存储设备驱动ioctl操作

一、获得设备几何参数：磁头数、扇区数、柱面数

/* including <linux/hdreg.h> also fails */

struct hd_geometry {

unsigned char heads;

unsigned char sectors;

unsigned short cylinders;

unsigned long start;

};

#define HDIO_GETGEO 0x0301 /* get device geometry */

ioctl (dev, HDIO_GETGEO, &geometry)