diff --git a/drivers/md/md.c b/drivers/md/md.c
index ba201db6afce..9a84a74747f8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -6701,9 +6701,9 @@ static void status_unused(struct seq_file *seq)
static void status_resync(struct seq_file *seq, struct mddev *mddev)
{
sector_t max_sectors, resync, res;
- unsigned long dt, db;
- sector_t rt;
- int scale;
+ unsigned long dt, db = 0;
+ sector_t rt, curr_mark_cnt, resync_mark_cnt;
+ int scale, recovery_active;
unsigned int per_milli;
if (mddev->curr_resync <= 3)
@@ -6759,22 +6759,30 @@ static void status_resync(struct seq_file *seq, struct mddev *mddev)
* db: blocks written from mark until now
* rt: remaining time
*
- * rt is a sector_t, so could be 32bit or 64bit.
- * So we divide before multiply in case it is 32bit and close
- * to the limit.
- * We scale the divisor (db) by 32 to avoid losing precision
- * near the end of resync when the number of remaining sectors
- * is close to 'db'.
- * We then divide rt by 32 after multiplying by db to compensate.
- * The '+1' avoids division by zero if db is very small.
+ * rt is a sector_t, which is always 64bit now. We are keeping
+ * the original algorithm, but it is not really necessary.
+ *
+ * Original algorithm:
+ * So we divide before multiply in case it is 32bit and close
+ * to the limit.
+ * We scale the divisor (db) by 32 to avoid losing precision
+ * near the end of resync when the number of remaining sectors
+ * is close to 'db'.
+ * We then divide rt by 32 after multiplying by db to compensate.
+ * The '+1' avoids division by zero if db is very small.
*/
dt = ((jiffies - mddev->resync_mark) / HZ);
if (!dt) dt++;
- db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
- - mddev->resync_mark_cnt;
+
+ curr_mark_cnt = mddev->curr_mark_cnt;
+ recovery_active = atomic_read(&mddev->recovery_active);
+ resync_mark_cnt = mddev->resync_mark_cnt;
+
+ if (curr_mark_cnt >= (recovery_active + resync_mark_cnt))
+ db = curr_mark_cnt - (recovery_active + resync_mark_cnt);
rt = max_sectors - resync; /* number of remaining sectors */
- sector_div(rt, db/32+1);
+ rt = div64_u64(rt, db/32+1);
rt *= dt;
rt >>= 5;