cddl/usr.sbin/zfsd/case_file.cc

   1 /*-
   2  * Copyright (c) 2011, 2012, 2013, 2014, 2016 Spectra Logic Corporation
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions, and the following disclaimer,
  10  *    without modification.
  11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  12  *    substantially similar to the "NO WARRANTY" disclaimer below
  13  *    ("Disclaimer") and any redistribution must be conditioned upon
  14  *    including a substantially similar Disclaimer requirement for further
  15  *    binary redistribution.
  16  *
  17  * NO WARRANTY
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28  * POSSIBILITY OF SUCH DAMAGES.
  29  *
  30  * Authors: Justin T. Gibbs     (Spectra Logic Corporation)
  31  */
  32
  33 /**
  34  * \file case_file.cc
  35  *
  36  * We keep case files for any leaf vdev that is not in the optimal state.
  37  * However, we only serialize to disk those events that need to be preserved
  38  * across reboots.  For now, this is just a log of soft errors which we
  39  * accumulate in order to mark a device as degraded.
  40  */
  41 #include <sys/cdefs.h>
  42 #include <sys/time.h>
  43
  44 #include <sys/fs/zfs.h>
  45
  46 #include <dirent.h>
  47 #include <iomanip>
  48 #include <fstream>
  49 #include <functional>
  50 #include <sstream>
  51 #include <syslog.h>
  52 #include <unistd.h>
  53
  54 #include <libzfs.h>
  55
  56 #include <list>
  57 #include <map>
  58 #include <string>
  59
  60 #include <devdctl/guid.h>
  61 #include <devdctl/event.h>
  62 #include <devdctl/event_factory.h>
  63 #include <devdctl/exception.h>
  64 #include <devdctl/consumer.h>
  65
  66 #include "callout.h"
  67 #include "vdev_iterator.h"
  68 #include "zfsd_event.h"
  69 #include "case_file.h"
  70 #include "vdev.h"
  71 #include "zfsd.h"
  72 #include "zfsd_exception.h"
  73 #include "zpool_list.h"
  74
  75 __FBSDID("$FreeBSD$");
  76
  77 /*============================ Namespace Control =============================*/
  78 using std::auto_ptr;
  79 using std::hex;
  80 using std::ifstream;
  81 using std::stringstream;
  82 using std::setfill;
  83 using std::setw;
  84
  85 using DevdCtl::Event;
  86 using DevdCtl::EventFactory;
  87 using DevdCtl::EventList;
  88 using DevdCtl::Guid;
  89 using DevdCtl::ParseException;
  90
  91 /*--------------------------------- CaseFile ---------------------------------*/
  92 //- CaseFile Static Data -------------------------------------------------------
  93
  94 CaseFileList  CaseFile::s_activeCases;
  95 const string  CaseFile::s_caseFilePath = "/var/db/zfsd/cases";
  96 const timeval CaseFile::s_removeGracePeriod = { 60 /*sec*/, 0 /*usec*/};
  97
  98 //- CaseFile Static Public Methods ---------------------------------------------
  99 CaseFile *
 100 CaseFile::Find(Guid poolGUID, Guid vdevGUID)
 101 {
 102         for (CaseFileList::iterator curCase = s_activeCases.begin();
 103              curCase != s_activeCases.end(); curCase++) {
 104
 105                 if (((*curCase)->PoolGUID() != poolGUID
 106                   && Guid::InvalidGuid() != poolGUID)
 107                  || (*curCase)->VdevGUID() != vdevGUID)
 108                         continue;
 109
 110                 /*
 111                  * We only carry one active case per-vdev.
 112                  */
 113                 return (*curCase);
 114         }
 115         return (NULL);
 116 }
 117
 118 CaseFile *
 119 CaseFile::Find(const string &physPath)
 120 {
 121         CaseFile *result = NULL;
 122
 123         for (CaseFileList::iterator curCase = s_activeCases.begin();
 124              curCase != s_activeCases.end(); curCase++) {
 125
 126                 if ((*curCase)->PhysicalPath() != physPath)
 127                         continue;
 128
 129                 if (result != NULL) {
 130                         syslog(LOG_WARNING, "Multiple casefiles found for "
 131                             "physical path %s.  "
 132                             "This is most likely a bug in zfsd",
 133                             physPath.c_str());
 134                 }
 135                 result = *curCase;
 136         }
 137         return (result);
 138 }
 139
 140
 141 void
 142 CaseFile::ReEvaluateByGuid(Guid poolGUID, const ZfsEvent &event)
 143 {
 144         CaseFileList::iterator casefile;
 145         for (casefile = s_activeCases.begin(); casefile != s_activeCases.end();){
 146                 CaseFileList::iterator next = casefile;
 147                 next++;
 148                 if (poolGUID == (*casefile)->PoolGUID())
 149                         (*casefile)->ReEvaluate(event);
 150                 casefile = next;
 151         }
 152 }
 153
 154 CaseFile &
 155 CaseFile::Create(Vdev &vdev)
 156 {
 157         CaseFile *activeCase;
 158
 159         activeCase = Find(vdev.PoolGUID(), vdev.GUID());
 160         if (activeCase == NULL)
 161                 activeCase = new CaseFile(vdev);
 162
 163         return (*activeCase);
 164 }
 165
 166 void
 167 CaseFile::DeSerialize()
 168 {
 169         struct dirent **caseFiles;
 170
 171         int numCaseFiles(scandir(s_caseFilePath.c_str(), &caseFiles,
 172                          DeSerializeSelector, /*compar*/NULL));
 173
 174         if (numCaseFiles == -1)
 175                 return;
 176         if (numCaseFiles == 0) {
 177                 free(caseFiles);
 178                 return;
 179         }
 180
 181         for (int i = 0; i < numCaseFiles; i++) {
 182
 183                 DeSerializeFile(caseFiles[i]->d_name);
 184                 free(caseFiles[i]);
 185         }
 186         free(caseFiles);
 187 }
 188
 189 bool
 190 CaseFile::Empty()
 191 {
 192         return (s_activeCases.empty());
 193 }
 194
 195 void
 196 CaseFile::LogAll()
 197 {
 198         for (CaseFileList::iterator curCase = s_activeCases.begin();
 199              curCase != s_activeCases.end(); curCase++)
 200                 (*curCase)->Log();
 201 }
 202
 203 void
 204 CaseFile::PurgeAll()
 205 {
 206         /*
 207          * Serialize casefiles before deleting them so that they can be reread
 208          * and revalidated during BuildCaseFiles.
 209          * CaseFiles remove themselves from this list on destruction.
 210          */
 211         while (s_activeCases.size() != 0) {
 212                 CaseFile *casefile = s_activeCases.front();
 213                 casefile->Serialize();
 214                 delete casefile;
 215         }
 216
 217 }
 218
 219 //- CaseFile Public Methods ----------------------------------------------------
 220 bool
 221 CaseFile::RefreshVdevState()
 222 {
 223         ZpoolList zpl(ZpoolList::ZpoolByGUID, &m_poolGUID);
 224         zpool_handle_t *casePool(zpl.empty() ? NULL : zpl.front());
 225         if (casePool == NULL)
 226                 return (false);
 227
 228         Vdev vd(casePool, CaseVdev(casePool));
 229         if (vd.DoesNotExist())
 230                 return (false);
 231
 232         m_vdevState    = vd.State();
 233         m_vdevPhysPath = vd.PhysicalPath();
 234         return (true);
 235 }
 236
 237 bool
 238 CaseFile::ReEvaluate(const string &devPath, const string &physPath, Vdev *vdev)
 239 {
 240         ZpoolList zpl(ZpoolList::ZpoolByGUID, &m_poolGUID);
 241         zpool_handle_t *pool(zpl.empty() ? NULL : zpl.front());
 242
 243         if (pool == NULL || !RefreshVdevState()) {
 244                 /*
 245                  * The pool or vdev for this case file is no longer
 246                  * part of the configuration.  This can happen
 247                  * if we process a device arrival notification
 248                  * before seeing the ZFS configuration change
 249                  * event.
 250                  */
 251                 syslog(LOG_INFO,
 252                        "CaseFile::ReEvaluate(%s,%s) Pool/Vdev unconfigured.  "
 253                        "Closing\n",
 254                        PoolGUIDString().c_str(),
 255                        VdevGUIDString().c_str());
 256                 Close();
 257
 258                 /*
 259                  * Since this event was not used to close this
 260                  * case, do not report it as consumed.
 261                  */
 262                 return (/*consumed*/false);
 263         }
 264
 265         if (VdevState() > VDEV_STATE_CANT_OPEN) {
 266                 /*
 267                  * For now, newly discovered devices only help for
 268                  * devices that are missing.  In the future, we might
 269                  * use a newly inserted spare to replace a degraded
 270                  * or faulted device.
 271                  */
 272                 syslog(LOG_INFO, "CaseFile::ReEvaluate(%s,%s): Pool/Vdev ignored",
 273                     PoolGUIDString().c_str(), VdevGUIDString().c_str());
 274                 return (/*consumed*/false);
 275         }
 276
 277         if (vdev != NULL
 278          && ( vdev->PoolGUID() == m_poolGUID
 279            || vdev->PoolGUID() == Guid::InvalidGuid())
 280          && vdev->GUID() == m_vdevGUID) {
 281
 282                 zpool_vdev_online(pool, vdev->GUIDString().c_str(),
 283                                   ZFS_ONLINE_CHECKREMOVE | ZFS_ONLINE_UNSPARE,
 284                                   &m_vdevState);
 285                 syslog(LOG_INFO, "Onlined vdev(%s/%s:%s).  State now %s.\n",
 286                        zpool_get_name(pool), vdev->GUIDString().c_str(),
 287                        devPath.c_str(),
 288                        zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 289
 290                 /*
 291                  * Check the vdev state post the online action to see
 292                  * if we can retire this case.
 293                  */
 294                 CloseIfSolved();
 295
 296                 return (/*consumed*/true);
 297         }
 298
 299         /*
 300          * If the auto-replace policy is enabled, and we have physical
 301          * path information, try a physical path replacement.
 302          */
 303         if (zpool_get_prop_int(pool, ZPOOL_PROP_AUTOREPLACE, NULL) == 0) {
 304                 syslog(LOG_INFO,
 305                        "CaseFile(%s:%s:%s): AutoReplace not set.  "
 306                        "Ignoring device insertion.\n",
 307                        PoolGUIDString().c_str(),
 308                        VdevGUIDString().c_str(),
 309                        zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 310                 return (/*consumed*/false);
 311         }
 312
 313         if (PhysicalPath().empty()) {
 314                 syslog(LOG_INFO,
 315                        "CaseFile(%s:%s:%s): No physical path information.  "
 316                        "Ignoring device insertion.\n",
 317                        PoolGUIDString().c_str(),
 318                        VdevGUIDString().c_str(),
 319                        zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 320                 return (/*consumed*/false);
 321         }
 322
 323         if (physPath != PhysicalPath()) {
 324                 syslog(LOG_INFO,
 325                        "CaseFile(%s:%s:%s): Physical path mismatch.  "
 326                        "Ignoring device insertion.\n",
 327                        PoolGUIDString().c_str(),
 328                        VdevGUIDString().c_str(),
 329                        zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 330                 return (/*consumed*/false);
 331         }
 332
 333         /* Write a label on the newly inserted disk. */
 334         if (zpool_label_disk(g_zfsHandle, pool, devPath.c_str()) != 0) {
 335                 syslog(LOG_ERR,
 336                        "Replace vdev(%s/%s) by physical path (label): %s: %s\n",
 337                        zpool_get_name(pool), VdevGUIDString().c_str(),
 338                        libzfs_error_action(g_zfsHandle),
 339                        libzfs_error_description(g_zfsHandle));
 340                 return (/*consumed*/false);
 341         }
 342
 343         syslog(LOG_INFO, "CaseFile::ReEvaluate(%s/%s): Replacing with %s",
 344             PoolGUIDString().c_str(), VdevGUIDString().c_str(),
 345             devPath.c_str());
 346         return (Replace(VDEV_TYPE_DISK, devPath.c_str(), /*isspare*/false));
 347 }
 348
 349 bool
 350 CaseFile::ReEvaluate(const ZfsEvent &event)
 351 {
 352         bool consumed(false);
 353
 354         if (event.Value("type") == "misc.fs.zfs.vdev_remove") {
 355                 /*
 356                  * The Vdev we represent has been removed from the
 357                  * configuration.  This case is no longer of value.
 358                  */
 359                 Close();
 360
 361                 return (/*consumed*/true);
 362         } else if (event.Value("type") == "misc.fs.zfs.pool_destroy") {
 363                 /* This Pool has been destroyed.  Discard the case */
 364                 Close();
 365
 366                 return (/*consumed*/true);
 367         } else if (event.Value("type") == "misc.fs.zfs.config_sync") {
 368                 RefreshVdevState();
 369                 if (VdevState() < VDEV_STATE_HEALTHY)
 370                         consumed = ActivateSpare();
 371         }
 372
 373
 374         if (event.Value("class") == "resource.fs.zfs.removed") {
 375                 bool spare_activated;
 376
 377                 if (!RefreshVdevState()) {
 378                         /*
 379                          * The pool or vdev for this case file is no longer
 380                          * part of the configuration.  This can happen
 381                          * if we process a device arrival notification
 382                          * before seeing the ZFS configuration change
 383                          * event.
 384                          */
 385                         syslog(LOG_INFO,
 386                                "CaseFile::ReEvaluate(%s,%s) Pool/Vdev "
 387                                "unconfigured.  Closing\n",
 388                                PoolGUIDString().c_str(),
 389                                VdevGUIDString().c_str());
 390                         /*
 391                          * Close the case now so we won't waste cycles in the
 392                          * system rescan
 393                          */
 394                         Close();
 395
 396                         /*
 397                          * Since this event was not used to close this
 398                          * case, do not report it as consumed.
 399                          */
 400                         return (/*consumed*/false);
 401                 }
 402
 403                 /*
 404                  * Discard any tentative I/O error events for
 405                  * this case.  They were most likely caused by the
 406                  * hot-unplug of this device.
 407                  */
 408                 PurgeTentativeEvents();
 409
 410                 /* Try to activate spares if they are available */
 411                 spare_activated = ActivateSpare();
 412
 413                 /*
 414                  * Rescan the drives in the system to see if a recent
 415                  * drive arrival can be used to solve this case.
 416                  */
 417                 ZfsDaemon::RequestSystemRescan();
 418
 419                 /*
 420                  * Consume the event if we successfully activated a spare.
 421                  * Otherwise, leave it in the unconsumed events list so that the
 422                  * future addition of a spare to this pool might be able to
 423                  * close the case
 424                  */
 425                 consumed = spare_activated;
 426         } else if (event.Value("class") == "resource.fs.zfs.statechange") {
 427                 RefreshVdevState();
 428                 /*
 429                  * If this vdev is DEGRADED, FAULTED, or UNAVAIL, try to
 430                  * activate a hotspare.  Otherwise, ignore the event
 431                  */
 432                 if (VdevState() == VDEV_STATE_FAULTED ||
 433                     VdevState() == VDEV_STATE_DEGRADED ||
 434                     VdevState() == VDEV_STATE_CANT_OPEN)
 435                         (void) ActivateSpare();
 436                 consumed = true;
 437         }
 438         else if (event.Value("class") == "ereport.fs.zfs.io" ||
 439                  event.Value("class") == "ereport.fs.zfs.checksum") {
 440
 441                 m_tentativeEvents.push_front(event.DeepCopy());
 442                 RegisterCallout(event);
 443                 consumed = true;
 444         }
 445
 446         bool closed(CloseIfSolved());
 447
 448         return (consumed || closed);
 449 }
 450
 451 /* Find a Vdev containing the vdev with the given GUID */
 452 static nvlist_t*
 453 find_parent(nvlist_t *pool_config, nvlist_t *config, DevdCtl::Guid child_guid)
 454 {
 455         nvlist_t **vdevChildren;
 456         int        error;
 457         unsigned   ch, numChildren;
 458
 459         error = nvlist_lookup_nvlist_array(config, ZPOOL_CONFIG_CHILDREN,
 460                                            &vdevChildren, &numChildren);
 461
 462         if (error != 0 || numChildren == 0)
 463                 return (NULL);
 464
 465         for (ch = 0; ch < numChildren; ch++) {
 466                 nvlist *result;
 467                 Vdev vdev(pool_config, vdevChildren[ch]);
 468
 469                 if (vdev.GUID() == child_guid)
 470                         return (config);
 471
 472                 result = find_parent(pool_config, vdevChildren[ch], child_guid);
 473                 if (result != NULL)
 474                         return (result);
 475         }
 476
 477         return (NULL);
 478 }
 479
 480 bool
 481 CaseFile::ActivateSpare() {
 482         nvlist_t        *config, *nvroot, *parent_config;
 483         nvlist_t       **spares;
 484         char            *devPath, *vdev_type;
 485         const char      *poolname;
 486         u_int            nspares, i;
 487         int              error;
 488
 489         ZpoolList zpl(ZpoolList::ZpoolByGUID, &m_poolGUID);
 490         zpool_handle_t  *zhp(zpl.empty() ? NULL : zpl.front());
 491         if (zhp == NULL) {
 492                 syslog(LOG_ERR, "CaseFile::ActivateSpare: Could not find pool "
 493                        "for pool_guid %" PRIu64".", (uint64_t)m_poolGUID);
 494                 return (false);
 495         }
 496         poolname = zpool_get_name(zhp);
 497         config = zpool_get_config(zhp, NULL);
 498         if (config == NULL) {
 499                 syslog(LOG_ERR, "CaseFile::ActivateSpare: Could not find pool "
 500                        "config for pool %s", poolname);
 501                 return (false);
 502         }
 503         error = nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot);
 504         if (error != 0){
 505                 syslog(LOG_ERR, "CaseFile::ActivateSpare: Could not find vdev "
 506                        "tree for pool %s", poolname);
 507                 return (false);
 508         }
 509
 510         parent_config = find_parent(config, nvroot, m_vdevGUID);
 511         if (parent_config != NULL) {
 512                 char *parent_type;
 513
 514                 /*
 515                  * Don't activate spares for members of a "replacing" vdev.
 516                  * They're already dealt with.  Sparing them will just drag out
 517                  * the resilver process.
 518                  */
 519                 error = nvlist_lookup_string(parent_config,
 520                     ZPOOL_CONFIG_TYPE, &parent_type);
 521                 if (error == 0 && strcmp(parent_type, VDEV_TYPE_REPLACING) == 0)
 522                         return (false);
 523         }
 524
 525         nspares = 0;
 526         nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
 527                                    &nspares);
 528         if (nspares == 0) {
 529                 /* The pool has no spares configured */
 530                 syslog(LOG_INFO, "CaseFile::ActivateSpare: "
 531                        "No spares available for pool %s", poolname);
 532                 return (false);
 533         }
 534         for (i = 0; i < nspares; i++) {
 535                 uint64_t    *nvlist_array;
 536                 vdev_stat_t *vs;
 537                 uint_t       nstats;
 538
 539                 if (nvlist_lookup_uint64_array(spares[i],
 540                     ZPOOL_CONFIG_VDEV_STATS, &nvlist_array, &nstats) != 0) {
 541                         syslog(LOG_ERR, "CaseFile::ActivateSpare: Could not "
 542                                "find vdev stats for pool %s, spare %d",
 543                                poolname, i);
 544                         return (false);
 545                 }
 546                 vs = reinterpret_cast<vdev_stat_t *>(nvlist_array);
 547
 548                 if ((vs->vs_aux != VDEV_AUX_SPARED)
 549                  && (vs->vs_state == VDEV_STATE_HEALTHY)) {
 550                         /* We found a usable spare */
 551                         break;
 552                 }
 553         }
 554
 555         if (i == nspares) {
 556                 /* No available spares were found */
 557                 return (false);
 558         }
 559
 560         error = nvlist_lookup_string(spares[i], ZPOOL_CONFIG_PATH, &devPath);
 561         if (error != 0) {
 562                 syslog(LOG_ERR, "CaseFile::ActivateSpare: Cannot determine "
 563                        "the path of pool %s, spare %d. Error %d",
 564                        poolname, i, error);
 565                 return (false);
 566         }
 567
 568         error = nvlist_lookup_string(spares[i], ZPOOL_CONFIG_TYPE, &vdev_type);
 569         if (error != 0) {
 570                 syslog(LOG_ERR, "CaseFile::ActivateSpare: Cannot determine "
 571                        "the vdev type of pool %s, spare %d. Error %d",
 572                        poolname, i, error);
 573                 return (false);
 574         }
 575
 576         return (Replace(vdev_type, devPath, /*isspare*/true));
 577 }
 578
 579 void
 580 CaseFile::RegisterCallout(const Event &event)
 581 {
 582         timeval now, countdown, elapsed, timestamp, zero, remaining;
 583
 584         gettimeofday(&now, 0);
 585         timestamp = event.GetTimestamp();
 586         timersub(&now, &timestamp, &elapsed);
 587         timersub(&s_removeGracePeriod, &elapsed, &countdown);
 588         /*
 589          * If countdown is <= zero, Reset the timer to the
 590          * smallest positive time value instead
 591          */
 592         timerclear(&zero);
 593         if (timercmp(&countdown, &zero, <=)) {
 594                 timerclear(&countdown);
 595                 countdown.tv_usec = 1;
 596         }
 597
 598         remaining = m_tentativeTimer.TimeRemaining();
 599
 600         if (!m_tentativeTimer.IsPending()
 601          || timercmp(&countdown, &remaining, <))
 602                 m_tentativeTimer.Reset(countdown, OnGracePeriodEnded, this);
 603 }
 604
 605
 606 bool
 607 CaseFile::CloseIfSolved()
 608 {
 609         if (m_events.empty()
 610          && m_tentativeEvents.empty()) {
 611
 612                 /*
 613                  * We currently do not track or take actions on
 614                  * devices in the degraded or faulted state.
 615                  * Once we have support for spare pools, we'll
 616                  * retain these cases so that any spares added in
 617                  * the future can be applied to them.
 618                  */
 619                 switch (VdevState()) {
 620                 case VDEV_STATE_HEALTHY:
 621                         /* No need to keep cases for healthy vdevs */
 622                         Close();
 623                         return (true);
 624                 case VDEV_STATE_REMOVED:
 625                 case VDEV_STATE_CANT_OPEN:
 626                         /*
 627                          * Keep open.  We may solve it with a newly inserted
 628                          * device.
 629                          */
 630                 case VDEV_STATE_FAULTED:
 631                 case VDEV_STATE_DEGRADED:
 632                         /*
 633                          * Keep open.  We may solve it with the future
 634                          * addition of a spare to the pool
 635                          */
 636                 case VDEV_STATE_UNKNOWN:
 637                 case VDEV_STATE_CLOSED:
 638                 case VDEV_STATE_OFFLINE:
 639                         /*
 640                          * Keep open?  This may not be the correct behavior,
 641                          * but it's what we've always done
 642                          */
 643                         ;
 644                 }
 645
 646                 /*
 647                  * Re-serialize the case in order to remove any
 648                  * previous event data.
 649                  */
 650                 Serialize();
 651         }
 652
 653         return (false);
 654 }
 655
 656 void
 657 CaseFile::Log()
 658 {
 659         syslog(LOG_INFO, "CaseFile(%s,%s,%s)\n", PoolGUIDString().c_str(),
 660                VdevGUIDString().c_str(), PhysicalPath().c_str());
 661         syslog(LOG_INFO, "\tVdev State = %s\n",
 662                zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 663         if (m_tentativeEvents.size() != 0) {
 664                 syslog(LOG_INFO, "\t=== Tentative Events ===\n");
 665                 for (EventList::iterator event(m_tentativeEvents.begin());
 666                      event != m_tentativeEvents.end(); event++)
 667                         (*event)->Log(LOG_INFO);
 668         }
 669         if (m_events.size() != 0) {
 670                 syslog(LOG_INFO, "\t=== Events ===\n");
 671                 for (EventList::iterator event(m_events.begin());
 672                      event != m_events.end(); event++)
 673                         (*event)->Log(LOG_INFO);
 674         }
 675 }
 676
 677 //- CaseFile Static Protected Methods ------------------------------------------
 678 void
 679 CaseFile::OnGracePeriodEnded(void *arg)
 680 {
 681         CaseFile &casefile(*static_cast<CaseFile *>(arg));
 682
 683         casefile.OnGracePeriodEnded();
 684 }
 685
 686 int
 687 CaseFile::DeSerializeSelector(const struct dirent *dirEntry)
 688 {
 689         uint64_t poolGUID;
 690         uint64_t vdevGUID;
 691
 692         if (dirEntry->d_type == DT_REG
 693          && sscanf(dirEntry->d_name, "pool_%" PRIu64 "_vdev_%" PRIu64 ".case",
 694                    &poolGUID, &vdevGUID) == 2)
 695                 return (1);
 696         return (0);
 697 }
 698
 699 void
 700 CaseFile::DeSerializeFile(const char *fileName)
 701 {
 702         string    fullName(s_caseFilePath + '/' + fileName);
 703         CaseFile *existingCaseFile(NULL);
 704         CaseFile *caseFile(NULL);
 705
 706         try {
 707                 uint64_t poolGUID;
 708                 uint64_t vdevGUID;
 709                 nvlist_t *vdevConf;
 710
 711                 if (sscanf(fileName, "pool_%" PRIu64 "_vdev_%" PRIu64 ".case",
 712                        &poolGUID, &vdevGUID) != 2) {
 713                         throw ZfsdException("CaseFile::DeSerialize: "
 714                             "Unintelligible CaseFile filename %s.\n", fileName);
 715                 }
 716                 existingCaseFile = Find(Guid(poolGUID), Guid(vdevGUID));
 717                 if (existingCaseFile != NULL) {
 718                         /*
 719                          * If the vdev is already degraded or faulted,
 720                          * there's no point in keeping the state around
 721                          * that we use to put a drive into the degraded
 722                          * state.  However, if the vdev is simply missing,
 723                          * preserve the case data in the hopes that it will
 724                          * return.
 725                          */
 726                         caseFile = existingCaseFile;
 727                         vdev_state curState(caseFile->VdevState());
 728                         if (curState > VDEV_STATE_CANT_OPEN
 729                          && curState < VDEV_STATE_HEALTHY) {
 730                                 unlink(fileName);
 731                                 return;
 732                         }
 733                 } else {
 734                         ZpoolList zpl(ZpoolList::ZpoolByGUID, &poolGUID);
 735                         if (zpl.empty()
 736                          || (vdevConf = VdevIterator(zpl.front())
 737                                                     .Find(vdevGUID)) == NULL) {
 738                                 /*
 739                                  * Either the pool no longer exists
 740                                  * or this vdev is no longer a member of
 741                                  * the pool.
 742                                  */
 743                                 unlink(fullName.c_str());
 744                                 return;
 745                         }
 746
 747                         /*
 748                          * Any vdev we find that does not have a case file
 749                          * must be in the healthy state and thus worthy of
 750                          * continued SERD data tracking.
 751                          */
 752                         caseFile = new CaseFile(Vdev(zpl.front(), vdevConf));
 753                 }
 754
 755                 ifstream caseStream(fullName.c_str());
 756                 if (!caseStream)
 757                         throw ZfsdException("CaseFile::DeSerialize: Unable to "
 758                                             "read %s.\n", fileName);
 759
 760                 caseFile->DeSerialize(caseStream);
 761         } catch (const ParseException &exp) {
 762
 763                 exp.Log();
 764                 if (caseFile != existingCaseFile)
 765                         delete caseFile;
 766
 767                 /*
 768                  * Since we can't parse the file, unlink it so we don't
 769                  * trip over it again.
 770                  */
 771                 unlink(fileName);
 772         } catch (const ZfsdException &zfsException) {
 773
 774                 zfsException.Log();
 775                 if (caseFile != existingCaseFile)
 776                         delete caseFile;
 777         }
 778 }
 779
 780 //- CaseFile Protected Methods -------------------------------------------------
 781 CaseFile::CaseFile(const Vdev &vdev)
 782  : m_poolGUID(vdev.PoolGUID()),
 783    m_vdevGUID(vdev.GUID()),
 784    m_vdevState(vdev.State()),
 785    m_vdevPhysPath(vdev.PhysicalPath())
 786 {
 787         stringstream guidString;
 788
 789         guidString << m_vdevGUID;
 790         m_vdevGUIDString = guidString.str();
 791         guidString.str("");
 792         guidString << m_poolGUID;
 793         m_poolGUIDString = guidString.str();
 794
 795         s_activeCases.push_back(this);
 796
 797         syslog(LOG_INFO, "Creating new CaseFile:\n");
 798         Log();
 799 }
 800
 801 CaseFile::~CaseFile()
 802 {
 803         PurgeEvents();
 804         PurgeTentativeEvents();
 805         m_tentativeTimer.Stop();
 806         s_activeCases.remove(this);
 807 }
 808
 809 void
 810 CaseFile::PurgeEvents()
 811 {
 812         for (EventList::iterator event(m_events.begin());
 813              event != m_events.end(); event++)
 814                 delete *event;
 815
 816         m_events.clear();
 817 }
 818
 819 void
 820 CaseFile::PurgeTentativeEvents()
 821 {
 822         for (EventList::iterator event(m_tentativeEvents.begin());
 823              event != m_tentativeEvents.end(); event++)
 824                 delete *event;
 825
 826         m_tentativeEvents.clear();
 827 }
 828
 829 void
 830 CaseFile::SerializeEvList(const EventList events, int fd,
 831                 const char* prefix) const
 832 {
 833         if (events.empty())
 834                 return;
 835         for (EventList::const_iterator curEvent = events.begin();
 836              curEvent != events.end(); curEvent++) {
 837                 const string &eventString((*curEvent)->GetEventString());
 838
 839                 // TODO: replace many write(2) calls with a single writev(2)
 840                 if (prefix)
 841                         write(fd, prefix, strlen(prefix));
 842                 write(fd, eventString.c_str(), eventString.length());
 843         }
 844 }
 845
 846 void
 847 CaseFile::Serialize()
 848 {
 849         stringstream saveFile;
 850
 851         saveFile << setfill('0')
 852                  << s_caseFilePath << "/"
 853                  << "pool_" << PoolGUIDString()
 854                  << "_vdev_" << VdevGUIDString()
 855                  << ".case";
 856
 857         if (m_events.empty() && m_tentativeEvents.empty()) {
 858                 unlink(saveFile.str().c_str());
 859                 return;
 860         }
 861
 862         int fd(open(saveFile.str().c_str(), O_CREAT|O_TRUNC|O_WRONLY, 0644));
 863         if (fd == -1) {
 864                 syslog(LOG_ERR, "CaseFile::Serialize: Unable to open %s.\n",
 865                        saveFile.str().c_str());
 866                 return;
 867         }
 868         SerializeEvList(m_events, fd);
 869         SerializeEvList(m_tentativeEvents, fd, "tentative ");
 870         close(fd);
 871 }
 872
 873 /*
 874  * XXX: This method assumes that events may not contain embedded newlines.  If
 875  * ever events can contain embedded newlines, then CaseFile must switch
 876  * serialization formats
 877  */
 878 void
 879 CaseFile::DeSerialize(ifstream &caseStream)
 880 {
 881         string        evString;
 882         const EventFactory &factory(ZfsDaemon::Get().GetFactory());
 883
 884         caseStream >> std::noskipws >> std::ws;
 885         while (caseStream.good()) {
 886                 /*
 887                  * Outline:
 888                  * read the beginning of a line and check it for
 889                  * "tentative".  If found, discard "tentative".
 890                  * Create a new event
 891                  * continue
 892                  */
 893                 EventList* destEvents;
 894                 const string tentFlag("tentative ");
 895                 string line;
 896                 std::stringbuf lineBuf;
 897
 898                 caseStream.get(lineBuf);
 899                 caseStream.ignore();  /*discard the newline character*/
 900                 line = lineBuf.str();
 901                 if (line.compare(0, tentFlag.size(), tentFlag) == 0) {
 902                         /* Discard "tentative" */
 903                         line.erase(0, tentFlag.size());
 904                         destEvents = &m_tentativeEvents;
 905                 } else {
 906                         destEvents = &m_events;
 907                 }
 908                 Event *event(Event::CreateEvent(factory, line));
 909                 if (event != NULL) {
 910                         destEvents->push_back(event);
 911                         RegisterCallout(*event);
 912                 }
 913         }
 914 }
 915
 916 void
 917 CaseFile::Close()
 918 {
 919         /*
 920          * This case is no longer relevant.  Clean up our
 921          * serialization file, and delete the case.
 922          */
 923         syslog(LOG_INFO, "CaseFile(%s,%s) closed - State %s\n",
 924                PoolGUIDString().c_str(), VdevGUIDString().c_str(),
 925                zpool_state_to_name(VdevState(), VDEV_AUX_NONE));
 926
 927         /*
 928          * Serialization of a Case with no event data, clears the
 929          * Serialization data for that event.
 930          */
 931         PurgeEvents();
 932         Serialize();
 933
 934         delete this;
 935 }
 936
 937 void
 938 CaseFile::OnGracePeriodEnded()
 939 {
 940         bool should_fault, should_degrade;
 941         ZpoolList zpl(ZpoolList::ZpoolByGUID, &m_poolGUID);
 942         zpool_handle_t *zhp(zpl.empty() ? NULL : zpl.front());
 943
 944         m_events.splice(m_events.begin(), m_tentativeEvents);
 945         should_fault = ShouldFault();
 946         should_degrade = ShouldDegrade();
 947
 948         if (should_fault || should_degrade) {
 949                 if (zhp == NULL
 950                  || (VdevIterator(zhp).Find(m_vdevGUID)) == NULL) {
 951                         /*
 952                          * Either the pool no longer exists
 953                          * or this vdev is no longer a member of
 954                          * the pool.
 955                          */
 956                         Close();
 957                         return;
 958                 }
 959
 960         }
 961
 962         /* A fault condition has priority over a degrade condition */
 963         if (ShouldFault()) {
 964                 /* Fault the vdev and close the case. */
 965                 if (zpool_vdev_fault(zhp, (uint64_t)m_vdevGUID,
 966                                        VDEV_AUX_ERR_EXCEEDED) == 0) {
 967                         syslog(LOG_INFO, "Faulting vdev(%s/%s)",
 968                                PoolGUIDString().c_str(),
 969                                VdevGUIDString().c_str());
 970                         Close();
 971                         return;
 972                 }
 973                 else {
 974                         syslog(LOG_ERR, "Fault vdev(%s/%s): %s: %s\n",
 975                                PoolGUIDString().c_str(),
 976                                VdevGUIDString().c_str(),
 977                                libzfs_error_action(g_zfsHandle),
 978                                libzfs_error_description(g_zfsHandle));
 979                 }
 980         }
 981         else if (ShouldDegrade()) {
 982                 /* Degrade the vdev and close the case. */
 983                 if (zpool_vdev_degrade(zhp, (uint64_t)m_vdevGUID,
 984                                        VDEV_AUX_ERR_EXCEEDED) == 0) {
 985                         syslog(LOG_INFO, "Degrading vdev(%s/%s)",
 986                                PoolGUIDString().c_str(),
 987                                VdevGUIDString().c_str());
 988                         Close();
 989                         return;
 990                 }
 991                 else {
 992                         syslog(LOG_ERR, "Degrade vdev(%s/%s): %s: %s\n",
 993                                PoolGUIDString().c_str(),
 994                                VdevGUIDString().c_str(),
 995                                libzfs_error_action(g_zfsHandle),
 996                                libzfs_error_description(g_zfsHandle));
 997                 }
 998         }
 999         Serialize();
1000 }
1001
1002 Vdev
1003 CaseFile::BeingReplacedBy(zpool_handle_t *zhp) {
1004         Vdev vd(zhp, CaseVdev(zhp));
1005         std::list<Vdev> children;
1006         std::list<Vdev>::iterator children_it;
1007
1008         Vdev parent(vd.Parent());
1009         Vdev replacing(NonexistentVdev);
1010
1011         /*
1012          * To determine whether we are being replaced by another spare that
1013          * is still working, then make sure that it is currently spared and
1014          * that the spare is either resilvering or healthy.  If any of these
1015          * conditions fail, then we are not being replaced by a spare.
1016          *
1017          * If the spare is healthy, then the case file should be closed very
1018          * soon after this check.
1019          */
1020         if (parent.DoesNotExist()
1021          || parent.Name(zhp, /*verbose*/false) != "spare")
1022                 return (NonexistentVdev);
1023
1024         children = parent.Children();
1025         children_it = children.begin();
1026         for (;children_it != children.end(); children_it++) {
1027                 Vdev child = *children_it;
1028
1029                 /* Skip our vdev. */
1030                 if (child.GUID() == VdevGUID())
1031                         continue;
1032                 /*
1033                  * Accept the first child that doesn't match our GUID, or
1034                  * any resilvering/healthy device if one exists.
1035                  */
1036                 if (replacing.DoesNotExist() || child.IsResilvering()
1037                  || child.State() == VDEV_STATE_HEALTHY)
1038                         replacing = child;
1039         }
1040
1041         return (replacing);
1042 }
1043
1044 bool
1045 CaseFile::Replace(const char* vdev_type, const char* path, bool isspare) {
1046         nvlist_t *nvroot, *newvd;
1047         const char *poolname;
1048         string oldstr(VdevGUIDString());
1049         bool retval = true;
1050
1051         /* Figure out what pool we're working on */
1052         ZpoolList zpl(ZpoolList::ZpoolByGUID, &m_poolGUID);
1053         zpool_handle_t *zhp(zpl.empty() ? NULL : zpl.front());
1054         if (zhp == NULL) {
1055                 syslog(LOG_ERR, "CaseFile::Replace: could not find pool for "
1056                        "pool_guid %" PRIu64 ".", (uint64_t)m_poolGUID);
1057                 return (false);
1058         }
1059         poolname = zpool_get_name(zhp);
1060         Vdev vd(zhp, CaseVdev(zhp));
1061         Vdev replaced(BeingReplacedBy(zhp));
1062
1063         if (isspare && !vd.IsSpare() && !replaced.DoesNotExist()) {
1064                 /* If we are already being replaced by a working spare, pass. */
1065                 if (replaced.IsResilvering()
1066                  || replaced.State() == VDEV_STATE_HEALTHY) {
1067                         syslog(LOG_INFO, "CaseFile::Replace(%s->%s): already "
1068                             "replaced", VdevGUIDString().c_str(), path);
1069                         return (/*consumed*/false);
1070                 }
1071                 /*
1072                  * If we have already been replaced by a spare, but that spare
1073                  * is broken, we must spare the spare, not the original device.
1074                  */
1075                 oldstr = replaced.GUIDString();
1076                 syslog(LOG_INFO, "CaseFile::Replace(%s->%s): sparing "
1077                     "broken spare %s instead", VdevGUIDString().c_str(),
1078                     path, oldstr.c_str());
1079         }
1080
1081         /*
1082          * Build a root vdev/leaf vdev configuration suitable for
1083          * zpool_vdev_attach. Only enough data for the kernel to find
1084          * the device (i.e. type and disk device node path) are needed.
1085          */
1086         nvroot = NULL;
1087         newvd = NULL;
1088
1089         if (nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) != 0
1090          || nvlist_alloc(&newvd, NV_UNIQUE_NAME, 0) != 0) {
1091                 syslog(LOG_ERR, "Replace vdev(%s/%s): Unable to allocate "
1092                     "configuration data.", poolname, oldstr.c_str());
1093                 if (nvroot != NULL)
1094                         nvlist_free(nvroot);
1095                 return (false);
1096         }
1097         if (nvlist_add_string(newvd, ZPOOL_CONFIG_TYPE, vdev_type) != 0
1098          || nvlist_add_string(newvd, ZPOOL_CONFIG_PATH, path) != 0
1099          || nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE, VDEV_TYPE_ROOT) != 0
1100          || nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
1101                                     &newvd, 1) != 0) {
1102                 syslog(LOG_ERR, "Replace vdev(%s/%s): Unable to initialize "
1103                     "configuration data.", poolname, oldstr.c_str());
1104                 nvlist_free(newvd);
1105                 nvlist_free(nvroot);
1106                 return (true);
1107         }
1108
1109         /* Data was copied when added to the root vdev. */
1110         nvlist_free(newvd);
1111
1112         retval = (zpool_vdev_attach(zhp, oldstr.c_str(), path, nvroot,
1113             /*replace*/B_TRUE) == 0);
1114         if (retval)
1115                 syslog(LOG_INFO, "Replacing vdev(%s/%s) with %s\n",
1116                     poolname, oldstr.c_str(), path);
1117         else
1118                 syslog(LOG_ERR, "Replace vdev(%s/%s): %s: %s\n",
1119                     poolname, oldstr.c_str(), libzfs_error_action(g_zfsHandle),
1120                     libzfs_error_description(g_zfsHandle));
1121         nvlist_free(nvroot);
1122
1123         return (retval);
1124 }
1125
1126 /* Does the argument event refer to a checksum error? */
1127 static bool
1128 IsChecksumEvent(const Event* const event)
1129 {
1130         return ("ereport.fs.zfs.checksum" == event->Value("type"));
1131 }
1132
1133 /* Does the argument event refer to an IO error? */
1134 static bool
1135 IsIOEvent(const Event* const event)
1136 {
1137         return ("ereport.fs.zfs.io" == event->Value("type"));
1138 }
1139
1140 bool
1141 CaseFile::ShouldDegrade() const
1142 {
1143         return (std::count_if(m_events.begin(), m_events.end(),
1144                               IsChecksumEvent) > ZFS_DEGRADE_IO_COUNT);
1145 }
1146
1147 bool
1148 CaseFile::ShouldFault() const
1149 {
1150         return (std::count_if(m_events.begin(), m_events.end(),
1151                               IsIOEvent) > ZFS_DEGRADE_IO_COUNT);
1152 }
1153
1154 nvlist_t *
1155 CaseFile::CaseVdev(zpool_handle_t *zhp) const
1156 {
1157         return (VdevIterator(zhp).Find(VdevGUID()));
1158 }