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 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 24 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 26 */ 27 28 #include <sys/zfs_context.h> 29 #include <sys/spa_impl.h> 30 #include <sys/spa_boot.h> 31 #include <sys/zio.h> 32 #include <sys/zio_checksum.h> 33 #include <sys/zio_compress.h> 34 #include <sys/dmu.h> 35 #include <sys/dmu_tx.h> 36 #include <sys/zap.h> 37 #include <sys/zil.h> 38 #include <sys/vdev_impl.h> 39 #include <sys/metaslab.h> 40 #include <sys/uberblock_impl.h> 41 #include <sys/txg.h> 42 #include <sys/avl.h> 43 #include <sys/unique.h> 44 #include <sys/dsl_pool.h> 45 #include <sys/dsl_dir.h> 46 #include <sys/dsl_prop.h> 47 #include <sys/dsl_scan.h> 48 #include <sys/fs/zfs.h> 49 #include <sys/metaslab_impl.h> 50 #include <sys/arc.h> 51 #include <sys/ddt.h> 52 #include "zfs_prop.h" 53 #include "zfeature_common.h" 54 55 /* 56 * SPA locking 57 * 58 * There are four basic locks for managing spa_t structures: 59 * 60 * spa_namespace_lock (global mutex) 61 * 62 * This lock must be acquired to do any of the following: 63 * 64 * - Lookup a spa_t by name 65 * - Add or remove a spa_t from the namespace 66 * - Increase spa_refcount from non-zero 67 * - Check if spa_refcount is zero 68 * - Rename a spa_t 69 * - add/remove/attach/detach devices 70 * - Held for the duration of create/destroy/import/export 71 * 72 * It does not need to handle recursion. A create or destroy may 73 * reference objects (files or zvols) in other pools, but by 74 * definition they must have an existing reference, and will never need 75 * to lookup a spa_t by name. 76 * 77 * spa_refcount (per-spa refcount_t protected by mutex) 78 * 79 * This reference count keep track of any active users of the spa_t. The 80 * spa_t cannot be destroyed or freed while this is non-zero. Internally, 81 * the refcount is never really 'zero' - opening a pool implicitly keeps 82 * some references in the DMU. Internally we check against spa_minref, but 83 * present the image of a zero/non-zero value to consumers. 84 * 85 * spa_config_lock[] (per-spa array of rwlocks) 86 * 87 * This protects the spa_t from config changes, and must be held in 88 * the following circumstances: 89 * 90 * - RW_READER to perform I/O to the spa 91 * - RW_WRITER to change the vdev config 92 * 93 * The locking order is fairly straightforward: 94 * 95 * spa_namespace_lock -> spa_refcount 96 * 97 * The namespace lock must be acquired to increase the refcount from 0 98 * or to check if it is zero. 99 * 100 * spa_refcount -> spa_config_lock[] 101 * 102 * There must be at least one valid reference on the spa_t to acquire 103 * the config lock. 104 * 105 * spa_namespace_lock -> spa_config_lock[] 106 * 107 * The namespace lock must always be taken before the config lock. 108 * 109 * 110 * The spa_namespace_lock can be acquired directly and is globally visible. 111 * 112 * The namespace is manipulated using the following functions, all of which 113 * require the spa_namespace_lock to be held. 114 * 115 * spa_lookup() Lookup a spa_t by name. 116 * 117 * spa_add() Create a new spa_t in the namespace. 118 * 119 * spa_remove() Remove a spa_t from the namespace. This also 120 * frees up any memory associated with the spa_t. 121 * 122 * spa_next() Returns the next spa_t in the system, or the 123 * first if NULL is passed. 124 * 125 * spa_evict_all() Shutdown and remove all spa_t structures in 126 * the system. 127 * 128 * spa_guid_exists() Determine whether a pool/device guid exists. 129 * 130 * The spa_refcount is manipulated using the following functions: 131 * 132 * spa_open_ref() Adds a reference to the given spa_t. Must be 133 * called with spa_namespace_lock held if the 134 * refcount is currently zero. 135 * 136 * spa_close() Remove a reference from the spa_t. This will 137 * not free the spa_t or remove it from the 138 * namespace. No locking is required. 139 * 140 * spa_refcount_zero() Returns true if the refcount is currently 141 * zero. Must be called with spa_namespace_lock 142 * held. 143 * 144 * The spa_config_lock[] is an array of rwlocks, ordered as follows: 145 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV. 146 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}(). 147 * 148 * To read the configuration, it suffices to hold one of these locks as reader. 149 * To modify the configuration, you must hold all locks as writer. To modify 150 * vdev state without altering the vdev tree's topology (e.g. online/offline), 151 * you must hold SCL_STATE and SCL_ZIO as writer. 152 * 153 * We use these distinct config locks to avoid recursive lock entry. 154 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces 155 * block allocations (SCL_ALLOC), which may require reading space maps 156 * from disk (dmu_read() -> zio_read() -> SCL_ZIO). 157 * 158 * The spa config locks cannot be normal rwlocks because we need the 159 * ability to hand off ownership. For example, SCL_ZIO is acquired 160 * by the issuing thread and later released by an interrupt thread. 161 * They do, however, obey the usual write-wanted semantics to prevent 162 * writer (i.e. system administrator) starvation. 163 * 164 * The lock acquisition rules are as follows: 165 * 166 * SCL_CONFIG 167 * Protects changes to the vdev tree topology, such as vdev 168 * add/remove/attach/detach. Protects the dirty config list 169 * (spa_config_dirty_list) and the set of spares and l2arc devices. 170 * 171 * SCL_STATE 172 * Protects changes to pool state and vdev state, such as vdev 173 * online/offline/fault/degrade/clear. Protects the dirty state list 174 * (spa_state_dirty_list) and global pool state (spa_state). 175 * 176 * SCL_ALLOC 177 * Protects changes to metaslab groups and classes. 178 * Held as reader by metaslab_alloc() and metaslab_claim(). 179 * 180 * SCL_ZIO 181 * Held by bp-level zios (those which have no io_vd upon entry) 182 * to prevent changes to the vdev tree. The bp-level zio implicitly 183 * protects all of its vdev child zios, which do not hold SCL_ZIO. 184 * 185 * SCL_FREE 186 * Protects changes to metaslab groups and classes. 187 * Held as reader by metaslab_free(). SCL_FREE is distinct from 188 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free 189 * blocks in zio_done() while another i/o that holds either 190 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete. 191 * 192 * SCL_VDEV 193 * Held as reader to prevent changes to the vdev tree during trivial 194 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the 195 * other locks, and lower than all of them, to ensure that it's safe 196 * to acquire regardless of caller context. 197 * 198 * In addition, the following rules apply: 199 * 200 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list. 201 * The lock ordering is SCL_CONFIG > spa_props_lock. 202 * 203 * (b) I/O operations on leaf vdevs. For any zio operation that takes 204 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(), 205 * or zio_write_phys() -- the caller must ensure that the config cannot 206 * cannot change in the interim, and that the vdev cannot be reopened. 207 * SCL_STATE as reader suffices for both. 208 * 209 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit(). 210 * 211 * spa_vdev_enter() Acquire the namespace lock and the config lock 212 * for writing. 213 * 214 * spa_vdev_exit() Release the config lock, wait for all I/O 215 * to complete, sync the updated configs to the 216 * cache, and release the namespace lock. 217 * 218 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit(). 219 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual 220 * locking is, always, based on spa_namespace_lock and spa_config_lock[]. 221 * 222 * spa_rename() is also implemented within this file since it requires 223 * manipulation of the namespace. 224 */ 225 226 static avl_tree_t spa_namespace_avl; 227 kmutex_t spa_namespace_lock; 228 static kcondvar_t spa_namespace_cv; 229 static int spa_active_count; 230 int spa_max_replication_override = SPA_DVAS_PER_BP; 231 232 static kmutex_t spa_spare_lock; 233 static avl_tree_t spa_spare_avl; 234 static kmutex_t spa_l2cache_lock; 235 static avl_tree_t spa_l2cache_avl; 236 237 kmem_cache_t *spa_buffer_pool; 238 int spa_mode_global; 239 240 #ifdef ZFS_DEBUG 241 /* Everything except dprintf and spa is on by default in debug builds */ 242 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA); 243 #else 244 int zfs_flags = 0; 245 #endif 246 247 /* 248 * zfs_recover can be set to nonzero to attempt to recover from 249 * otherwise-fatal errors, typically caused by on-disk corruption. When 250 * set, calls to zfs_panic_recover() will turn into warning messages. 251 * This should only be used as a last resort, as it typically results 252 * in leaked space, or worse. 253 */ 254 boolean_t zfs_recover = B_FALSE; 255 256 /* 257 * If destroy encounters an EIO while reading metadata (e.g. indirect 258 * blocks), space referenced by the missing metadata can not be freed. 259 * Normally this causes the background destroy to become "stalled", as 260 * it is unable to make forward progress. While in this stalled state, 261 * all remaining space to free from the error-encountering filesystem is 262 * "temporarily leaked". Set this flag to cause it to ignore the EIO, 263 * permanently leak the space from indirect blocks that can not be read, 264 * and continue to free everything else that it can. 265 * 266 * The default, "stalling" behavior is useful if the storage partially 267 * fails (i.e. some but not all i/os fail), and then later recovers. In 268 * this case, we will be able to continue pool operations while it is 269 * partially failed, and when it recovers, we can continue to free the 270 * space, with no leaks. However, note that this case is actually 271 * fairly rare. 272 * 273 * Typically pools either (a) fail completely (but perhaps temporarily, 274 * e.g. a top-level vdev going offline), or (b) have localized, 275 * permanent errors (e.g. disk returns the wrong data due to bit flip or 276 * firmware bug). In case (a), this setting does not matter because the 277 * pool will be suspended and the sync thread will not be able to make 278 * forward progress regardless. In case (b), because the error is 279 * permanent, the best we can do is leak the minimum amount of space, 280 * which is what setting this flag will do. Therefore, it is reasonable 281 * for this flag to normally be set, but we chose the more conservative 282 * approach of not setting it, so that there is no possibility of 283 * leaking space in the "partial temporary" failure case. 284 */ 285 boolean_t zfs_free_leak_on_eio = B_FALSE; 286 287 /* 288 * Expiration time in milliseconds. This value has two meanings. First it is 289 * used to determine when the spa_deadman() logic should fire. By default the 290 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds. 291 * Secondly, the value determines if an I/O is considered "hung". Any I/O that 292 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting 293 * in a system panic. 294 */ 295 uint64_t zfs_deadman_synctime_ms = 1000000ULL; 296 297 /* 298 * Check time in milliseconds. This defines the frequency at which we check 299 * for hung I/O. 300 */ 301 uint64_t zfs_deadman_checktime_ms = 5000ULL; 302 303 /* 304 * Override the zfs deadman behavior via /etc/system. By default the 305 * deadman is enabled except on VMware and sparc deployments. 306 */ 307 int zfs_deadman_enabled = -1; 308 309 /* 310 * The worst case is single-sector max-parity RAID-Z blocks, in which 311 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1) 312 * times the size; so just assume that. Add to this the fact that 313 * we can have up to 3 DVAs per bp, and one more factor of 2 because 314 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together, 315 * the worst case is: 316 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24 317 */ 318 int spa_asize_inflation = 24; 319 320 /* 321 * Normally, we don't allow the last 3.2% (1/(2^spa_slop_shift)) of space in 322 * the pool to be consumed. This ensures that we don't run the pool 323 * completely out of space, due to unaccounted changes (e.g. to the MOS). 324 * It also limits the worst-case time to allocate space. If we have 325 * less than this amount of free space, most ZPL operations (e.g. write, 326 * create) will return ENOSPC. 327 * 328 * Certain operations (e.g. file removal, most administrative actions) can 329 * use half the slop space. They will only return ENOSPC if less than half 330 * the slop space is free. Typically, once the pool has less than the slop 331 * space free, the user will use these operations to free up space in the pool. 332 * These are the operations that call dsl_pool_adjustedsize() with the netfree 333 * argument set to TRUE. 334 * 335 * A very restricted set of operations are always permitted, regardless of 336 * the amount of free space. These are the operations that call 337 * dsl_sync_task(ZFS_SPACE_CHECK_NONE), e.g. "zfs destroy". If these 338 * operations result in a net increase in the amount of space used, 339 * it is possible to run the pool completely out of space, causing it to 340 * be permanently read-only. 341 * 342 * See also the comments in zfs_space_check_t. 343 */ 344 int spa_slop_shift = 5; 345 346 /* 347 * ========================================================================== 348 * SPA config locking 349 * ========================================================================== 350 */ 351 static void 352 spa_config_lock_init(spa_t *spa) 353 { 354 for (int i = 0; i < SCL_LOCKS; i++) { 355 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 356 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL); 357 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL); 358 refcount_create_untracked(&scl->scl_count); 359 scl->scl_writer = NULL; 360 scl->scl_write_wanted = 0; 361 } 362 } 363 364 static void 365 spa_config_lock_destroy(spa_t *spa) 366 { 367 for (int i = 0; i < SCL_LOCKS; i++) { 368 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 369 mutex_destroy(&scl->scl_lock); 370 cv_destroy(&scl->scl_cv); 371 refcount_destroy(&scl->scl_count); 372 ASSERT(scl->scl_writer == NULL); 373 ASSERT(scl->scl_write_wanted == 0); 374 } 375 } 376 377 int 378 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw) 379 { 380 for (int i = 0; i < SCL_LOCKS; i++) { 381 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 382 if (!(locks & (1 << i))) 383 continue; 384 mutex_enter(&scl->scl_lock); 385 if (rw == RW_READER) { 386 if (scl->scl_writer || scl->scl_write_wanted) { 387 mutex_exit(&scl->scl_lock); 388 spa_config_exit(spa, locks ^ (1 << i), tag); 389 return (0); 390 } 391 } else { 392 ASSERT(scl->scl_writer != curthread); 393 if (!refcount_is_zero(&scl->scl_count)) { 394 mutex_exit(&scl->scl_lock); 395 spa_config_exit(spa, locks ^ (1 << i), tag); 396 return (0); 397 } 398 scl->scl_writer = curthread; 399 } 400 (void) refcount_add(&scl->scl_count, tag); 401 mutex_exit(&scl->scl_lock); 402 } 403 return (1); 404 } 405 406 void 407 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw) 408 { 409 int wlocks_held = 0; 410 411 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY); 412 413 for (int i = 0; i < SCL_LOCKS; i++) { 414 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 415 if (scl->scl_writer == curthread) 416 wlocks_held |= (1 << i); 417 if (!(locks & (1 << i))) 418 continue; 419 mutex_enter(&scl->scl_lock); 420 if (rw == RW_READER) { 421 while (scl->scl_writer || scl->scl_write_wanted) { 422 cv_wait(&scl->scl_cv, &scl->scl_lock); 423 } 424 } else { 425 ASSERT(scl->scl_writer != curthread); 426 while (!refcount_is_zero(&scl->scl_count)) { 427 scl->scl_write_wanted++; 428 cv_wait(&scl->scl_cv, &scl->scl_lock); 429 scl->scl_write_wanted--; 430 } 431 scl->scl_writer = curthread; 432 } 433 (void) refcount_add(&scl->scl_count, tag); 434 mutex_exit(&scl->scl_lock); 435 } 436 ASSERT(wlocks_held <= locks); 437 } 438 439 void 440 spa_config_exit(spa_t *spa, int locks, void *tag) 441 { 442 for (int i = SCL_LOCKS - 1; i >= 0; i--) { 443 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 444 if (!(locks & (1 << i))) 445 continue; 446 mutex_enter(&scl->scl_lock); 447 ASSERT(!refcount_is_zero(&scl->scl_count)); 448 if (refcount_remove(&scl->scl_count, tag) == 0) { 449 ASSERT(scl->scl_writer == NULL || 450 scl->scl_writer == curthread); 451 scl->scl_writer = NULL; /* OK in either case */ 452 cv_broadcast(&scl->scl_cv); 453 } 454 mutex_exit(&scl->scl_lock); 455 } 456 } 457 458 int 459 spa_config_held(spa_t *spa, int locks, krw_t rw) 460 { 461 int locks_held = 0; 462 463 for (int i = 0; i < SCL_LOCKS; i++) { 464 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 465 if (!(locks & (1 << i))) 466 continue; 467 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) || 468 (rw == RW_WRITER && scl->scl_writer == curthread)) 469 locks_held |= 1 << i; 470 } 471 472 return (locks_held); 473 } 474 475 /* 476 * ========================================================================== 477 * SPA namespace functions 478 * ========================================================================== 479 */ 480 481 /* 482 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. 483 * Returns NULL if no matching spa_t is found. 484 */ 485 spa_t * 486 spa_lookup(const char *name) 487 { 488 static spa_t search; /* spa_t is large; don't allocate on stack */ 489 spa_t *spa; 490 avl_index_t where; 491 char *cp; 492 493 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 494 495 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name)); 496 497 /* 498 * If it's a full dataset name, figure out the pool name and 499 * just use that. 500 */ 501 cp = strpbrk(search.spa_name, "/@#"); 502 if (cp != NULL) 503 *cp = '\0'; 504 505 spa = avl_find(&spa_namespace_avl, &search, &where); 506 507 return (spa); 508 } 509 510 /* 511 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms. 512 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues 513 * looking for potentially hung I/Os. 514 */ 515 void 516 spa_deadman(void *arg) 517 { 518 spa_t *spa = arg; 519 520 /* 521 * Disable the deadman timer if the pool is suspended. 522 */ 523 if (spa_suspended(spa)) { 524 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY)); 525 return; 526 } 527 528 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu", 529 (gethrtime() - spa->spa_sync_starttime) / NANOSEC, 530 ++spa->spa_deadman_calls); 531 if (zfs_deadman_enabled) 532 vdev_deadman(spa->spa_root_vdev); 533 } 534 535 /* 536 * Create an uninitialized spa_t with the given name. Requires 537 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already 538 * exist by calling spa_lookup() first. 539 */ 540 spa_t * 541 spa_add(const char *name, nvlist_t *config, const char *altroot) 542 { 543 spa_t *spa; 544 spa_config_dirent_t *dp; 545 cyc_handler_t hdlr; 546 cyc_time_t when; 547 548 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 549 550 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); 551 552 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL); 553 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL); 554 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL); 555 mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL); 556 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL); 557 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL); 558 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL); 559 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL); 560 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL); 561 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL); 562 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL); 563 564 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL); 565 cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL); 566 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL); 567 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL); 568 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL); 569 570 for (int t = 0; t < TXG_SIZE; t++) 571 bplist_create(&spa->spa_free_bplist[t]); 572 573 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name)); 574 spa->spa_state = POOL_STATE_UNINITIALIZED; 575 spa->spa_freeze_txg = UINT64_MAX; 576 spa->spa_final_txg = UINT64_MAX; 577 spa->spa_load_max_txg = UINT64_MAX; 578 spa->spa_proc = &p0; 579 spa->spa_proc_state = SPA_PROC_NONE; 580 581 hdlr.cyh_func = spa_deadman; 582 hdlr.cyh_arg = spa; 583 hdlr.cyh_level = CY_LOW_LEVEL; 584 585 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms); 586 587 /* 588 * This determines how often we need to check for hung I/Os after 589 * the cyclic has already fired. Since checking for hung I/Os is 590 * an expensive operation we don't want to check too frequently. 591 * Instead wait for 5 seconds before checking again. 592 */ 593 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms); 594 when.cyt_when = CY_INFINITY; 595 mutex_enter(&cpu_lock); 596 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when); 597 mutex_exit(&cpu_lock); 598 599 refcount_create(&spa->spa_refcount); 600 spa_config_lock_init(spa); 601 602 avl_add(&spa_namespace_avl, spa); 603 604 /* 605 * Set the alternate root, if there is one. 606 */ 607 if (altroot) { 608 spa->spa_root = spa_strdup(altroot); 609 spa_active_count++; 610 } 611 612 /* 613 * Every pool starts with the default cachefile 614 */ 615 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t), 616 offsetof(spa_config_dirent_t, scd_link)); 617 618 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP); 619 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path); 620 list_insert_head(&spa->spa_config_list, dp); 621 622 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME, 623 KM_SLEEP) == 0); 624 625 if (config != NULL) { 626 nvlist_t *features; 627 628 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 629 &features) == 0) { 630 VERIFY(nvlist_dup(features, &spa->spa_label_features, 631 0) == 0); 632 } 633 634 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0); 635 } 636 637 if (spa->spa_label_features == NULL) { 638 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME, 639 KM_SLEEP) == 0); 640 } 641 642 spa->spa_iokstat = kstat_create("zfs", 0, name, 643 "disk", KSTAT_TYPE_IO, 1, 0); 644 if (spa->spa_iokstat) { 645 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock; 646 kstat_install(spa->spa_iokstat); 647 } 648 649 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0); 650 651 /* 652 * As a pool is being created, treat all features as disabled by 653 * setting SPA_FEATURE_DISABLED for all entries in the feature 654 * refcount cache. 655 */ 656 for (int i = 0; i < SPA_FEATURES; i++) { 657 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED; 658 } 659 660 return (spa); 661 } 662 663 /* 664 * Removes a spa_t from the namespace, freeing up any memory used. Requires 665 * spa_namespace_lock. This is called only after the spa_t has been closed and 666 * deactivated. 667 */ 668 void 669 spa_remove(spa_t *spa) 670 { 671 spa_config_dirent_t *dp; 672 673 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 674 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 675 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0); 676 677 nvlist_free(spa->spa_config_splitting); 678 679 avl_remove(&spa_namespace_avl, spa); 680 cv_broadcast(&spa_namespace_cv); 681 682 if (spa->spa_root) { 683 spa_strfree(spa->spa_root); 684 spa_active_count--; 685 } 686 687 while ((dp = list_head(&spa->spa_config_list)) != NULL) { 688 list_remove(&spa->spa_config_list, dp); 689 if (dp->scd_path != NULL) 690 spa_strfree(dp->scd_path); 691 kmem_free(dp, sizeof (spa_config_dirent_t)); 692 } 693 694 list_destroy(&spa->spa_config_list); 695 696 nvlist_free(spa->spa_label_features); 697 nvlist_free(spa->spa_load_info); 698 spa_config_set(spa, NULL); 699 700 mutex_enter(&cpu_lock); 701 if (spa->spa_deadman_cycid != CYCLIC_NONE) 702 cyclic_remove(spa->spa_deadman_cycid); 703 mutex_exit(&cpu_lock); 704 spa->spa_deadman_cycid = CYCLIC_NONE; 705 706 refcount_destroy(&spa->spa_refcount); 707 708 spa_config_lock_destroy(spa); 709 710 kstat_delete(spa->spa_iokstat); 711 spa->spa_iokstat = NULL; 712 713 for (int t = 0; t < TXG_SIZE; t++) 714 bplist_destroy(&spa->spa_free_bplist[t]); 715 716 cv_destroy(&spa->spa_async_cv); 717 cv_destroy(&spa->spa_evicting_os_cv); 718 cv_destroy(&spa->spa_proc_cv); 719 cv_destroy(&spa->spa_scrub_io_cv); 720 cv_destroy(&spa->spa_suspend_cv); 721 722 mutex_destroy(&spa->spa_async_lock); 723 mutex_destroy(&spa->spa_errlist_lock); 724 mutex_destroy(&spa->spa_errlog_lock); 725 mutex_destroy(&spa->spa_evicting_os_lock); 726 mutex_destroy(&spa->spa_history_lock); 727 mutex_destroy(&spa->spa_proc_lock); 728 mutex_destroy(&spa->spa_props_lock); 729 mutex_destroy(&spa->spa_scrub_lock); 730 mutex_destroy(&spa->spa_suspend_lock); 731 mutex_destroy(&spa->spa_vdev_top_lock); 732 mutex_destroy(&spa->spa_iokstat_lock); 733 734 kmem_free(spa, sizeof (spa_t)); 735 } 736 737 /* 738 * Given a pool, return the next pool in the namespace, or NULL if there is 739 * none. If 'prev' is NULL, return the first pool. 740 */ 741 spa_t * 742 spa_next(spa_t *prev) 743 { 744 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 745 746 if (prev) 747 return (AVL_NEXT(&spa_namespace_avl, prev)); 748 else 749 return (avl_first(&spa_namespace_avl)); 750 } 751 752 /* 753 * ========================================================================== 754 * SPA refcount functions 755 * ========================================================================== 756 */ 757 758 /* 759 * Add a reference to the given spa_t. Must have at least one reference, or 760 * have the namespace lock held. 761 */ 762 void 763 spa_open_ref(spa_t *spa, void *tag) 764 { 765 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || 766 MUTEX_HELD(&spa_namespace_lock)); 767 (void) refcount_add(&spa->spa_refcount, tag); 768 } 769 770 /* 771 * Remove a reference to the given spa_t. Must have at least one reference, or 772 * have the namespace lock held. 773 */ 774 void 775 spa_close(spa_t *spa, void *tag) 776 { 777 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || 778 MUTEX_HELD(&spa_namespace_lock)); 779 (void) refcount_remove(&spa->spa_refcount, tag); 780 } 781 782 /* 783 * Remove a reference to the given spa_t held by a dsl dir that is 784 * being asynchronously released. Async releases occur from a taskq 785 * performing eviction of dsl datasets and dirs. The namespace lock 786 * isn't held and the hold by the object being evicted may contribute to 787 * spa_minref (e.g. dataset or directory released during pool export), 788 * so the asserts in spa_close() do not apply. 789 */ 790 void 791 spa_async_close(spa_t *spa, void *tag) 792 { 793 (void) refcount_remove(&spa->spa_refcount, tag); 794 } 795 796 /* 797 * Check to see if the spa refcount is zero. Must be called with 798 * spa_namespace_lock held. We really compare against spa_minref, which is the 799 * number of references acquired when opening a pool 800 */ 801 boolean_t 802 spa_refcount_zero(spa_t *spa) 803 { 804 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 805 806 return (refcount_count(&spa->spa_refcount) == spa->spa_minref); 807 } 808 809 /* 810 * ========================================================================== 811 * SPA spare and l2cache tracking 812 * ========================================================================== 813 */ 814 815 /* 816 * Hot spares and cache devices are tracked using the same code below, 817 * for 'auxiliary' devices. 818 */ 819 820 typedef struct spa_aux { 821 uint64_t aux_guid; 822 uint64_t aux_pool; 823 avl_node_t aux_avl; 824 int aux_count; 825 } spa_aux_t; 826 827 static int 828 spa_aux_compare(const void *a, const void *b) 829 { 830 const spa_aux_t *sa = a; 831 const spa_aux_t *sb = b; 832 833 if (sa->aux_guid < sb->aux_guid) 834 return (-1); 835 else if (sa->aux_guid > sb->aux_guid) 836 return (1); 837 else 838 return (0); 839 } 840 841 void 842 spa_aux_add(vdev_t *vd, avl_tree_t *avl) 843 { 844 avl_index_t where; 845 spa_aux_t search; 846 spa_aux_t *aux; 847 848 search.aux_guid = vd->vdev_guid; 849 if ((aux = avl_find(avl, &search, &where)) != NULL) { 850 aux->aux_count++; 851 } else { 852 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); 853 aux->aux_guid = vd->vdev_guid; 854 aux->aux_count = 1; 855 avl_insert(avl, aux, where); 856 } 857 } 858 859 void 860 spa_aux_remove(vdev_t *vd, avl_tree_t *avl) 861 { 862 spa_aux_t search; 863 spa_aux_t *aux; 864 avl_index_t where; 865 866 search.aux_guid = vd->vdev_guid; 867 aux = avl_find(avl, &search, &where); 868 869 ASSERT(aux != NULL); 870 871 if (--aux->aux_count == 0) { 872 avl_remove(avl, aux); 873 kmem_free(aux, sizeof (spa_aux_t)); 874 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { 875 aux->aux_pool = 0ULL; 876 } 877 } 878 879 boolean_t 880 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) 881 { 882 spa_aux_t search, *found; 883 884 search.aux_guid = guid; 885 found = avl_find(avl, &search, NULL); 886 887 if (pool) { 888 if (found) 889 *pool = found->aux_pool; 890 else 891 *pool = 0ULL; 892 } 893 894 if (refcnt) { 895 if (found) 896 *refcnt = found->aux_count; 897 else 898 *refcnt = 0; 899 } 900 901 return (found != NULL); 902 } 903 904 void 905 spa_aux_activate(vdev_t *vd, avl_tree_t *avl) 906 { 907 spa_aux_t search, *found; 908 avl_index_t where; 909 910 search.aux_guid = vd->vdev_guid; 911 found = avl_find(avl, &search, &where); 912 ASSERT(found != NULL); 913 ASSERT(found->aux_pool == 0ULL); 914 915 found->aux_pool = spa_guid(vd->vdev_spa); 916 } 917 918 /* 919 * Spares are tracked globally due to the following constraints: 920 * 921 * - A spare may be part of multiple pools. 922 * - A spare may be added to a pool even if it's actively in use within 923 * another pool. 924 * - A spare in use in any pool can only be the source of a replacement if 925 * the target is a spare in the same pool. 926 * 927 * We keep track of all spares on the system through the use of a reference 928 * counted AVL tree. When a vdev is added as a spare, or used as a replacement 929 * spare, then we bump the reference count in the AVL tree. In addition, we set 930 * the 'vdev_isspare' member to indicate that the device is a spare (active or 931 * inactive). When a spare is made active (used to replace a device in the 932 * pool), we also keep track of which pool its been made a part of. 933 * 934 * The 'spa_spare_lock' protects the AVL tree. These functions are normally 935 * called under the spa_namespace lock as part of vdev reconfiguration. The 936 * separate spare lock exists for the status query path, which does not need to 937 * be completely consistent with respect to other vdev configuration changes. 938 */ 939 940 static int 941 spa_spare_compare(const void *a, const void *b) 942 { 943 return (spa_aux_compare(a, b)); 944 } 945 946 void 947 spa_spare_add(vdev_t *vd) 948 { 949 mutex_enter(&spa_spare_lock); 950 ASSERT(!vd->vdev_isspare); 951 spa_aux_add(vd, &spa_spare_avl); 952 vd->vdev_isspare = B_TRUE; 953 mutex_exit(&spa_spare_lock); 954 } 955 956 void 957 spa_spare_remove(vdev_t *vd) 958 { 959 mutex_enter(&spa_spare_lock); 960 ASSERT(vd->vdev_isspare); 961 spa_aux_remove(vd, &spa_spare_avl); 962 vd->vdev_isspare = B_FALSE; 963 mutex_exit(&spa_spare_lock); 964 } 965 966 boolean_t 967 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) 968 { 969 boolean_t found; 970 971 mutex_enter(&spa_spare_lock); 972 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); 973 mutex_exit(&spa_spare_lock); 974 975 return (found); 976 } 977 978 void 979 spa_spare_activate(vdev_t *vd) 980 { 981 mutex_enter(&spa_spare_lock); 982 ASSERT(vd->vdev_isspare); 983 spa_aux_activate(vd, &spa_spare_avl); 984 mutex_exit(&spa_spare_lock); 985 } 986 987 /* 988 * Level 2 ARC devices are tracked globally for the same reasons as spares. 989 * Cache devices currently only support one pool per cache device, and so 990 * for these devices the aux reference count is currently unused beyond 1. 991 */ 992 993 static int 994 spa_l2cache_compare(const void *a, const void *b) 995 { 996 return (spa_aux_compare(a, b)); 997 } 998 999 void 1000 spa_l2cache_add(vdev_t *vd) 1001 { 1002 mutex_enter(&spa_l2cache_lock); 1003 ASSERT(!vd->vdev_isl2cache); 1004 spa_aux_add(vd, &spa_l2cache_avl); 1005 vd->vdev_isl2cache = B_TRUE; 1006 mutex_exit(&spa_l2cache_lock); 1007 } 1008 1009 void 1010 spa_l2cache_remove(vdev_t *vd) 1011 { 1012 mutex_enter(&spa_l2cache_lock); 1013 ASSERT(vd->vdev_isl2cache); 1014 spa_aux_remove(vd, &spa_l2cache_avl); 1015 vd->vdev_isl2cache = B_FALSE; 1016 mutex_exit(&spa_l2cache_lock); 1017 } 1018 1019 boolean_t 1020 spa_l2cache_exists(uint64_t guid, uint64_t *pool) 1021 { 1022 boolean_t found; 1023 1024 mutex_enter(&spa_l2cache_lock); 1025 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); 1026 mutex_exit(&spa_l2cache_lock); 1027 1028 return (found); 1029 } 1030 1031 void 1032 spa_l2cache_activate(vdev_t *vd) 1033 { 1034 mutex_enter(&spa_l2cache_lock); 1035 ASSERT(vd->vdev_isl2cache); 1036 spa_aux_activate(vd, &spa_l2cache_avl); 1037 mutex_exit(&spa_l2cache_lock); 1038 } 1039 1040 /* 1041 * ========================================================================== 1042 * SPA vdev locking 1043 * ========================================================================== 1044 */ 1045 1046 /* 1047 * Lock the given spa_t for the purpose of adding or removing a vdev. 1048 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 1049 * It returns the next transaction group for the spa_t. 1050 */ 1051 uint64_t 1052 spa_vdev_enter(spa_t *spa) 1053 { 1054 mutex_enter(&spa->spa_vdev_top_lock); 1055 mutex_enter(&spa_namespace_lock); 1056 return (spa_vdev_config_enter(spa)); 1057 } 1058 1059 /* 1060 * Internal implementation for spa_vdev_enter(). Used when a vdev 1061 * operation requires multiple syncs (i.e. removing a device) while 1062 * keeping the spa_namespace_lock held. 1063 */ 1064 uint64_t 1065 spa_vdev_config_enter(spa_t *spa) 1066 { 1067 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1068 1069 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1070 1071 return (spa_last_synced_txg(spa) + 1); 1072 } 1073 1074 /* 1075 * Used in combination with spa_vdev_config_enter() to allow the syncing 1076 * of multiple transactions without releasing the spa_namespace_lock. 1077 */ 1078 void 1079 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) 1080 { 1081 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1082 1083 int config_changed = B_FALSE; 1084 1085 ASSERT(txg > spa_last_synced_txg(spa)); 1086 1087 spa->spa_pending_vdev = NULL; 1088 1089 /* 1090 * Reassess the DTLs. 1091 */ 1092 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 1093 1094 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { 1095 config_changed = B_TRUE; 1096 spa->spa_config_generation++; 1097 } 1098 1099 /* 1100 * Verify the metaslab classes. 1101 */ 1102 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); 1103 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); 1104 1105 spa_config_exit(spa, SCL_ALL, spa); 1106 1107 /* 1108 * Panic the system if the specified tag requires it. This 1109 * is useful for ensuring that configurations are updated 1110 * transactionally. 1111 */ 1112 if (zio_injection_enabled) 1113 zio_handle_panic_injection(spa, tag, 0); 1114 1115 /* 1116 * Note: this txg_wait_synced() is important because it ensures 1117 * that there won't be more than one config change per txg. 1118 * This allows us to use the txg as the generation number. 1119 */ 1120 if (error == 0) 1121 txg_wait_synced(spa->spa_dsl_pool, txg); 1122 1123 if (vd != NULL) { 1124 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL); 1125 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1126 vdev_free(vd); 1127 spa_config_exit(spa, SCL_ALL, spa); 1128 } 1129 1130 /* 1131 * If the config changed, update the config cache. 1132 */ 1133 if (config_changed) 1134 spa_config_sync(spa, B_FALSE, B_TRUE); 1135 } 1136 1137 /* 1138 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 1139 * locking of spa_vdev_enter(), we also want make sure the transactions have 1140 * synced to disk, and then update the global configuration cache with the new 1141 * information. 1142 */ 1143 int 1144 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 1145 { 1146 spa_vdev_config_exit(spa, vd, txg, error, FTAG); 1147 mutex_exit(&spa_namespace_lock); 1148 mutex_exit(&spa->spa_vdev_top_lock); 1149 1150 return (error); 1151 } 1152 1153 /* 1154 * Lock the given spa_t for the purpose of changing vdev state. 1155 */ 1156 void 1157 spa_vdev_state_enter(spa_t *spa, int oplocks) 1158 { 1159 int locks = SCL_STATE_ALL | oplocks; 1160 1161 /* 1162 * Root pools may need to read of the underlying devfs filesystem 1163 * when opening up a vdev. Unfortunately if we're holding the 1164 * SCL_ZIO lock it will result in a deadlock when we try to issue 1165 * the read from the root filesystem. Instead we "prefetch" 1166 * the associated vnodes that we need prior to opening the 1167 * underlying devices and cache them so that we can prevent 1168 * any I/O when we are doing the actual open. 1169 */ 1170 if (spa_is_root(spa)) { 1171 int low = locks & ~(SCL_ZIO - 1); 1172 int high = locks & ~low; 1173 1174 spa_config_enter(spa, high, spa, RW_WRITER); 1175 vdev_hold(spa->spa_root_vdev); 1176 spa_config_enter(spa, low, spa, RW_WRITER); 1177 } else { 1178 spa_config_enter(spa, locks, spa, RW_WRITER); 1179 } 1180 spa->spa_vdev_locks = locks; 1181 } 1182 1183 int 1184 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) 1185 { 1186 boolean_t config_changed = B_FALSE; 1187 1188 if (vd != NULL || error == 0) 1189 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, 1190 0, 0, B_FALSE); 1191 1192 if (vd != NULL) { 1193 vdev_state_dirty(vd->vdev_top); 1194 config_changed = B_TRUE; 1195 spa->spa_config_generation++; 1196 } 1197 1198 if (spa_is_root(spa)) 1199 vdev_rele(spa->spa_root_vdev); 1200 1201 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); 1202 spa_config_exit(spa, spa->spa_vdev_locks, spa); 1203 1204 /* 1205 * If anything changed, wait for it to sync. This ensures that, 1206 * from the system administrator's perspective, zpool(1M) commands 1207 * are synchronous. This is important for things like zpool offline: 1208 * when the command completes, you expect no further I/O from ZFS. 1209 */ 1210 if (vd != NULL) 1211 txg_wait_synced(spa->spa_dsl_pool, 0); 1212 1213 /* 1214 * If the config changed, update the config cache. 1215 */ 1216 if (config_changed) { 1217 mutex_enter(&spa_namespace_lock); 1218 spa_config_sync(spa, B_FALSE, B_TRUE); 1219 mutex_exit(&spa_namespace_lock); 1220 } 1221 1222 return (error); 1223 } 1224 1225 /* 1226 * ========================================================================== 1227 * Miscellaneous functions 1228 * ========================================================================== 1229 */ 1230 1231 void 1232 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx) 1233 { 1234 if (!nvlist_exists(spa->spa_label_features, feature)) { 1235 fnvlist_add_boolean(spa->spa_label_features, feature); 1236 /* 1237 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't 1238 * dirty the vdev config because lock SCL_CONFIG is not held. 1239 * Thankfully, in this case we don't need to dirty the config 1240 * because it will be written out anyway when we finish 1241 * creating the pool. 1242 */ 1243 if (tx->tx_txg != TXG_INITIAL) 1244 vdev_config_dirty(spa->spa_root_vdev); 1245 } 1246 } 1247 1248 void 1249 spa_deactivate_mos_feature(spa_t *spa, const char *feature) 1250 { 1251 if (nvlist_remove_all(spa->spa_label_features, feature) == 0) 1252 vdev_config_dirty(spa->spa_root_vdev); 1253 } 1254 1255 /* 1256 * Rename a spa_t. 1257 */ 1258 int 1259 spa_rename(const char *name, const char *newname) 1260 { 1261 spa_t *spa; 1262 int err; 1263 1264 /* 1265 * Lookup the spa_t and grab the config lock for writing. We need to 1266 * actually open the pool so that we can sync out the necessary labels. 1267 * It's OK to call spa_open() with the namespace lock held because we 1268 * allow recursive calls for other reasons. 1269 */ 1270 mutex_enter(&spa_namespace_lock); 1271 if ((err = spa_open(name, &spa, FTAG)) != 0) { 1272 mutex_exit(&spa_namespace_lock); 1273 return (err); 1274 } 1275 1276 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1277 1278 avl_remove(&spa_namespace_avl, spa); 1279 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); 1280 avl_add(&spa_namespace_avl, spa); 1281 1282 /* 1283 * Sync all labels to disk with the new names by marking the root vdev 1284 * dirty and waiting for it to sync. It will pick up the new pool name 1285 * during the sync. 1286 */ 1287 vdev_config_dirty(spa->spa_root_vdev); 1288 1289 spa_config_exit(spa, SCL_ALL, FTAG); 1290 1291 txg_wait_synced(spa->spa_dsl_pool, 0); 1292 1293 /* 1294 * Sync the updated config cache. 1295 */ 1296 spa_config_sync(spa, B_FALSE, B_TRUE); 1297 1298 spa_close(spa, FTAG); 1299 1300 mutex_exit(&spa_namespace_lock); 1301 1302 return (0); 1303 } 1304 1305 /* 1306 * Return the spa_t associated with given pool_guid, if it exists. If 1307 * device_guid is non-zero, determine whether the pool exists *and* contains 1308 * a device with the specified device_guid. 1309 */ 1310 spa_t * 1311 spa_by_guid(uint64_t pool_guid, uint64_t device_guid) 1312 { 1313 spa_t *spa; 1314 avl_tree_t *t = &spa_namespace_avl; 1315 1316 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1317 1318 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 1319 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 1320 continue; 1321 if (spa->spa_root_vdev == NULL) 1322 continue; 1323 if (spa_guid(spa) == pool_guid) { 1324 if (device_guid == 0) 1325 break; 1326 1327 if (vdev_lookup_by_guid(spa->spa_root_vdev, 1328 device_guid) != NULL) 1329 break; 1330 1331 /* 1332 * Check any devices we may be in the process of adding. 1333 */ 1334 if (spa->spa_pending_vdev) { 1335 if (vdev_lookup_by_guid(spa->spa_pending_vdev, 1336 device_guid) != NULL) 1337 break; 1338 } 1339 } 1340 } 1341 1342 return (spa); 1343 } 1344 1345 /* 1346 * Determine whether a pool with the given pool_guid exists. 1347 */ 1348 boolean_t 1349 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 1350 { 1351 return (spa_by_guid(pool_guid, device_guid) != NULL); 1352 } 1353 1354 char * 1355 spa_strdup(const char *s) 1356 { 1357 size_t len; 1358 char *new; 1359 1360 len = strlen(s); 1361 new = kmem_alloc(len + 1, KM_SLEEP); 1362 bcopy(s, new, len); 1363 new[len] = '\0'; 1364 1365 return (new); 1366 } 1367 1368 void 1369 spa_strfree(char *s) 1370 { 1371 kmem_free(s, strlen(s) + 1); 1372 } 1373 1374 uint64_t 1375 spa_get_random(uint64_t range) 1376 { 1377 uint64_t r; 1378 1379 ASSERT(range != 0); 1380 1381 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 1382 1383 return (r % range); 1384 } 1385 1386 uint64_t 1387 spa_generate_guid(spa_t *spa) 1388 { 1389 uint64_t guid = spa_get_random(-1ULL); 1390 1391 if (spa != NULL) { 1392 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) 1393 guid = spa_get_random(-1ULL); 1394 } else { 1395 while (guid == 0 || spa_guid_exists(guid, 0)) 1396 guid = spa_get_random(-1ULL); 1397 } 1398 1399 return (guid); 1400 } 1401 1402 void 1403 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp) 1404 { 1405 char type[256]; 1406 char *checksum = NULL; 1407 char *compress = NULL; 1408 1409 if (bp != NULL) { 1410 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) { 1411 dmu_object_byteswap_t bswap = 1412 DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); 1413 (void) snprintf(type, sizeof (type), "bswap %s %s", 1414 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ? 1415 "metadata" : "data", 1416 dmu_ot_byteswap[bswap].ob_name); 1417 } else { 1418 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name, 1419 sizeof (type)); 1420 } 1421 if (!BP_IS_EMBEDDED(bp)) { 1422 checksum = 1423 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; 1424 } 1425 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; 1426 } 1427 1428 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum, 1429 compress); 1430 } 1431 1432 void 1433 spa_freeze(spa_t *spa) 1434 { 1435 uint64_t freeze_txg = 0; 1436 1437 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1438 if (spa->spa_freeze_txg == UINT64_MAX) { 1439 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 1440 spa->spa_freeze_txg = freeze_txg; 1441 } 1442 spa_config_exit(spa, SCL_ALL, FTAG); 1443 if (freeze_txg != 0) 1444 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 1445 } 1446 1447 void 1448 zfs_panic_recover(const char *fmt, ...) 1449 { 1450 va_list adx; 1451 1452 va_start(adx, fmt); 1453 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); 1454 va_end(adx); 1455 } 1456 1457 /* 1458 * This is a stripped-down version of strtoull, suitable only for converting 1459 * lowercase hexadecimal numbers that don't overflow. 1460 */ 1461 uint64_t 1462 strtonum(const char *str, char **nptr) 1463 { 1464 uint64_t val = 0; 1465 char c; 1466 int digit; 1467 1468 while ((c = *str) != '\0') { 1469 if (c >= '0' && c <= '9') 1470 digit = c - '0'; 1471 else if (c >= 'a' && c <= 'f') 1472 digit = 10 + c - 'a'; 1473 else 1474 break; 1475 1476 val *= 16; 1477 val += digit; 1478 1479 str++; 1480 } 1481 1482 if (nptr) 1483 *nptr = (char *)str; 1484 1485 return (val); 1486 } 1487 1488 /* 1489 * ========================================================================== 1490 * Accessor functions 1491 * ========================================================================== 1492 */ 1493 1494 boolean_t 1495 spa_shutting_down(spa_t *spa) 1496 { 1497 return (spa->spa_async_suspended); 1498 } 1499 1500 dsl_pool_t * 1501 spa_get_dsl(spa_t *spa) 1502 { 1503 return (spa->spa_dsl_pool); 1504 } 1505 1506 boolean_t 1507 spa_is_initializing(spa_t *spa) 1508 { 1509 return (spa->spa_is_initializing); 1510 } 1511 1512 blkptr_t * 1513 spa_get_rootblkptr(spa_t *spa) 1514 { 1515 return (&spa->spa_ubsync.ub_rootbp); 1516 } 1517 1518 void 1519 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 1520 { 1521 spa->spa_uberblock.ub_rootbp = *bp; 1522 } 1523 1524 void 1525 spa_altroot(spa_t *spa, char *buf, size_t buflen) 1526 { 1527 if (spa->spa_root == NULL) 1528 buf[0] = '\0'; 1529 else 1530 (void) strncpy(buf, spa->spa_root, buflen); 1531 } 1532 1533 int 1534 spa_sync_pass(spa_t *spa) 1535 { 1536 return (spa->spa_sync_pass); 1537 } 1538 1539 char * 1540 spa_name(spa_t *spa) 1541 { 1542 return (spa->spa_name); 1543 } 1544 1545 uint64_t 1546 spa_guid(spa_t *spa) 1547 { 1548 dsl_pool_t *dp = spa_get_dsl(spa); 1549 uint64_t guid; 1550 1551 /* 1552 * If we fail to parse the config during spa_load(), we can go through 1553 * the error path (which posts an ereport) and end up here with no root 1554 * vdev. We stash the original pool guid in 'spa_config_guid' to handle 1555 * this case. 1556 */ 1557 if (spa->spa_root_vdev == NULL) 1558 return (spa->spa_config_guid); 1559 1560 guid = spa->spa_last_synced_guid != 0 ? 1561 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid; 1562 1563 /* 1564 * Return the most recently synced out guid unless we're 1565 * in syncing context. 1566 */ 1567 if (dp && dsl_pool_sync_context(dp)) 1568 return (spa->spa_root_vdev->vdev_guid); 1569 else 1570 return (guid); 1571 } 1572 1573 uint64_t 1574 spa_load_guid(spa_t *spa) 1575 { 1576 /* 1577 * This is a GUID that exists solely as a reference for the 1578 * purposes of the arc. It is generated at load time, and 1579 * is never written to persistent storage. 1580 */ 1581 return (spa->spa_load_guid); 1582 } 1583 1584 uint64_t 1585 spa_last_synced_txg(spa_t *spa) 1586 { 1587 return (spa->spa_ubsync.ub_txg); 1588 } 1589 1590 uint64_t 1591 spa_first_txg(spa_t *spa) 1592 { 1593 return (spa->spa_first_txg); 1594 } 1595 1596 uint64_t 1597 spa_syncing_txg(spa_t *spa) 1598 { 1599 return (spa->spa_syncing_txg); 1600 } 1601 1602 pool_state_t 1603 spa_state(spa_t *spa) 1604 { 1605 return (spa->spa_state); 1606 } 1607 1608 spa_load_state_t 1609 spa_load_state(spa_t *spa) 1610 { 1611 return (spa->spa_load_state); 1612 } 1613 1614 uint64_t 1615 spa_freeze_txg(spa_t *spa) 1616 { 1617 return (spa->spa_freeze_txg); 1618 } 1619 1620 /* ARGSUSED */ 1621 uint64_t 1622 spa_get_asize(spa_t *spa, uint64_t lsize) 1623 { 1624 return (lsize * spa_asize_inflation); 1625 } 1626 1627 /* 1628 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%), 1629 * or at least 32MB. 1630 * 1631 * See the comment above spa_slop_shift for details. 1632 */ 1633 uint64_t 1634 spa_get_slop_space(spa_t *spa) { 1635 uint64_t space = spa_get_dspace(spa); 1636 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1)); 1637 } 1638 1639 uint64_t 1640 spa_get_dspace(spa_t *spa) 1641 { 1642 return (spa->spa_dspace); 1643 } 1644 1645 void 1646 spa_update_dspace(spa_t *spa) 1647 { 1648 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + 1649 ddt_get_dedup_dspace(spa); 1650 } 1651 1652 /* 1653 * Return the failure mode that has been set to this pool. The default 1654 * behavior will be to block all I/Os when a complete failure occurs. 1655 */ 1656 uint8_t 1657 spa_get_failmode(spa_t *spa) 1658 { 1659 return (spa->spa_failmode); 1660 } 1661 1662 boolean_t 1663 spa_suspended(spa_t *spa) 1664 { 1665 return (spa->spa_suspended); 1666 } 1667 1668 uint64_t 1669 spa_version(spa_t *spa) 1670 { 1671 return (spa->spa_ubsync.ub_version); 1672 } 1673 1674 boolean_t 1675 spa_deflate(spa_t *spa) 1676 { 1677 return (spa->spa_deflate); 1678 } 1679 1680 metaslab_class_t * 1681 spa_normal_class(spa_t *spa) 1682 { 1683 return (spa->spa_normal_class); 1684 } 1685 1686 metaslab_class_t * 1687 spa_log_class(spa_t *spa) 1688 { 1689 return (spa->spa_log_class); 1690 } 1691 1692 void 1693 spa_evicting_os_register(spa_t *spa, objset_t *os) 1694 { 1695 mutex_enter(&spa->spa_evicting_os_lock); 1696 list_insert_head(&spa->spa_evicting_os_list, os); 1697 mutex_exit(&spa->spa_evicting_os_lock); 1698 } 1699 1700 void 1701 spa_evicting_os_deregister(spa_t *spa, objset_t *os) 1702 { 1703 mutex_enter(&spa->spa_evicting_os_lock); 1704 list_remove(&spa->spa_evicting_os_list, os); 1705 cv_broadcast(&spa->spa_evicting_os_cv); 1706 mutex_exit(&spa->spa_evicting_os_lock); 1707 } 1708 1709 void 1710 spa_evicting_os_wait(spa_t *spa) 1711 { 1712 mutex_enter(&spa->spa_evicting_os_lock); 1713 while (!list_is_empty(&spa->spa_evicting_os_list)) 1714 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock); 1715 mutex_exit(&spa->spa_evicting_os_lock); 1716 1717 dmu_buf_user_evict_wait(); 1718 } 1719 1720 int 1721 spa_max_replication(spa_t *spa) 1722 { 1723 /* 1724 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to 1725 * handle BPs with more than one DVA allocated. Set our max 1726 * replication level accordingly. 1727 */ 1728 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) 1729 return (1); 1730 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 1731 } 1732 1733 int 1734 spa_prev_software_version(spa_t *spa) 1735 { 1736 return (spa->spa_prev_software_version); 1737 } 1738 1739 uint64_t 1740 spa_deadman_synctime(spa_t *spa) 1741 { 1742 return (spa->spa_deadman_synctime); 1743 } 1744 1745 uint64_t 1746 dva_get_dsize_sync(spa_t *spa, const dva_t *dva) 1747 { 1748 uint64_t asize = DVA_GET_ASIZE(dva); 1749 uint64_t dsize = asize; 1750 1751 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); 1752 1753 if (asize != 0 && spa->spa_deflate) { 1754 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 1755 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; 1756 } 1757 1758 return (dsize); 1759 } 1760 1761 uint64_t 1762 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) 1763 { 1764 uint64_t dsize = 0; 1765 1766 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1767 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1768 1769 return (dsize); 1770 } 1771 1772 uint64_t 1773 bp_get_dsize(spa_t *spa, const blkptr_t *bp) 1774 { 1775 uint64_t dsize = 0; 1776 1777 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 1778 1779 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1780 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1781 1782 spa_config_exit(spa, SCL_VDEV, FTAG); 1783 1784 return (dsize); 1785 } 1786 1787 /* 1788 * ========================================================================== 1789 * Initialization and Termination 1790 * ========================================================================== 1791 */ 1792 1793 static int 1794 spa_name_compare(const void *a1, const void *a2) 1795 { 1796 const spa_t *s1 = a1; 1797 const spa_t *s2 = a2; 1798 int s; 1799 1800 s = strcmp(s1->spa_name, s2->spa_name); 1801 if (s > 0) 1802 return (1); 1803 if (s < 0) 1804 return (-1); 1805 return (0); 1806 } 1807 1808 int 1809 spa_busy(void) 1810 { 1811 return (spa_active_count); 1812 } 1813 1814 void 1815 spa_boot_init() 1816 { 1817 spa_config_load(); 1818 } 1819 1820 void 1821 spa_init(int mode) 1822 { 1823 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 1824 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); 1825 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); 1826 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 1827 1828 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 1829 offsetof(spa_t, spa_avl)); 1830 1831 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), 1832 offsetof(spa_aux_t, aux_avl)); 1833 1834 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), 1835 offsetof(spa_aux_t, aux_avl)); 1836 1837 spa_mode_global = mode; 1838 1839 #ifdef _KERNEL 1840 spa_arch_init(); 1841 #else 1842 if (spa_mode_global != FREAD && dprintf_find_string("watch")) { 1843 arc_procfd = open("/proc/self/ctl", O_WRONLY); 1844 if (arc_procfd == -1) { 1845 perror("could not enable watchpoints: " 1846 "opening /proc/self/ctl failed: "); 1847 } else { 1848 arc_watch = B_TRUE; 1849 } 1850 } 1851 #endif 1852 1853 refcount_init(); 1854 unique_init(); 1855 range_tree_init(); 1856 zio_init(); 1857 dmu_init(); 1858 zil_init(); 1859 vdev_cache_stat_init(); 1860 zfs_prop_init(); 1861 zpool_prop_init(); 1862 zpool_feature_init(); 1863 spa_config_load(); 1864 l2arc_start(); 1865 } 1866 1867 void 1868 spa_fini(void) 1869 { 1870 l2arc_stop(); 1871 1872 spa_evict_all(); 1873 1874 vdev_cache_stat_fini(); 1875 zil_fini(); 1876 dmu_fini(); 1877 zio_fini(); 1878 range_tree_fini(); 1879 unique_fini(); 1880 refcount_fini(); 1881 1882 avl_destroy(&spa_namespace_avl); 1883 avl_destroy(&spa_spare_avl); 1884 avl_destroy(&spa_l2cache_avl); 1885 1886 cv_destroy(&spa_namespace_cv); 1887 mutex_destroy(&spa_namespace_lock); 1888 mutex_destroy(&spa_spare_lock); 1889 mutex_destroy(&spa_l2cache_lock); 1890 } 1891 1892 /* 1893 * Return whether this pool has slogs. No locking needed. 1894 * It's not a problem if the wrong answer is returned as it's only for 1895 * performance and not correctness 1896 */ 1897 boolean_t 1898 spa_has_slogs(spa_t *spa) 1899 { 1900 return (spa->spa_log_class->mc_rotor != NULL); 1901 } 1902 1903 spa_log_state_t 1904 spa_get_log_state(spa_t *spa) 1905 { 1906 return (spa->spa_log_state); 1907 } 1908 1909 void 1910 spa_set_log_state(spa_t *spa, spa_log_state_t state) 1911 { 1912 spa->spa_log_state = state; 1913 } 1914 1915 boolean_t 1916 spa_is_root(spa_t *spa) 1917 { 1918 return (spa->spa_is_root); 1919 } 1920 1921 boolean_t 1922 spa_writeable(spa_t *spa) 1923 { 1924 return (!!(spa->spa_mode & FWRITE)); 1925 } 1926 1927 /* 1928 * Returns true if there is a pending sync task in any of the current 1929 * syncing txg, the current quiescing txg, or the current open txg. 1930 */ 1931 boolean_t 1932 spa_has_pending_synctask(spa_t *spa) 1933 { 1934 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks)); 1935 } 1936 1937 int 1938 spa_mode(spa_t *spa) 1939 { 1940 return (spa->spa_mode); 1941 } 1942 1943 uint64_t 1944 spa_bootfs(spa_t *spa) 1945 { 1946 return (spa->spa_bootfs); 1947 } 1948 1949 uint64_t 1950 spa_delegation(spa_t *spa) 1951 { 1952 return (spa->spa_delegation); 1953 } 1954 1955 objset_t * 1956 spa_meta_objset(spa_t *spa) 1957 { 1958 return (spa->spa_meta_objset); 1959 } 1960 1961 enum zio_checksum 1962 spa_dedup_checksum(spa_t *spa) 1963 { 1964 return (spa->spa_dedup_checksum); 1965 } 1966 1967 /* 1968 * Reset pool scan stat per scan pass (or reboot). 1969 */ 1970 void 1971 spa_scan_stat_init(spa_t *spa) 1972 { 1973 /* data not stored on disk */ 1974 spa->spa_scan_pass_start = gethrestime_sec(); 1975 spa->spa_scan_pass_exam = 0; 1976 vdev_scan_stat_init(spa->spa_root_vdev); 1977 } 1978 1979 /* 1980 * Get scan stats for zpool status reports 1981 */ 1982 int 1983 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) 1984 { 1985 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; 1986 1987 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) 1988 return (SET_ERROR(ENOENT)); 1989 bzero(ps, sizeof (pool_scan_stat_t)); 1990 1991 /* data stored on disk */ 1992 ps->pss_func = scn->scn_phys.scn_func; 1993 ps->pss_start_time = scn->scn_phys.scn_start_time; 1994 ps->pss_end_time = scn->scn_phys.scn_end_time; 1995 ps->pss_to_examine = scn->scn_phys.scn_to_examine; 1996 ps->pss_examined = scn->scn_phys.scn_examined; 1997 ps->pss_to_process = scn->scn_phys.scn_to_process; 1998 ps->pss_processed = scn->scn_phys.scn_processed; 1999 ps->pss_errors = scn->scn_phys.scn_errors; 2000 ps->pss_state = scn->scn_phys.scn_state; 2001 2002 /* data not stored on disk */ 2003 ps->pss_pass_start = spa->spa_scan_pass_start; 2004 ps->pss_pass_exam = spa->spa_scan_pass_exam; 2005 2006 return (0); 2007 } 2008 2009 boolean_t 2010 spa_debug_enabled(spa_t *spa) 2011 { 2012 return (spa->spa_debug); 2013 } 2014 2015 int 2016 spa_maxblocksize(spa_t *spa) 2017 { 2018 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) 2019 return (SPA_MAXBLOCKSIZE); 2020 else 2021 return (SPA_OLD_MAXBLOCKSIZE); 2022 } 2023