lvm.h

unxi下共享内存的使用

/*
 * include/linux/lvm.h
 * kernel/lvm.h
 * tools/lib/lvm.h
 *
 * Copyright (C) 1997 - 2001  Heinz Mauelshagen, Sistina Software
 *
 * February-November 1997
 * May-July 1998
 * January-March,July,September,October,Dezember 1999
 * January,February,July,November 2000
 * January-March,June,July 2001
 *
 * lvm is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * lvm is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */

/*
 * Changelog
 *
 *    10/10/1997 - beginning of new structure creation
 *    12/05/1998 - incorporated structures from lvm_v1.h and deleted lvm_v1.h
 *    07/06/1998 - avoided LVM_KMALLOC_MAX define by using vmalloc/vfree
 *                 instead of kmalloc/kfree
 *    01/07/1998 - fixed wrong LVM_MAX_SIZE
 *    07/07/1998 - extended pe_t structure by ios member (for statistic)
 *    02/08/1998 - changes for official char/block major numbers
 *    07/08/1998 - avoided init_module() and cleanup_module() to be static
 *    29/08/1998 - seprated core and disk structure type definitions
 *    01/09/1998 - merged kernel integration version (mike)
 *    20/01/1999 - added LVM_PE_DISK_OFFSET macro for use in
 *                 vg_read_with_pv_and_lv(), pv_move_pe(), pv_show_pe_text()...
 *    18/02/1999 - added definition of time_disk_t structure for;
 *                 keeps time stamps on disk for nonatomic writes (future)
 *    15/03/1999 - corrected LV() and VG() macro definition to use argument
 *                 instead of minor
 *    03/07/1999 - define for genhd.c name handling
 *    23/07/1999 - implemented snapshot part
 *    08/12/1999 - changed LVM_LV_SIZE_MAX macro to reflect current 1TB limit
 *    01/01/2000 - extended lv_v2 core structure by wait_queue member
 *    12/02/2000 - integrated Andrea Arcagnelli's snapshot work
 *    18/02/2000 - seperated user and kernel space parts by
 *                 #ifdef them with __KERNEL__
 *    08/03/2000 - implemented cluster/shared bits for vg_access
 *    26/06/2000 - implemented snapshot persistency and resizing support
 *    02/11/2000 - added hash table size member to lv structure
 *    12/11/2000 - removed unneeded timestamp definitions
 *    24/12/2000 - removed LVM_TO_{CORE,DISK}*, use cpu_{from, to}_le*
 *                 instead - Christoph Hellwig
 *    22/01/2001 - Change ulong to uint32_t
 *    14/02/2001 - changed LVM_SNAPSHOT_MIN_CHUNK to 1 page
 *    20/02/2001 - incremented IOP version to 11 because of incompatible
 *                 change in VG activation (in order to support devfs better)
 *    01/03/2001 - Revert to IOP10 and add VG_CREATE_OLD call for compatibility
 *    08/03/2001 - new lv_t (in core) version number 5: changed page member
 *                 to (struct kiobuf *) to use for COW exception table io
 *    26/03/2001 - changed lv_v4 to lv_v5 in structure definition (HM)
 *    21/06/2001 - changed BLOCK_SIZE back to 1024 for non S/390
 *    22/06/2001 - added Andreas Dilger's PE on 4k boundary alignment enhancements
 *    19/07/2001 - added rwsem compatibility macros for 2.2 kernels
 *    13/11/2001 - reduced userspace inclusion of kernel headers to a minimum
 *
 */


#ifndef _LVM_H_INCLUDE
#define _LVM_H_INCLUDE

#define LVM_RELEASE_NAME "1.0.3"
#define LVM_RELEASE_DATE "19/02/2002"

#define	_LVM_KERNEL_H_VERSION	"LVM "LVM_RELEASE_NAME" ("LVM_RELEASE_DATE")"

#include <linux/version.h>

/*
 * preprocessor definitions
 */
/* if you like emergency reset code in the driver */
#define	LVM_TOTAL_RESET

#ifdef __KERNEL__
#undef LVM_HD_NAME /* display nice names in /proc/partitions */

/* lots of debugging output (see driver source)
   #define DEBUG_LVM_GET_INFO
   #define DEBUG
   #define DEBUG_MAP
   #define DEBUG_MAP_SIZE
   #define DEBUG_IOCTL
   #define DEBUG_READ
   #define DEBUG_GENDISK
   #define DEBUG_VG_CREATE
   #define DEBUG_DEVICE
   #define DEBUG_KFREE
 */

#include <linux/kdev_t.h>
#include <linux/list.h>
#include <asm/types.h>
#include <linux/major.h>
#else
/* This prevents the need to include <linux/list.h> which
   causes problems on some platforms. It's not nice but then
   neither is the alternative. */
struct list_head {
        struct list_head *next, *prev;
};
#define __KERNEL__
#include <linux/kdev_t.h>
#undef __KERNEL__
#endif				/* #ifndef __KERNEL__ */


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

#include <asm/semaphore.h>
#endif				/* #ifdef __KERNEL__ */


#include <asm/page.h>

#if !defined ( LVM_BLK_MAJOR) || !defined ( LVM_CHAR_MAJOR)
#error Bad include/linux/major.h - LVM MAJOR undefined
#endif

#ifdef	BLOCK_SIZE
#undef	BLOCK_SIZE
#endif

#ifdef CONFIG_ARCH_S390
#define BLOCK_SIZE	4096
#else
#define BLOCK_SIZE	1024
#endif

#ifndef	SECTOR_SIZE
#define SECTOR_SIZE	512
#endif

/* structure version */
#define LVM_STRUCT_VERSION 1

#define	LVM_DIR_PREFIX	"/dev/"

/*
 * i/o protocol version
 *
 * defined here for the driver and defined seperate in the
 * user land tools/lib/liblvm.h
 *
 */
#define	LVM_DRIVER_IOP_VERSION	        10

#define LVM_NAME        "lvm"
#define LVM_GLOBAL	"global"
#define LVM_DIR		"lvm"
#define LVM_VG_SUBDIR	"VGs"
#define LVM_LV_SUBDIR	"LVs"
#define LVM_PV_SUBDIR	"PVs"

/*
 * VG/LV indexing macros
 */
/* character minor maps directly to volume group */
#define	VG_CHR(a) ( a)

/* block minor indexes into a volume group/logical volume indirection table */
#define	VG_BLK(a)	( vg_lv_map[a].vg_number)
#define LV_BLK(a)	( vg_lv_map[a].lv_number)

/*
 * absolute limits for VGs, PVs per VG and LVs per VG
 */
#define ABS_MAX_VG	99
#define ABS_MAX_PV	256
#define ABS_MAX_LV	256	/* caused by 8 bit minor */

#define MAX_VG  ABS_MAX_VG
#define MAX_LV	ABS_MAX_LV
#define	MAX_PV	ABS_MAX_PV

#if ( MAX_VG > ABS_MAX_VG)
#undef MAX_VG
#define MAX_VG ABS_MAX_VG
#endif

#if ( MAX_LV > ABS_MAX_LV)
#undef MAX_LV
#define MAX_LV ABS_MAX_LV
#endif


/*
 * VGDA: default disk spaces and offsets
 *
 *   There's space after the structures for later extensions.
 *   The physical volume structure holds offset and size definitions
 *   for itself (well, kind of redundant ;-) and all other structure{s| arrays};
 *
 *   In recent versions since LVM 0.9.1 we align to 4k offsets in order to ease
 *   future kernel reads of the metadata.
 *
 *   offset               what                               size
 *   ---------------      --------------------------------   ------------
 *   0                    physical volume structure          pv->pv_on_disk.size
 *                                                           (~500 byte)
 *   pv->vg_on_disk.base  volume group structure             pv->vg_on_disk.size
 *
 *   pv->uuidlist_on_disk.base                               128 byte each
 *                        uuidlist of physical volumes
 *                        holding one uuid per physical volume
 *
 *   pv->lv_on_disk.base  logical volume structures;         pv->lv_on_disk.size
 *                        one structure per logical volume   (~300 byte each)
 *
 *   pv->pe_on_disk.base  physical extent alloc. structs     pv->pe_on_disk.size
 *                        one strcuture per physical extent  (4 byte each)
 *
 *   End of disk -        first physical extent              default 4 megabyte
 *   PE total *
 *   PE size
 *   (rounded to 64k offset today)
 *
 *   pv->pe_on_disk.base + pv->pe_on_disk.size == start of first physical extent
 *
 */

/* DONT TOUCH THESE !!! */

/*
 * LVM_PE_T_MAX corresponds to:
 *
 * 8KB PE size can map a ~512 MB logical volume at the cost of 1MB memory,
 *
 * 128MB PE size can map a 8TB logical volume at the same cost of memory.
 *
 * Default PE size of 4 MB gives a maximum logical volume size of 256 GB.
 *
 * Maximum PE size of 16GB gives a maximum logical volume size of 1024 TB.
 *
 * AFAIK, the actual kernels limit this to 2 TB.
 *
 * Should be a sufficient spectrum ;*)
 */

/* This is the usable size of pe_disk_t.le_num !!!        v     v */
#define	LVM_PE_T_MAX		( ( 1 << ( sizeof ( uint16_t) * 8)) - 2)

#define	LVM_LV_SIZE_MAX(a)	( ( long long) LVM_PE_T_MAX * (a)->pe_size > ( long long) 1024*1024/SECTOR_SIZE*1024*1024 ? ( long long) 1024*1024/SECTOR_SIZE*1024*1024 : ( long long) LVM_PE_T_MAX * (a)->pe_size)
#define	LVM_MIN_PE_SIZE		( 8192L / SECTOR_SIZE) /* 8 KB in sectors */
#define	LVM_MAX_PE_SIZE		( 16L * 1024L * 1024L / SECTOR_SIZE * 1024)	/* 16GB in sectors */
#define	LVM_DEFAULT_PE_SIZE	( 4096L * 1024 / SECTOR_SIZE)	/* 4 MB in sectors */
#define	LVM_DEFAULT_STRIPE_SIZE	16L	/* 16 KB  */
#define	LVM_MIN_STRIPE_SIZE	( PAGE_SIZE/SECTOR_SIZE)	/* PAGESIZE in sectors */
#define	LVM_MAX_STRIPE_SIZE	( 512L * 1024 / SECTOR_SIZE)	/* 512 KB in sectors */
#define	LVM_MAX_STRIPES		128	/* max # of stripes */
#define	LVM_MAX_SIZE            ( 1024LU * 1024 / SECTOR_SIZE * 1024 * 1024)	/* 1TB[sectors] */
#define	LVM_MAX_MIRRORS    	2	/* future use */
#define	LVM_MIN_READ_AHEAD	0	/* minimum read ahead sectors */
#define	LVM_DEFAULT_READ_AHEAD	1024	/* sectors for 512k scsi segments */
#define	LVM_MAX_READ_AHEAD	10000	/* maximum read ahead sectors */
#define	LVM_MAX_LV_IO_TIMEOUT	60	/* seconds I/O timeout (future use) */
#define	LVM_PARTITION           0xfe	/* LVM partition id */
#define	LVM_NEW_PARTITION       0x8e	/* new LVM partition id (10/09/1999) */
#define	LVM_PE_SIZE_PV_SIZE_REL	5	/* max relation PV size and PE size */

#define	LVM_SNAPSHOT_MAX_CHUNK	1024	/* 1024 KB */
#define	LVM_SNAPSHOT_DEF_CHUNK	64	/* 64  KB */
#define	LVM_SNAPSHOT_MIN_CHUNK	(PAGE_SIZE/1024)	/* 4 or 8 KB */

#define	UNDEF	-1

/*
 * ioctls
 * FIXME: the last parameter to _IO{W,R,WR} is a data type.  The macro will
 *	  expand this using sizeof(), so putting "1" there is misleading
 *	  because sizeof(1) = sizeof(int) = sizeof(2) = 4 on a 32-bit machine!
 */
/* volume group */
#define	VG_CREATE_OLD           _IOW ( 0xfe, 0x00, 1)
#define	VG_REMOVE               _IOW ( 0xfe, 0x01, 1)

#define	VG_EXTEND               _IOW ( 0xfe, 0x03, 1)
#define	VG_REDUCE               _IOW ( 0xfe, 0x04, 1)

#define	VG_STATUS               _IOWR ( 0xfe, 0x05, 1)
#define	VG_STATUS_GET_COUNT     _IOWR ( 0xfe, 0x06, 1)
#define	VG_STATUS_GET_NAMELIST  _IOWR ( 0xfe, 0x07, 1)

#define	VG_SET_EXTENDABLE       _IOW ( 0xfe, 0x08, 1)
#define	VG_RENAME		_IOW ( 0xfe, 0x09, 1)

/* Since 0.9beta6 */
#define	VG_CREATE               _IOW ( 0xfe, 0x0a, 1)

/* logical volume */
#define	LV_CREATE               _IOW ( 0xfe, 0x20, 1)
#define	LV_REMOVE               _IOW ( 0xfe, 0x21, 1)

#define	LV_ACTIVATE             _IO ( 0xfe, 0x22)
#define	LV_DEACTIVATE           _IO ( 0xfe, 0x23)

#define	LV_EXTEND               _IOW ( 0xfe, 0x24, 1)
#define	LV_REDUCE               _IOW ( 0xfe, 0x25, 1)

#define	LV_STATUS_BYNAME        _IOWR ( 0xfe, 0x26, 1)
#define	LV_STATUS_BYINDEX       _IOWR ( 0xfe, 0x27, 1)

#define LV_SET_ACCESS           _IOW ( 0xfe, 0x28, 1)
#define LV_SET_ALLOCATION       _IOW ( 0xfe, 0x29, 1)
#define LV_SET_STATUS           _IOW ( 0xfe, 0x2a, 1)

#define LE_REMAP                _IOW ( 0xfe, 0x2b, 1)

#define LV_SNAPSHOT_USE_RATE    _IOWR ( 0xfe, 0x2c, 1)

#define	LV_STATUS_BYDEV		_IOWR ( 0xfe, 0x2e, 1)

#define	LV_RENAME		_IOW ( 0xfe, 0x2f, 1)

#define	LV_BMAP			_IOWR ( 0xfe, 0x30, 1)


/* physical volume */
#define	PV_STATUS               _IOWR ( 0xfe, 0x40, 1)
#define	PV_CHANGE               _IOWR ( 0xfe, 0x41, 1)
#define	PV_FLUSH                _IOW ( 0xfe, 0x42, 1)

/* physical extent */
#define	PE_LOCK_UNLOCK          _IOW ( 0xfe, 0x50, 1)

/* i/o protocol version */
#define	LVM_GET_IOP_VERSION     _IOR ( 0xfe, 0x98, 1)

#ifdef LVM_TOTAL_RESET
/* special reset function for testing purposes */
#define	LVM_RESET               _IO ( 0xfe, 0x99)
#endif

/* lock the logical volume manager */
#if LVM_DRIVER_IOP_VERSION > 11
#define	LVM_LOCK_LVM            _IO ( 0xfe, 0x9A)
#else
/* This is actually the same as _IO ( 0xff, 0x00), oops.  Remove for IOP 12+ */
#define	LVM_LOCK_LVM            _IO ( 0xfe, 0x100)
#endif
/* END ioctls */


/*
 * Status flags
 */
/* volume group */
#define	VG_ACTIVE            0x01	/* vg_status */
#define	VG_EXPORTED          0x02	/*     "     */
#define	VG_EXTENDABLE        0x04	/*     "     */

#define	VG_READ              0x01	/* vg_access */
#define	VG_WRITE             0x02	/*     "     */
#define	VG_CLUSTERED         0x04	/*     "     */
#define	VG_SHARED            0x08	/*     "     */

/* logical volume */
#define	LV_ACTIVE            0x01	/* lv_status */
#define	LV_SPINDOWN          0x02	/*     "     */