Re: [PATCH 0/3] fanotify support for btrfs sub-volumes

Christian Brauner
2023-11-06T09:57:06Z

> 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.