Create.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 Create(char *mddev, int mdfd,
  35            int chunk, int level, int layout, unsigned long size, int raiddisks, int sparedisks,
  36            int subdevs, mddev_dev_t devlist,
  37            int runstop, int verbose, int force)
  38 {
  39         /*
  40          * Create a new raid array.
  41          *
  42          * First check that necessary details are available
  43          * (i.e. level, raid-disks)
  44          *
  45          * Then check each disk to see what might be on it
  46          * and report anything interesting.
  47          *
  48          * If anything looks odd, and runstop not set,
  49          * abort.
  50          *
  51          * SET_ARRAY_INFO and ADD_NEW_DISK, and
  52          * if runstop==run, or raiddisks diskswere used,
  53          * RUN_ARRAY
  54          */
  55         unsigned long long minsize=0, maxsize=0;
  56         char *mindisc = NULL;
  57         char *maxdisc = NULL;
  58         int dnum;
  59         mddev_dev_t dv;
  60         int fail=0, warn=0;
  61         struct stat stb;
  62         int first_missing = MD_SB_DISKS*2;
  63         int missing_disks = 0;
  64         int insert_point = MD_SB_DISKS*2; /* where to insert a missing drive */
  65         mddev_dev_t moved_disk = NULL; /* the disk that was moved out of the insert point */
  66
  67         mdu_array_info_t array;
  68
  69
  70         if (md_get_version(mdfd) < 9000) {
  71                 fprintf(stderr, Name ": Create requires md driver version 0.90.0 or later\n");
  72                 return 1;
  73         }
  74         if (level == UnSet) {
  75                 fprintf(stderr,
  76                         Name ": a RAID level is needed to create an array.\n");
  77                 return 1;
  78         }
  79         if (raiddisks < 1) {
  80                 fprintf(stderr,
  81                         Name ": a number of --raid-devices must be given to create an array\n");
  82                 return 1;
  83         }
  84         if (raiddisks < 4 && level == 6) {
  85                 fprintf(stderr,
  86                         Name ": at least 4 raid-devices needed for level 6\n");
  87                 return 1;
  88         }
  89         if (raiddisks > 256 && level == 6) {
  90                 fprintf(stderr,
  91                         Name ": no more than 256 raid-devices supported for level 6\n");
  92                 return 1;
  93         }
  94         if (raiddisks < 2 && level >= 4) {
  95                 fprintf(stderr,
  96                         Name ": at least 2 raid-devices needed for level 4 or 5\n");
  97                 return 1;
  98         }
  99         if (raiddisks+sparedisks > MD_SB_DISKS) {
 100                 fprintf(stderr,
 101                         Name ": too many devices requested: %d+%d > %d\n",
 102                         raiddisks, sparedisks, MD_SB_DISKS);
 103                 return 1;
 104         }
 105         if (subdevs > raiddisks+sparedisks) {
 106                 fprintf(stderr, Name ": You have listed more devices (%d) than are in the array(%d)!\n", subdevs, raiddisks+sparedisks);
 107                 return 1;
 108         }
 109         if (subdevs < raiddisks+sparedisks) {
 110                 fprintf(stderr, Name ": You haven't given enough devices (real or missing) to create this array\n");
 111                 return 1;
 112         }
 113
 114         /* now set some defaults */
 115         if (layout == UnSet)
 116                 switch(level) {
 117                 default: /* no layout */
 118                         layout = 0;
 119                         break;
 120                 case 10:
 121                         layout = 0x102; /* near=2, far=1 */
 122                         if (verbose)
 123                                 fprintf(stderr,
 124                                         Name ": layout defaults to n1\n");
 125                         break;
 126                 case 5:
 127                 case 6:
 128                         layout = map_name(r5layout, "default");
 129                         if (verbose)
 130                                 fprintf(stderr,
 131                                         Name ": layout defaults to %s\n", map_num(r5layout, layout));
 132                         break;
 133                 case LEVEL_FAULTY:
 134                         layout = map_name(faultylayout, "default");
 135
 136                         if (verbose)
 137                                 fprintf(stderr,
 138                                         Name ": layout defaults to %s\n", map_num(faultylayout, layout));
 139                         break;
 140                 }
 141
 142         if (level == 10)
 143                 /* check layout fits in array*/
 144                 if ((layout&255) * ((layout>>8)&255) > raiddisks) {
 145                         fprintf(stderr, Name ": that layout requires at least %d devices\n",
 146                                 (layout&255) * ((layout>>8)&255));
 147                         return 1;
 148                 }
 149
 150         switch(level) {
 151         case 4:
 152         case 5:
 153         case 10:
 154         case 6:
 155         case 0:
 156         case -1: /* linear */
 157                 if (chunk == 0) {
 158                         chunk = 64;
 159                         if (verbose)
 160                                 fprintf(stderr, Name ": chunk size defaults to 64K\n");
 161                 }
 162                 break;
 163         default: /* raid1, multipath */
 164                 if (chunk) {
 165                         chunk = 0;
 166                         if (verbose)
 167                                 fprintf(stderr, Name ": chunk size ignored for this level\n");
 168                 }
 169                 break;
 170         }
 171
 172         /* now look at the subdevs */
 173         array.active_disks = 0;
 174         array.working_disks = 0;
 175         dnum = 0;
 176         for (dv=devlist; dv; dv=dv->next, dnum++) {
 177                 char *dname = dv->devname;
 178                 unsigned long dsize;
 179                 unsigned long long ldsize, freesize;
 180                 int fd;
 181                 if (strcasecmp(dname, "missing")==0) {
 182                         if (first_missing > dnum)
 183                                 first_missing = dnum;
 184                         missing_disks ++;
 185                         continue;
 186                 }
 187                 array.working_disks++;
 188                 if (dnum < raiddisks)
 189                         array.active_disks++;
 190                 fd = open(dname, O_RDONLY|O_EXCL, 0);
 191                 if (fd <0 ) {
 192                         fprintf(stderr, Name ": Cannot open %s: %s\n",
 193                                 dname, strerror(errno));
 194                         fail=1;
 195                         continue;
 196                 }
 197 #ifdef BLKGETSIZE64
 198                 if (ioctl(fd, BLKGETSIZE64, &ldsize)==0)
 199                         ;
 200                 else
 201 #endif
 202                 if (ioctl(fd, BLKGETSIZE, &dsize)) {
 203                         fprintf(stderr, Name ": Cannot get size of %s: %s\n",
 204                                 dname, strerror(errno));
 205                         fail = 1;
 206                         close(fd);
 207                         continue;
 208                 }
 209                 else {
 210                         ldsize = dsize;
 211                         dsize <<= 9;
 212                 }
 213                 if (ldsize < MD_RESERVED_SECTORS*2LL*512LL) {
 214                         fprintf(stderr, Name ": %s is too small: %luK\n",
 215                                 dname, (unsigned long)(ldsize>>10));
 216                         fail = 1;
 217                         close(fd);
 218                         continue;
 219                 }
 220                 freesize = MD_NEW_SIZE_SECTORS((ldsize>>9));
 221                 freesize /= 2;
 222
 223                 if (size && freesize < size) {
 224                         fprintf(stderr, Name ": %s is smaller that given size."
 225                                 " %lluK < %luK + superblock\n", dname, freesize, size);
 226                         fail = 1;
 227                         close(fd);
 228                         continue;
 229                 }
 230                 if (maxdisc == NULL || (maxdisc && freesize > maxsize)) {
 231                         maxdisc = dname;
 232                         maxsize = freesize;
 233                 }
 234                 if (mindisc ==NULL || (mindisc && freesize < minsize)) {
 235                         mindisc = dname;
 236                         minsize = freesize;
 237                 }
 238                 warn |= check_ext2(fd, dname);
 239                 warn |= check_reiser(fd, dname);
 240                 warn |= check_raid(fd, dname);
 241                 close(fd);
 242         }
 243         if (fail) {
 244                 fprintf(stderr, Name ": create aborted\n");
 245                 return 1;
 246         }
 247         if (size == 0) {
 248                 if (mindisc == NULL) {
 249                         fprintf(stderr, Name ": no size and no drives given - aborting create.\n");
 250                         return 1;
 251                 }
 252                 if (level > 0) {
 253                         /* size is meaningful */
 254                         if (minsize > 0x100000000ULL) {
 255                                 fprintf(stderr, Name ": devices too large for RAID level %d\n", level);
 256                                 return 1;
 257                         }
 258                         size = minsize;
 259                         if (verbose)
 260                                 fprintf(stderr, Name ": size set to %luK\n", size);
 261                 }
 262         }
 263         if (level > 0 && ((maxsize-size)*100 > maxsize)) {
 264                 fprintf(stderr, Name ": largest drive (%s) exceed size (%luK) by more than 1%%\n",
 265                         maxdisc, size);
 266                 warn = 1;
 267         }
 268
 269         if (warn) {
 270                 if (runstop!= 1) {
 271                         if (!ask("Continue creating array? ")) {
 272                                 fprintf(stderr, Name ": create aborted.\n");
 273                                 return 1;
 274                         }
 275                 } else {
 276                         if (verbose)
 277                                 fprintf(stderr, Name ": creation continuing despite oddities due to --run\n");
 278                 }
 279         }
 280
 281         /* If this is  raid5, we want to configure the last active slot
 282          * as missing, so that a reconstruct happens (faster than re-parity)
 283          * FIX: Can we do this for raid6 as well?
 284          */
 285         if (force == 0 && first_missing >= raiddisks) {
 286                 switch ( level ) {
 287                 case 5:
 288                         insert_point = raiddisks-1;
 289                         sparedisks++;
 290                         array.active_disks--;
 291                         missing_disks++;
 292                         break;
 293                 default:
 294                         break;
 295                 }
 296         }
 297
 298         /* Ok, lets try some ioctls */
 299
 300         array.level = level;
 301         array.size = size;
 302         array.raid_disks = raiddisks;
 303         /* The kernel should *know* what md_minor we are dealing
 304          * with, but it chooses to trust me instead. Sigh
 305          */
 306         array.md_minor = 0;
 307         if (fstat(mdfd, &stb)==0)
 308                 array.md_minor = minor(stb.st_rdev);
 309         array.not_persistent = 0;
 310         /*** FIX: Need to do something about RAID-6 here ***/
 311         if ( ( (level == 5) &&
 312                (insert_point < raiddisks || first_missing < raiddisks) )
 313              ||
 314              ( level == 6 && missing_disks == 2)
 315                 )
 316                 array.state = 1; /* clean, but one+ drive will be missing */
 317         else
 318                 array.state = 0; /* not clean, but no errors */
 319
 320         /* There is lots of redundancy in these disk counts,
 321          * raid_disks is the most meaningful value
 322          *          it describes the geometry of the array
 323          *          it is constant
 324          * nr_disks is total number of used slots.
 325          *          it should be raid_disks+spare_disks
 326          * spare_disks is the number of extra disks present
 327          *          see above
 328          * active_disks is the number of working disks in
 329          *          active slots. (With raid_disks)
 330          * working_disks is the total number of working disks,
 331          *          including spares
 332          * failed_disks is the number of disks marked failed
 333          *
 334          * Ideally, the kernel would keep these (except raid_disks)
 335          * up-to-date as we ADD_NEW_DISK, but it doesn't (yet).
 336          * So for now, we assume that all raid and spare
 337          * devices will be given.
 338          */
 339         array.spare_disks=sparedisks;
 340         array.failed_disks=missing_disks;
 341         array.nr_disks = array.working_disks + array.failed_disks;
 342         array.layout = layout;
 343         array.chunk_size = chunk*1024;
 344
 345         if (ioctl(mdfd, SET_ARRAY_INFO, &array)) {
 346                 fprintf(stderr, Name ": SET_ARRAY_INFO failed for %s: %s\n",
 347                         mddev, strerror(errno));
 348                 return 1;
 349         }
 350
 351         for (dnum=0, dv = devlist ; dv ; dv=(dv->next)?(dv->next):moved_disk, dnum++) {
 352                 int fd;
 353                 struct stat stb;
 354                 mdu_disk_info_t disk;
 355
 356                 disk.number = dnum;
 357                 if (dnum == insert_point) {
 358                         moved_disk = dv;
 359                 }
 360                 disk.raid_disk = disk.number;
 361                 if (disk.raid_disk < raiddisks)
 362                         disk.state = 6; /* active and in sync */
 363                 else
 364                         disk.state = 0;
 365                 if (dnum == insert_point ||
 366                     strcasecmp(dv->devname, "missing")==0) {
 367                         disk.major = 0;
 368                         disk.minor = 0;
 369                         disk.state = 1; /* faulty */
 370                 } else {
 371                         fd = open(dv->devname, O_RDONLY|O_EXCL, 0);
 372                         if (fd < 0) {
 373                                 fprintf(stderr, Name ": failed to open %s after earlier success - aborting\n",
 374                                         dv->devname);
 375                                 return 1;
 376                         }
 377                         fstat(fd, &stb);
 378                         disk.major = major(stb.st_rdev);
 379                         disk.minor = minor(stb.st_rdev);
 380                         close(fd);
 381                 }
 382                 if (ioctl(mdfd, ADD_NEW_DISK, &disk)) {
 383                         fprintf(stderr, Name ": ADD_NEW_DISK for %s failed: %s\n",
 384                                 dv->devname, strerror(errno));
 385                         return 1;
 386                 }
 387                 if (dv == moved_disk && dnum != insert_point) break;
 388         }
 389
 390         /* param is not actually used */
 391         if (runstop == 1 || subdevs >= raiddisks) {
 392                 mdu_param_t param;
 393                 if (ioctl(mdfd, RUN_ARRAY, &param)) {
 394                         fprintf(stderr, Name ": RUN_ARRAY failed: %s\n",
 395                                 strerror(errno));
 396                         Manage_runstop(mddev, mdfd, -1);
 397                         return 1;
 398                 }
 399                 fprintf(stderr, Name ": array %s started.\n", mddev);
 400         } else {
 401                 fprintf(stderr, Name ": not starting array - not enough devices.\n");
 402         }
 403         return 0;
 404 }