really changing at all.

Just dropping this note here for future me or future you, something useful may come from implementing this.