1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2015 by Delphix. All rights reserved. 24 * Copyright 2015 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 26 * Copyright 2013 Saso Kiselkov. All rights reserved. 27 * Copyright (c) 2014 Integros [integros.com] 28 */ 29 30 #include <sys/zfs_context.h> 31 #include <sys/spa_impl.h> 32 #include <sys/spa_boot.h> 33 #include <sys/zio.h> 34 #include <sys/zio_checksum.h> 35 #include <sys/zio_compress.h> 36 #include <sys/dmu.h> 37 #include <sys/dmu_tx.h> 38 #include <sys/zap.h> 39 #include <sys/zil.h> 40 #include <sys/vdev_impl.h> 41 #include <sys/metaslab.h> 42 #include <sys/uberblock_impl.h> 43 #include <sys/txg.h> 44 #include <sys/avl.h> 45 #include <sys/unique.h> 46 #include <sys/dsl_pool.h> 47 #include <sys/dsl_dir.h> 48 #include <sys/dsl_prop.h> 49 #include <sys/dsl_scan.h> 50 #include <sys/fs/zfs.h> 51 #include <sys/metaslab_impl.h> 52 #include <sys/arc.h> 53 #include <sys/ddt.h> 54 #include "zfs_prop.h" 55 #include <sys/zfeature.h> 56 57 /* 58 * SPA locking 59 * 60 * There are four basic locks for managing spa_t structures: 61 * 62 * spa_namespace_lock (global mutex) 63 * 64 * This lock must be acquired to do any of the following: 65 * 66 * - Lookup a spa_t by name 67 * - Add or remove a spa_t from the namespace 68 * - Increase spa_refcount from non-zero 69 * - Check if spa_refcount is zero 70 * - Rename a spa_t 71 * - add/remove/attach/detach devices 72 * - Held for the duration of create/destroy/import/export 73 * 74 * It does not need to handle recursion. A create or destroy may 75 * reference objects (files or zvols) in other pools, but by 76 * definition they must have an existing reference, and will never need 77 * to lookup a spa_t by name. 78 * 79 * spa_refcount (per-spa refcount_t protected by mutex) 80 * 81 * This reference count keep track of any active users of the spa_t. The 82 * spa_t cannot be destroyed or freed while this is non-zero. Internally, 83 * the refcount is never really 'zero' - opening a pool implicitly keeps 84 * some references in the DMU. Internally we check against spa_minref, but 85 * present the image of a zero/non-zero value to consumers. 86 * 87 * spa_config_lock[] (per-spa array of rwlocks) 88 * 89 * This protects the spa_t from config changes, and must be held in 90 * the following circumstances: 91 * 92 * - RW_READER to perform I/O to the spa 93 * - RW_WRITER to change the vdev config 94 * 95 * The locking order is fairly straightforward: 96 * 97 * spa_namespace_lock -> spa_refcount 98 * 99 * The namespace lock must be acquired to increase the refcount from 0 100 * or to check if it is zero. 101 * 102 * spa_refcount -> spa_config_lock[] 103 * 104 * There must be at least one valid reference on the spa_t to acquire 105 * the config lock. 106 * 107 * spa_namespace_lock -> spa_config_lock[] 108 * 109 * The namespace lock must always be taken before the config lock. 110 * 111 * 112 * The spa_namespace_lock can be acquired directly and is globally visible. 113 * 114 * The namespace is manipulated using the following functions, all of which 115 * require the spa_namespace_lock to be held. 116 * 117 * spa_lookup() Lookup a spa_t by name. 118 * 119 * spa_add() Create a new spa_t in the namespace. 120 * 121 * spa_remove() Remove a spa_t from the namespace. This also 122 * frees up any memory associated with the spa_t. 123 * 124 * spa_next() Returns the next spa_t in the system, or the 125 * first if NULL is passed. 126 * 127 * spa_evict_all() Shutdown and remove all spa_t structures in 128 * the system. 129 * 130 * spa_guid_exists() Determine whether a pool/device guid exists. 131 * 132 * The spa_refcount is manipulated using the following functions: 133 * 134 * spa_open_ref() Adds a reference to the given spa_t. Must be 135 * called with spa_namespace_lock held if the 136 * refcount is currently zero. 137 * 138 * spa_close() Remove a reference from the spa_t. This will 139 * not free the spa_t or remove it from the 140 * namespace. No locking is required. 141 * 142 * spa_refcount_zero() Returns true if the refcount is currently 143 * zero. Must be called with spa_namespace_lock 144 * held. 145 * 146 * The spa_config_lock[] is an array of rwlocks, ordered as follows: 147 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV. 148 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}(). 149 * 150 * To read the configuration, it suffices to hold one of these locks as reader. 151 * To modify the configuration, you must hold all locks as writer. To modify 152 * vdev state without altering the vdev tree's topology (e.g. online/offline), 153 * you must hold SCL_STATE and SCL_ZIO as writer. 154 * 155 * We use these distinct config locks to avoid recursive lock entry. 156 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces 157 * block allocations (SCL_ALLOC), which may require reading space maps 158 * from disk (dmu_read() -> zio_read() -> SCL_ZIO). 159 * 160 * The spa config locks cannot be normal rwlocks because we need the 161 * ability to hand off ownership. For example, SCL_ZIO is acquired 162 * by the issuing thread and later released by an interrupt thread. 163 * They do, however, obey the usual write-wanted semantics to prevent 164 * writer (i.e. system administrator) starvation. 165 * 166 * The lock acquisition rules are as follows: 167 * 168 * SCL_CONFIG 169 * Protects changes to the vdev tree topology, such as vdev 170 * add/remove/attach/detach. Protects the dirty config list 171 * (spa_config_dirty_list) and the set of spares and l2arc devices. 172 * 173 * SCL_STATE 174 * Protects changes to pool state and vdev state, such as vdev 175 * online/offline/fault/degrade/clear. Protects the dirty state list 176 * (spa_state_dirty_list) and global pool state (spa_state). 177 * 178 * SCL_ALLOC 179 * Protects changes to metaslab groups and classes. 180 * Held as reader by metaslab_alloc() and metaslab_claim(). 181 * 182 * SCL_ZIO 183 * Held by bp-level zios (those which have no io_vd upon entry) 184 * to prevent changes to the vdev tree. The bp-level zio implicitly 185 * protects all of its vdev child zios, which do not hold SCL_ZIO. 186 * 187 * SCL_FREE 188 * Protects changes to metaslab groups and classes. 189 * Held as reader by metaslab_free(). SCL_FREE is distinct from 190 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free 191 * blocks in zio_done() while another i/o that holds either 192 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete. 193 * 194 * SCL_VDEV 195 * Held as reader to prevent changes to the vdev tree during trivial 196 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the 197 * other locks, and lower than all of them, to ensure that it's safe 198 * to acquire regardless of caller context. 199 * 200 * In addition, the following rules apply: 201 * 202 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list. 203 * The lock ordering is SCL_CONFIG > spa_props_lock. 204 * 205 * (b) I/O operations on leaf vdevs. For any zio operation that takes 206 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(), 207 * or zio_write_phys() -- the caller must ensure that the config cannot 208 * cannot change in the interim, and that the vdev cannot be reopened. 209 * SCL_STATE as reader suffices for both. 210 * 211 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit(). 212 * 213 * spa_vdev_enter() Acquire the namespace lock and the config lock 214 * for writing. 215 * 216 * spa_vdev_exit() Release the config lock, wait for all I/O 217 * to complete, sync the updated configs to the 218 * cache, and release the namespace lock. 219 * 220 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit(). 221 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual 222 * locking is, always, based on spa_namespace_lock and spa_config_lock[]. 223 * 224 * spa_rename() is also implemented within this file since it requires 225 * manipulation of the namespace. 226 */ 227 228 static avl_tree_t spa_namespace_avl; 229 kmutex_t spa_namespace_lock; 230 static kcondvar_t spa_namespace_cv; 231 static int spa_active_count; 232 int spa_max_replication_override = SPA_DVAS_PER_BP; 233 234 static kmutex_t spa_spare_lock; 235 static avl_tree_t spa_spare_avl; 236 static kmutex_t spa_l2cache_lock; 237 static avl_tree_t spa_l2cache_avl; 238 239 kmem_cache_t *spa_buffer_pool; 240 int spa_mode_global; 241 242 #ifdef ZFS_DEBUG 243 /* Everything except dprintf and spa is on by default in debug builds */ 244 int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA); 245 #else 246 int zfs_flags = 0; 247 #endif 248 249 /* 250 * zfs_recover can be set to nonzero to attempt to recover from 251 * otherwise-fatal errors, typically caused by on-disk corruption. When 252 * set, calls to zfs_panic_recover() will turn into warning messages. 253 * This should only be used as a last resort, as it typically results 254 * in leaked space, or worse. 255 */ 256 boolean_t zfs_recover = B_FALSE; 257 258 /* 259 * If destroy encounters an EIO while reading metadata (e.g. indirect 260 * blocks), space referenced by the missing metadata can not be freed. 261 * Normally this causes the background destroy to become "stalled", as 262 * it is unable to make forward progress. While in this stalled state, 263 * all remaining space to free from the error-encountering filesystem is 264 * "temporarily leaked". Set this flag to cause it to ignore the EIO, 265 * permanently leak the space from indirect blocks that can not be read, 266 * and continue to free everything else that it can. 267 * 268 * The default, "stalling" behavior is useful if the storage partially 269 * fails (i.e. some but not all i/os fail), and then later recovers. In 270 * this case, we will be able to continue pool operations while it is 271 * partially failed, and when it recovers, we can continue to free the 272 * space, with no leaks. However, note that this case is actually 273 * fairly rare. 274 * 275 * Typically pools either (a) fail completely (but perhaps temporarily, 276 * e.g. a top-level vdev going offline), or (b) have localized, 277 * permanent errors (e.g. disk returns the wrong data due to bit flip or 278 * firmware bug). In case (a), this setting does not matter because the 279 * pool will be suspended and the sync thread will not be able to make 280 * forward progress regardless. In case (b), because the error is 281 * permanent, the best we can do is leak the minimum amount of space, 282 * which is what setting this flag will do. Therefore, it is reasonable 283 * for this flag to normally be set, but we chose the more conservative 284 * approach of not setting it, so that there is no possibility of 285 * leaking space in the "partial temporary" failure case. 286 */ 287 boolean_t zfs_free_leak_on_eio = B_FALSE; 288 289 /* 290 * Expiration time in milliseconds. This value has two meanings. First it is 291 * used to determine when the spa_deadman() logic should fire. By default the 292 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds. 293 * Secondly, the value determines if an I/O is considered "hung". Any I/O that 294 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting 295 * in a system panic. 296 */ 297 uint64_t zfs_deadman_synctime_ms = 1000000ULL; 298 299 /* 300 * Check time in milliseconds. This defines the frequency at which we check 301 * for hung I/O. 302 */ 303 uint64_t zfs_deadman_checktime_ms = 5000ULL; 304 305 /* 306 * Override the zfs deadman behavior via /etc/system. By default the 307 * deadman is enabled except on VMware and sparc deployments. 308 */ 309 int zfs_deadman_enabled = -1; 310 311 /* 312 * The worst case is single-sector max-parity RAID-Z blocks, in which 313 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1) 314 * times the size; so just assume that. Add to this the fact that 315 * we can have up to 3 DVAs per bp, and one more factor of 2 because 316 * the block may be dittoed with up to 3 DVAs by ddt_sync(). All together, 317 * the worst case is: 318 * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24 319 */ 320 int spa_asize_inflation = 24; 321 322 /* 323 * Normally, we don't allow the last 3.2% (1/(2^spa_slop_shift)) of space in 324 * the pool to be consumed. This ensures that we don't run the pool 325 * completely out of space, due to unaccounted changes (e.g. to the MOS). 326 * It also limits the worst-case time to allocate space. If we have 327 * less than this amount of free space, most ZPL operations (e.g. write, 328 * create) will return ENOSPC. 329 * 330 * Certain operations (e.g. file removal, most administrative actions) can 331 * use half the slop space. They will only return ENOSPC if less than half 332 * the slop space is free. Typically, once the pool has less than the slop 333 * space free, the user will use these operations to free up space in the pool. 334 * These are the operations that call dsl_pool_adjustedsize() with the netfree 335 * argument set to TRUE. 336 * 337 * A very restricted set of operations are always permitted, regardless of 338 * the amount of free space. These are the operations that call 339 * dsl_sync_task(ZFS_SPACE_CHECK_NONE), e.g. "zfs destroy". If these 340 * operations result in a net increase in the amount of space used, 341 * it is possible to run the pool completely out of space, causing it to 342 * be permanently read-only. 343 * 344 * See also the comments in zfs_space_check_t. 345 */ 346 int spa_slop_shift = 5; 347 348 /* 349 * ========================================================================== 350 * SPA config locking 351 * ========================================================================== 352 */ 353 static void 354 spa_config_lock_init(spa_t *spa) 355 { 356 for (int i = 0; i < SCL_LOCKS; i++) { 357 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 358 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL); 359 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL); 360 refcount_create_untracked(&scl->scl_count); 361 scl->scl_writer = NULL; 362 scl->scl_write_wanted = 0; 363 } 364 } 365 366 static void 367 spa_config_lock_destroy(spa_t *spa) 368 { 369 for (int i = 0; i < SCL_LOCKS; i++) { 370 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 371 mutex_destroy(&scl->scl_lock); 372 cv_destroy(&scl->scl_cv); 373 refcount_destroy(&scl->scl_count); 374 ASSERT(scl->scl_writer == NULL); 375 ASSERT(scl->scl_write_wanted == 0); 376 } 377 } 378 379 int 380 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw) 381 { 382 for (int i = 0; i < SCL_LOCKS; i++) { 383 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 384 if (!(locks & (1 << i))) 385 continue; 386 mutex_enter(&scl->scl_lock); 387 if (rw == RW_READER) { 388 if (scl->scl_writer || scl->scl_write_wanted) { 389 mutex_exit(&scl->scl_lock); 390 spa_config_exit(spa, locks & ((1 << i) - 1), 391 tag); 392 return (0); 393 } 394 } else { 395 ASSERT(scl->scl_writer != curthread); 396 if (!refcount_is_zero(&scl->scl_count)) { 397 mutex_exit(&scl->scl_lock); 398 spa_config_exit(spa, locks & ((1 << i) - 1), 399 tag); 400 return (0); 401 } 402 scl->scl_writer = curthread; 403 } 404 (void) refcount_add(&scl->scl_count, tag); 405 mutex_exit(&scl->scl_lock); 406 } 407 return (1); 408 } 409 410 void 411 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw) 412 { 413 int wlocks_held = 0; 414 415 ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY); 416 417 for (int i = 0; i < SCL_LOCKS; i++) { 418 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 419 if (scl->scl_writer == curthread) 420 wlocks_held |= (1 << i); 421 if (!(locks & (1 << i))) 422 continue; 423 mutex_enter(&scl->scl_lock); 424 if (rw == RW_READER) { 425 while (scl->scl_writer || scl->scl_write_wanted) { 426 cv_wait(&scl->scl_cv, &scl->scl_lock); 427 } 428 } else { 429 ASSERT(scl->scl_writer != curthread); 430 while (!refcount_is_zero(&scl->scl_count)) { 431 scl->scl_write_wanted++; 432 cv_wait(&scl->scl_cv, &scl->scl_lock); 433 scl->scl_write_wanted--; 434 } 435 scl->scl_writer = curthread; 436 } 437 (void) refcount_add(&scl->scl_count, tag); 438 mutex_exit(&scl->scl_lock); 439 } 440 ASSERT(wlocks_held <= locks); 441 } 442 443 void 444 spa_config_exit(spa_t *spa, int locks, void *tag) 445 { 446 for (int i = SCL_LOCKS - 1; i >= 0; i--) { 447 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 448 if (!(locks & (1 << i))) 449 continue; 450 mutex_enter(&scl->scl_lock); 451 ASSERT(!refcount_is_zero(&scl->scl_count)); 452 if (refcount_remove(&scl->scl_count, tag) == 0) { 453 ASSERT(scl->scl_writer == NULL || 454 scl->scl_writer == curthread); 455 scl->scl_writer = NULL; /* OK in either case */ 456 cv_broadcast(&scl->scl_cv); 457 } 458 mutex_exit(&scl->scl_lock); 459 } 460 } 461 462 int 463 spa_config_held(spa_t *spa, int locks, krw_t rw) 464 { 465 int locks_held = 0; 466 467 for (int i = 0; i < SCL_LOCKS; i++) { 468 spa_config_lock_t *scl = &spa->spa_config_lock[i]; 469 if (!(locks & (1 << i))) 470 continue; 471 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) || 472 (rw == RW_WRITER && scl->scl_writer == curthread)) 473 locks_held |= 1 << i; 474 } 475 476 return (locks_held); 477 } 478 479 /* 480 * ========================================================================== 481 * SPA namespace functions 482 * ========================================================================== 483 */ 484 485 /* 486 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. 487 * Returns NULL if no matching spa_t is found. 488 */ 489 spa_t * 490 spa_lookup(const char *name) 491 { 492 static spa_t search; /* spa_t is large; don't allocate on stack */ 493 spa_t *spa; 494 avl_index_t where; 495 char *cp; 496 497 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 498 499 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name)); 500 501 /* 502 * If it's a full dataset name, figure out the pool name and 503 * just use that. 504 */ 505 cp = strpbrk(search.spa_name, "/@#"); 506 if (cp != NULL) 507 *cp = '\0'; 508 509 spa = avl_find(&spa_namespace_avl, &search, &where); 510 511 return (spa); 512 } 513 514 /* 515 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms. 516 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues 517 * looking for potentially hung I/Os. 518 */ 519 void 520 spa_deadman(void *arg) 521 { 522 spa_t *spa = arg; 523 524 /* 525 * Disable the deadman timer if the pool is suspended. 526 */ 527 if (spa_suspended(spa)) { 528 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY)); 529 return; 530 } 531 532 zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu", 533 (gethrtime() - spa->spa_sync_starttime) / NANOSEC, 534 ++spa->spa_deadman_calls); 535 if (zfs_deadman_enabled) 536 vdev_deadman(spa->spa_root_vdev); 537 } 538 539 /* 540 * Create an uninitialized spa_t with the given name. Requires 541 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already 542 * exist by calling spa_lookup() first. 543 */ 544 spa_t * 545 spa_add(const char *name, nvlist_t *config, const char *altroot) 546 { 547 spa_t *spa; 548 spa_config_dirent_t *dp; 549 cyc_handler_t hdlr; 550 cyc_time_t when; 551 552 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 553 554 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); 555 556 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL); 557 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL); 558 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL); 559 mutex_init(&spa->spa_evicting_os_lock, NULL, MUTEX_DEFAULT, NULL); 560 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL); 561 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL); 562 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL); 563 mutex_init(&spa->spa_cksum_tmpls_lock, NULL, MUTEX_DEFAULT, NULL); 564 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL); 565 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL); 566 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL); 567 mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL); 568 569 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL); 570 cv_init(&spa->spa_evicting_os_cv, NULL, CV_DEFAULT, NULL); 571 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL); 572 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL); 573 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL); 574 575 for (int t = 0; t < TXG_SIZE; t++) 576 bplist_create(&spa->spa_free_bplist[t]); 577 578 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name)); 579 spa->spa_state = POOL_STATE_UNINITIALIZED; 580 spa->spa_freeze_txg = UINT64_MAX; 581 spa->spa_final_txg = UINT64_MAX; 582 spa->spa_load_max_txg = UINT64_MAX; 583 spa->spa_proc = &p0; 584 spa->spa_proc_state = SPA_PROC_NONE; 585 586 hdlr.cyh_func = spa_deadman; 587 hdlr.cyh_arg = spa; 588 hdlr.cyh_level = CY_LOW_LEVEL; 589 590 spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms); 591 592 /* 593 * This determines how often we need to check for hung I/Os after 594 * the cyclic has already fired. Since checking for hung I/Os is 595 * an expensive operation we don't want to check too frequently. 596 * Instead wait for 5 seconds before checking again. 597 */ 598 when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms); 599 when.cyt_when = CY_INFINITY; 600 mutex_enter(&cpu_lock); 601 spa->spa_deadman_cycid = cyclic_add(&hdlr, &when); 602 mutex_exit(&cpu_lock); 603 604 refcount_create(&spa->spa_refcount); 605 spa_config_lock_init(spa); 606 607 avl_add(&spa_namespace_avl, spa); 608 609 /* 610 * Set the alternate root, if there is one. 611 */ 612 if (altroot) { 613 spa->spa_root = spa_strdup(altroot); 614 spa_active_count++; 615 } 616 617 /* 618 * Every pool starts with the default cachefile 619 */ 620 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t), 621 offsetof(spa_config_dirent_t, scd_link)); 622 623 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP); 624 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path); 625 list_insert_head(&spa->spa_config_list, dp); 626 627 VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME, 628 KM_SLEEP) == 0); 629 630 if (config != NULL) { 631 nvlist_t *features; 632 633 if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ, 634 &features) == 0) { 635 VERIFY(nvlist_dup(features, &spa->spa_label_features, 636 0) == 0); 637 } 638 639 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0); 640 } 641 642 if (spa->spa_label_features == NULL) { 643 VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME, 644 KM_SLEEP) == 0); 645 } 646 647 spa->spa_iokstat = kstat_create("zfs", 0, name, 648 "disk", KSTAT_TYPE_IO, 1, 0); 649 if (spa->spa_iokstat) { 650 spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock; 651 kstat_install(spa->spa_iokstat); 652 } 653 654 spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0); 655 656 spa->spa_min_ashift = INT_MAX; 657 spa->spa_max_ashift = 0; 658 659 /* 660 * As a pool is being created, treat all features as disabled by 661 * setting SPA_FEATURE_DISABLED for all entries in the feature 662 * refcount cache. 663 */ 664 for (int i = 0; i < SPA_FEATURES; i++) { 665 spa->spa_feat_refcount_cache[i] = SPA_FEATURE_DISABLED; 666 } 667 668 return (spa); 669 } 670 671 /* 672 * Removes a spa_t from the namespace, freeing up any memory used. Requires 673 * spa_namespace_lock. This is called only after the spa_t has been closed and 674 * deactivated. 675 */ 676 void 677 spa_remove(spa_t *spa) 678 { 679 spa_config_dirent_t *dp; 680 681 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 682 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 683 ASSERT3U(refcount_count(&spa->spa_refcount), ==, 0); 684 685 nvlist_free(spa->spa_config_splitting); 686 687 avl_remove(&spa_namespace_avl, spa); 688 cv_broadcast(&spa_namespace_cv); 689 690 if (spa->spa_root) { 691 spa_strfree(spa->spa_root); 692 spa_active_count--; 693 } 694 695 while ((dp = list_head(&spa->spa_config_list)) != NULL) { 696 list_remove(&spa->spa_config_list, dp); 697 if (dp->scd_path != NULL) 698 spa_strfree(dp->scd_path); 699 kmem_free(dp, sizeof (spa_config_dirent_t)); 700 } 701 702 list_destroy(&spa->spa_config_list); 703 704 nvlist_free(spa->spa_label_features); 705 nvlist_free(spa->spa_load_info); 706 spa_config_set(spa, NULL); 707 708 mutex_enter(&cpu_lock); 709 if (spa->spa_deadman_cycid != CYCLIC_NONE) 710 cyclic_remove(spa->spa_deadman_cycid); 711 mutex_exit(&cpu_lock); 712 spa->spa_deadman_cycid = CYCLIC_NONE; 713 714 refcount_destroy(&spa->spa_refcount); 715 716 spa_config_lock_destroy(spa); 717 718 kstat_delete(spa->spa_iokstat); 719 spa->spa_iokstat = NULL; 720 721 for (int t = 0; t < TXG_SIZE; t++) 722 bplist_destroy(&spa->spa_free_bplist[t]); 723 724 zio_checksum_templates_free(spa); 725 726 cv_destroy(&spa->spa_async_cv); 727 cv_destroy(&spa->spa_evicting_os_cv); 728 cv_destroy(&spa->spa_proc_cv); 729 cv_destroy(&spa->spa_scrub_io_cv); 730 cv_destroy(&spa->spa_suspend_cv); 731 732 mutex_destroy(&spa->spa_async_lock); 733 mutex_destroy(&spa->spa_errlist_lock); 734 mutex_destroy(&spa->spa_errlog_lock); 735 mutex_destroy(&spa->spa_evicting_os_lock); 736 mutex_destroy(&spa->spa_history_lock); 737 mutex_destroy(&spa->spa_proc_lock); 738 mutex_destroy(&spa->spa_props_lock); 739 mutex_destroy(&spa->spa_cksum_tmpls_lock); 740 mutex_destroy(&spa->spa_scrub_lock); 741 mutex_destroy(&spa->spa_suspend_lock); 742 mutex_destroy(&spa->spa_vdev_top_lock); 743 mutex_destroy(&spa->spa_iokstat_lock); 744 745 kmem_free(spa, sizeof (spa_t)); 746 } 747 748 /* 749 * Given a pool, return the next pool in the namespace, or NULL if there is 750 * none. If 'prev' is NULL, return the first pool. 751 */ 752 spa_t * 753 spa_next(spa_t *prev) 754 { 755 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 756 757 if (prev) 758 return (AVL_NEXT(&spa_namespace_avl, prev)); 759 else 760 return (avl_first(&spa_namespace_avl)); 761 } 762 763 /* 764 * ========================================================================== 765 * SPA refcount functions 766 * ========================================================================== 767 */ 768 769 /* 770 * Add a reference to the given spa_t. Must have at least one reference, or 771 * have the namespace lock held. 772 */ 773 void 774 spa_open_ref(spa_t *spa, void *tag) 775 { 776 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref || 777 MUTEX_HELD(&spa_namespace_lock)); 778 (void) refcount_add(&spa->spa_refcount, tag); 779 } 780 781 /* 782 * Remove a reference to the given spa_t. Must have at least one reference, or 783 * have the namespace lock held. 784 */ 785 void 786 spa_close(spa_t *spa, void *tag) 787 { 788 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref || 789 MUTEX_HELD(&spa_namespace_lock)); 790 (void) refcount_remove(&spa->spa_refcount, tag); 791 } 792 793 /* 794 * Remove a reference to the given spa_t held by a dsl dir that is 795 * being asynchronously released. Async releases occur from a taskq 796 * performing eviction of dsl datasets and dirs. The namespace lock 797 * isn't held and the hold by the object being evicted may contribute to 798 * spa_minref (e.g. dataset or directory released during pool export), 799 * so the asserts in spa_close() do not apply. 800 */ 801 void 802 spa_async_close(spa_t *spa, void *tag) 803 { 804 (void) refcount_remove(&spa->spa_refcount, tag); 805 } 806 807 /* 808 * Check to see if the spa refcount is zero. Must be called with 809 * spa_namespace_lock held. We really compare against spa_minref, which is the 810 * number of references acquired when opening a pool 811 */ 812 boolean_t 813 spa_refcount_zero(spa_t *spa) 814 { 815 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 816 817 return (refcount_count(&spa->spa_refcount) == spa->spa_minref); 818 } 819 820 /* 821 * ========================================================================== 822 * SPA spare and l2cache tracking 823 * ========================================================================== 824 */ 825 826 /* 827 * Hot spares and cache devices are tracked using the same code below, 828 * for 'auxiliary' devices. 829 */ 830 831 typedef struct spa_aux { 832 uint64_t aux_guid; 833 uint64_t aux_pool; 834 avl_node_t aux_avl; 835 int aux_count; 836 } spa_aux_t; 837 838 static int 839 spa_aux_compare(const void *a, const void *b) 840 { 841 const spa_aux_t *sa = a; 842 const spa_aux_t *sb = b; 843 844 if (sa->aux_guid < sb->aux_guid) 845 return (-1); 846 else if (sa->aux_guid > sb->aux_guid) 847 return (1); 848 else 849 return (0); 850 } 851 852 void 853 spa_aux_add(vdev_t *vd, avl_tree_t *avl) 854 { 855 avl_index_t where; 856 spa_aux_t search; 857 spa_aux_t *aux; 858 859 search.aux_guid = vd->vdev_guid; 860 if ((aux = avl_find(avl, &search, &where)) != NULL) { 861 aux->aux_count++; 862 } else { 863 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP); 864 aux->aux_guid = vd->vdev_guid; 865 aux->aux_count = 1; 866 avl_insert(avl, aux, where); 867 } 868 } 869 870 void 871 spa_aux_remove(vdev_t *vd, avl_tree_t *avl) 872 { 873 spa_aux_t search; 874 spa_aux_t *aux; 875 avl_index_t where; 876 877 search.aux_guid = vd->vdev_guid; 878 aux = avl_find(avl, &search, &where); 879 880 ASSERT(aux != NULL); 881 882 if (--aux->aux_count == 0) { 883 avl_remove(avl, aux); 884 kmem_free(aux, sizeof (spa_aux_t)); 885 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) { 886 aux->aux_pool = 0ULL; 887 } 888 } 889 890 boolean_t 891 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl) 892 { 893 spa_aux_t search, *found; 894 895 search.aux_guid = guid; 896 found = avl_find(avl, &search, NULL); 897 898 if (pool) { 899 if (found) 900 *pool = found->aux_pool; 901 else 902 *pool = 0ULL; 903 } 904 905 if (refcnt) { 906 if (found) 907 *refcnt = found->aux_count; 908 else 909 *refcnt = 0; 910 } 911 912 return (found != NULL); 913 } 914 915 void 916 spa_aux_activate(vdev_t *vd, avl_tree_t *avl) 917 { 918 spa_aux_t search, *found; 919 avl_index_t where; 920 921 search.aux_guid = vd->vdev_guid; 922 found = avl_find(avl, &search, &where); 923 ASSERT(found != NULL); 924 ASSERT(found->aux_pool == 0ULL); 925 926 found->aux_pool = spa_guid(vd->vdev_spa); 927 } 928 929 /* 930 * Spares are tracked globally due to the following constraints: 931 * 932 * - A spare may be part of multiple pools. 933 * - A spare may be added to a pool even if it's actively in use within 934 * another pool. 935 * - A spare in use in any pool can only be the source of a replacement if 936 * the target is a spare in the same pool. 937 * 938 * We keep track of all spares on the system through the use of a reference 939 * counted AVL tree. When a vdev is added as a spare, or used as a replacement 940 * spare, then we bump the reference count in the AVL tree. In addition, we set 941 * the 'vdev_isspare' member to indicate that the device is a spare (active or 942 * inactive). When a spare is made active (used to replace a device in the 943 * pool), we also keep track of which pool its been made a part of. 944 * 945 * The 'spa_spare_lock' protects the AVL tree. These functions are normally 946 * called under the spa_namespace lock as part of vdev reconfiguration. The 947 * separate spare lock exists for the status query path, which does not need to 948 * be completely consistent with respect to other vdev configuration changes. 949 */ 950 951 static int 952 spa_spare_compare(const void *a, const void *b) 953 { 954 return (spa_aux_compare(a, b)); 955 } 956 957 void 958 spa_spare_add(vdev_t *vd) 959 { 960 mutex_enter(&spa_spare_lock); 961 ASSERT(!vd->vdev_isspare); 962 spa_aux_add(vd, &spa_spare_avl); 963 vd->vdev_isspare = B_TRUE; 964 mutex_exit(&spa_spare_lock); 965 } 966 967 void 968 spa_spare_remove(vdev_t *vd) 969 { 970 mutex_enter(&spa_spare_lock); 971 ASSERT(vd->vdev_isspare); 972 spa_aux_remove(vd, &spa_spare_avl); 973 vd->vdev_isspare = B_FALSE; 974 mutex_exit(&spa_spare_lock); 975 } 976 977 boolean_t 978 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt) 979 { 980 boolean_t found; 981 982 mutex_enter(&spa_spare_lock); 983 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl); 984 mutex_exit(&spa_spare_lock); 985 986 return (found); 987 } 988 989 void 990 spa_spare_activate(vdev_t *vd) 991 { 992 mutex_enter(&spa_spare_lock); 993 ASSERT(vd->vdev_isspare); 994 spa_aux_activate(vd, &spa_spare_avl); 995 mutex_exit(&spa_spare_lock); 996 } 997 998 /* 999 * Level 2 ARC devices are tracked globally for the same reasons as spares. 1000 * Cache devices currently only support one pool per cache device, and so 1001 * for these devices the aux reference count is currently unused beyond 1. 1002 */ 1003 1004 static int 1005 spa_l2cache_compare(const void *a, const void *b) 1006 { 1007 return (spa_aux_compare(a, b)); 1008 } 1009 1010 void 1011 spa_l2cache_add(vdev_t *vd) 1012 { 1013 mutex_enter(&spa_l2cache_lock); 1014 ASSERT(!vd->vdev_isl2cache); 1015 spa_aux_add(vd, &spa_l2cache_avl); 1016 vd->vdev_isl2cache = B_TRUE; 1017 mutex_exit(&spa_l2cache_lock); 1018 } 1019 1020 void 1021 spa_l2cache_remove(vdev_t *vd) 1022 { 1023 mutex_enter(&spa_l2cache_lock); 1024 ASSERT(vd->vdev_isl2cache); 1025 spa_aux_remove(vd, &spa_l2cache_avl); 1026 vd->vdev_isl2cache = B_FALSE; 1027 mutex_exit(&spa_l2cache_lock); 1028 } 1029 1030 boolean_t 1031 spa_l2cache_exists(uint64_t guid, uint64_t *pool) 1032 { 1033 boolean_t found; 1034 1035 mutex_enter(&spa_l2cache_lock); 1036 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl); 1037 mutex_exit(&spa_l2cache_lock); 1038 1039 return (found); 1040 } 1041 1042 void 1043 spa_l2cache_activate(vdev_t *vd) 1044 { 1045 mutex_enter(&spa_l2cache_lock); 1046 ASSERT(vd->vdev_isl2cache); 1047 spa_aux_activate(vd, &spa_l2cache_avl); 1048 mutex_exit(&spa_l2cache_lock); 1049 } 1050 1051 /* 1052 * ========================================================================== 1053 * SPA vdev locking 1054 * ========================================================================== 1055 */ 1056 1057 /* 1058 * Lock the given spa_t for the purpose of adding or removing a vdev. 1059 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 1060 * It returns the next transaction group for the spa_t. 1061 */ 1062 uint64_t 1063 spa_vdev_enter(spa_t *spa) 1064 { 1065 mutex_enter(&spa->spa_vdev_top_lock); 1066 mutex_enter(&spa_namespace_lock); 1067 return (spa_vdev_config_enter(spa)); 1068 } 1069 1070 /* 1071 * Internal implementation for spa_vdev_enter(). Used when a vdev 1072 * operation requires multiple syncs (i.e. removing a device) while 1073 * keeping the spa_namespace_lock held. 1074 */ 1075 uint64_t 1076 spa_vdev_config_enter(spa_t *spa) 1077 { 1078 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1079 1080 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1081 1082 return (spa_last_synced_txg(spa) + 1); 1083 } 1084 1085 /* 1086 * Used in combination with spa_vdev_config_enter() to allow the syncing 1087 * of multiple transactions without releasing the spa_namespace_lock. 1088 */ 1089 void 1090 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag) 1091 { 1092 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1093 1094 int config_changed = B_FALSE; 1095 1096 ASSERT(txg > spa_last_synced_txg(spa)); 1097 1098 spa->spa_pending_vdev = NULL; 1099 1100 /* 1101 * Reassess the DTLs. 1102 */ 1103 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 1104 1105 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) { 1106 config_changed = B_TRUE; 1107 spa->spa_config_generation++; 1108 } 1109 1110 /* 1111 * Verify the metaslab classes. 1112 */ 1113 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0); 1114 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0); 1115 1116 spa_config_exit(spa, SCL_ALL, spa); 1117 1118 /* 1119 * Panic the system if the specified tag requires it. This 1120 * is useful for ensuring that configurations are updated 1121 * transactionally. 1122 */ 1123 if (zio_injection_enabled) 1124 zio_handle_panic_injection(spa, tag, 0); 1125 1126 /* 1127 * Note: this txg_wait_synced() is important because it ensures 1128 * that there won't be more than one config change per txg. 1129 * This allows us to use the txg as the generation number. 1130 */ 1131 if (error == 0) 1132 txg_wait_synced(spa->spa_dsl_pool, txg); 1133 1134 if (vd != NULL) { 1135 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL); 1136 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER); 1137 vdev_free(vd); 1138 spa_config_exit(spa, SCL_ALL, spa); 1139 } 1140 1141 /* 1142 * If the config changed, update the config cache. 1143 */ 1144 if (config_changed) 1145 spa_config_sync(spa, B_FALSE, B_TRUE); 1146 } 1147 1148 /* 1149 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 1150 * locking of spa_vdev_enter(), we also want make sure the transactions have 1151 * synced to disk, and then update the global configuration cache with the new 1152 * information. 1153 */ 1154 int 1155 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 1156 { 1157 spa_vdev_config_exit(spa, vd, txg, error, FTAG); 1158 mutex_exit(&spa_namespace_lock); 1159 mutex_exit(&spa->spa_vdev_top_lock); 1160 1161 return (error); 1162 } 1163 1164 /* 1165 * Lock the given spa_t for the purpose of changing vdev state. 1166 */ 1167 void 1168 spa_vdev_state_enter(spa_t *spa, int oplocks) 1169 { 1170 int locks = SCL_STATE_ALL | oplocks; 1171 1172 /* 1173 * Root pools may need to read of the underlying devfs filesystem 1174 * when opening up a vdev. Unfortunately if we're holding the 1175 * SCL_ZIO lock it will result in a deadlock when we try to issue 1176 * the read from the root filesystem. Instead we "prefetch" 1177 * the associated vnodes that we need prior to opening the 1178 * underlying devices and cache them so that we can prevent 1179 * any I/O when we are doing the actual open. 1180 */ 1181 if (spa_is_root(spa)) { 1182 int low = locks & ~(SCL_ZIO - 1); 1183 int high = locks & ~low; 1184 1185 spa_config_enter(spa, high, spa, RW_WRITER); 1186 vdev_hold(spa->spa_root_vdev); 1187 spa_config_enter(spa, low, spa, RW_WRITER); 1188 } else { 1189 spa_config_enter(spa, locks, spa, RW_WRITER); 1190 } 1191 spa->spa_vdev_locks = locks; 1192 } 1193 1194 int 1195 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error) 1196 { 1197 boolean_t config_changed = B_FALSE; 1198 1199 if (vd != NULL || error == 0) 1200 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev, 1201 0, 0, B_FALSE); 1202 1203 if (vd != NULL) { 1204 vdev_state_dirty(vd->vdev_top); 1205 config_changed = B_TRUE; 1206 spa->spa_config_generation++; 1207 } 1208 1209 if (spa_is_root(spa)) 1210 vdev_rele(spa->spa_root_vdev); 1211 1212 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL); 1213 spa_config_exit(spa, spa->spa_vdev_locks, spa); 1214 1215 /* 1216 * If anything changed, wait for it to sync. This ensures that, 1217 * from the system administrator's perspective, zpool(1M) commands 1218 * are synchronous. This is important for things like zpool offline: 1219 * when the command completes, you expect no further I/O from ZFS. 1220 */ 1221 if (vd != NULL) 1222 txg_wait_synced(spa->spa_dsl_pool, 0); 1223 1224 /* 1225 * If the config changed, update the config cache. 1226 */ 1227 if (config_changed) { 1228 mutex_enter(&spa_namespace_lock); 1229 spa_config_sync(spa, B_FALSE, B_TRUE); 1230 mutex_exit(&spa_namespace_lock); 1231 } 1232 1233 return (error); 1234 } 1235 1236 /* 1237 * ========================================================================== 1238 * Miscellaneous functions 1239 * ========================================================================== 1240 */ 1241 1242 void 1243 spa_activate_mos_feature(spa_t *spa, const char *feature, dmu_tx_t *tx) 1244 { 1245 if (!nvlist_exists(spa->spa_label_features, feature)) { 1246 fnvlist_add_boolean(spa->spa_label_features, feature); 1247 /* 1248 * When we are creating the pool (tx_txg==TXG_INITIAL), we can't 1249 * dirty the vdev config because lock SCL_CONFIG is not held. 1250 * Thankfully, in this case we don't need to dirty the config 1251 * because it will be written out anyway when we finish 1252 * creating the pool. 1253 */ 1254 if (tx->tx_txg != TXG_INITIAL) 1255 vdev_config_dirty(spa->spa_root_vdev); 1256 } 1257 } 1258 1259 void 1260 spa_deactivate_mos_feature(spa_t *spa, const char *feature) 1261 { 1262 if (nvlist_remove_all(spa->spa_label_features, feature) == 0) 1263 vdev_config_dirty(spa->spa_root_vdev); 1264 } 1265 1266 /* 1267 * Rename a spa_t. 1268 */ 1269 int 1270 spa_rename(const char *name, const char *newname) 1271 { 1272 spa_t *spa; 1273 int err; 1274 1275 /* 1276 * Lookup the spa_t and grab the config lock for writing. We need to 1277 * actually open the pool so that we can sync out the necessary labels. 1278 * It's OK to call spa_open() with the namespace lock held because we 1279 * allow recursive calls for other reasons. 1280 */ 1281 mutex_enter(&spa_namespace_lock); 1282 if ((err = spa_open(name, &spa, FTAG)) != 0) { 1283 mutex_exit(&spa_namespace_lock); 1284 return (err); 1285 } 1286 1287 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1288 1289 avl_remove(&spa_namespace_avl, spa); 1290 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name)); 1291 avl_add(&spa_namespace_avl, spa); 1292 1293 /* 1294 * Sync all labels to disk with the new names by marking the root vdev 1295 * dirty and waiting for it to sync. It will pick up the new pool name 1296 * during the sync. 1297 */ 1298 vdev_config_dirty(spa->spa_root_vdev); 1299 1300 spa_config_exit(spa, SCL_ALL, FTAG); 1301 1302 txg_wait_synced(spa->spa_dsl_pool, 0); 1303 1304 /* 1305 * Sync the updated config cache. 1306 */ 1307 spa_config_sync(spa, B_FALSE, B_TRUE); 1308 1309 spa_close(spa, FTAG); 1310 1311 mutex_exit(&spa_namespace_lock); 1312 1313 return (0); 1314 } 1315 1316 /* 1317 * Return the spa_t associated with given pool_guid, if it exists. If 1318 * device_guid is non-zero, determine whether the pool exists *and* contains 1319 * a device with the specified device_guid. 1320 */ 1321 spa_t * 1322 spa_by_guid(uint64_t pool_guid, uint64_t device_guid) 1323 { 1324 spa_t *spa; 1325 avl_tree_t *t = &spa_namespace_avl; 1326 1327 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 1328 1329 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 1330 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 1331 continue; 1332 if (spa->spa_root_vdev == NULL) 1333 continue; 1334 if (spa_guid(spa) == pool_guid) { 1335 if (device_guid == 0) 1336 break; 1337 1338 if (vdev_lookup_by_guid(spa->spa_root_vdev, 1339 device_guid) != NULL) 1340 break; 1341 1342 /* 1343 * Check any devices we may be in the process of adding. 1344 */ 1345 if (spa->spa_pending_vdev) { 1346 if (vdev_lookup_by_guid(spa->spa_pending_vdev, 1347 device_guid) != NULL) 1348 break; 1349 } 1350 } 1351 } 1352 1353 return (spa); 1354 } 1355 1356 /* 1357 * Determine whether a pool with the given pool_guid exists. 1358 */ 1359 boolean_t 1360 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 1361 { 1362 return (spa_by_guid(pool_guid, device_guid) != NULL); 1363 } 1364 1365 char * 1366 spa_strdup(const char *s) 1367 { 1368 size_t len; 1369 char *new; 1370 1371 len = strlen(s); 1372 new = kmem_alloc(len + 1, KM_SLEEP); 1373 bcopy(s, new, len); 1374 new[len] = '\0'; 1375 1376 return (new); 1377 } 1378 1379 void 1380 spa_strfree(char *s) 1381 { 1382 kmem_free(s, strlen(s) + 1); 1383 } 1384 1385 uint64_t 1386 spa_get_random(uint64_t range) 1387 { 1388 uint64_t r; 1389 1390 ASSERT(range != 0); 1391 1392 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 1393 1394 return (r % range); 1395 } 1396 1397 uint64_t 1398 spa_generate_guid(spa_t *spa) 1399 { 1400 uint64_t guid = spa_get_random(-1ULL); 1401 1402 if (spa != NULL) { 1403 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid)) 1404 guid = spa_get_random(-1ULL); 1405 } else { 1406 while (guid == 0 || spa_guid_exists(guid, 0)) 1407 guid = spa_get_random(-1ULL); 1408 } 1409 1410 return (guid); 1411 } 1412 1413 void 1414 snprintf_blkptr(char *buf, size_t buflen, const blkptr_t *bp) 1415 { 1416 char type[256]; 1417 char *checksum = NULL; 1418 char *compress = NULL; 1419 1420 if (bp != NULL) { 1421 if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) { 1422 dmu_object_byteswap_t bswap = 1423 DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); 1424 (void) snprintf(type, sizeof (type), "bswap %s %s", 1425 DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ? 1426 "metadata" : "data", 1427 dmu_ot_byteswap[bswap].ob_name); 1428 } else { 1429 (void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name, 1430 sizeof (type)); 1431 } 1432 if (!BP_IS_EMBEDDED(bp)) { 1433 checksum = 1434 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name; 1435 } 1436 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name; 1437 } 1438 1439 SNPRINTF_BLKPTR(snprintf, ' ', buf, buflen, bp, type, checksum, 1440 compress); 1441 } 1442 1443 void 1444 spa_freeze(spa_t *spa) 1445 { 1446 uint64_t freeze_txg = 0; 1447 1448 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER); 1449 if (spa->spa_freeze_txg == UINT64_MAX) { 1450 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 1451 spa->spa_freeze_txg = freeze_txg; 1452 } 1453 spa_config_exit(spa, SCL_ALL, FTAG); 1454 if (freeze_txg != 0) 1455 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 1456 } 1457 1458 void 1459 zfs_panic_recover(const char *fmt, ...) 1460 { 1461 va_list adx; 1462 1463 va_start(adx, fmt); 1464 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx); 1465 va_end(adx); 1466 } 1467 1468 /* 1469 * This is a stripped-down version of strtoull, suitable only for converting 1470 * lowercase hexadecimal numbers that don't overflow. 1471 */ 1472 uint64_t 1473 strtonum(const char *str, char **nptr) 1474 { 1475 uint64_t val = 0; 1476 char c; 1477 int digit; 1478 1479 while ((c = *str) != '\0') { 1480 if (c >= '0' && c <= '9') 1481 digit = c - '0'; 1482 else if (c >= 'a' && c <= 'f') 1483 digit = 10 + c - 'a'; 1484 else 1485 break; 1486 1487 val *= 16; 1488 val += digit; 1489 1490 str++; 1491 } 1492 1493 if (nptr) 1494 *nptr = (char *)str; 1495 1496 return (val); 1497 } 1498 1499 /* 1500 * ========================================================================== 1501 * Accessor functions 1502 * ========================================================================== 1503 */ 1504 1505 boolean_t 1506 spa_shutting_down(spa_t *spa) 1507 { 1508 return (spa->spa_async_suspended); 1509 } 1510 1511 dsl_pool_t * 1512 spa_get_dsl(spa_t *spa) 1513 { 1514 return (spa->spa_dsl_pool); 1515 } 1516 1517 boolean_t 1518 spa_is_initializing(spa_t *spa) 1519 { 1520 return (spa->spa_is_initializing); 1521 } 1522 1523 blkptr_t * 1524 spa_get_rootblkptr(spa_t *spa) 1525 { 1526 return (&spa->spa_ubsync.ub_rootbp); 1527 } 1528 1529 void 1530 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 1531 { 1532 spa->spa_uberblock.ub_rootbp = *bp; 1533 } 1534 1535 void 1536 spa_altroot(spa_t *spa, char *buf, size_t buflen) 1537 { 1538 if (spa->spa_root == NULL) 1539 buf[0] = '\0'; 1540 else 1541 (void) strncpy(buf, spa->spa_root, buflen); 1542 } 1543 1544 int 1545 spa_sync_pass(spa_t *spa) 1546 { 1547 return (spa->spa_sync_pass); 1548 } 1549 1550 char * 1551 spa_name(spa_t *spa) 1552 { 1553 return (spa->spa_name); 1554 } 1555 1556 uint64_t 1557 spa_guid(spa_t *spa) 1558 { 1559 dsl_pool_t *dp = spa_get_dsl(spa); 1560 uint64_t guid; 1561 1562 /* 1563 * If we fail to parse the config during spa_load(), we can go through 1564 * the error path (which posts an ereport) and end up here with no root 1565 * vdev. We stash the original pool guid in 'spa_config_guid' to handle 1566 * this case. 1567 */ 1568 if (spa->spa_root_vdev == NULL) 1569 return (spa->spa_config_guid); 1570 1571 guid = spa->spa_last_synced_guid != 0 ? 1572 spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid; 1573 1574 /* 1575 * Return the most recently synced out guid unless we're 1576 * in syncing context. 1577 */ 1578 if (dp && dsl_pool_sync_context(dp)) 1579 return (spa->spa_root_vdev->vdev_guid); 1580 else 1581 return (guid); 1582 } 1583 1584 uint64_t 1585 spa_load_guid(spa_t *spa) 1586 { 1587 /* 1588 * This is a GUID that exists solely as a reference for the 1589 * purposes of the arc. It is generated at load time, and 1590 * is never written to persistent storage. 1591 */ 1592 return (spa->spa_load_guid); 1593 } 1594 1595 uint64_t 1596 spa_last_synced_txg(spa_t *spa) 1597 { 1598 return (spa->spa_ubsync.ub_txg); 1599 } 1600 1601 uint64_t 1602 spa_first_txg(spa_t *spa) 1603 { 1604 return (spa->spa_first_txg); 1605 } 1606 1607 uint64_t 1608 spa_syncing_txg(spa_t *spa) 1609 { 1610 return (spa->spa_syncing_txg); 1611 } 1612 1613 pool_state_t 1614 spa_state(spa_t *spa) 1615 { 1616 return (spa->spa_state); 1617 } 1618 1619 spa_load_state_t 1620 spa_load_state(spa_t *spa) 1621 { 1622 return (spa->spa_load_state); 1623 } 1624 1625 uint64_t 1626 spa_freeze_txg(spa_t *spa) 1627 { 1628 return (spa->spa_freeze_txg); 1629 } 1630 1631 /* ARGSUSED */ 1632 uint64_t 1633 spa_get_asize(spa_t *spa, uint64_t lsize) 1634 { 1635 return (lsize * spa_asize_inflation); 1636 } 1637 1638 /* 1639 * Return the amount of slop space in bytes. It is 1/32 of the pool (3.2%), 1640 * or at least 32MB. 1641 * 1642 * See the comment above spa_slop_shift for details. 1643 */ 1644 uint64_t 1645 spa_get_slop_space(spa_t *spa) { 1646 uint64_t space = spa_get_dspace(spa); 1647 return (MAX(space >> spa_slop_shift, SPA_MINDEVSIZE >> 1)); 1648 } 1649 1650 uint64_t 1651 spa_get_dspace(spa_t *spa) 1652 { 1653 return (spa->spa_dspace); 1654 } 1655 1656 void 1657 spa_update_dspace(spa_t *spa) 1658 { 1659 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) + 1660 ddt_get_dedup_dspace(spa); 1661 } 1662 1663 /* 1664 * Return the failure mode that has been set to this pool. The default 1665 * behavior will be to block all I/Os when a complete failure occurs. 1666 */ 1667 uint8_t 1668 spa_get_failmode(spa_t *spa) 1669 { 1670 return (spa->spa_failmode); 1671 } 1672 1673 boolean_t 1674 spa_suspended(spa_t *spa) 1675 { 1676 return (spa->spa_suspended); 1677 } 1678 1679 uint64_t 1680 spa_version(spa_t *spa) 1681 { 1682 return (spa->spa_ubsync.ub_version); 1683 } 1684 1685 boolean_t 1686 spa_deflate(spa_t *spa) 1687 { 1688 return (spa->spa_deflate); 1689 } 1690 1691 metaslab_class_t * 1692 spa_normal_class(spa_t *spa) 1693 { 1694 return (spa->spa_normal_class); 1695 } 1696 1697 metaslab_class_t * 1698 spa_log_class(spa_t *spa) 1699 { 1700 return (spa->spa_log_class); 1701 } 1702 1703 void 1704 spa_evicting_os_register(spa_t *spa, objset_t *os) 1705 { 1706 mutex_enter(&spa->spa_evicting_os_lock); 1707 list_insert_head(&spa->spa_evicting_os_list, os); 1708 mutex_exit(&spa->spa_evicting_os_lock); 1709 } 1710 1711 void 1712 spa_evicting_os_deregister(spa_t *spa, objset_t *os) 1713 { 1714 mutex_enter(&spa->spa_evicting_os_lock); 1715 list_remove(&spa->spa_evicting_os_list, os); 1716 cv_broadcast(&spa->spa_evicting_os_cv); 1717 mutex_exit(&spa->spa_evicting_os_lock); 1718 } 1719 1720 void 1721 spa_evicting_os_wait(spa_t *spa) 1722 { 1723 mutex_enter(&spa->spa_evicting_os_lock); 1724 while (!list_is_empty(&spa->spa_evicting_os_list)) 1725 cv_wait(&spa->spa_evicting_os_cv, &spa->spa_evicting_os_lock); 1726 mutex_exit(&spa->spa_evicting_os_lock); 1727 1728 dmu_buf_user_evict_wait(); 1729 } 1730 1731 int 1732 spa_max_replication(spa_t *spa) 1733 { 1734 /* 1735 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to 1736 * handle BPs with more than one DVA allocated. Set our max 1737 * replication level accordingly. 1738 */ 1739 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS) 1740 return (1); 1741 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 1742 } 1743 1744 int 1745 spa_prev_software_version(spa_t *spa) 1746 { 1747 return (spa->spa_prev_software_version); 1748 } 1749 1750 uint64_t 1751 spa_deadman_synctime(spa_t *spa) 1752 { 1753 return (spa->spa_deadman_synctime); 1754 } 1755 1756 uint64_t 1757 dva_get_dsize_sync(spa_t *spa, const dva_t *dva) 1758 { 1759 uint64_t asize = DVA_GET_ASIZE(dva); 1760 uint64_t dsize = asize; 1761 1762 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); 1763 1764 if (asize != 0 && spa->spa_deflate) { 1765 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); 1766 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio; 1767 } 1768 1769 return (dsize); 1770 } 1771 1772 uint64_t 1773 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp) 1774 { 1775 uint64_t dsize = 0; 1776 1777 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1778 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1779 1780 return (dsize); 1781 } 1782 1783 uint64_t 1784 bp_get_dsize(spa_t *spa, const blkptr_t *bp) 1785 { 1786 uint64_t dsize = 0; 1787 1788 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); 1789 1790 for (int d = 0; d < BP_GET_NDVAS(bp); d++) 1791 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]); 1792 1793 spa_config_exit(spa, SCL_VDEV, FTAG); 1794 1795 return (dsize); 1796 } 1797 1798 /* 1799 * ========================================================================== 1800 * Initialization and Termination 1801 * ========================================================================== 1802 */ 1803 1804 static int 1805 spa_name_compare(const void *a1, const void *a2) 1806 { 1807 const spa_t *s1 = a1; 1808 const spa_t *s2 = a2; 1809 int s; 1810 1811 s = strcmp(s1->spa_name, s2->spa_name); 1812 if (s > 0) 1813 return (1); 1814 if (s < 0) 1815 return (-1); 1816 return (0); 1817 } 1818 1819 int 1820 spa_busy(void) 1821 { 1822 return (spa_active_count); 1823 } 1824 1825 void 1826 spa_boot_init() 1827 { 1828 spa_config_load(); 1829 } 1830 1831 void 1832 spa_init(int mode) 1833 { 1834 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 1835 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL); 1836 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL); 1837 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 1838 1839 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 1840 offsetof(spa_t, spa_avl)); 1841 1842 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t), 1843 offsetof(spa_aux_t, aux_avl)); 1844 1845 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t), 1846 offsetof(spa_aux_t, aux_avl)); 1847 1848 spa_mode_global = mode; 1849 1850 #ifdef _KERNEL 1851 spa_arch_init(); 1852 #else 1853 if (spa_mode_global != FREAD && dprintf_find_string("watch")) { 1854 arc_procfd = open("/proc/self/ctl", O_WRONLY); 1855 if (arc_procfd == -1) { 1856 perror("could not enable watchpoints: " 1857 "opening /proc/self/ctl failed: "); 1858 } else { 1859 arc_watch = B_TRUE; 1860 } 1861 } 1862 #endif 1863 1864 refcount_init(); 1865 unique_init(); 1866 range_tree_init(); 1867 zio_init(); 1868 dmu_init(); 1869 zil_init(); 1870 vdev_cache_stat_init(); 1871 zfs_prop_init(); 1872 zpool_prop_init(); 1873 zpool_feature_init(); 1874 spa_config_load(); 1875 l2arc_start(); 1876 } 1877 1878 void 1879 spa_fini(void) 1880 { 1881 l2arc_stop(); 1882 1883 spa_evict_all(); 1884 1885 vdev_cache_stat_fini(); 1886 zil_fini(); 1887 dmu_fini(); 1888 zio_fini(); 1889 range_tree_fini(); 1890 unique_fini(); 1891 refcount_fini(); 1892 1893 avl_destroy(&spa_namespace_avl); 1894 avl_destroy(&spa_spare_avl); 1895 avl_destroy(&spa_l2cache_avl); 1896 1897 cv_destroy(&spa_namespace_cv); 1898 mutex_destroy(&spa_namespace_lock); 1899 mutex_destroy(&spa_spare_lock); 1900 mutex_destroy(&spa_l2cache_lock); 1901 } 1902 1903 /* 1904 * Return whether this pool has slogs. No locking needed. 1905 * It's not a problem if the wrong answer is returned as it's only for 1906 * performance and not correctness 1907 */ 1908 boolean_t 1909 spa_has_slogs(spa_t *spa) 1910 { 1911 return (spa->spa_log_class->mc_rotor != NULL); 1912 } 1913 1914 spa_log_state_t 1915 spa_get_log_state(spa_t *spa) 1916 { 1917 return (spa->spa_log_state); 1918 } 1919 1920 void 1921 spa_set_log_state(spa_t *spa, spa_log_state_t state) 1922 { 1923 spa->spa_log_state = state; 1924 } 1925 1926 boolean_t 1927 spa_is_root(spa_t *spa) 1928 { 1929 return (spa->spa_is_root); 1930 } 1931 1932 boolean_t 1933 spa_writeable(spa_t *spa) 1934 { 1935 return (!!(spa->spa_mode & FWRITE)); 1936 } 1937 1938 /* 1939 * Returns true if there is a pending sync task in any of the current 1940 * syncing txg, the current quiescing txg, or the current open txg. 1941 */ 1942 boolean_t 1943 spa_has_pending_synctask(spa_t *spa) 1944 { 1945 return (!txg_all_lists_empty(&spa->spa_dsl_pool->dp_sync_tasks)); 1946 } 1947 1948 int 1949 spa_mode(spa_t *spa) 1950 { 1951 return (spa->spa_mode); 1952 } 1953 1954 uint64_t 1955 spa_bootfs(spa_t *spa) 1956 { 1957 return (spa->spa_bootfs); 1958 } 1959 1960 uint64_t 1961 spa_delegation(spa_t *spa) 1962 { 1963 return (spa->spa_delegation); 1964 } 1965 1966 objset_t * 1967 spa_meta_objset(spa_t *spa) 1968 { 1969 return (spa->spa_meta_objset); 1970 } 1971 1972 enum zio_checksum 1973 spa_dedup_checksum(spa_t *spa) 1974 { 1975 return (spa->spa_dedup_checksum); 1976 } 1977 1978 /* 1979 * Reset pool scan stat per scan pass (or reboot). 1980 */ 1981 void 1982 spa_scan_stat_init(spa_t *spa) 1983 { 1984 /* data not stored on disk */ 1985 spa->spa_scan_pass_start = gethrestime_sec(); 1986 spa->spa_scan_pass_exam = 0; 1987 vdev_scan_stat_init(spa->spa_root_vdev); 1988 } 1989 1990 /* 1991 * Get scan stats for zpool status reports 1992 */ 1993 int 1994 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps) 1995 { 1996 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL; 1997 1998 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE) 1999 return (SET_ERROR(ENOENT)); 2000 bzero(ps, sizeof (pool_scan_stat_t)); 2001 2002 /* data stored on disk */ 2003 ps->pss_func = scn->scn_phys.scn_func; 2004 ps->pss_start_time = scn->scn_phys.scn_start_time; 2005 ps->pss_end_time = scn->scn_phys.scn_end_time; 2006 ps->pss_to_examine = scn->scn_phys.scn_to_examine; 2007 ps->pss_examined = scn->scn_phys.scn_examined; 2008 ps->pss_to_process = scn->scn_phys.scn_to_process; 2009 ps->pss_processed = scn->scn_phys.scn_processed; 2010 ps->pss_errors = scn->scn_phys.scn_errors; 2011 ps->pss_state = scn->scn_phys.scn_state; 2012 2013 /* data not stored on disk */ 2014 ps->pss_pass_start = spa->spa_scan_pass_start; 2015 ps->pss_pass_exam = spa->spa_scan_pass_exam; 2016 2017 return (0); 2018 } 2019 2020 boolean_t 2021 spa_debug_enabled(spa_t *spa) 2022 { 2023 return (spa->spa_debug); 2024 } 2025 2026 int 2027 spa_maxblocksize(spa_t *spa) 2028 { 2029 if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) 2030 return (SPA_MAXBLOCKSIZE); 2031 else 2032 return (SPA_OLD_MAXBLOCKSIZE); 2033 } 2034