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 * 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), tag); 390 return (0); 391 } 392 } else { 393 ASSERT(scl->scl_writer != curthread); 394 if (!refcount_is_zero(&scl->scl_count)) { 395 mutex_exit(&scl->scl_lock); 396 spa_config_exit(spa, locks ^ (1 << i), tag); 397 return (0); 398 } 399 scl->scl_writer = curthread; 400 } 401 (void) refcount_add(&scl->scl_count, tag); 402 mutex_exit(&scl->scl_lock); 403 } 404 return (1); 405 } 406 407 void 408 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw) 409 { 410 int wlocks_held = 0; 411 412 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY); 413 414 for (int i = 0; i < SCL_LOCKS; i++) { 415 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 416 if (scl->scl_writer == curthread) 417 wlocks_held |= (1 << i); 418 if (!(locks & (1 << i))) 419 continue; 420 mutex_enter(&scl->scl_lock); 421 if (rw == RW_READER) { 422 while (scl->scl_writer || scl->scl_write_wanted) { 423 cv_wait(&scl->scl_cv, &scl->scl_lock); 424 } 425 } else { 426 ASSERT(scl->scl_writer != curthread); 427 while (!refcount_is_zero(&scl->scl_count)) { 428 scl->scl_write_wanted++; 429 cv_wait(&scl->scl_cv, &scl->scl_lock); 430 scl->scl_write_wanted--; 431 } 432 scl->scl_writer = curthread; 433 } 434 (void) refcount_add(&scl->scl_count, tag); 435 mutex_exit(&scl->scl_lock); 436 } 437 ASSERT(wlocks_held <= locks); 438 } 439 440 void 441 spa_config_exit(spa_t *spa, int locks, void *tag) 442 { 443 for (int i = SCL_LOCKS - 1; i >= 0; i--) { 444 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 445 if (!(locks & (1 << i))) 446 continue; 447 mutex_enter(&scl->scl_lock); 448 ASSERT(!refcount_is_zero(&scl->scl_count)); 449 if (refcount_remove(&scl->scl_count, tag) == 0) { 450 ASSERT(scl->scl_writer == NULL || 451 scl->scl_writer == curthread); 452 scl->scl_writer = NULL; /* OK in either case */ 453 cv_broadcast(&scl->scl_cv); 454 } 455 mutex_exit(&scl->scl_lock); 456 } 457 } 458 459 int 460 spa_config_held(spa_t *spa, int locks, krw_t rw) 461 { 462 int locks_held = 0; 463 464 for (int i = 0; i < SCL_LOCKS; i++) { 465 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 466 if (!(locks & (1 << i))) 467 continue; 468 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) || 469 (rw == RW_WRITER && scl->scl_writer == curthread)) 470 locks_held |= 1 << i; 471 } 472 473 return (locks_held); 474 } 475 476 /* 477 * ========================================================================== 478 * SPA namespace functions 479 * ========================================================================== 480 */ 481 482 /* 483 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. 484 * Returns NULL if no matching spa_t is found. 485 */ 486 spa_t * 487 spa_lookup(const char *name) 488 { 489 static spa_t search; /* spa_t is large; don't allocate on stack */ 490 spa_t *spa; 491 avl_index_t where; 492 char *cp; 493 494 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 495 496 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name)); 497 498 /* 499 * If it's a full dataset name, figure out the pool name and 500 * just use that. 501 */ 502 cp = strpbrk(search.spa_name, "/@#"); 503 if (cp != NULL) 504 *cp = '\0'; 505 506 spa = avl_find(&spa_namespace_avl, &search, &where); 507 508 return (spa); 509 } 510 511 /* 512 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms. 513 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues 514 * looking for potentially hung I/Os. 515 */ 516 void 517 spa_deadman(void *arg) 518 { 519 spa_t *spa = arg; 520 521 /* 522 * Disable the deadman timer if the pool is suspended. 523 */ 524 if (spa_suspended(spa)) { 525 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY)); 526 return; 527 } 528 529 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu", 530 (gethrtime() - spa->spa_sync_starttime) / NANOSEC, 531 ++spa->spa_deadman_calls); 532 if (zfs_deadman_enabled) 533 vdev_deadman(spa->spa_root_vdev); 534 } 535 536 /* 537 * Create an uninitialized spa_t with the given name. Requires 538 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already 539 * exist by calling spa_lookup() first. 540 */ 541 spa_t * 542 spa_add(const char *name, nvlist_t *config, const char *altroot) 543 { 544 spa_t *spa; 545 spa_config_dirent_t *dp; 546 cyc_handler_t hdlr; 547 cyc_time_t when; 548 549 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 550 551 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); 552 553 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL); 554 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL); 555 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL); 556 mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL); 557 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL); 558 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL); 559 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL); 560 mutex_init(&spa->spa_cksum_tmpls_lock, NULL, MUTEX_DEFAULT, NULL); 561 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL); 562 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL); 563 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL); 564 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL); 565 566 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL); 567 cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL); 568 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL); 569 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL); 570 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL); 571 572 for (int t = 0; t < TXG_SIZE; t++) 573 bplist_create(&spa->spa_free_bplist[t]); 574 575 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name)); 576 spa->spa_state = POOL_STATE_UNINITIALIZED; 577 spa->spa_freeze_txg = UINT64_MAX; 578 spa->spa_final_txg = UINT64_MAX; 579 spa->spa_load_max_txg = UINT64_MAX; 580 spa->spa_proc = &p0; 581 spa->spa_proc_state = SPA_PROC_NONE; 582 583 hdlr.cyh_func = spa_deadman; 584 hdlr.cyh_arg = spa; 585 hdlr.cyh_level = CY_LOW_LEVEL; 586 587 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms); 588 589 /* 590 * This determines how often we need to check for hung I/Os after 591 * the cyclic has already fired. Since checking for hung I/Os is 592 * an expensive operation we don't want to check too frequently. 593 * Instead wait for 5 seconds before checking again. 594 */ 595 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms); 596 when.cyt_when = CY_INFINITY; 597 mutex_enter(&cpu_lock); 598 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when); 599 mutex_exit(&cpu_lock); 600 601 refcount_create(&spa->spa_refcount); 602 spa_config_lock_init(spa); 603 604 avl_add(&spa_namespace_avl, spa); 605 606 /* 607 * Set the alternate root, if there is one. 608 */ 609 if (altroot) { 610 spa->spa_root = spa_strdup(altroot); 611 spa_active_count++; 612 } 613 614 /* 615 * Every pool starts with the default cachefile 616 */ 617 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t), 618 offsetof(spa_config_dirent_t, scd_link)); 619 620 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP); 621 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path); 622 list_insert_head(&spa->spa_config_list, dp); 623 624 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME, 625 KM_SLEEP) == 0); 626 627 if (config != NULL) { 628 nvlist_t *features; 629 630 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 631 &features) == 0) { 632 VERIFY(nvlist_dup(features, &spa->spa_label_features, 633 0) == 0); 634 } 635 636 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0); 637 } 638 639 if (spa->spa_label_features == NULL) { 640 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME, 641 KM_SLEEP) == 0); 642 } 643 644 spa->spa_iokstat = kstat_create("zfs", 0, name, 645 "disk", KSTAT_TYPE_IO, 1, 0); 646 if (spa->spa_iokstat) { 647 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock; 648 kstat_install(spa->spa_iokstat); 649 } 650 651 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0); 652 653 spa->spa_min_ashift = INT_MAX; 654 spa->spa_max_ashift = 0; 655 656 /* 657 * As a pool is being created, treat all features as disabled by 658 * setting SPA_FEATURE_DISABLED for all entries in the feature 659 * refcount cache. 660 */ 661 for (int i = 0; i < SPA_FEATURES; i++) { 662 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED; 663 } 664 665 return (spa); 666 } 667 668 /* 669 * Removes a spa_t from the namespace, freeing up any memory used. Requires 670 * spa_namespace_lock. This is called only after the spa_t has been closed and 671 * deactivated. 672 */ 673 void 674 spa_remove(spa_t *spa) 675 { 676 spa_config_dirent_t *dp; 677 678 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 679 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 680 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0); 681 682 nvlist_free(spa->spa_config_splitting); 683 684 avl_remove(&spa_namespace_avl, spa); 685 cv_broadcast(&spa_namespace_cv); 686 687 if (spa->spa_root) { 688 spa_strfree(spa->spa_root); 689 spa_active_count--; 690 } 691 692 while ((dp = list_head(&spa->spa_config_list)) != NULL) { 693 list_remove(&spa->spa_config_list, dp); 694 if (dp->scd_path != NULL) 695 spa_strfree(dp->scd_path); 696 kmem_free(dp, sizeof (spa_config_dirent_t)); 697 } 698 699 list_destroy(&spa->spa_config_list); 700 701 nvlist_free(spa->spa_label_features); 702 nvlist_free(spa->spa_load_info); 703 spa_config_set(spa, NULL); 704 705 mutex_enter(&cpu_lock); 706 if (spa->spa_deadman_cycid != CYCLIC_NONE) 707 cyclic_remove(spa->spa_deadman_cycid); 708 mutex_exit(&cpu_lock); 709 spa->spa_deadman_cycid = CYCLIC_NONE; 710 711 refcount_destroy(&spa->spa_refcount); 712 713 spa_config_lock_destroy(spa); 714 715 kstat_delete(spa->spa_iokstat); 716 spa->spa_iokstat = NULL; 717 718 for (int t = 0; t < TXG_SIZE; t++) 719 bplist_destroy(&spa->spa_free_bplist[t]); 720 721 zio_checksum_templates_free(spa); 722 723 cv_destroy(&spa->spa_async_cv); 724 cv_destroy(&spa->spa_evicting_os_cv); 725 cv_destroy(&spa->spa_proc_cv); 726 cv_destroy(&spa->spa_scrub_io_cv); 727 cv_destroy(&spa->spa_suspend_cv); 728 729 mutex_destroy(&spa->spa_async_lock); 730 mutex_destroy(&spa->spa_errlist_lock); 731 mutex_destroy(&spa->spa_errlog_lock); 732 mutex_destroy(&spa->spa_evicting_os_lock); 733 mutex_destroy(&spa->spa_history_lock); 734 mutex_destroy(&spa->spa_proc_lock); 735 mutex_destroy(&spa->spa_props_lock); 736 mutex_destroy(&spa->spa_cksum_tmpls_lock); 737 mutex_destroy(&spa->spa_scrub_lock); 738 mutex_destroy(&spa->spa_suspend_lock); 739 mutex_destroy(&spa->spa_vdev_top_lock); 740 mutex_destroy(&spa->spa_iokstat_lock); 741 742 kmem_free(spa, sizeof (spa_t)); 743 } 744 745 /* 746 * Given a pool, return the next pool in the namespace, or NULL if there is 747 * none. If 'prev' is NULL, return the first pool. 748 */ 749 spa_t * 750 spa_next(spa_t *prev) 751 { 752 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 753 754 if (prev) 755 return (AVL_NEXT(&spa_namespace_avl, prev)); 756 else 757 return (avl_first(&spa_namespace_avl)); 758 } 759 760 /* 761 * ========================================================================== 762 * SPA refcount functions 763 * ========================================================================== 764 */ 765 766 /* 767 * Add a reference to the given spa_t. Must have at least one reference, or 768 * have the namespace lock held. 769 */ 770 void 771 spa_open_ref(spa_t *spa, void *tag) 772 { 773 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || 774 MUTEX_HELD(&spa_namespace_lock)); 775 (void) refcount_add(&spa->spa_refcount, tag); 776 } 777 778 /* 779 * Remove a reference to the given spa_t. Must have at least one reference, or 780 * have the namespace lock held. 781 */ 782 void 783 spa_close(spa_t *spa, void *tag) 784 { 785 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || 786 MUTEX_HELD(&spa_namespace_lock)); 787 (void) refcount_remove(&spa->spa_refcount, tag); 788 } 789 790 /* 791 * Remove a reference to the given spa_t held by a dsl dir that is 792 * being asynchronously released. Async releases occur from a taskq 793 * performing eviction of dsl datasets and dirs. The namespace lock 794 * isn't held and the hold by the object being evicted may contribute to 795 * spa_minref (e.g. dataset or directory released during pool export), 796 * so the asserts in spa_close() do not apply. 797 */ 798 void 799 spa_async_close(spa_t *spa, void *tag) 800 { 801 (void) refcount_remove(&spa->spa_refcount, tag); 802 } 803 804 /* 805 * Check to see if the spa refcount is zero. Must be called with 806 * spa_namespace_lock held. We really compare against spa_minref, which is the 807 * number of references acquired when opening a pool 808 */ 809 boolean_t 810 spa_refcount_zero(spa_t *spa) 811 { 812 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 813 814 return (refcount_count(&spa->spa_refcount) == spa->spa_minref); 815 } 816 817 /* 818 * ========================================================================== 819 * SPA spare and l2cache tracking 820 * ========================================================================== 821 */ 822 823 /* 824 * Hot spares and cache devices are tracked using the same code below, 825 * for 'auxiliary' devices. 826 */ 827 828 typedef struct spa_aux { 829 uint64_t aux_guid; 830 uint64_t aux_pool; 831 avl_node_t aux_avl; 832 int aux_count; 833 } spa_aux_t; 834 835 static int 836 spa_aux_compare(const void *a, const void *b) 837 { 838 const spa_aux_t *sa = a; 839 const spa_aux_t *sb = b; 840 841 if (sa->aux_guid < sb->aux_guid) 842 return (-1); 843 else if (sa->aux_guid > sb->aux_guid) 844 return (1); 845 else 846 return (0); 847 } 848 849 void 850 spa_aux_add(vdev_t *vd, avl_tree_t *avl) 851 { 852 avl_index_t where; 853 spa_aux_t search; 854 spa_aux_t *aux; 855 856 search.aux_guid = vd->vdev_guid; 857 if ((aux = avl_find(avl, &search, &where)) != NULL) { 858 aux->aux_count++; 859 } else { 860 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); 861 aux->aux_guid = vd->vdev_guid; 862 aux->aux_count = 1; 863 avl_insert(avl, aux, where); 864 } 865 } 866 867 void 868 spa_aux_remove(vdev_t *vd, avl_tree_t *avl) 869 { 870 spa_aux_t search; 871 spa_aux_t *aux; 872 avl_index_t where; 873 874 search.aux_guid = vd->vdev_guid; 875 aux = avl_find(avl, &search, &where); 876 877 ASSERT(aux != NULL); 878 879 if (--aux->aux_count == 0) { 880 avl_remove(avl, aux); 881 kmem_free(aux, sizeof (spa_aux_t)); 882 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { 883 aux->aux_pool = 0ULL; 884 } 885 } 886 887 boolean_t 888 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) 889 { 890 spa_aux_t search, *found; 891 892 search.aux_guid = guid; 893 found = avl_find(avl, &search, NULL); 894 895 if (pool) { 896 if (found) 897 *pool = found->aux_pool; 898 else 899 *pool = 0ULL; 900 } 901 902 if (refcnt) { 903 if (found) 904 *refcnt = found->aux_count; 905 else 906 *refcnt = 0; 907 } 908 909 return (found != NULL); 910 } 911 912 void 913 spa_aux_activate(vdev_t *vd, avl_tree_t *avl) 914 { 915 spa_aux_t search, *found; 916 avl_index_t where; 917 918 search.aux_guid = vd->vdev_guid; 919 found = avl_find(avl, &search, &where); 920 ASSERT(found != NULL); 921 ASSERT(found->aux_pool == 0ULL); 922 923 found->aux_pool = spa_guid(vd->vdev_spa); 924 } 925 926 /* 927 * Spares are tracked globally due to the following constraints: 928 * 929 * - A spare may be part of multiple pools. 930 * - A spare may be added to a pool even if it's actively in use within 931 * another pool. 932 * - A spare in use in any pool can only be the source of a replacement if 933 * the target is a spare in the same pool. 934 * 935 * We keep track of all spares on the system through the use of a reference 936 * counted AVL tree. When a vdev is added as a spare, or used as a replacement 937 * spare, then we bump the reference count in the AVL tree. In addition, we set 938 * the 'vdev_isspare' member to indicate that the device is a spare (active or 939 * inactive). When a spare is made active (used to replace a device in the 940 * pool), we also keep track of which pool its been made a part of. 941 * 942 * The 'spa_spare_lock' protects the AVL tree. These functions are normally 943 * called under the spa_namespace lock as part of vdev reconfiguration. The 944 * separate spare lock exists for the status query path, which does not need to 945 * be completely consistent with respect to other vdev configuration changes. 946 */ 947 948 static int 949 spa_spare_compare(const void *a, const void *b) 950 { 951 return (spa_aux_compare(a, b)); 952 } 953 954 void 955 spa_spare_add(vdev_t *vd) 956 { 957 mutex_enter(&spa_spare_lock); 958 ASSERT(!vd->vdev_isspare); 959 spa_aux_add(vd, &spa_spare_avl); 960 vd->vdev_isspare = B_TRUE; 961 mutex_exit(&spa_spare_lock); 962 } 963 964 void 965 spa_spare_remove(vdev_t *vd) 966 { 967 mutex_enter(&spa_spare_lock); 968 ASSERT(vd->vdev_isspare); 969 spa_aux_remove(vd, &spa_spare_avl); 970 vd->vdev_isspare = B_FALSE; 971 mutex_exit(&spa_spare_lock); 972 } 973 974 boolean_t 975 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) 976 { 977 boolean_t found; 978 979 mutex_enter(&spa_spare_lock); 980 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); 981 mutex_exit(&spa_spare_lock); 982 983 return (found); 984 } 985 986 void 987 spa_spare_activate(vdev_t *vd) 988 { 989 mutex_enter(&spa_spare_lock); 990 ASSERT(vd->vdev_isspare); 991 spa_aux_activate(vd, &spa_spare_avl); 992 mutex_exit(&spa_spare_lock); 993 } 994 995 /* 996 * Level 2 ARC devices are tracked globally for the same reasons as spares. 997 * Cache devices currently only support one pool per cache device, and so 998 * for these devices the aux reference count is currently unused beyond 1. 999 */ 1000 1001 static int 1002 spa_l2cache_compare(const void *a, const void *b) 1003 { 1004 return (spa_aux_compare(a, b)); 1005 } 1006 1007 void 1008 spa_l2cache_add(vdev_t *vd) 1009 { 1010 mutex_enter(&spa_l2cache_lock); 1011 ASSERT(!vd->vdev_isl2cache); 1012 spa_aux_add(vd, &spa_l2cache_avl); 1013 vd->vdev_isl2cache = B_TRUE; 1014 mutex_exit(&spa_l2cache_lock); 1015 } 1016 1017 void 1018 spa_l2cache_remove(vdev_t *vd) 1019 { 1020 mutex_enter(&spa_l2cache_lock); 1021 ASSERT(vd->vdev_isl2cache); 1022 spa_aux_remove(vd, &spa_l2cache_avl); 1023 vd->vdev_isl2cache = B_FALSE; 1024 mutex_exit(&spa_l2cache_lock); 1025 } 1026 1027 boolean_t 1028 spa_l2cache_exists(uint64_t guid, uint64_t *pool) 1029 { 1030 boolean_t found; 1031 1032 mutex_enter(&spa_l2cache_lock); 1033 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); 1034 mutex_exit(&spa_l2cache_lock); 1035 1036 return (found); 1037 } 1038 1039 void 1040 spa_l2cache_activate(vdev_t *vd) 1041 { 1042 mutex_enter(&spa_l2cache_lock); 1043 ASSERT(vd->vdev_isl2cache); 1044 spa_aux_activate(vd, &spa_l2cache_avl); 1045 mutex_exit(&spa_l2cache_lock); 1046 } 1047 1048 /* 1049 * ========================================================================== 1050 * SPA vdev locking 1051 * ========================================================================== 1052 */ 1053 1054 /* 1055 * Lock the given spa_t for the purpose of adding or removing a vdev. 1056 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 1057 * It returns the next transaction group for the spa_t. 1058 */ 1059 uint64_t 1060 spa_vdev_enter(spa_t *spa) 1061 { 1062 mutex_enter(&spa->spa_vdev_top_lock); 1063 mutex_enter(&spa_namespace_lock); 1064 return (spa_vdev_config_enter(spa)); 1065 } 1066 1067 /* 1068 * Internal implementation for spa_vdev_enter(). Used when a vdev 1069 * operation requires multiple syncs (i.e. removing a device) while 1070 * keeping the spa_namespace_lock held. 1071 */ 1072 uint64_t 1073 spa_vdev_config_enter(spa_t *spa) 1074 { 1075 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1076 1077 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1078 1079 return (spa_last_synced_txg(spa) + 1); 1080 } 1081 1082 /* 1083 * Used in combination with spa_vdev_config_enter() to allow the syncing 1084 * of multiple transactions without releasing the spa_namespace_lock. 1085 */ 1086 void 1087 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) 1088 { 1089 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1090 1091 int config_changed = B_FALSE; 1092 1093 ASSERT(txg > spa_last_synced_txg(spa)); 1094 1095 spa->spa_pending_vdev = NULL; 1096 1097 /* 1098 * Reassess the DTLs. 1099 */ 1100 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 1101 1102 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { 1103 config_changed = B_TRUE; 1104 spa->spa_config_generation++; 1105 } 1106 1107 /* 1108 * Verify the metaslab classes. 1109 */ 1110 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); 1111 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); 1112 1113 spa_config_exit(spa, SCL_ALL, spa); 1114 1115 /* 1116 * Panic the system if the specified tag requires it. This 1117 * is useful for ensuring that configurations are updated 1118 * transactionally. 1119 */ 1120 if (zio_injection_enabled) 1121 zio_handle_panic_injection(spa, tag, 0); 1122 1123 /* 1124 * Note: this txg_wait_synced() is important because it ensures 1125 * that there won't be more than one config change per txg. 1126 * This allows us to use the txg as the generation number. 1127 */ 1128 if (error == 0) 1129 txg_wait_synced(spa->spa_dsl_pool, txg); 1130 1131 if (vd != NULL) { 1132 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL); 1133 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1134 vdev_free(vd); 1135 spa_config_exit(spa, SCL_ALL, spa); 1136 } 1137 1138 /* 1139 * If the config changed, update the config cache. 1140 */ 1141 if (config_changed) 1142 spa_config_sync(spa, B_FALSE, B_TRUE); 1143 } 1144 1145 /* 1146 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 1147 * locking of spa_vdev_enter(), we also want make sure the transactions have 1148 * synced to disk, and then update the global configuration cache with the new 1149 * information. 1150 */ 1151 int 1152 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 1153 { 1154 spa_vdev_config_exit(spa, vd, txg, error, FTAG); 1155 mutex_exit(&spa_namespace_lock); 1156 mutex_exit(&spa->spa_vdev_top_lock); 1157 1158 return (error); 1159 } 1160 1161 /* 1162 * Lock the given spa_t for the purpose of changing vdev state. 1163 */ 1164 void 1165 spa_vdev_state_enter(spa_t *spa, int oplocks) 1166 { 1167 int locks = SCL_STATE_ALL | oplocks; 1168 1169 /* 1170 * Root pools may need to read of the underlying devfs filesystem 1171 * when opening up a vdev. Unfortunately if we're holding the 1172 * SCL_ZIO lock it will result in a deadlock when we try to issue 1173 * the read from the root filesystem. Instead we "prefetch" 1174 * the associated vnodes that we need prior to opening the 1175 * underlying devices and cache them so that we can prevent 1176 * any I/O when we are doing the actual open. 1177 */ 1178 if (spa_is_root(spa)) { 1179 int low = locks & ~(SCL_ZIO - 1); 1180 int high = locks & ~low; 1181 1182 spa_config_enter(spa, high, spa, RW_WRITER); 1183 vdev_hold(spa->spa_root_vdev); 1184 spa_config_enter(spa, low, spa, RW_WRITER); 1185 } else { 1186 spa_config_enter(spa, locks, spa, RW_WRITER); 1187 } 1188 spa->spa_vdev_locks = locks; 1189 } 1190 1191 int 1192 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) 1193 { 1194 boolean_t config_changed = B_FALSE; 1195 1196 if (vd != NULL || error == 0) 1197 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, 1198 0, 0, B_FALSE); 1199 1200 if (vd != NULL) { 1201 vdev_state_dirty(vd->vdev_top); 1202 config_changed = B_TRUE; 1203 spa->spa_config_generation++; 1204 } 1205 1206 if (spa_is_root(spa)) 1207 vdev_rele(spa->spa_root_vdev); 1208 1209 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); 1210 spa_config_exit(spa, spa->spa_vdev_locks, spa); 1211 1212 /* 1213 * If anything changed, wait for it to sync. This ensures that, 1214 * from the system administrator's perspective, zpool(1M) commands 1215 * are synchronous. This is important for things like zpool offline: 1216 * when the command completes, you expect no further I/O from ZFS. 1217 */ 1218 if (vd != NULL) 1219 txg_wait_synced(spa->spa_dsl_pool, 0); 1220 1221 /* 1222 * If the config changed, update the config cache. 1223 */ 1224 if (config_changed) { 1225 mutex_enter(&spa_namespace_lock); 1226 spa_config_sync(spa, B_FALSE, B_TRUE); 1227 mutex_exit(&spa_namespace_lock); 1228 } 1229 1230 return (error); 1231 } 1232 1233 /* 1234 * ========================================================================== 1235 * Miscellaneous functions 1236 * ========================================================================== 1237 */ 1238 1239 void 1240 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx) 1241 { 1242 if (!nvlist_exists(spa->spa_label_features, feature)) { 1243 fnvlist_add_boolean(spa->spa_label_features, feature); 1244 /* 1245 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't 1246 * dirty the vdev config because lock SCL_CONFIG is not held. 1247 * Thankfully, in this case we don't need to dirty the config 1248 * because it will be written out anyway when we finish 1249 * creating the pool. 1250 */ 1251 if (tx->tx_txg != TXG_INITIAL) 1252 vdev_config_dirty(spa->spa_root_vdev); 1253 } 1254 } 1255 1256 void 1257 spa_deactivate_mos_feature(spa_t *spa, const char *feature) 1258 { 1259 if (nvlist_remove_all(spa->spa_label_features, feature) == 0) 1260 vdev_config_dirty(spa->spa_root_vdev); 1261 } 1262 1263 /* 1264 * Rename a spa_t. 1265 */ 1266 int 1267 spa_rename(const char *name, const char *newname) 1268 { 1269 spa_t *spa; 1270 int err; 1271 1272 /* 1273 * Lookup the spa_t and grab the config lock for writing. We need to 1274 * actually open the pool so that we can sync out the necessary labels. 1275 * It's OK to call spa_open() with the namespace lock held because we 1276 * allow recursive calls for other reasons. 1277 */ 1278 mutex_enter(&spa_namespace_lock); 1279 if ((err = spa_open(name, &spa, FTAG)) != 0) { 1280 mutex_exit(&spa_namespace_lock); 1281 return (err); 1282 } 1283 1284 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1285 1286 avl_remove(&spa_namespace_avl, spa); 1287 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); 1288 avl_add(&spa_namespace_avl, spa); 1289 1290 /* 1291 * Sync all labels to disk with the new names by marking the root vdev 1292 * dirty and waiting for it to sync. It will pick up the new pool name 1293 * during the sync. 1294 */ 1295 vdev_config_dirty(spa->spa_root_vdev); 1296 1297 spa_config_exit(spa, SCL_ALL, FTAG); 1298 1299 txg_wait_synced(spa->spa_dsl_pool, 0); 1300 1301 /* 1302 * Sync the updated config cache. 1303 */ 1304 spa_config_sync(spa, B_FALSE, B_TRUE); 1305 1306 spa_close(spa, FTAG); 1307 1308 mutex_exit(&spa_namespace_lock); 1309 1310 return (0); 1311 } 1312 1313 /* 1314 * Return the spa_t associated with given pool_guid, if it exists. If 1315 * device_guid is non-zero, determine whether the pool exists *and* contains 1316 * a device with the specified device_guid. 1317 */ 1318 spa_t * 1319 spa_by_guid(uint64_t pool_guid, uint64_t device_guid) 1320 { 1321 spa_t *spa; 1322 avl_tree_t *t = &spa_namespace_avl; 1323 1324 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1325 1326 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 1327 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 1328 continue; 1329 if (spa->spa_root_vdev == NULL) 1330 continue; 1331 if (spa_guid(spa) == pool_guid) { 1332 if (device_guid == 0) 1333 break; 1334 1335 if (vdev_lookup_by_guid(spa->spa_root_vdev, 1336 device_guid) != NULL) 1337 break; 1338 1339 /* 1340 * Check any devices we may be in the process of adding. 1341 */ 1342 if (spa->spa_pending_vdev) { 1343 if (vdev_lookup_by_guid(spa->spa_pending_vdev, 1344 device_guid) != NULL) 1345 break; 1346 } 1347 } 1348 } 1349 1350 return (spa); 1351 } 1352 1353 /* 1354 * Determine whether a pool with the given pool_guid exists. 1355 */ 1356 boolean_t 1357 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 1358 { 1359 return (spa_by_guid(pool_guid, device_guid) != NULL); 1360 } 1361 1362 char * 1363 spa_strdup(const char *s) 1364 { 1365 size_t len; 1366 char *new; 1367 1368 len = strlen(s); 1369 new = kmem_alloc(len + 1, KM_SLEEP); 1370 bcopy(s, new, len); 1371 new[len] = '\0'; 1372 1373 return (new); 1374 } 1375 1376 void 1377 spa_strfree(char *s) 1378 { 1379 kmem_free(s, strlen(s) + 1); 1380 } 1381 1382 uint64_t 1383 spa_get_random(uint64_t range) 1384 { 1385 uint64_t r; 1386 1387 ASSERT(range != 0); 1388 1389 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 1390 1391 return (r % range); 1392 } 1393 1394 uint64_t 1395 spa_generate_guid(spa_t *spa) 1396 { 1397 uint64_t guid = spa_get_random(-1ULL); 1398 1399 if (spa != NULL) { 1400 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) 1401 guid = spa_get_random(-1ULL); 1402 } else { 1403 while (guid == 0 || spa_guid_exists(guid, 0)) 1404 guid = spa_get_random(-1ULL); 1405 } 1406 1407 return (guid); 1408 } 1409 1410 void 1411 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp) 1412 { 1413 char type[256]; 1414 char *checksum = NULL; 1415 char *compress = NULL; 1416 1417 if (bp != NULL) { 1418 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) { 1419 dmu_object_byteswap_t bswap = 1420 DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); 1421 (void) snprintf(type, sizeof (type), "bswap %s %s", 1422 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ? 1423 "metadata" : "data", 1424 dmu_ot_byteswap[bswap].ob_name); 1425 } else { 1426 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name, 1427 sizeof (type)); 1428 } 1429 if (!BP_IS_EMBEDDED(bp)) { 1430 checksum = 1431 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; 1432 } 1433 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; 1434 } 1435 1436 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum, 1437 compress); 1438 } 1439 1440 void 1441 spa_freeze(spa_t *spa) 1442 { 1443 uint64_t freeze_txg = 0; 1444 1445 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1446 if (spa->spa_freeze_txg == UINT64_MAX) { 1447 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 1448 spa->spa_freeze_txg = freeze_txg; 1449 } 1450 spa_config_exit(spa, SCL_ALL, FTAG); 1451 if (freeze_txg != 0) 1452 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 1453 } 1454 1455 void 1456 zfs_panic_recover(const char *fmt, ...) 1457 { 1458 va_list adx; 1459 1460 va_start(adx, fmt); 1461 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); 1462 va_end(adx); 1463 } 1464 1465 /* 1466 * This is a stripped-down version of strtoull, suitable only for converting 1467 * lowercase hexadecimal numbers that don't overflow. 1468 */ 1469 uint64_t 1470 strtonum(const char *str, char **nptr) 1471 { 1472 uint64_t val = 0; 1473 char c; 1474 int digit; 1475 1476 while ((c = *str) != '\0') { 1477 if (c >= '0' && c <= '9') 1478 digit = c - '0'; 1479 else if (c >= 'a' && c <= 'f') 1480 digit = 10 + c - 'a'; 1481 else 1482 break; 1483 1484 val *= 16; 1485 val += digit; 1486 1487 str++; 1488 } 1489 1490 if (nptr) 1491 *nptr = (char *)str; 1492 1493 return (val); 1494 } 1495 1496 /* 1497 * ========================================================================== 1498 * Accessor functions 1499 * ========================================================================== 1500 */ 1501 1502 boolean_t 1503 spa_shutting_down(spa_t *spa) 1504 { 1505 return (spa->spa_async_suspended); 1506 } 1507 1508 dsl_pool_t * 1509 spa_get_dsl(spa_t *spa) 1510 { 1511 return (spa->spa_dsl_pool); 1512 } 1513 1514 boolean_t 1515 spa_is_initializing(spa_t *spa) 1516 { 1517 return (spa->spa_is_initializing); 1518 } 1519 1520 blkptr_t * 1521 spa_get_rootblkptr(spa_t *spa) 1522 { 1523 return (&spa->spa_ubsync.ub_rootbp); 1524 } 1525 1526 void 1527 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 1528 { 1529 spa->spa_uberblock.ub_rootbp = *bp; 1530 } 1531 1532 void 1533 spa_altroot(spa_t *spa, char *buf, size_t buflen) 1534 { 1535 if (spa->spa_root == NULL) 1536 buf[0] = '\0'; 1537 else 1538 (void) strncpy(buf, spa->spa_root, buflen); 1539 } 1540 1541 int 1542 spa_sync_pass(spa_t *spa) 1543 { 1544 return (spa->spa_sync_pass); 1545 } 1546 1547 char * 1548 spa_name(spa_t *spa) 1549 { 1550 return (spa->spa_name); 1551 } 1552 1553 uint64_t 1554 spa_guid(spa_t *spa) 1555 { 1556 dsl_pool_t *dp = spa_get_dsl(spa); 1557 uint64_t guid; 1558 1559 /* 1560 * If we fail to parse the config during spa_load(), we can go through 1561 * the error path (which posts an ereport) and end up here with no root 1562 * vdev. We stash the original pool guid in 'spa_config_guid' to handle 1563 * this case. 1564 */ 1565 if (spa->spa_root_vdev == NULL) 1566 return (spa->spa_config_guid); 1567 1568 guid = spa->spa_last_synced_guid != 0 ? 1569 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid; 1570 1571 /* 1572 * Return the most recently synced out guid unless we're 1573 * in syncing context. 1574 */ 1575 if (dp && dsl_pool_sync_context(dp)) 1576 return (spa->spa_root_vdev->vdev_guid); 1577 else 1578 return (guid); 1579 } 1580 1581 uint64_t 1582 spa_load_guid(spa_t *spa) 1583 { 1584 /* 1585 * This is a GUID that exists solely as a reference for the 1586 * purposes of the arc. It is generated at load time, and 1587 * is never written to persistent storage. 1588 */ 1589 return (spa->spa_load_guid); 1590 } 1591 1592 uint64_t 1593 spa_last_synced_txg(spa_t *spa) 1594 { 1595 return (spa->spa_ubsync.ub_txg); 1596 } 1597 1598 uint64_t 1599 spa_first_txg(spa_t *spa) 1600 { 1601 return (spa->spa_first_txg); 1602 } 1603 1604 uint64_t 1605 spa_syncing_txg(spa_t *spa) 1606 { 1607 return (spa->spa_syncing_txg); 1608 } 1609 1610 pool_state_t 1611 spa_state(spa_t *spa) 1612 { 1613 return (spa->spa_state); 1614 } 1615 1616 spa_load_state_t 1617 spa_load_state(spa_t *spa) 1618 { 1619 return (spa->spa_load_state); 1620 } 1621 1622 uint64_t 1623 spa_freeze_txg(spa_t *spa) 1624 { 1625 return (spa->spa_freeze_txg); 1626 } 1627 1628 /* ARGSUSED */ 1629 uint64_t 1630 spa_get_asize(spa_t *spa, uint64_t lsize) 1631 { 1632 return (lsize * spa_asize_inflation); 1633 } 1634 1635 /* 1636 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%), 1637 * or at least 32MB. 1638 * 1639 * See the comment above spa_slop_shift for details. 1640 */ 1641 uint64_t 1642 spa_get_slop_space(spa_t *spa) { 1643 uint64_t space = spa_get_dspace(spa); 1644 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1)); 1645 } 1646 1647 uint64_t 1648 spa_get_dspace(spa_t *spa) 1649 { 1650 return (spa->spa_dspace); 1651 } 1652 1653 void 1654 spa_update_dspace(spa_t *spa) 1655 { 1656 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + 1657 ddt_get_dedup_dspace(spa); 1658 } 1659 1660 /* 1661 * Return the failure mode that has been set to this pool. The default 1662 * behavior will be to block all I/Os when a complete failure occurs. 1663 */ 1664 uint8_t 1665 spa_get_failmode(spa_t *spa) 1666 { 1667 return (spa->spa_failmode); 1668 } 1669 1670 boolean_t 1671 spa_suspended(spa_t *spa) 1672 { 1673 return (spa->spa_suspended); 1674 } 1675 1676 uint64_t 1677 spa_version(spa_t *spa) 1678 { 1679 return (spa->spa_ubsync.ub_version); 1680 } 1681 1682 boolean_t 1683 spa_deflate(spa_t *spa) 1684 { 1685 return (spa->spa_deflate); 1686 } 1687 1688 metaslab_class_t * 1689 spa_normal_class(spa_t *spa) 1690 { 1691 return (spa->spa_normal_class); 1692 } 1693 1694 metaslab_class_t * 1695 spa_log_class(spa_t *spa) 1696 { 1697 return (spa->spa_log_class); 1698 } 1699 1700 void 1701 spa_evicting_os_register(spa_t *spa, objset_t *os) 1702 { 1703 mutex_enter(&spa->spa_evicting_os_lock); 1704 list_insert_head(&spa->spa_evicting_os_list, os); 1705 mutex_exit(&spa->spa_evicting_os_lock); 1706 } 1707 1708 void 1709 spa_evicting_os_deregister(spa_t *spa, objset_t *os) 1710 { 1711 mutex_enter(&spa->spa_evicting_os_lock); 1712 list_remove(&spa->spa_evicting_os_list, os); 1713 cv_broadcast(&spa->spa_evicting_os_cv); 1714 mutex_exit(&spa->spa_evicting_os_lock); 1715 } 1716 1717 void 1718 spa_evicting_os_wait(spa_t *spa) 1719 { 1720 mutex_enter(&spa->spa_evicting_os_lock); 1721 while (!list_is_empty(&spa->spa_evicting_os_list)) 1722 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock); 1723 mutex_exit(&spa->spa_evicting_os_lock); 1724 1725 dmu_buf_user_evict_wait(); 1726 } 1727 1728 int 1729 spa_max_replication(spa_t *spa) 1730 { 1731 /* 1732 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to 1733 * handle BPs with more than one DVA allocated. Set our max 1734 * replication level accordingly. 1735 */ 1736 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) 1737 return (1); 1738 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 1739 } 1740 1741 int 1742 spa_prev_software_version(spa_t *spa) 1743 { 1744 return (spa->spa_prev_software_version); 1745 } 1746 1747 uint64_t 1748 spa_deadman_synctime(spa_t *spa) 1749 { 1750 return (spa->spa_deadman_synctime); 1751 } 1752 1753 uint64_t 1754 dva_get_dsize_sync(spa_t *spa, const dva_t *dva) 1755 { 1756 uint64_t asize = DVA_GET_ASIZE(dva); 1757 uint64_t dsize = asize; 1758 1759 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); 1760 1761 if (asize != 0 && spa->spa_deflate) { 1762 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 1763 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; 1764 } 1765 1766 return (dsize); 1767 } 1768 1769 uint64_t 1770 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) 1771 { 1772 uint64_t dsize = 0; 1773 1774 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1775 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1776 1777 return (dsize); 1778 } 1779 1780 uint64_t 1781 bp_get_dsize(spa_t *spa, const blkptr_t *bp) 1782 { 1783 uint64_t dsize = 0; 1784 1785 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 1786 1787 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1788 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1789 1790 spa_config_exit(spa, SCL_VDEV, FTAG); 1791 1792 return (dsize); 1793 } 1794 1795 /* 1796 * ========================================================================== 1797 * Initialization and Termination 1798 * ========================================================================== 1799 */ 1800 1801 static int 1802 spa_name_compare(const void *a1, const void *a2) 1803 { 1804 const spa_t *s1 = a1; 1805 const spa_t *s2 = a2; 1806 int s; 1807 1808 s = strcmp(s1->spa_name, s2->spa_name); 1809 if (s > 0) 1810 return (1); 1811 if (s < 0) 1812 return (-1); 1813 return (0); 1814 } 1815 1816 int 1817 spa_busy(void) 1818 { 1819 return (spa_active_count); 1820 } 1821 1822 void 1823 spa_boot_init() 1824 { 1825 spa_config_load(); 1826 } 1827 1828 void 1829 spa_init(int mode) 1830 { 1831 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 1832 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); 1833 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); 1834 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 1835 1836 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 1837 offsetof(spa_t, spa_avl)); 1838 1839 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), 1840 offsetof(spa_aux_t, aux_avl)); 1841 1842 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), 1843 offsetof(spa_aux_t, aux_avl)); 1844 1845 spa_mode_global = mode; 1846 1847 #ifdef _KERNEL 1848 spa_arch_init(); 1849 #else 1850 if (spa_mode_global != FREAD && dprintf_find_string("watch")) { 1851 arc_procfd = open("/proc/self/ctl", O_WRONLY); 1852 if (arc_procfd == -1) { 1853 perror("could not enable watchpoints: " 1854 "opening /proc/self/ctl failed: "); 1855 } else { 1856 arc_watch = B_TRUE; 1857 } 1858 } 1859 #endif 1860 1861 refcount_init(); 1862 unique_init(); 1863 range_tree_init(); 1864 zio_init(); 1865 dmu_init(); 1866 zil_init(); 1867 vdev_cache_stat_init(); 1868 zfs_prop_init(); 1869 zpool_prop_init(); 1870 zpool_feature_init(); 1871 spa_config_load(); 1872 l2arc_start(); 1873 } 1874 1875 void 1876 spa_fini(void) 1877 { 1878 l2arc_stop(); 1879 1880 spa_evict_all(); 1881 1882 vdev_cache_stat_fini(); 1883 zil_fini(); 1884 dmu_fini(); 1885 zio_fini(); 1886 range_tree_fini(); 1887 unique_fini(); 1888 refcount_fini(); 1889 1890 avl_destroy(&spa_namespace_avl); 1891 avl_destroy(&spa_spare_avl); 1892 avl_destroy(&spa_l2cache_avl); 1893 1894 cv_destroy(&spa_namespace_cv); 1895 mutex_destroy(&spa_namespace_lock); 1896 mutex_destroy(&spa_spare_lock); 1897 mutex_destroy(&spa_l2cache_lock); 1898 } 1899 1900 /* 1901 * Return whether this pool has slogs. No locking needed. 1902 * It's not a problem if the wrong answer is returned as it's only for 1903 * performance and not correctness 1904 */ 1905 boolean_t 1906 spa_has_slogs(spa_t *spa) 1907 { 1908 return (spa->spa_log_class->mc_rotor != NULL); 1909 } 1910 1911 spa_log_state_t 1912 spa_get_log_state(spa_t *spa) 1913 { 1914 return (spa->spa_log_state); 1915 } 1916 1917 void 1918 spa_set_log_state(spa_t *spa, spa_log_state_t state) 1919 { 1920 spa->spa_log_state = state; 1921 } 1922 1923 boolean_t 1924 spa_is_root(spa_t *spa) 1925 { 1926 return (spa->spa_is_root); 1927 } 1928 1929 boolean_t 1930 spa_writeable(spa_t *spa) 1931 { 1932 return (!!(spa->spa_mode & FWRITE)); 1933 } 1934 1935 /* 1936 * Returns true if there is a pending sync task in any of the current 1937 * syncing txg, the current quiescing txg, or the current open txg. 1938 */ 1939 boolean_t 1940 spa_has_pending_synctask(spa_t *spa) 1941 { 1942 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks)); 1943 } 1944 1945 int 1946 spa_mode(spa_t *spa) 1947 { 1948 return (spa->spa_mode); 1949 } 1950 1951 uint64_t 1952 spa_bootfs(spa_t *spa) 1953 { 1954 return (spa->spa_bootfs); 1955 } 1956 1957 uint64_t 1958 spa_delegation(spa_t *spa) 1959 { 1960 return (spa->spa_delegation); 1961 } 1962 1963 objset_t * 1964 spa_meta_objset(spa_t *spa) 1965 { 1966 return (spa->spa_meta_objset); 1967 } 1968 1969 enum zio_checksum 1970 spa_dedup_checksum(spa_t *spa) 1971 { 1972 return (spa->spa_dedup_checksum); 1973 } 1974 1975 /* 1976 * Reset pool scan stat per scan pass (or reboot). 1977 */ 1978 void 1979 spa_scan_stat_init(spa_t *spa) 1980 { 1981 /* data not stored on disk */ 1982 spa->spa_scan_pass_start = gethrestime_sec(); 1983 spa->spa_scan_pass_exam = 0; 1984 vdev_scan_stat_init(spa->spa_root_vdev); 1985 } 1986 1987 /* 1988 * Get scan stats for zpool status reports 1989 */ 1990 int 1991 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) 1992 { 1993 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; 1994 1995 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) 1996 return (SET_ERROR(ENOENT)); 1997 bzero(ps, sizeof (pool_scan_stat_t)); 1998 1999 /* data stored on disk */ 2000 ps->pss_func = scn->scn_phys.scn_func; 2001 ps->pss_start_time = scn->scn_phys.scn_start_time; 2002 ps->pss_end_time = scn->scn_phys.scn_end_time; 2003 ps->pss_to_examine = scn->scn_phys.scn_to_examine; 2004 ps->pss_examined = scn->scn_phys.scn_examined; 2005 ps->pss_to_process = scn->scn_phys.scn_to_process; 2006 ps->pss_processed = scn->scn_phys.scn_processed; 2007 ps->pss_errors = scn->scn_phys.scn_errors; 2008 ps->pss_state = scn->scn_phys.scn_state; 2009 2010 /* data not stored on disk */ 2011 ps->pss_pass_start = spa->spa_scan_pass_start; 2012 ps->pss_pass_exam = spa->spa_scan_pass_exam; 2013 2014 return (0); 2015 } 2016 2017 boolean_t 2018 spa_debug_enabled(spa_t *spa) 2019 { 2020 return (spa->spa_debug); 2021 } 2022 2023 int 2024 spa_maxblocksize(spa_t *spa) 2025 { 2026 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) 2027 return (SPA_MAXBLOCKSIZE); 2028 else 2029 return (SPA_OLD_MAXBLOCKSIZE); 2030 } 2031