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0001 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 0002 /* 0003 md_p.h : physical layout of Linux RAID devices 0004 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman 0005 0006 This program is free software; you can redistribute it and/or modify 0007 it under the terms of the GNU General Public License as published by 0008 the Free Software Foundation; either version 2, or (at your option) 0009 any later version. 0010 0011 You should have received a copy of the GNU General Public License 0012 (for example /usr/src/linux/COPYING); if not, write to the Free 0013 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 0014 */ 0015 0016 #ifndef _MD_P_H 0017 #define _MD_P_H 0018 0019 #include <linux/types.h> 0020 #include <asm/byteorder.h> 0021 0022 /* 0023 * RAID superblock. 0024 * 0025 * The RAID superblock maintains some statistics on each RAID configuration. 0026 * Each real device in the RAID set contains it near the end of the device. 0027 * Some of the ideas are copied from the ext2fs implementation. 0028 * 0029 * We currently use 4096 bytes as follows: 0030 * 0031 * word offset function 0032 * 0033 * 0 - 31 Constant generic RAID device information. 0034 * 32 - 63 Generic state information. 0035 * 64 - 127 Personality specific information. 0036 * 128 - 511 12 32-words descriptors of the disks in the raid set. 0037 * 512 - 911 Reserved. 0038 * 912 - 1023 Disk specific descriptor. 0039 */ 0040 0041 /* 0042 * If x is the real device size in bytes, we return an apparent size of: 0043 * 0044 * y = (x & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES 0045 * 0046 * and place the 4kB superblock at offset y. 0047 */ 0048 #define MD_RESERVED_BYTES (64 * 1024) 0049 #define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) 0050 0051 #define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) 0052 0053 #define MD_SB_BYTES 4096 0054 #define MD_SB_WORDS (MD_SB_BYTES / 4) 0055 #define MD_SB_SECTORS (MD_SB_BYTES / 512) 0056 0057 /* 0058 * The following are counted in 32-bit words 0059 */ 0060 #define MD_SB_GENERIC_OFFSET 0 0061 #define MD_SB_PERSONALITY_OFFSET 64 0062 #define MD_SB_DISKS_OFFSET 128 0063 #define MD_SB_DESCRIPTOR_OFFSET 992 0064 0065 #define MD_SB_GENERIC_CONSTANT_WORDS 32 0066 #define MD_SB_GENERIC_STATE_WORDS 32 0067 #define MD_SB_GENERIC_WORDS (MD_SB_GENERIC_CONSTANT_WORDS + MD_SB_GENERIC_STATE_WORDS) 0068 #define MD_SB_PERSONALITY_WORDS 64 0069 #define MD_SB_DESCRIPTOR_WORDS 32 0070 #define MD_SB_DISKS 27 0071 #define MD_SB_DISKS_WORDS (MD_SB_DISKS*MD_SB_DESCRIPTOR_WORDS) 0072 #define MD_SB_RESERVED_WORDS (1024 - MD_SB_GENERIC_WORDS - MD_SB_PERSONALITY_WORDS - MD_SB_DISKS_WORDS - MD_SB_DESCRIPTOR_WORDS) 0073 #define MD_SB_EQUAL_WORDS (MD_SB_GENERIC_WORDS + MD_SB_PERSONALITY_WORDS + MD_SB_DISKS_WORDS) 0074 0075 /* 0076 * Device "operational" state bits 0077 */ 0078 #define MD_DISK_FAULTY 0 /* disk is faulty / operational */ 0079 #define MD_DISK_ACTIVE 1 /* disk is running or spare disk */ 0080 #define MD_DISK_SYNC 2 /* disk is in sync with the raid set */ 0081 #define MD_DISK_REMOVED 3 /* disk is in sync with the raid set */ 0082 #define MD_DISK_CLUSTER_ADD 4 /* Initiate a disk add across the cluster 0083 * For clustered enviroments only. 0084 */ 0085 #define MD_DISK_CANDIDATE 5 /* disk is added as spare (local) until confirmed 0086 * For clustered enviroments only. 0087 */ 0088 #define MD_DISK_FAILFAST 10 /* Send REQ_FAILFAST if there are multiple 0089 * devices available - and don't try to 0090 * correct read errors. 0091 */ 0092 0093 #define MD_DISK_WRITEMOSTLY 9 /* disk is "write-mostly" is RAID1 config. 0094 * read requests will only be sent here in 0095 * dire need 0096 */ 0097 #define MD_DISK_JOURNAL 18 /* disk is used as the write journal in RAID-5/6 */ 0098 0099 #define MD_DISK_ROLE_SPARE 0xffff 0100 #define MD_DISK_ROLE_FAULTY 0xfffe 0101 #define MD_DISK_ROLE_JOURNAL 0xfffd 0102 #define MD_DISK_ROLE_MAX 0xff00 /* max value of regular disk role */ 0103 0104 typedef struct mdp_device_descriptor_s { 0105 __u32 number; /* 0 Device number in the entire set */ 0106 __u32 major; /* 1 Device major number */ 0107 __u32 minor; /* 2 Device minor number */ 0108 __u32 raid_disk; /* 3 The role of the device in the raid set */ 0109 __u32 state; /* 4 Operational state */ 0110 __u32 reserved[MD_SB_DESCRIPTOR_WORDS - 5]; 0111 } mdp_disk_t; 0112 0113 #define MD_SB_MAGIC 0xa92b4efc 0114 0115 /* 0116 * Superblock state bits 0117 */ 0118 #define MD_SB_CLEAN 0 0119 #define MD_SB_ERRORS 1 0120 0121 #define MD_SB_CLUSTERED 5 /* MD is clustered */ 0122 #define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */ 0123 0124 /* 0125 * Notes: 0126 * - if an array is being reshaped (restriped) in order to change 0127 * the number of active devices in the array, 'raid_disks' will be 0128 * the larger of the old and new numbers. 'delta_disks' will 0129 * be the "new - old". So if +ve, raid_disks is the new value, and 0130 * "raid_disks-delta_disks" is the old. If -ve, raid_disks is the 0131 * old value and "raid_disks+delta_disks" is the new (smaller) value. 0132 */ 0133 0134 0135 typedef struct mdp_superblock_s { 0136 /* 0137 * Constant generic information 0138 */ 0139 __u32 md_magic; /* 0 MD identifier */ 0140 __u32 major_version; /* 1 major version to which the set conforms */ 0141 __u32 minor_version; /* 2 minor version ... */ 0142 __u32 patch_version; /* 3 patchlevel version ... */ 0143 __u32 gvalid_words; /* 4 Number of used words in this section */ 0144 __u32 set_uuid0; /* 5 Raid set identifier */ 0145 __u32 ctime; /* 6 Creation time */ 0146 __u32 level; /* 7 Raid personality */ 0147 __u32 size; /* 8 Apparent size of each individual disk */ 0148 __u32 nr_disks; /* 9 total disks in the raid set */ 0149 __u32 raid_disks; /* 10 disks in a fully functional raid set */ 0150 __u32 md_minor; /* 11 preferred MD minor device number */ 0151 __u32 not_persistent; /* 12 does it have a persistent superblock */ 0152 __u32 set_uuid1; /* 13 Raid set identifier #2 */ 0153 __u32 set_uuid2; /* 14 Raid set identifier #3 */ 0154 __u32 set_uuid3; /* 15 Raid set identifier #4 */ 0155 __u32 gstate_creserved[MD_SB_GENERIC_CONSTANT_WORDS - 16]; 0156 0157 /* 0158 * Generic state information 0159 */ 0160 __u32 utime; /* 0 Superblock update time */ 0161 __u32 state; /* 1 State bits (clean, ...) */ 0162 __u32 active_disks; /* 2 Number of currently active disks */ 0163 __u32 working_disks; /* 3 Number of working disks */ 0164 __u32 failed_disks; /* 4 Number of failed disks */ 0165 __u32 spare_disks; /* 5 Number of spare disks */ 0166 __u32 sb_csum; /* 6 checksum of the whole superblock */ 0167 #if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN) 0168 __u32 events_hi; /* 7 high-order of superblock update count */ 0169 __u32 events_lo; /* 8 low-order of superblock update count */ 0170 __u32 cp_events_hi; /* 9 high-order of checkpoint update count */ 0171 __u32 cp_events_lo; /* 10 low-order of checkpoint update count */ 0172 #elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN) 0173 __u32 events_lo; /* 7 low-order of superblock update count */ 0174 __u32 events_hi; /* 8 high-order of superblock update count */ 0175 __u32 cp_events_lo; /* 9 low-order of checkpoint update count */ 0176 __u32 cp_events_hi; /* 10 high-order of checkpoint update count */ 0177 #else 0178 #error unspecified endianness 0179 #endif 0180 __u32 recovery_cp; /* 11 recovery checkpoint sector count */ 0181 /* There are only valid for minor_version > 90 */ 0182 __u64 reshape_position; /* 12,13 next address in array-space for reshape */ 0183 __u32 new_level; /* 14 new level we are reshaping to */ 0184 __u32 delta_disks; /* 15 change in number of raid_disks */ 0185 __u32 new_layout; /* 16 new layout */ 0186 __u32 new_chunk; /* 17 new chunk size (bytes) */ 0187 __u32 gstate_sreserved[MD_SB_GENERIC_STATE_WORDS - 18]; 0188 0189 /* 0190 * Personality information 0191 */ 0192 __u32 layout; /* 0 the array's physical layout */ 0193 __u32 chunk_size; /* 1 chunk size in bytes */ 0194 __u32 root_pv; /* 2 LV root PV */ 0195 __u32 root_block; /* 3 LV root block */ 0196 __u32 pstate_reserved[MD_SB_PERSONALITY_WORDS - 4]; 0197 0198 /* 0199 * Disks information 0200 */ 0201 mdp_disk_t disks[MD_SB_DISKS]; 0202 0203 /* 0204 * Reserved 0205 */ 0206 __u32 reserved[MD_SB_RESERVED_WORDS]; 0207 0208 /* 0209 * Active descriptor 0210 */ 0211 mdp_disk_t this_disk; 0212 0213 } mdp_super_t; 0214 0215 static inline __u64 md_event(mdp_super_t *sb) { 0216 __u64 ev = sb->events_hi; 0217 return (ev<<32)| sb->events_lo; 0218 } 0219 0220 #define MD_SUPERBLOCK_1_TIME_SEC_MASK ((1ULL<<40) - 1) 0221 0222 /* 0223 * The version-1 superblock : 0224 * All numeric fields are little-endian. 0225 * 0226 * total size: 256 bytes plus 2 per device. 0227 * 1K allows 384 devices. 0228 */ 0229 struct mdp_superblock_1 { 0230 /* constant array information - 128 bytes */ 0231 __le32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */ 0232 __le32 major_version; /* 1 */ 0233 __le32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */ 0234 __le32 pad0; /* always set to 0 when writing */ 0235 0236 __u8 set_uuid[16]; /* user-space generated. */ 0237 char set_name[32]; /* set and interpreted by user-space */ 0238 0239 __le64 ctime; /* lo 40 bits are seconds, top 24 are microseconds or 0*/ 0240 __le32 level; /* -4 (multipath), -1 (linear), 0,1,4,5 */ 0241 __le32 layout; /* only for raid5 and raid10 currently */ 0242 __le64 size; /* used size of component devices, in 512byte sectors */ 0243 0244 __le32 chunksize; /* in 512byte sectors */ 0245 __le32 raid_disks; 0246 union { 0247 __le32 bitmap_offset; /* sectors after start of superblock that bitmap starts 0248 * NOTE: signed, so bitmap can be before superblock 0249 * only meaningful of feature_map[0] is set. 0250 */ 0251 0252 /* only meaningful when feature_map[MD_FEATURE_PPL] is set */ 0253 struct { 0254 __le16 offset; /* sectors from start of superblock that ppl starts (signed) */ 0255 __le16 size; /* ppl size in sectors */ 0256 } ppl; 0257 }; 0258 0259 /* These are only valid with feature bit '4' */ 0260 __le32 new_level; /* new level we are reshaping to */ 0261 __le64 reshape_position; /* next address in array-space for reshape */ 0262 __le32 delta_disks; /* change in number of raid_disks */ 0263 __le32 new_layout; /* new layout */ 0264 __le32 new_chunk; /* new chunk size (512byte sectors) */ 0265 __le32 new_offset; /* signed number to add to data_offset in new 0266 * layout. 0 == no-change. This can be 0267 * different on each device in the array. 0268 */ 0269 0270 /* constant this-device information - 64 bytes */ 0271 __le64 data_offset; /* sector start of data, often 0 */ 0272 __le64 data_size; /* sectors in this device that can be used for data */ 0273 __le64 super_offset; /* sector start of this superblock */ 0274 union { 0275 __le64 recovery_offset;/* sectors before this offset (from data_offset) have been recovered */ 0276 __le64 journal_tail;/* journal tail of journal device (from data_offset) */ 0277 }; 0278 __le32 dev_number; /* permanent identifier of this device - not role in raid */ 0279 __le32 cnt_corrected_read; /* number of read errors that were corrected by re-writing */ 0280 __u8 device_uuid[16]; /* user-space setable, ignored by kernel */ 0281 __u8 devflags; /* per-device flags. Only two defined...*/ 0282 #define WriteMostly1 1 /* mask for writemostly flag in above */ 0283 #define FailFast1 2 /* Should avoid retries and fixups and just fail */ 0284 /* Bad block log. If there are any bad blocks the feature flag is set. 0285 * If offset and size are non-zero, that space is reserved and available 0286 */ 0287 __u8 bblog_shift; /* shift from sectors to block size */ 0288 __le16 bblog_size; /* number of sectors reserved for list */ 0289 __le32 bblog_offset; /* sector offset from superblock to bblog, 0290 * signed - not unsigned */ 0291 0292 /* array state information - 64 bytes */ 0293 __le64 utime; /* 40 bits second, 24 bits microseconds */ 0294 __le64 events; /* incremented when superblock updated */ 0295 __le64 resync_offset; /* data before this offset (from data_offset) known to be in sync */ 0296 __le32 sb_csum; /* checksum up to devs[max_dev] */ 0297 __le32 max_dev; /* size of devs[] array to consider */ 0298 __u8 pad3[64-32]; /* set to 0 when writing */ 0299 0300 /* device state information. Indexed by dev_number. 0301 * 2 bytes per device 0302 * Note there are no per-device state flags. State information is rolled 0303 * into the 'roles' value. If a device is spare or faulty, then it doesn't 0304 * have a meaningful role. 0305 */ 0306 __le16 dev_roles[]; /* role in array, or 0xffff for a spare, or 0xfffe for faulty */ 0307 }; 0308 0309 /* feature_map bits */ 0310 #define MD_FEATURE_BITMAP_OFFSET 1 0311 #define MD_FEATURE_RECOVERY_OFFSET 2 /* recovery_offset is present and 0312 * must be honoured 0313 */ 0314 #define MD_FEATURE_RESHAPE_ACTIVE 4 0315 #define MD_FEATURE_BAD_BLOCKS 8 /* badblock list is not empty */ 0316 #define MD_FEATURE_REPLACEMENT 16 /* This device is replacing an 0317 * active device with same 'role'. 0318 * 'recovery_offset' is also set. 0319 */ 0320 #define MD_FEATURE_RESHAPE_BACKWARDS 32 /* Reshape doesn't change number 0321 * of devices, but is going 0322 * backwards anyway. 0323 */ 0324 #define MD_FEATURE_NEW_OFFSET 64 /* new_offset must be honoured */ 0325 #define MD_FEATURE_RECOVERY_BITMAP 128 /* recovery that is happening 0326 * is guided by bitmap. 0327 */ 0328 #define MD_FEATURE_CLUSTERED 256 /* clustered MD */ 0329 #define MD_FEATURE_JOURNAL 512 /* support write cache */ 0330 #define MD_FEATURE_PPL 1024 /* support PPL */ 0331 #define MD_FEATURE_MULTIPLE_PPLS 2048 /* support for multiple PPLs */ 0332 #define MD_FEATURE_RAID0_LAYOUT 4096 /* layout is meaningful for RAID0 */ 0333 #define MD_FEATURE_ALL (MD_FEATURE_BITMAP_OFFSET \ 0334 |MD_FEATURE_RECOVERY_OFFSET \ 0335 |MD_FEATURE_RESHAPE_ACTIVE \ 0336 |MD_FEATURE_BAD_BLOCKS \ 0337 |MD_FEATURE_REPLACEMENT \ 0338 |MD_FEATURE_RESHAPE_BACKWARDS \ 0339 |MD_FEATURE_NEW_OFFSET \ 0340 |MD_FEATURE_RECOVERY_BITMAP \ 0341 |MD_FEATURE_CLUSTERED \ 0342 |MD_FEATURE_JOURNAL \ 0343 |MD_FEATURE_PPL \ 0344 |MD_FEATURE_MULTIPLE_PPLS \ 0345 |MD_FEATURE_RAID0_LAYOUT \ 0346 ) 0347 0348 struct r5l_payload_header { 0349 __le16 type; 0350 __le16 flags; 0351 } __attribute__ ((__packed__)); 0352 0353 enum r5l_payload_type { 0354 R5LOG_PAYLOAD_DATA = 0, 0355 R5LOG_PAYLOAD_PARITY = 1, 0356 R5LOG_PAYLOAD_FLUSH = 2, 0357 }; 0358 0359 struct r5l_payload_data_parity { 0360 struct r5l_payload_header header; 0361 __le32 size; /* sector. data/parity size. each 4k 0362 * has a checksum */ 0363 __le64 location; /* sector. For data, it's raid sector. For 0364 * parity, it's stripe sector */ 0365 __le32 checksum[]; 0366 } __attribute__ ((__packed__)); 0367 0368 enum r5l_payload_data_parity_flag { 0369 R5LOG_PAYLOAD_FLAG_DISCARD = 1, /* payload is discard */ 0370 /* 0371 * RESHAPED/RESHAPING is only set when there is reshape activity. Note, 0372 * both data/parity of a stripe should have the same flag set 0373 * 0374 * RESHAPED: reshape is running, and this stripe finished reshape 0375 * RESHAPING: reshape is running, and this stripe isn't reshaped 0376 */ 0377 R5LOG_PAYLOAD_FLAG_RESHAPED = 2, 0378 R5LOG_PAYLOAD_FLAG_RESHAPING = 3, 0379 }; 0380 0381 struct r5l_payload_flush { 0382 struct r5l_payload_header header; 0383 __le32 size; /* flush_stripes size, bytes */ 0384 __le64 flush_stripes[]; 0385 } __attribute__ ((__packed__)); 0386 0387 enum r5l_payload_flush_flag { 0388 R5LOG_PAYLOAD_FLAG_FLUSH_STRIPE = 1, /* data represents whole stripe */ 0389 }; 0390 0391 struct r5l_meta_block { 0392 __le32 magic; 0393 __le32 checksum; 0394 __u8 version; 0395 __u8 __zero_pading_1; 0396 __le16 __zero_pading_2; 0397 __le32 meta_size; /* whole size of the block */ 0398 0399 __le64 seq; 0400 __le64 position; /* sector, start from rdev->data_offset, current position */ 0401 struct r5l_payload_header payloads[]; 0402 } __attribute__ ((__packed__)); 0403 0404 #define R5LOG_VERSION 0x1 0405 #define R5LOG_MAGIC 0x6433c509 0406 0407 struct ppl_header_entry { 0408 __le64 data_sector; /* raid sector of the new data */ 0409 __le32 pp_size; /* length of partial parity */ 0410 __le32 data_size; /* length of data */ 0411 __le32 parity_disk; /* member disk containing parity */ 0412 __le32 checksum; /* checksum of partial parity data for this 0413 * entry (~crc32c) */ 0414 } __attribute__ ((__packed__)); 0415 0416 #define PPL_HEADER_SIZE 4096 0417 #define PPL_HDR_RESERVED 512 0418 #define PPL_HDR_ENTRY_SPACE \ 0419 (PPL_HEADER_SIZE - PPL_HDR_RESERVED - 4 * sizeof(__le32) - sizeof(__le64)) 0420 #define PPL_HDR_MAX_ENTRIES \ 0421 (PPL_HDR_ENTRY_SPACE / sizeof(struct ppl_header_entry)) 0422 0423 struct ppl_header { 0424 __u8 reserved[PPL_HDR_RESERVED];/* reserved space, fill with 0xff */ 0425 __le32 signature; /* signature (family number of volume) */ 0426 __le32 padding; /* zero pad */ 0427 __le64 generation; /* generation number of the header */ 0428 __le32 entries_count; /* number of entries in entry array */ 0429 __le32 checksum; /* checksum of the header (~crc32c) */ 0430 struct ppl_header_entry entries[PPL_HDR_MAX_ENTRIES]; 0431 } __attribute__ ((__packed__)); 0432 0433 #endif
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