xfs: don't mix reflink and DAX mode for now

Since we don't have a strategy for handling both DAX and reflink,
for now we'll just prohibit both being set at the same time.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

4 files changed, 13 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index f1b9d97c540f..8de9a3a29589 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -407,6 +407,10 @@ xfs_dinode_verify(
         if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
                 return false;
 
+        /* don't let reflink and dax mix */
+        if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
+                return false;
+
         return true;
 }
 
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 0726df88bce2..54c27edb74bc 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1055,6 +1055,10 @@ xfs_file_share_range(
         if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
                 return -EINVAL;
 
+        /* Don't share DAX file data for now. */
+        if (IS_DAX(inode_in) || IS_DAX(inode_out))
+                return -EINVAL;
+
         /* Are we going all the way to the end? */
         isize = i_size_read(inode_in);
         if (isize == 0)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index c65d9eacf54d..8b9f31c54c1e 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1038,6 +1038,10 @@ xfs_ioctl_setattr_xflags(
         if ((fa->fsx_xflags & FS_XFLAG_REALTIME) && xfs_is_reflink_inode(ip))
                 return -EINVAL;
 
+        /* Don't allow us to set DAX mode for a reflinked file for now. */
+        if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip))
+                return -EINVAL;
+
         /*
          * Can't modify an immutable/append-only file unless
          * we have appropriate permission.
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index b24c3102fa93..5945b64f77cc 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1144,6 +1144,7 @@ xfs_diflags_to_iflags(
                 inode->i_flags |= S_NOATIME;
         if (S_ISREG(inode->i_mode) &&
             ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
+            !xfs_is_reflink_inode(ip) &&
             (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
              ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
                 inode->i_flags |= S_DAX;