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) 2006-2009 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(char *devnm, char *devname, char *attr)
  61 {
  62         char fname[50];
  63         int fd;
  64
  65         sprintf(fname, "/sys/block/%s/md/", devnm);
  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 void sysfs_init_dev(struct mdinfo *mdi, unsigned long devid)
  78 {
  79         snprintf(mdi->sys_name,
  80                  sizeof(mdi->sys_name), "dev-%s", devid2kname(devid));
  81 }
  82
  83 void sysfs_init(struct mdinfo *mdi, int fd, char *devnm)
  84 {
  85         mdi->sys_name[0] = 0;
  86         if (fd >= 0) {
  87                 mdu_version_t vers;
  88                 if (ioctl(fd, RAID_VERSION, &vers) != 0)
  89                         return;
  90                 devnm = fd2devnm(fd);
  91         }
  92         if (devnm == NULL)
  93                 return;
  94         strcpy(mdi->sys_name, devnm);
  95 }
  96
  97 struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
  98 {
  99         char fname[PATH_MAX];
 100         char buf[PATH_MAX];
 101         char *base;
 102         char *dbase;
 103         struct mdinfo *sra;
 104         struct mdinfo *dev, **devp;
 105         DIR *dir = NULL;
 106         struct dirent *de;
 107
 108         sra = xcalloc(1, sizeof(*sra));
 109         sysfs_init(sra, fd, devnm);
 110         if (sra->sys_name[0] == 0) {
 111                 free(sra);
 112                 return NULL;
 113         }
 114
 115         sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
 116         base = fname + strlen(fname);
 117
 118         sra->devs = NULL;
 119         if (options & GET_VERSION) {
 120                 strcpy(base, "metadata_version");
 121                 if (load_sys(fname, buf))
 122                         goto abort;
 123                 if (strncmp(buf, "none", 4) == 0) {
 124                         sra->array.major_version =
 125                                 sra->array.minor_version = -1;
 126                         strcpy(sra->text_version, "");
 127                 } else if (strncmp(buf, "external:", 9) == 0) {
 128                         sra->array.major_version = -1;
 129                         sra->array.minor_version = -2;
 130                         strcpy(sra->text_version, buf+9);
 131                 } else {
 132                         sscanf(buf, "%d.%d",
 133                                &sra->array.major_version,
 134                                &sra->array.minor_version);
 135                         strcpy(sra->text_version, buf);
 136                 }
 137         }
 138         if (options & GET_LEVEL) {
 139                 strcpy(base, "level");
 140                 if (load_sys(fname, buf))
 141                         goto abort;
 142                 sra->array.level = map_name(pers, buf);
 143         }
 144         if (options & GET_LAYOUT) {
 145                 strcpy(base, "layout");
 146                 if (load_sys(fname, buf))
 147                         goto abort;
 148                 sra->array.layout = strtoul(buf, NULL, 0);
 149         }
 150         if (options & GET_DISKS) {
 151                 strcpy(base, "raid_disks");
 152                 if (load_sys(fname, buf))
 153                         goto abort;
 154                 sra->array.raid_disks = strtoul(buf, NULL, 0);
 155         }
 156         if (options & GET_DEGRADED) {
 157                 strcpy(base, "degraded");
 158                 if (load_sys(fname, buf))
 159                         goto abort;
 160                 sra->array.failed_disks = strtoul(buf, NULL, 0);
 161         }
 162         if (options & GET_COMPONENT) {
 163                 strcpy(base, "component_size");
 164                 if (load_sys(fname, buf))
 165                         goto abort;
 166                 sra->component_size = strtoull(buf, NULL, 0);
 167                 /* sysfs reports "K", but we want sectors */
 168                 sra->component_size *= 2;
 169         }
 170         if (options & GET_CHUNK) {
 171                 strcpy(base, "chunk_size");
 172                 if (load_sys(fname, buf))
 173                         goto abort;
 174                 sra->array.chunk_size = strtoul(buf, NULL, 0);
 175         }
 176         if (options & GET_CACHE) {
 177                 strcpy(base, "stripe_cache_size");
 178                 if (load_sys(fname, buf))
 179                         /* Probably level doesn't support it */
 180                         sra->cache_size = 0;
 181                 else
 182                         sra->cache_size = strtoul(buf, NULL, 0);
 183         }
 184         if (options & GET_MISMATCH) {
 185                 strcpy(base, "mismatch_cnt");
 186                 if (load_sys(fname, buf))
 187                         goto abort;
 188                 sra->mismatch_cnt = strtoul(buf, NULL, 0);
 189         }
 190         if (options & GET_SAFEMODE) {
 191                 int scale = 1;
 192                 int dot = 0;
 193                 unsigned i;
 194                 unsigned long msec;
 195                 size_t len;
 196
 197                 strcpy(base, "safe_mode_delay");
 198                 if (load_sys(fname, buf))
 199                         goto abort;
 200
 201                 /* remove a period, and count digits after it */
 202                 len = strlen(buf);
 203                 for (i = 0; i < len; i++) {
 204                         if (dot) {
 205                                 if (isdigit(buf[i])) {
 206                                         buf[i-1] = buf[i];
 207                                         scale *= 10;
 208                                 }
 209                                 buf[i] = 0;
 210                         } else if (buf[i] == '.') {
 211                                 dot=1;
 212                                 buf[i] = 0;
 213                         }
 214                 }
 215                 msec = strtoul(buf, NULL, 10);
 216                 msec = (msec * 1000) / scale;
 217                 sra->safe_mode_delay = msec;
 218         }
 219         if (options & GET_BITMAP_LOCATION) {
 220                 strcpy(base, "bitmap/location");
 221                 if (load_sys(fname, buf))
 222                         goto abort;
 223                 if (strncmp(buf, "file", 4) == 0)
 224                         sra->bitmap_offset = 1;
 225                 else if (strncmp(buf, "none", 4) == 0)
 226                         sra->bitmap_offset = 0;
 227                 else if (buf[0] == '+')
 228                         sra->bitmap_offset = strtol(buf+1, NULL, 10);
 229                 else
 230                         goto abort;
 231         }
 232
 233         if (options & GET_ARRAY_STATE) {
 234                 strcpy(base, "array_state");
 235                 if (load_sys(fname, sra->sysfs_array_state))
 236                         goto abort;
 237         } else
 238                 sra->sysfs_array_state[0] = 0;
 239
 240         if (! (options & GET_DEVS))
 241                 return sra;
 242
 243         /* Get all the devices as well */
 244         *base = 0;
 245         dir = opendir(fname);
 246         if (!dir)
 247                 goto abort;
 248         sra->array.spare_disks = 0;
 249
 250         devp = &sra->devs;
 251         sra->devs = NULL;
 252         while ((de = readdir(dir)) != NULL) {
 253                 char *ep;
 254                 if (de->d_ino == 0 ||
 255                     strncmp(de->d_name, "dev-", 4) != 0)
 256                         continue;
 257                 strcpy(base, de->d_name);
 258                 dbase = base + strlen(base);
 259                 *dbase++ = '/';
 260
 261                 dev = xmalloc(sizeof(*dev));
 262
 263                 /* Always get slot, major, minor */
 264                 strcpy(dbase, "slot");
 265                 if (load_sys(fname, buf)) {
 266                         /* hmm... unable to read 'slot' maybe the device
 267                          * is going away?
 268                          */
 269                         strcpy(dbase, "block");
 270                         if (readlink(fname, buf, sizeof(buf)) < 0 &&
 271                             errno != ENAMETOOLONG) {
 272                                 /* ...yup device is gone */
 273                                 free(dev);
 274                                 continue;
 275                         } else {
 276                                 /* slot is unreadable but 'block' link
 277                                  * still intact... something bad is happening
 278                                  * so abort
 279                                  */
 280                                 free(dev);
 281                                 goto abort;
 282                         }
 283
 284                 }
 285                 strcpy(dev->sys_name, de->d_name);
 286                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 287                 if (*ep) dev->disk.raid_disk = -1;
 288
 289                 strcpy(dbase, "block/dev");
 290                 if (load_sys(fname, buf)) {
 291                         /* assume this is a stale reference to a hot
 292                          * removed device
 293                          */
 294                         free(dev);
 295                         continue;
 296                 }
 297                 sra->array.nr_disks++;
 298                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 299
 300                 /* special case check for block devices that can go 'offline' */
 301                 strcpy(dbase, "block/device/state");
 302                 if (load_sys(fname, buf) == 0 &&
 303                     strncmp(buf, "offline", 7) == 0) {
 304                         free(dev);
 305                         continue;
 306                 }
 307
 308                 /* finally add this disk to the array */
 309                 *devp = dev;
 310                 devp = & dev->next;
 311                 dev->next = NULL;
 312
 313                 if (options & GET_OFFSET) {
 314                         strcpy(dbase, "offset");
 315                         if (load_sys(fname, buf))
 316                                 goto abort;
 317                         dev->data_offset = strtoull(buf, NULL, 0);
 318                         strcpy(dbase, "new_offset");
 319                         if (load_sys(fname, buf) == 0)
 320                                 dev->new_data_offset = strtoull(buf, NULL, 0);
 321                         else
 322                                 dev->new_data_offset = dev->data_offset;
 323                 }
 324                 if (options & GET_SIZE) {
 325                         strcpy(dbase, "size");
 326                         if (load_sys(fname, buf))
 327                                 goto abort;
 328                         dev->component_size = strtoull(buf, NULL, 0) * 2;
 329                 }
 330                 if (options & GET_STATE) {
 331                         dev->disk.state = 0;
 332                         strcpy(dbase, "state");
 333                         if (load_sys(fname, buf))
 334                                 goto abort;
 335                         if (strstr(buf, "in_sync"))
 336                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 337                         if (strstr(buf, "faulty"))
 338                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 339                         if (dev->disk.state == 0)
 340                                 sra->array.spare_disks++;
 341                 }
 342                 if (options & GET_ERROR) {
 343                         strcpy(buf, "errors");
 344                         if (load_sys(fname, buf))
 345                                 goto abort;
 346                         dev->errors = strtoul(buf, NULL, 0);
 347                 }
 348         }
 349         closedir(dir);
 350         return sra;
 351
 352  abort:
 353         if (dir)
 354                 closedir(dir);
 355         sysfs_free(sra);
 356         return NULL;
 357 }
 358
 359 int sysfs_attr_match(const char *attr, const char *str)
 360 {
 361         /* See if attr, read from a sysfs file, matches
 362          * str.  They must either be the same, or attr can
 363          * have a trailing newline or comma
 364          */
 365         while (*attr && *str && *attr == *str) {
 366                 attr++;
 367                 str++;
 368         }
 369
 370         if (*str || (*attr && *attr != ',' && *attr != '\n'))
 371                 return 0;
 372         return 1;
 373 }
 374
 375 int sysfs_match_word(const char *word, char **list)
 376 {
 377         int n;
 378         for (n=0; list[n]; n++)
 379                 if (sysfs_attr_match(word, list[n]))
 380                         break;
 381         return n;
 382 }
 383
 384 unsigned long long get_component_size(int fd)
 385 {
 386         /* Find out the component size of the array.
 387          * We cannot trust GET_ARRAY_INFO ioctl as it's
 388          * size field is only 32bits.
 389          * So look in /sys/block/mdXXX/md/component_size
 390          *
 391          * This returns in units of sectors.
 392          */
 393         struct stat stb;
 394         char fname[50];
 395         int n;
 396         if (fstat(fd, &stb)) return 0;
 397         if (major(stb.st_rdev) != (unsigned)get_mdp_major())
 398                 sprintf(fname, "/sys/block/md%d/md/component_size",
 399                         (int)minor(stb.st_rdev));
 400         else
 401                 sprintf(fname, "/sys/block/md_d%d/md/component_size",
 402                         (int)minor(stb.st_rdev)>>MdpMinorShift);
 403         fd = open(fname, O_RDONLY);
 404         if (fd < 0)
 405                 return 0;
 406         n = read(fd, fname, sizeof(fname));
 407         close(fd);
 408         if (n < 0 || n == sizeof(fname))
 409                 return 0;
 410         fname[n] = 0;
 411         return strtoull(fname, NULL, 10) * 2;
 412 }
 413
 414 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 415                   char *name, char *val)
 416 {
 417         char fname[50];
 418         unsigned int n;
 419         int fd;
 420
 421         sprintf(fname, "/sys/block/%s/md/%s/%s",
 422                 sra->sys_name, dev?dev->sys_name:"", name);
 423         fd = open(fname, O_WRONLY);
 424         if (fd < 0)
 425                 return -1;
 426         n = write(fd, val, strlen(val));
 427         close(fd);
 428         if (n != strlen(val)) {
 429                 dprintf("failed to write '%s' to '%s' (%s)\n",
 430                         val, fname, strerror(errno));
 431                 return -1;
 432         }
 433         return 0;
 434 }
 435
 436 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 437                   char *name, unsigned long long val)
 438 {
 439         char valstr[50];
 440         sprintf(valstr, "%llu", val);
 441         return sysfs_set_str(sra, dev, name, valstr);
 442 }
 443
 444 int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
 445                          char *name, long long val)
 446 {
 447         char valstr[50];
 448         sprintf(valstr, "%lli", val);
 449         return sysfs_set_str(sra, dev, name, valstr);
 450 }
 451
 452 int sysfs_uevent(struct mdinfo *sra, char *event)
 453 {
 454         char fname[50];
 455         int n;
 456         int fd;
 457
 458         sprintf(fname, "/sys/block/%s/uevent",
 459                 sra->sys_name);
 460         fd = open(fname, O_WRONLY);
 461         if (fd < 0)
 462                 return -1;
 463         n = write(fd, event, strlen(event));
 464         close(fd);
 465         if (n != (int)strlen(event)) {
 466                 dprintf("failed to write '%s' to '%s' (%s)\n",
 467                         event, fname, strerror(errno));
 468                 return -1;
 469         }
 470         return 0;
 471 }
 472
 473 int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
 474 {
 475         char fname[50];
 476         struct stat st;
 477
 478         sprintf(fname, "/sys/block/%s/md/%s/%s",
 479                 sra->sys_name, dev?dev->sys_name:"", name);
 480
 481         return stat(fname, &st) == 0;
 482 }
 483
 484 int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 485                        char *name)
 486 {
 487         char fname[50];
 488         int fd;
 489
 490         sprintf(fname, "/sys/block/%s/md/%s/%s",
 491                 sra->sys_name, dev?dev->sys_name:"", name);
 492         fd = open(fname, O_RDWR);
 493         if (fd < 0)
 494                 fd = open(fname, O_RDONLY);
 495         return fd;
 496 }
 497
 498 int sysfs_fd_get_ll(int fd, unsigned long long *val)
 499 {
 500         char buf[50];
 501         int n;
 502         char *ep;
 503
 504         lseek(fd, 0, 0);
 505         n = read(fd, buf, sizeof(buf));
 506         if (n <= 0 || n == sizeof(buf))
 507                 return -2;
 508         buf[n] = 0;
 509         *val = strtoull(buf, &ep, 0);
 510         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 511                 return -1;
 512         return 0;
 513 }
 514
 515 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 516                        char *name, unsigned long long *val)
 517 {
 518         int n;
 519         int fd;
 520
 521         fd = sysfs_get_fd(sra, dev, name);
 522         if (fd < 0)
 523                 return -1;
 524         n = sysfs_fd_get_ll(fd, val);
 525         close(fd);
 526         return n;
 527 }
 528
 529 int sysfs_fd_get_two(int fd, unsigned long long *v1, unsigned long long *v2)
 530 {
 531         /* two numbers in this sysfs file, either
 532          *  NNN (NNN)
 533          * or
 534          *  NNN / NNN
 535          */
 536         char buf[80];
 537         int n;
 538         char *ep, *ep2;
 539
 540         lseek(fd, 0, 0);
 541         n = read(fd, buf, sizeof(buf));
 542         if (n <= 0 || n == sizeof(buf))
 543                 return -2;
 544         buf[n] = 0;
 545         *v1 = strtoull(buf, &ep, 0);
 546         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 547                 return -1;
 548         while (*ep == ' ' || *ep == '/' || *ep == '(')
 549                 ep++;
 550         *v2 = strtoull(ep, &ep2, 0);
 551         if (ep2 == ep || (*ep2 != 0 && *ep2 != '\n' && *ep2 != ' ' && *ep2 != ')')) {
 552                 *v2 = *v1;
 553                 return 1;
 554         }
 555         return 2;
 556 }
 557
 558 int sysfs_get_two(struct mdinfo *sra, struct mdinfo *dev,
 559                   char *name, unsigned long long *v1, unsigned long long *v2)
 560 {
 561         int n;
 562         int fd;
 563
 564         fd = sysfs_get_fd(sra, dev, name);
 565         if (fd < 0)
 566                 return -1;
 567         n = sysfs_fd_get_two(fd, v1, v2);
 568         close(fd);
 569         return n;
 570 }
 571
 572 int sysfs_fd_get_str(int fd, char *val, int size)
 573 {
 574         int n;
 575
 576         lseek(fd, 0, 0);
 577         n = read(fd, val, size);
 578         if (n <= 0 || n == size)
 579                 return -1;
 580         val[n] = 0;
 581         return n;
 582 }
 583
 584 int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
 585                        char *name, char *val, int size)
 586 {
 587         int n;
 588         int fd;
 589
 590         fd = sysfs_get_fd(sra, dev, name);
 591         if (fd < 0)
 592                 return -1;
 593         n = sysfs_fd_get_str(fd, val, size);
 594         close(fd);
 595         return n;
 596 }
 597
 598 int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
 599 {
 600         unsigned long sec;
 601         unsigned long msec;
 602         char delay[30];
 603
 604         sec = ms / 1000;
 605         msec = ms % 1000;
 606
 607         sprintf(delay, "%ld.%03ld\n", sec, msec);
 608         /*             this '\n' ^ needed for kernels older than 2.6.28 */
 609         return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
 610 }
 611
 612 int sysfs_set_array(struct mdinfo *info, int vers)
 613 {
 614         int rv = 0;
 615         char ver[100];
 616         int raid_disks = info->array.raid_disks;
 617
 618         ver[0] = 0;
 619         if (info->array.major_version == -1 &&
 620             info->array.minor_version == -2) {
 621                 char buf[1024];
 622
 623                 strcat(strcpy(ver, "external:"), info->text_version);
 624
 625                 /* meta version might already be set if we are setting
 626                  * new geometry for a reshape.  In that case we don't
 627                  * want to over-write the 'readonly' flag that is
 628                  * stored in the metadata version.  So read the current
 629                  * version first, and preserve the flag
 630                  */
 631                 if (sysfs_get_str(info, NULL, "metadata_version",
 632                                   buf, 1024) > 0)
 633                         if (strlen(buf) >= 9 && buf[9] == '-')
 634                                 ver[9] = '-';
 635
 636                 if ((vers % 100) < 2 ||
 637                     sysfs_set_str(info, NULL, "metadata_version",
 638                                   ver) < 0) {
 639                         pr_err("This kernel does not support external metadata.\n");
 640                         return 1;
 641                 }
 642         }
 643         if (info->array.level < 0)
 644                 return 0; /* FIXME */
 645         rv |= sysfs_set_str(info, NULL, "level",
 646                             map_num(pers, info->array.level));
 647         if (info->reshape_active && info->delta_disks != UnSet)
 648                 raid_disks -= info->delta_disks;
 649         rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
 650         rv |= sysfs_set_num(info, NULL, "chunk_size", info->array.chunk_size);
 651         rv |= sysfs_set_num(info, NULL, "layout", info->array.layout);
 652         rv |= sysfs_set_num(info, NULL, "component_size", info->component_size/2);
 653         if (info->custom_array_size) {
 654                 int rc;
 655
 656                 rc = sysfs_set_num(info, NULL, "array_size",
 657                                    info->custom_array_size/2);
 658                 if (rc && errno == ENOENT) {
 659                         pr_err("This kernel does not have the md/array_size attribute, the array may be larger than expected\n");
 660                         rc = 0;
 661                 }
 662                 rv |= rc;
 663         }
 664
 665         if (info->array.level > 0)
 666                 rv |= sysfs_set_num(info, NULL, "resync_start", info->resync_start);
 667
 668         if (info->reshape_active) {
 669                 rv |= sysfs_set_num(info, NULL, "reshape_position",
 670                                     info->reshape_progress);
 671                 rv |= sysfs_set_num(info, NULL, "chunk_size", info->new_chunk);
 672                 rv |= sysfs_set_num(info, NULL, "layout", info->new_layout);
 673                 rv |= sysfs_set_num(info, NULL, "raid_disks",
 674                                     info->array.raid_disks);
 675                 /* We don't set 'new_level' here.  That can only happen
 676                  * once the reshape completes.
 677                  */
 678         }
 679         return rv;
 680 }
 681
 682 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
 683 {
 684         char dv[PATH_MAX];
 685         char nm[PATH_MAX];
 686         char *dname;
 687         int rv;
 688
 689         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 690         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 691         if (rv)
 692                 return rv;
 693
 694         memset(nm, 0, sizeof(nm));
 695         dname = devid2kname(makedev(sd->disk.major, sd->disk.minor));
 696         strcpy(sd->sys_name, "dev-");
 697         strcpy(sd->sys_name+4, dname);
 698
 699         /* test write to see if 'recovery_start' is available */
 700         if (resume && sd->recovery_start < MaxSector &&
 701             sysfs_set_num(sra, sd, "recovery_start", 0)) {
 702                 sysfs_set_str(sra, sd, "state", "remove");
 703                 return -1;
 704         }
 705
 706         rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 707         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 708         if (sra->array.level != LEVEL_CONTAINER) {
 709                 if (sd->recovery_start == MaxSector)
 710                         /* This can correctly fail if array isn't started,
 711                          * yet, so just ignore status for now.
 712                          */
 713                         sysfs_set_str(sra, sd, "state", "insync");
 714                 if (sd->disk.raid_disk >= 0)
 715                         rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 716                 if (resume)
 717                         sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
 718         }
 719         return rv;
 720 }
 721
 722 #if 0
 723 int sysfs_disk_to_sg(int fd)
 724 {
 725         /* from an open block device, try find and open its corresponding
 726          * scsi_generic interface
 727          */
 728         struct stat st;
 729         char path[256];
 730         char sg_path[256];
 731         char sg_major_minor[10];
 732         char *c;
 733         DIR *dir;
 734         struct dirent *de;
 735         int major, minor, rv;
 736
 737         if (fstat(fd, &st))
 738                 return -1;
 739
 740         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 741                  major(st.st_rdev), minor(st.st_rdev));
 742
 743         dir = opendir(path);
 744         if (!dir)
 745                 return -1;
 746
 747         de = readdir(dir);
 748         while (de) {
 749                 if (strncmp("scsi_generic:", de->d_name,
 750                             strlen("scsi_generic:")) == 0)
 751                         break;
 752                 de = readdir(dir);
 753         }
 754         closedir(dir);
 755
 756         if (!de)
 757                 return -1;
 758
 759         snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
 760         fd = open(sg_path, O_RDONLY);
 761         if (fd < 0)
 762                 return fd;
 763
 764         rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
 765         close(fd);
 766         if (rv < 0 || rv == sizeof(sg_major_minor))
 767                 return -1;
 768         else
 769                 sg_major_minor[rv - 1] = '\0';
 770
 771         c = strchr(sg_major_minor, ':');
 772         *c = '\0';
 773         c++;
 774         major = strtol(sg_major_minor, NULL, 10);
 775         minor = strtol(c, NULL, 10);
 776         snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
 777                  (int) getpid(), major, minor);
 778         if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
 779                         fd = open(path, O_RDONLY);
 780                         unlink(path);
 781                         return fd;
 782         }
 783
 784         return -1;
 785 }
 786 #endif
 787
 788 int sysfs_disk_to_scsi_id(int fd, __u32 *id)
 789 {
 790         /* from an open block device, try to retrieve it scsi_id */
 791         struct stat st;
 792         char path[256];
 793         DIR *dir;
 794         struct dirent *de;
 795         int host, bus, target, lun;
 796
 797         if (fstat(fd, &st))
 798                 return 1;
 799
 800         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device/scsi_device",
 801                  major(st.st_rdev), minor(st.st_rdev));
 802
 803         dir = opendir(path);
 804         if (!dir)
 805                 return 1;
 806
 807         for (de = readdir(dir); de; de = readdir(dir)) {
 808                 int count;
 809
 810                 if (de->d_type != DT_DIR)
 811                         continue;
 812
 813                 count = sscanf(de->d_name, "%d:%d:%d:%d", &host, &bus, &target, &lun);
 814                 if (count == 4)
 815                         break;
 816         }
 817         closedir(dir);
 818
 819         if (!de)
 820                 return 1;
 821
 822         *id = (host << 24) | (bus << 16) | (target << 8) | (lun << 0);
 823         return 0;
 824 }
 825
 826 int sysfs_unique_holder(char *devnm, long rdev)
 827 {
 828         /* Check that devnm is a holder of rdev,
 829          * and is the only holder.
 830          * we should be locked against races by
 831          * an O_EXCL on devnm
 832          * Return values:
 833          *  0 - not unique, not even a holder
 834          *  1 - unique, this is the only holder.
 835          *  2/3 - not unique, there is another holder
 836          * -1 - error, cannot find the holders
 837          */
 838         DIR *dir;
 839         struct dirent *de;
 840         char dirname[100];
 841         char l;
 842         int ret = 0;
 843         sprintf(dirname, "/sys/dev/block/%d:%d/holders",
 844                 major(rdev), minor(rdev));
 845         dir = opendir(dirname);
 846         if (!dir)
 847                 return -1;
 848         l = strlen(dirname);
 849         while ((de = readdir(dir)) != NULL) {
 850                 char buf[100];
 851                 char *sl;
 852                 int n;
 853
 854                 if (de->d_ino == 0)
 855                         continue;
 856                 if (de->d_name[0] == '.')
 857                         continue;
 858                 strcpy(dirname+l, "/");
 859                 strcat(dirname+l, de->d_name);
 860                 n = readlink(dirname, buf, sizeof(buf)-1);
 861                 if (n <= 0)
 862                         continue;
 863                 buf[n] = 0;
 864                 sl = strrchr(buf, '/');
 865                 if (!sl)
 866                         continue;
 867                 sl++;
 868
 869                 if (strcmp(devnm, sl) == 0)
 870                         ret |= 1;
 871                 else
 872                         ret |= 2;
 873         }
 874         closedir(dir);
 875         return ret;
 876 }
 877
 878 int sysfs_freeze_array(struct mdinfo *sra)
 879 {
 880         /* Try to freeze resync/rebuild on this array/container.
 881          * Return -1 if the array is busy,
 882          * return 0 if this kernel doesn't support 'frozen'
 883          * return 1 if it worked.
 884          */
 885         char buf[20];
 886
 887         if (!sysfs_attribute_available(sra, NULL, "sync_action"))
 888                 return 1; /* no sync_action == frozen */
 889         if (sysfs_get_str(sra, NULL, "sync_action", buf, 20) <= 0)
 890                 return 0;
 891         if (strcmp(buf, "frozen\n") == 0)
 892                 /* Already frozen */
 893                 return 0;
 894         if (strcmp(buf, "idle\n") != 0 && strcmp(buf, "recover\n") != 0)
 895                 return -1;
 896         if (sysfs_set_str(sra, NULL, "sync_action", "frozen") < 0)
 897                 return 0;
 898         return 1;
 899 }
 900
 901 int sysfs_wait(int fd, int *msec)
 902 {
 903         /* Wait up to '*msec' for fd to have an exception condition.
 904          * if msec == NULL, wait indefinitely.
 905          */
 906         fd_set fds;
 907         int n;
 908         FD_ZERO(&fds);
 909         FD_SET(fd, &fds);
 910         if (msec == NULL)
 911                 n = select(fd+1, NULL, NULL, &fds, NULL);
 912         else if (*msec < 0)
 913                 n = 0;
 914         else {
 915                 struct timeval start, end, tv;
 916                 gettimeofday(&start, NULL);
 917                 if (*msec < 1000) {
 918                         tv.tv_sec = 0;
 919                         tv.tv_usec = (*msec)*1000;
 920                 } else {
 921                         tv.tv_sec = (*msec)/1000;
 922                         tv.tv_usec = 0;
 923                 }
 924                 n = select(fd+1, NULL, NULL, &fds, &tv);
 925                 gettimeofday(&end, NULL);
 926                 end.tv_sec -= start.tv_sec;
 927                 *msec -= (end.tv_sec * 1000 + end.tv_usec/1000
 928                           - start.tv_usec/1000) + 1;
 929         }
 930         return n;
 931 }