\subsection*{gendisk}
The \ds{gendisk} data structure holds information about a hard disk.
They are used during initialization when the disks are found and then probed for partitions.
\SeeModule{include/linux/\\genhd.h}
\begin{tscreen}\begin{verbatim}
struct hd_struct {
    long start_sect;
    long nr_sects;
};

struct gendisk {
    int major;               /* major number of driver */
    const char *major_name;  /* name of major driver */
    int minor_shift;         /* number of times minor is shifted to
                                get real minor */
    int max_p;               /* maximum partitions per device */
    int max_nr;              /* maximum number of real devices */

    void (*init)(struct gendisk *); 
                             /* Initialization called before we 
                                do our thing */
    struct hd_struct *part;  /* partition table */
    int *sizes;              /* device size in blocks, copied to 
                                blk_size[] */
    int nr_real;             /* number of real devices */

    void *real_devices;      /* internal use */
    struct gendisk *next;
};
\end{verbatim}\end{tscreen}
