Monitor.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@cse.unsw.edu.au>
  23  *    Paper: Neil Brown
  24  *           School of Computer Science and Engineering
  25  *           The University of New South Wales
  26  *           Sydney, 2052
  27  *           Australia
  28  */
  29
  30 #include        "mdadm.h"
  31 #include        "md_p.h"
  32 #include        "md_u.h"
  33 #include        <sys/wait.h>
  34 #include        <sys/signal.h>
  35
  36 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *cmd);
  37
  38 static char *percentalerts[] = {
  39         "RebuildStarted",
  40         "Rebuild20",
  41         "Rebuild40",
  42         "Rebuild60",
  43         "Rebuild80",
  44 };
  45
  46 int Monitor(mddev_dev_t devlist,
  47             char *mailaddr, char *alert_cmd,
  48             int period, int daemonise, int scan, int oneshot,
  49             char *config)
  50 {
  51         /*
  52          * Every few seconds, scan every md device looking for changes
  53          * When a change is found, log it, possibly run the alert command,
  54          * and possibly send Email
  55          *
  56          * For each array, we record:
  57          *   Update time
  58          *   active/working/failed/spare drives
  59          *   State of each device.
  60          *   %rebuilt if rebuilding
  61          *
  62          * If the update time changes, check out all the data again
  63          * It is possible that we cannot get the state of each device
  64          * due to bugs in the md kernel module.
  65          * We also read /proc/mdstat to get rebuild percent,
  66          * and to get state on all active devices incase of kernel bug.
  67          *
  68          * Events are:
  69          *    Fail
  70          *      An active device had Faulty set or Active/Sync removed
  71          *    FailSpare
  72          *      A spare device had Faulty set
  73          *    SpareActive
  74          *      An active device had a reverse transition
  75          *    RebuildStarted
  76          *      percent went from -1 to +ve
  77          *    Rebuild20 Rebuild40 Rebuild60 Rebuild80
  78          *      percent went from below to not-below that number
  79          *    DeviceDisappeared
  80          *      Couldn't access a device which was previously visible
  81          *
  82          * if we detect an array with active<raid and spare==0
  83          * we look at other arrays that have same spare-group
  84          * If we find one with active==raid and spare>0,
  85          *  and if we can get_disk_info and find a name
  86          *  Then we hot-remove and hot-add to the other array
  87          *
  88          * If devlist is NULL, then we can monitor everything because --scan
  89          * was given.  We get an initial list from config file and add anything
  90          * that appears in /proc/mdstat
  91          */
  92
  93         struct state {
  94                 char *devname;
  95                 int devnum;     /* to sync with mdstat info */
  96                 long utime;
  97                 int err;
  98                 char *spare_group;
  99                 int active, working, failed, spare, raid;
 100                 int expected_spares;
 101                 int devstate[MD_SB_DISKS];
 102                 int devid[MD_SB_DISKS];
 103                 int percent;
 104                 struct state *next;
 105         } *statelist = NULL;
 106         int finished = 0;
 107         struct mdstat_ent *mdstat = NULL;
 108
 109         if (!mailaddr) {
 110                 mailaddr = conf_get_mailaddr(config);
 111                 if (mailaddr && ! scan)
 112                         fprintf(stderr, Name ": Monitor using email address \"%s\" from config file\n",
 113                                mailaddr);
 114         }
 115         if (!alert_cmd) {
 116                 alert_cmd = conf_get_program(config);
 117                 if (alert_cmd && ! scan)
 118                         fprintf(stderr, Name ": Monitor using program \"%s\" from config file\n",
 119                                alert_cmd);
 120         }
 121         if (scan && !mailaddr && !alert_cmd) {
 122                 fprintf(stderr, Name ": No mail address or alert command - not monitoring.\n");
 123                 return 1;
 124         }
 125
 126         if (daemonise) {
 127                 int pid = fork();
 128                 if (pid > 0) {
 129                         printf("%d\n", pid);
 130                         return 0;
 131                 }
 132                 if (pid < 0) {
 133                         perror("daemonise");
 134                         return 1;
 135                 }
 136                 close(0);
 137                 open("/dev/null", 3);
 138                 dup2(0,1);
 139                 dup2(0,2);
 140                 setsid();
 141         }
 142
 143         if (devlist == NULL) {
 144                 mddev_ident_t mdlist = conf_get_ident(config, NULL);
 145                 for (; mdlist; mdlist=mdlist->next) {
 146                         struct state *st = malloc(sizeof *st);
 147                         if (st == NULL)
 148                                 continue;
 149                         st->devname = strdup(mdlist->devname);
 150                         st->utime = 0;
 151                         st->next = statelist;
 152                         st->err = 0;
 153                         st->devnum = -1;
 154                         st->percent = -2;
 155                         st->expected_spares = mdlist->spare_disks;
 156                         if (mdlist->spare_group)
 157                                 st->spare_group = strdup(mdlist->spare_group);
 158                         else
 159                                 st->spare_group = NULL;
 160                         statelist = st;
 161                 }
 162         } else {
 163                 mddev_dev_t dv;
 164                 for (dv=devlist ; dv; dv=dv->next) {
 165                         struct state *st = malloc(sizeof *st);
 166                         if (st == NULL)
 167                                 continue;
 168                         st->devname = strdup(dv->devname);
 169                         st->utime = 0;
 170                         st->next = statelist;
 171                         st->err = 0;
 172                         st->devnum = -1;
 173                         st->percent = -2;
 174                         st->expected_spares = -1;
 175                         st->spare_group = NULL;
 176                         statelist = st;
 177                 }
 178         }
 179
 180
 181         while (! finished) {
 182                 int new_found = 0;
 183                 struct state *st;
 184
 185                 if (mdstat)
 186                         free_mdstat(mdstat);
 187                 mdstat = mdstat_read();
 188
 189                 for (st=statelist; st; st=st->next) {
 190                         mdu_array_info_t array;
 191                         struct mdstat_ent *mse;
 192                         char *dev = st->devname;
 193                         int fd;
 194                         int i;
 195
 196                         fd = open(dev, O_RDONLY);
 197                         if (fd < 0) {
 198                                 if (!st->err)
 199                                         alert("DeviceDisappeared", dev, NULL,
 200                                               mailaddr, alert_cmd);
 201 /*                                      fprintf(stderr, Name ": cannot open %s: %s\n",
 202                                                 dev, strerror(errno));
 203 */                              st->err=1;
 204                                 continue;
 205                         }
 206                         if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
 207                                 if (!st->err)
 208                                         alert("DeviceDisappeared", dev, NULL,
 209                                               mailaddr, alert_cmd);
 210 /*                                      fprintf(stderr, Name ": cannot get array info for %s: %s\n",
 211                                                 dev, strerror(errno));
 212 */                              st->err=1;
 213                                 close(fd);
 214                                 continue;
 215                         }
 216                         if (array.level != 1 && array.level != 5 && array.level != -4) {
 217                                 if (!st->err)
 218                                         alert("DeviceDisappeared", dev, "Wrong-Level",
 219                                               mailaddr, alert_cmd);
 220                                 st->err = 1;
 221                                 close(fd);
 222                                 continue;
 223                         }
 224                         if (st->devnum < 0) {
 225                                 struct stat stb;
 226                                 if (fstat(fd, &stb) == 0 &&
 227                                     (S_IFMT&stb.st_mode)==S_IFBLK)
 228                                         st->devnum = MINOR(stb.st_rdev);
 229                         }
 230
 231                         for (mse = mdstat ; mse ; mse=mse->next)
 232                                 if (mse->devnum == st->devnum) {
 233                                         mse->devnum = -1; /* flag it as "used" */
 234                                         break;
 235                                 }
 236
 237                         if (st->utime == array.utime &&
 238                             st->failed == array.failed_disks &&
 239                             st->working == array.working_disks &&
 240                             st->spare == array.spare_disks &&
 241                             (mse == NULL  || (
 242                                     mse->percent == st->percent
 243                                     ))) {
 244                                 close(fd);
 245                                 st->err = 0;
 246                                 continue;
 247                         }
 248                         if (st->utime == 0 && /* new array */
 249                             mse &&      /* is in /proc/mdstat */
 250                             mse->pattern && strchr(mse->pattern, '_') /* degraded */
 251                                 )
 252                                 alert("DegradedArray", dev, NULL, mailaddr, alert_cmd);
 253
 254                         if (st->utime == 0 && /* new array */
 255                             st->expected_spares > 0 &&
 256                             array.spare_disks < st->expected_spares)
 257                                 alert("SparesMissing", dev, NULL, mailaddr, alert_cmd);
 258                         if (mse &&
 259                             st->percent == -1 &&
 260                             mse->percent >= 0)
 261                                 alert("RebuildStarted", dev, NULL, mailaddr, alert_cmd);
 262                         if (mse &&
 263                             st->percent >= 0 &&
 264                             mse->percent >= 0 &&
 265                             (mse->percent / 20) > (st->percent / 20))
 266                                 alert(percentalerts[mse->percent/20],
 267                                       dev, NULL, mailaddr, alert_cmd);
 268
 269                         if (mse)
 270                                 st->percent = mse->percent;
 271
 272                         for (i=0; i<MD_SB_DISKS; i++) {
 273                                 mdu_disk_info_t disc;
 274                                 int newstate=0;
 275                                 int change;
 276                                 char *dv = NULL;
 277                                 disc.number = i;
 278                                 if (ioctl(fd, GET_DISK_INFO, &disc)>= 0) {
 279                                         newstate = disc.state;
 280                                         dv = map_dev(disc.major, disc.minor);
 281                                 } else if (mse &&  mse->pattern && i < strlen(mse->pattern))
 282                                         switch(mse->pattern[i]) {
 283                                         case 'U': newstate = 6 /* ACTIVE/SYNC */; break;
 284                                         case '_': newstate = 0; break;
 285                                         }
 286                                 change = newstate ^ st->devstate[i];
 287                                 if (st->utime && change && !st->err) {
 288                                         if (i < array.raid_disks &&
 289                                             (((newstate&change)&(1<<MD_DISK_FAULTY)) ||
 290                                              ((st->devstate[i]&change)&(1<<MD_DISK_ACTIVE)) ||
 291                                              ((st->devstate[i]&change)&(1<<MD_DISK_SYNC)))
 292                                                 )
 293                                                 alert("Fail", dev, dv, mailaddr, alert_cmd);
 294                                         else if (i>=array.raid_disks &&
 295                                                  (disc.major || disc.minor) &&
 296                                                  st->devid[i] == MKDEV(disc.major, disc.minor) &&
 297                                                  ((newstate&change)&(1<<MD_DISK_FAULTY))
 298                                                 )
 299                                                 alert("FailSpare", dev, dv, mailaddr, alert_cmd);
 300                                         else if (i < array.raid_disks &&
 301                                                  (((st->devstate[i]&change)&(1<<MD_DISK_FAULTY)) ||
 302                                                   ((newstate&change)&(1<<MD_DISK_ACTIVE)) ||
 303                                                   ((newstate&change)&(1<<MD_DISK_SYNC)))
 304                                                 )
 305                                                 alert("SpareActive", dev, dv, mailaddr, alert_cmd);
 306                                 }
 307                                 st->devstate[i] = disc.state;
 308                                 st->devid[i] = MKDEV(disc.major, disc.minor);
 309                         }
 310                         close(fd);
 311                         st->active = array.active_disks;
 312                         st->working = array.working_disks;
 313                         st->spare = array.spare_disks;
 314                         st->failed = array.failed_disks;
 315                         st->utime = array.utime;
 316                         st->raid = array.raid_disks;
 317                         st->err = 0;
 318                 }
 319                 /* now check if there are any new devices found in mdstat */
 320                 if (scan) {
 321                         struct mdstat_ent *mse;
 322                         for (mse=mdstat; mse; mse=mse->next)
 323                                 if (mse->devnum >= 0 &&
 324                                     (strcmp(mse->level, "raid1")==0 ||
 325                                      strcmp(mse->level, "raid5")==0 ||
 326                                      strcmp(mse->level, "multipath")==0)
 327                                         ) {
 328                                         struct state *st = malloc(sizeof *st);
 329                                         if (st == NULL)
 330                                                 continue;
 331                                         st->devname = strdup(get_md_name(mse->devnum));
 332                                         st->utime = 0;
 333                                         st->next = statelist;
 334                                         st->err = 1;
 335                                         st->devnum = mse->devnum;
 336                                         st->percent = -2;
 337                                         st->spare_group = NULL;
 338                                         statelist = st;
 339                                         alert("NewArray", st->devname, NULL, mailaddr, alert_cmd);
 340                                         new_found = 1;
 341                                 }
 342                 }
 343                 /* If an array has active < raid && spare == 0 && spare_group != NULL
 344                  * Look for another array with spare > 0 and active == raid and same spare_group
 345                  *  if found, choose a device and hotremove/hotadd
 346                  */
 347                 for (st = statelist; st; st=st->next)
 348                         if (st->active < st->raid &&
 349                             st->spare == 0 &&
 350                             st->spare_group != NULL) {
 351                                 struct state *st2;
 352                                 for (st2=statelist ; st2 ; st2=st2->next)
 353                                         if (st2 != st &&
 354                                             st2->spare > 0 &&
 355                                             st2->active == st2->raid &&
 356                                             st2->spare_group != NULL &&
 357                                             strcmp(st->spare_group, st2->spare_group) == 0) {
 358                                                 /* try to remove and add */
 359                                                 int fd1 = open(st->devname, O_RDONLY);
 360                                                 int fd2 = open(st2->devname, O_RDONLY);
 361                                                 int dev = -1;
 362                                                 int d;
 363                                                 if (fd1 < 0 || fd2 < 0) {
 364                                                         if (fd1>=0) close(fd1);
 365                                                         if (fd2>=0) close(fd2);
 366                                                         continue;
 367                                                 }
 368                                                 for (d=st2->raid; d<MD_SB_DISKS; d++) {
 369                                                         if (st2->devid[d] > 0 &&
 370                                                             st2->devstate[d] == 0) {
 371                                                                 dev = st2->devid[d];
 372                                                                 break;
 373                                                         }
 374                                                 }
 375                                                 if (dev > 0) {
 376                                                         if (ioctl(fd2, HOT_REMOVE_DISK,
 377                                                                   (unsigned long)dev) == 0) {
 378                                                                 if (ioctl(fd1, HOT_ADD_DISK,
 379                                                                           (unsigned long)dev) == 0) {
 380                                                                         alert("MoveSpare", st->devname, st2->devname, mailaddr, alert_cmd);
 381                                                                         close(fd1);
 382                                                                         close(fd2);
 383                                                                         break;
 384                                                                 }
 385                                                                 else ioctl(fd2, HOT_ADD_DISK, (unsigned long) dev);
 386                                                         }
 387                                                 }
 388                                                 close(fd1);
 389                                                 close(fd2);
 390                                         }
 391                         }
 392                 if (!new_found) {
 393                         if (oneshot)
 394                                 break;
 395                         else
 396                                 sleep(period);
 397                 }
 398         }
 399         return 0;
 400 }
 401
 402
 403 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *cmd)
 404 {
 405         if (!cmd && !mailaddr) {
 406                 time_t now = time(0);
 407
 408                 printf("%1.15s: %s on %s %s\n", ctime(&now)+4, event, dev, disc?disc:"unknown device");
 409         }
 410         if (cmd) {
 411                 int pid = fork();
 412                 switch(pid) {
 413                 default:
 414                         waitpid(pid, NULL, 0);
 415                         break;
 416                 case -1:
 417                         break;
 418                 case 0:
 419                         execl(cmd, cmd, event, dev, disc, NULL);
 420                         exit(2);
 421                 }
 422         }
 423         if (mailaddr &&
 424             (strncmp(event, "Fail", 4)==0 ||
 425              strncmp(event, "Degrade", 7)==0)) {
 426                 FILE *mp = popen(Sendmail, "w");
 427                 if (mp) {
 428                         char hname[256];
 429                         gethostname(hname, sizeof(hname));
 430                         signal(SIGPIPE, SIG_IGN);
 431                         fprintf(mp, "From: " Name " monitoring <root>\n");
 432                         fprintf(mp, "To: %s\n", mailaddr);
 433                         fprintf(mp, "Subject: %s event on %s:%s\n\n", event, dev, hname);
 434
 435                         fprintf(mp, "This is an automatically generated mail message from " Name "\n");
 436                         fprintf(mp, "running on %s\n\n", hname);
 437
 438                         fprintf(mp, "A %s event had been detected on md device %s.\n\n", event, dev);
 439
 440                         if (disc)
 441                                 fprintf(mp, "It could be related to component device %s.\n\n", disc);
 442
 443                         fprintf(mp, "Faithfully yours, etc.\n");
 444                         fclose(mp);
 445                 }
 446
 447         }
 448         /* FIXME log the event to syslog maybe */
 449 }