util.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@cse.unsw.edu.au>
  23  *    Paper: Neil Brown
  24  *           School of Computer Science and Engineering
  25  *           The University of New South Wales
  26  *           Sydney, 2052
  27  *           Australia
  28  */
  29
  30 #include        "mdadm.h"
  31 #include        "md_p.h"
  32 #include        <sys/utsname.h>
  33 #include        <ctype.h>
  34
  35 /*
  36  * Parse a 128 bit uuid in 4 integers
  37  * format is 32 hexx nibbles with options :.<space> separator
  38  * If not exactly 32 hex digits are found, return 0
  39  * else return 1
  40  */
  41 int parse_uuid(char *str, int uuid[4])
  42 {
  43     int hit = 0; /* number of Hex digIT */
  44     int i;
  45     char c;
  46     for (i=0; i<4; i++) uuid[i]=0;
  47
  48     while ((c= *str++)) {
  49         int n;
  50         if (c>='0' && c<='9')
  51             n = c-'0';
  52         else if (c>='a' && c <= 'f')
  53             n = 10 + c - 'a';
  54         else if (c>='A' && c <= 'F')
  55             n = 10 + c - 'A';
  56         else if (strchr(":. -", c))
  57             continue;
  58         else return 0;
  59
  60         if (hit<32) {
  61             uuid[hit/8] <<= 4;
  62             uuid[hit/8] += n;
  63         }
  64         hit++;
  65     }
  66     if (hit == 32)
  67         return 1;
  68     return 0;
  69
  70 }
  71
  72
  73 /*
  74  * Get the md version number.
  75  * We use the RAID_VERSION ioctl if it is supported
  76  * If not, but we have a block device with major '9', we assume
  77  * 0.36.0
  78  *
  79  * Return version number as 24 but number - assume version parts
  80  * always < 255
  81  */
  82
  83 int md_get_version(int fd)
  84 {
  85     struct stat stb;
  86     mdu_version_t vers;
  87
  88     if (fstat(fd, &stb)<0)
  89         return -1;
  90     if ((S_IFMT&stb.st_mode) != S_IFBLK)
  91         return -1;
  92
  93     if (ioctl(fd, RAID_VERSION, &vers) == 0)
  94         return  (vers.major*10000) + (vers.minor*100) + vers.patchlevel;
  95     if (errno == EACCES)
  96             return -1;
  97     if (MAJOR(stb.st_rdev) == MD_MAJOR)
  98         return (3600);
  99     return -1;
 100 }
 101
 102
 103 int get_linux_version()
 104 {
 105         struct utsname name;
 106         char *cp;
 107         int a,b,c;
 108         if (uname(&name) <0)
 109                 return -1;
 110
 111         cp = name.release;
 112         a = strtoul(cp, &cp, 10);
 113         if (*cp != '.') return -1;
 114         b = strtoul(cp+1, &cp, 10);
 115         if (*cp != '.') return -1;
 116         c = strtoul(cp+1, NULL, 10);
 117
 118         return (a*1000000)+(b*1000)+c;
 119 }
 120
 121 int enough(int level, int raid_disks, int avail_disks)
 122 {
 123         switch (level) {
 124         case 10: return 1; /* a lie, but it is hard to tell */
 125
 126         case -4:
 127                 return avail_disks>= 1;
 128         case -1:
 129         case 0:
 130                 return avail_disks == raid_disks;
 131         case 1:
 132                 return avail_disks >= 1;
 133         case 4:
 134         case 5:
 135                 return avail_disks >= raid_disks-1;
 136         case 6:
 137                 return avail_disks >= raid_disks-2;
 138         default:
 139                 return 0;
 140         }
 141 }
 142
 143 int same_uuid(int a[4], int b[4])
 144 {
 145     if (a[0]==b[0] &&
 146         a[1]==b[1] &&
 147         a[2]==b[2] &&
 148         a[3]==b[3])
 149         return 1;
 150     return 0;
 151 }
 152
 153 void uuid_from_super(int uuid[4], mdp_super_t *super)
 154 {
 155     uuid[0] = super->set_uuid0;
 156     if (super->minor_version >= 90) {
 157         uuid[1] = super->set_uuid1;
 158         uuid[2] = super->set_uuid2;
 159         uuid[3] = super->set_uuid3;
 160     } else {
 161         uuid[1] = 0;
 162         uuid[2] = 0;
 163         uuid[3] = 0;
 164     }
 165 }
 166
 167 int compare_super(mdp_super_t *first, mdp_super_t *second)
 168 {
 169     /*
 170      * return:
 171      *  0 same, or first was empty, and second was copied
 172      *  1 second had wrong number
 173      *  2 wrong uuid
 174      *  3 wrong other info
 175      */
 176     int uuid1[4], uuid2[4];
 177     if (second->md_magic != MD_SB_MAGIC)
 178         return 1;
 179     if (first-> md_magic != MD_SB_MAGIC) {
 180         memcpy(first, second, sizeof(*first));
 181         return 0;
 182     }
 183
 184     uuid_from_super(uuid1, first);
 185     uuid_from_super(uuid2, second);
 186     if (!same_uuid(uuid1, uuid2))
 187         return 2;
 188     if (first->major_version != second->major_version ||
 189         first->minor_version != second->minor_version ||
 190         first->patch_version != second->patch_version ||
 191         first->gvalid_words  != second->gvalid_words  ||
 192         first->ctime         != second->ctime         ||
 193         first->level         != second->level         ||
 194         first->size          != second->size          ||
 195         first->raid_disks    != second->raid_disks    )
 196         return 3;
 197
 198     return 0;
 199 }
 200
 201 int load_super(int fd, mdp_super_t *super)
 202 {
 203         /* try to read in the superblock
 204          *
 205          * return
 206          *   0 - success
 207          *   1 - no block size
 208          *   2 - too small
 209          *   3 - no seek
 210          *   4 - no read
 211          *   5 - no magic
 212          *   6 - wrong major version
 213          */
 214         unsigned long size;
 215         unsigned long long offset;
 216
 217         if (ioctl(fd, BLKGETSIZE, &size))
 218                 return 1;
 219
 220         if (size < MD_RESERVED_SECTORS*2)
 221                 return 2;
 222
 223         offset = MD_NEW_SIZE_SECTORS(size);
 224
 225         offset *= 512;
 226
 227         ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
 228
 229         if (lseek64(fd, offset, 0)< 0LL)
 230                 return 3;
 231
 232         if (read(fd, super, sizeof(*super)) != sizeof(*super))
 233                 return 4;
 234
 235         if (super->md_magic != MD_SB_MAGIC)
 236                 return 5;
 237
 238         if (super->major_version != 0)
 239                 return 6;
 240         return 0;
 241 }
 242
 243 int store_super(int fd, mdp_super_t *super)
 244 {
 245         long size;
 246         long long offset;
 247
 248         if (ioctl(fd, BLKGETSIZE, &size))
 249                 return 1;
 250
 251         if (size < MD_RESERVED_SECTORS*2)
 252                 return 2;
 253
 254         offset = MD_NEW_SIZE_SECTORS(size);
 255
 256         offset *= 512;
 257
 258         if (lseek64(fd, offset, 0)< 0LL)
 259                 return 3;
 260
 261         if (write(fd, super, sizeof(*super)) != sizeof(*super))
 262                 return 4;
 263
 264         return 0;
 265 }
 266
 267
 268
 269 int check_ext2(int fd, char *name)
 270 {
 271         /*
 272          * Check for an ext2fs file system.
 273          * Superblock is always 1K at 1K offset
 274          *
 275          * s_magic is le16 at 56 == 0xEF53
 276          * report mtime - le32 at 44
 277          * blocks - le32 at 4
 278          * logblksize - le32 at 24
 279          */
 280         unsigned char sb[1024];
 281         time_t mtime;
 282         int size, bsize;
 283         if (lseek(fd, 1024,0)!= 1024)
 284                 return 0;
 285         if (read(fd, sb, 1024)!= 1024)
 286                 return 0;
 287         if (sb[56] != 0x53 || sb[57] != 0xef)
 288                 return 0;
 289
 290         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 291         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 292         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 293         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 294                 name);
 295         fprintf(stderr,"    size=%dK  mtime=%s",
 296                 size*(1<<bsize), ctime(&mtime));
 297         return 1;
 298 }
 299
 300 int check_reiser(int fd, char *name)
 301 {
 302         /*
 303          * superblock is at 64K
 304          * size is 1024;
 305          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 306          *
 307          */
 308         unsigned char sb[1024];
 309         int size;
 310         if (lseek(fd, 64*1024, 0) != 64*1024)
 311                 return 0;
 312         if (read(fd, sb, 1024) != 1024)
 313                 return 0;
 314         if (strncmp(sb+52, "ReIsErFs",8)!=0 &&
 315             strncmp(sb+52, "ReIsEr2Fs",9)!=0)
 316                 return 0;
 317         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 318         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 319         fprintf(stderr, "    size = %dK\n", size*4);
 320
 321         return 1;
 322 }
 323
 324 int check_raid(int fd, char *name)
 325 {
 326         mdp_super_t super;
 327         time_t crtime;
 328         if (load_super(fd, &super))
 329                 return 0;
 330         /* Looks like a raid array .. */
 331         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 332                 name);
 333         crtime = super.ctime;
 334         fprintf(stderr, "    level=%d devices=%d ctime=%s",
 335                 super.level, super.raid_disks, ctime(&crtime));
 336         return 1;
 337 }
 338
 339
 340 int ask(char *mesg)
 341 {
 342         char *add = "";
 343         int i;
 344         for (i=0; i<5; i++) {
 345                 char buf[100];
 346                 fprintf(stderr, "%s%s", mesg, add);
 347                 fflush(stderr);
 348                 if (fgets(buf, 100, stdin)==NULL)
 349                         return 0;
 350                 if (buf[0]=='y' || buf[0]=='Y')
 351                         return 1;
 352                 if (buf[0]=='n' || buf[0]=='N')
 353                         return 0;
 354                 add = "(y/n) ";
 355         }
 356         fprintf(stderr, Name ": assuming 'no'\n");
 357         return 0;
 358 }
 359
 360 char *map_num(mapping_t *map, int num)
 361 {
 362         while (map->name) {
 363                 if (map->num == num)
 364                         return map->name;
 365                 map++;
 366         }
 367         return NULL;
 368 }
 369
 370 int map_name(mapping_t *map, char *name)
 371 {
 372         while (map->name) {
 373                 if (strcmp(map->name, name)==0)
 374                         return map->num;
 375                 map++;
 376         }
 377         return UnSet;
 378 }
 379
 380
 381 int is_standard(char *dev)
 382 {
 383         /* tests if dev is a "standard" md dev name.
 384          * i.e if the last component is "/dNN" or "/mdNN",
 385          * where NN is a string of digits
 386          */
 387         dev = strrchr(dev, '/');
 388         if (!dev)
 389                 return 0;
 390         if (strncmp(dev, "/d",2)==0)
 391                 dev += 2;
 392         else if (strncmp(dev, "/md", 3)==0)
 393                 dev += 3;
 394         else
 395                 return 0;
 396         if (!*dev)
 397                 return 0;
 398         while (isdigit(*dev))
 399                 dev++;
 400         if (*dev)
 401                 return 0;
 402         return 1;
 403 }
 404
 405
 406 /*
 407  * convert a major/minor pair for a block device into a name in /dev, if possible.
 408  * On the first call, walk /dev collecting name.
 409  * Put them in a simple linked listfor now.
 410  */
 411 struct devmap {
 412     int major, minor;
 413     char *name;
 414     struct devmap *next;
 415 } *devlist = NULL;
 416 int devlist_ready = 0;
 417
 418 #ifdef UCLIBC
 419 char *map_dev(int major, int minor)
 420 {
 421 #if 0
 422         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 423                 major, minor);
 424 #endif
 425         return NULL;
 426 }
 427 #else
 428 #define  __USE_XOPEN_EXTENDED
 429 #include <ftw.h>
 430
 431
 432 #ifndef __dietlibc__
 433 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 434 #else
 435 int add_dev(const char *name, const struct stat *stb, int flag)
 436 #endif
 437 {
 438     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 439         char *n = strdup(name);
 440         struct devmap *dm = malloc(sizeof(*dm));
 441         if (dm) {
 442             dm->major = MAJOR(stb->st_rdev);
 443             dm->minor = MINOR(stb->st_rdev);
 444             dm->name = n;
 445             dm->next = devlist;
 446             devlist = dm;
 447         }
 448     }
 449     return 0;
 450 }
 451
 452 /*
 453  * Find a block device with the right major/minor number.
 454  * Avoid /dev/mdNN and /dev/md/dNN is possible
 455  */
 456 char *map_dev(int major, int minor)
 457 {
 458         struct devmap *p;
 459         char *std = NULL;
 460         if (!devlist_ready) {
 461 #ifndef __dietlibc__
 462                 nftw("/dev", add_dev, 10, FTW_PHYS);
 463 #else
 464                 ftw("/dev", add_dev, 10);
 465 #endif
 466                 devlist_ready=1;
 467         }
 468
 469         for (p=devlist; p; p=p->next)
 470                 if (p->major == major &&
 471                     p->minor == minor) {
 472                         if (is_standard(p->name))
 473                                 std = p->name;
 474                         else
 475                                 return p->name;
 476                 }
 477         return std;
 478 }
 479
 480 #endif
 481
 482 unsigned long calc_sb_csum(mdp_super_t *super)
 483 {
 484         unsigned int  oldcsum = super->sb_csum;
 485         unsigned long long newcsum = 0;
 486         unsigned long csum;
 487         int i;
 488         unsigned int *superc = (int*) super;
 489         super->sb_csum = 0;
 490
 491         for(i=0; i<MD_SB_BYTES/4; i++)
 492                 newcsum+= superc[i];
 493         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 494         super->sb_csum = oldcsum;
 495         return csum;
 496 }
 497
 498 char *human_size(long long bytes)
 499 {
 500         static char buf[30];
 501
 502
 503         if (bytes < 5000*1024)
 504                 buf[0]=0;
 505         else if (bytes < 2*1024LL*1024LL*1024LL)
 506                 sprintf(buf, " (%ld.%02ld MiB %ld.%02ld MB)",
 507                         (long)(bytes>>20),
 508                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100),
 509                         (long)(bytes/1000/1000),
 510                         (long)(((bytes%1000000)+5000)/10000)
 511                         );
 512         else
 513                 sprintf(buf, " (%ld.%02ld GiB %ld.%02ld GB)",
 514                         (long)(bytes>>30),
 515                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100),
 516                         (long)(bytes/1000LL/1000LL/1000LL),
 517                         (long)((((bytes/1000)%1000000)+5000)/10000)
 518                         );
 519         return buf;
 520 }
 521
 522 char *human_size_brief(long long bytes)
 523 {
 524         static char buf[30];
 525
 526
 527         if (bytes < 5000*1024)
 528                 sprintf(buf, "%ld.%02ldKiB",
 529                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 530                         );
 531         else if (bytes < 2*1024LL*1024LL*1024LL)
 532                 sprintf(buf, "%ld.%02ldMiB",
 533                         (long)(bytes>>20),
 534                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 535                         );
 536         else
 537                 sprintf(buf, "%ld.%02ldGiB",
 538                         (long)(bytes>>30),
 539                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 540                         );
 541         return buf;
 542 }
 543
 544 int get_mdp_major(void)
 545 {
 546 static int mdp_major = -1;
 547         FILE *fl;
 548         char *w;
 549         int have_block = 0;
 550         int have_devices = 0;
 551         int last_num = -1;
 552
 553         if (mdp_major != -1)
 554                 return mdp_major;
 555         fl = fopen("/proc/devices", "r");
 556         if (!fl)
 557                 return -1;
 558         while ((w = conf_word(fl, 1))) {
 559                 if (have_block && strcmp(w, "devices:")==0)
 560                         have_devices = 1;
 561                 have_block =  (strcmp(w, "Block")==0);
 562                 if (isdigit(w[0]))
 563                         last_num = atoi(w);
 564                 if (have_devices && strcmp(w, "mdp")==0)
 565                         mdp_major = last_num;
 566                 free(w);
 567         }
 568         fclose(fl);
 569         return mdp_major;
 570 }
 571
 572
 573
 574 char *get_md_name(int dev)
 575 {
 576         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 577         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 578         static char devname[50];
 579         struct stat stb;
 580         dev_t rdev;
 581         char *dn;
 582
 583         if (dev < 0) {
 584                 int mdp =  get_mdp_major();
 585                 if (mdp < 0) return NULL;
 586                 rdev = MKDEV(mdp, (-1-dev)<<6);
 587                 sprintf(devname, "/dev/md/d%d", -1-dev);
 588                 if (stat(devname, &stb) == 0
 589                     && (S_IFMT&stb.st_mode) == S_IFBLK
 590                     && (stb.st_rdev == rdev))
 591                         return devname;
 592         } else {
 593                 rdev = MKDEV(MD_MAJOR, dev);
 594                 sprintf(devname, "/dev/md%d", dev);
 595                 if (stat(devname, &stb) == 0
 596                     && (S_IFMT&stb.st_mode) == S_IFBLK
 597                     && (stb.st_rdev == rdev))
 598                         return devname;
 599
 600                 sprintf(devname, "/dev/md/%d", dev);
 601                 if (stat(devname, &stb) == 0
 602                     && (S_IFMT&stb.st_mode) == S_IFBLK
 603                     && (stb.st_rdev == rdev))
 604                         return devname;
 605         }
 606         dn = map_dev(MAJOR(rdev), MINOR(rdev));
 607         if (dn)
 608                 return dn;
 609         sprintf(devname, "/dev/.tmp.md%d", dev);
 610         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 611                 if (errno != EEXIST)
 612                         return NULL;
 613
 614         if (stat(devname, &stb) == 0
 615             && (S_IFMT&stb.st_mode) == S_IFBLK
 616             && (stb.st_rdev == rdev))
 617                 return devname;
 618         unlink(devname);
 619         return NULL;
 620 }
 621
 622 void put_md_name(char *name)
 623 {
 624         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 625                 unlink(name);
 626 }