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 #include        <values.h>
  36
  37 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *cmd);
  38
  39 static char *percentalerts[] = {
  40         "RebuildStarted",
  41         "Rebuild20",
  42         "Rebuild40",
  43         "Rebuild60",
  44         "Rebuild80",
  45 };
  46
  47 int Monitor(mddev_dev_t devlist,
  48             char *mailaddr, char *alert_cmd,
  49             int period, int daemonise, int scan, int oneshot,
  50             char *config, int test)
  51 {
  52         /*
  53          * Every few seconds, scan every md device looking for changes
  54          * When a change is found, log it, possibly run the alert command,
  55          * and possibly send Email
  56          *
  57          * For each array, we record:
  58          *   Update time
  59          *   active/working/failed/spare drives
  60          *   State of each device.
  61          *   %rebuilt if rebuilding
  62          *
  63          * If the update time changes, check out all the data again
  64          * It is possible that we cannot get the state of each device
  65          * due to bugs in the md kernel module.
  66          * We also read /proc/mdstat to get rebuild percent,
  67          * and to get state on all active devices incase of kernel bug.
  68          *
  69          * Events are:
  70          *    Fail
  71          *      An active device had Faulty set or Active/Sync removed
  72          *    FailSpare
  73          *      A spare device had Faulty set
  74          *    SpareActive
  75          *      An active device had a reverse transition
  76          *    RebuildStarted
  77          *      percent went from -1 to +ve
  78          *    Rebuild20 Rebuild40 Rebuild60 Rebuild80
  79          *      percent went from below to not-below that number
  80          *    DeviceDisappeared
  81          *      Couldn't access a device which was previously visible
  82          *
  83          * if we detect an array with active<raid and spare==0
  84          * we look at other arrays that have same spare-group
  85          * If we find one with active==raid and spare>0,
  86          *  and if we can get_disk_info and find a name
  87          *  Then we hot-remove and hot-add to the other array
  88          *
  89          * If devlist is NULL, then we can monitor everything because --scan
  90          * was given.  We get an initial list from config file and add anything
  91          * that appears in /proc/mdstat
  92          */
  93
  94         struct state {
  95                 char *devname;
  96                 int devnum;     /* to sync with mdstat info */
  97                 long utime;
  98                 int err;
  99                 char *spare_group;
 100                 int active, working, failed, spare, raid;
 101                 int expected_spares;
 102                 int devstate[MD_SB_DISKS];
 103                 int devid[MD_SB_DISKS];
 104                 int percent;
 105                 struct state *next;
 106         } *statelist = NULL;
 107         int finished = 0;
 108         struct mdstat_ent *mdstat = NULL;
 109
 110         if (!mailaddr) {
 111                 mailaddr = conf_get_mailaddr(config);
 112                 if (mailaddr && ! scan)
 113                         fprintf(stderr, Name ": Monitor using email address \"%s\" from config file\n",
 114                                mailaddr);
 115         }
 116         if (!alert_cmd) {
 117                 alert_cmd = conf_get_program(config);
 118                 if (alert_cmd && ! scan)
 119                         fprintf(stderr, Name ": Monitor using program \"%s\" from config file\n",
 120                                alert_cmd);
 121         }
 122         if (scan && !mailaddr && !alert_cmd) {
 123                 fprintf(stderr, Name ": No mail address or alert command - not monitoring.\n");
 124                 return 1;
 125         }
 126
 127         if (daemonise) {
 128                 int pid = fork();
 129                 if (pid > 0) {
 130                         printf("%d\n", pid);
 131                         return 0;
 132                 }
 133                 if (pid < 0) {
 134                         perror("daemonise");
 135                         return 1;
 136                 }
 137                 close(0);
 138                 open("/dev/null", 3);
 139                 dup2(0,1);
 140                 dup2(0,2);
 141                 setsid();
 142         }
 143
 144         if (devlist == NULL) {
 145                 mddev_ident_t mdlist = conf_get_ident(config, NULL);
 146                 for (; mdlist; mdlist=mdlist->next) {
 147                         struct state *st = malloc(sizeof *st);
 148                         if (st == NULL)
 149                                 continue;
 150                         st->devname = strdup(mdlist->devname);
 151                         st->utime = 0;
 152                         st->next = statelist;
 153                         st->err = 0;
 154                         st->devnum = MAXINT;
 155                         st->percent = -2;
 156                         st->expected_spares = mdlist->spare_disks;
 157                         if (mdlist->spare_group)
 158                                 st->spare_group = strdup(mdlist->spare_group);
 159                         else
 160                                 st->spare_group = NULL;
 161                         statelist = st;
 162                 }
 163         } else {
 164                 mddev_dev_t dv;
 165                 for (dv=devlist ; dv; dv=dv->next) {
 166                         struct state *st = malloc(sizeof *st);
 167                         if (st == NULL)
 168                                 continue;
 169                         st->devname = strdup(dv->devname);
 170                         st->utime = 0;
 171                         st->next = statelist;
 172                         st->err = 0;
 173                         st->devnum = MAXINT;
 174                         st->percent = -2;
 175                         st->expected_spares = -1;
 176                         st->spare_group = NULL;
 177                         statelist = st;
 178                 }
 179         }
 180
 181
 182         while (! finished) {
 183                 int new_found = 0;
 184                 struct state *st;
 185
 186                 if (mdstat)
 187                         free_mdstat(mdstat);
 188                 mdstat = mdstat_read(oneshot?0:1);
 189
 190                 for (st=statelist; st; st=st->next) {
 191                         mdu_array_info_t array;
 192                         struct mdstat_ent *mse = NULL, *mse2;
 193                         char *dev = st->devname;
 194                         int fd;
 195                         unsigned int i;
 196
 197                         if (test)
 198                                 alert("TestMessage", dev, NULL, mailaddr, alert_cmd);
 199                         fd = open(dev, O_RDONLY);
 200                         if (fd < 0) {
 201                                 if (!st->err)
 202                                         alert("DeviceDisappeared", dev, NULL,
 203                                               mailaddr, alert_cmd);
 204 /*                                      fprintf(stderr, Name ": cannot open %s: %s\n",
 205                                                 dev, strerror(errno));
 206 */                              st->err=1;
 207                                 continue;
 208                         }
 209                         if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
 210                                 if (!st->err)
 211                                         alert("DeviceDisappeared", dev, NULL,
 212                                               mailaddr, alert_cmd);
 213 /*                                      fprintf(stderr, Name ": cannot get array info for %s: %s\n",
 214                                                 dev, strerror(errno));
 215 */                              st->err=1;
 216                                 close(fd);
 217                                 continue;
 218                         }
 219                         if (array.level != 1 && array.level != 5 && array.level != -4) {
 220                                 if (!st->err)
 221                                         alert("DeviceDisappeared", dev, "Wrong-Level",
 222                                               mailaddr, alert_cmd);
 223                                 st->err = 1;
 224                                 close(fd);
 225                                 continue;
 226                         }
 227                         if (st->devnum == MAXINT) {
 228                                 struct stat stb;
 229                                 if (fstat(fd, &stb) == 0 &&
 230                                     (S_IFMT&stb.st_mode)==S_IFBLK) {
 231                                         if (MAJOR(stb.st_rdev) == MD_MAJOR)
 232                                                 st->devnum = MINOR(stb.st_rdev);
 233                                         else
 234                                                 st->devnum = -1- (MINOR(stb.st_rdev)>>6);
 235                                 }
 236                         }
 237
 238                         for (mse2 = mdstat ; mse2 ; mse2=mse2->next)
 239                                 if (mse2->devnum == st->devnum) {
 240                                         mse2->devnum = MAXINT; /* flag it as "used" */
 241                                         mse = mse2;
 242                                 }
 243
 244                         if (st->utime == array.utime &&
 245                             st->failed == array.failed_disks &&
 246                             st->working == array.working_disks &&
 247                             st->spare == array.spare_disks &&
 248                             (mse == NULL  || (
 249                                     mse->percent == st->percent
 250                                     ))) {
 251                                 close(fd);
 252                                 st->err = 0;
 253                                 continue;
 254                         }
 255                         if (st->utime == 0 && /* new array */
 256                             mse &&      /* is in /proc/mdstat */
 257                             mse->pattern && strchr(mse->pattern, '_') /* degraded */
 258                                 )
 259                                 alert("DegradedArray", dev, NULL, mailaddr, alert_cmd);
 260
 261                         if (st->utime == 0 && /* new array */
 262                             st->expected_spares > 0 &&
 263                             array.spare_disks < st->expected_spares)
 264                                 alert("SparesMissing", dev, NULL, mailaddr, alert_cmd);
 265                         if (mse &&
 266                             st->percent == -1 &&
 267                             mse->percent >= 0)
 268                                 alert("RebuildStarted", dev, NULL, mailaddr, alert_cmd);
 269                         if (mse &&
 270                             st->percent >= 0 &&
 271                             mse->percent >= 0 &&
 272                             (mse->percent / 20) > (st->percent / 20))
 273                                 alert(percentalerts[mse->percent/20],
 274                                       dev, NULL, mailaddr, alert_cmd);
 275
 276                         if (mse &&
 277                             mse->percent == -1 &&
 278                             st->percent >= 0)
 279                                 alert("RebuildFinished", dev, NULL, mailaddr, alert_cmd);
 280
 281                         if (mse)
 282                                 st->percent = mse->percent;
 283
 284                         for (i=0; i<MD_SB_DISKS; i++) {
 285                                 mdu_disk_info_t disc;
 286                                 int newstate=0;
 287                                 int change;
 288                                 char *dv = NULL;
 289                                 disc.number = i;
 290                                 if (ioctl(fd, GET_DISK_INFO, &disc)>= 0) {
 291                                         newstate = disc.state;
 292                                         dv = map_dev(disc.major, disc.minor);
 293                                 } else if (mse &&  mse->pattern && i < strlen(mse->pattern))
 294                                         switch(mse->pattern[i]) {
 295                                         case 'U': newstate = 6 /* ACTIVE/SYNC */; break;
 296                                         case '_': newstate = 0; break;
 297                                         }
 298                                 change = newstate ^ st->devstate[i];
 299                                 if (st->utime && change && !st->err) {
 300                                         if (i < (unsigned)array.raid_disks &&
 301                                             (((newstate&change)&(1<<MD_DISK_FAULTY)) ||
 302                                              ((st->devstate[i]&change)&(1<<MD_DISK_ACTIVE)) ||
 303                                              ((st->devstate[i]&change)&(1<<MD_DISK_SYNC)))
 304                                                 )
 305                                                 alert("Fail", dev, dv, mailaddr, alert_cmd);
 306                                         else if (i >= (unsigned)array.raid_disks &&
 307                                                  (disc.major || disc.minor) &&
 308                                                  st->devid[i] == MKDEV(disc.major, disc.minor) &&
 309                                                  ((newstate&change)&(1<<MD_DISK_FAULTY))
 310                                                 )
 311                                                 alert("FailSpare", dev, dv, mailaddr, alert_cmd);
 312                                         else if (i < (unsigned)array.raid_disks &&
 313                                                  (((st->devstate[i]&change)&(1<<MD_DISK_FAULTY)) ||
 314                                                   ((newstate&change)&(1<<MD_DISK_ACTIVE)) ||
 315                                                   ((newstate&change)&(1<<MD_DISK_SYNC)))
 316                                                 )
 317                                                 alert("SpareActive", dev, dv, mailaddr, alert_cmd);
 318                                 }
 319                                 st->devstate[i] = disc.state;
 320                                 st->devid[i] = MKDEV(disc.major, disc.minor);
 321                         }
 322                         close(fd);
 323                         st->active = array.active_disks;
 324                         st->working = array.working_disks;
 325                         st->spare = array.spare_disks;
 326                         st->failed = array.failed_disks;
 327                         st->utime = array.utime;
 328                         st->raid = array.raid_disks;
 329                         st->err = 0;
 330                 }
 331                 /* now check if there are any new devices found in mdstat */
 332                 if (scan) {
 333                         struct mdstat_ent *mse;
 334                         for (mse=mdstat; mse; mse=mse->next)
 335                                 if (mse->devnum != MAXINT &&
 336                                     (strcmp(mse->level, "raid1")==0 ||
 337                                      strcmp(mse->level, "raid5")==0 ||
 338                                      strcmp(mse->level, "multipath")==0)
 339                                         ) {
 340                                         struct state *st = malloc(sizeof *st);
 341                                         mdu_array_info_t array;
 342                                         int fd;
 343                                         if (st == NULL)
 344                                                 continue;
 345                                         st->devname = strdup(get_md_name(mse->devnum));
 346                                         if ((fd = open(st->devname, O_RDONLY)) < 0 ||
 347                                             ioctl(fd, GET_ARRAY_INFO, &array)< 0) {
 348                                                 /* no such array */
 349                                                 if (fd >=0) close(fd);
 350                                                 free(st->devname);
 351                                                 free(st);
 352                                                 continue;
 353                                         }
 354                                         close(fd);
 355                                         st->utime = 0;
 356                                         st->next = statelist;
 357                                         st->err = 1;
 358                                         st->devnum = mse->devnum;
 359                                         st->percent = -2;
 360                                         st->spare_group = NULL;
 361                                         st->expected_spares = -1;
 362                                         statelist = st;
 363                                         alert("NewArray", st->devname, NULL, mailaddr, alert_cmd);
 364                                         new_found = 1;
 365                                 }
 366                 }
 367                 /* If an array has active < raid && spare == 0 && spare_group != NULL
 368                  * Look for another array with spare > 0 and active == raid and same spare_group
 369                  *  if found, choose a device and hotremove/hotadd
 370                  */
 371                 for (st = statelist; st; st=st->next)
 372                         if (st->active < st->raid &&
 373                             st->spare == 0 &&
 374                             st->spare_group != NULL) {
 375                                 struct state *st2;
 376                                 for (st2=statelist ; st2 ; st2=st2->next)
 377                                         if (st2 != st &&
 378                                             st2->spare > 0 &&
 379                                             st2->active == st2->raid &&
 380                                             st2->spare_group != NULL &&
 381                                             strcmp(st->spare_group, st2->spare_group) == 0) {
 382                                                 /* try to remove and add */
 383                                                 int fd1 = open(st->devname, O_RDONLY);
 384                                                 int fd2 = open(st2->devname, O_RDONLY);
 385                                                 int dev = -1;
 386                                                 int d;
 387                                                 if (fd1 < 0 || fd2 < 0) {
 388                                                         if (fd1>=0) close(fd1);
 389                                                         if (fd2>=0) close(fd2);
 390                                                         continue;
 391                                                 }
 392                                                 for (d=st2->raid; d<MD_SB_DISKS; d++) {
 393                                                         if (st2->devid[d] > 0 &&
 394                                                             st2->devstate[d] == 0) {
 395                                                                 dev = st2->devid[d];
 396                                                                 break;
 397                                                         }
 398                                                 }
 399                                                 if (dev > 0) {
 400                                                         if (ioctl(fd2, HOT_REMOVE_DISK,
 401                                                                   (unsigned long)dev) == 0) {
 402                                                                 if (ioctl(fd1, HOT_ADD_DISK,
 403                                                                           (unsigned long)dev) == 0) {
 404                                                                         alert("MoveSpare", st->devname, st2->devname, mailaddr, alert_cmd);
 405                                                                         close(fd1);
 406                                                                         close(fd2);
 407                                                                         break;
 408                                                                 }
 409                                                                 else ioctl(fd2, HOT_ADD_DISK, (unsigned long) dev);
 410                                                         }
 411                                                 }
 412                                                 close(fd1);
 413                                                 close(fd2);
 414                                         }
 415                         }
 416                 if (!new_found) {
 417                         if (oneshot)
 418                                 break;
 419                         else
 420                                 mdstat_wait(period);
 421                 }
 422                 test = 0;
 423         }
 424         return 0;
 425 }
 426
 427
 428 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *cmd)
 429 {
 430         if (!cmd && !mailaddr) {
 431                 time_t now = time(0);
 432
 433                 printf("%1.15s: %s on %s %s\n", ctime(&now)+4, event, dev, disc?disc:"unknown device");
 434         }
 435         if (cmd) {
 436                 int pid = fork();
 437                 switch(pid) {
 438                 default:
 439                         waitpid(pid, NULL, 0);
 440                         break;
 441                 case -1:
 442                         break;
 443                 case 0:
 444                         execl(cmd, cmd, event, dev, disc, NULL);
 445                         exit(2);
 446                 }
 447         }
 448         if (mailaddr &&
 449             (strncmp(event, "Fail", 4)==0 ||
 450              strncmp(event, "Test", 4)==0 ||
 451              strncmp(event, "Degrade", 7)==0)) {
 452                 FILE *mp = popen(Sendmail, "w");
 453                 if (mp) {
 454                         char hname[256];
 455                         gethostname(hname, sizeof(hname));
 456                         signal(SIGPIPE, SIG_IGN);
 457                         fprintf(mp, "From: " Name " monitoring <root>\n");
 458                         fprintf(mp, "To: %s\n", mailaddr);
 459                         fprintf(mp, "Subject: %s event on %s:%s\n\n", event, dev, hname);
 460
 461                         fprintf(mp, "This is an automatically generated mail message from " Name "\n");
 462                         fprintf(mp, "running on %s\n\n", hname);
 463
 464                         fprintf(mp, "A %s event had been detected on md device %s.\n\n", event, dev);
 465
 466                         if (disc)
 467                                 fprintf(mp, "It could be related to component device %s.\n\n", disc);
 468
 469                         fprintf(mp, "Faithfully yours, etc.\n");
 470                         fclose(mp);
 471                 }
 472
 473         }
 474         /* FIXME log the event to syslog maybe */
 475 }