> Another thing is, the st_dev situation has to be kept, as there are too many > legacy programs that relies on this to distinguish btrfs subvolume > boundaries, this would never be changed unfortunately, even if we had some > better solution (like the proposed extra subvolid through statx). It would retain backwards compatibility as userspace would need to explicitly query for STATX_SUBVOLUME otherwise they get they fake st_dev. > Which I believe the per-subvolume-vfsmount and the automount behavior for > subvolume can help a lot. Very much opposed to this at this point. I've seen the code for this in the prior patchset and it's implication nothing about this makes me want this.
