On Wed, 03 Aug 2011 17:31:23 -0700 Dan Williams <dan.j.williams@xxxxxxxxx>
wrote:
> All updates that occur under STRIPE_ACTIVE should be globally visible
> when STRIPE_ACTIVE clears. test_and_set_bit() implies a barrier, but
> clear_bit() does not.
>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
>
> This at least was the guarantee we had with sh->lock...
>
> drivers/md/raid5.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index dbae459..bd95123 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -3116,7 +3116,7 @@ static void handle_stripe(struct stripe_head *sh)
> struct r5dev *pdev, *qdev;
>
> clear_bit(STRIPE_HANDLE, &sh->state);
> - if (test_and_set_bit(STRIPE_ACTIVE, &sh->state)) {
> + if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
> /* already being handled, ensure it gets handled
> * again when current action finishes */
> set_bit(STRIPE_HANDLE, &sh->state);
> @@ -3377,7 +3377,7 @@ finish:
>
> return_io(s.return_bi);
>
> - clear_bit(STRIPE_ACTIVE, &sh->state);
> + clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
> }
>
> static void raid5_activate_delayed(raid5_conf_t *conf)
>
> --
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sorry for missing this before...
I makes perfect sense. I've applied it and should send it upstream shortly.
Thanks,
NeilBrown
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