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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24
  25 /*
  26  * Pool import support functions.
  27  *
  28  * To import a pool, we rely on reading the configuration information from the
  29  * ZFS label of each device.  If we successfully read the label, then we
  30  * organize the configuration information in the following hierarchy:
  31  *
  32  *      pool guid -> toplevel vdev guid -> label txg
  33  *
  34  * Duplicate entries matching this same tuple will be discarded.  Once we have
  35  * examined every device, we pick the best label txg config for each toplevel
  36  * vdev.  We then arrange these toplevel vdevs into a complete pool config, and
  37  * update any paths that have changed.  Finally, we attempt to import the pool
  38  * using our derived config, and record the results.
  39  */
  40
  41 #include <ctype.h>
  42 #include <devid.h>
  43 #include <dirent.h>
  44 #include <errno.h>
  45 #include <libintl.h>
  46 #include <stddef.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <sys/stat.h>
  50 #include <unistd.h>
  51 #include <fcntl.h>
  52 #include <sys/vtoc.h>
  53 #include <sys/dktp/fdisk.h>
  54 #include <sys/efi_partition.h>
  55 #include <thread_pool.h>
  56
  57 #include <sys/vdev_impl.h>
  58
  59 #include "libzfs.h"
  60 #include "libzfs_impl.h"
  61
  62 /*
  63  * Intermediate structures used to gather configuration information.
  64  */
  65 typedef struct config_entry {
  66         uint64_t                ce_txg;
  67         nvlist_t                *ce_config;
  68         struct config_entry     *ce_next;
  69 } config_entry_t;
  70
  71 typedef struct vdev_entry {
  72         uint64_t                ve_guid;
  73         config_entry_t          *ve_configs;
  74         struct vdev_entry       *ve_next;
  75 } vdev_entry_t;
  76
  77 typedef struct pool_entry {
  78         uint64_t                pe_guid;
  79         vdev_entry_t            *pe_vdevs;
  80         struct pool_entry       *pe_next;
  81 } pool_entry_t;
  82
  83 typedef struct name_entry {
  84         char                    *ne_name;
  85         uint64_t                ne_guid;
  86         struct name_entry       *ne_next;
  87 } name_entry_t;
  88
  89 typedef struct pool_list {
  90         pool_entry_t            *pools;
  91         name_entry_t            *names;
  92 } pool_list_t;
  93
  94 static char *
  95 get_devid(const char *path)
  96 {
  97         int fd;
  98         ddi_devid_t devid;
  99         char *minor, *ret;
 100
 101         if ((fd = open(path, O_RDONLY)) < 0)
 102                 return (NULL);
 103
 104         minor = NULL;
 105         ret = NULL;
 106         if (devid_get(fd, &devid) == 0) {
 107                 if (devid_get_minor_name(fd, &minor) == 0)
 108                         ret = devid_str_encode(devid, minor);
 109                 if (minor != NULL)
 110                         devid_str_free(minor);
 111                 devid_free(devid);
 112         }
 113         (void) close(fd);
 114
 115         return (ret);
 116 }
 117
 118
 119 /*
 120  * Go through and fix up any path and/or devid information for the given vdev
 121  * configuration.
 122  */
 123 static int
 124 fix_paths(nvlist_t *nv, name_entry_t *names)
 125 {
 126         nvlist_t **child;
 127         uint_t c, children;
 128         uint64_t guid;
 129         name_entry_t *ne, *best;
 130         char *path, *devid;
 131         int matched;
 132
 133         if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
 134             &child, &children) == 0) {
 135                 for (c = 0; c < children; c++)
 136                         if (fix_paths(child[c], names) != 0)
 137                                 return (-1);
 138                 return (0);
 139         }
 140
 141         /*
 142          * This is a leaf (file or disk) vdev.  In either case, go through
 143          * the name list and see if we find a matching guid.  If so, replace
 144          * the path and see if we can calculate a new devid.
 145          *
 146          * There may be multiple names associated with a particular guid, in
 147          * which case we have overlapping slices or multiple paths to the same
 148          * disk.  If this is the case, then we want to pick the path that is
 149          * the most similar to the original, where "most similar" is the number
 150          * of matching characters starting from the end of the path.  This will
 151          * preserve slice numbers even if the disks have been reorganized, and
 152          * will also catch preferred disk names if multiple paths exist.
 153          */
 154         verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &guid) == 0);
 155         if (nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &path) != 0)
 156                 path = NULL;
 157
 158         matched = 0;
 159         best = NULL;
 160         for (ne = names; ne != NULL; ne = ne->ne_next) {
 161                 if (ne->ne_guid == guid) {
 162                         const char *src, *dst;
 163                         int count;
 164
 165                         if (path == NULL) {
 166                                 best = ne;
 167                                 break;
 168                         }
 169
 170                         src = ne->ne_name + strlen(ne->ne_name) - 1;
 171                         dst = path + strlen(path) - 1;
 172                         for (count = 0; src >= ne->ne_name && dst >= path;
 173                             src--, dst--, count++)
 174                                 if (*src != *dst)
 175                                         break;
 176
 177                         /*
 178                          * At this point, 'count' is the number of characters
 179                          * matched from the end.
 180                          */
 181                         if (count > matched || best == NULL) {
 182                                 best = ne;
 183                                 matched = count;
 184                         }
 185                 }
 186         }
 187
 188         if (best == NULL)
 189                 return (0);
 190
 191         if (nvlist_add_string(nv, ZPOOL_CONFIG_PATH, best->ne_name) != 0)
 192                 return (-1);
 193
 194         if ((devid = get_devid(best->ne_name)) == NULL) {
 195                 (void) nvlist_remove_all(nv, ZPOOL_CONFIG_DEVID);
 196         } else {
 197                 if (nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, devid) != 0)
 198                         return (-1);
 199                 devid_str_free(devid);
 200         }
 201
 202         return (0);
 203 }
 204
 205 /*
 206  * Add the given configuration to the list of known devices.
 207  */
 208 static int
 209 add_config(libzfs_handle_t *hdl, pool_list_t *pl, const char *path,
 210     nvlist_t *config)
 211 {
 212         uint64_t pool_guid, vdev_guid, top_guid, txg, state;
 213         pool_entry_t *pe;
 214         vdev_entry_t *ve;
 215         config_entry_t *ce;
 216         name_entry_t *ne;
 217
 218         /*
 219          * If this is a hot spare not currently in use or level 2 cache
 220          * device, add it to the list of names to translate, but don't do
 221          * anything else.
 222          */
 223         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
 224             &state) == 0 &&
 225             (state == POOL_STATE_SPARE || state == POOL_STATE_L2CACHE) &&
 226             nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, &vdev_guid) == 0) {
 227                 if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
 228                         return (-1);
 229
 230                 if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
 231                         free(ne);
 232                         return (-1);
 233                 }
 234                 ne->ne_guid = vdev_guid;
 235                 ne->ne_next = pl->names;
 236                 pl->names = ne;
 237                 return (0);
 238         }
 239
 240         /*
 241          * If we have a valid config but cannot read any of these fields, then
 242          * it means we have a half-initialized label.  In vdev_label_init()
 243          * we write a label with txg == 0 so that we can identify the device
 244          * in case the user refers to the same disk later on.  If we fail to
 245          * create the pool, we'll be left with a label in this state
 246          * which should not be considered part of a valid pool.
 247          */
 248         if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 249             &pool_guid) != 0 ||
 250             nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
 251             &vdev_guid) != 0 ||
 252             nvlist_lookup_uint64(config, ZPOOL_CONFIG_TOP_GUID,
 253             &top_guid) != 0 ||
 254             nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
 255             &txg) != 0 || txg == 0) {
 256                 nvlist_free(config);
 257                 return (0);
 258         }
 259
 260         /*
 261          * First, see if we know about this pool.  If not, then add it to the
 262          * list of known pools.
 263          */
 264         for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
 265                 if (pe->pe_guid == pool_guid)
 266                         break;
 267         }
 268
 269         if (pe == NULL) {
 270                 if ((pe = zfs_alloc(hdl, sizeof (pool_entry_t))) == NULL) {
 271                         nvlist_free(config);
 272                         return (-1);
 273                 }
 274                 pe->pe_guid = pool_guid;
 275                 pe->pe_next = pl->pools;
 276                 pl->pools = pe;
 277         }
 278
 279         /*
 280          * Second, see if we know about this toplevel vdev.  Add it if its
 281          * missing.
 282          */
 283         for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
 284                 if (ve->ve_guid == top_guid)
 285                         break;
 286         }
 287
 288         if (ve == NULL) {
 289                 if ((ve = zfs_alloc(hdl, sizeof (vdev_entry_t))) == NULL) {
 290                         nvlist_free(config);
 291                         return (-1);
 292                 }
 293                 ve->ve_guid = top_guid;
 294                 ve->ve_next = pe->pe_vdevs;
 295                 pe->pe_vdevs = ve;
 296         }
 297
 298         /*
 299          * Third, see if we have a config with a matching transaction group.  If
 300          * so, then we do nothing.  Otherwise, add it to the list of known
 301          * configs.
 302          */
 303         for (ce = ve->ve_configs; ce != NULL; ce = ce->ce_next) {
 304                 if (ce->ce_txg == txg)
 305                         break;
 306         }
 307
 308         if (ce == NULL) {
 309                 if ((ce = zfs_alloc(hdl, sizeof (config_entry_t))) == NULL) {
 310                         nvlist_free(config);
 311                         return (-1);
 312                 }
 313                 ce->ce_txg = txg;
 314                 ce->ce_config = config;
 315                 ce->ce_next = ve->ve_configs;
 316                 ve->ve_configs = ce;
 317         } else {
 318                 nvlist_free(config);
 319         }
 320
 321         /*
 322          * At this point we've successfully added our config to the list of
 323          * known configs.  The last thing to do is add the vdev guid -> path
 324          * mappings so that we can fix up the configuration as necessary before
 325          * doing the import.
 326          */
 327         if ((ne = zfs_alloc(hdl, sizeof (name_entry_t))) == NULL)
 328                 return (-1);
 329
 330         if ((ne->ne_name = zfs_strdup(hdl, path)) == NULL) {
 331                 free(ne);
 332                 return (-1);
 333         }
 334
 335         ne->ne_guid = vdev_guid;
 336         ne->ne_next = pl->names;
 337         pl->names = ne;
 338
 339         return (0);
 340 }
 341
 342 /*
 343  * Returns true if the named pool matches the given GUID.
 344  */
 345 static int
 346 pool_active(libzfs_handle_t *hdl, const char *name, uint64_t guid,
 347     boolean_t *isactive)
 348 {
 349         zpool_handle_t *zhp;
 350         uint64_t theguid;
 351
 352         if (zpool_open_silent(hdl, name, &zhp) != 0)
 353                 return (-1);
 354
 355         if (zhp == NULL) {
 356                 *isactive = B_FALSE;
 357                 return (0);
 358         }
 359
 360         verify(nvlist_lookup_uint64(zhp->zpool_config, ZPOOL_CONFIG_POOL_GUID,
 361             &theguid) == 0);
 362
 363         zpool_close(zhp);
 364
 365         *isactive = (theguid == guid);
 366         return (0);
 367 }
 368
 369 static nvlist_t *
 370 refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
 371 {
 372         nvlist_t *nvl;
 373         zfs_cmd_t zc = { 0 };
 374         int err;
 375
 376         if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0)
 377                 return (NULL);
 378
 379         if (zcmd_alloc_dst_nvlist(hdl, &zc,
 380             zc.zc_nvlist_conf_size * 2) != 0) {
 381                 zcmd_free_nvlists(&zc);
 382                 return (NULL);
 383         }
 384
 385         while ((err = ioctl(hdl->libzfs_fd, ZFS_IOC_POOL_TRYIMPORT,
 386             &zc)) != 0 && errno == ENOMEM) {
 387                 if (zcmd_expand_dst_nvlist(hdl, &zc) != 0) {
 388                         zcmd_free_nvlists(&zc);
 389                         return (NULL);
 390                 }
 391         }
 392
 393         if (err) {
 394                 zcmd_free_nvlists(&zc);
 395                 return (NULL);
 396         }
 397
 398         if (zcmd_read_dst_nvlist(hdl, &zc, &nvl) != 0) {
 399                 zcmd_free_nvlists(&zc);
 400                 return (NULL);
 401         }
 402
 403         zcmd_free_nvlists(&zc);
 404         return (nvl);
 405 }
 406
 407 /*
 408  * Determine if the vdev id is a hole in the namespace.
 409  */
 410 boolean_t
 411 vdev_is_hole(uint64_t *hole_array, uint_t holes, uint_t id)
 412 {
 413         for (int c = 0; c < holes; c++) {
 414
 415                 /* Top-level is a hole */
 416                 if (hole_array[c] == id)
 417                         return (B_TRUE);
 418         }
 419         return (B_FALSE);
 420 }
 421
 422 /*
 423  * Convert our list of pools into the definitive set of configurations.  We
 424  * start by picking the best config for each toplevel vdev.  Once that's done,
 425  * we assemble the toplevel vdevs into a full config for the pool.  We make a
 426  * pass to fix up any incorrect paths, and then add it to the main list to
 427  * return to the user.
 428  */
 429 static nvlist_t *
 430 get_configs(libzfs_handle_t *hdl, pool_list_t *pl, boolean_t active_ok)
 431 {
 432         pool_entry_t *pe;
 433         vdev_entry_t *ve;
 434         config_entry_t *ce;
 435         nvlist_t *ret = NULL, *config = NULL, *tmp, *nvtop, *nvroot;
 436         nvlist_t **spares, **l2cache;
 437         uint_t i, nspares, nl2cache;
 438         boolean_t config_seen;
 439         uint64_t best_txg;
 440         char *name, *hostname;
 441         uint64_t version, guid;
 442         uint_t children = 0;
 443         nvlist_t **child = NULL;
 444         uint_t holes;
 445         uint64_t *hole_array, max_id;
 446         uint_t c;
 447         boolean_t isactive;
 448         uint64_t hostid;
 449         nvlist_t *nvl;
 450         boolean_t found_one = B_FALSE;
 451         boolean_t valid_top_config = B_FALSE;
 452
 453         if (nvlist_alloc(&ret, 0, 0) != 0)
 454                 goto nomem;
 455
 456         for (pe = pl->pools; pe != NULL; pe = pe->pe_next) {
 457                 uint64_t id, max_txg = 0;
 458
 459                 if (nvlist_alloc(&config, NV_UNIQUE_NAME, 0) != 0)
 460                         goto nomem;
 461                 config_seen = B_FALSE;
 462
 463                 /*
 464                  * Iterate over all toplevel vdevs.  Grab the pool configuration
 465                  * from the first one we find, and then go through the rest and
 466                  * add them as necessary to the 'vdevs' member of the config.
 467                  */
 468                 for (ve = pe->pe_vdevs; ve != NULL; ve = ve->ve_next) {
 469
 470                         /*
 471                          * Determine the best configuration for this vdev by
 472                          * selecting the config with the latest transaction
 473                          * group.
 474                          */
 475                         best_txg = 0;
 476                         for (ce = ve->ve_configs; ce != NULL;
 477                             ce = ce->ce_next) {
 478
 479                                 if (ce->ce_txg > best_txg) {
 480                                         tmp = ce->ce_config;
 481                                         best_txg = ce->ce_txg;
 482                                 }
 483                         }
 484
 485                         /*
 486                          * We rely on the fact that the max txg for the
 487                          * pool will contain the most up-to-date information
 488                          * about the valid top-levels in the vdev namespace.
 489                          */
 490                         if (best_txg > max_txg) {
 491                                 (void) nvlist_remove(config,
 492                                     ZPOOL_CONFIG_VDEV_CHILDREN,
 493                                     DATA_TYPE_UINT64);
 494                                 (void) nvlist_remove(config,
 495                                     ZPOOL_CONFIG_HOLE_ARRAY,
 496                                     DATA_TYPE_UINT64_ARRAY);
 497
 498                                 max_txg = best_txg;
 499                                 hole_array = NULL;
 500                                 holes = 0;
 501                                 max_id = 0;
 502                                 valid_top_config = B_FALSE;
 503
 504                                 if (nvlist_lookup_uint64(tmp,
 505                                     ZPOOL_CONFIG_VDEV_CHILDREN, &max_id) == 0) {
 506                                         verify(nvlist_add_uint64(config,
 507                                             ZPOOL_CONFIG_VDEV_CHILDREN,
 508                                             max_id) == 0);
 509                                         valid_top_config = B_TRUE;
 510                                 }
 511
 512                                 if (nvlist_lookup_uint64_array(tmp,
 513                                     ZPOOL_CONFIG_HOLE_ARRAY, &hole_array,
 514                                     &holes) == 0) {
 515                                         verify(nvlist_add_uint64_array(config,
 516                                             ZPOOL_CONFIG_HOLE_ARRAY,
 517                                             hole_array, holes) == 0);
 518                                 }
 519                         }
 520
 521                         if (!config_seen) {
 522                                 /*
 523                                  * Copy the relevant pieces of data to the pool
 524                                  * configuration:
 525                                  *
 526                                  *      version
 527                                  *      pool guid
 528                                  *      name
 529                                  *      pool state
 530                                  *      hostid (if available)
 531                                  *      hostname (if available)
 532                                  */
 533                                 uint64_t state;
 534
 535                                 verify(nvlist_lookup_uint64(tmp,
 536                                     ZPOOL_CONFIG_VERSION, &version) == 0);
 537                                 if (nvlist_add_uint64(config,
 538                                     ZPOOL_CONFIG_VERSION, version) != 0)
 539                                         goto nomem;
 540                                 verify(nvlist_lookup_uint64(tmp,
 541                                     ZPOOL_CONFIG_POOL_GUID, &guid) == 0);
 542                                 if (nvlist_add_uint64(config,
 543                                     ZPOOL_CONFIG_POOL_GUID, guid) != 0)
 544                                         goto nomem;
 545                                 verify(nvlist_lookup_string(tmp,
 546                                     ZPOOL_CONFIG_POOL_NAME, &name) == 0);
 547                                 if (nvlist_add_string(config,
 548                                     ZPOOL_CONFIG_POOL_NAME, name) != 0)
 549                                         goto nomem;
 550                                 verify(nvlist_lookup_uint64(tmp,
 551                                     ZPOOL_CONFIG_POOL_STATE, &state) == 0);
 552                                 if (nvlist_add_uint64(config,
 553                                     ZPOOL_CONFIG_POOL_STATE, state) != 0)
 554                                         goto nomem;
 555                                 hostid = 0;
 556                                 if (nvlist_lookup_uint64(tmp,
 557                                     ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
 558                                         if (nvlist_add_uint64(config,
 559                                             ZPOOL_CONFIG_HOSTID, hostid) != 0)
 560                                                 goto nomem;
 561                                         verify(nvlist_lookup_string(tmp,
 562                                             ZPOOL_CONFIG_HOSTNAME,
 563                                             &hostname) == 0);
 564                                         if (nvlist_add_string(config,
 565                                             ZPOOL_CONFIG_HOSTNAME,
 566                                             hostname) != 0)
 567                                                 goto nomem;
 568                                 }
 569
 570                                 config_seen = B_TRUE;
 571                         }
 572
 573                         /*
 574                          * Add this top-level vdev to the child array.
 575                          */
 576                         verify(nvlist_lookup_nvlist(tmp,
 577                             ZPOOL_CONFIG_VDEV_TREE, &nvtop) == 0);
 578                         verify(nvlist_lookup_uint64(nvtop, ZPOOL_CONFIG_ID,
 579                             &id) == 0);
 580
 581                         if (id >= children) {
 582                                 nvlist_t **newchild;
 583
 584                                 newchild = zfs_alloc(hdl, (id + 1) *
 585                                     sizeof (nvlist_t *));
 586                                 if (newchild == NULL)
 587                                         goto nomem;
 588
 589                                 for (c = 0; c < children; c++)
 590                                         newchild[c] = child[c];
 591
 592                                 free(child);
 593                                 child = newchild;
 594                                 children = id + 1;
 595                         }
 596                         if (nvlist_dup(nvtop, &child[id], 0) != 0)
 597                                 goto nomem;
 598
 599                 }
 600
 601                 /*
 602                  * If we have information about all the top-levels then
 603                  * clean up the nvlist which we've constructed. This
 604                  * means removing any extraneous devices that are
 605                  * beyond the valid range or adding devices to the end
 606                  * of our array which appear to be missing.
 607                  */
 608                 if (valid_top_config) {
 609                         if (max_id < children) {
 610                                 for (c = max_id; c < children; c++)
 611                                         nvlist_free(child[c]);
 612                                 children = max_id;
 613                         } else if (max_id > children) {
 614                                 nvlist_t **newchild;
 615
 616                                 newchild = zfs_alloc(hdl, (max_id) *
 617                                     sizeof (nvlist_t *));
 618                                 if (newchild == NULL)
 619                                         goto nomem;
 620
 621                                 for (c = 0; c < children; c++)
 622                                         newchild[c] = child[c];
 623
 624                                 free(child);
 625                                 child = newchild;
 626                                 children = max_id;
 627                         }
 628                 }
 629
 630                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 631                     &guid) == 0);
 632
 633                 /*
 634                  * The vdev namespace may contain holes as a result of
 635                  * device removal. We must add them back into the vdev
 636                  * tree before we process any missing devices.
 637                  */
 638                 if (holes > 0) {
 639                         ASSERT(valid_top_config);
 640
 641                         for (c = 0; c < children; c++) {
 642                                 nvlist_t *holey;
 643
 644                                 if (child[c] != NULL ||
 645                                     !vdev_is_hole(hole_array, holes, c))
 646                                         continue;
 647
 648                                 if (nvlist_alloc(&holey, NV_UNIQUE_NAME,
 649                                     0) != 0)
 650                                         goto nomem;
 651
 652                                 /*
 653                                  * Holes in the namespace are treated as
 654                                  * "hole" top-level vdevs and have a
 655                                  * special flag set on them.
 656                                  */
 657                                 if (nvlist_add_string(holey,
 658                                     ZPOOL_CONFIG_TYPE,
 659                                     VDEV_TYPE_HOLE) != 0 ||
 660                                     nvlist_add_uint64(holey,
 661                                     ZPOOL_CONFIG_ID, c) != 0 ||
 662                                     nvlist_add_uint64(holey,
 663                                     ZPOOL_CONFIG_GUID, 0ULL) != 0)
 664                                         goto nomem;
 665                                 child[c] = holey;
 666                         }
 667                 }
 668
 669                 /*
 670                  * Look for any missing top-level vdevs.  If this is the case,
 671                  * create a faked up 'missing' vdev as a placeholder.  We cannot
 672                  * simply compress the child array, because the kernel performs
 673                  * certain checks to make sure the vdev IDs match their location
 674                  * in the configuration.
 675                  */
 676                 for (c = 0; c < children; c++) {
 677                         if (child[c] == NULL) {
 678                                 nvlist_t *missing;
 679                                 if (nvlist_alloc(&missing, NV_UNIQUE_NAME,
 680                                     0) != 0)
 681                                         goto nomem;
 682                                 if (nvlist_add_string(missing,
 683                                     ZPOOL_CONFIG_TYPE,
 684                                     VDEV_TYPE_MISSING) != 0 ||
 685                                     nvlist_add_uint64(missing,
 686                                     ZPOOL_CONFIG_ID, c) != 0 ||
 687                                     nvlist_add_uint64(missing,
 688                                     ZPOOL_CONFIG_GUID, 0ULL) != 0) {
 689                                         nvlist_free(missing);
 690                                         goto nomem;
 691                                 }
 692                                 child[c] = missing;
 693                         }
 694                 }
 695
 696                 /*
 697                  * Put all of this pool's top-level vdevs into a root vdev.
 698                  */
 699                 if (nvlist_alloc(&nvroot, NV_UNIQUE_NAME, 0) != 0)
 700                         goto nomem;
 701                 if (nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
 702                     VDEV_TYPE_ROOT) != 0 ||
 703                     nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) != 0 ||
 704                     nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, guid) != 0 ||
 705                     nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
 706                     child, children) != 0) {
 707                         nvlist_free(nvroot);
 708                         goto nomem;
 709                 }
 710
 711                 for (c = 0; c < children; c++)
 712                         nvlist_free(child[c]);
 713                 free(child);
 714                 children = 0;
 715                 child = NULL;
 716
 717                 /*
 718                  * Go through and fix up any paths and/or devids based on our
 719                  * known list of vdev GUID -> path mappings.
 720                  */
 721                 if (fix_paths(nvroot, pl->names) != 0) {
 722                         nvlist_free(nvroot);
 723                         goto nomem;
 724                 }
 725
 726                 /*
 727                  * Add the root vdev to this pool's configuration.
 728                  */
 729                 if (nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
 730                     nvroot) != 0) {
 731                         nvlist_free(nvroot);
 732                         goto nomem;
 733                 }
 734                 nvlist_free(nvroot);
 735
 736                 /*
 737                  * zdb uses this path to report on active pools that were
 738                  * imported or created using -R.
 739                  */
 740                 if (active_ok)
 741                         goto add_pool;
 742
 743                 /*
 744                  * Determine if this pool is currently active, in which case we
 745                  * can't actually import it.
 746                  */
 747                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
 748                     &name) == 0);
 749                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
 750                     &guid) == 0);
 751
 752                 if (pool_active(hdl, name, guid, &isactive) != 0)
 753                         goto error;
 754
 755                 if (isactive) {
 756                         nvlist_free(config);
 757                         config = NULL;
 758                         continue;
 759                 }
 760
 761                 if ((nvl = refresh_config(hdl, config)) == NULL) {
 762                         nvlist_free(config);
 763                         config = NULL;
 764                         continue;
 765                 }
 766
 767                 nvlist_free(config);
 768                 config = nvl;
 769
 770                 /*
 771                  * Go through and update the paths for spares, now that we have
 772                  * them.
 773                  */
 774                 verify(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
 775                     &nvroot) == 0);
 776                 if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
 777                     &spares, &nspares) == 0) {
 778                         for (i = 0; i < nspares; i++) {
 779                                 if (fix_paths(spares[i], pl->names) != 0)
 780                                         goto nomem;
 781                         }
 782                 }
 783
 784                 /*
 785                  * Update the paths for l2cache devices.
 786                  */
 787                 if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
 788                     &l2cache, &nl2cache) == 0) {
 789                         for (i = 0; i < nl2cache; i++) {
 790                                 if (fix_paths(l2cache[i], pl->names) != 0)
 791                                         goto nomem;
 792                         }
 793                 }
 794
 795                 /*
 796                  * Restore the original information read from the actual label.
 797                  */
 798                 (void) nvlist_remove(config, ZPOOL_CONFIG_HOSTID,
 799                     DATA_TYPE_UINT64);
 800                 (void) nvlist_remove(config, ZPOOL_CONFIG_HOSTNAME,
 801                     DATA_TYPE_STRING);
 802                 if (hostid != 0) {
 803                         verify(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID,
 804                             hostid) == 0);
 805                         verify(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME,
 806                             hostname) == 0);
 807                 }
 808
 809 add_pool:
 810                 /*
 811                  * Add this pool to the list of configs.
 812                  */
 813                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
 814                     &name) == 0);
 815                 if (nvlist_add_nvlist(ret, name, config) != 0)
 816                         goto nomem;
 817
 818                 found_one = B_TRUE;
 819                 nvlist_free(config);
 820                 config = NULL;
 821         }
 822
 823         if (!found_one) {
 824                 nvlist_free(ret);
 825                 ret = NULL;
 826         }
 827
 828         return (ret);
 829
 830 nomem:
 831         (void) no_memory(hdl);
 832 error:
 833         nvlist_free(config);
 834         nvlist_free(ret);
 835         for (c = 0; c < children; c++)
 836                 nvlist_free(child[c]);
 837         free(child);
 838
 839         return (NULL);
 840 }
 841
 842 /*
 843  * Return the offset of the given label.
 844  */
 845 static uint64_t
 846 label_offset(uint64_t size, int l)
 847 {
 848         ASSERT(P2PHASE_TYPED(size, sizeof (vdev_label_t), uint64_t) == 0);
 849         return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ?
 850             0 : size - VDEV_LABELS * sizeof (vdev_label_t)));
 851 }
 852
 853 /*
 854  * Given a file descriptor, read the label information and return an nvlist
 855  * describing the configuration, if there is one.
 856  */
 857 int
 858 zpool_read_label(int fd, nvlist_t **config)
 859 {
 860         struct stat64 statbuf;
 861         int l;
 862         vdev_label_t *label;
 863         uint64_t state, txg, size;
 864
 865         *config = NULL;
 866
 867         if (fstat64(fd, &statbuf) == -1)
 868                 return (0);
 869         size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
 870
 871         if ((label = malloc(sizeof (vdev_label_t))) == NULL)
 872                 return (-1);
 873
 874         for (l = 0; l < VDEV_LABELS; l++) {
 875                 if (pread64(fd, label, sizeof (vdev_label_t),
 876                     label_offset(size, l)) != sizeof (vdev_label_t))
 877                         continue;
 878
 879                 if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
 880                     sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0)
 881                         continue;
 882
 883                 if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
 884                     &state) != 0 || state > POOL_STATE_L2CACHE) {
 885                         nvlist_free(*config);
 886                         continue;
 887                 }
 888
 889                 if (state != POOL_STATE_SPARE && state != POOL_STATE_L2CACHE &&
 890                     (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
 891                     &txg) != 0 || txg == 0)) {
 892                         nvlist_free(*config);
 893                         continue;
 894                 }
 895
 896                 free(label);
 897                 return (0);
 898         }
 899
 900         free(label);
 901         *config = NULL;
 902         return (0);
 903 }
 904
 905 typedef struct rdsk_node {
 906         char *rn_name;
 907         int rn_dfd;
 908         libzfs_handle_t *rn_hdl;
 909         nvlist_t *rn_config;
 910         avl_tree_t *rn_avl;
 911         avl_node_t rn_node;
 912         boolean_t rn_nozpool;
 913 } rdsk_node_t;
 914
 915 static int
 916 slice_cache_compare(const void *arg1, const void *arg2)
 917 {
 918         const char  *nm1 = ((rdsk_node_t *)arg1)->rn_name;
 919         const char  *nm2 = ((rdsk_node_t *)arg2)->rn_name;
 920         char *nm1slice, *nm2slice;
 921         int rv;
 922
 923         /*
 924          * slices zero and two are the most likely to provide results,
 925          * so put those first
 926          */
 927         nm1slice = strstr(nm1, "s0");
 928         nm2slice = strstr(nm2, "s0");
 929         if (nm1slice && !nm2slice) {
 930                 return (-1);
 931         }
 932         if (!nm1slice && nm2slice) {
 933                 return (1);
 934         }
 935         nm1slice = strstr(nm1, "s2");
 936         nm2slice = strstr(nm2, "s2");
 937         if (nm1slice && !nm2slice) {
 938                 return (-1);
 939         }
 940         if (!nm1slice && nm2slice) {
 941                 return (1);
 942         }
 943
 944         rv = strcmp(nm1, nm2);
 945         if (rv == 0)
 946                 return (0);
 947         return (rv > 0 ? 1 : -1);
 948 }
 949
 950 static void
 951 check_one_slice(avl_tree_t *r, char *diskname, uint_t partno,
 952     diskaddr_t size, uint_t blksz)
 953 {
 954         rdsk_node_t tmpnode;
 955         rdsk_node_t *node;
 956         char sname[MAXNAMELEN];
 957
 958         tmpnode.rn_name = &sname[0];
 959         (void) snprintf(tmpnode.rn_name, MAXNAMELEN, "%s%u",
 960             diskname, partno);
 961         /*
 962          * protect against division by zero for disk labels that
 963          * contain a bogus sector size
 964          */
 965         if (blksz == 0)
 966                 blksz = DEV_BSIZE;
 967         /* too small to contain a zpool? */
 968         if ((size < (SPA_MINDEVSIZE / blksz)) &&
 969             (node = avl_find(r, &tmpnode, NULL)))
 970                 node->rn_nozpool = B_TRUE;
 971 }
 972
 973 static void
 974 nozpool_all_slices(avl_tree_t *r, const char *sname)
 975 {
 976         char diskname[MAXNAMELEN];
 977         char *ptr;
 978         int i;
 979
 980         (void) strncpy(diskname, sname, MAXNAMELEN);
 981         if (((ptr = strrchr(diskname, 's')) == NULL) &&
 982             ((ptr = strrchr(diskname, 'p')) == NULL))
 983                 return;
 984         ptr[0] = 's';
 985         ptr[1] = '\0';
 986         for (i = 0; i < NDKMAP; i++)
 987                 check_one_slice(r, diskname, i, 0, 1);
 988         ptr[0] = 'p';
 989         for (i = 0; i <= FD_NUMPART; i++)
 990                 check_one_slice(r, diskname, i, 0, 1);
 991 }
 992
 993 static void
 994 check_slices(avl_tree_t *r, int fd, const char *sname)
 995 {
 996         struct extvtoc vtoc;
 997         struct dk_gpt *gpt;
 998         char diskname[MAXNAMELEN];
 999         char *ptr;
1000         int i;
1001
1002         (void) strncpy(diskname, sname, MAXNAMELEN);
1003         if ((ptr = strrchr(diskname, 's')) == NULL || !isdigit(ptr[1]))
1004                 return;
1005         ptr[1] = '\0';
1006
1007         if (read_extvtoc(fd, &vtoc) >= 0) {
1008                 for (i = 0; i < NDKMAP; i++)
1009                         check_one_slice(r, diskname, i,
1010                             vtoc.v_part[i].p_size, vtoc.v_sectorsz);
1011         } else if (efi_alloc_and_read(fd, &gpt) >= 0) {
1012                 /*
1013                  * on x86 we'll still have leftover links that point
1014                  * to slices s[9-15], so use NDKMAP instead
1015                  */
1016                 for (i = 0; i < NDKMAP; i++)
1017                         check_one_slice(r, diskname, i,
1018                             gpt->efi_parts[i].p_size, gpt->efi_lbasize);
1019                 /* nodes p[1-4] are never used with EFI labels */
1020                 ptr[0] = 'p';
1021                 for (i = 1; i <= FD_NUMPART; i++)
1022                         check_one_slice(r, diskname, i, 0, 1);
1023                 efi_free(gpt);
1024         }
1025 }
1026
1027 static void
1028 zpool_open_func(void *arg)
1029 {
1030         rdsk_node_t *rn = arg;
1031         struct stat64 statbuf;
1032         nvlist_t *config;
1033         int fd;
1034
1035         if (rn->rn_nozpool)
1036                 return;
1037         if ((fd = openat64(rn->rn_dfd, rn->rn_name, O_RDONLY)) < 0) {
1038                 /* symlink to a device that's no longer there */
1039                 if (errno == ENOENT)
1040                         nozpool_all_slices(rn->rn_avl, rn->rn_name);
1041                 return;
1042         }
1043         /*
1044          * Ignore failed stats.  We only want regular
1045          * files, character devs and block devs.
1046          */
1047         if (fstat64(fd, &statbuf) != 0 ||
1048             (!S_ISREG(statbuf.st_mode) &&
1049             !S_ISCHR(statbuf.st_mode) &&
1050             !S_ISBLK(statbuf.st_mode))) {
1051                 (void) close(fd);
1052                 return;
1053         }
1054         /* this file is too small to hold a zpool */
1055         if (S_ISREG(statbuf.st_mode) &&
1056             statbuf.st_size < SPA_MINDEVSIZE) {
1057                 (void) close(fd);
1058                 return;
1059         } else if (!S_ISREG(statbuf.st_mode)) {
1060                 /*
1061                  * Try to read the disk label first so we don't have to
1062                  * open a bunch of minor nodes that can't have a zpool.
1063                  */
1064                 check_slices(rn->rn_avl, fd, rn->rn_name);
1065         }
1066
1067         if ((zpool_read_label(fd, &config)) != 0) {
1068                 (void) close(fd);
1069                 (void) no_memory(rn->rn_hdl);
1070                 return;
1071         }
1072         (void) close(fd);
1073
1074
1075         rn->rn_config = config;
1076         if (config != NULL) {
1077                 assert(rn->rn_nozpool == B_FALSE);
1078         }
1079 }
1080
1081 /*
1082  * Given a file descriptor, clear (zero) the label information.  This function
1083  * is currently only used in the appliance stack as part of the ZFS sysevent
1084  * module.
1085  */
1086 int
1087 zpool_clear_label(int fd)
1088 {
1089         struct stat64 statbuf;
1090         int l;
1091         vdev_label_t *label;
1092         uint64_t size;
1093
1094         if (fstat64(fd, &statbuf) == -1)
1095                 return (0);
1096         size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
1097
1098         if ((label = calloc(sizeof (vdev_label_t), 1)) == NULL)
1099                 return (-1);
1100
1101         for (l = 0; l < VDEV_LABELS; l++) {
1102                 if (pwrite64(fd, label, sizeof (vdev_label_t),
1103                     label_offset(size, l)) != sizeof (vdev_label_t))
1104                         return (-1);
1105         }
1106
1107         free(label);
1108         return (0);
1109 }
1110
1111 /*
1112  * Given a list of directories to search, find all pools stored on disk.  This
1113  * includes partial pools which are not available to import.  If no args are
1114  * given (argc is 0), then the default directory (/dev/dsk) is searched.
1115  * poolname or guid (but not both) are provided by the caller when trying
1116  * to import a specific pool.
1117  */
1118 static nvlist_t *
1119 zpool_find_import_impl(libzfs_handle_t *hdl, importargs_t *iarg)
1120 {
1121         int i, dirs = iarg->paths;
1122         DIR *dirp = NULL;
1123         struct dirent64 *dp;
1124         char path[MAXPATHLEN];
1125         char *end, **dir = iarg->path;
1126         size_t pathleft;
1127         nvlist_t *ret = NULL;
1128         static char *default_dir = "/dev/dsk";
1129         pool_list_t pools = { 0 };
1130         pool_entry_t *pe, *penext;
1131         vdev_entry_t *ve, *venext;
1132         config_entry_t *ce, *cenext;
1133         name_entry_t *ne, *nenext;
1134         avl_tree_t slice_cache;
1135         rdsk_node_t *slice;
1136         void *cookie;
1137
1138         if (dirs == 0) {
1139                 dirs = 1;
1140                 dir = &default_dir;
1141         }
1142
1143         /*
1144          * Go through and read the label configuration information from every
1145          * possible device, organizing the information according to pool GUID
1146          * and toplevel GUID.
1147          */
1148         for (i = 0; i < dirs; i++) {
1149                 tpool_t *t;
1150                 char *rdsk;
1151                 int dfd;
1152
1153                 /* use realpath to normalize the path */
1154                 if (realpath(dir[i], path) == 0) {
1155                         (void) zfs_error_fmt(hdl, EZFS_BADPATH,
1156                             dgettext(TEXT_DOMAIN, "cannot open '%s'"), dir[i]);
1157                         goto error;
1158                 }
1159                 end = &path[strlen(path)];
1160                 *end++ = '/';
1161                 *end = 0;
1162                 pathleft = &path[sizeof (path)] - end;
1163
1164                 /*
1165                  * Using raw devices instead of block devices when we're
1166                  * reading the labels skips a bunch of slow operations during
1167                  * close(2) processing, so we replace /dev/dsk with /dev/rdsk.
1168                  */
1169                 if (strcmp(path, "/dev/dsk/") == 0)
1170                         rdsk = "/dev/rdsk/";
1171                 else
1172                         rdsk = path;
1173
1174                 if ((dfd = open64(rdsk, O_RDONLY)) < 0 ||
1175                     (dirp = fdopendir(dfd)) == NULL) {
1176                         zfs_error_aux(hdl, strerror(errno));
1177                         (void) zfs_error_fmt(hdl, EZFS_BADPATH,
1178                             dgettext(TEXT_DOMAIN, "cannot open '%s'"),
1179                             rdsk);
1180                         goto error;
1181                 }
1182
1183                 avl_create(&slice_cache, slice_cache_compare,
1184                     sizeof (rdsk_node_t), offsetof(rdsk_node_t, rn_node));
1185                 /*
1186                  * This is not MT-safe, but we have no MT consumers of libzfs
1187                  */
1188                 while ((dp = readdir64(dirp)) != NULL) {
1189                         const char *name = dp->d_name;
1190                         if (name[0] == '.' &&
1191                             (name[1] == 0 || (name[1] == '.' && name[2] == 0)))
1192                                 continue;
1193
1194                         slice = zfs_alloc(hdl, sizeof (rdsk_node_t));
1195                         slice->rn_name = zfs_strdup(hdl, name);
1196                         slice->rn_avl = &slice_cache;
1197                         slice->rn_dfd = dfd;
1198                         slice->rn_hdl = hdl;
1199                         slice->rn_nozpool = B_FALSE;
1200                         avl_add(&slice_cache, slice);
1201                 }
1202                 /*
1203                  * create a thread pool to do all of this in parallel;
1204                  * rn_nozpool is not protected, so this is racy in that
1205                  * multiple tasks could decide that the same slice can
1206                  * not hold a zpool, which is benign.  Also choose
1207                  * double the number of processors; we hold a lot of
1208                  * locks in the kernel, so going beyond this doesn't
1209                  * buy us much.
1210                  */
1211                 t = tpool_create(1, 2 * sysconf(_SC_NPROCESSORS_ONLN),
1212                     0, NULL);
1213                 for (slice = avl_first(&slice_cache); slice;
1214                     (slice = avl_walk(&slice_cache, slice,
1215                     AVL_AFTER)))
1216                         (void) tpool_dispatch(t, zpool_open_func, slice);
1217                 tpool_wait(t);
1218                 tpool_destroy(t);
1219
1220                 cookie = NULL;
1221                 while ((slice = avl_destroy_nodes(&slice_cache,
1222                     &cookie)) != NULL) {
1223                         if (slice->rn_config != NULL) {
1224                                 nvlist_t *config = slice->rn_config;
1225                                 boolean_t matched = B_TRUE;
1226
1227                                 if (iarg->poolname != NULL) {
1228                                         char *pname;
1229
1230                                         matched = nvlist_lookup_string(config,
1231                                             ZPOOL_CONFIG_POOL_NAME,
1232                                             &pname) == 0 &&
1233                                             strcmp(iarg->poolname, pname) == 0;
1234                                 } else if (iarg->guid != 0) {
1235                                         uint64_t this_guid;
1236
1237                                         matched = nvlist_lookup_uint64(config,
1238                                             ZPOOL_CONFIG_POOL_GUID,
1239                                             &this_guid) == 0 &&
1240                                             iarg->guid == this_guid;
1241                                 }
1242                                 if (!matched) {
1243                                         nvlist_free(config);
1244                                         config = NULL;
1245                                         continue;
1246                                 }
1247                                 /* use the non-raw path for the config */
1248                                 (void) strlcpy(end, slice->rn_name, pathleft);
1249                                 if (add_config(hdl, &pools, path, config) != 0)
1250                                         goto error;
1251                         }
1252                         free(slice->rn_name);
1253                         free(slice);
1254                 }
1255                 avl_destroy(&slice_cache);
1256
1257                 (void) closedir(dirp);
1258                 dirp = NULL;
1259         }
1260
1261         ret = get_configs(hdl, &pools, iarg->can_be_active);
1262
1263 error:
1264         for (pe = pools.pools; pe != NULL; pe = penext) {
1265                 penext = pe->pe_next;
1266                 for (ve = pe->pe_vdevs; ve != NULL; ve = venext) {
1267                         venext = ve->ve_next;
1268                         for (ce = ve->ve_configs; ce != NULL; ce = cenext) {
1269                                 cenext = ce->ce_next;
1270                                 if (ce->ce_config)
1271                                         nvlist_free(ce->ce_config);
1272                                 free(ce);
1273                         }
1274                         free(ve);
1275                 }
1276                 free(pe);
1277         }
1278
1279         for (ne = pools.names; ne != NULL; ne = nenext) {
1280                 nenext = ne->ne_next;
1281                 if (ne->ne_name)
1282                         free(ne->ne_name);
1283                 free(ne);
1284         }
1285
1286         if (dirp)
1287                 (void) closedir(dirp);
1288
1289         return (ret);
1290 }
1291
1292 nvlist_t *
1293 zpool_find_import(libzfs_handle_t *hdl, int argc, char **argv)
1294 {
1295         importargs_t iarg = { 0 };
1296
1297         iarg.paths = argc;
1298         iarg.path = argv;
1299
1300         return (zpool_find_import_impl(hdl, &iarg));
1301 }
1302
1303 /*
1304  * Given a cache file, return the contents as a list of importable pools.
1305  * poolname or guid (but not both) are provided by the caller when trying
1306  * to import a specific pool.
1307  */
1308 nvlist_t *
1309 zpool_find_import_cached(libzfs_handle_t *hdl, const char *cachefile,
1310     char *poolname, uint64_t guid)
1311 {
1312         char *buf;
1313         int fd;
1314         struct stat64 statbuf;
1315         nvlist_t *raw, *src, *dst;
1316         nvlist_t *pools;
1317         nvpair_t *elem;
1318         char *name;
1319         uint64_t this_guid;
1320         boolean_t active;
1321
1322         verify(poolname == NULL || guid == 0);
1323
1324         if ((fd = open(cachefile, O_RDONLY)) < 0) {
1325                 zfs_error_aux(hdl, "%s", strerror(errno));
1326                 (void) zfs_error(hdl, EZFS_BADCACHE,
1327                     dgettext(TEXT_DOMAIN, "failed to open cache file"));
1328                 return (NULL);
1329         }
1330
1331         if (fstat64(fd, &statbuf) != 0) {
1332                 zfs_error_aux(hdl, "%s", strerror(errno));
1333                 (void) close(fd);
1334                 (void) zfs_error(hdl, EZFS_BADCACHE,
1335                     dgettext(TEXT_DOMAIN, "failed to get size of cache file"));
1336                 return (NULL);
1337         }
1338
1339         if ((buf = zfs_alloc(hdl, statbuf.st_size)) == NULL) {
1340                 (void) close(fd);
1341                 return (NULL);
1342         }
1343
1344         if (read(fd, buf, statbuf.st_size) != statbuf.st_size) {
1345                 (void) close(fd);
1346                 free(buf);
1347                 (void) zfs_error(hdl, EZFS_BADCACHE,
1348                     dgettext(TEXT_DOMAIN,
1349                     "failed to read cache file contents"));
1350                 return (NULL);
1351         }
1352
1353         (void) close(fd);
1354
1355         if (nvlist_unpack(buf, statbuf.st_size, &raw, 0) != 0) {
1356                 free(buf);
1357                 (void) zfs_error(hdl, EZFS_BADCACHE,
1358                     dgettext(TEXT_DOMAIN,
1359                     "invalid or corrupt cache file contents"));
1360                 return (NULL);
1361         }
1362
1363         free(buf);
1364
1365         /*
1366          * Go through and get the current state of the pools and refresh their
1367          * state.
1368          */
1369         if (nvlist_alloc(&pools, 0, 0) != 0) {
1370                 (void) no_memory(hdl);
1371                 nvlist_free(raw);
1372                 return (NULL);
1373         }
1374
1375         elem = NULL;
1376         while ((elem = nvlist_next_nvpair(raw, elem)) != NULL) {
1377                 verify(nvpair_value_nvlist(elem, &src) == 0);
1378
1379                 verify(nvlist_lookup_string(src, ZPOOL_CONFIG_POOL_NAME,
1380                     &name) == 0);
1381                 if (poolname != NULL && strcmp(poolname, name) != 0)
1382                         continue;
1383
1384                 verify(nvlist_lookup_uint64(src, ZPOOL_CONFIG_POOL_GUID,
1385                     &this_guid) == 0);
1386                 if (guid != 0) {
1387                         verify(nvlist_lookup_uint64(src, ZPOOL_CONFIG_POOL_GUID,
1388                             &this_guid) == 0);
1389                         if (guid != this_guid)
1390                                 continue;
1391                 }
1392
1393                 if (pool_active(hdl, name, this_guid, &active) != 0) {
1394                         nvlist_free(raw);
1395                         nvlist_free(pools);
1396                         return (NULL);
1397                 }
1398
1399                 if (active)
1400                         continue;
1401
1402                 if ((dst = refresh_config(hdl, src)) == NULL) {
1403                         nvlist_free(raw);
1404                         nvlist_free(pools);
1405                         return (NULL);
1406                 }
1407
1408                 if (nvlist_add_nvlist(pools, nvpair_name(elem), dst) != 0) {
1409                         (void) no_memory(hdl);
1410                         nvlist_free(dst);
1411                         nvlist_free(raw);
1412                         nvlist_free(pools);
1413                         return (NULL);
1414                 }
1415                 nvlist_free(dst);
1416         }
1417
1418         nvlist_free(raw);
1419         return (pools);
1420 }
1421
1422 static int
1423 name_or_guid_exists(zpool_handle_t *zhp, void *data)
1424 {
1425         importargs_t *import = data;
1426         int found = 0;
1427
1428         if (import->poolname != NULL) {
1429                 char *pool_name;
1430
1431                 verify(nvlist_lookup_string(zhp->zpool_config,
1432                     ZPOOL_CONFIG_POOL_NAME, &pool_name) == 0);
1433                 if (strcmp(pool_name, import->poolname) == 0)
1434                         found = 1;
1435         } else {
1436                 uint64_t pool_guid;
1437
1438                 verify(nvlist_lookup_uint64(zhp->zpool_config,
1439                     ZPOOL_CONFIG_POOL_GUID, &pool_guid) == 0);
1440                 if (pool_guid == import->guid)
1441                         found = 1;
1442         }
1443
1444         zpool_close(zhp);
1445         return (found);
1446 }
1447
1448 nvlist_t *
1449 zpool_search_import(libzfs_handle_t *hdl, importargs_t *import)
1450 {
1451         verify(import->poolname == NULL || import->guid == 0);
1452
1453         if (import->unique)
1454                 import->exists = zpool_iter(hdl, name_or_guid_exists, import);
1455
1456         if (import->cachefile != NULL)
1457                 return (zpool_find_import_cached(hdl, import->cachefile,
1458                     import->poolname, import->guid));
1459
1460         return (zpool_find_import_impl(hdl, import));
1461 }
1462
1463 boolean_t
1464 find_guid(nvlist_t *nv, uint64_t guid)
1465 {
1466         uint64_t tmp;
1467         nvlist_t **child;
1468         uint_t c, children;
1469
1470         verify(nvlist_lookup_uint64(nv, ZPOOL_CONFIG_GUID, &tmp) == 0);
1471         if (tmp == guid)
1472                 return (B_TRUE);
1473
1474         if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1475             &child, &children) == 0) {
1476                 for (c = 0; c < children; c++)
1477                         if (find_guid(child[c], guid))
1478                                 return (B_TRUE);
1479         }
1480
1481         return (B_FALSE);
1482 }
1483
1484 typedef struct aux_cbdata {
1485         const char      *cb_type;
1486         uint64_t        cb_guid;
1487         zpool_handle_t  *cb_zhp;
1488 } aux_cbdata_t;
1489
1490 static int
1491 find_aux(zpool_handle_t *zhp, void *data)
1492 {
1493         aux_cbdata_t *cbp = data;
1494         nvlist_t **list;
1495         uint_t i, count;
1496         uint64_t guid;
1497         nvlist_t *nvroot;
1498
1499         verify(nvlist_lookup_nvlist(zhp->zpool_config, ZPOOL_CONFIG_VDEV_TREE,
1500             &nvroot) == 0);
1501
1502         if (nvlist_lookup_nvlist_array(nvroot, cbp->cb_type,
1503             &list, &count) == 0) {
1504                 for (i = 0; i < count; i++) {
1505                         verify(nvlist_lookup_uint64(list[i],
1506                             ZPOOL_CONFIG_GUID, &guid) == 0);
1507                         if (guid == cbp->cb_guid) {
1508                                 cbp->cb_zhp = zhp;
1509                                 return (1);
1510                         }
1511                 }
1512         }
1513
1514         zpool_close(zhp);
1515         return (0);
1516 }
1517
1518 /*
1519  * Determines if the pool is in use.  If so, it returns true and the state of
1520  * the pool as well as the name of the pool.  Both strings are allocated and
1521  * must be freed by the caller.
1522  */
1523 int
1524 zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
1525     boolean_t *inuse)
1526 {
1527         nvlist_t *config;
1528         char *name;
1529         boolean_t ret;
1530         uint64_t guid, vdev_guid;
1531         zpool_handle_t *zhp;
1532         nvlist_t *pool_config;
1533         uint64_t stateval, isspare;
1534         aux_cbdata_t cb = { 0 };
1535         boolean_t isactive;
1536
1537         *inuse = B_FALSE;
1538
1539         if (zpool_read_label(fd, &config) != 0) {
1540                 (void) no_memory(hdl);
1541                 return (-1);
1542         }
1543
1544         if (config == NULL)
1545                 return (0);
1546
1547         verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE,
1548             &stateval) == 0);
1549         verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID,
1550             &vdev_guid) == 0);
1551
1552         if (stateval != POOL_STATE_SPARE && stateval != POOL_STATE_L2CACHE) {
1553                 verify(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
1554                     &name) == 0);
1555                 verify(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
1556                     &guid) == 0);
1557         }
1558
1559         switch (stateval) {
1560         case POOL_STATE_EXPORTED:
1561                 /*
1562                  * A pool with an exported state may in fact be imported
1563                  * read-only, so check the in-core state to see if it's
1564                  * active and imported read-only.  If it is, set
1565                  * its state to active.
1566                  */
1567                 if (pool_active(hdl, name, guid, &isactive) == 0 && isactive &&
1568                     (zhp = zpool_open_canfail(hdl, name)) != NULL &&
1569                     zpool_get_prop_int(zhp, ZPOOL_PROP_READONLY, NULL))
1570                         stateval = POOL_STATE_ACTIVE;
1571
1572                 ret = B_TRUE;
1573                 break;
1574
1575         case POOL_STATE_ACTIVE:
1576                 /*
1577                  * For an active pool, we have to determine if it's really part
1578                  * of a currently active pool (in which case the pool will exist
1579                  * and the guid will be the same), or whether it's part of an
1580                  * active pool that was disconnected without being explicitly
1581                  * exported.
1582                  */
1583                 if (pool_active(hdl, name, guid, &isactive) != 0) {
1584                         nvlist_free(config);
1585                         return (-1);
1586                 }
1587
1588                 if (isactive) {
1589                         /*
1590                          * Because the device may have been removed while
1591                          * offlined, we only report it as active if the vdev is
1592                          * still present in the config.  Otherwise, pretend like
1593                          * it's not in use.
1594                          */
1595                         if ((zhp = zpool_open_canfail(hdl, name)) != NULL &&
1596                             (pool_config = zpool_get_config(zhp, NULL))
1597                             != NULL) {
1598                                 nvlist_t *nvroot;
1599
1600                                 verify(nvlist_lookup_nvlist(pool_config,
1601                                     ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
1602                                 ret = find_guid(nvroot, vdev_guid);
1603                         } else {
1604                                 ret = B_FALSE;
1605                         }
1606
1607                         /*
1608                          * If this is an active spare within another pool, we
1609                          * treat it like an unused hot spare.  This allows the
1610                          * user to create a pool with a hot spare that currently
1611                          * in use within another pool.  Since we return B_TRUE,
1612                          * libdiskmgt will continue to prevent generic consumers
1613                          * from using the device.
1614                          */
1615                         if (ret && nvlist_lookup_uint64(config,
1616                             ZPOOL_CONFIG_IS_SPARE, &isspare) == 0 && isspare)
1617                                 stateval = POOL_STATE_SPARE;
1618
1619                         if (zhp != NULL)
1620                                 zpool_close(zhp);
1621                 } else {
1622                         stateval = POOL_STATE_POTENTIALLY_ACTIVE;
1623                         ret = B_TRUE;
1624                 }
1625                 break;
1626
1627         case POOL_STATE_SPARE:
1628                 /*
1629                  * For a hot spare, it can be either definitively in use, or
1630                  * potentially active.  To determine if it's in use, we iterate
1631                  * over all pools in the system and search for one with a spare
1632                  * with a matching guid.
1633                  *
1634                  * Due to the shared nature of spares, we don't actually report
1635                  * the potentially active case as in use.  This means the user
1636                  * can freely create pools on the hot spares of exported pools,
1637                  * but to do otherwise makes the resulting code complicated, and
1638                  * we end up having to deal with this case anyway.
1639                  */
1640                 cb.cb_zhp = NULL;
1641                 cb.cb_guid = vdev_guid;
1642                 cb.cb_type = ZPOOL_CONFIG_SPARES;
1643                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
1644                         name = (char *)zpool_get_name(cb.cb_zhp);
1645                         ret = TRUE;
1646                 } else {
1647                         ret = FALSE;
1648                 }
1649                 break;
1650
1651         case POOL_STATE_L2CACHE:
1652
1653                 /*
1654                  * Check if any pool is currently using this l2cache device.
1655                  */
1656                 cb.cb_zhp = NULL;
1657                 cb.cb_guid = vdev_guid;
1658                 cb.cb_type = ZPOOL_CONFIG_L2CACHE;
1659                 if (zpool_iter(hdl, find_aux, &cb) == 1) {
1660                         name = (char *)zpool_get_name(cb.cb_zhp);
1661                         ret = TRUE;
1662                 } else {
1663                         ret = FALSE;
1664                 }
1665                 break;
1666
1667         default:
1668                 ret = B_FALSE;
1669         }
1670
1671
1672         if (ret) {
1673                 if ((*namestr = zfs_strdup(hdl, name)) == NULL) {
1674                         if (cb.cb_zhp)
1675                                 zpool_close(cb.cb_zhp);
1676                         nvlist_free(config);
1677                         return (-1);
1678                 }
1679                 *state = (pool_state_t)stateval;
1680         }
1681
1682         if (cb.cb_zhp)
1683                 zpool_close(cb.cb_zhp);
1684
1685         nvlist_free(config);
1686         *inuse = ret;
1687         return (0);
1688 }