policy.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2009 Neil Brown <neilb@suse.de>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@suse.de>
  23  */
  24
  25 #include "mdadm.h"
  26 #include <dirent.h>
  27 #include <fnmatch.h>
  28 #include <ctype.h>
  29 #include "dlink.h"
  30 /*
  31  * Policy module for mdadm.
  32  * A policy statement about a device lists a set of values for each
  33  * of a set of names.  Each value can have a metadata type as context.
  34  *
  35  * names include:
  36  *   action - the actions that can be taken on hot-plug
  37  *   domain - the domain(s) that the device is part of
  38  *
  39  * Policy information is extracted from various sources, but
  40  * particularly from a set of policy rules in mdadm.conf
  41  */
  42
  43 static void pol_new(struct dev_policy **pol, char *name, const char *val,
  44                     const char *metadata)
  45 {
  46         struct dev_policy *n = xmalloc(sizeof(*n));
  47         const char *real_metadata = NULL;
  48         int i;
  49
  50         n->name = name;
  51         n->value = val;
  52
  53         /* We need to normalise the metadata name */
  54         if (metadata) {
  55                 for (i = 0; superlist[i] ; i++)
  56                         if (strcmp(metadata, superlist[i]->name) == 0) {
  57                                 real_metadata = superlist[i]->name;
  58                                 break;
  59                         }
  60                 if (!real_metadata) {
  61                         if (strcmp(metadata, "1") == 0 ||
  62                             strcmp(metadata, "1.0") == 0 ||
  63                             strcmp(metadata, "1.1") == 0 ||
  64                             strcmp(metadata, "1.2") == 0)
  65                                 real_metadata = super1.name;
  66                 }
  67                 if (!real_metadata) {
  68                         static const char *prev = NULL;
  69                         if (prev != metadata) {
  70                                 pr_err("metadata=%s unrecognised - ignoring rule\n",
  71                                         metadata);
  72                                 prev = metadata;
  73                         }
  74                         real_metadata = "unknown";
  75                 }
  76         }
  77
  78         n->metadata = real_metadata;
  79         n->next = *pol;
  80         *pol = n;
  81 }
  82
  83 static int pol_lesseq(struct dev_policy *a, struct dev_policy *b)
  84 {
  85         int cmp;
  86
  87         if (a->name < b->name)
  88                 return 1;
  89         if (a->name > b->name)
  90                 return 0;
  91
  92         cmp = strcmp(a->value, b->value);
  93         if (cmp < 0)
  94                 return 1;
  95         if (cmp > 0)
  96                 return 0;
  97
  98         return (a->metadata <= b->metadata);
  99 }
 100
 101 static void pol_sort(struct dev_policy **pol)
 102 {
 103         /* sort policy list in *pol by name/metadata/value
 104          * using merge sort
 105          */
 106
 107         struct dev_policy *pl[2];
 108         pl[0] = *pol;
 109         pl[1] = NULL;
 110
 111         do {
 112                 struct dev_policy **plp[2], *p[2];
 113                 int curr = 0;
 114                 struct dev_policy nul = { NULL, NULL, NULL, NULL };
 115                 struct dev_policy *prev = &nul;
 116                 int next = 0;
 117
 118                 /* p[] are the two lists that we are merging.
 119                  * plp[] are the ends of the two lists we create
 120                  * from the merge.
 121                  * 'curr' is which of plp[] that we are currently
 122                  *   adding items to.
 123                  * 'next' is which if p[] we will take the next
 124                  *   item from.
 125                  * 'prev' is that last value, which was placed in
 126                  * plp[curr].
 127                  */
 128                 plp[0] = &pl[0];
 129                 plp[1] = &pl[1];
 130                 p[0] = pl[0];
 131                 p[1] = pl[1];
 132
 133                 /* take least of p[0] and p[1]
 134                  * if it is larger than prev, add to
 135                  * plp[curr], else swap curr then add
 136                  */
 137                 while (p[0] || p[1]) {
 138                         if (p[next] == NULL ||
 139                             (p[1-next] != NULL &&
 140                              !(pol_lesseq(prev, p[1-next])
 141                                ^pol_lesseq(prev, p[next])
 142                                ^pol_lesseq(p[next], p[1-next])))
 143                                 )
 144                                 next = 1 - next;
 145
 146                         if (!pol_lesseq(prev, p[next]))
 147                                 curr = 1 - curr;
 148
 149                         *plp[curr] = prev = p[next];
 150                         plp[curr] = &p[next]->next;
 151                         p[next] = p[next]->next;
 152                 }
 153                 *plp[0] = NULL;
 154                 *plp[1] = NULL;
 155         } while (pl[0] && pl[1]);
 156         if (pl[0])
 157                 *pol = pl[0];
 158         else
 159                 *pol = pl[1];
 160 }
 161
 162 static void pol_dedup(struct dev_policy *pol)
 163 {
 164         /* This is a sorted list - remove duplicates. */
 165         while (pol && pol->next) {
 166                 if (pol_lesseq(pol->next, pol)) {
 167                         struct dev_policy *tmp = pol->next;
 168                         pol->next = tmp->next;
 169                         free(tmp);
 170                 } else
 171                         pol = pol->next;
 172         }
 173 }
 174
 175 /*
 176  * pol_find finds the first entry in the policy
 177  * list to match name.
 178  * If it returns non-NULL there is at least one
 179  * value, but how many can only be found by
 180  * iterating through the list.
 181  */
 182 struct dev_policy *pol_find(struct dev_policy *pol, char *name)
 183 {
 184         while (pol && pol->name < name)
 185                 pol = pol->next;
 186
 187         if (!pol || pol->name != name)
 188                 return NULL;
 189         return pol;
 190 }
 191
 192 static char *disk_path(struct mdinfo *disk)
 193 {
 194         struct stat stb;
 195         int prefix_len;
 196         DIR *by_path;
 197         char symlink[PATH_MAX] = "/dev/disk/by-path/";
 198         char nm[PATH_MAX];
 199         struct dirent *ent;
 200         int rv;
 201
 202         by_path = opendir(symlink);
 203         if (by_path) {
 204                 prefix_len = strlen(symlink);
 205                 while ((ent = readdir(by_path)) != NULL) {
 206                         if (ent->d_type != DT_LNK)
 207                                 continue;
 208                         strncpy(symlink + prefix_len,
 209                                         ent->d_name,
 210                                         sizeof(symlink) - prefix_len);
 211                         if (stat(symlink, &stb) < 0)
 212                                 continue;
 213                         if ((stb.st_mode & S_IFMT) != S_IFBLK)
 214                                 continue;
 215                         if (stb.st_rdev != makedev(disk->disk.major, disk->disk.minor))
 216                                 continue;
 217                         closedir(by_path);
 218                         return xstrdup(ent->d_name);
 219                 }
 220                 closedir(by_path);
 221         }
 222         /* A NULL path isn't really acceptable - use the devname.. */
 223         sprintf(symlink, "/sys/dev/block/%d:%d", disk->disk.major, disk->disk.minor);
 224         rv = readlink(symlink, nm, sizeof(nm)-1);
 225         if (rv > 0) {
 226                 char *dname;
 227                 nm[rv] = 0;
 228                 dname = strrchr(nm, '/');
 229                 if (dname)
 230                         return xstrdup(dname + 1);
 231         }
 232         return xstrdup("unknown");
 233 }
 234
 235 char type_part[] = "part";
 236 char type_disk[] = "disk";
 237 static char *disk_type(struct mdinfo *disk)
 238 {
 239         char buf[30+20+20];
 240         struct stat stb;
 241         sprintf(buf, "/sys/dev/block/%d:%d/partition",
 242                 disk->disk.major, disk->disk.minor);
 243         if (stat(buf, &stb) == 0)
 244                 return type_part;
 245         else
 246                 return type_disk;
 247 }
 248
 249 static int pol_match(struct rule *rule, char *path, char *type)
 250 {
 251         /* check if this rule matches on path and type */
 252         int pathok = 0; /* 0 == no path, 1 == match, -1 == no match yet */
 253         int typeok = 0;
 254
 255         while (rule) {
 256                 if (rule->name == rule_path) {
 257                         if (pathok == 0)
 258                                 pathok = -1;
 259                         if (path && fnmatch(rule->value, path, 0) == 0)
 260                                 pathok = 1;
 261                 }
 262                 if (rule->name == rule_type) {
 263                         if (typeok == 0)
 264                                 typeok = -1;
 265                         if (type && strcmp(rule->value, type) == 0)
 266                                 typeok = 1;
 267                 }
 268                 rule = rule->next;
 269         }
 270         return pathok >= 0 && typeok >= 0;
 271 }
 272
 273 static void pol_merge(struct dev_policy **pol, struct rule *rule)
 274 {
 275         /* copy any name assignments from rule into pol */
 276         struct rule *r;
 277         char *metadata = NULL;
 278         for (r = rule; r ; r = r->next)
 279                 if (r->name == pol_metadata)
 280                         metadata = r->value;
 281
 282         for (r = rule; r ; r = r->next)
 283                 if (r->name == pol_act ||
 284                     r->name == pol_domain ||
 285                     r->name == pol_auto)
 286                         pol_new(pol, r->name, r->value, metadata);
 287 }
 288
 289 static int path_has_part(char *path, char **part)
 290 {
 291         /* check if path ends with "-partNN" and
 292          * if it does, place a pointer to "-pathNN"
 293          * in 'part'.
 294          */
 295         int l;
 296         if (!path)
 297                 return 0;
 298         l = strlen(path);
 299         while (l > 1 && isdigit(path[l-1]))
 300                 l--;
 301         if (l < 5 || strncmp(path+l-5, "-part", 5) != 0)
 302                 return 0;
 303         *part = path+l-4;
 304         return 1;
 305 }
 306
 307 static void pol_merge_part(struct dev_policy **pol, struct rule *rule, char *part)
 308 {
 309         /* copy any name assignments from rule into pol, appending
 310          * -part to any domain.  The string with -part appended is
 311          * stored with the rule so it has a lifetime to match
 312          * the rule.
 313          */
 314         struct rule *r;
 315         char *metadata = NULL;
 316         for (r = rule; r ; r = r->next)
 317                 if (r->name == pol_metadata)
 318                         metadata = r->value;
 319
 320         for (r = rule; r ; r = r->next) {
 321                 if (r->name == pol_act)
 322                         pol_new(pol, r->name, r->value, metadata);
 323                 else if (r->name == pol_domain) {
 324                         char *dom;
 325                         int len;
 326                         if (r->dups == NULL)
 327                                 r->dups = dl_head();
 328                         len = strlen(r->value);
 329                         for (dom = dl_next(r->dups); dom != r->dups;
 330                              dom = dl_next(dom))
 331                                 if (strcmp(dom+len+1, part)== 0)
 332                                         break;
 333                         if (dom == r->dups) {
 334                                 char *newdom = dl_strndup(
 335                                         r->value, len + 1 + strlen(part));
 336                                 strcat(strcat(newdom, "-"), part);
 337                                 dl_add(r->dups, newdom);
 338                                 dom = newdom;
 339                         }
 340                         pol_new(pol, r->name, dom, metadata);
 341                 }
 342         }
 343 }
 344
 345 static struct pol_rule *config_rules = NULL;
 346 static struct pol_rule **config_rules_end = NULL;
 347 static int config_rules_has_path = 0;
 348
 349 /*
 350  * most policy comes from a set policy rules that are
 351  * read from the config file.
 352  * path_policy() gathers policy information for the
 353  * disk described in the given a 'path' and a 'type'.
 354  */
 355 struct dev_policy *path_policy(char *path, char *type)
 356 {
 357         struct pol_rule *rules;
 358         struct dev_policy *pol = NULL;
 359         int i;
 360
 361         rules = config_rules;
 362
 363         while (rules) {
 364                 char *part;
 365                 if (rules->type == rule_policy)
 366                         if (pol_match(rules->rule, path, type))
 367                                 pol_merge(&pol, rules->rule);
 368                 if (rules->type == rule_part && strcmp(type, type_part) == 0)
 369                         if (path_has_part(path, &part)) {
 370                                 *part = 0;
 371                                 if (pol_match(rules->rule, path, type_disk))
 372                                         pol_merge_part(&pol, rules->rule, part+1);
 373                                 *part = '-';
 374                         }
 375                 rules = rules->next;
 376         }
 377
 378         /* Now add any metadata-specific internal knowledge
 379          * about this path
 380          */
 381         for (i=0; path && superlist[i]; i++)
 382                 if (superlist[i]->get_disk_controller_domain) {
 383                         const char *d =
 384                                 superlist[i]->get_disk_controller_domain(path);
 385                         if (d)
 386                                 pol_new(&pol, pol_domain, d, superlist[i]->name);
 387                 }
 388
 389         pol_sort(&pol);
 390         pol_dedup(pol);
 391         return pol;
 392 }
 393
 394 void pol_add(struct dev_policy **pol,
 395                     char *name, char *val,
 396                     char *metadata)
 397 {
 398         pol_new(pol, name, val, metadata);
 399         pol_sort(pol);
 400         pol_dedup(*pol);
 401 }
 402
 403 /*
 404  * disk_policy() gathers policy information for the
 405  * disk described in the given mdinfo (disk.{major,minor}).
 406  */
 407 struct dev_policy *disk_policy(struct mdinfo *disk)
 408 {
 409         char *path = NULL;
 410         char *type = disk_type(disk);
 411         struct dev_policy *pol = NULL;
 412
 413         if (config_rules_has_path)
 414                 path = disk_path(disk);
 415
 416         pol = path_policy(path, type);
 417
 418         free(path);
 419         return pol;
 420 }
 421
 422 struct dev_policy *devid_policy(int dev)
 423 {
 424         struct mdinfo disk;
 425         disk.disk.major = major(dev);
 426         disk.disk.minor = minor(dev);
 427         return disk_policy(&disk);
 428 }
 429
 430 /*
 431  * process policy rules read from config file.
 432  */
 433
 434 char rule_path[] = "path";
 435 char rule_type[] = "type";
 436
 437 char rule_policy[] = "policy";
 438 char rule_part[] = "part-policy";
 439
 440 char pol_metadata[] = "metadata";
 441 char pol_act[] = "action";
 442 char pol_domain[] = "domain";
 443 char pol_auto[] = "auto";
 444
 445 static int try_rule(char *w, char *name, struct rule **rp)
 446 {
 447         struct rule *r;
 448         int len = strlen(name);
 449         if (strncmp(w, name, len) != 0 ||
 450             w[len] != '=')
 451                 return 0;
 452         r = xmalloc(sizeof(*r));
 453         r->next = *rp;
 454         r->name = name;
 455         r->value = xstrdup(w+len+1);
 456         r->dups = NULL;
 457         *rp = r;
 458         return 1;
 459 }
 460
 461 void policyline(char *line, char *type)
 462 {
 463         struct pol_rule *pr;
 464         char *w;
 465
 466         if (config_rules_end == NULL)
 467                 config_rules_end = &config_rules;
 468
 469         pr = xmalloc(sizeof(*pr));
 470         pr->type = type;
 471         pr->rule = NULL;
 472         for (w = dl_next(line); w != line ; w = dl_next(w)) {
 473                 if (try_rule(w, rule_path, &pr->rule))
 474                         config_rules_has_path = 1;
 475                 else if (! try_rule(w, rule_type, &pr->rule) &&
 476                          ! try_rule(w, pol_metadata, &pr->rule) &&
 477                          ! try_rule(w, pol_act, &pr->rule) &&
 478                          ! try_rule(w, pol_domain, &pr->rule) &&
 479                          ! try_rule(w, pol_auto, &pr->rule))
 480                         pr_err("policy rule %s unrecognised and ignored\n",
 481                                 w);
 482         }
 483         pr->next = config_rules;
 484         config_rules = pr;
 485 }
 486
 487 void policy_add(char *type, ...)
 488 {
 489         va_list ap;
 490         struct pol_rule *pr;
 491         char *name, *val;
 492
 493         pr = xmalloc(sizeof(*pr));
 494         pr->type = type;
 495         pr->rule = NULL;
 496
 497         va_start(ap, type);
 498         while ((name = va_arg(ap, char*)) != NULL) {
 499                 struct rule *r;
 500
 501                 val = va_arg(ap, char*);
 502                 r = xmalloc(sizeof(*r));
 503                 r->next = pr->rule;
 504                 r->name = name;
 505                 r->value = xstrdup(val);
 506                 r->dups = NULL;
 507                 pr->rule = r;
 508         }
 509         pr->next = config_rules;
 510         config_rules = pr;
 511         va_end(ap);
 512 }
 513
 514 void policy_free(void)
 515 {
 516         while (config_rules) {
 517                 struct pol_rule *pr = config_rules;
 518                 struct rule *r;
 519
 520                 config_rules = config_rules->next;
 521
 522                 for (r = pr->rule; r; ) {
 523                         struct rule *next = r->next;
 524                         free(r->value);
 525                         if (r->dups)
 526                                 free_line(r->dups);
 527                         free(r);
 528                         r = next;
 529                 }
 530                 free(pr);
 531         }
 532         config_rules_end = NULL;
 533         config_rules_has_path = 0;
 534 }
 535
 536 void dev_policy_free(struct dev_policy *p)
 537 {
 538         struct dev_policy *t;
 539         while (p) {
 540                 t = p;
 541                 p = p->next;
 542                 free(t);
 543         }
 544 }
 545
 546 static enum policy_action map_act(const char *act)
 547 {
 548         if (strcmp(act, "include") == 0)
 549                 return act_include;
 550         if (strcmp(act, "re-add") == 0)
 551                 return act_re_add;
 552         if (strcmp(act, "spare") == 0)
 553                 return act_spare;
 554         if (strcmp(act, "spare-same-slot") == 0)
 555                 return act_spare_same_slot;
 556         if (strcmp(act, "force-spare") == 0)
 557                 return act_force_spare;
 558         return act_err;
 559 }
 560
 561 static enum policy_action policy_action(struct dev_policy *plist, const char *metadata)
 562 {
 563         enum policy_action rv = act_default;
 564         struct dev_policy *p;
 565
 566         plist = pol_find(plist, pol_act);
 567         pol_for_each(p, plist, metadata) {
 568                 enum policy_action a = map_act(p->value);
 569                 if (a > rv)
 570                         rv = a;
 571         }
 572         return rv;
 573 }
 574
 575 int policy_action_allows(struct dev_policy *plist, const char *metadata, enum policy_action want)
 576 {
 577         enum policy_action act = policy_action(plist, metadata);
 578
 579         if (act == act_err)
 580                 return 0;
 581         return (act >= want);
 582 }
 583
 584 int disk_action_allows(struct mdinfo *disk, const char *metadata, enum policy_action want)
 585 {
 586         struct dev_policy *pol = disk_policy(disk);
 587         int rv = policy_action_allows(pol, metadata, want);
 588
 589         dev_policy_free(pol);
 590         return rv;
 591 }
 592
 593 /* Domain policy:
 594  * Any device can have a list of domains asserted by different policy
 595  * statements.
 596  * An array also has a list of domains comprising all the domains of
 597  * all the devices in an array.
 598  * Where an array has a spare-group, that becomes an addition domain for
 599  * every device in the array and thus for the array.
 600  *
 601  * We keep the list of domains in a sorted linked list
 602  * As dev policies are already sorted, this is fairly easy to manage.
 603  */
 604
 605 static struct domainlist **domain_merge_one(struct domainlist **domp,
 606                                             const char *domain)
 607 {
 608         /* merge a domain name into a sorted list and return the
 609          * location of the insertion or match
 610          */
 611         struct domainlist *dom = *domp;
 612
 613         while (dom && strcmp(dom->dom, domain) < 0) {
 614                 domp = &dom->next;
 615                 dom = *domp;
 616         }
 617         if (dom == NULL || strcmp(dom->dom, domain) != 0) {
 618                 dom = xmalloc(sizeof(*dom));
 619                 dom->next = *domp;
 620                 dom->dom = domain;
 621                 *domp = dom;
 622         }
 623         return domp;
 624 }
 625
 626 #if (DEBUG)
 627 void dump_policy(struct dev_policy *policy)
 628 {
 629         while (policy) {
 630                 dprintf("policy: %p name: %s value: %s metadata: %s\n",
 631                         policy,
 632                         policy->name,
 633                         policy->value,
 634                         policy->metadata);
 635                 policy = policy->next;
 636         }
 637 }
 638 #endif
 639
 640 void domain_merge(struct domainlist **domp, struct dev_policy *pollist,
 641                          const char *metadata)
 642 {
 643         /* Add to 'domp' all the domains in pol that apply to 'metadata'
 644          * which are not already in domp
 645          */
 646         struct dev_policy *pol;
 647         pollist = pol_find(pollist, pol_domain);
 648         pol_for_each(pol, pollist, metadata)
 649                 domain_merge_one(domp, pol->value);
 650 }
 651
 652 int domain_test(struct domainlist *dom, struct dev_policy *pol,
 653                 const char *metadata)
 654 {
 655         /* Check that all domains in pol (for metadata) are also in
 656          * dom.  Both lists are sorted.
 657          * If pol has no domains, we don't really know about this device
 658          * so we allow caller to choose:
 659          * -1:  has no domains
 660          *  0:  has domains, not all match
 661          *  1:  has domains, all match
 662          */
 663         int found_any = -1;
 664         struct dev_policy *p;
 665
 666         pol = pol_find(pol, pol_domain);
 667         pol_for_each(p, pol, metadata) {
 668                 found_any = 1;
 669                 while (dom && strcmp(dom->dom, p->value) < 0)
 670                         dom = dom->next;
 671                 if (!dom || strcmp(dom->dom, p->value) != 0)
 672                         return 0;
 673         }
 674         return found_any;
 675 }
 676
 677 void domainlist_add_dev(struct domainlist **dom, int devid, const char *metadata)
 678 {
 679         struct dev_policy *pol = devid_policy(devid);
 680         domain_merge(dom, pol, metadata);
 681         dev_policy_free(pol);
 682 }
 683
 684 struct domainlist *domain_from_array(struct mdinfo *mdi, const char *metadata)
 685 {
 686         struct domainlist *domlist = NULL;
 687
 688         if (!mdi)
 689                 return NULL;
 690         for (mdi = mdi->devs ; mdi ; mdi = mdi->next)
 691                 domainlist_add_dev(&domlist, makedev(mdi->disk.major,
 692                                                      mdi->disk.minor),
 693                                    metadata);
 694
 695         return domlist;
 696 }
 697
 698 void domain_add(struct domainlist **domp, char *domain)
 699 {
 700         domain_merge_one(domp, domain);
 701 }
 702
 703 void domain_free(struct domainlist *dl)
 704 {
 705         while (dl) {
 706                 struct domainlist *head = dl;
 707                 dl = dl->next;
 708                 free(head);
 709         }
 710 }
 711
 712 /*
 713  * same-path policy.
 714  * Some policy decisions are guided by knowledge of which
 715  * array previously owned the device at a given physical location (path).
 716  * When removing a device from an array we might record the array against
 717  * the path, and when finding a new device, we might look for which
 718  * array previously used that path.
 719  *
 720  * The 'array' is described by a map_ent, and the path by a the disk in an
 721  * mdinfo, or a string.
 722  */
 723
 724 void policy_save_path(char *id_path, struct map_ent *array)
 725 {
 726         char path[PATH_MAX];
 727         FILE *f = NULL;
 728
 729         if (mkdir(FAILED_SLOTS_DIR, S_IRWXU) < 0 && errno != EEXIST) {
 730                 pr_err("can't create file to save path "
 731                         "to old disk: %s\n", strerror(errno));
 732                 return;
 733         }
 734
 735         snprintf(path, PATH_MAX, FAILED_SLOTS_DIR "/%s", id_path);
 736         f = fopen(path, "w");
 737         if (!f) {
 738                 pr_err("can't create file to"
 739                         " save path to old disk: %s\n",
 740                         strerror(errno));
 741                 return;
 742         }
 743
 744         if (fprintf(f, "%s %08x:%08x:%08x:%08x\n",
 745                     array->metadata,
 746                     array->uuid[0], array->uuid[1],
 747                     array->uuid[2], array->uuid[3]) <= 0)
 748                 pr_err("Failed to write to "
 749                        "<id_path> cookie\n");
 750
 751         fclose(f);
 752 }
 753
 754 int policy_check_path(struct mdinfo *disk, struct map_ent *array)
 755 {
 756         char path[PATH_MAX];
 757         FILE *f = NULL;
 758         char *id_path = disk_path(disk);
 759         int rv;
 760
 761         if (!id_path)
 762                 return 0;
 763
 764         snprintf(path, PATH_MAX, FAILED_SLOTS_DIR "/%s", id_path);
 765         f = fopen(path, "r");
 766         if (!f) {
 767                 free(id_path);
 768                 return 0;
 769         }
 770
 771         rv = fscanf(f, " %s %x:%x:%x:%x\n",
 772                     array->metadata,
 773                     array->uuid,
 774                     array->uuid+1,
 775                     array->uuid+2,
 776                     array->uuid+3);
 777         fclose(f);
 778         free(id_path);
 779         return rv == 5;
 780 }
 781
 782 /* invocation of udev rule file */
 783 char udev_template_start[] =
 784 "# do not edit this file, it is automatically generated by mdadm\n"
 785 "\n";
 786
 787 /* find rule named rule_type and return its value */
 788 char *find_rule(struct rule *rule, char *rule_type)
 789 {
 790         while (rule) {
 791                 if (rule->name == rule_type)
 792                         return rule->value;
 793
 794                 rule = rule->next;
 795         }
 796         return NULL;
 797 }
 798
 799 #define UDEV_RULE_FORMAT \
 800 "ACTION==\"add\", SUBSYSTEM==\"block\", " \
 801 "ENV{DEVTYPE}==\"%s\", ENV{ID_PATH}==\"%s\", " \
 802 "RUN+=\"/sbin/mdadm --incremental $env{DEVNAME}\"\n"
 803
 804 #define UDEV_RULE_FORMAT_NOTYPE \
 805 "ACTION==\"add\", SUBSYSTEM==\"block\", " \
 806 "ENV{ID_PATH}==\"%s\", " \
 807 "RUN+=\"/sbin/mdadm --incremental $env{DEVNAME}\"\n"
 808
 809 /* Write rule in the rule file. Use format from UDEV_RULE_FORMAT */
 810 int write_rule(struct rule *rule, int fd, int force_part)
 811 {
 812         char line[1024];
 813         char *pth = find_rule(rule, rule_path);
 814         char *typ = find_rule(rule, rule_type);
 815         if (!pth)
 816                 return -1;
 817
 818         if (force_part)
 819                 typ = type_part;
 820         if (typ)
 821                 snprintf(line, sizeof(line) - 1, UDEV_RULE_FORMAT, typ, pth);
 822         else
 823                 snprintf(line, sizeof(line) - 1, UDEV_RULE_FORMAT_NOTYPE, pth);
 824         return write(fd, line, strlen(line)) == (int)strlen(line);
 825 }
 826
 827 /* Generate single entry in udev rule basing on POLICY line found in config
 828  * file. Take only those with paths, only first occurrence if paths are equal
 829  * and if actions supports handling of spares (>=act_spare_same_slot)
 830  */
 831 int generate_entries(int fd)
 832 {
 833         struct pol_rule *loop, *dup;
 834         char *loop_value, *dup_value;
 835         int duplicate;
 836
 837         for (loop = config_rules; loop; loop = loop->next) {
 838                 if (loop->type != rule_policy && loop->type != rule_part)
 839                         continue;
 840                 duplicate = 0;
 841
 842                 /* only policies with paths and with actions supporting
 843                  * bare disks are considered */
 844                 loop_value = find_rule(loop->rule, pol_act);
 845                 if (!loop_value || map_act(loop_value) < act_spare_same_slot)
 846                         continue;
 847                 loop_value = find_rule(loop->rule, rule_path);
 848                 if (!loop_value)
 849                         continue;
 850                 for (dup = config_rules; dup != loop; dup = dup->next) {
 851                         if (dup->type != rule_policy && loop->type != rule_part)
 852                                 continue;
 853                         dup_value = find_rule(dup->rule, pol_act);
 854                         if (!dup_value || map_act(dup_value) < act_spare_same_slot)
 855                                 continue;
 856                         dup_value = find_rule(dup->rule, rule_path);
 857                         if (!dup_value)
 858                                 continue;
 859                         if (strcmp(loop_value, dup_value) == 0) {
 860                                 duplicate = 1;
 861                                 break;
 862                         }
 863                 }
 864
 865                 /* not a dup or first occurrence */
 866                 if (!duplicate)
 867                         if (!write_rule(loop->rule, fd, loop->type == rule_part) )
 868                                 return 0;
 869         }
 870         return 1;
 871 }
 872
 873 /* Write_rules routine creates dynamic udev rules used to handle
 874  * hot-plug events for bare devices (and making them spares)
 875  */
 876 int Write_rules(char *rule_name)
 877 {
 878         int fd;
 879         char udev_rule_file[PATH_MAX];
 880
 881         if (rule_name) {
 882                 strncpy(udev_rule_file, rule_name, sizeof(udev_rule_file) - 6);
 883                 udev_rule_file[sizeof(udev_rule_file) - 6] = '\0';
 884                 strcat(udev_rule_file, ".temp");
 885                 fd = creat(udev_rule_file,
 886                            S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 887                 if (fd == -1)
 888                         return 1;
 889         } else
 890                 fd = 1;
 891
 892         /* write static invocation */
 893         if (write(fd, udev_template_start,
 894                   sizeof(udev_template_start) - 1)
 895             != (int)sizeof(udev_template_start)-1)
 896                 goto abort;
 897
 898         /* iterate, if none created or error occurred, remove file */
 899         if (generate_entries(fd) < 0)
 900                 goto abort;
 901
 902         fsync(fd);
 903         if (rule_name) {
 904                 close(fd);
 905                 rename(udev_rule_file, rule_name);
 906         }
 907         return 0;
 908 abort:
 909         if (rule_name) {
 910                 close(fd);
 911                 unlink(udev_rule_file);
 912         }
 913         return 1;
 914 }