+ /*
+ * For the initial read, we must guess at the sector
+ * size based on the block device. It's enough to
+ * get the sb_sectsize out of the superblock and
+ * then reread with the proper length.
+ * We don't verify it yet, because it may not be complete.
+ */
+ sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
+ buf_ops = NULL;
+