[PATCH 4.9 039/177] md/raid10: wait up frozen array in handle_write_completed

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Guoqing Jiang <gqjiang@xxxxxxxx>


[ Upstream commit cf25ae78fc50010f66b9be945017796da34c434d ]

Since nr_queued is changed, we need to call wake_up here
if the array is already frozen and waiting for condition
"nr_pending == nr_queued + extra" to be true.

And commit 824e47daddbf ("RAID1: avoid unnecessary spin
locks in I/O barrier code") which has already added the
wake_up for raid1.

Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
Signed-off-by: Shaohua Li <shli@xxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/md/raid10.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2704,6 +2704,11 @@ static void handle_write_completed(struc
 			list_add(&r10_bio->retry_list, &conf->bio_end_io_list);
 			conf->nr_queued++;
 			spin_unlock_irq(&conf->device_lock);
+			/*
+			 * In case freeze_array() is waiting for condition
+			 * nr_pending == nr_queued + extra to be true.
+			 */
+			wake_up(&conf->wait_barrier);
 			md_wakeup_thread(conf->mddev->thread);
 		} else {
 			if (test_bit(R10BIO_WriteError,