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