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/spa.h> 29 #include <sys/fm/fs/zfs.h> 30 #include <sys/spa_impl.h> 31 #include <sys/nvpair.h> 32 #include <sys/uio.h> 33 #include <sys/fs/zfs.h> 34 #include <sys/vdev_impl.h> 35 #include <sys/zfs_ioctl.h> 36 #include <sys/utsname.h> 37 #include <sys/systeminfo.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 62 static 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 */ 68 const 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 */ 75 void 76 spa_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%s", 91 (rootdir != NULL) ? "./" : "", 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 VERIFY(nvpair_value_nvlist(nvpair, &child) == 0); 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); 136 137 out: 138 if (buf != NULL) 139 kmem_free(buf, fsize); 140 141 kobj_close_file(file); 142 } 143 144 static int 145 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl) 146 { 147 size_t buflen; 148 char *buf; 149 vnode_t *vp; 150 int oflags = FWRITE | FTRUNC | FCREAT | FOFFMAX; 151 char *temp; 152 int err; 153 154 /* 155 * If the nvlist is empty (NULL), then remove the old cachefile. 156 */ 157 if (nvl == NULL) { 158 err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE); 159 return (err); 160 } 161 162 /* 163 * Pack the configuration into a buffer. 164 */ 165 VERIFY(nvlist_size(nvl, &buflen, NV_ENCODE_XDR) == 0); 166 167 buf = kmem_alloc(buflen, KM_SLEEP); 168 temp = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 169 170 VERIFY(nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_XDR, 171 KM_SLEEP) == 0); 172 173 /* 174 * Write the configuration to disk. We need to do the traditional 175 * 'write to temporary file, sync, move over original' to make sure we 176 * always have a consistent view of the data. 177 */ 178 (void) snprintf(temp, MAXPATHLEN, "%s.tmp", dp->scd_path); 179 180 err = vn_open(temp, UIO_SYSSPACE, oflags, 0644, &vp, CRCREAT, 0); 181 if (err == 0) { 182 err = vn_rdwr(UIO_WRITE, vp, buf, buflen, 0, UIO_SYSSPACE, 183 0, RLIM64_INFINITY, kcred, NULL); 184 if (err == 0) 185 err = VOP_FSYNC(vp, FSYNC, kcred, NULL); 186 if (err == 0) 187 err = vn_rename(temp, dp->scd_path, UIO_SYSSPACE); 188 (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL); 189 VN_RELE(vp); 190 } 191 192 (void) vn_remove(temp, UIO_SYSSPACE, RMFILE); 193 194 kmem_free(buf, buflen); 195 kmem_free(temp, MAXPATHLEN); 196 return (err); 197 } 198 199 /* 200 * Synchronize pool configuration to disk. This must be called with the 201 * namespace lock held. Synchronizing the pool cache is typically done after 202 * the configuration has been synced to the MOS. This exposes a window where 203 * the MOS config will have been updated but the cache file has not. If 204 * the system were to crash at that instant then the cached config may not 205 * contain the correct information to open the pool and an explicity import 206 * would be required. 207 */ 208 void 209 spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent) 210 { 211 spa_config_dirent_t *dp, *tdp; 212 nvlist_t *nvl; 213 boolean_t ccw_failure; 214 int error; 215 216 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 217 218 if (rootdir == NULL || !(spa_mode_global & FWRITE)) 219 return; 220 221 /* 222 * Iterate over all cachefiles for the pool, past or present. When the 223 * cachefile is changed, the new one is pushed onto this list, allowing 224 * us to update previous cachefiles that no longer contain this pool. 225 */ 226 ccw_failure = B_FALSE; 227 for (dp = list_head(&target->spa_config_list); dp != NULL; 228 dp = list_next(&target->spa_config_list, dp)) { 229 spa_t *spa = NULL; 230 if (dp->scd_path == NULL) 231 continue; 232 233 /* 234 * Iterate over all pools, adding any matching pools to 'nvl'. 235 */ 236 nvl = NULL; 237 while ((spa = spa_next(spa)) != NULL) { 238 /* 239 * Skip over our own pool if we're about to remove 240 * ourselves from the spa namespace or any pool that 241 * is readonly. Since we cannot guarantee that a 242 * readonly pool would successfully import upon reboot, 243 * we don't allow them to be written to the cache file. 244 */ 245 if ((spa == target && removing) || 246 !spa_writeable(spa)) 247 continue; 248 249 mutex_enter(&spa->spa_props_lock); 250 tdp = list_head(&spa->spa_config_list); 251 if (spa->spa_config == NULL || 252 tdp->scd_path == NULL || 253 strcmp(tdp->scd_path, dp->scd_path) != 0) { 254 mutex_exit(&spa->spa_props_lock); 255 continue; 256 } 257 258 if (nvl == NULL) 259 VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, 260 KM_SLEEP) == 0); 261 262 VERIFY(nvlist_add_nvlist(nvl, spa->spa_name, 263 spa->spa_config) == 0); 264 mutex_exit(&spa->spa_props_lock); 265 } 266 267 error = spa_config_write(dp, nvl); 268 if (error != 0) 269 ccw_failure = B_TRUE; 270 nvlist_free(nvl); 271 } 272 273 if (ccw_failure) { 274 /* 275 * Keep trying so that configuration data is 276 * written if/when any temporary filesystem 277 * resource issues are resolved. 278 */ 279 if (target->spa_ccw_fail_time == 0) { 280 zfs_ereport_post(FM_EREPORT_ZFS_CONFIG_CACHE_WRITE, 281 target, NULL, NULL, 0, 0); 282 } 283 target->spa_ccw_fail_time = gethrtime(); 284 spa_async_request(target, SPA_ASYNC_CONFIG_UPDATE); 285 } else { 286 /* 287 * Do not rate limit future attempts to update 288 * the config cache. 289 */ 290 target->spa_ccw_fail_time = 0; 291 } 292 293 /* 294 * Remove any config entries older than the current one. 295 */ 296 dp = list_head(&target->spa_config_list); 297 while ((tdp = list_next(&target->spa_config_list, dp)) != NULL) { 298 list_remove(&target->spa_config_list, tdp); 299 if (tdp->scd_path != NULL) 300 spa_strfree(tdp->scd_path); 301 kmem_free(tdp, sizeof (spa_config_dirent_t)); 302 } 303 304 spa_config_generation++; 305 306 if (postsysevent) 307 spa_event_notify(target, NULL, ESC_ZFS_CONFIG_SYNC); 308 } 309 310 /* 311 * Sigh. Inside a local zone, we don't have access to /etc/zfs/zpool.cache, 312 * and we don't want to allow the local zone to see all the pools anyway. 313 * So we have to invent the ZFS_IOC_CONFIG ioctl to grab the configuration 314 * information for all pool visible within the zone. 315 */ 316 nvlist_t * 317 spa_all_configs(uint64_t *generation) 318 { 319 nvlist_t *pools; 320 spa_t *spa = NULL; 321 322 if (*generation == spa_config_generation) 323 return (NULL); 324 325 VERIFY(nvlist_alloc(&pools, NV_UNIQUE_NAME, KM_SLEEP) == 0); 326 327 mutex_enter(&spa_namespace_lock); 328 while ((spa = spa_next(spa)) != NULL) { 329 if (INGLOBALZONE(curproc) || 330 zone_dataset_visible(spa_name(spa), NULL)) { 331 mutex_enter(&spa->spa_props_lock); 332 VERIFY(nvlist_add_nvlist(pools, spa_name(spa), 333 spa->spa_config) == 0); 334 mutex_exit(&spa->spa_props_lock); 335 } 336 } 337 *generation = spa_config_generation; 338 mutex_exit(&spa_namespace_lock); 339 340 return (pools); 341 } 342 343 void 344 spa_config_set(spa_t *spa, nvlist_t *config) 345 { 346 mutex_enter(&spa->spa_props_lock); 347 nvlist_free(spa->spa_config); 348 spa->spa_config = config; 349 mutex_exit(&spa->spa_props_lock); 350 } 351 352 /* 353 * Generate the pool's configuration based on the current in-core state. 354 * 355 * We infer whether to generate a complete config or just one top-level config 356 * based on whether vd is the root vdev. 357 */ 358 nvlist_t * 359 spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats) 360 { 361 nvlist_t *config, *nvroot; 362 vdev_t *rvd = spa->spa_root_vdev; 363 unsigned long hostid = 0; 364 boolean_t locked = B_FALSE; 365 uint64_t split_guid; 366 367 if (vd == NULL) { 368 vd = rvd; 369 locked = B_TRUE; 370 spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER); 371 } 372 373 ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER) == 374 (SCL_CONFIG | SCL_STATE)); 375 376 /* 377 * If txg is -1, report the current value of spa->spa_config_txg. 378 */ 379 if (txg == -1ULL) 380 txg = spa->spa_config_txg; 381 382 VERIFY(nvlist_alloc(&config, NV_UNIQUE_NAME, KM_SLEEP) == 0); 383 384 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, 385 spa_version(spa)) == 0); 386 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, 387 spa_name(spa)) == 0); 388 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, 389 spa_state(spa)) == 0); 390 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, 391 txg) == 0); 392 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID, 393 spa_guid(spa)) == 0); 394 VERIFY(spa->spa_comment == NULL || nvlist_add_string(config, 395 ZPOOL_CONFIG_COMMENT, spa->spa_comment) == 0); 396 397 398 #ifdef _KERNEL 399 hostid = zone_get_hostid(NULL); 400 #else /* _KERNEL */ 401 /* 402 * We're emulating the system's hostid in userland, so we can't use 403 * zone_get_hostid(). 404 */ 405 (void) ddi_strtoul(hw_serial, NULL, 10, &hostid); 406 #endif /* _KERNEL */ 407 if (hostid != 0) { 408 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, 409 hostid) == 0); 410 } 411 VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, 412 utsname.nodename) == 0); 413 414 if (vd != rvd) { 415 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID, 416 vd->vdev_top->vdev_guid) == 0); 417 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_GUID, 418 vd->vdev_guid) == 0); 419 if (vd->vdev_isspare) 420 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_SPARE, 421 1ULL) == 0); 422 if (vd->vdev_islog) 423 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_IS_LOG, 424 1ULL) == 0); 425 vd = vd->vdev_top; /* label contains top config */ 426 } else { 427 /* 428 * Only add the (potentially large) split information 429 * in the mos config, and not in the vdev labels 430 */ 431 if (spa->spa_config_splitting != NULL) 432 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_SPLIT, 433 spa->spa_config_splitting) == 0); 434 } 435 436 /* 437 * Add the top-level config. We even add this on pools which 438 * don't support holes in the namespace. 439 */ 440 vdev_top_config_generate(spa, config); 441 442 /* 443 * If we're splitting, record the original pool's guid. 444 */ 445 if (spa->spa_config_splitting != NULL && 446 nvlist_lookup_uint64(spa->spa_config_splitting, 447 ZPOOL_CONFIG_SPLIT_GUID, &split_guid) == 0) { 448 VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_SPLIT_GUID, 449 split_guid) == 0); 450 } 451 452 nvroot = vdev_config_generate(spa, vd, getstats, 0); 453 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0); 454 nvlist_free(nvroot); 455 456 /* 457 * Store what's necessary for reading the MOS in the label. 458 */ 459 VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 460 spa->spa_label_features) == 0); 461 462 if (getstats && spa_load_state(spa) == SPA_LOAD_NONE) { 463 ddt_histogram_t *ddh; 464 ddt_stat_t *dds; 465 ddt_object_t *ddo; 466 467 ddh = kmem_zalloc(sizeof (ddt_histogram_t), KM_SLEEP); 468 ddt_get_dedup_histogram(spa, ddh); 469 VERIFY(nvlist_add_uint64_array(config, 470 ZPOOL_CONFIG_DDT_HISTOGRAM, 471 (uint64_t *)ddh, sizeof (*ddh) / sizeof (uint64_t)) == 0); 472 kmem_free(ddh, sizeof (ddt_histogram_t)); 473 474 ddo = kmem_zalloc(sizeof (ddt_object_t), KM_SLEEP); 475 ddt_get_dedup_object_stats(spa, ddo); 476 VERIFY(nvlist_add_uint64_array(config, 477 ZPOOL_CONFIG_DDT_OBJ_STATS, 478 (uint64_t *)ddo, sizeof (*ddo) / sizeof (uint64_t)) == 0); 479 kmem_free(ddo, sizeof (ddt_object_t)); 480 481 dds = kmem_zalloc(sizeof (ddt_stat_t), KM_SLEEP); 482 ddt_get_dedup_stats(spa, dds); 483 VERIFY(nvlist_add_uint64_array(config, 484 ZPOOL_CONFIG_DDT_STATS, 485 (uint64_t *)dds, sizeof (*dds) / sizeof (uint64_t)) == 0); 486 kmem_free(dds, sizeof (ddt_stat_t)); 487 } 488 489 if (locked) 490 spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG); 491 492 return (config); 493 } 494 495 /* 496 * Update all disk labels, generate a fresh config based on the current 497 * in-core state, and sync the global config cache (do not sync the config 498 * cache if this is a booting rootpool). 499 */ 500 void 501 spa_config_update(spa_t *spa, int what) 502 { 503 vdev_t *rvd = spa->spa_root_vdev; 504 uint64_t txg; 505 int c; 506 507 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 508 509 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 510 txg = spa_last_synced_txg(spa) + 1; 511 if (what == SPA_CONFIG_UPDATE_POOL) { 512 vdev_config_dirty(rvd); 513 } else { 514 /* 515 * If we have top-level vdevs that were added but have 516 * not yet been prepared for allocation, do that now. 517 * (It's safe now because the config cache is up to date, 518 * so it will be able to translate the new DVAs.) 519 * See comments in spa_vdev_add() for full details. 520 */ 521 for (c = 0; c < rvd->vdev_children; c++) { 522 vdev_t *tvd = rvd->vdev_child[c]; 523 if (tvd->vdev_ms_array == 0) 524 vdev_metaslab_set_size(tvd); 525 vdev_expand(tvd, txg); 526 } 527 } 528 spa_config_exit(spa, SCL_ALL, FTAG); 529 530 /* 531 * Wait for the mosconfig to be regenerated and synced. 532 */ 533 txg_wait_synced(spa->spa_dsl_pool, txg); 534 535 /* 536 * Update the global config cache to reflect the new mosconfig. 537 */ 538 if (!spa->spa_is_root) 539 spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL); 540 541 if (what == SPA_CONFIG_UPDATE_POOL) 542 spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS); 543 } 544