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