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.
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.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
25 #include <sys/zfs_context.h>
26 #include <sys/spa_impl.h>
28 #include <sys/zio_checksum.h>
29 #include <sys/zio_compress.h>
31 #include <sys/dmu_tx.h>
34 #include <sys/vdev_impl.h>
35 #include <sys/metaslab.h>
36 #include <sys/uberblock_impl.h>
39 #include <sys/unique.h>
40 #include <sys/dsl_pool.h>
41 #include <sys/dsl_dir.h>
42 #include <sys/dsl_prop.h>
43 #include <sys/dsl_scan.h>
44 #include <sys/fs/zfs.h>
45 #include <sys/metaslab_impl.h>
53 * There are four basic locks for managing spa_t structures:
55 * spa_namespace_lock (global mutex)
57 * This lock must be acquired to do any of the following:
59 * - Lookup a spa_t by name
60 * - Add or remove a spa_t from the namespace
61 * - Increase spa_refcount from non-zero
62 * - Check if spa_refcount is zero
64 * - add/remove/attach/detach devices
65 * - Held for the duration of create/destroy/import/export
67 * It does not need to handle recursion. A create or destroy may
68 * reference objects (files or zvols) in other pools, but by
69 * definition they must have an existing reference, and will never need
70 * to lookup a spa_t by name.
72 * spa_refcount (per-spa refcount_t protected by mutex)
74 * This reference count keep track of any active users of the spa_t. The
75 * spa_t cannot be destroyed or freed while this is non-zero. Internally,
76 * the refcount is never really 'zero' - opening a pool implicitly keeps
77 * some references in the DMU. Internally we check against spa_minref, but
78 * present the image of a zero/non-zero value to consumers.
80 * spa_config_lock[] (per-spa array of rwlocks)
82 * This protects the spa_t from config changes, and must be held in
83 * the following circumstances:
85 * - RW_READER to perform I/O to the spa
86 * - RW_WRITER to change the vdev config
88 * The locking order is fairly straightforward:
90 * spa_namespace_lock -> spa_refcount
92 * The namespace lock must be acquired to increase the refcount from 0
93 * or to check if it is zero.
95 * spa_refcount -> spa_config_lock[]
97 * There must be at least one valid reference on the spa_t to acquire
100 * spa_namespace_lock -> spa_config_lock[]
102 * The namespace lock must always be taken before the config lock.
105 * The spa_namespace_lock can be acquired directly and is globally visible.
107 * The namespace is manipulated using the following functions, all of which
108 * require the spa_namespace_lock to be held.
110 * spa_lookup() Lookup a spa_t by name.
112 * spa_add() Create a new spa_t in the namespace.
114 * spa_remove() Remove a spa_t from the namespace. This also
115 * frees up any memory associated with the spa_t.
117 * spa_next() Returns the next spa_t in the system, or the
118 * first if NULL is passed.
120 * spa_evict_all() Shutdown and remove all spa_t structures in
123 * spa_guid_exists() Determine whether a pool/device guid exists.
125 * The spa_refcount is manipulated using the following functions:
127 * spa_open_ref() Adds a reference to the given spa_t. Must be
128 * called with spa_namespace_lock held if the
129 * refcount is currently zero.
131 * spa_close() Remove a reference from the spa_t. This will
132 * not free the spa_t or remove it from the
133 * namespace. No locking is required.
135 * spa_refcount_zero() Returns true if the refcount is currently
136 * zero. Must be called with spa_namespace_lock
139 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
140 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
141 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
143 * To read the configuration, it suffices to hold one of these locks as reader.
144 * To modify the configuration, you must hold all locks as writer. To modify
145 * vdev state without altering the vdev tree's topology (e.g. online/offline),
146 * you must hold SCL_STATE and SCL_ZIO as writer.
148 * We use these distinct config locks to avoid recursive lock entry.
149 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
150 * block allocations (SCL_ALLOC), which may require reading space maps
151 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
153 * The spa config locks cannot be normal rwlocks because we need the
154 * ability to hand off ownership. For example, SCL_ZIO is acquired
155 * by the issuing thread and later released by an interrupt thread.
156 * They do, however, obey the usual write-wanted semantics to prevent
157 * writer (i.e. system administrator) starvation.
159 * The lock acquisition rules are as follows:
162 * Protects changes to the vdev tree topology, such as vdev
163 * add/remove/attach/detach. Protects the dirty config list
164 * (spa_config_dirty_list) and the set of spares and l2arc devices.
167 * Protects changes to pool state and vdev state, such as vdev
168 * online/offline/fault/degrade/clear. Protects the dirty state list
169 * (spa_state_dirty_list) and global pool state (spa_state).
172 * Protects changes to metaslab groups and classes.
173 * Held as reader by metaslab_alloc() and metaslab_claim().
176 * Held by bp-level zios (those which have no io_vd upon entry)
177 * to prevent changes to the vdev tree. The bp-level zio implicitly
178 * protects all of its vdev child zios, which do not hold SCL_ZIO.
181 * Protects changes to metaslab groups and classes.
182 * Held as reader by metaslab_free(). SCL_FREE is distinct from
183 * SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
184 * blocks in zio_done() while another i/o that holds either
185 * SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
188 * Held as reader to prevent changes to the vdev tree during trivial
189 * inquiries such as bp_get_dsize(). SCL_VDEV is distinct from the
190 * other locks, and lower than all of them, to ensure that it's safe
191 * to acquire regardless of caller context.
193 * In addition, the following rules apply:
195 * (a) spa_props_lock protects pool properties, spa_config and spa_config_list.
196 * The lock ordering is SCL_CONFIG > spa_props_lock.
198 * (b) I/O operations on leaf vdevs. For any zio operation that takes
199 * an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
200 * or zio_write_phys() -- the caller must ensure that the config cannot
201 * cannot change in the interim, and that the vdev cannot be reopened.
202 * SCL_STATE as reader suffices for both.
204 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
206 * spa_vdev_enter() Acquire the namespace lock and the config lock
209 * spa_vdev_exit() Release the config lock, wait for all I/O
210 * to complete, sync the updated configs to the
211 * cache, and release the namespace lock.
213 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
214 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
215 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
217 * spa_rename() is also implemented within this file since is requires
218 * manipulation of the namespace.
221 static avl_tree_t spa_namespace_avl;
222 kmutex_t spa_namespace_lock;
223 static kcondvar_t spa_namespace_cv;
224 static int spa_active_count;
225 int spa_max_replication_override = SPA_DVAS_PER_BP;
227 static kmutex_t spa_spare_lock;
228 static avl_tree_t spa_spare_avl;
229 static kmutex_t spa_l2cache_lock;
230 static avl_tree_t spa_l2cache_avl;
232 kmem_cache_t *spa_buffer_pool;
236 /* Everything except dprintf is on by default in debug builds */
237 int zfs_flags = ~ZFS_DEBUG_DPRINTF;
243 * zfs_recover can be set to nonzero to attempt to recover from
244 * otherwise-fatal errors, typically caused by on-disk corruption. When
245 * set, calls to zfs_panic_recover() will turn into warning messages.
251 * ==========================================================================
253 * ==========================================================================
256 spa_config_lock_init(spa_t *spa)
258 for (int i = 0; i < SCL_LOCKS; i++) {
259 spa_config_lock_t *scl = &spa->spa_config_lock[i];
260 mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
261 cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
262 refcount_create(&scl->scl_count);
263 scl->scl_writer = NULL;
264 scl->scl_write_wanted = 0;
269 spa_config_lock_destroy(spa_t *spa)
271 for (int i = 0; i < SCL_LOCKS; i++) {
272 spa_config_lock_t *scl = &spa->spa_config_lock[i];
273 mutex_destroy(&scl->scl_lock);
274 cv_destroy(&scl->scl_cv);
275 refcount_destroy(&scl->scl_count);
276 ASSERT(scl->scl_writer == NULL);
277 ASSERT(scl->scl_write_wanted == 0);
282 spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
284 for (int i = 0; i < SCL_LOCKS; i++) {
285 spa_config_lock_t *scl = &spa->spa_config_lock[i];
286 if (!(locks & (1 << i)))
288 mutex_enter(&scl->scl_lock);
289 if (rw == RW_READER) {
290 if (scl->scl_writer || scl->scl_write_wanted) {
291 mutex_exit(&scl->scl_lock);
292 spa_config_exit(spa, locks ^ (1 << i), tag);
296 ASSERT(scl->scl_writer != curthread);
297 if (!refcount_is_zero(&scl->scl_count)) {
298 mutex_exit(&scl->scl_lock);
299 spa_config_exit(spa, locks ^ (1 << i), tag);
302 scl->scl_writer = curthread;
304 (void) refcount_add(&scl->scl_count, tag);
305 mutex_exit(&scl->scl_lock);
311 spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
315 for (int i = 0; i < SCL_LOCKS; i++) {
316 spa_config_lock_t *scl = &spa->spa_config_lock[i];
317 if (scl->scl_writer == curthread)
318 wlocks_held |= (1 << i);
319 if (!(locks & (1 << i)))
321 mutex_enter(&scl->scl_lock);
322 if (rw == RW_READER) {
323 while (scl->scl_writer || scl->scl_write_wanted) {
324 cv_wait(&scl->scl_cv, &scl->scl_lock);
327 ASSERT(scl->scl_writer != curthread);
328 while (!refcount_is_zero(&scl->scl_count)) {
329 scl->scl_write_wanted++;
330 cv_wait(&scl->scl_cv, &scl->scl_lock);
331 scl->scl_write_wanted--;
333 scl->scl_writer = curthread;
335 (void) refcount_add(&scl->scl_count, tag);
336 mutex_exit(&scl->scl_lock);
338 ASSERT(wlocks_held <= locks);
342 spa_config_exit(spa_t *spa, int locks, void *tag)
344 for (int i = SCL_LOCKS - 1; i >= 0; i--) {
345 spa_config_lock_t *scl = &spa->spa_config_lock[i];
346 if (!(locks & (1 << i)))
348 mutex_enter(&scl->scl_lock);
349 ASSERT(!refcount_is_zero(&scl->scl_count));
350 if (refcount_remove(&scl->scl_count, tag) == 0) {
351 ASSERT(scl->scl_writer == NULL ||
352 scl->scl_writer == curthread);
353 scl->scl_writer = NULL; /* OK in either case */
354 cv_broadcast(&scl->scl_cv);
356 mutex_exit(&scl->scl_lock);
361 spa_config_held(spa_t *spa, int locks, krw_t rw)
365 for (int i = 0; i < SCL_LOCKS; i++) {
366 spa_config_lock_t *scl = &spa->spa_config_lock[i];
367 if (!(locks & (1 << i)))
369 if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
370 (rw == RW_WRITER && scl->scl_writer == curthread))
371 locks_held |= 1 << i;
378 * ==========================================================================
379 * SPA namespace functions
380 * ==========================================================================
384 * Lookup the named spa_t in the AVL tree. The spa_namespace_lock must be held.
385 * Returns NULL if no matching spa_t is found.
388 spa_lookup(const char *name)
390 static spa_t search; /* spa_t is large; don't allocate on stack */
396 ASSERT(MUTEX_HELD(&spa_namespace_lock));
399 * If it's a full dataset name, figure out the pool name and
402 cp = strpbrk(name, "/@");
408 (void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
409 spa = avl_find(&spa_namespace_avl, &search, &where);
418 * Create an uninitialized spa_t with the given name. Requires
419 * spa_namespace_lock. The caller must ensure that the spa_t doesn't already
420 * exist by calling spa_lookup() first.
423 spa_add(const char *name, nvlist_t *config, const char *altroot)
426 spa_config_dirent_t *dp;
428 ASSERT(MUTEX_HELD(&spa_namespace_lock));
430 spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
432 mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
433 mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
434 mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
435 mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
436 mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
437 mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
438 mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
439 mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
440 mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
442 cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
443 cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
444 cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
445 cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
447 for (int t = 0; t < TXG_SIZE; t++)
448 bplist_create(&spa->spa_free_bplist[t]);
450 (void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
451 spa->spa_state = POOL_STATE_UNINITIALIZED;
452 spa->spa_freeze_txg = UINT64_MAX;
453 spa->spa_final_txg = UINT64_MAX;
454 spa->spa_load_max_txg = UINT64_MAX;
456 spa->spa_proc_state = SPA_PROC_NONE;
458 refcount_create(&spa->spa_refcount);
459 spa_config_lock_init(spa);
461 avl_add(&spa_namespace_avl, spa);
464 * Set the alternate root, if there is one.
467 spa->spa_root = spa_strdup(altroot);
472 * Every pool starts with the default cachefile
474 list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
475 offsetof(spa_config_dirent_t, scd_link));
477 dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
478 dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
479 list_insert_head(&spa->spa_config_list, dp);
482 VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
488 * Removes a spa_t from the namespace, freeing up any memory used. Requires
489 * spa_namespace_lock. This is called only after the spa_t has been closed and
493 spa_remove(spa_t *spa)
495 spa_config_dirent_t *dp;
497 ASSERT(MUTEX_HELD(&spa_namespace_lock));
498 ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
500 nvlist_free(spa->spa_config_splitting);
502 avl_remove(&spa_namespace_avl, spa);
503 cv_broadcast(&spa_namespace_cv);
506 spa_strfree(spa->spa_root);
510 while ((dp = list_head(&spa->spa_config_list)) != NULL) {
511 list_remove(&spa->spa_config_list, dp);
512 if (dp->scd_path != NULL)
513 spa_strfree(dp->scd_path);
514 kmem_free(dp, sizeof (spa_config_dirent_t));
517 list_destroy(&spa->spa_config_list);
519 spa_config_set(spa, NULL);
521 refcount_destroy(&spa->spa_refcount);
523 spa_config_lock_destroy(spa);
525 for (int t = 0; t < TXG_SIZE; t++)
526 bplist_destroy(&spa->spa_free_bplist[t]);
528 cv_destroy(&spa->spa_async_cv);
529 cv_destroy(&spa->spa_proc_cv);
530 cv_destroy(&spa->spa_scrub_io_cv);
531 cv_destroy(&spa->spa_suspend_cv);
533 mutex_destroy(&spa->spa_async_lock);
534 mutex_destroy(&spa->spa_errlist_lock);
535 mutex_destroy(&spa->spa_errlog_lock);
536 mutex_destroy(&spa->spa_history_lock);
537 mutex_destroy(&spa->spa_proc_lock);
538 mutex_destroy(&spa->spa_props_lock);
539 mutex_destroy(&spa->spa_scrub_lock);
540 mutex_destroy(&spa->spa_suspend_lock);
541 mutex_destroy(&spa->spa_vdev_top_lock);
543 kmem_free(spa, sizeof (spa_t));
547 * Given a pool, return the next pool in the namespace, or NULL if there is
548 * none. If 'prev' is NULL, return the first pool.
551 spa_next(spa_t *prev)
553 ASSERT(MUTEX_HELD(&spa_namespace_lock));
556 return (AVL_NEXT(&spa_namespace_avl, prev));
558 return (avl_first(&spa_namespace_avl));
562 * ==========================================================================
563 * SPA refcount functions
564 * ==========================================================================
568 * Add a reference to the given spa_t. Must have at least one reference, or
569 * have the namespace lock held.
572 spa_open_ref(spa_t *spa, void *tag)
574 ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
575 MUTEX_HELD(&spa_namespace_lock));
576 (void) refcount_add(&spa->spa_refcount, tag);
580 * Remove a reference to the given spa_t. Must have at least one reference, or
581 * have the namespace lock held.
584 spa_close(spa_t *spa, void *tag)
586 ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
587 MUTEX_HELD(&spa_namespace_lock));
588 (void) refcount_remove(&spa->spa_refcount, tag);
592 * Check to see if the spa refcount is zero. Must be called with
593 * spa_namespace_lock held. We really compare against spa_minref, which is the
594 * number of references acquired when opening a pool
597 spa_refcount_zero(spa_t *spa)
599 ASSERT(MUTEX_HELD(&spa_namespace_lock));
601 return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
605 * ==========================================================================
606 * SPA spare and l2cache tracking
607 * ==========================================================================
611 * Hot spares and cache devices are tracked using the same code below,
612 * for 'auxiliary' devices.
615 typedef struct spa_aux {
623 spa_aux_compare(const void *a, const void *b)
625 const spa_aux_t *sa = a;
626 const spa_aux_t *sb = b;
628 if (sa->aux_guid < sb->aux_guid)
630 else if (sa->aux_guid > sb->aux_guid)
637 spa_aux_add(vdev_t *vd, avl_tree_t *avl)
643 search.aux_guid = vd->vdev_guid;
644 if ((aux = avl_find(avl, &search, &where)) != NULL) {
647 aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
648 aux->aux_guid = vd->vdev_guid;
650 avl_insert(avl, aux, where);
655 spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
661 search.aux_guid = vd->vdev_guid;
662 aux = avl_find(avl, &search, &where);
666 if (--aux->aux_count == 0) {
667 avl_remove(avl, aux);
668 kmem_free(aux, sizeof (spa_aux_t));
669 } else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
670 aux->aux_pool = 0ULL;
675 spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
677 spa_aux_t search, *found;
679 search.aux_guid = guid;
680 found = avl_find(avl, &search, NULL);
684 *pool = found->aux_pool;
691 *refcnt = found->aux_count;
696 return (found != NULL);
700 spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
702 spa_aux_t search, *found;
705 search.aux_guid = vd->vdev_guid;
706 found = avl_find(avl, &search, &where);
707 ASSERT(found != NULL);
708 ASSERT(found->aux_pool == 0ULL);
710 found->aux_pool = spa_guid(vd->vdev_spa);
714 * Spares are tracked globally due to the following constraints:
716 * - A spare may be part of multiple pools.
717 * - A spare may be added to a pool even if it's actively in use within
719 * - A spare in use in any pool can only be the source of a replacement if
720 * the target is a spare in the same pool.
722 * We keep track of all spares on the system through the use of a reference
723 * counted AVL tree. When a vdev is added as a spare, or used as a replacement
724 * spare, then we bump the reference count in the AVL tree. In addition, we set
725 * the 'vdev_isspare' member to indicate that the device is a spare (active or
726 * inactive). When a spare is made active (used to replace a device in the
727 * pool), we also keep track of which pool its been made a part of.
729 * The 'spa_spare_lock' protects the AVL tree. These functions are normally
730 * called under the spa_namespace lock as part of vdev reconfiguration. The
731 * separate spare lock exists for the status query path, which does not need to
732 * be completely consistent with respect to other vdev configuration changes.
736 spa_spare_compare(const void *a, const void *b)
738 return (spa_aux_compare(a, b));
742 spa_spare_add(vdev_t *vd)
744 mutex_enter(&spa_spare_lock);
745 ASSERT(!vd->vdev_isspare);
746 spa_aux_add(vd, &spa_spare_avl);
747 vd->vdev_isspare = B_TRUE;
748 mutex_exit(&spa_spare_lock);
752 spa_spare_remove(vdev_t *vd)
754 mutex_enter(&spa_spare_lock);
755 ASSERT(vd->vdev_isspare);
756 spa_aux_remove(vd, &spa_spare_avl);
757 vd->vdev_isspare = B_FALSE;
758 mutex_exit(&spa_spare_lock);
762 spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
766 mutex_enter(&spa_spare_lock);
767 found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
768 mutex_exit(&spa_spare_lock);
774 spa_spare_activate(vdev_t *vd)
776 mutex_enter(&spa_spare_lock);
777 ASSERT(vd->vdev_isspare);
778 spa_aux_activate(vd, &spa_spare_avl);
779 mutex_exit(&spa_spare_lock);
783 * Level 2 ARC devices are tracked globally for the same reasons as spares.
784 * Cache devices currently only support one pool per cache device, and so
785 * for these devices the aux reference count is currently unused beyond 1.
789 spa_l2cache_compare(const void *a, const void *b)
791 return (spa_aux_compare(a, b));
795 spa_l2cache_add(vdev_t *vd)
797 mutex_enter(&spa_l2cache_lock);
798 ASSERT(!vd->vdev_isl2cache);
799 spa_aux_add(vd, &spa_l2cache_avl);
800 vd->vdev_isl2cache = B_TRUE;
801 mutex_exit(&spa_l2cache_lock);
805 spa_l2cache_remove(vdev_t *vd)
807 mutex_enter(&spa_l2cache_lock);
808 ASSERT(vd->vdev_isl2cache);
809 spa_aux_remove(vd, &spa_l2cache_avl);
810 vd->vdev_isl2cache = B_FALSE;
811 mutex_exit(&spa_l2cache_lock);
815 spa_l2cache_exists(uint64_t guid, uint64_t *pool)
819 mutex_enter(&spa_l2cache_lock);
820 found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
821 mutex_exit(&spa_l2cache_lock);
827 spa_l2cache_activate(vdev_t *vd)
829 mutex_enter(&spa_l2cache_lock);
830 ASSERT(vd->vdev_isl2cache);
831 spa_aux_activate(vd, &spa_l2cache_avl);
832 mutex_exit(&spa_l2cache_lock);
836 * ==========================================================================
838 * ==========================================================================
842 * Lock the given spa_t for the purpose of adding or removing a vdev.
843 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
844 * It returns the next transaction group for the spa_t.
847 spa_vdev_enter(spa_t *spa)
849 mutex_enter(&spa->spa_vdev_top_lock);
850 mutex_enter(&spa_namespace_lock);
851 return (spa_vdev_config_enter(spa));
855 * Internal implementation for spa_vdev_enter(). Used when a vdev
856 * operation requires multiple syncs (i.e. removing a device) while
857 * keeping the spa_namespace_lock held.
860 spa_vdev_config_enter(spa_t *spa)
862 ASSERT(MUTEX_HELD(&spa_namespace_lock));
864 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
866 return (spa_last_synced_txg(spa) + 1);
870 * Used in combination with spa_vdev_config_enter() to allow the syncing
871 * of multiple transactions without releasing the spa_namespace_lock.
874 spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
876 ASSERT(MUTEX_HELD(&spa_namespace_lock));
878 int config_changed = B_FALSE;
880 ASSERT(txg > spa_last_synced_txg(spa));
882 spa->spa_pending_vdev = NULL;
887 vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
890 * If the config changed, notify the scrub that it must restart.
891 * This will initiate a resilver if needed.
893 if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
894 config_changed = B_TRUE;
895 spa->spa_config_generation++;
899 * Verify the metaslab classes.
901 ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
902 ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
904 spa_config_exit(spa, SCL_ALL, spa);
907 * Panic the system if the specified tag requires it. This
908 * is useful for ensuring that configurations are updated
911 if (zio_injection_enabled)
912 zio_handle_panic_injection(spa, tag, 0);
915 * Note: this txg_wait_synced() is important because it ensures
916 * that there won't be more than one config change per txg.
917 * This allows us to use the txg as the generation number.
920 txg_wait_synced(spa->spa_dsl_pool, txg);
923 ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
924 spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
926 spa_config_exit(spa, SCL_ALL, spa);
930 * If the config changed, update the config cache.
933 spa_config_sync(spa, B_FALSE, B_TRUE);
937 * Unlock the spa_t after adding or removing a vdev. Besides undoing the
938 * locking of spa_vdev_enter(), we also want make sure the transactions have
939 * synced to disk, and then update the global configuration cache with the new
943 spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
945 spa_vdev_config_exit(spa, vd, txg, error, FTAG);
946 mutex_exit(&spa_namespace_lock);
947 mutex_exit(&spa->spa_vdev_top_lock);
953 * Lock the given spa_t for the purpose of changing vdev state.
956 spa_vdev_state_enter(spa_t *spa, int oplocks)
958 int locks = SCL_STATE_ALL | oplocks;
961 * Root pools may need to read of the underlying devfs filesystem
962 * when opening up a vdev. Unfortunately if we're holding the
963 * SCL_ZIO lock it will result in a deadlock when we try to issue
964 * the read from the root filesystem. Instead we "prefetch"
965 * the associated vnodes that we need prior to opening the
966 * underlying devices and cache them so that we can prevent
967 * any I/O when we are doing the actual open.
969 if (spa_is_root(spa)) {
970 int low = locks & ~(SCL_ZIO - 1);
971 int high = locks & ~low;
973 spa_config_enter(spa, high, spa, RW_WRITER);
974 vdev_hold(spa->spa_root_vdev);
975 spa_config_enter(spa, low, spa, RW_WRITER);
977 spa_config_enter(spa, locks, spa, RW_WRITER);
979 spa->spa_vdev_locks = locks;
983 spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
985 boolean_t config_changed = B_FALSE;
987 if (vd != NULL || error == 0)
988 vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
992 vdev_state_dirty(vd->vdev_top);
993 config_changed = B_TRUE;
994 spa->spa_config_generation++;
997 if (spa_is_root(spa))
998 vdev_rele(spa->spa_root_vdev);
1000 ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1001 spa_config_exit(spa, spa->spa_vdev_locks, spa);
1004 * If anything changed, wait for it to sync. This ensures that,
1005 * from the system administrator's perspective, zpool(1M) commands
1006 * are synchronous. This is important for things like zpool offline:
1007 * when the command completes, you expect no further I/O from ZFS.
1010 txg_wait_synced(spa->spa_dsl_pool, 0);
1013 * If the config changed, update the config cache.
1015 if (config_changed) {
1016 mutex_enter(&spa_namespace_lock);
1017 spa_config_sync(spa, B_FALSE, B_TRUE);
1018 mutex_exit(&spa_namespace_lock);
1025 * ==========================================================================
1026 * Miscellaneous functions
1027 * ==========================================================================
1034 spa_rename(const char *name, const char *newname)
1040 * Lookup the spa_t and grab the config lock for writing. We need to
1041 * actually open the pool so that we can sync out the necessary labels.
1042 * It's OK to call spa_open() with the namespace lock held because we
1043 * allow recursive calls for other reasons.
1045 mutex_enter(&spa_namespace_lock);
1046 if ((err = spa_open(name, &spa, FTAG)) != 0) {
1047 mutex_exit(&spa_namespace_lock);
1051 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1053 avl_remove(&spa_namespace_avl, spa);
1054 (void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1055 avl_add(&spa_namespace_avl, spa);
1058 * Sync all labels to disk with the new names by marking the root vdev
1059 * dirty and waiting for it to sync. It will pick up the new pool name
1062 vdev_config_dirty(spa->spa_root_vdev);
1064 spa_config_exit(spa, SCL_ALL, FTAG);
1066 txg_wait_synced(spa->spa_dsl_pool, 0);
1069 * Sync the updated config cache.
1071 spa_config_sync(spa, B_FALSE, B_TRUE);
1073 spa_close(spa, FTAG);
1075 mutex_exit(&spa_namespace_lock);
1081 * Determine whether a pool with given pool_guid exists. If device_guid is
1082 * non-zero, determine whether the pool exists *and* contains a device with the
1083 * specified device_guid.
1086 spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1089 avl_tree_t *t = &spa_namespace_avl;
1091 ASSERT(MUTEX_HELD(&spa_namespace_lock));
1093 for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1094 if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1096 if (spa->spa_root_vdev == NULL)
1098 if (spa_guid(spa) == pool_guid) {
1099 if (device_guid == 0)
1102 if (vdev_lookup_by_guid(spa->spa_root_vdev,
1103 device_guid) != NULL)
1107 * Check any devices we may be in the process of adding.
1109 if (spa->spa_pending_vdev) {
1110 if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1111 device_guid) != NULL)
1117 return (spa != NULL);
1121 spa_strdup(const char *s)
1127 new = kmem_alloc(len + 1, KM_SLEEP);
1135 spa_strfree(char *s)
1137 kmem_free(s, strlen(s) + 1);
1141 spa_get_random(uint64_t range)
1147 (void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1153 spa_generate_guid(spa_t *spa)
1155 uint64_t guid = spa_get_random(-1ULL);
1158 while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1159 guid = spa_get_random(-1ULL);
1161 while (guid == 0 || spa_guid_exists(guid, 0))
1162 guid = spa_get_random(-1ULL);
1169 sprintf_blkptr(char *buf, const blkptr_t *bp)
1172 char *checksum = NULL;
1173 char *compress = NULL;
1176 type = dmu_ot[BP_GET_TYPE(bp)].ot_name;
1177 checksum = zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1178 compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1181 SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress);
1185 spa_freeze(spa_t *spa)
1187 uint64_t freeze_txg = 0;
1189 spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1190 if (spa->spa_freeze_txg == UINT64_MAX) {
1191 freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1192 spa->spa_freeze_txg = freeze_txg;
1194 spa_config_exit(spa, SCL_ALL, FTAG);
1195 if (freeze_txg != 0)
1196 txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1200 zfs_panic_recover(const char *fmt, ...)
1205 vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1210 * This is a stripped-down version of strtoull, suitable only for converting
1211 * lowercase hexidecimal numbers that don't overflow.
1214 strtonum(const char *str, char **nptr)
1220 while ((c = *str) != '\0') {
1221 if (c >= '0' && c <= '9')
1223 else if (c >= 'a' && c <= 'f')
1224 digit = 10 + c - 'a';
1235 *nptr = (char *)str;
1241 * ==========================================================================
1242 * Accessor functions
1243 * ==========================================================================
1247 spa_shutting_down(spa_t *spa)
1249 return (spa->spa_async_suspended);
1253 spa_get_dsl(spa_t *spa)
1255 return (spa->spa_dsl_pool);
1259 spa_get_rootblkptr(spa_t *spa)
1261 return (&spa->spa_ubsync.ub_rootbp);
1265 spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1267 spa->spa_uberblock.ub_rootbp = *bp;
1271 spa_altroot(spa_t *spa, char *buf, size_t buflen)
1273 if (spa->spa_root == NULL)
1276 (void) strncpy(buf, spa->spa_root, buflen);
1280 spa_sync_pass(spa_t *spa)
1282 return (spa->spa_sync_pass);
1286 spa_name(spa_t *spa)
1288 return (spa->spa_name);
1292 spa_guid(spa_t *spa)
1295 * If we fail to parse the config during spa_load(), we can go through
1296 * the error path (which posts an ereport) and end up here with no root
1297 * vdev. We stash the original pool guid in 'spa_load_guid' to handle
1300 if (spa->spa_root_vdev != NULL)
1301 return (spa->spa_root_vdev->vdev_guid);
1303 return (spa->spa_load_guid);
1307 spa_last_synced_txg(spa_t *spa)
1309 return (spa->spa_ubsync.ub_txg);
1313 spa_first_txg(spa_t *spa)
1315 return (spa->spa_first_txg);
1319 spa_syncing_txg(spa_t *spa)
1321 return (spa->spa_syncing_txg);
1325 spa_state(spa_t *spa)
1327 return (spa->spa_state);
1331 spa_load_state(spa_t *spa)
1333 return (spa->spa_load_state);
1337 spa_freeze_txg(spa_t *spa)
1339 return (spa->spa_freeze_txg);
1344 spa_get_asize(spa_t *spa, uint64_t lsize)
1347 * The worst case is single-sector max-parity RAID-Z blocks, in which
1348 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
1349 * times the size; so just assume that. Add to this the fact that
1350 * we can have up to 3 DVAs per bp, and one more factor of 2 because
1351 * the block may be dittoed with up to 3 DVAs by ddt_sync().
1353 return (lsize * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2);
1357 spa_get_dspace(spa_t *spa)
1359 return (spa->spa_dspace);
1363 spa_update_dspace(spa_t *spa)
1365 spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1366 ddt_get_dedup_dspace(spa);
1370 * Return the failure mode that has been set to this pool. The default
1371 * behavior will be to block all I/Os when a complete failure occurs.
1374 spa_get_failmode(spa_t *spa)
1376 return (spa->spa_failmode);
1380 spa_suspended(spa_t *spa)
1382 return (spa->spa_suspended);
1386 spa_version(spa_t *spa)
1388 return (spa->spa_ubsync.ub_version);
1392 spa_deflate(spa_t *spa)
1394 return (spa->spa_deflate);
1398 spa_normal_class(spa_t *spa)
1400 return (spa->spa_normal_class);
1404 spa_log_class(spa_t *spa)
1406 return (spa->spa_log_class);
1410 spa_max_replication(spa_t *spa)
1413 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1414 * handle BPs with more than one DVA allocated. Set our max
1415 * replication level accordingly.
1417 if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1419 return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1423 spa_prev_software_version(spa_t *spa)
1425 return (spa->spa_prev_software_version);
1429 dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1431 uint64_t asize = DVA_GET_ASIZE(dva);
1432 uint64_t dsize = asize;
1434 ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1436 if (asize != 0 && spa->spa_deflate) {
1437 vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1438 dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1445 bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1449 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1450 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1456 bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1460 spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1462 for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1463 dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1465 spa_config_exit(spa, SCL_VDEV, FTAG);
1471 * ==========================================================================
1472 * Initialization and Termination
1473 * ==========================================================================
1477 spa_name_compare(const void *a1, const void *a2)
1479 const spa_t *s1 = a1;
1480 const spa_t *s2 = a2;
1483 s = strcmp(s1->spa_name, s2->spa_name);
1494 return (spa_active_count);
1506 mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1507 mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1508 mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1509 cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1511 avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1512 offsetof(spa_t, spa_avl));
1514 avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1515 offsetof(spa_aux_t, aux_avl));
1517 avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1518 offsetof(spa_aux_t, aux_avl));
1520 spa_mode_global = mode;
1527 vdev_cache_stat_init();
1541 vdev_cache_stat_fini();
1548 avl_destroy(&spa_namespace_avl);
1549 avl_destroy(&spa_spare_avl);
1550 avl_destroy(&spa_l2cache_avl);
1552 cv_destroy(&spa_namespace_cv);
1553 mutex_destroy(&spa_namespace_lock);
1554 mutex_destroy(&spa_spare_lock);
1555 mutex_destroy(&spa_l2cache_lock);
1559 * Return whether this pool has slogs. No locking needed.
1560 * It's not a problem if the wrong answer is returned as it's only for
1561 * performance and not correctness
1564 spa_has_slogs(spa_t *spa)
1566 return (spa->spa_log_class->mc_rotor != NULL);
1570 spa_get_log_state(spa_t *spa)
1572 return (spa->spa_log_state);
1576 spa_set_log_state(spa_t *spa, spa_log_state_t state)
1578 spa->spa_log_state = state;
1582 spa_is_root(spa_t *spa)
1584 return (spa->spa_is_root);
1588 spa_writeable(spa_t *spa)
1590 return (!!(spa->spa_mode & FWRITE));
1594 spa_mode(spa_t *spa)
1596 return (spa->spa_mode);
1600 spa_bootfs(spa_t *spa)
1602 return (spa->spa_bootfs);
1606 spa_delegation(spa_t *spa)
1608 return (spa->spa_delegation);
1612 spa_meta_objset(spa_t *spa)
1614 return (spa->spa_meta_objset);
1618 spa_dedup_checksum(spa_t *spa)
1620 return (spa->spa_dedup_checksum);
1624 * Reset pool scan stat per scan pass (or reboot).
1627 spa_scan_stat_init(spa_t *spa)
1629 /* data not stored on disk */
1630 spa->spa_scan_pass_start = gethrestime_sec();
1631 spa->spa_scan_pass_exam = 0;
1632 vdev_scan_stat_init(spa->spa_root_vdev);
1636 * Get scan stats for zpool status reports
1639 spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1641 dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1643 if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1645 bzero(ps, sizeof (pool_scan_stat_t));
1647 /* data stored on disk */
1648 ps->pss_func = scn->scn_phys.scn_func;
1649 ps->pss_start_time = scn->scn_phys.scn_start_time;
1650 ps->pss_end_time = scn->scn_phys.scn_end_time;
1651 ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1652 ps->pss_examined = scn->scn_phys.scn_examined;
1653 ps->pss_to_process = scn->scn_phys.scn_to_process;
1654 ps->pss_processed = scn->scn_phys.scn_processed;
1655 ps->pss_errors = scn->scn_phys.scn_errors;
1656 ps->pss_state = scn->scn_phys.scn_state;
1658 /* data not stored on disk */
1659 ps->pss_pass_start = spa->spa_scan_pass_start;
1660 ps->pss_pass_exam = spa->spa_scan_pass_exam;