1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/md/md.h b/drivers/md/md.h
index a536f5458097..7ab5ea155452 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -150,6 +150,12 @@ struct mddev_s
         int                             external_size; /* size managed
                                                         * externally */
         __u64                           events;
+        /* If the last 'event' was simply a clean->dirty transition, and
+         * we didn't write it to the spares, then it is safe and simple
+         * to just decrement the event count on a dirty->clean transition.
+         * So we record that possibility here.
+         */
+        int                             can_decrease_events;
 
         char                            uuid[16];