[PATCH 4/6] xfs: add DAX truncate support

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

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@xxxxxxxxxx>
---
 fs/xfs/xfs_iops.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 9f38142..3ff24c3 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_dax);
+       else
+               error = block_truncate_page(inode->i_mapping, newsize,
+                                           xfs_get_blocks);
        if (error)
                return error;
        truncate_setsize(inode, newsize);
-- 
2.0.0