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 int 144spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 145{ 146 size_t buflen; 147 char *buf; 148 vnode_t *vp; 149 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 150 char *temp; 151 int err; 152 153 /* 154 * If the nvlist is empty (NULL), then remove the old cachefile. 155 */ 156 if (nvl == NULL) { 157 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 158 return (err); 159 } 160 161 /* 162 * Pack the configuration into a buffer. 163 */ 164 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0); 165 166 buf = kmem_alloc(buflen, KM_SLEEP); 167 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 168 169 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR, 170 KM_SLEEP) == 0); 171 172 /* 173 * Write the configuration to disk. We need to do the traditional 174 * 'write to temporary file, sync, move over original' to make sure we 175 * always have a consistent view of the data. 176 */ 177 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 178 179 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 180 if (err == 0) { 181 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 182 0, RLIM64_INFINITY, kcred, NULL); 183 if (err == 0) 184 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 185 if (err == 0) 186 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 187 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 188 } 189 190 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 191 192 kmem_free(buf, buflen); 193 kmem_free(temp, MAXPATHLEN); 194 return (err); 195} 196 197/* 198 * Synchronize pool configuration to disk. This must be called with the 199 * namespace lock held. Synchronizing the pool cache is typically done after 200 * the configuration has been synced to the MOS. This exposes a window where 201 * the MOS config will have been updated but the cache file has not. If 202 * the system were to crash at that instant then the cached config may not 203 * contain the correct information to open the pool and an explicity import 204 * would be required. 205 */ 206void 207spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) 208{ 209 spa_config_dirent_t *dp, *tdp; 210 nvlist_t *nvl; 211 boolean_t ccw_failure; 212 int error; 213 214 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 215 216 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 217 return; 218 219 /* 220 * Iterate over all cachefiles for the pool, past or present. When the 221 * cachefile is changed, the new one is pushed onto this list, allowing 222 * us to update previous cachefiles that no longer contain this pool. 223 */ 224 ccw_failure = B_FALSE; 225 for (dp = list_head(&target->spa_config_list); dp != NULL; 226 dp = list_next(&target->spa_config_list, dp)) { 227 spa_t *spa = NULL; 228 if (dp->scd_path == NULL) 229 continue; 230 231 /* 232 * Iterate over all pools, adding any matching pools to 'nvl'. 233 */ 234 nvl = NULL; 235 while ((spa = spa_next(spa)) != NULL) { 236 /* 237 * Skip over our own pool if we're about to remove 238 * ourselves from the spa namespace or any pool that 239 * is readonly. Since we cannot guarantee that a 240 * readonly pool would successfully import upon reboot, 241 * we don't allow them to be written to the cache file. 242 */ 243 if ((spa == target && removing) || 244 !spa_writeable(spa)) 245 continue; 246 247 mutex_enter(&spa->spa_props_lock); 248 tdp = list_head(&spa->spa_config_list); 249 if (spa->spa_config == NULL || 250 tdp->scd_path == NULL || 251 strcmp(tdp->scd_path, dp->scd_path) != 0) { 252 mutex_exit(&spa->spa_props_lock); 253 continue; 254 } 255 256 if (nvl == NULL) 257 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, 258 KM_SLEEP) == 0); 259 260 VERIFY(nvlist_add_nvlist(nvl, spa->spa_name, 261 spa->spa_config) == 0); 262 mutex_exit(&spa->spa_props_lock); 263 } 264 265 error = spa_config_write(dp, nvl); 266 if (error != 0) 267 ccw_failure = B_TRUE; 268 nvlist_free(nvl); 269 } 270 271 if (ccw_failure) { 272 /* 273 * Keep trying so that configuration data is 274 * written if/when any temporary filesystem 275 * resource issues are resolved. 276 */ 277 if (target->spa_ccw_fail_time == 0) { 278 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 279 target, NULL, NULL, 0, 0); 280 } 281 target->spa_ccw_fail_time = gethrtime(); 282 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 283 } else { 284 /* 285 * Do not rate limit future attempts to update 286 * the config cache. 287 */ 288 target->spa_ccw_fail_time = 0; 289 } 290 291 /* 292 * Remove any config entries older than the current one. 293 */ 294 dp = list_head(&target->spa_config_list); 295 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 296 list_remove(&target->spa_config_list, tdp); 297 if (tdp->scd_path != NULL) 298 spa_strfree(tdp->scd_path); 299 kmem_free(tdp, sizeof (spa_config_dirent_t)); 300 } 301 302 spa_config_generation++; 303 304 if (postsysevent) 305 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC); 306} 307 308/* 309 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 310 * and we don't want to allow the local zone to see all the pools anyway. 311 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 312 * information for all pool visible within the zone. 313 */ 314nvlist_t * 315spa_all_configs(uint64_t *generation) 316{ 317 nvlist_t *pools; 318 spa_t *spa = NULL; 319 320 if (*generation == spa_config_generation) 321 return (NULL); 322 323 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0); 324 325 mutex_enter(&spa_namespace_lock); 326 while ((spa = spa_next(spa)) != NULL) { 327 if (INGLOBALZONE(curthread) || 328 zone_dataset_visible(spa_name(spa), NULL)) { 329 mutex_enter(&spa->spa_props_lock); 330 VERIFY(nvlist_add_nvlist(pools, spa_name(spa), 331 spa->spa_config) == 0); 332 mutex_exit(&spa->spa_props_lock); 333 } 334 } 335 *generation = spa_config_generation; 336 mutex_exit(&spa_namespace_lock); 337 338 return (pools); 339} 340 341void 342spa_config_set(spa_t *spa, nvlist_t *config) 343{ 344 mutex_enter(&spa->spa_props_lock); 345 if (spa->spa_config != NULL) 346 nvlist_free(spa->spa_config); 347 spa->spa_config = config; 348 mutex_exit(&spa->spa_props_lock); 349} 350 351/* 352 * Generate the pool's configuration based on the current in-core state. 353 * 354 * We infer whether to generate a complete config or just one top-level config 355 * based on whether vd is the root vdev. 356 */ 357nvlist_t * 358spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 359{ 360 nvlist_t *config, *nvroot; 361 vdev_t *rvd = spa->spa_root_vdev; 362 unsigned long hostid = 0; 363 boolean_t locked = B_FALSE; 364 uint64_t split_guid; 365 366 if (vd == NULL) { 367 vd = rvd; 368 locked = B_TRUE; 369 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 370 } 371 372 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 373 (SCL_CONFIG | SCL_STATE)); 374 375 /* 376 * If txg is -1, report the current value of spa->spa_config_txg. 377 */ 378 if (txg == -1ULL) 379 txg = spa->spa_config_txg; 380 381 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 382 383 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, 384 spa_version(spa)) == 0); 385 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, 386 spa_name(spa)) == 0); 387 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, 388 spa_state(spa)) == 0); 389 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, 390 txg) == 0); 391 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, 392 spa_guid(spa)) == 0); 393 VERIFY(spa->spa_comment == NULL || nvlist_add_string(config, 394 ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0); 395 396 397#ifdef _KERNEL 398 hostid = zone_get_hostid(NULL); 399#else /* _KERNEL */ 400 /* 401 * We're emulating the system's hostid in userland, so we can't use 402 * zone_get_hostid(). 403 */ 404 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid); 405#endif /* _KERNEL */ 406 if (hostid != 0) { 407 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, 408 hostid) == 0); 409 } 410 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, 411 utsname.nodename) == 0); 412 413 if (vd != rvd) { 414 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 415 vd->vdev_top->vdev_guid) == 0); 416 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 417 vd->vdev_guid) == 0); 418 if (vd->vdev_isspare) 419 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE, 420 1ULL) == 0); 421 if (vd->vdev_islog) 422 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG, 423 1ULL) == 0); 424 vd = vd->vdev_top; /* label contains top config */ 425 } else { 426 /* 427 * Only add the (potentially large) split information 428 * in the mos config, and not in the vdev labels 429 */ 430 if (spa->spa_config_splitting != NULL) 431 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 432 spa->spa_config_splitting) == 0); 433 } 434 435 /* 436 * Add the top-level config. We even add this on pools which 437 * don't support holes in the namespace. 438 */ 439 vdev_top_config_generate(spa, config); 440 441 /* 442 * If we're splitting, record the original pool's guid. 443 */ 444 if (spa->spa_config_splitting != NULL && 445 nvlist_lookup_uint64(spa->spa_config_splitting, 446 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 447 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 448 split_guid) == 0); 449 } 450 451 nvroot = vdev_config_generate(spa, vd, getstats, 0); 452 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0); 453 nvlist_free(nvroot); 454 455 /* 456 * Store what's necessary for reading the MOS in the label. 457 */ 458 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 459 spa->spa_label_features) == 0); 460 461 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 462 ddt_histogram_t *ddh; 463 ddt_stat_t *dds; 464 ddt_object_t *ddo; 465 466 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 467 ddt_get_dedup_histogram(spa, ddh); 468 VERIFY(nvlist_add_uint64_array(config, 469 ZPOOL_CONFIG_DDT_HISTOGRAM, 470 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0); 471 kmem_free(ddh, sizeof (ddt_histogram_t)); 472 473 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 474 ddt_get_dedup_object_stats(spa, ddo); 475 VERIFY(nvlist_add_uint64_array(config, 476 ZPOOL_CONFIG_DDT_OBJ_STATS, 477 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0); 478 kmem_free(ddo, sizeof (ddt_object_t)); 479 480 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 481 ddt_get_dedup_stats(spa, dds); 482 VERIFY(nvlist_add_uint64_array(config, 483 ZPOOL_CONFIG_DDT_STATS, 484 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0); 485 kmem_free(dds, sizeof (ddt_stat_t)); 486 } 487 488 if (locked) 489 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 490 491 return (config); 492} 493 494/* 495 * Update all disk labels, generate a fresh config based on the current 496 * in-core state, and sync the global config cache (do not sync the config 497 * cache if this is a booting rootpool). 498 */ 499void 500spa_config_update(spa_t *spa, int what) 501{ 502 vdev_t *rvd = spa->spa_root_vdev; 503 uint64_t txg; 504 int c; 505 506 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 507 508 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 509 txg = spa_last_synced_txg(spa) + 1; 510 if (what == SPA_CONFIG_UPDATE_POOL) { 511 vdev_config_dirty(rvd); 512 } else { 513 /* 514 * If we have top-level vdevs that were added but have 515 * not yet been prepared for allocation, do that now. 516 * (It's safe now because the config cache is up to date, 517 * so it will be able to translate the new DVAs.) 518 * See comments in spa_vdev_add() for full details. 519 */ 520 for (c = 0; c < rvd->vdev_children; c++) { 521 vdev_t *tvd = rvd->vdev_child[c]; 522 if (tvd->vdev_ms_array == 0) { 523 vdev_ashift_optimize(tvd); 524 vdev_metaslab_set_size(tvd); 525 } 526 vdev_expand(tvd, txg); 527 } 528 } 529 spa_config_exit(spa, SCL_ALL, FTAG); 530 531 /* 532 * Wait for the mosconfig to be regenerated and synced. 533 */ 534 txg_wait_synced(spa->spa_dsl_pool, txg); 535 536 /* 537 * Update the global config cache to reflect the new mosconfig. 538 */ 539 if (!spa->spa_is_root) 540 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL); 541 542 if (what == SPA_CONFIG_UPDATE_POOL) 543 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 544} 545