1 // SPDX-License-Identifier: CDDL-1.0 2 /* 3 * CDDL HEADER START 4 * 5 * The contents of this file are subject to the terms of the 6 * Common Development and Distribution License (the "License"). 7 * You may not use this file except in compliance with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or https://opensource.org/licenses/CDDL-1.0. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 25 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 26 * Copyright (c) 2011, 2020 by Delphix. All rights reserved. 27 * Copyright 2017 Joyent, Inc. 28 * Copyright (c) 2021, Colm Buckley <colm@tuatha.org> 29 */ 30 31 #include <sys/spa.h> 32 #include <sys/file.h> 33 #include <sys/fm/fs/zfs.h> 34 #include <sys/spa_impl.h> 35 #include <sys/nvpair.h> 36 #include <sys/fs/zfs.h> 37 #include <sys/vdev_impl.h> 38 #include <sys/zfs_ioctl.h> 39 #include <sys/systeminfo.h> 40 #include <sys/sunddi.h> 41 #include <sys/zfeature.h> 42 #include <sys/zfs_file.h> 43 #include <sys/zfs_context.h> 44 #ifdef _KERNEL 45 #include <sys/zone.h> 46 #endif 47 48 /* 49 * Pool configuration repository. 50 * 51 * Pool configuration is stored as a packed nvlist on the filesystem. When 52 * pools are imported they are added to the /etc/zfs/zpool.cache file and 53 * removed from it when exported. For each cache file, we have a single nvlist 54 * which holds all the configuration information. Pools can also have the 55 * 'cachefile' property set which allows this config to be stored in an 56 * alternate location under the control of external software. 57 * 58 * The kernel independantly maintains an AVL tree of imported pools. See the 59 * "SPA locking" comment in spa.c. Whenever a pool configuration is modified 60 * we call spa_write_cachefile() which walks through all the active pools and 61 * writes the updated configuration to to /etc/zfs/zpool.cache file. 62 */ 63 64 static uint64_t spa_config_generation = 1; 65 66 /* 67 * This can be overridden in userland to preserve an alternate namespace for 68 * userland pools when doing testing. 69 */ 70 char *spa_config_path = (char *)ZPOOL_CACHE; 71 72 static int 73 spa_config_remove(spa_config_dirent_t *dp) 74 { 75 int error = 0; 76 77 /* 78 * Remove the cache file. If zfs_file_unlink() in not supported by the 79 * platform fallback to truncating the file which is functionally 80 * equivalent. 81 */ 82 error = zfs_file_unlink(dp->scd_path); 83 if (error == EOPNOTSUPP) { 84 int flags = O_RDWR | O_TRUNC; 85 zfs_file_t *fp; 86 87 error = zfs_file_open(dp->scd_path, flags, 0644, &fp); 88 if (error == 0) { 89 (void) zfs_file_fsync(fp, O_SYNC); 90 (void) zfs_file_close(fp); 91 } 92 } 93 94 return (error); 95 } 96 97 static int 98 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 99 { 100 size_t buflen; 101 char *buf; 102 int oflags = O_RDWR | O_TRUNC | O_CREAT | O_LARGEFILE; 103 char *temp; 104 int err; 105 zfs_file_t *fp; 106 107 /* 108 * If the nvlist is empty (NULL), then remove the old cachefile. 109 */ 110 if (nvl == NULL) { 111 err = spa_config_remove(dp); 112 if (err == ENOENT) 113 err = 0; 114 115 return (err); 116 } 117 118 /* 119 * Pack the configuration into a buffer. 120 */ 121 buf = fnvlist_pack(nvl, &buflen); 122 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 123 124 /* 125 * Write the configuration to disk. Due to the complexity involved 126 * in performing a rename and remove from within the kernel the file 127 * is instead truncated and overwritten in place. This way we always 128 * have a consistent view of the data or a zero length file. 129 */ 130 err = zfs_file_open(dp->scd_path, oflags, 0644, &fp); 131 if (err == 0) { 132 err = zfs_file_write(fp, buf, buflen, NULL); 133 if (err == 0) 134 err = zfs_file_fsync(fp, O_SYNC); 135 136 zfs_file_close(fp); 137 if (err) 138 (void) spa_config_remove(dp); 139 } 140 fnvlist_pack_free(buf, buflen); 141 kmem_free(temp, MAXPATHLEN); 142 return (err); 143 } 144 145 /* 146 * Synchronize pool configuration to disk. This must be called with the 147 * namespace lock held. Synchronizing the pool cache is typically done after 148 * the configuration has been synced to the MOS. This exposes a window where 149 * the MOS config will have been updated but the cache file has not. If 150 * the system were to crash at that instant then the cached config may not 151 * contain the correct information to open the pool and an explicit import 152 * would be required. 153 */ 154 void 155 spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent, 156 boolean_t postblkidevent) 157 { 158 spa_config_dirent_t *dp, *tdp; 159 nvlist_t *nvl; 160 const char *pool_name; 161 boolean_t ccw_failure; 162 int error = 0; 163 164 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 165 166 if (!(spa_mode_global & SPA_MODE_WRITE)) 167 return; 168 169 /* 170 * Iterate over all cachefiles for the pool, past or present. When the 171 * cachefile is changed, the new one is pushed onto this list, allowing 172 * us to update previous cachefiles that no longer contain this pool. 173 */ 174 ccw_failure = B_FALSE; 175 for (dp = list_head(&target->spa_config_list); dp != NULL; 176 dp = list_next(&target->spa_config_list, dp)) { 177 spa_t *spa = NULL; 178 if (dp->scd_path == NULL) 179 continue; 180 181 /* 182 * Iterate over all pools, adding any matching pools to 'nvl'. 183 */ 184 nvl = NULL; 185 while ((spa = spa_next(spa)) != NULL) { 186 /* 187 * Skip over our own pool if we're about to remove 188 * ourselves from the spa namespace or any pool that 189 * is readonly. Since we cannot guarantee that a 190 * readonly pool would successfully import upon reboot, 191 * we don't allow them to be written to the cache file. 192 */ 193 if ((spa == target && removing) || 194 !spa_writeable(spa)) 195 continue; 196 197 mutex_enter(&spa->spa_props_lock); 198 tdp = list_head(&spa->spa_config_list); 199 if (spa->spa_config == NULL || 200 tdp == NULL || 201 tdp->scd_path == NULL || 202 strcmp(tdp->scd_path, dp->scd_path) != 0) { 203 mutex_exit(&spa->spa_props_lock); 204 continue; 205 } 206 207 if (nvl == NULL) 208 nvl = fnvlist_alloc(); 209 210 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) 211 pool_name = fnvlist_lookup_string( 212 spa->spa_config, ZPOOL_CONFIG_POOL_NAME); 213 else 214 pool_name = spa_name(spa); 215 216 fnvlist_add_nvlist(nvl, pool_name, spa->spa_config); 217 mutex_exit(&spa->spa_props_lock); 218 } 219 220 error = spa_config_write(dp, nvl); 221 if (error != 0) 222 ccw_failure = B_TRUE; 223 nvlist_free(nvl); 224 } 225 226 if (ccw_failure) { 227 /* 228 * Keep trying so that configuration data is 229 * written if/when any temporary filesystem 230 * resource issues are resolved. 231 */ 232 if (target->spa_ccw_fail_time == 0) { 233 (void) zfs_ereport_post( 234 FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 235 target, NULL, NULL, NULL, 0); 236 } 237 target->spa_ccw_fail_time = gethrtime(); 238 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 239 } else { 240 /* 241 * Do not rate limit future attempts to update 242 * the config cache. 243 */ 244 target->spa_ccw_fail_time = 0; 245 } 246 247 /* 248 * Remove any config entries older than the current one. 249 */ 250 dp = list_head(&target->spa_config_list); 251 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 252 list_remove(&target->spa_config_list, tdp); 253 if (tdp->scd_path != NULL) 254 spa_strfree(tdp->scd_path); 255 kmem_free(tdp, sizeof (spa_config_dirent_t)); 256 } 257 258 spa_config_generation++; 259 260 if (postsysevent) 261 spa_event_notify(target, NULL, NULL, ESC_ZFS_CONFIG_SYNC); 262 263 /* 264 * Post udev event to sync blkid information if the pool is created 265 * or a new vdev is added to the pool. 266 */ 267 if ((target->spa_root_vdev) && postblkidevent) { 268 vdev_post_kobj_evt(target->spa_root_vdev); 269 for (int i = 0; i < target->spa_l2cache.sav_count; i++) 270 vdev_post_kobj_evt(target->spa_l2cache.sav_vdevs[i]); 271 for (int i = 0; i < target->spa_spares.sav_count; i++) 272 vdev_post_kobj_evt(target->spa_spares.sav_vdevs[i]); 273 } 274 } 275 276 /* 277 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 278 * and we don't want to allow the local zone to see all the pools anyway. 279 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 280 * information for all pool visible within the zone. 281 */ 282 int 283 spa_all_configs(uint64_t *generation, nvlist_t **pools) 284 { 285 spa_t *spa = NULL; 286 287 if (*generation == spa_config_generation) 288 return (SET_ERROR(EEXIST)); 289 290 int error = mutex_enter_interruptible(&spa_namespace_lock); 291 if (error) 292 return (SET_ERROR(EINTR)); 293 294 *pools = fnvlist_alloc(); 295 while ((spa = spa_next(spa)) != NULL) { 296 if (INGLOBALZONE(curproc) || 297 zone_dataset_visible(spa_name(spa), NULL)) { 298 mutex_enter(&spa->spa_props_lock); 299 fnvlist_add_nvlist(*pools, spa_name(spa), 300 spa->spa_config); 301 mutex_exit(&spa->spa_props_lock); 302 } 303 } 304 *generation = spa_config_generation; 305 mutex_exit(&spa_namespace_lock); 306 307 return (0); 308 } 309 310 void 311 spa_config_set(spa_t *spa, nvlist_t *config) 312 { 313 mutex_enter(&spa->spa_props_lock); 314 if (spa->spa_config != NULL && spa->spa_config != config) 315 nvlist_free(spa->spa_config); 316 spa->spa_config = config; 317 mutex_exit(&spa->spa_props_lock); 318 } 319 320 /* 321 * Generate the pool's configuration based on the current in-core state. 322 * 323 * We infer whether to generate a complete config or just one top-level config 324 * based on whether vd is the root vdev. 325 */ 326 nvlist_t * 327 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 328 { 329 nvlist_t *config, *nvroot; 330 vdev_t *rvd = spa->spa_root_vdev; 331 unsigned long hostid = 0; 332 boolean_t locked = B_FALSE; 333 uint64_t split_guid; 334 const char *pool_name; 335 336 if (vd == NULL) { 337 vd = rvd; 338 locked = B_TRUE; 339 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 340 } 341 342 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 343 (SCL_CONFIG | SCL_STATE)); 344 345 /* 346 * If txg is -1, report the current value of spa->spa_config_txg. 347 */ 348 if (txg == -1ULL) 349 txg = spa->spa_config_txg; 350 351 /* 352 * Originally, users had to handle spa namespace collisions by either 353 * exporting the already imported pool or by specifying a new name for 354 * the pool with a conflicting name. In the case of root pools from 355 * virtual guests, neither approach to collision resolution is 356 * reasonable. This is addressed by extending the new name syntax with 357 * an option to specify that the new name is temporary. When specified, 358 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us 359 * to use the previous name, which we do below. 360 */ 361 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { 362 VERIFY0(nvlist_lookup_string(spa->spa_config, 363 ZPOOL_CONFIG_POOL_NAME, &pool_name)); 364 } else 365 pool_name = spa_name(spa); 366 367 config = fnvlist_alloc(); 368 369 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)); 370 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name); 371 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)); 372 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg); 373 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 374 fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA, spa->spa_errata); 375 if (spa->spa_comment != NULL) 376 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT, 377 spa->spa_comment); 378 if (spa->spa_compatibility != NULL) 379 fnvlist_add_string(config, ZPOOL_CONFIG_COMPATIBILITY, 380 spa->spa_compatibility); 381 382 hostid = spa_get_hostid(spa); 383 if (hostid != 0) 384 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid); 385 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname()->nodename); 386 387 int config_gen_flags = 0; 388 if (vd != rvd) { 389 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 390 vd->vdev_top->vdev_guid); 391 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 392 vd->vdev_guid); 393 if (vd->vdev_isspare) 394 fnvlist_add_uint64(config, 395 ZPOOL_CONFIG_IS_SPARE, 1ULL); 396 if (vd->vdev_islog) 397 fnvlist_add_uint64(config, 398 ZPOOL_CONFIG_IS_LOG, 1ULL); 399 vd = vd->vdev_top; /* label contains top config */ 400 } else { 401 /* 402 * Only add the (potentially large) split information 403 * in the mos config, and not in the vdev labels 404 */ 405 if (spa->spa_config_splitting != NULL) 406 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 407 spa->spa_config_splitting); 408 409 fnvlist_add_boolean(config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS); 410 411 config_gen_flags |= VDEV_CONFIG_MOS; 412 } 413 414 /* 415 * Add the top-level config. We even add this on pools which 416 * don't support holes in the namespace. 417 */ 418 vdev_top_config_generate(spa, config); 419 420 /* 421 * If we're splitting, record the original pool's guid. 422 */ 423 if (spa->spa_config_splitting != NULL && 424 nvlist_lookup_uint64(spa->spa_config_splitting, 425 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 426 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, split_guid); 427 } 428 429 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags); 430 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot); 431 nvlist_free(nvroot); 432 433 /* 434 * Store what's necessary for reading the MOS in the label. 435 */ 436 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 437 spa->spa_label_features); 438 439 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 440 ddt_histogram_t *ddh; 441 ddt_stat_t *dds; 442 ddt_object_t *ddo; 443 444 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 445 ddt_get_dedup_histogram(spa, ddh); 446 fnvlist_add_uint64_array(config, 447 ZPOOL_CONFIG_DDT_HISTOGRAM, 448 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)); 449 kmem_free(ddh, sizeof (ddt_histogram_t)); 450 451 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 452 ddt_get_dedup_object_stats(spa, ddo); 453 fnvlist_add_uint64_array(config, 454 ZPOOL_CONFIG_DDT_OBJ_STATS, 455 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)); 456 kmem_free(ddo, sizeof (ddt_object_t)); 457 458 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 459 ddt_get_dedup_stats(spa, dds); 460 fnvlist_add_uint64_array(config, 461 ZPOOL_CONFIG_DDT_STATS, 462 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)); 463 kmem_free(dds, sizeof (ddt_stat_t)); 464 } 465 466 if (locked) 467 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 468 469 return (config); 470 } 471 472 /* 473 * Update all disk labels, generate a fresh config based on the current 474 * in-core state, and sync the global config cache (do not sync the config 475 * cache if this is a booting rootpool). 476 */ 477 void 478 spa_config_update(spa_t *spa, int what) 479 { 480 vdev_t *rvd = spa->spa_root_vdev; 481 uint64_t txg; 482 int c; 483 484 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 485 486 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 487 txg = spa_last_synced_txg(spa) + 1; 488 if (what == SPA_CONFIG_UPDATE_POOL) { 489 vdev_config_dirty(rvd); 490 } else { 491 /* 492 * If we have top-level vdevs that were added but have 493 * not yet been prepared for allocation, do that now. 494 * (It's safe now because the config cache is up to date, 495 * so it will be able to translate the new DVAs.) 496 * See comments in spa_vdev_add() for full details. 497 */ 498 for (c = 0; c < rvd->vdev_children; c++) { 499 vdev_t *tvd = rvd->vdev_child[c]; 500 501 /* 502 * Explicitly skip vdevs that are indirect or 503 * log vdevs that are being removed. The reason 504 * is that both of those can have vdev_ms_array 505 * set to 0 and we wouldn't want to change their 506 * metaslab size nor call vdev_expand() on them. 507 */ 508 if (!vdev_is_concrete(tvd) || 509 (tvd->vdev_islog && tvd->vdev_removing)) 510 continue; 511 512 if (tvd->vdev_ms_array == 0) 513 vdev_metaslab_set_size(tvd); 514 vdev_expand(tvd, txg); 515 } 516 } 517 spa_config_exit(spa, SCL_ALL, FTAG); 518 519 /* 520 * Wait for the mosconfig to be regenerated and synced. 521 */ 522 txg_wait_synced(spa->spa_dsl_pool, txg); 523 524 /* 525 * Update the global config cache to reflect the new mosconfig. 526 */ 527 if (!spa->spa_is_root) { 528 spa_write_cachefile(spa, B_FALSE, 529 what != SPA_CONFIG_UPDATE_POOL, 530 what != SPA_CONFIG_UPDATE_POOL); 531 } 532 533 if (what == SPA_CONFIG_UPDATE_POOL) 534 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 535 } 536 537 EXPORT_SYMBOL(spa_all_configs); 538 EXPORT_SYMBOL(spa_config_set); 539 EXPORT_SYMBOL(spa_config_generate); 540 EXPORT_SYMBOL(spa_config_update); 541 542 #ifdef __linux__ 543 /* string sysctls require a char array on FreeBSD */ 544 ZFS_MODULE_PARAM(zfs_spa, spa_, config_path, STRING, ZMOD_RD, 545 "SPA config file (/etc/zfs/zpool.cache)"); 546 #endif 547