spa_config.c revision 332525
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, 2015 by Delphix. All rights reserved. 26 * Copyright 2017 Joyent, Inc. 27 */ 28 29#include <sys/zfs_context.h> 30#include <sys/spa.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/utsname.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 63static 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 */ 69const 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 */ 76void 77spa_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", spa_config_path); 92 93 file = kobj_open_file(pathname); 94 95 kmem_free(pathname, MAXPATHLEN); 96 97 if (file == (struct _buf *)-1) 98 return; 99 100 if (kobj_get_filesize(file, &fsize) != 0) 101 goto out; 102 103 buf = kmem_alloc(fsize, KM_SLEEP); 104 105 /* 106 * Read the nvlist from the file. 107 */ 108 if (kobj_read_file(file, buf, fsize, 0) < 0) 109 goto out; 110 111 /* 112 * Unpack the nvlist. 113 */ 114 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 115 goto out; 116 117 /* 118 * Iterate over all elements in the nvlist, creating a new spa_t for 119 * each one with the specified configuration. 120 */ 121 mutex_enter(&spa_namespace_lock); 122 nvpair = NULL; 123 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 124 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 125 continue; 126 127 child = fnvpair_value_nvlist(nvpair); 128 129 if (spa_lookup(nvpair_name(nvpair)) != NULL) 130 continue; 131 (void) spa_add(nvpair_name(nvpair), child, NULL); 132 } 133 mutex_exit(&spa_namespace_lock); 134 135 nvlist_free(nvlist); 136 137out: 138 if (buf != NULL) 139 kmem_free(buf, fsize); 140 141 kobj_close_file(file); 142} 143 144static void 145spa_config_clean(nvlist_t *nvl) 146{ 147 nvlist_t **child; 148 nvlist_t *nvroot = NULL; 149 uint_t c, children; 150 151 if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child, 152 &children) == 0) { 153 for (c = 0; c < children; c++) 154 spa_config_clean(child[c]); 155 } 156 157 if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0) 158 spa_config_clean(nvroot); 159 160 nvlist_remove(nvl, ZPOOL_CONFIG_VDEV_STATS, DATA_TYPE_UINT64_ARRAY); 161 nvlist_remove(nvl, ZPOOL_CONFIG_SCAN_STATS, DATA_TYPE_UINT64_ARRAY); 162} 163 164static int 165spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 166{ 167 size_t buflen; 168 char *buf; 169 vnode_t *vp; 170 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 171 char *temp; 172 int err; 173 174 /* 175 * If the nvlist is empty (NULL), then remove the old cachefile. 176 */ 177 if (nvl == NULL) { 178 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 179 return (err); 180 } 181 182 /* 183 * Pack the configuration into a buffer. 184 */ 185 buf = fnvlist_pack(nvl, &buflen); 186 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 187 188 /* 189 * Write the configuration to disk. We need to do the traditional 190 * 'write to temporary file, sync, move over original' to make sure we 191 * always have a consistent view of the data. 192 */ 193 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 194 195 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 196 if (err == 0) { 197 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 198 0, RLIM64_INFINITY, kcred, NULL); 199 if (err == 0) 200 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 201 if (err == 0) 202 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 203 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 204 } 205 206 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 207 208 fnvlist_pack_free(buf, buflen); 209 kmem_free(temp, MAXPATHLEN); 210 return (err); 211} 212 213/* 214 * Synchronize pool configuration to disk. This must be called with the 215 * namespace lock held. Synchronizing the pool cache is typically done after 216 * the configuration has been synced to the MOS. This exposes a window where 217 * the MOS config will have been updated but the cache file has not. If 218 * the system were to crash at that instant then the cached config may not 219 * contain the correct information to open the pool and an explicit import 220 * would be required. 221 */ 222void 223spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent) 224{ 225 spa_config_dirent_t *dp, *tdp; 226 nvlist_t *nvl; 227 boolean_t ccw_failure; 228 int error; 229 230 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 231 232 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 233 return; 234 235 /* 236 * Iterate over all cachefiles for the pool, past or present. When the 237 * cachefile is changed, the new one is pushed onto this list, allowing 238 * us to update previous cachefiles that no longer contain this pool. 239 */ 240 ccw_failure = B_FALSE; 241 for (dp = list_head(&target->spa_config_list); dp != NULL; 242 dp = list_next(&target->spa_config_list, dp)) { 243 spa_t *spa = NULL; 244 if (dp->scd_path == NULL) 245 continue; 246 247 /* 248 * Iterate over all pools, adding any matching pools to 'nvl'. 249 */ 250 nvl = NULL; 251 while ((spa = spa_next(spa)) != NULL) { 252 nvlist_t *nvroot = NULL; 253 /* 254 * Skip over our own pool if we're about to remove 255 * ourselves from the spa namespace or any pool that 256 * is readonly. Since we cannot guarantee that a 257 * readonly pool would successfully import upon reboot, 258 * we don't allow them to be written to the cache file. 259 */ 260 if ((spa == target && removing) || 261 (spa_state(spa) == POOL_STATE_ACTIVE && 262 !spa_writeable(spa))) 263 continue; 264 265 mutex_enter(&spa->spa_props_lock); 266 tdp = list_head(&spa->spa_config_list); 267 if (spa->spa_config == NULL || 268 tdp->scd_path == NULL || 269 strcmp(tdp->scd_path, dp->scd_path) != 0) { 270 mutex_exit(&spa->spa_props_lock); 271 continue; 272 } 273 274 if (nvl == NULL) 275 nvl = fnvlist_alloc(); 276 277 fnvlist_add_nvlist(nvl, spa->spa_name, 278 spa->spa_config); 279 mutex_exit(&spa->spa_props_lock); 280 281 if (nvlist_lookup_nvlist(nvl, spa->spa_name, &nvroot) == 0) 282 spa_config_clean(nvroot); 283 } 284 285 error = spa_config_write(dp, nvl); 286 if (error != 0) 287 ccw_failure = B_TRUE; 288 nvlist_free(nvl); 289 } 290 291 if (ccw_failure) { 292 /* 293 * Keep trying so that configuration data is 294 * written if/when any temporary filesystem 295 * resource issues are resolved. 296 */ 297 if (target->spa_ccw_fail_time == 0) { 298 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 299 target, NULL, NULL, 0, 0); 300 } 301 target->spa_ccw_fail_time = gethrtime(); 302 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 303 } else { 304 /* 305 * Do not rate limit future attempts to update 306 * the config cache. 307 */ 308 target->spa_ccw_fail_time = 0; 309 } 310 311 /* 312 * Remove any config entries older than the current one. 313 */ 314 dp = list_head(&target->spa_config_list); 315 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 316 list_remove(&target->spa_config_list, tdp); 317 if (tdp->scd_path != NULL) 318 spa_strfree(tdp->scd_path); 319 kmem_free(tdp, sizeof (spa_config_dirent_t)); 320 } 321 322 spa_config_generation++; 323 324 if (postsysevent) 325 spa_event_notify(target, NULL, NULL, ESC_ZFS_CONFIG_SYNC); 326} 327 328/* 329 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 330 * and we don't want to allow the local zone to see all the pools anyway. 331 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 332 * information for all pool visible within the zone. 333 */ 334nvlist_t * 335spa_all_configs(uint64_t *generation) 336{ 337 nvlist_t *pools; 338 spa_t *spa = NULL; 339 340 if (*generation == spa_config_generation) 341 return (NULL); 342 343 pools = fnvlist_alloc(); 344 345 mutex_enter(&spa_namespace_lock); 346 while ((spa = spa_next(spa)) != NULL) { 347 if (INGLOBALZONE(curthread) || 348 zone_dataset_visible(spa_name(spa), NULL)) { 349 mutex_enter(&spa->spa_props_lock); 350 fnvlist_add_nvlist(pools, spa_name(spa), 351 spa->spa_config); 352 mutex_exit(&spa->spa_props_lock); 353 } 354 } 355 *generation = spa_config_generation; 356 mutex_exit(&spa_namespace_lock); 357 358 return (pools); 359} 360 361void 362spa_config_set(spa_t *spa, nvlist_t *config) 363{ 364 mutex_enter(&spa->spa_props_lock); 365 nvlist_free(spa->spa_config); 366 spa->spa_config = config; 367 mutex_exit(&spa->spa_props_lock); 368} 369 370/* 371 * Generate the pool's configuration based on the current in-core state. 372 * 373 * We infer whether to generate a complete config or just one top-level config 374 * based on whether vd is the root vdev. 375 */ 376nvlist_t * 377spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 378{ 379 nvlist_t *config, *nvroot; 380 vdev_t *rvd = spa->spa_root_vdev; 381 unsigned long hostid = 0; 382 boolean_t locked = B_FALSE; 383 uint64_t split_guid; 384 385 if (vd == NULL) { 386 vd = rvd; 387 locked = B_TRUE; 388 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 389 } 390 391 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 392 (SCL_CONFIG | SCL_STATE)); 393 394 /* 395 * If txg is -1, report the current value of spa->spa_config_txg. 396 */ 397 if (txg == -1ULL) 398 txg = spa->spa_config_txg; 399 400 config = fnvlist_alloc(); 401 402 fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa)); 403 fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, spa_name(spa)); 404 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, spa_state(spa)); 405 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, txg); 406 fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); 407 if (spa->spa_comment != NULL) { 408 fnvlist_add_string(config, ZPOOL_CONFIG_COMMENT, 409 spa->spa_comment); 410 } 411 412#ifdef _KERNEL 413 hostid = zone_get_hostid(NULL); 414#else /* _KERNEL */ 415 /* 416 * We're emulating the system's hostid in userland, so we can't use 417 * zone_get_hostid(). 418 */ 419 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid); 420#endif /* _KERNEL */ 421 if (hostid != 0) { 422 fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid); 423 } 424 fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname.nodename); 425 426 int config_gen_flags = 0; 427 if (vd != rvd) { 428 fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 429 vd->vdev_top->vdev_guid); 430 fnvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 431 vd->vdev_guid); 432 if (vd->vdev_isspare) { 433 fnvlist_add_uint64(config, 434 ZPOOL_CONFIG_IS_SPARE, 1ULL); 435 } 436 if (vd->vdev_islog) { 437 fnvlist_add_uint64(config, 438 ZPOOL_CONFIG_IS_LOG, 1ULL); 439 } 440 vd = vd->vdev_top; /* label contains top config */ 441 } else { 442 /* 443 * Only add the (potentially large) split information 444 * in the mos config, and not in the vdev labels 445 */ 446 if (spa->spa_config_splitting != NULL) 447 fnvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 448 spa->spa_config_splitting); 449 fnvlist_add_boolean(config, 450 ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS); 451 452 config_gen_flags |= VDEV_CONFIG_MOS; 453 } 454 455 /* 456 * Add the top-level config. We even add this on pools which 457 * don't support holes in the namespace. 458 */ 459 vdev_top_config_generate(spa, config); 460 461 /* 462 * If we're splitting, record the original pool's guid. 463 */ 464 if (spa->spa_config_splitting != NULL && 465 nvlist_lookup_uint64(spa->spa_config_splitting, 466 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 467 fnvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 468 split_guid); 469 } 470 471 nvroot = vdev_config_generate(spa, vd, getstats, config_gen_flags); 472 fnvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot); 473 nvlist_free(nvroot); 474 475 /* 476 * Store what's necessary for reading the MOS in the label. 477 */ 478 fnvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 479 spa->spa_label_features); 480 481 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 482 ddt_histogram_t *ddh; 483 ddt_stat_t *dds; 484 ddt_object_t *ddo; 485 486 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 487 ddt_get_dedup_histogram(spa, ddh); 488 fnvlist_add_uint64_array(config, 489 ZPOOL_CONFIG_DDT_HISTOGRAM, 490 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)); 491 kmem_free(ddh, sizeof (ddt_histogram_t)); 492 493 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 494 ddt_get_dedup_object_stats(spa, ddo); 495 fnvlist_add_uint64_array(config, 496 ZPOOL_CONFIG_DDT_OBJ_STATS, 497 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)); 498 kmem_free(ddo, sizeof (ddt_object_t)); 499 500 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 501 ddt_get_dedup_stats(spa, dds); 502 fnvlist_add_uint64_array(config, 503 ZPOOL_CONFIG_DDT_STATS, 504 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)); 505 kmem_free(dds, sizeof (ddt_stat_t)); 506 } 507 508 if (locked) 509 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 510 511 return (config); 512} 513 514/* 515 * Update all disk labels, generate a fresh config based on the current 516 * in-core state, and sync the global config cache (do not sync the config 517 * cache if this is a booting rootpool). 518 */ 519void 520spa_config_update(spa_t *spa, int what) 521{ 522 vdev_t *rvd = spa->spa_root_vdev; 523 uint64_t txg; 524 int c; 525 526 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 527 528 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 529 txg = spa_last_synced_txg(spa) + 1; 530 if (what == SPA_CONFIG_UPDATE_POOL) { 531 vdev_config_dirty(rvd); 532 } else { 533 /* 534 * If we have top-level vdevs that were added but have 535 * not yet been prepared for allocation, do that now. 536 * (It's safe now because the config cache is up to date, 537 * so it will be able to translate the new DVAs.) 538 * See comments in spa_vdev_add() for full details. 539 */ 540 for (c = 0; c < rvd->vdev_children; c++) { 541 vdev_t *tvd = rvd->vdev_child[c]; 542 if (tvd->vdev_ms_array == 0) { 543 vdev_ashift_optimize(tvd); 544 vdev_metaslab_set_size(tvd); 545 } 546 vdev_expand(tvd, txg); 547 } 548 } 549 spa_config_exit(spa, SCL_ALL, FTAG); 550 551 /* 552 * Wait for the mosconfig to be regenerated and synced. 553 */ 554 txg_wait_synced(spa->spa_dsl_pool, txg); 555 556 /* 557 * Update the global config cache to reflect the new mosconfig. 558 */ 559 spa_write_cachefile(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL); 560 561 if (what == SPA_CONFIG_UPDATE_POOL) 562 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 563} 564