raid6check.c

   1 /*
   2  * raid6check - extended consistency check for RAID-6
   3  *
   4  * Copyright (C) 2011 Piergiorgio Sartor
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Piergiorgio Sartor
  22  *    Based on "restripe.c" from "mdadm" codebase
  23  */
  24
  25 #include "mdadm.h"
  26 #include <stdint.h>
  27 #include <signal.h>
  28 #include <sys/mman.h>
  29
  30 #define CHECK_PAGE_BITS (12)
  31 #define CHECK_PAGE_SIZE (1 << CHECK_PAGE_BITS)
  32
  33 char const Name[] = "raid6check";
  34
  35 enum repair {
  36         NO_REPAIR = 0,
  37         MANUAL_REPAIR,
  38         AUTO_REPAIR
  39 };
  40
  41 int geo_map(int block, unsigned long long stripe, int raid_disks,
  42             int level, int layout);
  43 int is_ddf(int layout);
  44 void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size);
  45 void make_tables(void);
  46 void ensure_zero_has_size(int chunk_size);
  47 void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs,
  48                        int neg_offset);
  49 void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
  50                        uint8_t **ptrs, int neg_offset);
  51 void xor_blocks(char *target, char **sources, int disks, int size);
  52
  53 /* Collect per stripe consistency information */
  54 void raid6_collect(int chunk_size, uint8_t *p, uint8_t *q,
  55                    char *chunkP, char *chunkQ, int *results)
  56 {
  57         int i;
  58         int data_id;
  59         uint8_t Px, Qx;
  60         extern uint8_t raid6_gflog[];
  61
  62         for(i = 0; i < chunk_size; i++) {
  63                 Px = (uint8_t)chunkP[i] ^ (uint8_t)p[i];
  64                 Qx = (uint8_t)chunkQ[i] ^ (uint8_t)q[i];
  65
  66                 if((Px != 0) && (Qx == 0))
  67                         results[i] = -1;
  68
  69                 if((Px == 0) && (Qx != 0))
  70                         results[i] = -2;
  71
  72                 if((Px != 0) && (Qx != 0)) {
  73                         data_id = (raid6_gflog[Qx] - raid6_gflog[Px]);
  74                         if(data_id < 0) data_id += 255;
  75                         results[i] = data_id;
  76                 }
  77
  78                 if((Px == 0) && (Qx == 0))
  79                         results[i] = -255;
  80         }
  81 }
  82
  83 /* Try to find out if a specific disk has problems in a CHECK_PAGE_SIZE page size */
  84 int raid6_stats_blk(int *results, int raid_disks)
  85 {
  86         int i;
  87         int curr_broken_disk = -255;
  88         int prev_broken_disk = -255;
  89         int broken_status = 0;
  90
  91         for(i = 0; i < CHECK_PAGE_SIZE; i++) {
  92
  93                 if(results[i] != -255)
  94                         curr_broken_disk = results[i];
  95
  96                 if(curr_broken_disk >= raid_disks)
  97                         broken_status = 2;
  98
  99                 switch(broken_status) {
 100                 case 0:
 101                         if(curr_broken_disk != -255) {
 102                                 prev_broken_disk = curr_broken_disk;
 103                                 broken_status = 1;
 104                         }
 105                         break;
 106
 107                 case 1:
 108                         if(curr_broken_disk != prev_broken_disk)
 109                                 broken_status = 2;
 110                         break;
 111
 112                 case 2:
 113                 default:
 114                         curr_broken_disk = prev_broken_disk = -65535;
 115                         break;
 116                 }
 117         }
 118
 119         return curr_broken_disk;
 120 }
 121
 122 /* Collect disks status for a strip in CHECK_PAGE_SIZE page size blocks */
 123 void raid6_stats(int *disk, int *results, int raid_disks, int chunk_size)
 124 {
 125         int i, j;
 126
 127         for(i = 0, j = 0; i < chunk_size; i += CHECK_PAGE_SIZE, j++) {
 128                 disk[j] = raid6_stats_blk(&results[i], raid_disks);
 129         }
 130 }
 131
 132 int lock_stripe(struct mdinfo *info, unsigned long long start,
 133                 int chunk_size, int data_disks, sighandler_t *sig) {
 134         int rv;
 135         if(mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
 136                 return 2;
 137         }
 138
 139         sig[0] = signal(SIGTERM, SIG_IGN);
 140         sig[1] = signal(SIGINT, SIG_IGN);
 141         sig[2] = signal(SIGQUIT, SIG_IGN);
 142
 143         rv = sysfs_set_num(info, NULL, "suspend_lo", start * chunk_size * data_disks);
 144         rv |= sysfs_set_num(info, NULL, "suspend_hi", (start + 1) * chunk_size * data_disks);
 145         return rv * 256;
 146 }
 147
 148 int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig) {
 149         int rv;
 150         rv = sysfs_set_num(info, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL);
 151         rv |= sysfs_set_num(info, NULL, "suspend_hi", 0);
 152         rv |= sysfs_set_num(info, NULL, "suspend_lo", 0);
 153
 154         signal(SIGQUIT, sig[2]);
 155         signal(SIGINT, sig[1]);
 156         signal(SIGTERM, sig[0]);
 157
 158         if(munlockall() != 0)
 159                 return 3;
 160         return rv * 256;
 161 }
 162
 163 /* Autorepair */
 164 int autorepair(int *disk, unsigned long long start, int chunk_size,
 165                 char *name[], int raid_disks, int syndrome_disks, char **blocks_page,
 166                 char **blocks, uint8_t *p, int *block_index_for_slot,
 167                 int *source, unsigned long long *offsets)
 168 {
 169         int i, j;
 170         int pages_to_write_count = 0;
 171         int page_to_write[chunk_size >> CHECK_PAGE_BITS];
 172         for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
 173                 if (disk[j] >= -2 && block_index_for_slot[disk[j]] >= 0) {
 174                         int slot = block_index_for_slot[disk[j]];
 175                         printf("Auto-repairing slot %d (%s)\n", slot, name[slot]);
 176                         pages_to_write_count++;
 177                         page_to_write[j] = 1;
 178                         for(i = -2; i < syndrome_disks; i++) {
 179                                 blocks_page[i] = blocks[i] + j * CHECK_PAGE_SIZE;
 180                         }
 181                         if (disk[j] == -2) {
 182                                 qsyndrome(p, (uint8_t*)blocks_page[-2],
 183                                           (uint8_t**)blocks_page,
 184                                           syndrome_disks, CHECK_PAGE_SIZE);
 185                         }
 186                         else {
 187                                 char *all_but_failed_blocks[syndrome_disks];
 188                                 for(i = 0; i < syndrome_disks; i++) {
 189                                         if (i == disk[j])
 190                                                 all_but_failed_blocks[i] = blocks_page[-1];
 191                                         else
 192                                                 all_but_failed_blocks[i] = blocks_page[i];
 193                                 }
 194                                 xor_blocks(blocks_page[disk[j]],
 195                                            all_but_failed_blocks, syndrome_disks,
 196                                            CHECK_PAGE_SIZE);
 197                         }
 198                 }
 199                 else {
 200                         page_to_write[j] = 0;
 201                 }
 202         }
 203
 204         if(pages_to_write_count > 0) {
 205                 int write_res = 0;
 206                 for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
 207                         if(page_to_write[j] == 1) {
 208                                 int slot = block_index_for_slot[disk[j]];
 209                                 lseek64(source[slot], offsets[slot] + start * chunk_size + j * CHECK_PAGE_SIZE, SEEK_SET);
 210                                 write_res += write(source[slot],
 211                                                    blocks[disk[j]] + j * CHECK_PAGE_SIZE,
 212                                                    CHECK_PAGE_SIZE);
 213                         }
 214                 }
 215
 216                 if (write_res != (CHECK_PAGE_SIZE * pages_to_write_count)) {
 217                         fprintf(stderr, "Failed to write a full chunk.\n");
 218                         return -1;
 219                 }
 220         }
 221
 222         return 0;
 223 }
 224
 225 /* Manual repair */
 226 int manual_repair(int chunk_size, int syndrome_disks,
 227                   int failed_slot1, int failed_slot2,
 228                   unsigned long long start, int *block_index_for_slot,
 229                   char *name[], char **stripes, char **blocks, uint8_t *p,
 230                   int *source, unsigned long long *offsets)
 231 {
 232         int i;
 233         int fd1 = block_index_for_slot[failed_slot1];
 234         int fd2 = block_index_for_slot[failed_slot2];
 235         printf("Repairing stripe %llu\n", start);
 236         printf("Assuming slots %d (%s) and %d (%s) are incorrect\n",
 237                fd1, name[fd1],
 238                fd2, name[fd2]);
 239
 240         if (failed_slot1 == -2 || failed_slot2 == -2) {
 241                 char *all_but_failed_blocks[syndrome_disks];
 242                 int failed_data_or_p;
 243
 244                 if (failed_slot1 == -2)
 245                         failed_data_or_p = failed_slot2;
 246                 else
 247                         failed_data_or_p = failed_slot1;
 248
 249                 printf("Repairing D/P(%d) and Q\n", failed_data_or_p);
 250
 251                 for (i = 0; i < syndrome_disks; i++) {
 252                         if (i == failed_data_or_p)
 253                                 all_but_failed_blocks[i] = blocks[-1];
 254                         else
 255                                 all_but_failed_blocks[i] = blocks[i];
 256                 }
 257                 xor_blocks(blocks[failed_data_or_p],
 258                            all_but_failed_blocks, syndrome_disks, chunk_size);
 259                 qsyndrome(p, (uint8_t*)blocks[-2], (uint8_t**)blocks,
 260                           syndrome_disks, chunk_size);
 261         } else {
 262                 ensure_zero_has_size(chunk_size);
 263                 if (failed_slot1 == -1 || failed_slot2 == -1) {
 264                         int failed_data;
 265                         if (failed_slot1 == -1)
 266                                 failed_data = failed_slot2;
 267                         else
 268                                 failed_data = failed_slot1;
 269                                 printf("Repairing D(%d) and P\n", failed_data);
 270                         raid6_datap_recov(syndrome_disks+2, chunk_size,
 271                                           failed_data, (uint8_t**)blocks, 1);
 272                 } else {
 273                         printf("Repairing D and D\n");
 274                         raid6_2data_recov(syndrome_disks+2, chunk_size,
 275                                           failed_slot1, failed_slot2,
 276                                           (uint8_t**)blocks, 1);
 277                 }
 278         }
 279
 280         int write_res1, write_res2;
 281         off64_t seek_res;
 282
 283         seek_res = lseek64(source[fd1],
 284                            offsets[fd1] + start * chunk_size, SEEK_SET);
 285         if (seek_res < 0) {
 286                 fprintf(stderr, "lseek failed for failed_disk1\n");
 287                 return -1;
 288         }
 289         write_res1 = write(source[fd1], blocks[failed_slot1], chunk_size);
 290
 291         seek_res = lseek64(source[fd2],
 292                            offsets[fd2] + start * chunk_size, SEEK_SET);
 293         if (seek_res < 0) {
 294                 fprintf(stderr, "lseek failed for failed_disk2\n");
 295                 return -1;
 296         }
 297         write_res2 = write(source[fd2], blocks[failed_slot2], chunk_size);
 298
 299         if (write_res1 != chunk_size || write_res2 != chunk_size) {
 300                 fprintf(stderr, "Failed to write a complete chunk.\n");
 301                 return -2;
 302         }
 303
 304         return 0;
 305 }
 306
 307 int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
 308                   int raid_disks, int chunk_size, int level, int layout,
 309                   unsigned long long start, unsigned long long length, char *name[],
 310                   enum repair repair, int failed_disk1, int failed_disk2)
 311 {
 312         /* read the data and p and q blocks, and check we got them right */
 313         int data_disks = raid_disks - 2;
 314         int syndrome_disks = data_disks + is_ddf(layout) * 2;
 315         char *stripe_buf;
 316
 317         /* stripes[] is indexed by raid_disk and holds chunks from each device */
 318         char **stripes = xmalloc(raid_disks * sizeof(char*));
 319
 320         /* blocks[] is indexed by syndrome number and points to either one of the
 321          * chunks from 'stripes[]', or to a chunk of zeros. -1 and -2 are
 322          * P and Q */
 323         char **blocks = xmalloc((syndrome_disks + 2) * sizeof(char*));
 324
 325         /* blocks_page[] is a temporary index to just one page of the chunks
 326          * that blocks[] points to. */
 327         char **blocks_page = xmalloc((syndrome_disks + 2) * sizeof(char*));
 328
 329         /* block_index_for_slot[] provides the reverse mapping from blocks to stripes.
 330          * The index is a syndrome position, the content is a raid_disk number.
 331          * indicies -1 and -2 work, and are P and Q disks */
 332         int *block_index_for_slot = xmalloc((syndrome_disks+2) * sizeof(int));
 333
 334         /* 'p' and 'q' contain calcualted P and Q, to be compared with
 335          * blocks[-1] and blocks[-2];
 336          */
 337         uint8_t *p = xmalloc(chunk_size);
 338         uint8_t *q = xmalloc(chunk_size);
 339         char *zero = xmalloc(chunk_size);
 340         int *results = xmalloc(chunk_size * sizeof(int));
 341         sighandler_t *sig = xmalloc(3 * sizeof(sighandler_t));
 342
 343         int i, j;
 344         int diskP, diskQ, diskD;
 345         int err = 0;
 346
 347         extern int tables_ready;
 348
 349         if (!tables_ready)
 350                 make_tables();
 351
 352         if (posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size) != 0)
 353                 exit(4);
 354         block_index_for_slot += 2;
 355         blocks += 2;
 356         blocks_page += 2;
 357
 358         memset(zero, 0, chunk_size);
 359         for ( i = 0 ; i < raid_disks ; i++)
 360                 stripes[i] = stripe_buf + i * chunk_size;
 361
 362         while (length > 0) {
 363                 /* The syndrome number of the broken disk is recorded
 364                  * in 'disk[]' which allows a different broken disk for
 365                  * each page.
 366                  */
 367                 int disk[chunk_size >> CHECK_PAGE_BITS];
 368
 369                 err = lock_stripe(info, start, chunk_size, data_disks, sig);
 370                 if(err != 0) {
 371                         if (err != 2)
 372                                 unlock_all_stripes(info, sig);
 373                         goto exitCheck;
 374                 }
 375                 for (i = 0 ; i < raid_disks ; i++) {
 376                         off64_t seek_res = lseek64(source[i], offsets[i] + start * chunk_size,
 377                                                    SEEK_SET);
 378                         if (seek_res < 0) {
 379                                 fprintf(stderr, "lseek to source %d failed\n", i);
 380                                 unlock_all_stripes(info, sig);
 381                                 err = -1;
 382                                 goto exitCheck;
 383                         }
 384                         int read_res = read(source[i], stripes[i], chunk_size);
 385                         if (read_res < chunk_size) {
 386                                 fprintf(stderr, "Failed to read complete chunk disk %d, aborting\n", i);
 387                                 unlock_all_stripes(info, sig);
 388                                 err = -1;
 389                                 goto exitCheck;
 390                         }
 391                 }
 392
 393                 diskP = geo_map(-1, start, raid_disks, level, layout);
 394                 block_index_for_slot[-1] = diskP;
 395                 blocks[-1] = stripes[diskP];
 396
 397                 diskQ = geo_map(-2, start, raid_disks, level, layout);
 398                 block_index_for_slot[-2] = diskQ;
 399                 blocks[-2] = stripes[diskQ];
 400
 401                 if (!is_ddf(layout)) {
 402                         /* The syndrome-order of disks starts immediately after 'Q',
 403                          * but skips P */
 404                         diskD = diskQ;
 405                         for (i = 0 ; i < data_disks ; i++) {
 406                                 diskD = diskD + 1;
 407                                 if (diskD >= raid_disks)
 408                                         diskD = 0;
 409                                 if (diskD == diskP)
 410                                         diskD += 1;
 411                                 if (diskD >= raid_disks)
 412                                         diskD = 0;
 413                                 blocks[i] = stripes[diskD];
 414                                 block_index_for_slot[i] = diskD;
 415                         }
 416                 } else {
 417                         /* The syndrome-order exactly follows raid-disk
 418                          * numbers, with ZERO in place of P and Q
 419                          */
 420                         for (i = 0 ; i < raid_disks; i++) {
 421                                 if (i == diskP || i == diskQ) {
 422                                         blocks[i] = zero;
 423                                         block_index_for_slot[i] = -1;
 424                                 } else {
 425                                         blocks[i] = stripes[i];
 426                                         block_index_for_slot[i] = i;
 427                                 }
 428                         }
 429                 }
 430
 431                 qsyndrome(p, q, (uint8_t**)blocks, syndrome_disks, chunk_size);
 432
 433                 raid6_collect(chunk_size, p, q, stripes[diskP], stripes[diskQ], results);
 434                 raid6_stats(disk, results, raid_disks, chunk_size);
 435
 436                 for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
 437                         int role = disk[j];
 438                         if (role >= -2) {
 439                                 int slot = block_index_for_slot[role];
 440                                 if (slot >= 0)
 441                                         printf("Error detected at stripe %llu, page %d: possible failed disk slot %d: %d --> %s\n",
 442                                                start, j, role, slot, name[slot]);
 443                                 else
 444                                         printf("Error detected at stripe %llu, page %d: failed slot %d should be zeros\n",
 445                                                start, j, role);
 446                         } else if(disk[j] == -65535) {
 447                                 printf("Error detected at stripe %llu, page %d: disk slot unknown\n", start, j);
 448                         }
 449                 }
 450
 451                 if(repair == AUTO_REPAIR) {
 452                         err = autorepair(disk, start, chunk_size,
 453                                         name, raid_disks, syndrome_disks, blocks_page,
 454                                         blocks, p, block_index_for_slot,
 455                                         source, offsets);
 456                         if(err != 0) {
 457                                 unlock_all_stripes(info, sig);
 458                                 goto exitCheck;
 459                         }
 460                 }
 461
 462                 if(repair == MANUAL_REPAIR) {
 463                         int failed_slot1 = -1, failed_slot2 = -1;
 464                         for (i = -2; i < syndrome_disks; i++) {
 465                                 if (block_index_for_slot[i] == failed_disk1)
 466                                         failed_slot1 = i;
 467                                 if (block_index_for_slot[i] == failed_disk2)
 468                                         failed_slot2 = i;
 469                         }
 470                         err = manual_repair(chunk_size, syndrome_disks,
 471                                             failed_slot1, failed_slot2,
 472                                             start, block_index_for_slot,
 473                                             name, stripes, blocks, p,
 474                                             source, offsets);
 475                         if(err == -1) {
 476                                 unlock_all_stripes(info, sig);
 477                                 goto exitCheck;
 478                         }
 479                 }
 480
 481                 err = unlock_all_stripes(info, sig);
 482                 if(err != 0) {
 483                         goto exitCheck;
 484                 }
 485
 486                 length--;
 487                 start++;
 488         }
 489
 490 exitCheck:
 491
 492         free(stripe_buf);
 493         free(stripes);
 494         free(blocks-2);
 495         free(blocks_page-2);
 496         free(block_index_for_slot-2);
 497         free(p);
 498         free(q);
 499         free(results);
 500         free(sig);
 501
 502         return err;
 503 }
 504
 505 unsigned long long getnum(char *str, char **err)
 506 {
 507         char *e;
 508         unsigned long long rv = strtoull(str, &e, 10);
 509         if (e==str || *e) {
 510                 *err = str;
 511                 return 0;
 512         }
 513         return rv;
 514 }
 515
 516 int main(int argc, char *argv[])
 517 {
 518         /* md_device start length */
 519         int *fds = NULL;
 520         char *buf = NULL;
 521         char **disk_name = NULL;
 522         unsigned long long *offsets = NULL;
 523         int raid_disks = 0;
 524         int active_disks;
 525         int chunk_size = 0;
 526         int layout = -1;
 527         int level = 6;
 528         enum repair repair = NO_REPAIR;
 529         int failed_disk1 = -1;
 530         int failed_disk2 = -1;
 531         unsigned long long start, length;
 532         int i;
 533         int mdfd;
 534         struct mdinfo *info = NULL, *comp = NULL;
 535         char *err = NULL;
 536         int exit_err = 0;
 537         int close_flag = 0;
 538         char *prg = strrchr(argv[0], '/');
 539
 540         if (prg == NULL)
 541                 prg = argv[0];
 542         else
 543                 prg++;
 544
 545         if (argc < 4) {
 546                 fprintf(stderr, "Usage: %s md_device start_stripe length_stripes [autorepair]\n", prg);
 547                 fprintf(stderr, "   or: %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg);
 548                 exit_err = 1;
 549                 goto exitHere;
 550         }
 551
 552         mdfd = open(argv[1], O_RDONLY);
 553         if(mdfd < 0) {
 554                 perror(argv[1]);
 555                 fprintf(stderr, "%s: cannot open %s\n", prg, argv[1]);
 556                 exit_err = 2;
 557                 goto exitHere;
 558         }
 559
 560         info = sysfs_read(mdfd, NULL,
 561                           GET_LEVEL|
 562                           GET_LAYOUT|
 563                           GET_DISKS|
 564                           GET_DEGRADED |
 565                           GET_COMPONENT|
 566                           GET_CHUNK|
 567                           GET_DEVS|
 568                           GET_OFFSET|
 569                           GET_SIZE);
 570
 571         if(info == NULL) {
 572                 fprintf(stderr, "%s: Error reading sysfs information of %s\n", prg, argv[1]);
 573                 exit_err = 9;
 574                 goto exitHere;
 575         }
 576
 577         if(info->array.level != level) {
 578                 fprintf(stderr, "%s: %s not a RAID-6\n", prg, argv[1]);
 579                 exit_err = 3;
 580                 goto exitHere;
 581         }
 582
 583         if(info->array.failed_disks > 0) {
 584                 fprintf(stderr, "%s: %s degraded array\n", prg, argv[1]);
 585                 exit_err = 8;
 586                 goto exitHere;
 587         }
 588
 589         printf("layout: %d\n", info->array.layout);
 590         printf("disks: %d\n", info->array.raid_disks);
 591         printf("component size: %llu\n", info->component_size * 512);
 592         printf("total stripes: %llu\n", (info->component_size * 512) / info->array.chunk_size);
 593         printf("chunk size: %d\n", info->array.chunk_size);
 594         printf("\n");
 595
 596         comp = info->devs;
 597         for(i = 0, active_disks = 0; active_disks < info->array.raid_disks; i++) {
 598                 printf("disk: %d - offset: %llu - size: %llu - name: %s - slot: %d\n",
 599                         i, comp->data_offset * 512, comp->component_size * 512,
 600                         map_dev(comp->disk.major, comp->disk.minor, 0),
 601                         comp->disk.raid_disk);
 602                 if(comp->disk.raid_disk >= 0)
 603                         active_disks++;
 604                 comp = comp->next;
 605         }
 606         printf("\n");
 607
 608         close(mdfd);
 609
 610         raid_disks = info->array.raid_disks;
 611         chunk_size = info->array.chunk_size;
 612         layout = info->array.layout;
 613         if (strcmp(argv[2], "repair")==0) {
 614                 if (argc < 6) {
 615                         fprintf(stderr, "For repair mode, call %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg);
 616                         exit_err = 1;
 617                         goto exitHere;
 618                 }
 619                 repair = MANUAL_REPAIR;
 620                 start = getnum(argv[3], &err);
 621                 length = 1;
 622                 failed_disk1 = getnum(argv[4], &err);
 623                 failed_disk2 = getnum(argv[5], &err);
 624
 625                 if(failed_disk1 >= info->array.raid_disks) {
 626                         fprintf(stderr, "%s: failed_slot_1 index is higher than number of devices in raid\n", prg);
 627                         exit_err = 4;
 628                         goto exitHere;
 629                 }
 630                 if(failed_disk2 >= info->array.raid_disks) {
 631                         fprintf(stderr, "%s: failed_slot_2 index is higher than number of devices in raid\n", prg);
 632                         exit_err = 4;
 633                         goto exitHere;
 634                 }
 635                 if(failed_disk1 == failed_disk2) {
 636                         fprintf(stderr, "%s: failed_slot_1 and failed_slot_2 are the same\n", prg);
 637                         exit_err = 4;
 638                         goto exitHere;
 639                 }
 640         }
 641         else {
 642                 start = getnum(argv[2], &err);
 643                 length = getnum(argv[3], &err);
 644                 if (argc >= 5 && strcmp(argv[4], "autorepair")==0)
 645                         repair = AUTO_REPAIR;
 646         }
 647
 648         if (err) {
 649                 fprintf(stderr, "%s: Bad number: %s\n", prg, err);
 650                 exit_err = 4;
 651                 goto exitHere;
 652         }
 653
 654         if(start > ((info->component_size * 512) / chunk_size)) {
 655                 start = (info->component_size * 512) / chunk_size;
 656                 fprintf(stderr, "%s: start beyond disks size\n", prg);
 657         }
 658
 659         if((length == 0) ||
 660            ((length + start) > ((info->component_size * 512) / chunk_size))) {
 661                 length = (info->component_size * 512) / chunk_size - start;
 662         }
 663
 664         disk_name = xmalloc(raid_disks * sizeof(*disk_name));
 665         fds = xmalloc(raid_disks * sizeof(*fds));
 666         offsets = xcalloc(raid_disks, sizeof(*offsets));
 667         buf = xmalloc(raid_disks * chunk_size);
 668
 669         for(i=0; i<raid_disks; i++) {
 670                 fds[i] = -1;
 671         }
 672         close_flag = 1;
 673
 674         comp = info->devs;
 675         for (i=0, active_disks=0; active_disks<raid_disks; i++) {
 676                 int disk_slot = comp->disk.raid_disk;
 677                 if(disk_slot >= 0) {
 678                         disk_name[disk_slot] = map_dev(comp->disk.major, comp->disk.minor, 0);
 679                         offsets[disk_slot] = comp->data_offset * 512;
 680                         fds[disk_slot] = open(disk_name[disk_slot], O_RDWR | O_DIRECT);
 681                         if (fds[disk_slot] < 0) {
 682                                 perror(disk_name[disk_slot]);
 683                                 fprintf(stderr,"%s: cannot open %s\n", prg, disk_name[disk_slot]);
 684                                 exit_err = 6;
 685                                 goto exitHere;
 686                         }
 687                         active_disks++;
 688                 }
 689                 comp = comp->next;
 690         }
 691
 692         int rv = check_stripes(info, fds, offsets,
 693                                raid_disks, chunk_size, level, layout,
 694                                start, length, disk_name, repair, failed_disk1, failed_disk2);
 695         if (rv != 0) {
 696                 fprintf(stderr, "%s: check_stripes returned %d\n", prg, rv);
 697                 exit_err = 7;
 698                 goto exitHere;
 699         }
 700
 701 exitHere:
 702
 703         if (close_flag)
 704                 for(i = 0; i < raid_disks; i++)
 705                         close(fds[i]);
 706
 707         free(disk_name);
 708         free(fds);
 709         free(offsets);
 710         free(buf);
 711
 712         exit(exit_err);
 713 }