Re: [PATCH 1/1] cciss: use timeout to ensure scan thread exits

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 16 Jun 2009 15:43:25 -0500
"Mike Miller (OS Dev)" <mikem@beardog.cca.cpqcorp.net> wrote:

> Patch 1 of 1
> 
> This patch implements wait_for_completion_interruptible_timeout in the
> scan_thread function to ensure it will exit cleanly during rmmod. Calling
> complete in cciss_remove_one caused a race condition. Using the wait with a
> timeout seems to work around that but it does fire the thread. The overhead
> should be minimal.
> 
> Changelog:
> Replace wait_for_completion_interruptible with
> wait_for_completion_interruptible_timeout in scan_thread().
> Use 5 second timeout value to avoid race.
> 
> Signed-off-by: Mike Miller
> 
> diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
> index 4d4d5e0..76e7c10 100644
> --- a/drivers/block/cciss.c
> +++ b/drivers/block/cciss.c
> @@ -3043,7 +3043,7 @@ static int scan_thread(void *data)
>  	h->rescan_wait = &wait;
>  
>  	for (;;) {
> -		rc = wait_for_completion_interruptible(&wait);
> +		rc = wait_for_completion_interruptible_timeout(&wait, 5);
>  		if (kthread_should_stop())
>  			break;
>  		if (!rc)

c'mon Mike, that's a hack.