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(struct mdinfo *mdi, int fd, char *devnm)
  78 {
  79         mdi->sys_name[0] = 0;
  80         if (fd >= 0) {
  81                 mdu_version_t vers;
  82                 if (ioctl(fd, RAID_VERSION, &vers) != 0)
  83                         return;
  84                 devnm = fd2devnm(fd);
  85         }
  86         if (devnm == NULL)
  87                 return;
  88         strcpy(mdi->sys_name, devnm);
  89 }
  90
  91
  92 struct mdinfo *sysfs_read(int fd, char *devnm, unsigned long options)
  93 {
  94         char fname[PATH_MAX];
  95         char buf[PATH_MAX];
  96         char *base;
  97         char *dbase;
  98         struct mdinfo *sra;
  99         struct mdinfo *dev;
 100         DIR *dir = NULL;
 101         struct dirent *de;
 102
 103         sra = xcalloc(1, sizeof(*sra));
 104         sysfs_init(sra, fd, devnm);
 105         if (sra->sys_name[0] == 0) {
 106                 free(sra);
 107                 return NULL;
 108         }
 109
 110         sprintf(fname, "/sys/block/%s/md/", sra->sys_name);
 111         base = fname + strlen(fname);
 112
 113         sra->devs = NULL;
 114         if (options & GET_VERSION) {
 115                 strcpy(base, "metadata_version");
 116                 if (load_sys(fname, buf))
 117                         goto abort;
 118                 if (strncmp(buf, "none", 4) == 0) {
 119                         sra->array.major_version =
 120                                 sra->array.minor_version = -1;
 121                         strcpy(sra->text_version, "");
 122                 } else if (strncmp(buf, "external:", 9) == 0) {
 123                         sra->array.major_version = -1;
 124                         sra->array.minor_version = -2;
 125                         strcpy(sra->text_version, buf+9);
 126                 } else {
 127                         sscanf(buf, "%d.%d",
 128                                &sra->array.major_version,
 129                                &sra->array.minor_version);
 130                         strcpy(sra->text_version, buf);
 131                 }
 132         }
 133         if (options & GET_LEVEL) {
 134                 strcpy(base, "level");
 135                 if (load_sys(fname, buf))
 136                         goto abort;
 137                 sra->array.level = map_name(pers, buf);
 138         }
 139         if (options & GET_LAYOUT) {
 140                 strcpy(base, "layout");
 141                 if (load_sys(fname, buf))
 142                         goto abort;
 143                 sra->array.layout = strtoul(buf, NULL, 0);
 144         }
 145         if (options & GET_DISKS) {
 146                 strcpy(base, "raid_disks");
 147                 if (load_sys(fname, buf))
 148                         goto abort;
 149                 sra->array.raid_disks = strtoul(buf, NULL, 0);
 150         }
 151         if (options & GET_DEGRADED) {
 152                 strcpy(base, "degraded");
 153                 if (load_sys(fname, buf))
 154                         goto abort;
 155                 sra->array.failed_disks = strtoul(buf, NULL, 0);
 156         }
 157         if (options & GET_COMPONENT) {
 158                 strcpy(base, "component_size");
 159                 if (load_sys(fname, buf))
 160                         goto abort;
 161                 sra->component_size = strtoull(buf, NULL, 0);
 162                 /* sysfs reports "K", but we want sectors */
 163                 sra->component_size *= 2;
 164         }
 165         if (options & GET_CHUNK) {
 166                 strcpy(base, "chunk_size");
 167                 if (load_sys(fname, buf))
 168                         goto abort;
 169                 sra->array.chunk_size = strtoul(buf, NULL, 0);
 170         }
 171         if (options & GET_CACHE) {
 172                 strcpy(base, "stripe_cache_size");
 173                 if (load_sys(fname, buf))
 174                         /* Probably level doesn't support it */
 175                         sra->cache_size = 0;
 176                 else
 177                         sra->cache_size = strtoul(buf, NULL, 0);
 178         }
 179         if (options & GET_MISMATCH) {
 180                 strcpy(base, "mismatch_cnt");
 181                 if (load_sys(fname, buf))
 182                         goto abort;
 183                 sra->mismatch_cnt = strtoul(buf, NULL, 0);
 184         }
 185         if (options & GET_SAFEMODE) {
 186                 int scale = 1;
 187                 int dot = 0;
 188                 unsigned i;
 189                 unsigned long msec;
 190                 size_t len;
 191
 192                 strcpy(base, "safe_mode_delay");
 193                 if (load_sys(fname, buf))
 194                         goto abort;
 195
 196                 /* remove a period, and count digits after it */
 197                 len = strlen(buf);
 198                 for (i = 0; i < len; i++) {
 199                         if (dot) {
 200                                 if (isdigit(buf[i])) {
 201                                         buf[i-1] = buf[i];
 202                                         scale *= 10;
 203                                 }
 204                                 buf[i] = 0;
 205                         } else if (buf[i] == '.') {
 206                                 dot=1;
 207                                 buf[i] = 0;
 208                         }
 209                 }
 210                 msec = strtoul(buf, NULL, 10);
 211                 msec = (msec * 1000) / scale;
 212                 sra->safe_mode_delay = msec;
 213         }
 214         if (options & GET_BITMAP_LOCATION) {
 215                 strcpy(base, "bitmap/location");
 216                 if (load_sys(fname, buf))
 217                         goto abort;
 218                 if (strncmp(buf, "file", 4) == 0)
 219                         sra->bitmap_offset = 1;
 220                 else if (strncmp(buf, "none", 4) == 0)
 221                         sra->bitmap_offset = 0;
 222                 else if (buf[0] == '+')
 223                         sra->bitmap_offset = strtol(buf+1, NULL, 10);
 224                 else
 225                         goto abort;
 226         }
 227
 228         if (! (options & GET_DEVS))
 229                 return sra;
 230
 231         /* Get all the devices as well */
 232         *base = 0;
 233         dir = opendir(fname);
 234         if (!dir)
 235                 goto abort;
 236         sra->array.spare_disks = 0;
 237
 238         while ((de = readdir(dir)) != NULL) {
 239                 char *ep;
 240                 if (de->d_ino == 0 ||
 241                     strncmp(de->d_name, "dev-", 4) != 0)
 242                         continue;
 243                 strcpy(base, de->d_name);
 244                 dbase = base + strlen(base);
 245                 *dbase++ = '/';
 246
 247                 dev = xmalloc(sizeof(*dev));
 248
 249                 /* Always get slot, major, minor */
 250                 strcpy(dbase, "slot");
 251                 if (load_sys(fname, buf)) {
 252                         /* hmm... unable to read 'slot' maybe the device
 253                          * is going away?
 254                          */
 255                         strcpy(dbase, "block");
 256                         if (readlink(fname, buf, sizeof(buf)) < 0 &&
 257                             errno != ENAMETOOLONG) {
 258                                 /* ...yup device is gone */
 259                                 free(dev);
 260                                 continue;
 261                         } else {
 262                                 /* slot is unreadable but 'block' link
 263                                  * still intact... something bad is happening
 264                                  * so abort
 265                                  */
 266                                 free(dev);
 267                                 goto abort;
 268                         }
 269
 270                 }
 271                 strcpy(dev->sys_name, de->d_name);
 272                 dev->disk.raid_disk = strtoul(buf, &ep, 10);
 273                 if (*ep) dev->disk.raid_disk = -1;
 274
 275                 strcpy(dbase, "block/dev");
 276                 if (load_sys(fname, buf)) {
 277                         /* assume this is a stale reference to a hot
 278                          * removed device
 279                          */
 280                         free(dev);
 281                         continue;
 282                 }
 283                 sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 284
 285                 /* special case check for block devices that can go 'offline' */
 286                 strcpy(dbase, "block/device/state");
 287                 if (load_sys(fname, buf) == 0 &&
 288                     strncmp(buf, "offline", 7) == 0) {
 289                         free(dev);
 290                         continue;
 291                 }
 292
 293                 /* finally add this disk to the array */
 294                 dev->next = sra->devs;
 295                 sra->devs = dev;
 296
 297                 if (options & GET_OFFSET) {
 298                         strcpy(dbase, "offset");
 299                         if (load_sys(fname, buf))
 300                                 goto abort;
 301                         dev->data_offset = strtoull(buf, NULL, 0);
 302                         strcpy(dbase, "new_offset");
 303                         if (load_sys(fname, buf) == 0)
 304                                 dev->new_data_offset = strtoull(buf, NULL, 0);
 305                         else
 306                                 dev->new_data_offset = dev->data_offset;
 307                 }
 308                 if (options & GET_SIZE) {
 309                         strcpy(dbase, "size");
 310                         if (load_sys(fname, buf))
 311                                 goto abort;
 312                         dev->component_size = strtoull(buf, NULL, 0) * 2;
 313                 }
 314                 if (options & GET_STATE) {
 315                         dev->disk.state = 0;
 316                         strcpy(dbase, "state");
 317                         if (load_sys(fname, buf))
 318                                 goto abort;
 319                         if (strstr(buf, "in_sync"))
 320                                 dev->disk.state |= (1<<MD_DISK_SYNC);
 321                         if (strstr(buf, "faulty"))
 322                                 dev->disk.state |= (1<<MD_DISK_FAULTY);
 323                         if (dev->disk.state == 0)
 324                                 sra->array.spare_disks++;
 325                 }
 326                 if (options & GET_ERROR) {
 327                         strcpy(buf, "errors");
 328                         if (load_sys(fname, buf))
 329                                 goto abort;
 330                         dev->errors = strtoul(buf, NULL, 0);
 331                 }
 332         }
 333         closedir(dir);
 334         return sra;
 335
 336  abort:
 337         if (dir)
 338                 closedir(dir);
 339         sysfs_free(sra);
 340         return NULL;
 341 }
 342
 343 int sysfs_attr_match(const char *attr, const char *str)
 344 {
 345         /* See if attr, read from a sysfs file, matches
 346          * str.  They must either be the same, or attr can
 347          * have a trailing newline or comma
 348          */
 349         while (*attr && *str && *attr == *str) {
 350                 attr++;
 351                 str++;
 352         }
 353
 354         if (*str || (*attr && *attr != ',' && *attr != '\n'))
 355                 return 0;
 356         return 1;
 357 }
 358
 359 int sysfs_match_word(const char *word, char **list)
 360 {
 361         int n;
 362         for (n=0; list[n]; n++)
 363                 if (sysfs_attr_match(word, list[n]))
 364                         break;
 365         return n;
 366 }
 367
 368 unsigned long long get_component_size(int fd)
 369 {
 370         /* Find out the component size of the array.
 371          * We cannot trust GET_ARRAY_INFO ioctl as it's
 372          * size field is only 32bits.
 373          * So look in /sys/block/mdXXX/md/component_size
 374          *
 375          * This returns in units of sectors.
 376          */
 377         struct stat stb;
 378         char fname[50];
 379         int n;
 380         if (fstat(fd, &stb)) return 0;
 381         if (major(stb.st_rdev) != (unsigned)get_mdp_major())
 382                 sprintf(fname, "/sys/block/md%d/md/component_size",
 383                         (int)minor(stb.st_rdev));
 384         else
 385                 sprintf(fname, "/sys/block/md_d%d/md/component_size",
 386                         (int)minor(stb.st_rdev)>>MdpMinorShift);
 387         fd = open(fname, O_RDONLY);
 388         if (fd < 0)
 389                 return 0;
 390         n = read(fd, fname, sizeof(fname));
 391         close(fd);
 392         if (n < 0 || n == sizeof(fname))
 393                 return 0;
 394         fname[n] = 0;
 395         return strtoull(fname, NULL, 10) * 2;
 396 }
 397
 398 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 399                   char *name, char *val)
 400 {
 401         char fname[50];
 402         unsigned int n;
 403         int fd;
 404
 405         sprintf(fname, "/sys/block/%s/md/%s/%s",
 406                 sra->sys_name, dev?dev->sys_name:"", name);
 407         fd = open(fname, O_WRONLY);
 408         if (fd < 0)
 409                 return -1;
 410         n = write(fd, val, strlen(val));
 411         close(fd);
 412         if (n != strlen(val)) {
 413                 dprintf(Name ": failed to write '%s' to '%s' (%s)\n",
 414                         val, fname, strerror(errno));
 415                 return -1;
 416         }
 417         return 0;
 418 }
 419
 420 int sysfs_set_num(struct mdinfo *sra, struct mdinfo *dev,
 421                   char *name, unsigned long long val)
 422 {
 423         char valstr[50];
 424         sprintf(valstr, "%llu", val);
 425         return sysfs_set_str(sra, dev, name, valstr);
 426 }
 427
 428 int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
 429                          char *name, long long val)
 430 {
 431         char valstr[50];
 432         sprintf(valstr, "%lli", val);
 433         return sysfs_set_str(sra, dev, name, valstr);
 434 }
 435
 436 int sysfs_uevent(struct mdinfo *sra, char *event)
 437 {
 438         char fname[50];
 439         int n;
 440         int fd;
 441
 442         sprintf(fname, "/sys/block/%s/uevent",
 443                 sra->sys_name);
 444         fd = open(fname, O_WRONLY);
 445         if (fd < 0)
 446                 return -1;
 447         n = write(fd, event, strlen(event));
 448         close(fd);
 449         if (n != (int)strlen(event)) {
 450                 dprintf(Name ": failed to write '%s' to '%s' (%s)\n",
 451                         event, fname, strerror(errno));
 452                 return -1;
 453         }
 454         return 0;
 455 }
 456
 457 int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
 458 {
 459         char fname[50];
 460         struct stat st;
 461
 462         sprintf(fname, "/sys/block/%s/md/%s/%s",
 463                 sra->sys_name, dev?dev->sys_name:"", name);
 464
 465         return stat(fname, &st) == 0;
 466 }
 467
 468 int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 469                        char *name)
 470 {
 471         char fname[50];
 472         int fd;
 473
 474         sprintf(fname, "/sys/block/%s/md/%s/%s",
 475                 sra->sys_name, dev?dev->sys_name:"", name);
 476         fd = open(fname, O_RDWR);
 477         if (fd < 0)
 478                 fd = open(fname, O_RDONLY);
 479         return fd;
 480 }
 481
 482 int sysfs_fd_get_ll(int fd, unsigned long long *val)
 483 {
 484         char buf[50];
 485         int n;
 486         char *ep;
 487
 488         lseek(fd, 0, 0);
 489         n = read(fd, buf, sizeof(buf));
 490         if (n <= 0)
 491                 return -2;
 492         buf[n] = 0;
 493         *val = strtoull(buf, &ep, 0);
 494         if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
 495                 return -1;
 496         return 0;
 497 }
 498
 499 int sysfs_get_ll(struct mdinfo *sra, struct mdinfo *dev,
 500                        char *name, unsigned long long *val)
 501 {
 502         int n;
 503         int fd;
 504
 505         fd = sysfs_get_fd(sra, dev, name);
 506         if (fd < 0)
 507                 return -1;
 508         n = sysfs_fd_get_ll(fd, val);
 509         close(fd);
 510         return n;
 511 }
 512
 513 int sysfs_fd_get_str(int fd, char *val, int size)
 514 {
 515         int n;
 516
 517         lseek(fd, 0, 0);
 518         n = read(fd, val, size);
 519         if (n <= 0)
 520                 return -1;
 521         val[n] = 0;
 522         return n;
 523 }
 524
 525 int sysfs_get_str(struct mdinfo *sra, struct mdinfo *dev,
 526                        char *name, char *val, int size)
 527 {
 528         int n;
 529         int fd;
 530
 531         fd = sysfs_get_fd(sra, dev, name);
 532         if (fd < 0)
 533                 return -1;
 534         n = sysfs_fd_get_str(fd, val, size);
 535         close(fd);
 536         return n;
 537 }
 538
 539 int sysfs_set_safemode(struct mdinfo *sra, unsigned long ms)
 540 {
 541         unsigned long sec;
 542         unsigned long msec;
 543         char delay[30];
 544
 545         sec = ms / 1000;
 546         msec = ms % 1000;
 547
 548         sprintf(delay, "%ld.%03ld\n", sec, msec);
 549         /*             this '\n' ^ needed for kernels older than 2.6.28 */
 550         return sysfs_set_str(sra, NULL, "safe_mode_delay", delay);
 551 }
 552
 553 int sysfs_set_array(struct mdinfo *info, int vers)
 554 {
 555         int rv = 0;
 556         char ver[100];
 557         int raid_disks = info->array.raid_disks;
 558
 559         ver[0] = 0;
 560         if (info->array.major_version == -1 &&
 561             info->array.minor_version == -2) {
 562                 char buf[1024];
 563
 564                 strcat(strcpy(ver, "external:"), info->text_version);
 565
 566                 /* meta version might already be set if we are setting
 567                  * new geometry for a reshape.  In that case we don't
 568                  * want to over-write the 'readonly' flag that is
 569                  * stored in the metadata version.  So read the current
 570                  * version first, and preserve the flag
 571                  */
 572                 if (sysfs_get_str(info, NULL, "metadata_version",
 573                                   buf, 1024) > 0)
 574                         if (strlen(buf) >= 9 && buf[9] == '-')
 575                                 ver[9] = '-';
 576
 577                 if ((vers % 100) < 2 ||
 578                     sysfs_set_str(info, NULL, "metadata_version",
 579                                   ver) < 0) {
 580                         pr_err("This kernel does not "
 581                                 "support external metadata.\n");
 582                         return 1;
 583                 }
 584         }
 585         if (info->array.level < 0)
 586                 return 0; /* FIXME */
 587         rv |= sysfs_set_str(info, NULL, "level",
 588                             map_num(pers, info->array.level));
 589         if (info->reshape_active && info->delta_disks != UnSet)
 590                 raid_disks -= info->delta_disks;
 591         rv |= sysfs_set_num(info, NULL, "raid_disks", raid_disks);
 592         rv |= sysfs_set_num(info, NULL, "chunk_size", info->array.chunk_size);
 593         rv |= sysfs_set_num(info, NULL, "layout", info->array.layout);
 594         rv |= sysfs_set_num(info, NULL, "component_size", info->component_size/2);
 595         if (info->custom_array_size) {
 596                 int rc;
 597
 598                 rc = sysfs_set_num(info, NULL, "array_size",
 599                                    info->custom_array_size/2);
 600                 if (rc && errno == ENOENT) {
 601                         pr_err("This kernel does not "
 602                                 "have the md/array_size attribute, "
 603                                 "the array may be larger than expected\n");
 604                         rc = 0;
 605                 }
 606                 rv |= rc;
 607         }
 608
 609         if (info->array.level > 0)
 610                 rv |= sysfs_set_num(info, NULL, "resync_start", info->resync_start);
 611
 612         if (info->reshape_active) {
 613                 rv |= sysfs_set_num(info, NULL, "reshape_position",
 614                                     info->reshape_progress);
 615                 rv |= sysfs_set_num(info, NULL, "chunk_size", info->new_chunk);
 616                 rv |= sysfs_set_num(info, NULL, "layout", info->new_layout);
 617                 rv |= sysfs_set_num(info, NULL, "raid_disks",
 618                                     info->array.raid_disks);
 619                 /* We don't set 'new_level' here.  That can only happen
 620                  * once the reshape completes.
 621                  */
 622         }
 623         return rv;
 624 }
 625
 626 int sysfs_add_disk(struct mdinfo *sra, struct mdinfo *sd, int resume)
 627 {
 628         char dv[PATH_MAX];
 629         char nm[PATH_MAX];
 630         char *dname;
 631         int rv;
 632
 633         sprintf(dv, "%d:%d", sd->disk.major, sd->disk.minor);
 634         rv = sysfs_set_str(sra, NULL, "new_dev", dv);
 635         if (rv)
 636                 return rv;
 637
 638         memset(nm, 0, sizeof(nm));
 639         dname = devid2devnm(makedev(sd->disk.major, sd->disk.minor));
 640         strcpy(sd->sys_name, "dev-");
 641         strcpy(sd->sys_name+4, dname);
 642
 643         /* test write to see if 'recovery_start' is available */
 644         if (resume && sd->recovery_start < MaxSector &&
 645             sysfs_set_num(sra, sd, "recovery_start", 0)) {
 646                 sysfs_set_str(sra, sd, "state", "remove");
 647                 return -1;
 648         }
 649
 650         rv = sysfs_set_num(sra, sd, "offset", sd->data_offset);
 651         rv |= sysfs_set_num(sra, sd, "size", (sd->component_size+1) / 2);
 652         if (sra->array.level != LEVEL_CONTAINER) {
 653                 if (sd->recovery_start == MaxSector)
 654                         /* This can correctly fail if array isn't started,
 655                          * yet, so just ignore status for now.
 656                          */
 657                         sysfs_set_str(sra, sd, "state", "insync");
 658                 if (sd->disk.raid_disk >= 0)
 659                         rv |= sysfs_set_num(sra, sd, "slot", sd->disk.raid_disk);
 660                 if (resume)
 661                         sysfs_set_num(sra, sd, "recovery_start", sd->recovery_start);
 662         }
 663         return rv;
 664 }
 665
 666 #if 0
 667 int sysfs_disk_to_sg(int fd)
 668 {
 669         /* from an open block device, try find and open its corresponding
 670          * scsi_generic interface
 671          */
 672         struct stat st;
 673         char path[256];
 674         char sg_path[256];
 675         char sg_major_minor[8];
 676         char *c;
 677         DIR *dir;
 678         struct dirent *de;
 679         int major, minor, rv;
 680
 681         if (fstat(fd, &st))
 682                 return -1;
 683
 684         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device",
 685                  major(st.st_rdev), minor(st.st_rdev));
 686
 687         dir = opendir(path);
 688         if (!dir)
 689                 return -1;
 690
 691         de = readdir(dir);
 692         while (de) {
 693                 if (strncmp("scsi_generic:", de->d_name,
 694                             strlen("scsi_generic:")) == 0)
 695                         break;
 696                 de = readdir(dir);
 697         }
 698         closedir(dir);
 699
 700         if (!de)
 701                 return -1;
 702
 703         snprintf(sg_path, sizeof(sg_path), "%s/%s/dev", path, de->d_name);
 704         fd = open(sg_path, O_RDONLY);
 705         if (fd < 0)
 706                 return fd;
 707
 708         rv = read(fd, sg_major_minor, sizeof(sg_major_minor));
 709         close(fd);
 710         if (rv < 0)
 711                 return -1;
 712         else
 713                 sg_major_minor[rv - 1] = '\0';
 714
 715         c = strchr(sg_major_minor, ':');
 716         *c = '\0';
 717         c++;
 718         major = strtol(sg_major_minor, NULL, 10);
 719         minor = strtol(c, NULL, 10);
 720         snprintf(path, sizeof(path), "/dev/.tmp.md.%d:%d:%d",
 721                  (int) getpid(), major, minor);
 722         if (mknod(path, S_IFCHR|0600, makedev(major, minor))==0) {
 723                         fd = open(path, O_RDONLY);
 724                         unlink(path);
 725                         return fd;
 726         }
 727
 728         return -1;
 729 }
 730 #endif
 731
 732 int sysfs_disk_to_scsi_id(int fd, __u32 *id)
 733 {
 734         /* from an open block device, try to retrieve it scsi_id */
 735         struct stat st;
 736         char path[256];
 737         DIR *dir;
 738         struct dirent *de;
 739         int host, bus, target, lun;
 740
 741         if (fstat(fd, &st))
 742                 return 1;
 743
 744         snprintf(path, sizeof(path), "/sys/dev/block/%d:%d/device/scsi_device",
 745                  major(st.st_rdev), minor(st.st_rdev));
 746
 747         dir = opendir(path);
 748         if (!dir)
 749                 return 1;
 750
 751         for (de = readdir(dir); de; de = readdir(dir)) {
 752                 int count;
 753
 754                 if (de->d_type != DT_DIR)
 755                         continue;
 756
 757                 count = sscanf(de->d_name, "%d:%d:%d:%d", &host, &bus, &target, &lun);
 758                 if (count == 4)
 759                         break;
 760         }
 761         closedir(dir);
 762
 763         if (!de)
 764                 return 1;
 765
 766         *id = (host << 24) | (bus << 16) | (target << 8) | (lun << 0);
 767         return 0;
 768 }
 769
 770
 771 int sysfs_unique_holder(char *devnm, long rdev)
 772 {
 773         /* Check that devnm is a holder of rdev,
 774          * and is the only holder.
 775          * we should be locked against races by
 776          * an O_EXCL on devnm
 777          * Return values:
 778          *  0 - not unique, not even a holder
 779          *  1 - unique, this is the only holder.
 780          *  2/3 - not unique, there is another holder
 781          * -1 - error, cannot find the holders
 782          */
 783         DIR *dir;
 784         struct dirent *de;
 785         char dirname[100];
 786         char l;
 787         int ret = 0;
 788         sprintf(dirname, "/sys/dev/block/%d:%d/holders",
 789                 major(rdev), minor(rdev));
 790         dir = opendir(dirname);
 791         if (!dir)
 792                 return -1;
 793         l = strlen(dirname);
 794         while ((de = readdir(dir)) != NULL) {
 795                 char buf[100];
 796                 char *sl;
 797                 int n;
 798
 799                 if (de->d_ino == 0)
 800                         continue;
 801                 if (de->d_name[0] == '.')
 802                         continue;
 803                 strcpy(dirname+l, "/");
 804                 strcat(dirname+l, de->d_name);
 805                 n = readlink(dirname, buf, sizeof(buf)-1);
 806                 if (n <= 0)
 807                         continue;
 808                 buf[n] = 0;
 809                 sl = strrchr(buf, '/');
 810                 if (!sl)
 811                         continue;
 812                 sl++;
 813
 814                 if (strcmp(devnm, sl) == 0)
 815                         ret |= 1;
 816                 else
 817                         ret |= 2;
 818         }
 819         closedir(dir);
 820         return ret;
 821 }
 822
 823 int sysfs_freeze_array(struct mdinfo *sra)
 824 {
 825         /* Try to freeze resync/rebuild on this array/container.
 826          * Return -1 if the array is busy,
 827          * return 0 if this kernel doesn't support 'frozen'
 828          * return 1 if it worked.
 829          */
 830         char buf[20];
 831
 832         if (!sysfs_attribute_available(sra, NULL, "sync_action"))
 833                 return 1; /* no sync_action == frozen */
 834         if (sysfs_get_str(sra, NULL, "sync_action", buf, 20) <= 0)
 835                 return 0;
 836         if (strcmp(buf, "frozen\n") == 0)
 837                 /* Already frozen */
 838                 return 0;
 839         if (strcmp(buf, "idle\n") != 0)
 840                 return -1;
 841         if (sysfs_set_str(sra, NULL, "sync_action", "frozen") < 0)
 842                 return 0;
 843         return 1;
 844 }