Re: [PATCH RESEND] block: warn if tag is greater than real_max_depth.

[Tao Ma <tm@tao.ma>]

Hi Jens,
	any option with this patch?

Thanks
Tao
On 09/14/2011 03:23 PM, Tao Ma wrote:
> From: Tao Ma <boyu.mt@taobao.com>
> 
> In case tag depth is reduced, it is max_depth not real_max_depth.
> So we should allow a request with tag >= max_depth, but for a
> tag >= real_max_depth, there really should be some problem.
> 
> Cc: Jens Axboe <jaxboe@fusionio.com>
> Signed-off-by: Tao Ma <boyu.mt@taobao.com>
> ---
>  block/blk-tag.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-tag.c b/block/blk-tag.c
> index ece65fc..e74d6d1 100644
> --- a/block/blk-tag.c
> +++ b/block/blk-tag.c
> @@ -286,12 +286,14 @@ void blk_queue_end_tag(struct request_queue *q, struct request *rq)
>  
>  	BUG_ON(tag == -1);
>  
> -	if (unlikely(tag >= bqt->real_max_depth))
> +	if (unlikely(tag >= bqt->max_depth)) {
>  		/*
>  		 * This can happen after tag depth has been reduced.
> -		 * FIXME: how about a warning or info message here?
> +		 * But tag shouldn't be larger than real_max_depth.
>  		 */
> +		WARN_ON(tag >= bqt->real_max_depth);
>  		return;
> +	}
>  
>  	list_del_init(&rq->queuelist);
>  	rq->cmd_flags &= ~REQ_QUEUED;