mdstat.c

   1 /*
   2  * mdstat - parse /proc/mdstat file. Part of:
   3  * mdadm - manage Linux "md" devices aka RAID arrays.
   4  *
   5  * Copyright (C) 2002-2009 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 /*
  27  * The /proc/mdstat file comes in at least 3 flavours:
  28  * In an unpatched 2.2 kernel (md 0.36.6):
  29  *  Personalities : [n raidx] ...
  30  *  read_ahead {not set|%d sectors}
  31  *  md0 : {in}active{ raidX /dev/hda...  %d blocks{ maxfault=%d}}
  32  *  md1 : .....
  33  *
  34  * Normally only 4 md lines, but all are listed.
  35  *
  36  * In a patched 2.2 kernel (md 0.90.0)
  37  *  Personalities : [raidx] ...
  38  *  read_ahead {not set|%d sectors}
  39  *  mdN : {in}active {(readonly)} raidX dev[%d]{(F)} ... %d blocks STATUS RESYNC
  40  *  ... Only initialised arrays listed
  41  *  unused devices: {dev dev ... | <none>}
  42  *
  43  * STATUS is personality dependant:
  44  *    linear:  %dk rounding
  45  *    raid0:   %dk chunks
  46  *    raid1:   [%d/%d] [U_U]   ( raid/working.  operational or not)
  47  *    raid5:   level 4/5, %dk chunk, algorithm %d [%d/%d] [U_U]
  48  *
  49  * RESYNC is  empty or:
  50  *    {resync|recovery}=%u%% finish=%u.%umin
  51  *  or
  52  *    resync=DELAYED
  53  *
  54  * In a 2.4 kernel (md 0.90.0/2.4)
  55  *  Personalities : [raidX] ...
  56  *  read_ahead {not set|%d sectors}
  57  *  mdN : {in}active {(read-only)} raidX dev[%d]{(F)} ...
  58  *       %d blocks STATUS
  59  *       RESYNC
  60  *  unused devices: {dev dev .. | <none>}
  61  *
  62  *  STATUS matches 0.90.0/2.2
  63  *  RESYNC includes [===>....],
  64  *          adds a space after {resync|recovery} and before and after '='
  65  *          adds a decimal to the recovery percent.
  66  *          adds (%d/%d) resync amount  and max_blocks, before finish.
  67  *          adds speed=%dK/sec after finish
  68  *
  69  *
  70  *
  71  * Out of this we want to extract:
  72  *   list of devices, active or not
  73  *   pattern of failed drives (so need number of drives)
  74  *   percent resync complete
  75  *
  76  * As continuation is indicated by leading space, we use
  77  *  conf_line from config.c to read logical lines
  78  *
  79  */
  80
  81 #include        "mdadm.h"
  82 #include        "dlink.h"
  83 #include        <sys/select.h>
  84 #include        <ctype.h>
  85
  86 static void free_member_devnames(struct dev_member *m)
  87 {
  88         while(m) {
  89                 struct dev_member *t = m;
  90
  91                 m = m->next;
  92                 free(t->name);
  93                 free(t);
  94         }
  95 }
  96
  97 static int add_member_devname(struct dev_member **m, char *name)
  98 {
  99         struct dev_member *new;
 100         char *t;
 101
 102         if ((t = strchr(name, '[')) == NULL)
 103                 /* not a device */
 104                 return 0;
 105
 106         new = xmalloc(sizeof(*new));
 107         new->name = strndup(name, t - name);
 108         new->next = *m;
 109         *m = new;
 110         return 1;
 111 }
 112
 113 void free_mdstat(struct mdstat_ent *ms)
 114 {
 115         while (ms) {
 116                 struct mdstat_ent *t;
 117                 free(ms->level);
 118                 free(ms->pattern);
 119                 free(ms->metadata_version);
 120                 free_member_devnames(ms->members);
 121                 t = ms;
 122                 ms = ms->next;
 123                 free(t);
 124         }
 125 }
 126
 127 static int mdstat_fd = -1;
 128 struct mdstat_ent *mdstat_read(int hold, int start)
 129 {
 130         FILE *f;
 131         struct mdstat_ent *all, *rv, **end, **insert_here;
 132         char *line;
 133         int fd;
 134
 135         if (hold && mdstat_fd != -1) {
 136                 off_t offset = lseek(mdstat_fd, 0L, 0);
 137                 if (offset == (off_t)-1) {
 138                         mdstat_close();
 139                         return NULL;
 140                 }
 141                 fd = dup(mdstat_fd);
 142                 if (fd >= 0)
 143                         f = fdopen(fd, "r");
 144                 else
 145                         return NULL;
 146         } else
 147                 f = fopen("/proc/mdstat", "r");
 148         if (f == NULL)
 149                 return NULL;
 150         else
 151                 fcntl(fileno(f), F_SETFD, FD_CLOEXEC);
 152
 153         all = NULL;
 154         end = &all;
 155         for (; (line = conf_line(f)) ; free_line(line)) {
 156                 struct mdstat_ent *ent;
 157                 char *w;
 158                 char devnm[32];
 159                 int in_devs = 0;
 160
 161                 if (strcmp(line, "Personalities")==0)
 162                         continue;
 163                 if (strcmp(line, "read_ahead")==0)
 164                         continue;
 165                 if (strcmp(line, "unused")==0)
 166                         continue;
 167                 insert_here = NULL;
 168                 /* Better be an md line.. */
 169                 if (strncmp(line, "md", 2)!= 0 || strlen(line) >= 32
 170                     || (line[2] != '_' && !isdigit(line[2])))
 171                         continue;
 172                 strcpy(devnm, line);
 173
 174                 ent = xmalloc(sizeof(*ent));
 175                 ent->level = ent->pattern= NULL;
 176                 ent->next = NULL;
 177                 ent->percent = RESYNC_NONE;
 178                 ent->active = -1;
 179                 ent->resync = 0;
 180                 ent->metadata_version = NULL;
 181                 ent->raid_disks = 0;
 182                 ent->devcnt = 0;
 183                 ent->members = NULL;
 184
 185                 strcpy(ent->devnm, devnm);
 186
 187                 for (w=dl_next(line); w!= line ; w=dl_next(w)) {
 188                         int l = strlen(w);
 189                         char *eq;
 190                         if (strcmp(w, "active")==0)
 191                                 ent->active = 1;
 192                         else if (strcmp(w, "inactive")==0) {
 193                                 ent->active = 0;
 194                                 in_devs = 1;
 195                         } else if (ent->active > 0 &&
 196                                  ent->level == NULL &&
 197                                  w[0] != '(' /*readonly*/) {
 198                                 ent->level = xstrdup(w);
 199                                 in_devs = 1;
 200                         } else if (in_devs && strcmp(w, "blocks")==0)
 201                                 in_devs = 0;
 202                         else if (in_devs) {
 203                                 char *ep = strchr(w, '[');
 204                                 ent->devcnt +=
 205                                         add_member_devname(&ent->members, w);
 206                                 if (ep && strncmp(w, "md", 2)==0) {
 207                                         /* This has an md device as a component.
 208                                          * If that device is already in the
 209                                          * list, make sure we insert before
 210                                          * there.
 211                                          */
 212                                         struct mdstat_ent **ih;
 213                                         ih = &all;
 214                                         while (ih != insert_here && *ih &&
 215                                                ((int)strlen((*ih)->devnm) != ep-w
 216                                                 || strncmp((*ih)->devnm, w, ep-w) != 0))
 217                                                 ih = & (*ih)->next;
 218                                         insert_here = ih;
 219                                 }
 220                         } else if (strcmp(w, "super") == 0 &&
 221                                    dl_next(w) != line) {
 222                                 w = dl_next(w);
 223                                 ent->metadata_version = xstrdup(w);
 224                         } else if (w[0] == '[' && isdigit(w[1])) {
 225                                 ent->raid_disks = atoi(w+1);
 226                         } else if (!ent->pattern &&
 227                                  w[0] == '[' &&
 228                                  (w[1] == 'U' || w[1] == '_')) {
 229                                 ent->pattern = xstrdup(w+1);
 230                                 if (ent->pattern[l-2]==']')
 231                                         ent->pattern[l-2] = '\0';
 232                         } else if (ent->percent == RESYNC_NONE &&
 233                                    strncmp(w, "re", 2)== 0 &&
 234                                    w[l-1] == '%' &&
 235                                    (eq=strchr(w, '=')) != NULL ) {
 236                                 ent->percent = atoi(eq+1);
 237                                 if (strncmp(w,"resync", 6)==0)
 238                                         ent->resync = 1;
 239                                 else if (strncmp(w, "reshape", 7)==0)
 240                                         ent->resync = 2;
 241                                 else
 242                                         ent->resync = 0;
 243                         } else if (ent->percent == RESYNC_NONE &&
 244                                    (w[0] == 'r' || w[0] == 'c')) {
 245                                 if (strncmp(w, "resync", 4)==0)
 246                                         ent->resync = 1;
 247                                 if (strncmp(w, "reshape", 7)==0)
 248                                         ent->resync = 2;
 249                                 if (strncmp(w, "recovery", 8)==0)
 250                                         ent->resync = 0;
 251                                 if (strncmp(w, "check", 5)==0)
 252                                         ent->resync = 3;
 253
 254                                 if (l > 8 && strcmp(w+l-8, "=DELAYED") == 0)
 255                                         ent->percent = RESYNC_DELAYED;
 256                                 if (l > 8 && strcmp(w+l-8, "=PENDING") == 0)
 257                                         ent->percent = RESYNC_PENDING;
 258                         } else if (ent->percent == RESYNC_NONE &&
 259                                    w[0] >= '0' &&
 260                                    w[0] <= '9' &&
 261                                    w[l-1] == '%') {
 262                                 ent->percent = atoi(w);
 263                         }
 264                 }
 265                 if (insert_here && (*insert_here)) {
 266                         ent->next = *insert_here;
 267                         *insert_here = ent;
 268                 } else {
 269                         *end = ent;
 270                         end = &ent->next;
 271                 }
 272         }
 273         if (hold && mdstat_fd == -1) {
 274                 mdstat_fd = dup(fileno(f));
 275                 fcntl(mdstat_fd, F_SETFD, FD_CLOEXEC);
 276         }
 277         fclose(f);
 278
 279         /* If we might want to start array,
 280          * reverse the order, so that components comes before composites
 281          */
 282         if (start) {
 283                 rv = NULL;
 284                 while (all) {
 285                         struct mdstat_ent *e = all;
 286                         all = all->next;
 287                         e->next = rv;
 288                         rv = e;
 289                 }
 290         } else rv = all;
 291         return rv;
 292 }
 293
 294 void mdstat_close(void)
 295 {
 296         if (mdstat_fd >= 0)
 297                 close(mdstat_fd);
 298         mdstat_fd = -1;
 299 }
 300
 301 void mdstat_wait(int seconds)
 302 {
 303         fd_set fds;
 304         struct timeval tm;
 305         int maxfd = 0;
 306         FD_ZERO(&fds);
 307         if (mdstat_fd >= 0) {
 308                 FD_SET(mdstat_fd, &fds);
 309                 maxfd = mdstat_fd;
 310         }
 311         tm.tv_sec = seconds;
 312         tm.tv_usec = 0;
 313         select(maxfd + 1, NULL, NULL, &fds, &tm);
 314 }
 315
 316 void mdstat_wait_fd(int fd, const sigset_t *sigmask)
 317 {
 318         fd_set fds, rfds;
 319         int maxfd = 0;
 320
 321         FD_ZERO(&fds);
 322         FD_ZERO(&rfds);
 323         if (mdstat_fd >= 0)
 324                 FD_SET(mdstat_fd, &fds);
 325
 326         if (fd >= 0) {
 327                 struct stat stb;
 328                 fstat(fd, &stb);
 329                 if ((stb.st_mode & S_IFMT) == S_IFREG)
 330                         /* Must be a /proc or /sys fd, so expect
 331                          * POLLPRI
 332                          * i.e. an 'exceptional' event.
 333                          */
 334                         FD_SET(fd, &fds);
 335                 else
 336                         FD_SET(fd, &rfds);
 337
 338                 if (fd > maxfd)
 339                         maxfd = fd;
 340
 341         }
 342         if (mdstat_fd > maxfd)
 343                 maxfd = mdstat_fd;
 344
 345         pselect(maxfd + 1, &rfds, NULL, &fds,
 346                 NULL, sigmask);
 347 }
 348
 349 int mddev_busy(char *devnm)
 350 {
 351         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 352         struct mdstat_ent *me;
 353
 354         for (me = mdstat ; me ; me = me->next)
 355                 if (strcmp(me->devnm, devnm) == 0)
 356                         break;
 357         free_mdstat(mdstat);
 358         return me != NULL;
 359 }
 360
 361 struct mdstat_ent *mdstat_by_component(char *name)
 362 {
 363         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 364
 365         while (mdstat) {
 366                 struct dev_member *m;
 367                 struct mdstat_ent *ent;
 368                 if (mdstat->metadata_version &&
 369                     strncmp(mdstat->metadata_version, "external:", 9) == 0 &&
 370                     is_subarray(mdstat->metadata_version+9))
 371                         /* don't return subarrays, only containers */
 372                         ;
 373                 else for (m = mdstat->members; m; m = m->next) {
 374                                 if (strcmp(m->name, name) == 0) {
 375                                         free_mdstat(mdstat->next);
 376                                         mdstat->next = NULL;
 377                                         return mdstat;
 378                                 }
 379                         }
 380                 ent = mdstat;
 381                 mdstat = mdstat->next;
 382                 ent->next = NULL;
 383                 free_mdstat(ent);
 384         }
 385         return NULL;
 386 }
 387
 388 struct mdstat_ent *mdstat_by_subdev(char *subdev, char *container)
 389 {
 390         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 391         struct mdstat_ent *ent = NULL;
 392
 393         while (mdstat) {
 394                 /* metadata version must match:
 395                  *   external:[/-]%s/%s
 396                  * where first %s is 'container' and second %s is 'subdev'
 397                  */
 398                 if (ent)
 399                         free_mdstat(ent);
 400                 ent = mdstat;
 401                 mdstat = mdstat->next;
 402                 ent->next = NULL;
 403
 404                 if (ent->metadata_version == NULL ||
 405                     strncmp(ent->metadata_version, "external:", 9) != 0)
 406                         continue;
 407
 408                 if (!metadata_container_matches(ent->metadata_version+9,
 409                                                container) ||
 410                     !metadata_subdev_matches(ent->metadata_version+9,
 411                                              subdev))
 412                         continue;
 413
 414                 free_mdstat(mdstat);
 415                 return ent;
 416         }
 417         return NULL;
 418 }