On Thu, Sep 03, 2020 at 03:18:52PM +0300, Leon Romanovsky wrote:
> +struct sg_append {
> + struct scatterlist *prv; /* Previous entry to append */
> + unsigned int left_pages; /* Left pages to add to table */
> +};
I don't really see the point in this structure. Either pass it as
two separate arguments, or switch sg_alloc_table_append and the
internal helper to pass all arguments as a struct.
> + * A user may provide an offset at a start and a size of valid data in a buffer
> + * specified by the page array. A user may provide @append to chain pages to
This adds a few pointles > 80 char lines.
> +struct scatterlist *
> +sg_alloc_table_append(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, unsigned int max_segment,
> + gfp_t gfp_mask, struct sg_append *append)
> +{
> +#ifdef CONFIG_ARCH_NO_SG_CHAIN
> + if (append->left_pages)
> + return ERR_PTR(-EOPNOTSUPP);
> +#endif
Which makes this API entirely useless for !CONFIG_ARCH_NO_SG_CHAIN,
doesn't it? Wouldn't it make more sense to not provide it for that
case and add an explicitl dependency in the callers?
> + return alloc_from_pages_common(sgt, pages, n_pages, offset, size,
> + max_segment, gfp_mask, append);
And if we somehow manage to sort that out we can merge
sg_alloc_table_append and alloc_from_pages_common, reducing the amount
of wrappers that just make it too hard to follow the code.
> +EXPORT_SYMBOL(sg_alloc_table_append);
EXPORT_SYMBOL_GPL, please.
