spa_config.c revision 297115
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) 2013 by Delphix. All rights reserved. 26 */ 27 28#include <sys/zfs_context.h> 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/sunddi.h> 39#include <sys/zfeature.h> 40#ifdef _KERNEL 41#include <sys/kobj.h> 42#include <sys/zone.h> 43#endif 44 45/* 46 * Pool configuration repository. 47 * 48 * Pool configuration is stored as a packed nvlist on the filesystem. By 49 * default, all pools are stored in /etc/zfs/zpool.cache and loaded on boot 50 * (when the ZFS module is loaded). Pools can also have the 'cachefile' 51 * property set that allows them to be stored in an alternate location until 52 * the control of external software. 53 * 54 * For each cache file, we have a single nvlist which holds all the 55 * configuration information. When the module loads, we read this information 56 * from /etc/zfs/zpool.cache and populate the SPA namespace. This namespace is 57 * maintained independently in spa.c. Whenever the namespace is modified, or 58 * the configuration of a pool is changed, we call spa_config_sync(), which 59 * walks through all the active pools and writes the configuration to disk. 60 */ 61 62static uint64_t spa_config_generation = 1; 63 64/* 65 * This can be overridden in userland to preserve an alternate namespace for 66 * userland pools when doing testing. 67 */ 68const char *spa_config_path = ZPOOL_CACHE; 69 70/* 71 * Called when the module is first loaded, this routine loads the configuration 72 * file into the SPA namespace. It does not actually open or load the pools; it 73 * only populates the namespace. 74 */ 75void 76spa_config_load(void) 77{ 78 void *buf = NULL; 79 nvlist_t *nvlist, *child; 80 nvpair_t *nvpair; 81 char *pathname; 82 struct _buf *file; 83 uint64_t fsize; 84 85 /* 86 * Open the configuration file. 87 */ 88 pathname = kmem_alloc(MAXPATHLEN, KM_SLEEP); 89 90 (void) snprintf(pathname, MAXPATHLEN, "%s", spa_config_path); 91 92 file = kobj_open_file(pathname); 93 94 kmem_free(pathname, MAXPATHLEN); 95 96 if (file == (struct _buf *)-1) 97 return; 98 99 if (kobj_get_filesize(file, &fsize) != 0) 100 goto out; 101 102 buf = kmem_alloc(fsize, KM_SLEEP); 103 104 /* 105 * Read the nvlist from the file. 106 */ 107 if (kobj_read_file(file, buf, fsize, 0) < 0) 108 goto out; 109 110 /* 111 * Unpack the nvlist. 112 */ 113 if (nvlist_unpack(buf, fsize, &nvlist, KM_SLEEP) != 0) 114 goto out; 115 116 /* 117 * Iterate over all elements in the nvlist, creating a new spa_t for 118 * each one with the specified configuration. 119 */ 120 mutex_enter(&spa_namespace_lock); 121 nvpair = NULL; 122 while ((nvpair = nvlist_next_nvpair(nvlist, nvpair)) != NULL) { 123 if (nvpair_type(nvpair) != DATA_TYPE_NVLIST) 124 continue; 125 126 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0); 127 128 if (spa_lookup(nvpair_name(nvpair)) != NULL) 129 continue; 130 (void) spa_add(nvpair_name(nvpair), child, NULL); 131 } 132 mutex_exit(&spa_namespace_lock); 133 134 nvlist_free(nvlist); 135 136out: 137 if (buf != NULL) 138 kmem_free(buf, fsize); 139 140 kobj_close_file(file); 141} 142 143static void 144spa_config_clean(nvlist_t *nvl) 145{ 146 nvlist_t **child; 147 nvlist_t *nvroot = NULL; 148 uint_t c, children; 149 150 if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child, 151 &children) == 0) { 152 for (c = 0; c < children; c++) 153 spa_config_clean(child[c]); 154 } 155 156 if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0) 157 spa_config_clean(nvroot); 158 159 nvlist_remove(nvl, ZPOOL_CONFIG_VDEV_STATS, DATA_TYPE_UINT64_ARRAY); 160 nvlist_remove(nvl, ZPOOL_CONFIG_SCAN_STATS, DATA_TYPE_UINT64_ARRAY); 161} 162 163static int 164spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 165{ 166 size_t buflen; 167 char *buf; 168 vnode_t *vp; 169 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 170 char *temp; 171 int err; 172 173 /* 174 * If the nvlist is empty (NULL), then remove the old cachefile. 175 */ 176 if (nvl == NULL) { 177 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 178 return (err); 179 } 180 181 /* 182 * Pack the configuration into a buffer. 183 */ 184 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0); 185 186 buf = kmem_alloc(buflen, KM_SLEEP); 187 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 188 189 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR, 190 KM_SLEEP) == 0); 191 192 /* 193 * Write the configuration to disk. We need to do the traditional 194 * 'write to temporary file, sync, move over original' to make sure we 195 * always have a consistent view of the data. 196 */ 197 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 198 199 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 200 if (err == 0) { 201 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 202 0, RLIM64_INFINITY, kcred, NULL); 203 if (err == 0) 204 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 205 if (err == 0) 206 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 207 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 208 } 209 210 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 211 212 kmem_free(buf, buflen); 213 kmem_free(temp, MAXPATHLEN); 214 return (err); 215} 216 217/* 218 * Synchronize pool configuration to disk. This must be called with the 219 * namespace lock held. Synchronizing the pool cache is typically done after 220 * the configuration has been synced to the MOS. This exposes a window where 221 * the MOS config will have been updated but the cache file has not. If 222 * the system were to crash at that instant then the cached config may not 223 * contain the correct information to open the pool and an explicity import 224 * would be required. 225 */ 226void 227spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) 228{ 229 spa_config_dirent_t *dp, *tdp; 230 nvlist_t *nvl; 231 boolean_t ccw_failure; 232 int error; 233 234 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 235 236 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 237 return; 238 239 /* 240 * Iterate over all cachefiles for the pool, past or present. When the 241 * cachefile is changed, the new one is pushed onto this list, allowing 242 * us to update previous cachefiles that no longer contain this pool. 243 */ 244 ccw_failure = B_FALSE; 245 for (dp = list_head(&target->spa_config_list); dp != NULL; 246 dp = list_next(&target->spa_config_list, dp)) { 247 spa_t *spa = NULL; 248 if (dp->scd_path == NULL) 249 continue; 250 251 /* 252 * Iterate over all pools, adding any matching pools to 'nvl'. 253 */ 254 nvl = NULL; 255 while ((spa = spa_next(spa)) != NULL) { 256 nvlist_t *nvroot = NULL; 257 /* 258 * Skip over our own pool if we're about to remove 259 * ourselves from the spa namespace or any pool that 260 * is readonly. Since we cannot guarantee that a 261 * readonly pool would successfully import upon reboot, 262 * we don't allow them to be written to the cache file. 263 */ 264 if ((spa == target && removing) || 265 (spa_state(spa) == POOL_STATE_ACTIVE && 266 !spa_writeable(spa))) 267 continue; 268 269 mutex_enter(&spa->spa_props_lock); 270 tdp = list_head(&spa->spa_config_list); 271 if (spa->spa_config == NULL || 272 tdp->scd_path == NULL || 273 strcmp(tdp->scd_path, dp->scd_path) != 0) { 274 mutex_exit(&spa->spa_props_lock); 275 continue; 276 } 277 278 if (nvl == NULL) 279 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, 280 KM_SLEEP) == 0); 281 282 VERIFY(nvlist_add_nvlist(nvl, spa->spa_name, 283 spa->spa_config) == 0); 284 mutex_exit(&spa->spa_props_lock); 285 286 if (nvlist_lookup_nvlist(nvl, spa->spa_name, &nvroot) == 0) 287 spa_config_clean(nvroot); 288 } 289 290 error = spa_config_write(dp, nvl); 291 if (error != 0) 292 ccw_failure = B_TRUE; 293 nvlist_free(nvl); 294 } 295 296 if (ccw_failure) { 297 /* 298 * Keep trying so that configuration data is 299 * written if/when any temporary filesystem 300 * resource issues are resolved. 301 */ 302 if (target->spa_ccw_fail_time == 0) { 303 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 304 target, NULL, NULL, 0, 0); 305 } 306 target->spa_ccw_fail_time = gethrtime(); 307 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 308 } else { 309 /* 310 * Do not rate limit future attempts to update 311 * the config cache. 312 */ 313 target->spa_ccw_fail_time = 0; 314 } 315 316 /* 317 * Remove any config entries older than the current one. 318 */ 319 dp = list_head(&target->spa_config_list); 320 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 321 list_remove(&target->spa_config_list, tdp); 322 if (tdp->scd_path != NULL) 323 spa_strfree(tdp->scd_path); 324 kmem_free(tdp, sizeof (spa_config_dirent_t)); 325 } 326 327 spa_config_generation++; 328 329 if (postsysevent) 330 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC); 331} 332 333/* 334 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 335 * and we don't want to allow the local zone to see all the pools anyway. 336 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 337 * information for all pool visible within the zone. 338 */ 339nvlist_t * 340spa_all_configs(uint64_t *generation) 341{ 342 nvlist_t *pools; 343 spa_t *spa = NULL; 344 345 if (*generation == spa_config_generation) 346 return (NULL); 347 348 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0); 349 350 mutex_enter(&spa_namespace_lock); 351 while ((spa = spa_next(spa)) != NULL) { 352 if (INGLOBALZONE(curthread) || 353 zone_dataset_visible(spa_name(spa), NULL)) { 354 mutex_enter(&spa->spa_props_lock); 355 VERIFY(nvlist_add_nvlist(pools, spa_name(spa), 356 spa->spa_config) == 0); 357 mutex_exit(&spa->spa_props_lock); 358 } 359 } 360 *generation = spa_config_generation; 361 mutex_exit(&spa_namespace_lock); 362 363 return (pools); 364} 365 366void 367spa_config_set(spa_t *spa, nvlist_t *config) 368{ 369 mutex_enter(&spa->spa_props_lock); 370 nvlist_free(spa->spa_config); 371 spa->spa_config = config; 372 mutex_exit(&spa->spa_props_lock); 373} 374 375/* 376 * Generate the pool's configuration based on the current in-core state. 377 * 378 * We infer whether to generate a complete config or just one top-level config 379 * based on whether vd is the root vdev. 380 */ 381nvlist_t * 382spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 383{ 384 nvlist_t *config, *nvroot; 385 vdev_t *rvd = spa->spa_root_vdev; 386 unsigned long hostid = 0; 387 boolean_t locked = B_FALSE; 388 uint64_t split_guid; 389 390 if (vd == NULL) { 391 vd = rvd; 392 locked = B_TRUE; 393 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 394 } 395 396 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 397 (SCL_CONFIG | SCL_STATE)); 398 399 /* 400 * If txg is -1, report the current value of spa->spa_config_txg. 401 */ 402 if (txg == -1ULL) 403 txg = spa->spa_config_txg; 404 405 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 406 407 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, 408 spa_version(spa)) == 0); 409 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, 410 spa_name(spa)) == 0); 411 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, 412 spa_state(spa)) == 0); 413 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, 414 txg) == 0); 415 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, 416 spa_guid(spa)) == 0); 417 VERIFY(spa->spa_comment == NULL || nvlist_add_string(config, 418 ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0); 419 420 421#ifdef _KERNEL 422 hostid = zone_get_hostid(NULL); 423#else /* _KERNEL */ 424 /* 425 * We're emulating the system's hostid in userland, so we can't use 426 * zone_get_hostid(). 427 */ 428 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid); 429#endif /* _KERNEL */ 430 if (hostid != 0) { 431 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, 432 hostid) == 0); 433 } 434 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, 435 utsname.nodename) == 0); 436 437 if (vd != rvd) { 438 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 439 vd->vdev_top->vdev_guid) == 0); 440 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 441 vd->vdev_guid) == 0); 442 if (vd->vdev_isspare) 443 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE, 444 1ULL) == 0); 445 if (vd->vdev_islog) 446 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG, 447 1ULL) == 0); 448 vd = vd->vdev_top; /* label contains top config */ 449 } else { 450 /* 451 * Only add the (potentially large) split information 452 * in the mos config, and not in the vdev labels 453 */ 454 if (spa->spa_config_splitting != NULL) 455 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 456 spa->spa_config_splitting) == 0); 457 } 458 459 /* 460 * Add the top-level config. We even add this on pools which 461 * don't support holes in the namespace. 462 */ 463 vdev_top_config_generate(spa, config); 464 465 /* 466 * If we're splitting, record the original pool's guid. 467 */ 468 if (spa->spa_config_splitting != NULL && 469 nvlist_lookup_uint64(spa->spa_config_splitting, 470 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 471 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 472 split_guid) == 0); 473 } 474 475 nvroot = vdev_config_generate(spa, vd, getstats, 0); 476 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0); 477 nvlist_free(nvroot); 478 479 /* 480 * Store what's necessary for reading the MOS in the label. 481 */ 482 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 483 spa->spa_label_features) == 0); 484 485 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 486 ddt_histogram_t *ddh; 487 ddt_stat_t *dds; 488 ddt_object_t *ddo; 489 490 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 491 ddt_get_dedup_histogram(spa, ddh); 492 VERIFY(nvlist_add_uint64_array(config, 493 ZPOOL_CONFIG_DDT_HISTOGRAM, 494 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0); 495 kmem_free(ddh, sizeof (ddt_histogram_t)); 496 497 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 498 ddt_get_dedup_object_stats(spa, ddo); 499 VERIFY(nvlist_add_uint64_array(config, 500 ZPOOL_CONFIG_DDT_OBJ_STATS, 501 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0); 502 kmem_free(ddo, sizeof (ddt_object_t)); 503 504 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 505 ddt_get_dedup_stats(spa, dds); 506 VERIFY(nvlist_add_uint64_array(config, 507 ZPOOL_CONFIG_DDT_STATS, 508 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0); 509 kmem_free(dds, sizeof (ddt_stat_t)); 510 } 511 512 if (locked) 513 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 514 515 return (config); 516} 517 518/* 519 * Update all disk labels, generate a fresh config based on the current 520 * in-core state, and sync the global config cache (do not sync the config 521 * cache if this is a booting rootpool). 522 */ 523void 524spa_config_update(spa_t *spa, int what) 525{ 526 vdev_t *rvd = spa->spa_root_vdev; 527 uint64_t txg; 528 int c; 529 530 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 531 532 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 533 txg = spa_last_synced_txg(spa) + 1; 534 if (what == SPA_CONFIG_UPDATE_POOL) { 535 vdev_config_dirty(rvd); 536 } else { 537 /* 538 * If we have top-level vdevs that were added but have 539 * not yet been prepared for allocation, do that now. 540 * (It's safe now because the config cache is up to date, 541 * so it will be able to translate the new DVAs.) 542 * See comments in spa_vdev_add() for full details. 543 */ 544 for (c = 0; c < rvd->vdev_children; c++) { 545 vdev_t *tvd = rvd->vdev_child[c]; 546 if (tvd->vdev_ms_array == 0) { 547 vdev_ashift_optimize(tvd); 548 vdev_metaslab_set_size(tvd); 549 } 550 vdev_expand(tvd, txg); 551 } 552 } 553 spa_config_exit(spa, SCL_ALL, FTAG); 554 555 /* 556 * Wait for the mosconfig to be regenerated and synced. 557 */ 558 txg_wait_synced(spa->spa_dsl_pool, txg); 559 560 /* 561 * Update the global config cache to reflect the new mosconfig. 562 */ 563 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL); 564 565 if (what == SPA_CONFIG_UPDATE_POOL) 566 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 567} 568