Re: [PATCH v2 05/11] md/raid5: add scribble region for buffer lists

[Andre Noll <maan@systemlinux.org>]

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On Mon, May 18, 2009 at 05:59:51PM -0700, Dan Williams wrote:

> +static size_t scribble_len(int num)
> +{
> +	size_t len;
> +
> +	/* return enough space for an array of page pointers and dma
> +	 * addresses for the ddf raid6 layout
> +	 */
> +	len = sizeof(struct page *) * (num+2) + sizeof(addr_conv_t) * (num+2);
> +
> +	return len;
> +}

The comment is a bit misleading as the function only returns the
_amount_ of space needed. It should probably also explain the meaning
of the "+2".

> +/* return a pointer to the address conversion region of the scribble buffer */
> +static addr_conv_t *sh_to_addr_conv(struct stripe_head *sh)
> +{
> +	return sh->scribble + sizeof(struct page *) * (sh->disks + 2);
> +}

Maybe it's safer to return NULL if sh->scribble is NULL.

Thanks
Andre
-- 
The only person who always got his work done by Friday was Robinson Crusoe


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