static int check_write_unsafe(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { /* assume that if the user specifies the format explicitly, then assume that they will continue to do so and provide no safety net */ if (!bs->probed) { return 0; } if (sector_num == 0 && nb_sectors > 0) { return check_for_block_signature(bs, buf); } return 0; }