On Mon, Nov 08, 2021 at 10:22:16AM +0800, Qu Wenruo wrote: > For kernel btrfs, it's not a big deal, as we will return different > st_dev for each subvolume. It is a big deal, as that behavior does break things and has been the source of constant troubnle and discussion. It needs to be fixed in btrfs eventually and absolutely not spread any further.