From: Ira Weiny <[email protected]>
xfs_ioctl_setattr_dax_invalidate() currently checks if the DAX flag is
changing as a quick check.
But the implementation mixes the physical (XFS_DIFLAG2_DAX) and
effective (S_DAX) DAX flags.
Remove the use of the effective flag when determining if a change of the
physical flag is required.
Signed-off-by: Ira Weiny <[email protected]>
---
fs/xfs/xfs_ioctl.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index d58f0d6a699e..0ea326290cca 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1319,9 +1319,11 @@ xfs_ioctl_setattr_dax_invalidate(
}
/* If the DAX state is not changing, we have nothing to do here. */
- if ((fa->fsx_xflags & FS_XFLAG_DAX) && IS_DAX(inode))
+ if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
+ (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
return 0;
- if (!(fa->fsx_xflags & FS_XFLAG_DAX) && !IS_DAX(inode))
+ if (!(fa->fsx_xflags & FS_XFLAG_DAX) &&
+ !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
return 0;
if (S_ISDIR(inode->i_mode))
--
2.20.1
On Sun, Oct 20, 2019 at 08:59:32AM -0700, [email protected] wrote:
> From: Ira Weiny <[email protected]>
>
> xfs_ioctl_setattr_dax_invalidate() currently checks if the DAX flag is
> changing as a quick check.
>
> But the implementation mixes the physical (XFS_DIFLAG2_DAX) and
> effective (S_DAX) DAX flags.
More nuanced than that.
The idea was that if the mount option was set, clearing the
per-inode flag would override the mount option. i.e. the mount
option sets the S_DAX flag at inode instantiation, so using
FSSETXATTR to ensure the FS_XFLAG_DAX is not set would override the
mount option setting, giving applications a way of guranteeing they
aren't using DAX to access the data.
So if the mount option is going to live on, I suspect that we want
to keep this code as it stands.
Cheers,
Dave.
--
Dave Chinner
[email protected]