On Mon, Apr 17 2017, Guoqing Jiang wrote:
> 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>
> ---
> drivers/md/raid10.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index 4167091..acb3f46 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -2704,6 +2704,11 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
> 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,
> --
> 2.10.0
Reviewed-by: NeilBrown <neilb@xxxxxxxx>
I think I looked at this once before and convinced myself that
md_wakeup_thread() would wake up the only thread that might be waiting
in freeze_array(). This is completely wrong, so I don't know why I
thought it:-(
Thanks,
NeilBrown
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