MD: fix invalid stored role for a disk - try2

Commit d595567dc4f0 (MD: fix invalid stored role for a disk) broke linear
hotadd. Let's only fix the role for disks in raid1/10.
Based on Guoqing's original patch.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>

drivers/md/md.c

@@ -1774,10 +1774,6 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
 			} else
 				set_bit(In_sync, &rdev->flags);
 			rdev->raid_disk = role;
-			if (role >= mddev->raid_disks) {
-				rdev->saved_raid_disk = -1;
-				rdev->raid_disk = -1;
-			}
 			break;
 		}
 		if (sb->devflags & WriteMostly1)

drivers/md/raid1.c

@@ -1734,6 +1734,7 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	 */
 	if (rdev->saved_raid_disk >= 0 &&
 	    rdev->saved_raid_disk >= first &&
+	    rdev->saved_raid_disk < conf->raid_disks &&
 	    conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
 		first = last = rdev->saved_raid_disk;
 

drivers/md/raid10.c

@@ -1808,6 +1808,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		first = last = rdev->raid_disk;
 
 	if (rdev->saved_raid_disk >= first &&
+	    rdev->saved_raid_disk < conf->geo.raid_disks &&
 	    conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
 		mirror = rdev->saved_raid_disk;
 	else