Re: [PATCH 6/6] block: add large command support

[Boaz Harrosh <bharrosh@panasas.com>]

On Fri, Apr 25 2008 at 19:23 +0300, FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote:
> This patch changes rq->cmd from the static array to a pointer to
> support large commands.
> 
> We rarely handle large commands. So for optimization, a struct request
> still has a static array for a command. rq_init sets rq->cmd pointer
> to the static array.
> 
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Cc: Jens Axboe <jens.axboe@oracle.com>

Please, if not to late, add:
Cc: Boaz Harrosh <bharrosh@panasas.com>

> ---
>  block/blk-core.c       |    1 +
>  include/linux/blkdev.h |    5 +++--
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-core.c b/block/blk-core.c
> index a89adcc..35ae1c0 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -117,6 +117,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
>  	rq->sector = rq->hard_sector = (sector_t) -1;
>  	INIT_HLIST_NODE(&rq->hash);
>  	RB_CLEAR_NODE(&rq->rb_node);
> +	rq->cmd = rq->__cmd;
>  	rq->tag = -1;
>  	rq->ref_count = 1;
>  }
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index d17032c..08df1ea 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -215,8 +215,9 @@ struct request {
>  	/*
>  	 * when request is used as a packet command carrier
>  	 */
> -	unsigned int cmd_len;
> -	unsigned char cmd[BLK_MAX_CDB];
> +	unsigned short cmd_len;
> +	unsigned char __cmd[BLK_MAX_CDB];
> +	unsigned char *cmd;
>  
>  	unsigned int data_len;
>  	unsigned int extra_len;	/* length of alignment and padding */