int (*prepare_for_input) (int dev, int bufsize, int nbufs);
int (*prepare_for_output) (int dev, int bufsize, int nbufs);
void (*halt_io) (int dev);
int (*local_qlen)(int dev);
void (*copy_user) (int dev,
char *localbuf, int localoffs,
int (*prepare_for_input) (int dev, int bufsize, int nbufs);
int (*prepare_for_output) (int dev, int bufsize, int nbufs);
void (*halt_io) (int dev);
int (*local_qlen)(int dev);
void (*copy_user) (int dev,
char *localbuf, int localoffs,