md/raid1/10: add missed blk plug

flush_pending_writes isn't always called with block plug, so add it, and plug
works in nested way.

Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index cc9d337a1ed3..6df398e3a008 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -809,11 +809,15 @@ static void flush_pending_writes(struct r1conf *conf)
         spin_lock_irq(&conf->device_lock);
 
         if (conf->pending_bio_list.head) {
+                struct blk_plug plug;
                 struct bio *bio;
+
                 bio = bio_list_get(&conf->pending_bio_list);
                 conf->pending_count = 0;
                 spin_unlock_irq(&conf->device_lock);
+                blk_start_plug(&plug);
                 flush_bio_list(conf, bio);
+                blk_finish_plug(&plug);
         } else
                 spin_unlock_irq(&conf->device_lock);
 }