sysfs.c

   1 /*
   2  * sysfs - extract md related information from sysfs.  Part of:
   3  * mdadm - manage Linux "md" devices aka RAID arrays.
   4  *
   5  * Copyright (C) 2006 Neil Brown <neilb@suse.de>
   6  *
   7  *
   8  *    This program is free software; you can redistribute it and/or modify
   9  *    it under the terms of the GNU General Public License as published by
  10  *    the Free Software Foundation; either version 2 of the License, or
  11  *    (at your option) any later version.
  12  *
  13  *    This program is distributed in the hope that it will be useful,
  14  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *    GNU General Public License for more details.
  17  *
  18  *    You should have received a copy of the GNU General Public License
  19  *    along with this program; if not, write to the Free Software
  20  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  *    Author: Neil Brown
  23  *    Email: <neilb@suse.de>
  24  */
  25
  26 #include        "mdadm.h"
  27 #include        <dirent.h>
  28 #include        <ctype.h>
  29
  30 int load_sys(char *path, char *buf)
  31 {
  32         int fd = open(path, O_RDONLY);
  33         int n;
  34         if (fd < 0)
  35                 return -1;
  36         n = read(fd, buf, 1024);
  37         close(fd);
  38         if (n <0 || n >= 1024)
  39                 return -1;
  40         buf[n] = 0;
  41         if (n && buf[n-1] == '\n')
  42                 buf[n-1] = 0;
  43         return 0;
  44 }
  45
  46 void sysfs_free(struct mdinfo *sra)
  47 {
  48         while (sra) {
  49                 struct mdinfo *sra2 = sra->next;
  50                 while (sra->devs) {
  51                         struct mdinfo *d = sra->devs;
  52                         sra->devs = d->next;
  53                         free(d);
  54                 }
  55                 free(sra);
  56                 sra = sra2;
  57         }
  58 }
  59
  60 int sysfs_open(int devnum, char *devname, char *attr)
  61 {
  62         char fname[50];
  63         int fd;
  64
  65         sprintf(fname, "/sys/block/%s/md/", devnum2devname(devnum));
  66         if (devname) {
  67                 strcat(fname, devname);
  68                 strcat(fname, "/");
  69         }
  70         strcat(fname, attr);
  71         fd = open(fname, O_RDWR);
  72         if (fd < 0 && errno == EACCES)
  73                 fd = open(fname, O_RDONLY);
  74         return fd;
  75 }
  76
  77 struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options)
  78 {
  79         /* Longest possible name in sysfs, mounted at /sys, is
  80          *  /sys/block/md_dXXX/md/dev-XXXXX/block/dev
  81          *  /sys/block/md_dXXX/md/metadata_version
  82          * which is about 41 characters.  50 should do for now
  83          */
  84         char fname[50];
  85         char buf[1024];
  86         char *base;
  87         char *dbase;
  88         struct mdinfo *sra;
  89         struct mdinfo *dev;
  90         DIR *dir = NULL;
  91         struct dirent *de;
  92
  93         sra = malloc(sizeof(*sra));
  94         if (sra == NULL)
  95                 return sra;
  96         sra->next = NULL;
  97
  98         if (fd >= 0) {
  99                 struct stat stb;
 100                 mdu_version_t vers;
 101                 if (fstat(fd, &stb)) return NULL;
 102                 if (ioctl(fd, RAID_VERSION, &vers) != 0)
 103                         return NULL;
 104                 if (major(stb.st_rdev)==9)
 105                         sprintf(sra->sys_name, "md%d", (int)minor(stb.st_rdev));
 106                 else
 107                         sprintf(sra->sys_name, "md_d%d",
 108                                 (int)minor(stb.st_rdev)>>MdpMinorShift);
 109         } else {
 110                 if (devnum >= 0)
 111                         sprintf(sra->sys_name, "md%d", devnum);
 112                 else
 113                         sprintf(sra->sys_name, "md_d%d",
 114                                 -1-devnum);
 115         }
 116         sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
 117         base = fname + strlen(fname);
 118
 119         sra->devs = NULL;
 120         if (options & GET_VERSION) {
 121                 strcpy(base, "metadata_version");
 122                 if (load_sys(fname, buf))
 123                         goto abort;
 124                 if (strncmp(buf, "none", 4) == 0) {
 125                         sra->array.major_version =
 126                                 sra->array.minor_version = -1;
 127                         strcpy(sra->text_version, "");
 128                 } else if (strncmp(buf, "external:", 9) == 0) {
 129                         sra->array.major_version = -1;
 130                         sra->array.minor_version = -2;
 131                         strcpy(sra->text_version, buf+9);
 132                 } else {
 133                         sscanf(buf, "%d.%d",
 134                                &sra->array.major_version,
 135                                &sra->array.minor_version);
 136                         strcpy(sra->text_version, buf);
 137                 }
 138         }
 139         if (options & GET_LEVEL) {
 140                 strcpy(base, "level");
 141                 if (load_sys(fname, buf))
 142                         goto abort;
 143                 sra->array.level = map_name(pers, buf);
 144         }
 145         if (options & GET_LAYOUT) {
 146                 strcpy(base, "layout");
 147                 if (load_sys(fname, buf))
 148                         goto abort;
 149                 sra->array.layout = strtoul(buf, NULL, 0);
 150         }
 151         if (options & GET_DISKS) {
 152                 strcpy(base, "raid_disks");
 153                 if (load_sys(fname, buf))
 154                         goto abort;
 155                 sra->array.raid_disks = strtoul(buf, NULL, 0);
 156         }
 157         if (options & GET_DEGRADED) {
 158                 strcpy(base, "degraded");
 159                 if (load_sys(fname, buf))
 160                         goto abort;
 161                 sra->array.failed_disks = strtoul(buf, NULL, 0);
 162         }
 163         if (options & GET_COMPONENT) {
 164                 strcpy(base, "component_size");
 165                 if (load_sys(fname, buf))
 166                         goto abort;
 167                 sra->component_size = strtoull(buf, NULL, 0);
 168                 /* sysfs reports "K", but we want sectors */
 169                 sra->component_size *= 2;
 170         }
 171         if (options & GET_CHUNK) {
 172                 strcpy(base, "chunk_size");
 173                 if (load_sys(fname, buf))
 174                         goto abort;
 175                 sra->array.chunk_size = strtoul(buf, NULL, 0);
 176         }
 177         if (options & GET_CACHE) {
 178                 strcpy(base, "stripe_cache_size");
 179                 if (load_sys(fname, buf))
 180                         goto abort;
 181                 sra->cache_size = strtoul(buf, NULL, 0);
 182         }
 183         if (options & GET_MISMATCH) {
 184                 strcpy(base, "mismatch_cnt");
 185                 if (load_sys(fname, buf))
 186                         goto abort;
 187                 sra->mismatch_cnt = strtoul(buf, NULL, 0);
 188         }
 189         if (options & GET_SAFEMODE) {
 190                 int scale = 1;
 191                 int dot = 0;
 192                 int i;
 193                 unsigned long msec;
 194                 size_t len;
 195
 196                 strcpy(base, "safe_mode_delay");
 197                 if (load_sys(fname, buf))
 198                         goto abort;
 199
 200                 /* remove a period, and count digits after it */
 201                 len = strlen(buf);
 202                 for (i = 0; i < len; i++) {
 203                         if (dot) {
 204                                 if (isdigit(buf[i])) {
 205                                         buf[i-1] = buf[i];
 206                                         scale *= 10;
 207                                 }
 208                                 buf[i] = 0;
 209                         } else if (buf[i] == '.') {
 210                                 dot=1;
 211                                 buf[i] = 0;
 212                         }
 213                 }
 214                 msec = strtoul(buf, NULL, 10);
 215                 msec = (msec * 1000) / scale;
 216                 sra->safe_mode_delay = msec;
 217         }
 218
 219         if (! (options & GET_DEVS))
 220                 return sra;
 221
 222         /* Get all the devices as well */
 223         *base = 0;
 224         dir = opendir(fname);
 225         if (!dir)
 226                 goto abort;
 227         sra->array.spare_disks = 0;
 228
 229         while ((de = readdir(dir)) != NULL) {
 230                 char *ep;
 231                 if (de->d_ino == 0 ||
 232                     strncmp(de->d_name, "dev-", 4) != 0)
 233                         continue;
 234                 strcpy(base, de->d_name);
 235                 dbase = base + strlen(base);
 236                 *dbase++ = '/';
 237
 238                 dev = malloc(sizeof(*dev));
 239                 if (!dev)
 240                         goto abort;
 241                 dev->next = sra->devs;
 242                 sra->devs = dev;
 243                 strcpy(dev->sys_name, de->d_name);
 244
 245                 /* Always get slot, major, minor */
 246                 strcpy(dbase, "slot");
 247                 if (load_sys(fname, buf))
 248                         goto abort;
 249                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 250                 if (*ep) dev->disk.raid_disk = -1;
 251
 252                 strcpy(dbase, "block/dev");
 253                 if (load_sys(fname, buf))
 254                         goto abort;
 255                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 256
 257                 if (options & GET_OFFSET) {
 258                         strcpy(dbase, "offset");
 259                         if (load_sys(fname, buf))
 260                                 goto abort;
 261                         dev->data_offset = strtoull(buf, NULL, 0);
 262                 }
 263                 if (options & GET_SIZE) {
 264                         strcpy(dbase, "size");
 265                         if (load_sys(fname, buf))
 266                                 goto abort;
 267                         dev->component_size = strtoull(buf, NULL, 0) * 2;
 268                 }
 269                 if (options & GET_STATE) {
 270                         dev->disk.state = 0;
 271                         strcpy(dbase, "state");
 272                         if (load_sys(fname, buf))
 273                                 goto abort;
 274                         if (strstr(buf, "in_sync"))
 275                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 276                         if (strstr(buf, "faulty"))
 277                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 278                         if (dev->disk.state == 0)
 279                                 sra->array.spare_disks++;
 280                 }
 281                 if (options & GET_ERROR) {
 282                         strcpy(buf, "errors");
 283                         if (load_sys(fname, buf))
 284                                 goto abort;
 285                         dev->errors = strtoul(buf, NULL, 0);
 286                 }
 287         }
 288         closedir(dir);
 289         return sra;
 290
 291  abort:
 292         if (dir)
 293                 closedir(dir);
 294         sysfs_free(sra);
 295         return NULL;
 296 }
 297
 298 int sysfs_attr_match(const char *attr, const char *str)
 299 {
 300         /* See if attr, read from a sysfs file, matches
 301          * str.  They must either be the same, or attr can
 302          * have a trailing newline or comma
 303          */
 304         while (*attr && *str && *attr == *str) {
 305                 attr++;
 306                 str++;
 307         }
 308
 309         if (*str || (*attr && *attr != ',' && *attr != '\n'))
 310                 return 0;
 311         return 1;
 312 }
 313
 314 int sysfs_match_word(const char *word, char **list)
 315 {
 316         int n;
 317         for (n=0; list[n]; n++)
 318                 if (sysfs_attr_match(word, list[n]))
 319                         break;
 320         return n;
 321 }
 322
 323 unsigned long long get_component_size(int fd)
 324 {
 325         /* Find out the component size of the array.
 326          * We cannot trust GET_ARRAY_INFO ioctl as it's
 327          * size field is only 32bits.
 328          * So look in /sys/block/mdXXX/md/component_size
 329          *
 330          * This returns in units of sectors.
 331          */
 332         struct stat stb;
 333         char fname[50];
 334         int n;
 335         if (fstat(fd, &stb)) return 0;
 336         if (major(stb.st_rdev) == 9)
 337                 sprintf(fname, "/sys/block/md%d/md/component_size",
 338                         (int)minor(stb.st_rdev));
 339         else
 340                 sprintf(fname, "/sys/block/md_d%d/md/component_size",
 341                         (int)minor(stb.st_rdev)>>MdpMinorShift);
 342         fd = open(fname, O_RDONLY);
 343         if (fd < 0)
 344                 return 0;
 345         n = read(fd, fname, sizeof(fname));
 346         close(fd);
 347         if (n == sizeof(fname))
 348                 return 0;
 349         fname[n] = 0;
 350         return strtoull(fname, NULL, 10) * 2;
 351 }
 352
 353 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 354                   char *name, char *val)
 355 {
 356         char fname[50];
 357         int n;
 358         int fd;
 359
 360         sprintf(fname, "/sys/block/%s/md/%s/%s",
 361                 sra->sys_name, dev?dev->sys_name:"", name);
 362         fd = open(fname, O_WRONLY);
 363         if (fd < 0)
 364                 return -1;
 365         n = write(fd, val, strlen(val));
 366         close(fd);
 367         if (n != strlen(val))
 368                 return -1;
 369         return 0;
 370 }
 371
 372 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 373                   char *name, unsigned long long val)
 374 {
 375         char valstr[50];
 376         sprintf(valstr, "%llu", val);
 377         return sysfs_set_str(sra, dev, name, valstr);
 378 }
 379
 380 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 381                        char *name, unsigned long long *val)
 382 {
 383         char fname[50];
 384         char buf[50];
 385         int n;
 386         int fd;
 387         char *ep;
 388         sprintf(fname, "/sys/block/%s/md/%s/%s",
 389                 sra->sys_name, dev?dev->sys_name:"", name);
 390         fd = open(fname, O_RDONLY);
 391         if (fd < 0)
 392                 return -1;
 393         n = read(fd, buf, sizeof(buf));
 394         close(fd);
 395         if (n <= 0)
 396                 return -1;
 397         buf[n] = 0;
 398         *val = strtoull(buf, &ep, 0);
 399         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 400                 return -1;
 401         return 0;
 402 }
 403
 404 int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
 405 {
 406         unsigned long sec;
 407         unsigned long msec;
 408         char delay[30];
 409
 410         sec = ms / 1000;
 411         msec = ms - (sec * 1000);
 412
 413         sprintf(delay, "%ld.%ld", sec, msec);
 414         return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
 415 }
 416
 417 int sysfs_set_array(struct mdinfo *sra,
 418                     struct mdinfo *info)
 419 {
 420         int rv = 0;
 421         sra->array = info->array;
 422
 423         if (info->array.level < 0)
 424                 return 0; /* FIXME */
 425         rv |= sysfs_set_str(sra, NULL, "level",
 426                             map_num(pers, info->array.level));
 427         rv |= sysfs_set_num(sra, NULL, "raid_disks", info->array.raid_disks);
 428         rv |= sysfs_set_num(sra, NULL, "chunk_size", info->array.chunk_size);
 429         rv |= sysfs_set_num(sra, NULL, "layout", info->array.layout);
 430         rv |= sysfs_set_num(sra, NULL, "component_size", info->component_size/2);
 431         rv |= sysfs_set_num(sra, NULL, "resync_start", info->resync_start);
 432         sra->array = info->array;
 433         return rv;
 434 }
 435
 436 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd)
 437 {
 438         char dv[100];
 439         char nm[100];
 440         struct mdinfo *sd2;
 441         char *dname;
 442         int rv;
 443
 444         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 445         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 446         if (rv)
 447                 return rv;
 448
 449         memset(nm, 0, sizeof(nm));
 450         sprintf(dv, "/sys/dev/block/%d:%d", sd->disk.major, sd->disk.minor);
 451         rv = readlink(dv, nm, sizeof(nm));
 452         if (rv <= 0)
 453                 return -1;
 454         nm[rv] = '\0';
 455         dname = strrchr(nm, '/');
 456         if (dname) dname++;
 457         strcpy(sd->sys_name, "dev-");
 458         strcpy(sd->sys_name+4, dname);
 459
 460         rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 461         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 462         if (sra->array.level != LEVEL_CONTAINER) {
 463                 rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 464 //              rv |= sysfs_set_str(sra, sd, "state", "in_sync");
 465         }
 466         if (! rv) {
 467                 sd2 = malloc(sizeof(*sd2));
 468                 *sd2 = *sd;
 469                 sd2->next = sra->devs;
 470                 sra->devs = sd2;
 471         }
 472         return rv;
 473 }
 474
 475 #if 0
 476 int sysfs_disk_to_sg(int fd)
 477 {
 478         /* from an open block device, try find and open its corresponding
 479          * scsi_generic interface
 480          */
 481         struct stat st;
 482         char path[256];
 483         char sg_path[256];
 484         char sg_major_minor[8];
 485         char *c;
 486         DIR *dir;
 487         struct dirent *de;
 488         int major, minor, rv;
 489
 490         if (fstat(fd, &st))
 491                 return -1;
 492
 493         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 494                  major(st.st_rdev), minor(st.st_rdev));
 495
 496         dir = opendir(path);
 497         if (!dir)
 498                 return -1;
 499
 500         de = readdir(dir);
 501         while (de) {
 502                 if (strncmp("scsi_generic:", de->d_name,
 503                             strlen("scsi_generic:")) == 0)
 504                         break;
 505                 de = readdir(dir);
 506         }
 507         closedir(dir);
 508
 509         if (!de)
 510                 return -1;
 511
 512         snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
 513         fd = open(sg_path, O_RDONLY);
 514         if (fd < 0)
 515                 return fd;
 516
 517         rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
 518         close(fd);
 519         if (rv < 0)
 520                 return -1;
 521         else
 522                 sg_major_minor[rv - 1] = '\0';
 523
 524         c = strchr(sg_major_minor, ':');
 525         *c = '\0';
 526         c++;
 527         major = strtol(sg_major_minor, NULL, 10);
 528         minor = strtol(c, NULL, 10);
 529         snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
 530                  (int) getpid(), major, minor);
 531         if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
 532                         fd = open(path, O_RDONLY);
 533                         unlink(path);
 534                         return fd;
 535         }
 536
 537         return -1;
 538 }
 539 #endif
 540
 541 int sysfs_disk_to_scsi_id(int fd, __u32 *id)
 542 {
 543         /* from an open block device, try to retrieve it scsi_id */
 544         struct stat st;
 545         char path[256];
 546         char *c1, *c2;
 547         DIR *dir;
 548         struct dirent *de;
 549
 550         if (fstat(fd, &st))
 551                 return 1;
 552
 553         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 554                  major(st.st_rdev), minor(st.st_rdev));
 555
 556         dir = opendir(path);
 557         if (!dir)
 558                 return 1;
 559
 560         de = readdir(dir);
 561         while (de) {
 562                 if (strncmp("scsi_disk:", de->d_name,
 563                             strlen("scsi_disk:")) == 0)
 564                         break;
 565                 de = readdir(dir);
 566         }
 567         closedir(dir);
 568
 569         if (!de)
 570                 return 1;
 571
 572         c1 = strchr(de->d_name, ':');
 573         c1++;
 574         c2 = strchr(c1, ':');
 575         *c2 = '\0';
 576         *id = strtol(c1, NULL, 10) << 24; /* host */
 577         c1 = c2 + 1;
 578         c2 = strchr(c1, ':');
 579         *c2 = '\0';
 580         *id |= strtol(c1, NULL, 10) << 16; /* channel */
 581         c1 = c2 + 1;
 582         c2 = strchr(c1, ':');
 583         *c2 = '\0';
 584         *id |= strtol(c1, NULL, 10) << 8; /* lun */
 585         c1 = c2 + 1;
 586         *id |= strtol(c1, NULL, 10); /* id */
 587
 588         return 0;
 589 }
 590
 591
 592 int sysfs_unique_holder(int devnum, long rdev)
 593 {
 594         /* Check that devnum is a holder of rdev,
 595          * and is the only holder.
 596          * we should be locked against races by
 597          * an O_EXCL on devnum
 598          */
 599         DIR *dir;
 600         struct dirent *de;
 601         char dirname[100];
 602         char l;
 603         int found = 0;
 604         sprintf(dirname, "/sys/dev/block/%d:%d/holders",
 605                 major(rdev), minor(rdev));
 606         dir = opendir(dirname);
 607         errno = ENOENT;
 608         if (!dir)
 609                 return 0;
 610         l = strlen(dirname);
 611         while ((de = readdir(dir)) != NULL) {
 612                 char buf[10];
 613                 int n;
 614                 int mj, mn;
 615                 char c;
 616                 int fd;
 617
 618                 if (de->d_ino == 0)
 619                         continue;
 620                 if (de->d_name[0] == '.')
 621                         continue;
 622                 strcpy(dirname+l, "/");
 623                 strcat(dirname+l, de->d_name);
 624                 strcat(dirname+l, "/dev");
 625                 fd = open(dirname, O_RDONLY);
 626                 if (fd < 0) {
 627                         errno = ENOENT;
 628                         break;
 629                 }
 630                 n = read(fd, buf, sizeof(buf)-1);
 631                 close(fd);
 632                 buf[n] = 0;
 633                 if (sscanf(buf, "%d:%d%c", &mj, &mn, &c) != 3 ||
 634                     c != '\n') {
 635                         errno = ENOENT;
 636                         break;
 637                 }
 638                 if (mj != MD_MAJOR)
 639                         mn = -1-(mn>>6);
 640
 641                 if (devnum != mn) {
 642                         errno = EEXIST;
 643                         break;
 644                 }
 645                 found = 1;
 646         }
 647         closedir(dir);
 648         if (de)
 649                 return 0;
 650         else
 651                 return found;
 652 }