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        <ctype.h>
  52
  53 #define mapnames(base) { #base, #base ".new", #base ".lock"}
  54 char *mapname[3][3] = {
  55         mapnames(/var/run/mdadm/map),
  56         mapnames(/var/run/mdadm.map),
  57         mapnames(/dev/.mdadm.map)
  58 };
  59
  60 int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT | O_TRUNC };
  61 char *mapsmode[3] = { "r", "w", "w"};
  62
  63 FILE *open_map(int modenum, int *choice)
  64 {
  65         int i;
  66         for (i = 0 ; i < 3 ; i++) {
  67                 int fd = open(mapname[i][modenum], mapmode[modenum], 0600);
  68                 if (fd >= 0) {
  69                         *choice = i;
  70                         return fdopen(fd, mapsmode[modenum]);
  71                 }
  72         }
  73         return NULL;
  74 }
  75
  76 int map_write(struct map_ent *mel)
  77 {
  78         FILE *f;
  79         int err;
  80         int which;
  81
  82         f = open_map(1, &which);
  83
  84         if (!f)
  85                 return 0;
  86         for (; mel; mel = mel->next) {
  87                 if (mel->bad)
  88                         continue;
  89                 if (mel->devnum < 0)
  90                         fprintf(f, "mdp%d ", -1-mel->devnum);
  91                 else
  92                         fprintf(f, "md%d ", mel->devnum);
  93                 fprintf(f, "%s ", mel->metadata);
  94                 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
  95                         mel->uuid[1], mel->uuid[2], mel->uuid[3]);
  96                 fprintf(f, "%s\n", mel->path?:"");
  97         }
  98         fflush(f);
  99         err = ferror(f);
 100         fclose(f);
 101         if (err) {
 102                 unlink(mapname[which][1]);
 103                 return 0;
 104         }
 105         return rename(mapname[which][1],
 106                       mapname[which][0]) == 0;
 107 }
 108
 109
 110 static FILE *lf = NULL;
 111 static int lwhich = 0;
 112 int map_lock(struct map_ent **melp)
 113 {
 114         if (lf == NULL) {
 115                 lf = open_map(2, &lwhich);
 116                 if (lf == NULL)
 117                         return -1;
 118                 if (lockf(fileno(lf), F_LOCK, 0) != 0) {
 119                         fclose(lf);
 120                         lf = NULL;
 121                         return -1;
 122                 }
 123         }
 124         if (*melp)
 125                 map_free(*melp);
 126         map_read(melp);
 127         return 0;
 128 }
 129
 130 void map_unlock(struct map_ent **melp)
 131 {
 132         if (lf)
 133                 fclose(lf);
 134         unlink(mapname[lwhich][2]);
 135         lf = NULL;
 136 }
 137
 138 void map_add(struct map_ent **melp,
 139             int devnum, char *metadata, int uuid[4], char *path)
 140 {
 141         struct map_ent *me = malloc(sizeof(*me));
 142
 143         me->devnum = devnum;
 144         strcpy(me->metadata, metadata);
 145         memcpy(me->uuid, uuid, 16);
 146         me->path = path ? strdup(path) : NULL;
 147         me->next = *melp;
 148         me->bad = 0;
 149         *melp = me;
 150 }
 151
 152 void map_read(struct map_ent **melp)
 153 {
 154         FILE *f;
 155         char buf[8192];
 156         char path[200];
 157         int devnum, uuid[4];
 158         char metadata[30];
 159         char nam[4];
 160         int which;
 161
 162         *melp = NULL;
 163
 164         f = open_map(0, &which);
 165         if (!f) {
 166                 RebuildMap();
 167                 f = open_map(0, &which);
 168         }
 169         if (!f)
 170                 return;
 171
 172         while (fgets(buf, sizeof(buf), f)) {
 173                 path[0] = 0;
 174                 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
 175                            nam, &devnum, metadata, uuid, uuid+1,
 176                            uuid+2, uuid+3, path) >= 7) {
 177                         if (strncmp(nam, "md", 2) != 0)
 178                                 continue;
 179                         if (nam[2] == 'p')
 180                                 devnum = -1 - devnum;
 181                         map_add(melp, devnum, metadata, uuid, path);
 182                 }
 183         }
 184         fclose(f);
 185 }
 186
 187 void map_free(struct map_ent *map)
 188 {
 189         while (map) {
 190                 struct map_ent *mp = map;
 191                 map = mp->next;
 192                 free(mp->path);
 193                 free(mp);
 194         }
 195 }
 196
 197 int map_update(struct map_ent **mpp, int devnum, char *metadata,
 198                int *uuid, char *path)
 199 {
 200         struct map_ent *map, *mp;
 201         int rv;
 202
 203         if (mpp && *mpp)
 204                 map = *mpp;
 205         else
 206                 map_read(&map);
 207
 208         for (mp = map ; mp ; mp=mp->next)
 209                 if (mp->devnum == devnum) {
 210                         strcpy(mp->metadata, metadata);
 211                         memcpy(mp->uuid, uuid, 16);
 212                         free(mp->path);
 213                         mp->path = path ? strdup(path) : NULL;
 214                         break;
 215                 }
 216         if (!mp)
 217                 map_add(&map, devnum, metadata, uuid, path);
 218         if (mpp)
 219                 *mpp = NULL;
 220         rv = map_write(map);
 221         map_free(map);
 222         return rv;
 223 }
 224
 225 void map_delete(struct map_ent **mapp, int devnum)
 226 {
 227         struct map_ent *mp;
 228
 229         if (*mapp == NULL)
 230                 map_read(mapp);
 231
 232         for (mp = *mapp; mp; mp = *mapp) {
 233                 if (mp->devnum == devnum) {
 234                         *mapp = mp->next;
 235                         free(mp->path);
 236                         free(mp);
 237                 } else
 238                         mapp = & mp->next;
 239         }
 240 }
 241
 242 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
 243 {
 244         struct map_ent *mp;
 245         if (!*map)
 246                 map_read(map);
 247
 248         for (mp = *map ; mp ; mp = mp->next) {
 249                 if (memcmp(uuid, mp->uuid, 16) != 0)
 250                         continue;
 251                 if (!mddev_busy(mp->devnum)) {
 252                         mp->bad = 1;
 253                         continue;
 254                 }
 255                 return mp;
 256         }
 257         return NULL;
 258 }
 259
 260 struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
 261 {
 262         struct map_ent *mp;
 263         if (!*map)
 264                 map_read(map);
 265
 266         for (mp = *map ; mp ; mp = mp->next) {
 267                 if (mp->devnum != devnum)
 268                         continue;
 269                 if (!mddev_busy(mp->devnum)) {
 270                         mp->bad = 1;
 271                         continue;
 272                 }
 273                 return mp;
 274         }
 275         return NULL;
 276 }
 277
 278 struct map_ent *map_by_name(struct map_ent **map, char *name)
 279 {
 280         struct map_ent *mp;
 281         if (!*map)
 282                 map_read(map);
 283
 284         for (mp = *map ; mp ; mp = mp->next) {
 285                 if (!mp->path)
 286                         continue;
 287                 if (strncmp(mp->path, "/dev/md/", 8) != 0)
 288                         continue;
 289                 if (strcmp(mp->path+8, name) != 0)
 290                         continue;
 291                 if (!mddev_busy(mp->devnum)) {
 292                         mp->bad = 1;
 293                         continue;
 294                 }
 295                 return mp;
 296         }
 297         return NULL;
 298 }
 299
 300 void RebuildMap(void)
 301 {
 302         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 303         struct mdstat_ent *md;
 304         struct map_ent *map = NULL;
 305         int mdp = get_mdp_major();
 306         int require_homehost;
 307         char sys_hostname[256];
 308         char *homehost = conf_get_homehost(&require_homehost);
 309
 310         if (homehost == NULL || strcmp(homehost, "<system>")==0) {
 311                 if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
 312                         sys_hostname[sizeof(sys_hostname)-1] = 0;
 313                         homehost = sys_hostname;
 314                 }
 315         }
 316
 317         for (md = mdstat ; md ; md = md->next) {
 318                 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS|SKIP_GONE_DEVS);
 319                 struct mdinfo *sd;
 320
 321                 if (!sra)
 322                         continue;
 323
 324                 for (sd = sra->devs ; sd ; sd = sd->next) {
 325                         char namebuf[100];
 326                         char dn[30];
 327                         int dfd;
 328                         int ok;
 329                         struct supertype *st;
 330                         char *path;
 331                         struct mdinfo info;
 332
 333                         sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
 334                         dfd = dev_open(dn, O_RDONLY);
 335                         if (dfd < 0)
 336                                 continue;
 337                         st = guess_super(dfd);
 338                         if ( st == NULL)
 339                                 ok = -1;
 340                         else
 341                                 ok = st->ss->load_super(st, dfd, NULL);
 342                         close(dfd);
 343                         if (ok != 0)
 344                                 continue;
 345                         st->ss->getinfo_super(st, &info);
 346                         if (md->devnum >= 0)
 347                                 path = map_dev(MD_MAJOR, md->devnum, 0);
 348                         else
 349                                 path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
 350                         if (path == NULL ||
 351                             strncmp(path, "/dev/md/", 8) != 0) {
 352                                 /* We would really like a name that provides
 353                                  * an MD_DEVNAME for udev.
 354                                  * The name needs to be unique both in /dev/md/
 355                                  * and in this mapfile.
 356                                  * It needs to match watch -I or -As would come
 357                                  * up with.
 358                                  * That means:
 359                                  *   Check if array is in mdadm.conf
 360                                  *        - if so use that.
 361                                  *   determine trustworthy from homehost etc
 362                                  *   find a unique name based on metadata name.
 363                                  *
 364                                  */
 365                                 struct mddev_ident_s *match = conf_match(&info, st);
 366                                 struct stat stb;
 367                                 if (match && match->devname && match->devname[0] == '/') {
 368                                         path = match->devname;
 369                                         if (path[0] != '/') {
 370                                                 strcpy(namebuf, "/dev/md/");
 371                                                 strcat(namebuf, path);
 372                                                 path = namebuf;
 373                                         }
 374                                 } else {
 375                                         int unum = 0;
 376                                         char *sep = "_";
 377                                         const char *name;
 378                                         int conflict = 1;
 379                                         if ((homehost == NULL ||
 380                                              st->ss->match_home(st, homehost) != 1) &&
 381                                             st->ss->match_home(st, "any") != 1 &&
 382                                             (require_homehost
 383                                              || ! conf_name_is_free(info.name)))
 384                                                 /* require a numeric suffix */
 385                                                 unum = 0;
 386                                         else
 387                                                 /* allow name to be used as-is if no conflict */
 388                                                 unum = -1;
 389                                         name = info.name;
 390                                         if (!*name) {
 391                                                 name = st->ss->name;
 392                                                 if (!isdigit(name[strlen(name)-1]) &&
 393                                                     unum == -1) {
 394                                                         unum = 0;
 395                                                         sep = "";
 396                                                 }
 397                                         }
 398                                         if (strchr(name, ':'))
 399                                                 /* probably a uniquifying
 400                                                  * hostname prefix.  Allow
 401                                                  * without a suffix
 402                                                  */
 403                                                 unum = -1;
 404
 405                                         while (conflict) {
 406                                                 if (unum >= 0)
 407                                                         sprintf(namebuf, "/dev/md/%s%s%d",
 408                                                                 name, sep, unum);
 409                                                 else
 410                                                         sprintf(namebuf, "/dev/md/%s",
 411                                                                 name);
 412                                                 unum++;
 413                                                 if (lstat(namebuf, &stb) != 0 &&
 414                                                     (map == NULL ||
 415                                                      !map_by_name(&map, namebuf+8)))
 416                                                         conflict = 0;
 417                                         }
 418                                         path = namebuf;
 419                                 }
 420                         }
 421                         map_add(&map, md->devnum,
 422                                 info.text_version,
 423                                 info.uuid, path);
 424                         st->ss->free_super(st);
 425                         break;
 426                 }
 427                 sysfs_free(sra);
 428         }
 429         map_write(map);
 430         map_free(map);
 431         for (md = mdstat ; md ; md = md->next) {
 432                 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_VERSION);
 433                 sysfs_uevent(sra, "change");
 434                 sysfs_free(sra);
 435         }
 436         free_mdstat(mdstat);
 437 }