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 #define MAX_SYSFS_PATH_LEN      120
  31
  32 int load_sys(char *path, char *buf, int len)
  33 {
  34         int fd = open(path, O_RDONLY);
  35         int n;
  36         if (fd < 0)
  37                 return -1;
  38         n = read(fd, buf, len);
  39         close(fd);
  40         if (n <0 || n >= len)
  41                 return -1;
  42         buf[n] = 0;
  43         if (n && buf[n-1] == '\n')
  44                 buf[n-1] = 0;
  45         return 0;
  46 }
  47
  48 void sysfs_free(struct mdinfo *sra)
  49 {
  50         while (sra) {
  51                 struct mdinfo *sra2 = sra->next;
  52                 while (sra->devs) {
  53                         struct mdinfo *d = sra->devs;
  54                         sra->devs = d->next;
  55                         free(d->bb.entries);
  56                         free(d);
  57                 }
  58                 free(sra->bb.entries);
  59                 free(sra);
  60                 sra = sra2;
  61         }
  62 }
  63
  64 int sysfs_open(char *devnm, char *devname, char *attr)
  65 {
  66         char fname[MAX_SYSFS_PATH_LEN];
  67         int fd;
  68
  69         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/", devnm);
  70         if (devname) {
  71                 strncat(fname, devname, MAX_SYSFS_PATH_LEN - strlen(fname));
  72                 strncat(fname, "/", MAX_SYSFS_PATH_LEN - strlen(fname));
  73         }
  74         strncat(fname, attr, MAX_SYSFS_PATH_LEN - strlen(fname));
  75         fd = open(fname, O_RDWR);
  76         if (fd < 0 && errno == EACCES)
  77                 fd = open(fname, O_RDONLY);
  78         return fd;
  79 }
  80
  81 void sysfs_init_dev(struct mdinfo *mdi, unsigned long devid)
  82 {
  83         snprintf(mdi->sys_name,
  84                  sizeof(mdi->sys_name), "dev-%s", devid2kname(devid));
  85 }
  86
  87 int sysfs_init(struct mdinfo *mdi, int fd, char *devnm)
  88 {
  89         struct stat stb;
  90         char fname[MAX_SYSFS_PATH_LEN];
  91         int retval = -ENODEV;
  92
  93         mdi->sys_name[0] = 0;
  94         if (fd >= 0)
  95                 devnm = fd2devnm(fd);
  96
  97         if (devnm == NULL)
  98                 goto out;
  99
 100         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md", devnm);
 101
 102         if (stat(fname, &stb))
 103                 goto out;
 104         if (!S_ISDIR(stb.st_mode))
 105                 goto out;
 106         strcpy(mdi->sys_name, devnm);
 107
 108         retval = 0;
 109 out:
 110         return retval;
 111 }
 112
 113 struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
 114 {
 115         char fname[PATH_MAX];
 116         char buf[PATH_MAX];
 117         char *base;
 118         char *dbase;
 119         struct mdinfo *sra;
 120         struct mdinfo *dev, **devp;
 121         DIR *dir = NULL;
 122         struct dirent *de;
 123
 124         sra = xcalloc(1, sizeof(*sra));
 125         if (sysfs_init(sra, fd, devnm)) {
 126                 free(sra);
 127                 return NULL;
 128         }
 129
 130         sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
 131         base = fname + strlen(fname);
 132
 133         sra->devs = NULL;
 134         if (options & GET_VERSION) {
 135                 strcpy(base, "metadata_version");
 136                 if (load_sys(fname, buf, sizeof(buf)))
 137                         goto abort;
 138                 if (strncmp(buf, "none", 4) == 0) {
 139                         sra->array.major_version =
 140                                 sra->array.minor_version = -1;
 141                         strcpy(sra->text_version, "");
 142                 } else if (strncmp(buf, "external:", 9) == 0) {
 143                         sra->array.major_version = -1;
 144                         sra->array.minor_version = -2;
 145                         strcpy(sra->text_version, buf+9);
 146                 } else {
 147                         sscanf(buf, "%d.%d",
 148                                &sra->array.major_version,
 149                                &sra->array.minor_version);
 150                         strcpy(sra->text_version, buf);
 151                 }
 152         }
 153         if (options & GET_LEVEL) {
 154                 strcpy(base, "level");
 155                 if (load_sys(fname, buf, sizeof(buf)))
 156                         goto abort;
 157                 sra->array.level = map_name(pers, buf);
 158         }
 159         if (options & GET_LAYOUT) {
 160                 strcpy(base, "layout");
 161                 if (load_sys(fname, buf, sizeof(buf)))
 162                         goto abort;
 163                 sra->array.layout = strtoul(buf, NULL, 0);
 164         }
 165         if (options & GET_DISKS) {
 166                 strcpy(base, "raid_disks");
 167                 if (load_sys(fname, buf, sizeof(buf)))
 168                         goto abort;
 169                 sra->array.raid_disks = strtoul(buf, NULL, 0);
 170         }
 171         if (options & GET_DEGRADED) {
 172                 strcpy(base, "degraded");
 173                 if (load_sys(fname, buf, sizeof(buf)))
 174                         goto abort;
 175                 sra->array.failed_disks = strtoul(buf, NULL, 0);
 176         }
 177         if (options & GET_COMPONENT) {
 178                 strcpy(base, "component_size");
 179                 if (load_sys(fname, buf, sizeof(buf)))
 180                         goto abort;
 181                 sra->component_size = strtoull(buf, NULL, 0);
 182                 /* sysfs reports "K", but we want sectors */
 183                 sra->component_size *= 2;
 184         }
 185         if (options & GET_CHUNK) {
 186                 strcpy(base, "chunk_size");
 187                 if (load_sys(fname, buf, sizeof(buf)))
 188                         goto abort;
 189                 sra->array.chunk_size = strtoul(buf, NULL, 0);
 190         }
 191         if (options & GET_CACHE) {
 192                 strcpy(base, "stripe_cache_size");
 193                 if (load_sys(fname, buf, sizeof(buf)))
 194                         /* Probably level doesn't support it */
 195                         sra->cache_size = 0;
 196                 else
 197                         sra->cache_size = strtoul(buf, NULL, 0);
 198         }
 199         if (options & GET_MISMATCH) {
 200                 strcpy(base, "mismatch_cnt");
 201                 if (load_sys(fname, buf, sizeof(buf)))
 202                         goto abort;
 203                 sra->mismatch_cnt = strtoul(buf, NULL, 0);
 204         }
 205         if (options & GET_SAFEMODE) {
 206                 int scale = 1;
 207                 int dot = 0;
 208                 unsigned i;
 209                 unsigned long msec;
 210                 size_t len;
 211
 212                 strcpy(base, "safe_mode_delay");
 213                 if (load_sys(fname, buf, sizeof(buf)))
 214                         goto abort;
 215
 216                 /* remove a period, and count digits after it */
 217                 len = strlen(buf);
 218                 for (i = 0; i < len; i++) {
 219                         if (dot) {
 220                                 if (isdigit(buf[i])) {
 221                                         buf[i-1] = buf[i];
 222                                         scale *= 10;
 223                                 }
 224                                 buf[i] = 0;
 225                         } else if (buf[i] == '.') {
 226                                 dot=1;
 227                                 buf[i] = 0;
 228                         }
 229                 }
 230                 msec = strtoul(buf, NULL, 10);
 231                 msec = (msec * 1000) / scale;
 232                 sra->safe_mode_delay = msec;
 233         }
 234         if (options & GET_BITMAP_LOCATION) {
 235                 strcpy(base, "bitmap/location");
 236                 if (load_sys(fname, buf, sizeof(buf)))
 237                         goto abort;
 238                 if (strncmp(buf, "file", 4) == 0)
 239                         sra->bitmap_offset = 1;
 240                 else if (strncmp(buf, "none", 4) == 0)
 241                         sra->bitmap_offset = 0;
 242                 else if (buf[0] == '+')
 243                         sra->bitmap_offset = strtol(buf+1, NULL, 10);
 244                 else
 245                         goto abort;
 246         }
 247
 248         if (options & GET_ARRAY_STATE) {
 249                 strcpy(base, "array_state");
 250                 if (load_sys(fname, buf, sizeof(buf)))
 251                         goto abort;
 252                 sra->array_state = map_name(sysfs_array_states, buf);
 253         }
 254
 255         if (options & GET_CONSISTENCY_POLICY) {
 256                 strcpy(base, "consistency_policy");
 257                 if (load_sys(fname, buf, sizeof(buf)))
 258                         sra->consistency_policy = CONSISTENCY_POLICY_UNKNOWN;
 259                 else
 260                         sra->consistency_policy = map_name(consistency_policies,
 261                                                            buf);
 262         }
 263
 264         if (! (options & GET_DEVS))
 265                 return sra;
 266
 267         /* Get all the devices as well */
 268         *base = 0;
 269         dir = opendir(fname);
 270         if (!dir)
 271                 goto abort;
 272         sra->array.spare_disks = 0;
 273         sra->array.active_disks = 0;
 274         sra->array.failed_disks = 0;
 275
 276         devp = &sra->devs;
 277         sra->devs = NULL;
 278         while ((de = readdir(dir)) != NULL) {
 279                 char *ep;
 280                 if (de->d_ino == 0 ||
 281                     strncmp(de->d_name, "dev-", 4) != 0)
 282                         continue;
 283                 strcpy(base, de->d_name);
 284                 dbase = base + strlen(base);
 285                 *dbase++ = '/';
 286
 287                 dev = xcalloc(1, sizeof(*dev));
 288
 289                 /* Always get slot, major, minor */
 290                 strcpy(dbase, "slot");
 291                 if (load_sys(fname, buf, sizeof(buf))) {
 292                         /* hmm... unable to read 'slot' maybe the device
 293                          * is going away?
 294                          */
 295                         strcpy(dbase, "block");
 296                         if (readlink(fname, buf, sizeof(buf)) < 0 &&
 297                             errno != ENAMETOOLONG) {
 298                                 /* ...yup device is gone */
 299                                 free(dev);
 300                                 continue;
 301                         } else {
 302                                 /* slot is unreadable but 'block' link
 303                                  * still intact... something bad is happening
 304                                  * so abort
 305                                  */
 306                                 free(dev);
 307                                 goto abort;
 308                         }
 309
 310                 }
 311                 strcpy(dev->sys_name, de->d_name);
 312                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 313                 if (*ep) dev->disk.raid_disk = -1;
 314
 315                 strcpy(dbase, "block/dev");
 316                 if (load_sys(fname, buf, sizeof(buf))) {
 317                         /* assume this is a stale reference to a hot
 318                          * removed device
 319                          */
 320                         free(dev);
 321                         continue;
 322                 }
 323                 sra->array.nr_disks++;
 324                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 325
 326                 /* special case check for block devices that can go 'offline' */
 327                 strcpy(dbase, "block/device/state");
 328                 if (load_sys(fname, buf, sizeof(buf)) == 0 &&
 329                     strncmp(buf, "offline", 7) == 0) {
 330                         free(dev);
 331                         continue;
 332                 }
 333
 334                 /* finally add this disk to the array */
 335                 *devp = dev;
 336                 devp = & dev->next;
 337                 dev->next = NULL;
 338
 339                 if (options & GET_OFFSET) {
 340                         strcpy(dbase, "offset");
 341                         if (load_sys(fname, buf, sizeof(buf)))
 342                                 goto abort;
 343                         dev->data_offset = strtoull(buf, NULL, 0);
 344                         strcpy(dbase, "new_offset");
 345                         if (load_sys(fname, buf, sizeof(buf)) == 0)
 346                                 dev->new_data_offset = strtoull(buf, NULL, 0);
 347                         else
 348                                 dev->new_data_offset = dev->data_offset;
 349                 }
 350                 if (options & GET_SIZE) {
 351                         strcpy(dbase, "size");
 352                         if (load_sys(fname, buf, sizeof(buf)))
 353                                 goto abort;
 354                         dev->component_size = strtoull(buf, NULL, 0) * 2;
 355                 }
 356                 if (options & GET_STATE) {
 357                         dev->disk.state = 0;
 358                         strcpy(dbase, "state");
 359                         if (load_sys(fname, buf, sizeof(buf)))
 360                                 goto abort;
 361                         if (strstr(buf, "in_sync")) {
 362                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 363                                 sra->array.active_disks++;
 364                         }
 365                         if (strstr(buf, "faulty")) {
 366                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 367                                 sra->array.failed_disks++;
 368                         }
 369                         if (dev->disk.state == 0)
 370                                 sra->array.spare_disks++;
 371                 }
 372                 if (options & GET_ERROR) {
 373                         strcpy(buf, "errors");
 374                         if (load_sys(fname, buf, sizeof(buf)))
 375                                 goto abort;
 376                         dev->errors = strtoul(buf, NULL, 0);
 377                 }
 378         }
 379         closedir(dir);
 380         return sra;
 381
 382  abort:
 383         if (dir)
 384                 closedir(dir);
 385         sysfs_free(sra);
 386         return NULL;
 387 }
 388
 389 int sysfs_attr_match(const char *attr, const char *str)
 390 {
 391         /* See if attr, read from a sysfs file, matches
 392          * str.  They must either be the same, or attr can
 393          * have a trailing newline or comma
 394          */
 395         while (*attr && *str && *attr == *str) {
 396                 attr++;
 397                 str++;
 398         }
 399
 400         if (*str || (*attr && *attr != ',' && *attr != '\n'))
 401                 return 0;
 402         return 1;
 403 }
 404
 405 int sysfs_match_word(const char *word, char **list)
 406 {
 407         int n;
 408         for (n=0; list[n]; n++)
 409                 if (sysfs_attr_match(word, list[n]))
 410                         break;
 411         return n;
 412 }
 413
 414 unsigned long long get_component_size(int fd)
 415 {
 416         /* Find out the component size of the array.
 417          * We cannot trust GET_ARRAY_INFO ioctl as it's
 418          * size field is only 32bits.
 419          * So look in /sys/block/mdXXX/md/component_size
 420          *
 421          * This returns in units of sectors.
 422          */
 423         struct stat stb;
 424         char fname[MAX_SYSFS_PATH_LEN];
 425         int n;
 426         if (fstat(fd, &stb))
 427                 return 0;
 428         snprintf(fname, MAX_SYSFS_PATH_LEN,
 429                  "/sys/block/%s/md/component_size", stat2devnm(&stb));
 430         fd = open(fname, O_RDONLY);
 431         if (fd < 0)
 432                 return 0;
 433         n = read(fd, fname, sizeof(fname));
 434         close(fd);
 435         if (n < 0 || n == sizeof(fname))
 436                 return 0;
 437         fname[n] = 0;
 438         return strtoull(fname, NULL, 10) * 2;
 439 }
 440
 441 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 442                   char *name, char *val)
 443 {
 444         char fname[MAX_SYSFS_PATH_LEN];
 445         unsigned int n;
 446         int fd;
 447
 448         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 449                 sra->sys_name, dev?dev->sys_name:"", name);
 450         fd = open(fname, O_WRONLY);
 451         if (fd < 0)
 452                 return -1;
 453         n = write(fd, val, strlen(val));
 454         close(fd);
 455         if (n != strlen(val)) {
 456                 dprintf("failed to write '%s' to '%s' (%s)\n",
 457                         val, fname, strerror(errno));
 458                 return -1;
 459         }
 460         return 0;
 461 }
 462
 463 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 464                   char *name, unsigned long long val)
 465 {
 466         char valstr[50];
 467         sprintf(valstr, "%llu", val);
 468         return sysfs_set_str(sra, dev, name, valstr);
 469 }
 470
 471 int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
 472                          char *name, long long val)
 473 {
 474         char valstr[50];
 475         sprintf(valstr, "%lli", val);
 476         return sysfs_set_str(sra, dev, name, valstr);
 477 }
 478
 479 int sysfs_uevent(struct mdinfo *sra, char *event)
 480 {
 481         char fname[MAX_SYSFS_PATH_LEN];
 482         int n;
 483         int fd;
 484
 485         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/uevent",
 486                 sra->sys_name);
 487         fd = open(fname, O_WRONLY);
 488         if (fd < 0)
 489                 return -1;
 490         n = write(fd, event, strlen(event));
 491         close(fd);
 492         if (n != (int)strlen(event)) {
 493                 dprintf("failed to write '%s' to '%s' (%s)\n",
 494                         event, fname, strerror(errno));
 495                 return -1;
 496         }
 497         return 0;
 498 }
 499
 500 int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
 501 {
 502         char fname[MAX_SYSFS_PATH_LEN];
 503         struct stat st;
 504
 505         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 506                 sra->sys_name, dev?dev->sys_name:"", name);
 507
 508         return stat(fname, &st) == 0;
 509 }
 510
 511 int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 512                        char *name)
 513 {
 514         char fname[MAX_SYSFS_PATH_LEN];
 515         int fd;
 516
 517         snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 518                 sra->sys_name, dev?dev->sys_name:"", name);
 519         fd = open(fname, O_RDWR);
 520         if (fd < 0)
 521                 fd = open(fname, O_RDONLY);
 522         return fd;
 523 }
 524
 525 int sysfs_fd_get_ll(int fd, unsigned long long *val)
 526 {
 527         char buf[50];
 528         int n;
 529         char *ep;
 530
 531         lseek(fd, 0, 0);
 532         n = read(fd, buf, sizeof(buf));
 533         if (n <= 0 || n == sizeof(buf))
 534                 return -2;
 535         buf[n] = 0;
 536         *val = strtoull(buf, &ep, 0);
 537         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 538                 return -1;
 539         return 0;
 540 }
 541
 542 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 543                        char *name, unsigned long long *val)
 544 {
 545         int n;
 546         int fd;
 547
 548         fd = sysfs_get_fd(sra, dev, name);
 549         if (fd < 0)
 550                 return -1;
 551         n = sysfs_fd_get_ll(fd, val);
 552         close(fd);
 553         return n;
 554 }
 555
 556 int sysfs_fd_get_two(int fd, unsigned long long *v1, unsigned long long *v2)
 557 {
 558         /* two numbers in this sysfs file, either
 559          *  NNN (NNN)
 560          * or
 561          *  NNN / NNN
 562          */
 563         char buf[80];
 564         int n;
 565         char *ep, *ep2;
 566
 567         lseek(fd, 0, 0);
 568         n = read(fd, buf, sizeof(buf));
 569         if (n <= 0 || n == sizeof(buf))
 570                 return -2;
 571         buf[n] = 0;
 572         *v1 = strtoull(buf, &ep, 0);
 573         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 574                 return -1;
 575         while (*ep == ' ' || *ep == '/' || *ep == '(')
 576                 ep++;
 577         *v2 = strtoull(ep, &ep2, 0);
 578         if (ep2 == ep || (*ep2 != 0 && *ep2 != '\n' && *ep2 != ' ' && *ep2 != ')')) {
 579                 *v2 = *v1;
 580                 return 1;
 581         }
 582         return 2;
 583 }
 584
 585 int sysfs_get_two(struct mdinfo *sra, struct mdinfo *dev,
 586                   char *name, unsigned long long *v1, unsigned long long *v2)
 587 {
 588         int n;
 589         int fd;
 590
 591         fd = sysfs_get_fd(sra, dev, name);
 592         if (fd < 0)
 593                 return -1;
 594         n = sysfs_fd_get_two(fd, v1, v2);
 595         close(fd);
 596         return n;
 597 }
 598
 599 int sysfs_fd_get_str(int fd, char *val, int size)
 600 {
 601         int n;
 602
 603         lseek(fd, 0, 0);
 604         n = read(fd, val, size);
 605         if (n <= 0 || n == size)
 606                 return -1;
 607         val[n] = 0;
 608         return n;
 609 }
 610
 611 int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
 612                        char *name, char *val, int size)
 613 {
 614         int n;
 615         int fd;
 616
 617         fd = sysfs_get_fd(sra, dev, name);
 618         if (fd < 0)
 619                 return -1;
 620         n = sysfs_fd_get_str(fd, val, size);
 621         close(fd);
 622         return n;
 623 }
 624
 625 int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
 626 {
 627         unsigned long sec;
 628         unsigned long msec;
 629         char delay[30];
 630
 631         sec = ms / 1000;
 632         msec = ms % 1000;
 633
 634         sprintf(delay, "%ld.%03ld\n", sec, msec);
 635         /*             this '\n' ^ needed for kernels older than 2.6.28 */
 636         return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
 637 }
 638
 639 int sysfs_set_array(struct mdinfo *info, int vers)
 640 {
 641         int rv = 0;
 642         char ver[100];
 643         int raid_disks = info->array.raid_disks;
 644
 645         ver[0] = 0;
 646         if (info->array.major_version == -1 &&
 647             info->array.minor_version == -2) {
 648                 char buf[1024];
 649
 650                 strcat(strcpy(ver, "external:"), info->text_version);
 651
 652                 /* meta version might already be set if we are setting
 653                  * new geometry for a reshape.  In that case we don't
 654                  * want to over-write the 'readonly' flag that is
 655                  * stored in the metadata version.  So read the current
 656                  * version first, and preserve the flag
 657                  */
 658                 if (sysfs_get_str(info, NULL, "metadata_version",
 659                                   buf, 1024) > 0)
 660                         if (strlen(buf) >= 9 && buf[9] == '-')
 661                                 ver[9] = '-';
 662
 663                 if ((vers % 100) < 2 ||
 664                     sysfs_set_str(info, NULL, "metadata_version",
 665                                   ver) < 0) {
 666                         pr_err("This kernel does not support external metadata.\n");
 667                         return 1;
 668                 }
 669         }
 670         if (info->array.level < 0)
 671                 return 0; /* FIXME */
 672         rv |= sysfs_set_str(info, NULL, "level",
 673                             map_num(pers, info->array.level));
 674         if (info->reshape_active && info->delta_disks != UnSet)
 675                 raid_disks -= info->delta_disks;
 676         rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
 677         rv |= sysfs_set_num(info, NULL, "chunk_size", info->array.chunk_size);
 678         rv |= sysfs_set_num(info, NULL, "layout", info->array.layout);
 679         rv |= sysfs_set_num(info, NULL, "component_size", info->component_size/2);
 680         if (info->custom_array_size) {
 681                 int rc;
 682
 683                 rc = sysfs_set_num(info, NULL, "array_size",
 684                                    info->custom_array_size/2);
 685                 if (rc && errno == ENOENT) {
 686                         pr_err("This kernel does not have the md/array_size attribute, the array may be larger than expected\n");
 687                         rc = 0;
 688                 }
 689                 rv |= rc;
 690         }
 691
 692         if (info->array.level > 0)
 693                 rv |= sysfs_set_num(info, NULL, "resync_start", info->resync_start);
 694
 695         if (info->reshape_active) {
 696                 rv |= sysfs_set_num(info, NULL, "reshape_position",
 697                                     info->reshape_progress);
 698                 rv |= sysfs_set_num(info, NULL, "chunk_size", info->new_chunk);
 699                 rv |= sysfs_set_num(info, NULL, "layout", info->new_layout);
 700                 rv |= sysfs_set_num(info, NULL, "raid_disks",
 701                                     info->array.raid_disks);
 702                 /* We don't set 'new_level' here.  That can only happen
 703                  * once the reshape completes.
 704                  */
 705         }
 706
 707         if (info->consistency_policy == CONSISTENCY_POLICY_PPL) {
 708                 if (sysfs_set_str(info, NULL, "consistency_policy",
 709                                   map_num(consistency_policies,
 710                                           info->consistency_policy))) {
 711                         pr_err("This kernel does not support PPL\n");
 712                         return 1;
 713                 }
 714         }
 715
 716         return rv;
 717 }
 718
 719 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
 720 {
 721         char dv[PATH_MAX];
 722         char nm[PATH_MAX];
 723         char *dname;
 724         int rv;
 725         int i;
 726
 727         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 728         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 729         if (rv)
 730                 return rv;
 731
 732         memset(nm, 0, sizeof(nm));
 733         dname = devid2kname(makedev(sd->disk.major, sd->disk.minor));
 734         strcpy(sd->sys_name, "dev-");
 735         strcpy(sd->sys_name+4, dname);
 736
 737         /* test write to see if 'recovery_start' is available */
 738         if (resume && sd->recovery_start < MaxSector &&
 739             sysfs_set_num(sra, sd, "recovery_start", 0)) {
 740                 sysfs_set_str(sra, sd, "state", "remove");
 741                 return -1;
 742         }
 743
 744         rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 745         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 746         if (sra->array.level != LEVEL_CONTAINER) {
 747                 if (sd->consistency_policy == CONSISTENCY_POLICY_PPL) {
 748                         rv |= sysfs_set_num(sra, sd, "ppl_sector", sd->ppl_sector);
 749                         rv |= sysfs_set_num(sra, sd, "ppl_size", sd->ppl_size);
 750                 }
 751                 if (sd->recovery_start == MaxSector)
 752                         /* This can correctly fail if array isn't started,
 753                          * yet, so just ignore status for now.
 754                          */
 755                         sysfs_set_str(sra, sd, "state", "insync");
 756                 if (sd->disk.raid_disk >= 0)
 757                         rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 758                 if (resume)
 759                         sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
 760         }
 761         if (sd->bb.supported) {
 762                 if (sysfs_set_str(sra, sd, "state", "external_bbl")) {
 763                         /*
 764                          * backward compatibility - if kernel doesn't support
 765                          * bad blocks for external metadata, let it continue
 766                          * as long as there are none known so far
 767                          */
 768                         if (sd->bb.count) {
 769                                 pr_err("The kernel has no support for bad blocks in external metadata\n");
 770                                 return -1;
 771                         }
 772                 }
 773
 774                 for (i = 0; i < sd->bb.count; i++) {
 775                         char s[30];
 776                         const struct md_bb_entry *entry = &sd->bb.entries[i];
 777
 778                         snprintf(s, sizeof(s) - 1, "%llu %d\n", entry->sector,
 779                                  entry->length);
 780                         rv |= sysfs_set_str(sra, sd, "bad_blocks", s);
 781                 }
 782         }
 783         return rv;
 784 }
 785
 786 #if 0
 787 int sysfs_disk_to_sg(int fd)
 788 {
 789         /* from an open block device, try find and open its corresponding
 790          * scsi_generic interface
 791          */
 792         struct stat st;
 793         char path[256];
 794         char sg_path[256];
 795         char sg_major_minor[10];
 796         char *c;
 797         DIR *dir;
 798         struct dirent *de;
 799         int major, minor, rv;
 800
 801         if (fstat(fd, &st))
 802                 return -1;
 803
 804         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 805                  major(st.st_rdev), minor(st.st_rdev));
 806
 807         dir = opendir(path);
 808         if (!dir)
 809                 return -1;
 810
 811         de = readdir(dir);
 812         while (de) {
 813                 if (strncmp("scsi_generic:", de->d_name,
 814                             strlen("scsi_generic:")) == 0)
 815                         break;
 816                 de = readdir(dir);
 817         }
 818         closedir(dir);
 819
 820         if (!de)
 821                 return -1;
 822
 823         snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
 824         fd = open(sg_path, O_RDONLY);
 825         if (fd < 0)
 826                 return fd;
 827
 828         rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
 829         close(fd);
 830         if (rv < 0 || rv == sizeof(sg_major_minor))
 831                 return -1;
 832         else
 833                 sg_major_minor[rv - 1] = '\0';
 834
 835         c = strchr(sg_major_minor, ':');
 836         *c = '\0';
 837         c++;
 838         major = strtol(sg_major_minor, NULL, 10);
 839         minor = strtol(c, NULL, 10);
 840         snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
 841                  (int) getpid(), major, minor);
 842         if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
 843                         fd = open(path, O_RDONLY);
 844                         unlink(path);
 845                         return fd;
 846         }
 847
 848         return -1;
 849 }
 850 #endif
 851
 852 int sysfs_disk_to_scsi_id(int fd, __u32 *id)
 853 {
 854         /* from an open block device, try to retrieve it scsi_id */
 855         struct stat st;
 856         char path[256];
 857         DIR *dir;
 858         struct dirent *de;
 859         int host, bus, target, lun;
 860
 861         if (fstat(fd, &st))
 862                 return 1;
 863
 864         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device/scsi_device",
 865                  major(st.st_rdev), minor(st.st_rdev));
 866
 867         dir = opendir(path);
 868         if (!dir)
 869                 return 1;
 870
 871         for (de = readdir(dir); de; de = readdir(dir)) {
 872                 int count;
 873
 874                 if (de->d_type != DT_DIR)
 875                         continue;
 876
 877                 count = sscanf(de->d_name, "%d:%d:%d:%d", &host, &bus, &target, &lun);
 878                 if (count == 4)
 879                         break;
 880         }
 881         closedir(dir);
 882
 883         if (!de)
 884                 return 1;
 885
 886         *id = (host << 24) | (bus << 16) | (target << 8) | (lun << 0);
 887         return 0;
 888 }
 889
 890 int sysfs_unique_holder(char *devnm, long rdev)
 891 {
 892         /* Check that devnm is a holder of rdev,
 893          * and is the only holder.
 894          * we should be locked against races by
 895          * an O_EXCL on devnm
 896          * Return values:
 897          *  0 - not unique, not even a holder
 898          *  1 - unique, this is the only holder.
 899          *  2/3 - not unique, there is another holder
 900          * -1 - error, cannot find the holders
 901          */
 902         DIR *dir;
 903         struct dirent *de;
 904         char dirname[100];
 905         char l;
 906         int ret = 0;
 907         sprintf(dirname, "/sys/dev/block/%d:%d/holders",
 908                 major(rdev), minor(rdev));
 909         dir = opendir(dirname);
 910         if (!dir)
 911                 return -1;
 912         l = strlen(dirname);
 913         while ((de = readdir(dir)) != NULL) {
 914                 char buf[100];
 915                 char *sl;
 916                 int n;
 917
 918                 if (de->d_ino == 0)
 919                         continue;
 920                 if (de->d_name[0] == '.')
 921                         continue;
 922                 strcpy(dirname+l, "/");
 923                 strcat(dirname+l, de->d_name);
 924                 n = readlink(dirname, buf, sizeof(buf)-1);
 925                 if (n <= 0)
 926                         continue;
 927                 buf[n] = 0;
 928                 sl = strrchr(buf, '/');
 929                 if (!sl)
 930                         continue;
 931                 sl++;
 932
 933                 if (strcmp(devnm, sl) == 0)
 934                         ret |= 1;
 935                 else
 936                         ret |= 2;
 937         }
 938         closedir(dir);
 939         return ret;
 940 }
 941
 942 int sysfs_freeze_array(struct mdinfo *sra)
 943 {
 944         /* Try to freeze resync/rebuild on this array/container.
 945          * Return -1 if the array is busy,
 946          * return 0 if this kernel doesn't support 'frozen'
 947          * return 1 if it worked.
 948          */
 949         char buf[20];
 950
 951         if (!sysfs_attribute_available(sra, NULL, "sync_action"))
 952                 return 1; /* no sync_action == frozen */
 953         if (sysfs_get_str(sra, NULL, "sync_action", buf, 20) <= 0)
 954                 return 0;
 955         if (strcmp(buf, "frozen\n") == 0)
 956                 /* Already frozen */
 957                 return 0;
 958         if (strcmp(buf, "idle\n") != 0 && strcmp(buf, "recover\n") != 0)
 959                 return -1;
 960         if (sysfs_set_str(sra, NULL, "sync_action", "frozen") < 0)
 961                 return 0;
 962         return 1;
 963 }
 964
 965 int sysfs_wait(int fd, int *msec)
 966 {
 967         /* Wait up to '*msec' for fd to have an exception condition.
 968          * if msec == NULL, wait indefinitely.
 969          */
 970         fd_set fds;
 971         int n;
 972         FD_ZERO(&fds);
 973         FD_SET(fd, &fds);
 974         if (msec == NULL)
 975                 n = select(fd+1, NULL, NULL, &fds, NULL);
 976         else if (*msec < 0)
 977                 n = 0;
 978         else {
 979                 struct timeval start, end, tv;
 980                 gettimeofday(&start, NULL);
 981                 if (*msec < 1000) {
 982                         tv.tv_sec = 0;
 983                         tv.tv_usec = (*msec)*1000;
 984                 } else {
 985                         tv.tv_sec = (*msec)/1000;
 986                         tv.tv_usec = 0;
 987                 }
 988                 n = select(fd+1, NULL, NULL, &fds, &tv);
 989                 gettimeofday(&end, NULL);
 990                 end.tv_sec -= start.tv_sec;
 991                 *msec -= (end.tv_sec * 1000 + end.tv_usec/1000
 992                           - start.tv_usec/1000) + 1;
 993         }
 994         return n;
 995 }