| Message ID | 20201202214145.1563433-1-ira.weiny@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | common/rc: Fix _check_s_dax() | expand |
On Wed, Dec 02, 2020 at 01:41:45PM -0800, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > 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@redhat.com/ > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > --- > > 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.
On 12/3/20 2:15 AM, Christoph Hellwig wrote: > On Wed, Dec 02, 2020 at 01:41:45PM -0800, ira.weiny@intel.com wrote: >> From: Ira Weiny <ira.weiny@intel.com> >> >> 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@redhat.com/ >> >> Signed-off-by: Ira Weiny <ira.weiny@intel.com> >> --- >> >> 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
On Thu, Dec 03, 2020 at 11:55:50AM -0600, Eric Sandeen wrote: > *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. Yes, that's what I'd prefer.
On Thu, Dec 03, 2020 at 07:08:39PM +0100, Christoph Hellwig wrote: > On Thu, Dec 03, 2020 at 11:55:50AM -0600, Eric Sandeen wrote: > > *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. > > Yes, that's what I'd prefer. Sorry for the misunderstanding. V3 on it's way. Ira
diff --git a/common/rc b/common/rc index b5a504e0dcb4..322e682e5239 100644 --- a/common/rc +++ b/common/rc @@ -3221,11 +3221,24 @@ _check_s_dax() local exp_s_dax=$2 local attributes=$($XFS_IO_PROG -c 'statx -r' $target | awk '/stat.attributes / { print $3 }') - if [ $exp_s_dax -eq 0 ]; then - (( attributes & 0x2000 )) && echo "$target has unexpected S_DAX flag" - else - (( attributes & 0x2000 )) || echo "$target doesn't have expected S_DAX flag" - fi + + # The attribute bit value, STATX_ATTR_DAX (0x2000), conflicted with + # STATX_ATTR_MOUNT_ROOT. Therefore, STATX_ATTR_DAX was changed to + # 0x00200000. + # + # 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. + + if [ $(( attributes & 0x00200000 )) -ne 0 ] || [ $(( attributes & 0x2000 )) -ne 0 ]; then + if [ $exp_s_dax -eq 0 ]; then + echo "$target has unexpected S_DAX flag" + fi + else + if [ $exp_s_dax -ne 0 ]; then + echo "$target doesn't have expected S_DAX flag" + fi + fi } _check_xflag()