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, 2015 by Delphix. All rights reserved. 24 * Copyright 2015 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 26 * Copyright 2013 Saso Kiselkov. All rights reserved. 27 */ 28 29 #include <sys/zfs_context.h> 30 #include <sys/spa_impl.h> 31 #include <sys/spa_boot.h> 32 #include <sys/zio.h> 33 #include <sys/zio_checksum.h> 34 #include <sys/zio_compress.h> 35 #include <sys/dmu.h> 36 #include <sys/dmu_tx.h> 37 #include <sys/zap.h> 38 #include <sys/zil.h> 39 #include <sys/vdev_impl.h> 40 #include <sys/metaslab.h> 41 #include <sys/uberblock_impl.h> 42 #include <sys/txg.h> 43 #include <sys/avl.h> 44 #include <sys/unique.h> 45 #include <sys/dsl_pool.h> 46 #include <sys/dsl_dir.h> 47 #include <sys/dsl_prop.h> 48 #include <sys/dsl_scan.h> 49 #include <sys/fs/zfs.h> 50 #include <sys/metaslab_impl.h> 51 #include <sys/arc.h> 52 #include <sys/ddt.h> 53 #include "zfs_prop.h" 54 #include <sys/zfeature.h> 55 56 /* 57 * SPA locking 58 * 59 * There are four basic locks for managing spa_t structures: 60 * 61 * spa_namespace_lock (global mutex) 62 * 63 * This lock must be acquired to do any of the following: 64 * 65 * - Lookup a spa_t by name 66 * - Add or remove a spa_t from the namespace 67 * - Increase spa_refcount from non-zero 68 * - Check if spa_refcount is zero 69 * - Rename a spa_t 70 * - add/remove/attach/detach devices 71 * - Held for the duration of create/destroy/import/export 72 * 73 * It does not need to handle recursion. A create or destroy may 74 * reference objects (files or zvols) in other pools, but by 75 * definition they must have an existing reference, and will never need 76 * to lookup a spa_t by name. 77 * 78 * spa_refcount (per-spa refcount_t protected by mutex) 79 * 80 * This reference count keep track of any active users of the spa_t. The 81 * spa_t cannot be destroyed or freed while this is non-zero. Internally, 82 * the refcount is never really 'zero' - opening a pool implicitly keeps 83 * some references in the DMU. Internally we check against spa_minref, but 84 * present the image of a zero/non-zero value to consumers. 85 * 86 * spa_config_lock[] (per-spa array of rwlocks) 87 * 88 * This protects the spa_t from config changes, and must be held in 89 * the following circumstances: 90 * 91 * - RW_READER to perform I/O to the spa 92 * - RW_WRITER to change the vdev config 93 * 94 * The locking order is fairly straightforward: 95 * 96 * spa_namespace_lock -> spa_refcount 97 * 98 * The namespace lock must be acquired to increase the refcount from 0 99 * or to check if it is zero. 100 * 101 * spa_refcount -> spa_config_lock[] 102 * 103 * There must be at least one valid reference on the spa_t to acquire 104 * the config lock. 105 * 106 * spa_namespace_lock -> spa_config_lock[] 107 * 108 * The namespace lock must always be taken before the config lock. 109 * 110 * 111 * The spa_namespace_lock can be acquired directly and is globally visible. 112 * 113 * The namespace is manipulated using the following functions, all of which 114 * require the spa_namespace_lock to be held. 115 * 116 * spa_lookup() Lookup a spa_t by name. 117 * 118 * spa_add() Create a new spa_t in the namespace. 119 * 120 * spa_remove() Remove a spa_t from the namespace. This also 121 * frees up any memory associated with the spa_t. 122 * 123 * spa_next() Returns the next spa_t in the system, or the 124 * first if NULL is passed. 125 * 126 * spa_evict_all() Shutdown and remove all spa_t structures in 127 * the system. 128 * 129 * spa_guid_exists() Determine whether a pool/device guid exists. 130 * 131 * The spa_refcount is manipulated using the following functions: 132 * 133 * spa_open_ref() Adds a reference to the given spa_t. Must be 134 * called with spa_namespace_lock held if the 135 * refcount is currently zero. 136 * 137 * spa_close() Remove a reference from the spa_t. This will 138 * not free the spa_t or remove it from the 139 * namespace. No locking is required. 140 * 141 * spa_refcount_zero() Returns true if the refcount is currently 142 * zero. Must be called with spa_namespace_lock 143 * held. 144 * 145 * The spa_config_lock[] is an array of rwlocks, ordered as follows: 146 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV. 147 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}(). 148 * 149 * To read the configuration, it suffices to hold one of these locks as reader. 150 * To modify the configuration, you must hold all locks as writer. To modify 151 * vdev state without altering the vdev tree's topology (e.g. online/offline), 152 * you must hold SCL_STATE and SCL_ZIO as writer. 153 * 154 * We use these distinct config locks to avoid recursive lock entry. 155 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces 156 * block allocations (SCL_ALLOC), which may require reading space maps 157 * from disk (dmu_read() -> zio_read() -> SCL_ZIO). 158 * 159 * The spa config locks cannot be normal rwlocks because we need the 160 * ability to hand off ownership. For example, SCL_ZIO is acquired 161 * by the issuing thread and later released by an interrupt thread. 162 * They do, however, obey the usual write-wanted semantics to prevent 163 * writer (i.e. system administrator) starvation. 164 * 165 * The lock acquisition rules are as follows: 166 * 167 * SCL_CONFIG 168 * Protects changes to the vdev tree topology, such as vdev 169 * add/remove/attach/detach. Protects the dirty config list 170 * (spa_config_dirty_list) and the set of spares and l2arc devices. 171 * 172 * SCL_STATE 173 * Protects changes to pool state and vdev state, such as vdev 174 * online/offline/fault/degrade/clear. Protects the dirty state list 175 * (spa_state_dirty_list) and global pool state (spa_state). 176 * 177 * SCL_ALLOC 178 * Protects changes to metaslab groups and classes. 179 * Held as reader by metaslab_alloc() and metaslab_claim(). 180 * 181 * SCL_ZIO 182 * Held by bp-level zios (those which have no io_vd upon entry) 183 * to prevent changes to the vdev tree. The bp-level zio implicitly 184 * protects all of its vdev child zios, which do not hold SCL_ZIO. 185 * 186 * SCL_FREE 187 * Protects changes to metaslab groups and classes. 188 * Held as reader by metaslab_free(). SCL_FREE is distinct from 189 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free 190 * blocks in zio_done() while another i/o that holds either 191 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete. 192 * 193 * SCL_VDEV 194 * Held as reader to prevent changes to the vdev tree during trivial 195 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the 196 * other locks, and lower than all of them, to ensure that it's safe 197 * to acquire regardless of caller context. 198 * 199 * In addition, the following rules apply: 200 * 201 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list. 202 * The lock ordering is SCL_CONFIG > spa_props_lock. 203 * 204 * (b) I/O operations on leaf vdevs. For any zio operation that takes 205 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(), 206 * or zio_write_phys() -- the caller must ensure that the config cannot 207 * cannot change in the interim, and that the vdev cannot be reopened. 208 * SCL_STATE as reader suffices for both. 209 * 210 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit(). 211 * 212 * spa_vdev_enter() Acquire the namespace lock and the config lock 213 * for writing. 214 * 215 * spa_vdev_exit() Release the config lock, wait for all I/O 216 * to complete, sync the updated configs to the 217 * cache, and release the namespace lock. 218 * 219 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit(). 220 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual 221 * locking is, always, based on spa_namespace_lock and spa_config_lock[]. 222 * 223 * spa_rename() is also implemented within this file since it requires 224 * manipulation of the namespace. 225 */ 226 227 static avl_tree_t spa_namespace_avl; 228 kmutex_t spa_namespace_lock; 229 static kcondvar_t spa_namespace_cv; 230 static int spa_active_count; 231 int spa_max_replication_override = SPA_DVAS_PER_BP; 232 233 static kmutex_t spa_spare_lock; 234 static avl_tree_t spa_spare_avl; 235 static kmutex_t spa_l2cache_lock; 236 static avl_tree_t spa_l2cache_avl; 237 238 kmem_cache_t *spa_buffer_pool; 239 int spa_mode_global; 240 241 #ifdef ZFS_DEBUG 242 /* Everything except dprintf and spa is on by default in debug builds */ 243 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA); 244 #else 245 int zfs_flags = 0; 246 #endif 247 248 /* 249 * zfs_recover can be set to nonzero to attempt to recover from 250 * otherwise-fatal errors, typically caused by on-disk corruption. When 251 * set, calls to zfs_panic_recover() will turn into warning messages. 252 * This should only be used as a last resort, as it typically results 253 * in leaked space, or worse. 254 */ 255 boolean_t zfs_recover = B_FALSE; 256 257 /* 258 * If destroy encounters an EIO while reading metadata (e.g. indirect 259 * blocks), space referenced by the missing metadata can not be freed. 260 * Normally this causes the background destroy to become "stalled", as 261 * it is unable to make forward progress. While in this stalled state, 262 * all remaining space to free from the error-encountering filesystem is 263 * "temporarily leaked". Set this flag to cause it to ignore the EIO, 264 * permanently leak the space from indirect blocks that can not be read, 265 * and continue to free everything else that it can. 266 * 267 * The default, "stalling" behavior is useful if the storage partially 268 * fails (i.e. some but not all i/os fail), and then later recovers. In 269 * this case, we will be able to continue pool operations while it is 270 * partially failed, and when it recovers, we can continue to free the 271 * space, with no leaks. However, note that this case is actually 272 * fairly rare. 273 * 274 * Typically pools either (a) fail completely (but perhaps temporarily, 275 * e.g. a top-level vdev going offline), or (b) have localized, 276 * permanent errors (e.g. disk returns the wrong data due to bit flip or 277 * firmware bug). In case (a), this setting does not matter because the 278 * pool will be suspended and the sync thread will not be able to make 279 * forward progress regardless. In case (b), because the error is 280 * permanent, the best we can do is leak the minimum amount of space, 281 * which is what setting this flag will do. Therefore, it is reasonable 282 * for this flag to normally be set, but we chose the more conservative 283 * approach of not setting it, so that there is no possibility of 284 * leaking space in the "partial temporary" failure case. 285 */ 286 boolean_t zfs_free_leak_on_eio = B_FALSE; 287 288 /* 289 * Expiration time in milliseconds. This value has two meanings. First it is 290 * used to determine when the spa_deadman() logic should fire. By default the 291 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds. 292 * Secondly, the value determines if an I/O is considered "hung". Any I/O that 293 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting 294 * in a system panic. 295 */ 296 uint64_t zfs_deadman_synctime_ms = 1000000ULL; 297 298 /* 299 * Check time in milliseconds. This defines the frequency at which we check 300 * for hung I/O. 301 */ 302 uint64_t zfs_deadman_checktime_ms = 5000ULL; 303 304 /* 305 * Override the zfs deadman behavior via /etc/system. By default the 306 * deadman is enabled except on VMware and sparc deployments. 307 */ 308 int zfs_deadman_enabled = -1; 309 310 /* 311 * The worst case is single-sector max-parity RAID-Z blocks, in which 312 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1) 313 * times the size; so just assume that. Add to this the fact that 314 * we can have up to 3 DVAs per bp, and one more factor of 2 because 315 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together, 316 * the worst case is: 317 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24 318 */ 319 int spa_asize_inflation = 24; 320 321 /* 322 * Normally, we don't allow the last 3.2% (1/(2^spa_slop_shift)) of space in 323 * the pool to be consumed. This ensures that we don't run the pool 324 * completely out of space, due to unaccounted changes (e.g. to the MOS). 325 * It also limits the worst-case time to allocate space. If we have 326 * less than this amount of free space, most ZPL operations (e.g. write, 327 * create) will return ENOSPC. 328 * 329 * Certain operations (e.g. file removal, most administrative actions) can 330 * use half the slop space. They will only return ENOSPC if less than half 331 * the slop space is free. Typically, once the pool has less than the slop 332 * space free, the user will use these operations to free up space in the pool. 333 * These are the operations that call dsl_pool_adjustedsize() with the netfree 334 * argument set to TRUE. 335 * 336 * A very restricted set of operations are always permitted, regardless of 337 * the amount of free space. These are the operations that call 338 * dsl_sync_task(ZFS_SPACE_CHECK_NONE), e.g. "zfs destroy". If these 339 * operations result in a net increase in the amount of space used, 340 * it is possible to run the pool completely out of space, causing it to 341 * be permanently read-only. 342 * 343 * See also the comments in zfs_space_check_t. 344 */ 345 int spa_slop_shift = 5; 346 347 /* 348 * ========================================================================== 349 * SPA config locking 350 * ========================================================================== 351 */ 352 static void 353 spa_config_lock_init(spa_t *spa) 354 { 355 for (int i = 0; i < SCL_LOCKS; i++) { 356 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 357 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL); 358 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL); 359 refcount_create_untracked(&scl->scl_count); 360 scl->scl_writer = NULL; 361 scl->scl_write_wanted = 0; 362 } 363 } 364 365 static void 366 spa_config_lock_destroy(spa_t *spa) 367 { 368 for (int i = 0; i < SCL_LOCKS; i++) { 369 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 370 mutex_destroy(&scl->scl_lock); 371 cv_destroy(&scl->scl_cv); 372 refcount_destroy(&scl->scl_count); 373 ASSERT(scl->scl_writer == NULL); 374 ASSERT(scl->scl_write_wanted == 0); 375 } 376 } 377 378 int 379 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw) 380 { 381 for (int i = 0; i < SCL_LOCKS; i++) { 382 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 383 if (!(locks & (1 << i))) 384 continue; 385 mutex_enter(&scl->scl_lock); 386 if (rw == RW_READER) { 387 if (scl->scl_writer || scl->scl_write_wanted) { 388 mutex_exit(&scl->scl_lock); 389 spa_config_exit(spa, locks & ((1 << i) - 1), 390 tag); 391 return (0); 392 } 393 } else { 394 ASSERT(scl->scl_writer != curthread); 395 if (!refcount_is_zero(&scl->scl_count)) { 396 mutex_exit(&scl->scl_lock); 397 spa_config_exit(spa, locks & ((1 << i) - 1), 398 tag); 399 return (0); 400 } 401 scl->scl_writer = curthread; 402 } 403 (void) refcount_add(&scl->scl_count, tag); 404 mutex_exit(&scl->scl_lock); 405 } 406 return (1); 407 } 408 409 void 410 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw) 411 { 412 int wlocks_held = 0; 413 414 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY); 415 416 for (int i = 0; i < SCL_LOCKS; i++) { 417 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 418 if (scl->scl_writer == curthread) 419 wlocks_held |= (1 << i); 420 if (!(locks & (1 << i))) 421 continue; 422 mutex_enter(&scl->scl_lock); 423 if (rw == RW_READER) { 424 while (scl->scl_writer || scl->scl_write_wanted) { 425 cv_wait(&scl->scl_cv, &scl->scl_lock); 426 } 427 } else { 428 ASSERT(scl->scl_writer != curthread); 429 while (!refcount_is_zero(&scl->scl_count)) { 430 scl->scl_write_wanted++; 431 cv_wait(&scl->scl_cv, &scl->scl_lock); 432 scl->scl_write_wanted--; 433 } 434 scl->scl_writer = curthread; 435 } 436 (void) refcount_add(&scl->scl_count, tag); 437 mutex_exit(&scl->scl_lock); 438 } 439 ASSERT(wlocks_held <= locks); 440 } 441 442 void 443 spa_config_exit(spa_t *spa, int locks, void *tag) 444 { 445 for (int i = SCL_LOCKS - 1; i >= 0; i--) { 446 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 447 if (!(locks & (1 << i))) 448 continue; 449 mutex_enter(&scl->scl_lock); 450 ASSERT(!refcount_is_zero(&scl->scl_count)); 451 if (refcount_remove(&scl->scl_count, tag) == 0) { 452 ASSERT(scl->scl_writer == NULL || 453 scl->scl_writer == curthread); 454 scl->scl_writer = NULL; /* OK in either case */ 455 cv_broadcast(&scl->scl_cv); 456 } 457 mutex_exit(&scl->scl_lock); 458 } 459 } 460 461 int 462 spa_config_held(spa_t *spa, int locks, krw_t rw) 463 { 464 int locks_held = 0; 465 466 for (int i = 0; i < SCL_LOCKS; i++) { 467 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 468 if (!(locks & (1 << i))) 469 continue; 470 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) || 471 (rw == RW_WRITER && scl->scl_writer == curthread)) 472 locks_held |= 1 << i; 473 } 474 475 return (locks_held); 476 } 477 478 /* 479 * ========================================================================== 480 * SPA namespace functions 481 * ========================================================================== 482 */ 483 484 /* 485 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. 486 * Returns NULL if no matching spa_t is found. 487 */ 488 spa_t * 489 spa_lookup(const char *name) 490 { 491 static spa_t search; /* spa_t is large; don't allocate on stack */ 492 spa_t *spa; 493 avl_index_t where; 494 char *cp; 495 496 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 497 498 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name)); 499 500 /* 501 * If it's a full dataset name, figure out the pool name and 502 * just use that. 503 */ 504 cp = strpbrk(search.spa_name, "/@#"); 505 if (cp != NULL) 506 *cp = '\0'; 507 508 spa = avl_find(&spa_namespace_avl, &search, &where); 509 510 return (spa); 511 } 512 513 /* 514 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms. 515 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues 516 * looking for potentially hung I/Os. 517 */ 518 void 519 spa_deadman(void *arg) 520 { 521 spa_t *spa = arg; 522 523 /* 524 * Disable the deadman timer if the pool is suspended. 525 */ 526 if (spa_suspended(spa)) { 527 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY)); 528 return; 529 } 530 531 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu", 532 (gethrtime() - spa->spa_sync_starttime) / NANOSEC, 533 ++spa->spa_deadman_calls); 534 if (zfs_deadman_enabled) 535 vdev_deadman(spa->spa_root_vdev); 536 } 537 538 /* 539 * Create an uninitialized spa_t with the given name. Requires 540 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already 541 * exist by calling spa_lookup() first. 542 */ 543 spa_t * 544 spa_add(const char *name, nvlist_t *config, const char *altroot) 545 { 546 spa_t *spa; 547 spa_config_dirent_t *dp; 548 cyc_handler_t hdlr; 549 cyc_time_t when; 550 551 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 552 553 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); 554 555 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL); 556 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL); 557 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL); 558 mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL); 559 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL); 560 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL); 561 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL); 562 mutex_init(&spa->spa_cksum_tmpls_lock, NULL, MUTEX_DEFAULT, NULL); 563 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL); 564 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL); 565 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL); 566 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL); 567 568 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL); 569 cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL); 570 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL); 571 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL); 572 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL); 573 574 for (int t = 0; t < TXG_SIZE; t++) 575 bplist_create(&spa->spa_free_bplist[t]); 576 577 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name)); 578 spa->spa_state = POOL_STATE_UNINITIALIZED; 579 spa->spa_freeze_txg = UINT64_MAX; 580 spa->spa_final_txg = UINT64_MAX; 581 spa->spa_load_max_txg = UINT64_MAX; 582 spa->spa_proc = &p0; 583 spa->spa_proc_state = SPA_PROC_NONE; 584 585 hdlr.cyh_func = spa_deadman; 586 hdlr.cyh_arg = spa; 587 hdlr.cyh_level = CY_LOW_LEVEL; 588 589 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms); 590 591 /* 592 * This determines how often we need to check for hung I/Os after 593 * the cyclic has already fired. Since checking for hung I/Os is 594 * an expensive operation we don't want to check too frequently. 595 * Instead wait for 5 seconds before checking again. 596 */ 597 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms); 598 when.cyt_when = CY_INFINITY; 599 mutex_enter(&cpu_lock); 600 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when); 601 mutex_exit(&cpu_lock); 602 603 refcount_create(&spa->spa_refcount); 604 spa_config_lock_init(spa); 605 606 avl_add(&spa_namespace_avl, spa); 607 608 /* 609 * Set the alternate root, if there is one. 610 */ 611 if (altroot) { 612 spa->spa_root = spa_strdup(altroot); 613 spa_active_count++; 614 } 615 616 /* 617 * Every pool starts with the default cachefile 618 */ 619 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t), 620 offsetof(spa_config_dirent_t, scd_link)); 621 622 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP); 623 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path); 624 list_insert_head(&spa->spa_config_list, dp); 625 626 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME, 627 KM_SLEEP) == 0); 628 629 if (config != NULL) { 630 nvlist_t *features; 631 632 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 633 &features) == 0) { 634 VERIFY(nvlist_dup(features, &spa->spa_label_features, 635 0) == 0); 636 } 637 638 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0); 639 } 640 641 if (spa->spa_label_features == NULL) { 642 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME, 643 KM_SLEEP) == 0); 644 } 645 646 spa->spa_iokstat = kstat_create("zfs", 0, name, 647 "disk", KSTAT_TYPE_IO, 1, 0); 648 if (spa->spa_iokstat) { 649 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock; 650 kstat_install(spa->spa_iokstat); 651 } 652 653 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0); 654 655 spa->spa_min_ashift = INT_MAX; 656 spa->spa_max_ashift = 0; 657 658 /* 659 * As a pool is being created, treat all features as disabled by 660 * setting SPA_FEATURE_DISABLED for all entries in the feature 661 * refcount cache. 662 */ 663 for (int i = 0; i < SPA_FEATURES; i++) { 664 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED; 665 } 666 667 return (spa); 668 } 669 670 /* 671 * Removes a spa_t from the namespace, freeing up any memory used. Requires 672 * spa_namespace_lock. This is called only after the spa_t has been closed and 673 * deactivated. 674 */ 675 void 676 spa_remove(spa_t *spa) 677 { 678 spa_config_dirent_t *dp; 679 680 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 681 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 682 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0); 683 684 nvlist_free(spa->spa_config_splitting); 685 686 avl_remove(&spa_namespace_avl, spa); 687 cv_broadcast(&spa_namespace_cv); 688 689 if (spa->spa_root) { 690 spa_strfree(spa->spa_root); 691 spa_active_count--; 692 } 693 694 while ((dp = list_head(&spa->spa_config_list)) != NULL) { 695 list_remove(&spa->spa_config_list, dp); 696 if (dp->scd_path != NULL) 697 spa_strfree(dp->scd_path); 698 kmem_free(dp, sizeof (spa_config_dirent_t)); 699 } 700 701 list_destroy(&spa->spa_config_list); 702 703 nvlist_free(spa->spa_label_features); 704 nvlist_free(spa->spa_load_info); 705 spa_config_set(spa, NULL); 706 707 mutex_enter(&cpu_lock); 708 if (spa->spa_deadman_cycid != CYCLIC_NONE) 709 cyclic_remove(spa->spa_deadman_cycid); 710 mutex_exit(&cpu_lock); 711 spa->spa_deadman_cycid = CYCLIC_NONE; 712 713 refcount_destroy(&spa->spa_refcount); 714 715 spa_config_lock_destroy(spa); 716 717 kstat_delete(spa->spa_iokstat); 718 spa->spa_iokstat = NULL; 719 720 for (int t = 0; t < TXG_SIZE; t++) 721 bplist_destroy(&spa->spa_free_bplist[t]); 722 723 zio_checksum_templates_free(spa); 724 725 cv_destroy(&spa->spa_async_cv); 726 cv_destroy(&spa->spa_evicting_os_cv); 727 cv_destroy(&spa->spa_proc_cv); 728 cv_destroy(&spa->spa_scrub_io_cv); 729 cv_destroy(&spa->spa_suspend_cv); 730 731 mutex_destroy(&spa->spa_async_lock); 732 mutex_destroy(&spa->spa_errlist_lock); 733 mutex_destroy(&spa->spa_errlog_lock); 734 mutex_destroy(&spa->spa_evicting_os_lock); 735 mutex_destroy(&spa->spa_history_lock); 736 mutex_destroy(&spa->spa_proc_lock); 737 mutex_destroy(&spa->spa_props_lock); 738 mutex_destroy(&spa->spa_cksum_tmpls_lock); 739 mutex_destroy(&spa->spa_scrub_lock); 740 mutex_destroy(&spa->spa_suspend_lock); 741 mutex_destroy(&spa->spa_vdev_top_lock); 742 mutex_destroy(&spa->spa_iokstat_lock); 743 744 kmem_free(spa, sizeof (spa_t)); 745 } 746 747 /* 748 * Given a pool, return the next pool in the namespace, or NULL if there is 749 * none. If 'prev' is NULL, return the first pool. 750 */ 751 spa_t * 752 spa_next(spa_t *prev) 753 { 754 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 755 756 if (prev) 757 return (AVL_NEXT(&spa_namespace_avl, prev)); 758 else 759 return (avl_first(&spa_namespace_avl)); 760 } 761 762 /* 763 * ========================================================================== 764 * SPA refcount functions 765 * ========================================================================== 766 */ 767 768 /* 769 * Add a reference to the given spa_t. Must have at least one reference, or 770 * have the namespace lock held. 771 */ 772 void 773 spa_open_ref(spa_t *spa, void *tag) 774 { 775 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || 776 MUTEX_HELD(&spa_namespace_lock)); 777 (void) refcount_add(&spa->spa_refcount, tag); 778 } 779 780 /* 781 * Remove a reference to the given spa_t. Must have at least one reference, or 782 * have the namespace lock held. 783 */ 784 void 785 spa_close(spa_t *spa, void *tag) 786 { 787 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || 788 MUTEX_HELD(&spa_namespace_lock)); 789 (void) refcount_remove(&spa->spa_refcount, tag); 790 } 791 792 /* 793 * Remove a reference to the given spa_t held by a dsl dir that is 794 * being asynchronously released. Async releases occur from a taskq 795 * performing eviction of dsl datasets and dirs. The namespace lock 796 * isn't held and the hold by the object being evicted may contribute to 797 * spa_minref (e.g. dataset or directory released during pool export), 798 * so the asserts in spa_close() do not apply. 799 */ 800 void 801 spa_async_close(spa_t *spa, void *tag) 802 { 803 (void) refcount_remove(&spa->spa_refcount, tag); 804 } 805 806 /* 807 * Check to see if the spa refcount is zero. Must be called with 808 * spa_namespace_lock held. We really compare against spa_minref, which is the 809 * number of references acquired when opening a pool 810 */ 811 boolean_t 812 spa_refcount_zero(spa_t *spa) 813 { 814 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 815 816 return (refcount_count(&spa->spa_refcount) == spa->spa_minref); 817 } 818 819 /* 820 * ========================================================================== 821 * SPA spare and l2cache tracking 822 * ========================================================================== 823 */ 824 825 /* 826 * Hot spares and cache devices are tracked using the same code below, 827 * for 'auxiliary' devices. 828 */ 829 830 typedef struct spa_aux { 831 uint64_t aux_guid; 832 uint64_t aux_pool; 833 avl_node_t aux_avl; 834 int aux_count; 835 } spa_aux_t; 836 837 static int 838 spa_aux_compare(const void *a, const void *b) 839 { 840 const spa_aux_t *sa = a; 841 const spa_aux_t *sb = b; 842 843 if (sa->aux_guid < sb->aux_guid) 844 return (-1); 845 else if (sa->aux_guid > sb->aux_guid) 846 return (1); 847 else 848 return (0); 849 } 850 851 void 852 spa_aux_add(vdev_t *vd, avl_tree_t *avl) 853 { 854 avl_index_t where; 855 spa_aux_t search; 856 spa_aux_t *aux; 857 858 search.aux_guid = vd->vdev_guid; 859 if ((aux = avl_find(avl, &search, &where)) != NULL) { 860 aux->aux_count++; 861 } else { 862 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); 863 aux->aux_guid = vd->vdev_guid; 864 aux->aux_count = 1; 865 avl_insert(avl, aux, where); 866 } 867 } 868 869 void 870 spa_aux_remove(vdev_t *vd, avl_tree_t *avl) 871 { 872 spa_aux_t search; 873 spa_aux_t *aux; 874 avl_index_t where; 875 876 search.aux_guid = vd->vdev_guid; 877 aux = avl_find(avl, &search, &where); 878 879 ASSERT(aux != NULL); 880 881 if (--aux->aux_count == 0) { 882 avl_remove(avl, aux); 883 kmem_free(aux, sizeof (spa_aux_t)); 884 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { 885 aux->aux_pool = 0ULL; 886 } 887 } 888 889 boolean_t 890 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) 891 { 892 spa_aux_t search, *found; 893 894 search.aux_guid = guid; 895 found = avl_find(avl, &search, NULL); 896 897 if (pool) { 898 if (found) 899 *pool = found->aux_pool; 900 else 901 *pool = 0ULL; 902 } 903 904 if (refcnt) { 905 if (found) 906 *refcnt = found->aux_count; 907 else 908 *refcnt = 0; 909 } 910 911 return (found != NULL); 912 } 913 914 void 915 spa_aux_activate(vdev_t *vd, avl_tree_t *avl) 916 { 917 spa_aux_t search, *found; 918 avl_index_t where; 919 920 search.aux_guid = vd->vdev_guid; 921 found = avl_find(avl, &search, &where); 922 ASSERT(found != NULL); 923 ASSERT(found->aux_pool == 0ULL); 924 925 found->aux_pool = spa_guid(vd->vdev_spa); 926 } 927 928 /* 929 * Spares are tracked globally due to the following constraints: 930 * 931 * - A spare may be part of multiple pools. 932 * - A spare may be added to a pool even if it's actively in use within 933 * another pool. 934 * - A spare in use in any pool can only be the source of a replacement if 935 * the target is a spare in the same pool. 936 * 937 * We keep track of all spares on the system through the use of a reference 938 * counted AVL tree. When a vdev is added as a spare, or used as a replacement 939 * spare, then we bump the reference count in the AVL tree. In addition, we set 940 * the 'vdev_isspare' member to indicate that the device is a spare (active or 941 * inactive). When a spare is made active (used to replace a device in the 942 * pool), we also keep track of which pool its been made a part of. 943 * 944 * The 'spa_spare_lock' protects the AVL tree. These functions are normally 945 * called under the spa_namespace lock as part of vdev reconfiguration. The 946 * separate spare lock exists for the status query path, which does not need to 947 * be completely consistent with respect to other vdev configuration changes. 948 */ 949 950 static int 951 spa_spare_compare(const void *a, const void *b) 952 { 953 return (spa_aux_compare(a, b)); 954 } 955 956 void 957 spa_spare_add(vdev_t *vd) 958 { 959 mutex_enter(&spa_spare_lock); 960 ASSERT(!vd->vdev_isspare); 961 spa_aux_add(vd, &spa_spare_avl); 962 vd->vdev_isspare = B_TRUE; 963 mutex_exit(&spa_spare_lock); 964 } 965 966 void 967 spa_spare_remove(vdev_t *vd) 968 { 969 mutex_enter(&spa_spare_lock); 970 ASSERT(vd->vdev_isspare); 971 spa_aux_remove(vd, &spa_spare_avl); 972 vd->vdev_isspare = B_FALSE; 973 mutex_exit(&spa_spare_lock); 974 } 975 976 boolean_t 977 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) 978 { 979 boolean_t found; 980 981 mutex_enter(&spa_spare_lock); 982 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); 983 mutex_exit(&spa_spare_lock); 984 985 return (found); 986 } 987 988 void 989 spa_spare_activate(vdev_t *vd) 990 { 991 mutex_enter(&spa_spare_lock); 992 ASSERT(vd->vdev_isspare); 993 spa_aux_activate(vd, &spa_spare_avl); 994 mutex_exit(&spa_spare_lock); 995 } 996 997 /* 998 * Level 2 ARC devices are tracked globally for the same reasons as spares. 999 * Cache devices currently only support one pool per cache device, and so 1000 * for these devices the aux reference count is currently unused beyond 1. 1001 */ 1002 1003 static int 1004 spa_l2cache_compare(const void *a, const void *b) 1005 { 1006 return (spa_aux_compare(a, b)); 1007 } 1008 1009 void 1010 spa_l2cache_add(vdev_t *vd) 1011 { 1012 mutex_enter(&spa_l2cache_lock); 1013 ASSERT(!vd->vdev_isl2cache); 1014 spa_aux_add(vd, &spa_l2cache_avl); 1015 vd->vdev_isl2cache = B_TRUE; 1016 mutex_exit(&spa_l2cache_lock); 1017 } 1018 1019 void 1020 spa_l2cache_remove(vdev_t *vd) 1021 { 1022 mutex_enter(&spa_l2cache_lock); 1023 ASSERT(vd->vdev_isl2cache); 1024 spa_aux_remove(vd, &spa_l2cache_avl); 1025 vd->vdev_isl2cache = B_FALSE; 1026 mutex_exit(&spa_l2cache_lock); 1027 } 1028 1029 boolean_t 1030 spa_l2cache_exists(uint64_t guid, uint64_t *pool) 1031 { 1032 boolean_t found; 1033 1034 mutex_enter(&spa_l2cache_lock); 1035 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); 1036 mutex_exit(&spa_l2cache_lock); 1037 1038 return (found); 1039 } 1040 1041 void 1042 spa_l2cache_activate(vdev_t *vd) 1043 { 1044 mutex_enter(&spa_l2cache_lock); 1045 ASSERT(vd->vdev_isl2cache); 1046 spa_aux_activate(vd, &spa_l2cache_avl); 1047 mutex_exit(&spa_l2cache_lock); 1048 } 1049 1050 /* 1051 * ========================================================================== 1052 * SPA vdev locking 1053 * ========================================================================== 1054 */ 1055 1056 /* 1057 * Lock the given spa_t for the purpose of adding or removing a vdev. 1058 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 1059 * It returns the next transaction group for the spa_t. 1060 */ 1061 uint64_t 1062 spa_vdev_enter(spa_t *spa) 1063 { 1064 mutex_enter(&spa->spa_vdev_top_lock); 1065 mutex_enter(&spa_namespace_lock); 1066 return (spa_vdev_config_enter(spa)); 1067 } 1068 1069 /* 1070 * Internal implementation for spa_vdev_enter(). Used when a vdev 1071 * operation requires multiple syncs (i.e. removing a device) while 1072 * keeping the spa_namespace_lock held. 1073 */ 1074 uint64_t 1075 spa_vdev_config_enter(spa_t *spa) 1076 { 1077 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1078 1079 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1080 1081 return (spa_last_synced_txg(spa) + 1); 1082 } 1083 1084 /* 1085 * Used in combination with spa_vdev_config_enter() to allow the syncing 1086 * of multiple transactions without releasing the spa_namespace_lock. 1087 */ 1088 void 1089 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) 1090 { 1091 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1092 1093 int config_changed = B_FALSE; 1094 1095 ASSERT(txg > spa_last_synced_txg(spa)); 1096 1097 spa->spa_pending_vdev = NULL; 1098 1099 /* 1100 * Reassess the DTLs. 1101 */ 1102 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 1103 1104 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { 1105 config_changed = B_TRUE; 1106 spa->spa_config_generation++; 1107 } 1108 1109 /* 1110 * Verify the metaslab classes. 1111 */ 1112 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); 1113 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); 1114 1115 spa_config_exit(spa, SCL_ALL, spa); 1116 1117 /* 1118 * Panic the system if the specified tag requires it. This 1119 * is useful for ensuring that configurations are updated 1120 * transactionally. 1121 */ 1122 if (zio_injection_enabled) 1123 zio_handle_panic_injection(spa, tag, 0); 1124 1125 /* 1126 * Note: this txg_wait_synced() is important because it ensures 1127 * that there won't be more than one config change per txg. 1128 * This allows us to use the txg as the generation number. 1129 */ 1130 if (error == 0) 1131 txg_wait_synced(spa->spa_dsl_pool, txg); 1132 1133 if (vd != NULL) { 1134 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL); 1135 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1136 vdev_free(vd); 1137 spa_config_exit(spa, SCL_ALL, spa); 1138 } 1139 1140 /* 1141 * If the config changed, update the config cache. 1142 */ 1143 if (config_changed) 1144 spa_config_sync(spa, B_FALSE, B_TRUE); 1145 } 1146 1147 /* 1148 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 1149 * locking of spa_vdev_enter(), we also want make sure the transactions have 1150 * synced to disk, and then update the global configuration cache with the new 1151 * information. 1152 */ 1153 int 1154 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 1155 { 1156 spa_vdev_config_exit(spa, vd, txg, error, FTAG); 1157 mutex_exit(&spa_namespace_lock); 1158 mutex_exit(&spa->spa_vdev_top_lock); 1159 1160 return (error); 1161 } 1162 1163 /* 1164 * Lock the given spa_t for the purpose of changing vdev state. 1165 */ 1166 void 1167 spa_vdev_state_enter(spa_t *spa, int oplocks) 1168 { 1169 int locks = SCL_STATE_ALL | oplocks; 1170 1171 /* 1172 * Root pools may need to read of the underlying devfs filesystem 1173 * when opening up a vdev. Unfortunately if we're holding the 1174 * SCL_ZIO lock it will result in a deadlock when we try to issue 1175 * the read from the root filesystem. Instead we "prefetch" 1176 * the associated vnodes that we need prior to opening the 1177 * underlying devices and cache them so that we can prevent 1178 * any I/O when we are doing the actual open. 1179 */ 1180 if (spa_is_root(spa)) { 1181 int low = locks & ~(SCL_ZIO - 1); 1182 int high = locks & ~low; 1183 1184 spa_config_enter(spa, high, spa, RW_WRITER); 1185 vdev_hold(spa->spa_root_vdev); 1186 spa_config_enter(spa, low, spa, RW_WRITER); 1187 } else { 1188 spa_config_enter(spa, locks, spa, RW_WRITER); 1189 } 1190 spa->spa_vdev_locks = locks; 1191 } 1192 1193 int 1194 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) 1195 { 1196 boolean_t config_changed = B_FALSE; 1197 1198 if (vd != NULL || error == 0) 1199 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, 1200 0, 0, B_FALSE); 1201 1202 if (vd != NULL) { 1203 vdev_state_dirty(vd->vdev_top); 1204 config_changed = B_TRUE; 1205 spa->spa_config_generation++; 1206 } 1207 1208 if (spa_is_root(spa)) 1209 vdev_rele(spa->spa_root_vdev); 1210 1211 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); 1212 spa_config_exit(spa, spa->spa_vdev_locks, spa); 1213 1214 /* 1215 * If anything changed, wait for it to sync. This ensures that, 1216 * from the system administrator's perspective, zpool(1M) commands 1217 * are synchronous. This is important for things like zpool offline: 1218 * when the command completes, you expect no further I/O from ZFS. 1219 */ 1220 if (vd != NULL) 1221 txg_wait_synced(spa->spa_dsl_pool, 0); 1222 1223 /* 1224 * If the config changed, update the config cache. 1225 */ 1226 if (config_changed) { 1227 mutex_enter(&spa_namespace_lock); 1228 spa_config_sync(spa, B_FALSE, B_TRUE); 1229 mutex_exit(&spa_namespace_lock); 1230 } 1231 1232 return (error); 1233 } 1234 1235 /* 1236 * ========================================================================== 1237 * Miscellaneous functions 1238 * ========================================================================== 1239 */ 1240 1241 void 1242 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx) 1243 { 1244 if (!nvlist_exists(spa->spa_label_features, feature)) { 1245 fnvlist_add_boolean(spa->spa_label_features, feature); 1246 /* 1247 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't 1248 * dirty the vdev config because lock SCL_CONFIG is not held. 1249 * Thankfully, in this case we don't need to dirty the config 1250 * because it will be written out anyway when we finish 1251 * creating the pool. 1252 */ 1253 if (tx->tx_txg != TXG_INITIAL) 1254 vdev_config_dirty(spa->spa_root_vdev); 1255 } 1256 } 1257 1258 void 1259 spa_deactivate_mos_feature(spa_t *spa, const char *feature) 1260 { 1261 if (nvlist_remove_all(spa->spa_label_features, feature) == 0) 1262 vdev_config_dirty(spa->spa_root_vdev); 1263 } 1264 1265 /* 1266 * Rename a spa_t. 1267 */ 1268 int 1269 spa_rename(const char *name, const char *newname) 1270 { 1271 spa_t *spa; 1272 int err; 1273 1274 /* 1275 * Lookup the spa_t and grab the config lock for writing. We need to 1276 * actually open the pool so that we can sync out the necessary labels. 1277 * It's OK to call spa_open() with the namespace lock held because we 1278 * allow recursive calls for other reasons. 1279 */ 1280 mutex_enter(&spa_namespace_lock); 1281 if ((err = spa_open(name, &spa, FTAG)) != 0) { 1282 mutex_exit(&spa_namespace_lock); 1283 return (err); 1284 } 1285 1286 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1287 1288 avl_remove(&spa_namespace_avl, spa); 1289 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); 1290 avl_add(&spa_namespace_avl, spa); 1291 1292 /* 1293 * Sync all labels to disk with the new names by marking the root vdev 1294 * dirty and waiting for it to sync. It will pick up the new pool name 1295 * during the sync. 1296 */ 1297 vdev_config_dirty(spa->spa_root_vdev); 1298 1299 spa_config_exit(spa, SCL_ALL, FTAG); 1300 1301 txg_wait_synced(spa->spa_dsl_pool, 0); 1302 1303 /* 1304 * Sync the updated config cache. 1305 */ 1306 spa_config_sync(spa, B_FALSE, B_TRUE); 1307 1308 spa_close(spa, FTAG); 1309 1310 mutex_exit(&spa_namespace_lock); 1311 1312 return (0); 1313 } 1314 1315 /* 1316 * Return the spa_t associated with given pool_guid, if it exists. If 1317 * device_guid is non-zero, determine whether the pool exists *and* contains 1318 * a device with the specified device_guid. 1319 */ 1320 spa_t * 1321 spa_by_guid(uint64_t pool_guid, uint64_t device_guid) 1322 { 1323 spa_t *spa; 1324 avl_tree_t *t = &spa_namespace_avl; 1325 1326 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1327 1328 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 1329 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 1330 continue; 1331 if (spa->spa_root_vdev == NULL) 1332 continue; 1333 if (spa_guid(spa) == pool_guid) { 1334 if (device_guid == 0) 1335 break; 1336 1337 if (vdev_lookup_by_guid(spa->spa_root_vdev, 1338 device_guid) != NULL) 1339 break; 1340 1341 /* 1342 * Check any devices we may be in the process of adding. 1343 */ 1344 if (spa->spa_pending_vdev) { 1345 if (vdev_lookup_by_guid(spa->spa_pending_vdev, 1346 device_guid) != NULL) 1347 break; 1348 } 1349 } 1350 } 1351 1352 return (spa); 1353 } 1354 1355 /* 1356 * Determine whether a pool with the given pool_guid exists. 1357 */ 1358 boolean_t 1359 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 1360 { 1361 return (spa_by_guid(pool_guid, device_guid) != NULL); 1362 } 1363 1364 char * 1365 spa_strdup(const char *s) 1366 { 1367 size_t len; 1368 char *new; 1369 1370 len = strlen(s); 1371 new = kmem_alloc(len + 1, KM_SLEEP); 1372 bcopy(s, new, len); 1373 new[len] = '\0'; 1374 1375 return (new); 1376 } 1377 1378 void 1379 spa_strfree(char *s) 1380 { 1381 kmem_free(s, strlen(s) + 1); 1382 } 1383 1384 uint64_t 1385 spa_get_random(uint64_t range) 1386 { 1387 uint64_t r; 1388 1389 ASSERT(range != 0); 1390 1391 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 1392 1393 return (r % range); 1394 } 1395 1396 uint64_t 1397 spa_generate_guid(spa_t *spa) 1398 { 1399 uint64_t guid = spa_get_random(-1ULL); 1400 1401 if (spa != NULL) { 1402 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) 1403 guid = spa_get_random(-1ULL); 1404 } else { 1405 while (guid == 0 || spa_guid_exists(guid, 0)) 1406 guid = spa_get_random(-1ULL); 1407 } 1408 1409 return (guid); 1410 } 1411 1412 void 1413 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp) 1414 { 1415 char type[256]; 1416 char *checksum = NULL; 1417 char *compress = NULL; 1418 1419 if (bp != NULL) { 1420 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) { 1421 dmu_object_byteswap_t bswap = 1422 DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); 1423 (void) snprintf(type, sizeof (type), "bswap %s %s", 1424 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ? 1425 "metadata" : "data", 1426 dmu_ot_byteswap[bswap].ob_name); 1427 } else { 1428 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name, 1429 sizeof (type)); 1430 } 1431 if (!BP_IS_EMBEDDED(bp)) { 1432 checksum = 1433 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; 1434 } 1435 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; 1436 } 1437 1438 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum, 1439 compress); 1440 } 1441 1442 void 1443 spa_freeze(spa_t *spa) 1444 { 1445 uint64_t freeze_txg = 0; 1446 1447 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1448 if (spa->spa_freeze_txg == UINT64_MAX) { 1449 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 1450 spa->spa_freeze_txg = freeze_txg; 1451 } 1452 spa_config_exit(spa, SCL_ALL, FTAG); 1453 if (freeze_txg != 0) 1454 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 1455 } 1456 1457 void 1458 zfs_panic_recover(const char *fmt, ...) 1459 { 1460 va_list adx; 1461 1462 va_start(adx, fmt); 1463 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); 1464 va_end(adx); 1465 } 1466 1467 /* 1468 * This is a stripped-down version of strtoull, suitable only for converting 1469 * lowercase hexadecimal numbers that don't overflow. 1470 */ 1471 uint64_t 1472 strtonum(const char *str, char **nptr) 1473 { 1474 uint64_t val = 0; 1475 char c; 1476 int digit; 1477 1478 while ((c = *str) != '\0') { 1479 if (c >= '0' && c <= '9') 1480 digit = c - '0'; 1481 else if (c >= 'a' && c <= 'f') 1482 digit = 10 + c - 'a'; 1483 else 1484 break; 1485 1486 val *= 16; 1487 val += digit; 1488 1489 str++; 1490 } 1491 1492 if (nptr) 1493 *nptr = (char *)str; 1494 1495 return (val); 1496 } 1497 1498 /* 1499 * ========================================================================== 1500 * Accessor functions 1501 * ========================================================================== 1502 */ 1503 1504 boolean_t 1505 spa_shutting_down(spa_t *spa) 1506 { 1507 return (spa->spa_async_suspended); 1508 } 1509 1510 dsl_pool_t * 1511 spa_get_dsl(spa_t *spa) 1512 { 1513 return (spa->spa_dsl_pool); 1514 } 1515 1516 boolean_t 1517 spa_is_initializing(spa_t *spa) 1518 { 1519 return (spa->spa_is_initializing); 1520 } 1521 1522 blkptr_t * 1523 spa_get_rootblkptr(spa_t *spa) 1524 { 1525 return (&spa->spa_ubsync.ub_rootbp); 1526 } 1527 1528 void 1529 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 1530 { 1531 spa->spa_uberblock.ub_rootbp = *bp; 1532 } 1533 1534 void 1535 spa_altroot(spa_t *spa, char *buf, size_t buflen) 1536 { 1537 if (spa->spa_root == NULL) 1538 buf[0] = '\0'; 1539 else 1540 (void) strncpy(buf, spa->spa_root, buflen); 1541 } 1542 1543 int 1544 spa_sync_pass(spa_t *spa) 1545 { 1546 return (spa->spa_sync_pass); 1547 } 1548 1549 char * 1550 spa_name(spa_t *spa) 1551 { 1552 return (spa->spa_name); 1553 } 1554 1555 uint64_t 1556 spa_guid(spa_t *spa) 1557 { 1558 dsl_pool_t *dp = spa_get_dsl(spa); 1559 uint64_t guid; 1560 1561 /* 1562 * If we fail to parse the config during spa_load(), we can go through 1563 * the error path (which posts an ereport) and end up here with no root 1564 * vdev. We stash the original pool guid in 'spa_config_guid' to handle 1565 * this case. 1566 */ 1567 if (spa->spa_root_vdev == NULL) 1568 return (spa->spa_config_guid); 1569 1570 guid = spa->spa_last_synced_guid != 0 ? 1571 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid; 1572 1573 /* 1574 * Return the most recently synced out guid unless we're 1575 * in syncing context. 1576 */ 1577 if (dp && dsl_pool_sync_context(dp)) 1578 return (spa->spa_root_vdev->vdev_guid); 1579 else 1580 return (guid); 1581 } 1582 1583 uint64_t 1584 spa_load_guid(spa_t *spa) 1585 { 1586 /* 1587 * This is a GUID that exists solely as a reference for the 1588 * purposes of the arc. It is generated at load time, and 1589 * is never written to persistent storage. 1590 */ 1591 return (spa->spa_load_guid); 1592 } 1593 1594 uint64_t 1595 spa_last_synced_txg(spa_t *spa) 1596 { 1597 return (spa->spa_ubsync.ub_txg); 1598 } 1599 1600 uint64_t 1601 spa_first_txg(spa_t *spa) 1602 { 1603 return (spa->spa_first_txg); 1604 } 1605 1606 uint64_t 1607 spa_syncing_txg(spa_t *spa) 1608 { 1609 return (spa->spa_syncing_txg); 1610 } 1611 1612 pool_state_t 1613 spa_state(spa_t *spa) 1614 { 1615 return (spa->spa_state); 1616 } 1617 1618 spa_load_state_t 1619 spa_load_state(spa_t *spa) 1620 { 1621 return (spa->spa_load_state); 1622 } 1623 1624 uint64_t 1625 spa_freeze_txg(spa_t *spa) 1626 { 1627 return (spa->spa_freeze_txg); 1628 } 1629 1630 /* ARGSUSED */ 1631 uint64_t 1632 spa_get_asize(spa_t *spa, uint64_t lsize) 1633 { 1634 return (lsize * spa_asize_inflation); 1635 } 1636 1637 /* 1638 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%), 1639 * or at least 32MB. 1640 * 1641 * See the comment above spa_slop_shift for details. 1642 */ 1643 uint64_t 1644 spa_get_slop_space(spa_t *spa) { 1645 uint64_t space = spa_get_dspace(spa); 1646 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1)); 1647 } 1648 1649 uint64_t 1650 spa_get_dspace(spa_t *spa) 1651 { 1652 return (spa->spa_dspace); 1653 } 1654 1655 void 1656 spa_update_dspace(spa_t *spa) 1657 { 1658 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + 1659 ddt_get_dedup_dspace(spa); 1660 } 1661 1662 /* 1663 * Return the failure mode that has been set to this pool. The default 1664 * behavior will be to block all I/Os when a complete failure occurs. 1665 */ 1666 uint8_t 1667 spa_get_failmode(spa_t *spa) 1668 { 1669 return (spa->spa_failmode); 1670 } 1671 1672 boolean_t 1673 spa_suspended(spa_t *spa) 1674 { 1675 return (spa->spa_suspended); 1676 } 1677 1678 uint64_t 1679 spa_version(spa_t *spa) 1680 { 1681 return (spa->spa_ubsync.ub_version); 1682 } 1683 1684 boolean_t 1685 spa_deflate(spa_t *spa) 1686 { 1687 return (spa->spa_deflate); 1688 } 1689 1690 metaslab_class_t * 1691 spa_normal_class(spa_t *spa) 1692 { 1693 return (spa->spa_normal_class); 1694 } 1695 1696 metaslab_class_t * 1697 spa_log_class(spa_t *spa) 1698 { 1699 return (spa->spa_log_class); 1700 } 1701 1702 void 1703 spa_evicting_os_register(spa_t *spa, objset_t *os) 1704 { 1705 mutex_enter(&spa->spa_evicting_os_lock); 1706 list_insert_head(&spa->spa_evicting_os_list, os); 1707 mutex_exit(&spa->spa_evicting_os_lock); 1708 } 1709 1710 void 1711 spa_evicting_os_deregister(spa_t *spa, objset_t *os) 1712 { 1713 mutex_enter(&spa->spa_evicting_os_lock); 1714 list_remove(&spa->spa_evicting_os_list, os); 1715 cv_broadcast(&spa->spa_evicting_os_cv); 1716 mutex_exit(&spa->spa_evicting_os_lock); 1717 } 1718 1719 void 1720 spa_evicting_os_wait(spa_t *spa) 1721 { 1722 mutex_enter(&spa->spa_evicting_os_lock); 1723 while (!list_is_empty(&spa->spa_evicting_os_list)) 1724 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock); 1725 mutex_exit(&spa->spa_evicting_os_lock); 1726 1727 dmu_buf_user_evict_wait(); 1728 } 1729 1730 int 1731 spa_max_replication(spa_t *spa) 1732 { 1733 /* 1734 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to 1735 * handle BPs with more than one DVA allocated. Set our max 1736 * replication level accordingly. 1737 */ 1738 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) 1739 return (1); 1740 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 1741 } 1742 1743 int 1744 spa_prev_software_version(spa_t *spa) 1745 { 1746 return (spa->spa_prev_software_version); 1747 } 1748 1749 uint64_t 1750 spa_deadman_synctime(spa_t *spa) 1751 { 1752 return (spa->spa_deadman_synctime); 1753 } 1754 1755 uint64_t 1756 dva_get_dsize_sync(spa_t *spa, const dva_t *dva) 1757 { 1758 uint64_t asize = DVA_GET_ASIZE(dva); 1759 uint64_t dsize = asize; 1760 1761 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); 1762 1763 if (asize != 0 && spa->spa_deflate) { 1764 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 1765 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; 1766 } 1767 1768 return (dsize); 1769 } 1770 1771 uint64_t 1772 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) 1773 { 1774 uint64_t dsize = 0; 1775 1776 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1777 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1778 1779 return (dsize); 1780 } 1781 1782 uint64_t 1783 bp_get_dsize(spa_t *spa, const blkptr_t *bp) 1784 { 1785 uint64_t dsize = 0; 1786 1787 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 1788 1789 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1790 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1791 1792 spa_config_exit(spa, SCL_VDEV, FTAG); 1793 1794 return (dsize); 1795 } 1796 1797 /* 1798 * ========================================================================== 1799 * Initialization and Termination 1800 * ========================================================================== 1801 */ 1802 1803 static int 1804 spa_name_compare(const void *a1, const void *a2) 1805 { 1806 const spa_t *s1 = a1; 1807 const spa_t *s2 = a2; 1808 int s; 1809 1810 s = strcmp(s1->spa_name, s2->spa_name); 1811 if (s > 0) 1812 return (1); 1813 if (s < 0) 1814 return (-1); 1815 return (0); 1816 } 1817 1818 int 1819 spa_busy(void) 1820 { 1821 return (spa_active_count); 1822 } 1823 1824 void 1825 spa_boot_init() 1826 { 1827 spa_config_load(); 1828 } 1829 1830 void 1831 spa_init(int mode) 1832 { 1833 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 1834 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); 1835 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); 1836 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 1837 1838 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 1839 offsetof(spa_t, spa_avl)); 1840 1841 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), 1842 offsetof(spa_aux_t, aux_avl)); 1843 1844 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), 1845 offsetof(spa_aux_t, aux_avl)); 1846 1847 spa_mode_global = mode; 1848 1849 #ifdef _KERNEL 1850 spa_arch_init(); 1851 #else 1852 if (spa_mode_global != FREAD && dprintf_find_string("watch")) { 1853 arc_procfd = open("/proc/self/ctl", O_WRONLY); 1854 if (arc_procfd == -1) { 1855 perror("could not enable watchpoints: " 1856 "opening /proc/self/ctl failed: "); 1857 } else { 1858 arc_watch = B_TRUE; 1859 } 1860 } 1861 #endif 1862 1863 refcount_init(); 1864 unique_init(); 1865 range_tree_init(); 1866 zio_init(); 1867 dmu_init(); 1868 zil_init(); 1869 vdev_cache_stat_init(); 1870 zfs_prop_init(); 1871 zpool_prop_init(); 1872 zpool_feature_init(); 1873 spa_config_load(); 1874 l2arc_start(); 1875 } 1876 1877 void 1878 spa_fini(void) 1879 { 1880 l2arc_stop(); 1881 1882 spa_evict_all(); 1883 1884 vdev_cache_stat_fini(); 1885 zil_fini(); 1886 dmu_fini(); 1887 zio_fini(); 1888 range_tree_fini(); 1889 unique_fini(); 1890 refcount_fini(); 1891 1892 avl_destroy(&spa_namespace_avl); 1893 avl_destroy(&spa_spare_avl); 1894 avl_destroy(&spa_l2cache_avl); 1895 1896 cv_destroy(&spa_namespace_cv); 1897 mutex_destroy(&spa_namespace_lock); 1898 mutex_destroy(&spa_spare_lock); 1899 mutex_destroy(&spa_l2cache_lock); 1900 } 1901 1902 /* 1903 * Return whether this pool has slogs. No locking needed. 1904 * It's not a problem if the wrong answer is returned as it's only for 1905 * performance and not correctness 1906 */ 1907 boolean_t 1908 spa_has_slogs(spa_t *spa) 1909 { 1910 return (spa->spa_log_class->mc_rotor != NULL); 1911 } 1912 1913 spa_log_state_t 1914 spa_get_log_state(spa_t *spa) 1915 { 1916 return (spa->spa_log_state); 1917 } 1918 1919 void 1920 spa_set_log_state(spa_t *spa, spa_log_state_t state) 1921 { 1922 spa->spa_log_state = state; 1923 } 1924 1925 boolean_t 1926 spa_is_root(spa_t *spa) 1927 { 1928 return (spa->spa_is_root); 1929 } 1930 1931 boolean_t 1932 spa_writeable(spa_t *spa) 1933 { 1934 return (!!(spa->spa_mode & FWRITE)); 1935 } 1936 1937 /* 1938 * Returns true if there is a pending sync task in any of the current 1939 * syncing txg, the current quiescing txg, or the current open txg. 1940 */ 1941 boolean_t 1942 spa_has_pending_synctask(spa_t *spa) 1943 { 1944 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks)); 1945 } 1946 1947 int 1948 spa_mode(spa_t *spa) 1949 { 1950 return (spa->spa_mode); 1951 } 1952 1953 uint64_t 1954 spa_bootfs(spa_t *spa) 1955 { 1956 return (spa->spa_bootfs); 1957 } 1958 1959 uint64_t 1960 spa_delegation(spa_t *spa) 1961 { 1962 return (spa->spa_delegation); 1963 } 1964 1965 objset_t * 1966 spa_meta_objset(spa_t *spa) 1967 { 1968 return (spa->spa_meta_objset); 1969 } 1970 1971 enum zio_checksum 1972 spa_dedup_checksum(spa_t *spa) 1973 { 1974 return (spa->spa_dedup_checksum); 1975 } 1976 1977 /* 1978 * Reset pool scan stat per scan pass (or reboot). 1979 */ 1980 void 1981 spa_scan_stat_init(spa_t *spa) 1982 { 1983 /* data not stored on disk */ 1984 spa->spa_scan_pass_start = gethrestime_sec(); 1985 spa->spa_scan_pass_exam = 0; 1986 vdev_scan_stat_init(spa->spa_root_vdev); 1987 } 1988 1989 /* 1990 * Get scan stats for zpool status reports 1991 */ 1992 int 1993 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) 1994 { 1995 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; 1996 1997 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) 1998 return (SET_ERROR(ENOENT)); 1999 bzero(ps, sizeof (pool_scan_stat_t)); 2000 2001 /* data stored on disk */ 2002 ps->pss_func = scn->scn_phys.scn_func; 2003 ps->pss_start_time = scn->scn_phys.scn_start_time; 2004 ps->pss_end_time = scn->scn_phys.scn_end_time; 2005 ps->pss_to_examine = scn->scn_phys.scn_to_examine; 2006 ps->pss_examined = scn->scn_phys.scn_examined; 2007 ps->pss_to_process = scn->scn_phys.scn_to_process; 2008 ps->pss_processed = scn->scn_phys.scn_processed; 2009 ps->pss_errors = scn->scn_phys.scn_errors; 2010 ps->pss_state = scn->scn_phys.scn_state; 2011 2012 /* data not stored on disk */ 2013 ps->pss_pass_start = spa->spa_scan_pass_start; 2014 ps->pss_pass_exam = spa->spa_scan_pass_exam; 2015 2016 return (0); 2017 } 2018 2019 boolean_t 2020 spa_debug_enabled(spa_t *spa) 2021 { 2022 return (spa->spa_debug); 2023 } 2024 2025 int 2026 spa_maxblocksize(spa_t *spa) 2027 { 2028 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) 2029 return (SPA_MAXBLOCKSIZE); 2030 else 2031 return (SPA_OLD_MAXBLOCKSIZE); 2032 } 2033