static int msb_cache_flush()

in core/ms_block.c [1533:1604]

• 50 lines of code
• 11 McCabe index (conditional complexity)

static int msb_cache_flush(struct msb_data *msb)
{
	struct scatterlist sg;
	struct ms_extra_data_register extra;
	int page, offset, error;
	u16 pba, lba;

	if (msb->read_only)
		return -EROFS;

	if (msb->cache_block_lba == MS_BLOCK_INVALID)
		return 0;

	lba = msb->cache_block_lba;
	pba = msb->lba_to_pba_table[lba];

	dbg_verbose("Flushing the write cache of pba %d (LBA %d)",
						pba, msb->cache_block_lba);

	sg_init_one(&sg, msb->cache , msb->block_size);

	/* Read all missing pages in cache */
	for (page = 0; page < msb->pages_in_block; page++) {

		if (test_bit(page, &msb->valid_cache_bitmap))
			continue;

		offset = page * msb->page_size;

		dbg_verbose("reading non-present sector %d of cache block %d",
			page, lba);
		error = msb_read_page(msb, pba, page, &extra, &sg, offset);

		/* Bad pages are copied with 00 page status */
		if (error == -EBADMSG) {
			pr_err("read error on sector %d, contents probably damaged", page);
			continue;
		}

		if (error)
			return error;

		if ((extra.overwrite_flag & MEMSTICK_OV_PG_NORMAL) !=
							MEMSTICK_OV_PG_NORMAL) {
			dbg("page %d is marked as bad", page);
			continue;
		}

		set_bit(page, &msb->valid_cache_bitmap);
	}

	/* Write the cache now */
	error = msb_update_block(msb, msb->cache_block_lba, &sg, 0);
	pba = msb->lba_to_pba_table[msb->cache_block_lba];

	/* Mark invalid pages */
	if (!error) {
		for (page = 0; page < msb->pages_in_block; page++) {

			if (test_bit(page, &msb->valid_cache_bitmap))
				continue;

			dbg("marking page %d as containing damaged data",
				page);
			msb_set_overwrite_flag(msb,
				pba , page, 0xFF & ~MEMSTICK_OV_PG_NORMAL);
		}
	}

	msb_cache_discard(msb);
	return error;
}