1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2 /* 3 md_p.h : physical layout of Linux RAID devices 4 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman 5 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) 9 any later version. 10 */ 11 12 #ifndef _MD_P_H 13 #define _MD_P_H 14 15 #include <linux/types.h> 16 #include <asm/byteorder.h> 17 18 /* 19 * RAID superblock. 20 * 21 * The RAID superblock maintains some statistics on each RAID configuration. 22 * Each real device in the RAID set contains it near the end of the device. 23 * Some of the ideas are copied from the ext2fs implementation. 24 * 25 * We currently use 4096 bytes as follows: 26 * 27 * word offset function 28 * 29 * 0 - 31 Constant generic RAID device information. 30 * 32 - 63 Generic state information. 31 * 64 - 127 Personality specific information. 32 * 128 - 511 12 32-words descriptors of the disks in the raid set. 33 * 512 - 911 Reserved. 34 * 912 - 1023 Disk specific descriptor. 35 */ 36 37 /* 38 * If x is the real device size in bytes, we return an apparent size of: 39 * 40 * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES 41 * 42 * and place the 4kB superblock at offset y. 43 */ 44 #define MD_RESERVED_BYTES (64 * 1024) 45 #define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) 46 47 #define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) 48 49 #define MD_SB_BYTES 4096 50 #define MD_SB_WORDS (MD_SB_BYTES / 4) 51 #define MD_SB_SECTORS (MD_SB_BYTES / 512) 52 53 /* 54 * The following are counted in 32-bit words 55 */ 56 #define MD_SB_GENERIC_OFFSET 0 57 #define MD_SB_PERSONALITY_OFFSET 64 58 #define MD_SB_DISKS_OFFSET 128 59 #define MD_SB_DESCRIPTOR_OFFSET 992 60 61 #define MD_SB_GENERIC_CONSTANT_WORDS 32 62 #define MD_SB_GENERIC_STATE_WORDS 32 63 #define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS) 64 #define MD_SB_PERSONALITY_WORDS 64 65 #define MD_SB_DESCRIPTOR_WORDS 32 66 #define MD_SB_DISKS 27 67 #define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS) 68 #define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS) 69 #define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS) 70 71 /* 72 * Device "operational" state bits 73 */ 74 #define MD_DISK_FAULTY 0 /* disk is faulty / operational */ 75 #define MD_DISK_ACTIVE 1 /* disk is running or spare disk */ 76 #define MD_DISK_SYNC 2 /* disk is in sync with the raid set */ 77 #define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */ 78 #define MD_DISK_CLUSTER_ADD 4 /* Initiate a disk add across the cluster 79 * For clustered enviroments only. 80 */ 81 #define MD_DISK_CANDIDATE 5 /* disk is added as spare (local) until confirmed 82 * For clustered enviroments only. 83 */ 84 #define MD_DISK_FAILFAST 10 /* Send REQ_FAILFAST if there are multiple 85 * devices available - and don't try to 86 * correct read errors. 87 */ 88 89 #define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config. 90 * read requests will only be sent here in 91 * dire need 92 */ 93 #define MD_DISK_JOURNAL 18 /* disk is used as the write journal in RAID-5/6 */ 94 95 #define MD_DISK_ROLE_SPARE 0xffff 96 #define MD_DISK_ROLE_FAULTY 0xfffe 97 #define MD_DISK_ROLE_JOURNAL 0xfffd 98 #define MD_DISK_ROLE_MAX 0xff00 /* max value of regular disk role */ 99 100 typedef struct mdp_device_descriptor_s { 101 __u32 number; /* 0 Device number in the entire set */ 102 __u32 major; /* 1 Device major number */ 103 __u32 minor; /* 2 Device minor number */ 104 __u32 raid_disk; /* 3 The role of the device in the raid set */ 105 __u32 state; /* 4 Operational state */ 106 __u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5]; 107 } mdp_disk_t; 108 109 #define MD_SB_MAGIC 0xa92b4efc 110 111 /* 112 * Superblock state bits 113 */ 114 #define MD_SB_CLEAN 0 115 #define MD_SB_ERRORS 1 116 117 #define MD_SB_CLUSTERED 5 /* MD is clustered */ 118 #define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */ 119 120 /* 121 * Notes: 122 * - if an array is being reshaped (restriped) in order to change 123 * the number of active devices in the array, 'raid_disks' will be 124 * the larger of the old and new numbers. 'delta_disks' will 125 * be the "new - old". So if +ve, raid_disks is the new value, and 126 * "raid_disks-delta_disks" is the old. If -ve, raid_disks is the 127 * old value and "raid_disks+delta_disks" is the new (smaller) value. 128 */ 129 130 131 typedef struct mdp_superblock_s { 132 /* 133 * Constant generic information 134 */ 135 __u32 md_magic; /* 0 MD identifier */ 136 __u32 major_version; /* 1 major version to which the set conforms */ 137 __u32 minor_version; /* 2 minor version ... */ 138 __u32 patch_version; /* 3 patchlevel version ... */ 139 __u32 gvalid_words; /* 4 Number of used words in this section */ 140 __u32 set_uuid0; /* 5 Raid set identifier */ 141 __u32 ctime; /* 6 Creation time */ 142 __u32 level; /* 7 Raid personality */ 143 __u32 size; /* 8 Apparent size of each individual disk */ 144 __u32 nr_disks; /* 9 total disks in the raid set */ 145 __u32 raid_disks; /* 10 disks in a fully functional raid set */ 146 __u32 md_minor; /* 11 preferred MD minor device number */ 147 __u32 not_persistent; /* 12 does it have a persistent superblock */ 148 __u32 set_uuid1; /* 13 Raid set identifier #2 */ 149 __u32 set_uuid2; /* 14 Raid set identifier #3 */ 150 __u32 set_uuid3; /* 15 Raid set identifier #4 */ 151 __u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16]; 152 153 /* 154 * Generic state information 155 */ 156 __u32 utime; /* 0 Superblock update time */ 157 __u32 state; /* 1 State bits (clean, ...) */ 158 __u32 active_disks; /* 2 Number of currently active disks */ 159 __u32 working_disks; /* 3 Number of working disks */ 160 __u32 failed_disks; /* 4 Number of failed disks */ 161 __u32 spare_disks; /* 5 Number of spare disks */ 162 __u32 sb_csum; /* 6 checksum of the whole superblock */ 163 #if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) 164 __u32 events_hi; /* 7 high-order of superblock update count */ 165 __u32 events_lo; /* 8 low-order of superblock update count */ 166 __u32 cp_events_hi; /* 9 high-order of checkpoint update count */ 167 __u32 cp_events_lo; /* 10 low-order of checkpoint update count */ 168 #elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) 169 __u32 events_lo; /* 7 low-order of superblock update count */ 170 __u32 events_hi; /* 8 high-order of superblock update count */ 171 __u32 cp_events_lo; /* 9 low-order of checkpoint update count */ 172 __u32 cp_events_hi; /* 10 high-order of checkpoint update count */ 173 #else 174 #error unspecified endianness 175 #endif 176 __u32 recovery_cp; /* 11 recovery checkpoint sector count */ 177 /* There are only valid for minor_version > 90 */ 178 __u64 reshape_position; /* 12,13 next address in array-space for reshape */ 179 __u32 new_level; /* 14 new level we are reshaping to */ 180 __u32 delta_disks; /* 15 change in number of raid_disks */ 181 __u32 new_layout; /* 16 new layout */ 182 __u32 new_chunk; /* 17 new chunk size (bytes) */ 183 __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18]; 184 185 /* 186 * Personality information 187 */ 188 __u32 layout; /* 0 the array's physical layout */ 189 __u32 chunk_size; /* 1 chunk size in bytes */ 190 __u32 root_pv; /* 2 LV root PV */ 191 __u32 root_block; /* 3 LV root block */ 192 __u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4]; 193 194 /* 195 * Disks information 196 */ 197 mdp_disk_t disks[MD_SB_DISKS]; 198 199 /* 200 * Reserved 201 */ 202 __u32 reserved[MD_SB_RESERVED_WORDS]; 203 204 /* 205 * Active descriptor 206 */ 207 mdp_disk_t this_disk; 208 209 } mdp_super_t; 210 md_event(mdp_super_t * sb)211 static inline __u64 md_event(mdp_super_t *sb) { 212 __u64 ev = sb->events_hi; 213 return (ev<<32)| sb->events_lo; 214 } 215 216 #define MD_SUPERBLOCK_1_TIME_SEC_MASK ((1ULL<<40) - 1) 217 218 /* 219 * The version-1 superblock : 220 * All numeric fields are little-endian. 221 * 222 * total size: 256 bytes plus 2 per device. 223 * 1K allows 384 devices. 224 */ 225 struct mdp_superblock_1 { 226 /* constant array information - 128 bytes */ 227 __le32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */ 228 __le32 major_version; /* 1 */ 229 __le32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */ 230 __le32 pad0; /* always set to 0 when writing */ 231 232 __u8 set_uuid[16]; /* user-space generated. */ 233 char set_name[32]; /* set and interpreted by user-space */ 234 235 __le64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/ 236 __le32 level; /* 0,1,4,5 */ 237 __le32 layout; /* only for raid5 and raid10 currently */ 238 __le64 size; /* used size of component devices, in 512byte sectors */ 239 240 __le32 chunksize; /* in 512byte sectors */ 241 __le32 raid_disks; 242 union { 243 __le32 bitmap_offset; /* sectors after start of superblock that bitmap starts 244 * NOTE: signed, so bitmap can be before superblock 245 * only meaningful of feature_map[0] is set. 246 */ 247 248 /* only meaningful when feature_map[MD_FEATURE_PPL] is set */ 249 struct { 250 __le16 offset; /* sectors from start of superblock that ppl starts (signed) */ 251 __le16 size; /* ppl size in sectors */ 252 } ppl; 253 }; 254 255 /* These are only valid with feature bit '4' */ 256 __le32 new_level; /* new level we are reshaping to */ 257 __le64 reshape_position; /* next address in array-space for reshape */ 258 __le32 delta_disks; /* change in number of raid_disks */ 259 __le32 new_layout; /* new layout */ 260 __le32 new_chunk; /* new chunk size (512byte sectors) */ 261 __le32 new_offset; /* signed number to add to data_offset in new 262 * layout. 0 == no-change. This can be 263 * different on each device in the array. 264 */ 265 266 /* constant this-device information - 64 bytes */ 267 __le64 data_offset; /* sector start of data, often 0 */ 268 __le64 data_size; /* sectors in this device that can be used for data */ 269 __le64 super_offset; /* sector start of this superblock */ 270 union { 271 __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */ 272 __le64 journal_tail;/* journal tail of journal device (from data_offset) */ 273 }; 274 __le32 dev_number; /* permanent identifier of this device - not role in raid */ 275 __le32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */ 276 __u8 device_uuid[16]; /* user-space setable, ignored by kernel */ 277 __u8 devflags; /* per-device flags. Only two defined...*/ 278 #define WriteMostly1 1 /* mask for writemostly flag in above */ 279 #define FailFast1 2 /* Should avoid retries and fixups and just fail */ 280 /* Bad block log. If there are any bad blocks the feature flag is set. 281 * If offset and size are non-zero, that space is reserved and available 282 */ 283 __u8 bblog_shift; /* shift from sectors to block size */ 284 __le16 bblog_size; /* number of sectors reserved for list */ 285 __le32 bblog_offset; /* sector offset from superblock to bblog, 286 * signed - not unsigned */ 287 288 /* array state information - 64 bytes */ 289 __le64 utime; /* 40 bits second, 24 bits microseconds */ 290 __le64 events; /* incremented when superblock updated */ 291 __le64 resync_offset; /* data before this offset (from data_offset) known to be in sync */ 292 __le32 sb_csum; /* checksum up to devs[max_dev] */ 293 __le32 max_dev; /* size of devs[] array to consider */ 294 __u8 pad3[64-32]; /* set to 0 when writing */ 295 296 /* device state information. Indexed by dev_number. 297 * 2 bytes per device 298 * Note there are no per-device state flags. State information is rolled 299 * into the 'roles' value. If a device is spare or faulty, then it doesn't 300 * have a meaningful role. 301 */ 302 __le16 dev_roles[]; /* role in array, or 0xffff for a spare, or 0xfffe for faulty */ 303 }; 304 305 /* feature_map bits */ 306 #define MD_FEATURE_BITMAP_OFFSET 1 307 #define MD_FEATURE_RECOVERY_OFFSET 2 /* recovery_offset is present and 308 * must be honoured 309 */ 310 #define MD_FEATURE_RESHAPE_ACTIVE 4 311 #define MD_FEATURE_BAD_BLOCKS 8 /* badblock list is not empty */ 312 #define MD_FEATURE_REPLACEMENT 16 /* This device is replacing an 313 * active device with same 'role'. 314 * 'recovery_offset' is also set. 315 */ 316 #define MD_FEATURE_RESHAPE_BACKWARDS 32 /* Reshape doesn't change number 317 * of devices, but is going 318 * backwards anyway. 319 */ 320 #define MD_FEATURE_NEW_OFFSET 64 /* new_offset must be honoured */ 321 #define MD_FEATURE_RECOVERY_BITMAP 128 /* recovery that is happening 322 * is guided by bitmap. 323 */ 324 #define MD_FEATURE_CLUSTERED 256 /* clustered MD */ 325 #define MD_FEATURE_JOURNAL 512 /* support write cache */ 326 #define MD_FEATURE_PPL 1024 /* support PPL */ 327 #define MD_FEATURE_MULTIPLE_PPLS 2048 /* support for multiple PPLs */ 328 #define MD_FEATURE_RAID0_LAYOUT 4096 /* layout is meaningful for RAID0 */ 329 #define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \ 330 |MD_FEATURE_RECOVERY_OFFSET \ 331 |MD_FEATURE_RESHAPE_ACTIVE \ 332 |MD_FEATURE_BAD_BLOCKS \ 333 |MD_FEATURE_REPLACEMENT \ 334 |MD_FEATURE_RESHAPE_BACKWARDS \ 335 |MD_FEATURE_NEW_OFFSET \ 336 |MD_FEATURE_RECOVERY_BITMAP \ 337 |MD_FEATURE_CLUSTERED \ 338 |MD_FEATURE_JOURNAL \ 339 |MD_FEATURE_PPL \ 340 |MD_FEATURE_MULTIPLE_PPLS \ 341 |MD_FEATURE_RAID0_LAYOUT \ 342 ) 343 344 struct r5l_payload_header { 345 __le16 type; 346 __le16 flags; 347 } __attribute__ ((__packed__)); 348 349 enum r5l_payload_type { 350 R5LOG_PAYLOAD_DATA = 0, 351 R5LOG_PAYLOAD_PARITY = 1, 352 R5LOG_PAYLOAD_FLUSH = 2, 353 }; 354 355 struct r5l_payload_data_parity { 356 struct r5l_payload_header header; 357 __le32 size; /* sector. data/parity size. each 4k 358 * has a checksum */ 359 __le64 location; /* sector. For data, it's raid sector. For 360 * parity, it's stripe sector */ 361 __le32 checksum[]; 362 } __attribute__ ((__packed__)); 363 364 enum r5l_payload_data_parity_flag { 365 R5LOG_PAYLOAD_FLAG_DISCARD = 1, /* payload is discard */ 366 /* 367 * RESHAPED/RESHAPING is only set when there is reshape activity. Note, 368 * both data/parity of a stripe should have the same flag set 369 * 370 * RESHAPED: reshape is running, and this stripe finished reshape 371 * RESHAPING: reshape is running, and this stripe isn't reshaped 372 */ 373 R5LOG_PAYLOAD_FLAG_RESHAPED = 2, 374 R5LOG_PAYLOAD_FLAG_RESHAPING = 3, 375 }; 376 377 struct r5l_payload_flush { 378 struct r5l_payload_header header; 379 __le32 size; /* flush_stripes size, bytes */ 380 __le64 flush_stripes[]; 381 } __attribute__ ((__packed__)); 382 383 enum r5l_payload_flush_flag { 384 R5LOG_PAYLOAD_FLAG_FLUSH_STRIPE = 1, /* data represents whole stripe */ 385 }; 386 387 struct r5l_meta_block { 388 __le32 magic; 389 __le32 checksum; 390 __u8 version; 391 __u8 __zero_pading_1; 392 __le16 __zero_pading_2; 393 __le32 meta_size; /* whole size of the block */ 394 395 __le64 seq; 396 __le64 position; /* sector, start from rdev->data_offset, current position */ 397 struct r5l_payload_header payloads[]; 398 } __attribute__ ((__packed__)); 399 400 #define R5LOG_VERSION 0x1 401 #define R5LOG_MAGIC 0x6433c509 402 403 struct ppl_header_entry { 404 __le64 data_sector; /* raid sector of the new data */ 405 __le32 pp_size; /* length of partial parity */ 406 __le32 data_size; /* length of data */ 407 __le32 parity_disk; /* member disk containing parity */ 408 __le32 checksum; /* checksum of partial parity data for this 409 * entry (~crc32c) */ 410 } __attribute__ ((__packed__)); 411 412 #define PPL_HEADER_SIZE 4096 413 #define PPL_HDR_RESERVED 512 414 #define PPL_HDR_ENTRY_SPACE \ 415 (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(__le32) - sizeof(__le64)) 416 #define PPL_HDR_MAX_ENTRIES \ 417 (PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry)) 418 419 struct ppl_header { 420 __u8 reserved[PPL_HDR_RESERVED];/* reserved space, fill with 0xff */ 421 __le32 signature; /* signature (family number of volume) */ 422 __le32 padding; /* zero pad */ 423 __le64 generation; /* generation number of the header */ 424 __le32 entries_count; /* number of entries in entry array */ 425 __le32 checksum; /* checksum of the header (~crc32c) */ 426 struct ppl_header_entry entries[PPL_HDR_MAX_ENTRIES]; 427 } __attribute__ ((__packed__)); 428 429 #endif 430