1 /* 2 * Copyright (C) 2010-2011 Neil Brown 3 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved. 4 * 5 * This file is released under the GPL. 6 */ 7 8 #include <linux/slab.h> 9 #include <linux/module.h> 10 11 #include "md.h" 12 #include "raid1.h" 13 #include "raid5.h" 14 #include "bitmap.h" 15 16 #include <linux/device-mapper.h> 17 18 #define DM_MSG_PREFIX "raid" 19 20 /* 21 * The following flags are used by dm-raid.c to set up the array state. 22 * They must be cleared before md_run is called. 23 */ 24 #define FirstUse 10 /* rdev flag */ 25 26 struct raid_dev { 27 /* 28 * Two DM devices, one to hold metadata and one to hold the 29 * actual data/parity. The reason for this is to not confuse 30 * ti->len and give more flexibility in altering size and 31 * characteristics. 32 * 33 * While it is possible for this device to be associated 34 * with a different physical device than the data_dev, it 35 * is intended for it to be the same. 36 * |--------- Physical Device ---------| 37 * |- meta_dev -|------ data_dev ------| 38 */ 39 struct dm_dev *meta_dev; 40 struct dm_dev *data_dev; 41 struct md_rdev rdev; 42 }; 43 44 /* 45 * Flags for rs->print_flags field. 46 */ 47 #define DMPF_SYNC 0x1 48 #define DMPF_NOSYNC 0x2 49 #define DMPF_REBUILD 0x4 50 #define DMPF_DAEMON_SLEEP 0x8 51 #define DMPF_MIN_RECOVERY_RATE 0x10 52 #define DMPF_MAX_RECOVERY_RATE 0x20 53 #define DMPF_MAX_WRITE_BEHIND 0x40 54 #define DMPF_STRIPE_CACHE 0x80 55 #define DMPF_REGION_SIZE 0X100 56 struct raid_set { 57 struct dm_target *ti; 58 59 uint32_t bitmap_loaded; 60 uint32_t print_flags; 61 62 struct mddev md; 63 struct raid_type *raid_type; 64 struct dm_target_callbacks callbacks; 65 66 struct raid_dev dev[0]; 67 }; 68 69 /* Supported raid types and properties. */ 70 static struct raid_type { 71 const char *name; /* RAID algorithm. */ 72 const char *descr; /* Descriptor text for logging. */ 73 const unsigned parity_devs; /* # of parity devices. */ 74 const unsigned minimal_devs; /* minimal # of devices in set. */ 75 const unsigned level; /* RAID level. */ 76 const unsigned algorithm; /* RAID algorithm. */ 77 } raid_types[] = { 78 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */}, 79 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0}, 80 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC}, 81 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC}, 82 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC}, 83 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC}, 84 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART}, 85 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART}, 86 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE} 87 }; 88 89 static struct raid_type *get_raid_type(char *name) 90 { 91 int i; 92 93 for (i = 0; i < ARRAY_SIZE(raid_types); i++) 94 if (!strcmp(raid_types[i].name, name)) 95 return &raid_types[i]; 96 97 return NULL; 98 } 99 100 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs) 101 { 102 unsigned i; 103 struct raid_set *rs; 104 sector_t sectors_per_dev; 105 106 if (raid_devs <= raid_type->parity_devs) { 107 ti->error = "Insufficient number of devices"; 108 return ERR_PTR(-EINVAL); 109 } 110 111 sectors_per_dev = ti->len; 112 if ((raid_type->level > 1) && 113 sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) { 114 ti->error = "Target length not divisible by number of data devices"; 115 return ERR_PTR(-EINVAL); 116 } 117 118 rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL); 119 if (!rs) { 120 ti->error = "Cannot allocate raid context"; 121 return ERR_PTR(-ENOMEM); 122 } 123 124 mddev_init(&rs->md); 125 126 rs->ti = ti; 127 rs->raid_type = raid_type; 128 rs->md.raid_disks = raid_devs; 129 rs->md.level = raid_type->level; 130 rs->md.new_level = rs->md.level; 131 rs->md.dev_sectors = sectors_per_dev; 132 rs->md.layout = raid_type->algorithm; 133 rs->md.new_layout = rs->md.layout; 134 rs->md.delta_disks = 0; 135 rs->md.recovery_cp = 0; 136 137 for (i = 0; i < raid_devs; i++) 138 md_rdev_init(&rs->dev[i].rdev); 139 140 /* 141 * Remaining items to be initialized by further RAID params: 142 * rs->md.persistent 143 * rs->md.external 144 * rs->md.chunk_sectors 145 * rs->md.new_chunk_sectors 146 */ 147 148 return rs; 149 } 150 151 static void context_free(struct raid_set *rs) 152 { 153 int i; 154 155 for (i = 0; i < rs->md.raid_disks; i++) { 156 if (rs->dev[i].meta_dev) 157 dm_put_device(rs->ti, rs->dev[i].meta_dev); 158 if (rs->dev[i].rdev.sb_page) 159 put_page(rs->dev[i].rdev.sb_page); 160 rs->dev[i].rdev.sb_page = NULL; 161 rs->dev[i].rdev.sb_loaded = 0; 162 if (rs->dev[i].data_dev) 163 dm_put_device(rs->ti, rs->dev[i].data_dev); 164 } 165 166 kfree(rs); 167 } 168 169 /* 170 * For every device we have two words 171 * <meta_dev>: meta device name or '-' if missing 172 * <data_dev>: data device name or '-' if missing 173 * 174 * The following are permitted: 175 * - - 176 * - <data_dev> 177 * <meta_dev> <data_dev> 178 * 179 * The following is not allowed: 180 * <meta_dev> - 181 * 182 * This code parses those words. If there is a failure, 183 * the caller must use context_free to unwind the operations. 184 */ 185 static int dev_parms(struct raid_set *rs, char **argv) 186 { 187 int i; 188 int rebuild = 0; 189 int metadata_available = 0; 190 int ret = 0; 191 192 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) { 193 rs->dev[i].rdev.raid_disk = i; 194 195 rs->dev[i].meta_dev = NULL; 196 rs->dev[i].data_dev = NULL; 197 198 /* 199 * There are no offsets, since there is a separate device 200 * for data and metadata. 201 */ 202 rs->dev[i].rdev.data_offset = 0; 203 rs->dev[i].rdev.mddev = &rs->md; 204 205 if (strcmp(argv[0], "-")) { 206 ret = dm_get_device(rs->ti, argv[0], 207 dm_table_get_mode(rs->ti->table), 208 &rs->dev[i].meta_dev); 209 rs->ti->error = "RAID metadata device lookup failure"; 210 if (ret) 211 return ret; 212 213 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL); 214 if (!rs->dev[i].rdev.sb_page) 215 return -ENOMEM; 216 } 217 218 if (!strcmp(argv[1], "-")) { 219 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) && 220 (!rs->dev[i].rdev.recovery_offset)) { 221 rs->ti->error = "Drive designated for rebuild not specified"; 222 return -EINVAL; 223 } 224 225 rs->ti->error = "No data device supplied with metadata device"; 226 if (rs->dev[i].meta_dev) 227 return -EINVAL; 228 229 continue; 230 } 231 232 ret = dm_get_device(rs->ti, argv[1], 233 dm_table_get_mode(rs->ti->table), 234 &rs->dev[i].data_dev); 235 if (ret) { 236 rs->ti->error = "RAID device lookup failure"; 237 return ret; 238 } 239 240 if (rs->dev[i].meta_dev) { 241 metadata_available = 1; 242 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev; 243 } 244 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev; 245 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks); 246 if (!test_bit(In_sync, &rs->dev[i].rdev.flags)) 247 rebuild++; 248 } 249 250 if (metadata_available) { 251 rs->md.external = 0; 252 rs->md.persistent = 1; 253 rs->md.major_version = 2; 254 } else if (rebuild && !rs->md.recovery_cp) { 255 /* 256 * Without metadata, we will not be able to tell if the array 257 * is in-sync or not - we must assume it is not. Therefore, 258 * it is impossible to rebuild a drive. 259 * 260 * Even if there is metadata, the on-disk information may 261 * indicate that the array is not in-sync and it will then 262 * fail at that time. 263 * 264 * User could specify 'nosync' option if desperate. 265 */ 266 DMERR("Unable to rebuild drive while array is not in-sync"); 267 rs->ti->error = "RAID device lookup failure"; 268 return -EINVAL; 269 } 270 271 return 0; 272 } 273 274 /* 275 * validate_region_size 276 * @rs 277 * @region_size: region size in sectors. If 0, pick a size (4MiB default). 278 * 279 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size'). 280 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap. 281 * 282 * Returns: 0 on success, -EINVAL on failure. 283 */ 284 static int validate_region_size(struct raid_set *rs, unsigned long region_size) 285 { 286 unsigned long min_region_size = rs->ti->len / (1 << 21); 287 288 if (!region_size) { 289 /* 290 * Choose a reasonable default. All figures in sectors. 291 */ 292 if (min_region_size > (1 << 13)) { 293 DMINFO("Choosing default region size of %lu sectors", 294 region_size); 295 region_size = min_region_size; 296 } else { 297 DMINFO("Choosing default region size of 4MiB"); 298 region_size = 1 << 13; /* sectors */ 299 } 300 } else { 301 /* 302 * Validate user-supplied value. 303 */ 304 if (region_size > rs->ti->len) { 305 rs->ti->error = "Supplied region size is too large"; 306 return -EINVAL; 307 } 308 309 if (region_size < min_region_size) { 310 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)", 311 region_size, min_region_size); 312 rs->ti->error = "Supplied region size is too small"; 313 return -EINVAL; 314 } 315 316 if (!is_power_of_2(region_size)) { 317 rs->ti->error = "Region size is not a power of 2"; 318 return -EINVAL; 319 } 320 321 if (region_size < rs->md.chunk_sectors) { 322 rs->ti->error = "Region size is smaller than the chunk size"; 323 return -EINVAL; 324 } 325 } 326 327 /* 328 * Convert sectors to bytes. 329 */ 330 rs->md.bitmap_info.chunksize = (region_size << 9); 331 332 return 0; 333 } 334 335 /* 336 * Possible arguments are... 337 * <chunk_size> [optional_args] 338 * 339 * Argument definitions 340 * <chunk_size> The number of sectors per disk that 341 * will form the "stripe" 342 * [[no]sync] Force or prevent recovery of the 343 * entire array 344 * [rebuild <idx>] Rebuild the drive indicated by the index 345 * [daemon_sleep <ms>] Time between bitmap daemon work to 346 * clear bits 347 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization 348 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization 349 * [write_mostly <idx>] Indicate a write mostly drive via index 350 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm) 351 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs 352 * [region_size <sectors>] Defines granularity of bitmap 353 */ 354 static int parse_raid_params(struct raid_set *rs, char **argv, 355 unsigned num_raid_params) 356 { 357 unsigned i, rebuild_cnt = 0; 358 unsigned long value, region_size = 0; 359 char *key; 360 361 /* 362 * First, parse the in-order required arguments 363 * "chunk_size" is the only argument of this type. 364 */ 365 if ((strict_strtoul(argv[0], 10, &value) < 0)) { 366 rs->ti->error = "Bad chunk size"; 367 return -EINVAL; 368 } else if (rs->raid_type->level == 1) { 369 if (value) 370 DMERR("Ignoring chunk size parameter for RAID 1"); 371 value = 0; 372 } else if (!is_power_of_2(value)) { 373 rs->ti->error = "Chunk size must be a power of 2"; 374 return -EINVAL; 375 } else if (value < 8) { 376 rs->ti->error = "Chunk size value is too small"; 377 return -EINVAL; 378 } 379 380 rs->md.new_chunk_sectors = rs->md.chunk_sectors = value; 381 argv++; 382 num_raid_params--; 383 384 /* 385 * We set each individual device as In_sync with a completed 386 * 'recovery_offset'. If there has been a device failure or 387 * replacement then one of the following cases applies: 388 * 389 * 1) User specifies 'rebuild'. 390 * - Device is reset when param is read. 391 * 2) A new device is supplied. 392 * - No matching superblock found, resets device. 393 * 3) Device failure was transient and returns on reload. 394 * - Failure noticed, resets device for bitmap replay. 395 * 4) Device hadn't completed recovery after previous failure. 396 * - Superblock is read and overrides recovery_offset. 397 * 398 * What is found in the superblocks of the devices is always 399 * authoritative, unless 'rebuild' or '[no]sync' was specified. 400 */ 401 for (i = 0; i < rs->md.raid_disks; i++) { 402 set_bit(In_sync, &rs->dev[i].rdev.flags); 403 rs->dev[i].rdev.recovery_offset = MaxSector; 404 } 405 406 /* 407 * Second, parse the unordered optional arguments 408 */ 409 for (i = 0; i < num_raid_params; i++) { 410 if (!strcasecmp(argv[i], "nosync")) { 411 rs->md.recovery_cp = MaxSector; 412 rs->print_flags |= DMPF_NOSYNC; 413 continue; 414 } 415 if (!strcasecmp(argv[i], "sync")) { 416 rs->md.recovery_cp = 0; 417 rs->print_flags |= DMPF_SYNC; 418 continue; 419 } 420 421 /* The rest of the optional arguments come in key/value pairs */ 422 if ((i + 1) >= num_raid_params) { 423 rs->ti->error = "Wrong number of raid parameters given"; 424 return -EINVAL; 425 } 426 427 key = argv[i++]; 428 if (strict_strtoul(argv[i], 10, &value) < 0) { 429 rs->ti->error = "Bad numerical argument given in raid params"; 430 return -EINVAL; 431 } 432 433 if (!strcasecmp(key, "rebuild")) { 434 rebuild_cnt++; 435 if (((rs->raid_type->level != 1) && 436 (rebuild_cnt > rs->raid_type->parity_devs)) || 437 ((rs->raid_type->level == 1) && 438 (rebuild_cnt > (rs->md.raid_disks - 1)))) { 439 rs->ti->error = "Too many rebuild devices specified for given RAID type"; 440 return -EINVAL; 441 } 442 if (value > rs->md.raid_disks) { 443 rs->ti->error = "Invalid rebuild index given"; 444 return -EINVAL; 445 } 446 clear_bit(In_sync, &rs->dev[value].rdev.flags); 447 rs->dev[value].rdev.recovery_offset = 0; 448 rs->print_flags |= DMPF_REBUILD; 449 } else if (!strcasecmp(key, "write_mostly")) { 450 if (rs->raid_type->level != 1) { 451 rs->ti->error = "write_mostly option is only valid for RAID1"; 452 return -EINVAL; 453 } 454 if (value >= rs->md.raid_disks) { 455 rs->ti->error = "Invalid write_mostly drive index given"; 456 return -EINVAL; 457 } 458 set_bit(WriteMostly, &rs->dev[value].rdev.flags); 459 } else if (!strcasecmp(key, "max_write_behind")) { 460 if (rs->raid_type->level != 1) { 461 rs->ti->error = "max_write_behind option is only valid for RAID1"; 462 return -EINVAL; 463 } 464 rs->print_flags |= DMPF_MAX_WRITE_BEHIND; 465 466 /* 467 * In device-mapper, we specify things in sectors, but 468 * MD records this value in kB 469 */ 470 value /= 2; 471 if (value > COUNTER_MAX) { 472 rs->ti->error = "Max write-behind limit out of range"; 473 return -EINVAL; 474 } 475 rs->md.bitmap_info.max_write_behind = value; 476 } else if (!strcasecmp(key, "daemon_sleep")) { 477 rs->print_flags |= DMPF_DAEMON_SLEEP; 478 if (!value || (value > MAX_SCHEDULE_TIMEOUT)) { 479 rs->ti->error = "daemon sleep period out of range"; 480 return -EINVAL; 481 } 482 rs->md.bitmap_info.daemon_sleep = value; 483 } else if (!strcasecmp(key, "stripe_cache")) { 484 rs->print_flags |= DMPF_STRIPE_CACHE; 485 486 /* 487 * In device-mapper, we specify things in sectors, but 488 * MD records this value in kB 489 */ 490 value /= 2; 491 492 if (rs->raid_type->level < 5) { 493 rs->ti->error = "Inappropriate argument: stripe_cache"; 494 return -EINVAL; 495 } 496 if (raid5_set_cache_size(&rs->md, (int)value)) { 497 rs->ti->error = "Bad stripe_cache size"; 498 return -EINVAL; 499 } 500 } else if (!strcasecmp(key, "min_recovery_rate")) { 501 rs->print_flags |= DMPF_MIN_RECOVERY_RATE; 502 if (value > INT_MAX) { 503 rs->ti->error = "min_recovery_rate out of range"; 504 return -EINVAL; 505 } 506 rs->md.sync_speed_min = (int)value; 507 } else if (!strcasecmp(key, "max_recovery_rate")) { 508 rs->print_flags |= DMPF_MAX_RECOVERY_RATE; 509 if (value > INT_MAX) { 510 rs->ti->error = "max_recovery_rate out of range"; 511 return -EINVAL; 512 } 513 rs->md.sync_speed_max = (int)value; 514 } else if (!strcasecmp(key, "region_size")) { 515 rs->print_flags |= DMPF_REGION_SIZE; 516 region_size = value; 517 } else { 518 DMERR("Unable to parse RAID parameter: %s", key); 519 rs->ti->error = "Unable to parse RAID parameters"; 520 return -EINVAL; 521 } 522 } 523 524 if (validate_region_size(rs, region_size)) 525 return -EINVAL; 526 527 if (rs->md.chunk_sectors) 528 rs->ti->split_io = rs->md.chunk_sectors; 529 else 530 rs->ti->split_io = region_size; 531 532 if (rs->md.chunk_sectors) 533 rs->ti->split_io = rs->md.chunk_sectors; 534 else 535 rs->ti->split_io = region_size; 536 537 /* Assume there are no metadata devices until the drives are parsed */ 538 rs->md.persistent = 0; 539 rs->md.external = 1; 540 541 return 0; 542 } 543 544 static void do_table_event(struct work_struct *ws) 545 { 546 struct raid_set *rs = container_of(ws, struct raid_set, md.event_work); 547 548 dm_table_event(rs->ti->table); 549 } 550 551 static int raid_is_congested(struct dm_target_callbacks *cb, int bits) 552 { 553 struct raid_set *rs = container_of(cb, struct raid_set, callbacks); 554 555 if (rs->raid_type->level == 1) 556 return md_raid1_congested(&rs->md, bits); 557 558 return md_raid5_congested(&rs->md, bits); 559 } 560 561 /* 562 * This structure is never routinely used by userspace, unlike md superblocks. 563 * Devices with this superblock should only ever be accessed via device-mapper. 564 */ 565 #define DM_RAID_MAGIC 0x64526D44 566 struct dm_raid_superblock { 567 __le32 magic; /* "DmRd" */ 568 __le32 features; /* Used to indicate possible future changes */ 569 570 __le32 num_devices; /* Number of devices in this array. (Max 64) */ 571 __le32 array_position; /* The position of this drive in the array */ 572 573 __le64 events; /* Incremented by md when superblock updated */ 574 __le64 failed_devices; /* Bit field of devices to indicate failures */ 575 576 /* 577 * This offset tracks the progress of the repair or replacement of 578 * an individual drive. 579 */ 580 __le64 disk_recovery_offset; 581 582 /* 583 * This offset tracks the progress of the initial array 584 * synchronisation/parity calculation. 585 */ 586 __le64 array_resync_offset; 587 588 /* 589 * RAID characteristics 590 */ 591 __le32 level; 592 __le32 layout; 593 __le32 stripe_sectors; 594 595 __u8 pad[452]; /* Round struct to 512 bytes. */ 596 /* Always set to 0 when writing. */ 597 } __packed; 598 599 static int read_disk_sb(struct md_rdev *rdev, int size) 600 { 601 BUG_ON(!rdev->sb_page); 602 603 if (rdev->sb_loaded) 604 return 0; 605 606 if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) { 607 DMERR("Failed to read device superblock"); 608 return -EINVAL; 609 } 610 611 rdev->sb_loaded = 1; 612 613 return 0; 614 } 615 616 static void super_sync(struct mddev *mddev, struct md_rdev *rdev) 617 { 618 struct md_rdev *r, *t; 619 uint64_t failed_devices; 620 struct dm_raid_superblock *sb; 621 622 sb = page_address(rdev->sb_page); 623 failed_devices = le64_to_cpu(sb->failed_devices); 624 625 rdev_for_each(r, t, mddev) 626 if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags)) 627 failed_devices |= (1ULL << r->raid_disk); 628 629 memset(sb, 0, sizeof(*sb)); 630 631 sb->magic = cpu_to_le32(DM_RAID_MAGIC); 632 sb->features = cpu_to_le32(0); /* No features yet */ 633 634 sb->num_devices = cpu_to_le32(mddev->raid_disks); 635 sb->array_position = cpu_to_le32(rdev->raid_disk); 636 637 sb->events = cpu_to_le64(mddev->events); 638 sb->failed_devices = cpu_to_le64(failed_devices); 639 640 sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset); 641 sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp); 642 643 sb->level = cpu_to_le32(mddev->level); 644 sb->layout = cpu_to_le32(mddev->layout); 645 sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors); 646 } 647 648 /* 649 * super_load 650 * 651 * This function creates a superblock if one is not found on the device 652 * and will decide which superblock to use if there's a choice. 653 * 654 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise 655 */ 656 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev) 657 { 658 int ret; 659 struct dm_raid_superblock *sb; 660 struct dm_raid_superblock *refsb; 661 uint64_t events_sb, events_refsb; 662 663 rdev->sb_start = 0; 664 rdev->sb_size = sizeof(*sb); 665 666 ret = read_disk_sb(rdev, rdev->sb_size); 667 if (ret) 668 return ret; 669 670 sb = page_address(rdev->sb_page); 671 if (sb->magic != cpu_to_le32(DM_RAID_MAGIC)) { 672 super_sync(rdev->mddev, rdev); 673 674 set_bit(FirstUse, &rdev->flags); 675 676 /* Force writing of superblocks to disk */ 677 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags); 678 679 /* Any superblock is better than none, choose that if given */ 680 return refdev ? 0 : 1; 681 } 682 683 if (!refdev) 684 return 1; 685 686 events_sb = le64_to_cpu(sb->events); 687 688 refsb = page_address(refdev->sb_page); 689 events_refsb = le64_to_cpu(refsb->events); 690 691 return (events_sb > events_refsb) ? 1 : 0; 692 } 693 694 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev) 695 { 696 int role; 697 struct raid_set *rs = container_of(mddev, struct raid_set, md); 698 uint64_t events_sb; 699 uint64_t failed_devices; 700 struct dm_raid_superblock *sb; 701 uint32_t new_devs = 0; 702 uint32_t rebuilds = 0; 703 struct md_rdev *r, *t; 704 struct dm_raid_superblock *sb2; 705 706 sb = page_address(rdev->sb_page); 707 events_sb = le64_to_cpu(sb->events); 708 failed_devices = le64_to_cpu(sb->failed_devices); 709 710 /* 711 * Initialise to 1 if this is a new superblock. 712 */ 713 mddev->events = events_sb ? : 1; 714 715 /* 716 * Reshaping is not currently allowed 717 */ 718 if ((le32_to_cpu(sb->level) != mddev->level) || 719 (le32_to_cpu(sb->layout) != mddev->layout) || 720 (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) { 721 DMERR("Reshaping arrays not yet supported."); 722 return -EINVAL; 723 } 724 725 /* We can only change the number of devices in RAID1 right now */ 726 if ((rs->raid_type->level != 1) && 727 (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) { 728 DMERR("Reshaping arrays not yet supported."); 729 return -EINVAL; 730 } 731 732 if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))) 733 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset); 734 735 /* 736 * During load, we set FirstUse if a new superblock was written. 737 * There are two reasons we might not have a superblock: 738 * 1) The array is brand new - in which case, all of the 739 * devices must have their In_sync bit set. Also, 740 * recovery_cp must be 0, unless forced. 741 * 2) This is a new device being added to an old array 742 * and the new device needs to be rebuilt - in which 743 * case the In_sync bit will /not/ be set and 744 * recovery_cp must be MaxSector. 745 */ 746 rdev_for_each(r, t, mddev) { 747 if (!test_bit(In_sync, &r->flags)) { 748 if (!test_bit(FirstUse, &r->flags)) 749 DMERR("Superblock area of " 750 "rebuild device %d should have been " 751 "cleared.", r->raid_disk); 752 set_bit(FirstUse, &r->flags); 753 rebuilds++; 754 } else if (test_bit(FirstUse, &r->flags)) 755 new_devs++; 756 } 757 758 if (!rebuilds) { 759 if (new_devs == mddev->raid_disks) { 760 DMINFO("Superblocks created for new array"); 761 set_bit(MD_ARRAY_FIRST_USE, &mddev->flags); 762 } else if (new_devs) { 763 DMERR("New device injected " 764 "into existing array without 'rebuild' " 765 "parameter specified"); 766 return -EINVAL; 767 } 768 } else if (new_devs) { 769 DMERR("'rebuild' devices cannot be " 770 "injected into an array with other first-time devices"); 771 return -EINVAL; 772 } else if (mddev->recovery_cp != MaxSector) { 773 DMERR("'rebuild' specified while array is not in-sync"); 774 return -EINVAL; 775 } 776 777 /* 778 * Now we set the Faulty bit for those devices that are 779 * recorded in the superblock as failed. 780 */ 781 rdev_for_each(r, t, mddev) { 782 if (!r->sb_page) 783 continue; 784 sb2 = page_address(r->sb_page); 785 sb2->failed_devices = 0; 786 787 /* 788 * Check for any device re-ordering. 789 */ 790 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) { 791 role = le32_to_cpu(sb2->array_position); 792 if (role != r->raid_disk) { 793 if (rs->raid_type->level != 1) { 794 rs->ti->error = "Cannot change device " 795 "positions in RAID array"; 796 return -EINVAL; 797 } 798 DMINFO("RAID1 device #%d now at position #%d", 799 role, r->raid_disk); 800 } 801 802 /* 803 * Partial recovery is performed on 804 * returning failed devices. 805 */ 806 if (failed_devices & (1 << role)) 807 set_bit(Faulty, &r->flags); 808 } 809 } 810 811 return 0; 812 } 813 814 static int super_validate(struct mddev *mddev, struct md_rdev *rdev) 815 { 816 struct dm_raid_superblock *sb = page_address(rdev->sb_page); 817 818 /* 819 * If mddev->events is not set, we know we have not yet initialized 820 * the array. 821 */ 822 if (!mddev->events && super_init_validation(mddev, rdev)) 823 return -EINVAL; 824 825 mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */ 826 rdev->mddev->bitmap_info.default_offset = 4096 >> 9; 827 if (!test_bit(FirstUse, &rdev->flags)) { 828 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset); 829 if (rdev->recovery_offset != MaxSector) 830 clear_bit(In_sync, &rdev->flags); 831 } 832 833 /* 834 * If a device comes back, set it as not In_sync and no longer faulty. 835 */ 836 if (test_bit(Faulty, &rdev->flags)) { 837 clear_bit(Faulty, &rdev->flags); 838 clear_bit(In_sync, &rdev->flags); 839 rdev->saved_raid_disk = rdev->raid_disk; 840 rdev->recovery_offset = 0; 841 } 842 843 clear_bit(FirstUse, &rdev->flags); 844 845 return 0; 846 } 847 848 /* 849 * Analyse superblocks and select the freshest. 850 */ 851 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) 852 { 853 int ret; 854 struct md_rdev *rdev, *freshest, *tmp; 855 struct mddev *mddev = &rs->md; 856 857 freshest = NULL; 858 rdev_for_each(rdev, tmp, mddev) { 859 if (!rdev->meta_bdev) 860 continue; 861 862 ret = super_load(rdev, freshest); 863 864 switch (ret) { 865 case 1: 866 freshest = rdev; 867 break; 868 case 0: 869 break; 870 default: 871 ti->error = "Failed to load superblock"; 872 return ret; 873 } 874 } 875 876 if (!freshest) 877 return 0; 878 879 /* 880 * Validation of the freshest device provides the source of 881 * validation for the remaining devices. 882 */ 883 ti->error = "Unable to assemble array: Invalid superblocks"; 884 if (super_validate(mddev, freshest)) 885 return -EINVAL; 886 887 rdev_for_each(rdev, tmp, mddev) 888 if ((rdev != freshest) && super_validate(mddev, rdev)) 889 return -EINVAL; 890 891 return 0; 892 } 893 894 /* 895 * Construct a RAID4/5/6 mapping: 896 * Args: 897 * <raid_type> <#raid_params> <raid_params> \ 898 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> } 899 * 900 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for 901 * details on possible <raid_params>. 902 */ 903 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) 904 { 905 int ret; 906 struct raid_type *rt; 907 unsigned long num_raid_params, num_raid_devs; 908 struct raid_set *rs = NULL; 909 910 /* Must have at least <raid_type> <#raid_params> */ 911 if (argc < 2) { 912 ti->error = "Too few arguments"; 913 return -EINVAL; 914 } 915 916 /* raid type */ 917 rt = get_raid_type(argv[0]); 918 if (!rt) { 919 ti->error = "Unrecognised raid_type"; 920 return -EINVAL; 921 } 922 argc--; 923 argv++; 924 925 /* number of RAID parameters */ 926 if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) { 927 ti->error = "Cannot understand number of RAID parameters"; 928 return -EINVAL; 929 } 930 argc--; 931 argv++; 932 933 /* Skip over RAID params for now and find out # of devices */ 934 if (num_raid_params + 1 > argc) { 935 ti->error = "Arguments do not agree with counts given"; 936 return -EINVAL; 937 } 938 939 if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) || 940 (num_raid_devs >= INT_MAX)) { 941 ti->error = "Cannot understand number of raid devices"; 942 return -EINVAL; 943 } 944 945 rs = context_alloc(ti, rt, (unsigned)num_raid_devs); 946 if (IS_ERR(rs)) 947 return PTR_ERR(rs); 948 949 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params); 950 if (ret) 951 goto bad; 952 953 ret = -EINVAL; 954 955 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */ 956 argv += num_raid_params + 1; 957 958 if (argc != (num_raid_devs * 2)) { 959 ti->error = "Supplied RAID devices does not match the count given"; 960 goto bad; 961 } 962 963 ret = dev_parms(rs, argv); 964 if (ret) 965 goto bad; 966 967 rs->md.sync_super = super_sync; 968 ret = analyse_superblocks(ti, rs); 969 if (ret) 970 goto bad; 971 972 INIT_WORK(&rs->md.event_work, do_table_event); 973 ti->private = rs; 974 975 mutex_lock(&rs->md.reconfig_mutex); 976 ret = md_run(&rs->md); 977 rs->md.in_sync = 0; /* Assume already marked dirty */ 978 mutex_unlock(&rs->md.reconfig_mutex); 979 980 if (ret) { 981 ti->error = "Fail to run raid array"; 982 goto bad; 983 } 984 985 rs->callbacks.congested_fn = raid_is_congested; 986 dm_table_add_target_callbacks(ti->table, &rs->callbacks); 987 988 mddev_suspend(&rs->md); 989 return 0; 990 991 bad: 992 context_free(rs); 993 994 return ret; 995 } 996 997 static void raid_dtr(struct dm_target *ti) 998 { 999 struct raid_set *rs = ti->private; 1000 1001 list_del_init(&rs->callbacks.list); 1002 md_stop(&rs->md); 1003 context_free(rs); 1004 } 1005 1006 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context) 1007 { 1008 struct raid_set *rs = ti->private; 1009 struct mddev *mddev = &rs->md; 1010 1011 mddev->pers->make_request(mddev, bio); 1012 1013 return DM_MAPIO_SUBMITTED; 1014 } 1015 1016 static int raid_status(struct dm_target *ti, status_type_t type, 1017 char *result, unsigned maxlen) 1018 { 1019 struct raid_set *rs = ti->private; 1020 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */ 1021 unsigned sz = 0; 1022 int i, array_in_sync = 0; 1023 sector_t sync; 1024 1025 switch (type) { 1026 case STATUSTYPE_INFO: 1027 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks); 1028 1029 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery)) 1030 sync = rs->md.curr_resync_completed; 1031 else 1032 sync = rs->md.recovery_cp; 1033 1034 if (sync >= rs->md.resync_max_sectors) { 1035 array_in_sync = 1; 1036 sync = rs->md.resync_max_sectors; 1037 } else { 1038 /* 1039 * The array may be doing an initial sync, or it may 1040 * be rebuilding individual components. If all the 1041 * devices are In_sync, then it is the array that is 1042 * being initialized. 1043 */ 1044 for (i = 0; i < rs->md.raid_disks; i++) 1045 if (!test_bit(In_sync, &rs->dev[i].rdev.flags)) 1046 array_in_sync = 1; 1047 } 1048 /* 1049 * Status characters: 1050 * 'D' = Dead/Failed device 1051 * 'a' = Alive but not in-sync 1052 * 'A' = Alive and in-sync 1053 */ 1054 for (i = 0; i < rs->md.raid_disks; i++) { 1055 if (test_bit(Faulty, &rs->dev[i].rdev.flags)) 1056 DMEMIT("D"); 1057 else if (!array_in_sync || 1058 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1059 DMEMIT("a"); 1060 else 1061 DMEMIT("A"); 1062 } 1063 1064 /* 1065 * In-sync ratio: 1066 * The in-sync ratio shows the progress of: 1067 * - Initializing the array 1068 * - Rebuilding a subset of devices of the array 1069 * The user can distinguish between the two by referring 1070 * to the status characters. 1071 */ 1072 DMEMIT(" %llu/%llu", 1073 (unsigned long long) sync, 1074 (unsigned long long) rs->md.resync_max_sectors); 1075 1076 break; 1077 case STATUSTYPE_TABLE: 1078 /* The string you would use to construct this array */ 1079 for (i = 0; i < rs->md.raid_disks; i++) { 1080 if ((rs->print_flags & DMPF_REBUILD) && 1081 rs->dev[i].data_dev && 1082 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1083 raid_param_cnt += 2; /* for rebuilds */ 1084 if (rs->dev[i].data_dev && 1085 test_bit(WriteMostly, &rs->dev[i].rdev.flags)) 1086 raid_param_cnt += 2; 1087 } 1088 1089 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2); 1090 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)) 1091 raid_param_cnt--; 1092 1093 DMEMIT("%s %u %u", rs->raid_type->name, 1094 raid_param_cnt, rs->md.chunk_sectors); 1095 1096 if ((rs->print_flags & DMPF_SYNC) && 1097 (rs->md.recovery_cp == MaxSector)) 1098 DMEMIT(" sync"); 1099 if (rs->print_flags & DMPF_NOSYNC) 1100 DMEMIT(" nosync"); 1101 1102 for (i = 0; i < rs->md.raid_disks; i++) 1103 if ((rs->print_flags & DMPF_REBUILD) && 1104 rs->dev[i].data_dev && 1105 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1106 DMEMIT(" rebuild %u", i); 1107 1108 if (rs->print_flags & DMPF_DAEMON_SLEEP) 1109 DMEMIT(" daemon_sleep %lu", 1110 rs->md.bitmap_info.daemon_sleep); 1111 1112 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE) 1113 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min); 1114 1115 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE) 1116 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max); 1117 1118 for (i = 0; i < rs->md.raid_disks; i++) 1119 if (rs->dev[i].data_dev && 1120 test_bit(WriteMostly, &rs->dev[i].rdev.flags)) 1121 DMEMIT(" write_mostly %u", i); 1122 1123 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND) 1124 DMEMIT(" max_write_behind %lu", 1125 rs->md.bitmap_info.max_write_behind); 1126 1127 if (rs->print_flags & DMPF_STRIPE_CACHE) { 1128 struct r5conf *conf = rs->md.private; 1129 1130 /* convert from kiB to sectors */ 1131 DMEMIT(" stripe_cache %d", 1132 conf ? conf->max_nr_stripes * 2 : 0); 1133 } 1134 1135 if (rs->print_flags & DMPF_REGION_SIZE) 1136 DMEMIT(" region_size %lu", 1137 rs->md.bitmap_info.chunksize >> 9); 1138 1139 DMEMIT(" %d", rs->md.raid_disks); 1140 for (i = 0; i < rs->md.raid_disks; i++) { 1141 if (rs->dev[i].meta_dev) 1142 DMEMIT(" %s", rs->dev[i].meta_dev->name); 1143 else 1144 DMEMIT(" -"); 1145 1146 if (rs->dev[i].data_dev) 1147 DMEMIT(" %s", rs->dev[i].data_dev->name); 1148 else 1149 DMEMIT(" -"); 1150 } 1151 } 1152 1153 return 0; 1154 } 1155 1156 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) 1157 { 1158 struct raid_set *rs = ti->private; 1159 unsigned i; 1160 int ret = 0; 1161 1162 for (i = 0; !ret && i < rs->md.raid_disks; i++) 1163 if (rs->dev[i].data_dev) 1164 ret = fn(ti, 1165 rs->dev[i].data_dev, 1166 0, /* No offset on data devs */ 1167 rs->md.dev_sectors, 1168 data); 1169 1170 return ret; 1171 } 1172 1173 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) 1174 { 1175 struct raid_set *rs = ti->private; 1176 unsigned chunk_size = rs->md.chunk_sectors << 9; 1177 struct r5conf *conf = rs->md.private; 1178 1179 blk_limits_io_min(limits, chunk_size); 1180 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded)); 1181 } 1182 1183 static void raid_presuspend(struct dm_target *ti) 1184 { 1185 struct raid_set *rs = ti->private; 1186 1187 md_stop_writes(&rs->md); 1188 } 1189 1190 static void raid_postsuspend(struct dm_target *ti) 1191 { 1192 struct raid_set *rs = ti->private; 1193 1194 mddev_suspend(&rs->md); 1195 } 1196 1197 static void raid_resume(struct dm_target *ti) 1198 { 1199 struct raid_set *rs = ti->private; 1200 1201 if (!rs->bitmap_loaded) { 1202 bitmap_load(&rs->md); 1203 rs->bitmap_loaded = 1; 1204 } else 1205 md_wakeup_thread(rs->md.thread); 1206 1207 mddev_resume(&rs->md); 1208 } 1209 1210 static struct target_type raid_target = { 1211 .name = "raid", 1212 .version = {1, 1, 0}, 1213 .module = THIS_MODULE, 1214 .ctr = raid_ctr, 1215 .dtr = raid_dtr, 1216 .map = raid_map, 1217 .status = raid_status, 1218 .iterate_devices = raid_iterate_devices, 1219 .io_hints = raid_io_hints, 1220 .presuspend = raid_presuspend, 1221 .postsuspend = raid_postsuspend, 1222 .resume = raid_resume, 1223 }; 1224 1225 static int __init dm_raid_init(void) 1226 { 1227 return dm_register_target(&raid_target); 1228 } 1229 1230 static void __exit dm_raid_exit(void) 1231 { 1232 dm_unregister_target(&raid_target); 1233 } 1234 1235 module_init(dm_raid_init); 1236 module_exit(dm_raid_exit); 1237 1238 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target"); 1239 MODULE_ALIAS("dm-raid4"); 1240 MODULE_ALIAS("dm-raid5"); 1241 MODULE_ALIAS("dm-raid6"); 1242 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>"); 1243 MODULE_LICENSE("GPL"); 1244