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 layout,
 122            char *avail, int avail_disks)
 123 {
 124         int copies, first;
 125         switch (level) {
 126         case 10:
 127                 /* This is the tricky one - we need to check
 128                  * which actual disks are present.
 129                  */
 130                 copies = (layout&255)* (layout>>8);
 131                 first=0;
 132                 do {
 133                         /* there must be one of the 'copies' form 'first' */
 134                         int n = copies;
 135                         int cnt=0;
 136                         while (n--) {
 137                                 if (avail[first])
 138                                         cnt++;
 139                                 first = (first+1) % raid_disks;
 140                         }
 141                         if (cnt == 0)
 142                                 return 0;
 143
 144                 } while (first != 0);
 145                 return 1;
 146
 147         case -4:
 148                 return avail_disks>= 1;
 149         case -1:
 150         case 0:
 151                 return avail_disks == raid_disks;
 152         case 1:
 153                 return avail_disks >= 1;
 154         case 4:
 155         case 5:
 156                 return avail_disks >= raid_disks-1;
 157         case 6:
 158                 return avail_disks >= raid_disks-2;
 159         default:
 160                 return 0;
 161         }
 162 }
 163
 164 int same_uuid(int a[4], int b[4], int swapuuid)
 165 {
 166         if (swapuuid) {
 167                 /* parse uuids are hostendian.
 168                  * uuid's from some superblocks are big-ending
 169                  * if there is a difference, we need to swap..
 170                  */
 171                 unsigned char *ac = (unsigned char *)a;
 172                 unsigned char *bc = (unsigned char *)b;
 173                 int i;
 174                 for (i=0; i<16; i+= 4) {
 175                         if (ac[i+0] != bc[i+3] ||
 176                             ac[i+1] != bc[i+2] ||
 177                             ac[i+2] != bc[i+1] ||
 178                             ac[i+3] != bc[i+0])
 179                                 return 0;
 180                 }
 181                 return 1;
 182         } else {
 183                 if (a[0]==b[0] &&
 184                     a[1]==b[1] &&
 185                     a[2]==b[2] &&
 186                     a[3]==b[3])
 187                         return 1;
 188                 return 0;
 189         }
 190 }
 191
 192 int check_ext2(int fd, char *name)
 193 {
 194         /*
 195          * Check for an ext2fs file system.
 196          * Superblock is always 1K at 1K offset
 197          *
 198          * s_magic is le16 at 56 == 0xEF53
 199          * report mtime - le32 at 44
 200          * blocks - le32 at 4
 201          * logblksize - le32 at 24
 202          */
 203         unsigned char sb[1024];
 204         time_t mtime;
 205         int size, bsize;
 206         if (lseek(fd, 1024,0)!= 1024)
 207                 return 0;
 208         if (read(fd, sb, 1024)!= 1024)
 209                 return 0;
 210         if (sb[56] != 0x53 || sb[57] != 0xef)
 211                 return 0;
 212
 213         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 214         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 215         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 216         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 217                 name);
 218         fprintf(stderr,"    size=%dK  mtime=%s",
 219                 size*(1<<bsize), ctime(&mtime));
 220         return 1;
 221 }
 222
 223 int check_reiser(int fd, char *name)
 224 {
 225         /*
 226          * superblock is at 64K
 227          * size is 1024;
 228          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 229          *
 230          */
 231         unsigned char sb[1024];
 232         unsigned long size;
 233         if (lseek(fd, 64*1024, 0) != 64*1024)
 234                 return 0;
 235         if (read(fd, sb, 1024) != 1024)
 236                 return 0;
 237         if (strncmp((char*)sb+52, "ReIsErFs",8)!=0 &&
 238             strncmp((char*)sb+52, "ReIsEr2Fs",9)!=0)
 239                 return 0;
 240         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 241         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 242         fprintf(stderr, "    size = %luK\n", size*4);
 243
 244         return 1;
 245 }
 246
 247 int check_raid(int fd, char *name)
 248 {
 249         void *super;
 250         struct mdinfo info;
 251         time_t crtime;
 252         char *level;
 253         struct supertype *st = guess_super(fd);
 254
 255         if (!st) return 0;
 256         st->ss->load_super(st, fd, &super, name);
 257         /* Looks like a raid array .. */
 258         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 259                 name);
 260         st->ss->getinfo_super(&info, super);
 261         free(super);
 262         crtime = info.array.ctime;
 263         level = map_num(pers, info.array.level);
 264         if (!level) level = "-unknown-";
 265         fprintf(stderr, "    level=%s devices=%d ctime=%s",
 266                 level, info.array.raid_disks, ctime(&crtime));
 267         return 1;
 268 }
 269
 270 int ask(char *mesg)
 271 {
 272         char *add = "";
 273         int i;
 274         for (i=0; i<5; i++) {
 275                 char buf[100];
 276                 fprintf(stderr, "%s%s", mesg, add);
 277                 fflush(stderr);
 278                 if (fgets(buf, 100, stdin)==NULL)
 279                         return 0;
 280                 if (buf[0]=='y' || buf[0]=='Y')
 281                         return 1;
 282                 if (buf[0]=='n' || buf[0]=='N')
 283                         return 0;
 284                 add = "(y/n) ";
 285         }
 286         fprintf(stderr, Name ": assuming 'no'\n");
 287         return 0;
 288 }
 289
 290 char *map_num(mapping_t *map, int num)
 291 {
 292         while (map->name) {
 293                 if (map->num == num)
 294                         return map->name;
 295                 map++;
 296         }
 297         return NULL;
 298 }
 299
 300 int map_name(mapping_t *map, char *name)
 301 {
 302         while (map->name) {
 303                 if (strcmp(map->name, name)==0)
 304                         return map->num;
 305                 map++;
 306         }
 307         return UnSet;
 308 }
 309
 310
 311 int is_standard(char *dev, int *nump)
 312 {
 313         /* tests if dev is a "standard" md dev name.
 314          * i.e if the last component is "/dNN" or "/mdNN",
 315          * where NN is a string of digits
 316          */
 317         char *d = strrchr(dev, '/');
 318         int type=0;
 319         int num;
 320         if (!d)
 321                 return 0;
 322         if (strncmp(d, "/d",2)==0)
 323                 d += 2, type=1; /* /dev/md/dN{pM} */
 324         else if (strncmp(d, "/md_d", 5)==0)
 325                 d += 5, type=1; /* /dev/md_dNpM */
 326         else if (strncmp(d, "/md", 3)==0)
 327                 d += 3, type=-1; /* /dev/mdN */
 328         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 329                 d += 1, type=-1; /* /dev/md/N */
 330         else
 331                 return 0;
 332         if (!*d)
 333                 return 0;
 334         num = atoi(d);
 335         while (isdigit(*d))
 336                 d++;
 337         if (*d)
 338                 return 0;
 339         if (nump) *nump = num;
 340
 341         return type;
 342 }
 343
 344
 345 /*
 346  * convert a major/minor pair for a block device into a name in /dev, if possible.
 347  * On the first call, walk /dev collecting name.
 348  * Put them in a simple linked listfor now.
 349  */
 350 struct devmap {
 351     int major, minor;
 352     char *name;
 353     struct devmap *next;
 354 } *devlist = NULL;
 355 int devlist_ready = 0;
 356
 357 #ifdef UCLIBC
 358 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 359 {
 360 }
 361 char *map_dev(int major, int minor)
 362 {
 363 #if 0
 364         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 365                 major, minor);
 366 #endif
 367         return NULL;
 368 }
 369 #else
 370
 371 #ifdef __dietlibc__
 372 int add_dev_1(const char *name, const struct stat *stb, int flag)
 373 {
 374         return add_dev(name, stb, flag, NULL);
 375 }
 376 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
 377 {
 378         ftw(path, add_dev_1, nopenfd);
 379 }
 380 #endif
 381
 382 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 383 {
 384     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 385         char *n = strdup(name);
 386         struct devmap *dm = malloc(sizeof(*dm));
 387         if (dm) {
 388             dm->major = major(stb->st_rdev);
 389             dm->minor = minor(stb->st_rdev);
 390             dm->name = n;
 391             dm->next = devlist;
 392             devlist = dm;
 393         }
 394     }
 395     return 0;
 396 }
 397
 398 /*
 399  * Find a block device with the right major/minor number.
 400  * If we find multiple names, choose the shortest.
 401  * If we find a non-standard name, it is probably there
 402  * deliberately so prefer it over a standard name.
 403  * This applies only to names for MD devices.
 404  */
 405 char *map_dev(int major, int minor)
 406 {
 407         struct devmap *p;
 408         char *std = NULL, *nonstd=NULL;
 409         if (!devlist_ready) {
 410                 nftw("/dev", add_dev, 10, FTW_PHYS);
 411                 devlist_ready=1;
 412         }
 413
 414         for (p=devlist; p; p=p->next)
 415                 if (p->major == major &&
 416                     p->minor == minor) {
 417                         if (is_standard(p->name, NULL)) {
 418                                 if (std == NULL ||
 419                                     strlen(p->name) < strlen(std))
 420                                         std = p->name;
 421                         } else {
 422                                 if (nonstd == NULL ||
 423                                     strlen(p->name) < strlen(nonstd))
 424                                         nonstd = p->name;
 425                         }
 426                 }
 427         return nonstd ? nonstd : std;
 428 }
 429
 430 #endif
 431
 432 unsigned long calc_csum(void *super, int bytes)
 433 {
 434         unsigned long long newcsum = 0;
 435         int i;
 436         unsigned int csum;
 437         unsigned int *superc = (unsigned int*) super;
 438
 439         for(i=0; i<bytes/4; i++)
 440                 newcsum+= superc[i];
 441         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 442 #ifdef __alpha__
 443 /* The in-kernel checksum calculation is always 16bit on
 444  * the alpha, though it is 32 bit on i386...
 445  * I wonder what it is elsewhere... (it uses and API in
 446  * a way that it shouldn't).
 447  */
 448         csum = (csum & 0xffff) + (csum >> 16);
 449         csum = (csum & 0xffff) + (csum >> 16);
 450 #endif
 451         return csum;
 452 }
 453
 454 char *human_size(long long bytes)
 455 {
 456         static char buf[30];
 457
 458         /* We convert bytes to either centi-M{ega,ibi}bytes or
 459          * centi-G{igi,ibi}bytes, with appropriate rounding,
 460          * and then print 1/100th of those as a decimal.
 461          * We allow upto 2048Megabytes before converting to
 462          * gigabytes, as that shows more precision and isn't
 463          * too large a number.
 464          * Terrabytes are not yet handled.
 465          */
 466
 467         if (bytes < 5000*1024)
 468                 buf[0]=0;
 469         else if (bytes < 2*1024LL*1024LL*1024LL) {
 470                 long cMiB = (bytes / ( (1LL<<20) / 200LL ) +1) /2;
 471                 long cMB  = (bytes / ( 1000000LL / 200LL ) +1) /2;
 472                 snprintf(buf, sizeof(buf), " (%ld.%02ld MiB %ld.%02ld MB)",
 473                         cMiB/100 , cMiB % 100,
 474                         cMB/100, cMB % 100);
 475         } else {
 476                 long cGiB = (bytes / ( (1LL<<30) / 200LL ) +1) /2;
 477                 long cGB  = (bytes / (1000000000LL/200LL ) +1) /2;
 478                 snprintf(buf, sizeof(buf), " (%ld.%02ld GiB %ld.%02ld GB)",
 479                         cGiB/100 , cGiB % 100,
 480                         cGB/100, cGB % 100);
 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                 snprintf(buf, sizeof(buf), "%ld.%02ldKiB",
 492                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 493                         );
 494         else if (bytes < 2*1024LL*1024LL*1024LL)
 495                 snprintf(buf, sizeof(buf), "%ld.%02ldMiB",
 496                         (long)(bytes>>20),
 497                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 498                         );
 499         else
 500                 snprintf(buf, sizeof(buf), "%ld.%02ldGiB",
 501                         (long)(bytes>>30),
 502                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 503                         );
 504         return buf;
 505 }
 506
 507 int get_mdp_major(void)
 508 {
 509 static int mdp_major = -1;
 510         FILE *fl;
 511         char *w;
 512         int have_block = 0;
 513         int have_devices = 0;
 514         int last_num = -1;
 515
 516         if (mdp_major != -1)
 517                 return mdp_major;
 518         fl = fopen("/proc/devices", "r");
 519         if (!fl)
 520                 return -1;
 521         while ((w = conf_word(fl, 1))) {
 522                 if (have_block && strcmp(w, "devices:")==0)
 523                         have_devices = 1;
 524                 have_block =  (strcmp(w, "Block")==0);
 525                 if (isdigit(w[0]))
 526                         last_num = atoi(w);
 527                 if (have_devices && strcmp(w, "mdp")==0)
 528                         mdp_major = last_num;
 529                 free(w);
 530         }
 531         fclose(fl);
 532         return mdp_major;
 533 }
 534
 535
 536
 537 char *get_md_name(int dev)
 538 {
 539         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 540         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 541         static char devname[50];
 542         struct stat stb;
 543         dev_t rdev;
 544         char *dn;
 545
 546         if (dev < 0) {
 547                 int mdp =  get_mdp_major();
 548                 if (mdp < 0) return NULL;
 549                 rdev = makedev(mdp, (-1-dev)<<6);
 550                 snprintf(devname, sizeof(devname), "/dev/md/d%d", -1-dev);
 551                 if (stat(devname, &stb) == 0
 552                     && (S_IFMT&stb.st_mode) == S_IFBLK
 553                     && (stb.st_rdev == rdev))
 554                         return devname;
 555         } else {
 556                 rdev = makedev(MD_MAJOR, dev);
 557                 snprintf(devname, sizeof(devname), "/dev/md%d", dev);
 558                 if (stat(devname, &stb) == 0
 559                     && (S_IFMT&stb.st_mode) == S_IFBLK
 560                     && (stb.st_rdev == rdev))
 561                         return devname;
 562
 563                 snprintf(devname, sizeof(devname), "/dev/md/%d", dev);
 564                 if (stat(devname, &stb) == 0
 565                     && (S_IFMT&stb.st_mode) == S_IFBLK
 566                     && (stb.st_rdev == rdev))
 567                         return devname;
 568         }
 569         dn = map_dev(major(rdev), minor(rdev));
 570         if (dn)
 571                 return dn;
 572         snprintf(devname, sizeof(devname), "/dev/.tmp.md%d", dev);
 573         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 574                 if (errno != EEXIST)
 575                         return NULL;
 576
 577         if (stat(devname, &stb) == 0
 578             && (S_IFMT&stb.st_mode) == S_IFBLK
 579             && (stb.st_rdev == rdev))
 580                 return devname;
 581         unlink(devname);
 582         return NULL;
 583 }
 584
 585 void put_md_name(char *name)
 586 {
 587         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 588                 unlink(name);
 589 }
 590
 591 int dev_open(char *dev, int flags)
 592 {
 593         /* like 'open', but if 'dev' matches %d:%d, create a temp
 594          * block device and open that
 595          */
 596         char *e;
 597         int fd = -1;
 598         char devname[32];
 599         int major = strtoul(dev, &e, 0);
 600         int minor;
 601         if (e > dev && *e == ':' && e[1] &&
 602             (minor = strtoul(e+1, &e, 0)) >= 0 &&
 603             *e == 0) {
 604                 snprintf(devname, sizeof(devname), "/dev/.tmp.md.%d:%d", major, minor);
 605                 if (mknod(devname, S_IFBLK|0600, makedev(major, minor))==0) {
 606                         fd = open(devname, flags);
 607                         unlink(devname);
 608                 }
 609         } else
 610                 fd = open(dev, flags);
 611         return fd;
 612 }
 613
 614 struct superswitch *superlist[] = { &super0, &super1, NULL };
 615
 616 struct supertype *super_by_version(int vers, int minor)
 617 {
 618         struct supertype *st = malloc(sizeof(*st));
 619         if (!st) return st;
 620         if (vers == 0) {
 621                 st->ss = &super0;
 622                 st->max_devs = MD_SB_DISKS;
 623         }
 624
 625         if (vers == 1) {
 626                 st->ss = &super1;
 627                 st->max_devs = 384;
 628         }
 629         st->minor_version = minor;
 630         return st;
 631 }
 632
 633 struct supertype *guess_super(int fd)
 634 {
 635         /* try each load_super to find the best match,
 636          * and return the best superswitch
 637          */
 638         struct superswitch  *ss;
 639         struct supertype *st;
 640         unsigned long besttime = 0;
 641         int bestsuper = -1;
 642
 643         void *sbp = NULL;
 644         int i;
 645
 646         st = malloc(sizeof(*st));
 647         memset(st, 0, sizeof(*st));
 648         for (i=0 ; superlist[i]; i++) {
 649                 int rv;
 650                 ss = superlist[i];
 651                 st->ss = NULL;
 652                 rv = ss->load_super(st, fd, &sbp, NULL);
 653                 if (rv == 0) {
 654                         struct mdinfo info;
 655                         ss->getinfo_super(&info, sbp);
 656                         if (bestsuper == -1 ||
 657                             besttime < info.array.ctime) {
 658                                 bestsuper = i;
 659                                 besttime = info.array.ctime;
 660                         }
 661                         free(sbp);
 662                 }
 663         }
 664         if (bestsuper != -1) {
 665                 int rv;
 666                 st->ss = NULL;
 667                 rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
 668                 if (rv == 0) {
 669                         free(sbp);
 670                         return st;
 671                 }
 672         }
 673         free(st);
 674         return NULL;
 675 }
 676
 677
 678 #ifdef __TINYC__
 679 /* tinyc doesn't optimize this check in ioctl.h out ... */
 680 unsigned int __invalid_size_argument_for_IOC = 0;
 681 #endif
 682