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