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 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 spa->spa_min_ashift = INT_MAX; 652 spa->spa_max_ashift = 0; 653 654 /* 655 * As a pool is being created, treat all features as disabled by 656 * setting SPA_FEATURE_DISABLED for all entries in the feature 657 * refcount cache. 658 */ 659 for (int i = 0; i < SPA_FEATURES; i++) { 660 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED; 661 } 662 663 return (spa); 664 } 665 666 /* 667 * Removes a spa_t from the namespace, freeing up any memory used. Requires 668 * spa_namespace_lock. This is called only after the spa_t has been closed and 669 * deactivated. 670 */ 671 void 672 spa_remove(spa_t *spa) 673 { 674 spa_config_dirent_t *dp; 675 676 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 677 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 678 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0); 679 680 nvlist_free(spa->spa_config_splitting); 681 682 avl_remove(&spa_namespace_avl, spa); 683 cv_broadcast(&spa_namespace_cv); 684 685 if (spa->spa_root) { 686 spa_strfree(spa->spa_root); 687 spa_active_count--; 688 } 689 690 while ((dp = list_head(&spa->spa_config_list)) != NULL) { 691 list_remove(&spa->spa_config_list, dp); 692 if (dp->scd_path != NULL) 693 spa_strfree(dp->scd_path); 694 kmem_free(dp, sizeof (spa_config_dirent_t)); 695 } 696 697 list_destroy(&spa->spa_config_list); 698 699 nvlist_free(spa->spa_label_features); 700 nvlist_free(spa->spa_load_info); 701 spa_config_set(spa, NULL); 702 703 mutex_enter(&cpu_lock); 704 if (spa->spa_deadman_cycid != CYCLIC_NONE) 705 cyclic_remove(spa->spa_deadman_cycid); 706 mutex_exit(&cpu_lock); 707 spa->spa_deadman_cycid = CYCLIC_NONE; 708 709 refcount_destroy(&spa->spa_refcount); 710 711 spa_config_lock_destroy(spa); 712 713 kstat_delete(spa->spa_iokstat); 714 spa->spa_iokstat = NULL; 715 716 for (int t = 0; t < TXG_SIZE; t++) 717 bplist_destroy(&spa->spa_free_bplist[t]); 718 719 cv_destroy(&spa->spa_async_cv); 720 cv_destroy(&spa->spa_evicting_os_cv); 721 cv_destroy(&spa->spa_proc_cv); 722 cv_destroy(&spa->spa_scrub_io_cv); 723 cv_destroy(&spa->spa_suspend_cv); 724 725 mutex_destroy(&spa->spa_async_lock); 726 mutex_destroy(&spa->spa_errlist_lock); 727 mutex_destroy(&spa->spa_errlog_lock); 728 mutex_destroy(&spa->spa_evicting_os_lock); 729 mutex_destroy(&spa->spa_history_lock); 730 mutex_destroy(&spa->spa_proc_lock); 731 mutex_destroy(&spa->spa_props_lock); 732 mutex_destroy(&spa->spa_scrub_lock); 733 mutex_destroy(&spa->spa_suspend_lock); 734 mutex_destroy(&spa->spa_vdev_top_lock); 735 mutex_destroy(&spa->spa_iokstat_lock); 736 737 kmem_free(spa, sizeof (spa_t)); 738 } 739 740 /* 741 * Given a pool, return the next pool in the namespace, or NULL if there is 742 * none. If 'prev' is NULL, return the first pool. 743 */ 744 spa_t * 745 spa_next(spa_t *prev) 746 { 747 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 748 749 if (prev) 750 return (AVL_NEXT(&spa_namespace_avl, prev)); 751 else 752 return (avl_first(&spa_namespace_avl)); 753 } 754 755 /* 756 * ========================================================================== 757 * SPA refcount functions 758 * ========================================================================== 759 */ 760 761 /* 762 * Add a reference to the given spa_t. Must have at least one reference, or 763 * have the namespace lock held. 764 */ 765 void 766 spa_open_ref(spa_t *spa, void *tag) 767 { 768 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || 769 MUTEX_HELD(&spa_namespace_lock)); 770 (void) refcount_add(&spa->spa_refcount, tag); 771 } 772 773 /* 774 * Remove a reference to the given spa_t. Must have at least one reference, or 775 * have the namespace lock held. 776 */ 777 void 778 spa_close(spa_t *spa, void *tag) 779 { 780 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || 781 MUTEX_HELD(&spa_namespace_lock)); 782 (void) refcount_remove(&spa->spa_refcount, tag); 783 } 784 785 /* 786 * Remove a reference to the given spa_t held by a dsl dir that is 787 * being asynchronously released. Async releases occur from a taskq 788 * performing eviction of dsl datasets and dirs. The namespace lock 789 * isn't held and the hold by the object being evicted may contribute to 790 * spa_minref (e.g. dataset or directory released during pool export), 791 * so the asserts in spa_close() do not apply. 792 */ 793 void 794 spa_async_close(spa_t *spa, void *tag) 795 { 796 (void) refcount_remove(&spa->spa_refcount, tag); 797 } 798 799 /* 800 * Check to see if the spa refcount is zero. Must be called with 801 * spa_namespace_lock held. We really compare against spa_minref, which is the 802 * number of references acquired when opening a pool 803 */ 804 boolean_t 805 spa_refcount_zero(spa_t *spa) 806 { 807 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 808 809 return (refcount_count(&spa->spa_refcount) == spa->spa_minref); 810 } 811 812 /* 813 * ========================================================================== 814 * SPA spare and l2cache tracking 815 * ========================================================================== 816 */ 817 818 /* 819 * Hot spares and cache devices are tracked using the same code below, 820 * for 'auxiliary' devices. 821 */ 822 823 typedef struct spa_aux { 824 uint64_t aux_guid; 825 uint64_t aux_pool; 826 avl_node_t aux_avl; 827 int aux_count; 828 } spa_aux_t; 829 830 static int 831 spa_aux_compare(const void *a, const void *b) 832 { 833 const spa_aux_t *sa = a; 834 const spa_aux_t *sb = b; 835 836 if (sa->aux_guid < sb->aux_guid) 837 return (-1); 838 else if (sa->aux_guid > sb->aux_guid) 839 return (1); 840 else 841 return (0); 842 } 843 844 void 845 spa_aux_add(vdev_t *vd, avl_tree_t *avl) 846 { 847 avl_index_t where; 848 spa_aux_t search; 849 spa_aux_t *aux; 850 851 search.aux_guid = vd->vdev_guid; 852 if ((aux = avl_find(avl, &search, &where)) != NULL) { 853 aux->aux_count++; 854 } else { 855 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); 856 aux->aux_guid = vd->vdev_guid; 857 aux->aux_count = 1; 858 avl_insert(avl, aux, where); 859 } 860 } 861 862 void 863 spa_aux_remove(vdev_t *vd, avl_tree_t *avl) 864 { 865 spa_aux_t search; 866 spa_aux_t *aux; 867 avl_index_t where; 868 869 search.aux_guid = vd->vdev_guid; 870 aux = avl_find(avl, &search, &where); 871 872 ASSERT(aux != NULL); 873 874 if (--aux->aux_count == 0) { 875 avl_remove(avl, aux); 876 kmem_free(aux, sizeof (spa_aux_t)); 877 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { 878 aux->aux_pool = 0ULL; 879 } 880 } 881 882 boolean_t 883 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) 884 { 885 spa_aux_t search, *found; 886 887 search.aux_guid = guid; 888 found = avl_find(avl, &search, NULL); 889 890 if (pool) { 891 if (found) 892 *pool = found->aux_pool; 893 else 894 *pool = 0ULL; 895 } 896 897 if (refcnt) { 898 if (found) 899 *refcnt = found->aux_count; 900 else 901 *refcnt = 0; 902 } 903 904 return (found != NULL); 905 } 906 907 void 908 spa_aux_activate(vdev_t *vd, avl_tree_t *avl) 909 { 910 spa_aux_t search, *found; 911 avl_index_t where; 912 913 search.aux_guid = vd->vdev_guid; 914 found = avl_find(avl, &search, &where); 915 ASSERT(found != NULL); 916 ASSERT(found->aux_pool == 0ULL); 917 918 found->aux_pool = spa_guid(vd->vdev_spa); 919 } 920 921 /* 922 * Spares are tracked globally due to the following constraints: 923 * 924 * - A spare may be part of multiple pools. 925 * - A spare may be added to a pool even if it's actively in use within 926 * another pool. 927 * - A spare in use in any pool can only be the source of a replacement if 928 * the target is a spare in the same pool. 929 * 930 * We keep track of all spares on the system through the use of a reference 931 * counted AVL tree. When a vdev is added as a spare, or used as a replacement 932 * spare, then we bump the reference count in the AVL tree. In addition, we set 933 * the 'vdev_isspare' member to indicate that the device is a spare (active or 934 * inactive). When a spare is made active (used to replace a device in the 935 * pool), we also keep track of which pool its been made a part of. 936 * 937 * The 'spa_spare_lock' protects the AVL tree. These functions are normally 938 * called under the spa_namespace lock as part of vdev reconfiguration. The 939 * separate spare lock exists for the status query path, which does not need to 940 * be completely consistent with respect to other vdev configuration changes. 941 */ 942 943 static int 944 spa_spare_compare(const void *a, const void *b) 945 { 946 return (spa_aux_compare(a, b)); 947 } 948 949 void 950 spa_spare_add(vdev_t *vd) 951 { 952 mutex_enter(&spa_spare_lock); 953 ASSERT(!vd->vdev_isspare); 954 spa_aux_add(vd, &spa_spare_avl); 955 vd->vdev_isspare = B_TRUE; 956 mutex_exit(&spa_spare_lock); 957 } 958 959 void 960 spa_spare_remove(vdev_t *vd) 961 { 962 mutex_enter(&spa_spare_lock); 963 ASSERT(vd->vdev_isspare); 964 spa_aux_remove(vd, &spa_spare_avl); 965 vd->vdev_isspare = B_FALSE; 966 mutex_exit(&spa_spare_lock); 967 } 968 969 boolean_t 970 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) 971 { 972 boolean_t found; 973 974 mutex_enter(&spa_spare_lock); 975 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); 976 mutex_exit(&spa_spare_lock); 977 978 return (found); 979 } 980 981 void 982 spa_spare_activate(vdev_t *vd) 983 { 984 mutex_enter(&spa_spare_lock); 985 ASSERT(vd->vdev_isspare); 986 spa_aux_activate(vd, &spa_spare_avl); 987 mutex_exit(&spa_spare_lock); 988 } 989 990 /* 991 * Level 2 ARC devices are tracked globally for the same reasons as spares. 992 * Cache devices currently only support one pool per cache device, and so 993 * for these devices the aux reference count is currently unused beyond 1. 994 */ 995 996 static int 997 spa_l2cache_compare(const void *a, const void *b) 998 { 999 return (spa_aux_compare(a, b)); 1000 } 1001 1002 void 1003 spa_l2cache_add(vdev_t *vd) 1004 { 1005 mutex_enter(&spa_l2cache_lock); 1006 ASSERT(!vd->vdev_isl2cache); 1007 spa_aux_add(vd, &spa_l2cache_avl); 1008 vd->vdev_isl2cache = B_TRUE; 1009 mutex_exit(&spa_l2cache_lock); 1010 } 1011 1012 void 1013 spa_l2cache_remove(vdev_t *vd) 1014 { 1015 mutex_enter(&spa_l2cache_lock); 1016 ASSERT(vd->vdev_isl2cache); 1017 spa_aux_remove(vd, &spa_l2cache_avl); 1018 vd->vdev_isl2cache = B_FALSE; 1019 mutex_exit(&spa_l2cache_lock); 1020 } 1021 1022 boolean_t 1023 spa_l2cache_exists(uint64_t guid, uint64_t *pool) 1024 { 1025 boolean_t found; 1026 1027 mutex_enter(&spa_l2cache_lock); 1028 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); 1029 mutex_exit(&spa_l2cache_lock); 1030 1031 return (found); 1032 } 1033 1034 void 1035 spa_l2cache_activate(vdev_t *vd) 1036 { 1037 mutex_enter(&spa_l2cache_lock); 1038 ASSERT(vd->vdev_isl2cache); 1039 spa_aux_activate(vd, &spa_l2cache_avl); 1040 mutex_exit(&spa_l2cache_lock); 1041 } 1042 1043 /* 1044 * ========================================================================== 1045 * SPA vdev locking 1046 * ========================================================================== 1047 */ 1048 1049 /* 1050 * Lock the given spa_t for the purpose of adding or removing a vdev. 1051 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 1052 * It returns the next transaction group for the spa_t. 1053 */ 1054 uint64_t 1055 spa_vdev_enter(spa_t *spa) 1056 { 1057 mutex_enter(&spa->spa_vdev_top_lock); 1058 mutex_enter(&spa_namespace_lock); 1059 return (spa_vdev_config_enter(spa)); 1060 } 1061 1062 /* 1063 * Internal implementation for spa_vdev_enter(). Used when a vdev 1064 * operation requires multiple syncs (i.e. removing a device) while 1065 * keeping the spa_namespace_lock held. 1066 */ 1067 uint64_t 1068 spa_vdev_config_enter(spa_t *spa) 1069 { 1070 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1071 1072 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1073 1074 return (spa_last_synced_txg(spa) + 1); 1075 } 1076 1077 /* 1078 * Used in combination with spa_vdev_config_enter() to allow the syncing 1079 * of multiple transactions without releasing the spa_namespace_lock. 1080 */ 1081 void 1082 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) 1083 { 1084 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1085 1086 int config_changed = B_FALSE; 1087 1088 ASSERT(txg > spa_last_synced_txg(spa)); 1089 1090 spa->spa_pending_vdev = NULL; 1091 1092 /* 1093 * Reassess the DTLs. 1094 */ 1095 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 1096 1097 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { 1098 config_changed = B_TRUE; 1099 spa->spa_config_generation++; 1100 } 1101 1102 /* 1103 * Verify the metaslab classes. 1104 */ 1105 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); 1106 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); 1107 1108 spa_config_exit(spa, SCL_ALL, spa); 1109 1110 /* 1111 * Panic the system if the specified tag requires it. This 1112 * is useful for ensuring that configurations are updated 1113 * transactionally. 1114 */ 1115 if (zio_injection_enabled) 1116 zio_handle_panic_injection(spa, tag, 0); 1117 1118 /* 1119 * Note: this txg_wait_synced() is important because it ensures 1120 * that there won't be more than one config change per txg. 1121 * This allows us to use the txg as the generation number. 1122 */ 1123 if (error == 0) 1124 txg_wait_synced(spa->spa_dsl_pool, txg); 1125 1126 if (vd != NULL) { 1127 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL); 1128 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1129 vdev_free(vd); 1130 spa_config_exit(spa, SCL_ALL, spa); 1131 } 1132 1133 /* 1134 * If the config changed, update the config cache. 1135 */ 1136 if (config_changed) 1137 spa_config_sync(spa, B_FALSE, B_TRUE); 1138 } 1139 1140 /* 1141 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 1142 * locking of spa_vdev_enter(), we also want make sure the transactions have 1143 * synced to disk, and then update the global configuration cache with the new 1144 * information. 1145 */ 1146 int 1147 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 1148 { 1149 spa_vdev_config_exit(spa, vd, txg, error, FTAG); 1150 mutex_exit(&spa_namespace_lock); 1151 mutex_exit(&spa->spa_vdev_top_lock); 1152 1153 return (error); 1154 } 1155 1156 /* 1157 * Lock the given spa_t for the purpose of changing vdev state. 1158 */ 1159 void 1160 spa_vdev_state_enter(spa_t *spa, int oplocks) 1161 { 1162 int locks = SCL_STATE_ALL | oplocks; 1163 1164 /* 1165 * Root pools may need to read of the underlying devfs filesystem 1166 * when opening up a vdev. Unfortunately if we're holding the 1167 * SCL_ZIO lock it will result in a deadlock when we try to issue 1168 * the read from the root filesystem. Instead we "prefetch" 1169 * the associated vnodes that we need prior to opening the 1170 * underlying devices and cache them so that we can prevent 1171 * any I/O when we are doing the actual open. 1172 */ 1173 if (spa_is_root(spa)) { 1174 int low = locks & ~(SCL_ZIO - 1); 1175 int high = locks & ~low; 1176 1177 spa_config_enter(spa, high, spa, RW_WRITER); 1178 vdev_hold(spa->spa_root_vdev); 1179 spa_config_enter(spa, low, spa, RW_WRITER); 1180 } else { 1181 spa_config_enter(spa, locks, spa, RW_WRITER); 1182 } 1183 spa->spa_vdev_locks = locks; 1184 } 1185 1186 int 1187 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) 1188 { 1189 boolean_t config_changed = B_FALSE; 1190 1191 if (vd != NULL || error == 0) 1192 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, 1193 0, 0, B_FALSE); 1194 1195 if (vd != NULL) { 1196 vdev_state_dirty(vd->vdev_top); 1197 config_changed = B_TRUE; 1198 spa->spa_config_generation++; 1199 } 1200 1201 if (spa_is_root(spa)) 1202 vdev_rele(spa->spa_root_vdev); 1203 1204 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); 1205 spa_config_exit(spa, spa->spa_vdev_locks, spa); 1206 1207 /* 1208 * If anything changed, wait for it to sync. This ensures that, 1209 * from the system administrator's perspective, zpool(1M) commands 1210 * are synchronous. This is important for things like zpool offline: 1211 * when the command completes, you expect no further I/O from ZFS. 1212 */ 1213 if (vd != NULL) 1214 txg_wait_synced(spa->spa_dsl_pool, 0); 1215 1216 /* 1217 * If the config changed, update the config cache. 1218 */ 1219 if (config_changed) { 1220 mutex_enter(&spa_namespace_lock); 1221 spa_config_sync(spa, B_FALSE, B_TRUE); 1222 mutex_exit(&spa_namespace_lock); 1223 } 1224 1225 return (error); 1226 } 1227 1228 /* 1229 * ========================================================================== 1230 * Miscellaneous functions 1231 * ========================================================================== 1232 */ 1233 1234 void 1235 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx) 1236 { 1237 if (!nvlist_exists(spa->spa_label_features, feature)) { 1238 fnvlist_add_boolean(spa->spa_label_features, feature); 1239 /* 1240 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't 1241 * dirty the vdev config because lock SCL_CONFIG is not held. 1242 * Thankfully, in this case we don't need to dirty the config 1243 * because it will be written out anyway when we finish 1244 * creating the pool. 1245 */ 1246 if (tx->tx_txg != TXG_INITIAL) 1247 vdev_config_dirty(spa->spa_root_vdev); 1248 } 1249 } 1250 1251 void 1252 spa_deactivate_mos_feature(spa_t *spa, const char *feature) 1253 { 1254 if (nvlist_remove_all(spa->spa_label_features, feature) == 0) 1255 vdev_config_dirty(spa->spa_root_vdev); 1256 } 1257 1258 /* 1259 * Rename a spa_t. 1260 */ 1261 int 1262 spa_rename(const char *name, const char *newname) 1263 { 1264 spa_t *spa; 1265 int err; 1266 1267 /* 1268 * Lookup the spa_t and grab the config lock for writing. We need to 1269 * actually open the pool so that we can sync out the necessary labels. 1270 * It's OK to call spa_open() with the namespace lock held because we 1271 * allow recursive calls for other reasons. 1272 */ 1273 mutex_enter(&spa_namespace_lock); 1274 if ((err = spa_open(name, &spa, FTAG)) != 0) { 1275 mutex_exit(&spa_namespace_lock); 1276 return (err); 1277 } 1278 1279 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1280 1281 avl_remove(&spa_namespace_avl, spa); 1282 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); 1283 avl_add(&spa_namespace_avl, spa); 1284 1285 /* 1286 * Sync all labels to disk with the new names by marking the root vdev 1287 * dirty and waiting for it to sync. It will pick up the new pool name 1288 * during the sync. 1289 */ 1290 vdev_config_dirty(spa->spa_root_vdev); 1291 1292 spa_config_exit(spa, SCL_ALL, FTAG); 1293 1294 txg_wait_synced(spa->spa_dsl_pool, 0); 1295 1296 /* 1297 * Sync the updated config cache. 1298 */ 1299 spa_config_sync(spa, B_FALSE, B_TRUE); 1300 1301 spa_close(spa, FTAG); 1302 1303 mutex_exit(&spa_namespace_lock); 1304 1305 return (0); 1306 } 1307 1308 /* 1309 * Return the spa_t associated with given pool_guid, if it exists. If 1310 * device_guid is non-zero, determine whether the pool exists *and* contains 1311 * a device with the specified device_guid. 1312 */ 1313 spa_t * 1314 spa_by_guid(uint64_t pool_guid, uint64_t device_guid) 1315 { 1316 spa_t *spa; 1317 avl_tree_t *t = &spa_namespace_avl; 1318 1319 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1320 1321 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 1322 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 1323 continue; 1324 if (spa->spa_root_vdev == NULL) 1325 continue; 1326 if (spa_guid(spa) == pool_guid) { 1327 if (device_guid == 0) 1328 break; 1329 1330 if (vdev_lookup_by_guid(spa->spa_root_vdev, 1331 device_guid) != NULL) 1332 break; 1333 1334 /* 1335 * Check any devices we may be in the process of adding. 1336 */ 1337 if (spa->spa_pending_vdev) { 1338 if (vdev_lookup_by_guid(spa->spa_pending_vdev, 1339 device_guid) != NULL) 1340 break; 1341 } 1342 } 1343 } 1344 1345 return (spa); 1346 } 1347 1348 /* 1349 * Determine whether a pool with the given pool_guid exists. 1350 */ 1351 boolean_t 1352 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 1353 { 1354 return (spa_by_guid(pool_guid, device_guid) != NULL); 1355 } 1356 1357 char * 1358 spa_strdup(const char *s) 1359 { 1360 size_t len; 1361 char *new; 1362 1363 len = strlen(s); 1364 new = kmem_alloc(len + 1, KM_SLEEP); 1365 bcopy(s, new, len); 1366 new[len] = '\0'; 1367 1368 return (new); 1369 } 1370 1371 void 1372 spa_strfree(char *s) 1373 { 1374 kmem_free(s, strlen(s) + 1); 1375 } 1376 1377 uint64_t 1378 spa_get_random(uint64_t range) 1379 { 1380 uint64_t r; 1381 1382 ASSERT(range != 0); 1383 1384 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 1385 1386 return (r % range); 1387 } 1388 1389 uint64_t 1390 spa_generate_guid(spa_t *spa) 1391 { 1392 uint64_t guid = spa_get_random(-1ULL); 1393 1394 if (spa != NULL) { 1395 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) 1396 guid = spa_get_random(-1ULL); 1397 } else { 1398 while (guid == 0 || spa_guid_exists(guid, 0)) 1399 guid = spa_get_random(-1ULL); 1400 } 1401 1402 return (guid); 1403 } 1404 1405 void 1406 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp) 1407 { 1408 char type[256]; 1409 char *checksum = NULL; 1410 char *compress = NULL; 1411 1412 if (bp != NULL) { 1413 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) { 1414 dmu_object_byteswap_t bswap = 1415 DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); 1416 (void) snprintf(type, sizeof (type), "bswap %s %s", 1417 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ? 1418 "metadata" : "data", 1419 dmu_ot_byteswap[bswap].ob_name); 1420 } else { 1421 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name, 1422 sizeof (type)); 1423 } 1424 if (!BP_IS_EMBEDDED(bp)) { 1425 checksum = 1426 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; 1427 } 1428 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; 1429 } 1430 1431 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum, 1432 compress); 1433 } 1434 1435 void 1436 spa_freeze(spa_t *spa) 1437 { 1438 uint64_t freeze_txg = 0; 1439 1440 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1441 if (spa->spa_freeze_txg == UINT64_MAX) { 1442 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 1443 spa->spa_freeze_txg = freeze_txg; 1444 } 1445 spa_config_exit(spa, SCL_ALL, FTAG); 1446 if (freeze_txg != 0) 1447 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 1448 } 1449 1450 void 1451 zfs_panic_recover(const char *fmt, ...) 1452 { 1453 va_list adx; 1454 1455 va_start(adx, fmt); 1456 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); 1457 va_end(adx); 1458 } 1459 1460 /* 1461 * This is a stripped-down version of strtoull, suitable only for converting 1462 * lowercase hexadecimal numbers that don't overflow. 1463 */ 1464 uint64_t 1465 strtonum(const char *str, char **nptr) 1466 { 1467 uint64_t val = 0; 1468 char c; 1469 int digit; 1470 1471 while ((c = *str) != '\0') { 1472 if (c >= '0' && c <= '9') 1473 digit = c - '0'; 1474 else if (c >= 'a' && c <= 'f') 1475 digit = 10 + c - 'a'; 1476 else 1477 break; 1478 1479 val *= 16; 1480 val += digit; 1481 1482 str++; 1483 } 1484 1485 if (nptr) 1486 *nptr = (char *)str; 1487 1488 return (val); 1489 } 1490 1491 /* 1492 * ========================================================================== 1493 * Accessor functions 1494 * ========================================================================== 1495 */ 1496 1497 boolean_t 1498 spa_shutting_down(spa_t *spa) 1499 { 1500 return (spa->spa_async_suspended); 1501 } 1502 1503 dsl_pool_t * 1504 spa_get_dsl(spa_t *spa) 1505 { 1506 return (spa->spa_dsl_pool); 1507 } 1508 1509 boolean_t 1510 spa_is_initializing(spa_t *spa) 1511 { 1512 return (spa->spa_is_initializing); 1513 } 1514 1515 blkptr_t * 1516 spa_get_rootblkptr(spa_t *spa) 1517 { 1518 return (&spa->spa_ubsync.ub_rootbp); 1519 } 1520 1521 void 1522 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 1523 { 1524 spa->spa_uberblock.ub_rootbp = *bp; 1525 } 1526 1527 void 1528 spa_altroot(spa_t *spa, char *buf, size_t buflen) 1529 { 1530 if (spa->spa_root == NULL) 1531 buf[0] = '\0'; 1532 else 1533 (void) strncpy(buf, spa->spa_root, buflen); 1534 } 1535 1536 int 1537 spa_sync_pass(spa_t *spa) 1538 { 1539 return (spa->spa_sync_pass); 1540 } 1541 1542 char * 1543 spa_name(spa_t *spa) 1544 { 1545 return (spa->spa_name); 1546 } 1547 1548 uint64_t 1549 spa_guid(spa_t *spa) 1550 { 1551 dsl_pool_t *dp = spa_get_dsl(spa); 1552 uint64_t guid; 1553 1554 /* 1555 * If we fail to parse the config during spa_load(), we can go through 1556 * the error path (which posts an ereport) and end up here with no root 1557 * vdev. We stash the original pool guid in 'spa_config_guid' to handle 1558 * this case. 1559 */ 1560 if (spa->spa_root_vdev == NULL) 1561 return (spa->spa_config_guid); 1562 1563 guid = spa->spa_last_synced_guid != 0 ? 1564 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid; 1565 1566 /* 1567 * Return the most recently synced out guid unless we're 1568 * in syncing context. 1569 */ 1570 if (dp && dsl_pool_sync_context(dp)) 1571 return (spa->spa_root_vdev->vdev_guid); 1572 else 1573 return (guid); 1574 } 1575 1576 uint64_t 1577 spa_load_guid(spa_t *spa) 1578 { 1579 /* 1580 * This is a GUID that exists solely as a reference for the 1581 * purposes of the arc. It is generated at load time, and 1582 * is never written to persistent storage. 1583 */ 1584 return (spa->spa_load_guid); 1585 } 1586 1587 uint64_t 1588 spa_last_synced_txg(spa_t *spa) 1589 { 1590 return (spa->spa_ubsync.ub_txg); 1591 } 1592 1593 uint64_t 1594 spa_first_txg(spa_t *spa) 1595 { 1596 return (spa->spa_first_txg); 1597 } 1598 1599 uint64_t 1600 spa_syncing_txg(spa_t *spa) 1601 { 1602 return (spa->spa_syncing_txg); 1603 } 1604 1605 pool_state_t 1606 spa_state(spa_t *spa) 1607 { 1608 return (spa->spa_state); 1609 } 1610 1611 spa_load_state_t 1612 spa_load_state(spa_t *spa) 1613 { 1614 return (spa->spa_load_state); 1615 } 1616 1617 uint64_t 1618 spa_freeze_txg(spa_t *spa) 1619 { 1620 return (spa->spa_freeze_txg); 1621 } 1622 1623 /* ARGSUSED */ 1624 uint64_t 1625 spa_get_asize(spa_t *spa, uint64_t lsize) 1626 { 1627 return (lsize * spa_asize_inflation); 1628 } 1629 1630 /* 1631 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%), 1632 * or at least 32MB. 1633 * 1634 * See the comment above spa_slop_shift for details. 1635 */ 1636 uint64_t 1637 spa_get_slop_space(spa_t *spa) { 1638 uint64_t space = spa_get_dspace(spa); 1639 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1)); 1640 } 1641 1642 uint64_t 1643 spa_get_dspace(spa_t *spa) 1644 { 1645 return (spa->spa_dspace); 1646 } 1647 1648 void 1649 spa_update_dspace(spa_t *spa) 1650 { 1651 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + 1652 ddt_get_dedup_dspace(spa); 1653 } 1654 1655 /* 1656 * Return the failure mode that has been set to this pool. The default 1657 * behavior will be to block all I/Os when a complete failure occurs. 1658 */ 1659 uint8_t 1660 spa_get_failmode(spa_t *spa) 1661 { 1662 return (spa->spa_failmode); 1663 } 1664 1665 boolean_t 1666 spa_suspended(spa_t *spa) 1667 { 1668 return (spa->spa_suspended); 1669 } 1670 1671 uint64_t 1672 spa_version(spa_t *spa) 1673 { 1674 return (spa->spa_ubsync.ub_version); 1675 } 1676 1677 boolean_t 1678 spa_deflate(spa_t *spa) 1679 { 1680 return (spa->spa_deflate); 1681 } 1682 1683 metaslab_class_t * 1684 spa_normal_class(spa_t *spa) 1685 { 1686 return (spa->spa_normal_class); 1687 } 1688 1689 metaslab_class_t * 1690 spa_log_class(spa_t *spa) 1691 { 1692 return (spa->spa_log_class); 1693 } 1694 1695 void 1696 spa_evicting_os_register(spa_t *spa, objset_t *os) 1697 { 1698 mutex_enter(&spa->spa_evicting_os_lock); 1699 list_insert_head(&spa->spa_evicting_os_list, os); 1700 mutex_exit(&spa->spa_evicting_os_lock); 1701 } 1702 1703 void 1704 spa_evicting_os_deregister(spa_t *spa, objset_t *os) 1705 { 1706 mutex_enter(&spa->spa_evicting_os_lock); 1707 list_remove(&spa->spa_evicting_os_list, os); 1708 cv_broadcast(&spa->spa_evicting_os_cv); 1709 mutex_exit(&spa->spa_evicting_os_lock); 1710 } 1711 1712 void 1713 spa_evicting_os_wait(spa_t *spa) 1714 { 1715 mutex_enter(&spa->spa_evicting_os_lock); 1716 while (!list_is_empty(&spa->spa_evicting_os_list)) 1717 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock); 1718 mutex_exit(&spa->spa_evicting_os_lock); 1719 1720 dmu_buf_user_evict_wait(); 1721 } 1722 1723 int 1724 spa_max_replication(spa_t *spa) 1725 { 1726 /* 1727 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to 1728 * handle BPs with more than one DVA allocated. Set our max 1729 * replication level accordingly. 1730 */ 1731 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) 1732 return (1); 1733 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 1734 } 1735 1736 int 1737 spa_prev_software_version(spa_t *spa) 1738 { 1739 return (spa->spa_prev_software_version); 1740 } 1741 1742 uint64_t 1743 spa_deadman_synctime(spa_t *spa) 1744 { 1745 return (spa->spa_deadman_synctime); 1746 } 1747 1748 uint64_t 1749 dva_get_dsize_sync(spa_t *spa, const dva_t *dva) 1750 { 1751 uint64_t asize = DVA_GET_ASIZE(dva); 1752 uint64_t dsize = asize; 1753 1754 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); 1755 1756 if (asize != 0 && spa->spa_deflate) { 1757 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 1758 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; 1759 } 1760 1761 return (dsize); 1762 } 1763 1764 uint64_t 1765 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) 1766 { 1767 uint64_t dsize = 0; 1768 1769 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1770 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1771 1772 return (dsize); 1773 } 1774 1775 uint64_t 1776 bp_get_dsize(spa_t *spa, const blkptr_t *bp) 1777 { 1778 uint64_t dsize = 0; 1779 1780 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 1781 1782 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1783 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1784 1785 spa_config_exit(spa, SCL_VDEV, FTAG); 1786 1787 return (dsize); 1788 } 1789 1790 /* 1791 * ========================================================================== 1792 * Initialization and Termination 1793 * ========================================================================== 1794 */ 1795 1796 static int 1797 spa_name_compare(const void *a1, const void *a2) 1798 { 1799 const spa_t *s1 = a1; 1800 const spa_t *s2 = a2; 1801 int s; 1802 1803 s = strcmp(s1->spa_name, s2->spa_name); 1804 if (s > 0) 1805 return (1); 1806 if (s < 0) 1807 return (-1); 1808 return (0); 1809 } 1810 1811 int 1812 spa_busy(void) 1813 { 1814 return (spa_active_count); 1815 } 1816 1817 void 1818 spa_boot_init() 1819 { 1820 spa_config_load(); 1821 } 1822 1823 void 1824 spa_init(int mode) 1825 { 1826 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 1827 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); 1828 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); 1829 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 1830 1831 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 1832 offsetof(spa_t, spa_avl)); 1833 1834 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), 1835 offsetof(spa_aux_t, aux_avl)); 1836 1837 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), 1838 offsetof(spa_aux_t, aux_avl)); 1839 1840 spa_mode_global = mode; 1841 1842 #ifdef _KERNEL 1843 spa_arch_init(); 1844 #else 1845 if (spa_mode_global != FREAD && dprintf_find_string("watch")) { 1846 arc_procfd = open("/proc/self/ctl", O_WRONLY); 1847 if (arc_procfd == -1) { 1848 perror("could not enable watchpoints: " 1849 "opening /proc/self/ctl failed: "); 1850 } else { 1851 arc_watch = B_TRUE; 1852 } 1853 } 1854 #endif 1855 1856 refcount_init(); 1857 unique_init(); 1858 range_tree_init(); 1859 zio_init(); 1860 dmu_init(); 1861 zil_init(); 1862 vdev_cache_stat_init(); 1863 zfs_prop_init(); 1864 zpool_prop_init(); 1865 zpool_feature_init(); 1866 spa_config_load(); 1867 l2arc_start(); 1868 } 1869 1870 void 1871 spa_fini(void) 1872 { 1873 l2arc_stop(); 1874 1875 spa_evict_all(); 1876 1877 vdev_cache_stat_fini(); 1878 zil_fini(); 1879 dmu_fini(); 1880 zio_fini(); 1881 range_tree_fini(); 1882 unique_fini(); 1883 refcount_fini(); 1884 1885 avl_destroy(&spa_namespace_avl); 1886 avl_destroy(&spa_spare_avl); 1887 avl_destroy(&spa_l2cache_avl); 1888 1889 cv_destroy(&spa_namespace_cv); 1890 mutex_destroy(&spa_namespace_lock); 1891 mutex_destroy(&spa_spare_lock); 1892 mutex_destroy(&spa_l2cache_lock); 1893 } 1894 1895 /* 1896 * Return whether this pool has slogs. No locking needed. 1897 * It's not a problem if the wrong answer is returned as it's only for 1898 * performance and not correctness 1899 */ 1900 boolean_t 1901 spa_has_slogs(spa_t *spa) 1902 { 1903 return (spa->spa_log_class->mc_rotor != NULL); 1904 } 1905 1906 spa_log_state_t 1907 spa_get_log_state(spa_t *spa) 1908 { 1909 return (spa->spa_log_state); 1910 } 1911 1912 void 1913 spa_set_log_state(spa_t *spa, spa_log_state_t state) 1914 { 1915 spa->spa_log_state = state; 1916 } 1917 1918 boolean_t 1919 spa_is_root(spa_t *spa) 1920 { 1921 return (spa->spa_is_root); 1922 } 1923 1924 boolean_t 1925 spa_writeable(spa_t *spa) 1926 { 1927 return (!!(spa->spa_mode & FWRITE)); 1928 } 1929 1930 /* 1931 * Returns true if there is a pending sync task in any of the current 1932 * syncing txg, the current quiescing txg, or the current open txg. 1933 */ 1934 boolean_t 1935 spa_has_pending_synctask(spa_t *spa) 1936 { 1937 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks)); 1938 } 1939 1940 int 1941 spa_mode(spa_t *spa) 1942 { 1943 return (spa->spa_mode); 1944 } 1945 1946 uint64_t 1947 spa_bootfs(spa_t *spa) 1948 { 1949 return (spa->spa_bootfs); 1950 } 1951 1952 uint64_t 1953 spa_delegation(spa_t *spa) 1954 { 1955 return (spa->spa_delegation); 1956 } 1957 1958 objset_t * 1959 spa_meta_objset(spa_t *spa) 1960 { 1961 return (spa->spa_meta_objset); 1962 } 1963 1964 enum zio_checksum 1965 spa_dedup_checksum(spa_t *spa) 1966 { 1967 return (spa->spa_dedup_checksum); 1968 } 1969 1970 /* 1971 * Reset pool scan stat per scan pass (or reboot). 1972 */ 1973 void 1974 spa_scan_stat_init(spa_t *spa) 1975 { 1976 /* data not stored on disk */ 1977 spa->spa_scan_pass_start = gethrestime_sec(); 1978 spa->spa_scan_pass_exam = 0; 1979 vdev_scan_stat_init(spa->spa_root_vdev); 1980 } 1981 1982 /* 1983 * Get scan stats for zpool status reports 1984 */ 1985 int 1986 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) 1987 { 1988 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; 1989 1990 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) 1991 return (SET_ERROR(ENOENT)); 1992 bzero(ps, sizeof (pool_scan_stat_t)); 1993 1994 /* data stored on disk */ 1995 ps->pss_func = scn->scn_phys.scn_func; 1996 ps->pss_start_time = scn->scn_phys.scn_start_time; 1997 ps->pss_end_time = scn->scn_phys.scn_end_time; 1998 ps->pss_to_examine = scn->scn_phys.scn_to_examine; 1999 ps->pss_examined = scn->scn_phys.scn_examined; 2000 ps->pss_to_process = scn->scn_phys.scn_to_process; 2001 ps->pss_processed = scn->scn_phys.scn_processed; 2002 ps->pss_errors = scn->scn_phys.scn_errors; 2003 ps->pss_state = scn->scn_phys.scn_state; 2004 2005 /* data not stored on disk */ 2006 ps->pss_pass_start = spa->spa_scan_pass_start; 2007 ps->pss_pass_exam = spa->spa_scan_pass_exam; 2008 2009 return (0); 2010 } 2011 2012 boolean_t 2013 spa_debug_enabled(spa_t *spa) 2014 { 2015 return (spa->spa_debug); 2016 } 2017 2018 int 2019 spa_maxblocksize(spa_t *spa) 2020 { 2021 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) 2022 return (SPA_MAXBLOCKSIZE); 2023 else 2024 return (SPA_OLD_MAXBLOCKSIZE); 2025 } 2026