raid10: include bio_end_io_list in nr_queued to prevent freeze_array hang

This is the raid10 counterpart of the bug fixed by Nate
(raid1: include bio_end_io_list in nr_queued to prevent freeze_array hang)

Fixes: 95af587e95(md/raid10: ensure device failure recorded before write request returns)
Cc: stable@vger.kernel.org (V4.3+)
Cc: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 1c1447dd3417..e3fd725d5c4d 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2664,6 +2664,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
                 if (fail) {
                         spin_lock_irq(&conf->device_lock);
                         list_add(&r10_bio->retry_list, &conf->bio_end_io_list);
+                        conf->nr_queued++;
                         spin_unlock_irq(&conf->device_lock);
                         md_wakeup_thread(conf->mddev->thread);
                 } else {
@@ -2691,8 +2692,10 @@ static void raid10d(struct md_thread *thread)
                 LIST_HEAD(tmp);
                 spin_lock_irqsave(&conf->device_lock, flags);
                 if (!test_bit(MD_CHANGE_PENDING, &mddev->flags)) {
-                        list_add(&tmp, &conf->bio_end_io_list);
-                        list_del_init(&conf->bio_end_io_list);
+                        while (!list_empty(&conf->bio_end_io_list)) {
+                                list_move(conf->bio_end_io_list.prev, &tmp);
+                                conf->nr_queued--;
+                        }
                 }
                 spin_unlock_irqrestore(&conf->device_lock, flags);
                 while (!list_empty(&tmp)) {