2 md.h : Multiple Devices driver for Linux
3 Copyright (C) 1994-1996 Marc ZYNGIER
4 <zyngier@ufr-info-p7.ibp.fr> or <maz@gloups.fdn.fr>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 You should have received a copy of the GNU General Public License
12 (for example /usr/src/linux/COPYING); if not, write to the Free
13 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 /* don't include the kernel RAID header! */
22 typedef unsigned int md_u32;
23 typedef unsigned short md_u16;
24 typedef unsigned char md_u8;
26 /*#include <linux/major.h>*/
27 #include <sys/ioctl.h>
29 #define MD_MAJOR MAJOR_MD
32 * Different major versions are not compatible.
33 * Different minor versions are only downward compatible.
34 * Different patchlevel versions are downward and upward compatible.
46 #define MD_READAHEAD (256 * 1024)
48 /* These are the ioctls for md versions < 0.50 */
49 #define REGISTER_MD_DEV _IO (MD_MAJOR, 1)
50 #define START_MD _IO (MD_MAJOR, 2)
51 #define STOP_MD _IO (MD_MAJOR, 3)
54 #define RAID_VERSION _IOR (MD_MAJOR, 0x10, struct md_version)
55 #define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, md_array_info_t)
56 #define GET_DISK_INFO _IOR (MD_MAJOR, 0x12, md_disk_info_t)
57 #define PRINT_RAID_DEBUG _IO (MD_MAJOR, 0x13)
60 #define CLEAR_ARRAY _IO (MD_MAJOR, 0x20)
61 #define ADD_NEW_DISK _IOW (MD_MAJOR, 0x21, md_disk_info_t)
62 #define HOT_REMOVE_DISK _IO (MD_MAJOR, 0x22)
63 #define SET_ARRAY_INFO _IOW (MD_MAJOR, 0x23, md_array_info_t)
64 #define SET_DISK_INFO _IO (MD_MAJOR, 0x24)
65 #define WRITE_RAID_INFO _IO (MD_MAJOR, 0x25)
66 #define UNPROTECT_ARRAY _IO (MD_MAJOR, 0x26)
67 #define PROTECT_ARRAY _IO (MD_MAJOR, 0x27)
68 #define HOT_ADD_DISK _IO (MD_MAJOR, 0x28)
71 #define RUN_ARRAY _IOW (MD_MAJOR, 0x30, struct md_param)
72 #define START_ARRAY _IO (MD_MAJOR, 0x31)
73 #define STOP_ARRAY _IO (MD_MAJOR, 0x32)
74 #define STOP_ARRAY_RO _IO (MD_MAJOR, 0x33)
75 #define RESTART_ARRAY_RW _IO (MD_MAJOR, 0x34)
78 /* for raid < 0.50 only */
79 #define MD_PERSONALITY_SHIFT 16
81 #define MD_RESERVED 0UL
87 #define TRANSLUCENT 5UL
89 #define MAX_PERSONALITY 7UL
94 * The MD superblock maintains some statistics on each MD configuration.
95 * Each real device in the MD set contains it near the end of the device.
96 * Some of the ideas are copied from the ext2fs implementation.
98 * We currently use 4096 bytes as follows:
100 * word offset function
102 * 0 - 31 Constant generic MD device information.
103 * 32 - 63 Generic state information.
104 * 64 - 127 Personality specific information.
105 * 128 - 511 12 32-words descriptors of the disks in the raid set.
106 * 512 - 911 Reserved.
107 * 912 - 1023 Disk specific descriptor.
111 * If x is the real device size in bytes, we return an apparent size of:
113 * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES
115 * and place the 4kB superblock at offset y.
117 #define MD_RESERVED_BYTES (64 * 1024)
118 #define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512)
119 #define MD_RESERVED_BLOCKS (MD_RESERVED_BYTES / BLOCK_SIZE)
121 #define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS)
122 #define MD_NEW_SIZE_BLOCKS(x) ((x & ~(MD_RESERVED_BLOCKS - 1)) - MD_RESERVED_BLOCKS)
124 #define MD_SB_BYTES 4096
125 #define MD_SB_WORDS (MD_SB_BYTES / 4)
126 #define MD_SB_BLOCKS (MD_SB_BYTES / BLOCK_SIZE)
127 #define MD_SB_SECTORS (MD_SB_BYTES / 512)
130 * The following are counted in 32-bit words
132 #define MD_SB_GENERIC_OFFSET 0
133 #define MD_SB_PERSONALITY_OFFSET 64
134 #define MD_SB_DISKS_OFFSET 128
135 #define MD_SB_DESCRIPTOR_OFFSET 992
137 #define MD_SB_GENERIC_CONSTANT_WORDS 32
138 #define MD_SB_GENERIC_STATE_WORDS 32
139 #define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS)
140 #define MD_SB_PERSONALITY_WORDS 64
141 #define MD_SB_DISKS_WORDS 384
142 #define MD_SB_DESCRIPTOR_WORDS 32
143 #define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS)
144 #define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS)
145 #define MD_SB_DISKS (MD_SB_DISKS_WORDS / MD_SB_DESCRIPTOR_WORDS)
148 * Device "operational" state bits
150 #define MD_DISK_FAULTY 0 /* disk is faulty / operational */
151 #define MD_DISK_ACTIVE 1 /* disk is running or spare disk */
152 #define MD_DISK_SYNC 2 /* disk is in sync with the raid set */
154 typedef struct md_device_descriptor_s {
155 md_u32 number; /* 0 Device number in the entire set */
156 md_u32 major; /* 1 Device major number */
157 md_u32 minor; /* 2 Device minor number */
158 md_u32 raid_disk; /* 3 The role of the device in the raid set */
159 md_u32 state; /* 4 Operational state */
160 md_u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5];
163 #define MD_SB_MAGIC 0xa92b4efc
166 * Superblock state bits
168 #define MD_SB_CLEAN 0
169 #define MD_SB_ERRORS 1
171 typedef struct md_superblock_s {
173 * Constant generic information
175 md_u32 md_magic; /* 0 MD identifier */
176 md_u32 major_version; /* 1 major version to which the set conforms */
177 md_u32 minor_version; /* 2 minor version ... */
178 md_u32 patch_version; /* 3 patchlevel version ... */
179 md_u32 gvalid_words; /* 4 Number of used words in this section */
180 md_u32 set_magic; /* 5 Raid set identifier */
181 md_u32 ctime; /* 6 Creation time */
182 md_u32 level; /* 7 Raid personality */
183 md_u32 size; /* 8 Apparent size of each individual disk */
184 md_u32 nr_disks; /* 9 total disks in the raid set */
185 md_u32 raid_disks; /* 10 disks in a fully functional raid set */
186 md_u32 md_minor; /* 11 preferred MD minor device number */
187 md_u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 12];
190 * Generic state information
192 md_u32 utime; /* 0 Superblock update time */
193 md_u32 state; /* 1 State bits (clean, ...) */
194 md_u32 active_disks; /* 2 Number of currently active disks */
195 md_u32 working_disks; /* 3 Number of working disks */
196 md_u32 failed_disks; /* 4 Number of failed disks */
197 md_u32 spare_disks; /* 5 Number of spare disks */
198 md_u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 6];
201 * Personality information
203 md_u32 layout; /* 0 the array's physical layout */
204 md_u32 chunk_size; /* 1 chunk size in bytes */
205 md_u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 2];
210 md_descriptor_t disks[MD_SB_DISKS];
215 md_u32 reserved[MD_SB_RESERVED_WORDS];
220 md_descriptor_t descriptor;
225 * options passed in raidstart:
228 #define MAX_CHUNK_SIZE (4096*1024)
232 int personality; /* 1,2,3,4 */
233 int chunk_size; /* in bytes */
234 int max_fault; /* unused for now */
237 typedef struct md_array_info_s {
239 * Generic constant information
241 md_u32 major_version;
242 md_u32 minor_version;
243 md_u32 patch_version;
250 md_u32 not_persistent;
253 * Generic state information
255 md_u32 utime; /* 0 Superblock update time */
256 md_u32 state; /* 1 State bits (clean, ...) */
257 md_u32 active_disks; /* 2 Number of currently active disks */
258 md_u32 working_disks; /* 3 Number of working disks */
259 md_u32 failed_disks; /* 4 Number of failed disks */
260 md_u32 spare_disks; /* 5 Number of spare disks */
263 * Personality information
265 md_u32 layout; /* 0 the array's physical layout */
266 md_u32 chunk_size; /* 1 chunk size in bytes */
270 typedef struct md_disk_info_s {
272 * configuration/status of one particular disk
284 * Supported RAID5 algorithms
286 #define RAID5_ALGORITHM_LEFT_ASYMMETRIC 0
287 #define RAID5_ALGORITHM_RIGHT_ASYMMETRIC 1
288 #define RAID5_ALGORITHM_LEFT_SYMMETRIC 2
289 #define RAID5_ALGORITHM_RIGHT_SYMMETRIC 3