xfs: add DAX truncate support

When we truncate a DAX file, we need to call through the DAX page
truncation path rather than through block_truncate_page() so that
mappings and block zeroing are all handled correctly. Otherwise,
truncate does not need to change.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f4cd7204e236..0994f95c368f 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -851,7 +851,11 @@ xfs_setattr_size(
          * to hope that the caller sees ENOMEM and retries the truncate
          * operation.
          */
-        error = block_truncate_page(inode->i_mapping, newsize, xfs_get_blocks);
+        if (IS_DAX(inode))
+                error = dax_truncate_page(inode, newsize, xfs_get_blocks_direct);
+        else
+                error = block_truncate_page(inode->i_mapping, newsize,
+                                            xfs_get_blocks);
         if (error)
                 return error;
         truncate_setsize(inode, newsize);