Eric Sandeen [off-list ref] wrote:

-	if (IS_DAX(inode))
-		stat->attributes |= STATX_ATTR_DAX;
-

This could probably be left in and not distributed amongst the filesytems
provided that any filesystem that might turn it on sets the bit in the
attributes_mask.

I'm presuming that the core doesn't turn it on without the filesystem buying
in.

David