zfs/lib/libzfs/libzfs_import.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "@(#)libzfs_import.c    1.24    08/04/08 SMI"
  27
  28 /*
  29  * Pool import support functions.
  30  *
  31  * To import a pool, we rely on reading the configuration information from the
  32  * ZFS label of each device.  If we successfully read the label, then we
  33  * organize the configuration information in the following hierarchy:
  34  *
  35  *      pool guid -> toplevel vdev guid -> label txg
  36  *
  37  * Duplicate entries matching this same tuple will be discarded.  Once we have
  38  * examined every device, we pick the best label txg config for each toplevel
  39  * vdev.  We then arrange these toplevel vdevs into a complete pool config, and
  40  * update any paths that have changed.  Finally, we attempt to import the pool
  41  * using our derived config, and record the results.
  42  */
  43
  44 #include <devid.h>
  45 #include <dirent.h>
  46 #include <errno.h>
  47 #include <libintl.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <sys/stat.h>
  51 #include <unistd.h>
  52 #include <fcntl.h>
  53
  54 #include <sys/vdev_impl.h>
  55
  56 #include "libzfs.h"
  57 #include "libzfs_impl.h"
  58
  59 /*
  60  * Intermediate structures used to gather configuration information.
  61  */
  62 typedef struct config_entry {
  63         uint64_t                ce_txg;
  64         nvlist_t                *ce_config;
  65         struct config_entry     *ce_next;
  66 } config_entry_t;
  67
  68 typedef struct vdev_entry {
  69         uint64_t                ve_guid;
  70         config_entry_t          *ve_configs;
  71         struct vdev_entry       *ve_next;
  72 } vdev_entry_t;
  73
  74 typedef struct pool_entry {
  75         uint64_t                pe_guid;
  76         vdev_entry_t            *pe_vdevs;
  77         struct pool_entry       *pe_next;
  78 } pool_entry_t;
  79
  80 typedef struct name_entry {
  81         char                    *ne_name;
  82         uint64_t                ne_guid;
  83         struct name_entry       *ne_next;
  84 } name_entry_t;
  85
  86 typedef struct pool_list {
  87         pool_entry_t            *pools;
  88         name_entry_t            *names;
  89 } pool_list_t;
  90
  91 static char *
  92 get_devid(const char *path)
  93 {
  94         int fd;
  95         ddi_devid_t devid;
  96         char *minor, *ret;
  97
  98         if ((fd = open(path, O_RDONLY)) < 0)
  99                 return (NULL);
 100
 101         minor = NULL;
 102         ret = NULL;
 103         if (devid_get(fd, &devid) == 0) {
 104                 if (devid_get_minor_name(fd, &minor) == 0)
 105                         ret = devid_str_encode(devid, minor);
 106                 if (minor != NULL)
 107                         devid_str_free(minor);
 108                 devid_free(devid);
 109         }
 110         (void) close(fd);
 111
 112         return (ret);
 113 }
 114
 115
 116 /*
 117  * Go through and fix up any path and/or devid information for the given vdev
 118  * configuration.
 119  */
 120 static int
 121 fix_paths(nvlist_t *nv, name_entry_t *names)
 122 {
 123         nvlist_t **child;
 124         uint_t c, children;
 125         uint64_t guid;
 126         name_entry_t *ne, *best;
 127         char *path, *devid;
 128         int matched;
 129
 130         if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 131             &child, &children) == 0) {
 132                 for (c = 0; c < children; c++)
 133                         if (fix_paths(child[c], names) != 0)
 134                                 return (-1);
 135                 return (0);
 136         }
 137
 138         /*
 139          * This is a leaf (file or disk) vdev.  In either case, go through
 140          * the name list and see if we find a matching guid.  If so, replace
 141          * the path and see if we can calculate a new devid.
 142          *
 143          * There may be multiple names associated with a particular guid, in
 144          * which case we have overlapping slices or multiple paths to the same
 145          * disk.  If this is the case, then we want to pick the path that is
 146          * the most similar to the original, where "most similar" is the number
 147          * of matching characters starting from the end of the path.  This will
 148          * preserve slice numbers even if the disks have been reorganized, and
 149          * will also catch preferred disk names if multiple paths exist.
 150          */
 151         verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) == 0);
 152         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
 153                 path = NULL;
 154
 155         matched = 0;
 156         best = NULL;
 157         for (ne = names; ne != NULL; ne = ne->ne_next) {
 158                 if (ne->ne_guid == guid) {
 159                         const char *src, *dst;
 160                         int count;
 161
 162                         if (path == NULL) {
 163                                 best = ne;
 164                                 break;
 165                         }
 166
 167                         src = ne->ne_name + strlen(ne->ne_name) - 1;
 168                         dst = path + strlen(path) - 1;
 169                         for (count = 0; src >= ne->ne_name && dst >= path;
 170                             src--, dst--, count++)
 171                                 if (*src != *dst)
 172                                         break;
 173
 174                         /*
 175                          * At this point, 'count' is the number of characters
 176                          * matched from the end.
 177                          */
 178                         if (count > matched || best == NULL) {
 179                                 best = ne;
 180                                 matched = count;
 181                         }
 182                 }
 183         }
 184
 185         if (best == NULL)
 186                 return (0);
 187
 188         if (nvlist_add_string(nv, ZPOOL_CONFIG_PATH, best->ne_name) != 0)
 189                 return (-1);
 190
 191         if ((devid = get_devid(best->ne_name)) == NULL) {
 192                 (void) nvlist_remove_all(nv, ZPOOL_CONFIG_DEVID);
 193         } else {
 194                 if (nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, devid) != 0)
 195                         return (-1);
 196                 devid_str_free(devid);
 197         }
 198
 199         return (0);
 200 }
 201
 202 /*
 203  * Add the given configuration to the list of known devices.
 204  */
 205 static int
 206 add_config(libzfs_handle_t *hdl, pool_list_t *pl, const char *path,
 207     nvlist_t *config)
 208 {
 209         uint64_t pool_guid, vdev_guid, top_guid, txg, state;
 210         pool_entry_t *pe;
 211         vdev_entry_t *ve;
 212         config_entry_t *ce;
 213         name_entry_t *ne;
 214
 215         /*
 216          * If this is a hot spare not currently in use or level 2 cache
 217          * device, add it to the list of names to translate, but don't do
 218          * anything else.
 219          */
 220         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 221             &state) == 0 &&
 222             (state == POOL_STATE_SPARE || state == POOL_STATE_L2CACHE) &&
 223             nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &vdev_guid) == 0) {
 224                 if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
 225                         return (-1);
 226
 227                 if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
 228                         free(ne);
 229                         return (-1);
 230                 }
 231                 ne->ne_guid = vdev_guid;
 232                 ne->ne_next = pl->names;
 233                 pl->names = ne;
 234                 return (0);
 235         }
 236
 237         /*
 238          * If we have a valid config but cannot read any of these fields, then
 239          * it means we have a half-initialized label.  In vdev_label_init()
 240          * we write a label with txg == 0 so that we can identify the device
 241          * in case the user refers to the same disk later on.  If we fail to
 242          * create the pool, we'll be left with a label in this state
 243          * which should not be considered part of a valid pool.
 244          */
 245         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 246             &pool_guid) != 0 ||
 247             nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
 248             &vdev_guid) != 0 ||
 249             nvlist_lookup_uint64(config, ZPOOL_CONFIG_TOP_GUID,
 250             &top_guid) != 0 ||
 251             nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 252             &txg) != 0 || txg == 0) {
 253                 nvlist_free(config);
 254                 return (0);
 255         }
 256
 257         /*
 258          * First, see if we know about this pool.  If not, then add it to the
 259          * list of known pools.
 260          */
 261         for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
 262                 if (pe->pe_guid == pool_guid)
 263                         break;
 264         }
 265
 266         if (pe == NULL) {
 267                 if ((pe = zfs_alloc(hdl, sizeof (pool_entry_t))) == NULL) {
 268                         nvlist_free(config);
 269                         return (-1);
 270                 }
 271                 pe->pe_guid = pool_guid;
 272                 pe->pe_next = pl->pools;
 273                 pl->pools = pe;
 274         }
 275
 276         /*
 277          * Second, see if we know about this toplevel vdev.  Add it if its
 278          * missing.
 279          */
 280         for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
 281                 if (ve->ve_guid == top_guid)
 282                         break;
 283         }
 284
 285         if (ve == NULL) {
 286                 if ((ve = zfs_alloc(hdl, sizeof (vdev_entry_t))) == NULL) {
 287                         nvlist_free(config);
 288                         return (-1);
 289                 }
 290                 ve->ve_guid = top_guid;
 291                 ve->ve_next = pe->pe_vdevs;
 292                 pe->pe_vdevs = ve;
 293         }
 294
 295         /*
 296          * Third, see if we have a config with a matching transaction group.  If
 297          * so, then we do nothing.  Otherwise, add it to the list of known
 298          * configs.
 299          */
 300         for (ce = ve->ve_configs; ce != NULL; ce = ce->ce_next) {
 301                 if (ce->ce_txg == txg)
 302                         break;
 303         }
 304
 305         if (ce == NULL) {
 306                 if ((ce = zfs_alloc(hdl, sizeof (config_entry_t))) == NULL) {
 307                         nvlist_free(config);
 308                         return (-1);
 309                 }
 310                 ce->ce_txg = txg;
 311                 ce->ce_config = config;
 312                 ce->ce_next = ve->ve_configs;
 313                 ve->ve_configs = ce;
 314         } else {
 315                 nvlist_free(config);
 316         }
 317
 318         /*
 319          * At this point we've successfully added our config to the list of
 320          * known configs.  The last thing to do is add the vdev guid -> path
 321          * mappings so that we can fix up the configuration as necessary before
 322          * doing the import.
 323          */
 324         if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
 325                 return (-1);
 326
 327         if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
 328                 free(ne);
 329                 return (-1);
 330         }
 331
 332         ne->ne_guid = vdev_guid;
 333         ne->ne_next = pl->names;
 334         pl->names = ne;
 335
 336         return (0);
 337 }
 338
 339 /*
 340  * Returns true if the named pool matches the given GUID.
 341  */
 342 static int
 343 pool_active(libzfs_handle_t *hdl, const char *name, uint64_t guid,
 344     boolean_t *isactive)
 345 {
 346         zpool_handle_t *zhp;
 347         uint64_t theguid;
 348
 349         if (zpool_open_silent(hdl, name, &zhp) != 0)
 350                 return (-1);
 351
 352         if (zhp == NULL) {
 353                 *isactive = B_FALSE;
 354                 return (0);
 355         }
 356
 357         verify(nvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_POOL_GUID,
 358             &theguid) == 0);
 359
 360         zpool_close(zhp);
 361
 362         *isactive = (theguid == guid);
 363         return (0);
 364 }
 365
 366 static nvlist_t *
 367 refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
 368 {
 369         nvlist_t *nvl;
 370         zfs_cmd_t zc = { 0 };
 371         int err;
 372
 373         if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0)
 374                 return (NULL);
 375
 376         if (zcmd_alloc_dst_nvlist(hdl, &zc,
 377             zc.zc_nvlist_conf_size * 2) != 0) {
 378                 zcmd_free_nvlists(&zc);
 379                 return (NULL);
 380         }
 381
 382         while ((err = ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_TRYIMPORT,
 383             &zc)) != 0 && errno == ENOMEM) {
 384                 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 385                         zcmd_free_nvlists(&zc);
 386                         return (NULL);
 387                 }
 388         }
 389
 390         if (err) {
 391                 (void) zpool_standard_error(hdl, errno,
 392                     dgettext(TEXT_DOMAIN, "cannot discover pools"));
 393                 zcmd_free_nvlists(&zc);
 394                 return (NULL);
 395         }
 396
 397         if (zcmd_read_dst_nvlist(hdl, &zc, &nvl) != 0) {
 398                 zcmd_free_nvlists(&zc);
 399                 return (NULL);
 400         }
 401
 402         zcmd_free_nvlists(&zc);
 403         return (nvl);
 404 }
 405
 406 /*
 407  * Convert our list of pools into the definitive set of configurations.  We
 408  * start by picking the best config for each toplevel vdev.  Once that's done,
 409  * we assemble the toplevel vdevs into a full config for the pool.  We make a
 410  * pass to fix up any incorrect paths, and then add it to the main list to
 411  * return to the user.
 412  */
 413 static nvlist_t *
 414 get_configs(libzfs_handle_t *hdl, pool_list_t *pl, boolean_t active_ok)
 415 {
 416         pool_entry_t *pe;
 417         vdev_entry_t *ve;
 418         config_entry_t *ce;
 419         nvlist_t *ret = NULL, *config = NULL, *tmp, *nvtop, *nvroot;
 420         nvlist_t **spares, **l2cache;
 421         uint_t i, nspares, nl2cache;
 422         boolean_t config_seen;
 423         uint64_t best_txg;
 424         char *name, *hostname;
 425         uint64_t version, guid;
 426         uint_t children = 0;
 427         nvlist_t **child = NULL;
 428         uint_t c;
 429         boolean_t isactive;
 430         uint64_t hostid;
 431         nvlist_t *nvl;
 432
 433         if (nvlist_alloc(&ret, 0, 0) != 0)
 434                 goto nomem;
 435
 436         for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
 437                 uint64_t id;
 438
 439                 if (nvlist_alloc(&config, NV_UNIQUE_NAME, 0) != 0)
 440                         goto nomem;
 441                 config_seen = B_FALSE;
 442
 443                 /*
 444                  * Iterate over all toplevel vdevs.  Grab the pool configuration
 445                  * from the first one we find, and then go through the rest and
 446                  * add them as necessary to the 'vdevs' member of the config.
 447                  */
 448                 for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
 449
 450                         /*
 451                          * Determine the best configuration for this vdev by
 452                          * selecting the config with the latest transaction
 453                          * group.
 454                          */
 455                         best_txg = 0;
 456                         for (ce = ve->ve_configs; ce != NULL;
 457                             ce = ce->ce_next) {
 458
 459                                 if (ce->ce_txg > best_txg) {
 460                                         tmp = ce->ce_config;
 461                                         best_txg = ce->ce_txg;
 462                                 }
 463                         }
 464
 465                         if (!config_seen) {
 466                                 /*
 467                                  * Copy the relevant pieces of data to the pool
 468                                  * configuration:
 469                                  *
 470                                  *      version
 471                                  *      pool guid
 472                                  *      name
 473                                  *      pool state
 474                                  *      hostid (if available)
 475                                  *      hostname (if available)
 476                                  */
 477                                 uint64_t state;
 478
 479                                 verify(nvlist_lookup_uint64(tmp,
 480                                     ZPOOL_CONFIG_VERSION, &version) == 0);
 481                                 if (nvlist_add_uint64(config,
 482                                     ZPOOL_CONFIG_VERSION, version) != 0)
 483                                         goto nomem;
 484                                 verify(nvlist_lookup_uint64(tmp,
 485                                     ZPOOL_CONFIG_POOL_GUID, &guid) == 0);
 486                                 if (nvlist_add_uint64(config,
 487                                     ZPOOL_CONFIG_POOL_GUID, guid) != 0)
 488                                         goto nomem;
 489                                 verify(nvlist_lookup_string(tmp,
 490                                     ZPOOL_CONFIG_POOL_NAME, &name) == 0);
 491                                 if (nvlist_add_string(config,
 492                                     ZPOOL_CONFIG_POOL_NAME, name) != 0)
 493                                         goto nomem;
 494                                 verify(nvlist_lookup_uint64(tmp,
 495                                     ZPOOL_CONFIG_POOL_STATE, &state) == 0);
 496                                 if (nvlist_add_uint64(config,
 497                                     ZPOOL_CONFIG_POOL_STATE, state) != 0)
 498                                         goto nomem;
 499                                 hostid = 0;
 500                                 if (nvlist_lookup_uint64(tmp,
 501                                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
 502                                         if (nvlist_add_uint64(config,
 503                                             ZPOOL_CONFIG_HOSTID, hostid) != 0)
 504                                                 goto nomem;
 505                                         verify(nvlist_lookup_string(tmp,
 506                                             ZPOOL_CONFIG_HOSTNAME,
 507                                             &hostname) == 0);
 508                                         if (nvlist_add_string(config,
 509                                             ZPOOL_CONFIG_HOSTNAME,
 510                                             hostname) != 0)
 511                                                 goto nomem;
 512                                 }
 513
 514                                 config_seen = B_TRUE;
 515                         }
 516
 517                         /*
 518                          * Add this top-level vdev to the child array.
 519                          */
 520                         verify(nvlist_lookup_nvlist(tmp,
 521                             ZPOOL_CONFIG_VDEV_TREE, &nvtop) == 0);
 522                         verify(nvlist_lookup_uint64(nvtop, ZPOOL_CONFIG_ID,
 523                             &id) == 0);
 524                         if (id >= children) {
 525                                 nvlist_t **newchild;
 526
 527                                 newchild = zfs_alloc(hdl, (id + 1) *
 528                                     sizeof (nvlist_t *));
 529                                 if (newchild == NULL)
 530                                         goto nomem;
 531
 532                                 for (c = 0; c < children; c++)
 533                                         newchild[c] = child[c];
 534
 535                                 free(child);
 536                                 child = newchild;
 537                                 children = id + 1;
 538                         }
 539                         if (nvlist_dup(nvtop, &child[id], 0) != 0)
 540                                 goto nomem;
 541
 542                 }
 543
 544                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 545                     &guid) == 0);
 546
 547                 /*
 548                  * Look for any missing top-level vdevs.  If this is the case,
 549                  * create a faked up 'missing' vdev as a placeholder.  We cannot
 550                  * simply compress the child array, because the kernel performs
 551                  * certain checks to make sure the vdev IDs match their location
 552                  * in the configuration.
 553                  */
 554                 for (c = 0; c < children; c++)
 555                         if (child[c] == NULL) {
 556                                 nvlist_t *missing;
 557                                 if (nvlist_alloc(&missing, NV_UNIQUE_NAME,
 558                                     0) != 0)
 559                                         goto nomem;
 560                                 if (nvlist_add_string(missing,
 561                                     ZPOOL_CONFIG_TYPE,
 562                                     VDEV_TYPE_MISSING) != 0 ||
 563                                     nvlist_add_uint64(missing,
 564                                     ZPOOL_CONFIG_ID, c) != 0 ||
 565                                     nvlist_add_uint64(missing,
 566                                     ZPOOL_CONFIG_GUID, 0ULL) != 0) {
 567                                         nvlist_free(missing);
 568                                         goto nomem;
 569                                 }
 570                                 child[c] = missing;
 571                         }
 572
 573                 /*
 574                  * Put all of this pool's top-level vdevs into a root vdev.
 575                  */
 576                 if (nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) != 0)
 577                         goto nomem;
 578                 if (nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
 579                     VDEV_TYPE_ROOT) != 0 ||
 580                     nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) != 0 ||
 581                     nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, guid) != 0 ||
 582                     nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
 583                     child, children) != 0) {
 584                         nvlist_free(nvroot);
 585                         goto nomem;
 586                 }
 587
 588                 for (c = 0; c < children; c++)
 589                         nvlist_free(child[c]);
 590                 free(child);
 591                 children = 0;
 592                 child = NULL;
 593
 594                 /*
 595                  * Go through and fix up any paths and/or devids based on our
 596                  * known list of vdev GUID -> path mappings.
 597                  */
 598                 if (fix_paths(nvroot, pl->names) != 0) {
 599                         nvlist_free(nvroot);
 600                         goto nomem;
 601                 }
 602
 603                 /*
 604                  * Add the root vdev to this pool's configuration.
 605                  */
 606                 if (nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
 607                     nvroot) != 0) {
 608                         nvlist_free(nvroot);
 609                         goto nomem;
 610                 }
 611                 nvlist_free(nvroot);
 612
 613                 /*
 614                  * zdb uses this path to report on active pools that were
 615                  * imported or created using -R.
 616                  */
 617                 if (active_ok)
 618                         goto add_pool;
 619
 620                 /*
 621                  * Determine if this pool is currently active, in which case we
 622                  * can't actually import it.
 623                  */
 624                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
 625                     &name) == 0);
 626                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 627                     &guid) == 0);
 628
 629                 if (pool_active(hdl, name, guid, &isactive) != 0)
 630                         goto error;
 631
 632                 if (isactive) {
 633                         nvlist_free(config);
 634                         config = NULL;
 635                         continue;
 636                 }
 637
 638                 if ((nvl = refresh_config(hdl, config)) == NULL)
 639                         goto error;
 640
 641                 nvlist_free(config);
 642                 config = nvl;
 643
 644                 /*
 645                  * Go through and update the paths for spares, now that we have
 646                  * them.
 647                  */
 648                 verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
 649                     &nvroot) == 0);
 650                 if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
 651                     &spares, &nspares) == 0) {
 652                         for (i = 0; i < nspares; i++) {
 653                                 if (fix_paths(spares[i], pl->names) != 0)
 654                                         goto nomem;
 655                         }
 656                 }
 657
 658                 /*
 659                  * Update the paths for l2cache devices.
 660                  */
 661                 if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
 662                     &l2cache, &nl2cache) == 0) {
 663                         for (i = 0; i < nl2cache; i++) {
 664                                 if (fix_paths(l2cache[i], pl->names) != 0)
 665                                         goto nomem;
 666                         }
 667                 }
 668
 669                 /*
 670                  * Restore the original information read from the actual label.
 671                  */
 672                 (void) nvlist_remove(config, ZPOOL_CONFIG_HOSTID,
 673                     DATA_TYPE_UINT64);
 674                 (void) nvlist_remove(config, ZPOOL_CONFIG_HOSTNAME,
 675                     DATA_TYPE_STRING);
 676                 if (hostid != 0) {
 677                         verify(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 678                             hostid) == 0);
 679                         verify(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
 680                             hostname) == 0);
 681                 }
 682
 683 add_pool:
 684                 /*
 685                  * Add this pool to the list of configs.
 686                  */
 687                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
 688                     &name) == 0);
 689                 if (nvlist_add_nvlist(ret, name, config) != 0)
 690                         goto nomem;
 691
 692                 nvlist_free(config);
 693                 config = NULL;
 694         }
 695
 696         return (ret);
 697
 698 nomem:
 699         (void) no_memory(hdl);
 700 error:
 701         nvlist_free(config);
 702         nvlist_free(ret);
 703         for (c = 0; c < children; c++)
 704                 nvlist_free(child[c]);
 705         free(child);
 706
 707         return (NULL);
 708 }
 709
 710 /*
 711  * Return the offset of the given label.
 712  */
 713 static uint64_t
 714 label_offset(uint64_t size, int l)
 715 {
 716         ASSERT(P2PHASE_TYPED(size, sizeof (vdev_label_t), uint64_t) == 0);
 717         return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
 718             0 : size - VDEV_LABELS * sizeof (vdev_label_t)));
 719 }
 720
 721 /*
 722  * Given a file descriptor, read the label information and return an nvlist
 723  * describing the configuration, if there is one.
 724  */
 725 int
 726 zpool_read_label(int fd, nvlist_t **config)
 727 {
 728         struct stat64 statbuf;
 729         int l;
 730         vdev_label_t *label;
 731         uint64_t state, txg, size;
 732
 733         *config = NULL;
 734
 735         if (fstat64(fd, &statbuf) == -1)
 736                 return (0);
 737         size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
 738
 739         if ((label = malloc(sizeof (vdev_label_t))) == NULL)
 740                 return (-1);
 741
 742         for (l = 0; l < VDEV_LABELS; l++) {
 743                 if (pread(fd, label, sizeof (vdev_label_t),
 744                     label_offset(size, l)) != sizeof (vdev_label_t))
 745                         continue;
 746
 747                 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
 748                     sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0)
 749                         continue;
 750
 751                 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
 752                     &state) != 0 || state > POOL_STATE_L2CACHE) {
 753                         nvlist_free(*config);
 754                         continue;
 755                 }
 756
 757                 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
 758                     (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
 759                     &txg) != 0 || txg == 0)) {
 760                         nvlist_free(*config);
 761                         continue;
 762                 }
 763
 764                 free(label);
 765                 return (0);
 766         }
 767
 768         free(label);
 769         *config = NULL;
 770         return (0);
 771 }
 772
 773 /*
 774  * Given a list of directories to search, find all pools stored on disk.  This
 775  * includes partial pools which are not available to import.  If no args are
 776  * given (argc is 0), then the default directory (/dev/dsk) is searched.
 777  */
 778 nvlist_t *
 779 zpool_find_import(libzfs_handle_t *hdl, int argc, char **argv,
 780     boolean_t active_ok)
 781 {
 782         int i;
 783         DIR *dirp = NULL;
 784         struct dirent64 *dp;
 785         char path[MAXPATHLEN];
 786         char *end;
 787         size_t pathleft;
 788         struct stat64 statbuf;
 789         nvlist_t *ret = NULL, *config;
 790         static char *default_dir = "/dev/dsk";
 791         int fd;
 792         pool_list_t pools = { 0 };
 793         pool_entry_t *pe, *penext;
 794         vdev_entry_t *ve, *venext;
 795         config_entry_t *ce, *cenext;
 796         name_entry_t *ne, *nenext;
 797
 798         if (argc == 0) {
 799                 argc = 1;
 800                 argv = &default_dir;
 801         }
 802
 803         /*
 804          * Go through and read the label configuration information from every
 805          * possible device, organizing the information according to pool GUID
 806          * and toplevel GUID.
 807          */
 808         for (i = 0; i < argc; i++) {
 809                 char *rdsk;
 810                 int dfd;
 811
 812                 /* use realpath to normalize the path */
 813                 if (realpath(argv[i], path) == 0) {
 814                         (void) zfs_error_fmt(hdl, EZFS_BADPATH,
 815                             dgettext(TEXT_DOMAIN, "cannot open '%s'"),
 816                             argv[i]);
 817                         goto error;
 818                 }
 819                 end = &path[strlen(path)];
 820                 *end++ = '/';
 821                 *end = 0;
 822                 pathleft = &path[sizeof (path)] - end;
 823
 824                 /*
 825                  * Using raw devices instead of block devices when we're
 826                  * reading the labels skips a bunch of slow operations during
 827                  * close(2) processing, so we replace /dev/dsk with /dev/rdsk.
 828                  */
 829                 if (strcmp(path, "/dev/dsk/") == 0)
 830                         rdsk = "/dev/rdsk/";
 831                 else
 832                         rdsk = path;
 833
 834                 if ((dfd = open64(rdsk, O_RDONLY)) < 0 ||
 835                     (dirp = fdopendir(dfd)) == NULL) {
 836                         zfs_error_aux(hdl, strerror(errno));
 837                         (void) zfs_error_fmt(hdl, EZFS_BADPATH,
 838                             dgettext(TEXT_DOMAIN, "cannot open '%s'"),
 839                             rdsk);
 840                         goto error;
 841                 }
 842
 843                 /*
 844                  * This is not MT-safe, but we have no MT consumers of libzfs
 845                  */
 846                 while ((dp = readdir64(dirp)) != NULL) {
 847                         const char *name = dp->d_name;
 848                         if (name[0] == '.' &&
 849                             (name[1] == 0 || (name[1] == '.' && name[2] == 0)))
 850                                 continue;
 851
 852                         if ((fd = openat64(dfd, name, O_RDONLY)) < 0)
 853                                 continue;
 854
 855                         /*
 856                          * Ignore failed stats.  We only want regular
 857                          * files, character devs and block devs.
 858                          */
 859                         if (fstat64(fd, &statbuf) != 0 ||
 860                             (!S_ISREG(statbuf.st_mode) &&
 861                             !S_ISCHR(statbuf.st_mode) &&
 862                             !S_ISBLK(statbuf.st_mode))) {
 863                                 (void) close(fd);
 864                                 continue;
 865                         }
 866
 867                         if ((zpool_read_label(fd, &config)) != 0) {
 868                                 (void) close(fd);
 869                                 (void) no_memory(hdl);
 870                                 goto error;
 871                         }
 872
 873                         (void) close(fd);
 874
 875                         if (config != NULL) {
 876                                 /* use the non-raw path for the config */
 877                                 (void) strlcpy(end, name, pathleft);
 878                                 if (add_config(hdl, &pools, path, config) != 0)
 879                                         goto error;
 880                         }
 881                 }
 882
 883                 (void) closedir(dirp);
 884                 dirp = NULL;
 885         }
 886
 887         ret = get_configs(hdl, &pools, active_ok);
 888
 889 error:
 890         for (pe = pools.pools; pe != NULL; pe = penext) {
 891                 penext = pe->pe_next;
 892                 for (ve = pe->pe_vdevs; ve != NULL; ve = venext) {
 893                         venext = ve->ve_next;
 894                         for (ce = ve->ve_configs; ce != NULL; ce = cenext) {
 895                                 cenext = ce->ce_next;
 896                                 if (ce->ce_config)
 897                                         nvlist_free(ce->ce_config);
 898                                 free(ce);
 899                         }
 900                         free(ve);
 901                 }
 902                 free(pe);
 903         }
 904
 905         for (ne = pools.names; ne != NULL; ne = nenext) {
 906                 nenext = ne->ne_next;
 907                 if (ne->ne_name)
 908                         free(ne->ne_name);
 909                 free(ne);
 910         }
 911
 912         if (dirp)
 913                 (void) closedir(dirp);
 914
 915         return (ret);
 916 }
 917
 918 /*
 919  * Given a cache file, return the contents as a list of importable pools.
 920  */
 921 nvlist_t *
 922 zpool_find_import_cached(libzfs_handle_t *hdl, const char *cachefile,
 923     boolean_t active_ok)
 924 {
 925         char *buf;
 926         int fd;
 927         struct stat64 statbuf;
 928         nvlist_t *raw, *src, *dst;
 929         nvlist_t *pools;
 930         nvpair_t *elem;
 931         char *name;
 932         uint64_t guid;
 933         boolean_t active;
 934
 935         if ((fd = open(cachefile, O_RDONLY)) < 0) {
 936                 zfs_error_aux(hdl, "%s", strerror(errno));
 937                 (void) zfs_error(hdl, EZFS_BADCACHE,
 938                     dgettext(TEXT_DOMAIN, "failed to open cache file"));
 939                 return (NULL);
 940         }
 941
 942         if (fstat64(fd, &statbuf) != 0) {
 943                 zfs_error_aux(hdl, "%s", strerror(errno));
 944                 (void) close(fd);
 945                 (void) zfs_error(hdl, EZFS_BADCACHE,
 946                     dgettext(TEXT_DOMAIN, "failed to get size of cache file"));
 947                 return (NULL);
 948         }
 949
 950         if ((buf = zfs_alloc(hdl, statbuf.st_size)) == NULL) {
 951                 (void) close(fd);
 952                 return (NULL);
 953         }
 954
 955         if (read(fd, buf, statbuf.st_size) != statbuf.st_size) {
 956                 (void) close(fd);
 957                 free(buf);
 958                 (void) zfs_error(hdl, EZFS_BADCACHE,
 959                     dgettext(TEXT_DOMAIN,
 960                     "failed to read cache file contents"));
 961                 return (NULL);
 962         }
 963
 964         (void) close(fd);
 965
 966         if (nvlist_unpack(buf, statbuf.st_size, &raw, 0) != 0) {
 967                 free(buf);
 968                 (void) zfs_error(hdl, EZFS_BADCACHE,
 969                     dgettext(TEXT_DOMAIN,
 970                     "invalid or corrupt cache file contents"));
 971                 return (NULL);
 972         }
 973
 974         free(buf);
 975
 976         /*
 977          * Go through and get the current state of the pools and refresh their
 978          * state.
 979          */
 980         if (nvlist_alloc(&pools, 0, 0) != 0) {
 981                 (void) no_memory(hdl);
 982                 nvlist_free(raw);
 983                 return (NULL);
 984         }
 985
 986         elem = NULL;
 987         while ((elem = nvlist_next_nvpair(raw, elem)) != NULL) {
 988                 verify(nvpair_value_nvlist(elem, &src) == 0);
 989
 990                 verify(nvlist_lookup_string(src, ZPOOL_CONFIG_POOL_NAME,
 991                     &name) == 0);
 992                 verify(nvlist_lookup_uint64(src, ZPOOL_CONFIG_POOL_GUID,
 993                     &guid) == 0);
 994
 995                 if (!active_ok) {
 996                         if (pool_active(hdl, name, guid, &active) != 0) {
 997                                 nvlist_free(raw);
 998                                 nvlist_free(pools);
 999                                 return (NULL);
1000                         }
1001
1002                         if (active)
1003                                 continue;
1004
1005                         if ((dst = refresh_config(hdl, src)) == NULL) {
1006                                 nvlist_free(raw);
1007                                 nvlist_free(pools);
1008                                 return (NULL);
1009                         }
1010
1011                         if (nvlist_add_nvlist(pools, nvpair_name(elem), dst)
1012                             != 0) {
1013                                 (void) no_memory(hdl);
1014                                 nvlist_free(dst);
1015                                 nvlist_free(raw);
1016                                 nvlist_free(pools);
1017                                 return (NULL);
1018                         }
1019                         nvlist_free(dst);
1020                 } else {
1021                         if (nvlist_add_nvlist(pools, nvpair_name(elem), src)
1022                             != 0) {
1023                                 (void) no_memory(hdl);
1024                                 nvlist_free(raw);
1025                                 nvlist_free(pools);
1026                                 return (NULL);
1027                         }
1028                 }
1029         }
1030
1031         nvlist_free(raw);
1032         return (pools);
1033 }
1034
1035
1036 boolean_t
1037 find_guid(nvlist_t *nv, uint64_t guid)
1038 {
1039         uint64_t tmp;
1040         nvlist_t **child;
1041         uint_t c, children;
1042
1043         verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &tmp) == 0);
1044         if (tmp == guid)
1045                 return (B_TRUE);
1046
1047         if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1048             &child, &children) == 0) {
1049                 for (c = 0; c < children; c++)
1050                         if (find_guid(child[c], guid))
1051                                 return (B_TRUE);
1052         }
1053
1054         return (B_FALSE);
1055 }
1056
1057 typedef struct aux_cbdata {
1058         const char      *cb_type;
1059         uint64_t        cb_guid;
1060         zpool_handle_t  *cb_zhp;
1061 } aux_cbdata_t;
1062
1063 static int
1064 find_aux(zpool_handle_t *zhp, void *data)
1065 {
1066         aux_cbdata_t *cbp = data;
1067         nvlist_t **list;
1068         uint_t i, count;
1069         uint64_t guid;
1070         nvlist_t *nvroot;
1071
1072         verify(nvlist_lookup_nvlist(zhp->zpool_config, ZPOOL_CONFIG_VDEV_TREE,
1073             &nvroot) == 0);
1074
1075         if (nvlist_lookup_nvlist_array(nvroot, cbp->cb_type,
1076             &list, &count) == 0) {
1077                 for (i = 0; i < count; i++) {
1078                         verify(nvlist_lookup_uint64(list[i],
1079                             ZPOOL_CONFIG_GUID, &guid) == 0);
1080                         if (guid == cbp->cb_guid) {
1081                                 cbp->cb_zhp = zhp;
1082                                 return (1);
1083                         }
1084                 }
1085         }
1086
1087         zpool_close(zhp);
1088         return (0);
1089 }
1090
1091 /*
1092  * Determines if the pool is in use.  If so, it returns true and the state of
1093  * the pool as well as the name of the pool.  Both strings are allocated and
1094  * must be freed by the caller.
1095  */
1096 int
1097 zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
1098     boolean_t *inuse)
1099 {
1100         nvlist_t *config;
1101         char *name;
1102         boolean_t ret;
1103         uint64_t guid, vdev_guid;
1104         zpool_handle_t *zhp;
1105         nvlist_t *pool_config;
1106         uint64_t stateval, isspare;
1107         aux_cbdata_t cb = { 0 };
1108         boolean_t isactive;
1109
1110         *inuse = B_FALSE;
1111
1112         if (zpool_read_label(fd, &config) != 0) {
1113                 (void) no_memory(hdl);
1114                 return (-1);
1115         }
1116
1117         if (config == NULL)
1118                 return (0);
1119
1120         verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
1121             &stateval) == 0);
1122         verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
1123             &vdev_guid) == 0);
1124
1125         if (stateval != POOL_STATE_SPARE && stateval != POOL_STATE_L2CACHE) {
1126                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
1127                     &name) == 0);
1128                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
1129                     &guid) == 0);
1130         }
1131
1132         switch (stateval) {
1133         case POOL_STATE_EXPORTED:
1134                 ret = B_TRUE;
1135                 break;
1136
1137         case POOL_STATE_ACTIVE:
1138                 /*
1139                  * For an active pool, we have to determine if it's really part
1140                  * of a currently active pool (in which case the pool will exist
1141                  * and the guid will be the same), or whether it's part of an
1142                  * active pool that was disconnected without being explicitly
1143                  * exported.
1144                  */
1145                 if (pool_active(hdl, name, guid, &isactive) != 0) {
1146                         nvlist_free(config);
1147                         return (-1);
1148                 }
1149
1150                 if (isactive) {
1151                         /*
1152                          * Because the device may have been removed while
1153                          * offlined, we only report it as active if the vdev is
1154                          * still present in the config.  Otherwise, pretend like
1155                          * it's not in use.
1156                          */
1157                         if ((zhp = zpool_open_canfail(hdl, name)) != NULL &&
1158                             (pool_config = zpool_get_config(zhp, NULL))
1159                             != NULL) {
1160                                 nvlist_t *nvroot;
1161
1162                                 verify(nvlist_lookup_nvlist(pool_config,
1163                                     ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
1164                                 ret = find_guid(nvroot, vdev_guid);
1165                         } else {
1166                                 ret = B_FALSE;
1167                         }
1168
1169                         /*
1170                          * If this is an active spare within another pool, we
1171                          * treat it like an unused hot spare.  This allows the
1172                          * user to create a pool with a hot spare that currently
1173                          * in use within another pool.  Since we return B_TRUE,
1174                          * libdiskmgt will continue to prevent generic consumers
1175                          * from using the device.
1176                          */
1177                         if (ret && nvlist_lookup_uint64(config,
1178                             ZPOOL_CONFIG_IS_SPARE, &isspare) == 0 && isspare)
1179                                 stateval = POOL_STATE_SPARE;
1180
1181                         if (zhp != NULL)
1182                                 zpool_close(zhp);
1183                 } else {
1184                         stateval = POOL_STATE_POTENTIALLY_ACTIVE;
1185                         ret = B_TRUE;
1186                 }
1187                 break;
1188
1189         case POOL_STATE_SPARE:
1190                 /*
1191                  * For a hot spare, it can be either definitively in use, or
1192                  * potentially active.  To determine if it's in use, we iterate
1193                  * over all pools in the system and search for one with a spare
1194                  * with a matching guid.
1195                  *
1196                  * Due to the shared nature of spares, we don't actually report
1197                  * the potentially active case as in use.  This means the user
1198                  * can freely create pools on the hot spares of exported pools,
1199                  * but to do otherwise makes the resulting code complicated, and
1200                  * we end up having to deal with this case anyway.
1201                  */
1202                 cb.cb_zhp = NULL;
1203                 cb.cb_guid = vdev_guid;
1204                 cb.cb_type = ZPOOL_CONFIG_SPARES;
1205                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
1206                         name = (char *)zpool_get_name(cb.cb_zhp);
1207                         ret = TRUE;
1208                 } else {
1209                         ret = FALSE;
1210                 }
1211                 break;
1212
1213         case POOL_STATE_L2CACHE:
1214
1215                 /*
1216                  * Check if any pool is currently using this l2cache device.
1217                  */
1218                 cb.cb_zhp = NULL;
1219                 cb.cb_guid = vdev_guid;
1220                 cb.cb_type = ZPOOL_CONFIG_L2CACHE;
1221                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
1222                         name = (char *)zpool_get_name(cb.cb_zhp);
1223                         ret = TRUE;
1224                 } else {
1225                         ret = FALSE;
1226                 }
1227                 break;
1228
1229         default:
1230                 ret = B_FALSE;
1231         }
1232
1233
1234         if (ret) {
1235                 if ((*namestr = zfs_strdup(hdl, name)) == NULL) {
1236                         if (cb.cb_zhp)
1237                                 zpool_close(cb.cb_zhp);
1238                         nvlist_free(config);
1239                         return (-1);
1240                 }
1241                 *state = (pool_state_t)stateval;
1242         }
1243
1244         if (cb.cb_zhp)
1245                 zpool_close(cb.cb_zhp);
1246
1247         nvlist_free(config);
1248         *inuse = ret;
1249         return (0);
1250 }