1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 180949e94a7b..c194955aecae 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2695,6 +2695,7 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
         ssize_t rv = len;
         struct mdk_personality *pers;
         void *priv;
+        mdk_rdev_t *rdev;
 
         if (mddev->pers == NULL) {
                 if (len == 0)
@@ -2774,6 +2775,12 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
         mddev_suspend(mddev);
         mddev->pers->stop(mddev);
         module_put(mddev->pers->owner);
+        /* Invalidate devices that are now superfluous */
+        list_for_each_entry(rdev, &mddev->disks, same_set)
+                if (rdev->raid_disk >= mddev->raid_disks) {
+                        rdev->raid_disk = -1;
+                        clear_bit(In_sync, &rdev->flags);
+                }
         mddev->pers = pers;
         mddev->private = priv;
         strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));