[PATCH 2/5] md/raid1: clean up request counts properly in close_sync()

[NeilBrown <neilb@suse.de>]

If there are outstanding writes when close_sync is called,
the change to ->start_next_window might cause them to
decrement the wrong counter when they complete.  Fix this
by merging the two counters into the one that will be decremented.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 drivers/md/raid1.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index f66f67e5a423..65afd8aa6608 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1544,8 +1544,13 @@ static void close_sync(struct r1conf *conf)
 	mempool_destroy(conf->r1buf_pool);
 	conf->r1buf_pool = NULL;
 
+	spin_lock_irq(&conf->resync_lock);
 	conf->next_resync = 0;
 	conf->start_next_window = MaxSector;
+	conf->current_window_requests +=
+		conf->next_window_requests;
+	conf->next_window_requests = 0;
+	spin_unlock_irq(&conf->resync_lock);
 }
 
 static int raid1_spare_active(struct mddev *mddev)