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 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2011, 2020 by Delphix. All rights reserved. 26 * Copyright 2017 Joyent, Inc. 27 */ 28 29 #include <sys/spa.h> 30 #include <sys/file.h> 31 #include <sys/fm/fs/zfs.h> 32 #include <sys/spa_impl.h> 33 #include <sys/nvpair.h> 34 #include <sys/uio.h> 35 #include <sys/fs/zfs.h> 36 #include <sys/vdev_impl.h> 37 #include <sys/zfs_ioctl.h> 38 #include <sys/systeminfo.h> 39 #include <sys/sunddi.h> 40 #include <sys/zfeature.h> 41 #include <sys/zfs_file.h> 42 #ifdef _KERNEL 43 #include <sys/zone.h> 44 #endif 45 46 /* 47 * Pool configuration repository. 48 * 49 * Pool configuration is stored as a packed nvlist on the filesystem. By 50 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot 51 * (when the ZFS module is loaded). Pools can also have the 'cachefile' 52 * property set that allows them to be stored in an alternate location until 53 * the control of external software. 54 * 55 * For each cache file, we have a single nvlist which holds all the 56 * configuration information. When the module loads, we read this information 57 * from /etc/zfs/zpool.cache and populate the SPA namespace. This namespace is 58 * maintained independently in spa.c. Whenever the namespace is modified, or 59 * the configuration of a pool is changed, we call spa_write_cachefile(), which 60 * walks through all the active pools and writes the configuration to disk. 61 */ 62 63 static uint64_t spa_config_generation = 1; 64 65 /* 66 * This can be overridden in userland to preserve an alternate namespace for 67 * userland pools when doing testing. 68 */ 69 char *spa_config_path = ZPOOL_CACHE; 70 int zfs_autoimport_disable = 1; 71 72 /* 73 * Called when the module is first loaded, this routine loads the configuration 74 * file into the SPA namespace. It does not actually open or load the pools; it 75 * only populates the namespace. 76 */ 77 void 78 spa_config_load(void) 79 { 80 void *buf = NULL; 81 nvlist_t *nvlist, *child; 82 nvpair_t *nvpair; 83 char *pathname; 84 zfs_file_t *fp; 85 zfs_file_attr_t zfa; 86 uint64_t fsize; 87 int err; 88 89 #ifdef _KERNEL 90 if (zfs_autoimport_disable) 91 return; 92 #endif 93 94 /* 95 * Open the configuration file. 96 */ 97 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP); 98 99 (void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path); 100 101 err = zfs_file_open(pathname, O_RDONLY, 0, &fp); 102 103 #ifdef __FreeBSD__ 104 if (err) 105 err = zfs_file_open(ZPOOL_CACHE_BOOT, O_RDONLY, 0, &fp); 106 #endif 107 kmem_free(pathname, MAXPATHLEN); 108 109 if (err) 110 return; 111 112 if (zfs_file_getattr(fp, &zfa)) 113 goto out; 114 115 fsize = zfa.zfa_size; 116 buf = kmem_alloc(fsize, KM_SLEEP); 117 118 /* 119 * Read the nvlist from the file. 120 */ 121 if (zfs_file_read(fp, buf, fsize, NULL) < 0) 122 goto out; 123 124 /* 125 * Unpack the nvlist. 126 */ 127 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 128 goto out; 129 130 /* 131 * Iterate over all elements in the nvlist, creating a new spa_t for 132 * each one with the specified configuration. 133 */ 134 mutex_enter(&spa_namespace_lock); 135 nvpair = NULL; 136 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 137 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 138 continue; 139 140 child = fnvpair_value_nvlist(nvpair); 141 142 if (spa_lookup(nvpair_name(nvpair)) != NULL) 143 continue; 144 (void) spa_add(nvpair_name(nvpair), child, NULL); 145 } 146 mutex_exit(&spa_namespace_lock); 147 148 nvlist_free(nvlist); 149 150 out: 151 if (buf != NULL) 152 kmem_free(buf, fsize); 153 154 zfs_file_close(fp); 155 } 156 157 static int 158 spa_config_remove(spa_config_dirent_t *dp) 159 { 160 int error = 0; 161 162 /* 163 * Remove the cache file. If zfs_file_unlink() in not supported by the 164 * platform fallback to truncating the file which is functionally 165 * equivalent. 166 */ 167 error = zfs_file_unlink(dp->scd_path); 168 if (error == EOPNOTSUPP) { 169 int flags = O_RDWR | O_TRUNC; 170 zfs_file_t *fp; 171 172 error = zfs_file_open(dp->scd_path, flags, 0644, &fp); 173 if (error == 0) { 174 (void) zfs_file_fsync(fp, O_SYNC); 175 (void) zfs_file_close(fp); 176 } 177 } 178 179 return (error); 180 } 181 182 static int 183 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 184 { 185 size_t buflen; 186 char *buf; 187 int oflags = O_RDWR | O_TRUNC | O_CREAT | O_LARGEFILE; 188 char *temp; 189 int err; 190 zfs_file_t *fp; 191 192 /* 193 * If the nvlist is empty (NULL), then remove the old cachefile. 194 */ 195 if (nvl == NULL) { 196 err = spa_config_remove(dp); 197 if (err == ENOENT) 198 err = 0; 199 200 return (err); 201 } 202 203 /* 204 * Pack the configuration into a buffer. 205 */ 206 buf = fnvlist_pack(nvl, &buflen); 207 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 208 209 /* 210 * Write the configuration to disk. Due to the complexity involved 211 * in performing a rename and remove from within the kernel the file 212 * is instead truncated and overwritten in place. This way we always 213 * have a consistent view of the data or a zero length file. 214 */ 215 err = zfs_file_open(dp->scd_path, oflags, 0644, &fp); 216 if (err == 0) { 217 err = zfs_file_write(fp, buf, buflen, NULL); 218 if (err == 0) 219 err = zfs_file_fsync(fp, O_SYNC); 220 221 zfs_file_close(fp); 222 if (err) 223 (void) spa_config_remove(dp); 224 } 225 fnvlist_pack_free(buf, buflen); 226 kmem_free(temp, MAXPATHLEN); 227 return (err); 228 } 229 230 /* 231 * Synchronize pool configuration to disk. This must be called with the 232 * namespace lock held. Synchronizing the pool cache is typically done after 233 * the configuration has been synced to the MOS. This exposes a window where 234 * the MOS config will have been updated but the cache file has not. If 235 * the system were to crash at that instant then the cached config may not 236 * contain the correct information to open the pool and an explicit import 237 * would be required. 238 */ 239 void 240 spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent) 241 { 242 spa_config_dirent_t *dp, *tdp; 243 nvlist_t *nvl; 244 char *pool_name; 245 boolean_t ccw_failure; 246 int error = 0; 247 248 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 249 250 if (!(spa_mode_global & SPA_MODE_WRITE)) 251 return; 252 253 /* 254 * Iterate over all cachefiles for the pool, past or present. When the 255 * cachefile is changed, the new one is pushed onto this list, allowing 256 * us to update previous cachefiles that no longer contain this pool. 257 */ 258 ccw_failure = B_FALSE; 259 for (dp = list_head(&target->spa_config_list); dp != NULL; 260 dp = list_next(&target->spa_config_list, dp)) { 261 spa_t *spa = NULL; 262 if (dp->scd_path == NULL) 263 continue; 264 265 /* 266 * Iterate over all pools, adding any matching pools to 'nvl'. 267 */ 268 nvl = NULL; 269 while ((spa = spa_next(spa)) != NULL) { 270 /* 271 * Skip over our own pool if we're about to remove 272 * ourselves from the spa namespace or any pool that 273 * is readonly. Since we cannot guarantee that a 274 * readonly pool would successfully import upon reboot, 275 * we don't allow them to be written to the cache file. 276 */ 277 if ((spa == target && removing) || 278 !spa_writeable(spa)) 279 continue; 280 281 mutex_enter(&spa->spa_props_lock); 282 tdp = list_head(&spa->spa_config_list); 283 if (spa->spa_config == NULL || 284 tdp == NULL || 285 tdp->scd_path == NULL || 286 strcmp(tdp->scd_path, dp->scd_path) != 0) { 287 mutex_exit(&spa->spa_props_lock); 288 continue; 289 } 290 291 if (nvl == NULL) 292 nvl = fnvlist_alloc(); 293 294 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) 295 pool_name = fnvlist_lookup_string( 296 spa->spa_config, ZPOOL_CONFIG_POOL_NAME); 297 else 298 pool_name = spa_name(spa); 299 300 fnvlist_add_nvlist(nvl, pool_name, spa->spa_config); 301 mutex_exit(&spa->spa_props_lock); 302 } 303 304 error = spa_config_write(dp, nvl); 305 if (error != 0) 306 ccw_failure = B_TRUE; 307 nvlist_free(nvl); 308 } 309 310 if (ccw_failure) { 311 /* 312 * Keep trying so that configuration data is 313 * written if/when any temporary filesystem 314 * resource issues are resolved. 315 */ 316 if (target->spa_ccw_fail_time == 0) { 317 (void) zfs_ereport_post( 318 FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 319 target, NULL, NULL, NULL, 0); 320 } 321 target->spa_ccw_fail_time = gethrtime(); 322 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 323 } else { 324 /* 325 * Do not rate limit future attempts to update 326 * the config cache. 327 */ 328 target->spa_ccw_fail_time = 0; 329 } 330 331 /* 332 * Remove any config entries older than the current one. 333 */ 334 dp = list_head(&target->spa_config_list); 335 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 336 list_remove(&target->spa_config_list, tdp); 337 if (tdp->scd_path != NULL) 338 spa_strfree(tdp->scd_path); 339 kmem_free(tdp, sizeof (spa_config_dirent_t)); 340 } 341 342 spa_config_generation++; 343 344 if (postsysevent) 345 spa_event_notify(target, NULL, NULL, ESC_ZFS_CONFIG_SYNC); 346 } 347 348 /* 349 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 350 * and we don't want to allow the local zone to see all the pools anyway. 351 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 352 * information for all pool visible within the zone. 353 */ 354 nvlist_t * 355 spa_all_configs(uint64_t *generation) 356 { 357 nvlist_t *pools; 358 spa_t *spa = NULL; 359 360 if (*generation == spa_config_generation) 361 return (NULL); 362 363 pools = fnvlist_alloc(); 364 365 mutex_enter(&spa_namespace_lock); 366 while ((spa = spa_next(spa)) != NULL) { 367 if (INGLOBALZONE(curproc) || 368 zone_dataset_visible(spa_name(spa), NULL)) { 369 mutex_enter(&spa->spa_props_lock); 370 fnvlist_add_nvlist(pools, spa_name(spa), 371 spa->spa_config); 372 mutex_exit(&spa->spa_props_lock); 373 } 374 } 375 *generation = spa_config_generation; 376 mutex_exit(&spa_namespace_lock); 377 378 return (pools); 379 } 380 381 void 382 spa_config_set(spa_t *spa, nvlist_t *config) 383 { 384 mutex_enter(&spa->spa_props_lock); 385 if (spa->spa_config != NULL && spa->spa_config != config) 386 nvlist_free(spa->spa_config); 387 spa->spa_config = config; 388 mutex_exit(&spa->spa_props_lock); 389 } 390 391 /* 392 * Generate the pool's configuration based on the current in-core state. 393 * 394 * We infer whether to generate a complete config or just one top-level config 395 * based on whether vd is the root vdev. 396 */ 397 nvlist_t * 398 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 399 { 400 nvlist_t *config, *nvroot; 401 vdev_t *rvd = spa->spa_root_vdev; 402 unsigned long hostid = 0; 403 boolean_t locked = B_FALSE; 404 uint64_t split_guid; 405 char *pool_name; 406 407 if (vd == NULL) { 408 vd = rvd; 409 locked = B_TRUE; 410 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 411 } 412 413 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 414 (SCL_CONFIG | SCL_STATE)); 415 416 /* 417 * If txg is -1, report the current value of spa->spa_config_txg. 418 */ 419 if (txg == -1ULL) 420 txg = spa->spa_config_txg; 421 422 /* 423 * Originally, users had to handle spa namespace collisions by either 424 * exporting the already imported pool or by specifying a new name for 425 * the pool with a conflicting name. In the case of root pools from 426 * virtual guests, neither approach to collision resolution is 427 * reasonable. This is addressed by extending the new name syntax with 428 * an option to specify that the new name is temporary. When specified, 429 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us 430 * to use the previous name, which we do below. 431 */ 432 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { 433 VERIFY0(nvlist_lookup_string(spa->spa_config, 434 ZPOOL_CONFIG_POOL_NAME, &pool_name)); 435 } else 436 pool_name = spa_name(spa); 437 438 config = fnvlist_alloc(); 439 440 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)); 441 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name); 442 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)); 443 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg); 444 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 445 fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA, spa->spa_errata); 446 if (spa->spa_comment != NULL) 447 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT, 448 spa->spa_comment); 449 450 hostid = spa_get_hostid(spa); 451 if (hostid != 0) 452 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid); 453 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname()->nodename); 454 455 int config_gen_flags = 0; 456 if (vd != rvd) { 457 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 458 vd->vdev_top->vdev_guid); 459 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 460 vd->vdev_guid); 461 if (vd->vdev_isspare) 462 fnvlist_add_uint64(config, 463 ZPOOL_CONFIG_IS_SPARE, 1ULL); 464 if (vd->vdev_islog) 465 fnvlist_add_uint64(config, 466 ZPOOL_CONFIG_IS_LOG, 1ULL); 467 vd = vd->vdev_top; /* label contains top config */ 468 } else { 469 /* 470 * Only add the (potentially large) split information 471 * in the mos config, and not in the vdev labels 472 */ 473 if (spa->spa_config_splitting != NULL) 474 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 475 spa->spa_config_splitting); 476 477 fnvlist_add_boolean(config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS); 478 479 config_gen_flags |= VDEV_CONFIG_MOS; 480 } 481 482 /* 483 * Add the top-level config. We even add this on pools which 484 * don't support holes in the namespace. 485 */ 486 vdev_top_config_generate(spa, config); 487 488 /* 489 * If we're splitting, record the original pool's guid. 490 */ 491 if (spa->spa_config_splitting != NULL && 492 nvlist_lookup_uint64(spa->spa_config_splitting, 493 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 494 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, split_guid); 495 } 496 497 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags); 498 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot); 499 nvlist_free(nvroot); 500 501 /* 502 * Store what's necessary for reading the MOS in the label. 503 */ 504 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 505 spa->spa_label_features); 506 507 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 508 ddt_histogram_t *ddh; 509 ddt_stat_t *dds; 510 ddt_object_t *ddo; 511 512 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 513 ddt_get_dedup_histogram(spa, ddh); 514 fnvlist_add_uint64_array(config, 515 ZPOOL_CONFIG_DDT_HISTOGRAM, 516 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)); 517 kmem_free(ddh, sizeof (ddt_histogram_t)); 518 519 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 520 ddt_get_dedup_object_stats(spa, ddo); 521 fnvlist_add_uint64_array(config, 522 ZPOOL_CONFIG_DDT_OBJ_STATS, 523 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)); 524 kmem_free(ddo, sizeof (ddt_object_t)); 525 526 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 527 ddt_get_dedup_stats(spa, dds); 528 fnvlist_add_uint64_array(config, 529 ZPOOL_CONFIG_DDT_STATS, 530 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)); 531 kmem_free(dds, sizeof (ddt_stat_t)); 532 } 533 534 if (locked) 535 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 536 537 return (config); 538 } 539 540 /* 541 * Update all disk labels, generate a fresh config based on the current 542 * in-core state, and sync the global config cache (do not sync the config 543 * cache if this is a booting rootpool). 544 */ 545 void 546 spa_config_update(spa_t *spa, int what) 547 { 548 vdev_t *rvd = spa->spa_root_vdev; 549 uint64_t txg; 550 int c; 551 552 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 553 554 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 555 txg = spa_last_synced_txg(spa) + 1; 556 if (what == SPA_CONFIG_UPDATE_POOL) { 557 vdev_config_dirty(rvd); 558 } else { 559 /* 560 * If we have top-level vdevs that were added but have 561 * not yet been prepared for allocation, do that now. 562 * (It's safe now because the config cache is up to date, 563 * so it will be able to translate the new DVAs.) 564 * See comments in spa_vdev_add() for full details. 565 */ 566 for (c = 0; c < rvd->vdev_children; c++) { 567 vdev_t *tvd = rvd->vdev_child[c]; 568 569 /* 570 * Explicitly skip vdevs that are indirect or 571 * log vdevs that are being removed. The reason 572 * is that both of those can have vdev_ms_array 573 * set to 0 and we wouldn't want to change their 574 * metaslab size nor call vdev_expand() on them. 575 */ 576 if (!vdev_is_concrete(tvd) || 577 (tvd->vdev_islog && tvd->vdev_removing)) 578 continue; 579 580 if (tvd->vdev_ms_array == 0) 581 vdev_metaslab_set_size(tvd); 582 vdev_expand(tvd, txg); 583 } 584 } 585 spa_config_exit(spa, SCL_ALL, FTAG); 586 587 /* 588 * Wait for the mosconfig to be regenerated and synced. 589 */ 590 txg_wait_synced(spa->spa_dsl_pool, txg); 591 592 /* 593 * Update the global config cache to reflect the new mosconfig. 594 */ 595 if (!spa->spa_is_root) { 596 spa_write_cachefile(spa, B_FALSE, 597 what != SPA_CONFIG_UPDATE_POOL); 598 } 599 600 if (what == SPA_CONFIG_UPDATE_POOL) 601 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 602 } 603 604 EXPORT_SYMBOL(spa_config_load); 605 EXPORT_SYMBOL(spa_all_configs); 606 EXPORT_SYMBOL(spa_config_set); 607 EXPORT_SYMBOL(spa_config_generate); 608 EXPORT_SYMBOL(spa_config_update); 609 610 /* BEGIN CSTYLED */ 611 #ifdef __linux__ 612 /* string sysctls require a char array on FreeBSD */ 613 ZFS_MODULE_PARAM(zfs_spa, spa_, config_path, STRING, ZMOD_RD, 614 "SPA config file (/etc/zfs/zpool.cache)"); 615 #endif 616 617 ZFS_MODULE_PARAM(zfs, zfs_, autoimport_disable, INT, ZMOD_RW, 618 "Disable pool import at module load"); 619 /* END CSTYLED */ 620