Monitor.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2006 Neil Brown <neilb@suse.de>
   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 #include        <syslog.h>
  37
  38 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *mailfrom,
  39                   char *cmd, int dosyslog);
  40
  41 static char *percentalerts[] = {
  42         "RebuildStarted",
  43         "Rebuild20",
  44         "Rebuild40",
  45         "Rebuild60",
  46         "Rebuild80",
  47 };
  48
  49 /* The largest number of disks current arrays can manage is 384
  50  * This really should be dynamically, but that will have to wait
  51  * At least it isn't MD_SB_DISKS.
  52  */
  53 #define MaxDisks 384
  54 int Monitor(mddev_dev_t devlist,
  55             char *mailaddr, char *alert_cmd,
  56             int period, int daemonise, int scan, int oneshot,
  57             int dosyslog, int test, char* pidfile)
  58 {
  59         /*
  60          * Every few seconds, scan every md device looking for changes
  61          * When a change is found, log it, possibly run the alert command,
  62          * and possibly send Email
  63          *
  64          * For each array, we record:
  65          *   Update time
  66          *   active/working/failed/spare drives
  67          *   State of each device.
  68          *   %rebuilt if rebuilding
  69          *
  70          * If the update time changes, check out all the data again
  71          * It is possible that we cannot get the state of each device
  72          * due to bugs in the md kernel module.
  73          * We also read /proc/mdstat to get rebuild percent,
  74          * and to get state on all active devices incase of kernel bug.
  75          *
  76          * Events are:
  77          *    Fail
  78          *      An active device had Faulty set or Active/Sync removed
  79          *    FailSpare
  80          *      A spare device had Faulty set
  81          *    SpareActive
  82          *      An active device had a reverse transition
  83          *    RebuildStarted
  84          *      percent went from -1 to +ve
  85          *    Rebuild20 Rebuild40 Rebuild60 Rebuild80
  86          *      percent went from below to not-below that number
  87          *    DeviceDisappeared
  88          *      Couldn't access a device which was previously visible
  89          *
  90          * if we detect an array with active<raid and spare==0
  91          * we look at other arrays that have same spare-group
  92          * If we find one with active==raid and spare>0,
  93          *  and if we can get_disk_info and find a name
  94          *  Then we hot-remove and hot-add to the other array
  95          *
  96          * If devlist is NULL, then we can monitor everything because --scan
  97          * was given.  We get an initial list from config file and add anything
  98          * that appears in /proc/mdstat
  99          */
 100
 101         struct state {
 102                 char *devname;
 103                 int devnum;     /* to sync with mdstat info */
 104                 long utime;
 105                 int err;
 106                 char *spare_group;
 107                 int active, working, failed, spare, raid;
 108                 int expected_spares;
 109                 int devstate[MaxDisks];
 110                 int devid[MaxDisks];
 111                 int percent;
 112                 struct state *next;
 113         } *statelist = NULL;
 114         int finished = 0;
 115         struct mdstat_ent *mdstat = NULL;
 116         char *mailfrom = NULL;
 117
 118         if (!mailaddr) {
 119                 mailaddr = conf_get_mailaddr();
 120                 if (mailaddr && ! scan)
 121                         fprintf(stderr, Name ": Monitor using email address \"%s\" from config file\n",
 122                                mailaddr);
 123         }
 124         mailfrom = conf_get_mailfrom();
 125
 126         if (!alert_cmd) {
 127                 alert_cmd = conf_get_program();
 128                 if (alert_cmd && ! scan)
 129                         fprintf(stderr, Name ": Monitor using program \"%s\" from config file\n",
 130                                alert_cmd);
 131         }
 132         if (scan && !mailaddr && !alert_cmd) {
 133                 fprintf(stderr, Name ": No mail address or alert command - not monitoring.\n");
 134                 return 1;
 135         }
 136
 137         if (daemonise) {
 138                 int pid = fork();
 139                 if (pid > 0) {
 140                         if (!pidfile)
 141                                 printf("%d\n", pid);
 142                         else {
 143                                 FILE *pid_file;
 144                                 pid_file=fopen(pidfile, "w");
 145                                 if (!pid_file)
 146                                         perror("cannot create pid file");
 147                                 else {
 148                                         fprintf(pid_file,"%d\n", pid);
 149                                         fclose(pid_file);
 150                                 }
 151                         }
 152                         return 0;
 153                 }
 154                 if (pid < 0) {
 155                         perror("daemonise");
 156                         return 1;
 157                 }
 158                 close(0);
 159                 open("/dev/null", 3);
 160                 dup2(0,1);
 161                 dup2(0,2);
 162                 setsid();
 163         }
 164
 165         if (devlist == NULL) {
 166                 mddev_ident_t mdlist = conf_get_ident(NULL);
 167                 for (; mdlist; mdlist=mdlist->next) {
 168                         struct state *st = malloc(sizeof *st);
 169                         if (st == NULL)
 170                                 continue;
 171                         st->devname = strdup(mdlist->devname);
 172                         st->utime = 0;
 173                         st->next = statelist;
 174                         st->err = 0;
 175                         st->devnum = MAXINT;
 176                         st->percent = -2;
 177                         st->expected_spares = mdlist->spare_disks;
 178                         if (mdlist->spare_group)
 179                                 st->spare_group = strdup(mdlist->spare_group);
 180                         else
 181                                 st->spare_group = NULL;
 182                         statelist = st;
 183                 }
 184         } else {
 185                 mddev_dev_t dv;
 186                 for (dv=devlist ; dv; dv=dv->next) {
 187                         mddev_ident_t mdlist = conf_get_ident(dv->devname);
 188                         struct state *st = malloc(sizeof *st);
 189                         if (st == NULL)
 190                                 continue;
 191                         st->devname = strdup(dv->devname);
 192                         st->utime = 0;
 193                         st->next = statelist;
 194                         st->err = 0;
 195                         st->devnum = MAXINT;
 196                         st->percent = -2;
 197                         st->expected_spares = -1;
 198                         st->spare_group = NULL;
 199                         if (mdlist) {
 200                                 st->expected_spares = mdlist->spare_disks;
 201                                 if (mdlist->spare_group)
 202                                         st->spare_group = strdup(mdlist->spare_group);
 203                         }
 204                         statelist = st;
 205                 }
 206         }
 207
 208
 209         while (! finished) {
 210                 int new_found = 0;
 211                 struct state *st;
 212
 213                 if (mdstat)
 214                         free_mdstat(mdstat);
 215                 mdstat = mdstat_read(oneshot?0:1, 0);
 216
 217                 for (st=statelist; st; st=st->next) {
 218                         struct { int state, major, minor; } info[MaxDisks];
 219                         mdu_array_info_t array;
 220                         struct mdstat_ent *mse = NULL, *mse2;
 221                         char *dev = st->devname;
 222                         int fd;
 223                         unsigned int i;
 224
 225                         if (test)
 226                                 alert("TestMessage", dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 227                         fd = open(dev, O_RDONLY);
 228                         if (fd < 0) {
 229                                 if (!st->err)
 230                                         alert("DeviceDisappeared", dev, NULL,
 231                                               mailaddr, mailfrom, alert_cmd, dosyslog);
 232 /*                                      fprintf(stderr, Name ": cannot open %s: %s\n",
 233                                                 dev, strerror(errno));
 234 */                              st->err=1;
 235                                 continue;
 236                         }
 237                         if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
 238                                 if (!st->err)
 239                                         alert("DeviceDisappeared", dev, NULL,
 240                                               mailaddr, mailfrom, alert_cmd, dosyslog);
 241 /*                                      fprintf(stderr, Name ": cannot get array info for %s: %s\n",
 242                                                 dev, strerror(errno));
 243 */                              st->err=1;
 244                                 close(fd);
 245                                 continue;
 246                         }
 247                         if (array.level != 1 && array.level != 5 && array.level != -4 &&
 248                                 array.level != 6 && array.level != 10) {
 249                                 if (!st->err)
 250                                         alert("DeviceDisappeared", dev, "Wrong-Level",
 251                                               mailaddr, mailfrom, alert_cmd, dosyslog);
 252                                 st->err = 1;
 253                                 close(fd);
 254                                 continue;
 255                         }
 256                         if (st->devnum == MAXINT) {
 257                                 struct stat stb;
 258                                 if (fstat(fd, &stb) == 0 &&
 259                                     (S_IFMT&stb.st_mode)==S_IFBLK) {
 260                                         if (major(stb.st_rdev) == MD_MAJOR)
 261                                                 st->devnum = minor(stb.st_rdev);
 262                                         else
 263                                                 st->devnum = -1- (minor(stb.st_rdev)>>6);
 264                                 }
 265                         }
 266
 267                         for (mse2 = mdstat ; mse2 ; mse2=mse2->next)
 268                                 if (mse2->devnum == st->devnum) {
 269                                         mse2->devnum = MAXINT; /* flag it as "used" */
 270                                         mse = mse2;
 271                                 }
 272
 273                         if (st->utime == array.utime &&
 274                             st->failed == array.failed_disks &&
 275                             st->working == array.working_disks &&
 276                             st->spare == array.spare_disks &&
 277                             (mse == NULL  || (
 278                                     mse->percent == st->percent
 279                                     ))) {
 280                                 close(fd);
 281                                 st->err = 0;
 282                                 continue;
 283                         }
 284                         if (st->utime == 0 && /* new array */
 285                             mse &&      /* is in /proc/mdstat */
 286                             mse->pattern && strchr(mse->pattern, '_') /* degraded */
 287                                 )
 288                                 alert("DegradedArray", dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 289
 290                         if (st->utime == 0 && /* new array */
 291                             st->expected_spares > 0 &&
 292                             array.spare_disks < st->expected_spares)
 293                                 alert("SparesMissing", dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 294                         if (mse &&
 295                             st->percent == -1 &&
 296                             mse->percent >= 0)
 297                                 alert("RebuildStarted", dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 298                         if (mse &&
 299                             st->percent >= 0 &&
 300                             mse->percent >= 0 &&
 301                             (mse->percent / 20) > (st->percent / 20))
 302                                 alert(percentalerts[mse->percent/20],
 303                                       dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 304
 305                         if (mse &&
 306                             mse->percent == -1 &&
 307                             st->percent >= 0) {
 308                                 /* Rebuild/sync/whatever just finished.
 309                                  * If there is a number in /mismatch_cnt,
 310                                  * we should report that.
 311                                  */
 312                                 struct sysarray *sra =
 313                                        sysfs_read(-1, st->devnum, GET_MISMATCH);
 314                                 if (sra && sra->mismatch_cnt > 0) {
 315                                         char cnt[40];
 316                                         sprintf(cnt, " mismatches found: %d", sra->mismatch_cnt);
 317                                         alert("RebuildFinished", dev, cnt, mailaddr, mailfrom, alert_cmd, dosyslog);
 318                                 } else
 319                                         alert("RebuildFinished", dev, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 320                                 if (sra)
 321                                         free(sra);
 322                         }
 323
 324                         if (mse)
 325                                 st->percent = mse->percent;
 326
 327
 328                         for (i=0; i<MaxDisks && i <= array.raid_disks + array.nr_disks;
 329                              i++) {
 330                                 mdu_disk_info_t disc;
 331                                 disc.number = i;
 332                                 if (ioctl(fd, GET_DISK_INFO, &disc) >= 0) {
 333                                         info[i].state = disc.state;
 334                                         info[i].major = disc.major;
 335                                         info[i].minor = disc.minor;
 336                                 } else
 337                                         info[i].major = info[i].minor = 0;
 338                         }
 339                         close(fd);
 340
 341                         for (i=0; i<MaxDisks; i++) {
 342                                 mdu_disk_info_t disc = {0};
 343                                 int newstate=0;
 344                                 int change;
 345                                 char *dv = NULL;
 346                                 disc.number = i;
 347                                 if (i > array.raid_disks + array.nr_disks) {
 348                                         newstate = 0;
 349                                         disc.major = disc.minor = 0;
 350                                 } else if (info[i].major || info[i].minor) {
 351                                         newstate = info[i].state;
 352                                         dv = map_dev(info[i].major, info[i].minor, 1);
 353                                         disc.state = newstate;
 354                                         disc.major = info[i].major;
 355                                         disc.minor = info[i].minor;
 356                                 } else if (mse &&  mse->pattern && i < strlen(mse->pattern)) {
 357                                         switch(mse->pattern[i]) {
 358                                         case 'U': newstate = 6 /* ACTIVE/SYNC */; break;
 359                                         case '_': newstate = 0; break;
 360                                         }
 361                                         disc.major = disc.minor = 0;
 362                                 }
 363                                 if (dv == NULL && st->devid[i])
 364                                         dv = map_dev(major(st->devid[i]),
 365                                                      minor(st->devid[i]), 1);
 366                                 change = newstate ^ st->devstate[i];
 367                                 if (st->utime && change && !st->err) {
 368                                         if (i < (unsigned)array.raid_disks &&
 369                                             (((newstate&change)&(1<<MD_DISK_FAULTY)) ||
 370                                              ((st->devstate[i]&change)&(1<<MD_DISK_ACTIVE)) ||
 371                                              ((st->devstate[i]&change)&(1<<MD_DISK_SYNC)))
 372                                                 )
 373                                                 alert("Fail", dev, dv, mailaddr, mailfrom, alert_cmd, dosyslog);
 374                                         else if (i >= (unsigned)array.raid_disks &&
 375                                                  (disc.major || disc.minor) &&
 376                                                  st->devid[i] == makedev(disc.major, disc.minor) &&
 377                                                  ((newstate&change)&(1<<MD_DISK_FAULTY))
 378                                                 )
 379                                                 alert("FailSpare", dev, dv, mailaddr, mailfrom, alert_cmd, dosyslog);
 380                                         else if (i < (unsigned)array.raid_disks &&
 381                                                  (((st->devstate[i]&change)&(1<<MD_DISK_FAULTY)) ||
 382                                                   ((newstate&change)&(1<<MD_DISK_ACTIVE)) ||
 383                                                   ((newstate&change)&(1<<MD_DISK_SYNC)))
 384                                                 )
 385                                                 alert("SpareActive", dev, dv, mailaddr, mailfrom, alert_cmd, dosyslog);
 386                                 }
 387                                 st->devstate[i] = newstate;
 388                                 st->devid[i] = makedev(disc.major, disc.minor);
 389                         }
 390                         st->active = array.active_disks;
 391                         st->working = array.working_disks;
 392                         st->spare = array.spare_disks;
 393                         st->failed = array.failed_disks;
 394                         st->utime = array.utime;
 395                         st->raid = array.raid_disks;
 396                         st->err = 0;
 397                 }
 398                 /* now check if there are any new devices found in mdstat */
 399                 if (scan) {
 400                         struct mdstat_ent *mse;
 401                         for (mse=mdstat; mse; mse=mse->next)
 402                                 if (mse->devnum != MAXINT &&
 403                                     (strcmp(mse->level, "raid1")==0 ||
 404                                      strcmp(mse->level, "raid5")==0 ||
 405                                      strcmp(mse->level, "multipath")==0)
 406                                         ) {
 407                                         struct state *st = malloc(sizeof *st);
 408                                         mdu_array_info_t array;
 409                                         int fd;
 410                                         if (st == NULL)
 411                                                 continue;
 412                                         st->devname = strdup(get_md_name(mse->devnum));
 413                                         if ((fd = open(st->devname, O_RDONLY)) < 0 ||
 414                                             ioctl(fd, GET_ARRAY_INFO, &array)< 0) {
 415                                                 /* no such array */
 416                                                 if (fd >=0) close(fd);
 417                                                 put_md_name(st->devname);
 418                                                 free(st->devname);
 419                                                 free(st);
 420                                                 continue;
 421                                         }
 422                                         close(fd);
 423                                         st->utime = 0;
 424                                         st->next = statelist;
 425                                         st->err = 1;
 426                                         st->devnum = mse->devnum;
 427                                         st->percent = -2;
 428                                         st->spare_group = NULL;
 429                                         st->expected_spares = -1;
 430                                         statelist = st;
 431                                         alert("NewArray", st->devname, NULL, mailaddr, mailfrom, alert_cmd, dosyslog);
 432                                         new_found = 1;
 433                                 }
 434                 }
 435                 /* If an array has active < raid && spare == 0 && spare_group != NULL
 436                  * Look for another array with spare > 0 and active == raid and same spare_group
 437                  *  if found, choose a device and hotremove/hotadd
 438                  */
 439                 for (st = statelist; st; st=st->next)
 440                         if (st->active < st->raid &&
 441                             st->spare == 0 &&
 442                             st->spare_group != NULL) {
 443                                 struct state *st2;
 444                                 for (st2=statelist ; st2 ; st2=st2->next)
 445                                         if (st2 != st &&
 446                                             st2->spare > 0 &&
 447                                             st2->active == st2->raid &&
 448                                             st2->spare_group != NULL &&
 449                                             strcmp(st->spare_group, st2->spare_group) == 0) {
 450                                                 /* try to remove and add */
 451                                                 int fd1 = open(st->devname, O_RDONLY);
 452                                                 int fd2 = open(st2->devname, O_RDONLY);
 453                                                 int dev = -1;
 454                                                 int d;
 455                                                 if (fd1 < 0 || fd2 < 0) {
 456                                                         if (fd1>=0) close(fd1);
 457                                                         if (fd2>=0) close(fd2);
 458                                                         continue;
 459                                                 }
 460                                                 for (d=st2->raid; d < MaxDisks; d++) {
 461                                                         if (st2->devid[d] > 0 &&
 462                                                             st2->devstate[d] == 0) {
 463                                                                 dev = st2->devid[d];
 464                                                                 break;
 465                                                         }
 466                                                 }
 467                                                 if (dev > 0) {
 468                                                         if (ioctl(fd2, HOT_REMOVE_DISK,
 469                                                                   (unsigned long)dev) == 0) {
 470                                                                 if (ioctl(fd1, HOT_ADD_DISK,
 471                                                                           (unsigned long)dev) == 0) {
 472                                                                         alert("MoveSpare", st->devname, st2->devname, mailaddr, mailfrom, alert_cmd, dosyslog);
 473                                                                         close(fd1);
 474                                                                         close(fd2);
 475                                                                         break;
 476                                                                 }
 477                                                                 else ioctl(fd2, HOT_ADD_DISK, (unsigned long) dev);
 478                                                         }
 479                                                 }
 480                                                 close(fd1);
 481                                                 close(fd2);
 482                                         }
 483                         }
 484                 if (!new_found) {
 485                         if (oneshot)
 486                                 break;
 487                         else
 488                                 mdstat_wait(period);
 489                 }
 490                 test = 0;
 491         }
 492         if (pidfile)
 493                 unlink(pidfile);
 494         return 0;
 495 }
 496
 497
 498 static void alert(char *event, char *dev, char *disc, char *mailaddr, char *mailfrom, char *cmd,
 499                   int dosyslog)
 500 {
 501         int priority;
 502
 503         if (!cmd && !mailaddr) {
 504                 time_t now = time(0);
 505
 506                 printf("%1.15s: %s on %s %s\n", ctime(&now)+4, event, dev, disc?disc:"unknown device");
 507         }
 508         if (cmd) {
 509                 int pid = fork();
 510                 switch(pid) {
 511                 default:
 512                         waitpid(pid, NULL, 0);
 513                         break;
 514                 case -1:
 515                         break;
 516                 case 0:
 517                         execl(cmd, cmd, event, dev, disc, NULL);
 518                         exit(2);
 519                 }
 520         }
 521         if (mailaddr &&
 522             (strncmp(event, "Fail", 4)==0 ||
 523              strncmp(event, "Test", 4)==0 ||
 524              strncmp(event, "Spares", 6)==0 ||
 525              strncmp(event, "Degrade", 7)==0)) {
 526                 FILE *mp = popen(Sendmail, "w");
 527                 if (mp) {
 528                         FILE *mdstat;
 529                         char hname[256];
 530                         gethostname(hname, sizeof(hname));
 531                         signal(SIGPIPE, SIG_IGN);
 532                         if (mailfrom)
 533                                 fprintf(mp, "From: %s\n", mailfrom);
 534                         else
 535                                 fprintf(mp, "From: " Name " monitoring <root>\n");
 536                         fprintf(mp, "To: %s\n", mailaddr);
 537                         fprintf(mp, "Subject: %s event on %s:%s\n\n", event, dev, hname);
 538
 539                         fprintf(mp, "This is an automatically generated mail message from " Name "\n");
 540                         fprintf(mp, "running on %s\n\n", hname);
 541
 542                         fprintf(mp, "A %s event had been detected on md device %s.\n\n", event, dev);
 543
 544                         if (disc && disc[0] != ' ')
 545                                 fprintf(mp, "It could be related to component device %s.\n\n", disc);
 546                         if (disc && disc[0] == ' ')
 547                                 fprintf(mp, "Extra information:%s.\n\n", disc);
 548
 549                         fprintf(mp, "Faithfully yours, etc.\n");
 550
 551                         mdstat = fopen("/proc/mdstat", "r");
 552                         if (mdstat) {
 553                                 char buf[8192];
 554                                 int n;
 555                                 fprintf(mp, "\nP.S. The /proc/mdstat file currently contains the following:\n\n");
 556                                 while ( (n=fread(buf, 1, sizeof(buf), mdstat)) > 0)
 557                                         n=fwrite(buf, 1, n, mp); /* yes, i don't care about the result */
 558                                 fclose(mdstat);
 559                         }
 560                         fclose(mp);
 561                 }
 562
 563         }
 564
 565         /* log the event to syslog maybe */
 566         if (dosyslog) {
 567                 /* Log at a different severity depending on the event.
 568                  *
 569                  * These are the critical events:  */
 570                 if (strncmp(event, "Fail", 4)==0 ||
 571                     strncmp(event, "Degrade", 7)==0 ||
 572                     strncmp(event, "DeviceDisappeared", 17)==0)
 573                         priority = LOG_CRIT;
 574                 /* Good to know about, but are not failures: */
 575                 else if (strncmp(event, "Rebuild", 7)==0 ||
 576                          strncmp(event, "MoveSpare", 9)==0 ||
 577                          strncmp(event, "Spares", 6) != 0)
 578                         priority = LOG_WARNING;
 579                 /* Everything else: */
 580                 else
 581                         priority = LOG_INFO;
 582
 583                 if (disc)
 584                         syslog(priority, "%s event detected on md device %s, component device %s", event, dev, disc);
 585                 else
 586                         syslog(priority, "%s event detected on md device %s", event, dev);
 587         }
 588 }
 589
 590 /* Not really Monitor but ... */
 591 int Wait(char *dev)
 592 {
 593         struct stat stb;
 594         int devnum;
 595         int rv = 1;
 596
 597         if (stat(dev, &stb) != 0) {
 598                 fprintf(stderr, Name ": Cannot find %s: %s\n", dev,
 599                         strerror(errno));
 600                 return 2;
 601         }
 602         if (major(stb.st_rdev) == MD_MAJOR)
 603                 devnum = minor(stb.st_rdev);
 604         else
 605                 devnum = -1-(minor(stb.st_rdev)/64);
 606
 607         while(1) {
 608                 struct mdstat_ent *ms = mdstat_read(1, 0);
 609                 struct mdstat_ent *e;
 610
 611                 for (e=ms ; e; e=e->next)
 612                         if (e->devnum == devnum)
 613                                 break;
 614
 615                 if (!e || e->percent < 0) {
 616                         free_mdstat(ms);
 617                         return rv;
 618                 }
 619                 free(ms);
 620                 rv = 0;
 621                 mdstat_wait(5);
 622         }
 623 }