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, 2018 by Delphix. All rights reserved. 26 * Copyright 2017 Joyent, Inc. 27 */ 28 29 #include <sys/spa.h> 30 #include <sys/fm/fs/zfs.h> 31 #include <sys/spa_impl.h> 32 #include <sys/nvpair.h> 33 #include <sys/uio.h> 34 #include <sys/fs/zfs.h> 35 #include <sys/vdev_impl.h> 36 #include <sys/zfs_ioctl.h> 37 #include <sys/utsname.h> 38 #include <sys/systeminfo.h> 39 #include <sys/sunddi.h> 40 #include <sys/zfeature.h> 41 #ifdef _KERNEL 42 #include <sys/kobj.h> 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 const char *spa_config_path = ZPOOL_CACHE; 70 71 /* 72 * Called when the module is first loaded, this routine loads the configuration 73 * file into the SPA namespace. It does not actually open or load the pools; it 74 * only populates the namespace. 75 */ 76 void 77 spa_config_load(void) 78 { 79 void *buf = NULL; 80 nvlist_t *nvlist, *child; 81 nvpair_t *nvpair; 82 char *pathname; 83 struct _buf *file; 84 uint64_t fsize; 85 86 /* 87 * Open the configuration file. 88 */ 89 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP); 90 91 (void) snprintf(pathname, MAXPATHLEN, "%s%s", 92 (rootdir != NULL) ? "./" : "", spa_config_path); 93 94 file = kobj_open_file(pathname); 95 96 kmem_free(pathname, MAXPATHLEN); 97 98 if (file == (struct _buf *)-1) 99 return; 100 101 if (kobj_get_filesize(file, &fsize) != 0) 102 goto out; 103 104 buf = kmem_alloc(fsize, KM_SLEEP); 105 106 /* 107 * Read the nvlist from the file. 108 */ 109 if (kobj_read_file(file, buf, fsize, 0) < 0) 110 goto out; 111 112 /* 113 * Unpack the nvlist. 114 */ 115 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 116 goto out; 117 118 /* 119 * Iterate over all elements in the nvlist, creating a new spa_t for 120 * each one with the specified configuration. 121 */ 122 mutex_enter(&spa_namespace_lock); 123 nvpair = NULL; 124 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 125 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 126 continue; 127 128 child = fnvpair_value_nvlist(nvpair); 129 130 if (spa_lookup(nvpair_name(nvpair)) != NULL) 131 continue; 132 (void) spa_add(nvpair_name(nvpair), child, NULL); 133 } 134 mutex_exit(&spa_namespace_lock); 135 136 nvlist_free(nvlist); 137 138 out: 139 if (buf != NULL) 140 kmem_free(buf, fsize); 141 142 kobj_close_file(file); 143 } 144 145 static int 146 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 147 { 148 size_t buflen; 149 char *buf; 150 vnode_t *vp; 151 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 152 char *temp; 153 int err; 154 155 /* 156 * If the nvlist is empty (NULL), then remove the old cachefile. 157 */ 158 if (nvl == NULL) { 159 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 160 return (err); 161 } 162 163 /* 164 * Pack the configuration into a buffer. 165 */ 166 buf = fnvlist_pack(nvl, &buflen); 167 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 168 169 /* 170 * Write the configuration to disk. We need to do the traditional 171 * 'write to temporary file, sync, move over original' to make sure we 172 * always have a consistent view of the data. 173 */ 174 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 175 176 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 177 if (err == 0) { 178 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 179 0, RLIM64_INFINITY, kcred, NULL); 180 if (err == 0) 181 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 182 if (err == 0) 183 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 184 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 185 VN_RELE(vp); 186 } 187 188 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 189 190 fnvlist_pack_free(buf, buflen); 191 kmem_free(temp, MAXPATHLEN); 192 return (err); 193 } 194 195 /* 196 * Synchronize pool configuration to disk. This must be called with the 197 * namespace lock held. Synchronizing the pool cache is typically done after 198 * the configuration has been synced to the MOS. This exposes a window where 199 * the MOS config will have been updated but the cache file has not. If 200 * the system were to crash at that instant then the cached config may not 201 * contain the correct information to open the pool and an explicit import 202 * would be required. 203 */ 204 void 205 spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent) 206 { 207 spa_config_dirent_t *dp, *tdp; 208 nvlist_t *nvl; 209 boolean_t ccw_failure; 210 int error; 211 char *pool_name; 212 213 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 214 215 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 216 return; 217 218 /* 219 * Iterate over all cachefiles for the pool, past or present. When the 220 * cachefile is changed, the new one is pushed onto this list, allowing 221 * us to update previous cachefiles that no longer contain this pool. 222 */ 223 ccw_failure = B_FALSE; 224 for (dp = list_head(&target->spa_config_list); dp != NULL; 225 dp = list_next(&target->spa_config_list, dp)) { 226 spa_t *spa = NULL; 227 if (dp->scd_path == NULL) 228 continue; 229 230 /* 231 * Iterate over all pools, adding any matching pools to 'nvl'. 232 */ 233 nvl = NULL; 234 while ((spa = spa_next(spa)) != NULL) { 235 /* 236 * Skip over our own pool if we're about to remove 237 * ourselves from the spa namespace or any pool that 238 * is readonly. Since we cannot guarantee that a 239 * readonly pool would successfully import upon reboot, 240 * we don't allow them to be written to the cache file. 241 */ 242 if ((spa == target && removing) || 243 !spa_writeable(spa)) 244 continue; 245 246 mutex_enter(&spa->spa_props_lock); 247 tdp = list_head(&spa->spa_config_list); 248 if (spa->spa_config == NULL || 249 tdp->scd_path == NULL || 250 strcmp(tdp->scd_path, dp->scd_path) != 0) { 251 mutex_exit(&spa->spa_props_lock); 252 continue; 253 } 254 255 if (nvl == NULL) 256 nvl = fnvlist_alloc(); 257 258 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { 259 pool_name = fnvlist_lookup_string( 260 spa->spa_config, ZPOOL_CONFIG_POOL_NAME); 261 } else { 262 pool_name = spa_name(spa); 263 } 264 265 fnvlist_add_nvlist(nvl, pool_name, 266 spa->spa_config); 267 mutex_exit(&spa->spa_props_lock); 268 } 269 270 error = spa_config_write(dp, nvl); 271 if (error != 0) 272 ccw_failure = B_TRUE; 273 nvlist_free(nvl); 274 } 275 276 if (ccw_failure) { 277 /* 278 * Keep trying so that configuration data is 279 * written if/when any temporary filesystem 280 * resource issues are resolved. 281 */ 282 if (target->spa_ccw_fail_time == 0) { 283 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 284 target, NULL, NULL, 0, 0); 285 } 286 target->spa_ccw_fail_time = gethrtime(); 287 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 288 } else { 289 /* 290 * Do not rate limit future attempts to update 291 * the config cache. 292 */ 293 target->spa_ccw_fail_time = 0; 294 } 295 296 /* 297 * Remove any config entries older than the current one. 298 */ 299 dp = list_head(&target->spa_config_list); 300 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 301 list_remove(&target->spa_config_list, tdp); 302 if (tdp->scd_path != NULL) 303 spa_strfree(tdp->scd_path); 304 kmem_free(tdp, sizeof (spa_config_dirent_t)); 305 } 306 307 spa_config_generation++; 308 309 if (postsysevent) 310 spa_event_notify(target, NULL, NULL, ESC_ZFS_CONFIG_SYNC); 311 } 312 313 /* 314 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 315 * and we don't want to allow the local zone to see all the pools anyway. 316 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 317 * information for all pool visible within the zone. 318 */ 319 nvlist_t * 320 spa_all_configs(uint64_t *generation) 321 { 322 nvlist_t *pools; 323 spa_t *spa = NULL; 324 325 if (*generation == spa_config_generation) 326 return (NULL); 327 328 pools = fnvlist_alloc(); 329 330 mutex_enter(&spa_namespace_lock); 331 while ((spa = spa_next(spa)) != NULL) { 332 if (INGLOBALZONE(curproc) || 333 zone_dataset_visible(spa_name(spa), NULL)) { 334 mutex_enter(&spa->spa_props_lock); 335 fnvlist_add_nvlist(pools, spa_name(spa), 336 spa->spa_config); 337 mutex_exit(&spa->spa_props_lock); 338 } 339 } 340 *generation = spa_config_generation; 341 mutex_exit(&spa_namespace_lock); 342 343 return (pools); 344 } 345 346 void 347 spa_config_set(spa_t *spa, nvlist_t *config) 348 { 349 mutex_enter(&spa->spa_props_lock); 350 if (spa->spa_config != NULL && spa->spa_config != config) 351 nvlist_free(spa->spa_config); 352 spa->spa_config = config; 353 mutex_exit(&spa->spa_props_lock); 354 } 355 356 /* 357 * Generate the pool's configuration based on the current in-core state. 358 * 359 * We infer whether to generate a complete config or just one top-level config 360 * based on whether vd is the root vdev. 361 */ 362 nvlist_t * 363 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 364 { 365 nvlist_t *config, *nvroot; 366 vdev_t *rvd = spa->spa_root_vdev; 367 unsigned long hostid = 0; 368 boolean_t locked = B_FALSE; 369 uint64_t split_guid; 370 char *pool_name; 371 372 if (vd == NULL) { 373 vd = rvd; 374 locked = B_TRUE; 375 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 376 } 377 378 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 379 (SCL_CONFIG | SCL_STATE)); 380 381 /* 382 * If txg is -1, report the current value of spa->spa_config_txg. 383 */ 384 if (txg == -1ULL) 385 txg = spa->spa_config_txg; 386 387 /* 388 * Originally, users had to handle spa namespace collisions by either 389 * exporting the already imported pool or by specifying a new name for 390 * the pool with a conflicting name. In the case of root pools from 391 * virtual guests, neither approach to collision resolution is 392 * reasonable. This is addressed by extending the new name syntax with 393 * an option to specify that the new name is temporary. When specified, 394 * ZFS_IMPORT_TEMP_NAME will be set in spa->spa_import_flags to tell us 395 * to use the previous name, which we do below. 396 */ 397 if (spa->spa_import_flags & ZFS_IMPORT_TEMP_NAME) { 398 pool_name = fnvlist_lookup_string(spa->spa_config, 399 ZPOOL_CONFIG_POOL_NAME); 400 } else { 401 pool_name = spa_name(spa); 402 } 403 404 config = fnvlist_alloc(); 405 406 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)); 407 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, pool_name); 408 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)); 409 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg); 410 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 411 if (spa->spa_comment != NULL) { 412 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT, 413 spa->spa_comment); 414 } 415 416 hostid = spa_get_hostid(); 417 if (hostid != 0) { 418 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid); 419 } 420 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname.nodename); 421 422 int config_gen_flags = 0; 423 if (vd != rvd) { 424 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 425 vd->vdev_top->vdev_guid); 426 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 427 vd->vdev_guid); 428 if (vd->vdev_isspare) { 429 fnvlist_add_uint64(config, 430 ZPOOL_CONFIG_IS_SPARE, 1ULL); 431 } 432 if (vd->vdev_islog) { 433 fnvlist_add_uint64(config, 434 ZPOOL_CONFIG_IS_LOG, 1ULL); 435 } 436 vd = vd->vdev_top; /* label contains top config */ 437 } else { 438 /* 439 * Only add the (potentially large) split information 440 * in the mos config, and not in the vdev labels 441 */ 442 if (spa->spa_config_splitting != NULL) 443 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 444 spa->spa_config_splitting); 445 fnvlist_add_boolean(config, 446 ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS); 447 448 config_gen_flags |= VDEV_CONFIG_MOS; 449 } 450 451 /* 452 * Add the top-level config. We even add this on pools which 453 * don't support holes in the namespace. 454 */ 455 vdev_top_config_generate(spa, config); 456 457 /* 458 * If we're splitting, record the original pool's guid. 459 */ 460 if (spa->spa_config_splitting != NULL && 461 nvlist_lookup_uint64(spa->spa_config_splitting, 462 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 463 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 464 split_guid); 465 } 466 467 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags); 468 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot); 469 nvlist_free(nvroot); 470 471 /* 472 * Store what's necessary for reading the MOS in the label. 473 */ 474 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 475 spa->spa_label_features); 476 477 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 478 ddt_histogram_t *ddh; 479 ddt_stat_t *dds; 480 ddt_object_t *ddo; 481 482 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 483 ddt_get_dedup_histogram(spa, ddh); 484 fnvlist_add_uint64_array(config, 485 ZPOOL_CONFIG_DDT_HISTOGRAM, 486 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)); 487 kmem_free(ddh, sizeof (ddt_histogram_t)); 488 489 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 490 ddt_get_dedup_object_stats(spa, ddo); 491 fnvlist_add_uint64_array(config, 492 ZPOOL_CONFIG_DDT_OBJ_STATS, 493 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)); 494 kmem_free(ddo, sizeof (ddt_object_t)); 495 496 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 497 ddt_get_dedup_stats(spa, dds); 498 fnvlist_add_uint64_array(config, 499 ZPOOL_CONFIG_DDT_STATS, 500 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)); 501 kmem_free(dds, sizeof (ddt_stat_t)); 502 } 503 504 if (locked) 505 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 506 507 return (config); 508 } 509 510 /* 511 * Update all disk labels, generate a fresh config based on the current 512 * in-core state, and sync the global config cache (do not sync the config 513 * cache if this is a booting rootpool). 514 */ 515 void 516 spa_config_update(spa_t *spa, int what) 517 { 518 vdev_t *rvd = spa->spa_root_vdev; 519 uint64_t txg; 520 int c; 521 522 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 523 524 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 525 txg = spa_last_synced_txg(spa) + 1; 526 if (what == SPA_CONFIG_UPDATE_POOL) { 527 vdev_config_dirty(rvd); 528 } else { 529 /* 530 * If we have top-level vdevs that were added but have 531 * not yet been prepared for allocation, do that now. 532 * (It's safe now because the config cache is up to date, 533 * so it will be able to translate the new DVAs.) 534 * See comments in spa_vdev_add() for full details. 535 */ 536 for (c = 0; c < rvd->vdev_children; c++) { 537 vdev_t *tvd = rvd->vdev_child[c]; 538 539 /* 540 * Explicitly skip vdevs that are indirect or 541 * log vdevs that are being removed. The reason 542 * is that both of those can have vdev_ms_array 543 * set to 0 and we wouldn't want to change their 544 * metaslab size nor call vdev_expand() on them. 545 */ 546 if (!vdev_is_concrete(tvd) || 547 (tvd->vdev_islog && tvd->vdev_removing)) 548 continue; 549 550 if (tvd->vdev_ms_array == 0) 551 vdev_metaslab_set_size(tvd); 552 vdev_expand(tvd, txg); 553 } 554 } 555 spa_config_exit(spa, SCL_ALL, FTAG); 556 557 /* 558 * Wait for the mosconfig to be regenerated and synced. 559 */ 560 txg_wait_synced(spa->spa_dsl_pool, txg); 561 562 /* 563 * Update the global config cache to reflect the new mosconfig. 564 */ 565 if (!spa->spa_is_root) { 566 spa_write_cachefile(spa, B_FALSE, 567 what != SPA_CONFIG_UPDATE_POOL); 568 } 569 570 if (what == SPA_CONFIG_UPDATE_POOL) 571 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 572 } 573