/*
  * maximal error of a stat counter.
  */
-static inline unsigned long wb_stat_error(struct bdi_writeback *wb)
+static inline unsigned long wb_stat_error(void)
 {
 #ifdef CONFIG_SMP
        return nr_cpu_ids * WB_STAT_BATCH;
 
         * actually dirty; with m+n sitting in the percpu
         * deltas.
         */
-       if (dtc->wb_thresh < 2 * wb_stat_error(wb)) {
+       if (dtc->wb_thresh < 2 * wb_stat_error()) {
                wb_reclaimable = wb_stat_sum(wb, WB_RECLAIMABLE);
                dtc->wb_dirty = wb_reclaimable + wb_stat_sum(wb, WB_WRITEBACK);
        } else {
                 * more page. However wb_dirty has accounting errors.  So use
                 * the larger and more IO friendly wb_stat_error.
                 */
-               if (sdtc->wb_dirty <= wb_stat_error(wb))
+               if (sdtc->wb_dirty <= wb_stat_error())
                        break;
 
                if (fatal_signal_pending(current))