Assemble.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
   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: Neil Brown
  22  *    Email: <neilb@cse.unsw.edu.au>
  23  *    Paper: Neil Brown
  24  *           School of Computer Science and Engineering
  25  *           The University of New South Wales
  26  *           Sydney, 2052
  27  *           Australia
  28  */
  29
  30 #include        "mdadm.h"
  31 #include        "md_u.h"
  32 #include        "md_p.h"
  33
  34 int Assemble(char *mddev, int mdfd,
  35              mddev_ident_t ident, char *conffile,
  36              mddev_dev_t devlist,
  37              int readonly, int runstop,
  38              char *update,
  39              int verbose, int force)
  40 {
  41         /*
  42          * The task of Assemble is to find a collection of
  43          * devices that should (according to their superblocks)
  44          * form an array, and to give this collection to the MD driver.
  45          * In Linux-2.4 and later, this involves submitting a
  46          * SET_ARRAY_INFO ioctl with no arg - to prepare
  47          * the array - and then submit a number of
  48          * ADD_NEW_DISK ioctls to add disks into
  49          * the array.  Finally RUN_ARRAY might
  50          * be submitted to start the array.
  51          *
  52          * Much of the work of Assemble is in finding and/or
  53          * checking the disks to make sure they look right.
  54          *
  55          * If mddev is not set, then scan must be and we
  56          *  read through the config file for dev+uuid mapping
  57          *  We recurse, setting mddev, for each device that
  58          *    - isn't running
  59          *    - has a valid uuid (or any uuid if !uuidset
  60          *
  61          * If mddev is set, we try to determine state of md.
  62          *   check version - must be at least 0.90.0
  63          *   check kernel version.  must be at least 2.4.
  64          *    If not, we can possibly fall back on START_ARRAY
  65          *   Try to GET_ARRAY_INFO.
  66          *     If possible, give up
  67          *     If not, try to STOP_ARRAY just to make sure
  68          *
  69          * If !uuidset and scan, look in conf-file for uuid
  70          *       If not found, give up
  71          * If !devlist and scan and uuidset, get list of devs from conf-file
  72          *
  73          * For each device:
  74          *   Check superblock - discard if bad
  75          *   Check uuid (set if we don't have one) - discard if no match
  76          *   Check superblock similarity if we have a superblock - discard if different
  77          *   Record events, devicenum, utime
  78          * This should give us a list of devices for the array
  79          * We should collect the most recent event and utime numbers
  80          *
  81          * Count disks with recent enough event count
  82          * While force && !enough disks
  83          *    Choose newest rejected disks, update event count
  84          *     mark clean and rewrite superblock
  85          * If recent kernel:
  86          *    SET_ARRAY_INFO
  87          *    foreach device with recent events : ADD_NEW_DISK
  88          *    if runstop == 1 || "enough" disks and runstop==0 -> RUN_ARRAY
  89          * If old kernel:
  90          *    Check the device numbers in superblock are right
  91          *    update superblock if any changes
  92          *    START_ARRAY
  93          *
  94          */
  95         int old_linux = 0;
  96         int vers;
  97         mdu_array_info_t array;
  98         mdp_super_t first_super, super;
  99         struct {
 100                 char *devname;
 101                 int major, minor;
 102                 int oldmajor, oldminor;
 103                 long long events;
 104                 time_t utime;
 105                 int uptodate;
 106                 int state;
 107                 int raid_disk;
 108         } *devices;
 109         int *best = NULL; /* indexed by raid_disk */
 110         int bestcnt = 0;
 111         int devcnt = 0, okcnt, sparecnt;
 112         int req_cnt;
 113         int i;
 114         int most_recent = 0;
 115         int chosen_drive;
 116         int change = 0;
 117         int inargv = 0;
 118         int start_partial_ok = force || devlist==NULL;
 119         int num_devs;
 120         mddev_dev_t tmpdev;
 121
 122         vers = md_get_version(mdfd);
 123         if (vers <= 0) {
 124                 fprintf(stderr, Name ": %s appears not to be an md device.\n", mddev);
 125                 return 1;
 126         }
 127         if (vers < 9000) {
 128                 fprintf(stderr, Name ": Assemble requires driver version 0.90.0 or later.\n"
 129                         "    Upgrade your kernel or try --build\n");
 130                 return 1;
 131         }
 132         if (get_linux_version() < 2004000)
 133                 old_linux = 1;
 134
 135         if (ioctl(mdfd, GET_ARRAY_INFO, &array)>=0) {
 136                 fprintf(stderr, Name ": device %s already active - cannot assemble it\n",
 137                         mddev);
 138                 return 1;
 139         }
 140         ioctl(mdfd, STOP_ARRAY, NULL); /* just incase it was started but has no content */
 141
 142         /*
 143          * If any subdevs are listed, then any that don't
 144          * match ident are discarded.  Remainder must all match and
 145          * become the array.
 146          * If no subdevs, then we scan all devices in the config file, but
 147          * there must be something in the identity
 148          */
 149
 150         if (!devlist &&
 151             ident->uuid_set == 0 &&
 152             ident->super_minor < 0 &&
 153             ident->devices == NULL) {
 154                 fprintf(stderr, Name ": No identity information available for %s - cannot assemble.\n",
 155                         mddev);
 156                 return 1;
 157         }
 158         if (devlist == NULL)
 159                 devlist = conf_get_devs(conffile);
 160         else inargv = 1;
 161
 162         tmpdev = devlist; num_devs = 0;
 163         while (tmpdev) {
 164                 num_devs++;
 165                 tmpdev = tmpdev->next;
 166         }
 167         best = malloc(num_devs * sizeof(*best));
 168         devices = malloc(num_devs * sizeof(*devices));
 169
 170         first_super.md_magic = 0;
 171         for (i=0; i<num_devs; i++)
 172                 best[i] = -1;
 173
 174         if (verbose)
 175             fprintf(stderr, Name ": looking for devices for %s\n",
 176                     mddev);
 177
 178         while ( devlist) {
 179                 char *devname;
 180                 int this_uuid[4];
 181                 int dfd;
 182                 struct stat stb;
 183                 int havesuper=0;
 184
 185                 devname = devlist->devname;
 186                 devlist = devlist->next;
 187
 188                 if (ident->devices &&
 189                     !match_oneof(ident->devices, devname)) {
 190                         if (inargv || verbose)
 191                                 fprintf(stderr, Name ": %s is not one of %s\n", devname, ident->devices);
 192                         continue;
 193                 }
 194
 195                 dfd = open(devname, O_RDONLY, 0);
 196                 if (dfd < 0) {
 197                         if (inargv || verbose)
 198                                 fprintf(stderr, Name ": cannot open device %s: %s\n",
 199                                         devname, strerror(errno));
 200                 } else if (fstat(dfd, &stb)< 0) {
 201                         /* Impossible! */
 202                         fprintf(stderr, Name ": fstat failed for %s: %s\n",
 203                                 devname, strerror(errno));
 204                         close(dfd);
 205                 } else if ((stb.st_mode & S_IFMT) != S_IFBLK) {
 206                         fprintf(stderr, Name ": %s is not a block device.\n",
 207                                 devname);
 208                         close(dfd);
 209                 } else if (load_super(dfd, &super)) {
 210                         if (inargv || verbose)
 211                                 fprintf( stderr, Name ": no RAID superblock on %s\n",
 212                                          devname);
 213                         close(dfd);
 214                 } else {
 215                         havesuper =1;
 216                         uuid_from_super(this_uuid, &super);
 217                         close(dfd);
 218                 }
 219
 220                 if (ident->uuid_set &&
 221                     (!havesuper || same_uuid(this_uuid, ident->uuid)==0)) {
 222                         if (inargv || verbose)
 223                                 fprintf(stderr, Name ": %s has wrong uuid.\n",
 224                                         devname);
 225                         continue;
 226                 }
 227                 if (ident->super_minor >= 0 &&
 228                     (!havesuper || ident->super_minor != super.md_minor)) {
 229                         if (inargv || verbose)
 230                                 fprintf(stderr, Name ": %s has wrong super-minor.\n",
 231                                         devname);
 232                         continue;
 233                 }
 234                 if (ident->level != -10 &&
 235                     (!havesuper|| ident->level != super.level)) {
 236                         if (inargv || verbose)
 237                                 fprintf(stderr, Name ": %s has wrong raid level.\n",
 238                                         devname);
 239                         continue;
 240                 }
 241                 if (ident->raid_disks != -1 &&
 242                     (!havesuper || ident->raid_disks!= super.raid_disks)) {
 243                         if (inargv || verbose)
 244                                 fprintf(stderr, Name ": %s requires wrong number of drives.\n",
 245                                         devname);
 246                         continue;
 247                 }
 248
 249                 /* If we are this far, then we are commited to this device.
 250                  * If the super_block doesn't exist, or doesn't match others,
 251                  * then we cannot continue
 252                  */
 253
 254                 if (!havesuper) {
 255                         fprintf(stderr, Name ": %s has no superblock - assembly aborted\n",
 256                                 devname);
 257                         return 1;
 258                 }
 259                 if (compare_super(&first_super, &super)) {
 260                         fprintf(stderr, Name ": superblock on %s doesn't match others - assembly aborted\n",
 261                                 devname);
 262                         return 1;
 263                 }
 264
 265
 266                 /* this is needed until we get a more relaxed super block format */
 267                 if (devcnt >= MD_SB_DISKS) {
 268                     fprintf(stderr, Name ": ouch - too many devices appear to be in this array. Ignoring %s\n",
 269                             devname);
 270                     continue;
 271                 }
 272
 273                 /* looks like a good enough match to update the super block if needed */
 274                 if (update) {
 275                         if (strcmp(update, "sparc2.2")==0 ) {
 276                                 /* 2.2 sparc put the events in the wrong place
 277                                  * So we copy the tail of the superblock
 278                                  * up 4 bytes before continuing
 279                                  */
 280                                 __u32 *sb32 = (__u32*)&super;
 281                                 memcpy(sb32+MD_SB_GENERIC_CONSTANT_WORDS+7,
 282                                        sb32+MD_SB_GENERIC_CONSTANT_WORDS+7+1,
 283                                        (MD_SB_WORDS - (MD_SB_GENERIC_CONSTANT_WORDS+7+1))*4);
 284                                 fprintf (stderr, Name ": adjusting superblock of %s for 2.2/sparc compatability.\n",
 285                                          devname);
 286                         }
 287                         if (strcmp(update, "super-minor") ==0) {
 288                                 struct stat stb2;
 289                                 fstat(mdfd, &stb2);
 290                                 super.md_minor = MINOR(stb2.st_rdev);
 291                                 if (verbose)
 292                                         fprintf(stderr, Name ": updating superblock of %s with minor number %d\n",
 293                                                 devname, super.md_minor);
 294                         }
 295                         super.sb_csum = calc_sb_csum(&super);
 296                         dfd = open(devname, O_RDWR, 0);
 297                         if (dfd < 0)
 298                                 fprintf(stderr, Name ": Cannot open %s for superblock update\n",
 299                                         devname);
 300                         else if (store_super(dfd, &super))
 301                                 fprintf(stderr, Name ": Could not re-write superblock on %s.\n",
 302                                         devname);
 303                         if (dfd >= 0)
 304                                 close(dfd);
 305                 }
 306
 307                 if (verbose)
 308                         fprintf(stderr, Name ": %s is identified as a member of %s, slot %d.\n",
 309                                 devname, mddev, super.this_disk.raid_disk);
 310                 devices[devcnt].devname = devname;
 311                 devices[devcnt].major = MAJOR(stb.st_rdev);
 312                 devices[devcnt].minor = MINOR(stb.st_rdev);
 313                 devices[devcnt].oldmajor = super.this_disk.major;
 314                 devices[devcnt].oldminor = super.this_disk.minor;
 315                 devices[devcnt].events = md_event(&super);
 316                 devices[devcnt].utime = super.utime;
 317                 devices[devcnt].raid_disk = super.this_disk.raid_disk;
 318                 devices[devcnt].uptodate = 0;
 319                 devices[devcnt].state = super.this_disk.state;
 320                 if (most_recent < devcnt) {
 321                         if (devices[devcnt].events
 322                             > devices[most_recent].events)
 323                                 most_recent = devcnt;
 324                 }
 325                 if (super.level == -4)
 326                         /* with multipath, the raid_disk from the superblock is meaningless */
 327                         i = devcnt;
 328                 else
 329                         i = devices[devcnt].raid_disk;
 330                 if (i>=0 && i < 10000) {
 331                         if (i >= bestcnt) {
 332                                 int newbestcnt = i+10;
 333                                 int *newbest = malloc(sizeof(int)*newbestcnt);
 334                                 int c;
 335                                 for (c=0; c < newbestcnt; c++)
 336                                         if (c < bestcnt)
 337                                                 newbest[c] = best[c];
 338                                         else
 339                                                 newbest[c] = -1;
 340                                 if (best)free(best);
 341                                 best = newbest;
 342                                 bestcnt = newbestcnt;
 343                         }
 344                         if (best[i] == -1
 345                             || devices[best[i]].events < devices[devcnt].events)
 346                                 best[i] = devcnt;
 347                 }
 348                 devcnt++;
 349         }
 350
 351         if (devcnt == 0) {
 352                 fprintf(stderr, Name ": no devices found for %s\n",
 353                         mddev);
 354                 return 1;
 355         }
 356         /* now we have some devices that might be suitable.
 357          * I wonder how many
 358          */
 359         okcnt = 0;
 360         sparecnt=0;
 361         for (i=0; i< bestcnt ;i++) {
 362                 int j = best[i];
 363                 int event_margin = !force;
 364                 if (j < 0) continue;
 365                 /* note: we ignore error flags in multipath arrays
 366                  * as they don't make sense
 367                  */
 368                 if (first_super.level != -4)
 369                         if (!(devices[j].state & (1<<MD_DISK_SYNC))) {
 370                                 if (!(devices[j].state & (1<<MD_DISK_FAULTY)))
 371                                         sparecnt++;
 372                                 continue;
 373                         }
 374                 if (devices[j].events+event_margin >=
 375                     devices[most_recent].events) {
 376                         devices[j].uptodate = 1;
 377                         if (i < first_super.raid_disks)
 378                                 okcnt++;
 379                         else
 380                                 sparecnt++;
 381                 }
 382         }
 383         while (force && !enough(first_super.level, first_super.raid_disks, okcnt)) {
 384                 /* Choose the newest best drive which is
 385                  * not up-to-date, update the superblock
 386                  * and add it.
 387                  */
 388                 int fd;
 389                 chosen_drive = -1;
 390                 for (i=0; i<first_super.raid_disks && i < bestcnt; i++) {
 391                         int j = best[i];
 392                         if (j>=0 &&
 393                             !devices[j].uptodate &&
 394                             devices[j].events > 0 &&
 395                             (chosen_drive < 0 ||
 396                              devices[j].events > devices[chosen_drive].events))
 397                                 chosen_drive = j;
 398                 }
 399                 if (chosen_drive < 0)
 400                         break;
 401                 fprintf(stderr, Name ": forcing event count in %s(%d) from %d upto %d\n",
 402                         devices[chosen_drive].devname, devices[chosen_drive].raid_disk,
 403                         (int)(devices[chosen_drive].events),
 404                         (int)(devices[most_recent].events));
 405                 fd = open(devices[chosen_drive].devname, O_RDWR);
 406                 if (fd < 0) {
 407                         fprintf(stderr, Name ": Couldn't open %s for write - not updating\n",
 408                                 devices[chosen_drive].devname);
 409                         devices[chosen_drive].events = 0;
 410                         continue;
 411                 }
 412                 if (load_super(fd, &super)) {
 413                         close(fd);
 414                         fprintf(stderr, Name ": RAID superblock disappeared from %s - not updating.\n",
 415                                 devices[chosen_drive].devname);
 416                         devices[chosen_drive].events = 0;
 417                         continue;
 418                 }
 419                 super.events_hi = (devices[most_recent].events>>32)&0xFFFFFFFF;
 420                 super.events_lo = (devices[most_recent].events)&0xFFFFFFFF;
 421                 if (super.level == 5 || super.level == 4) {
 422                         /* need to force clean */
 423                         super.state = (1<<MD_SB_CLEAN);
 424                 }
 425                 super.sb_csum = calc_sb_csum(&super);
 426 /*DRYRUN*/      if (store_super(fd, &super)) {
 427                         close(fd);
 428                         fprintf(stderr, Name ": Could not re-write superblock on %s\n",
 429                                 devices[chosen_drive].devname);
 430                         devices[chosen_drive].events = 0;
 431                         continue;
 432                 }
 433                 close(fd);
 434                 devices[chosen_drive].events = devices[most_recent].events;
 435                 devices[chosen_drive].uptodate = 1;
 436                 okcnt++;
 437         }
 438
 439         /* Now we want to look at the superblock which the kernel will base things on
 440          * and compare the devices that we think are working with the devices that the
 441          * superblock thinks are working.
 442          * If there are differences and --force is given, then update this chosen
 443          * superblock.
 444          */
 445         chosen_drive = -1;
 446         for (i=0; chosen_drive < 0 && i<bestcnt; i++) {
 447                 int j = best[i];
 448                 int fd;
 449                 if (j<0)
 450                         continue;
 451                 if (!devices[j].uptodate)
 452                         continue;
 453                 chosen_drive = j;
 454                 if ((fd=open(devices[j].devname, O_RDONLY))< 0) {
 455                         fprintf(stderr, Name ": Cannot open %s: %s\n",
 456                                 devices[j].devname, strerror(errno));
 457                         return 1;
 458                 }
 459                 if (load_super(fd, &super)) {
 460                         close(fd);
 461                         fprintf(stderr, Name ": RAID superblock has disappeared from %s\n",
 462                                 devices[j].devname);
 463                         return 1;
 464                 }
 465                 close(fd);
 466         }
 467
 468         for (i=0; i<bestcnt; i++) {
 469                 int j = best[i];
 470                 int desired_state;
 471
 472                 if (i < super.raid_disks)
 473                         desired_state = (1<<MD_DISK_ACTIVE) | (1<<MD_DISK_SYNC);
 474                 else
 475                         desired_state = 0;
 476
 477                 if (j<0)
 478                         continue;
 479                 if (!devices[j].uptodate)
 480                         continue;
 481 #if 0
 482 This doesnt work yet
 483                 if (devices[j].major != super.disks[i].major ||
 484                     devices[j].minor != super.disks[i].minor) {
 485                         change |= 1;
 486                         super.disks[i].major = devices[j].major;
 487                         super.disks[i].minor = devices[j].minor;
 488                 }
 489 #endif
 490                 if (devices[j].oldmajor != super.disks[i].major ||
 491                     devices[j].oldminor != super.disks[i].minor) {
 492                         change |= 2;
 493                         super.disks[i].major = devices[j].oldmajor;
 494                         super.disks[i].minor = devices[j].oldminor;
 495                 }
 496                 if (devices[j].uptodate &&
 497                     (super.disks[i].state != desired_state)) {
 498                         if (force) {
 499                                 fprintf(stderr, Name ": "
 500                                         "clearing FAULTY flag for device %d in %s for %s\n",
 501                                         j, mddev, devices[j].devname);
 502                                 super.disks[i].state = desired_state;
 503                                 change |= 2;
 504                         } else {
 505                                 fprintf(stderr, Name ": "
 506                                         "device %d in %s has wrong state in superblock, but %s seems ok\n",
 507                                         i, mddev, devices[j].devname);
 508                         }
 509                 }
 510                 if (!devices[j].uptodate &&
 511                     !(super.disks[i].state & (1 << MD_DISK_FAULTY))) {
 512                         fprintf(stderr, Name ": devices %d of %s is not marked FAULTY in superblock, but cannot be found\n",
 513                                 i, mddev);
 514                 }
 515         }
 516         if (force && (super.level == 4 || super.level == 5) &&
 517             okcnt == super.raid_disks-1) {
 518                 super.state = (1<< MD_SB_CLEAN);
 519                 change |= 2;
 520         }
 521
 522         if ((force && (change & 2))
 523             || (old_linux && (change & 1))) {
 524                 int fd;
 525                 super.sb_csum = calc_sb_csum(&super);
 526                 fd = open(devices[chosen_drive].devname, O_RDWR);
 527                 if (fd < 0) {
 528                         fprintf(stderr, Name ": Could open %s for write - cannot Assemble array.\n",
 529                                 devices[chosen_drive].devname);
 530                         return 1;
 531                 }
 532                 if (store_super(fd, &super)) {
 533                         close(fd);
 534                         fprintf(stderr, Name ": Could not re-write superblock on %s\n",
 535                                 devices[chosen_drive].devname);
 536                         return 1;
 537                 }
 538                 close(fd);
 539                 change = 0;
 540         }
 541
 542         /* count number of in-sync devices according to the superblock.
 543          * We must have this number to start the array without -s or -R
 544          */
 545         req_cnt = 0;
 546         for (i=0; i<MD_SB_DISKS; i++)
 547                 if ((first_super.disks[i].state & (1<<MD_DISK_SYNC)) &&
 548                     (first_super.disks[i].state & (1<<MD_DISK_ACTIVE)) &&
 549                     !(first_super.disks[i].state & (1<<MD_DISK_FAULTY)))
 550                         req_cnt ++;
 551
 552
 553         /* Almost ready to actually *do* something */
 554         if (!old_linux) {
 555                 if (ioctl(mdfd, SET_ARRAY_INFO, NULL) != 0) {
 556                         fprintf(stderr, Name ": SET_ARRAY_INFO failed for %s: %s\n",
 557                                 mddev, strerror(errno));
 558                         return 1;
 559                 }
 560                 /* First, add the raid disks, but add the chosen one last */
 561                 for (i=0; i<= bestcnt; i++) {
 562                         int j;
 563                         if (i < bestcnt) {
 564                                 j = best[i];
 565                                 if (j == chosen_drive)
 566                                         continue;
 567                         } else
 568                                 j = chosen_drive;
 569
 570                         if (j >= 0 /* && devices[j].uptodate */) {
 571                                 mdu_disk_info_t disk;
 572                                 memset(&disk, 0, sizeof(disk));
 573                                 disk.major = devices[j].major;
 574                                 disk.minor = devices[j].minor;
 575                                 if (ioctl(mdfd, ADD_NEW_DISK, &disk)!=0) {
 576                                         fprintf(stderr, Name ": failed to add %s to %s: %s\n",
 577                                                 devices[j].devname,
 578                                                 mddev,
 579                                                 strerror(errno));
 580                                         if (i < first_super.raid_disks)
 581                                                 okcnt--;
 582                                         else
 583                                                 sparecnt--;
 584                                 } else if (verbose)
 585                                         fprintf(stderr, Name ": added %s to %s as %d\n",
 586                                                 devices[j].devname, mddev, devices[j].raid_disk);
 587                         } else if (verbose && i < first_super.raid_disks)
 588                                 fprintf(stderr, Name ": no uptodate device for slot %d of %s\n",
 589                                         i, mddev);
 590                 }
 591
 592                 if (runstop == 1 ||
 593                     (runstop == 0 &&
 594                      ( enough(first_super.level, first_super.raid_disks, okcnt) &&
 595                        (okcnt >= req_cnt || start_partial_ok)
 596                              ))) {
 597                         if (ioctl(mdfd, RUN_ARRAY, NULL)==0) {
 598                                 fprintf(stderr, Name ": %s has been started with %d drive%s",
 599                                         mddev, okcnt, okcnt==1?"":"s");
 600                                 if (okcnt < first_super.raid_disks)
 601                                         fprintf(stderr, " (out of %d)", first_super.raid_disks);
 602                                 if (sparecnt)
 603                                         fprintf(stderr, " and %d spare%s", sparecnt, sparecnt==1?"":"s");
 604                                 fprintf(stderr, ".\n");
 605                                 return 0;
 606                         }
 607                         fprintf(stderr, Name ": failed to RUN_ARRAY %s: %s\n",
 608                                 mddev, strerror(errno));
 609                         return 1;
 610                 }
 611                 if (runstop == -1) {
 612                         fprintf(stderr, Name ": %s assembled from %d drive%s, but not started.\n",
 613                                 mddev, okcnt, okcnt==1?"":"s");
 614                         return 0;
 615                 }
 616                 fprintf(stderr, Name ": %s assembled from %d drive%s", mddev, okcnt, okcnt==1?"":"s");
 617                 if (sparecnt)
 618                         fprintf(stderr, " and %d spare%s", sparecnt, sparecnt==1?"":"s");
 619                 if (!enough(first_super.level, first_super.raid_disks, okcnt))
 620                         fprintf(stderr, " - not enough to start the array.\n");
 621                 else {
 622                         if (req_cnt == first_super.raid_disks)
 623                                 fprintf(stderr, " - need all %d to start it", req_cnt);
 624                         else
 625                                 fprintf(stderr, " - need %d of %d to start", req_cnt, first_super.raid_disks);
 626                         fprintf(stderr, " (use --run to insist).\n");
 627                 }
 628                 return 1;
 629         } else {
 630                 /* The "chosen_drive" is a good choice, and if necessary, the superblock has
 631                  * been updated to point to the current locations of devices.
 632                  * so we can just start the array
 633                  */
 634                 unsigned long dev;
 635                 dev = MKDEV(devices[chosen_drive].major,
 636                             devices[chosen_drive].minor);
 637                 if (ioctl(mdfd, START_ARRAY, dev)) {
 638                     fprintf(stderr, Name ": Cannot start array: %s\n",
 639                             strerror(errno));
 640                 }
 641
 642         }
 643         return 0;
 644 }