mapfile.c

   1 /*
   2  * mapfile - manage /var/run/mdadm.map. 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  *    Paper: Neil Brown
  25  *           Novell Inc
  26  *           GPO Box Q1283
  27  *           QVB Post Office, NSW 1230
  28  *           Australia
  29  */
  30
  31 /* /var/run/mdadm.map is used to track arrays being created in --incremental
  32  * more.  It particularly allows lookup from UUID to array device, but
  33  * also allows the array device name to be easily found.
  34  *
  35  * The map file is line based with space separated fields.  The fields are:
  36  *  Device id  -  mdX or mdpX  where X is a number.
  37  *  metadata   -  0.90 1.0 1.1 1.2 ddf ...
  38  *  UUID       -  uuid of the array
  39  *  path       -  path where device created: /dev/md/home
  40  *
  41  * The preferred location for the map file is /var/run/mdadm.map.
  42  * However /var/run may not exist or be writable in early boot.  And if
  43  * no-one has created /var/run/mdadm, we still want to survive.
  44  * So possible locations are:
  45  *   /var/run/mdadm/map  /var/run/mdadm.map  /dev/.mdadm.map
  46  * the last, because udev requires a writable /dev very early.
  47  * We read from the first one that exists and write to the first
  48  * one that we can.
  49  */
  50 #include        "mdadm.h"
  51 #include        <sys/file.h>
  52 #include        <ctype.h>
  53
  54 #define mapnames(base) { base, base ".new", base ".lock"}
  55 char *mapname[3][3] = {
  56         mapnames(VAR_RUN "/map"),
  57         mapnames("/var/run/mdadm.map"),
  58         mapnames(ALT_RUN "/map")
  59 };
  60
  61 int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT | O_TRUNC };
  62 char *mapsmode[3] = { "r", "w", "w"};
  63
  64 FILE *open_map(int modenum, int *choice)
  65 {
  66         int i;
  67         for (i = 0 ; i < 3 ; i++) {
  68                 int fd = open(mapname[i][modenum], mapmode[modenum], 0600);
  69                 if (fd >= 0) {
  70                         *choice = i;
  71                         return fdopen(fd, mapsmode[modenum]);
  72                 }
  73         }
  74         return NULL;
  75 }
  76
  77 int map_write(struct map_ent *mel)
  78 {
  79         FILE *f;
  80         int err;
  81         int which;
  82
  83         f = open_map(1, &which);
  84
  85         if (!f)
  86                 return 0;
  87         for (; mel; mel = mel->next) {
  88                 if (mel->bad)
  89                         continue;
  90                 if (mel->devnum < 0)
  91                         fprintf(f, "mdp%d ", -1-mel->devnum);
  92                 else
  93                         fprintf(f, "md%d ", mel->devnum);
  94                 fprintf(f, "%s ", mel->metadata);
  95                 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
  96                         mel->uuid[1], mel->uuid[2], mel->uuid[3]);
  97                 fprintf(f, "%s\n", mel->path?:"");
  98         }
  99         fflush(f);
 100         err = ferror(f);
 101         fclose(f);
 102         if (err) {
 103                 unlink(mapname[which][1]);
 104                 return 0;
 105         }
 106         return rename(mapname[which][1],
 107                       mapname[which][0]) == 0;
 108 }
 109
 110
 111 static FILE *lf = NULL;
 112 static int lwhich = 0;
 113 int map_lock(struct map_ent **melp)
 114 {
 115         if (lf == NULL) {
 116                 lf = open_map(2, &lwhich);
 117                 if (lf == NULL)
 118                         return -1;
 119                 if (flock(fileno(lf), LOCK_EX) != 0) {
 120                         fclose(lf);
 121                         lf = NULL;
 122                         return -1;
 123                 }
 124         }
 125         if (*melp)
 126                 map_free(*melp);
 127         map_read(melp);
 128         return 0;
 129 }
 130
 131 void map_unlock(struct map_ent **melp)
 132 {
 133         if (lf) {
 134                 flock(fileno(lf), LOCK_UN);
 135                 fclose(lf);
 136         }
 137         unlink(mapname[lwhich][2]);
 138         lf = NULL;
 139 }
 140
 141 void map_add(struct map_ent **melp,
 142             int devnum, char *metadata, int uuid[4], char *path)
 143 {
 144         struct map_ent *me = malloc(sizeof(*me));
 145
 146         me->devnum = devnum;
 147         strcpy(me->metadata, metadata);
 148         memcpy(me->uuid, uuid, 16);
 149         me->path = path ? strdup(path) : NULL;
 150         me->next = *melp;
 151         me->bad = 0;
 152         *melp = me;
 153 }
 154
 155 void map_read(struct map_ent **melp)
 156 {
 157         FILE *f;
 158         char buf[8192];
 159         char path[200];
 160         int devnum, uuid[4];
 161         char metadata[30];
 162         char nam[4];
 163         int which;
 164
 165         *melp = NULL;
 166
 167         f = open_map(0, &which);
 168         if (!f) {
 169                 RebuildMap();
 170                 f = open_map(0, &which);
 171         }
 172         if (!f)
 173                 return;
 174
 175         while (fgets(buf, sizeof(buf), f)) {
 176                 path[0] = 0;
 177                 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
 178                            nam, &devnum, metadata, uuid, uuid+1,
 179                            uuid+2, uuid+3, path) >= 7) {
 180                         if (strncmp(nam, "md", 2) != 0)
 181                                 continue;
 182                         if (nam[2] == 'p')
 183                                 devnum = -1 - devnum;
 184                         map_add(melp, devnum, metadata, uuid, path);
 185                 }
 186         }
 187         fclose(f);
 188 }
 189
 190 void map_free(struct map_ent *map)
 191 {
 192         while (map) {
 193                 struct map_ent *mp = map;
 194                 map = mp->next;
 195                 free(mp->path);
 196                 free(mp);
 197         }
 198 }
 199
 200 int map_update(struct map_ent **mpp, int devnum, char *metadata,
 201                int *uuid, char *path)
 202 {
 203         struct map_ent *map, *mp;
 204         int rv;
 205
 206         if (mpp && *mpp)
 207                 map = *mpp;
 208         else
 209                 map_read(&map);
 210
 211         for (mp = map ; mp ; mp=mp->next)
 212                 if (mp->devnum == devnum) {
 213                         strcpy(mp->metadata, metadata);
 214                         memcpy(mp->uuid, uuid, 16);
 215                         free(mp->path);
 216                         mp->path = path ? strdup(path) : NULL;
 217                         break;
 218                 }
 219         if (!mp)
 220                 map_add(&map, devnum, metadata, uuid, path);
 221         if (mpp)
 222                 *mpp = NULL;
 223         rv = map_write(map);
 224         map_free(map);
 225         return rv;
 226 }
 227
 228 void map_delete(struct map_ent **mapp, int devnum)
 229 {
 230         struct map_ent *mp;
 231
 232         if (*mapp == NULL)
 233                 map_read(mapp);
 234
 235         for (mp = *mapp; mp; mp = *mapp) {
 236                 if (mp->devnum == devnum) {
 237                         *mapp = mp->next;
 238                         free(mp->path);
 239                         free(mp);
 240                 } else
 241                         mapp = & mp->next;
 242         }
 243 }
 244
 245 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 246 {
 247         struct map_ent *mp;
 248         if (!*map)
 249                 map_read(map);
 250
 251         for (mp = *map ; mp ; mp = mp->next) {
 252                 if (memcmp(uuid, mp->uuid, 16) != 0)
 253                         continue;
 254                 if (!mddev_busy(mp->devnum)) {
 255                         mp->bad = 1;
 256                         continue;
 257                 }
 258                 return mp;
 259         }
 260         return NULL;
 261 }
 262
 263 struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
 264 {
 265         struct map_ent *mp;
 266         if (!*map)
 267                 map_read(map);
 268
 269         for (mp = *map ; mp ; mp = mp->next) {
 270                 if (mp->devnum != devnum)
 271                         continue;
 272                 if (!mddev_busy(mp->devnum)) {
 273                         mp->bad = 1;
 274                         continue;
 275                 }
 276                 return mp;
 277         }
 278         return NULL;
 279 }
 280
 281 struct map_ent *map_by_name(struct map_ent **map, char *name)
 282 {
 283         struct map_ent *mp;
 284         if (!*map)
 285                 map_read(map);
 286
 287         for (mp = *map ; mp ; mp = mp->next) {
 288                 if (!mp->path)
 289                         continue;
 290                 if (strncmp(mp->path, "/dev/md/", 8) != 0)
 291                         continue;
 292                 if (strcmp(mp->path+8, name) != 0)
 293                         continue;
 294                 if (!mddev_busy(mp->devnum)) {
 295                         mp->bad = 1;
 296                         continue;
 297                 }
 298                 return mp;
 299         }
 300         return NULL;
 301 }
 302
 303 /* sets the proper subarray and container_dev according to the metadata
 304  * version super_by_fd does this automatically, this routine is meant as
 305  * a supplement for guess_super()
 306  */
 307 static void set_member_info(struct supertype *st, struct mdstat_ent *ent)
 308 {
 309
 310         st->subarray[0] = '\0';
 311
 312         if (ent->metadata_version == NULL ||
 313             strncmp(ent->metadata_version, "external:", 9) != 0)
 314                 return;
 315
 316         if (is_subarray(&ent->metadata_version[9])) {
 317                 char version[strlen(ent->metadata_version)+1];
 318                 char *subarray;
 319                 char *name = &version[10];
 320
 321                 strcpy(version, ent->metadata_version);
 322                 subarray = strrchr(version, '/');
 323                 name = &version[10];
 324
 325                 if (!subarray)
 326                         return;
 327                 *subarray++ = '\0';
 328
 329                 st->container_dev = devname2devnum(name);
 330                 strncpy(st->subarray, subarray, sizeof(st->subarray));
 331         }
 332 }
 333
 334 void RebuildMap(void)
 335 {
 336         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 337         struct mdstat_ent *md;
 338         struct map_ent *map = NULL;
 339         int mdp = get_mdp_major();
 340         int require_homehost;
 341         char sys_hostname[256];
 342         char *homehost = conf_get_homehost(&require_homehost);
 343
 344         if (homehost == NULL || strcmp(homehost, "<system>")==0) {
 345                 if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
 346                         sys_hostname[sizeof(sys_hostname)-1] = 0;
 347                         homehost = sys_hostname;
 348                 }
 349         }
 350
 351         for (md = mdstat ; md ; md = md->next) {
 352                 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS|SKIP_GONE_DEVS);
 353                 struct mdinfo *sd;
 354
 355                 if (!sra)
 356                         continue;
 357
 358                 for (sd = sra->devs ; sd ; sd = sd->next) {
 359                         char namebuf[100];
 360                         char dn[30];
 361                         int dfd;
 362                         int ok;
 363                         struct supertype *st;
 364                         char *path;
 365                         struct mdinfo info;
 366
 367                         sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
 368                         dfd = dev_open(dn, O_RDONLY);
 369                         if (dfd < 0)
 370                                 continue;
 371                         st = guess_super(dfd);
 372                         if ( st == NULL)
 373                                 ok = -1;
 374                         else {
 375                                 set_member_info(st, md);
 376                                 ok = st->ss->load_super(st, dfd, NULL);
 377                         }
 378                         close(dfd);
 379                         if (ok != 0)
 380                                 continue;
 381                         st->ss->getinfo_super(st, &info);
 382                         if (md->devnum >= 0)
 383                                 path = map_dev(MD_MAJOR, md->devnum, 0);
 384                         else
 385                                 path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
 386                         if (path == NULL ||
 387                             strncmp(path, "/dev/md/", 8) != 0) {
 388                                 /* We would really like a name that provides
 389                                  * an MD_DEVNAME for udev.
 390                                  * The name needs to be unique both in /dev/md/
 391                                  * and in this mapfile.
 392                                  * It needs to match watch -I or -As would come
 393                                  * up with.
 394                                  * That means:
 395                                  *   Check if array is in mdadm.conf
 396                                  *        - if so use that.
 397                                  *   determine trustworthy from homehost etc
 398                                  *   find a unique name based on metadata name.
 399                                  *
 400                                  */
 401                                 struct mddev_ident_s *match = conf_match(&info, st);
 402                                 struct stat stb;
 403                                 if (match && match->devname && match->devname[0] == '/') {
 404                                         path = match->devname;
 405                                         if (path[0] != '/') {
 406                                                 strcpy(namebuf, "/dev/md/");
 407                                                 strcat(namebuf, path);
 408                                                 path = namebuf;
 409                                         }
 410                                 } else {
 411                                         int unum = 0;
 412                                         char *sep = "_";
 413                                         const char *name;
 414                                         int conflict = 1;
 415                                         if ((homehost == NULL ||
 416                                              st->ss->match_home(st, homehost) != 1) &&
 417                                             st->ss->match_home(st, "any") != 1 &&
 418                                             (require_homehost
 419                                              || ! conf_name_is_free(info.name)))
 420                                                 /* require a numeric suffix */
 421                                                 unum = 0;
 422                                         else
 423                                                 /* allow name to be used as-is if no conflict */
 424                                                 unum = -1;
 425                                         name = info.name;
 426                                         if (!*name) {
 427                                                 name = st->ss->name;
 428                                                 if (!isdigit(name[strlen(name)-1]) &&
 429                                                     unum == -1) {
 430                                                         unum = 0;
 431                                                         sep = "";
 432                                                 }
 433                                         }
 434                                         if (strchr(name, ':'))
 435                                                 /* probably a uniquifying
 436                                                  * hostname prefix.  Allow
 437                                                  * without a suffix
 438                                                  */
 439                                                 unum = -1;
 440
 441                                         while (conflict) {
 442                                                 if (unum >= 0)
 443                                                         sprintf(namebuf, "/dev/md/%s%s%d",
 444                                                                 name, sep, unum);
 445                                                 else
 446                                                         sprintf(namebuf, "/dev/md/%s",
 447                                                                 name);
 448                                                 unum++;
 449                                                 if (lstat(namebuf, &stb) != 0 &&
 450                                                     (map == NULL ||
 451                                                      !map_by_name(&map, namebuf+8)))
 452                                                         conflict = 0;
 453                                         }
 454                                         path = namebuf;
 455                                 }
 456                         }
 457                         map_add(&map, md->devnum,
 458                                 info.text_version,
 459                                 info.uuid, path);
 460                         st->ss->free_super(st);
 461                         break;
 462                 }
 463                 sysfs_free(sra);
 464         }
 465         map_write(map);
 466         map_free(map);
 467         for (md = mdstat ; md ; md = md->next) {
 468                 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_VERSION);
 469                 sysfs_uevent(sra, "change");
 470                 sysfs_free(sra);
 471         }
 472         free_mdstat(mdstat);
 473 }