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 void free_mdstat(struct mdstat_ent *ms)
  87 {
  88         while (ms) {
  89                 struct mdstat_ent *t;
  90                 if (ms->dev) free(ms->dev);
  91                 if (ms->level) free(ms->level);
  92                 if (ms->pattern) free(ms->pattern);
  93                 if (ms->metadata_version) free(ms->metadata_version);
  94                 t = ms;
  95                 ms = ms->next;
  96                 free(t);
  97         }
  98 }
  99
 100 static int mdstat_fd = -1;
 101 struct mdstat_ent *mdstat_read(int hold, int start)
 102 {
 103         FILE *f;
 104         struct mdstat_ent *all, *rv, **end, **insert_here;
 105         char *line;
 106
 107         if (hold && mdstat_fd != -1) {
 108                 lseek(mdstat_fd, 0L, 0);
 109                 f = fdopen(dup(mdstat_fd), "r");
 110         } else
 111                 f = fopen("/proc/mdstat", "r");
 112         if (f == NULL)
 113                 return NULL;
 114         else
 115                 fcntl(fileno(f), F_SETFD, FD_CLOEXEC);
 116
 117         all = NULL;
 118         end = &all;
 119         for (; (line = conf_line(f)) ; free_line(line)) {
 120                 struct mdstat_ent *ent;
 121                 char *w;
 122                 int devnum;
 123                 int in_devs = 0;
 124                 char *ep;
 125
 126                 if (strcmp(line, "Personalities")==0)
 127                         continue;
 128                 if (strcmp(line, "read_ahead")==0)
 129                         continue;
 130                 if (strcmp(line, "unused")==0)
 131                         continue;
 132                 insert_here = NULL;
 133                 /* Better be an md line.. */
 134                 if (strncmp(line, "md", 2)!= 0)
 135                         continue;
 136                 if (strncmp(line, "md_d", 4) == 0)
 137                         devnum = -1-strtoul(line+4, &ep, 10);
 138                 else if (strncmp(line, "md", 2) == 0)
 139                         devnum = strtoul(line+2, &ep, 10);
 140                 else
 141                         continue;
 142                 if (ep == NULL || *ep ) {
 143                         /* fprintf(stderr, Name ": bad /proc/mdstat line starts: %s\n", line); */
 144                         continue;
 145                 }
 146
 147                 ent = malloc(sizeof(*ent));
 148                 if (!ent) {
 149                         fprintf(stderr, Name ": malloc failed reading /proc/mdstat.\n");
 150                         free_line(line);
 151                         break;
 152                 }
 153                 ent->dev = ent->level = ent->pattern= NULL;
 154                 ent->next = NULL;
 155                 ent->percent = -1;
 156                 ent->active = -1;
 157                 ent->resync = 0;
 158                 ent->metadata_version = NULL;
 159                 ent->raid_disks = 0;
 160                 ent->chunk_size = 0;
 161                 ent->devcnt = 0;
 162
 163                 ent->dev = strdup(line);
 164                 ent->devnum = devnum;
 165
 166                 for (w=dl_next(line); w!= line ; w=dl_next(w)) {
 167                         int l = strlen(w);
 168                         char *eq;
 169                         if (strcmp(w, "active")==0)
 170                                 ent->active = 1;
 171                         else if (strcmp(w, "inactive")==0)
 172                                 ent->active = 0;
 173                         else if (ent->active >=0 &&
 174                                  ent->level == NULL &&
 175                                  w[0] != '(' /*readonly*/) {
 176                                 ent->level = strdup(w);
 177                                 in_devs = 1;
 178                         } else if (in_devs && strcmp(w, "blocks")==0)
 179                                 in_devs = 0;
 180                         else if (in_devs) {
 181                                 ent->devcnt++;
 182                                 if (strncmp(w, "md", 2)==0) {
 183                                         /* This has an md device as a component.
 184                                          * If that device is already in the
 185                                          * list, make sure we insert before
 186                                          * there.
 187                                          */
 188                                         struct mdstat_ent **ih;
 189                                         int dn2 = devname2devnum(w);
 190                                         ih = &all;
 191                                         while (ih != insert_here && *ih &&
 192                                                (*ih)->devnum != dn2)
 193                                                 ih = & (*ih)->next;
 194                                         insert_here = ih;
 195                                 }
 196                         } else if (strcmp(w, "super") == 0 &&
 197                                    dl_next(w) != line) {
 198                                 w = dl_next(w);
 199                                 ent->metadata_version = strdup(w);
 200                         } else if (w[0] == '[' && isdigit(w[1])) {
 201                                 ent->raid_disks = atoi(w+1);
 202                         } else if (!ent->pattern &&
 203                                  w[0] == '[' &&
 204                                  (w[1] == 'U' || w[1] == '_')) {
 205                                 ent->pattern = strdup(w+1);
 206                                 if (ent->pattern[l-2]==']')
 207                                         ent->pattern[l-2] = '\0';
 208                         } else if (ent->percent == -1 &&
 209                                    strncmp(w, "re", 2)== 0 &&
 210                                    w[l-1] == '%' &&
 211                                    (eq=strchr(w, '=')) != NULL ) {
 212                                 ent->percent = atoi(eq+1);
 213                                 if (strncmp(w,"resync", 4)==0)
 214                                         ent->resync = 1;
 215                         } else if (ent->percent == -1 &&
 216                                    strncmp(w, "resync", 4)==0) {
 217                                 ent->resync = 1;
 218                         } else if (ent->percent == -1 &&
 219                                    w[0] >= '0' &&
 220                                    w[0] <= '9' &&
 221                                    w[l-1] == '%') {
 222                                 ent->percent = atoi(w);
 223                         }
 224                 }
 225                 if (insert_here && (*insert_here)) {
 226                         ent->next = *insert_here;
 227                         *insert_here = ent;
 228                 } else {
 229                         *end = ent;
 230                         end = &ent->next;
 231                 }
 232         }
 233         if (hold && mdstat_fd == -1) {
 234                 mdstat_fd = dup(fileno(f));
 235                 fcntl(mdstat_fd, F_SETFD, FD_CLOEXEC);
 236         }
 237         fclose(f);
 238
 239         /* If we might want to start array,
 240          * reverse the order, so that components comes before composites
 241          */
 242         if (start) {
 243                 rv = NULL;
 244                 while (all) {
 245                         struct mdstat_ent *e = all;
 246                         all = all->next;
 247                         e->next = rv;
 248                         rv = e;
 249                 }
 250         } else rv = all;
 251         return rv;
 252 }
 253
 254 void mdstat_wait(int seconds)
 255 {
 256         fd_set fds;
 257         struct timeval tm;
 258         int maxfd = 0;
 259         FD_ZERO(&fds);
 260         if (mdstat_fd >= 0) {
 261                 FD_SET(mdstat_fd, &fds);
 262                 maxfd = mdstat_fd;
 263         }
 264         tm.tv_sec = seconds;
 265         tm.tv_usec = 0;
 266         select(maxfd + 1, NULL, NULL, &fds, &tm);
 267 }
 268
 269 void mdstat_wait_fd(int fd, const sigset_t *sigmask)
 270 {
 271         fd_set fds, rfds;
 272         int maxfd = fd;
 273
 274         FD_ZERO(&fds);
 275         FD_ZERO(&rfds);
 276         if (mdstat_fd >= 0)
 277                 FD_SET(mdstat_fd, &fds);
 278         if (fd >= 0) {
 279                 struct stat stb;
 280                 fstat(fd, &stb);
 281                 if ((stb.st_mode & S_IFMT) == S_IFREG)
 282                         /* Must be a /proc or /sys fd, so expect
 283                          * POLLPRI
 284                          * i.e. an 'exceptional' event.
 285                          */
 286                         FD_SET(fd, &fds);
 287                 else
 288                         FD_SET(fd, &rfds);
 289         }
 290         if (mdstat_fd > maxfd)
 291                 maxfd = mdstat_fd;
 292
 293         pselect(maxfd + 1, &rfds, NULL, &fds,
 294                 NULL, sigmask);
 295 }
 296
 297 int mddev_busy(int devnum)
 298 {
 299         struct mdstat_ent *mdstat = mdstat_read(0, 0);
 300         struct mdstat_ent *me;
 301
 302         for (me = mdstat ; me ; me = me->next)
 303                 if (me->devnum == devnum)
 304                         break;
 305         free_mdstat(mdstat);
 306         return me != NULL;
 307 }