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md.h : Multiple Devices driver for Linux
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Copyright (C) 1994-96 Marc ZYNGIER
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<zyngier@ufr-info-p7.ibp.fr> or
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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You should have received a copy of the GNU General Public License
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(for example /usr/src/linux/COPYING); if not, write to the Free
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Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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/* don't include the kernel RAID header! */
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typedef unsigned int md_u32;
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typedef unsigned short md_u16;
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typedef unsigned char md_u8;
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#include <linux/major.h>
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#include <sys/ioctl.h>
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* Different major versions are not compatible.
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* Different minor versions are only downward compatible.
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* Different patchlevel versions are downward and upward compatible.
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#define MD_READAHEAD (256 * 1024)
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/* These are the ioctls for md versions < 0.50 */
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#define REGISTER_MD_DEV _IO (MD_MAJOR, 1)
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#define START_MD _IO (MD_MAJOR, 2)
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#define STOP_MD _IO (MD_MAJOR, 3)
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#define RAID_VERSION _IOR (MD_MAJOR, 0x10, struct md_version)
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#define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, md_array_info_t)
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#define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, md_disk_info_t)
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#define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13)
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#define CLEAR_ARRAY _IO (MD_MAJOR, 0x20)
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#define ADD_NEW_DISK _IOW (MD_MAJOR, 0x21, md_disk_info_t)
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#define HOT_REMOVE_DISK _IO (MD_MAJOR, 0x22)
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#define SET_ARRAY_INFO _IOW (MD_MAJOR, 0x23, md_array_info_t)
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#define SET_DISK_INFO _IO (MD_MAJOR, 0x24)
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#define WRITE_RAID_INFO _IO (MD_MAJOR, 0x25)
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#define UNPROTECT_ARRAY _IO (MD_MAJOR, 0x26)
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#define PROTECT_ARRAY _IO (MD_MAJOR, 0x27)
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#define HOT_ADD_DISK _IO (MD_MAJOR, 0x28)
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#define RUN_ARRAY _IOW (MD_MAJOR, 0x30, struct md_param)
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#define START_ARRAY _IO (MD_MAJOR, 0x31)
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#define STOP_ARRAY _IO (MD_MAJOR, 0x32)
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#define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
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#define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
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/* for raid < 0.50 only */
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#define MD_PERSONALITY_SHIFT 16
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#define MD_RESERVED 0UL
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#define TRANSLUCENT 5UL
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#define MAX_PERSONALITY 7UL
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* The MD superblock maintains some statistics on each MD configuration.
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* Each real device in the MD set contains it near the end of the device.
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* Some of the ideas are copied from the ext2fs implementation.
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* We currently use 4096 bytes as follows:
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* word offset function
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* 0 - 31 Constant generic MD device information.
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* 32 - 63 Generic state information.
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* 64 - 127 Personality specific information.
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* 128 - 511 12 32-words descriptors of the disks in the raid set.
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* 512 - 911 Reserved.
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* 912 - 1023 Disk specific descriptor.
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* If x is the real device size in bytes, we return an apparent size of:
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* y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
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* and place the 4kB superblock at offset y.
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#define MD_RESERVED_BYTES (64 * 1024)
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#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512)
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#define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE)
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#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
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#define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS)
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#define MD_SB_BYTES 4096
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#define MD_SB_WORDS (MD_SB_BYTES / 4)
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#define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE)
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#define MD_SB_SECTORS (MD_SB_BYTES / 512)
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* The following are counted in 32-bit words
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#define MD_SB_GENERIC_OFFSET 0
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#define MD_SB_PERSONALITY_OFFSET 64
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#define MD_SB_DISKS_OFFSET 128
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#define MD_SB_DESCRIPTOR_OFFSET 992
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#define MD_SB_GENERIC_CONSTANT_WORDS 32
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#define MD_SB_GENERIC_STATE_WORDS 32
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#define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
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#define MD_SB_PERSONALITY_WORDS 64
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#define MD_SB_DISKS_WORDS 384
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#define MD_SB_DESCRIPTOR_WORDS 32
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#define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
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#define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
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#define MD_SB_DISKS (MD_SB_DISKS_WORDS / MD_SB_DESCRIPTOR_WORDS)
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* Device "operational" state bits
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#define MD_DISK_FAULTY 0 /* disk is faulty / operational */
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#define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
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#define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
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typedef struct md_device_descriptor_s {
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md_u32 number; /* 0 Device number in the entire set */
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md_u32 majorno; /* 1 Device major number */
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md_u32 minorno; /* 2 Device minor number */
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md_u32 raid_disk; /* 3 The role of the device in the raid set */
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md_u32 state; /* 4 Operational state */
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md_u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5];
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#define MD_SB_MAGIC 0xa92b4efc
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* Superblock state bits
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#define MD_SB_CLEAN 0
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#define MD_SB_ERRORS 1
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typedef struct md_superblock_s {
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* Constant generic information
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md_u32 md_magic; /* 0 MD identifier */
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md_u32 major_version; /* 1 major version to which the set conforms */
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md_u32 minor_version; /* 2 minor version ... */
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md_u32 patch_version; /* 3 patchlevel version ... */
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md_u32 gvalid_words; /* 4 Number of used words in this section */
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md_u32 set_magic; /* 5 Raid set identifier */
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md_u32 ctime; /* 6 Creation time */
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md_u32 level; /* 7 Raid personality */
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md_u32 size; /* 8 Apparent size of each individual disk */
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md_u32 nr_disks; /* 9 total disks in the raid set */
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md_u32 raid_disks; /* 10 disks in a fully functional raid set */
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md_u32 md_minor; /* 11 preferred MD minor device number */
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md_u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 12];
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* Generic state information
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md_u32 utime; /* 0 Superblock update time */
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md_u32 state; /* 1 State bits (clean, ...) */
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md_u32 active_disks; /* 2 Number of currently active disks */
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md_u32 working_disks; /* 3 Number of working disks */
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md_u32 failed_disks; /* 4 Number of failed disks */
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md_u32 spare_disks; /* 5 Number of spare disks */
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md_u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 6];
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* Personality information
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md_u32 layout; /* 0 the array's physical layout */
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md_u32 chunk_size; /* 1 chunk size in bytes */
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md_u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 2];
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md_descriptor_t disks[MD_SB_DISKS];
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md_u32 reserved[MD_SB_RESERVED_WORDS];
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md_descriptor_t descriptor;
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* options passed in raidstart:
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#define MAX_CHUNK_SIZE (4096*1024)
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int personality; /* 1,2,3,4 */
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int chunk_size; /* in bytes */
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int max_fault; /* unused for now */
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typedef struct md_array_info_s {
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* Generic constant information
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md_u32 major_version;
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md_u32 minor_version;
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md_u32 patch_version;
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md_u32 not_persistent;
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* Generic state information
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md_u32 utime; /* 0 Superblock update time */
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md_u32 state; /* 1 State bits (clean, ...) */
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md_u32 active_disks; /* 2 Number of currently active disks */
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md_u32 working_disks; /* 3 Number of working disks */
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md_u32 failed_disks; /* 4 Number of failed disks */
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md_u32 spare_disks; /* 5 Number of spare disks */
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* Personality information
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md_u32 layout; /* 0 the array's physical layout */
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md_u32 chunk_size; /* 1 chunk size in bytes */
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typedef struct md_disk_info_s {
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* configuration/status of one particular disk
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* Supported RAID5 algorithms
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#define RAID5_ALGORITHM_LEFT_ASYMMETRIC 0
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#define RAID5_ALGORITHM_RIGHT_ASYMMETRIC 1
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#define RAID5_ALGORITHM_LEFT_SYMMETRIC 2
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#define RAID5_ALGORITHM_RIGHT_SYMMETRIC 3
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include/md-int.h
