static int msb_read_boot_blocks()

in core/ms_block.c [1192:1253]

• 48 lines of code
• 9 McCabe index (conditional complexity)

static int msb_read_boot_blocks(struct msb_data *msb)
{
	int pba = 0;
	struct scatterlist sg;
	struct ms_extra_data_register extra;
	struct ms_boot_page *page;

	msb->boot_block_locations[0] = MS_BLOCK_INVALID;
	msb->boot_block_locations[1] = MS_BLOCK_INVALID;
	msb->boot_block_count = 0;

	dbg_verbose("Start of a scan for the boot blocks");

	if (!msb->boot_page) {
		page = kmalloc_array(2, sizeof(struct ms_boot_page),
				     GFP_KERNEL);
		if (!page)
			return -ENOMEM;

		msb->boot_page = page;
	} else
		page = msb->boot_page;

	msb->block_count = MS_BLOCK_MAX_BOOT_ADDR;

	for (pba = 0; pba < MS_BLOCK_MAX_BOOT_ADDR; pba++) {

		sg_init_one(&sg, page, sizeof(*page));
		if (msb_read_page(msb, pba, 0, &extra, &sg, 0)) {
			dbg("boot scan: can't read pba %d", pba);
			continue;
		}

		if (extra.management_flag & MEMSTICK_MANAGEMENT_SYSFLG) {
			dbg("management flag doesn't indicate boot block %d",
									pba);
			continue;
		}

		if (be16_to_cpu(page->header.block_id) != MS_BLOCK_BOOT_ID) {
			dbg("the pba at %d doesn't contain boot block ID", pba);
			continue;
		}

		msb_fix_boot_page_endianness(page);
		msb->boot_block_locations[msb->boot_block_count] = pba;

		page++;
		msb->boot_block_count++;

		if (msb->boot_block_count == 2)
			break;
	}

	if (!msb->boot_block_count) {
		pr_err("media doesn't contain master page, aborting");
		return -EIO;
	}

	dbg_verbose("End of scan for boot blocks");
	return 0;
}