+# LC_WB_RANGE_START
+# 2.6.20 rename struct writeback fields
+AC_DEFUN([LC_WB_RANGE_START],
+[AC_MSG_CHECKING([kernel has range_start in struct writeback_control])
+LB_LINUX_TRY_COMPILE([
+ #include <linux/fs.h>
+ #include <linux/sched.h>
+ #include <linux/writeback.h>
+],[
+ struct writeback_control wb;
+
+ wb.range_start = 0;
+],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_WB_RANGE_START, 1,
+ [writeback control has range_start field])
+],[
+ AC_MSG_RESULT(NO)
+])
+])