drbd: improve online-verify progress tracking

For a partial (resumed) online-verify, initialize rs_total not to total
bits, but to number of bits to check in this run, to match the meaning
rs_total has for actual resync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_main.c

@@ -961,6 +961,10 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
 /* helper for __drbd_set_state */
 static void set_ov_position(struct drbd_conf *mdev, enum drbd_conns cs)
 {
+	if (mdev->agreed_pro_version < 90)
+		mdev->ov_start_sector = 0;
+	mdev->rs_total = drbd_bm_bits(mdev);
+	mdev->ov_position = 0;
 	if (cs == C_VERIFY_T) {
 		/* starting online verify from an arbitrary position
 		 * does not fit well into the existing protocol.
@@ -970,11 +974,15 @@ static void set_ov_position(struct drbd_conf *mdev, enum drbd_conns cs)
 		mdev->ov_start_sector = ~(sector_t)0;
 	} else {
 		unsigned long bit = BM_SECT_TO_BIT(mdev->ov_start_sector);
-		if (bit >= mdev->rs_total)
+		if (bit >= mdev->rs_total) {
 			mdev->ov_start_sector =
 				BM_BIT_TO_SECT(mdev->rs_total - 1);
+			mdev->rs_total = 1;
+		} else
+			mdev->rs_total -= bit;
 		mdev->ov_position = mdev->ov_start_sector;
 	}
+	mdev->ov_left = mdev->rs_total;
 }
 
 static void drbd_resume_al(struct drbd_conf *mdev)
@@ -1081,7 +1089,7 @@ int __drbd_set_state(struct drbd_conf *mdev,
 	if ((os.conn == C_VERIFY_S || os.conn == C_VERIFY_T) &&
 	    ns.conn < C_CONNECTED) {
 		mdev->ov_start_sector =
-			BM_BIT_TO_SECT(mdev->rs_total - mdev->ov_left);
+			BM_BIT_TO_SECT(drbd_bm_bits(mdev) - mdev->ov_left);
 		dev_info(DEV, "Online Verify reached sector %llu\n",
 			(unsigned long long)mdev->ov_start_sector);
 	}
@@ -1106,14 +1114,7 @@ int __drbd_set_state(struct drbd_conf *mdev,
 		unsigned long now = jiffies;
 		int i;
 
-		mdev->ov_position = 0;
-		mdev->rs_total = drbd_bm_bits(mdev);
-		if (mdev->agreed_pro_version >= 90)
 		set_ov_position(mdev, ns.conn);
-		else
-			mdev->ov_start_sector = 0;
-		mdev->ov_left = mdev->rs_total
-			      - BM_SECT_TO_BIT(mdev->ov_position);
 		mdev->rs_start = now;
 		mdev->rs_last_events = 0;
 		mdev->rs_last_sect_ev = 0;
@@ -1121,7 +1122,7 @@ int __drbd_set_state(struct drbd_conf *mdev,
 		mdev->ov_last_oos_start = 0;
 
 		for (i = 0; i < DRBD_SYNC_MARKS; i++) {
-			mdev->rs_mark_left[i] = mdev->rs_total;
+			mdev->rs_mark_left[i] = mdev->ov_left;
 			mdev->rs_mark_time[i] = now;
 		}
 

drivers/block/drbd/drbd_proc.c

@@ -239,12 +239,13 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
 		    mdev->state.conn == C_SYNC_TARGET)
 			drbd_syncer_progress(mdev, seq);
 
-		if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T)
+		if (mdev->state.conn == C_VERIFY_S || mdev->state.conn == C_VERIFY_T) {
+			unsigned long bm_bits = drbd_bm_bits(mdev);
 			seq_printf(seq, "\t%3d%%      %lu/%lu\n",
-				   (int)((mdev->rs_total-mdev->ov_left) /
-					 (mdev->rs_total/100+1)),
-				   mdev->rs_total - mdev->ov_left,
-				   mdev->rs_total);
+				   (int)((bm_bits-mdev->ov_left) /
+					 (bm_bits/100+1)),
+				   bm_bits - mdev->ov_left, bm_bits);
+		}
 
 		if (proc_details >= 1 && get_ldev_if_state(mdev, D_FAILED)) {
 			lc_seq_printf_stats(seq, mdev->resync);

drivers/block/drbd/drbd_receiver.c

@@ -2005,7 +2005,8 @@ static int receive_DataRequest(struct drbd_conf *mdev, enum drbd_packets cmd, un
 		    mdev->agreed_pro_version >= 90) {
 			mdev->ov_start_sector = sector;
 			mdev->ov_position = sector;
-			mdev->ov_left = mdev->rs_total - BM_SECT_TO_BIT(sector);
+			mdev->ov_left = drbd_bm_bits(mdev) - BM_SECT_TO_BIT(sector);
+			mdev->rs_total = mdev->ov_left;
 			dev_info(DEV, "Online Verify start sector: %llu\n",
 					(unsigned long long)sector);
 		}