diff --git a/block/elevator.c b/block/elevator.c
index 3bcd37c2aa34..2161b6eea680 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -812,8 +812,13 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf,
 	 * reference during concurrent disk deletion:
 	 *   update_nr_hwq_lock -> kn->active (via del_gendisk -> kobject_del)
 	 *   kn->active -> update_nr_hwq_lock (via this sysfs write path)
+	 *
+	 * Use the writer lock instead of the reader lock of update_nr_hwq_lock
+	 * to serialize the two-stage elevator switch steps in
+	 * elevator_change(): the core switch step under the elevator lock and
+	 * the elevator_change_done() step outside the elevator lock.
 	 */
-	if (!down_read_trylock(&set->update_nr_hwq_lock)) {
+	if (!down_write_trylock(&set->update_nr_hwq_lock)) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -824,7 +829,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf,
 	} else {
 		ret = -ENOENT;
 	}
-	up_read(&set->update_nr_hwq_lock);
+	up_write(&set->update_nr_hwq_lock);
 
 out:
 	if (ctx.type)