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 void copy_uuid(void *a, int b[4], int swapuuid)
 250 {
 251         if (swapuuid) {
 252                 /* parse uuids are hostendian.
 253                  * uuid's from some superblocks are big-ending
 254                  * if there is a difference, we need to swap..
 255                  */
 256                 unsigned char *ac = (unsigned char *)a;
 257                 unsigned char *bc = (unsigned char *)b;
 258                 int i;
 259                 for (i=0; i<16; i+= 4) {
 260                         ac[i+0] = bc[i+3];
 261                         ac[i+1] = bc[i+2];
 262                         ac[i+2] = bc[i+1];
 263                         ac[i+3] = bc[i+0];
 264                 }
 265         } else
 266                 memcpy(a, b, 16);
 267 }
 268
 269 #ifndef MDASSEMBLE
 270 int check_ext2(int fd, char *name)
 271 {
 272         /*
 273          * Check for an ext2fs file system.
 274          * Superblock is always 1K at 1K offset
 275          *
 276          * s_magic is le16 at 56 == 0xEF53
 277          * report mtime - le32 at 44
 278          * blocks - le32 at 4
 279          * logblksize - le32 at 24
 280          */
 281         unsigned char sb[1024];
 282         time_t mtime;
 283         int size, bsize;
 284         if (lseek(fd, 1024,0)!= 1024)
 285                 return 0;
 286         if (read(fd, sb, 1024)!= 1024)
 287                 return 0;
 288         if (sb[56] != 0x53 || sb[57] != 0xef)
 289                 return 0;
 290
 291         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 292         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 293         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 294         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 295                 name);
 296         fprintf(stderr,"    size=%dK  mtime=%s",
 297                 size*(1<<bsize), ctime(&mtime));
 298         return 1;
 299 }
 300
 301 int check_reiser(int fd, char *name)
 302 {
 303         /*
 304          * superblock is at 64K
 305          * size is 1024;
 306          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 307          *
 308          */
 309         unsigned char sb[1024];
 310         unsigned long size;
 311         if (lseek(fd, 64*1024, 0) != 64*1024)
 312                 return 0;
 313         if (read(fd, sb, 1024) != 1024)
 314                 return 0;
 315         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 316             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 317                 return 0;
 318         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 319         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 320         fprintf(stderr, "    size = %luK\n", size*4);
 321
 322         return 1;
 323 }
 324
 325 int check_raid(int fd, char *name)
 326 {
 327         void *super;
 328         struct mdinfo info;
 329         time_t crtime;
 330         char *level;
 331         struct supertype *st = guess_super(fd);
 332
 333         if (!st) return 0;
 334         st->ss->load_super(st, fd, &super, name);
 335         /* Looks like a raid array .. */
 336         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 337                 name);
 338         st->ss->getinfo_super(&info, super);
 339         free(super);
 340         crtime = info.array.ctime;
 341         level = map_num(pers, info.array.level);
 342         if (!level) level = "-unknown-";
 343         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 344                 level, info.array.raid_disks, ctime(&crtime));
 345         return 1;
 346 }
 347
 348 int ask(char *mesg)
 349 {
 350         char *add = "";
 351         int i;
 352         for (i=0; i<5; i++) {
 353                 char buf[100];
 354                 fprintf(stderr, "%s%s", mesg, add);
 355                 fflush(stderr);
 356                 if (fgets(buf, 100, stdin)==NULL)
 357                         return 0;
 358                 if (buf[0]=='y' || buf[0]=='Y')
 359                         return 1;
 360                 if (buf[0]=='n' || buf[0]=='N')
 361                         return 0;
 362                 add = "(y/n) ";
 363         }
 364         fprintf(stderr, Name ": assuming 'no'\n");
 365         return 0;
 366 }
 367 #endif /* MDASSEMBLE */
 368
 369 char *map_num(mapping_t *map, int num)
 370 {
 371         while (map->name) {
 372                 if (map->num == num)
 373                         return map->name;
 374                 map++;
 375         }
 376         return NULL;
 377 }
 378
 379 int map_name(mapping_t *map, char *name)
 380 {
 381         while (map->name) {
 382                 if (strcmp(map->name, name)==0)
 383                         return map->num;
 384                 map++;
 385         }
 386         return UnSet;
 387 }
 388
 389
 390 int is_standard(char *dev, int *nump)
 391 {
 392         /* tests if dev is a "standard" md dev name.
 393          * i.e if the last component is "/dNN" or "/mdNN",
 394          * where NN is a string of digits
 395          */
 396         char *d = strrchr(dev, '/');
 397         int type=0;
 398         int num;
 399         if (!d)
 400                 return 0;
 401         if (strncmp(d, "/d",2)==0)
 402                 d += 2, type=1; /* /dev/md/dN{pM} */
 403         else if (strncmp(d, "/md_d", 5)==0)
 404                 d += 5, type=1; /* /dev/md_dNpM */
 405         else if (strncmp(d, "/md", 3)==0)
 406                 d += 3, type=-1; /* /dev/mdN */
 407         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 408                 d += 1, type=-1; /* /dev/md/N */
 409         else
 410                 return 0;
 411         if (!*d)
 412                 return 0;
 413         num = atoi(d);
 414         while (isdigit(*d))
 415                 d++;
 416         if (*d)
 417                 return 0;
 418         if (nump) *nump = num;
 419
 420         return type;
 421 }
 422
 423
 424 /*
 425  * convert a major/minor pair for a block device into a name in /dev, if possible.
 426  * On the first call, walk /dev collecting name.
 427  * Put them in a simple linked listfor now.
 428  */
 429 struct devmap {
 430     int major, minor;
 431     char *name;
 432     struct devmap *next;
 433 } *devlist = NULL;
 434 int devlist_ready = 0;
 435
 436 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 437 {
 438         struct stat st;
 439         if (S_ISLNK(stb->st_mode)) {
 440                 stat(name, &st);
 441                 stb = &st;
 442         }
 443
 444         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 445                 char *n = strdup(name);
 446                 struct devmap *dm = malloc(sizeof(*dm));
 447                 if (strncmp(n, "/dev/./", 7)==0)
 448                         strcpy(n+4, name+6);
 449                 if (dm) {
 450                         dm->major = major(stb->st_rdev);
 451                         dm->minor = minor(stb->st_rdev);
 452                         dm->name = n;
 453                         dm->next = devlist;
 454                         devlist = dm;
 455                 }
 456         }
 457         return 0;
 458 }
 459
 460 #ifndef HAVE_NFTW
 461 #ifdef HAVE_FTW
 462 int add_dev_1(const char *name, const struct stat *stb, int flag)
 463 {
 464         return add_dev(name, stb, flag, NULL);
 465 }
 466 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 467 {
 468         return ftw(path, add_dev_1, nopenfd);
 469 }
 470 #else
 471 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 472 {
 473         return 0;
 474 }
 475 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 476 {
 477         return 0;
 478 }
 479 #endif /* HAVE_FTW */
 480 #endif /* HAVE_NFTW */
 481
 482 /*
 483  * Find a block device with the right major/minor number.
 484  * If we find multiple names, choose the shortest.
 485  * If we find a non-standard name, it is probably there
 486  * deliberately so prefer it over a standard name.
 487  * This applies only to names for MD devices.
 488  */
 489 char *map_dev(int major, int minor, int create)
 490 {
 491         struct devmap *p;
 492         char *std = NULL, *nonstd=NULL;
 493         int did_check = 0;
 494
 495         if (major == 0 && minor == 0)
 496                         return NULL;
 497
 498  retry:
 499         if (!devlist_ready) {
 500                 char *dev = "/dev";
 501                 struct stat stb;
 502                 while(devlist) {
 503                         struct devmap *d = devlist;
 504                         devlist = d->next;
 505                         free(d->name);
 506                         free(d);
 507                 }
 508                 if (lstat(dev, &stb)==0 &&
 509                     S_ISLNK(stb.st_mode))
 510                         dev = "/dev/.";
 511                 nftw(dev, add_dev, 10, FTW_PHYS);
 512                 devlist_ready=1;
 513                 did_check = 1;
 514         }
 515
 516         for (p=devlist; p; p=p->next)
 517                 if (p->major == major &&
 518                     p->minor == minor) {
 519                         if (is_standard(p->name, NULL)) {
 520                                 if (std == NULL ||
 521                                     strlen(p->name) < strlen(std))
 522                                         std = p->name;
 523                         } else {
 524                                 if (nonstd == NULL ||
 525                                     strlen(p->name) < strlen(nonstd))
 526                                         nonstd = p->name;
 527                         }
 528                 }
 529         if (!std && !nonstd && !did_check) {
 530                 devlist_ready = 0;
 531                 goto retry;
 532         }
 533         if (create && !std && !nonstd) {
 534                 static char buf[30];
 535                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 536                 nonstd = buf;
 537         }
 538
 539         return nonstd ? nonstd : std;
 540 }
 541
 542 unsigned long calc_csum(void *super, int bytes)
 543 {
 544         unsigned long long newcsum = 0;
 545         int i;
 546         unsigned int csum;
 547         unsigned int *superc = (unsigned int*) super;
 548
 549         for(i=0; i<bytes/4; i++)
 550                 newcsum+= superc[i];
 551         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 552 #ifdef __alpha__
 553 /* The in-kernel checksum calculation is always 16bit on
 554  * the alpha, though it is 32 bit on i386...
 555  * I wonder what it is elsewhere... (it uses and API in
 556  * a way that it shouldn't).
 557  */
 558         csum = (csum & 0xffff) + (csum >> 16);
 559         csum = (csum & 0xffff) + (csum >> 16);
 560 #endif
 561         return csum;
 562 }
 563
 564 #ifndef MDASSEMBLE
 565 char *human_size(long long bytes)
 566 {
 567         static char buf[30];
 568
 569         /* We convert bytes to either centi-M{ega,ibi}bytes or
 570          * centi-G{igi,ibi}bytes, with appropriate rounding,
 571          * and then print 1/100th of those as a decimal.
 572          * We allow upto 2048Megabytes before converting to
 573          * gigabytes, as that shows more precision and isn't
 574          * too large a number.
 575          * Terrabytes are not yet handled.
 576          */
 577
 578         if (bytes < 5000*1024)
 579                 buf[0]=0;
 580         else if (bytes < 2*1024LL*1024LL*1024LL) {
 581                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 582                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 583                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 584                         cMiB/100 , cMiB % 100,
 585                         cMB/100, cMB % 100);
 586         } else {
 587                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 588                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 589                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 590                         cGiB/100 , cGiB % 100,
 591                         cGB/100, cGB % 100);
 592         }
 593         return buf;
 594 }
 595
 596 char *human_size_brief(long long bytes)
 597 {
 598         static char buf[30];
 599
 600
 601         if (bytes < 5000*1024)
 602                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 603                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 604                         );
 605         else if (bytes < 2*1024LL*1024LL*1024LL)
 606                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 607                         (long)(bytes>>20),
 608                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 609                         );
 610         else
 611                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 612                         (long)(bytes>>30),
 613                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 614                         );
 615         return buf;
 616 }
 617 #endif
 618
 619 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 620 int get_mdp_major(void)
 621 {
 622 static int mdp_major = -1;
 623         FILE *fl;
 624         char *w;
 625         int have_block = 0;
 626         int have_devices = 0;
 627         int last_num = -1;
 628
 629         if (mdp_major != -1)
 630                 return mdp_major;
 631         fl = fopen("/proc/devices", "r");
 632         if (!fl)
 633                 return -1;
 634         while ((w = conf_word(fl, 1))) {
 635                 if (have_block && strcmp(w, "devices:")==0)
 636                         have_devices = 1;
 637                 have_block =  (strcmp(w, "Block")==0);
 638                 if (isdigit(w[0]))
 639                         last_num = atoi(w);
 640                 if (have_devices && strcmp(w, "mdp")==0)
 641                         mdp_major = last_num;
 642                 free(w);
 643         }
 644         fclose(fl);
 645         return mdp_major;
 646 }
 647
 648
 649
 650 char *get_md_name(int dev)
 651 {
 652         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 653         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 654         static char devname[50];
 655         struct stat stb;
 656         dev_t rdev;
 657         char *dn;
 658
 659         if (dev < 0) {
 660                 int mdp =  get_mdp_major();
 661                 if (mdp < 0) return NULL;
 662                 rdev = makedev(mdp, (-1-dev)<<6);
 663                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 664                 if (stat(devname, &stb) == 0
 665                     && (S_IFMT&stb.st_mode) == S_IFBLK
 666                     && (stb.st_rdev == rdev))
 667                         return devname;
 668         } else {
 669                 rdev = makedev(MD_MAJOR, dev);
 670                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 671                 if (stat(devname, &stb) == 0
 672                     && (S_IFMT&stb.st_mode) == S_IFBLK
 673                     && (stb.st_rdev == rdev))
 674                         return devname;
 675
 676                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 677                 if (stat(devname, &stb) == 0
 678                     && (S_IFMT&stb.st_mode) == S_IFBLK
 679                     && (stb.st_rdev == rdev))
 680                         return devname;
 681         }
 682         dn = map_dev(major(rdev), minor(rdev), 0);
 683         if (dn)
 684                 return dn;
 685         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 686         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 687                 if (errno != EEXIST)
 688                         return NULL;
 689
 690         if (stat(devname, &stb) == 0
 691             && (S_IFMT&stb.st_mode) == S_IFBLK
 692             && (stb.st_rdev == rdev))
 693                 return devname;
 694         unlink(devname);
 695         return NULL;
 696 }
 697
 698 void put_md_name(char *name)
 699 {
 700         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 701                 unlink(name);
 702 }
 703 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 704
 705 int dev_open(char *dev, int flags)
 706 {
 707         /* like 'open', but if 'dev' matches %d:%d, create a temp
 708          * block device and open that
 709          */
 710         char *e;
 711         int fd = -1;
 712         char devname[32];
 713         int major;
 714         int minor;
 715
 716         if (!dev) return -1;
 717
 718         major = strtoul(dev, &e, 0);
 719         if (e > dev && *e == ':' && e[1] &&
 720             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 721             *e == 0) {
 722                 snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d", major, minor);
 723                 if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 724                         fd = open(devname, flags);
 725                         unlink(devname);
 726                 }
 727         } else
 728                 fd = open(dev, flags);
 729         return fd;
 730 }
 731
 732 struct superswitch *superlist[] = { &super0, &super1, NULL };
 733
 734 struct supertype *super_by_version(int vers, int minor)
 735 {
 736         struct supertype *st = malloc(sizeof(*st));
 737         if (!st) return st;
 738         if (vers == 0) {
 739                 st->ss = &super0;
 740                 st->max_devs = MD_SB_DISKS;
 741         }
 742
 743         if (vers == 1) {
 744                 st->ss = &super1;
 745                 st->max_devs = 384;
 746         }
 747         st->minor_version = minor;
 748         return st;
 749 }
 750
 751 struct supertype *guess_super(int fd)
 752 {
 753         /* try each load_super to find the best match,
 754          * and return the best superswitch
 755          */
 756         struct superswitch  *ss;
 757         struct supertype *st;
 758         unsigned long besttime = 0;
 759         int bestsuper = -1;
 760
 761         void *sbp = NULL;
 762         int i;
 763
 764         st = malloc(sizeof(*st));
 765         memset(st, 0, sizeof(*st));
 766         for (i=0 ; superlist[i]; i++) {
 767                 int rv;
 768                 ss = superlist[i];
 769                 st->ss = NULL;
 770                 rv = ss->load_super(st, fd, &sbp, NULL);
 771                 if (rv == 0) {
 772                         struct mdinfo info;
 773                         ss->getinfo_super(&info, sbp);
 774                         if (bestsuper == -1 ||
 775                             besttime < info.array.ctime) {
 776                                 bestsuper = i;
 777                                 besttime = info.array.ctime;
 778                         }
 779                         free(sbp);
 780                 }
 781         }
 782         if (bestsuper != -1) {
 783                 int rv;
 784                 st->ss = NULL;
 785                 rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
 786                 if (rv == 0) {
 787                         free(sbp);
 788                         return st;
 789                 }
 790         }
 791         free(st);
 792         return NULL;
 793 }
 794
 795 /* Return size of device in bytes */
 796 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 797 {
 798         unsigned long long ldsize;
 799 #ifdef BLKGETSIZE64
 800         if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
 801 #endif
 802         {
 803                 unsigned long dsize;
 804                 if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
 805                         ldsize = dsize;
 806                         ldsize <<= 9;
 807                 } else {
 808                         if (dname)
 809                                 fprintf(stderr, Name ": Cannot get size of %s: %s\b",
 810                                         dname, strerror(errno));
 811                         return 0;
 812                 }
 813         }
 814         *sizep = ldsize;
 815         return 1;
 816 }
 817
 818 #ifdef __TINYC__
 819 /* tinyc doesn't optimize this check in ioctl.h out ... */
 820 unsigned int __invalid_size_argument_for_IOC = 0;
 821 #endif
 822