dbtok
#define dbtok(x, b) \
#define dbtok(x) ((x) / (1024 / DEV_BSIZE))
#define dbtok(x) ((x) * (DEV_BSIZE / 1024))
#define dbtok(x) ((x) / (1024 / DEV_BSIZE))
#define dbtok(x) ((x) * (DEV_BSIZE / 1024))