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 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/zfs_context.h> 29 #include <sys/spa_impl.h> 30 #include <sys/zio.h> 31 #include <sys/zio_checksum.h> 32 #include <sys/zio_compress.h> 33 #include <sys/dmu.h> 34 #include <sys/dmu_tx.h> 35 #include <sys/zap.h> 36 #include <sys/zil.h> 37 #include <sys/vdev_impl.h> 38 #include <sys/metaslab.h> 39 #include <sys/uberblock_impl.h> 40 #include <sys/txg.h> 41 #include <sys/avl.h> 42 #include <sys/unique.h> 43 #include <sys/dsl_pool.h> 44 #include <sys/dsl_dir.h> 45 #include <sys/dsl_prop.h> 46 #include <sys/fs/zfs.h> 47 48 /* 49 * SPA locking 50 * 51 * There are four basic locks for managing spa_t structures: 52 * 53 * spa_namespace_lock (global mutex) 54 * 55 * This lock must be acquired to do any of the following: 56 * 57 * - Lookup a spa_t by name 58 * - Add or remove a spa_t from the namespace 59 * - Increase spa_refcount from non-zero 60 * - Check if spa_refcount is zero 61 * - Rename a spa_t 62 * - add/remove/attach/detach devices 63 * - Held for the duration of create/destroy/import/export 64 * 65 * It does not need to handle recursion. A create or destroy may 66 * reference objects (files or zvols) in other pools, but by 67 * definition they must have an existing reference, and will never need 68 * to lookup a spa_t by name. 69 * 70 * spa_refcount (per-spa refcount_t protected by mutex) 71 * 72 * This reference count keep track of any active users of the spa_t. The 73 * spa_t cannot be destroyed or freed while this is non-zero. Internally, 74 * the refcount is never really 'zero' - opening a pool implicitly keeps 75 * some references in the DMU. Internally we check against SPA_MINREF, but 76 * present the image of a zero/non-zero value to consumers. 77 * 78 * spa_config_lock (per-spa crazy rwlock) 79 * 80 * This SPA special is a recursive rwlock, capable of being acquired from 81 * asynchronous threads. It has protects the spa_t from config changes, 82 * and must be held in the following circumstances: 83 * 84 * - RW_READER to perform I/O to the spa 85 * - RW_WRITER to change the vdev config 86 * 87 * spa_config_cache_lock (per-spa mutex) 88 * 89 * This mutex prevents the spa_config nvlist from being updated. No 90 * other locks are required to obtain this lock, although implicitly you 91 * must have the namespace lock or non-zero refcount to have any kind 92 * of spa_t pointer at all. 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 and spa_config_cache_lock can be acquired directly and 112 * are globally visible. 113 * 114 * The namespace is manipulated using the following functions, all which require 115 * 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 manipulated using the following functions: 147 * 148 * spa_config_enter() Acquire the config lock as RW_READER or 149 * RW_WRITER. At least one reference on the spa_t 150 * must exist. 151 * 152 * spa_config_exit() Release the config lock. 153 * 154 * spa_config_held() Returns true if the config lock is currently 155 * held in the given state. 156 * 157 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit(). 158 * 159 * spa_vdev_enter() Acquire the namespace lock and the config lock 160 * for writing. 161 * 162 * spa_vdev_exit() Release the config lock, wait for all I/O 163 * to complete, sync the updated configs to the 164 * cache, and release the namespace lock. 165 * 166 * The spa_name() function also requires either the spa_namespace_lock 167 * or the spa_config_lock, as both are needed to do a rename. spa_rename() is 168 * also implemented within this file since is requires manipulation of the 169 * namespace. 170 */ 171 172 static avl_tree_t spa_namespace_avl; 173 kmutex_t spa_namespace_lock; 174 static kcondvar_t spa_namespace_cv; 175 static int spa_active_count; 176 static int spa_max_replication_override = SPA_DVAS_PER_BP; 177 178 kmem_cache_t *spa_buffer_pool; 179 int spa_mode; 180 181 #ifdef ZFS_DEBUG 182 int zfs_flags = ~0; 183 #else 184 int zfs_flags = 0; 185 #endif 186 187 #define SPA_MINREF 5 /* spa_refcnt for an open-but-idle pool */ 188 189 /* 190 * ========================================================================== 191 * SPA namespace functions 192 * ========================================================================== 193 */ 194 195 /* 196 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held. 197 * Returns NULL if no matching spa_t is found. 198 */ 199 spa_t * 200 spa_lookup(const char *name) 201 { 202 spa_t search, *spa; 203 avl_index_t where; 204 205 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 206 207 search.spa_name = (char *)name; 208 spa = avl_find(&spa_namespace_avl, &search, &where); 209 210 return (spa); 211 } 212 213 /* 214 * Create an uninitialized spa_t with the given name. Requires 215 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already 216 * exist by calling spa_lookup() first. 217 */ 218 spa_t * 219 spa_add(const char *name, const char *altroot) 220 { 221 spa_t *spa; 222 223 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 224 225 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP); 226 227 spa->spa_name = spa_strdup(name); 228 spa->spa_state = POOL_STATE_UNINITIALIZED; 229 spa->spa_freeze_txg = UINT64_MAX; 230 spa->spa_final_txg = UINT64_MAX; 231 232 refcount_create(&spa->spa_refcount); 233 refcount_create(&spa->spa_config_lock.scl_count); 234 235 avl_add(&spa_namespace_avl, spa); 236 237 /* 238 * Set the alternate root, if there is one. 239 */ 240 if (altroot) { 241 spa->spa_root = spa_strdup(altroot); 242 spa_active_count++; 243 } 244 245 return (spa); 246 } 247 248 /* 249 * Removes a spa_t from the namespace, freeing up any memory used. Requires 250 * spa_namespace_lock. This is called only after the spa_t has been closed and 251 * deactivated. 252 */ 253 void 254 spa_remove(spa_t *spa) 255 { 256 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 257 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED); 258 ASSERT(spa->spa_scrub_thread == NULL); 259 260 avl_remove(&spa_namespace_avl, spa); 261 cv_broadcast(&spa_namespace_cv); 262 263 if (spa->spa_root) { 264 spa_strfree(spa->spa_root); 265 spa_active_count--; 266 } 267 268 if (spa->spa_name) 269 spa_strfree(spa->spa_name); 270 271 spa_config_set(spa, NULL); 272 273 refcount_destroy(&spa->spa_refcount); 274 refcount_destroy(&spa->spa_config_lock.scl_count); 275 276 kmem_free(spa, sizeof (spa_t)); 277 } 278 279 /* 280 * Given a pool, return the next pool in the namespace, or NULL if there is 281 * none. If 'prev' is NULL, return the first pool. 282 */ 283 spa_t * 284 spa_next(spa_t *prev) 285 { 286 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 287 288 if (prev) 289 return (AVL_NEXT(&spa_namespace_avl, prev)); 290 else 291 return (avl_first(&spa_namespace_avl)); 292 } 293 294 /* 295 * ========================================================================== 296 * SPA refcount functions 297 * ========================================================================== 298 */ 299 300 /* 301 * Add a reference to the given spa_t. Must have at least one reference, or 302 * have the namespace lock held. 303 */ 304 void 305 spa_open_ref(spa_t *spa, void *tag) 306 { 307 ASSERT(refcount_count(&spa->spa_refcount) > SPA_MINREF || 308 MUTEX_HELD(&spa_namespace_lock)); 309 310 (void) refcount_add(&spa->spa_refcount, tag); 311 } 312 313 /* 314 * Remove a reference to the given spa_t. Must have at least one reference, or 315 * have the namespace lock held. 316 */ 317 void 318 spa_close(spa_t *spa, void *tag) 319 { 320 ASSERT(refcount_count(&spa->spa_refcount) > SPA_MINREF || 321 MUTEX_HELD(&spa_namespace_lock)); 322 323 (void) refcount_remove(&spa->spa_refcount, tag); 324 } 325 326 /* 327 * Check to see if the spa refcount is zero. Must be called with 328 * spa_namespace_lock held. We really compare against SPA_MINREF, which is the 329 * number of references acquired when opening a pool 330 */ 331 boolean_t 332 spa_refcount_zero(spa_t *spa) 333 { 334 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 335 336 return (refcount_count(&spa->spa_refcount) == SPA_MINREF); 337 } 338 339 /* 340 * ========================================================================== 341 * SPA config locking 342 * ========================================================================== 343 */ 344 345 /* 346 * Acquire the config lock. The config lock is a special rwlock that allows for 347 * recursive enters. Because these enters come from the same thread as well as 348 * asynchronous threads working on behalf of the owner, we must unilaterally 349 * allow all reads access as long at least one reader is held (even if a write 350 * is requested). This has the side effect of write starvation, but write locks 351 * are extremely rare, and a solution to this problem would be significantly 352 * more complex (if even possible). 353 * 354 * We would like to assert that the namespace lock isn't held, but this is a 355 * valid use during create. 356 */ 357 void 358 spa_config_enter(spa_t *spa, krw_t rw, void *tag) 359 { 360 spa_config_lock_t *scl = &spa->spa_config_lock; 361 362 mutex_enter(&scl->scl_lock); 363 364 if (scl->scl_writer != curthread) { 365 if (rw == RW_READER) { 366 while (scl->scl_writer != NULL) 367 cv_wait(&scl->scl_cv, &scl->scl_lock); 368 } else { 369 while (scl->scl_writer != NULL || 370 !refcount_is_zero(&scl->scl_count)) 371 cv_wait(&scl->scl_cv, &scl->scl_lock); 372 scl->scl_writer = curthread; 373 } 374 } 375 376 (void) refcount_add(&scl->scl_count, tag); 377 378 mutex_exit(&scl->scl_lock); 379 } 380 381 /* 382 * Release the spa config lock, notifying any waiters in the process. 383 */ 384 void 385 spa_config_exit(spa_t *spa, void *tag) 386 { 387 spa_config_lock_t *scl = &spa->spa_config_lock; 388 389 mutex_enter(&scl->scl_lock); 390 391 ASSERT(!refcount_is_zero(&scl->scl_count)); 392 if (refcount_remove(&scl->scl_count, tag) == 0) { 393 cv_broadcast(&scl->scl_cv); 394 scl->scl_writer = NULL; /* OK in either case */ 395 } 396 397 mutex_exit(&scl->scl_lock); 398 } 399 400 /* 401 * Returns true if the config lock is held in the given manner. 402 */ 403 boolean_t 404 spa_config_held(spa_t *spa, krw_t rw) 405 { 406 spa_config_lock_t *scl = &spa->spa_config_lock; 407 boolean_t held; 408 409 mutex_enter(&scl->scl_lock); 410 if (rw == RW_WRITER) 411 held = (scl->scl_writer == curthread); 412 else 413 held = !refcount_is_zero(&scl->scl_count); 414 mutex_exit(&scl->scl_lock); 415 416 return (held); 417 } 418 419 /* 420 * ========================================================================== 421 * SPA vdev locking 422 * ========================================================================== 423 */ 424 425 /* 426 * Lock the given spa_t for the purpose of adding or removing a vdev. 427 * Grabs the global spa_namespace_lock plus the spa config lock for writing. 428 * It returns the next transaction group for the spa_t. 429 */ 430 uint64_t 431 spa_vdev_enter(spa_t *spa) 432 { 433 /* 434 * Suspend scrub activity while we mess with the config. 435 */ 436 spa_scrub_suspend(spa); 437 438 mutex_enter(&spa_namespace_lock); 439 440 spa_config_enter(spa, RW_WRITER, spa); 441 442 return (spa_last_synced_txg(spa) + 1); 443 } 444 445 /* 446 * Unlock the spa_t after adding or removing a vdev. Besides undoing the 447 * locking of spa_vdev_enter(), we also want make sure the transactions have 448 * synced to disk, and then update the global configuration cache with the new 449 * information. 450 */ 451 int 452 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error) 453 { 454 int config_changed = B_FALSE; 455 456 ASSERT(txg > spa_last_synced_txg(spa)); 457 458 /* 459 * Reassess the DTLs. 460 */ 461 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE); 462 463 /* 464 * If the config changed, notify the scrub thread that it must restart. 465 */ 466 if (error == 0 && !list_is_empty(&spa->spa_dirty_list)) { 467 config_changed = B_TRUE; 468 spa_scrub_restart(spa, txg); 469 } 470 471 spa_config_exit(spa, spa); 472 473 /* 474 * Allow scrubbing to resume. 475 */ 476 spa_scrub_resume(spa); 477 478 /* 479 * Note: this txg_wait_synced() is important because it ensures 480 * that there won't be more than one config change per txg. 481 * This allows us to use the txg as the generation number. 482 */ 483 if (error == 0) 484 txg_wait_synced(spa->spa_dsl_pool, txg); 485 486 if (vd != NULL) { 487 ASSERT(!vd->vdev_detached || vd->vdev_dtl.smo_object == 0); 488 vdev_free(vd); 489 } 490 491 /* 492 * If the config changed, update the config cache. 493 */ 494 if (config_changed) 495 spa_config_sync(); 496 497 mutex_exit(&spa_namespace_lock); 498 499 return (error); 500 } 501 502 /* 503 * ========================================================================== 504 * Miscellaneous functions 505 * ========================================================================== 506 */ 507 508 /* 509 * Rename a spa_t. 510 */ 511 int 512 spa_rename(const char *name, const char *newname) 513 { 514 spa_t *spa; 515 int err; 516 517 /* 518 * Lookup the spa_t and grab the config lock for writing. We need to 519 * actually open the pool so that we can sync out the necessary labels. 520 * It's OK to call spa_open() with the namespace lock held because we 521 * allow recursive calls for other reasons. 522 */ 523 mutex_enter(&spa_namespace_lock); 524 if ((err = spa_open(name, &spa, FTAG)) != 0) { 525 mutex_exit(&spa_namespace_lock); 526 return (err); 527 } 528 529 spa_config_enter(spa, RW_WRITER, FTAG); 530 531 avl_remove(&spa_namespace_avl, spa); 532 spa_strfree(spa->spa_name); 533 spa->spa_name = spa_strdup(newname); 534 avl_add(&spa_namespace_avl, spa); 535 536 /* 537 * Sync all labels to disk with the new names by marking the root vdev 538 * dirty and waiting for it to sync. It will pick up the new pool name 539 * during the sync. 540 */ 541 vdev_config_dirty(spa->spa_root_vdev); 542 543 spa_config_exit(spa, FTAG); 544 545 txg_wait_synced(spa->spa_dsl_pool, 0); 546 547 /* 548 * Sync the updated config cache. 549 */ 550 spa_config_sync(); 551 552 spa_close(spa, FTAG); 553 554 mutex_exit(&spa_namespace_lock); 555 556 return (0); 557 } 558 559 560 /* 561 * Determine whether a pool with given pool_guid exists. If device_guid is 562 * non-zero, determine whether the pool exists *and* contains a device with the 563 * specified device_guid. 564 */ 565 boolean_t 566 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid) 567 { 568 spa_t *spa; 569 avl_tree_t *t = &spa_namespace_avl; 570 571 ASSERT(MUTEX_HELD(&spa_namespace_lock)); 572 573 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) { 574 if (spa->spa_state == POOL_STATE_UNINITIALIZED) 575 continue; 576 if (spa->spa_root_vdev == NULL) 577 continue; 578 if (spa_guid(spa) == pool_guid && (device_guid == 0 || 579 vdev_lookup_by_guid(spa->spa_root_vdev, device_guid))) 580 break; 581 } 582 583 return (spa != NULL); 584 } 585 586 char * 587 spa_strdup(const char *s) 588 { 589 size_t len; 590 char *new; 591 592 len = strlen(s); 593 new = kmem_alloc(len + 1, KM_SLEEP); 594 bcopy(s, new, len); 595 new[len] = '\0'; 596 597 return (new); 598 } 599 600 void 601 spa_strfree(char *s) 602 { 603 kmem_free(s, strlen(s) + 1); 604 } 605 606 uint64_t 607 spa_get_random(uint64_t range) 608 { 609 uint64_t r; 610 611 ASSERT(range != 0); 612 613 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t)); 614 615 return (r % range); 616 } 617 618 void 619 sprintf_blkptr(char *buf, int len, const blkptr_t *bp) 620 { 621 int d; 622 623 if (bp == NULL) { 624 (void) snprintf(buf, len, "<NULL>"); 625 return; 626 } 627 628 if (BP_IS_HOLE(bp)) { 629 (void) snprintf(buf, len, "<hole>"); 630 return; 631 } 632 633 (void) snprintf(buf, len, "[L%llu %s] %llxL/%llxP ", 634 (u_longlong_t)BP_GET_LEVEL(bp), 635 dmu_ot[BP_GET_TYPE(bp)].ot_name, 636 (u_longlong_t)BP_GET_LSIZE(bp), 637 (u_longlong_t)BP_GET_PSIZE(bp)); 638 639 for (d = 0; d < BP_GET_NDVAS(bp); d++) { 640 const dva_t *dva = &bp->blk_dva[d]; 641 (void) snprintf(buf + strlen(buf), len - strlen(buf), 642 "DVA[%d]=<%llu:%llx:%llx> ", d, 643 (u_longlong_t)DVA_GET_VDEV(dva), 644 (u_longlong_t)DVA_GET_OFFSET(dva), 645 (u_longlong_t)DVA_GET_ASIZE(dva)); 646 } 647 648 (void) snprintf(buf + strlen(buf), len - strlen(buf), 649 "%s %s %s %s birth=%llu fill=%llu cksum=%llx:%llx:%llx:%llx", 650 zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name, 651 zio_compress_table[BP_GET_COMPRESS(bp)].ci_name, 652 BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE", 653 BP_IS_GANG(bp) ? "gang" : "contiguous", 654 (u_longlong_t)bp->blk_birth, 655 (u_longlong_t)bp->blk_fill, 656 (u_longlong_t)bp->blk_cksum.zc_word[0], 657 (u_longlong_t)bp->blk_cksum.zc_word[1], 658 (u_longlong_t)bp->blk_cksum.zc_word[2], 659 (u_longlong_t)bp->blk_cksum.zc_word[3]); 660 } 661 662 void 663 spa_freeze(spa_t *spa) 664 { 665 uint64_t freeze_txg = 0; 666 667 spa_config_enter(spa, RW_WRITER, FTAG); 668 if (spa->spa_freeze_txg == UINT64_MAX) { 669 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE; 670 spa->spa_freeze_txg = freeze_txg; 671 } 672 spa_config_exit(spa, FTAG); 673 if (freeze_txg != 0) 674 txg_wait_synced(spa_get_dsl(spa), freeze_txg); 675 } 676 677 /* 678 * ========================================================================== 679 * Accessor functions 680 * ========================================================================== 681 */ 682 683 krwlock_t * 684 spa_traverse_rwlock(spa_t *spa) 685 { 686 return (&spa->spa_traverse_lock); 687 } 688 689 int 690 spa_traverse_wanted(spa_t *spa) 691 { 692 return (spa->spa_traverse_wanted); 693 } 694 695 dsl_pool_t * 696 spa_get_dsl(spa_t *spa) 697 { 698 return (spa->spa_dsl_pool); 699 } 700 701 blkptr_t * 702 spa_get_rootblkptr(spa_t *spa) 703 { 704 return (&spa->spa_ubsync.ub_rootbp); 705 } 706 707 void 708 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp) 709 { 710 spa->spa_uberblock.ub_rootbp = *bp; 711 } 712 713 void 714 spa_altroot(spa_t *spa, char *buf, size_t buflen) 715 { 716 if (spa->spa_root == NULL) 717 buf[0] = '\0'; 718 else 719 (void) strncpy(buf, spa->spa_root, buflen); 720 } 721 722 int 723 spa_sync_pass(spa_t *spa) 724 { 725 return (spa->spa_sync_pass); 726 } 727 728 char * 729 spa_name(spa_t *spa) 730 { 731 /* 732 * Accessing the name requires holding either the namespace lock or the 733 * config lock, both of which are required to do a rename. 734 */ 735 ASSERT(MUTEX_HELD(&spa_namespace_lock) || 736 spa_config_held(spa, RW_READER) || spa_config_held(spa, RW_WRITER)); 737 738 return (spa->spa_name); 739 } 740 741 uint64_t 742 spa_guid(spa_t *spa) 743 { 744 return (spa->spa_root_vdev->vdev_guid); 745 } 746 747 uint64_t 748 spa_last_synced_txg(spa_t *spa) 749 { 750 return (spa->spa_ubsync.ub_txg); 751 } 752 753 uint64_t 754 spa_first_txg(spa_t *spa) 755 { 756 return (spa->spa_first_txg); 757 } 758 759 int 760 spa_state(spa_t *spa) 761 { 762 return (spa->spa_state); 763 } 764 765 uint64_t 766 spa_freeze_txg(spa_t *spa) 767 { 768 return (spa->spa_freeze_txg); 769 } 770 771 /* 772 * In the future, this may select among different metaslab classes 773 * depending on the zdp. For now, there's no such distinction. 774 */ 775 metaslab_class_t * 776 spa_metaslab_class_select(spa_t *spa) 777 { 778 return (spa->spa_normal_class); 779 } 780 781 /* 782 * Return pool-wide allocated space. 783 */ 784 uint64_t 785 spa_get_alloc(spa_t *spa) 786 { 787 return (spa->spa_root_vdev->vdev_stat.vs_alloc); 788 } 789 790 /* 791 * Return pool-wide allocated space. 792 */ 793 uint64_t 794 spa_get_space(spa_t *spa) 795 { 796 return (spa->spa_root_vdev->vdev_stat.vs_space); 797 } 798 799 /* ARGSUSED */ 800 uint64_t 801 spa_get_asize(spa_t *spa, uint64_t lsize) 802 { 803 /* 804 * For now, the worst case is 512-byte RAID-Z blocks, in which 805 * case the space requirement is exactly 2x; so just assume that. 806 * Add to this the fact that we can have up to 3 DVAs per bp, and 807 * we have to multiply by a total of 6x. 808 */ 809 return (lsize * 6); 810 } 811 812 uint64_t 813 spa_version(spa_t *spa) 814 { 815 return (spa->spa_ubsync.ub_version); 816 } 817 818 int 819 spa_max_replication(spa_t *spa) 820 { 821 /* 822 * As of ZFS_VERSION == ZFS_VERSION_DITTO_BLOCKS, we are able to 823 * handle BPs with more than one DVA allocated. Set our max 824 * replication level accordingly. 825 */ 826 if (spa_version(spa) < ZFS_VERSION_DITTO_BLOCKS) 827 return (1); 828 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override)); 829 } 830 831 /* 832 * ========================================================================== 833 * Initialization and Termination 834 * ========================================================================== 835 */ 836 837 static int 838 spa_name_compare(const void *a1, const void *a2) 839 { 840 const spa_t *s1 = a1; 841 const spa_t *s2 = a2; 842 int s; 843 844 s = strcmp(s1->spa_name, s2->spa_name); 845 if (s > 0) 846 return (1); 847 if (s < 0) 848 return (-1); 849 return (0); 850 } 851 852 int 853 spa_busy(void) 854 { 855 return (spa_active_count); 856 } 857 858 void 859 spa_init(int mode) 860 { 861 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL); 862 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL); 863 864 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t), 865 offsetof(spa_t, spa_avl)); 866 867 spa_mode = mode; 868 869 refcount_init(); 870 unique_init(); 871 zio_init(); 872 dmu_init(); 873 zil_init(); 874 spa_config_load(); 875 } 876 877 void 878 spa_fini(void) 879 { 880 spa_evict_all(); 881 882 zil_fini(); 883 dmu_fini(); 884 zio_fini(); 885 refcount_fini(); 886 887 avl_destroy(&spa_namespace_avl); 888 889 cv_destroy(&spa_namespace_cv); 890 mutex_destroy(&spa_namespace_lock); 891 } 892