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