md: don't unregister the thread in mddev_suspend

This is
 - unnecessary because mddev_suspend is always followed by a call to
   ->stop, and each ->stop unregisters the thread, and
 - a problem as it makes it awkwards to suspend and then resume a
   device as we will want later.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index d3579fc..af0780a 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -254,6 +254,12 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
        return rv;
 }
 
+/* mddev_suspend makes sure no new requests are submitted
+ * to the device, and that any requests that have been submitted
+ * are completely handled.
+ * Once ->stop is called and completes, the module will be completely
+ * unused.
+ */
 static void mddev_suspend(mddev_t *mddev)
 {
        BUG_ON(mddev->suspended);
@@ -261,13 +267,6 @@ static void mddev_suspend(mddev_t *mddev)
        synchronize_rcu();
        wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
        mddev->pers->quiesce(mddev, 1);
-       md_unregister_thread(mddev->thread);
-       mddev->thread = NULL;
-       /* we now know that no code is executing in the personality module,
-        * except possibly the tail end of a ->bi_end_io function, but that
-        * is certain to complete before the module has a chance to get
-        * unloaded
-        */
 }
 
 static void mddev_resume(mddev_t *mddev)