util.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
   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_p.h"
  32 #include        <sys/utsname.h>
  33 #include        <ctype.h>
  34
  35 /*
  36  * following taken from linux/blkpg.h because they aren't
  37  * anywhere else and it isn't safe to #include linux/ * stuff.
  38  */
  39
  40 #define BLKPG      _IO(0x12,105)
  41
  42 /* The argument structure */
  43 struct blkpg_ioctl_arg {
  44         int op;
  45         int flags;
  46         int datalen;
  47         void *data;
  48 };
  49
  50 /* The subfunctions (for the op field) */
  51 #define BLKPG_ADD_PARTITION     1
  52 #define BLKPG_DEL_PARTITION     2
  53
  54 /* Sizes of name fields. Unused at present. */
  55 #define BLKPG_DEVNAMELTH        64
  56 #define BLKPG_VOLNAMELTH        64
  57
  58 /* The data structure for ADD_PARTITION and DEL_PARTITION */
  59 struct blkpg_partition {
  60         long long start;                /* starting offset in bytes */
  61         long long length;               /* length in bytes */
  62         int pno;                        /* partition number */
  63         char devname[BLKPG_DEVNAMELTH]; /* partition name, like sda5 or c0d1p2,
  64                                            to be used in kernel messages */
  65         char volname[BLKPG_VOLNAMELTH]; /* volume label */
  66 };
  67
  68 /*
  69  * Parse a 128 bit uuid in 4 integers
  70  * format is 32 hexx nibbles with options :.<space> separator
  71  * If not exactly 32 hex digits are found, return 0
  72  * else return 1
  73  */
  74 int parse_uuid(char *str, int uuid[4])
  75 {
  76     int hit = 0; /* number of Hex digIT */
  77     int i;
  78     char c;
  79     for (i=0; i<4; i++) uuid[i]=0;
  80
  81     while ((c= *str++)) {
  82         int n;
  83         if (c>='0' && c<='9')
  84             n = c-'0';
  85         else if (c>='a' && c <= 'f')
  86             n = 10 + c - 'a';
  87         else if (c>='A' && c <= 'F')
  88             n = 10 + c - 'A';
  89         else if (strchr(":. -", c))
  90             continue;
  91         else return 0;
  92
  93         if (hit<32) {
  94             uuid[hit/8] <<= 4;
  95             uuid[hit/8] += n;
  96         }
  97         hit++;
  98     }
  99     if (hit == 32)
 100         return 1;
 101     return 0;
 102
 103 }
 104
 105
 106 /*
 107  * Get the md version number.
 108  * We use the RAID_VERSION ioctl if it is supported
 109  * If not, but we have a block device with major '9', we assume
 110  * 0.36.0
 111  *
 112  * Return version number as 24 but number - assume version parts
 113  * always < 255
 114  */
 115
 116 int md_get_version(int fd)
 117 {
 118     struct stat stb;
 119     mdu_version_t vers;
 120
 121     if (fstat(fd, &stb)<0)
 122         return -1;
 123     if ((S_IFMT&stb.st_mode) != S_IFBLK)
 124         return -1;
 125
 126     if (ioctl(fd, RAID_VERSION, &vers) == 0)
 127         return  (vers.major*10000) + (vers.minor*100) + vers.patchlevel;
 128     if (errno == EACCES)
 129             return -1;
 130     if (major(stb.st_rdev) == MD_MAJOR)
 131         return (3600);
 132     return -1;
 133 }
 134
 135
 136 int get_linux_version()
 137 {
 138         struct utsname name;
 139         char *cp;
 140         int a,b,c;
 141         if (uname(&name) <0)
 142                 return -1;
 143
 144         cp = name.release;
 145         a = strtoul(cp, &cp, 10);
 146         if (*cp != '.') return -1;
 147         b = strtoul(cp+1, &cp, 10);
 148         if (*cp != '.') return -1;
 149         c = strtoul(cp+1, NULL, 10);
 150
 151         return (a*1000000)+(b*1000)+c;
 152 }
 153
 154 void remove_partitions(int fd)
 155 {
 156         /* remove partitions from this block devices.
 157          * This is used for components added to an array
 158          */
 159 #ifdef BLKPG_DEL_PARTITION
 160         struct blkpg_ioctl_arg a;
 161         struct blkpg_partition p;
 162
 163         a.op = BLKPG_DEL_PARTITION;
 164         a.data = (void*)&p;
 165         a.datalen = sizeof(p);
 166         a.flags = 0;
 167         memset(a.data, 0, a.datalen);
 168         for (p.pno=0; p.pno < 16; p.pno++)
 169                 ioctl(fd, BLKPG, &a);
 170 #endif
 171 }
 172
 173 int enough(int level, int raid_disks, int layout, int clean,
 174            char *avail, int avail_disks)
 175 {
 176         int copies, first;
 177         switch (level) {
 178         case 10:
 179                 /* This is the tricky one - we need to check
 180                  * which actual disks are present.
 181                  */
 182                 copies = (layout&255)* ((layout>>8) & 255);
 183                 first=0;
 184                 do {
 185                         /* there must be one of the 'copies' form 'first' */
 186                         int n = copies;
 187                         int cnt=0;
 188                         while (n--) {
 189                                 if (avail[first])
 190                                         cnt++;
 191                                 first = (first+1) % raid_disks;
 192                         }
 193                         if (cnt == 0)
 194                                 return 0;
 195
 196                 } while (first != 0);
 197                 return 1;
 198
 199         case -4:
 200                 return avail_disks>= 1;
 201         case -1:
 202         case 0:
 203                 return avail_disks == raid_disks;
 204         case 1:
 205                 return avail_disks >= 1;
 206         case 4:
 207         case 5:
 208                 if (clean)
 209                         return avail_disks >= raid_disks-1;
 210                 else
 211                         return avail_disks >= raid_disks;
 212         case 6:
 213                 if (clean)
 214                         return avail_disks >= raid_disks-2;
 215                 else
 216                         return avail_disks >= raid_disks;
 217         default:
 218                 return 0;
 219         }
 220 }
 221
 222 int same_uuid(int a[4], int b[4], int swapuuid)
 223 {
 224         if (swapuuid) {
 225                 /* parse uuids are hostendian.
 226                  * uuid's from some superblocks are big-ending
 227                  * if there is a difference, we need to swap..
 228                  */
 229                 unsigned char *ac = (unsigned char *)a;
 230                 unsigned char *bc = (unsigned char *)b;
 231                 int i;
 232                 for (i=0; i<16; i+= 4) {
 233                         if (ac[i+0] != bc[i+3] ||
 234                             ac[i+1] != bc[i+2] ||
 235                             ac[i+2] != bc[i+1] ||
 236                             ac[i+3] != bc[i+0])
 237                                 return 0;
 238                 }
 239                 return 1;
 240         } else {
 241                 if (a[0]==b[0] &&
 242                     a[1]==b[1] &&
 243                     a[2]==b[2] &&
 244                     a[3]==b[3])
 245                         return 1;
 246                 return 0;
 247         }
 248 }
 249
 250 #ifndef MDASSEMBLE
 251 int check_ext2(int fd, char *name)
 252 {
 253         /*
 254          * Check for an ext2fs file system.
 255          * Superblock is always 1K at 1K offset
 256          *
 257          * s_magic is le16 at 56 == 0xEF53
 258          * report mtime - le32 at 44
 259          * blocks - le32 at 4
 260          * logblksize - le32 at 24
 261          */
 262         unsigned char sb[1024];
 263         time_t mtime;
 264         int size, bsize;
 265         if (lseek(fd, 1024,0)!= 1024)
 266                 return 0;
 267         if (read(fd, sb, 1024)!= 1024)
 268                 return 0;
 269         if (sb[56] != 0x53 || sb[57] != 0xef)
 270                 return 0;
 271
 272         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 273         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 274         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 275         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 276                 name);
 277         fprintf(stderr,"    size=%dK  mtime=%s",
 278                 size*(1<<bsize), ctime(&mtime));
 279         return 1;
 280 }
 281
 282 int check_reiser(int fd, char *name)
 283 {
 284         /*
 285          * superblock is at 64K
 286          * size is 1024;
 287          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 288          *
 289          */
 290         unsigned char sb[1024];
 291         unsigned long size;
 292         if (lseek(fd, 64*1024, 0) != 64*1024)
 293                 return 0;
 294         if (read(fd, sb, 1024) != 1024)
 295                 return 0;
 296         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 297             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 298                 return 0;
 299         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 300         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 301         fprintf(stderr, "    size = %luK\n", size*4);
 302
 303         return 1;
 304 }
 305
 306 int check_raid(int fd, char *name)
 307 {
 308         void *super;
 309         struct mdinfo info;
 310         time_t crtime;
 311         char *level;
 312         struct supertype *st = guess_super(fd);
 313
 314         if (!st) return 0;
 315         st->ss->load_super(st, fd, &super, name);
 316         /* Looks like a raid array .. */
 317         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 318                 name);
 319         st->ss->getinfo_super(&info, super);
 320         free(super);
 321         crtime = info.array.ctime;
 322         level = map_num(pers, info.array.level);
 323         if (!level) level = "-unknown-";
 324         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 325                 level, info.array.raid_disks, ctime(&crtime));
 326         return 1;
 327 }
 328
 329 int ask(char *mesg)
 330 {
 331         char *add = "";
 332         int i;
 333         for (i=0; i<5; i++) {
 334                 char buf[100];
 335                 fprintf(stderr, "%s%s", mesg, add);
 336                 fflush(stderr);
 337                 if (fgets(buf, 100, stdin)==NULL)
 338                         return 0;
 339                 if (buf[0]=='y' || buf[0]=='Y')
 340                         return 1;
 341                 if (buf[0]=='n' || buf[0]=='N')
 342                         return 0;
 343                 add = "(y/n) ";
 344         }
 345         fprintf(stderr, Name ": assuming 'no'\n");
 346         return 0;
 347 }
 348 #endif /* MDASSEMBLE */
 349
 350 char *map_num(mapping_t *map, int num)
 351 {
 352         while (map->name) {
 353                 if (map->num == num)
 354                         return map->name;
 355                 map++;
 356         }
 357         return NULL;
 358 }
 359
 360 int map_name(mapping_t *map, char *name)
 361 {
 362         while (map->name) {
 363                 if (strcmp(map->name, name)==0)
 364                         return map->num;
 365                 map++;
 366         }
 367         return UnSet;
 368 }
 369
 370
 371 int is_standard(char *dev, int *nump)
 372 {
 373         /* tests if dev is a "standard" md dev name.
 374          * i.e if the last component is "/dNN" or "/mdNN",
 375          * where NN is a string of digits
 376          */
 377         char *d = strrchr(dev, '/');
 378         int type=0;
 379         int num;
 380         if (!d)
 381                 return 0;
 382         if (strncmp(d, "/d",2)==0)
 383                 d += 2, type=1; /* /dev/md/dN{pM} */
 384         else if (strncmp(d, "/md_d", 5)==0)
 385                 d += 5, type=1; /* /dev/md_dNpM */
 386         else if (strncmp(d, "/md", 3)==0)
 387                 d += 3, type=-1; /* /dev/mdN */
 388         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 389                 d += 1, type=-1; /* /dev/md/N */
 390         else
 391                 return 0;
 392         if (!*d)
 393                 return 0;
 394         num = atoi(d);
 395         while (isdigit(*d))
 396                 d++;
 397         if (*d)
 398                 return 0;
 399         if (nump) *nump = num;
 400
 401         return type;
 402 }
 403
 404
 405 /*
 406  * convert a major/minor pair for a block device into a name in /dev, if possible.
 407  * On the first call, walk /dev collecting name.
 408  * Put them in a simple linked listfor now.
 409  */
 410 struct devmap {
 411     int major, minor;
 412     char *name;
 413     struct devmap *next;
 414 } *devlist = NULL;
 415 int devlist_ready = 0;
 416
 417 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 418 {
 419         struct stat st;
 420         if (S_ISLNK(stb->st_mode)) {
 421                 stat(name, &st);
 422                 stb = &st;
 423         }
 424
 425         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 426                 char *n = strdup(name);
 427                 struct devmap *dm = malloc(sizeof(*dm));
 428                 if (strncmp(n, "/dev/./", 7)==0)
 429                         strcpy(n+4, name+6);
 430                 if (dm) {
 431                         dm->major = major(stb->st_rdev);
 432                         dm->minor = minor(stb->st_rdev);
 433                         dm->name = n;
 434                         dm->next = devlist;
 435                         devlist = dm;
 436                 }
 437         }
 438         return 0;
 439 }
 440
 441 #ifndef HAVE_NFTW
 442 #ifdef HAVE_FTW
 443 int add_dev_1(const char *name, const struct stat *stb, int flag)
 444 {
 445         return add_dev(name, stb, flag, NULL);
 446 }
 447 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 448 {
 449         return ftw(path, add_dev_1, nopenfd);
 450 }
 451 #else
 452 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 453 {
 454         return 0;
 455 }
 456 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 457 {
 458         return 0;
 459 }
 460 #endif /* HAVE_FTW */
 461 #endif /* HAVE_NFTW */
 462
 463 /*
 464  * Find a block device with the right major/minor number.
 465  * If we find multiple names, choose the shortest.
 466  * If we find a non-standard name, it is probably there
 467  * deliberately so prefer it over a standard name.
 468  * This applies only to names for MD devices.
 469  */
 470 char *map_dev(int major, int minor, int create)
 471 {
 472         struct devmap *p;
 473         char *std = NULL, *nonstd=NULL;
 474         int did_check = 0;
 475
 476         if (major == 0 && minor == 0)
 477                         return NULL;
 478
 479  retry:
 480         if (!devlist_ready) {
 481                 char *dev = "/dev";
 482                 struct stat stb;
 483                 while(devlist) {
 484                         struct devmap *d = devlist;
 485                         devlist = d->next;
 486                         free(d->name);
 487                         free(d);
 488                 }
 489                 if (lstat(dev, &stb)==0 &&
 490                     S_ISLNK(stb.st_mode))
 491                         dev = "/dev/.";
 492                 nftw(dev, add_dev, 10, FTW_PHYS);
 493                 devlist_ready=1;
 494                 did_check = 1;
 495         }
 496
 497         for (p=devlist; p; p=p->next)
 498                 if (p->major == major &&
 499                     p->minor == minor) {
 500                         if (is_standard(p->name, NULL)) {
 501                                 if (std == NULL ||
 502                                     strlen(p->name) < strlen(std))
 503                                         std = p->name;
 504                         } else {
 505                                 if (nonstd == NULL ||
 506                                     strlen(p->name) < strlen(nonstd))
 507                                         nonstd = p->name;
 508                         }
 509                 }
 510         if (!std && !nonstd && !did_check) {
 511                 devlist_ready = 0;
 512                 goto retry;
 513         }
 514         if (create && !std && !nonstd) {
 515                 static char buf[30];
 516                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 517                 nonstd = buf;
 518         }
 519
 520         return nonstd ? nonstd : std;
 521 }
 522
 523 unsigned long calc_csum(void *super, int bytes)
 524 {
 525         unsigned long long newcsum = 0;
 526         int i;
 527         unsigned int csum;
 528         unsigned int *superc = (unsigned int*) super;
 529
 530         for(i=0; i<bytes/4; i++)
 531                 newcsum+= superc[i];
 532         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 533 #ifdef __alpha__
 534 /* The in-kernel checksum calculation is always 16bit on
 535  * the alpha, though it is 32 bit on i386...
 536  * I wonder what it is elsewhere... (it uses and API in
 537  * a way that it shouldn't).
 538  */
 539         csum = (csum & 0xffff) + (csum >> 16);
 540         csum = (csum & 0xffff) + (csum >> 16);
 541 #endif
 542         return csum;
 543 }
 544
 545 #ifndef MDASSEMBLE
 546 char *human_size(long long bytes)
 547 {
 548         static char buf[30];
 549
 550         /* We convert bytes to either centi-M{ega,ibi}bytes or
 551          * centi-G{igi,ibi}bytes, with appropriate rounding,
 552          * and then print 1/100th of those as a decimal.
 553          * We allow upto 2048Megabytes before converting to
 554          * gigabytes, as that shows more precision and isn't
 555          * too large a number.
 556          * Terrabytes are not yet handled.
 557          */
 558
 559         if (bytes < 5000*1024)
 560                 buf[0]=0;
 561         else if (bytes < 2*1024LL*1024LL*1024LL) {
 562                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 563                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 564                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 565                         cMiB/100 , cMiB % 100,
 566                         cMB/100, cMB % 100);
 567         } else {
 568                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 569                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 570                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 571                         cGiB/100 , cGiB % 100,
 572                         cGB/100, cGB % 100);
 573         }
 574         return buf;
 575 }
 576
 577 char *human_size_brief(long long bytes)
 578 {
 579         static char buf[30];
 580
 581
 582         if (bytes < 5000*1024)
 583                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 584                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 585                         );
 586         else if (bytes < 2*1024LL*1024LL*1024LL)
 587                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 588                         (long)(bytes>>20),
 589                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 590                         );
 591         else
 592                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 593                         (long)(bytes>>30),
 594                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 595                         );
 596         return buf;
 597 }
 598 #endif
 599
 600 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 601 int get_mdp_major(void)
 602 {
 603 static int mdp_major = -1;
 604         FILE *fl;
 605         char *w;
 606         int have_block = 0;
 607         int have_devices = 0;
 608         int last_num = -1;
 609
 610         if (mdp_major != -1)
 611                 return mdp_major;
 612         fl = fopen("/proc/devices", "r");
 613         if (!fl)
 614                 return -1;
 615         while ((w = conf_word(fl, 1))) {
 616                 if (have_block && strcmp(w, "devices:")==0)
 617                         have_devices = 1;
 618                 have_block =  (strcmp(w, "Block")==0);
 619                 if (isdigit(w[0]))
 620                         last_num = atoi(w);
 621                 if (have_devices && strcmp(w, "mdp")==0)
 622                         mdp_major = last_num;
 623                 free(w);
 624         }
 625         fclose(fl);
 626         return mdp_major;
 627 }
 628
 629
 630
 631 char *get_md_name(int dev)
 632 {
 633         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 634         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 635         static char devname[50];
 636         struct stat stb;
 637         dev_t rdev;
 638         char *dn;
 639
 640         if (dev < 0) {
 641                 int mdp =  get_mdp_major();
 642                 if (mdp < 0) return NULL;
 643                 rdev = makedev(mdp, (-1-dev)<<6);
 644                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 645                 if (stat(devname, &stb) == 0
 646                     && (S_IFMT&stb.st_mode) == S_IFBLK
 647                     && (stb.st_rdev == rdev))
 648                         return devname;
 649         } else {
 650                 rdev = makedev(MD_MAJOR, dev);
 651                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 652                 if (stat(devname, &stb) == 0
 653                     && (S_IFMT&stb.st_mode) == S_IFBLK
 654                     && (stb.st_rdev == rdev))
 655                         return devname;
 656
 657                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 658                 if (stat(devname, &stb) == 0
 659                     && (S_IFMT&stb.st_mode) == S_IFBLK
 660                     && (stb.st_rdev == rdev))
 661                         return devname;
 662         }
 663         dn = map_dev(major(rdev), minor(rdev), 0);
 664         if (dn)
 665                 return dn;
 666         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 667         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 668                 if (errno != EEXIST)
 669                         return NULL;
 670
 671         if (stat(devname, &stb) == 0
 672             && (S_IFMT&stb.st_mode) == S_IFBLK
 673             && (stb.st_rdev == rdev))
 674                 return devname;
 675         unlink(devname);
 676         return NULL;
 677 }
 678
 679 void put_md_name(char *name)
 680 {
 681         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 682                 unlink(name);
 683 }
 684 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 685
 686 int dev_open(char *dev, int flags)
 687 {
 688         /* like 'open', but if 'dev' matches %d:%d, create a temp
 689          * block device and open that
 690          */
 691         char *e;
 692         int fd = -1;
 693         char devname[32];
 694         int major;
 695         int minor;
 696
 697         if (!dev) return -1;
 698
 699         major = strtoul(dev, &e, 0);
 700         if (e > dev && *e == ':' && e[1] &&
 701             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 702             *e == 0) {
 703                 snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d", major, minor);
 704                 if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 705                         fd = open(devname, flags);
 706                         unlink(devname);
 707                 }
 708         } else
 709                 fd = open(dev, flags);
 710         return fd;
 711 }
 712
 713 struct superswitch *superlist[] = { &super0, &super1, NULL };
 714
 715 struct supertype *super_by_version(int vers, int minor)
 716 {
 717         struct supertype *st = malloc(sizeof(*st));
 718         if (!st) return st;
 719         if (vers == 0) {
 720                 st->ss = &super0;
 721                 st->max_devs = MD_SB_DISKS;
 722         }
 723
 724         if (vers == 1) {
 725                 st->ss = &super1;
 726                 st->max_devs = 384;
 727         }
 728         st->minor_version = minor;
 729         return st;
 730 }
 731
 732 struct supertype *guess_super(int fd)
 733 {
 734         /* try each load_super to find the best match,
 735          * and return the best superswitch
 736          */
 737         struct superswitch  *ss;
 738         struct supertype *st;
 739         unsigned long besttime = 0;
 740         int bestsuper = -1;
 741
 742         void *sbp = NULL;
 743         int i;
 744
 745         st = malloc(sizeof(*st));
 746         memset(st, 0, sizeof(*st));
 747         for (i=0 ; superlist[i]; i++) {
 748                 int rv;
 749                 ss = superlist[i];
 750                 st->ss = NULL;
 751                 rv = ss->load_super(st, fd, &sbp, NULL);
 752                 if (rv == 0) {
 753                         struct mdinfo info;
 754                         ss->getinfo_super(&info, sbp);
 755                         if (bestsuper == -1 ||
 756                             besttime < info.array.ctime) {
 757                                 bestsuper = i;
 758                                 besttime = info.array.ctime;
 759                         }
 760                         free(sbp);
 761                 }
 762         }
 763         if (bestsuper != -1) {
 764                 int rv;
 765                 st->ss = NULL;
 766                 rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
 767                 if (rv == 0) {
 768                         free(sbp);
 769                         return st;
 770                 }
 771         }
 772         free(st);
 773         return NULL;
 774 }
 775
 776 /* Return size of device in bytes */
 777 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 778 {
 779         unsigned long long ldsize;
 780 #ifdef BLKGETSIZE64
 781         if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
 782 #endif
 783         {
 784                 unsigned long dsize;
 785                 if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
 786                         ldsize = dsize;
 787                         ldsize <<= 9;
 788                 } else {
 789                         if (dname)
 790                                 fprintf(stderr, Name ": Cannot get size of %s: %s\b",
 791                                         dname, strerror(errno));
 792                         return 0;
 793                 }
 794         }
 795         *sizep = ldsize;
 796         return 1;
 797 }
 798
 799 #ifdef __TINYC__
 800 /* tinyc doesn't optimize this check in ioctl.h out ... */
 801 unsigned int __invalid_size_argument_for_IOC = 0;
 802 #endif
 803