-extern struct address_space_operations affs_symlink_aops;
-extern struct address_space_operations affs_aops;
-extern struct address_space_operations affs_aops_ofs;
+extern const struct address_space_operations affs_symlink_aops;
+extern const struct address_space_operations affs_aops;
+extern const struct address_space_operations affs_aops_ofs;