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], int swapuuid)
 144 {
 145         if (swapuuid) {
 146                 /* parse uuids are hostendian.
 147                  * uuid's from some superblocks are big-ending
 148                  * if there is a difference, we need to swap..
 149                  */
 150                 unsigned char *ac = (unsigned char *)a;
 151                 unsigned char *bc = (unsigned char *)b;
 152                 int i;
 153                 for (i=0; i<16; i+= 4) {
 154                         if (ac[i+0] != bc[i+3] ||
 155                             ac[i+1] != bc[i+2] ||
 156                             ac[i+2] != bc[i+1] ||
 157                             ac[i+3] != bc[i+0])
 158                                 return 0;
 159                 }
 160                 return 1;
 161         } else {
 162                 if (a[0]==b[0] &&
 163                     a[1]==b[1] &&
 164                     a[2]==b[2] &&
 165                     a[3]==b[3])
 166                         return 1;
 167                 return 0;
 168         }
 169 }
 170
 171 int check_ext2(int fd, char *name)
 172 {
 173         /*
 174          * Check for an ext2fs file system.
 175          * Superblock is always 1K at 1K offset
 176          *
 177          * s_magic is le16 at 56 == 0xEF53
 178          * report mtime - le32 at 44
 179          * blocks - le32 at 4
 180          * logblksize - le32 at 24
 181          */
 182         unsigned char sb[1024];
 183         time_t mtime;
 184         int size, bsize;
 185         if (lseek(fd, 1024,0)!= 1024)
 186                 return 0;
 187         if (read(fd, sb, 1024)!= 1024)
 188                 return 0;
 189         if (sb[56] != 0x53 || sb[57] != 0xef)
 190                 return 0;
 191
 192         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 193         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 194         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 195         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 196                 name);
 197         fprintf(stderr,"    size=%dK  mtime=%s",
 198                 size*(1<<bsize), ctime(&mtime));
 199         return 1;
 200 }
 201
 202 int check_reiser(int fd, char *name)
 203 {
 204         /*
 205          * superblock is at 64K
 206          * size is 1024;
 207          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 208          *
 209          */
 210         unsigned char sb[1024];
 211         int size;
 212         if (lseek(fd, 64*1024, 0) != 64*1024)
 213                 return 0;
 214         if (read(fd, sb, 1024) != 1024)
 215                 return 0;
 216         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 217             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 218                 return 0;
 219         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 220         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 221         fprintf(stderr, "    size = %dK\n", size*4);
 222
 223         return 1;
 224 }
 225
 226 int check_raid(int fd, char *name)
 227 {
 228         void *super;
 229         struct mdinfo info;
 230         struct mddev_ident_s ident;
 231         time_t crtime;
 232         char *level;
 233         struct supertype *st = guess_super(fd);
 234
 235         if (!st) return 0;
 236         st->ss->load_super(st, fd, &super, name);
 237         /* Looks like a raid array .. */
 238         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 239                 name);
 240         st->ss->getinfo_super(&info, &ident, super);
 241         free(super);
 242         crtime = info.array.ctime;
 243         level = map_num(pers, info.array.level);
 244         if (!level) level = "-unknown-";
 245         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 246                 level, info.array.raid_disks, ctime(&crtime));
 247         return 1;
 248 }
 249
 250 int ask(char *mesg)
 251 {
 252         char *add = "";
 253         int i;
 254         for (i=0; i<5; i++) {
 255                 char buf[100];
 256                 fprintf(stderr, "%s%s", mesg, add);
 257                 fflush(stderr);
 258                 if (fgets(buf, 100, stdin)==NULL)
 259                         return 0;
 260                 if (buf[0]=='y' || buf[0]=='Y')
 261                         return 1;
 262                 if (buf[0]=='n' || buf[0]=='N')
 263                         return 0;
 264                 add = "(y/n) ";
 265         }
 266         fprintf(stderr, Name ": assuming 'no'\n");
 267         return 0;
 268 }
 269
 270 char *map_num(mapping_t *map, int num)
 271 {
 272         while (map->name) {
 273                 if (map->num == num)
 274                         return map->name;
 275                 map++;
 276         }
 277         return NULL;
 278 }
 279
 280 int map_name(mapping_t *map, char *name)
 281 {
 282         while (map->name) {
 283                 if (strcmp(map->name, name)==0)
 284                         return map->num;
 285                 map++;
 286         }
 287         return UnSet;
 288 }
 289
 290
 291 int is_standard(char *dev, int *nump)
 292 {
 293         /* tests if dev is a "standard" md dev name.
 294          * i.e if the last component is "/dNN" or "/mdNN",
 295          * where NN is a string of digits
 296          */
 297         char *d = strrchr(dev, '/');
 298         int type=0;
 299         int num;
 300         if (!d)
 301                 return 0;
 302         if (strncmp(d, "/d",2)==0)
 303                 d += 2, type=1; /* /dev/md/dN{pM} */
 304         else if (strncmp(d, "/md_d", 5)==0)
 305                 d += 5, type=1; /* /dev/md_dNpM */
 306         else if (strncmp(d, "/md", 3)==0)
 307                 d += 3, type=-1; /* /dev/mdN */
 308         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 309                 d += 1, type=-1; /* /dev/md/N */
 310         else
 311                 return 0;
 312         if (!*d)
 313                 return 0;
 314         num = atoi(d);
 315         while (isdigit(*d))
 316                 d++;
 317         if (*d)
 318                 return 0;
 319         if (nump) *nump = num;
 320
 321         return type;
 322 }
 323
 324
 325 /*
 326  * convert a major/minor pair for a block device into a name in /dev, if possible.
 327  * On the first call, walk /dev collecting name.
 328  * Put them in a simple linked listfor now.
 329  */
 330 struct devmap {
 331     int major, minor;
 332     char *name;
 333     struct devmap *next;
 334 } *devlist = NULL;
 335 int devlist_ready = 0;
 336
 337 #ifdef UCLIBC
 338 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 339 {
 340 }
 341 char *map_dev(int major, int minor)
 342 {
 343 #if 0
 344         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 345                 major, minor);
 346 #endif
 347         return NULL;
 348 }
 349 #else
 350
 351 #ifdef __dietlibc__
 352 int add_dev_1(const char *name, const struct stat *stb, int flag)
 353 {
 354         return add_dev(name, stb, flag, NULL);
 355 }
 356 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 357 {
 358         ftw(path, add_dev_1, nopenfd);
 359 }
 360 #endif
 361
 362 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 363 {
 364     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 365         char *n = strdup(name);
 366         struct devmap *dm = malloc(sizeof(*dm));
 367         if (dm) {
 368             dm->major = major(stb->st_rdev);
 369             dm->minor = minor(stb->st_rdev);
 370             dm->name = n;
 371             dm->next = devlist;
 372             devlist = dm;
 373         }
 374     }
 375     return 0;
 376 }
 377
 378 /*
 379  * Find a block device with the right major/minor number.
 380  * If we find multiple names, choose the shortest.
 381  * If we find a non-standard name, it is probably there
 382  * deliberately so prefer it over a standard name.
 383  * This applies only to names for MD devices.
 384  */
 385 char *map_dev(int major, int minor)
 386 {
 387         struct devmap *p;
 388         char *std = NULL, *nonstd=NULL;
 389         if (!devlist_ready) {
 390                 nftw("/dev", add_dev, 10, FTW_PHYS);
 391                 devlist_ready=1;
 392         }
 393
 394         for (p=devlist; p; p=p->next)
 395                 if (p->major == major &&
 396                     p->minor == minor) {
 397                         if (is_standard(p->name, NULL)) {
 398                                 if (std == NULL ||
 399                                     strlen(p->name) < strlen(std))
 400                                         std = p->name;
 401                         } else {
 402                                 if (nonstd == NULL ||
 403                                     strlen(p->name) < strlen(nonstd))
 404                                         nonstd = p->name;
 405                         }
 406                 }
 407         return nonstd ? nonstd : std;
 408 }
 409
 410 #endif
 411
 412 unsigned long calc_csum(void *super, int bytes)
 413 {
 414         unsigned long long newcsum = 0;
 415         int i;
 416         unsigned int csum;
 417         unsigned int *superc = (unsigned int*) super;
 418
 419         for(i=0; i<bytes/4; i++)
 420                 newcsum+= superc[i];
 421         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 422 #ifdef __alpha__
 423 /* The in-kernel checksum calculation is always 16bit on
 424  * the alpha, though it is 32 bit on i386...
 425  * I wonder what it is elsewhere... (it uses and API in
 426  * a way that it shouldn't).
 427  */
 428         csum = (csum & 0xffff) + (csum >> 16);
 429         csum = (csum & 0xffff) + (csum >> 16);
 430 #endif
 431         return csum;
 432 }
 433
 434 char *human_size(long long bytes)
 435 {
 436         static char buf[30];
 437
 438         /* We convert bytes to either centi-M{ega,ibi}bytes or
 439          * centi-G{igi,ibi}bytes, with appropriate rounding,
 440          * and then print 1/100th of those as a decimal.
 441          * We allow upto 2048Megabytes before converting to
 442          * gigabytes, as that shows more precision and isn't
 443          * too large a number.
 444          * Terrabytes are not yet handled.
 445          */
 446
 447         if (bytes < 5000*1024)
 448                 buf[0]=0;
 449         else if (bytes < 2*1024LL*1024LL*1024LL) {
 450                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 451                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 452                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 453                         cMiB/100 , cMiB % 100,
 454                         cMB/100, cMB % 100);
 455         } else {
 456                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 457                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 458                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 459                         cGiB/100 , cGiB % 100,
 460                         cGB/100, cGB % 100);
 461         }
 462         return buf;
 463 }
 464
 465 char *human_size_brief(long long bytes)
 466 {
 467         static char buf[30];
 468
 469
 470         if (bytes < 5000*1024)
 471                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 472                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 473                         );
 474         else if (bytes < 2*1024LL*1024LL*1024LL)
 475                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 476                         (long)(bytes>>20),
 477                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 478                         );
 479         else
 480                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 481                         (long)(bytes>>30),
 482                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 483                         );
 484         return buf;
 485 }
 486
 487 int get_mdp_major(void)
 488 {
 489 static int mdp_major = -1;
 490         FILE *fl;
 491         char *w;
 492         int have_block = 0;
 493         int have_devices = 0;
 494         int last_num = -1;
 495
 496         if (mdp_major != -1)
 497                 return mdp_major;
 498         fl = fopen("/proc/devices", "r");
 499         if (!fl)
 500                 return -1;
 501         while ((w = conf_word(fl, 1))) {
 502                 if (have_block && strcmp(w, "devices:")==0)
 503                         have_devices = 1;
 504                 have_block =  (strcmp(w, "Block")==0);
 505                 if (isdigit(w[0]))
 506                         last_num = atoi(w);
 507                 if (have_devices && strcmp(w, "mdp")==0)
 508                         mdp_major = last_num;
 509                 free(w);
 510         }
 511         fclose(fl);
 512         return mdp_major;
 513 }
 514
 515
 516
 517 char *get_md_name(int dev)
 518 {
 519         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 520         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 521         static char devname[50];
 522         struct stat stb;
 523         dev_t rdev;
 524         char *dn;
 525
 526         if (dev < 0) {
 527                 int mdp =  get_mdp_major();
 528                 if (mdp < 0) return NULL;
 529                 rdev = makedev(mdp, (-1-dev)<<6);
 530                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 531                 if (stat(devname, &stb) == 0
 532                     && (S_IFMT&stb.st_mode) == S_IFBLK
 533                     && (stb.st_rdev == rdev))
 534                         return devname;
 535         } else {
 536                 rdev = makedev(MD_MAJOR, dev);
 537                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 538                 if (stat(devname, &stb) == 0
 539                     && (S_IFMT&stb.st_mode) == S_IFBLK
 540                     && (stb.st_rdev == rdev))
 541                         return devname;
 542
 543                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 544                 if (stat(devname, &stb) == 0
 545                     && (S_IFMT&stb.st_mode) == S_IFBLK
 546                     && (stb.st_rdev == rdev))
 547                         return devname;
 548         }
 549         dn = map_dev(major(rdev), minor(rdev));
 550         if (dn)
 551                 return dn;
 552         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 553         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 554                 if (errno != EEXIST)
 555                         return NULL;
 556
 557         if (stat(devname, &stb) == 0
 558             && (S_IFMT&stb.st_mode) == S_IFBLK
 559             && (stb.st_rdev == rdev))
 560                 return devname;
 561         unlink(devname);
 562         return NULL;
 563 }
 564
 565 void put_md_name(char *name)
 566 {
 567         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 568                 unlink(name);
 569 }
 570
 571
 572
 573 struct superswitch *superlist[] = { &super0, &super1, NULL };
 574
 575 struct supertype *super_by_version(int vers, int minor)
 576 {
 577         struct supertype *st = malloc(sizeof(*st));
 578         if (!st) return st;
 579         if (vers == 0) {
 580                 st->ss = &super0;
 581                 st->max_devs = MD_SB_DISKS;
 582         }
 583
 584         if (vers == 1) {
 585                 st->ss = &super1;
 586                 st->max_devs = 384;
 587         }
 588         st->minor_version = minor;
 589         return st;
 590 }
 591
 592 struct supertype *guess_super(int fd)
 593 {
 594         /* try each load_super to find the best match,
 595          * and return the best superswitch
 596          */
 597         struct superswitch  *ss;
 598         struct supertype *st;
 599         unsigned long besttime = 0;
 600         int bestsuper = -1;
 601
 602         void *sbp = NULL;
 603         int i;
 604
 605         st = malloc(sizeof(*st));
 606         memset(st, 0, sizeof(*st));
 607         for (i=0 ; superlist[i]; i++) {
 608                 int rv;
 609                 ss = superlist[i];
 610                 st->ss = NULL;
 611                 rv = ss->load_super(st, fd, &sbp, NULL);
 612                 if (rv == 0) {
 613                         struct mdinfo info;
 614                         struct mddev_ident_s ident;
 615                         ss->getinfo_super(&info, &ident, sbp);
 616                         if (bestsuper == -1 ||
 617                             besttime < info.array.ctime) {
 618                                 bestsuper = i;
 619                                 besttime = info.array.ctime;
 620                         }
 621                         free(sbp);
 622                 }
 623         }
 624         if (bestsuper != -1) {
 625                 int rv;
 626                 st->ss = NULL;
 627                 rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
 628                 if (rv == 0) {
 629                         free(sbp);
 630                         return st;
 631                 }
 632         }
 633         free(st);
 634         return NULL;
 635 }
 636
 637 #ifdef __TINYC__
 638 /* tinyc doesn't optimize this check in ioctl.h out ... */
 639 unsigned int __invalid_size_argument_for_IOC = 0;
 640 #endif
 641