On Wed, Dec 02, 2020 at 01:41:45PM -0800, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > There is a conflict with the user visible statx bits 'mount root' and > 'dax'. The kernel is changing the dax bit to correct this conflict.[1] > > Adjust _check_s_dax() to use the new bit. Because DAX tests do not run > on root mounts, STATX_ATTR_MOUNT_ROOT should always be 0, therefore we > can allow either bit to indicate DAX and cover any kernel which may be > running. > > [1] https://lore.kernel.org/lkml/3e28d2c7-fbe5-298a-13ba-dcd8fd504666@xxxxxxxxxx/ > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > --- > > I went ahead and used Christoph's suggestion regarding using both bits. That wasn't my suggestion. I think we should always error out when the bit value shared with STATX_ATTR_MOUNT_ROOT is seen. Because that means the kernel is not using or fixed ABI we agreed to use going forward.
