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 md_rdev_clear(&rs->dev[i].rdev); 159 if (rs->dev[i].data_dev) 160 dm_put_device(rs->ti, rs->dev[i].data_dev); 161 } 162 163 kfree(rs); 164 } 165 166 /* 167 * For every device we have two words 168 * <meta_dev>: meta device name or '-' if missing 169 * <data_dev>: data device name or '-' if missing 170 * 171 * The following are permitted: 172 * - - 173 * - <data_dev> 174 * <meta_dev> <data_dev> 175 * 176 * The following is not allowed: 177 * <meta_dev> - 178 * 179 * This code parses those words. If there is a failure, 180 * the caller must use context_free to unwind the operations. 181 */ 182 static int dev_parms(struct raid_set *rs, char **argv) 183 { 184 int i; 185 int rebuild = 0; 186 int metadata_available = 0; 187 int ret = 0; 188 189 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) { 190 rs->dev[i].rdev.raid_disk = i; 191 192 rs->dev[i].meta_dev = NULL; 193 rs->dev[i].data_dev = NULL; 194 195 /* 196 * There are no offsets, since there is a separate device 197 * for data and metadata. 198 */ 199 rs->dev[i].rdev.data_offset = 0; 200 rs->dev[i].rdev.mddev = &rs->md; 201 202 if (strcmp(argv[0], "-")) { 203 ret = dm_get_device(rs->ti, argv[0], 204 dm_table_get_mode(rs->ti->table), 205 &rs->dev[i].meta_dev); 206 rs->ti->error = "RAID metadata device lookup failure"; 207 if (ret) 208 return ret; 209 210 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL); 211 if (!rs->dev[i].rdev.sb_page) 212 return -ENOMEM; 213 } 214 215 if (!strcmp(argv[1], "-")) { 216 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) && 217 (!rs->dev[i].rdev.recovery_offset)) { 218 rs->ti->error = "Drive designated for rebuild not specified"; 219 return -EINVAL; 220 } 221 222 rs->ti->error = "No data device supplied with metadata device"; 223 if (rs->dev[i].meta_dev) 224 return -EINVAL; 225 226 continue; 227 } 228 229 ret = dm_get_device(rs->ti, argv[1], 230 dm_table_get_mode(rs->ti->table), 231 &rs->dev[i].data_dev); 232 if (ret) { 233 rs->ti->error = "RAID device lookup failure"; 234 return ret; 235 } 236 237 if (rs->dev[i].meta_dev) { 238 metadata_available = 1; 239 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev; 240 } 241 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev; 242 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks); 243 if (!test_bit(In_sync, &rs->dev[i].rdev.flags)) 244 rebuild++; 245 } 246 247 if (metadata_available) { 248 rs->md.external = 0; 249 rs->md.persistent = 1; 250 rs->md.major_version = 2; 251 } else if (rebuild && !rs->md.recovery_cp) { 252 /* 253 * Without metadata, we will not be able to tell if the array 254 * is in-sync or not - we must assume it is not. Therefore, 255 * it is impossible to rebuild a drive. 256 * 257 * Even if there is metadata, the on-disk information may 258 * indicate that the array is not in-sync and it will then 259 * fail at that time. 260 * 261 * User could specify 'nosync' option if desperate. 262 */ 263 DMERR("Unable to rebuild drive while array is not in-sync"); 264 rs->ti->error = "RAID device lookup failure"; 265 return -EINVAL; 266 } 267 268 return 0; 269 } 270 271 /* 272 * validate_region_size 273 * @rs 274 * @region_size: region size in sectors. If 0, pick a size (4MiB default). 275 * 276 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size'). 277 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap. 278 * 279 * Returns: 0 on success, -EINVAL on failure. 280 */ 281 static int validate_region_size(struct raid_set *rs, unsigned long region_size) 282 { 283 unsigned long min_region_size = rs->ti->len / (1 << 21); 284 285 if (!region_size) { 286 /* 287 * Choose a reasonable default. All figures in sectors. 288 */ 289 if (min_region_size > (1 << 13)) { 290 DMINFO("Choosing default region size of %lu sectors", 291 region_size); 292 region_size = min_region_size; 293 } else { 294 DMINFO("Choosing default region size of 4MiB"); 295 region_size = 1 << 13; /* sectors */ 296 } 297 } else { 298 /* 299 * Validate user-supplied value. 300 */ 301 if (region_size > rs->ti->len) { 302 rs->ti->error = "Supplied region size is too large"; 303 return -EINVAL; 304 } 305 306 if (region_size < min_region_size) { 307 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)", 308 region_size, min_region_size); 309 rs->ti->error = "Supplied region size is too small"; 310 return -EINVAL; 311 } 312 313 if (!is_power_of_2(region_size)) { 314 rs->ti->error = "Region size is not a power of 2"; 315 return -EINVAL; 316 } 317 318 if (region_size < rs->md.chunk_sectors) { 319 rs->ti->error = "Region size is smaller than the chunk size"; 320 return -EINVAL; 321 } 322 } 323 324 /* 325 * Convert sectors to bytes. 326 */ 327 rs->md.bitmap_info.chunksize = (region_size << 9); 328 329 return 0; 330 } 331 332 /* 333 * Possible arguments are... 334 * <chunk_size> [optional_args] 335 * 336 * Argument definitions 337 * <chunk_size> The number of sectors per disk that 338 * will form the "stripe" 339 * [[no]sync] Force or prevent recovery of the 340 * entire array 341 * [rebuild <idx>] Rebuild the drive indicated by the index 342 * [daemon_sleep <ms>] Time between bitmap daemon work to 343 * clear bits 344 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization 345 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization 346 * [write_mostly <idx>] Indicate a write mostly drive via index 347 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm) 348 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs 349 * [region_size <sectors>] Defines granularity of bitmap 350 */ 351 static int parse_raid_params(struct raid_set *rs, char **argv, 352 unsigned num_raid_params) 353 { 354 unsigned i, rebuild_cnt = 0; 355 unsigned long value, region_size = 0; 356 char *key; 357 358 /* 359 * First, parse the in-order required arguments 360 * "chunk_size" is the only argument of this type. 361 */ 362 if ((strict_strtoul(argv[0], 10, &value) < 0)) { 363 rs->ti->error = "Bad chunk size"; 364 return -EINVAL; 365 } else if (rs->raid_type->level == 1) { 366 if (value) 367 DMERR("Ignoring chunk size parameter for RAID 1"); 368 value = 0; 369 } else if (!is_power_of_2(value)) { 370 rs->ti->error = "Chunk size must be a power of 2"; 371 return -EINVAL; 372 } else if (value < 8) { 373 rs->ti->error = "Chunk size value is too small"; 374 return -EINVAL; 375 } 376 377 rs->md.new_chunk_sectors = rs->md.chunk_sectors = value; 378 argv++; 379 num_raid_params--; 380 381 /* 382 * We set each individual device as In_sync with a completed 383 * 'recovery_offset'. If there has been a device failure or 384 * replacement then one of the following cases applies: 385 * 386 * 1) User specifies 'rebuild'. 387 * - Device is reset when param is read. 388 * 2) A new device is supplied. 389 * - No matching superblock found, resets device. 390 * 3) Device failure was transient and returns on reload. 391 * - Failure noticed, resets device for bitmap replay. 392 * 4) Device hadn't completed recovery after previous failure. 393 * - Superblock is read and overrides recovery_offset. 394 * 395 * What is found in the superblocks of the devices is always 396 * authoritative, unless 'rebuild' or '[no]sync' was specified. 397 */ 398 for (i = 0; i < rs->md.raid_disks; i++) { 399 set_bit(In_sync, &rs->dev[i].rdev.flags); 400 rs->dev[i].rdev.recovery_offset = MaxSector; 401 } 402 403 /* 404 * Second, parse the unordered optional arguments 405 */ 406 for (i = 0; i < num_raid_params; i++) { 407 if (!strcasecmp(argv[i], "nosync")) { 408 rs->md.recovery_cp = MaxSector; 409 rs->print_flags |= DMPF_NOSYNC; 410 continue; 411 } 412 if (!strcasecmp(argv[i], "sync")) { 413 rs->md.recovery_cp = 0; 414 rs->print_flags |= DMPF_SYNC; 415 continue; 416 } 417 418 /* The rest of the optional arguments come in key/value pairs */ 419 if ((i + 1) >= num_raid_params) { 420 rs->ti->error = "Wrong number of raid parameters given"; 421 return -EINVAL; 422 } 423 424 key = argv[i++]; 425 if (strict_strtoul(argv[i], 10, &value) < 0) { 426 rs->ti->error = "Bad numerical argument given in raid params"; 427 return -EINVAL; 428 } 429 430 if (!strcasecmp(key, "rebuild")) { 431 rebuild_cnt++; 432 if (((rs->raid_type->level != 1) && 433 (rebuild_cnt > rs->raid_type->parity_devs)) || 434 ((rs->raid_type->level == 1) && 435 (rebuild_cnt > (rs->md.raid_disks - 1)))) { 436 rs->ti->error = "Too many rebuild devices specified for given RAID type"; 437 return -EINVAL; 438 } 439 if (value > rs->md.raid_disks) { 440 rs->ti->error = "Invalid rebuild index given"; 441 return -EINVAL; 442 } 443 clear_bit(In_sync, &rs->dev[value].rdev.flags); 444 rs->dev[value].rdev.recovery_offset = 0; 445 rs->print_flags |= DMPF_REBUILD; 446 } else if (!strcasecmp(key, "write_mostly")) { 447 if (rs->raid_type->level != 1) { 448 rs->ti->error = "write_mostly option is only valid for RAID1"; 449 return -EINVAL; 450 } 451 if (value >= rs->md.raid_disks) { 452 rs->ti->error = "Invalid write_mostly drive index given"; 453 return -EINVAL; 454 } 455 set_bit(WriteMostly, &rs->dev[value].rdev.flags); 456 } else if (!strcasecmp(key, "max_write_behind")) { 457 if (rs->raid_type->level != 1) { 458 rs->ti->error = "max_write_behind option is only valid for RAID1"; 459 return -EINVAL; 460 } 461 rs->print_flags |= DMPF_MAX_WRITE_BEHIND; 462 463 /* 464 * In device-mapper, we specify things in sectors, but 465 * MD records this value in kB 466 */ 467 value /= 2; 468 if (value > COUNTER_MAX) { 469 rs->ti->error = "Max write-behind limit out of range"; 470 return -EINVAL; 471 } 472 rs->md.bitmap_info.max_write_behind = value; 473 } else if (!strcasecmp(key, "daemon_sleep")) { 474 rs->print_flags |= DMPF_DAEMON_SLEEP; 475 if (!value || (value > MAX_SCHEDULE_TIMEOUT)) { 476 rs->ti->error = "daemon sleep period out of range"; 477 return -EINVAL; 478 } 479 rs->md.bitmap_info.daemon_sleep = value; 480 } else if (!strcasecmp(key, "stripe_cache")) { 481 rs->print_flags |= DMPF_STRIPE_CACHE; 482 483 /* 484 * In device-mapper, we specify things in sectors, but 485 * MD records this value in kB 486 */ 487 value /= 2; 488 489 if (rs->raid_type->level < 5) { 490 rs->ti->error = "Inappropriate argument: stripe_cache"; 491 return -EINVAL; 492 } 493 if (raid5_set_cache_size(&rs->md, (int)value)) { 494 rs->ti->error = "Bad stripe_cache size"; 495 return -EINVAL; 496 } 497 } else if (!strcasecmp(key, "min_recovery_rate")) { 498 rs->print_flags |= DMPF_MIN_RECOVERY_RATE; 499 if (value > INT_MAX) { 500 rs->ti->error = "min_recovery_rate out of range"; 501 return -EINVAL; 502 } 503 rs->md.sync_speed_min = (int)value; 504 } else if (!strcasecmp(key, "max_recovery_rate")) { 505 rs->print_flags |= DMPF_MAX_RECOVERY_RATE; 506 if (value > INT_MAX) { 507 rs->ti->error = "max_recovery_rate out of range"; 508 return -EINVAL; 509 } 510 rs->md.sync_speed_max = (int)value; 511 } else if (!strcasecmp(key, "region_size")) { 512 rs->print_flags |= DMPF_REGION_SIZE; 513 region_size = value; 514 } else { 515 DMERR("Unable to parse RAID parameter: %s", key); 516 rs->ti->error = "Unable to parse RAID parameters"; 517 return -EINVAL; 518 } 519 } 520 521 if (validate_region_size(rs, region_size)) 522 return -EINVAL; 523 524 if (rs->md.chunk_sectors) 525 rs->ti->split_io = rs->md.chunk_sectors; 526 else 527 rs->ti->split_io = region_size; 528 529 if (rs->md.chunk_sectors) 530 rs->ti->split_io = rs->md.chunk_sectors; 531 else 532 rs->ti->split_io = region_size; 533 534 /* Assume there are no metadata devices until the drives are parsed */ 535 rs->md.persistent = 0; 536 rs->md.external = 1; 537 538 return 0; 539 } 540 541 static void do_table_event(struct work_struct *ws) 542 { 543 struct raid_set *rs = container_of(ws, struct raid_set, md.event_work); 544 545 dm_table_event(rs->ti->table); 546 } 547 548 static int raid_is_congested(struct dm_target_callbacks *cb, int bits) 549 { 550 struct raid_set *rs = container_of(cb, struct raid_set, callbacks); 551 552 if (rs->raid_type->level == 1) 553 return md_raid1_congested(&rs->md, bits); 554 555 return md_raid5_congested(&rs->md, bits); 556 } 557 558 /* 559 * This structure is never routinely used by userspace, unlike md superblocks. 560 * Devices with this superblock should only ever be accessed via device-mapper. 561 */ 562 #define DM_RAID_MAGIC 0x64526D44 563 struct dm_raid_superblock { 564 __le32 magic; /* "DmRd" */ 565 __le32 features; /* Used to indicate possible future changes */ 566 567 __le32 num_devices; /* Number of devices in this array. (Max 64) */ 568 __le32 array_position; /* The position of this drive in the array */ 569 570 __le64 events; /* Incremented by md when superblock updated */ 571 __le64 failed_devices; /* Bit field of devices to indicate failures */ 572 573 /* 574 * This offset tracks the progress of the repair or replacement of 575 * an individual drive. 576 */ 577 __le64 disk_recovery_offset; 578 579 /* 580 * This offset tracks the progress of the initial array 581 * synchronisation/parity calculation. 582 */ 583 __le64 array_resync_offset; 584 585 /* 586 * RAID characteristics 587 */ 588 __le32 level; 589 __le32 layout; 590 __le32 stripe_sectors; 591 592 __u8 pad[452]; /* Round struct to 512 bytes. */ 593 /* Always set to 0 when writing. */ 594 } __packed; 595 596 static int read_disk_sb(struct md_rdev *rdev, int size) 597 { 598 BUG_ON(!rdev->sb_page); 599 600 if (rdev->sb_loaded) 601 return 0; 602 603 if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) { 604 DMERR("Failed to read superblock of device at position %d", 605 rdev->raid_disk); 606 md_error(rdev->mddev, rdev); 607 return -EINVAL; 608 } 609 610 rdev->sb_loaded = 1; 611 612 return 0; 613 } 614 615 static void super_sync(struct mddev *mddev, struct md_rdev *rdev) 616 { 617 int i; 618 uint64_t failed_devices; 619 struct dm_raid_superblock *sb; 620 struct raid_set *rs = container_of(mddev, struct raid_set, md); 621 622 sb = page_address(rdev->sb_page); 623 failed_devices = le64_to_cpu(sb->failed_devices); 624 625 for (i = 0; i < mddev->raid_disks; i++) 626 if (!rs->dev[i].data_dev || 627 test_bit(Faulty, &(rs->dev[i].rdev.flags))) 628 failed_devices |= (1ULL << i); 629 630 memset(sb, 0, sizeof(*sb)); 631 632 sb->magic = cpu_to_le32(DM_RAID_MAGIC); 633 sb->features = cpu_to_le32(0); /* No features yet */ 634 635 sb->num_devices = cpu_to_le32(mddev->raid_disks); 636 sb->array_position = cpu_to_le32(rdev->raid_disk); 637 638 sb->events = cpu_to_le64(mddev->events); 639 sb->failed_devices = cpu_to_le64(failed_devices); 640 641 sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset); 642 sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp); 643 644 sb->level = cpu_to_le32(mddev->level); 645 sb->layout = cpu_to_le32(mddev->layout); 646 sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors); 647 } 648 649 /* 650 * super_load 651 * 652 * This function creates a superblock if one is not found on the device 653 * and will decide which superblock to use if there's a choice. 654 * 655 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise 656 */ 657 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev) 658 { 659 int ret; 660 struct dm_raid_superblock *sb; 661 struct dm_raid_superblock *refsb; 662 uint64_t events_sb, events_refsb; 663 664 rdev->sb_start = 0; 665 rdev->sb_size = sizeof(*sb); 666 667 ret = read_disk_sb(rdev, rdev->sb_size); 668 if (ret) 669 return ret; 670 671 sb = page_address(rdev->sb_page); 672 673 /* 674 * Two cases that we want to write new superblocks and rebuild: 675 * 1) New device (no matching magic number) 676 * 2) Device specified for rebuild (!In_sync w/ offset == 0) 677 */ 678 if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) || 679 (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) { 680 super_sync(rdev->mddev, rdev); 681 682 set_bit(FirstUse, &rdev->flags); 683 684 /* Force writing of superblocks to disk */ 685 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags); 686 687 /* Any superblock is better than none, choose that if given */ 688 return refdev ? 0 : 1; 689 } 690 691 if (!refdev) 692 return 1; 693 694 events_sb = le64_to_cpu(sb->events); 695 696 refsb = page_address(refdev->sb_page); 697 events_refsb = le64_to_cpu(refsb->events); 698 699 return (events_sb > events_refsb) ? 1 : 0; 700 } 701 702 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev) 703 { 704 int role; 705 struct raid_set *rs = container_of(mddev, struct raid_set, md); 706 uint64_t events_sb; 707 uint64_t failed_devices; 708 struct dm_raid_superblock *sb; 709 uint32_t new_devs = 0; 710 uint32_t rebuilds = 0; 711 struct md_rdev *r; 712 struct dm_raid_superblock *sb2; 713 714 sb = page_address(rdev->sb_page); 715 events_sb = le64_to_cpu(sb->events); 716 failed_devices = le64_to_cpu(sb->failed_devices); 717 718 /* 719 * Initialise to 1 if this is a new superblock. 720 */ 721 mddev->events = events_sb ? : 1; 722 723 /* 724 * Reshaping is not currently allowed 725 */ 726 if ((le32_to_cpu(sb->level) != mddev->level) || 727 (le32_to_cpu(sb->layout) != mddev->layout) || 728 (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) { 729 DMERR("Reshaping arrays not yet supported."); 730 return -EINVAL; 731 } 732 733 /* We can only change the number of devices in RAID1 right now */ 734 if ((rs->raid_type->level != 1) && 735 (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) { 736 DMERR("Reshaping arrays not yet supported."); 737 return -EINVAL; 738 } 739 740 if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))) 741 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset); 742 743 /* 744 * During load, we set FirstUse if a new superblock was written. 745 * There are two reasons we might not have a superblock: 746 * 1) The array is brand new - in which case, all of the 747 * devices must have their In_sync bit set. Also, 748 * recovery_cp must be 0, unless forced. 749 * 2) This is a new device being added to an old array 750 * and the new device needs to be rebuilt - in which 751 * case the In_sync bit will /not/ be set and 752 * recovery_cp must be MaxSector. 753 */ 754 rdev_for_each(r, mddev) { 755 if (!test_bit(In_sync, &r->flags)) { 756 DMINFO("Device %d specified for rebuild: " 757 "Clearing superblock", r->raid_disk); 758 rebuilds++; 759 } else if (test_bit(FirstUse, &r->flags)) 760 new_devs++; 761 } 762 763 if (!rebuilds) { 764 if (new_devs == mddev->raid_disks) { 765 DMINFO("Superblocks created for new array"); 766 set_bit(MD_ARRAY_FIRST_USE, &mddev->flags); 767 } else if (new_devs) { 768 DMERR("New device injected " 769 "into existing array without 'rebuild' " 770 "parameter specified"); 771 return -EINVAL; 772 } 773 } else if (new_devs) { 774 DMERR("'rebuild' devices cannot be " 775 "injected into an array with other first-time devices"); 776 return -EINVAL; 777 } else if (mddev->recovery_cp != MaxSector) { 778 DMERR("'rebuild' specified while array is not in-sync"); 779 return -EINVAL; 780 } 781 782 /* 783 * Now we set the Faulty bit for those devices that are 784 * recorded in the superblock as failed. 785 */ 786 rdev_for_each(r, mddev) { 787 if (!r->sb_page) 788 continue; 789 sb2 = page_address(r->sb_page); 790 sb2->failed_devices = 0; 791 792 /* 793 * Check for any device re-ordering. 794 */ 795 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) { 796 role = le32_to_cpu(sb2->array_position); 797 if (role != r->raid_disk) { 798 if (rs->raid_type->level != 1) { 799 rs->ti->error = "Cannot change device " 800 "positions in RAID array"; 801 return -EINVAL; 802 } 803 DMINFO("RAID1 device #%d now at position #%d", 804 role, r->raid_disk); 805 } 806 807 /* 808 * Partial recovery is performed on 809 * returning failed devices. 810 */ 811 if (failed_devices & (1 << role)) 812 set_bit(Faulty, &r->flags); 813 } 814 } 815 816 return 0; 817 } 818 819 static int super_validate(struct mddev *mddev, struct md_rdev *rdev) 820 { 821 struct dm_raid_superblock *sb = page_address(rdev->sb_page); 822 823 /* 824 * If mddev->events is not set, we know we have not yet initialized 825 * the array. 826 */ 827 if (!mddev->events && super_init_validation(mddev, rdev)) 828 return -EINVAL; 829 830 mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */ 831 rdev->mddev->bitmap_info.default_offset = 4096 >> 9; 832 if (!test_bit(FirstUse, &rdev->flags)) { 833 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset); 834 if (rdev->recovery_offset != MaxSector) 835 clear_bit(In_sync, &rdev->flags); 836 } 837 838 /* 839 * If a device comes back, set it as not In_sync and no longer faulty. 840 */ 841 if (test_bit(Faulty, &rdev->flags)) { 842 clear_bit(Faulty, &rdev->flags); 843 clear_bit(In_sync, &rdev->flags); 844 rdev->saved_raid_disk = rdev->raid_disk; 845 rdev->recovery_offset = 0; 846 } 847 848 clear_bit(FirstUse, &rdev->flags); 849 850 return 0; 851 } 852 853 /* 854 * Analyse superblocks and select the freshest. 855 */ 856 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) 857 { 858 int ret; 859 unsigned redundancy = 0; 860 struct raid_dev *dev; 861 struct md_rdev *rdev, *tmp, *freshest; 862 struct mddev *mddev = &rs->md; 863 864 switch (rs->raid_type->level) { 865 case 1: 866 redundancy = rs->md.raid_disks - 1; 867 break; 868 case 4: 869 case 5: 870 case 6: 871 redundancy = rs->raid_type->parity_devs; 872 break; 873 default: 874 ti->error = "Unknown RAID type"; 875 return -EINVAL; 876 } 877 878 freshest = NULL; 879 rdev_for_each_safe(rdev, tmp, mddev) { 880 if (!rdev->meta_bdev) 881 continue; 882 883 ret = super_load(rdev, freshest); 884 885 switch (ret) { 886 case 1: 887 freshest = rdev; 888 break; 889 case 0: 890 break; 891 default: 892 dev = container_of(rdev, struct raid_dev, rdev); 893 if (redundancy--) { 894 if (dev->meta_dev) 895 dm_put_device(ti, dev->meta_dev); 896 897 dev->meta_dev = NULL; 898 rdev->meta_bdev = NULL; 899 900 if (rdev->sb_page) 901 put_page(rdev->sb_page); 902 903 rdev->sb_page = NULL; 904 905 rdev->sb_loaded = 0; 906 907 /* 908 * We might be able to salvage the data device 909 * even though the meta device has failed. For 910 * now, we behave as though '- -' had been 911 * set for this device in the table. 912 */ 913 if (dev->data_dev) 914 dm_put_device(ti, dev->data_dev); 915 916 dev->data_dev = NULL; 917 rdev->bdev = NULL; 918 919 list_del(&rdev->same_set); 920 921 continue; 922 } 923 ti->error = "Failed to load superblock"; 924 return ret; 925 } 926 } 927 928 if (!freshest) 929 return 0; 930 931 /* 932 * Validation of the freshest device provides the source of 933 * validation for the remaining devices. 934 */ 935 ti->error = "Unable to assemble array: Invalid superblocks"; 936 if (super_validate(mddev, freshest)) 937 return -EINVAL; 938 939 rdev_for_each(rdev, mddev) 940 if ((rdev != freshest) && super_validate(mddev, rdev)) 941 return -EINVAL; 942 943 return 0; 944 } 945 946 /* 947 * Construct a RAID4/5/6 mapping: 948 * Args: 949 * <raid_type> <#raid_params> <raid_params> \ 950 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> } 951 * 952 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for 953 * details on possible <raid_params>. 954 */ 955 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) 956 { 957 int ret; 958 struct raid_type *rt; 959 unsigned long num_raid_params, num_raid_devs; 960 struct raid_set *rs = NULL; 961 962 /* Must have at least <raid_type> <#raid_params> */ 963 if (argc < 2) { 964 ti->error = "Too few arguments"; 965 return -EINVAL; 966 } 967 968 /* raid type */ 969 rt = get_raid_type(argv[0]); 970 if (!rt) { 971 ti->error = "Unrecognised raid_type"; 972 return -EINVAL; 973 } 974 argc--; 975 argv++; 976 977 /* number of RAID parameters */ 978 if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) { 979 ti->error = "Cannot understand number of RAID parameters"; 980 return -EINVAL; 981 } 982 argc--; 983 argv++; 984 985 /* Skip over RAID params for now and find out # of devices */ 986 if (num_raid_params + 1 > argc) { 987 ti->error = "Arguments do not agree with counts given"; 988 return -EINVAL; 989 } 990 991 if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) || 992 (num_raid_devs >= INT_MAX)) { 993 ti->error = "Cannot understand number of raid devices"; 994 return -EINVAL; 995 } 996 997 rs = context_alloc(ti, rt, (unsigned)num_raid_devs); 998 if (IS_ERR(rs)) 999 return PTR_ERR(rs); 1000 1001 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params); 1002 if (ret) 1003 goto bad; 1004 1005 ret = -EINVAL; 1006 1007 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */ 1008 argv += num_raid_params + 1; 1009 1010 if (argc != (num_raid_devs * 2)) { 1011 ti->error = "Supplied RAID devices does not match the count given"; 1012 goto bad; 1013 } 1014 1015 ret = dev_parms(rs, argv); 1016 if (ret) 1017 goto bad; 1018 1019 rs->md.sync_super = super_sync; 1020 ret = analyse_superblocks(ti, rs); 1021 if (ret) 1022 goto bad; 1023 1024 INIT_WORK(&rs->md.event_work, do_table_event); 1025 ti->private = rs; 1026 ti->num_flush_requests = 1; 1027 1028 mutex_lock(&rs->md.reconfig_mutex); 1029 ret = md_run(&rs->md); 1030 rs->md.in_sync = 0; /* Assume already marked dirty */ 1031 mutex_unlock(&rs->md.reconfig_mutex); 1032 1033 if (ret) { 1034 ti->error = "Fail to run raid array"; 1035 goto bad; 1036 } 1037 1038 rs->callbacks.congested_fn = raid_is_congested; 1039 dm_table_add_target_callbacks(ti->table, &rs->callbacks); 1040 1041 mddev_suspend(&rs->md); 1042 return 0; 1043 1044 bad: 1045 context_free(rs); 1046 1047 return ret; 1048 } 1049 1050 static void raid_dtr(struct dm_target *ti) 1051 { 1052 struct raid_set *rs = ti->private; 1053 1054 list_del_init(&rs->callbacks.list); 1055 md_stop(&rs->md); 1056 context_free(rs); 1057 } 1058 1059 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context) 1060 { 1061 struct raid_set *rs = ti->private; 1062 struct mddev *mddev = &rs->md; 1063 1064 mddev->pers->make_request(mddev, bio); 1065 1066 return DM_MAPIO_SUBMITTED; 1067 } 1068 1069 static int raid_status(struct dm_target *ti, status_type_t type, 1070 char *result, unsigned maxlen) 1071 { 1072 struct raid_set *rs = ti->private; 1073 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */ 1074 unsigned sz = 0; 1075 int i, array_in_sync = 0; 1076 sector_t sync; 1077 1078 switch (type) { 1079 case STATUSTYPE_INFO: 1080 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks); 1081 1082 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery)) 1083 sync = rs->md.curr_resync_completed; 1084 else 1085 sync = rs->md.recovery_cp; 1086 1087 if (sync >= rs->md.resync_max_sectors) { 1088 array_in_sync = 1; 1089 sync = rs->md.resync_max_sectors; 1090 } else { 1091 /* 1092 * The array may be doing an initial sync, or it may 1093 * be rebuilding individual components. If all the 1094 * devices are In_sync, then it is the array that is 1095 * being initialized. 1096 */ 1097 for (i = 0; i < rs->md.raid_disks; i++) 1098 if (!test_bit(In_sync, &rs->dev[i].rdev.flags)) 1099 array_in_sync = 1; 1100 } 1101 /* 1102 * Status characters: 1103 * 'D' = Dead/Failed device 1104 * 'a' = Alive but not in-sync 1105 * 'A' = Alive and in-sync 1106 */ 1107 for (i = 0; i < rs->md.raid_disks; i++) { 1108 if (test_bit(Faulty, &rs->dev[i].rdev.flags)) 1109 DMEMIT("D"); 1110 else if (!array_in_sync || 1111 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1112 DMEMIT("a"); 1113 else 1114 DMEMIT("A"); 1115 } 1116 1117 /* 1118 * In-sync ratio: 1119 * The in-sync ratio shows the progress of: 1120 * - Initializing the array 1121 * - Rebuilding a subset of devices of the array 1122 * The user can distinguish between the two by referring 1123 * to the status characters. 1124 */ 1125 DMEMIT(" %llu/%llu", 1126 (unsigned long long) sync, 1127 (unsigned long long) rs->md.resync_max_sectors); 1128 1129 break; 1130 case STATUSTYPE_TABLE: 1131 /* The string you would use to construct this array */ 1132 for (i = 0; i < rs->md.raid_disks; i++) { 1133 if ((rs->print_flags & DMPF_REBUILD) && 1134 rs->dev[i].data_dev && 1135 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1136 raid_param_cnt += 2; /* for rebuilds */ 1137 if (rs->dev[i].data_dev && 1138 test_bit(WriteMostly, &rs->dev[i].rdev.flags)) 1139 raid_param_cnt += 2; 1140 } 1141 1142 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2); 1143 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)) 1144 raid_param_cnt--; 1145 1146 DMEMIT("%s %u %u", rs->raid_type->name, 1147 raid_param_cnt, rs->md.chunk_sectors); 1148 1149 if ((rs->print_flags & DMPF_SYNC) && 1150 (rs->md.recovery_cp == MaxSector)) 1151 DMEMIT(" sync"); 1152 if (rs->print_flags & DMPF_NOSYNC) 1153 DMEMIT(" nosync"); 1154 1155 for (i = 0; i < rs->md.raid_disks; i++) 1156 if ((rs->print_flags & DMPF_REBUILD) && 1157 rs->dev[i].data_dev && 1158 !test_bit(In_sync, &rs->dev[i].rdev.flags)) 1159 DMEMIT(" rebuild %u", i); 1160 1161 if (rs->print_flags & DMPF_DAEMON_SLEEP) 1162 DMEMIT(" daemon_sleep %lu", 1163 rs->md.bitmap_info.daemon_sleep); 1164 1165 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE) 1166 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min); 1167 1168 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE) 1169 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max); 1170 1171 for (i = 0; i < rs->md.raid_disks; i++) 1172 if (rs->dev[i].data_dev && 1173 test_bit(WriteMostly, &rs->dev[i].rdev.flags)) 1174 DMEMIT(" write_mostly %u", i); 1175 1176 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND) 1177 DMEMIT(" max_write_behind %lu", 1178 rs->md.bitmap_info.max_write_behind); 1179 1180 if (rs->print_flags & DMPF_STRIPE_CACHE) { 1181 struct r5conf *conf = rs->md.private; 1182 1183 /* convert from kiB to sectors */ 1184 DMEMIT(" stripe_cache %d", 1185 conf ? conf->max_nr_stripes * 2 : 0); 1186 } 1187 1188 if (rs->print_flags & DMPF_REGION_SIZE) 1189 DMEMIT(" region_size %lu", 1190 rs->md.bitmap_info.chunksize >> 9); 1191 1192 DMEMIT(" %d", rs->md.raid_disks); 1193 for (i = 0; i < rs->md.raid_disks; i++) { 1194 if (rs->dev[i].meta_dev) 1195 DMEMIT(" %s", rs->dev[i].meta_dev->name); 1196 else 1197 DMEMIT(" -"); 1198 1199 if (rs->dev[i].data_dev) 1200 DMEMIT(" %s", rs->dev[i].data_dev->name); 1201 else 1202 DMEMIT(" -"); 1203 } 1204 } 1205 1206 return 0; 1207 } 1208 1209 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data) 1210 { 1211 struct raid_set *rs = ti->private; 1212 unsigned i; 1213 int ret = 0; 1214 1215 for (i = 0; !ret && i < rs->md.raid_disks; i++) 1216 if (rs->dev[i].data_dev) 1217 ret = fn(ti, 1218 rs->dev[i].data_dev, 1219 0, /* No offset on data devs */ 1220 rs->md.dev_sectors, 1221 data); 1222 1223 return ret; 1224 } 1225 1226 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) 1227 { 1228 struct raid_set *rs = ti->private; 1229 unsigned chunk_size = rs->md.chunk_sectors << 9; 1230 struct r5conf *conf = rs->md.private; 1231 1232 blk_limits_io_min(limits, chunk_size); 1233 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded)); 1234 } 1235 1236 static void raid_presuspend(struct dm_target *ti) 1237 { 1238 struct raid_set *rs = ti->private; 1239 1240 md_stop_writes(&rs->md); 1241 } 1242 1243 static void raid_postsuspend(struct dm_target *ti) 1244 { 1245 struct raid_set *rs = ti->private; 1246 1247 mddev_suspend(&rs->md); 1248 } 1249 1250 static void raid_resume(struct dm_target *ti) 1251 { 1252 struct raid_set *rs = ti->private; 1253 1254 set_bit(MD_CHANGE_DEVS, &rs->md.flags); 1255 if (!rs->bitmap_loaded) { 1256 bitmap_load(&rs->md); 1257 rs->bitmap_loaded = 1; 1258 } 1259 1260 clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery); 1261 mddev_resume(&rs->md); 1262 } 1263 1264 static struct target_type raid_target = { 1265 .name = "raid", 1266 .version = {1, 2, 0}, 1267 .module = THIS_MODULE, 1268 .ctr = raid_ctr, 1269 .dtr = raid_dtr, 1270 .map = raid_map, 1271 .status = raid_status, 1272 .iterate_devices = raid_iterate_devices, 1273 .io_hints = raid_io_hints, 1274 .presuspend = raid_presuspend, 1275 .postsuspend = raid_postsuspend, 1276 .resume = raid_resume, 1277 }; 1278 1279 static int __init dm_raid_init(void) 1280 { 1281 return dm_register_target(&raid_target); 1282 } 1283 1284 static void __exit dm_raid_exit(void) 1285 { 1286 dm_unregister_target(&raid_target); 1287 } 1288 1289 module_init(dm_raid_init); 1290 module_exit(dm_raid_exit); 1291 1292 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target"); 1293 MODULE_ALIAS("dm-raid4"); 1294 MODULE_ALIAS("dm-raid5"); 1295 MODULE_ALIAS("dm-raid6"); 1296 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>"); 1297 MODULE_LICENSE("GPL"); 1298