/*
md.h : Multiple Devices driver for Linux
Copyright (C) 1994-96 Marc ZYNGIER
<zyngier@ufr-info-p7.ibp.fr> or
<maz@gloups.fdn.fr>
This program 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.
You should have received a copy of the GNU General Public License
(for example /usr/src/linux/COPYING); if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _MD_H
#define _MD_H
#include <linux/major.h>
#include <linux/ioctl.h>
#include <linux/types.h>
/*
* Different major versions are not compatible.
* Different minor versions are only downward compatible.
* Different patchlevel versions are downward and upward compatible.
*/
#define MD_MAJOR_VERSION 0
#define MD_MINOR_VERSION 36
#define MD_PATCHLEVEL_VERSION 6
#define MD_DEFAULT_DISK_READAHEAD (256 * 1024)
/* ioctls */
#define REGISTER_DEV _IO (MD_MAJOR, 1)
#define START_MD _IO (MD_MAJOR, 2)
#define STOP_MD _IO (MD_MAJOR, 3)
#define REGISTER_DEV_NEW _IO (MD_MAJOR, 4)
/*
personalities :
Byte 0 : Chunk size factor
Byte 1 : Fault tolerance count for each physical device
( 0 means no fault tolerance,
0xFF means always tolerate faults), not used by now.
Byte 2 : Personality
Byte 3 : Reserved.
*/
#define FAULT_SHIFT 8
#define PERSONALITY_SHIFT 16
#define FACTOR_MASK 0x000000FFUL
#define FAULT_MASK 0x0000FF00UL
#define PERSONALITY_MASK 0x00FF0000UL
#define MD_RESERVED 0 /* Not used by now */
#define LINEAR (1UL << PERSONALITY_SHIFT)
#define STRIPED (2UL << PERSONALITY_SHIFT)
#define RAID0 STRIPED
#define RAID1 (3UL << PERSONALITY_SHIFT)
#define RAID5 (4UL << PERSONALITY_SHIFT)
#define MAX_PERSONALITY 5
/*
* MD superblock.
*
* The MD superblock maintains some statistics on each MD configuration.
* Each real device in the MD set contains it near the end of the device.
* Some of the ideas are copied from the ext2fs implementation.
*
* We currently use 4096 bytes as follows:
*
* word offset function
*
* 0 - 31 Constant generic MD device information.
* 32 - 63 Generic state information.
* 64 - 127 Personality specific information.
* 128 - 511 12 32-words descriptors of the disks in the raid set.
* 512 - 911 Reserved.
* 912 - 1023 Disk specific descriptor.
*/
/*
* If x is the real device size in bytes, we return an apparent size of:
*
* y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
*
* and place the 4kB superblock at offset y.
*/
#define MD_RESERVED_BYTES (64 * 1024)
#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512)
#define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE)
#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
#define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS)
#define MD_SB_BYTES 4096
#define MD_SB_WORDS (MD_SB_BYTES / 4)
#define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE)
#define MD_SB_SECTORS (MD_SB_BYTES / 512)
/*
* The following are counted in 32-bit words
*/
#define MD_SB_GENERIC_OFFSET 0
#define MD_SB_PERSONALITY_OFFSET 64
#define MD_SB_DISKS_OFFSET 128
#define MD_SB_DESCRIPTOR_OFFSET 992
#define MD_SB_GENERIC_CONSTANT_WORDS 32
#define MD_SB_GENERIC_STATE_WORDS 32
#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
#define MD_SB_PERSONALITY_WORDS 64
#define MD_SB_DISKS_WORDS 384
#define MD_SB_DESCRIPTOR_WORDS 32
#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
#define MD_SB_DISKS (MD_SB_DISKS_WORDS / MD_SB_DESCRIPTOR_WORDS)
/*
* Device "operational" state bits
*/
#define MD_FAULTY_DEVICE 0 /* Device is faulty / operational */
#define MD_ACTIVE_DEVICE 1 /* Device is a part or the raid set / spare disk */
#define MD_SYNC_DEVICE 2 /* Device is in sync with the raid set */
typedef struct md_device_descriptor_s {
__u32 number; /* 0 Device number in the entire set */
__u32 major; /* 1 Device major number */
__u32 minor; /* 2 Device minor number */
__u32 raid_disk; /* 3 The role of the device in the raid set */
__u32 state; /* 4 Operational state */
__u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5];
} md_descriptor_t;
#define MD_SB_MAGIC 0xa92b4efc
/*
* Superblock state bits
*/
#define MD_SB_CLEAN 0
#define MD_SB_ERRORS 1
typedef struct md_superblock_s {
/*
* Constant generic information
*/
__u32 md_magic; /* 0 MD identifier */
__u32 major_version; /* 1 major version to which the set conforms */
__u32 minor_version; /* 2 minor version to which the set conforms */
__u32 patch_version; /* 3 patchlevel version to which the set conforms */
__u32 gvalid_words; /* 4 Number of non-reserved words in this section */
__u32 set_magic; /* 5 Raid set identifier */
__u32 ctime; /* 6 Creation time */
__u32 level; /* 7 Raid personality (mirroring, raid5, ...) */
__u32 size; /* 8 Apparent size of each individual disk, in kB */
__u32 nr_disks; /* 9 Number of total disks in the raid set */
__u32 raid_disks; /* 10 Number of disks in a fully functional raid set */
__u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 11];
/*
* Generic state information
*/
__u32 utime; /* 0 Superblock update time */
__u32 state; /* 1 State bits (clean, ...) */
__u32 active_disks; /* 2 Number of currently active disks (some non-faulty disks might not be in sync) */
__u32 working_disks; /* 3 Number of working disks */
__u32 failed_disks; /* 4 Number of failed disks */
__u32 spare_disks; /* 5 Number of spare disks */
__u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 6];
/*
* Personality information
*/
__u32 parity_algorithm;
__u32 chunk_size;
__u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 2];
/*
* Disks information
*/
md_descriptor_t disks[MD_SB_DISKS];
/*
* Reserved
*/
__u32 reserved[MD_SB_RESERVED_WORDS];
/*
* Active descriptor
*/
md_descriptor_t descriptor;
} md_superblock_t;
#ifdef __KERNEL__
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <asm/semaphore.h>
/*
* Kernel-based reconstruction is mostly working, but still requires
* some additional work.
*/
#define SUPPORT_RECONSTRUCTION 0
#define MAX_REAL 8 /* Max number of physical dev per md dev */
#define MAX_MD_DEV 4 /* Max number of md dev */
#define FACTOR(a) ((a)->repartition & FACTOR_MASK)
#define MAX_FAULT(a) (((a)->repartition & FAULT_MASK)>>8)
#define PERSONALITY(a) ((a)->repartition & PERSONALITY_MASK)
#define FACTOR_SHIFT(a) (PAGE_SHIFT + (a) - 10)
struct real_dev
{
kdev_t dev; /* Device number */
int size; /* Device size (in blocks) */
int offset; /* Real device offset (in blocks) in md dev
(only used in linear mode) */
struct inode *inode; /* Lock inode */
md_superblock_t *sb;
u32 sb_offset;
};
struct md_dev;
#define SPARE_INACTIVE 0
#define SPARE_WRITE 1
#define SPARE_ACTIVE 2
struct md_personality
{
char *name;
int (*map)(struct md_dev *mddev, kdev_t *rdev,
unsigned long *rsector, unsigned long size);
int (*make_request)(struct md_dev *mddev, int rw, struct buffer_head * bh);
void (*end_request)(struct buffer_head * bh, int uptodate);
int (*run)(int minor, struct md_dev *mddev);
int (*stop)(int minor, struct md_dev *mddev);
int (*status)(char *page, int minor, struct md_dev *mddev);
int (*ioctl)(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg);
int max_invalid_dev;
int (*error_handler)(struct md_dev *mddev, kdev_t dev);
/*
* Some personalities (RAID-1, RAID-5) can get disks hot-added and
* hot-removed. Hot removal is different from failure. (failure marks
* a disk inactive, but the disk is still part of the array)
*/
int (*hot_add_disk) (struct md_dev *mddev, kdev_t dev);
int (*hot_remove_disk) (struct md_dev *mddev, kdev_t dev);
int (*mark_spare) (struct md_dev *mddev, md_descriptor_t *descriptor, int state);
};
struct md_dev
{
struct real_dev devices[MAX_REAL];
struct md_personality *pers;
md_superblock_t *sb;
int sb_dirty;
int repartition;
int busy;
int nb_dev;
void *private;
};
struct md_thread {
void (*run) (void *data);
void *data;
struct wait_queue *wqueue;
unsigned long flags;
struct semaphore *sem;
struct task_struct *tsk;
};
#define THREAD_WAKEUP 0
extern struct md_dev md_dev[MAX_MD_DEV];
extern int md_size[MAX_MD_DEV];
extern int md_maxreadahead[MAX_MD_DEV];
extern char *partition_name (kdev_t dev);
extern int register_md_personality (int p_num, struct md_personality *p);
extern int unregister_md_personality (int p_num);
extern struct md_thread *md_register_thread (void (*run) (void *data), void *data);
extern void md_unregister_thread (struct md_thread *thread);
extern void md_wakeup_thread(struct md_thread *thread);
extern int md_update_sb (int minor);
extern int md_do_sync(struct md_dev *mddev);
#endif __KERNEL__
#endif _MD_H