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,
  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 devstate[MD_SB_DISKS];
 101                 int devid[MD_SB_DISKS];
 102                 int percent;
 103                 struct state *next;
 104         } *statelist = NULL;
 105         int finished = 0;
 106         struct mdstat_ent *mdstat = NULL;
 107
 108         if (!mailaddr) {
 109                 mailaddr = conf_get_mailaddr(config);
 110                 if (mailaddr && ! scan)
 111                         fprintf(stderr, Name ": Monitor using email address \"%s\" from config file\n",
 112                                mailaddr);
 113         }
 114         if (!alert_cmd) {
 115                 alert_cmd = conf_get_program(config);
 116                 if (alert_cmd && ! scan)
 117                         fprintf(stderr, Name ": Monitor using program \"%s\" from config file\n",
 118                                alert_cmd);
 119         }
 120         if (scan && !mailaddr && !alert_cmd) {
 121                 fprintf(stderr, Name ": No mail address or alert command - not monitoring.\n");
 122                 return 1;
 123         }
 124
 125         if (daemonise) {
 126                 int pid = fork();
 127                 if (pid > 0) {
 128                         printf("%d\n", pid);
 129                         return 0;
 130                 }
 131                 if (pid < 0) {
 132                         perror("daemonise");
 133                         return 1;
 134                 }
 135                 close(0);
 136                 open("/dev/null", 3);
 137                 dup2(0,1);
 138                 dup2(0,2);
 139                 setsid();
 140         }
 141
 142         if (devlist == NULL) {
 143                 mddev_ident_t mdlist = conf_get_ident(config, NULL);
 144                 for (; mdlist; mdlist=mdlist->next) {
 145                         struct state *st = malloc(sizeof *st);
 146                         if (st == NULL)
 147                                 continue;
 148                         st->devname = strdup(mdlist->devname);
 149                         st->utime = 0;
 150                         st->next = statelist;
 151                         st->err = 0;
 152                         st->devnum = -1;
 153                         st->percent = -2;
 154                         if (mdlist->spare_group)
 155                                 st->spare_group = strdup(mdlist->spare_group);
 156                         else
 157                                 st->spare_group = NULL;
 158                         statelist = st;
 159                 }
 160         } else {
 161                 mddev_dev_t dv;
 162                 for (dv=devlist ; dv; dv=dv->next) {
 163                         struct state *st = malloc(sizeof *st);
 164                         if (st == NULL)
 165                                 continue;
 166                         st->devname = strdup(dv->devname);
 167                         st->utime = 0;
 168                         st->next = statelist;
 169                         st->err = 0;
 170                         st->devnum = -1;
 171                         st->percent = -2;
 172                         st->spare_group = NULL;
 173                         statelist = st;
 174                 }
 175         }
 176
 177
 178         while (! finished) {
 179                 struct state *st;
 180
 181                 if (mdstat)
 182                         free_mdstat(mdstat);
 183                 mdstat = mdstat_read();
 184
 185                 for (st=statelist; st; st=st->next) {
 186                         mdu_array_info_t array;
 187                         struct mdstat_ent *mse;
 188                         char *dev = st->devname;
 189                         int fd;
 190                         int i;
 191
 192                         fd = open(dev, O_RDONLY);
 193                         if (fd < 0) {
 194                                 if (!st->err)
 195                                         alert("DeviceDisappeared", dev, NULL,
 196                                               mailaddr, alert_cmd);
 197 /*                                      fprintf(stderr, Name ": cannot open %s: %s\n",
 198                                                 dev, strerror(errno));
 199 */                              st->err=1;
 200                                 continue;
 201                         }
 202                         if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
 203                                 if (!st->err)
 204                                         alert("DeviceDisappeared", dev, NULL,
 205                                               mailaddr, alert_cmd);
 206 /*                                      fprintf(stderr, Name ": cannot get array info for %s: %s\n",
 207                                                 dev, strerror(errno));
 208 */                              st->err=1;
 209                                 close(fd);
 210                                 continue;
 211                         }
 212                         if (array.level != 1 && array.level != 5 && array.level != -4) {
 213                                 if (!st->err)
 214                                         alert("DeviceDisappeared", dev, "Wrong-Level",
 215                                               mailaddr, alert_cmd);
 216                                 st->err = 1;
 217                                 close(fd);
 218                                 continue;
 219                         }
 220                         if (st->devnum < 0) {
 221                                 struct stat stb;
 222                                 if (fstat(fd, &stb) == 0 &&
 223                                     (S_IFMT&stb.st_mode)==S_IFBLK)
 224                                         st->devnum = MINOR(stb.st_rdev);
 225                         }
 226
 227                         for (mse = mdstat ; mse ; mse=mse->next)
 228                                 if (mse->devnum == st->devnum) {
 229                                         mse->devnum = -1; /* flag it as "used" */
 230                                         break;
 231                                 }
 232
 233                         if (st->utime == array.utime &&
 234                             st->failed == array.failed_disks &&
 235                             st->working == array.working_disks &&
 236                             st->spare == array.spare_disks &&
 237                             (mse == NULL  || (
 238                                     mse->percent == st->percent
 239                                     ))) {
 240                                 close(fd);
 241                                 st->err = 0;
 242                                 continue;
 243                         }
 244                         if (mse &&
 245                             st->percent == -1 &&
 246                             mse->percent >= 0)
 247                                 alert("RebuildStarted", dev, NULL, mailaddr, alert_cmd);
 248                         if (mse &&
 249                             st->percent >= 0 &&
 250                             mse->percent >= 0 &&
 251                             (mse->percent / 20) > (st->percent / 20))
 252                                 alert(percentalerts[mse->percent/20],
 253                                       dev, NULL, mailaddr, alert_cmd);
 254
 255                         if (mse)
 256                                 st->percent = mse->percent;
 257
 258                         for (i=0; i<MD_SB_DISKS; i++) {
 259                                 mdu_disk_info_t disc;
 260                                 int newstate=0;
 261                                 int change;
 262                                 char *dv = NULL;
 263                                 disc.number = i;
 264                                 if (ioctl(fd, GET_DISK_INFO, &disc)>= 0) {
 265                                         newstate = disc.state;
 266                                         dv = map_dev(disc.major, disc.minor);
 267                                 } else if (mse &&  mse->pattern && i < strlen(mse->pattern))
 268                                         switch(mse->pattern[i]) {
 269                                         case 'U': newstate = 6 /* ACTIVE/SYNC */; break;
 270                                         case '_': newstate = 0; break;
 271                                         }
 272                                 change = newstate ^ st->devstate[i];
 273                                 if (st->utime && change && !st->err) {
 274                                         if (i < array.raid_disks &&
 275                                             (((newstate&change)&(1<<MD_DISK_FAULTY)) ||
 276                                              ((st->devstate[i]&change)&(1<<MD_DISK_ACTIVE)) ||
 277                                              ((st->devstate[i]&change)&(1<<MD_DISK_SYNC)))
 278                                                 )
 279                                                 alert("Fail", dev, dv, mailaddr, alert_cmd);
 280                                         else if (i>=array.raid_disks &&
 281                                                  (disc.major || disc.minor) &&
 282                                                  st->devid[i] == MKDEV(disc.major, disc.minor) &&
 283                                                  ((newstate&change)&(1<<MD_DISK_FAULTY))
 284                                                 )
 285                                                 alert("FailSpare", dev, dv, mailaddr, alert_cmd);
 286                                         else if (i < array.raid_disks &&
 287                                                  (((st->devstate[i]&change)&(1<<MD_DISK_FAULTY)) ||
 288                                                   ((newstate&change)&(1<<MD_DISK_ACTIVE)) ||
 289                                                   ((newstate&change)&(1<<MD_DISK_SYNC)))
 290                                                 )
 291                                                 alert("SpareActive", dev, dv, mailaddr, alert_cmd);
 292                                 }
 293                                 st->devstate[i] = disc.state;
 294                                 st->devid[i] = MKDEV(disc.major, disc.minor);
 295                         }
 296                         close(fd);
 297                         st->active = array.active_disks;
 298                         st->working = array.working_disks;
 299                         st->spare = array.spare_disks;
 300                         st->failed = array.failed_disks;
 301                         st->utime = array.utime;
 302                         st->raid = array.raid_disks;
 303                         st->err = 0;
 304                 }
 305                 /* now check if there are any new devices found in mdstat */
 306                 if (scan) {
 307                         struct mdstat_ent *mse;
 308                         for (mse=mdstat; mse; mse=mse->next)
 309                                 if (mse->devnum >= 0 &&
 310                                     (strcmp(mse->level, "raid1")==0 ||
 311                                      strcmp(mse->level, "raid5")==0 ||
 312                                      strcmp(mse->level, "multipath")==0)
 313                                         ) {
 314                                         struct state *st = malloc(sizeof *st);
 315                                         if (st == NULL)
 316                                                 continue;
 317                                         st->devname = strdup(get_md_name(mse->devnum));
 318                                         st->utime = 0;
 319                                         st->next = statelist;
 320                                         st->err = 1;
 321                                         st->devnum = mse->devnum;
 322                                         st->percent = -2;
 323                                         st->spare_group = NULL;
 324                                         statelist = st;
 325                                         alert("NewArray", st->devname, NULL, mailaddr, alert_cmd);
 326                                 }
 327                 }
 328                 /* If an array has active < raid && spare == 0 && spare_group != NULL
 329                  * Look for another array with spare > 0 and active == raid and same spare_group
 330                  *  if found, choose a device and hotremove/hotadd
 331                  */
 332                 for (st = statelist; st; st=st->next)
 333                         if (st->active < st->raid &&
 334                             st->spare == 0 &&
 335                             st->spare_group != NULL) {
 336                                 struct state *st2;
 337                                 for (st2=statelist ; st2 ; st2=st2->next)
 338                                         if (st2 != st &&
 339                                             st2->spare > 0 &&
 340                                             st2->active == st2->raid &&
 341                                             st2->spare_group != NULL &&
 342                                             strcmp(st->spare_group, st2->spare_group) == 0) {
 343                                                 /* try to remove and add */
 344                                                 int fd1 = open(st->devname, O_RDONLY);
 345                                                 int fd2 = open(st2->devname, O_RDONLY);
 346                                                 int dev = -1;
 347                                                 int d;
 348                                                 if (fd1 < 0 || fd2 < 0) {
 349                                                         if (fd1>=0) close(fd1);
 350                                                         if (fd2>=0) close(fd2);
 351                                                         continue;
 352                                                 }
 353                                                 for (d=st2->raid; d<MD_SB_DISKS; d++) {
 354                                                         if (st2->devid[d] > 0 &&
 355                                                             st2->devstate[d] == 0) {
 356                                                                 dev = st2->devid[d];
 357                                                                 break;
 358                                                         }
 359                                                 }
 360                                                 if (dev > 0) {
 361                                                         if (ioctl(fd2, HOT_REMOVE_DISK,
 362                                                                   (unsigned long)dev) == 0) {
 363                                                                 if (ioctl(fd1, HOT_ADD_DISK,
 364                                                                           (unsigned long)dev) == 0) {
 365                                                                         alert("MoveSpare", st->devname, st2->devname, mailaddr, alert_cmd);
 366                                                                         close(fd1);
 367                                                                         close(fd2);
 368                                                                         break;
 369                                                                 }
 370                                                                 else ioctl(fd2, HOT_ADD_DISK, (unsigned long) dev);
 371                                                         }
 372                                                 }
 373                                                 close(fd1);
 374                                                 close(fd2);
 375                                         }
 376                         }
 377
 378                 sleep(period);
 379         }
 380         return 0;
 381 }
 382
 383
 384 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *cmd)
 385 {
 386         if (!cmd && !mailaddr) {
 387                 time_t now = time(0);
 388
 389                 printf("%1.15s: %s on %s %s\n", ctime(&now)+4, event, dev, disc?disc:"unknown device");
 390         }
 391         if (cmd) {
 392                 int pid = fork();
 393                 switch(pid) {
 394                 default:
 395                         waitpid(pid, NULL, 0);
 396                         break;
 397                 case -1:
 398                         break;
 399                 case 0:
 400                         execl(cmd, cmd, event, dev, disc, NULL);
 401                         exit(2);
 402                 }
 403         }
 404         if (mailaddr && strncmp(event, "Fail", 4)==0) {
 405                 FILE *mp = popen(Sendmail, "w");
 406                 if (mp) {
 407                         char hname[256];
 408                         gethostname(hname, sizeof(hname));
 409                         signal(SIGPIPE, SIG_IGN);
 410                         fprintf(mp, "From: " Name " monitoring <root>\n");
 411                         fprintf(mp, "To: %s\n", mailaddr);
 412                         fprintf(mp, "Subject: %s event on %s:%s\n\n", event, dev, hname);
 413
 414                         fprintf(mp, "This is an automatically generated mail message from " Name "\n");
 415                         fprintf(mp, "running on %s\n\n", hname);
 416
 417                         fprintf(mp, "A %s event had been detected on md device %s.\n\n", event, dev);
 418
 419                         if (disc)
 420                                 fprintf(mp, "It could be related to component device %s.\n\n", disc);
 421
 422                         fprintf(mp, "Faithfully yours, etc.\n");
 423                         fclose(mp);
 424                 }
 425
 426         }
 427         /* FIXME log the event to syslog maybe */
 428 }