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