md: remove special meaning of ->quiesce(.., 2)

The '2' argument means "wake up anything that is waiting".
This is an inelegant part of the design and was added
to help support management of suspend_lo/suspend_hi setting.
Now that suspend_lo/hi is managed in mddev_suspend/resume,
that need is gone.
These is still a couple of places where we call 'quiesce'
with an argument of '2', but they can safely be changed to
call ->quiesce(.., 1); ->quiesce(.., 0) which
achieve the same result at the small cost of pausing IO
briefly.

This removes a small "optimization" from suspend_{hi,lo}_store,
but it isn't clear that optimization served a useful purpose.
The code now is a lot clearer.

Suggested-by: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index bc81ecc..d0fd1bd 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -442,10 +442,11 @@ static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot)
 static void remove_suspend_info(struct mddev *mddev, int slot)
 {
 	struct md_cluster_info *cinfo = mddev->cluster_info;
+	mddev->pers->quiesce(mddev, 1);
 	spin_lock_irq(&cinfo->suspend_lock);
 	__remove_suspend_info(cinfo, slot);
 	spin_unlock_irq(&cinfo->suspend_lock);
-	mddev->pers->quiesce(mddev, 2);
+	mddev->pers->quiesce(mddev, 0);
 }
 
 
@@ -492,13 +493,12 @@ static void process_suspend_info(struct mddev *mddev,
 	s->lo = lo;
 	s->hi = hi;
 	mddev->pers->quiesce(mddev, 1);
-	mddev->pers->quiesce(mddev, 0);
 	spin_lock_irq(&cinfo->suspend_lock);
 	/* Remove existing entry (if exists) before adding */
 	__remove_suspend_info(cinfo, slot);
 	list_add(&s->list, &cinfo->suspend_list);
 	spin_unlock_irq(&cinfo->suspend_lock);
-	mddev->pers->quiesce(mddev, 2);
+	mddev->pers->quiesce(mddev, 0);
 }
 
 static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)