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/socket.h>
  33 #include        <sys/utsname.h>
  34 #include        <sys/wait.h>
  35 #include        <sys/un.h>
  36 #include        <ctype.h>
  37 #include        <dirent.h>
  38 #include        <signal.h>
  39
  40 /*
  41  * following taken from linux/blkpg.h because they aren't
  42  * anywhere else and it isn't safe to #include linux/ * stuff.
  43  */
  44
  45 #define BLKPG      _IO(0x12,105)
  46
  47 /* The argument structure */
  48 struct blkpg_ioctl_arg {
  49         int op;
  50         int flags;
  51         int datalen;
  52         void *data;
  53 };
  54
  55 /* The subfunctions (for the op field) */
  56 #define BLKPG_ADD_PARTITION     1
  57 #define BLKPG_DEL_PARTITION     2
  58
  59 /* Sizes of name fields. Unused at present. */
  60 #define BLKPG_DEVNAMELTH        64
  61 #define BLKPG_VOLNAMELTH        64
  62
  63 /* The data structure for ADD_PARTITION and DEL_PARTITION */
  64 struct blkpg_partition {
  65         long long start;                /* starting offset in bytes */
  66         long long length;               /* length in bytes */
  67         int pno;                        /* partition number */
  68         char devname[BLKPG_DEVNAMELTH]; /* partition name, like sda5 or c0d1p2,
  69                                            to be used in kernel messages */
  70         char volname[BLKPG_VOLNAMELTH]; /* volume label */
  71 };
  72
  73 /*
  74  * Parse a 128 bit uuid in 4 integers
  75  * format is 32 hexx nibbles with options :.<space> separator
  76  * If not exactly 32 hex digits are found, return 0
  77  * else return 1
  78  */
  79 int parse_uuid(char *str, int uuid[4])
  80 {
  81         int hit = 0; /* number of Hex digIT */
  82         int i;
  83         char c;
  84         for (i=0; i<4; i++) uuid[i]=0;
  85
  86         while ((c= *str++)) {
  87                 int n;
  88                 if (c>='0' && c<='9')
  89                         n = c-'0';
  90                 else if (c>='a' && c <= 'f')
  91                         n = 10 + c - 'a';
  92                 else if (c>='A' && c <= 'F')
  93                         n = 10 + c - 'A';
  94                 else if (strchr(":. -", c))
  95                         continue;
  96                 else return 0;
  97
  98                 if (hit<32) {
  99                         uuid[hit/8] <<= 4;
 100                         uuid[hit/8] += n;
 101                 }
 102                 hit++;
 103         }
 104         if (hit == 32)
 105                 return 1;
 106         return 0;
 107 }
 108
 109
 110 /*
 111  * Get the md version number.
 112  * We use the RAID_VERSION ioctl if it is supported
 113  * If not, but we have a block device with major '9', we assume
 114  * 0.36.0
 115  *
 116  * Return version number as 24 but number - assume version parts
 117  * always < 255
 118  */
 119
 120 int md_get_version(int fd)
 121 {
 122     struct stat stb;
 123     mdu_version_t vers;
 124
 125     if (fstat(fd, &stb)<0)
 126         return -1;
 127     if ((S_IFMT&stb.st_mode) != S_IFBLK)
 128         return -1;
 129
 130     if (ioctl(fd, RAID_VERSION, &vers) == 0)
 131         return  (vers.major*10000) + (vers.minor*100) + vers.patchlevel;
 132     if (errno == EACCES)
 133             return -1;
 134     if (major(stb.st_rdev) == MD_MAJOR)
 135         return (3600);
 136     return -1;
 137 }
 138
 139 int get_linux_version()
 140 {
 141         struct utsname name;
 142         char *cp;
 143         int a,b,c;
 144         if (uname(&name) <0)
 145                 return -1;
 146
 147         cp = name.release;
 148         a = strtoul(cp, &cp, 10);
 149         if (*cp != '.') return -1;
 150         b = strtoul(cp+1, &cp, 10);
 151         if (*cp != '.') return -1;
 152         c = strtoul(cp+1, NULL, 10);
 153
 154         return (a*1000000)+(b*1000)+c;
 155 }
 156
 157 void remove_partitions(int fd)
 158 {
 159         /* remove partitions from this block devices.
 160          * This is used for components added to an array
 161          */
 162 #ifdef BLKPG_DEL_PARTITION
 163         struct blkpg_ioctl_arg a;
 164         struct blkpg_partition p;
 165
 166         a.op = BLKPG_DEL_PARTITION;
 167         a.data = (void*)&p;
 168         a.datalen = sizeof(p);
 169         a.flags = 0;
 170         memset(a.data, 0, a.datalen);
 171         for (p.pno=0; p.pno < 16; p.pno++)
 172                 ioctl(fd, BLKPG, &a);
 173 #endif
 174 }
 175
 176 int enough(int level, int raid_disks, int layout, int clean,
 177            char *avail, int avail_disks)
 178 {
 179         int copies, first;
 180         switch (level) {
 181         case 10:
 182                 /* This is the tricky one - we need to check
 183                  * which actual disks are present.
 184                  */
 185                 copies = (layout&255)* ((layout>>8) & 255);
 186                 first=0;
 187                 do {
 188                         /* there must be one of the 'copies' form 'first' */
 189                         int n = copies;
 190                         int cnt=0;
 191                         while (n--) {
 192                                 if (avail[first])
 193                                         cnt++;
 194                                 first = (first+1) % raid_disks;
 195                         }
 196                         if (cnt == 0)
 197                                 return 0;
 198
 199                 } while (first != 0);
 200                 return 1;
 201
 202         case -4:
 203                 return avail_disks>= 1;
 204         case -1:
 205         case 0:
 206                 return avail_disks == raid_disks;
 207         case 1:
 208                 return avail_disks >= 1;
 209         case 4:
 210         case 5:
 211                 if (clean)
 212                         return avail_disks >= raid_disks-1;
 213                 else
 214                         return avail_disks >= raid_disks;
 215         case 6:
 216                 if (clean)
 217                         return avail_disks >= raid_disks-2;
 218                 else
 219                         return avail_disks >= raid_disks;
 220         default:
 221                 return 0;
 222         }
 223 }
 224
 225 int same_uuid(int a[4], int b[4], int swapuuid)
 226 {
 227         if (swapuuid) {
 228                 /* parse uuids are hostendian.
 229                  * uuid's from some superblocks are big-ending
 230                  * if there is a difference, we need to swap..
 231                  */
 232                 unsigned char *ac = (unsigned char *)a;
 233                 unsigned char *bc = (unsigned char *)b;
 234                 int i;
 235                 for (i=0; i<16; i+= 4) {
 236                         if (ac[i+0] != bc[i+3] ||
 237                             ac[i+1] != bc[i+2] ||
 238                             ac[i+2] != bc[i+1] ||
 239                             ac[i+3] != bc[i+0])
 240                                 return 0;
 241                 }
 242                 return 1;
 243         } else {
 244                 if (a[0]==b[0] &&
 245                     a[1]==b[1] &&
 246                     a[2]==b[2] &&
 247                     a[3]==b[3])
 248                         return 1;
 249                 return 0;
 250         }
 251 }
 252 void copy_uuid(void *a, int b[4], int swapuuid)
 253 {
 254         if (swapuuid) {
 255                 /* parse uuids are hostendian.
 256                  * uuid's from some superblocks are big-ending
 257                  * if there is a difference, we need to swap..
 258                  */
 259                 unsigned char *ac = (unsigned char *)a;
 260                 unsigned char *bc = (unsigned char *)b;
 261                 int i;
 262                 for (i=0; i<16; i+= 4) {
 263                         ac[i+0] = bc[i+3];
 264                         ac[i+1] = bc[i+2];
 265                         ac[i+2] = bc[i+1];
 266                         ac[i+3] = bc[i+0];
 267                 }
 268         } else
 269                 memcpy(a, b, 16);
 270 }
 271
 272 char *fname_from_uuid(struct supertype *st, struct mdinfo *info, char *buf)
 273 {
 274         int i;
 275         char uuid[16];
 276         char *c = buf;
 277         strcpy(c, "UUID-");
 278         c += strlen(c);
 279         copy_uuid(uuid, info->uuid, st->ss->swapuuid);
 280         for (i=0; i<16; i++) {
 281                 if (i && (i&3)==0) {
 282                         strcpy(c, "-");
 283                         c++;
 284                 }
 285                 sprintf(c,"%02x", (unsigned char)uuid[i]);
 286                 c+= 2;
 287         }
 288         return buf;
 289 }
 290
 291 #ifndef MDASSEMBLE
 292 int check_ext2(int fd, char *name)
 293 {
 294         /*
 295          * Check for an ext2fs file system.
 296          * Superblock is always 1K at 1K offset
 297          *
 298          * s_magic is le16 at 56 == 0xEF53
 299          * report mtime - le32 at 44
 300          * blocks - le32 at 4
 301          * logblksize - le32 at 24
 302          */
 303         unsigned char sb[1024];
 304         time_t mtime;
 305         int size, bsize;
 306         if (lseek(fd, 1024,0)!= 1024)
 307                 return 0;
 308         if (read(fd, sb, 1024)!= 1024)
 309                 return 0;
 310         if (sb[56] != 0x53 || sb[57] != 0xef)
 311                 return 0;
 312
 313         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 314         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 315         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 316         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 317                 name);
 318         fprintf(stderr,"    size=%dK  mtime=%s",
 319                 size*(1<<bsize), ctime(&mtime));
 320         return 1;
 321 }
 322
 323 int check_reiser(int fd, char *name)
 324 {
 325         /*
 326          * superblock is at 64K
 327          * size is 1024;
 328          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 329          *
 330          */
 331         unsigned char sb[1024];
 332         unsigned long size;
 333         if (lseek(fd, 64*1024, 0) != 64*1024)
 334                 return 0;
 335         if (read(fd, sb, 1024) != 1024)
 336                 return 0;
 337         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 338             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 339                 return 0;
 340         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 341         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 342         fprintf(stderr, "    size = %luK\n", size*4);
 343
 344         return 1;
 345 }
 346
 347 int check_raid(int fd, char *name)
 348 {
 349         struct mdinfo info;
 350         time_t crtime;
 351         char *level;
 352         struct supertype *st = guess_super(fd);
 353
 354         if (!st) return 0;
 355         st->ss->load_super(st, fd, name);
 356         /* Looks like a raid array .. */
 357         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 358                 name);
 359         st->ss->getinfo_super(st, &info);
 360         st->ss->free_super(st);
 361         crtime = info.array.ctime;
 362         level = map_num(pers, info.array.level);
 363         if (!level) level = "-unknown-";
 364         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 365                 level, info.array.raid_disks, ctime(&crtime));
 366         return 1;
 367 }
 368
 369 int ask(char *mesg)
 370 {
 371         char *add = "";
 372         int i;
 373         for (i=0; i<5; i++) {
 374                 char buf[100];
 375                 fprintf(stderr, "%s%s", mesg, add);
 376                 fflush(stderr);
 377                 if (fgets(buf, 100, stdin)==NULL)
 378                         return 0;
 379                 if (buf[0]=='y' || buf[0]=='Y')
 380                         return 1;
 381                 if (buf[0]=='n' || buf[0]=='N')
 382                         return 0;
 383                 add = "(y/n) ";
 384         }
 385         fprintf(stderr, Name ": assuming 'no'\n");
 386         return 0;
 387 }
 388 #endif /* MDASSEMBLE */
 389
 390 char *map_num(mapping_t *map, int num)
 391 {
 392         while (map->name) {
 393                 if (map->num == num)
 394                         return map->name;
 395                 map++;
 396         }
 397         return NULL;
 398 }
 399
 400 int map_name(mapping_t *map, char *name)
 401 {
 402         while (map->name) {
 403                 if (strcmp(map->name, name)==0)
 404                         return map->num;
 405                 map++;
 406         }
 407         return UnSet;
 408 }
 409
 410
 411 int is_standard(char *dev, int *nump)
 412 {
 413         /* tests if dev is a "standard" md dev name.
 414          * i.e if the last component is "/dNN" or "/mdNN",
 415          * where NN is a string of digits
 416          * Returns 1 if a partitionable standard,
 417          *   -1 if non-partitonable,
 418          *   0 if not a standard name.
 419          */
 420         char *d = strrchr(dev, '/');
 421         int type=0;
 422         int num;
 423         if (!d)
 424                 return 0;
 425         if (strncmp(d, "/d",2)==0)
 426                 d += 2, type=1; /* /dev/md/dN{pM} */
 427         else if (strncmp(d, "/md_d", 5)==0)
 428                 d += 5, type=1; /* /dev/md_dNpM */
 429         else if (strncmp(d, "/md", 3)==0)
 430                 d += 3, type=-1; /* /dev/mdN */
 431         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 432                 d += 1, type=-1; /* /dev/md/N */
 433         else
 434                 return 0;
 435         if (!*d)
 436                 return 0;
 437         num = atoi(d);
 438         while (isdigit(*d))
 439                 d++;
 440         if (*d)
 441                 return 0;
 442         if (nump) *nump = num;
 443
 444         return type;
 445 }
 446
 447
 448 /*
 449  * convert a major/minor pair for a block device into a name in /dev, if possible.
 450  * On the first call, walk /dev collecting name.
 451  * Put them in a simple linked listfor now.
 452  */
 453 struct devmap {
 454     int major, minor;
 455     char *name;
 456     struct devmap *next;
 457 } *devlist = NULL;
 458 int devlist_ready = 0;
 459
 460 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 461 {
 462         struct stat st;
 463         if (S_ISLNK(stb->st_mode)) {
 464                 stat(name, &st);
 465                 stb = &st;
 466         }
 467
 468         if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 469                 char *n = strdup(name);
 470                 struct devmap *dm = malloc(sizeof(*dm));
 471                 if (strncmp(n, "/dev/./", 7)==0)
 472                         strcpy(n+4, name+6);
 473                 if (dm) {
 474                         dm->major = major(stb->st_rdev);
 475                         dm->minor = minor(stb->st_rdev);
 476                         dm->name = n;
 477                         dm->next = devlist;
 478                         devlist = dm;
 479                 }
 480         }
 481         return 0;
 482 }
 483
 484 #ifndef HAVE_NFTW
 485 #ifdef HAVE_FTW
 486 int add_dev_1(const char *name, const struct stat *stb, int flag)
 487 {
 488         return add_dev(name, stb, flag, NULL);
 489 }
 490 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 491 {
 492         return ftw(path, add_dev_1, nopenfd);
 493 }
 494 #else
 495 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 496 {
 497         return 0;
 498 }
 499 #endif /* HAVE_FTW */
 500 #endif /* HAVE_NFTW */
 501
 502 /*
 503  * Find a block device with the right major/minor number.
 504  * If we find multiple names, choose the shortest.
 505  * If we find a non-standard name, it is probably there
 506  * deliberately so prefer it over a standard name.
 507  * This applies only to names for MD devices.
 508  */
 509 char *map_dev(int major, int minor, int create)
 510 {
 511         struct devmap *p;
 512         char *std = NULL, *nonstd=NULL;
 513         int did_check = 0;
 514
 515         if (major == 0 && minor == 0)
 516                         return NULL;
 517
 518  retry:
 519         if (!devlist_ready) {
 520                 char *dev = "/dev";
 521                 struct stat stb;
 522                 while(devlist) {
 523                         struct devmap *d = devlist;
 524                         devlist = d->next;
 525                         free(d->name);
 526                         free(d);
 527                 }
 528                 if (lstat(dev, &stb)==0 &&
 529                     S_ISLNK(stb.st_mode))
 530                         dev = "/dev/.";
 531                 nftw(dev, add_dev, 10, FTW_PHYS);
 532                 devlist_ready=1;
 533                 did_check = 1;
 534         }
 535
 536         for (p=devlist; p; p=p->next)
 537                 if (p->major == major &&
 538                     p->minor == minor) {
 539                         if (is_standard(p->name, NULL)) {
 540                                 if (std == NULL ||
 541                                     strlen(p->name) < strlen(std))
 542                                         std = p->name;
 543                         } else {
 544                                 if (nonstd == NULL ||
 545                                     strlen(p->name) < strlen(nonstd))
 546                                         nonstd = p->name;
 547                         }
 548                 }
 549         if (!std && !nonstd && !did_check) {
 550                 devlist_ready = 0;
 551                 goto retry;
 552         }
 553         if (create && !std && !nonstd) {
 554                 static char buf[30];
 555                 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
 556                 nonstd = buf;
 557         }
 558
 559         return nonstd ? nonstd : std;
 560 }
 561
 562 unsigned long calc_csum(void *super, int bytes)
 563 {
 564         unsigned long long newcsum = 0;
 565         int i;
 566         unsigned int csum;
 567         unsigned int *superc = (unsigned int*) super;
 568
 569         for(i=0; i<bytes/4; i++)
 570                 newcsum+= superc[i];
 571         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 572 #ifdef __alpha__
 573 /* The in-kernel checksum calculation is always 16bit on
 574  * the alpha, though it is 32 bit on i386...
 575  * I wonder what it is elsewhere... (it uses and API in
 576  * a way that it shouldn't).
 577  */
 578         csum = (csum & 0xffff) + (csum >> 16);
 579         csum = (csum & 0xffff) + (csum >> 16);
 580 #endif
 581         return csum;
 582 }
 583
 584 #ifndef MDASSEMBLE
 585 char *human_size(long long bytes)
 586 {
 587         static char buf[30];
 588
 589         /* We convert bytes to either centi-M{ega,ibi}bytes or
 590          * centi-G{igi,ibi}bytes, with appropriate rounding,
 591          * and then print 1/100th of those as a decimal.
 592          * We allow upto 2048Megabytes before converting to
 593          * gigabytes, as that shows more precision and isn't
 594          * too large a number.
 595          * Terrabytes are not yet handled.
 596          */
 597
 598         if (bytes < 5000*1024)
 599                 buf[0]=0;
 600         else if (bytes < 2*1024LL*1024LL*1024LL) {
 601                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 602                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 603                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 604                         cMiB/100 , cMiB % 100,
 605                         cMB/100, cMB % 100);
 606         } else {
 607                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 608                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 609                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 610                         cGiB/100 , cGiB % 100,
 611                         cGB/100, cGB % 100);
 612         }
 613         return buf;
 614 }
 615
 616 char *human_size_brief(long long bytes)
 617 {
 618         static char buf[30];
 619
 620         if (bytes < 5000*1024)
 621                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 622                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 623                         );
 624         else if (bytes < 2*1024LL*1024LL*1024LL)
 625                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 626                         (long)(bytes>>20),
 627                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 628                         );
 629         else
 630                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 631                         (long)(bytes>>30),
 632                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 633                         );
 634         return buf;
 635 }
 636 #endif
 637
 638 unsigned long long calc_array_size(int level, int raid_disks, int layout,
 639                                    int chunksize, unsigned long long devsize)
 640 {
 641         int data_disks = 0;
 642         switch (level) {
 643         case 0: data_disks = raid_disks; break;
 644         case 1: data_disks = 1; break;
 645         case 4:
 646         case 5: data_disks = raid_disks - 1; break;
 647         case 6: data_disks = raid_disks - 2; break;
 648         case 10: data_disks = raid_disks / (layout & 255) / ((layout>>8)&255);
 649                 break;
 650         }
 651         devsize &= ~(unsigned long long)((chunksize>>9)-1);
 652         return data_disks * devsize;
 653 }
 654
 655 int get_mdp_major(void)
 656 {
 657 static int mdp_major = -1;
 658         FILE *fl;
 659         char *w;
 660         int have_block = 0;
 661         int have_devices = 0;
 662         int last_num = -1;
 663
 664         if (mdp_major != -1)
 665                 return mdp_major;
 666         fl = fopen("/proc/devices", "r");
 667         if (!fl)
 668                 return -1;
 669         while ((w = conf_word(fl, 1))) {
 670                 if (have_block && strcmp(w, "devices:")==0)
 671                         have_devices = 1;
 672                 have_block =  (strcmp(w, "Block")==0);
 673                 if (isdigit(w[0]))
 674                         last_num = atoi(w);
 675                 if (have_devices && strcmp(w, "mdp")==0)
 676                         mdp_major = last_num;
 677                 free(w);
 678         }
 679         fclose(fl);
 680         return mdp_major;
 681 }
 682
 683 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 684 char *get_md_name(int dev)
 685 {
 686         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 687         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 688         static char devname[50];
 689         struct stat stb;
 690         dev_t rdev;
 691         char *dn;
 692
 693         if (dev < 0) {
 694                 int mdp =  get_mdp_major();
 695                 if (mdp < 0) return NULL;
 696                 rdev = makedev(mdp, (-1-dev)<<6);
 697                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 698                 if (stat(devname, &stb) == 0
 699                     && (S_IFMT&stb.st_mode) == S_IFBLK
 700                     && (stb.st_rdev == rdev))
 701                         return devname;
 702         } else {
 703                 rdev = makedev(MD_MAJOR, dev);
 704                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 705                 if (stat(devname, &stb) == 0
 706                     && (S_IFMT&stb.st_mode) == S_IFBLK
 707                     && (stb.st_rdev == rdev))
 708                         return devname;
 709
 710                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 711                 if (stat(devname, &stb) == 0
 712                     && (S_IFMT&stb.st_mode) == S_IFBLK
 713                     && (stb.st_rdev == rdev))
 714                         return devname;
 715         }
 716         dn = map_dev(major(rdev), minor(rdev), 0);
 717         if (dn)
 718                 return dn;
 719         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 720         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 721                 if (errno != EEXIST)
 722                         return NULL;
 723
 724         if (stat(devname, &stb) == 0
 725             && (S_IFMT&stb.st_mode) == S_IFBLK
 726             && (stb.st_rdev == rdev))
 727                 return devname;
 728         unlink(devname);
 729         return NULL;
 730 }
 731
 732 void put_md_name(char *name)
 733 {
 734         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 735                 unlink(name);
 736 }
 737
 738 int find_free_devnum(int use_partitions)
 739 {
 740         int devnum;
 741         for (devnum = 127; devnum != 128;
 742              devnum = devnum ? devnum-1 : (1<<22)-1) {
 743                 char *dn;
 744                 int _devnum;
 745
 746                 _devnum = use_partitions ? (-1-devnum) : devnum;
 747                 if (mddev_busy(_devnum))
 748                         continue;
 749                 /* make sure it is new to /dev too, at least as a
 750                  * non-standard */
 751                 dn = map_dev(dev2major(_devnum), dev2minor(_devnum), 0);
 752                 if (dn && ! is_standard(dn, NULL))
 753                         continue;
 754                 break;
 755         }
 756         if (devnum == 128)
 757                 return NoMdDev;
 758         return use_partitions ? (-1-devnum) : devnum;
 759 }
 760 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 761
 762 int dev_open(char *dev, int flags)
 763 {
 764         /* like 'open', but if 'dev' matches %d:%d, create a temp
 765          * block device and open that
 766          */
 767         char *e;
 768         int fd = -1;
 769         char devname[32];
 770         int major;
 771         int minor;
 772
 773         if (!dev) return -1;
 774
 775         major = strtoul(dev, &e, 0);
 776         if (e > dev && *e == ':' && e[1] &&
 777             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 778             *e == 0) {
 779                 snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d:%d",
 780                          (int)getpid(), major, minor);
 781                 if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 782                         fd = open(devname, flags|O_DIRECT);
 783                         unlink(devname);
 784                 }
 785         } else
 786                 fd = open(dev, flags|O_DIRECT);
 787         return fd;
 788 }
 789
 790 int open_dev_excl(int devnum)
 791 {
 792         char buf[20];
 793         int i;
 794
 795         sprintf(buf, "%d:%d", dev2major(devnum), dev2minor(devnum));
 796         for (i=0 ; i<25 ; i++) {
 797                 int fd = dev_open(buf, O_RDWR|O_EXCL);
 798                 if (fd >= 0)
 799                         return fd;
 800                 if (errno != EBUSY)
 801                         return fd;
 802                 usleep(200000);
 803         }
 804         return -1;
 805 }
 806
 807 struct superswitch *superlist[] = { &super0, &super1, &super_ddf, &super_imsm, NULL };
 808
 809 #if !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO)
 810
 811 struct supertype *super_by_fd(int fd)
 812 {
 813         mdu_array_info_t array;
 814         int vers;
 815         int minor;
 816         struct supertype *st = NULL;
 817         struct mdinfo *sra;
 818         char *verstr;
 819         char version[20];
 820         int i;
 821         char *subarray = NULL;
 822
 823         sra = sysfs_read(fd, 0, GET_VERSION);
 824
 825         if (sra) {
 826                 vers = sra->array.major_version;
 827                 minor = sra->array.minor_version;
 828                 verstr = sra->text_version;
 829         } else {
 830                 if (ioctl(fd, GET_ARRAY_INFO, &array))
 831                         array.major_version = array.minor_version = 0;
 832                 vers = array.major_version;
 833                 minor = array.minor_version;
 834                 verstr = "";
 835         }
 836
 837         if (vers != -1) {
 838                 sprintf(version, "%d.%d", vers, minor);
 839                 verstr = version;
 840         }
 841         if (minor == -2 && is_subarray(verstr)) {
 842                 char *dev = verstr+1;
 843                 subarray = strchr(dev, '/');
 844                 int devnum;
 845                 if (subarray)
 846                         *subarray++ = '\0';
 847                 devnum = devname2devnum(dev);
 848                 subarray = strdup(subarray);
 849                 if (sra)
 850                         sysfs_free(sra);
 851                 sra = sysfs_read(-1, devnum, GET_VERSION);
 852                 verstr = sra->text_version ? : "-no-metadata-";
 853         }
 854
 855         for (i = 0; st == NULL && superlist[i] ; i++)
 856                 st = superlist[i]->match_metadata_desc(verstr);
 857
 858         if (sra)
 859                 sysfs_free(sra);
 860         if (st) {
 861                 st->sb = NULL;
 862                 if (subarray) {
 863                         strncpy(st->subarray, subarray, 32);
 864                         st->subarray[31] = 0;
 865                         free(subarray);
 866                 } else
 867                         st->subarray[0] = 0;
 868         }
 869         return st;
 870 }
 871 #endif /* !defined(MDASSEMBLE) || defined(MDASSEMBLE) && defined(MDASSEMBLE_AUTO) */
 872
 873
 874 struct supertype *dup_super(struct supertype *orig)
 875 {
 876         struct supertype *st;
 877
 878         if (!orig)
 879                 return orig;
 880         st = malloc(sizeof(*st));
 881         if (!st)
 882                 return st;
 883         memset(st, 0, sizeof(*st));
 884         st->ss = orig->ss;
 885         st->max_devs = orig->max_devs;
 886         st->minor_version = orig->minor_version;
 887         strcpy(st->subarray, orig->subarray);
 888         st->sb = NULL;
 889         st->info = NULL;
 890         return st;
 891 }
 892
 893 struct supertype *guess_super(int fd)
 894 {
 895         /* try each load_super to find the best match,
 896          * and return the best superswitch
 897          */
 898         struct superswitch  *ss;
 899         struct supertype *st;
 900         unsigned long besttime = 0;
 901         int bestsuper = -1;
 902         int i;
 903
 904         st = malloc(sizeof(*st));
 905         for (i=0 ; superlist[i]; i++) {
 906                 int rv;
 907                 ss = superlist[i];
 908                 memset(st, 0, sizeof(*st));
 909                 rv = ss->load_super(st, fd, NULL);
 910                 if (rv == 0) {
 911                         struct mdinfo info;
 912                         st->ss->getinfo_super(st, &info);
 913                         if (bestsuper == -1 ||
 914                             besttime < info.array.ctime) {
 915                                 bestsuper = i;
 916                                 besttime = info.array.ctime;
 917                         }
 918                         ss->free_super(st);
 919                 }
 920         }
 921         if (bestsuper != -1) {
 922                 int rv;
 923                 memset(st, 0, sizeof(*st));
 924                 rv = superlist[bestsuper]->load_super(st, fd, NULL);
 925                 if (rv == 0) {
 926                         superlist[bestsuper]->free_super(st);
 927                         return st;
 928                 }
 929         }
 930         free(st);
 931         return NULL;
 932 }
 933
 934 /* Return size of device in bytes */
 935 int get_dev_size(int fd, char *dname, unsigned long long *sizep)
 936 {
 937         unsigned long long ldsize;
 938         struct stat st;
 939
 940         if (fstat(fd, &st) != -1 && S_ISREG(st.st_mode))
 941                 ldsize = (unsigned long long)st.st_size;
 942         else
 943 #ifdef BLKGETSIZE64
 944         if (ioctl(fd, BLKGETSIZE64, &ldsize) != 0)
 945 #endif
 946         {
 947                 unsigned long dsize;
 948                 if (ioctl(fd, BLKGETSIZE, &dsize) == 0) {
 949                         ldsize = dsize;
 950                         ldsize <<= 9;
 951                 } else {
 952                         if (dname)
 953                                 fprintf(stderr, Name ": Cannot get size of %s: %s\b",
 954                                         dname, strerror(errno));
 955                         return 0;
 956                 }
 957         }
 958         *sizep = ldsize;
 959         return 1;
 960 }
 961
 962 void get_one_disk(int mdfd, mdu_array_info_t *ainf, mdu_disk_info_t *disk)
 963 {
 964         int d;
 965         ioctl(mdfd, GET_ARRAY_INFO, ainf);
 966         for (d = 0 ; d < ainf->raid_disks + ainf->nr_disks ; d++)
 967                 if (ioctl(mdfd, GET_DISK_INFO, disk) == 0)
 968                         return;
 969 }
 970
 971 int open_container(int fd)
 972 {
 973         /* 'fd' is a block device.  Find out if it is in use
 974          * by a container, and return an open fd on that container.
 975          */
 976         char path[256];
 977         char *e;
 978         DIR *dir;
 979         struct dirent *de;
 980         int dfd, n;
 981         char buf[200];
 982         int major, minor;
 983         struct stat st;
 984
 985         if (fstat(fd, &st) != 0)
 986                 return -1;
 987         sprintf(path, "/sys/dev/block/%d:%d/holders",
 988                 (int)major(st.st_rdev), (int)minor(st.st_rdev));
 989         e = path + strlen(path);
 990
 991         dir = opendir(path);
 992         if (!dir)
 993                 return -1;
 994         while ((de = readdir(dir))) {
 995                 if (de->d_ino == 0)
 996                         continue;
 997                 if (de->d_name[0] == '.')
 998                         continue;
 999                 sprintf(e, "/%s/dev", de->d_name);
1000                 dfd = open(path, O_RDONLY);
1001                 if (dfd < 0)
1002                         continue;
1003                 n = read(dfd, buf, sizeof(buf));
1004                 close(dfd);
1005                 if (n <= 0 || n >= sizeof(buf))
1006                         continue;
1007                 buf[n] = 0;
1008                 if (sscanf(buf, "%d:%d", &major, &minor) != 2)
1009                         continue;
1010                 sprintf(buf, "%d:%d", major, minor);
1011                 dfd = dev_open(buf, O_RDONLY);
1012                 if (dfd >= 0) {
1013                         closedir(dir);
1014                         return dfd;
1015                 }
1016         }
1017         closedir(dir);
1018         return -1;
1019 }
1020
1021 int add_disk(int mdfd, struct supertype *st,
1022              struct mdinfo *sra, struct mdinfo *info)
1023 {
1024         /* Add a device to an array, in one of 2 ways. */
1025         int rv;
1026 #ifndef MDASSEMBLE
1027         if (st->ss->external) {
1028                 rv = sysfs_add_disk(sra, info);
1029                 if (! rv) {
1030                         struct mdinfo *sd2;
1031                         for (sd2 = sra->devs; sd2; sd2=sd2->next)
1032                                 if (sd2 == info)
1033                                         break;
1034                         if (sd2 == NULL) {
1035                                 sd2 = malloc(sizeof(*sd2));
1036                                 *sd2 = *info;
1037                                 sd2->next = sra->devs;
1038                                 sra->devs = sd2;
1039                         }
1040                 }
1041         } else
1042 #endif
1043                 rv = ioctl(mdfd, ADD_NEW_DISK, &info->disk);
1044         return rv;
1045 }
1046
1047 int set_array_info(int mdfd, struct supertype *st, struct mdinfo *info)
1048 {
1049         /* Initialise kernel's knowledge of array.
1050          * This varies between externally managed arrays
1051          * and older kernels
1052          */
1053         int vers = md_get_version(mdfd);
1054         int rv;
1055
1056 #ifndef MDASSEMBLE
1057         if (st->ss->external)
1058                 rv = sysfs_set_array(info, vers);
1059         else
1060 #endif
1061                 if ((vers % 100) >= 1) { /* can use different versions */
1062                 mdu_array_info_t inf;
1063                 memset(&inf, 0, sizeof(inf));
1064                 inf.major_version = info->array.major_version;
1065                 inf.minor_version = info->array.minor_version;
1066                 rv = ioctl(mdfd, SET_ARRAY_INFO, &inf);
1067         } else
1068                 rv = ioctl(mdfd, SET_ARRAY_INFO, NULL);
1069         return rv;
1070 }
1071
1072 char *devnum2devname(int num)
1073 {
1074         char name[100];
1075         if (num > 0)
1076                 sprintf(name, "md%d", num);
1077         else
1078                 sprintf(name, "md_d%d", -1-num);
1079         return strdup(name);
1080 }
1081
1082 int devname2devnum(char *name)
1083 {
1084         char *ep;
1085         int num;
1086         if (strncmp(name, "md_d", 4)==0)
1087                 num = -1-strtoul(name+4, &ep, 10);
1088         else
1089                 num = strtoul(name+2, &ep, 10);
1090         return num;
1091 }
1092
1093 int stat2devnum(struct stat *st)
1094 {
1095         if ((S_IFMT & st->st_mode) == S_IFBLK) {
1096                 if (major(st->st_rdev) == MD_MAJOR)
1097                         return minor(st->st_rdev);
1098                 else
1099                         return -1- (minor(st->st_rdev)>>6);
1100         }
1101         return -1;
1102
1103 }
1104
1105 int fd2devnum(int fd)
1106 {
1107         struct stat stb;
1108         if (fstat(fd, &stb) == 0)
1109                 return stat2devnum(&stb);
1110         return -1;
1111 }
1112
1113 int mdmon_running(int devnum)
1114 {
1115         char path[100];
1116         char pid[10];
1117         int fd;
1118         int n;
1119         sprintf(path, "/var/run/mdadm/%s.pid", devnum2devname(devnum));
1120         fd = open(path, O_RDONLY, 0);
1121
1122         if (fd < 0)
1123                 return 0;
1124         n = read(fd, pid, 9);
1125         close(fd);
1126         if (n <= 0)
1127                 return 0;
1128         if (kill(atoi(pid), 0) == 0)
1129                 return 1;
1130         return 0;
1131 }
1132
1133 int signal_mdmon(int devnum)
1134 {
1135         char path[100];
1136         char pid[10];
1137         int fd;
1138         int n;
1139         sprintf(path, "/var/run/mdadm/%s.pid", devnum2devname(devnum));
1140         fd = open(path, O_RDONLY, 0);
1141
1142         if (fd < 0)
1143                 return 0;
1144         n = read(fd, pid, 9);
1145         close(fd);
1146         if (n <= 0)
1147                 return 0;
1148         if (kill(atoi(pid), SIGUSR1) == 0)
1149                 return 1;
1150         return 0;
1151 }
1152
1153 int start_mdmon(int devnum)
1154 {
1155         int i;
1156         int len;
1157         pid_t pid;
1158         int status;
1159         char pathbuf[1024];
1160         char *paths[4] = {
1161                 pathbuf,
1162                 "/sbin/mdmon",
1163                 "mdmon",
1164                 NULL
1165         };
1166
1167         if (env_no_mdmon())
1168                 return 0;
1169
1170         len = readlink("/proc/self/exe", pathbuf, sizeof(pathbuf));
1171         if (len > 0) {
1172                 char *sl;
1173                 pathbuf[len] = 0;
1174                 sl = strrchr(pathbuf, '/');
1175                 if (sl)
1176                         sl++;
1177                 else
1178                         sl = pathbuf;
1179                 strcpy(sl, "mdmon");
1180         } else
1181                 pathbuf[0] = '\0';
1182
1183         switch(fork()) {
1184         case 0:
1185                 /* FIXME yuk. CLOSE_EXEC?? */
1186                 for (i=3; i < 100; i++)
1187                         close(i);
1188                 for (i=0; paths[i]; i++)
1189                         if (paths[i][0])
1190                                 execl(paths[i], "mdmon",
1191                                       map_dev(dev2major(devnum),
1192                                               dev2minor(devnum),
1193                                               1), NULL);
1194                 exit(1);
1195         case -1: fprintf(stderr, Name ": cannot run mdmon. "
1196                          "Array remains readonly\n");
1197                 return -1;
1198         default: /* parent - good */
1199                 pid = wait(&status);
1200                 if (pid < 0 || status != 0)
1201                         return -1;
1202         }
1203         return 0;
1204 }
1205
1206 int env_no_mdmon(void)
1207 {
1208         char *val = getenv("MDADM_NO_MDMON");
1209
1210         if (val && atoi(val) == 1)
1211                 return 1;
1212
1213         return 0;
1214 }
1215
1216 #ifndef MDASSEMBLE
1217 int flush_metadata_updates(struct supertype *st)
1218 {
1219         int sfd;
1220         if (!st->updates) {
1221                 st->update_tail = NULL;
1222                 return -1;
1223         }
1224
1225         sfd = connect_monitor(devnum2devname(st->container_dev));
1226         if (sfd < 0)
1227                 return -1;
1228
1229         while (st->updates) {
1230                 struct metadata_update *mu = st->updates;
1231                 st->updates = mu->next;
1232
1233                 send_message(sfd, mu, 0);
1234                 wait_reply(sfd, 0);
1235                 free(mu->buf);
1236                 free(mu);
1237         }
1238         ack(sfd, 0);
1239         wait_reply(sfd, 0);
1240         close(sfd);
1241         st->update_tail = NULL;
1242         return 0;
1243 }
1244
1245 void append_metadata_update(struct supertype *st, void *buf, int len)
1246 {
1247
1248         struct metadata_update *mu = malloc(sizeof(*mu));
1249
1250         mu->buf = buf;
1251         mu->len = len;
1252         mu->space = NULL;
1253         mu->next = NULL;
1254         *st->update_tail = mu;
1255         st->update_tail = &mu->next;
1256 }
1257 #endif /* MDASSEMBLE */
1258
1259 #ifdef __TINYC__
1260 /* tinyc doesn't optimize this check in ioctl.h out ... */
1261 unsigned int __invalid_size_argument_for_IOC = 0;
1262 #endif
1263