md-cluster/raid10: call update_size in md_reap_sync_thread

We need to change the capacity in all nodes after one node
finishs reshape. And as we did before, we can't change the
capacity directly in md_do_sync, instead, the capacity should
be only changed in update_size or received CHANGE_CAPACITY
msg.

So master node calls update_size after completes reshape in
md_reap_sync_thread, but we need to skip ops->update_size if
MD_CLOSING is set since reshaping could not be finish.
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

drivers/md/md.c

@@ -8623,9 +8623,11 @@ void md_do_sync(struct md_thread *thread)
 		mddev_lock_nointr(mddev);
 		md_set_array_sectors(mddev, mddev->pers->size(mddev, 0, 0));
 		mddev_unlock(mddev);
+		if (!mddev_is_clustered(mddev)) {
 			set_capacity(mddev->gendisk, mddev->array_sectors);
 			revalidate_disk(mddev->gendisk);
 		}
+	}
 
 	spin_lock(&mddev->lock);
 	if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
@@ -8968,6 +8970,8 @@ EXPORT_SYMBOL(md_check_recovery);
 void md_reap_sync_thread(struct mddev *mddev)
 {
 	struct md_rdev *rdev;
+	sector_t old_dev_sectors = mddev->dev_sectors;
+	bool is_reshaped = false;
 
 	/* resync has finished, collect result */
 	md_unregister_thread(&mddev->sync_thread);
@@ -8982,8 +8986,11 @@ void md_reap_sync_thread(struct mddev *mddev)
 		}
 	}
 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
-	    mddev->pers->finish_reshape)
+	    mddev->pers->finish_reshape) {
 		mddev->pers->finish_reshape(mddev);
+		if (mddev_is_clustered(mddev))
+			is_reshaped = true;
+	}
 
 	/* If array is no-longer degraded, then any saved_raid_disk
 	 * information must be scrapped.
@@ -9004,6 +9011,14 @@ void md_reap_sync_thread(struct mddev *mddev)
 	clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
 	clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
 	clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+	/*
+	 * We call md_cluster_ops->update_size here because sync_size could
+	 * be changed by md_update_sb, and MD_RECOVERY_RESHAPE is cleared,
+	 * so it is time to update size across cluster.
+	 */
+	if (mddev_is_clustered(mddev) && is_reshaped
+				      && !test_bit(MD_CLOSING, &mddev->flags))
+		md_cluster_ops->update_size(mddev, old_dev_sectors);
 	wake_up(&resync_wait);
 	/* flag recovery needed just to double check */
 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);