[Cluster-devel] [PATCH 10/17] dlm: use schedule_timeout instead of schedule in dlm_recoverd

[David Teigland <teigland@redhat.com>]

On Wed, Aug 09, 2017 at 05:51:01AM +0000, tsutomu.owa at toshiba.co.jp wrote:
> When dlm_recoverd_stop() is called between kthread_should_stop() and
> set_task_state(), dlm_recoverd will not wake up.

This works, but have you looked elsewhere in the kernel for kthread
examples we could copy that do a race-free check without a timeout?
Thanks

> 
> Signed-off-by: Tadashi Miyauchi <miyauchi@toshiba-tops.co.jp>
> Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp>
> ---
>  fs/dlm/recoverd.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
> index 6859b4b..d3956cc 100644
> --- a/fs/dlm/recoverd.c
> +++ b/fs/dlm/recoverd.c
> @@ -276,6 +276,7 @@ static void do_ls_recovery(struct dlm_ls *ls)
>  static int dlm_recoverd(void *arg)
>  {
>  	struct dlm_ls *ls;
> +	unsigned long timeout = (dlm_config.ci_recover_timer * HZ) >> 1;
>  
>  	ls = dlm_find_lockspace_local(arg);
>  	if (!ls) {
> @@ -291,7 +292,7 @@ static int dlm_recoverd(void *arg)
>  		set_current_state(TASK_INTERRUPTIBLE);
>  		if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
>  		    !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags))
> -			schedule();
> +			schedule_timeout(timeout);
>  		set_current_state(TASK_RUNNING);
>  
>  		if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
> -- 
> 2.7.4
> 
> 
>