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 Neil Brown <neilb@cse.unsw.edu.au>
   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@cse.unsw.edu.au>
  24  *    Paper: Neil Brown
  25  *           School of Computer Science and Engineering
  26  *           The University of New South Wales
  27  *           Sydney, 2052
  28  *           Australia
  29  */
  30
  31 /*
  32  * The /proc/mdstat file comes in at least 3 flavours:
  33  * In an unpatched 2.2 kernel (md 0.36.6):
  34  *  Personalities : [n raidx] ...
  35  *  read_ahead {not set|%d sectors}
  36  *  md0 : {in}active{ raidX /dev/hda...  %d blocks{ maxfault=%d}}
  37  *  md1 : .....
  38  *
  39  * Normally only 4 md lines, but all are listed.
  40  *
  41  * In a patched 2.2 kernel (md 0.90.0)
  42  *  Personalities : [raidx] ...
  43  *  read_ahead {not set|%d sectors}
  44  *  mdN : {in}active {(readonly)} raidX dev[%d]{(F)} ... %d blocks STATUS RESYNC
  45  *  ... Only initialised arrays listed
  46  *  unused: dev dev dev | <none>
  47  *
  48  * STATUS is personality dependant:
  49  *    linear:  %dk rounding
  50  *    raid0:   %dk chunks
  51  *    raid1:   [%d/%d] [U_U]   ( raid/working.  operational or not)
  52  *    raid5:   level 4/5, %dk chunk, algorithm %d [%d/%d] [U_U]
  53  *
  54  * RESYNC is  empty or:
  55  *    {resync|recovery}=%u%% finish=%u.%umin
  56  *  or
  57  *    resync=DELAYED
  58  *
  59  * In a 2.4 kernel (md 0.90.0/2.4)
  60  *  Personalities : [raidX] ...
  61  *  read_ahead {not set|%d sectors}
  62  *  mdN : {in}active {(read-only)} raidX dev[%d]{(F)} ...
  63  *       %d blocks STATUS
  64  *       RESYNC
  65  *  unused: dev dev .. | <none>
  66  *
  67  *  STATUS matches 0.90.0/2.2
  68  *  RESYNC includes [===>....],
  69  *          adds a space after {resync|recovery} and before and after '='
  70  *          adds a decimal to the recovery percent.
  71  *          adds (%d/%d) resync amount  and max_blocks, before finish.
  72  *          adds speed=%dK/sec after finish
  73  *
  74  *
  75  *
  76  * Out of this we want to extract:
  77  *   list of devices, active or not
  78  *   pattern of failed drives (so need number of drives)
  79  *   percent resync complete
  80  *
  81  * As continuation is indicated by leading space, we use
  82  *  conf_line from config.c to read logical lines
  83  *
  84  */
  85
  86 #include        "mdadm.h"
  87 #include        "dlink.h"
  88 #include        <sys/select.h>
  89
  90 void free_mdstat(struct mdstat_ent *ms)
  91 {
  92         while (ms) {
  93                 struct mdstat_ent *t;
  94                 if (ms->dev) free(ms->dev);
  95                 if (ms->level) free(ms->level);
  96                 if (ms->pattern) free(ms->pattern);
  97                 t = ms;
  98                 ms = ms->next;
  99                 free(t);
 100         }
 101 }
 102
 103 static int mdstat_fd = -1;
 104 struct mdstat_ent *mdstat_read(int hold)
 105 {
 106         FILE *f;
 107         struct mdstat_ent *all, **end;
 108         char *line;
 109
 110         if (hold && mdstat_fd != -1) {
 111                 lseek(mdstat_fd, 0L, 0);
 112                 f = fdopen(dup(mdstat_fd), "r");
 113         } else
 114                 f = fopen("/proc/mdstat", "r");
 115         if (f == NULL)
 116                 return NULL;
 117
 118         all = NULL;
 119         end = &all;
 120         for (; (line = conf_line(f)) ; free_line(line)) {
 121                 struct mdstat_ent *ent;
 122                 char *w;
 123                 int devnum;
 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                 /* Better be an md line.. */
 133                 if (strncmp(line, "md", 2)!= 0)
 134                         continue;
 135                 if (strncmp(line, "md_d", 4) == 0)
 136                         devnum = -1-strtoul(line+4, &ep, 10);
 137                 else if (strncmp(line, "md", 2) == 0)
 138                         devnum = strtoul(line+2, &ep, 10);
 139                 else
 140                         continue;
 141                 if (ep == NULL || *ep ) {
 142                         /* fprintf(stderr, Name ": bad /proc/mdstat line starts: %s\n", line); */
 143                         continue;
 144                 }
 145
 146                 ent = malloc(sizeof(*ent));
 147                 if (!ent) {
 148                         fprintf(stderr, Name ": malloc failed reading /proc/mdstat.\n");
 149                         free_line(line);
 150                         break;
 151                 }
 152                 ent->dev = ent->level = ent->pattern= NULL;
 153                 ent->next = NULL;
 154                 ent->percent = -1;
 155                 ent->active = -1;
 156                 ent->resync = 0;
 157
 158                 ent->dev = strdup(line);
 159                 ent->devnum = devnum;
 160
 161                 for (w=dl_next(line); w!= line ; w=dl_next(w)) {
 162                         int l = strlen(w);
 163                         char *eq;
 164                         if (strcmp(w, "active")==0)
 165                                 ent->active = 1;
 166                         else if (strcmp(w, "inactive")==0)
 167                                 ent->active = 0;
 168                         else if (ent->active >=0 &&
 169                                  ent->level == NULL &&
 170                                  w[0] != '(' /*readonly*/)
 171                                 ent->level = strdup(w);
 172                         else if (!ent->pattern &&
 173                                  w[0] == '[' &&
 174                                  (w[1] == 'U' || w[1] == '_')) {
 175                                 ent->pattern = strdup(w+1);
 176                                 if (ent->pattern[l-2]==']')
 177                                         ent->pattern[l-2] = '\0';
 178                         } else if (ent->percent == -1 &&
 179                                    strncmp(w, "re", 2)== 0 &&
 180                                    w[l-1] == '%' &&
 181                                    (eq=strchr(w, '=')) != NULL ) {
 182                                 ent->percent = atoi(eq+1);
 183                                 if (strncmp(w,"resync", 4)==0)
 184                                         ent->resync = 1;
 185                         } else if (ent->percent == -1 &&
 186                                    strncmp(w, "resync", 4)==0) {
 187                                 ent->resync = 1;
 188                         } else if (ent->percent == -1 &&
 189                                    w[0] >= '0' &&
 190                                    w[0] <= '9' &&
 191                                    w[l-1] == '%') {
 192                                 ent->percent = atoi(w);
 193                         }
 194                 }
 195                 *end = ent;
 196                 end = &ent->next;
 197         }
 198         if (hold && mdstat_fd == -1)
 199                 mdstat_fd = dup(fileno(f));
 200         fclose(f);
 201         return all;
 202 }
 203
 204 void mdstat_wait(int seconds)
 205 {
 206         fd_set fds;
 207         struct timeval tm;
 208         FD_ZERO(&fds);
 209         if (mdstat_fd >= 0)
 210                 FD_SET(mdstat_fd, &fds);
 211         tm.tv_sec = seconds;
 212         tm.tv_usec = 0;
 213         select(mdstat_fd >2 ? mdstat_fd+1:3, NULL, NULL, &fds, &tm);
 214 }