unsigned char discard_map[SIT_VBLOCK_MAP_SIZE]; /* segment discard bitmap */
 };
 
+/* minimum discard granularity, unit: block count */
+#define MIN_DISCARD_GRANULARITY                1
 /* default discard granularity of inner discard thread, unit: block count */
 #define DEFAULT_DISCARD_GRANULARITY            16
 /* default maximum discard granularity of ordered discard, unit: block count */
 
                dpolicy->sync = false;
                dpolicy->ordered = true;
                if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) {
-                       dpolicy->granularity = 1;
+                       dpolicy->granularity = MIN_DISCARD_GRANULARITY;
                        if (atomic_read(&dcc->discard_cmd_cnt))
                                dpolicy->max_interval =
                                        dcc->min_discard_issue_time;
        } else if (discard_type == DPOLICY_UMOUNT) {
                dpolicy->io_aware = false;
                /* we need to issue all to keep CP_TRIMMED_FLAG */
-               dpolicy->granularity = 1;
+               dpolicy->granularity = MIN_DISCARD_GRANULARITY;
                dpolicy->timeout = true;
        }
 }
 
        /* adjust parameters according to the volume size */
        if (MAIN_SEGS(sbi) <= SMALL_VOLUME_SEGMENTS) {
                if (f2fs_block_unit_discard(sbi))
-                       SM_I(sbi)->dcc_info->discard_granularity = 1;
+                       SM_I(sbi)->dcc_info->discard_granularity =
+                                               MIN_DISCARD_GRANULARITY;
                SM_I(sbi)->ipu_policy = 1 << F2FS_IPU_FORCE |
                                        1 << F2FS_IPU_HONOR_OPU_WRITE;
        }