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 = malloc(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->dev);
 118                 free(ms->level);
 119                 free(ms->pattern);
 120                 free(ms->metadata_version);
 121                 free_member_devnames(ms->members);
 122                 t = ms;
 123                 ms = ms->next;
 124                 free(t);
 125         }
 126 }
 127
 128 static int mdstat_fd = -1;
 129 struct mdstat_ent *mdstat_read(int hold, int start)
 130 {
 131         FILE *f;
 132         struct mdstat_ent *all, *rv, **end, **insert_here;
 133         char *line;
 134         int fd;
 135
 136         if (hold && mdstat_fd != -1) {
 137                 lseek(mdstat_fd, 0L, 0);
 138                 fd = dup(mdstat_fd);
 139                 if (fd >= 0)
 140                         f = fdopen(fd, "r");
 141                 else
 142                         return NULL;
 143         } else
 144                 f = fopen("/proc/mdstat", "r");
 145         if (f == NULL)
 146                 return NULL;
 147         else
 148                 fcntl(fileno(f), F_SETFD, FD_CLOEXEC);
 149
 150         all = NULL;
 151         end = &all;
 152         for (; (line = conf_line(f)) ; free_line(line)) {
 153                 struct mdstat_ent *ent;
 154                 char *w;
 155                 int devnum;
 156                 int in_devs = 0;
 157                 char *ep;
 158
 159                 if (strcmp(line, "Personalities")==0)
 160                         continue;
 161                 if (strcmp(line, "read_ahead")==0)
 162                         continue;
 163                 if (strcmp(line, "unused")==0)
 164                         continue;
 165                 insert_here = NULL;
 166                 /* Better be an md line.. */
 167                 if (strncmp(line, "md", 2)!= 0)
 168                         continue;
 169                 if (strncmp(line, "md_d", 4) == 0)
 170                         devnum = -1-strtoul(line+4, &ep, 10);
 171                 else if (strncmp(line, "md", 2) == 0)
 172                         devnum = strtoul(line+2, &ep, 10);
 173                 else
 174                         continue;
 175                 if (ep == NULL || *ep ) {
 176                         /* pr_err("bad /proc/mdstat line starts: %s\n", line); */
 177                         continue;
 178                 }
 179
 180                 ent = malloc(sizeof(*ent));
 181                 if (!ent) {
 182                         pr_err("malloc failed reading /proc/mdstat.\n");
 183                         free_line(line);
 184                         break;
 185                 }
 186                 ent->dev = ent->level = ent->pattern= NULL;
 187                 ent->next = NULL;
 188                 ent->percent = RESYNC_NONE;
 189                 ent->active = -1;
 190                 ent->resync = 0;
 191                 ent->metadata_version = NULL;
 192                 ent->raid_disks = 0;
 193                 ent->devcnt = 0;
 194                 ent->members = NULL;
 195
 196                 ent->dev = strdup(line);
 197                 ent->devnum = devnum;
 198
 199                 for (w=dl_next(line); w!= line ; w=dl_next(w)) {
 200                         int l = strlen(w);
 201                         char *eq;
 202                         if (strcmp(w, "active")==0)
 203                                 ent->active = 1;
 204                         else if (strcmp(w, "inactive")==0) {
 205                                 ent->active = 0;
 206                                 in_devs = 1;
 207                         } else if (ent->active > 0 &&
 208                                  ent->level == NULL &&
 209                                  w[0] != '(' /*readonly*/) {
 210                                 ent->level = strdup(w);
 211                                 in_devs = 1;
 212                         } else if (in_devs && strcmp(w, "blocks")==0)
 213                                 in_devs = 0;
 214                         else if (in_devs) {
 215                                 ent->devcnt +=
 216                                         add_member_devname(&ent->members, w);
 217                                 if (strncmp(w, "md", 2)==0) {
 218                                         /* This has an md device as a component.
 219                                          * If that device is already in the
 220                                          * list, make sure we insert before
 221                                          * there.
 222                                          */
 223                                         struct mdstat_ent **ih;
 224                                         int dn2 = devname2devnum(w);
 225                                         ih = &all;
 226                                         while (ih != insert_here && *ih &&
 227                                                (*ih)->devnum != dn2)
 228                                                 ih = & (*ih)->next;
 229                                         insert_here = ih;
 230                                 }
 231                         } else if (strcmp(w, "super") == 0 &&
 232                                    dl_next(w) != line) {
 233                                 w = dl_next(w);
 234                                 ent->metadata_version = strdup(w);
 235                         } else if (w[0] == '[' && isdigit(w[1])) {
 236                                 ent->raid_disks = atoi(w+1);
 237                         } else if (!ent->pattern &&
 238                                  w[0] == '[' &&
 239                                  (w[1] == 'U' || w[1] == '_')) {
 240                                 ent->pattern = strdup(w+1);
 241                                 if (ent->pattern[l-2]==']')
 242                                         ent->pattern[l-2] = '\0';
 243                         } else if (ent->percent == RESYNC_NONE &&
 244                                    strncmp(w, "re", 2)== 0 &&
 245                                    w[l-1] == '%' &&
 246                                    (eq=strchr(w, '=')) != NULL ) {
 247                                 ent->percent = atoi(eq+1);
 248                                 if (strncmp(w,"resync", 6)==0)
 249                                         ent->resync = 1;
 250                                 else if (strncmp(w, "reshape", 7)==0)
 251                                         ent->resync = 2;
 252                                 else
 253                                         ent->resync = 0;
 254                         } else if (ent->percent == RESYNC_NONE &&
 255                                    (w[0] == 'r' || w[0] == 'c')) {
 256                                 if (strncmp(w, "resync", 4)==0)
 257                                         ent->resync = 1;
 258                                 if (strncmp(w, "reshape", 7)==0)
 259                                         ent->resync = 2;
 260                                 if (strncmp(w, "recovery", 8)==0)
 261                                         ent->resync = 0;
 262                                 if (strncmp(w, "check", 5)==0)
 263                                         ent->resync = 3;
 264
 265                                 if (l > 8 && strcmp(w+l-8, "=DELAYED") == 0)
 266                                         ent->percent = RESYNC_DELAYED;
 267                                 if (l > 8 && strcmp(w+l-8, "=PENDING") == 0)
 268                                         ent->percent = RESYNC_PENDING;
 269                         } else if (ent->percent == RESYNC_NONE &&
 270                                    w[0] >= '0' &&
 271                                    w[0] <= '9' &&
 272                                    w[l-1] == '%') {
 273                                 ent->percent = atoi(w);
 274                         }
 275                 }
 276                 if (insert_here && (*insert_here)) {
 277                         ent->next = *insert_here;
 278                         *insert_here = ent;
 279                 } else {
 280                         *end = ent;
 281                         end = &ent->next;
 282                 }
 283         }
 284         if (hold && mdstat_fd == -1) {
 285                 mdstat_fd = dup(fileno(f));
 286                 fcntl(mdstat_fd, F_SETFD, FD_CLOEXEC);
 287         }
 288         fclose(f);
 289
 290         /* If we might want to start array,
 291          * reverse the order, so that components comes before composites
 292          */
 293         if (start) {
 294                 rv = NULL;
 295                 while (all) {
 296                         struct mdstat_ent *e = all;
 297                         all = all->next;
 298                         e->next = rv;
 299                         rv = e;
 300                 }
 301         } else rv = all;
 302         return rv;
 303 }
 304
 305 void mdstat_wait(int seconds)
 306 {
 307         fd_set fds;
 308         struct timeval tm;
 309         int maxfd = 0;
 310         FD_ZERO(&fds);
 311         if (mdstat_fd >= 0) {
 312                 FD_SET(mdstat_fd, &fds);
 313                 maxfd = mdstat_fd;
 314         }
 315         tm.tv_sec = seconds;
 316         tm.tv_usec = 0;
 317         select(maxfd + 1, NULL, NULL, &fds, &tm);
 318 }
 319
 320 void mdstat_wait_fd(int fd, const sigset_t *sigmask)
 321 {
 322         fd_set fds, rfds;
 323         int maxfd = 0;
 324
 325         FD_ZERO(&fds);
 326         FD_ZERO(&rfds);
 327         if (mdstat_fd >= 0)
 328                 FD_SET(mdstat_fd, &fds);
 329
 330         if (fd >= 0) {
 331                 struct stat stb;
 332                 fstat(fd, &stb);
 333                 if ((stb.st_mode & S_IFMT) == S_IFREG)
 334                         /* Must be a /proc or /sys fd, so expect
 335                          * POLLPRI
 336                          * i.e. an 'exceptional' event.
 337                          */
 338                         FD_SET(fd, &fds);
 339                 else
 340                         FD_SET(fd, &rfds);
 341
 342                 if (fd > maxfd)
 343                         maxfd = fd;
 344
 345         }
 346         if (mdstat_fd > maxfd)
 347                 maxfd = mdstat_fd;
 348
 349         pselect(maxfd + 1, &rfds, NULL, &fds,
 350                 NULL, sigmask);
 351 }
 352
 353 int mddev_busy(int devnum)
 354 {
 355         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 356         struct mdstat_ent *me;
 357
 358         for (me = mdstat ; me ; me = me->next)
 359                 if (me->devnum == devnum)
 360                         break;
 361         free_mdstat(mdstat);
 362         return me != NULL;
 363 }
 364
 365 struct mdstat_ent *mdstat_by_component(char *name)
 366 {
 367         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 368
 369         while (mdstat) {
 370                 struct dev_member *m;
 371                 struct mdstat_ent *ent;
 372                 if (mdstat->metadata_version &&
 373                     strncmp(mdstat->metadata_version, "external:", 9) == 0 &&
 374                     is_subarray(mdstat->metadata_version+9))
 375                         /* don't return subarrays, only containers */
 376                         ;
 377                 else for (m = mdstat->members; m; m = m->next) {
 378                                 if (strcmp(m->name, name) == 0) {
 379                                         free_mdstat(mdstat->next);
 380                                         mdstat->next = NULL;
 381                                         return mdstat;
 382                                 }
 383                         }
 384                 ent = mdstat;
 385                 mdstat = mdstat->next;
 386                 ent->next = NULL;
 387                 free_mdstat(ent);
 388         }
 389         return NULL;
 390 }
 391
 392 struct mdstat_ent *mdstat_by_subdev(char *subdev, int container)
 393 {
 394         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 395
 396         while (mdstat) {
 397                 struct mdstat_ent *ent;
 398                 char *pos;
 399                 /* metadata version must match:
 400                  *   external:[/-]md%d/%s
 401                  * where %d is 'container' and %s is 'subdev'
 402                  */
 403                 if (mdstat->metadata_version &&
 404                     strncmp(mdstat->metadata_version, "external:", 9) == 0 &&
 405                     strchr("/-", mdstat->metadata_version[9]) != NULL &&
 406                     strncmp(mdstat->metadata_version+10, "md", 2) == 0 &&
 407                     strtoul(mdstat->metadata_version+12, &pos, 10)
 408                     == (unsigned)container &&
 409                     pos > mdstat->metadata_version+12 &&
 410                     *pos == '/' &&
 411                     strcmp(pos+1, subdev) == 0
 412                         ) {
 413                         free_mdstat(mdstat->next);
 414                         mdstat->next = NULL;
 415                         return mdstat;
 416                 }
 417                 ent = mdstat;
 418                 mdstat = mdstat->next;
 419                 ent->next = NULL;
 420                 free_mdstat(ent);
 421         }
 422         return NULL;
 423 }