Merge tag 'md/4.2' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "A mixed bag

   - a few bug fixes
   - some performance improvement that decrease lock contention
   - some clean-up

  Nothing major"

* tag 'md/4.2' of git://neil.brown.name/md:
  md: clear Blocked flag on failed devices when array is read-only.
  md: unlock mddev_lock on an error path.
  md: clear mddev->private when it has been freed.
  md: fix a build warning
  md/raid5: ignore released_stripes check
  md/raid5: per hash value and exclusive wait_for_stripe
  md/raid5: split wait_for_stripe and introduce wait_for_quiescent
  wait: introduce wait_event_exclusive_cmd
  md: convert to kstrto*()
  md/raid10: make sync_request_write() call bio_copy_data()

include/linux/wait.h

@@ -358,6 +358,19 @@ do {									\
 	__ret;								\
 })
 
+#define __wait_event_exclusive_cmd(wq, condition, cmd1, cmd2)		\
+	(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 1, 0,	\
+			    cmd1; schedule(); cmd2)
+/*
+ * Just like wait_event_cmd(), except it sets exclusive flag
+ */
+#define wait_event_exclusive_cmd(wq, condition, cmd1, cmd2)		\
+do {									\
+	if (condition)							\
+		break;							\
+	__wait_event_exclusive_cmd(wq, condition, cmd1, cmd2);		\
+} while (0)
+
 #define __wait_event_cmd(wq, condition, cmd1, cmd2)			\
 	(void)___wait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, 0,	\
 			    cmd1; schedule(); cmd2)