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 dsize;
 216         unsigned long long offset;
 217
 218 #ifdef BLKGETSIZE64
 219         if (ioctl(fd, BLKGETSIZE64, &dsize) != 0)
 220 #endif
 221         {
 222                 if (ioctl(fd, BLKGETSIZE, &size))
 223                         return 1;
 224                 else
 225                         dsize = size << 9;
 226         }
 227
 228         if (dsize < MD_RESERVED_SECTORS*2)
 229                 return 2;
 230
 231         offset = MD_NEW_SIZE_SECTORS(dsize>>9);
 232
 233         offset *= 512;
 234
 235         ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
 236
 237         if (lseek64(fd, offset, 0)< 0LL)
 238                 return 3;
 239
 240         if (read(fd, super, sizeof(*super)) != sizeof(*super))
 241                 return 4;
 242
 243         if (super->md_magic != MD_SB_MAGIC)
 244                 return 5;
 245
 246         if (super->major_version != 0)
 247                 return 6;
 248         return 0;
 249 }
 250
 251 int store_super(int fd, mdp_super_t *super)
 252 {
 253         unsigned long size;
 254         unsigned long long dsize;
 255
 256         long long offset;
 257
 258 #ifdef BLKGETSIZE64
 259         if (ioctl(fd, BLKGETSIZE64, &dsize) != 0)
 260 #endif
 261         {
 262                 if (ioctl(fd, BLKGETSIZE, &size))
 263                         return 1;
 264                 else
 265                         dsize = ((unsigned long long)size) << 9;
 266         }
 267
 268         if (dsize < MD_RESERVED_SECTORS*2)
 269                 return 2;
 270
 271         offset = MD_NEW_SIZE_SECTORS(dsize>>9);
 272
 273         offset *= 512;
 274
 275         if (lseek64(fd, offset, 0)< 0LL)
 276                 return 3;
 277
 278         if (write(fd, super, sizeof(*super)) != sizeof(*super))
 279                 return 4;
 280
 281         return 0;
 282 }
 283
 284
 285
 286 int check_ext2(int fd, char *name)
 287 {
 288         /*
 289          * Check for an ext2fs file system.
 290          * Superblock is always 1K at 1K offset
 291          *
 292          * s_magic is le16 at 56 == 0xEF53
 293          * report mtime - le32 at 44
 294          * blocks - le32 at 4
 295          * logblksize - le32 at 24
 296          */
 297         unsigned char sb[1024];
 298         time_t mtime;
 299         int size, bsize;
 300         if (lseek(fd, 1024,0)!= 1024)
 301                 return 0;
 302         if (read(fd, sb, 1024)!= 1024)
 303                 return 0;
 304         if (sb[56] != 0x53 || sb[57] != 0xef)
 305                 return 0;
 306
 307         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 308         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 309         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 310         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 311                 name);
 312         fprintf(stderr,"    size=%dK  mtime=%s",
 313                 size*(1<<bsize), ctime(&mtime));
 314         return 1;
 315 }
 316
 317 int check_reiser(int fd, char *name)
 318 {
 319         /*
 320          * superblock is at 64K
 321          * size is 1024;
 322          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 323          *
 324          */
 325         unsigned char sb[1024];
 326         int size;
 327         if (lseek(fd, 64*1024, 0) != 64*1024)
 328                 return 0;
 329         if (read(fd, sb, 1024) != 1024)
 330                 return 0;
 331         if (strncmp(sb+52, "ReIsErFs",8)!=0 &&
 332             strncmp(sb+52, "ReIsEr2Fs",9)!=0)
 333                 return 0;
 334         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 335         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 336         fprintf(stderr, "    size = %dK\n", size*4);
 337
 338         return 1;
 339 }
 340
 341 int check_raid(int fd, char *name)
 342 {
 343         mdp_super_t super;
 344         time_t crtime;
 345         if (load_super(fd, &super))
 346                 return 0;
 347         /* Looks like a raid array .. */
 348         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 349                 name);
 350         crtime = super.ctime;
 351         fprintf(stderr, "    level=%d devices=%d ctime=%s",
 352                 super.level, super.raid_disks, ctime(&crtime));
 353         return 1;
 354 }
 355
 356
 357 int ask(char *mesg)
 358 {
 359         char *add = "";
 360         int i;
 361         for (i=0; i<5; i++) {
 362                 char buf[100];
 363                 fprintf(stderr, "%s%s", mesg, add);
 364                 fflush(stderr);
 365                 if (fgets(buf, 100, stdin)==NULL)
 366                         return 0;
 367                 if (buf[0]=='y' || buf[0]=='Y')
 368                         return 1;
 369                 if (buf[0]=='n' || buf[0]=='N')
 370                         return 0;
 371                 add = "(y/n) ";
 372         }
 373         fprintf(stderr, Name ": assuming 'no'\n");
 374         return 0;
 375 }
 376
 377 char *map_num(mapping_t *map, int num)
 378 {
 379         while (map->name) {
 380                 if (map->num == num)
 381                         return map->name;
 382                 map++;
 383         }
 384         return NULL;
 385 }
 386
 387 int map_name(mapping_t *map, char *name)
 388 {
 389         while (map->name) {
 390                 if (strcmp(map->name, name)==0)
 391                         return map->num;
 392                 map++;
 393         }
 394         return UnSet;
 395 }
 396
 397
 398 int is_standard(char *dev, int *nump)
 399 {
 400         /* tests if dev is a "standard" md dev name.
 401          * i.e if the last component is "/dNN" or "/mdNN",
 402          * where NN is a string of digits
 403          */
 404         char *d = strrchr(dev, '/');
 405         int type=0;
 406         int num;
 407         if (!d)
 408                 return 0;
 409         if (strncmp(d, "/d",2)==0)
 410                 d += 2, type=1; /* /dev/md/dN{pM} */
 411         else if (strncmp(d, "/md_d", 5)==0)
 412                 d += 5, type=1; /* /dev/md_dNpM */
 413         else if (strncmp(d, "/md", 3)==0)
 414                 d += 3, type=-1; /* /dev/mdN */
 415         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 416                 type = -1; /* /dev/md/N */
 417         else
 418                 return 0;
 419         if (!*d)
 420                 return 0;
 421         num = atoi(d);
 422         while (isdigit(*d))
 423                 d++;
 424         if (*d)
 425                 return 0;
 426         if (nump) *nump = num;
 427
 428         return type;
 429 }
 430
 431
 432 /*
 433  * convert a major/minor pair for a block device into a name in /dev, if possible.
 434  * On the first call, walk /dev collecting name.
 435  * Put them in a simple linked listfor now.
 436  */
 437 struct devmap {
 438     int major, minor;
 439     char *name;
 440     struct devmap *next;
 441 } *devlist = NULL;
 442 int devlist_ready = 0;
 443
 444 #ifdef UCLIBC
 445 char *map_dev(int major, int minor)
 446 {
 447 #if 0
 448         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 449                 major, minor);
 450 #endif
 451         return NULL;
 452 }
 453 #else
 454 #define  __USE_XOPEN_EXTENDED
 455 #include <ftw.h>
 456
 457
 458 #ifndef __dietlibc__
 459 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 460 #else
 461 int add_dev(const char *name, const struct stat *stb, int flag)
 462 #endif
 463 {
 464     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 465         char *n = strdup(name);
 466         struct devmap *dm = malloc(sizeof(*dm));
 467         if (dm) {
 468             dm->major = MAJOR(stb->st_rdev);
 469             dm->minor = MINOR(stb->st_rdev);
 470             dm->name = n;
 471             dm->next = devlist;
 472             devlist = dm;
 473         }
 474     }
 475     return 0;
 476 }
 477
 478 /*
 479  * Find a block device with the right major/minor number.
 480  * Avoid /dev/mdNN and /dev/md/dNN if possible
 481  */
 482 char *map_dev(int major, int minor)
 483 {
 484         struct devmap *p;
 485         char *std = NULL;
 486         if (!devlist_ready) {
 487 #ifndef __dietlibc__
 488                 nftw("/dev", add_dev, 10, FTW_PHYS);
 489 #else
 490                 ftw("/dev", add_dev, 10);
 491 #endif
 492                 devlist_ready=1;
 493         }
 494
 495         for (p=devlist; p; p=p->next)
 496                 if (p->major == major &&
 497                     p->minor == minor) {
 498                         if (is_standard(p->name, NULL))
 499                                 std = p->name;
 500                         else
 501                                 return p->name;
 502                 }
 503         return std;
 504 }
 505
 506 #endif
 507
 508 unsigned long calc_sb_csum(mdp_super_t *super)
 509 {
 510         unsigned int  oldcsum = super->sb_csum;
 511         unsigned long long newcsum = 0;
 512         unsigned long csum;
 513         int i;
 514         unsigned int *superc = (int*) super;
 515         super->sb_csum = 0;
 516
 517         for(i=0; i<MD_SB_BYTES/4; i++)
 518                 newcsum+= superc[i];
 519         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 520         super->sb_csum = oldcsum;
 521         return csum;
 522 }
 523
 524 char *human_size(long long bytes)
 525 {
 526         static char buf[30];
 527
 528
 529         if (bytes < 5000*1024)
 530                 buf[0]=0;
 531         else if (bytes < 2*1024LL*1024LL*1024LL)
 532                 sprintf(buf, " (%ld.%02ld MiB %ld.%02ld MB)",
 533                         (long)(bytes>>20),
 534                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100),
 535                         (long)(bytes/1000/1000),
 536                         (long)(((bytes%1000000)+5000)/10000)
 537                         );
 538         else
 539                 sprintf(buf, " (%ld.%02ld GiB %ld.%02ld GB)",
 540                         (long)(bytes>>30),
 541                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100),
 542                         (long)(bytes/1000LL/1000LL/1000LL),
 543                         (long)((((bytes/1000)%1000000)+5000)/10000)
 544                         );
 545         return buf;
 546 }
 547
 548 char *human_size_brief(long long bytes)
 549 {
 550         static char buf[30];
 551
 552
 553         if (bytes < 5000*1024)
 554                 sprintf(buf, "%ld.%02ldKiB",
 555                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 556                         );
 557         else if (bytes < 2*1024LL*1024LL*1024LL)
 558                 sprintf(buf, "%ld.%02ldMiB",
 559                         (long)(bytes>>20),
 560                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 561                         );
 562         else
 563                 sprintf(buf, "%ld.%02ldGiB",
 564                         (long)(bytes>>30),
 565                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 566                         );
 567         return buf;
 568 }
 569
 570 int get_mdp_major(void)
 571 {
 572 static int mdp_major = -1;
 573         FILE *fl;
 574         char *w;
 575         int have_block = 0;
 576         int have_devices = 0;
 577         int last_num = -1;
 578
 579         if (mdp_major != -1)
 580                 return mdp_major;
 581         fl = fopen("/proc/devices", "r");
 582         if (!fl)
 583                 return -1;
 584         while ((w = conf_word(fl, 1))) {
 585                 if (have_block && strcmp(w, "devices:")==0)
 586                         have_devices = 1;
 587                 have_block =  (strcmp(w, "Block")==0);
 588                 if (isdigit(w[0]))
 589                         last_num = atoi(w);
 590                 if (have_devices && strcmp(w, "mdp")==0)
 591                         mdp_major = last_num;
 592                 free(w);
 593         }
 594         fclose(fl);
 595         return mdp_major;
 596 }
 597
 598
 599
 600 char *get_md_name(int dev)
 601 {
 602         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 603         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 604         static char devname[50];
 605         struct stat stb;
 606         dev_t rdev;
 607         char *dn;
 608
 609         if (dev < 0) {
 610                 int mdp =  get_mdp_major();
 611                 if (mdp < 0) return NULL;
 612                 rdev = MKDEV(mdp, (-1-dev)<<6);
 613                 sprintf(devname, "/dev/md/d%d", -1-dev);
 614                 if (stat(devname, &stb) == 0
 615                     && (S_IFMT&stb.st_mode) == S_IFBLK
 616                     && (stb.st_rdev == rdev))
 617                         return devname;
 618         } else {
 619                 rdev = MKDEV(MD_MAJOR, dev);
 620                 sprintf(devname, "/dev/md%d", dev);
 621                 if (stat(devname, &stb) == 0
 622                     && (S_IFMT&stb.st_mode) == S_IFBLK
 623                     && (stb.st_rdev == rdev))
 624                         return devname;
 625
 626                 sprintf(devname, "/dev/md/%d", dev);
 627                 if (stat(devname, &stb) == 0
 628                     && (S_IFMT&stb.st_mode) == S_IFBLK
 629                     && (stb.st_rdev == rdev))
 630                         return devname;
 631         }
 632         dn = map_dev(major(rdev), minor(rdev));
 633         if (dn)
 634                 return dn;
 635         sprintf(devname, "/dev/.tmp.md%d", dev);
 636         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 637                 if (errno != EEXIST)
 638                         return NULL;
 639
 640         if (stat(devname, &stb) == 0
 641             && (S_IFMT&stb.st_mode) == S_IFBLK
 642             && (stb.st_rdev == rdev))
 643                 return devname;
 644         unlink(devname);
 645         return NULL;
 646 }
 647
 648 void put_md_name(char *name)
 649 {
 650         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 651                 unlink(name);
 652 }