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 | |
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 { |
345 | __le16 ; |
346 | __le16 ; |
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 ; |
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 ; |
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 { |
404 | __le64 ; /* raid sector of the new data */ |
405 | __le32 ; /* length of partial parity */ |
406 | __le32 ; /* length of data */ |
407 | __le32 ; /* member disk containing parity */ |
408 | __le32 ; /* checksum of partial parity data for this |
409 | * entry (~crc32c) */ |
410 | } __attribute__ ((__packed__)); |
411 | |
412 | #define 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 { |
420 | __u8 [PPL_HDR_RESERVED];/* reserved space, fill with 0xff */ |
421 | __le32 ; /* signature (family number of volume) */ |
422 | __le32 ; /* zero pad */ |
423 | __le64 ; /* generation number of the header */ |
424 | __le32 ; /* number of entries in entry array */ |
425 | __le32 ; /* checksum of the header (~crc32c) */ |
426 | struct ppl_header_entry [PPL_HDR_MAX_ENTRIES]; |
427 | } __attribute__ ((__packed__)); |
428 | |
429 | #endif |
430 | |