spa_misc.c revision 88ecc943b4eb72f7c4fbbd8435997b85ef171fc3
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 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#include <sys/zfs_context.h>
27#include <sys/spa_impl.h>
28#include <sys/zio.h>
29#include <sys/zio_checksum.h>
30#include <sys/zio_compress.h>
31#include <sys/dmu.h>
32#include <sys/dmu_tx.h>
33#include <sys/zap.h>
34#include <sys/zil.h>
35#include <sys/vdev_impl.h>
36#include <sys/metaslab.h>
37#include <sys/uberblock_impl.h>
38#include <sys/txg.h>
39#include <sys/avl.h>
40#include <sys/unique.h>
41#include <sys/dsl_pool.h>
42#include <sys/dsl_dir.h>
43#include <sys/dsl_prop.h>
44#include <sys/fs/zfs.h>
45#include <sys/metaslab_impl.h>
46#include <sys/sunddi.h>
47#include <sys/arc.h>
48#include "zfs_prop.h"
49
50/*
51 * SPA locking
52 *
53 * There are four basic locks for managing spa_t structures:
54 *
55 * spa_namespace_lock (global mutex)
56 *
57 *	This lock must be acquired to do any of the following:
58 *
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
63 *		- Rename a spa_t
64 *		- add/remove/attach/detach devices
65 *		- Held for the duration of create/destroy/import/export
66 *
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.
71 *
72 * spa_refcount (per-spa refcount_t protected by mutex)
73 *
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.
79 *
80 * spa_config_lock[] (per-spa array of rwlocks)
81 *
82 *	This protects the spa_t from config changes, and must be held in
83 *	the following circumstances:
84 *
85 *		- RW_READER to perform I/O to the spa
86 *		- RW_WRITER to change the vdev config
87 *
88 * The locking order is fairly straightforward:
89 *
90 *		spa_namespace_lock	->	spa_refcount
91 *
92 *	The namespace lock must be acquired to increase the refcount from 0
93 *	or to check if it is zero.
94 *
95 *		spa_refcount		->	spa_config_lock[]
96 *
97 *	There must be at least one valid reference on the spa_t to acquire
98 *	the config lock.
99 *
100 *		spa_namespace_lock	->	spa_config_lock[]
101 *
102 *	The namespace lock must always be taken before the config lock.
103 *
104 *
105 * The spa_namespace_lock can be acquired directly and is globally visible.
106 *
107 * The namespace is manipulated using the following functions, all of which
108 * require the spa_namespace_lock to be held.
109 *
110 *	spa_lookup()		Lookup a spa_t by name.
111 *
112 *	spa_add()		Create a new spa_t in the namespace.
113 *
114 *	spa_remove()		Remove a spa_t from the namespace.  This also
115 *				frees up any memory associated with the spa_t.
116 *
117 *	spa_next()		Returns the next spa_t in the system, or the
118 *				first if NULL is passed.
119 *
120 *	spa_evict_all()		Shutdown and remove all spa_t structures in
121 *				the system.
122 *
123 *	spa_guid_exists()	Determine whether a pool/device guid exists.
124 *
125 * The spa_refcount is manipulated using the following functions:
126 *
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.
130 *
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.
134 *
135 *	spa_refcount_zero()	Returns true if the refcount is currently
136 *				zero.  Must be called with spa_namespace_lock
137 *				held.
138 *
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}().
142 *
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.
147 *
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).
152 *
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.
158 *
159 * The lock acquisition rules are as follows:
160 *
161 * SCL_CONFIG
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.
165 *
166 * SCL_STATE
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).
170 *
171 * SCL_ALLOC
172 *	Protects changes to metaslab groups and classes.
173 *	Held as reader by metaslab_alloc() and metaslab_claim().
174 *
175 * SCL_ZIO
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.
179 *
180 * SCL_FREE
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.
186 *
187 * SCL_VDEV
188 *	Held as reader to prevent changes to the vdev tree during trivial
189 *	inquiries such as bp_get_dasize().  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.
192 *
193 * In addition, the following rules apply:
194 *
195 * (a)	spa_props_lock protects pool properties, spa_config and spa_config_list.
196 *	The lock ordering is SCL_CONFIG > spa_props_lock.
197 *
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.
203 *
204 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
205 *
206 *	spa_vdev_enter()	Acquire the namespace lock and the config lock
207 *				for writing.
208 *
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.
212 *
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[].
216 *
217 * spa_rename() is also implemented within this file since is requires
218 * manipulation of the namespace.
219 */
220
221static avl_tree_t spa_namespace_avl;
222kmutex_t spa_namespace_lock;
223static kcondvar_t spa_namespace_cv;
224static int spa_active_count;
225int spa_max_replication_override = SPA_DVAS_PER_BP;
226
227static kmutex_t spa_spare_lock;
228static avl_tree_t spa_spare_avl;
229static kmutex_t spa_l2cache_lock;
230static avl_tree_t spa_l2cache_avl;
231
232kmem_cache_t *spa_buffer_pool;
233int spa_mode_global;
234
235#ifdef ZFS_DEBUG
236/* Everything except dprintf is on by default in debug builds */
237int zfs_flags = ~ZFS_DEBUG_DPRINTF;
238#else
239int zfs_flags = 0;
240#endif
241
242/*
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.
246 */
247int zfs_recover = 0;
248
249
250/*
251 * ==========================================================================
252 * SPA config locking
253 * ==========================================================================
254 */
255static void
256spa_config_lock_init(spa_t *spa)
257{
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;
265	}
266}
267
268static void
269spa_config_lock_destroy(spa_t *spa)
270{
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);
278	}
279}
280
281int
282spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
283{
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)))
287			continue;
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);
293				return (0);
294			}
295		} else {
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);
300				return (0);
301			}
302			scl->scl_writer = curthread;
303		}
304		(void) refcount_add(&scl->scl_count, tag);
305		mutex_exit(&scl->scl_lock);
306	}
307	return (1);
308}
309
310void
311spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
312{
313	int wlocks_held = 0;
314
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)))
320			continue;
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);
325			}
326		} else {
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--;
332			}
333			scl->scl_writer = curthread;
334		}
335		(void) refcount_add(&scl->scl_count, tag);
336		mutex_exit(&scl->scl_lock);
337	}
338	ASSERT(wlocks_held <= locks);
339}
340
341void
342spa_config_exit(spa_t *spa, int locks, void *tag)
343{
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)))
347			continue;
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);
355		}
356		mutex_exit(&scl->scl_lock);
357	}
358}
359
360int
361spa_config_held(spa_t *spa, int locks, krw_t rw)
362{
363	int locks_held = 0;
364
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)))
368			continue;
369		if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
370		    (rw == RW_WRITER && scl->scl_writer == curthread))
371			locks_held |= 1 << i;
372	}
373
374	return (locks_held);
375}
376
377/*
378 * ==========================================================================
379 * SPA namespace functions
380 * ==========================================================================
381 */
382
383/*
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.
386 */
387spa_t *
388spa_lookup(const char *name)
389{
390	static spa_t search;	/* spa_t is large; don't allocate on stack */
391	spa_t *spa;
392	avl_index_t where;
393	char c;
394	char *cp;
395
396	ASSERT(MUTEX_HELD(&spa_namespace_lock));
397
398	/*
399	 * If it's a full dataset name, figure out the pool name and
400	 * just use that.
401	 */
402	cp = strpbrk(name, "/@");
403	if (cp) {
404		c = *cp;
405		*cp = '\0';
406	}
407
408	(void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
409	spa = avl_find(&spa_namespace_avl, &search, &where);
410
411	if (cp)
412		*cp = c;
413
414	return (spa);
415}
416
417/*
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.
421 */
422spa_t *
423spa_add(const char *name, const char *altroot)
424{
425	spa_t *spa;
426	spa_config_dirent_t *dp;
427
428	ASSERT(MUTEX_HELD(&spa_namespace_lock));
429
430	spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
431
432	mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
433	mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
434	mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
435	mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
436	mutex_init(&spa->spa_sync_bplist.bpl_lock, NULL, MUTEX_DEFAULT, NULL);
437	mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
438	mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
439
440	cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
441	cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
442	cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
443
444	(void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
445	spa->spa_state = POOL_STATE_UNINITIALIZED;
446	spa->spa_freeze_txg = UINT64_MAX;
447	spa->spa_final_txg = UINT64_MAX;
448
449	refcount_create(&spa->spa_refcount);
450	spa_config_lock_init(spa);
451
452	avl_add(&spa_namespace_avl, spa);
453
454	mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
455
456	/*
457	 * Set the alternate root, if there is one.
458	 */
459	if (altroot) {
460		spa->spa_root = spa_strdup(altroot);
461		spa_active_count++;
462	}
463
464	/*
465	 * Every pool starts with the default cachefile
466	 */
467	list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
468	    offsetof(spa_config_dirent_t, scd_link));
469
470	dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
471	dp->scd_path = spa_strdup(spa_config_path);
472	list_insert_head(&spa->spa_config_list, dp);
473
474	return (spa);
475}
476
477/*
478 * Removes a spa_t from the namespace, freeing up any memory used.  Requires
479 * spa_namespace_lock.  This is called only after the spa_t has been closed and
480 * deactivated.
481 */
482void
483spa_remove(spa_t *spa)
484{
485	spa_config_dirent_t *dp;
486
487	ASSERT(MUTEX_HELD(&spa_namespace_lock));
488	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
489
490	avl_remove(&spa_namespace_avl, spa);
491	cv_broadcast(&spa_namespace_cv);
492
493	if (spa->spa_root) {
494		spa_strfree(spa->spa_root);
495		spa_active_count--;
496	}
497
498	while ((dp = list_head(&spa->spa_config_list)) != NULL) {
499		list_remove(&spa->spa_config_list, dp);
500		if (dp->scd_path != NULL)
501			spa_strfree(dp->scd_path);
502		kmem_free(dp, sizeof (spa_config_dirent_t));
503	}
504
505	list_destroy(&spa->spa_config_list);
506
507	spa_config_set(spa, NULL);
508
509	refcount_destroy(&spa->spa_refcount);
510
511	spa_config_lock_destroy(spa);
512
513	cv_destroy(&spa->spa_async_cv);
514	cv_destroy(&spa->spa_scrub_io_cv);
515	cv_destroy(&spa->spa_suspend_cv);
516
517	mutex_destroy(&spa->spa_async_lock);
518	mutex_destroy(&spa->spa_scrub_lock);
519	mutex_destroy(&spa->spa_errlog_lock);
520	mutex_destroy(&spa->spa_errlist_lock);
521	mutex_destroy(&spa->spa_sync_bplist.bpl_lock);
522	mutex_destroy(&spa->spa_history_lock);
523	mutex_destroy(&spa->spa_props_lock);
524	mutex_destroy(&spa->spa_suspend_lock);
525
526	kmem_free(spa, sizeof (spa_t));
527}
528
529/*
530 * Given a pool, return the next pool in the namespace, or NULL if there is
531 * none.  If 'prev' is NULL, return the first pool.
532 */
533spa_t *
534spa_next(spa_t *prev)
535{
536	ASSERT(MUTEX_HELD(&spa_namespace_lock));
537
538	if (prev)
539		return (AVL_NEXT(&spa_namespace_avl, prev));
540	else
541		return (avl_first(&spa_namespace_avl));
542}
543
544/*
545 * ==========================================================================
546 * SPA refcount functions
547 * ==========================================================================
548 */
549
550/*
551 * Add a reference to the given spa_t.  Must have at least one reference, or
552 * have the namespace lock held.
553 */
554void
555spa_open_ref(spa_t *spa, void *tag)
556{
557	ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
558	    MUTEX_HELD(&spa_namespace_lock));
559	(void) refcount_add(&spa->spa_refcount, tag);
560}
561
562/*
563 * Remove a reference to the given spa_t.  Must have at least one reference, or
564 * have the namespace lock held.
565 */
566void
567spa_close(spa_t *spa, void *tag)
568{
569	ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
570	    MUTEX_HELD(&spa_namespace_lock));
571	(void) refcount_remove(&spa->spa_refcount, tag);
572}
573
574/*
575 * Check to see if the spa refcount is zero.  Must be called with
576 * spa_namespace_lock held.  We really compare against spa_minref, which is the
577 * number of references acquired when opening a pool
578 */
579boolean_t
580spa_refcount_zero(spa_t *spa)
581{
582	ASSERT(MUTEX_HELD(&spa_namespace_lock));
583
584	return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
585}
586
587/*
588 * ==========================================================================
589 * SPA spare and l2cache tracking
590 * ==========================================================================
591 */
592
593/*
594 * Hot spares and cache devices are tracked using the same code below,
595 * for 'auxiliary' devices.
596 */
597
598typedef struct spa_aux {
599	uint64_t	aux_guid;
600	uint64_t	aux_pool;
601	avl_node_t	aux_avl;
602	int		aux_count;
603} spa_aux_t;
604
605static int
606spa_aux_compare(const void *a, const void *b)
607{
608	const spa_aux_t *sa = a;
609	const spa_aux_t *sb = b;
610
611	if (sa->aux_guid < sb->aux_guid)
612		return (-1);
613	else if (sa->aux_guid > sb->aux_guid)
614		return (1);
615	else
616		return (0);
617}
618
619void
620spa_aux_add(vdev_t *vd, avl_tree_t *avl)
621{
622	avl_index_t where;
623	spa_aux_t search;
624	spa_aux_t *aux;
625
626	search.aux_guid = vd->vdev_guid;
627	if ((aux = avl_find(avl, &search, &where)) != NULL) {
628		aux->aux_count++;
629	} else {
630		aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
631		aux->aux_guid = vd->vdev_guid;
632		aux->aux_count = 1;
633		avl_insert(avl, aux, where);
634	}
635}
636
637void
638spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
639{
640	spa_aux_t search;
641	spa_aux_t *aux;
642	avl_index_t where;
643
644	search.aux_guid = vd->vdev_guid;
645	aux = avl_find(avl, &search, &where);
646
647	ASSERT(aux != NULL);
648
649	if (--aux->aux_count == 0) {
650		avl_remove(avl, aux);
651		kmem_free(aux, sizeof (spa_aux_t));
652	} else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
653		aux->aux_pool = 0ULL;
654	}
655}
656
657boolean_t
658spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
659{
660	spa_aux_t search, *found;
661
662	search.aux_guid = guid;
663	found = avl_find(avl, &search, NULL);
664
665	if (pool) {
666		if (found)
667			*pool = found->aux_pool;
668		else
669			*pool = 0ULL;
670	}
671
672	if (refcnt) {
673		if (found)
674			*refcnt = found->aux_count;
675		else
676			*refcnt = 0;
677	}
678
679	return (found != NULL);
680}
681
682void
683spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
684{
685	spa_aux_t search, *found;
686	avl_index_t where;
687
688	search.aux_guid = vd->vdev_guid;
689	found = avl_find(avl, &search, &where);
690	ASSERT(found != NULL);
691	ASSERT(found->aux_pool == 0ULL);
692
693	found->aux_pool = spa_guid(vd->vdev_spa);
694}
695
696/*
697 * Spares are tracked globally due to the following constraints:
698 *
699 * 	- A spare may be part of multiple pools.
700 * 	- A spare may be added to a pool even if it's actively in use within
701 *	  another pool.
702 * 	- A spare in use in any pool can only be the source of a replacement if
703 *	  the target is a spare in the same pool.
704 *
705 * We keep track of all spares on the system through the use of a reference
706 * counted AVL tree.  When a vdev is added as a spare, or used as a replacement
707 * spare, then we bump the reference count in the AVL tree.  In addition, we set
708 * the 'vdev_isspare' member to indicate that the device is a spare (active or
709 * inactive).  When a spare is made active (used to replace a device in the
710 * pool), we also keep track of which pool its been made a part of.
711 *
712 * The 'spa_spare_lock' protects the AVL tree.  These functions are normally
713 * called under the spa_namespace lock as part of vdev reconfiguration.  The
714 * separate spare lock exists for the status query path, which does not need to
715 * be completely consistent with respect to other vdev configuration changes.
716 */
717
718static int
719spa_spare_compare(const void *a, const void *b)
720{
721	return (spa_aux_compare(a, b));
722}
723
724void
725spa_spare_add(vdev_t *vd)
726{
727	mutex_enter(&spa_spare_lock);
728	ASSERT(!vd->vdev_isspare);
729	spa_aux_add(vd, &spa_spare_avl);
730	vd->vdev_isspare = B_TRUE;
731	mutex_exit(&spa_spare_lock);
732}
733
734void
735spa_spare_remove(vdev_t *vd)
736{
737	mutex_enter(&spa_spare_lock);
738	ASSERT(vd->vdev_isspare);
739	spa_aux_remove(vd, &spa_spare_avl);
740	vd->vdev_isspare = B_FALSE;
741	mutex_exit(&spa_spare_lock);
742}
743
744boolean_t
745spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
746{
747	boolean_t found;
748
749	mutex_enter(&spa_spare_lock);
750	found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
751	mutex_exit(&spa_spare_lock);
752
753	return (found);
754}
755
756void
757spa_spare_activate(vdev_t *vd)
758{
759	mutex_enter(&spa_spare_lock);
760	ASSERT(vd->vdev_isspare);
761	spa_aux_activate(vd, &spa_spare_avl);
762	mutex_exit(&spa_spare_lock);
763}
764
765/*
766 * Level 2 ARC devices are tracked globally for the same reasons as spares.
767 * Cache devices currently only support one pool per cache device, and so
768 * for these devices the aux reference count is currently unused beyond 1.
769 */
770
771static int
772spa_l2cache_compare(const void *a, const void *b)
773{
774	return (spa_aux_compare(a, b));
775}
776
777void
778spa_l2cache_add(vdev_t *vd)
779{
780	mutex_enter(&spa_l2cache_lock);
781	ASSERT(!vd->vdev_isl2cache);
782	spa_aux_add(vd, &spa_l2cache_avl);
783	vd->vdev_isl2cache = B_TRUE;
784	mutex_exit(&spa_l2cache_lock);
785}
786
787void
788spa_l2cache_remove(vdev_t *vd)
789{
790	mutex_enter(&spa_l2cache_lock);
791	ASSERT(vd->vdev_isl2cache);
792	spa_aux_remove(vd, &spa_l2cache_avl);
793	vd->vdev_isl2cache = B_FALSE;
794	mutex_exit(&spa_l2cache_lock);
795}
796
797boolean_t
798spa_l2cache_exists(uint64_t guid, uint64_t *pool)
799{
800	boolean_t found;
801
802	mutex_enter(&spa_l2cache_lock);
803	found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
804	mutex_exit(&spa_l2cache_lock);
805
806	return (found);
807}
808
809void
810spa_l2cache_activate(vdev_t *vd)
811{
812	mutex_enter(&spa_l2cache_lock);
813	ASSERT(vd->vdev_isl2cache);
814	spa_aux_activate(vd, &spa_l2cache_avl);
815	mutex_exit(&spa_l2cache_lock);
816}
817
818void
819spa_l2cache_space_update(vdev_t *vd, int64_t space, int64_t alloc)
820{
821	vdev_space_update(vd, space, alloc, B_FALSE);
822}
823
824/*
825 * ==========================================================================
826 * SPA vdev locking
827 * ==========================================================================
828 */
829
830/*
831 * Lock the given spa_t for the purpose of adding or removing a vdev.
832 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
833 * It returns the next transaction group for the spa_t.
834 */
835uint64_t
836spa_vdev_enter(spa_t *spa)
837{
838	mutex_enter(&spa_namespace_lock);
839	return (spa_vdev_config_enter(spa));
840}
841
842/*
843 * Internal implementation for spa_vdev_enter().  Used when a vdev
844 * operation requires multiple syncs (i.e. removing a device) while
845 * keeping the spa_namespace_lock held.
846 */
847uint64_t
848spa_vdev_config_enter(spa_t *spa)
849{
850	ASSERT(MUTEX_HELD(&spa_namespace_lock));
851
852	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
853
854	return (spa_last_synced_txg(spa) + 1);
855}
856
857/*
858 * Used in combination with spa_vdev_config_enter() to allow the syncing
859 * of multiple transactions without releasing the spa_namespace_lock.
860 */
861void
862spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
863{
864	ASSERT(MUTEX_HELD(&spa_namespace_lock));
865
866	int config_changed = B_FALSE;
867
868	ASSERT(txg > spa_last_synced_txg(spa));
869
870	spa->spa_pending_vdev = NULL;
871
872	/*
873	 * Reassess the DTLs.
874	 */
875	vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
876
877	/*
878	 * If the config changed, notify the scrub thread that it must restart.
879	 */
880	if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
881		dsl_pool_scrub_restart(spa->spa_dsl_pool);
882		config_changed = B_TRUE;
883	}
884
885	/*
886	 * Verify the metaslab classes.
887	 */
888	ASSERT(metaslab_class_validate(spa->spa_normal_class) == 0);
889	ASSERT(metaslab_class_validate(spa->spa_log_class) == 0);
890
891	spa_config_exit(spa, SCL_ALL, spa);
892
893	/*
894	 * Panic the system if the specified tag requires it.  This
895	 * is useful for ensuring that configurations are updated
896	 * transactionally.
897	 */
898	if (zio_injection_enabled)
899		zio_handle_panic_injection(spa, tag);
900
901	/*
902	 * Note: this txg_wait_synced() is important because it ensures
903	 * that there won't be more than one config change per txg.
904	 * This allows us to use the txg as the generation number.
905	 */
906	if (error == 0)
907		txg_wait_synced(spa->spa_dsl_pool, txg);
908
909	if (vd != NULL) {
910		ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
911		spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
912		vdev_free(vd);
913		spa_config_exit(spa, SCL_ALL, spa);
914	}
915
916	/*
917	 * If the config changed, update the config cache.
918	 */
919	if (config_changed)
920		spa_config_sync(spa, B_FALSE, B_TRUE);
921}
922
923/*
924 * Unlock the spa_t after adding or removing a vdev.  Besides undoing the
925 * locking of spa_vdev_enter(), we also want make sure the transactions have
926 * synced to disk, and then update the global configuration cache with the new
927 * information.
928 */
929int
930spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
931{
932	spa_vdev_config_exit(spa, vd, txg, error, FTAG);
933	mutex_exit(&spa_namespace_lock);
934
935	return (error);
936}
937
938/*
939 * Lock the given spa_t for the purpose of changing vdev state.
940 */
941void
942spa_vdev_state_enter(spa_t *spa)
943{
944	spa_config_enter(spa, SCL_STATE_ALL, spa, RW_WRITER);
945}
946
947int
948spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
949{
950	if (vd != NULL)
951		vdev_state_dirty(vd->vdev_top);
952
953	spa_config_exit(spa, SCL_STATE_ALL, spa);
954
955	/*
956	 * If anything changed, wait for it to sync.  This ensures that,
957	 * from the system administrator's perspective, zpool(1M) commands
958	 * are synchronous.  This is important for things like zpool offline:
959	 * when the command completes, you expect no further I/O from ZFS.
960	 */
961	if (vd != NULL)
962		txg_wait_synced(spa->spa_dsl_pool, 0);
963
964	return (error);
965}
966
967/*
968 * ==========================================================================
969 * Miscellaneous functions
970 * ==========================================================================
971 */
972
973/*
974 * Rename a spa_t.
975 */
976int
977spa_rename(const char *name, const char *newname)
978{
979	spa_t *spa;
980	int err;
981
982	/*
983	 * Lookup the spa_t and grab the config lock for writing.  We need to
984	 * actually open the pool so that we can sync out the necessary labels.
985	 * It's OK to call spa_open() with the namespace lock held because we
986	 * allow recursive calls for other reasons.
987	 */
988	mutex_enter(&spa_namespace_lock);
989	if ((err = spa_open(name, &spa, FTAG)) != 0) {
990		mutex_exit(&spa_namespace_lock);
991		return (err);
992	}
993
994	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
995
996	avl_remove(&spa_namespace_avl, spa);
997	(void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
998	avl_add(&spa_namespace_avl, spa);
999
1000	/*
1001	 * Sync all labels to disk with the new names by marking the root vdev
1002	 * dirty and waiting for it to sync.  It will pick up the new pool name
1003	 * during the sync.
1004	 */
1005	vdev_config_dirty(spa->spa_root_vdev);
1006
1007	spa_config_exit(spa, SCL_ALL, FTAG);
1008
1009	txg_wait_synced(spa->spa_dsl_pool, 0);
1010
1011	/*
1012	 * Sync the updated config cache.
1013	 */
1014	spa_config_sync(spa, B_FALSE, B_TRUE);
1015
1016	spa_close(spa, FTAG);
1017
1018	mutex_exit(&spa_namespace_lock);
1019
1020	return (0);
1021}
1022
1023
1024/*
1025 * Determine whether a pool with given pool_guid exists.  If device_guid is
1026 * non-zero, determine whether the pool exists *and* contains a device with the
1027 * specified device_guid.
1028 */
1029boolean_t
1030spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1031{
1032	spa_t *spa;
1033	avl_tree_t *t = &spa_namespace_avl;
1034
1035	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1036
1037	for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1038		if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1039			continue;
1040		if (spa->spa_root_vdev == NULL)
1041			continue;
1042		if (spa_guid(spa) == pool_guid) {
1043			if (device_guid == 0)
1044				break;
1045
1046			if (vdev_lookup_by_guid(spa->spa_root_vdev,
1047			    device_guid) != NULL)
1048				break;
1049
1050			/*
1051			 * Check any devices we may be in the process of adding.
1052			 */
1053			if (spa->spa_pending_vdev) {
1054				if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1055				    device_guid) != NULL)
1056					break;
1057			}
1058		}
1059	}
1060
1061	return (spa != NULL);
1062}
1063
1064char *
1065spa_strdup(const char *s)
1066{
1067	size_t len;
1068	char *new;
1069
1070	len = strlen(s);
1071	new = kmem_alloc(len + 1, KM_SLEEP);
1072	bcopy(s, new, len);
1073	new[len] = '\0';
1074
1075	return (new);
1076}
1077
1078void
1079spa_strfree(char *s)
1080{
1081	kmem_free(s, strlen(s) + 1);
1082}
1083
1084uint64_t
1085spa_get_random(uint64_t range)
1086{
1087	uint64_t r;
1088
1089	ASSERT(range != 0);
1090
1091	(void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1092
1093	return (r % range);
1094}
1095
1096void
1097sprintf_blkptr(char *buf, int len, const blkptr_t *bp)
1098{
1099	int d;
1100
1101	if (bp == NULL) {
1102		(void) snprintf(buf, len, "<NULL>");
1103		return;
1104	}
1105
1106	if (BP_IS_HOLE(bp)) {
1107		(void) snprintf(buf, len, "<hole>");
1108		return;
1109	}
1110
1111	(void) snprintf(buf, len, "[L%llu %s] %llxL/%llxP ",
1112	    (u_longlong_t)BP_GET_LEVEL(bp),
1113	    dmu_ot[BP_GET_TYPE(bp)].ot_name,
1114	    (u_longlong_t)BP_GET_LSIZE(bp),
1115	    (u_longlong_t)BP_GET_PSIZE(bp));
1116
1117	for (d = 0; d < BP_GET_NDVAS(bp); d++) {
1118		const dva_t *dva = &bp->blk_dva[d];
1119		(void) snprintf(buf + strlen(buf), len - strlen(buf),
1120		    "DVA[%d]=<%llu:%llx:%llx> ", d,
1121		    (u_longlong_t)DVA_GET_VDEV(dva),
1122		    (u_longlong_t)DVA_GET_OFFSET(dva),
1123		    (u_longlong_t)DVA_GET_ASIZE(dva));
1124	}
1125
1126	(void) snprintf(buf + strlen(buf), len - strlen(buf),
1127	    "%s %s %s %s birth=%llu fill=%llu cksum=%llx:%llx:%llx:%llx",
1128	    zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name,
1129	    zio_compress_table[BP_GET_COMPRESS(bp)].ci_name,
1130	    BP_GET_BYTEORDER(bp) == 0 ? "BE" : "LE",
1131	    BP_IS_GANG(bp) ? "gang" : "contiguous",
1132	    (u_longlong_t)bp->blk_birth,
1133	    (u_longlong_t)bp->blk_fill,
1134	    (u_longlong_t)bp->blk_cksum.zc_word[0],
1135	    (u_longlong_t)bp->blk_cksum.zc_word[1],
1136	    (u_longlong_t)bp->blk_cksum.zc_word[2],
1137	    (u_longlong_t)bp->blk_cksum.zc_word[3]);
1138}
1139
1140void
1141spa_freeze(spa_t *spa)
1142{
1143	uint64_t freeze_txg = 0;
1144
1145	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1146	if (spa->spa_freeze_txg == UINT64_MAX) {
1147		freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1148		spa->spa_freeze_txg = freeze_txg;
1149	}
1150	spa_config_exit(spa, SCL_ALL, FTAG);
1151	if (freeze_txg != 0)
1152		txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1153}
1154
1155void
1156zfs_panic_recover(const char *fmt, ...)
1157{
1158	va_list adx;
1159
1160	va_start(adx, fmt);
1161	vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1162	va_end(adx);
1163}
1164
1165/*
1166 * ==========================================================================
1167 * Accessor functions
1168 * ==========================================================================
1169 */
1170
1171boolean_t
1172spa_shutting_down(spa_t *spa)
1173{
1174	return (spa->spa_async_suspended);
1175}
1176
1177dsl_pool_t *
1178spa_get_dsl(spa_t *spa)
1179{
1180	return (spa->spa_dsl_pool);
1181}
1182
1183blkptr_t *
1184spa_get_rootblkptr(spa_t *spa)
1185{
1186	return (&spa->spa_ubsync.ub_rootbp);
1187}
1188
1189void
1190spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1191{
1192	spa->spa_uberblock.ub_rootbp = *bp;
1193}
1194
1195void
1196spa_altroot(spa_t *spa, char *buf, size_t buflen)
1197{
1198	if (spa->spa_root == NULL)
1199		buf[0] = '\0';
1200	else
1201		(void) strncpy(buf, spa->spa_root, buflen);
1202}
1203
1204int
1205spa_sync_pass(spa_t *spa)
1206{
1207	return (spa->spa_sync_pass);
1208}
1209
1210char *
1211spa_name(spa_t *spa)
1212{
1213	return (spa->spa_name);
1214}
1215
1216uint64_t
1217spa_guid(spa_t *spa)
1218{
1219	/*
1220	 * If we fail to parse the config during spa_load(), we can go through
1221	 * the error path (which posts an ereport) and end up here with no root
1222	 * vdev.  We stash the original pool guid in 'spa_load_guid' to handle
1223	 * this case.
1224	 */
1225	if (spa->spa_root_vdev != NULL)
1226		return (spa->spa_root_vdev->vdev_guid);
1227	else
1228		return (spa->spa_load_guid);
1229}
1230
1231uint64_t
1232spa_last_synced_txg(spa_t *spa)
1233{
1234	return (spa->spa_ubsync.ub_txg);
1235}
1236
1237uint64_t
1238spa_first_txg(spa_t *spa)
1239{
1240	return (spa->spa_first_txg);
1241}
1242
1243pool_state_t
1244spa_state(spa_t *spa)
1245{
1246	return (spa->spa_state);
1247}
1248
1249uint64_t
1250spa_freeze_txg(spa_t *spa)
1251{
1252	return (spa->spa_freeze_txg);
1253}
1254
1255/*
1256 * Return how much space is allocated in the pool (ie. sum of all asize)
1257 */
1258uint64_t
1259spa_get_alloc(spa_t *spa)
1260{
1261	return (spa->spa_root_vdev->vdev_stat.vs_alloc);
1262}
1263
1264/*
1265 * Return how much (raid-z inflated) space there is in the pool.
1266 */
1267uint64_t
1268spa_get_space(spa_t *spa)
1269{
1270	return (spa->spa_root_vdev->vdev_stat.vs_space);
1271}
1272
1273/*
1274 * Return the amount of raid-z-deflated space in the pool.
1275 */
1276uint64_t
1277spa_get_dspace(spa_t *spa)
1278{
1279	if (spa->spa_deflate)
1280		return (spa->spa_root_vdev->vdev_stat.vs_dspace);
1281	else
1282		return (spa->spa_root_vdev->vdev_stat.vs_space);
1283}
1284
1285/* ARGSUSED */
1286uint64_t
1287spa_get_asize(spa_t *spa, uint64_t lsize)
1288{
1289	/*
1290	 * For now, the worst case is 512-byte RAID-Z blocks, in which
1291	 * case the space requirement is exactly 2x; so just assume that.
1292	 * Add to this the fact that we can have up to 3 DVAs per bp, and
1293	 * we have to multiply by a total of 6x.
1294	 */
1295	return (lsize * 6);
1296}
1297
1298/*
1299 * Return the failure mode that has been set to this pool. The default
1300 * behavior will be to block all I/Os when a complete failure occurs.
1301 */
1302uint8_t
1303spa_get_failmode(spa_t *spa)
1304{
1305	return (spa->spa_failmode);
1306}
1307
1308boolean_t
1309spa_suspended(spa_t *spa)
1310{
1311	return (spa->spa_suspended);
1312}
1313
1314uint64_t
1315spa_version(spa_t *spa)
1316{
1317	return (spa->spa_ubsync.ub_version);
1318}
1319
1320/*
1321 * if there is a pool on top of zvols, there can be a situation where
1322 * a second vdev_set_state ioctl can come in (grabbing the pool's config
1323 * lock and then calling into the zvol's pool) before the config has
1324 * synced out from a previous vdev_set_state ioctl, resulting in
1325 * deadlock.
1326 */
1327boolean_t
1328spa_uses_zvols(spa_t *spa)
1329{
1330	boolean_t i;
1331
1332	spa_config_enter(spa, SCL_STATE_ALL, spa, RW_READER);
1333	i = vdev_uses_zvols(spa->spa_root_vdev);
1334	spa_config_exit(spa, SCL_STATE_ALL, spa);
1335	return (i);
1336}
1337
1338int
1339spa_max_replication(spa_t *spa)
1340{
1341	/*
1342	 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1343	 * handle BPs with more than one DVA allocated.  Set our max
1344	 * replication level accordingly.
1345	 */
1346	if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1347		return (1);
1348	return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1349}
1350
1351uint64_t
1352bp_get_dasize(spa_t *spa, const blkptr_t *bp)
1353{
1354	int sz = 0, i;
1355
1356	if (!spa->spa_deflate)
1357		return (BP_GET_ASIZE(bp));
1358
1359	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1360	for (i = 0; i < SPA_DVAS_PER_BP; i++) {
1361		vdev_t *vd =
1362		    vdev_lookup_top(spa, DVA_GET_VDEV(&bp->blk_dva[i]));
1363		if (vd)
1364			sz += (DVA_GET_ASIZE(&bp->blk_dva[i]) >>
1365			    SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1366	}
1367	spa_config_exit(spa, SCL_VDEV, FTAG);
1368	return (sz);
1369}
1370
1371/*
1372 * ==========================================================================
1373 * Initialization and Termination
1374 * ==========================================================================
1375 */
1376
1377static int
1378spa_name_compare(const void *a1, const void *a2)
1379{
1380	const spa_t *s1 = a1;
1381	const spa_t *s2 = a2;
1382	int s;
1383
1384	s = strcmp(s1->spa_name, s2->spa_name);
1385	if (s > 0)
1386		return (1);
1387	if (s < 0)
1388		return (-1);
1389	return (0);
1390}
1391
1392int
1393spa_busy(void)
1394{
1395	return (spa_active_count);
1396}
1397
1398void
1399spa_boot_init()
1400{
1401	spa_config_load();
1402}
1403
1404void
1405spa_init(int mode)
1406{
1407	mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1408	mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1409	mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1410	cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1411
1412	avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1413	    offsetof(spa_t, spa_avl));
1414
1415	avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1416	    offsetof(spa_aux_t, aux_avl));
1417
1418	avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1419	    offsetof(spa_aux_t, aux_avl));
1420
1421	spa_mode_global = mode;
1422
1423	refcount_init();
1424	unique_init();
1425	zio_init();
1426	dmu_init();
1427	zil_init();
1428	vdev_cache_stat_init();
1429	zfs_prop_init();
1430	zpool_prop_init();
1431	spa_config_load();
1432	l2arc_start();
1433}
1434
1435void
1436spa_fini(void)
1437{
1438	l2arc_stop();
1439
1440	spa_evict_all();
1441
1442	vdev_cache_stat_fini();
1443	zil_fini();
1444	dmu_fini();
1445	zio_fini();
1446	unique_fini();
1447	refcount_fini();
1448
1449	avl_destroy(&spa_namespace_avl);
1450	avl_destroy(&spa_spare_avl);
1451	avl_destroy(&spa_l2cache_avl);
1452
1453	cv_destroy(&spa_namespace_cv);
1454	mutex_destroy(&spa_namespace_lock);
1455	mutex_destroy(&spa_spare_lock);
1456	mutex_destroy(&spa_l2cache_lock);
1457}
1458
1459/*
1460 * Return whether this pool has slogs. No locking needed.
1461 * It's not a problem if the wrong answer is returned as it's only for
1462 * performance and not correctness
1463 */
1464boolean_t
1465spa_has_slogs(spa_t *spa)
1466{
1467	return (spa->spa_log_class->mc_rotor != NULL);
1468}
1469
1470/*
1471 * Return whether this pool is the root pool.
1472 */
1473boolean_t
1474spa_is_root(spa_t *spa)
1475{
1476	return (spa->spa_is_root);
1477}
1478
1479boolean_t
1480spa_writeable(spa_t *spa)
1481{
1482	return (!!(spa->spa_mode & FWRITE));
1483}
1484
1485int
1486spa_mode(spa_t *spa)
1487{
1488	return (spa->spa_mode);
1489}
1490