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, int len)
  31 {
  32         int fd = open(path, O_RDONLY);
  33         int n;
  34         if (fd < 0)
  35                 return -1;
  36         n = read(fd, buf, len);
  37         close(fd);
  38         if (n <0 || n >= len)
  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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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, sizeof(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                              sizeof(sra->sysfs_array_state)))
 237                         goto abort;
 238         } else
 239                 sra->sysfs_array_state[0] = 0;
 240
 241         if (! (options & GET_DEVS))
 242                 return sra;
 243
 244         /* Get all the devices as well */
 245         *base = 0;
 246         dir = opendir(fname);
 247         if (!dir)
 248                 goto abort;
 249         sra->array.spare_disks = 0;
 250
 251         devp = &sra->devs;
 252         sra->devs = NULL;
 253         while ((de = readdir(dir)) != NULL) {
 254                 char *ep;
 255                 if (de->d_ino == 0 ||
 256                     strncmp(de->d_name, "dev-", 4) != 0)
 257                         continue;
 258                 strcpy(base, de->d_name);
 259                 dbase = base + strlen(base);
 260                 *dbase++ = '/';
 261
 262                 dev = xmalloc(sizeof(*dev));
 263
 264                 /* Always get slot, major, minor */
 265                 strcpy(dbase, "slot");
 266                 if (load_sys(fname, buf, sizeof(buf))) {
 267                         /* hmm... unable to read 'slot' maybe the device
 268                          * is going away?
 269                          */
 270                         strcpy(dbase, "block");
 271                         if (readlink(fname, buf, sizeof(buf)) < 0 &&
 272                             errno != ENAMETOOLONG) {
 273                                 /* ...yup device is gone */
 274                                 free(dev);
 275                                 continue;
 276                         } else {
 277                                 /* slot is unreadable but 'block' link
 278                                  * still intact... something bad is happening
 279                                  * so abort
 280                                  */
 281                                 free(dev);
 282                                 goto abort;
 283                         }
 284
 285                 }
 286                 strcpy(dev->sys_name, de->d_name);
 287                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 288                 if (*ep) dev->disk.raid_disk = -1;
 289
 290                 strcpy(dbase, "block/dev");
 291                 if (load_sys(fname, buf, sizeof(buf))) {
 292                         /* assume this is a stale reference to a hot
 293                          * removed device
 294                          */
 295                         free(dev);
 296                         continue;
 297                 }
 298                 sra->array.nr_disks++;
 299                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 300
 301                 /* special case check for block devices that can go 'offline' */
 302                 strcpy(dbase, "block/device/state");
 303                 if (load_sys(fname, buf, sizeof(buf)) == 0 &&
 304                     strncmp(buf, "offline", 7) == 0) {
 305                         free(dev);
 306                         continue;
 307                 }
 308
 309                 /* finally add this disk to the array */
 310                 *devp = dev;
 311                 devp = & dev->next;
 312                 dev->next = NULL;
 313
 314                 if (options & GET_OFFSET) {
 315                         strcpy(dbase, "offset");
 316                         if (load_sys(fname, buf, sizeof(buf)))
 317                                 goto abort;
 318                         dev->data_offset = strtoull(buf, NULL, 0);
 319                         strcpy(dbase, "new_offset");
 320                         if (load_sys(fname, buf, sizeof(buf)) == 0)
 321                                 dev->new_data_offset = strtoull(buf, NULL, 0);
 322                         else
 323                                 dev->new_data_offset = dev->data_offset;
 324                 }
 325                 if (options & GET_SIZE) {
 326                         strcpy(dbase, "size");
 327                         if (load_sys(fname, buf, sizeof(buf)))
 328                                 goto abort;
 329                         dev->component_size = strtoull(buf, NULL, 0) * 2;
 330                 }
 331                 if (options & GET_STATE) {
 332                         dev->disk.state = 0;
 333                         strcpy(dbase, "state");
 334                         if (load_sys(fname, buf, sizeof(buf)))
 335                                 goto abort;
 336                         if (strstr(buf, "in_sync"))
 337                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 338                         if (strstr(buf, "faulty"))
 339                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 340                         if (dev->disk.state == 0)
 341                                 sra->array.spare_disks++;
 342                 }
 343                 if (options & GET_ERROR) {
 344                         strcpy(buf, "errors");
 345                         if (load_sys(fname, buf, sizeof(buf)))
 346                                 goto abort;
 347                         dev->errors = strtoul(buf, NULL, 0);
 348                 }
 349         }
 350         closedir(dir);
 351         return sra;
 352
 353  abort:
 354         if (dir)
 355                 closedir(dir);
 356         sysfs_free(sra);
 357         return NULL;
 358 }
 359
 360 int sysfs_attr_match(const char *attr, const char *str)
 361 {
 362         /* See if attr, read from a sysfs file, matches
 363          * str.  They must either be the same, or attr can
 364          * have a trailing newline or comma
 365          */
 366         while (*attr && *str && *attr == *str) {
 367                 attr++;
 368                 str++;
 369         }
 370
 371         if (*str || (*attr && *attr != ',' && *attr != '\n'))
 372                 return 0;
 373         return 1;
 374 }
 375
 376 int sysfs_match_word(const char *word, char **list)
 377 {
 378         int n;
 379         for (n=0; list[n]; n++)
 380                 if (sysfs_attr_match(word, list[n]))
 381                         break;
 382         return n;
 383 }
 384
 385 unsigned long long get_component_size(int fd)
 386 {
 387         /* Find out the component size of the array.
 388          * We cannot trust GET_ARRAY_INFO ioctl as it's
 389          * size field is only 32bits.
 390          * So look in /sys/block/mdXXX/md/component_size
 391          *
 392          * This returns in units of sectors.
 393          */
 394         struct stat stb;
 395         char fname[50];
 396         int n;
 397         if (fstat(fd, &stb))
 398                 return 0;
 399         if (major(stb.st_rdev) != (unsigned)get_mdp_major())
 400                 sprintf(fname, "/sys/block/md%d/md/component_size",
 401                         (int)minor(stb.st_rdev));
 402         else
 403                 sprintf(fname, "/sys/block/md_d%d/md/component_size",
 404                         (int)minor(stb.st_rdev)>>MdpMinorShift);
 405         fd = open(fname, O_RDONLY);
 406         if (fd < 0)
 407                 return 0;
 408         n = read(fd, fname, sizeof(fname));
 409         close(fd);
 410         if (n < 0 || n == sizeof(fname))
 411                 return 0;
 412         fname[n] = 0;
 413         return strtoull(fname, NULL, 10) * 2;
 414 }
 415
 416 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 417                   char *name, char *val)
 418 {
 419         char fname[50];
 420         unsigned int n;
 421         int fd;
 422
 423         sprintf(fname, "/sys/block/%s/md/%s/%s",
 424                 sra->sys_name, dev?dev->sys_name:"", name);
 425         fd = open(fname, O_WRONLY);
 426         if (fd < 0)
 427                 return -1;
 428         n = write(fd, val, strlen(val));
 429         close(fd);
 430         if (n != strlen(val)) {
 431                 dprintf("failed to write '%s' to '%s' (%s)\n",
 432                         val, fname, strerror(errno));
 433                 return -1;
 434         }
 435         return 0;
 436 }
 437
 438 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 439                   char *name, unsigned long long val)
 440 {
 441         char valstr[50];
 442         sprintf(valstr, "%llu", val);
 443         return sysfs_set_str(sra, dev, name, valstr);
 444 }
 445
 446 int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
 447                          char *name, long long val)
 448 {
 449         char valstr[50];
 450         sprintf(valstr, "%lli", val);
 451         return sysfs_set_str(sra, dev, name, valstr);
 452 }
 453
 454 int sysfs_uevent(struct mdinfo *sra, char *event)
 455 {
 456         char fname[50];
 457         int n;
 458         int fd;
 459
 460         sprintf(fname, "/sys/block/%s/uevent",
 461                 sra->sys_name);
 462         fd = open(fname, O_WRONLY);
 463         if (fd < 0)
 464                 return -1;
 465         n = write(fd, event, strlen(event));
 466         close(fd);
 467         if (n != (int)strlen(event)) {
 468                 dprintf("failed to write '%s' to '%s' (%s)\n",
 469                         event, fname, strerror(errno));
 470                 return -1;
 471         }
 472         return 0;
 473 }
 474
 475 int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
 476 {
 477         char fname[50];
 478         struct stat st;
 479
 480         sprintf(fname, "/sys/block/%s/md/%s/%s",
 481                 sra->sys_name, dev?dev->sys_name:"", name);
 482
 483         return stat(fname, &st) == 0;
 484 }
 485
 486 int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 487                        char *name)
 488 {
 489         char fname[50];
 490         int fd;
 491
 492         sprintf(fname, "/sys/block/%s/md/%s/%s",
 493                 sra->sys_name, dev?dev->sys_name:"", name);
 494         fd = open(fname, O_RDWR);
 495         if (fd < 0)
 496                 fd = open(fname, O_RDONLY);
 497         return fd;
 498 }
 499
 500 int sysfs_fd_get_ll(int fd, unsigned long long *val)
 501 {
 502         char buf[50];
 503         int n;
 504         char *ep;
 505
 506         lseek(fd, 0, 0);
 507         n = read(fd, buf, sizeof(buf));
 508         if (n <= 0 || n == sizeof(buf))
 509                 return -2;
 510         buf[n] = 0;
 511         *val = strtoull(buf, &ep, 0);
 512         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 513                 return -1;
 514         return 0;
 515 }
 516
 517 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 518                        char *name, unsigned long long *val)
 519 {
 520         int n;
 521         int fd;
 522
 523         fd = sysfs_get_fd(sra, dev, name);
 524         if (fd < 0)
 525                 return -1;
 526         n = sysfs_fd_get_ll(fd, val);
 527         close(fd);
 528         return n;
 529 }
 530
 531 int sysfs_fd_get_two(int fd, unsigned long long *v1, unsigned long long *v2)
 532 {
 533         /* two numbers in this sysfs file, either
 534          *  NNN (NNN)
 535          * or
 536          *  NNN / NNN
 537          */
 538         char buf[80];
 539         int n;
 540         char *ep, *ep2;
 541
 542         lseek(fd, 0, 0);
 543         n = read(fd, buf, sizeof(buf));
 544         if (n <= 0 || n == sizeof(buf))
 545                 return -2;
 546         buf[n] = 0;
 547         *v1 = strtoull(buf, &ep, 0);
 548         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 549                 return -1;
 550         while (*ep == ' ' || *ep == '/' || *ep == '(')
 551                 ep++;
 552         *v2 = strtoull(ep, &ep2, 0);
 553         if (ep2 == ep || (*ep2 != 0 && *ep2 != '\n' && *ep2 != ' ' && *ep2 != ')')) {
 554                 *v2 = *v1;
 555                 return 1;
 556         }
 557         return 2;
 558 }
 559
 560 int sysfs_get_two(struct mdinfo *sra, struct mdinfo *dev,
 561                   char *name, unsigned long long *v1, unsigned long long *v2)
 562 {
 563         int n;
 564         int fd;
 565
 566         fd = sysfs_get_fd(sra, dev, name);
 567         if (fd < 0)
 568                 return -1;
 569         n = sysfs_fd_get_two(fd, v1, v2);
 570         close(fd);
 571         return n;
 572 }
 573
 574 int sysfs_fd_get_str(int fd, char *val, int size)
 575 {
 576         int n;
 577
 578         lseek(fd, 0, 0);
 579         n = read(fd, val, size);
 580         if (n <= 0 || n == size)
 581                 return -1;
 582         val[n] = 0;
 583         return n;
 584 }
 585
 586 int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
 587                        char *name, char *val, int size)
 588 {
 589         int n;
 590         int fd;
 591
 592         fd = sysfs_get_fd(sra, dev, name);
 593         if (fd < 0)
 594                 return -1;
 595         n = sysfs_fd_get_str(fd, val, size);
 596         close(fd);
 597         return n;
 598 }
 599
 600 int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
 601 {
 602         unsigned long sec;
 603         unsigned long msec;
 604         char delay[30];
 605
 606         sec = ms / 1000;
 607         msec = ms % 1000;
 608
 609         sprintf(delay, "%ld.%03ld\n", sec, msec);
 610         /*             this '\n' ^ needed for kernels older than 2.6.28 */
 611         return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
 612 }
 613
 614 int sysfs_set_array(struct mdinfo *info, int vers)
 615 {
 616         int rv = 0;
 617         char ver[100];
 618         int raid_disks = info->array.raid_disks;
 619
 620         ver[0] = 0;
 621         if (info->array.major_version == -1 &&
 622             info->array.minor_version == -2) {
 623                 char buf[1024];
 624
 625                 strcat(strcpy(ver, "external:"), info->text_version);
 626
 627                 /* meta version might already be set if we are setting
 628                  * new geometry for a reshape.  In that case we don't
 629                  * want to over-write the 'readonly' flag that is
 630                  * stored in the metadata version.  So read the current
 631                  * version first, and preserve the flag
 632                  */
 633                 if (sysfs_get_str(info, NULL, "metadata_version",
 634                                   buf, 1024) > 0)
 635                         if (strlen(buf) >= 9 && buf[9] == '-')
 636                                 ver[9] = '-';
 637
 638                 if ((vers % 100) < 2 ||
 639                     sysfs_set_str(info, NULL, "metadata_version",
 640                                   ver) < 0) {
 641                         pr_err("This kernel does not support external metadata.\n");
 642                         return 1;
 643                 }
 644         }
 645         if (info->array.level < 0)
 646                 return 0; /* FIXME */
 647         rv |= sysfs_set_str(info, NULL, "level",
 648                             map_num(pers, info->array.level));
 649         if (info->reshape_active && info->delta_disks != UnSet)
 650                 raid_disks -= info->delta_disks;
 651         rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
 652         rv |= sysfs_set_num(info, NULL, "chunk_size", info->array.chunk_size);
 653         rv |= sysfs_set_num(info, NULL, "layout", info->array.layout);
 654         rv |= sysfs_set_num(info, NULL, "component_size", info->component_size/2);
 655         if (info->custom_array_size) {
 656                 int rc;
 657
 658                 rc = sysfs_set_num(info, NULL, "array_size",
 659                                    info->custom_array_size/2);
 660                 if (rc && errno == ENOENT) {
 661                         pr_err("This kernel does not have the md/array_size attribute, the array may be larger than expected\n");
 662                         rc = 0;
 663                 }
 664                 rv |= rc;
 665         }
 666
 667         if (info->array.level > 0)
 668                 rv |= sysfs_set_num(info, NULL, "resync_start", info->resync_start);
 669
 670         if (info->reshape_active) {
 671                 rv |= sysfs_set_num(info, NULL, "reshape_position",
 672                                     info->reshape_progress);
 673                 rv |= sysfs_set_num(info, NULL, "chunk_size", info->new_chunk);
 674                 rv |= sysfs_set_num(info, NULL, "layout", info->new_layout);
 675                 rv |= sysfs_set_num(info, NULL, "raid_disks",
 676                                     info->array.raid_disks);
 677                 /* We don't set 'new_level' here.  That can only happen
 678                  * once the reshape completes.
 679                  */
 680         }
 681         return rv;
 682 }
 683
 684 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
 685 {
 686         char dv[PATH_MAX];
 687         char nm[PATH_MAX];
 688         char *dname;
 689         int rv;
 690
 691         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 692         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 693         if (rv)
 694                 return rv;
 695
 696         memset(nm, 0, sizeof(nm));
 697         dname = devid2kname(makedev(sd->disk.major, sd->disk.minor));
 698         strcpy(sd->sys_name, "dev-");
 699         strcpy(sd->sys_name+4, dname);
 700
 701         /* test write to see if 'recovery_start' is available */
 702         if (resume && sd->recovery_start < MaxSector &&
 703             sysfs_set_num(sra, sd, "recovery_start", 0)) {
 704                 sysfs_set_str(sra, sd, "state", "remove");
 705                 return -1;
 706         }
 707
 708         rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 709         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 710         if (sra->array.level != LEVEL_CONTAINER) {
 711                 if (sd->recovery_start == MaxSector)
 712                         /* This can correctly fail if array isn't started,
 713                          * yet, so just ignore status for now.
 714                          */
 715                         sysfs_set_str(sra, sd, "state", "insync");
 716                 if (sd->disk.raid_disk >= 0)
 717                         rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 718                 if (resume)
 719                         sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
 720         }
 721         return rv;
 722 }
 723
 724 #if 0
 725 int sysfs_disk_to_sg(int fd)
 726 {
 727         /* from an open block device, try find and open its corresponding
 728          * scsi_generic interface
 729          */
 730         struct stat st;
 731         char path[256];
 732         char sg_path[256];
 733         char sg_major_minor[10];
 734         char *c;
 735         DIR *dir;
 736         struct dirent *de;
 737         int major, minor, rv;
 738
 739         if (fstat(fd, &st))
 740                 return -1;
 741
 742         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 743                  major(st.st_rdev), minor(st.st_rdev));
 744
 745         dir = opendir(path);
 746         if (!dir)
 747                 return -1;
 748
 749         de = readdir(dir);
 750         while (de) {
 751                 if (strncmp("scsi_generic:", de->d_name,
 752                             strlen("scsi_generic:")) == 0)
 753                         break;
 754                 de = readdir(dir);
 755         }
 756         closedir(dir);
 757
 758         if (!de)
 759                 return -1;
 760
 761         snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
 762         fd = open(sg_path, O_RDONLY);
 763         if (fd < 0)
 764                 return fd;
 765
 766         rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
 767         close(fd);
 768         if (rv < 0 || rv == sizeof(sg_major_minor))
 769                 return -1;
 770         else
 771                 sg_major_minor[rv - 1] = '\0';
 772
 773         c = strchr(sg_major_minor, ':');
 774         *c = '\0';
 775         c++;
 776         major = strtol(sg_major_minor, NULL, 10);
 777         minor = strtol(c, NULL, 10);
 778         snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
 779                  (int) getpid(), major, minor);
 780         if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
 781                         fd = open(path, O_RDONLY);
 782                         unlink(path);
 783                         return fd;
 784         }
 785
 786         return -1;
 787 }
 788 #endif
 789
 790 int sysfs_disk_to_scsi_id(int fd, __u32 *id)
 791 {
 792         /* from an open block device, try to retrieve it scsi_id */
 793         struct stat st;
 794         char path[256];
 795         DIR *dir;
 796         struct dirent *de;
 797         int host, bus, target, lun;
 798
 799         if (fstat(fd, &st))
 800                 return 1;
 801
 802         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device/scsi_device",
 803                  major(st.st_rdev), minor(st.st_rdev));
 804
 805         dir = opendir(path);
 806         if (!dir)
 807                 return 1;
 808
 809         for (de = readdir(dir); de; de = readdir(dir)) {
 810                 int count;
 811
 812                 if (de->d_type != DT_DIR)
 813                         continue;
 814
 815                 count = sscanf(de->d_name, "%d:%d:%d:%d", &host, &bus, &target, &lun);
 816                 if (count == 4)
 817                         break;
 818         }
 819         closedir(dir);
 820
 821         if (!de)
 822                 return 1;
 823
 824         *id = (host << 24) | (bus << 16) | (target << 8) | (lun << 0);
 825         return 0;
 826 }
 827
 828 int sysfs_unique_holder(char *devnm, long rdev)
 829 {
 830         /* Check that devnm is a holder of rdev,
 831          * and is the only holder.
 832          * we should be locked against races by
 833          * an O_EXCL on devnm
 834          * Return values:
 835          *  0 - not unique, not even a holder
 836          *  1 - unique, this is the only holder.
 837          *  2/3 - not unique, there is another holder
 838          * -1 - error, cannot find the holders
 839          */
 840         DIR *dir;
 841         struct dirent *de;
 842         char dirname[100];
 843         char l;
 844         int ret = 0;
 845         sprintf(dirname, "/sys/dev/block/%d:%d/holders",
 846                 major(rdev), minor(rdev));
 847         dir = opendir(dirname);
 848         if (!dir)
 849                 return -1;
 850         l = strlen(dirname);
 851         while ((de = readdir(dir)) != NULL) {
 852                 char buf[100];
 853                 char *sl;
 854                 int n;
 855
 856                 if (de->d_ino == 0)
 857                         continue;
 858                 if (de->d_name[0] == '.')
 859                         continue;
 860                 strcpy(dirname+l, "/");
 861                 strcat(dirname+l, de->d_name);
 862                 n = readlink(dirname, buf, sizeof(buf)-1);
 863                 if (n <= 0)
 864                         continue;
 865                 buf[n] = 0;
 866                 sl = strrchr(buf, '/');
 867                 if (!sl)
 868                         continue;
 869                 sl++;
 870
 871                 if (strcmp(devnm, sl) == 0)
 872                         ret |= 1;
 873                 else
 874                         ret |= 2;
 875         }
 876         closedir(dir);
 877         return ret;
 878 }
 879
 880 int sysfs_freeze_array(struct mdinfo *sra)
 881 {
 882         /* Try to freeze resync/rebuild on this array/container.
 883          * Return -1 if the array is busy,
 884          * return 0 if this kernel doesn't support 'frozen'
 885          * return 1 if it worked.
 886          */
 887         char buf[20];
 888
 889         if (!sysfs_attribute_available(sra, NULL, "sync_action"))
 890                 return 1; /* no sync_action == frozen */
 891         if (sysfs_get_str(sra, NULL, "sync_action", buf, 20) <= 0)
 892                 return 0;
 893         if (strcmp(buf, "frozen\n") == 0)
 894                 /* Already frozen */
 895                 return 0;
 896         if (strcmp(buf, "idle\n") != 0 && strcmp(buf, "recover\n") != 0)
 897                 return -1;
 898         if (sysfs_set_str(sra, NULL, "sync_action", "frozen") < 0)
 899                 return 0;
 900         return 1;
 901 }
 902
 903 int sysfs_wait(int fd, int *msec)
 904 {
 905         /* Wait up to '*msec' for fd to have an exception condition.
 906          * if msec == NULL, wait indefinitely.
 907          */
 908         fd_set fds;
 909         int n;
 910         FD_ZERO(&fds);
 911         FD_SET(fd, &fds);
 912         if (msec == NULL)
 913                 n = select(fd+1, NULL, NULL, &fds, NULL);
 914         else if (*msec < 0)
 915                 n = 0;
 916         else {
 917                 struct timeval start, end, tv;
 918                 gettimeofday(&start, NULL);
 919                 if (*msec < 1000) {
 920                         tv.tv_sec = 0;
 921                         tv.tv_usec = (*msec)*1000;
 922                 } else {
 923                         tv.tv_sec = (*msec)/1000;
 924                         tv.tv_usec = 0;
 925                 }
 926                 n = select(fd+1, NULL, NULL, &fds, &tv);
 927                 gettimeofday(&end, NULL);
 928                 end.tv_sec -= start.tv_sec;
 929                 *msec -= (end.tv_sec * 1000 + end.tv_usec/1000
 930                           - start.tv_usec/1000) + 1;
 931         }
 932         return n;
 933 }