[dm-devel] Re: [PATCH block#for-2.6.31] block: add request clone interface

[Jens Axboe]

On Tue, Jun 09 2009, Kiyoshi Ueda wrote:
> Hi Jens,
> 
> +/*
> + * Copy request information of the original request to the clone request.
> + */
> +static void __blk_rq_prep_clone(struct request *dst, struct request *src)
> +{
> +	dst->cpu = src->cpu;
> +	dst->cmd_flags = (rq_data_dir(src) | REQ_NOMERGE);
> +	dst->cmd_type = src->cmd_type;
> +	dst->__sector = blk_rq_pos(src);
> +	dst->__data_len = blk_rq_bytes(src);
> +	dst->nr_phys_segments = src->nr_phys_segments;
> +	dst->ioprio = src->ioprio;
> +	dst->buffer = src->buffer;
> +	dst->cmd_len = src->cmd_len;
> +	dst->cmd = src->cmd;

Are you making sure that 'src' always exists while 'dst' is alive?

-- 
Jens Axboe