static void space_valid()

in namespace_devs.c [536:586]

• 38 lines of code
• 8 McCabe index (conditional complexity)

static void space_valid(struct nd_region *nd_region, struct nvdimm_drvdata *ndd,
		struct nd_label_id *label_id, struct resource *prev,
		struct resource *next, struct resource *exist,
		resource_size_t n, struct resource *valid)
{
	bool is_reserve = strcmp(label_id->id, "pmem-reserve") == 0;
	bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0;
	unsigned long align;

	align = nd_region->align / nd_region->ndr_mappings;
	valid->start = ALIGN(valid->start, align);
	valid->end = ALIGN_DOWN(valid->end + 1, align) - 1;

	if (valid->start >= valid->end)
		goto invalid;

	if (is_reserve)
		return;

	if (!is_pmem) {
		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
		struct nvdimm_bus *nvdimm_bus;
		struct blk_alloc_info info = {
			.nd_mapping = nd_mapping,
			.available = nd_mapping->size,
			.res = valid,
		};

		WARN_ON(!is_nd_blk(&nd_region->dev));
		nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
		device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);
		return;
	}

	/* allocation needs to be contiguous, so this is all or nothing */
	if (resource_size(valid) < n)
		goto invalid;

	/* we've got all the space we need and no existing allocation */
	if (!exist)
		return;

	/* allocation needs to be contiguous with the existing namespace */
	if (valid->start == exist->end + 1
			|| valid->end == exist->start - 1)
		return;

 invalid:
	/* truncate @valid size to 0 */
	valid->end = valid->start - 1;
}