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 -4:
 125                 return avail_disks>= 1;
 126         case -1:
 127         case 0:
 128                 return avail_disks == raid_disks;
 129         case 1:
 130                 return avail_disks >= 1;
 131         case 4:
 132         case 5:
 133                 return avail_disks >= raid_disks-1;
 134         case 6:
 135                 return avail_disks >= raid_disks-2;
 136         default:
 137                 return 0;
 138         }
 139 }
 140
 141 int same_uuid(int a[4], int b[4])
 142 {
 143     if (a[0]==b[0] &&
 144         a[1]==b[1] &&
 145         a[2]==b[2] &&
 146         a[3]==b[3])
 147         return 1;
 148     return 0;
 149 }
 150
 151 void uuid_from_super(int uuid[4], mdp_super_t *super)
 152 {
 153     uuid[0] = super->set_uuid0;
 154     if (super->minor_version >= 90) {
 155         uuid[1] = super->set_uuid1;
 156         uuid[2] = super->set_uuid2;
 157         uuid[3] = super->set_uuid3;
 158     } else {
 159         uuid[1] = 0;
 160         uuid[2] = 0;
 161         uuid[3] = 0;
 162     }
 163 }
 164
 165 int compare_super(mdp_super_t *first, mdp_super_t *second)
 166 {
 167     /*
 168      * return:
 169      *  0 same, or first was empty, and second was copied
 170      *  1 second had wrong number
 171      *  2 wrong uuid
 172      *  3 wrong other info
 173      */
 174     int uuid1[4], uuid2[4];
 175     if (second->md_magic != MD_SB_MAGIC)
 176         return 1;
 177     if (first-> md_magic != MD_SB_MAGIC) {
 178         memcpy(first, second, sizeof(*first));
 179         return 0;
 180     }
 181
 182     uuid_from_super(uuid1, first);
 183     uuid_from_super(uuid2, second);
 184     if (!same_uuid(uuid1, uuid2))
 185         return 2;
 186     if (first->major_version != second->major_version ||
 187         first->minor_version != second->minor_version ||
 188         first->patch_version != second->patch_version ||
 189         first->gvalid_words  != second->gvalid_words  ||
 190         first->ctime         != second->ctime         ||
 191         first->level         != second->level         ||
 192         first->size          != second->size          ||
 193         first->raid_disks    != second->raid_disks    )
 194         return 3;
 195
 196     return 0;
 197 }
 198
 199 int load_super(int fd, mdp_super_t *super)
 200 {
 201         /* try to read in the superblock
 202          *
 203          * return
 204          *   0 - success
 205          *   1 - no block size
 206          *   2 - too small
 207          *   3 - no seek
 208          *   4 - no read
 209          *   5 - no magic
 210          *   6 - wrong major version
 211          */
 212         unsigned long size;
 213         unsigned long long offset;
 214
 215         if (ioctl(fd, BLKGETSIZE, &size))
 216                 return 1;
 217
 218         if (size < MD_RESERVED_SECTORS*2)
 219                 return 2;
 220
 221         offset = MD_NEW_SIZE_SECTORS(size);
 222
 223         offset *= 512;
 224
 225         ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
 226
 227         if (lseek64(fd, offset, 0)< 0LL)
 228                 return 3;
 229
 230         if (read(fd, super, sizeof(*super)) != sizeof(*super))
 231                 return 4;
 232
 233         if (super->md_magic != MD_SB_MAGIC)
 234                 return 5;
 235
 236         if (super->major_version != 0)
 237                 return 6;
 238         return 0;
 239 }
 240
 241 int store_super(int fd, mdp_super_t *super)
 242 {
 243         long size;
 244         long long offset;
 245
 246         if (ioctl(fd, BLKGETSIZE, &size))
 247                 return 1;
 248
 249         if (size < MD_RESERVED_SECTORS*2)
 250                 return 2;
 251
 252         offset = MD_NEW_SIZE_SECTORS(size);
 253
 254         offset *= 512;
 255
 256         if (lseek64(fd, offset, 0)< 0LL)
 257                 return 3;
 258
 259         if (write(fd, super, sizeof(*super)) != sizeof(*super))
 260                 return 4;
 261
 262         return 0;
 263 }
 264
 265
 266
 267 int check_ext2(int fd, char *name)
 268 {
 269         /*
 270          * Check for an ext2fs file system.
 271          * Superblock is always 1K at 1K offset
 272          *
 273          * s_magic is le16 at 56 == 0xEF53
 274          * report mtime - le32 at 44
 275          * blocks - le32 at 4
 276          * logblksize - le32 at 24
 277          */
 278         unsigned char sb[1024];
 279         time_t mtime;
 280         int size, bsize;
 281         if (lseek(fd, 1024,0)!= 1024)
 282                 return 0;
 283         if (read(fd, sb, 1024)!= 1024)
 284                 return 0;
 285         if (sb[56] != 0x53 || sb[57] != 0xef)
 286                 return 0;
 287
 288         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 289         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 290         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 291         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 292                 name);
 293         fprintf(stderr,"    size=%dK  mtime=%s",
 294                 size*(1<<bsize), ctime(&mtime));
 295         return 1;
 296 }
 297
 298 int check_reiser(int fd, char *name)
 299 {
 300         /*
 301          * superblock is at 64K
 302          * size is 1024;
 303          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 304          *
 305          */
 306         unsigned char sb[1024];
 307         int size;
 308         if (lseek(fd, 64*1024, 0) != 64*1024)
 309                 return 0;
 310         if (read(fd, sb, 1024) != 1024)
 311                 return 0;
 312         if (strncmp(sb+52, "ReIsErFs",8)!=0 &&
 313             strncmp(sb+52, "ReIsEr2Fs",9)!=0)
 314                 return 0;
 315         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 316         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 317         fprintf(stderr, "    size = %dK\n", size*4);
 318
 319         return 1;
 320 }
 321
 322 int check_raid(int fd, char *name)
 323 {
 324         mdp_super_t super;
 325         time_t crtime;
 326         if (load_super(fd, &super))
 327                 return 0;
 328         /* Looks like a raid array .. */
 329         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 330                 name);
 331         crtime = super.ctime;
 332         fprintf(stderr, "    level=%d devices=%d ctime=%s",
 333                 super.level, super.raid_disks, ctime(&crtime));
 334         return 1;
 335 }
 336
 337
 338 int ask(char *mesg)
 339 {
 340         char *add = "";
 341         int i;
 342         for (i=0; i<5; i++) {
 343                 char buf[100];
 344                 fprintf(stderr, "%s%s", mesg, add);
 345                 fflush(stderr);
 346                 if (fgets(buf, 100, stdin)==NULL)
 347                         return 0;
 348                 if (buf[0]=='y' || buf[0]=='Y')
 349                         return 1;
 350                 if (buf[0]=='n' || buf[0]=='N')
 351                         return 0;
 352                 add = "(y/n) ";
 353         }
 354         fprintf(stderr, Name ": assuming 'no'\n");
 355         return 0;
 356 }
 357
 358 char *map_num(mapping_t *map, int num)
 359 {
 360         while (map->name) {
 361                 if (map->num == num)
 362                         return map->name;
 363                 map++;
 364         }
 365         return NULL;
 366 }
 367
 368 int map_name(mapping_t *map, char *name)
 369 {
 370         while (map->name) {
 371                 if (strcmp(map->name, name)==0)
 372                         return map->num;
 373                 map++;
 374         }
 375         return UnSet;
 376 }
 377
 378 /*
 379  * convert a major/minor pair for a block device into a name in /dev, if possible.
 380  * On the first call, walk /dev collecting name.
 381  * Put them in a simple linked listfor now.
 382  */
 383 struct devmap {
 384     int major, minor;
 385     char *name;
 386     struct devmap *next;
 387 } *devlist = NULL;
 388 int devlist_ready = 0;
 389
 390 #ifdef UCLIBC
 391 char *map_dev(int major, int minor)
 392 {
 393 #if 0
 394         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 395                 major, minor);
 396 #endif
 397         return NULL;
 398 }
 399 #else
 400 #define  __USE_XOPEN_EXTENDED
 401 #include <ftw.h>
 402
 403
 404 #ifndef __dietlibc__
 405 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 406 #else
 407 int add_dev(const char *name, const struct stat *stb, int flag)
 408 #endif
 409 {
 410     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 411         char *n = strdup(name);
 412         struct devmap *dm = malloc(sizeof(*dm));
 413         if (dm) {
 414             dm->major = MAJOR(stb->st_rdev);
 415             dm->minor = MINOR(stb->st_rdev);
 416             dm->name = n;
 417             dm->next = devlist;
 418             devlist = dm;
 419         }
 420     }
 421     return 0;
 422 }
 423
 424 char *map_dev(int major, int minor)
 425 {
 426     struct devmap *p;
 427     if (!devlist_ready) {
 428 #ifndef __dietlibc__
 429         nftw("/dev", add_dev, 10, FTW_PHYS);
 430 #else
 431         ftw("/dev", add_dev, 10);
 432 #endif
 433         devlist_ready=1;
 434     }
 435
 436     for (p=devlist; p; p=p->next)
 437         if (p->major == major &&
 438             p->minor == minor)
 439             return p->name;
 440     return NULL;
 441 }
 442
 443 #endif
 444
 445 unsigned long calc_sb_csum(mdp_super_t *super)
 446 {
 447         unsigned int  oldcsum = super->sb_csum;
 448         unsigned long long newcsum = 0;
 449         unsigned long csum;
 450         int i;
 451         unsigned int *superc = (int*) super;
 452         super->sb_csum = 0;
 453
 454         for(i=0; i<MD_SB_BYTES/4; i++)
 455                 newcsum+= superc[i];
 456         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 457         super->sb_csum = oldcsum;
 458         return csum;
 459 }
 460
 461 char *human_size(long long bytes)
 462 {
 463         static char buf[30];
 464
 465
 466         if (bytes < 5000*1024)
 467                 buf[0]=0;
 468         else if (bytes < 2*1024LL*1024LL*1024LL)
 469                 sprintf(buf, " (%ld.%02ld MiB %ld.%02ld MB)",
 470                         (long)(bytes>>20),
 471                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100),
 472                         (long)(bytes/1000/1000),
 473                         (long)(((bytes%1000000)+5000)/10000)
 474                         );
 475         else
 476                 sprintf(buf, " (%ld.%02ld GiB %ld.%02ld GB)",
 477                         (long)(bytes>>30),
 478                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100),
 479                         (long)(bytes/1000LL/1000LL/1000LL),
 480                         (long)((((bytes/1000)%1000000)+5000)/10000)
 481                         );
 482         return buf;
 483 }
 484
 485 char *human_size_brief(long long bytes)
 486 {
 487         static char buf[30];
 488
 489
 490         if (bytes < 5000*1024)
 491                 sprintf(buf, "%ld.%02ldKiB",
 492                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 493                         );
 494         else if (bytes < 2*1024LL*1024LL*1024LL)
 495                 sprintf(buf, "%ld.%02ldMiB",
 496                         (long)(bytes>>20),
 497                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 498                         );
 499         else
 500                 sprintf(buf, "%ld.%02ldGiB",
 501                         (long)(bytes>>30),
 502                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 503                         );
 504         return buf;
 505 }
 506
 507 static int mdp_major = -1;
 508 void get_mdp_major(void)
 509 {
 510         FILE *fl = fopen("/proc/devices", "r");
 511         char *w;
 512         int have_block = 0;
 513         int have_devices = 0;
 514         int last_num = -1;
 515         if (!fl)
 516                 return;
 517         while ((w = conf_word(fl, 1))) {
 518                 if (have_block && strcmp(w, "devices:")==0)
 519                         have_devices = 1;
 520                 have_block =  (strcmp(w, "Block")==0);
 521                 if (isdigit(w[0]))
 522                         last_num = atoi(w);
 523                 if (have_devices && strcmp(w, "mdp")==0)
 524                         mdp_major = last_num;
 525                 free(w);
 526         }
 527         fclose(fl);
 528 }
 529
 530
 531
 532 char *get_md_name(int dev)
 533 {
 534         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 535         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 536         static char devname[50];
 537         struct stat stb;
 538         dev_t rdev;
 539
 540         if (dev < 0) {
 541
 542                 if (mdp_major < 0) get_mdp_major();
 543                 if (mdp_major < 0) return NULL;
 544                 rdev = MKDEV(mdp_major, (-1-dev)<<6);
 545                 sprintf(devname, "/dev/md/d%d", -1-dev);
 546                 if (stat(devname, &stb) == 0
 547                     && (S_IFMT&stb.st_mode) == S_IFBLK
 548                     && (stb.st_rdev == rdev))
 549                         return devname;
 550         } else {
 551                 rdev = MKDEV(MD_MAJOR, dev);
 552                 sprintf(devname, "/dev/md%d", dev);
 553                 if (stat(devname, &stb) == 0
 554                     && (S_IFMT&stb.st_mode) == S_IFBLK
 555                     && (stb.st_rdev == rdev))
 556                         return devname;
 557
 558                 sprintf(devname, "/dev/md/%d", dev);
 559                 if (stat(devname, &stb) == 0
 560                     && (S_IFMT&stb.st_mode) == S_IFBLK
 561                     && (stb.st_rdev == rdev))
 562                         return devname;
 563         }
 564         sprintf(devname, "/dev/.tmp.md%d", dev);
 565         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 566                 return NULL;
 567
 568         if (stat(devname, &stb) == 0
 569             && (S_IFMT&stb.st_mode) == S_IFBLK
 570             && (stb.st_rdev == rdev))
 571                 return devname;
 572         unlink(devname);
 573         return NULL;
 574 }
 575
 576 void put_md_name(char *name)
 577 {
 578         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 579                 unlink(name);
 580 }