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 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 verison 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 5:
 121                 case 6:
 122                         layout = map_name(r5layout, "default");
 123                         if (verbose)
 124                                 fprintf(stderr,
 125                                         Name ": layout defaults to %s\n", map_num(r5layout, layout));
 126                         break;
 127                 }
 128
 129         switch(level) {
 130         case 4:
 131         case 5:
 132         case 6:
 133         case 0:
 134         case -1: /* linear */
 135                 if (chunk == 0) {
 136                         chunk = 64;
 137                         if (verbose)
 138                                 fprintf(stderr, Name ": chunk size defaults to 64K\n");
 139                 }
 140                 break;
 141         default: /* raid1, multipath */
 142                 if (chunk) {
 143                         chunk = 0;
 144                         if (verbose)
 145                                 fprintf(stderr, Name ": chunk size ignored for this level\n");
 146                 }
 147                 break;
 148         }
 149
 150         /* now look at the subdevs */
 151         array.active_disks = 0;
 152         array.working_disks = 0;
 153         dnum = 0;
 154         for (dv=devlist; dv; dv=dv->next, dnum++) {
 155                 char *dname = dv->devname;
 156                 unsigned long dsize, freesize;
 157                 int fd;
 158                 if (strcasecmp(dname, "missing")==0) {
 159                         if (first_missing > dnum)
 160                                 first_missing = dnum;
 161                         missing_disks ++;
 162                         continue;
 163                 }
 164                 array.working_disks++;
 165                 if (dnum < raiddisks)
 166                         array.active_disks++;
 167                 fd = open(dname, O_RDONLY, 0);
 168                 if (fd <0 ) {
 169                         fprintf(stderr, Name ": Cannot open %s: %s\n",
 170                                 dname, strerror(errno));
 171                         fail=1;
 172                         continue;
 173                 }
 174                 if (ioctl(fd, BLKGETSIZE, &dsize)) {
 175                         fprintf(stderr, Name ": Cannot get size of %s: %s\n",
 176                                 dname, strerror(errno));
 177                         fail = 1;
 178                         close(fd);
 179                         continue;
 180                 }
 181                 if (dsize < MD_RESERVED_SECTORS*2) {
 182                         fprintf(stderr, Name ": %s is too small: %luK\n",
 183                                 dname, dsize/2);
 184                         fail = 1;
 185                         close(fd);
 186                         continue;
 187                 }
 188                 freesize = MD_NEW_SIZE_SECTORS(dsize);
 189                 freesize /= 2;
 190
 191                 if (size && freesize < size) {
 192                         fprintf(stderr, Name ": %s is smaller that given size."
 193                                 " %luK < %luK + superblock\n", dname, freesize, size);
 194                         fail = 1;
 195                         close(fd);
 196                         continue;
 197                 }
 198                 if (maxdisc == NULL || (maxdisc && freesize > maxsize)) {
 199                         maxdisc = dname;
 200                         maxsize = freesize;
 201                 }
 202                 if (mindisc ==NULL || (mindisc && freesize < minsize)) {
 203                         mindisc = dname;
 204                         minsize = freesize;
 205                 }
 206                 warn |= check_ext2(fd, dname);
 207                 warn |= check_reiser(fd, dname);
 208                 warn |= check_raid(fd, dname);
 209                 close(fd);
 210         }
 211         if (fail) {
 212                 fprintf(stderr, Name ": create aborted\n");
 213                 return 1;
 214         }
 215         if (size == 0) {
 216                 if (mindisc == NULL) {
 217                         fprintf(stderr, Name ": no size and no drives given - aborting create.\n");
 218                         return 1;
 219                 }
 220                 size = minsize;
 221                 if (verbose && level>0)
 222                         fprintf(stderr, Name ": size set to %luK\n", size);
 223         }
 224         if (level >= 1 && ((maxsize-size)*100 > maxsize)) {
 225                 fprintf(stderr, Name ": largest drive (%s) exceed size (%luK) by more than 1%%\n",
 226                         maxdisc, size);
 227                 warn = 1;
 228         }
 229
 230         if (warn) {
 231                 if (runstop!= 1) {
 232                         if (!ask("Continue creating array? ")) {
 233                                 fprintf(stderr, Name ": create aborted.\n");
 234                                 return 1;
 235                         }
 236                 } else {
 237                         if (verbose)
 238                                 fprintf(stderr, Name ": creation continuing despite oddities due to --run\n");
 239                 }
 240         }
 241
 242         /* If this is  raid5, we want to configure the last active slot
 243          * as missing, so that a reconstruct happens (faster than re-parity)
 244          * FIX: Can we do this for raid6 as well?
 245          */
 246         if (force == 0 && first_missing >= raiddisks) {
 247                 switch ( level ) {
 248                 case 5:
 249                         insert_point = raiddisks-1;
 250                         sparedisks++;
 251                         array.active_disks--;
 252                         missing_disks++;
 253                         break;
 254                 default:
 255                         break;
 256                 }
 257         }
 258
 259         /* Ok, lets try some ioctls */
 260
 261         array.level = level;
 262         array.size = size;
 263         array.raid_disks = raiddisks;
 264         /* The kernel should *know* what md_minor we are dealing
 265          * with, but it chooses to trust me instead. Sigh
 266          */
 267         array.md_minor = 0;
 268         if (fstat(mdfd, &stb)==0)
 269                 array.md_minor = MINOR(stb.st_rdev);
 270         array.not_persistent = 0;
 271         /*** FIX: Need to do something about RAID-6 here ***/
 272         if ( (level == 5 || level == 6) &&
 273              (insert_point < raiddisks || first_missing < raiddisks) )
 274                 array.state = 1; /* clean, but one+ drive will be missing */
 275         else
 276                 array.state = 0; /* not clean, but no errors */
 277
 278         /* There is lots of redundancy in these disk counts,
 279          * raid_disks is the most meaningful value
 280          *          it describes the geometry of the array
 281          *          it is constant
 282          * nr_disks is total number of used slots.
 283          *          it should be raid_disks+spare_disks
 284          * spare_disks is the number of extra disks present
 285          *          see above
 286          * active_disks is the number of working disks in
 287          *          active slots. (With raid_disks)
 288          * working_disks is the total number of working disks,
 289          *          including spares
 290          * failed_disks is the number of disks marked failed
 291          *
 292          * Ideally, the kernel would keep these (except raid_disks)
 293          * up-to-date as we ADD_NEW_DISK, but it doesn't (yet).
 294          * So for now, we assume that all raid and spare
 295          * devices will be given.
 296          */
 297         array.spare_disks=sparedisks;
 298         array.failed_disks=missing_disks;
 299         array.nr_disks = array.working_disks + array.failed_disks;
 300         array.layout = layout;
 301         array.chunk_size = chunk*1024;
 302
 303         if (ioctl(mdfd, SET_ARRAY_INFO, &array)) {
 304                 fprintf(stderr, Name ": SET_ARRAY_INFO failed for %s: %s\n",
 305                         mddev, strerror(errno));
 306                 return 1;
 307         }
 308
 309         for (dnum=0, dv = devlist ; dv ; dv=(dv->next)?(dv->next):moved_disk, dnum++) {
 310                 int fd;
 311                 struct stat stb;
 312                 mdu_disk_info_t disk;
 313
 314                 disk.number = dnum;
 315                 if (dnum == insert_point) {
 316                         moved_disk = dv;
 317                 }
 318                 disk.raid_disk = disk.number;
 319                 if (disk.raid_disk < raiddisks)
 320                         disk.state = 6; /* active and in sync */
 321                 else
 322                         disk.state = 0;
 323                 if (dnum == insert_point ||
 324                     strcasecmp(dv->devname, "missing")==0) {
 325                         disk.major = 0;
 326                         disk.minor = 0;
 327                         disk.state = 1; /* faulty */
 328                 } else {
 329                         fd = open(dv->devname, O_RDONLY, 0);
 330                         if (fd < 0) {
 331                                 fprintf(stderr, Name ": failed to open %s after earlier success - aborting\n",
 332                                         dv->devname);
 333                                 return 1;
 334                         }
 335                         fstat(fd, &stb);
 336                         disk.major = MAJOR(stb.st_rdev);
 337                         disk.minor = MINOR(stb.st_rdev);
 338                         close(fd);
 339                 }
 340                 if (ioctl(mdfd, ADD_NEW_DISK, &disk)) {
 341                         fprintf(stderr, Name ": ADD_NEW_DISK for %s failed: %s\n",
 342                                 dv->devname, strerror(errno));
 343                         return 1;
 344                 }
 345                 if (dv == moved_disk && dnum != insert_point) break;
 346         }
 347
 348         /* param is not actually used */
 349         if (runstop == 1 || subdevs >= raiddisks) {
 350                 mdu_param_t param;
 351                 if (ioctl(mdfd, RUN_ARRAY, &param)) {
 352                         fprintf(stderr, Name ": RUN_ARRAY failed: %s\n",
 353                                 strerror(errno));
 354                         return 1;
 355                 }
 356                 fprintf(stderr, Name ": array %s started.\n", mddev);
 357         } else {
 358                 fprintf(stderr, Name ": not starting array - not enough devices.\n");
 359         }
 360         return 0;
 361 }