Assemble.c

   1 /*
   2  * mdctl - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001 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        "mdctl.h"
  31 #include        "md_p.h"
  32 #include        "md_u.h"
  33
  34 int Assemble(char *mddev, int mdfd,
  35              int uuid[4], int uuidset,
  36              char *conffile, int scan,
  37              int subdevs, char **subdev,
  38              int readonly, int runstop,
  39              int verbose, int force)
  40 {
  41         /*
  42          * The task of Assemble is to submit a
  43          * SET_ARRAY_INFO ioctl with no arg - to prepare
  44          * the array - and then submit a number of
  45          * ADD_NEW_DISK ioctls to add disks into
  46          * the array.  Finally RUN_ARRAY might
  47          * be submitted to start the array.
  48          *
  49          * Much of the work of Assemble is in finding and/or
  50          * checking the disks to make sure they look right.
  51          *
  52          * If mddev is not set, then scan must be and we
  53          *  read through the config file for dev+uuid mapping
  54          *  We recurse, setting mddev, for each device that
  55          *    - isn't running
  56          *    - has a valid uuid (or any uuid if !uuidset
  57          *
  58          * If mddev is set, we try to determine state of md.
  59          *   check version - must be at least 0.90.0
  60          *   check kernel version.  must be at least 2.4.
  61          *    If not, we can possibly fall back on START_ARRAY
  62          *   Try to GET_ARRAY_INFO.
  63          *     If possible, give up
  64          *     If not, try to STOP_ARRAY just to make sure
  65          *
  66          * If !uuidset and scan, look in conf-file for uuid
  67          *       If not found, give up
  68          * If !subdevs and scan and uuidset, get list of devs from conf-file
  69          *
  70          * For each device:
  71          *   Check superblock - discard if bad
  72          *   Check uuid (set if we don't have one) - discard if no match
  73          *   Check superblock similarity if we have a superbloc - discard if different
  74          *   Record events, devicenum, utime
  75          * This should give us a list of devices for the array
  76          * We should collect the most recent event and utime numbers
  77          *
  78          * Count disks with recent enough event count
  79          * While force && !enough disks
  80          *    Choose newest rejected disks, update event count
  81          *     mark clean and rewrite superblock
  82          * If recent kernel:
  83          *    SET_ARRAY_INFO
  84          *    foreach device with recent events : ADD_NEW_DISK
  85          *    if runstop == 1 || "enough" disks and runstop==0 -> RUN_ARRAY
  86          * If old kernel:
  87          *    Check the device numbers in superblock are right
  88          *    update superblock if any changes
  89          *    START_ARRAY
  90          *
  91          */
  92         int old_linux = 0;
  93         int vers;
  94         mdu_array_info_t array;
  95         mddev_dev_t devlist = NULL;
  96         mdp_super_t first_super, super;
  97         struct {
  98                 char *devname;
  99                 int major, minor;
 100                 long long events;
 101                 time_t utime;
 102                 int uptodate;
 103         } devices[MD_SB_DISKS];
 104         int best[MD_SB_DISKS]; /* indexed by raid_disk */
 105         int devcnt = 0, okcnt;
 106         int i;
 107         int most_recent = 0;
 108
 109         if (!mddev && !scan) {
 110                 fputs(Name ": internal error - Assemble called with no device or --scan\n", stderr);
 111                 return 1;
 112         }
 113         if (!mddev) {
 114                 mddev_uuid_t device_list;
 115                 int found = 0;
 116                 device_list = conf_get_uuids(conffile);
 117                 if (!device_list) {
 118                         fprintf(stderr, Name ": No devices found in config file\n");
 119                         return 1;
 120                 }
 121                 for (; device_list; device_list=device_list->next) {
 122                         if (!uuidset || same_uuid(device_list->uuid,uuid)) {
 123                                 mdfd = open(device_list->devname, O_RDONLY, 0);
 124                                 if (mdfd < 0) {
 125                                         fprintf(stderr,
 126                                                 Name ": error opening %s: %s\n",
 127                                                 device_list->devname,
 128                                                 strerror(errno));
 129                                         continue;
 130                                 }
 131                                 if (Assemble(device_list->devname, mdfd,
 132                                          device_list->uuid, 1,
 133                                          conffile, 1,
 134                                          subdevs, subdev,
 135                                              readonly, runstop, verbose, force)==0)
 136                                         found++;
 137                                 close(mdfd);
 138                         }
 139                 }
 140                 if (found)
 141                         return 0;
 142                 fprintf(stderr,Name ": Did not successfully Assemble any devices\n");
 143                 return 1;
 144         }
 145
 146         /*
 147          * Ok, we have an mddev, check it out
 148          */
 149         vers = md_get_version(mdfd);
 150         if (vers <= 0) {
 151                 fprintf(stderr, Name ": %s appears not to be an md device.\n");
 152                 return 1;
 153         }
 154         if (vers < 9000) {
 155                 fprintf(stderr, Name ": Assemble requires driver version 0.90.0 or later.\n"
 156                         "    Upgrade your kernel or try --Build\n");
 157                 return 1;
 158         }
 159         if (get_linux_version() < 2004000)
 160                 old_linux = 1;
 161
 162         if (ioctl(mdfd, GET_ARRAY_INFO, &array)>=0) {
 163                 fprintf(stderr, Name ": device %s already active - cannot assemble it\n",
 164                         mddev);
 165                 return 1;
 166         }
 167         ioctl(mdfd, STOP_ARRAY, NULL); /* just incase it was started but has no content */
 168
 169         /*
 170          * We have a valid mddev, check out uuid
 171          */
 172         if (!uuidset && scan) {
 173                 /* device must be listed with uuid in conf file */
 174                 mddev_uuid_t device_list;
 175                 device_list = conf_get_uuids(conffile);
 176                 while (device_list &&
 177                        strcmp(device_list->devname, mddev) != 0)
 178                         device_list = device_list->next;
 179
 180                 if (!device_list) {
 181                         fprintf(stderr, Name ": --scan set and no uuid found for %s in config file.\n",
 182                                 mddev);
 183                         return 1;
 184                 }
 185                 /* the uuid is safe until next call to conf_get_uuids */
 186                 uuid = device_list->uuid;
 187                 uuidset = 1;
 188         }
 189
 190         /* Now to start looking at devices.
 191          * If no devices were given, but a uuid is available and
 192          * --scan was set, then we should scan all devices listed in the
 193          * config file
 194          *
 195          */
 196         if (subdevs==0 && scan && uuidset)
 197                 devlist = conf_get_devs(conffile);
 198
 199         if (subdevs == 0 && devlist == NULL) {
 200                 fprintf(stderr, Name ": no devices given for %s\n", mddev);
 201                 return 1;
 202         }
 203         /* now for each device */
 204         first_super.md_magic = 0;
 205         for (i=0; i<MD_SB_DISKS; i++)
 206                 best[i] = -1;
 207
 208         if (verbose)
 209             fprintf(stderr, Name ": looking for devices for %s\n",
 210                     mddev);
 211
 212         while (subdevs || devlist) {
 213                 char *devname;
 214                 int this_uuid[4];
 215                 int dfd;
 216                 struct stat stb;
 217                 int inargv;
 218                 if (subdevs) {
 219                         devname = *subdev++;
 220                         subdevs--;
 221                         inargv=1;
 222                 } else {
 223                         devname = devlist->devname;
 224                         devlist = devlist->next;
 225                         inargv=0;
 226                 }
 227
 228                 dfd = open(devname, O_RDONLY, 0);
 229                 if (dfd < 0) {
 230                         if (inargv || verbose)
 231                                 fprintf(stderr, Name ": cannot open device %s: %s\n",
 232                                         devname, strerror(errno));
 233                         continue;
 234                 }
 235                 if (fstat(dfd, &stb)< 0) {
 236                     /* Impossible! */
 237                     fprintf(stderr, Name ": fstat failed for %s: %s\n",
 238                             devname, strerror(errno));
 239                     close(dfd);
 240                     continue;
 241                 }
 242                 if ((stb.st_mode & S_IFMT) != S_IFBLK) {
 243                     fprintf(stderr, Name ": %d is not a block device.\n",
 244                             devname);
 245                     close(dfd);
 246                     continue;
 247                 }
 248                 if (load_super(dfd, &super)) {
 249                         if (inargv || verbose)
 250                                 fprintf( stderr, Name ": no RAID superblock on %s\n",
 251                                          devname);
 252                         close(dfd);
 253                         continue;
 254                 }
 255                 close(dfd);
 256                 uuid_from_super(this_uuid, &super);
 257                 if (uuidset && !same_uuid(this_uuid, uuid)) {
 258                     if (inargv || verbose)
 259                         fprintf(stderr, Name ": %s has wrong uuid.\n",
 260                                 devname);
 261                     continue;
 262                 }
 263                 if (compare_super(&first_super, &super)) {
 264                         if (inargv || verbose)
 265                                 fprintf(stderr, Name ": superblock on %s doesn't match\n",
 266                                         devname);
 267                         continue;
 268                 }
 269                 if (uuidset) {
 270                         uuid_from_super(this_uuid, &first_super);
 271                         if (!same_uuid(this_uuid, uuid)) {
 272                                 if (inargv || verbose)
 273                                         fprintf(stderr, Name ": %s has wrong uuid.\n",
 274                                                 devname);
 275                                 continue;
 276                         }
 277                 } else {
 278                         uuid_from_super(uuid, &first_super);
 279                         uuidset = 1;
 280                 }
 281
 282                 /* Ok, this one is at least worth considering */
 283                 if (devcnt >= MD_SB_DISKS) {
 284                     fprintf(stderr, Name ": ouch - too many devices appear to be in this array. Ignoring %s\n",
 285                             devname);
 286                     continue;
 287                 }
 288                 devices[devcnt].devname = devname;
 289                 devices[devcnt].major = MAJOR(stb.st_rdev);
 290                 devices[devcnt].minor = MINOR(stb.st_rdev);
 291                 devices[devcnt].events = md_event(&super);
 292                 devices[devcnt].utime = super.utime;
 293                 devices[devcnt].uptodate = 0;
 294                 if (most_recent < devcnt) {
 295                         if (devices[devcnt].events
 296                             > devices[most_recent].events)
 297                                 most_recent = devcnt;
 298                 }
 299                 i = super.this_disk.raid_disk;
 300                 if (best[i] == -1
 301                     || devices[best[i]].events < devices[devcnt].events) {
 302                         best[i] = devcnt;
 303                 }
 304                 devcnt++;
 305         }
 306
 307         if (devcnt == 0) {
 308                 fprintf(stderr, Name ": no devices found for %s\n",
 309                         mddev);
 310                 return 1;
 311         }
 312         /* now we have some devices that might be suitable.
 313          * I wonder how many
 314          */
 315         okcnt = 0;
 316         for (i=0; i< first_super.raid_disks;i++) {
 317                 int j = best[i];
 318                 if (j < 0) continue;
 319                 if (devices[j].events+1 >=
 320                     devices[most_recent].events) {
 321                         devices[j].uptodate = 1;
 322                         okcnt++;
 323                 }
 324         }
 325         while (force && !enough(first_super.level, first_super.raid_disks, okcnt)) {
 326                 /* Choose the newest best drive which is
 327                  * not up-to-date, update the superblock
 328                  * and add it.
 329                  */
 330                 fprintf(stderr,"NotImplementedYet\n");
 331                 /* FIXME */
 332                 exit(2);
 333         }
 334         /* Almost ready to actually *do* something */
 335         if (!old_linux) {
 336                 if (ioctl(mdfd, SET_ARRAY_INFO, NULL) != 0) {
 337                         fprintf(stderr, Name ": SET_ARRAY_INFO failed for %s: %s\n",
 338                                 mddev, strerror(errno));
 339                         return 1;
 340                 }
 341                 /* First, add the raid disks */
 342                 for (i=0; i<first_super.raid_disks; i++) {
 343                         int j = best[i];
 344                         if (devices[j].uptodate) {
 345                                 mdu_disk_info_t disk;
 346                                 memset(&disk, 0, sizeof(disk));
 347                                 disk.major = devices[j].major;
 348                                 disk.minor = devices[j].minor;
 349                                 if (ioctl(mdfd, ADD_NEW_DISK, &disk)!=0) {
 350                                         fprintf(stderr, Name ": failed to add %s to %s: %s\n",
 351                                                 devices[j].devname,
 352                                                 mddev,
 353                                                 strerror(errno));
 354                                         okcnt--;
 355                                 }
 356                         } else if (verbose)
 357                                 fprintf(stderr, Name ": no uptodate device for slot %d of %s\n",
 358                                         i, mddev);
 359                 }
 360                 if (runstop == 1 ||
 361                     (runstop == 0 &&
 362                      enough(first_super.level, first_super.raid_disks, okcnt))) {
 363                         if (ioctl(mdfd, RUN_ARRAY, NULL)==0) {
 364                                 fprintf(stderr, Name ": %s has been started with %d drives\n",
 365                                         mddev, okcnt);
 366                                 return 0;
 367                         }
 368                         fprintf(stderr, Name ": failed to RUN_ARRAY %s: %s\n",
 369                                 mddev, strerror(errno));
 370                         return 1;
 371                 }
 372                 if (runstop == -1) {
 373                         fprintf(stderr, Name ": %s assembled from %d drives, but not started.\n",
 374                                 mddev, okcnt);
 375                         return 0;
 376                 }
 377                 fprintf(stderr, Name ": %s assembled from %d drives - not enough to start it.\n",
 378                         mddev, okcnt);
 379                 return 1;
 380         } else {
 381                 /* It maybe just a case of calling START_ARRAY, but it may not..
 382                  * We need to pick a working device, read it's super block, and make
 383                  * sure all the device numbers and the minor number are right.
 384                  * Then we might need to re-write the super block.
 385                  * THEN we call START_ARRAY
 386                  * If the md_minor is wrong, wejust give up for now.  The alternate is to
 387                  * re-write ALL super blocks.
 388                  */
 389                 int chosen_drive = -1;
 390                 int change = 0;
 391                 int dev;
 392                 for (i=0; i<first_super.nr_disks; i++) {
 393                     if (!devices[i].uptodate)
 394                         continue;
 395                     if (chosen_drive == -1) {
 396                             int fd;
 397                             chosen_drive = i;
 398                             if (open(devices[i].devname, O_RDONLY)>= 0) {
 399                                     fprintf(stderr, Name ": Cannot open %s: %s\n",
 400                                             devices[i].devname, strerror(errno));
 401                                     return 1;
 402                             }
 403                             if (load_super(fd, &super)) {
 404                                     close(fd);
 405                                     fprintf(stderr, Name ": RAID superblock has disappeared from %s\n",
 406                                             devices[i].devname);
 407                                     return 1;
 408                             }
 409                             close(fd);
 410                     }
 411                     if (devices[i].major != super.disks[i].major ||
 412                         devices[i].minor != super.disks[i].minor) {
 413                         change = 1;
 414                         super.disks[i].major = devices[i].major;
 415                         super.disks[i].minor = devices[i].minor;
 416                     }
 417                 }
 418                 if (change) {
 419                     int fd;
 420                     super.sb_csum = calc_sb_csum(super);
 421                     fd = open(devices[chosen_drive].devname, O_RDWR);
 422                     if (fd < 0) {
 423                         fprintf(stderr, Name ": Could open %s for write - cannot Assemble array.\n",
 424                                 devices[chosen_drive].devname);
 425                         return 1;
 426                     }
 427                     if (store_super(fd, &super)) {
 428                         close(fd);
 429                         fprintf(stderr, Name ": Could not re-write superblock on %s\n",
 430                                 devices[chosen_drive].devname);
 431                         return 1;
 432                     }
 433                     close(fd);
 434                 }
 435                 dev = MKDEV(devices[chosen_drive].major,
 436                             devices[chosen_drive].minor);
 437                 if (ioctl(mdfd, START_ARRAY, dev)) {
 438                     fprintf(stderr, Name ": Cannot start array: %s\n",
 439                             strerror(errno));
 440                 }
 441
 442         }
 443 }