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 raid_disk;
 107         } *devices;
 108         int *best; /* indexed by raid_disk */
 109         int devcnt = 0, okcnt, sparecnt;
 110         int i;
 111         int most_recent = 0;
 112         int chosen_drive;
 113         int change = 0;
 114         int inargv = 0;
 115         int start_partial_ok = force || devlist==NULL;
 116         int num_devs;
 117         mddev_dev_t tmpdev;
 118
 119         vers = md_get_version(mdfd);
 120         if (vers <= 0) {
 121                 fprintf(stderr, Name ": %s appears not to be an md device.\n", mddev);
 122                 return 1;
 123         }
 124         if (vers < 9000) {
 125                 fprintf(stderr, Name ": Assemble requires driver version 0.90.0 or later.\n"
 126                         "    Upgrade your kernel or try --build\n");
 127                 return 1;
 128         }
 129         if (get_linux_version() < 2004000)
 130                 old_linux = 1;
 131
 132         if (ioctl(mdfd, GET_ARRAY_INFO, &array)>=0) {
 133                 fprintf(stderr, Name ": device %s already active - cannot assemble it\n",
 134                         mddev);
 135                 return 1;
 136         }
 137         ioctl(mdfd, STOP_ARRAY, NULL); /* just incase it was started but has no content */
 138
 139         /*
 140          * If any subdevs are listed, then any that don't
 141          * match ident are discarded.  Remainder must all match and
 142          * become the array.
 143          * If no subdevs, then we scan all devices in the config file, but
 144          * there must be something in the identity
 145          */
 146
 147         if (!devlist &&
 148             ident->uuid_set == 0 &&
 149             ident->super_minor < 0 &&
 150             ident->devices == NULL) {
 151                 fprintf(stderr, Name ": No identity information available for %s - cannot assemble.\n",
 152                         mddev);
 153                 return 1;
 154         }
 155         if (devlist == NULL)
 156                 devlist = conf_get_devs(conffile);
 157         else inargv = 1;
 158
 159         tmpdev = devlist; num_devs = 0;
 160         while (tmpdev) {
 161                 num_devs++;
 162                 tmpdev = tmpdev->next;
 163         }
 164         best = malloc(num_devs * sizeof(*best));
 165         devices = malloc(num_devs * sizeof(*devices));
 166
 167         first_super.md_magic = 0;
 168         for (i=0; i<num_devs; i++)
 169                 best[i] = -1;
 170
 171         if (verbose)
 172             fprintf(stderr, Name ": looking for devices for %s\n",
 173                     mddev);
 174
 175         while ( devlist) {
 176                 char *devname;
 177                 int this_uuid[4];
 178                 int dfd;
 179                 struct stat stb;
 180                 int havesuper=0;
 181
 182                 devname = devlist->devname;
 183                 devlist = devlist->next;
 184
 185                 if (ident->devices &&
 186                     !match_oneof(ident->devices, devname))
 187                         continue;
 188
 189                 dfd = open(devname, O_RDONLY, 0);
 190                 if (dfd < 0) {
 191                         if (inargv || verbose)
 192                                 fprintf(stderr, Name ": cannot open device %s: %s\n",
 193                                         devname, strerror(errno));
 194                 } else if (fstat(dfd, &stb)< 0) {
 195                         /* Impossible! */
 196                         fprintf(stderr, Name ": fstat failed for %s: %s\n",
 197                                 devname, strerror(errno));
 198                         close(dfd);
 199                 } else if ((stb.st_mode & S_IFMT) != S_IFBLK) {
 200                         fprintf(stderr, Name ": %s is not a block device.\n",
 201                                 devname);
 202                         close(dfd);
 203                 } else if (load_super(dfd, &super)) {
 204                         if (inargv || verbose)
 205                                 fprintf( stderr, Name ": no RAID superblock on %s\n",
 206                                          devname);
 207                         close(dfd);
 208                 } else {
 209                         havesuper =1;
 210                         uuid_from_super(this_uuid, &super);
 211                         close(dfd);
 212                 }
 213
 214                 if (ident->uuid_set &&
 215                     (!havesuper || same_uuid(this_uuid, ident->uuid)==0)) {
 216                         if (inargv || verbose)
 217                                 fprintf(stderr, Name ": %s has wrong uuid.\n",
 218                                         devname);
 219                         continue;
 220                 }
 221                 if (ident->super_minor >= 0 &&
 222                     (!havesuper || ident->super_minor != super.md_minor)) {
 223                         if (inargv || verbose)
 224                                 fprintf(stderr, Name ": %s has wrong super-minor.\n",
 225                                         devname);
 226                         continue;
 227                 }
 228                 if (ident->level != -10 &&
 229                     (!havesuper|| ident->level != super.level)) {
 230                         if (inargv || verbose)
 231                                 fprintf(stderr, Name ": %s has wrong raid level.\n",
 232                                         devname);
 233                         continue;
 234                 }
 235                 if (ident->raid_disks != -1 &&
 236                     (!havesuper || ident->raid_disks!= super.raid_disks)) {
 237                         if (inargv || verbose)
 238                                 fprintf(stderr, Name ": %s requires wrong number of drives.\n",
 239                                         devname);
 240                         continue;
 241                 }
 242
 243                 /* If we are this far, then we are commited to this device.
 244                  * If the super_block doesn't exist, or doesn't match others,
 245                  * then we cannot continue
 246                  */
 247
 248                 if (!havesuper) {
 249                         fprintf(stderr, Name ": %s has no superblock - assembly aborted\n",
 250                                 devname);
 251                         return 1;
 252                 }
 253                 if (compare_super(&first_super, &super)) {
 254                         fprintf(stderr, Name ": superblock on %s doesn't match others - assembly aborted\n",
 255                                 devname);
 256                         return 1;
 257                 }
 258
 259
 260                 /* this is needed until we get a more relaxed super block format */
 261                 if (devcnt >= MD_SB_DISKS) {
 262                     fprintf(stderr, Name ": ouch - too many devices appear to be in this array. Ignoring %s\n",
 263                             devname);
 264                     continue;
 265                 }
 266
 267                 /* looks like a good enough match to update the super block if needed */
 268                 if (update) {
 269                         if (strcmp(update, "sparc2.2")==0 ) {
 270                                 /* 2.2 sparc put the events in the wrong place
 271                                  * So we copy the tail of the superblock
 272                                  * up 4 bytes before continuing
 273                                  */
 274                                 __u32 *sb32 = (__u32*)&super;
 275                                 memcpy(sb32+MD_SB_GENERIC_CONSTANT_WORDS+7,
 276                                        sb32+MD_SB_GENERIC_CONSTANT_WORDS+7+1,
 277                                        (MD_SB_WORDS - (MD_SB_GENERIC_CONSTANT_WORDS+7+1))*4);
 278                                 fprintf (stderr, Name ": adjusting superblock of %s for 2.2/sparc compatability.\n",
 279                                          devname);
 280                         }
 281                         if (strcmp(update, "super-minor") ==0) {
 282                                 struct stat stb2;
 283                                 fstat(mdfd, &stb2);
 284                                 super.md_minor = MINOR(stb2.st_rdev);
 285                                 if (verbose)
 286                                         fprintf(stderr, Name ": updating superblock of %s with minor number %d\n",
 287                                                 devname, super.md_minor);
 288                         }
 289                         super.sb_csum = calc_sb_csum(&super);
 290                         dfd = open(devname, O_RDWR, 0);
 291                         if (dfd < 0)
 292                                 fprintf(stderr, Name ": Cannot open %s for superblock update\n",
 293                                         devname);
 294                         else if (store_super(dfd, &super))
 295                                 fprintf(stderr, Name ": Could not re-write superblock on %s.\n",
 296                                         devname);
 297                         if (dfd >= 0)
 298                                 close(dfd);
 299                 }
 300
 301                 if (verbose)
 302                         fprintf(stderr, Name ": %s is identified as a member of %s, slot %d.\n",
 303                                 devname, mddev, super.this_disk.raid_disk);
 304                 devices[devcnt].devname = devname;
 305                 devices[devcnt].major = MAJOR(stb.st_rdev);
 306                 devices[devcnt].minor = MINOR(stb.st_rdev);
 307                 devices[devcnt].oldmajor = super.this_disk.major;
 308                 devices[devcnt].oldminor = super.this_disk.minor;
 309                 devices[devcnt].events = md_event(&super);
 310                 devices[devcnt].utime = super.utime;
 311                 devices[devcnt].raid_disk = super.this_disk.raid_disk;
 312                 devices[devcnt].uptodate = 0;
 313                 if (most_recent < devcnt) {
 314                         if (devices[devcnt].events
 315                             > devices[most_recent].events)
 316                                 most_recent = devcnt;
 317                 }
 318                 if (super.level == -4)
 319                         /* with multipath, the raid_disk from the superblock is meaningless */
 320                         i = devcnt;
 321                 else
 322                         i = devices[devcnt].raid_disk;
 323                 if (i>=0 && i < num_devs)
 324                         if (best[i] == -1
 325                             || devices[best[i]].events < devices[devcnt].events)
 326                                 best[i] = devcnt;
 327
 328                 devcnt++;
 329         }
 330
 331         if (devcnt == 0) {
 332                 fprintf(stderr, Name ": no devices found for %s\n",
 333                         mddev);
 334                 return 1;
 335         }
 336         /* now we have some devices that might be suitable.
 337          * I wonder how many
 338          */
 339         okcnt = 0;
 340         sparecnt=0;
 341         for (i=0; i< num_devs ;i++) {
 342                 int j = best[i];
 343                 int event_margin = !force;
 344                 if (j < 0) continue;
 345                 if (devices[j].events+event_margin >=
 346                     devices[most_recent].events) {
 347                         devices[j].uptodate = 1;
 348                         if (i < first_super.raid_disks)
 349                                 okcnt++;
 350                         else
 351                                 sparecnt++;
 352                 }
 353         }
 354         while (force && !enough(first_super.level, first_super.raid_disks, okcnt)) {
 355                 /* Choose the newest best drive which is
 356                  * not up-to-date, update the superblock
 357                  * and add it.
 358                  */
 359                 int fd;
 360                 chosen_drive = -1;
 361                 for (i=0; i<first_super.raid_disks; i++) {
 362                         int j = best[i];
 363                         if (j>=0 &&
 364                             !devices[j].uptodate &&
 365                             devices[j].events > 0 &&
 366                             (chosen_drive < 0 ||
 367                              devices[j].events > devices[chosen_drive].events))
 368                                 chosen_drive = j;
 369                 }
 370                 if (chosen_drive < 0)
 371                         break;
 372                 fprintf(stderr, Name ": forcing event count in %s(%d) from %d upto %d\n",
 373                         devices[chosen_drive].devname, devices[chosen_drive].raid_disk,
 374                         (int)(devices[chosen_drive].events),
 375                         (int)(devices[most_recent].events));
 376                 fd = open(devices[chosen_drive].devname, O_RDWR);
 377                 if (fd < 0) {
 378                         fprintf(stderr, Name ": Couldn't open %s for write - not updating\n",
 379                                 devices[chosen_drive].devname);
 380                         devices[chosen_drive].events = 0;
 381                         continue;
 382                 }
 383                 if (load_super(fd, &super)) {
 384                         close(fd);
 385                         fprintf(stderr, Name ": RAID superblock disappeared from %s - not updating.\n",
 386                                 devices[chosen_drive].devname);
 387                         devices[chosen_drive].events = 0;
 388                         continue;
 389                 }
 390                 super.events_hi = (devices[most_recent].events>>32)&0xFFFFFFFF;
 391                 super.events_lo = (devices[most_recent].events)&0xFFFFFFFF;
 392                 if (super.level == 5 || super.level == 4) {
 393                         /* need to force clean */
 394                         super.state = 0;
 395                 }
 396                 super.sb_csum = calc_sb_csum(&super);
 397 /*DRYRUN*/      if (store_super(fd, &super)) {
 398                         close(fd);
 399                         fprintf(stderr, Name ": Could not re-write superblock on %s\n",
 400                                 devices[chosen_drive].devname);
 401                         devices[chosen_drive].events = 0;
 402                         continue;
 403                 }
 404                 close(fd);
 405                 devices[chosen_drive].events = devices[most_recent].events;
 406                 devices[chosen_drive].uptodate = 1;
 407                 okcnt++;
 408         }
 409
 410         /* Now we want to look at the superblock which the kernel will base things on
 411          * and compare the devices that we think are working with the devices that the
 412          * superblock thinks are working.
 413          * If there are differences and --force is given, then update this chosen
 414          * superblock.
 415          */
 416         chosen_drive = -1;
 417         for (i=0; chosen_drive < 0 && i<num_devs; i++) {
 418                 int j = best[i];
 419                 int fd;
 420                 if (j<0)
 421                         continue;
 422                 if (!devices[j].uptodate)
 423                         continue;
 424                 chosen_drive = j;
 425                 if ((fd=open(devices[j].devname, O_RDONLY))< 0) {
 426                         fprintf(stderr, Name ": Cannot open %s: %s\n",
 427                                 devices[j].devname, strerror(errno));
 428                         return 1;
 429                 }
 430                 if (load_super(fd, &super)) {
 431                         close(fd);
 432                         fprintf(stderr, Name ": RAID superblock has disappeared from %s\n",
 433                                 devices[j].devname);
 434                         return 1;
 435                 }
 436                 close(fd);
 437         }
 438
 439         for (i=0; i<num_devs; i++) {
 440                 int j = best[i];
 441                 int desired_state;
 442
 443                 if (i < super.raid_disks)
 444                         desired_state = (1<<MD_DISK_ACTIVE) | (1<<MD_DISK_SYNC);
 445                 else
 446                         desired_state = 0;
 447
 448                 if (j<0)
 449                         continue;
 450                 if (!devices[j].uptodate)
 451                         continue;
 452 #if 0
 453 This doesnt work yet
 454                 if (devices[j].major != super.disks[i].major ||
 455                     devices[j].minor != super.disks[i].minor) {
 456                         change |= 1;
 457                         super.disks[i].major = devices[j].major;
 458                         super.disks[i].minor = devices[j].minor;
 459                 }
 460 #endif
 461                 if (devices[j].oldmajor != super.disks[i].major ||
 462                     devices[j].oldminor != super.disks[i].minor) {
 463                         change |= 2;
 464                         super.disks[i].major = devices[j].oldmajor;
 465                         super.disks[i].minor = devices[j].oldminor;
 466                 }
 467                 if (devices[j].uptodate &&
 468                     (super.disks[i].state != desired_state)) {
 469                         if (force) {
 470                                 fprintf(stderr, Name ": "
 471                                         "clearing FAULTY flag for device %d in %s for %s\n",
 472                                         j, mddev, devices[j].devname);
 473                                 super.disks[i].state = desired_state;
 474                                 change |= 2;
 475                         } else {
 476                                 fprintf(stderr, Name ": "
 477                                         "device %d in %s has wrong state in superblock, but %s seems ok\n",
 478                                         i, mddev, devices[j].devname);
 479                         }
 480                 }
 481                 if (!devices[j].uptodate &&
 482                     !(super.disks[i].state & (1 << MD_DISK_FAULTY))) {
 483                         fprintf(stderr, Name ": devices %d of %s is not marked FAULTY in superblock, but cannot be found\n",
 484                                 i, mddev);
 485                 }
 486         }
 487
 488         if ((force && (change & 2))
 489             || (old_linux && (change & 1))) {
 490                 int fd;
 491                 super.sb_csum = calc_sb_csum(&super);
 492                 fd = open(devices[chosen_drive].devname, O_RDWR);
 493                 if (fd < 0) {
 494                         fprintf(stderr, Name ": Could open %s for write - cannot Assemble array.\n",
 495                                 devices[chosen_drive].devname);
 496                         return 1;
 497                 }
 498                 if (store_super(fd, &super)) {
 499                         close(fd);
 500                         fprintf(stderr, Name ": Could not re-write superblock on %s\n",
 501                                 devices[chosen_drive].devname);
 502                         return 1;
 503                 }
 504                 close(fd);
 505                 change = 0;
 506         }
 507
 508         /* Almost ready to actually *do* something */
 509         if (!old_linux) {
 510                 if (ioctl(mdfd, SET_ARRAY_INFO, NULL) != 0) {
 511                         fprintf(stderr, Name ": SET_ARRAY_INFO failed for %s: %s\n",
 512                                 mddev, strerror(errno));
 513                         return 1;
 514                 }
 515                 /* First, add the raid disks, but add the chosen one last */
 516                 for (i=0; i<= num_devs; i++) {
 517                         int j;
 518                         if (i < num_devs) {
 519                                 j = best[i];
 520                                 if (j == chosen_drive)
 521                                         continue;
 522                         } else
 523                                 j = chosen_drive;
 524
 525                         if (j >= 0 && devices[j].uptodate) {
 526                                 mdu_disk_info_t disk;
 527                                 memset(&disk, 0, sizeof(disk));
 528                                 disk.major = devices[j].major;
 529                                 disk.minor = devices[j].minor;
 530                                 if (ioctl(mdfd, ADD_NEW_DISK, &disk)!=0) {
 531                                         fprintf(stderr, Name ": failed to add %s to %s: %s\n",
 532                                                 devices[j].devname,
 533                                                 mddev,
 534                                                 strerror(errno));
 535                                         if (i < first_super.raid_disks)
 536                                                 okcnt--;
 537                                         else
 538                                                 sparecnt--;
 539                                 } else if (verbose)
 540                                         fprintf(stderr, Name ": added %s to %s as %d\n",
 541                                                 devices[j].devname, mddev, devices[j].raid_disk);
 542                         } else if (verbose && i < first_super.raid_disks)
 543                                 fprintf(stderr, Name ": no uptodate device for slot %d of %s\n",
 544                                         i, mddev);
 545                 }
 546
 547                 if (runstop == 1 ||
 548                     (runstop == 0 &&
 549                      ( first_super.raid_disks == okcnt
 550                        || (start_partial_ok && enough(first_super.level, first_super.raid_disks, okcnt)))
 551                             )) {
 552                         if (ioctl(mdfd, RUN_ARRAY, NULL)==0) {
 553                                 fprintf(stderr, Name ": %s has been started with %d drive%s",
 554                                         mddev, okcnt, okcnt==1?"":"s");
 555                                 if (sparecnt)
 556                                         fprintf(stderr, " and %d spare%s", sparecnt, sparecnt==1?"":"s");
 557                                 fprintf(stderr, ".\n");
 558                                 return 0;
 559                         }
 560                         fprintf(stderr, Name ": failed to RUN_ARRAY %s: %s\n",
 561                                 mddev, strerror(errno));
 562                         return 1;
 563                 }
 564                 if (runstop == -1) {
 565                         fprintf(stderr, Name ": %s assembled from %d drive%s, but not started.\n",
 566                                 mddev, okcnt, okcnt==1?"":"s");
 567                         return 0;
 568                 }
 569                 fprintf(stderr, Name ": %s assembled from %d drive%s - not enough to start it (use --run to insist).\n",
 570                         mddev, okcnt, okcnt==1?"":"s");
 571                 return 1;
 572         } else {
 573                 /* The "chosen_drive" is a good choice, and if necessary, the superblock has
 574                  * been updated to point to the current locations of devices.
 575                  * so we can just start the array
 576                  */
 577                 unsigned long dev;
 578                 dev = MKDEV(devices[chosen_drive].major,
 579                             devices[chosen_drive].minor);
 580                 if (ioctl(mdfd, START_ARRAY, dev)) {
 581                     fprintf(stderr, Name ": Cannot start array: %s\n",
 582                             strerror(errno));
 583                 }
 584
 585         }
 586         return 0;
 587 }