[PATCH 3.2 042/115] raid10: include bio_end_io_list in nr_queued to prevent freeze_array hang

[Ben Hutchings]

3.2.80-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Shaohua Li <shli@xxxxxx>

commit 23ddba80ebe836476bb2fa1f5ef305dd1c63dc0b upstream.

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: Nate Dailey <nate.dailey@xxxxxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/md/raid10.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2241,6 +2241,7 @@ static void handle_write_completed(struc
 		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 {
@@ -2267,8 +2268,10 @@ static void raid10d(struct mddev *mddev)
 		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)) {