genhd.h

linux得一些常用命令,以及linux环境下的c编程

#ifndef _LINUX_GENHD_H
#define _LINUX_GENHD_H

/*
 * 	genhd.h Copyright (C) 1992 Drew Eckhardt
 *	Generic hard disk header file by  
 * 		Drew Eckhardt
 *
 *		<[e-mail]>
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/major.h>

enum {
/* These three have identical behaviour; use the second one if DOS fdisk gets
   confused about extended/logical partitions starting past cylinder 1023. */
	DOS_EXTENDED_PARTITION = 5,
	LINUX_EXTENDED_PARTITION = 0x85,
	WIN98_EXTENDED_PARTITION = 0x0f,

	LINUX_SWAP_PARTITION = 0x82,
	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */

	SOLARIS_X86_PARTITION =	LINUX_SWAP_PARTITION,

	DM6_PARTITION =	0x54,	/* has DDO: use xlated geom & offset */
	EZD_PARTITION =	0x55,	/* EZ-DRIVE */
	DM6_AUX1PARTITION = 0x51,	/* no DDO:  use xlated geom */
	DM6_AUX3PARTITION = 0x53,	/* no DDO:  use xlated geom */

	FREEBSD_PARTITION = 0xa5,    /* FreeBSD Partition ID */
	OPENBSD_PARTITION = 0xa6,    /* OpenBSD Partition ID */
	NETBSD_PARTITION = 0xa9,   /* NetBSD Partition ID */
	BSDI_PARTITION = 0xb7,    /* BSDI Partition ID */
/* Ours is not to wonder why.. */
	BSD_PARTITION =	FREEBSD_PARTITION,
	MINIX_PARTITION = 0x81,  /* Minix Partition ID */
	PLAN9_PARTITION = 0x39,  /* Plan 9 Partition ID */
	UNIXWARE_PARTITION = 0x63,		/* Partition ID, same as */
						/* GNU_HURD and SCO Unix */
};

struct partition {
	unsigned char boot_ind;		/* 0x80 - active */
	unsigned char head;		/* starting head */
	unsigned char sector;		/* starting sector */
	unsigned char cyl;		/* starting cylinder */
	unsigned char sys_ind;		/* What partition type */
	unsigned char end_head;		/* end head */
	unsigned char end_sector;	/* end sector */
	unsigned char end_cyl;		/* end cylinder */
	unsigned int start_sect;	/* starting sector counting from 0 */
	unsigned int nr_sects;		/* nr of sectors in partition */
} __attribute__((packed));

#ifdef __KERNEL__
#  include <linux/devfs_fs_kernel.h>

struct hd_struct {
	unsigned long start_sect;
	unsigned long nr_sects;
	devfs_handle_t de;              /* primary (master) devfs entry  */
#ifdef CONFIG_DEVFS_FS
	int number;
#endif /* CONFIG_DEVFS_FS */
#ifdef CONFIG_BLK_STATS
	/* Performance stats: */
	unsigned int ios_in_flight;
	unsigned int io_ticks;
	unsigned int last_idle_time;
	unsigned int last_queue_change;
	unsigned int aveq;
	
	unsigned int rd_ios;
	unsigned int rd_merges;
	unsigned int rd_ticks;
	unsigned int rd_sectors;
	unsigned int wr_ios;
	unsigned int wr_merges;
	unsigned int wr_ticks;
	unsigned int wr_sectors;	
#endif /* CONFIG_BLK_STATS */
};

#define GENHD_FL_REMOVABLE  1

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 */

	struct hd_struct *part;		/* [indexed by minor] */
	int *sizes;			/* [idem], device size in blocks */
	int nr_real;			/* number of real devices */

	void *real_devices;		/* internal use */
	struct gendisk *next;
	struct block_device_operations *fops;

	devfs_handle_t *de_arr;         /* one per physical disc */
	char *flags;                    /* one per physical disc */
};

/* drivers/block/genhd.c */
extern struct gendisk *gendisk_head;

extern void add_gendisk(struct gendisk *gp);
extern void del_gendisk(struct gendisk *gp);
extern struct gendisk *get_gendisk(kdev_t dev);
extern int walk_gendisk(int (*walk)(struct gendisk *, void *), void *);

#endif  /*  __KERNEL__  */

#ifdef CONFIG_SOLARIS_X86_PARTITION

#define SOLARIS_X86_NUMSLICE	8
#define SOLARIS_X86_VTOC_SANE	(0x600DDEEEUL)

struct solaris_x86_slice {
	ushort	s_tag;			/* ID tag of partition */
	ushort	s_flag;			/* permission flags */
	unsigned int s_start;		/* start sector no of partition */
	unsigned int s_size;		/* # of blocks in partition */
};

struct solaris_x86_vtoc {
	unsigned int v_bootinfo[3];	/* info needed by mboot (unsupported) */
	unsigned int v_sanity;		/* to verify vtoc sanity */
	unsigned int v_version;		/* layout version */
	char	v_volume[8];		/* volume name */
	ushort	v_sectorsz;		/* sector size in bytes */
	ushort	v_nparts;		/* number of partitions */
	unsigned int v_reserved[10];	/* free space */
	struct solaris_x86_slice
		v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */
	unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp (unsupported) */
	char	v_asciilabel[128];	/* for compatibility */
};

#endif /* CONFIG_SOLARIS_X86_PARTITION */

#ifdef CONFIG_BSD_DISKLABEL
/*
 * BSD disklabel support by Yossi Gottlieb <[e-mail]>
 * updated by Marc Espie <[e-mail]>
 */

/* check against BSD src/sys/sys/disklabel.h for consistency */

#define BSD_DISKMAGIC	(0x82564557UL)	/* The disk magic number */
#define BSD_MAXPARTITIONS	8
#define OPENBSD_MAXPARTITIONS	16
#define BSD_FS_UNUSED		0	/* disklabel unused partition entry ID */
struct bsd_disklabel {
	__u32	d_magic;		/* the magic number */
	__s16	d_type;			/* drive type */
	__s16	d_subtype;		/* controller/d_type specific */
	char	d_typename[16];		/* type name, e.g. "eagle" */
	char	d_packname[16];			/* pack identifier */ 
	__u32	d_secsize;		/* # of bytes per sector */
	__u32	d_nsectors;		/* # of data sectors per track */
	__u32	d_ntracks;		/* # of tracks per cylinder */
	__u32	d_ncylinders;		/* # of data cylinders per unit */
	__u32	d_secpercyl;		/* # of data sectors per cylinder */
	__u32	d_secperunit;		/* # of data sectors per unit */
	__u16	d_sparespertrack;	/* # of spare sectors per track */
	__u16	d_sparespercyl;		/* # of spare sectors per cylinder */
	__u32	d_acylinders;		/* # of alt. cylinders per unit */
	__u16	d_rpm;			/* rotational speed */
	__u16	d_interleave;		/* hardware sector interleave */
	__u16	d_trackskew;		/* sector 0 skew, per track */
	__u16	d_cylskew;		/* sector 0 skew, per cylinder */
	__u32	d_headswitch;		/* head switch time, usec */
	__u32	d_trkseek;		/* track-to-track seek, usec */
	__u32	d_flags;		/* generic flags */
#define NDDATA 5
	__u32	d_drivedata[NDDATA];	/* drive-type specific information */
#define NSPARE 5
	__u32	d_spare[NSPARE];	/* reserved for future use */
	__u32	d_magic2;		/* the magic number (again) */
	__u16	d_checksum;		/* xor of data incl. partitions */

			/* filesystem and partition information: */
	__u16	d_npartitions;		/* number of partitions in following */
	__u32	d_bbsize;		/* size of boot area at sn0, bytes */
	__u32	d_sbsize;		/* max size of fs superblock, bytes */
	struct	bsd_partition {		/* the partition table */
		__u32	p_size;		/* number of sectors in partition */
		__u32	p_offset;	/* starting sector */
		__u32	p_fsize;	/* filesystem basic fragment size */
		__u8	p_fstype;	/* filesystem type, see below */
		__u8	p_frag;		/* filesystem fragments per block */
		__u16	p_cpg;		/* filesystem cylinders per group */
	} d_partitions[BSD_MAXPARTITIONS];	/* actually may be more */
};

#endif	/* CONFIG_BSD_DISKLABEL */

#ifdef CONFIG_UNIXWARE_DISKLABEL
/*
 * Unixware slices support by Andrzej Krzysztofowicz <[e-mail]>
 * and Krzysztof G. Baranowski <[e-mail]>
 */

#define UNIXWARE_DISKMAGIC     (0xCA5E600DUL)	/* The disk magic number */
#define UNIXWARE_DISKMAGIC2    (0x600DDEEEUL)	/* The slice table magic nr */
#define UNIXWARE_NUMSLICE      16
#define UNIXWARE_FS_UNUSED     0		/* Unused slice entry ID */

struct unixware_slice {
	__u16   s_label;	/* label */
	__u16   s_flags;	/* permission flags */
	__u32   start_sect;	/* starting sector */
	__u32   nr_sects;	/* number of sectors in slice */
};

struct unixware_disklabel {
	__u32   d_type;               	/* drive type */
	__u32   d_magic;                /* the magic number */
	__u32   d_version;              /* version number */
	char    d_serial[12];           /* serial number of the device */
	__u32   d_ncylinders;           /* # of data cylinders per device */
	__u32   d_ntracks;              /* # of tracks per cylinder */
	__u32   d_nsectors;             /* # of data sectors per track */
	__u32   d_secsize;              /* # of bytes per sector */
	__u32   d_part_start;           /* # of first sector of this partition */
	__u32   d_unknown1[12];         /* ? */
 	__u32	d_alt_tbl;              /* byte offset of alternate table */
 	__u32	d_alt_len;              /* byte length of alternate table */
 	__u32	d_phys_cyl;             /* # of physical cylinders per device */
 	__u32	d_phys_trk;             /* # of physical tracks per cylinder */
 	__u32	d_phys_sec;             /* # of physical sectors per track */
 	__u32	d_phys_bytes;           /* # of physical bytes per sector */
 	__u32	d_unknown2;             /* ? */
	__u32   d_unknown3;             /* ? */
	__u32	d_pad[8];               /* pad */

	struct unixware_vtoc {
		__u32	v_magic;		/* the magic number */
		__u32	v_version;		/* version number */
		char	v_name[8];		/* volume name */
		__u16	v_nslices;		/* # of slices */
		__u16	v_unknown1;		/* ? */
		__u32	v_reserved[10];		/* reserved */
		struct unixware_slice
			v_slice[UNIXWARE_NUMSLICE];	/* slice headers */
	} vtoc;

};  /* 408 */

#endif /* CONFIG_UNIXWARE_DISKLABEL */

#ifdef CONFIG_MINIX_SUBPARTITION
#   define MINIX_NR_SUBPARTITIONS  4
#endif /* CONFIG_MINIX_SUBPARTITION */

#ifdef __KERNEL__

char *disk_name (struct gendisk *hd, int minor, char *buf);

/* 
 * Account for the completion of an IO request (used by drivers which 
 * bypass the normal end_request processing) 
 */
struct request;

#ifdef CONFIG_BLK_STATS
extern void disk_round_stats(struct hd_struct *hd);
extern void req_new_io(struct request *req, int merge, int sectors);
extern void req_merged_io(struct request *req);
extern void req_finished_io(struct request *req);
#else
static inline void req_new_io(struct request *req, int merge, int sectors) { }
static inline void req_merged_io(struct request *req) { }
static inline void req_finished_io(struct request *req) { }
#endif /* CONFIG_BLK_STATS */

extern void devfs_register_partitions (struct gendisk *dev, int minor,
				       int unregister);



/*
 * FIXME: this should use genhd->minor_shift, but that is slow to look up.
 */
static inline unsigned int disk_index (kdev_t dev)
{
	int major = MAJOR(dev);
	int minor = MINOR(dev);
	unsigned int index;

	switch (major) {
		case DAC960_MAJOR+0:
			index = (minor & 0x00f8) >> 3;
			break;
		case SCSI_DISK0_MAJOR:
			index = (minor & 0x00f0) >> 4;
			break;
		case IDE0_MAJOR:	/* same as HD_MAJOR */
		case XT_DISK_MAJOR:
			index = (minor & 0x0040) >> 6;
			break;
		case IDE1_MAJOR:
			index = ((minor & 0x0040) >> 6) + 2;
			break;
		default:
			return 0;
	}
	return index;
}

#endif

#endif