On 12/3/20 2:15 AM, Christoph Hellwig wrote: > 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. *nod* and my suggestion was to explicitly test for the old/wrong value and offer the test-runner a hint about why it may have been set (missing the fix commit), but we should still ultimately fail the test when it is seen. -Eric