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 int check_ext2(int fd, char *name)
 154 {
 155         /*
 156          * Check for an ext2fs file system.
 157          * Superblock is always 1K at 1K offset
 158          *
 159          * s_magic is le16 at 56 == 0xEF53
 160          * report mtime - le32 at 44
 161          * blocks - le32 at 4
 162          * logblksize - le32 at 24
 163          */
 164         unsigned char sb[1024];
 165         time_t mtime;
 166         int size, bsize;
 167         if (lseek(fd, 1024,0)!= 1024)
 168                 return 0;
 169         if (read(fd, sb, 1024)!= 1024)
 170                 return 0;
 171         if (sb[56] != 0x53 || sb[57] != 0xef)
 172                 return 0;
 173
 174         mtime = sb[44]|(sb[45]|(sb[46]|sb[47]<<8)<<8)<<8;
 175         bsize = sb[24]|(sb[25]|(sb[26]|sb[27]<<8)<<8)<<8;
 176         size = sb[4]|(sb[5]|(sb[6]|sb[7]<<8)<<8)<<8;
 177         fprintf(stderr, Name ": %s appears to contain an ext2fs file system\n",
 178                 name);
 179         fprintf(stderr,"    size=%dK  mtime=%s",
 180                 size*(1<<bsize), ctime(&mtime));
 181         return 1;
 182 }
 183
 184 int check_reiser(int fd, char *name)
 185 {
 186         /*
 187          * superblock is at 64K
 188          * size is 1024;
 189          * Magic string "ReIsErFs" or "ReIsEr2Fs" at 52
 190          *
 191          */
 192         unsigned char sb[1024];
 193         int size;
 194         if (lseek(fd, 64*1024, 0) != 64*1024)
 195                 return 0;
 196         if (read(fd, sb, 1024) != 1024)
 197                 return 0;
 198         if (strncmp(sb+52, "ReIsErFs",8)!=0 &&
 199             strncmp(sb+52, "ReIsEr2Fs",9)!=0)
 200                 return 0;
 201         fprintf(stderr, Name ": %s appears to contain a reiserfs file system\n",name);
 202         size = sb[0]|(sb[1]|(sb[2]|sb[3]<<8)<<8)<<8;
 203         fprintf(stderr, "    size = %dK\n", size*4);
 204
 205         return 1;
 206 }
 207
 208 int check_raid(int fd, char *name)
 209 {
 210         void *super;
 211         struct mdinfo info;
 212         time_t crtime;
 213         struct supertype *st = guess_super(fd);
 214
 215         if (!st) return 0;
 216         st->ss->load_super(st, fd, &super, name);
 217         /* Looks like a raid array .. */
 218         fprintf(stderr, Name ": %s appears to be part of a raid array:\n",
 219                 name);
 220         st->ss->getinfo_super(&info, super);
 221         free(super);
 222         crtime = info.array.ctime;
 223         fprintf(stderr, "    level=%d devices=%d ctime=%s",
 224                 info.array.level, info.array.raid_disks, ctime(&crtime));
 225         return 1;
 226 }
 227
 228 int ask(char *mesg)
 229 {
 230         char *add = "";
 231         int i;
 232         for (i=0; i<5; i++) {
 233                 char buf[100];
 234                 fprintf(stderr, "%s%s", mesg, add);
 235                 fflush(stderr);
 236                 if (fgets(buf, 100, stdin)==NULL)
 237                         return 0;
 238                 if (buf[0]=='y' || buf[0]=='Y')
 239                         return 1;
 240                 if (buf[0]=='n' || buf[0]=='N')
 241                         return 0;
 242                 add = "(y/n) ";
 243         }
 244         fprintf(stderr, Name ": assuming 'no'\n");
 245         return 0;
 246 }
 247
 248 char *map_num(mapping_t *map, int num)
 249 {
 250         while (map->name) {
 251                 if (map->num == num)
 252                         return map->name;
 253                 map++;
 254         }
 255         return NULL;
 256 }
 257
 258 int map_name(mapping_t *map, char *name)
 259 {
 260         while (map->name) {
 261                 if (strcmp(map->name, name)==0)
 262                         return map->num;
 263                 map++;
 264         }
 265         return UnSet;
 266 }
 267
 268
 269 int is_standard(char *dev, int *nump)
 270 {
 271         /* tests if dev is a "standard" md dev name.
 272          * i.e if the last component is "/dNN" or "/mdNN",
 273          * where NN is a string of digits
 274          */
 275         char *d = strrchr(dev, '/');
 276         int type=0;
 277         int num;
 278         if (!d)
 279                 return 0;
 280         if (strncmp(d, "/d",2)==0)
 281                 d += 2, type=1; /* /dev/md/dN{pM} */
 282         else if (strncmp(d, "/md_d", 5)==0)
 283                 d += 5, type=1; /* /dev/md_dNpM */
 284         else if (strncmp(d, "/md", 3)==0)
 285                 d += 3, type=-1; /* /dev/mdN */
 286         else if (d-dev > 3 && strncmp(d-2, "md/", 3)==0)
 287                 type = -1; /* /dev/md/N */
 288         else
 289                 return 0;
 290         if (!*d)
 291                 return 0;
 292         num = atoi(d);
 293         while (isdigit(*d))
 294                 d++;
 295         if (*d)
 296                 return 0;
 297         if (nump) *nump = num;
 298
 299         return type;
 300 }
 301
 302
 303 /*
 304  * convert a major/minor pair for a block device into a name in /dev, if possible.
 305  * On the first call, walk /dev collecting name.
 306  * Put them in a simple linked listfor now.
 307  */
 308 struct devmap {
 309     int major, minor;
 310     char *name;
 311     struct devmap *next;
 312 } *devlist = NULL;
 313 int devlist_ready = 0;
 314
 315 #ifdef UCLIBC
 316 char *map_dev(int major, int minor)
 317 {
 318 #if 0
 319         fprintf(stderr, "Warning - fail to map %d,%d to a device name\n",
 320                 major, minor);
 321 #endif
 322         return NULL;
 323 }
 324 #else
 325 #define  __USE_XOPEN_EXTENDED
 326 #include <ftw.h>
 327
 328
 329 #ifndef __dietlibc__
 330 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
 331 #else
 332 int add_dev(const char *name, const struct stat *stb, int flag)
 333 #endif
 334 {
 335     if ((stb->st_mode&S_IFMT)== S_IFBLK) {
 336         char *n = strdup(name);
 337         struct devmap *dm = malloc(sizeof(*dm));
 338         if (dm) {
 339             dm->major = major(stb->st_rdev);
 340             dm->minor = minor(stb->st_rdev);
 341             dm->name = n;
 342             dm->next = devlist;
 343             devlist = dm;
 344         }
 345     }
 346     return 0;
 347 }
 348
 349 /*
 350  * Find a block device with the right major/minor number.
 351  * Avoid /dev/mdNN and /dev/md/dNN if possible
 352  */
 353 char *map_dev(int major, int minor)
 354 {
 355         struct devmap *p;
 356         char *std = NULL;
 357         if (!devlist_ready) {
 358 #ifndef __dietlibc__
 359                 nftw("/dev", add_dev, 10, FTW_PHYS);
 360 #else
 361                 ftw("/dev", add_dev, 10);
 362 #endif
 363                 devlist_ready=1;
 364         }
 365
 366         for (p=devlist; p; p=p->next)
 367                 if (p->major == major &&
 368                     p->minor == minor) {
 369                         if (is_standard(p->name, NULL))
 370                                 std = p->name;
 371                         else
 372                                 return p->name;
 373                 }
 374         return std;
 375 }
 376
 377 #endif
 378
 379 unsigned long calc_csum(void *super, int bytes)
 380 {
 381         unsigned long long newcsum = 0;
 382         int i;
 383         unsigned int csum;
 384         unsigned int *superc = (unsigned int*) super;
 385
 386         for(i=0; i<bytes/4; i++)
 387                 newcsum+= superc[i];
 388         csum = (newcsum& 0xffffffff) + (newcsum>>32);
 389 #ifdef __alpha__
 390 /* The in-kernel checksum calculation is always 16bit on
 391  * the alpha, though it is 32 bit on i386...
 392  * I wonder what it is elsewhere... (it uses and API in
 393  * a way that it shouldn't).
 394  */
 395         csum = (csum & 0xffff) + (csum >> 16);
 396         csum = (csum & 0xffff) + (csum >> 16);
 397 #endif
 398         return csum;
 399 }
 400
 401 char *human_size(long long bytes)
 402 {
 403         static char buf[30];
 404
 405
 406         if (bytes < 5000*1024)
 407                 buf[0]=0;
 408         else if (bytes < 2*1024LL*1024LL*1024LL)
 409                 sprintf(buf, " (%ld.%02ld MiB %ld.%02ld MB)",
 410                         (long)(bytes>>20),
 411                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100),
 412                         (long)(bytes/1000/1000),
 413                         (long)(((bytes%1000000)+5000)/10000)
 414                         );
 415         else
 416                 sprintf(buf, " (%ld.%02ld GiB %ld.%02ld GB)",
 417                         (long)(bytes>>30),
 418                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100),
 419                         (long)(bytes/1000LL/1000LL/1000LL),
 420                         (long)((((bytes/1000)%1000000)+5000)/10000)
 421                         );
 422         return buf;
 423 }
 424
 425 char *human_size_brief(long long bytes)
 426 {
 427         static char buf[30];
 428
 429
 430         if (bytes < 5000*1024)
 431                 sprintf(buf, "%ld.%02ldKiB",
 432                         (long)(bytes>>10), (long)(((bytes&1023)*100+512)/1024)
 433                         );
 434         else if (bytes < 2*1024LL*1024LL*1024LL)
 435                 sprintf(buf, "%ld.%02ldMiB",
 436                         (long)(bytes>>20),
 437                         (long)((bytes&0xfffff)+0x100000/200)/(0x100000/100)
 438                         );
 439         else
 440                 sprintf(buf, "%ld.%02ldGiB",
 441                         (long)(bytes>>30),
 442                         (long)(((bytes>>10)&0xfffff)+0x100000/200)/(0x100000/100)
 443                         );
 444         return buf;
 445 }
 446
 447 int get_mdp_major(void)
 448 {
 449 static int mdp_major = -1;
 450         FILE *fl;
 451         char *w;
 452         int have_block = 0;
 453         int have_devices = 0;
 454         int last_num = -1;
 455
 456         if (mdp_major != -1)
 457                 return mdp_major;
 458         fl = fopen("/proc/devices", "r");
 459         if (!fl)
 460                 return -1;
 461         while ((w = conf_word(fl, 1))) {
 462                 if (have_block && strcmp(w, "devices:")==0)
 463                         have_devices = 1;
 464                 have_block =  (strcmp(w, "Block")==0);
 465                 if (isdigit(w[0]))
 466                         last_num = atoi(w);
 467                 if (have_devices && strcmp(w, "mdp")==0)
 468                         mdp_major = last_num;
 469                 free(w);
 470         }
 471         fclose(fl);
 472         return mdp_major;
 473 }
 474
 475
 476
 477 char *get_md_name(int dev)
 478 {
 479         /* find /dev/md%d or /dev/md/%d or make a device /dev/.tmp.md%d */
 480         /* if dev < 0, want /dev/md/d%d or find mdp in /proc/devices ... */
 481         static char devname[50];
 482         struct stat stb;
 483         dev_t rdev;
 484         char *dn;
 485
 486         if (dev < 0) {
 487                 int mdp =  get_mdp_major();
 488                 if (mdp < 0) return NULL;
 489                 rdev = makedev(mdp, (-1-dev)<<6);
 490                 sprintf(devname, "/dev/md/d%d", -1-dev);
 491                 if (stat(devname, &stb) == 0
 492                     && (S_IFMT&stb.st_mode) == S_IFBLK
 493                     && (stb.st_rdev == rdev))
 494                         return devname;
 495         } else {
 496                 rdev = makedev(MD_MAJOR, dev);
 497                 sprintf(devname, "/dev/md%d", dev);
 498                 if (stat(devname, &stb) == 0
 499                     && (S_IFMT&stb.st_mode) == S_IFBLK
 500                     && (stb.st_rdev == rdev))
 501                         return devname;
 502
 503                 sprintf(devname, "/dev/md/%d", dev);
 504                 if (stat(devname, &stb) == 0
 505                     && (S_IFMT&stb.st_mode) == S_IFBLK
 506                     && (stb.st_rdev == rdev))
 507                         return devname;
 508         }
 509         dn = map_dev(major(rdev), minor(rdev));
 510         if (dn)
 511                 return dn;
 512         sprintf(devname, "/dev/.tmp.md%d", dev);
 513         if (mknod(devname, S_IFBLK | 0600, rdev) == -1)
 514                 if (errno != EEXIST)
 515                         return NULL;
 516
 517         if (stat(devname, &stb) == 0
 518             && (S_IFMT&stb.st_mode) == S_IFBLK
 519             && (stb.st_rdev == rdev))
 520                 return devname;
 521         unlink(devname);
 522         return NULL;
 523 }
 524
 525 void put_md_name(char *name)
 526 {
 527         if (strncmp(name, "/dev/.tmp.md", 12)==0)
 528                 unlink(name);
 529 }
 530
 531
 532
 533
 534 struct superswitch *superlist[] = { &super0, &super1, NULL };
 535
 536 struct supertype *super_by_version(int vers, int minor)
 537 {
 538         struct supertype *st = malloc(sizeof(*st));
 539         if (!st) return st;
 540         if (vers == 0)
 541                 st->ss = &super0;
 542
 543         if (vers == 1)
 544                 st->ss = &super1;
 545         st->minor_version = minor;
 546         return st;
 547 }
 548
 549 struct supertype *guess_super(int fd)
 550 {
 551         /* try each load_super to find the best match,
 552          * and return the best superswitch
 553          */
 554         struct superswitch  *ss;
 555         struct supertype *st;
 556         unsigned long besttime = 0;
 557         int bestsuper = -1;
 558
 559         void *sbp = NULL;
 560         int i;
 561
 562         st = malloc(sizeof(*st));
 563         memset(st, 0, sizeof(*st));
 564         for (i=0 ; superlist[i]; i++) {
 565                 int rv;
 566                 ss = superlist[i];
 567                 rv = ss->load_super(st, fd, &sbp, NULL);
 568                 if (rv == 0) {
 569                         struct mdinfo info;
 570                         ss->getinfo_super(&info, sbp);
 571                         if (bestsuper == -1 ||
 572                             besttime < info.array.ctime) {
 573                                 bestsuper = i;
 574                                 besttime = info.array.ctime;
 575                         }
 576                         st->ss = NULL;
 577                         free(sbp);
 578                 }
 579         }
 580         if (bestsuper != -1) {
 581                 int rv;
 582                 rv = superlist[bestsuper]->load_super(st, fd, &sbp, NULL);
 583                 if (rv == 0) {
 584                         free(sbp);
 585                         return st;
 586                 }
 587         }
 588         free(st);
 589         return NULL;
 590 }