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  * Get the md version number.
 107  * We use the RAID_VERSION ioctl if it is supported
 108  * If not, but we have a block device with major '9', we assume
 109  * 0.36.0
 110  *
 111  * Return version number as 24 but number - assume version parts
 112  * always < 255
 113  */
 114
 115 int md_get_version(int fd)
 116 {
 117     struct stat stb;
 118     mdu_version_t vers;
 119
 120     if (fstat(fd, &stb)<0)
 121         return -1;
 122     if ((S_IFMT&stb.st_mode) != S_IFBLK)
 123         return -1;
 124
 125     if (ioctl(fd, RAID_VERSION, &vers) == 0)
 126         return  (vers.major*10000) + (vers.minor*100) + vers.patchlevel;
 127     if (errno == EACCES)
 128             return -1;
 129     if (major(stb.st_rdev) == MD_MAJOR)
 130         return (3600);
 131     return -1;
 132 }
 133
 134 int get_linux_version()
 135 {
 136         struct utsname name;
 137         char *cp;
 138         int a,b,c;
 139         if (uname(&name) <0)
 140                 return -1;
 141
 142         cp = name.release;
 143         a = strtoul(cp, &cp, 10);
 144         if (*cp != '.') return -1;
 145         b = strtoul(cp+1, &cp, 10);
 146         if (*cp != '.') return -1;
 147         c = strtoul(cp+1, NULL, 10);
 148
 149         return (a*1000000)+(b*1000)+c;
 150 }
 151
 152 void remove_partitions(int fd)
 153 {
 154         /* remove partitions from this block devices.
 155          * This is used for components added to an array
 156          */
 157 #ifdef BLKPG_DEL_PARTITION
 158         struct blkpg_ioctl_arg a;
 159         struct blkpg_partition p;
 160
 161         a.op = BLKPG_DEL_PARTITION;
 162         a.data = (void*)&p;
 163         a.datalen = sizeof(p);
 164         a.flags = 0;
 165         memset(a.data, 0, a.datalen);
 166         for (p.pno=0; p.pno < 16; p.pno++)
 167                 ioctl(fd, BLKPG, &a);
 168 #endif
 169 }
 170
 171 int enough(int level, int raid_disks, int layout, int clean,
 172            char *avail, int avail_disks)
 173 {
 174         int copies, first;
 175         switch (level) {
 176         case 10:
 177                 /* This is the tricky one - we need to check
 178                  * which actual disks are present.
 179                  */
 180                 copies = (layout&255)* ((layout>>8) & 255);
 181                 first=0;
 182                 do {
 183                         /* there must be one of the 'copies' form 'first' */
 184                         int n = copies;
 185                         int cnt=0;
 186                         while (n--) {
 187                                 if (avail[first])
 188                                         cnt++;
 189                                 first = (first+1) % raid_disks;
 190                         }
 191                         if (cnt == 0)
 192                                 return 0;
 193
 194                 } while (first != 0);
 195                 return 1;
 196
 197         case -4:
 198                 return avail_disks>= 1;
 199         case -1:
 200         case 0:
 201                 return avail_disks == raid_disks;
 202         case 1:
 203                 return avail_disks >= 1;
 204         case 4:
 205         case 5:
 206                 if (clean)
 207                         return avail_disks >= raid_disks-1;
 208                 else
 209                         return avail_disks >= raid_disks;
 210         case 6:
 211                 if (clean)
 212                         return avail_disks >= raid_disks-2;
 213                 else
 214                         return avail_disks >= raid_disks;
 215         default:
 216                 return 0;
 217         }
 218 }
 219
 220 int same_uuid(int a[4], int b[4], int swapuuid)
 221 {
 222         if (swapuuid) {
 223                 /* parse uuids are hostendian.
 224                  * uuid's from some superblocks are big-ending
 225                  * if there is a difference, we need to swap..
 226                  */
 227                 unsigned char *ac = (unsigned char *)a;
 228                 unsigned char *bc = (unsigned char *)b;
 229                 int i;
 230                 for (i=0; i<16; i+= 4) {
 231                         if (ac[i+0] != bc[i+3] ||
 232                             ac[i+1] != bc[i+2] ||
 233                             ac[i+2] != bc[i+1] ||
 234                             ac[i+3] != bc[i+0])
 235                                 return 0;
 236                 }
 237                 return 1;
 238         } else {
 239                 if (a[0]==b[0] &&
 240                     a[1]==b[1] &&
 241                     a[2]==b[2] &&
 242                     a[3]==b[3])
 243                         return 1;
 244                 return 0;
 245         }
 246 }
 247 void copy_uuid(void *a, int b[4], int swapuuid)
 248 {
 249         if (swapuuid) {
 250                 /* parse uuids are hostendian.
 251                  * uuid's from some superblocks are big-ending
 252                  * if there is a difference, we need to swap..
 253                  */
 254                 unsigned char *ac = (unsigned char *)a;
 255                 unsigned char *bc = (unsigned char *)b;
 256                 int i;
 257                 for (i=0; i<16; i+= 4) {
 258                         ac[i+0] = bc[i+3];
 259                         ac[i+1] = bc[i+2];
 260                         ac[i+2] = bc[i+1];
 261                         ac[i+3] = bc[i+0];
 262                 }
 263         } else
 264                 memcpy(a, b, 16);
 265 }
 266
 267 #ifndef MDASSEMBLE
 268 int check_ext2(int fd, char *name)
 269 {
 270         /*
 271          * Check for an ext2fs file system.
 272          * Superblock is always 1K at 1K offset
 273          *
 274          * s_magic is le16 at 56 == 0xEF53
 275          * report mtime - le32 at 44
 276          * blocks - le32 at 4
 277          * logblksize - le32 at 24
 278          */
 279         unsigned char sb[1024];
 280         time_t mtime;
 281         int size, bsize;
 282         if (lseek(fd, 1024,0)!= 1024)
 283                 return 0;
 284         if (read(fd, sb, 1024)!= 1024)
 285                 return 0;
 286         if (sb[56] != 0x53 || sb[57] != 0xef)
 287                 return 0;
 288
 289         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 290         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 291         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 292         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 293                 name);
 294         fprintf(stderr,"    size=%dK  mtime=%s",
 295                 size*(1<<bsize), ctime(&mtime));
 296         return 1;
 297 }
 298
 299 int check_reiser(int fd, char *name)
 300 {
 301         /*
 302          * superblock is at 64K
 303          * size is 1024;
 304          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 305          *
 306          */
 307         unsigned char sb[1024];
 308         unsigned long size;
 309         if (lseek(fd, 64*1024, 0) != 64*1024)
 310                 return 0;
 311         if (read(fd, sb, 1024) != 1024)
 312                 return 0;
 313         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 314             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 315                 return 0;
 316         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 317         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 318         fprintf(stderr, "    size = %luK\n", size*4);
 319
 320         return 1;
 321 }
 322
 323 int check_raid(int fd, char *name)
 324 {
 325         struct mdinfo info;
 326         time_t crtime;
 327         char *level;
 328         struct supertype *st = guess_super(fd);
 329
 330         if (!st) return 0;
 331         st->ss->load_super(st, fd, name);
 332         /* Looks like a raid array .. */
 333         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 334                 name);
 335         st->ss->getinfo_super(st, &info);
 336         st->ss->free_super(st);
 337         crtime = info.array.ctime;
 338         level = map_num(pers, info.array.level);
 339         if (!level) level = "-unknown-";
 340         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 341                 level, info.array.raid_disks, ctime(&crtime));
 342         return 1;
 343 }
 344
 345 int ask(char *mesg)
 346 {
 347         char *add = "";
 348         int i;
 349         for (i=0; i<5; i++) {
 350                 char buf[100];
 351                 fprintf(stderr, "%s%s", mesg, add);
 352                 fflush(stderr);
 353                 if (fgets(buf, 100, stdin)==NULL)
 354                         return 0;
 355                 if (buf[0]=='y' || buf[0]=='Y')
 356                         return 1;
 357                 if (buf[0]=='n' || buf[0]=='N')
 358                         return 0;
 359                 add = "(y/n) ";
 360         }
 361         fprintf(stderr, Name ": assuming 'no'\n");
 362         return 0;
 363 }
 364 #endif /* MDASSEMBLE */
 365
 366 char *map_num(mapping_t *map, int num)
 367 {
 368         while (map->name) {
 369                 if (map->num == num)
 370                         return map->name;
 371                 map++;
 372         }
 373         return NULL;
 374 }
 375
 376 int map_name(mapping_t *map, char *name)
 377 {
 378         while (map->name) {
 379                 if (strcmp(map->name, name)==0)
 380                         return map->num;
 381                 map++;
 382         }
 383         return UnSet;
 384 }
 385
 386
 387 int is_standard(char *dev, int *nump)
 388 {
 389         /* tests if dev is a "standard" md dev name.
 390          * i.e if the last component is "/dNN" or "/mdNN",
 391          * where NN is a string of digits
 392          */
 393         char *d = strrchr(dev, '/');
 394         int type=0;
 395         int num;
 396         if (!d)
 397                 return 0;
 398         if (strncmp(d, "/d",2)==0)
 399                 d += 2, type=1; /* /dev/md/dN{pM} */
 400         else if (strncmp(d, "/md_d", 5)==0)
 401                 d += 5, type=1; /* /dev/md_dN{pM} */
 402         else if (strncmp(d, "/md", 3)==0)
 403                 d += 3, type=-1; /* /dev/mdN */
 404         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 405                 d += 1, type=-1; /* /dev/md/N */
 406         else
 407                 return 0;
 408         if (!*d)
 409                 return 0;
 410         num = atoi(d);
 411         while (isdigit(*d))
 412                 d++;
 413         if (*d)
 414                 return 0;
 415         if (nump) *nump = num;
 416
 417         return type;
 418 }
 419
 420
 421 /*
 422  * convert a major/minor pair for a block device into a name in /dev, if possible.
 423  * On the first call, walk /dev collecting name.
 424  * Put them in a simple linked listfor now.
 425  */
 426 struct devmap {
 427     int major, minor;
 428     char *name;
 429     struct devmap *next;
 430 } *devlist = NULL;
 431 int devlist_ready = 0;
 432
 433 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 434 {
 435         struct stat st;
 436
 437         if (S_ISLNK(stb->st_mode)) {
 438                 if (stat(name, &st) != 0)
 439                         return 0;
 440                 stb = &st;
 441         }
 442
 443         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 444                 char *n = strdup(name);
 445                 struct devmap *dm = malloc(sizeof(*dm));
 446                 if (strncmp(n, "/dev/./", 7)==0)
 447                         strcpy(n+4, name+6);
 448                 if (dm) {
 449                         dm->major = major(stb->st_rdev);
 450                         dm->minor = minor(stb->st_rdev);
 451                         dm->name = n;
 452                         dm->next = devlist;
 453                         devlist = dm;
 454                 }
 455         }
 456         return 0;
 457 }
 458
 459 #ifndef HAVE_NFTW
 460 #ifdef HAVE_FTW
 461 int add_dev_1(const char *name, const struct stat *stb, int flag)
 462 {
 463         return add_dev(name, stb, flag, NULL);
 464 }
 465 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 466 {
 467         return ftw(path, add_dev_1, nopenfd);
 468 }
 469 #else
 470 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 471 {
 472         return 0;
 473 }
 474 #endif /* HAVE_FTW */
 475 #endif /* HAVE_NFTW */
 476
 477 /*
 478  * Find a block device with the right major/minor number.
 479  * If we find multiple names, choose the shortest.
 480  * If we find a non-standard name, it is probably there
 481  * deliberately so prefer it over a standard name.
 482  * This applies only to names for MD devices.
 483  */
 484 char *map_dev(int major, int minor, int create)
 485 {
 486         struct devmap *p;
 487         char *std = NULL, *nonstd=NULL;
 488         int did_check = 0;
 489
 490         if (major == 0 && minor == 0)
 491                         return NULL;
 492
 493  retry:
 494         if (!devlist_ready) {
 495                 char *dev = "/dev";
 496                 struct stat stb;
 497                 while(devlist) {
 498                         struct devmap *d = devlist;
 499                         devlist = d->next;
 500                         free(d->name);
 501                         free(d);
 502                 }
 503                 if (lstat(dev, &stb)==0 &&
 504                     S_ISLNK(stb.st_mode))
 505                         dev = "/dev/.";
 506                 nftw(dev, add_dev, 10, FTW_PHYS);
 507                 devlist_ready=1;
 508                 did_check = 1;
 509         }
 510
 511         for (p=devlist; p; p=p->next)
 512                 if (p->major == major &&
 513                     p->minor == minor) {
 514                         if (is_standard(p->name, NULL)) {
 515                                 if (std == NULL ||
 516                                     strlen(p->name) < strlen(std))
 517                                         std = p->name;
 518                         } else {
 519                                 if (nonstd == NULL ||
 520                                     strlen(p->name) < strlen(nonstd))
 521                                         nonstd = p->name;
 522                         }
 523                 }
 524         if (!std && !nonstd && !did_check) {
 525                 devlist_ready = 0;
 526                 goto retry;
 527         }
 528         if (create && !std && !nonstd) {
 529                 static char buf[30];
 530                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 531                 nonstd = buf;
 532         }
 533
 534         return nonstd ? nonstd : std;
 535 }
 536
 537 unsigned long calc_csum(void *super, int bytes)
 538 {
 539         unsigned long long newcsum = 0;
 540         int i;
 541         unsigned int csum;
 542         unsigned int *superc = (unsigned int*) super;
 543
 544         for(i=0; i<bytes/4; i++)
 545                 newcsum+= superc[i];
 546         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 547 #ifdef __alpha__
 548 /* The in-kernel checksum calculation is always 16bit on
 549  * the alpha, though it is 32 bit on i386...
 550  * I wonder what it is elsewhere... (it uses and API in
 551  * a way that it shouldn't).
 552  */
 553         csum = (csum & 0xffff) + (csum >> 16);
 554         csum = (csum & 0xffff) + (csum >> 16);
 555 #endif
 556         return csum;
 557 }
 558
 559 #ifndef MDASSEMBLE
 560 char *human_size(long long bytes)
 561 {
 562         static char buf[30];
 563
 564         /* We convert bytes to either centi-M{ega,ibi}bytes or
 565          * centi-G{igi,ibi}bytes, with appropriate rounding,
 566          * and then print 1/100th of those as a decimal.
 567          * We allow upto 2048Megabytes before converting to
 568          * gigabytes, as that shows more precision and isn't
 569          * too large a number.
 570          * Terrabytes are not yet handled.
 571          */
 572
 573         if (bytes < 5000*1024)
 574                 buf[0]=0;
 575         else if (bytes < 2*1024LL*1024LL*1024LL) {
 576                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 577                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 578                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 579                         cMiB/100 , cMiB % 100,
 580                         cMB/100, cMB % 100);
 581         } else {
 582                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 583                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 584                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 585                         cGiB/100 , cGiB % 100,
 586                         cGB/100, cGB % 100);
 587         }
 588         return buf;
 589 }
 590
 591 char *human_size_brief(long long bytes)
 592 {
 593         static char buf[30];
 594
 595         if (bytes < 5000*1024)
 596                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 597                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 598                         );
 599         else if (bytes < 2*1024LL*1024LL*1024LL)
 600                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 601                         (long)(bytes>>20),
 602                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 603                         );
 604         else
 605                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 606                         (long)(bytes>>30),
 607                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 608                         );
 609         return buf;
 610 }
 611
 612 void print_r10_layout(int layout)
 613 {
 614         int near = layout & 255;
 615         int far = (layout >> 8) & 255;
 616         int offset = (layout&0x10000);
 617         char *sep = "";
 618
 619         if (near != 1) {
 620                 printf("%s near=%d", sep, near);
 621                 sep = ",";
 622         }
 623         if (far != 1)
 624                 printf("%s %s=%d", sep, offset?"offset":"far", far);
 625         if (near*far == 1)
 626                 printf("NO REDUNDANCY");
 627 }
 628 #endif
 629
 630 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 631 int get_mdp_major(void)
 632 {
 633 static int mdp_major = -1;
 634         FILE *fl;
 635         char *w;
 636         int have_block = 0;
 637         int have_devices = 0;
 638         int last_num = -1;
 639
 640         if (mdp_major != -1)
 641                 return mdp_major;
 642         fl = fopen("/proc/devices", "r");
 643         if (!fl)
 644                 return -1;
 645         while ((w = conf_word(fl, 1))) {
 646                 if (have_block && strcmp(w, "devices:")==0)
 647                         have_devices = 1;
 648                 have_block =  (strcmp(w, "Block")==0);
 649                 if (isdigit(w[0]))
 650                         last_num = atoi(w);
 651                 if (have_devices && strcmp(w, "mdp")==0)
 652                         mdp_major = last_num;
 653                 free(w);
 654         }
 655         fclose(fl);
 656         return mdp_major;
 657 }
 658
 659
 660
 661 char *get_md_name(int dev)
 662 {
 663         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 664         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 665         static char devname[50];
 666         struct stat stb;
 667         dev_t rdev;
 668         char *dn;
 669
 670         if (dev < 0) {
 671                 int mdp =  get_mdp_major();
 672                 if (mdp < 0) return NULL;
 673                 rdev = makedev(mdp, (-1-dev)<<6);
 674                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 675                 if (stat(devname, &stb) == 0
 676                     && (S_IFMT&stb.st_mode) == S_IFBLK
 677                     && (stb.st_rdev == rdev))
 678                         return devname;
 679         } else {
 680                 rdev = makedev(MD_MAJOR, dev);
 681                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 682                 if (stat(devname, &stb) == 0
 683                     && (S_IFMT&stb.st_mode) == S_IFBLK
 684                     && (stb.st_rdev == rdev))
 685                         return devname;
 686
 687                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 688                 if (stat(devname, &stb) == 0
 689                     && (S_IFMT&stb.st_mode) == S_IFBLK
 690                     && (stb.st_rdev == rdev))
 691                         return devname;
 692         }
 693         dn = map_dev(major(rdev), minor(rdev), 0);
 694         if (dn)
 695                 return dn;
 696         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 697         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 698                 if (errno != EEXIST)
 699                         return NULL;
 700
 701         if (stat(devname, &stb) == 0
 702             && (S_IFMT&stb.st_mode) == S_IFBLK
 703             && (stb.st_rdev == rdev))
 704                 return devname;
 705         unlink(devname);
 706         return NULL;
 707 }
 708
 709 void put_md_name(char *name)
 710 {
 711         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 712                 unlink(name);
 713 }
 714
 715 static int dev2major(int d)
 716 {
 717         if (d >= 0)
 718                 return MD_MAJOR;
 719         else
 720                 return get_mdp_major();
 721 }
 722
 723 static int dev2minor(int d)
 724 {
 725         if (d >= 0)
 726                 return d;
 727         return (-1-d) << MdpMinorShift;
 728 }
 729
 730 int find_free_devnum(int use_partitions)
 731 {
 732         int devnum;
 733         for (devnum = 127; devnum != 128;
 734              devnum = devnum ? devnum-1 : (1<<22)-1) {
 735                 char *dn;
 736                 int _devnum;
 737
 738                 _devnum = use_partitions ? (-1-devnum) : devnum;
 739                 if (mddev_busy(_devnum))
 740                         continue;
 741                 /* make sure it is new to /dev too, at least as a
 742                  * non-standard */
 743                 dn = map_dev(dev2major(_devnum), dev2minor(_devnum), 0);
 744                 if (dn && ! is_standard(dn, NULL))
 745                         continue;
 746                 break;
 747         }
 748         if (devnum == 128)
 749                 return NoMdDev;
 750         return use_partitions ? (-1-devnum) : devnum;
 751 }
 752 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 753
 754 int dev_open(char *dev, int flags)
 755 {
 756         /* like 'open', but if 'dev' matches %d:%d, create a temp
 757          * block device and open that
 758          */
 759         char *e;
 760         int fd = -1;
 761         char devname[32];
 762         int major;
 763         int minor;
 764
 765         if (!dev) return -1;
 766
 767         major = strtoul(dev, &e, 0);
 768         if (e > dev && *e == ':' && e[1] &&
 769             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 770             *e == 0) {
 771                 snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d", major, minor);
 772                 if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 773                         fd = open(devname, flags);
 774                         unlink(devname);
 775                 }
 776         } else
 777                 fd = open(dev, flags);
 778         return fd;
 779 }
 780
 781 struct superswitch *superlist[] = { &super0, &super1, NULL };
 782
 783 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 784 struct supertype *super_by_fd(int fd)
 785 {
 786         mdu_array_info_t array;
 787         int vers;
 788         int minor;
 789         struct supertype *st = NULL;
 790         struct mdinfo *sra;
 791         char *verstr;
 792         char version[20];
 793         int i;
 794
 795         sra = sysfs_read(fd, 0, GET_VERSION);
 796
 797         if (sra) {
 798                 vers = sra->array.major_version;
 799                 minor = sra->array.minor_version;
 800                 verstr = sra->text_version;
 801         } else {
 802                 if (ioctl(fd, GET_ARRAY_INFO, &array))
 803                         array.major_version = array.minor_version = 0;
 804                 vers = array.major_version;
 805                 minor = array.minor_version;
 806                 verstr = "";
 807         }
 808
 809         if (vers != -1) {
 810                 sprintf(version, "%d.%d", vers, minor);
 811                 verstr = version;
 812         }
 813         for (i = 0; st == NULL && superlist[i] ; i++)
 814                 st = superlist[i]->match_metadata_desc(verstr);
 815
 816         if (sra)
 817                 sysfs_free(sra);
 818         if (st)
 819                 st->sb = NULL;
 820         return st;
 821 }
 822 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 823
 824
 825 struct supertype *dup_super(struct supertype *st)
 826 {
 827         struct supertype *stnew = NULL;
 828         char *verstr = NULL;
 829         char version[20];
 830         int i;
 831
 832         if (!st)
 833                 return st;
 834
 835         if (st->minor_version == -1)
 836                 sprintf(version, "%d", st->ss->major);
 837         else
 838                 sprintf(version, "%d.%d", st->ss->major, st->minor_version);
 839         verstr = version;
 840
 841         for (i = 0; stnew == NULL && superlist[i] ; i++)
 842                 stnew = superlist[i]->match_metadata_desc(verstr);
 843
 844         if (stnew)
 845                 stnew->sb = NULL;
 846         return stnew;
 847 }
 848
 849 struct supertype *guess_super(int fd)
 850 {
 851         /* try each load_super to find the best match,
 852          * and return the best superswitch
 853          */
 854         struct superswitch  *ss;
 855         struct supertype *st;
 856         unsigned long besttime = 0;
 857         int bestsuper = -1;
 858         int i;
 859
 860         st = malloc(sizeof(*st));
 861         memset(st, 0, sizeof(*st));
 862         for (i=0 ; superlist[i]; i++) {
 863                 int rv;
 864                 ss = superlist[i];
 865                 st->ss = NULL;
 866                 rv = ss->load_super(st, fd, NULL);
 867                 if (rv == 0) {
 868                         struct mdinfo info;
 869                         st->ss->getinfo_super(st, &info);
 870                         if (bestsuper == -1 ||
 871                             besttime < info.array.ctime) {
 872                                 bestsuper = i;
 873                                 besttime = info.array.ctime;
 874                         }
 875                         ss->free_super(st);
 876                 }
 877         }
 878         if (bestsuper != -1) {
 879                 int rv;
 880                 st->ss = NULL;
 881                 rv = superlist[bestsuper]->load_super(st, fd, NULL);
 882                 if (rv == 0) {
 883                         superlist[bestsuper]->free_super(st);
 884                         return st;
 885                 }
 886         }
 887         free(st);
 888         return NULL;
 889 }
 890
 891 /* Return size of device in bytes */
 892 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 893 {
 894         unsigned long long ldsize;
 895         struct stat st;
 896
 897         if (fstat(fd, &st) != -1 && S_ISREG(st.st_mode))
 898                 ldsize = (unsigned long long)st.st_size;
 899         else
 900 #ifdef BLKGETSIZE64
 901         if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
 902 #endif
 903         {
 904                 unsigned long dsize;
 905                 if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
 906                         ldsize = dsize;
 907                         ldsize <<= 9;
 908                 } else {
 909                         if (dname)
 910                                 fprintf(stderr, Name ": Cannot get size of %s: %s\b",
 911                                         dname, strerror(errno));
 912                         return 0;
 913                 }
 914         }
 915         *sizep = ldsize;
 916         return 1;
 917 }
 918
 919 void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
 920 {
 921         int d;
 922         ioctl(mdfd, GET_ARRAY_INFO, ainf);
 923         for (d = 0 ; d < ainf->raid_disks + ainf->nr_disks ; d++)
 924                 if (ioctl(mdfd, GET_DISK_INFO, disk) == 0)
 925                         return;
 926 }
 927
 928 #ifdef __TINYC__
 929 /* tinyc doesn't optimize this check in ioctl.h out ... */
 930 unsigned int __invalid_size_argument_for_IOC = 0;
 931 #endif
 932