util.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2009 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@suse.de>
  23  */
  24
  25 #include        "mdadm.h"
  26 #include        "md_p.h"
  27 #include        <sys/socket.h>
  28 #include        <sys/utsname.h>
  29 #include        <sys/wait.h>
  30 #include        <sys/un.h>
  31 #include        <ctype.h>
  32 #include        <dirent.h>
  33 #include        <signal.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 #include "part.h"
  69
  70 /* Force a compilation error if condition is true */
  71 #define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
  72
  73 /* Force a compilation error if condition is true, but also produce a
  74    result (of value 0 and type size_t), so the expression can be used
  75    e.g. in a structure initializer (or where-ever else comma expressions
  76    aren't permitted). */
  77 #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
  78
  79 /*
  80  * Parse a 128 bit uuid in 4 integers
  81  * format is 32 hexx nibbles with options :.<space> separator
  82  * If not exactly 32 hex digits are found, return 0
  83  * else return 1
  84  */
  85 int parse_uuid(char *str, int uuid[4])
  86 {
  87         int hit = 0; /* number of Hex digIT */
  88         int i;
  89         char c;
  90         for (i=0; i<4; i++) uuid[i]=0;
  91
  92         while ((c= *str++)) {
  93                 int n;
  94                 if (c>='0' && c<='9')
  95                         n = c-'0';
  96                 else if (c>='a' && c <= 'f')
  97                         n = 10 + c - 'a';
  98                 else if (c>='A' && c <= 'F')
  99                         n = 10 + c - 'A';
 100                 else if (strchr(":. -", c))
 101                         continue;
 102                 else return 0;
 103
 104                 if (hit<32) {
 105                         uuid[hit/8] <<= 4;
 106                         uuid[hit/8] += n;
 107                 }
 108                 hit++;
 109         }
 110         if (hit == 32)
 111                 return 1;
 112         return 0;
 113 }
 114
 115
 116 /*
 117  * Get the md version number.
 118  * We use the RAID_VERSION ioctl if it is supported
 119  * If not, but we have a block device with major '9', we assume
 120  * 0.36.0
 121  *
 122  * Return version number as 24 but number - assume version parts
 123  * always < 255
 124  */
 125
 126 int md_get_version(int fd)
 127 {
 128     struct stat stb;
 129     mdu_version_t vers;
 130
 131     if (fstat(fd, &stb)<0)
 132         return -1;
 133     if ((S_IFMT&stb.st_mode) != S_IFBLK)
 134         return -1;
 135
 136     if (ioctl(fd, RAID_VERSION, &vers) == 0)
 137         return  (vers.major*10000) + (vers.minor*100) + vers.patchlevel;
 138     if (errno == EACCES)
 139             return -1;
 140     if (major(stb.st_rdev) == MD_MAJOR)
 141         return (3600);
 142     return -1;
 143 }
 144
 145 int get_linux_version()
 146 {
 147         struct utsname name;
 148         char *cp;
 149         int a,b,c;
 150         if (uname(&name) <0)
 151                 return -1;
 152
 153         cp = name.release;
 154         a = strtoul(cp, &cp, 10);
 155         if (*cp != '.') return -1;
 156         b = strtoul(cp+1, &cp, 10);
 157         if (*cp != '.') return -1;
 158         c = strtoul(cp+1, NULL, 10);
 159
 160         return (a*1000000)+(b*1000)+c;
 161 }
 162
 163 int mdadm_version(char *version)
 164 {
 165         int a, b, c;
 166         char *cp;
 167
 168         if (!version)
 169                 version = Version;
 170
 171         cp = strchr(version, '-');
 172         if (!cp || *(cp+1) != ' ' || *(cp+2) != 'v')
 173                 return -1;
 174         cp += 3;
 175         a = strtoul(cp, &cp, 10);
 176         if (*cp != '.')
 177                 return -1;
 178         b = strtoul(cp+1, &cp, 10);
 179         if (*cp == '.')
 180                 c = strtoul(cp+1, &cp, 10);
 181         else
 182                 c = 0;
 183         if (*cp != ' ' && *cp != '-')
 184                 return -1;
 185         return (a*1000000)+(b*1000)+c;
 186 }
 187
 188 #ifndef MDASSEMBLE
 189 long long parse_size(char *size)
 190 {
 191         /* parse 'size' which should be a number optionally
 192          * followed by 'K', 'M', or 'G'.
 193          * Without a suffix, K is assumed.
 194          * Number returned is in sectors (half-K)
 195          */
 196         char *c;
 197         long long s = strtoll(size, &c, 10);
 198         if (s > 0) {
 199                 switch (*c) {
 200                 case 'K':
 201                         c++;
 202                 default:
 203                         s *= 2;
 204                         break;
 205                 case 'M':
 206                         c++;
 207                         s *= 1024 * 2;
 208                         break;
 209                 case 'G':
 210                         c++;
 211                         s *= 1024 * 1024 * 2;
 212                         break;
 213                 }
 214         }
 215         if (*c)
 216                 s = 0;
 217         return s;
 218 }
 219
 220 int parse_layout_10(char *layout)
 221 {
 222         int copies, rv;
 223         char *cp;
 224         /* Parse the layout string for raid10 */
 225         /* 'f', 'o' or 'n' followed by a number <= raid_disks */
 226         if ((layout[0] !=  'n' && layout[0] != 'f' && layout[0] != 'o') ||
 227             (copies = strtoul(layout+1, &cp, 10)) < 1 ||
 228             copies > 200 ||
 229             *cp)
 230                 return -1;
 231         if (layout[0] == 'n')
 232                 rv = 256 + copies;
 233         else if (layout[0] == 'o')
 234                 rv = 0x10000 + (copies<<8) + 1;
 235         else
 236                 rv = 1 + (copies<<8);
 237         return rv;
 238 }
 239
 240 int parse_layout_faulty(char *layout)
 241 {
 242         /* Parse the layout string for 'faulty' */
 243         int ln = strcspn(layout, "0123456789");
 244         char *m = strdup(layout);
 245         int mode;
 246         m[ln] = 0;
 247         mode = map_name(faultylayout, m);
 248         if (mode == UnSet)
 249                 return -1;
 250
 251         return mode | (atoi(layout+ln)<< ModeShift);
 252 }
 253 #endif
 254
 255 void remove_partitions(int fd)
 256 {
 257         /* remove partitions from this block devices.
 258          * This is used for components added to an array
 259          */
 260 #ifdef BLKPG_DEL_PARTITION
 261         struct blkpg_ioctl_arg a;
 262         struct blkpg_partition p;
 263
 264         a.op = BLKPG_DEL_PARTITION;
 265         a.data = (void*)&p;
 266         a.datalen = sizeof(p);
 267         a.flags = 0;
 268         memset(a.data, 0, a.datalen);
 269         for (p.pno=0; p.pno < 16; p.pno++)
 270                 ioctl(fd, BLKPG, &a);
 271 #endif
 272 }
 273
 274 int test_partition(int fd)
 275 {
 276         /* Check if fd is a whole-disk or a partition.
 277          * BLKPG will return EINVAL on a partition, and BLKPG_DEL_PARTITION
 278          * will return ENXIO on an invalid partition number.
 279          */
 280         struct blkpg_ioctl_arg a;
 281         struct blkpg_partition p;
 282         a.op = BLKPG_DEL_PARTITION;
 283         a.data = (void*)&p;
 284         a.datalen = sizeof(p);
 285         a.flags = 0;
 286         memset(a.data, 0, a.datalen);
 287         p.pno = 1<<30;
 288         if (ioctl(fd, BLKPG, &a) == 0)
 289                 /* Very unlikely, but not a partition */
 290                 return 0;
 291         if (errno == ENXIO)
 292                 /* not a partition */
 293                 return 0;
 294
 295         return 1;
 296 }
 297
 298
 299 int enough(int level, int raid_disks, int layout, int clean,
 300            char *avail, int avail_disks)
 301 {
 302         int copies, first;
 303         switch (level) {
 304         case 10:
 305                 /* This is the tricky one - we need to check
 306                  * which actual disks are present.
 307                  */
 308                 copies = (layout&255)* ((layout>>8) & 255);
 309                 first=0;
 310                 do {
 311                         /* there must be one of the 'copies' form 'first' */
 312                         int n = copies;
 313                         int cnt=0;
 314                         while (n--) {
 315                                 if (avail[first])
 316                                         cnt++;
 317                                 first = (first+1) % raid_disks;
 318                         }
 319                         if (cnt == 0)
 320                                 return 0;
 321
 322                 } while (first != 0);
 323                 return 1;
 324
 325         case LEVEL_MULTIPATH:
 326                 return avail_disks>= 1;
 327         case LEVEL_LINEAR:
 328         case 0:
 329                 return avail_disks == raid_disks;
 330         case 1:
 331                 return avail_disks >= 1;
 332         case 4:
 333         case 5:
 334                 if (clean)
 335                         return avail_disks >= raid_disks-1;
 336                 else
 337                         return avail_disks >= raid_disks;
 338         case 6:
 339                 if (clean)
 340                         return avail_disks >= raid_disks-2;
 341                 else
 342                         return avail_disks >= raid_disks;
 343         default:
 344                 return 0;
 345         }
 346 }
 347
 348 int enough_fd(int fd)
 349 {
 350         struct mdu_array_info_s array;
 351         struct mdu_disk_info_s disk;
 352         int avail_disks = 0;
 353         int i;
 354         char *avail;
 355
 356         if (ioctl(fd, GET_ARRAY_INFO, &array) != 0 ||
 357             array.raid_disks <= 0)
 358                 return 0;
 359         avail = calloc(array.raid_disks, 1);
 360         for (i=0; i<array.raid_disks + array.nr_disks; i++) {
 361                 disk.number = i;
 362                 if (ioctl(fd, GET_DISK_INFO, &disk) != 0)
 363                         continue;
 364                 if (! (disk.state & (1<<MD_DISK_SYNC)))
 365                         continue;
 366                 if (disk.raid_disk < 0 || disk.raid_disk >= array.raid_disks)
 367                         continue;
 368                 avail_disks++;
 369                 avail[disk.raid_disk] = 1;
 370         }
 371         /* This is used on an active array, so assume it is clean */
 372         return enough(array.level, array.raid_disks, array.layout,
 373                       1,
 374                       avail, avail_disks);
 375 }
 376
 377
 378 const int uuid_zero[4] = { 0, 0, 0, 0 };
 379
 380 int same_uuid(int a[4], int b[4], int swapuuid)
 381 {
 382         if (swapuuid) {
 383                 /* parse uuids are hostendian.
 384                  * uuid's from some superblocks are big-ending
 385                  * if there is a difference, we need to swap..
 386                  */
 387                 unsigned char *ac = (unsigned char *)a;
 388                 unsigned char *bc = (unsigned char *)b;
 389                 int i;
 390                 for (i=0; i<16; i+= 4) {
 391                         if (ac[i+0] != bc[i+3] ||
 392                             ac[i+1] != bc[i+2] ||
 393                             ac[i+2] != bc[i+1] ||
 394                             ac[i+3] != bc[i+0])
 395                                 return 0;
 396                 }
 397                 return 1;
 398         } else {
 399                 if (a[0]==b[0] &&
 400                     a[1]==b[1] &&
 401                     a[2]==b[2] &&
 402                     a[3]==b[3])
 403                         return 1;
 404                 return 0;
 405         }
 406 }
 407 void copy_uuid(void *a, int b[4], int swapuuid)
 408 {
 409         if (swapuuid) {
 410                 /* parse uuids are hostendian.
 411                  * uuid's from some superblocks are big-ending
 412                  * if there is a difference, we need to swap..
 413                  */
 414                 unsigned char *ac = (unsigned char *)a;
 415                 unsigned char *bc = (unsigned char *)b;
 416                 int i;
 417                 for (i=0; i<16; i+= 4) {
 418                         ac[i+0] = bc[i+3];
 419                         ac[i+1] = bc[i+2];
 420                         ac[i+2] = bc[i+1];
 421                         ac[i+3] = bc[i+0];
 422                 }
 423         } else
 424                 memcpy(a, b, 16);
 425 }
 426
 427 char *__fname_from_uuid(int id[4], int swap, char *buf, char sep)
 428 {
 429         int i, j;
 430         char uuid[16];
 431         char *c = buf;
 432         strcpy(c, "UUID-");
 433         c += strlen(c);
 434         copy_uuid(uuid, id, swap);
 435         for (i = 0; i < 4; i++) {
 436                 if (i)
 437                         *c++ = sep;
 438                 for (j = 3; j >= 0; j--) {
 439                         sprintf(c,"%02x", (unsigned char) uuid[j+4*i]);
 440                         c+= 2;
 441                 }
 442         }
 443         return buf;
 444
 445 }
 446
 447 char *fname_from_uuid(struct supertype *st, struct mdinfo *info, char *buf, char sep)
 448 {
 449         // dirty hack to work around an issue with super1 superblocks...
 450         // super1 superblocks need swapuuid set in order for assembly to
 451         // work, but can't have it set if we want this printout to match
 452         // all the other uuid printouts in super1.c, so we force swapuuid
 453         // to 1 to make our printout match the rest of super1
 454         return __fname_from_uuid(info->uuid, (st->ss == &super1) ? 1 : st->ss->swapuuid, buf, sep);
 455 }
 456
 457 #ifndef MDASSEMBLE
 458 int check_ext2(int fd, char *name)
 459 {
 460         /*
 461          * Check for an ext2fs file system.
 462          * Superblock is always 1K at 1K offset
 463          *
 464          * s_magic is le16 at 56 == 0xEF53
 465          * report mtime - le32 at 44
 466          * blocks - le32 at 4
 467          * logblksize - le32 at 24
 468          */
 469         unsigned char sb[1024];
 470         time_t mtime;
 471         int size, bsize;
 472         if (lseek(fd, 1024,0)!= 1024)
 473                 return 0;
 474         if (read(fd, sb, 1024)!= 1024)
 475                 return 0;
 476         if (sb[56] != 0x53 || sb[57] != 0xef)
 477                 return 0;
 478
 479         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 480         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 481         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 482         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 483                 name);
 484         fprintf(stderr,"    size=%dK  mtime=%s",
 485                 size*(1<<bsize), ctime(&mtime));
 486         return 1;
 487 }
 488
 489 int check_reiser(int fd, char *name)
 490 {
 491         /*
 492          * superblock is at 64K
 493          * size is 1024;
 494          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 495          *
 496          */
 497         unsigned char sb[1024];
 498         unsigned long size;
 499         if (lseek(fd, 64*1024, 0) != 64*1024)
 500                 return 0;
 501         if (read(fd, sb, 1024) != 1024)
 502                 return 0;
 503         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 504             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 505                 return 0;
 506         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 507         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 508         fprintf(stderr, "    size = %luK\n", size*4);
 509
 510         return 1;
 511 }
 512
 513 int check_raid(int fd, char *name)
 514 {
 515         struct mdinfo info;
 516         time_t crtime;
 517         char *level;
 518         struct supertype *st = guess_super(fd);
 519
 520         if (!st) return 0;
 521         st->ss->load_super(st, fd, name);
 522         /* Looks like a raid array .. */
 523         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 524                 name);
 525         st->ss->getinfo_super(st, &info, NULL);
 526         st->ss->free_super(st);
 527         crtime = info.array.ctime;
 528         level = map_num(pers, info.array.level);
 529         if (!level) level = "-unknown-";
 530         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 531                 level, info.array.raid_disks, ctime(&crtime));
 532         return 1;
 533 }
 534
 535 int ask(char *mesg)
 536 {
 537         char *add = "";
 538         int i;
 539         for (i=0; i<5; i++) {
 540                 char buf[100];
 541                 fprintf(stderr, "%s%s", mesg, add);
 542                 fflush(stderr);
 543                 if (fgets(buf, 100, stdin)==NULL)
 544                         return 0;
 545                 if (buf[0]=='y' || buf[0]=='Y')
 546                         return 1;
 547                 if (buf[0]=='n' || buf[0]=='N')
 548                         return 0;
 549                 add = "(y/n) ";
 550         }
 551         fprintf(stderr, Name ": assuming 'no'\n");
 552         return 0;
 553 }
 554 #endif /* MDASSEMBLE */
 555
 556 char *map_num(mapping_t *map, int num)
 557 {
 558         while (map->name) {
 559                 if (map->num == num)
 560                         return map->name;
 561                 map++;
 562         }
 563         return NULL;
 564 }
 565
 566 int map_name(mapping_t *map, char *name)
 567 {
 568         while (map->name) {
 569                 if (strcmp(map->name, name)==0)
 570                         return map->num;
 571                 map++;
 572         }
 573         return UnSet;
 574 }
 575
 576
 577 int is_standard(char *dev, int *nump)
 578 {
 579         /* tests if dev is a "standard" md dev name.
 580          * i.e if the last component is "/dNN" or "/mdNN",
 581          * where NN is a string of digits
 582          * Returns 1 if a partitionable standard,
 583          *   -1 if non-partitonable,
 584          *   0 if not a standard name.
 585          */
 586         char *d = strrchr(dev, '/');
 587         int type=0;
 588         int num;
 589         if (!d)
 590                 return 0;
 591         if (strncmp(d, "/d",2)==0)
 592                 d += 2, type=1; /* /dev/md/dN{pM} */
 593         else if (strncmp(d, "/md_d", 5)==0)
 594                 d += 5, type=1; /* /dev/md_dN{pM} */
 595         else if (strncmp(d, "/md", 3)==0)
 596                 d += 3, type=-1; /* /dev/mdN */
 597         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 598                 d += 1, type=-1; /* /dev/md/N */
 599         else
 600                 return 0;
 601         if (!*d)
 602                 return 0;
 603         num = atoi(d);
 604         while (isdigit(*d))
 605                 d++;
 606         if (*d)
 607                 return 0;
 608         if (nump) *nump = num;
 609
 610         return type;
 611 }
 612
 613
 614 /*
 615  * convert a major/minor pair for a block device into a name in /dev, if possible.
 616  * On the first call, walk /dev collecting name.
 617  * Put them in a simple linked listfor now.
 618  */
 619 struct devmap {
 620     int major, minor;
 621     char *name;
 622     struct devmap *next;
 623 } *devlist = NULL;
 624 int devlist_ready = 0;
 625
 626 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 627 {
 628         struct stat st;
 629
 630         if (S_ISLNK(stb->st_mode)) {
 631                 if (stat(name, &st) != 0)
 632                         return 0;
 633                 stb = &st;
 634         }
 635
 636         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 637                 char *n = strdup(name);
 638                 struct devmap *dm = malloc(sizeof(*dm));
 639                 if (strncmp(n, "/dev/./", 7)==0)
 640                         strcpy(n+4, name+6);
 641                 if (dm) {
 642                         dm->major = major(stb->st_rdev);
 643                         dm->minor = minor(stb->st_rdev);
 644                         dm->name = n;
 645                         dm->next = devlist;
 646                         devlist = dm;
 647                 }
 648         }
 649         return 0;
 650 }
 651
 652 #ifndef HAVE_NFTW
 653 #ifdef HAVE_FTW
 654 int add_dev_1(const char *name, const struct stat *stb, int flag)
 655 {
 656         return add_dev(name, stb, flag, NULL);
 657 }
 658 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 659 {
 660         return ftw(path, add_dev_1, nopenfd);
 661 }
 662 #else
 663 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 664 {
 665         return 0;
 666 }
 667 #endif /* HAVE_FTW */
 668 #endif /* HAVE_NFTW */
 669
 670 /*
 671  * Find a block device with the right major/minor number.
 672  * If we find multiple names, choose the shortest.
 673  * If we find a name in /dev/md/, we prefer that.
 674  * This applies only to names for MD devices.
 675  */
 676 char *map_dev(int major, int minor, int create)
 677 {
 678         struct devmap *p;
 679         char *regular = NULL, *preferred=NULL;
 680         int did_check = 0;
 681
 682         if (major == 0 && minor == 0)
 683                         return NULL;
 684
 685  retry:
 686         if (!devlist_ready) {
 687                 char *dev = "/dev";
 688                 struct stat stb;
 689                 while(devlist) {
 690                         struct devmap *d = devlist;
 691                         devlist = d->next;
 692                         free(d->name);
 693                         free(d);
 694                 }
 695                 if (lstat(dev, &stb)==0 &&
 696                     S_ISLNK(stb.st_mode))
 697                         dev = "/dev/.";
 698                 nftw(dev, add_dev, 10, FTW_PHYS);
 699                 devlist_ready=1;
 700                 did_check = 1;
 701         }
 702
 703         for (p=devlist; p; p=p->next)
 704                 if (p->major == major &&
 705                     p->minor == minor) {
 706                         if (strncmp(p->name, "/dev/md/",8) == 0) {
 707                                 if (preferred == NULL ||
 708                                     strlen(p->name) < strlen(preferred))
 709                                         preferred = p->name;
 710                         } else {
 711                                 if (regular == NULL ||
 712                                     strlen(p->name) < strlen(regular))
 713                                         regular = p->name;
 714                         }
 715                 }
 716         if (!regular && !preferred && !did_check) {
 717                 devlist_ready = 0;
 718                 goto retry;
 719         }
 720         if (create && !regular && !preferred) {
 721                 static char buf[30];
 722                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 723                 regular = buf;
 724         }
 725
 726         return preferred ? preferred : regular;
 727 }
 728
 729 unsigned long calc_csum(void *super, int bytes)
 730 {
 731         unsigned long long newcsum = 0;
 732         int i;
 733         unsigned int csum;
 734         unsigned int *superc = (unsigned int*) super;
 735
 736         for(i=0; i<bytes/4; i++)
 737                 newcsum+= superc[i];
 738         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 739 #ifdef __alpha__
 740 /* The in-kernel checksum calculation is always 16bit on
 741  * the alpha, though it is 32 bit on i386...
 742  * I wonder what it is elsewhere... (it uses and API in
 743  * a way that it shouldn't).
 744  */
 745         csum = (csum & 0xffff) + (csum >> 16);
 746         csum = (csum & 0xffff) + (csum >> 16);
 747 #endif
 748         return csum;
 749 }
 750
 751 #ifndef MDASSEMBLE
 752 char *human_size(long long bytes)
 753 {
 754         static char buf[30];
 755
 756         /* We convert bytes to either centi-M{ega,ibi}bytes or
 757          * centi-G{igi,ibi}bytes, with appropriate rounding,
 758          * and then print 1/100th of those as a decimal.
 759          * We allow upto 2048Megabytes before converting to
 760          * gigabytes, as that shows more precision and isn't
 761          * too large a number.
 762          * Terrabytes are not yet handled.
 763          */
 764
 765         if (bytes < 5000*1024)
 766                 buf[0]=0;
 767         else if (bytes < 2*1024LL*1024LL*1024LL) {
 768                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 769                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 770                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 771                         cMiB/100 , cMiB % 100,
 772                         cMB/100, cMB % 100);
 773         } else {
 774                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 775                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 776                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 777                         cGiB/100 , cGiB % 100,
 778                         cGB/100, cGB % 100);
 779         }
 780         return buf;
 781 }
 782
 783 char *human_size_brief(long long bytes)
 784 {
 785         static char buf[30];
 786
 787         if (bytes < 5000*1024)
 788                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 789                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 790                         );
 791         else if (bytes < 2*1024LL*1024LL*1024LL)
 792                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 793                         (long)(bytes>>20),
 794                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 795                         );
 796         else
 797                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 798                         (long)(bytes>>30),
 799                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 800                         );
 801         return buf;
 802 }
 803
 804 void print_r10_layout(int layout)
 805 {
 806         int near = layout & 255;
 807         int far = (layout >> 8) & 255;
 808         int offset = (layout&0x10000);
 809         char *sep = "";
 810
 811         if (near != 1) {
 812                 printf("%s near=%d", sep, near);
 813                 sep = ",";
 814         }
 815         if (far != 1)
 816                 printf("%s %s=%d", sep, offset?"offset":"far", far);
 817         if (near*far == 1)
 818                 printf("NO REDUNDANCY");
 819 }
 820 #endif
 821
 822 unsigned long long calc_array_size(int level, int raid_disks, int layout,
 823                                    int chunksize, unsigned long long devsize)
 824 {
 825         int data_disks = 0;
 826         switch (level) {
 827         case 0: data_disks = raid_disks; break;
 828         case 1: data_disks = 1; break;
 829         case 4:
 830         case 5: data_disks = raid_disks - 1; break;
 831         case 6: data_disks = raid_disks - 2; break;
 832         case 10: data_disks = raid_disks / (layout & 255) / ((layout>>8)&255);
 833                 break;
 834         }
 835         devsize &= ~(unsigned long long)((chunksize>>9)-1);
 836         return data_disks * devsize;
 837 }
 838
 839 int get_mdp_major(void)
 840 {
 841 static int mdp_major = -1;
 842         FILE *fl;
 843         char *w;
 844         int have_block = 0;
 845         int have_devices = 0;
 846         int last_num = -1;
 847
 848         if (mdp_major != -1)
 849                 return mdp_major;
 850         fl = fopen("/proc/devices", "r");
 851         if (!fl)
 852                 return -1;
 853         while ((w = conf_word(fl, 1))) {
 854                 if (have_block && strcmp(w, "devices:")==0)
 855                         have_devices = 1;
 856                 have_block =  (strcmp(w, "Block")==0);
 857                 if (isdigit(w[0]))
 858                         last_num = atoi(w);
 859                 if (have_devices && strcmp(w, "mdp")==0)
 860                         mdp_major = last_num;
 861                 free(w);
 862         }
 863         fclose(fl);
 864         return mdp_major;
 865 }
 866
 867 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 868 char *get_md_name(int dev)
 869 {
 870         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 871         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 872         static char devname[50];
 873         struct stat stb;
 874         dev_t rdev;
 875         char *dn;
 876
 877         if (dev < 0) {
 878                 int mdp =  get_mdp_major();
 879                 if (mdp < 0) return NULL;
 880                 rdev = makedev(mdp, (-1-dev)<<6);
 881                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 882                 if (stat(devname, &stb) == 0
 883                     && (S_IFMT&stb.st_mode) == S_IFBLK
 884                     && (stb.st_rdev == rdev))
 885                         return devname;
 886         } else {
 887                 rdev = makedev(MD_MAJOR, dev);
 888                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 889                 if (stat(devname, &stb) == 0
 890                     && (S_IFMT&stb.st_mode) == S_IFBLK
 891                     && (stb.st_rdev == rdev))
 892                         return devname;
 893
 894                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 895                 if (stat(devname, &stb) == 0
 896                     && (S_IFMT&stb.st_mode) == S_IFBLK
 897                     && (stb.st_rdev == rdev))
 898                         return devname;
 899         }
 900         dn = map_dev(major(rdev), minor(rdev), 0);
 901         if (dn)
 902                 return dn;
 903         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 904         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 905                 if (errno != EEXIST)
 906                         return NULL;
 907
 908         if (stat(devname, &stb) == 0
 909             && (S_IFMT&stb.st_mode) == S_IFBLK
 910             && (stb.st_rdev == rdev))
 911                 return devname;
 912         unlink(devname);
 913         return NULL;
 914 }
 915
 916 void put_md_name(char *name)
 917 {
 918         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 919                 unlink(name);
 920 }
 921
 922 int find_free_devnum(int use_partitions)
 923 {
 924         int devnum;
 925         for (devnum = 127; devnum != 128;
 926              devnum = devnum ? devnum-1 : (1<<20)-1) {
 927                 char *dn;
 928                 int _devnum;
 929
 930                 _devnum = use_partitions ? (-1-devnum) : devnum;
 931                 if (mddev_busy(_devnum))
 932                         continue;
 933                 /* make sure it is new to /dev too, at least as a
 934                  * non-standard */
 935                 dn = map_dev(dev2major(_devnum), dev2minor(_devnum), 0);
 936                 if (dn && ! is_standard(dn, NULL))
 937                         continue;
 938                 break;
 939         }
 940         if (devnum == 128)
 941                 return NoMdDev;
 942         return use_partitions ? (-1-devnum) : devnum;
 943 }
 944 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 945
 946 int dev_open(char *dev, int flags)
 947 {
 948         /* like 'open', but if 'dev' matches %d:%d, create a temp
 949          * block device and open that
 950          */
 951         char *e;
 952         int fd = -1;
 953         char devname[32];
 954         int major;
 955         int minor;
 956
 957         if (!dev) return -1;
 958         flags |= O_DIRECT;
 959
 960         major = strtoul(dev, &e, 0);
 961         if (e > dev && *e == ':' && e[1] &&
 962             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 963             *e == 0) {
 964                 char *path = map_dev(major, minor, 0);
 965                 if (path)
 966                         fd = open(path, flags);
 967                 if (fd < 0) {
 968                         snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d:%d",
 969                                  (int)getpid(), major, minor);
 970                         if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 971                                 fd = open(devname, flags);
 972                                 unlink(devname);
 973                         }
 974                 }
 975                 if (fd < 0) {
 976                         snprintf(devname, sizeof(devname), "/tmp/.tmp.md.%d:%d:%d",
 977                                  (int)getpid(), major, minor);
 978                         if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 979                                 fd = open(devname, flags);
 980                                 unlink(devname);
 981                         }
 982                 }
 983         } else
 984                 fd = open(dev, flags);
 985         return fd;
 986 }
 987
 988 int open_dev(int devnum)
 989 {
 990         char buf[20];
 991
 992         sprintf(buf, "%d:%d", dev2major(devnum), dev2minor(devnum));
 993         return dev_open(buf, O_RDWR);
 994 }
 995
 996 int open_dev_excl(int devnum)
 997 {
 998         char buf[20];
 999         int i;
1000
1001         sprintf(buf, "%d:%d", dev2major(devnum), dev2minor(devnum));
1002         for (i=0 ; i<25 ; i++) {
1003                 int fd = dev_open(buf, O_RDWR|O_EXCL);
1004                 if (fd >= 0)
1005                         return fd;
1006                 if (errno != EBUSY)
1007                         return fd;
1008                 usleep(200000);
1009         }
1010         return -1;
1011 }
1012
1013 int same_dev(char *one, char *two)
1014 {
1015         struct stat st1, st2;
1016         if (stat(one, &st1) != 0)
1017                 return 0;
1018         if (stat(two, &st2) != 0)
1019                 return 0;
1020         if ((st1.st_mode & S_IFMT) != S_IFBLK)
1021                 return 0;
1022         if ((st2.st_mode & S_IFMT) != S_IFBLK)
1023                 return 0;
1024         return st1.st_rdev == st2.st_rdev;
1025 }
1026
1027 void wait_for(char *dev, int fd)
1028 {
1029         int i;
1030         struct stat stb_want;
1031
1032         if (fstat(fd, &stb_want) != 0 ||
1033             (stb_want.st_mode & S_IFMT) != S_IFBLK)
1034                 return;
1035
1036         for (i=0 ; i<25 ; i++) {
1037                 struct stat stb;
1038                 if (stat(dev, &stb) == 0 &&
1039                     (stb.st_mode & S_IFMT) == S_IFBLK &&
1040                     (stb.st_rdev == stb_want.st_rdev))
1041                         return;
1042                 usleep(200000);
1043         }
1044         if (i == 25)
1045                 dprintf("%s: timeout waiting for %s\n", __func__, dev);
1046 }
1047
1048 struct superswitch *superlist[] =
1049 {
1050         &super0, &super1,
1051         &super_ddf, &super_imsm,
1052         &mbr, &gpt,
1053         NULL };
1054
1055 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
1056
1057 struct supertype *super_by_fd(int fd, char **subarrayp)
1058 {
1059         mdu_array_info_t array;
1060         int vers;
1061         int minor;
1062         struct supertype *st = NULL;
1063         struct mdinfo *sra;
1064         char *verstr;
1065         char version[20];
1066         int i;
1067         char *subarray = NULL;
1068         int container = NoMdDev;
1069
1070         sra = sysfs_read(fd, 0, GET_VERSION);
1071
1072         if (sra) {
1073                 vers = sra->array.major_version;
1074                 minor = sra->array.minor_version;
1075                 verstr = sra->text_version;
1076         } else {
1077                 if (ioctl(fd, GET_ARRAY_INFO, &array))
1078                         array.major_version = array.minor_version = 0;
1079                 vers = array.major_version;
1080                 minor = array.minor_version;
1081                 verstr = "";
1082         }
1083
1084         if (vers != -1) {
1085                 sprintf(version, "%d.%d", vers, minor);
1086                 verstr = version;
1087         }
1088         if (minor == -2 && is_subarray(verstr)) {
1089                 char *dev = verstr+1;
1090
1091                 subarray = strchr(dev, '/');
1092                 if (subarray)
1093                         *subarray++ = '\0';
1094                 subarray = strdup(subarray);
1095                 container = devname2devnum(dev);
1096                 if (sra)
1097                         sysfs_free(sra);
1098                 sra = sysfs_read(-1, container, GET_VERSION);
1099                 if (sra && sra->text_version[0])
1100                         verstr = sra->text_version;
1101                 else
1102                         verstr = "-no-metadata-";
1103         }
1104
1105         for (i = 0; st == NULL && superlist[i] ; i++)
1106                 st = superlist[i]->match_metadata_desc(verstr);
1107
1108         if (sra)
1109                 sysfs_free(sra);
1110         if (st) {
1111                 st->sb = NULL;
1112                 if (subarrayp)
1113                         *subarrayp = subarray;
1114                 st->container_dev = container;
1115                 st->devnum = fd2devnum(fd);
1116         } else
1117                 free(subarray);
1118
1119         return st;
1120 }
1121 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
1122
1123 int dev_size_from_id(dev_t id, unsigned long long *size)
1124 {
1125         char buf[20];
1126         int fd;
1127
1128         sprintf(buf, "%d:%d", major(id), minor(id));
1129         fd = dev_open(buf, O_RDONLY);
1130         if (fd < 0)
1131                 return 0;
1132         if (get_dev_size(fd, NULL, size)) {
1133                 close(fd);
1134                 return 1;
1135         }
1136         close(fd);
1137         return 0;
1138 }
1139
1140 struct supertype *dup_super(struct supertype *orig)
1141 {
1142         struct supertype *st;
1143
1144         if (!orig)
1145                 return orig;
1146         st = malloc(sizeof(*st));
1147         if (!st)
1148                 return st;
1149         memset(st, 0, sizeof(*st));
1150         st->ss = orig->ss;
1151         st->max_devs = orig->max_devs;
1152         st->minor_version = orig->minor_version;
1153         st->sb = NULL;
1154         st->info = NULL;
1155         return st;
1156 }
1157
1158 struct supertype *guess_super_type(int fd, enum guess_types guess_type)
1159 {
1160         /* try each load_super to find the best match,
1161          * and return the best superswitch
1162          */
1163         struct superswitch  *ss;
1164         struct supertype *st;
1165         time_t besttime = 0;
1166         int bestsuper = -1;
1167         int i;
1168
1169         st = malloc(sizeof(*st));
1170         memset(st, 0, sizeof(*st));
1171         st->container_dev = NoMdDev;
1172
1173         for (i=0 ; superlist[i]; i++) {
1174                 int rv;
1175                 ss = superlist[i];
1176                 if (guess_type == guess_array && ss->add_to_super == NULL)
1177                         continue;
1178                 if (guess_type == guess_partitions && ss->add_to_super != NULL)
1179                         continue;
1180                 memset(st, 0, sizeof(*st));
1181                 rv = ss->load_super(st, fd, NULL);
1182                 if (rv == 0) {
1183                         struct mdinfo info;
1184                         st->ss->getinfo_super(st, &info, NULL);
1185                         if (bestsuper == -1 ||
1186                             besttime < info.array.ctime) {
1187                                 bestsuper = i;
1188                                 besttime = info.array.ctime;
1189                         }
1190                         ss->free_super(st);
1191                 }
1192         }
1193         if (bestsuper != -1) {
1194                 int rv;
1195                 memset(st, 0, sizeof(*st));
1196                 rv = superlist[bestsuper]->load_super(st, fd, NULL);
1197                 if (rv == 0) {
1198                         superlist[bestsuper]->free_super(st);
1199                         return st;
1200                 }
1201         }
1202         free(st);
1203         return NULL;
1204 }
1205
1206 /* Return size of device in bytes */
1207 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
1208 {
1209         unsigned long long ldsize;
1210         struct stat st;
1211
1212         if (fstat(fd, &st) != -1 && S_ISREG(st.st_mode))
1213                 ldsize = (unsigned long long)st.st_size;
1214         else
1215 #ifdef BLKGETSIZE64
1216         if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
1217 #endif
1218         {
1219                 unsigned long dsize;
1220                 if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
1221                         ldsize = dsize;
1222                         ldsize <<= 9;
1223                 } else {
1224                         if (dname)
1225                                 fprintf(stderr, Name ": Cannot get size of %s: %s\b",
1226                                         dname, strerror(errno));
1227                         return 0;
1228                 }
1229         }
1230         *sizep = ldsize;
1231         return 1;
1232 }
1233
1234 /* Return true if this can only be a container, not a member device.
1235  * i.e. is and md device and size is zero
1236  */
1237 int must_be_container(int fd)
1238 {
1239         unsigned long long size;
1240         if (md_get_version(fd) < 0)
1241                 return 0;
1242         if (get_dev_size(fd, NULL, &size) == 0)
1243                 return 1;
1244         if (size == 0)
1245                 return 1;
1246         return 0;
1247 }
1248
1249 /* Sets endofpart parameter to the last block used by the last GPT partition on the device.
1250  * Returns: 1 if successful
1251  *         -1 for unknown partition type
1252  *          0 for other errors
1253  */
1254 static int get_gpt_last_partition_end(int fd, unsigned long long *endofpart)
1255 {
1256         struct GPT gpt;
1257         unsigned char buf[512];
1258         unsigned char empty_gpt_entry[16]= {0};
1259         struct GPT_part_entry *part;
1260         unsigned long long curr_part_end;
1261         unsigned all_partitions, entry_size;
1262         unsigned part_nr;
1263
1264         *endofpart = 0;
1265
1266         BUILD_BUG_ON(sizeof(gpt) != 512);
1267         /* read GPT header */
1268         lseek(fd, 512, SEEK_SET);
1269         if (read(fd, &gpt, 512) != 512)
1270                 return 0;
1271
1272         /* get the number of partition entries and the entry size */
1273         all_partitions = __le32_to_cpu(gpt.part_cnt);
1274         entry_size = __le32_to_cpu(gpt.part_size);
1275
1276         /* Check GPT signature*/
1277         if (gpt.magic != GPT_SIGNATURE_MAGIC)
1278                 return -1;
1279
1280         /* sanity checks */
1281         if (all_partitions > 1024 ||
1282             entry_size > 512)
1283                 return -1;
1284
1285         /* read first GPT partition entries */
1286         if (read(fd, buf, 512) != 512)
1287                 return 0;
1288
1289         part = (struct GPT_part_entry*)buf;
1290
1291         for (part_nr=0; part_nr < all_partitions; part_nr++) {
1292                 /* is this valid partition? */
1293                 if (memcmp(part->type_guid, empty_gpt_entry, 16) != 0) {
1294                         /* check the last lba for the current partition */
1295                         curr_part_end = __le64_to_cpu(part->ending_lba);
1296                         if (curr_part_end > *endofpart)
1297                                 *endofpart = curr_part_end;
1298                 }
1299
1300                 part = (struct GPT_part_entry*)((unsigned char*)part + entry_size);
1301
1302                 if ((unsigned char *)part >= buf + 512) {
1303                         if (read(fd, buf, 512) != 512)
1304                                 return 0;
1305                         part = (struct GPT_part_entry*)buf;
1306                 }
1307         }
1308         return 1;
1309 }
1310
1311 /* Sets endofpart parameter to the last block used by the last partition on the device.
1312  * Returns: 1 if successful
1313  *         -1 for unknown partition type
1314  *          0 for other errors
1315  */
1316 static int get_last_partition_end(int fd, unsigned long long *endofpart)
1317 {
1318         struct MBR boot_sect;
1319         struct MBR_part_record *part;
1320         unsigned long long curr_part_end;
1321         unsigned part_nr;
1322         int retval = 0;
1323
1324         *endofpart = 0;
1325
1326         BUILD_BUG_ON(sizeof(boot_sect) != 512);
1327         /* read MBR */
1328         lseek(fd, 0, 0);
1329         if (read(fd, &boot_sect, 512) != 512)
1330                 goto abort;
1331
1332         /* check MBP signature */
1333         if (boot_sect.magic == MBR_SIGNATURE_MAGIC) {
1334                 retval = 1;
1335                 /* found the correct signature */
1336                 part = boot_sect.parts;
1337
1338                 for (part_nr=0; part_nr < MBR_PARTITIONS; part_nr++) {
1339                         /* check for GPT type */
1340                         if (part->part_type == MBR_GPT_PARTITION_TYPE) {
1341                                 retval = get_gpt_last_partition_end(fd, endofpart);
1342                                 break;
1343                         }
1344                         /* check the last used lba for the current partition  */
1345                         curr_part_end = __le32_to_cpu(part->first_sect_lba) +
1346                                 __le32_to_cpu(part->blocks_num);
1347                         if (curr_part_end > *endofpart)
1348                                 *endofpart = curr_part_end;
1349
1350                         part++;
1351                 }
1352         } else {
1353                 /* Unknown partition table */
1354                 retval = -1;
1355         }
1356  abort:
1357         return retval;
1358 }
1359
1360 int check_partitions(int fd, char *dname, unsigned long long freesize)
1361 {
1362         /*
1363          * Check where the last partition ends
1364          */
1365         unsigned long long endofpart;
1366         int ret;
1367
1368         if ((ret = get_last_partition_end(fd, &endofpart)) > 0) {
1369                 /* There appears to be a partition table here */
1370                 if (freesize == 0) {
1371                         /* partitions will not be visible in new device */
1372                         fprintf(stderr,
1373                                 Name ": partition table exists on %s but will be lost or\n"
1374                                 "       meaningless after creating array\n",
1375                                 dname);
1376                         return 1;
1377                 } else if (endofpart > freesize) {
1378                         /* last partition overlaps metadata */
1379                         fprintf(stderr,
1380                                 Name ": metadata will over-write last partition on %s.\n",
1381                                 dname);
1382                         return 1;
1383                 }
1384         }
1385         return 0;
1386 }
1387
1388 void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
1389 {
1390         int d;
1391         ioctl(mdfd, GET_ARRAY_INFO, ainf);
1392         for (d = 0 ; d < ainf->raid_disks + ainf->nr_disks ; d++)
1393                 if (ioctl(mdfd, GET_DISK_INFO, disk) == 0)
1394                         return;
1395 }
1396
1397 int open_container(int fd)
1398 {
1399         /* 'fd' is a block device.  Find out if it is in use
1400          * by a container, and return an open fd on that container.
1401          */
1402         char path[256];
1403         char *e;
1404         DIR *dir;
1405         struct dirent *de;
1406         int dfd, n;
1407         char buf[200];
1408         int major, minor;
1409         struct stat st;
1410
1411         if (fstat(fd, &st) != 0)
1412                 return -1;
1413         sprintf(path, "/sys/dev/block/%d:%d/holders",
1414                 (int)major(st.st_rdev), (int)minor(st.st_rdev));
1415         e = path + strlen(path);
1416
1417         dir = opendir(path);
1418         if (!dir)
1419                 return -1;
1420         while ((de = readdir(dir))) {
1421                 if (de->d_ino == 0)
1422                         continue;
1423                 if (de->d_name[0] == '.')
1424                         continue;
1425                 sprintf(e, "/%s/dev", de->d_name);
1426                 dfd = open(path, O_RDONLY);
1427                 if (dfd < 0)
1428                         continue;
1429                 n = read(dfd, buf, sizeof(buf));
1430                 close(dfd);
1431                 if (n <= 0 || (unsigned)n >= sizeof(buf))
1432                         continue;
1433                 buf[n] = 0;
1434                 if (sscanf(buf, "%d:%d", &major, &minor) != 2)
1435                         continue;
1436                 sprintf(buf, "%d:%d", major, minor);
1437                 dfd = dev_open(buf, O_RDONLY);
1438                 if (dfd >= 0) {
1439                         closedir(dir);
1440                         return dfd;
1441                 }
1442         }
1443         closedir(dir);
1444         return -1;
1445 }
1446
1447 struct superswitch *version_to_superswitch(char *vers)
1448 {
1449         int i;
1450
1451         for (i = 0; superlist[i]; i++) {
1452                 struct superswitch *ss = superlist[i];
1453
1454                 if (strcmp(vers, ss->name) == 0)
1455                         return ss;
1456         }
1457
1458         return NULL;
1459 }
1460
1461 int is_container_member(struct mdstat_ent *mdstat, char *container)
1462 {
1463         if (mdstat->metadata_version == NULL ||
1464             strncmp(mdstat->metadata_version, "external:", 9) != 0 ||
1465             !is_subarray(mdstat->metadata_version+9) ||
1466             strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 ||
1467             mdstat->metadata_version[10+strlen(container)] != '/')
1468                 return 0;
1469
1470         return 1;
1471 }
1472
1473 int is_subarray_active(char *subarray, char *container)
1474 {
1475         struct mdstat_ent *mdstat = mdstat_read(0, 0);
1476         struct mdstat_ent *ent;
1477
1478         for (ent = mdstat; ent; ent = ent->next)
1479                 if (is_container_member(ent, container))
1480                         if (!subarray ||
1481                             strcmp(to_subarray(ent, container), subarray) == 0)
1482                                 break;
1483
1484         free_mdstat(mdstat);
1485
1486         return ent != NULL;
1487 }
1488
1489 int is_container_active(char *container)
1490 {
1491         return is_subarray_active(NULL, container);
1492 }
1493
1494 /* open_subarray - opens a subarray in a container
1495  * @dev: container device name
1496  * @st: empty supertype
1497  * @quiet: block reporting errors flag
1498  *
1499  * On success returns an fd to a container and fills in *st
1500  */
1501 int open_subarray(char *dev, char *subarray, struct supertype *st, int quiet)
1502 {
1503         struct mdinfo *mdi;
1504         struct mdinfo *info;
1505         int fd, err = 1;
1506
1507         fd = open(dev, O_RDWR|O_EXCL);
1508         if (fd < 0) {
1509                 if (!quiet)
1510                         fprintf(stderr, Name ": Couldn't open %s, aborting\n",
1511                                 dev);
1512                 return 2;
1513         }
1514
1515         st->devnum = fd2devnum(fd);
1516         if (st->devnum == NoMdDev) {
1517                 if (!quiet)
1518                         fprintf(stderr,
1519                                 Name ": Failed to determine device number for %s\n",
1520                                 dev);
1521                 goto close_fd;
1522         }
1523
1524         mdi = sysfs_read(fd, st->devnum, GET_VERSION|GET_LEVEL);
1525         if (!mdi) {
1526                 if (!quiet)
1527                         fprintf(stderr, Name ": Failed to read sysfs for %s\n",
1528                                 dev);
1529                 goto close_fd;
1530         }
1531
1532         if (mdi->array.level != UnSet) {
1533                 if (!quiet)
1534                         fprintf(stderr, Name ": %s is not a container\n", dev);
1535                 goto free_sysfs;
1536         }
1537
1538         st->ss = version_to_superswitch(mdi->text_version);
1539         if (!st->ss) {
1540                 if (!quiet)
1541                         fprintf(stderr,
1542                                 Name ": Operation not supported for %s metadata\n",
1543                                 mdi->text_version);
1544                 goto free_sysfs;
1545         }
1546
1547         st->devname = devnum2devname(st->devnum);
1548         if (!st->devname) {
1549                 if (!quiet)
1550                         fprintf(stderr, Name ": Failed to allocate device name\n");
1551                 goto free_sysfs;
1552         }
1553
1554         if (!st->ss->load_container) {
1555                 if (!quiet)
1556                         fprintf(stderr, Name ": %s is not a container\n", dev);
1557                 goto free_name;
1558         }
1559
1560         if (st->ss->load_container(st, fd, NULL)) {
1561                 if (!quiet)
1562                         fprintf(stderr, Name ": Failed to load metadata for %s\n",
1563                                 dev);
1564                 goto free_name;
1565         }
1566
1567         info = st->ss->container_content(st, subarray);
1568         if (!info) {
1569                 if (!quiet)
1570                         fprintf(stderr, Name ": Failed to find subarray-%s in %s\n",
1571                                 subarray, dev);
1572                 goto free_super;
1573         }
1574         free(info);
1575
1576         err = 0;
1577
1578  free_super:
1579         if (err)
1580                 st->ss->free_super(st);
1581  free_name:
1582         if (err)
1583                 free(st->devname);
1584  free_sysfs:
1585         sysfs_free(mdi);
1586  close_fd:
1587         if (err)
1588                 close(fd);
1589
1590         if (err)
1591                 return -1;
1592         else
1593                 return fd;
1594 }
1595
1596 int add_disk(int mdfd, struct supertype *st,
1597              struct mdinfo *sra, struct mdinfo *info)
1598 {
1599         /* Add a device to an array, in one of 2 ways. */
1600         int rv;
1601 #ifndef MDASSEMBLE
1602         if (st->ss->external) {
1603                 if (info->disk.state & (1<<MD_DISK_SYNC))
1604                         info->recovery_start = MaxSector;
1605                 else
1606                         info->recovery_start = 0;
1607                 rv = sysfs_add_disk(sra, info, 0);
1608                 if (! rv) {
1609                         struct mdinfo *sd2;
1610                         for (sd2 = sra->devs; sd2; sd2=sd2->next)
1611                                 if (sd2 == info)
1612                                         break;
1613                         if (sd2 == NULL) {
1614                                 sd2 = malloc(sizeof(*sd2));
1615                                 *sd2 = *info;
1616                                 sd2->next = sra->devs;
1617                                 sra->devs = sd2;
1618                         }
1619                 }
1620         } else
1621 #endif
1622                 rv = ioctl(mdfd, ADD_NEW_DISK, &info->disk);
1623         return rv;
1624 }
1625
1626 int remove_disk(int mdfd, struct supertype *st,
1627                 struct mdinfo *sra, struct mdinfo *info)
1628 {
1629         int rv;
1630         /* Remove the disk given by 'info' from the array */
1631 #ifndef MDASSEMBLE
1632         if (st->ss->external)
1633                 rv = sysfs_set_str(sra, info, "slot", "none");
1634         else
1635 #endif
1636                 rv = ioctl(mdfd, HOT_REMOVE_DISK, makedev(info->disk.major,
1637                                                           info->disk.minor));
1638         return rv;
1639 }
1640
1641 int set_array_info(int mdfd, struct supertype *st, struct mdinfo *info)
1642 {
1643         /* Initialise kernel's knowledge of array.
1644          * This varies between externally managed arrays
1645          * and older kernels
1646          */
1647         int vers = md_get_version(mdfd);
1648         int rv;
1649
1650 #ifndef MDASSEMBLE
1651         if (st->ss->external)
1652                 rv = sysfs_set_array(info, vers);
1653         else
1654 #endif
1655                 if ((vers % 100) >= 1) { /* can use different versions */
1656                 mdu_array_info_t inf;
1657                 memset(&inf, 0, sizeof(inf));
1658                 inf.major_version = info->array.major_version;
1659                 inf.minor_version = info->array.minor_version;
1660                 rv = ioctl(mdfd, SET_ARRAY_INFO, &inf);
1661         } else
1662                 rv = ioctl(mdfd, SET_ARRAY_INFO, NULL);
1663         return rv;
1664 }
1665
1666 unsigned long long min_recovery_start(struct mdinfo *array)
1667 {
1668         /* find the minimum recovery_start in an array for metadata
1669          * formats that only record per-array recovery progress instead
1670          * of per-device
1671          */
1672         unsigned long long recovery_start = MaxSector;
1673         struct mdinfo *d;
1674
1675         for (d = array->devs; d; d = d->next)
1676                 recovery_start = min(recovery_start, d->recovery_start);
1677
1678         return recovery_start;
1679 }
1680
1681 void fmt_devname(char *name, int num)
1682 {
1683         if (num >= 0)
1684                 sprintf(name, "md%d", num);
1685         else
1686                 sprintf(name, "md_d%d", -1-num);
1687 }
1688
1689 char *devnum2devname(int num)
1690 {
1691         char name[100];
1692         fmt_devname(name,num);
1693         return strdup(name);
1694 }
1695
1696 int devname2devnum(char *name)
1697 {
1698         char *ep;
1699         int num;
1700         if (strncmp(name, "md_d", 4)==0)
1701                 num = -1-strtoul(name+4, &ep, 10);
1702         else
1703                 num = strtoul(name+2, &ep, 10);
1704         return num;
1705 }
1706
1707 int stat2devnum(struct stat *st)
1708 {
1709         char path[30];
1710         char link[200];
1711         char *cp;
1712         int n;
1713
1714         if ((S_IFMT & st->st_mode) == S_IFBLK) {
1715                 if (major(st->st_rdev) == MD_MAJOR)
1716                         return minor(st->st_rdev);
1717                 else if (major(st->st_rdev) == (unsigned)get_mdp_major())
1718                         return -1- (minor(st->st_rdev)>>MdpMinorShift);
1719
1720                 /* must be an extended-minor partition. Look at the
1721                  * /sys/dev/block/%d:%d link which must look like
1722                  * ../../block/mdXXX/mdXXXpYY
1723                  */
1724                 sprintf(path, "/sys/dev/block/%d:%d", major(st->st_rdev),
1725                         minor(st->st_rdev));
1726                 n = readlink(path, link, sizeof(link)-1);
1727                 if (n <= 0)
1728                         return NoMdDev;
1729                 link[n] = 0;
1730                 cp = strrchr(link, '/');
1731                 if (cp) *cp = 0;
1732                 cp = strchr(link, '/');
1733                 if (cp && strncmp(cp, "/md", 3) == 0)
1734                         return devname2devnum(cp+1);
1735         }
1736         return NoMdDev;
1737
1738 }
1739
1740 int fd2devnum(int fd)
1741 {
1742         struct stat stb;
1743         if (fstat(fd, &stb) == 0)
1744                 return stat2devnum(&stb);
1745         return NoMdDev;
1746 }
1747
1748 int mdmon_pid(int devnum)
1749 {
1750         char path[100];
1751         char pid[10];
1752         int fd;
1753         int n;
1754         char *devname = devnum2devname(devnum);
1755
1756         sprintf(path, "%s/%s.pid", MDMON_DIR, devname);
1757         free(devname);
1758
1759         fd = open(path, O_RDONLY | O_NOATIME, 0);
1760
1761         if (fd < 0)
1762                 return -1;
1763         n = read(fd, pid, 9);
1764         close(fd);
1765         if (n <= 0)
1766                 return -1;
1767         return atoi(pid);
1768 }
1769
1770 int mdmon_running(int devnum)
1771 {
1772         int pid = mdmon_pid(devnum);
1773         if (pid <= 0)
1774                 return 0;
1775         if (kill(pid, 0) == 0)
1776                 return 1;
1777         return 0;
1778 }
1779
1780 int start_mdmon(int devnum)
1781 {
1782         int i;
1783         int len;
1784         pid_t pid;
1785         int status;
1786         char pathbuf[1024];
1787         char *paths[4] = {
1788                 pathbuf,
1789                 "/sbin/mdmon",
1790                 "mdmon",
1791                 NULL
1792         };
1793
1794         if (check_env("MDADM_NO_MDMON"))
1795                 return 0;
1796
1797         len = readlink("/proc/self/exe", pathbuf, sizeof(pathbuf));
1798         if (len > 0) {
1799                 char *sl;
1800                 pathbuf[len] = 0;
1801                 sl = strrchr(pathbuf, '/');
1802                 if (sl)
1803                         sl++;
1804                 else
1805                         sl = pathbuf;
1806                 strcpy(sl, "mdmon");
1807         } else
1808                 pathbuf[0] = '\0';
1809
1810         switch(fork()) {
1811         case 0:
1812                 /* FIXME yuk. CLOSE_EXEC?? */
1813                 for (i=3; i < 100; i++)
1814                         close(i);
1815                 for (i=0; paths[i]; i++)
1816                         if (paths[i][0])
1817                                 execl(paths[i], "mdmon",
1818                                       devnum2devname(devnum),
1819                                       NULL);
1820                 exit(1);
1821         case -1: fprintf(stderr, Name ": cannot run mdmon. "
1822                          "Array remains readonly\n");
1823                 return -1;
1824         default: /* parent - good */
1825                 pid = wait(&status);
1826                 if (pid < 0 || status != 0)
1827                         return -1;
1828         }
1829         return 0;
1830 }
1831
1832 int check_env(char *name)
1833 {
1834         char *val = getenv(name);
1835
1836         if (val && atoi(val) == 1)
1837                 return 1;
1838
1839         return 0;
1840 }
1841
1842 __u32 random32(void)
1843 {
1844         __u32 rv;
1845         int rfd = open("/dev/urandom", O_RDONLY);
1846         if (rfd < 0 || read(rfd, &rv, 4) != 4)
1847                 rv = random();
1848         if (rfd >= 0)
1849                 close(rfd);
1850         return rv;
1851 }
1852
1853 #ifndef MDASSEMBLE
1854 int flush_metadata_updates(struct supertype *st)
1855 {
1856         int sfd;
1857         if (!st->updates) {
1858                 st->update_tail = NULL;
1859                 return -1;
1860         }
1861
1862         sfd = connect_monitor(devnum2devname(st->container_dev));
1863         if (sfd < 0)
1864                 return -1;
1865
1866         while (st->updates) {
1867                 struct metadata_update *mu = st->updates;
1868                 st->updates = mu->next;
1869
1870                 send_message(sfd, mu, 0);
1871                 wait_reply(sfd, 0);
1872                 free(mu->buf);
1873                 free(mu);
1874         }
1875         ack(sfd, 0);
1876         wait_reply(sfd, 0);
1877         close(sfd);
1878         st->update_tail = NULL;
1879         return 0;
1880 }
1881
1882 void append_metadata_update(struct supertype *st, void *buf, int len)
1883 {
1884
1885         struct metadata_update *mu = malloc(sizeof(*mu));
1886
1887         mu->buf = buf;
1888         mu->len = len;
1889         mu->space = NULL;
1890         mu->space_list = NULL;
1891         mu->next = NULL;
1892         *st->update_tail = mu;
1893         st->update_tail = &mu->next;
1894 }
1895 #endif /* MDASSEMBLE */
1896
1897 #ifdef __TINYC__
1898 /* tinyc doesn't optimize this check in ioctl.h out ... */
1899 unsigned int __invalid_size_argument_for_IOC = 0;
1900 #endif
1901
1902 int experimental(void)
1903 {
1904         if (check_env("MDADM_EXPERIMENTAL"))
1905                 return 1;
1906         else {
1907                 fprintf(stderr, Name ": To use this feature MDADM_EXPERIMENTAL enviroment variable has to defined.\n");
1908                 return 0;
1909         }
1910 }
1911