spa_misc.c revision dcba9f3fbefe06ad19972b4de0351924601e5767
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 2010 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/arc.h>
47#include <sys/ddt.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_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.
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, nvlist_t *config, 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_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);
441
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);
446
447	for (int t = 0; t < TXG_SIZE; t++)
448		bplist_init(&spa->spa_free_bplist[t]);
449	bplist_init(&spa->spa_deferred_bplist);
450
451	(void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
452	spa->spa_state = POOL_STATE_UNINITIALIZED;
453	spa->spa_freeze_txg = UINT64_MAX;
454	spa->spa_final_txg = UINT64_MAX;
455	spa->spa_load_max_txg = UINT64_MAX;
456	spa->spa_proc = &p0;
457	spa->spa_proc_state = SPA_PROC_NONE;
458
459	refcount_create(&spa->spa_refcount);
460	spa_config_lock_init(spa);
461
462	avl_add(&spa_namespace_avl, spa);
463
464	/*
465	 * Set the alternate root, if there is one.
466	 */
467	if (altroot) {
468		spa->spa_root = spa_strdup(altroot);
469		spa_active_count++;
470	}
471
472	/*
473	 * Every pool starts with the default cachefile
474	 */
475	list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
476	    offsetof(spa_config_dirent_t, scd_link));
477
478	dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
479	dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
480	list_insert_head(&spa->spa_config_list, dp);
481
482	if (config != NULL)
483		VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
484
485	return (spa);
486}
487
488/*
489 * Removes a spa_t from the namespace, freeing up any memory used.  Requires
490 * spa_namespace_lock.  This is called only after the spa_t has been closed and
491 * deactivated.
492 */
493void
494spa_remove(spa_t *spa)
495{
496	spa_config_dirent_t *dp;
497
498	ASSERT(MUTEX_HELD(&spa_namespace_lock));
499	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
500
501	nvlist_free(spa->spa_config_splitting);
502
503	avl_remove(&spa_namespace_avl, spa);
504	cv_broadcast(&spa_namespace_cv);
505
506	if (spa->spa_root) {
507		spa_strfree(spa->spa_root);
508		spa_active_count--;
509	}
510
511	while ((dp = list_head(&spa->spa_config_list)) != NULL) {
512		list_remove(&spa->spa_config_list, dp);
513		if (dp->scd_path != NULL)
514			spa_strfree(dp->scd_path);
515		kmem_free(dp, sizeof (spa_config_dirent_t));
516	}
517
518	list_destroy(&spa->spa_config_list);
519
520	spa_config_set(spa, NULL);
521
522	refcount_destroy(&spa->spa_refcount);
523
524	spa_config_lock_destroy(spa);
525
526	for (int t = 0; t < TXG_SIZE; t++)
527		bplist_fini(&spa->spa_free_bplist[t]);
528	bplist_fini(&spa->spa_deferred_bplist);
529
530	cv_destroy(&spa->spa_async_cv);
531	cv_destroy(&spa->spa_proc_cv);
532	cv_destroy(&spa->spa_scrub_io_cv);
533	cv_destroy(&spa->spa_suspend_cv);
534
535	mutex_destroy(&spa->spa_async_lock);
536	mutex_destroy(&spa->spa_errlist_lock);
537	mutex_destroy(&spa->spa_errlog_lock);
538	mutex_destroy(&spa->spa_history_lock);
539	mutex_destroy(&spa->spa_proc_lock);
540	mutex_destroy(&spa->spa_props_lock);
541	mutex_destroy(&spa->spa_scrub_lock);
542	mutex_destroy(&spa->spa_suspend_lock);
543	mutex_destroy(&spa->spa_vdev_top_lock);
544
545	kmem_free(spa, sizeof (spa_t));
546}
547
548/*
549 * Given a pool, return the next pool in the namespace, or NULL if there is
550 * none.  If 'prev' is NULL, return the first pool.
551 */
552spa_t *
553spa_next(spa_t *prev)
554{
555	ASSERT(MUTEX_HELD(&spa_namespace_lock));
556
557	if (prev)
558		return (AVL_NEXT(&spa_namespace_avl, prev));
559	else
560		return (avl_first(&spa_namespace_avl));
561}
562
563/*
564 * ==========================================================================
565 * SPA refcount functions
566 * ==========================================================================
567 */
568
569/*
570 * Add a reference to the given spa_t.  Must have at least one reference, or
571 * have the namespace lock held.
572 */
573void
574spa_open_ref(spa_t *spa, void *tag)
575{
576	ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
577	    MUTEX_HELD(&spa_namespace_lock));
578	(void) refcount_add(&spa->spa_refcount, tag);
579}
580
581/*
582 * Remove a reference to the given spa_t.  Must have at least one reference, or
583 * have the namespace lock held.
584 */
585void
586spa_close(spa_t *spa, void *tag)
587{
588	ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
589	    MUTEX_HELD(&spa_namespace_lock));
590	(void) refcount_remove(&spa->spa_refcount, tag);
591}
592
593/*
594 * Check to see if the spa refcount is zero.  Must be called with
595 * spa_namespace_lock held.  We really compare against spa_minref, which is the
596 * number of references acquired when opening a pool
597 */
598boolean_t
599spa_refcount_zero(spa_t *spa)
600{
601	ASSERT(MUTEX_HELD(&spa_namespace_lock));
602
603	return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
604}
605
606/*
607 * ==========================================================================
608 * SPA spare and l2cache tracking
609 * ==========================================================================
610 */
611
612/*
613 * Hot spares and cache devices are tracked using the same code below,
614 * for 'auxiliary' devices.
615 */
616
617typedef struct spa_aux {
618	uint64_t	aux_guid;
619	uint64_t	aux_pool;
620	avl_node_t	aux_avl;
621	int		aux_count;
622} spa_aux_t;
623
624static int
625spa_aux_compare(const void *a, const void *b)
626{
627	const spa_aux_t *sa = a;
628	const spa_aux_t *sb = b;
629
630	if (sa->aux_guid < sb->aux_guid)
631		return (-1);
632	else if (sa->aux_guid > sb->aux_guid)
633		return (1);
634	else
635		return (0);
636}
637
638void
639spa_aux_add(vdev_t *vd, avl_tree_t *avl)
640{
641	avl_index_t where;
642	spa_aux_t search;
643	spa_aux_t *aux;
644
645	search.aux_guid = vd->vdev_guid;
646	if ((aux = avl_find(avl, &search, &where)) != NULL) {
647		aux->aux_count++;
648	} else {
649		aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
650		aux->aux_guid = vd->vdev_guid;
651		aux->aux_count = 1;
652		avl_insert(avl, aux, where);
653	}
654}
655
656void
657spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
658{
659	spa_aux_t search;
660	spa_aux_t *aux;
661	avl_index_t where;
662
663	search.aux_guid = vd->vdev_guid;
664	aux = avl_find(avl, &search, &where);
665
666	ASSERT(aux != NULL);
667
668	if (--aux->aux_count == 0) {
669		avl_remove(avl, aux);
670		kmem_free(aux, sizeof (spa_aux_t));
671	} else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
672		aux->aux_pool = 0ULL;
673	}
674}
675
676boolean_t
677spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
678{
679	spa_aux_t search, *found;
680
681	search.aux_guid = guid;
682	found = avl_find(avl, &search, NULL);
683
684	if (pool) {
685		if (found)
686			*pool = found->aux_pool;
687		else
688			*pool = 0ULL;
689	}
690
691	if (refcnt) {
692		if (found)
693			*refcnt = found->aux_count;
694		else
695			*refcnt = 0;
696	}
697
698	return (found != NULL);
699}
700
701void
702spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
703{
704	spa_aux_t search, *found;
705	avl_index_t where;
706
707	search.aux_guid = vd->vdev_guid;
708	found = avl_find(avl, &search, &where);
709	ASSERT(found != NULL);
710	ASSERT(found->aux_pool == 0ULL);
711
712	found->aux_pool = spa_guid(vd->vdev_spa);
713}
714
715/*
716 * Spares are tracked globally due to the following constraints:
717 *
718 * 	- A spare may be part of multiple pools.
719 * 	- A spare may be added to a pool even if it's actively in use within
720 *	  another pool.
721 * 	- A spare in use in any pool can only be the source of a replacement if
722 *	  the target is a spare in the same pool.
723 *
724 * We keep track of all spares on the system through the use of a reference
725 * counted AVL tree.  When a vdev is added as a spare, or used as a replacement
726 * spare, then we bump the reference count in the AVL tree.  In addition, we set
727 * the 'vdev_isspare' member to indicate that the device is a spare (active or
728 * inactive).  When a spare is made active (used to replace a device in the
729 * pool), we also keep track of which pool its been made a part of.
730 *
731 * The 'spa_spare_lock' protects the AVL tree.  These functions are normally
732 * called under the spa_namespace lock as part of vdev reconfiguration.  The
733 * separate spare lock exists for the status query path, which does not need to
734 * be completely consistent with respect to other vdev configuration changes.
735 */
736
737static int
738spa_spare_compare(const void *a, const void *b)
739{
740	return (spa_aux_compare(a, b));
741}
742
743void
744spa_spare_add(vdev_t *vd)
745{
746	mutex_enter(&spa_spare_lock);
747	ASSERT(!vd->vdev_isspare);
748	spa_aux_add(vd, &spa_spare_avl);
749	vd->vdev_isspare = B_TRUE;
750	mutex_exit(&spa_spare_lock);
751}
752
753void
754spa_spare_remove(vdev_t *vd)
755{
756	mutex_enter(&spa_spare_lock);
757	ASSERT(vd->vdev_isspare);
758	spa_aux_remove(vd, &spa_spare_avl);
759	vd->vdev_isspare = B_FALSE;
760	mutex_exit(&spa_spare_lock);
761}
762
763boolean_t
764spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
765{
766	boolean_t found;
767
768	mutex_enter(&spa_spare_lock);
769	found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
770	mutex_exit(&spa_spare_lock);
771
772	return (found);
773}
774
775void
776spa_spare_activate(vdev_t *vd)
777{
778	mutex_enter(&spa_spare_lock);
779	ASSERT(vd->vdev_isspare);
780	spa_aux_activate(vd, &spa_spare_avl);
781	mutex_exit(&spa_spare_lock);
782}
783
784/*
785 * Level 2 ARC devices are tracked globally for the same reasons as spares.
786 * Cache devices currently only support one pool per cache device, and so
787 * for these devices the aux reference count is currently unused beyond 1.
788 */
789
790static int
791spa_l2cache_compare(const void *a, const void *b)
792{
793	return (spa_aux_compare(a, b));
794}
795
796void
797spa_l2cache_add(vdev_t *vd)
798{
799	mutex_enter(&spa_l2cache_lock);
800	ASSERT(!vd->vdev_isl2cache);
801	spa_aux_add(vd, &spa_l2cache_avl);
802	vd->vdev_isl2cache = B_TRUE;
803	mutex_exit(&spa_l2cache_lock);
804}
805
806void
807spa_l2cache_remove(vdev_t *vd)
808{
809	mutex_enter(&spa_l2cache_lock);
810	ASSERT(vd->vdev_isl2cache);
811	spa_aux_remove(vd, &spa_l2cache_avl);
812	vd->vdev_isl2cache = B_FALSE;
813	mutex_exit(&spa_l2cache_lock);
814}
815
816boolean_t
817spa_l2cache_exists(uint64_t guid, uint64_t *pool)
818{
819	boolean_t found;
820
821	mutex_enter(&spa_l2cache_lock);
822	found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
823	mutex_exit(&spa_l2cache_lock);
824
825	return (found);
826}
827
828void
829spa_l2cache_activate(vdev_t *vd)
830{
831	mutex_enter(&spa_l2cache_lock);
832	ASSERT(vd->vdev_isl2cache);
833	spa_aux_activate(vd, &spa_l2cache_avl);
834	mutex_exit(&spa_l2cache_lock);
835}
836
837/*
838 * ==========================================================================
839 * SPA vdev locking
840 * ==========================================================================
841 */
842
843/*
844 * Lock the given spa_t for the purpose of adding or removing a vdev.
845 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
846 * It returns the next transaction group for the spa_t.
847 */
848uint64_t
849spa_vdev_enter(spa_t *spa)
850{
851	mutex_enter(&spa->spa_vdev_top_lock);
852	mutex_enter(&spa_namespace_lock);
853	return (spa_vdev_config_enter(spa));
854}
855
856/*
857 * Internal implementation for spa_vdev_enter().  Used when a vdev
858 * operation requires multiple syncs (i.e. removing a device) while
859 * keeping the spa_namespace_lock held.
860 */
861uint64_t
862spa_vdev_config_enter(spa_t *spa)
863{
864	ASSERT(MUTEX_HELD(&spa_namespace_lock));
865
866	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
867
868	return (spa_last_synced_txg(spa) + 1);
869}
870
871/*
872 * Used in combination with spa_vdev_config_enter() to allow the syncing
873 * of multiple transactions without releasing the spa_namespace_lock.
874 */
875void
876spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
877{
878	ASSERT(MUTEX_HELD(&spa_namespace_lock));
879
880	int config_changed = B_FALSE;
881
882	ASSERT(txg > spa_last_synced_txg(spa));
883
884	spa->spa_pending_vdev = NULL;
885
886	/*
887	 * Reassess the DTLs.
888	 */
889	vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
890
891	/*
892	 * If the config changed, notify the scrub thread that it must restart.
893	 */
894	if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
895		dsl_pool_scrub_restart(spa->spa_dsl_pool);
896		config_changed = B_TRUE;
897		spa->spa_config_generation++;
898	}
899
900	/*
901	 * Verify the metaslab classes.
902	 */
903	ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
904	ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
905
906	spa_config_exit(spa, SCL_ALL, spa);
907
908	/*
909	 * Panic the system if the specified tag requires it.  This
910	 * is useful for ensuring that configurations are updated
911	 * transactionally.
912	 */
913	if (zio_injection_enabled)
914		zio_handle_panic_injection(spa, tag, 0);
915
916	/*
917	 * Note: this txg_wait_synced() is important because it ensures
918	 * that there won't be more than one config change per txg.
919	 * This allows us to use the txg as the generation number.
920	 */
921	if (error == 0)
922		txg_wait_synced(spa->spa_dsl_pool, txg);
923
924	if (vd != NULL) {
925		ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
926		spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
927		vdev_free(vd);
928		spa_config_exit(spa, SCL_ALL, spa);
929	}
930
931	/*
932	 * If the config changed, update the config cache.
933	 */
934	if (config_changed)
935		spa_config_sync(spa, B_FALSE, B_TRUE);
936}
937
938/*
939 * Unlock the spa_t after adding or removing a vdev.  Besides undoing the
940 * locking of spa_vdev_enter(), we also want make sure the transactions have
941 * synced to disk, and then update the global configuration cache with the new
942 * information.
943 */
944int
945spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
946{
947	spa_vdev_config_exit(spa, vd, txg, error, FTAG);
948	mutex_exit(&spa_namespace_lock);
949	mutex_exit(&spa->spa_vdev_top_lock);
950
951	return (error);
952}
953
954/*
955 * Lock the given spa_t for the purpose of changing vdev state.
956 */
957void
958spa_vdev_state_enter(spa_t *spa, int oplocks)
959{
960	int locks = SCL_STATE_ALL | oplocks;
961
962	/*
963	 * Root pools may need to read of the underlying devfs filesystem
964	 * when opening up a vdev.  Unfortunately if we're holding the
965	 * SCL_ZIO lock it will result in a deadlock when we try to issue
966	 * the read from the root filesystem.  Instead we "prefetch"
967	 * the associated vnodes that we need prior to opening the
968	 * underlying devices and cache them so that we can prevent
969	 * any I/O when we are doing the actual open.
970	 */
971	if (spa_is_root(spa)) {
972		spa_config_enter(spa, SCL_STATE | SCL_L2ARC, spa, RW_WRITER);
973		vdev_hold(spa->spa_root_vdev);
974		spa_config_enter(spa, SCL_ZIO | oplocks, spa, RW_WRITER);
975	} else {
976		spa_config_enter(spa, locks, spa, RW_WRITER);
977	}
978	spa->spa_vdev_locks = locks;
979}
980
981int
982spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
983{
984	boolean_t config_changed = B_FALSE;
985
986	if (vd != NULL || error == 0)
987		vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
988		    0, 0, B_FALSE);
989
990	if (vd != NULL) {
991		vdev_state_dirty(vd->vdev_top);
992		config_changed = B_TRUE;
993		spa->spa_config_generation++;
994	}
995
996	if (spa_is_root(spa))
997		vdev_rele(spa->spa_root_vdev);
998
999	ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1000	spa_config_exit(spa, spa->spa_vdev_locks, spa);
1001
1002	/*
1003	 * If anything changed, wait for it to sync.  This ensures that,
1004	 * from the system administrator's perspective, zpool(1M) commands
1005	 * are synchronous.  This is important for things like zpool offline:
1006	 * when the command completes, you expect no further I/O from ZFS.
1007	 */
1008	if (vd != NULL)
1009		txg_wait_synced(spa->spa_dsl_pool, 0);
1010
1011	/*
1012	 * If the config changed, update the config cache.
1013	 */
1014	if (config_changed) {
1015		mutex_enter(&spa_namespace_lock);
1016		spa_config_sync(spa, B_FALSE, B_TRUE);
1017		mutex_exit(&spa_namespace_lock);
1018	}
1019
1020	return (error);
1021}
1022
1023/*
1024 * ==========================================================================
1025 * Miscellaneous functions
1026 * ==========================================================================
1027 */
1028
1029/*
1030 * Rename a spa_t.
1031 */
1032int
1033spa_rename(const char *name, const char *newname)
1034{
1035	spa_t *spa;
1036	int err;
1037
1038	/*
1039	 * Lookup the spa_t and grab the config lock for writing.  We need to
1040	 * actually open the pool so that we can sync out the necessary labels.
1041	 * It's OK to call spa_open() with the namespace lock held because we
1042	 * allow recursive calls for other reasons.
1043	 */
1044	mutex_enter(&spa_namespace_lock);
1045	if ((err = spa_open(name, &spa, FTAG)) != 0) {
1046		mutex_exit(&spa_namespace_lock);
1047		return (err);
1048	}
1049
1050	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1051
1052	avl_remove(&spa_namespace_avl, spa);
1053	(void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1054	avl_add(&spa_namespace_avl, spa);
1055
1056	/*
1057	 * Sync all labels to disk with the new names by marking the root vdev
1058	 * dirty and waiting for it to sync.  It will pick up the new pool name
1059	 * during the sync.
1060	 */
1061	vdev_config_dirty(spa->spa_root_vdev);
1062
1063	spa_config_exit(spa, SCL_ALL, FTAG);
1064
1065	txg_wait_synced(spa->spa_dsl_pool, 0);
1066
1067	/*
1068	 * Sync the updated config cache.
1069	 */
1070	spa_config_sync(spa, B_FALSE, B_TRUE);
1071
1072	spa_close(spa, FTAG);
1073
1074	mutex_exit(&spa_namespace_lock);
1075
1076	return (0);
1077}
1078
1079
1080/*
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.
1084 */
1085boolean_t
1086spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1087{
1088	spa_t *spa;
1089	avl_tree_t *t = &spa_namespace_avl;
1090
1091	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1092
1093	for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1094		if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1095			continue;
1096		if (spa->spa_root_vdev == NULL)
1097			continue;
1098		if (spa_guid(spa) == pool_guid) {
1099			if (device_guid == 0)
1100				break;
1101
1102			if (vdev_lookup_by_guid(spa->spa_root_vdev,
1103			    device_guid) != NULL)
1104				break;
1105
1106			/*
1107			 * Check any devices we may be in the process of adding.
1108			 */
1109			if (spa->spa_pending_vdev) {
1110				if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1111				    device_guid) != NULL)
1112					break;
1113			}
1114		}
1115	}
1116
1117	return (spa != NULL);
1118}
1119
1120char *
1121spa_strdup(const char *s)
1122{
1123	size_t len;
1124	char *new;
1125
1126	len = strlen(s);
1127	new = kmem_alloc(len + 1, KM_SLEEP);
1128	bcopy(s, new, len);
1129	new[len] = '\0';
1130
1131	return (new);
1132}
1133
1134void
1135spa_strfree(char *s)
1136{
1137	kmem_free(s, strlen(s) + 1);
1138}
1139
1140uint64_t
1141spa_get_random(uint64_t range)
1142{
1143	uint64_t r;
1144
1145	ASSERT(range != 0);
1146
1147	(void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1148
1149	return (r % range);
1150}
1151
1152uint64_t
1153spa_generate_guid(spa_t *spa)
1154{
1155	uint64_t guid = spa_get_random(-1ULL);
1156
1157	if (spa != NULL) {
1158		while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1159			guid = spa_get_random(-1ULL);
1160	} else {
1161		while (guid == 0 || spa_guid_exists(guid, 0))
1162			guid = spa_get_random(-1ULL);
1163	}
1164
1165	return (guid);
1166}
1167
1168void
1169sprintf_blkptr(char *buf, const blkptr_t *bp)
1170{
1171	char *type = NULL;
1172	char *checksum = NULL;
1173	char *compress = NULL;
1174
1175	if (bp != 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;
1179	}
1180
1181	SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress);
1182}
1183
1184void
1185spa_freeze(spa_t *spa)
1186{
1187	uint64_t freeze_txg = 0;
1188
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;
1193	}
1194	spa_config_exit(spa, SCL_ALL, FTAG);
1195	if (freeze_txg != 0)
1196		txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1197}
1198
1199void
1200zfs_panic_recover(const char *fmt, ...)
1201{
1202	va_list adx;
1203
1204	va_start(adx, fmt);
1205	vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1206	va_end(adx);
1207}
1208
1209/*
1210 * ==========================================================================
1211 * Accessor functions
1212 * ==========================================================================
1213 */
1214
1215boolean_t
1216spa_shutting_down(spa_t *spa)
1217{
1218	return (spa->spa_async_suspended);
1219}
1220
1221dsl_pool_t *
1222spa_get_dsl(spa_t *spa)
1223{
1224	return (spa->spa_dsl_pool);
1225}
1226
1227blkptr_t *
1228spa_get_rootblkptr(spa_t *spa)
1229{
1230	return (&spa->spa_ubsync.ub_rootbp);
1231}
1232
1233void
1234spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1235{
1236	spa->spa_uberblock.ub_rootbp = *bp;
1237}
1238
1239void
1240spa_altroot(spa_t *spa, char *buf, size_t buflen)
1241{
1242	if (spa->spa_root == NULL)
1243		buf[0] = '\0';
1244	else
1245		(void) strncpy(buf, spa->spa_root, buflen);
1246}
1247
1248int
1249spa_sync_pass(spa_t *spa)
1250{
1251	return (spa->spa_sync_pass);
1252}
1253
1254char *
1255spa_name(spa_t *spa)
1256{
1257	return (spa->spa_name);
1258}
1259
1260uint64_t
1261spa_guid(spa_t *spa)
1262{
1263	/*
1264	 * If we fail to parse the config during spa_load(), we can go through
1265	 * the error path (which posts an ereport) and end up here with no root
1266	 * vdev.  We stash the original pool guid in 'spa_load_guid' to handle
1267	 * this case.
1268	 */
1269	if (spa->spa_root_vdev != NULL)
1270		return (spa->spa_root_vdev->vdev_guid);
1271	else
1272		return (spa->spa_load_guid);
1273}
1274
1275uint64_t
1276spa_last_synced_txg(spa_t *spa)
1277{
1278	return (spa->spa_ubsync.ub_txg);
1279}
1280
1281uint64_t
1282spa_first_txg(spa_t *spa)
1283{
1284	return (spa->spa_first_txg);
1285}
1286
1287uint64_t
1288spa_syncing_txg(spa_t *spa)
1289{
1290	return (spa->spa_syncing_txg);
1291}
1292
1293pool_state_t
1294spa_state(spa_t *spa)
1295{
1296	return (spa->spa_state);
1297}
1298
1299spa_load_state_t
1300spa_load_state(spa_t *spa)
1301{
1302	return (spa->spa_load_state);
1303}
1304
1305uint64_t
1306spa_freeze_txg(spa_t *spa)
1307{
1308	return (spa->spa_freeze_txg);
1309}
1310
1311/* ARGSUSED */
1312uint64_t
1313spa_get_asize(spa_t *spa, uint64_t lsize)
1314{
1315	/*
1316	 * The worst case is single-sector max-parity RAID-Z blocks, in which
1317	 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
1318	 * times the size; so just assume that.  Add to this the fact that
1319	 * we can have up to 3 DVAs per bp, and one more factor of 2 because
1320	 * the block may be dittoed with up to 3 DVAs by ddt_sync().
1321	 */
1322	return (lsize * (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2);
1323}
1324
1325uint64_t
1326spa_get_dspace(spa_t *spa)
1327{
1328	return (spa->spa_dspace);
1329}
1330
1331void
1332spa_update_dspace(spa_t *spa)
1333{
1334	spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1335	    ddt_get_dedup_dspace(spa);
1336}
1337
1338/*
1339 * Return the failure mode that has been set to this pool. The default
1340 * behavior will be to block all I/Os when a complete failure occurs.
1341 */
1342uint8_t
1343spa_get_failmode(spa_t *spa)
1344{
1345	return (spa->spa_failmode);
1346}
1347
1348boolean_t
1349spa_suspended(spa_t *spa)
1350{
1351	return (spa->spa_suspended);
1352}
1353
1354uint64_t
1355spa_version(spa_t *spa)
1356{
1357	return (spa->spa_ubsync.ub_version);
1358}
1359
1360boolean_t
1361spa_deflate(spa_t *spa)
1362{
1363	return (spa->spa_deflate);
1364}
1365
1366metaslab_class_t *
1367spa_normal_class(spa_t *spa)
1368{
1369	return (spa->spa_normal_class);
1370}
1371
1372metaslab_class_t *
1373spa_log_class(spa_t *spa)
1374{
1375	return (spa->spa_log_class);
1376}
1377
1378int
1379spa_max_replication(spa_t *spa)
1380{
1381	/*
1382	 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1383	 * handle BPs with more than one DVA allocated.  Set our max
1384	 * replication level accordingly.
1385	 */
1386	if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1387		return (1);
1388	return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1389}
1390
1391uint64_t
1392dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1393{
1394	uint64_t asize = DVA_GET_ASIZE(dva);
1395	uint64_t dsize = asize;
1396
1397	ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1398
1399	if (asize != 0 && spa->spa_deflate) {
1400		vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1401		dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1402	}
1403
1404	return (dsize);
1405}
1406
1407uint64_t
1408bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1409{
1410	uint64_t dsize = 0;
1411
1412	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1413		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1414
1415	return (dsize);
1416}
1417
1418uint64_t
1419bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1420{
1421	uint64_t dsize = 0;
1422
1423	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1424
1425	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1426		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1427
1428	spa_config_exit(spa, SCL_VDEV, FTAG);
1429
1430	return (dsize);
1431}
1432
1433/*
1434 * ==========================================================================
1435 * Initialization and Termination
1436 * ==========================================================================
1437 */
1438
1439static int
1440spa_name_compare(const void *a1, const void *a2)
1441{
1442	const spa_t *s1 = a1;
1443	const spa_t *s2 = a2;
1444	int s;
1445
1446	s = strcmp(s1->spa_name, s2->spa_name);
1447	if (s > 0)
1448		return (1);
1449	if (s < 0)
1450		return (-1);
1451	return (0);
1452}
1453
1454int
1455spa_busy(void)
1456{
1457	return (spa_active_count);
1458}
1459
1460void
1461spa_boot_init()
1462{
1463	spa_config_load();
1464}
1465
1466void
1467spa_init(int mode)
1468{
1469	mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1470	mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1471	mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1472	cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1473
1474	avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1475	    offsetof(spa_t, spa_avl));
1476
1477	avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1478	    offsetof(spa_aux_t, aux_avl));
1479
1480	avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1481	    offsetof(spa_aux_t, aux_avl));
1482
1483	spa_mode_global = mode;
1484
1485	refcount_init();
1486	unique_init();
1487	zio_init();
1488	dmu_init();
1489	zil_init();
1490	vdev_cache_stat_init();
1491	zfs_prop_init();
1492	zpool_prop_init();
1493	spa_config_load();
1494	l2arc_start();
1495}
1496
1497void
1498spa_fini(void)
1499{
1500	l2arc_stop();
1501
1502	spa_evict_all();
1503
1504	vdev_cache_stat_fini();
1505	zil_fini();
1506	dmu_fini();
1507	zio_fini();
1508	unique_fini();
1509	refcount_fini();
1510
1511	avl_destroy(&spa_namespace_avl);
1512	avl_destroy(&spa_spare_avl);
1513	avl_destroy(&spa_l2cache_avl);
1514
1515	cv_destroy(&spa_namespace_cv);
1516	mutex_destroy(&spa_namespace_lock);
1517	mutex_destroy(&spa_spare_lock);
1518	mutex_destroy(&spa_l2cache_lock);
1519}
1520
1521/*
1522 * Return whether this pool has slogs. No locking needed.
1523 * It's not a problem if the wrong answer is returned as it's only for
1524 * performance and not correctness
1525 */
1526boolean_t
1527spa_has_slogs(spa_t *spa)
1528{
1529	return (spa->spa_log_class->mc_rotor != NULL);
1530}
1531
1532spa_log_state_t
1533spa_get_log_state(spa_t *spa)
1534{
1535	return (spa->spa_log_state);
1536}
1537
1538void
1539spa_set_log_state(spa_t *spa, spa_log_state_t state)
1540{
1541	spa->spa_log_state = state;
1542}
1543
1544boolean_t
1545spa_is_root(spa_t *spa)
1546{
1547	return (spa->spa_is_root);
1548}
1549
1550boolean_t
1551spa_writeable(spa_t *spa)
1552{
1553	return (!!(spa->spa_mode & FWRITE));
1554}
1555
1556int
1557spa_mode(spa_t *spa)
1558{
1559	return (spa->spa_mode);
1560}
1561
1562uint64_t
1563spa_bootfs(spa_t *spa)
1564{
1565	return (spa->spa_bootfs);
1566}
1567
1568uint64_t
1569spa_delegation(spa_t *spa)
1570{
1571	return (spa->spa_delegation);
1572}
1573
1574objset_t *
1575spa_meta_objset(spa_t *spa)
1576{
1577	return (spa->spa_meta_objset);
1578}
1579
1580enum zio_checksum
1581spa_dedup_checksum(spa_t *spa)
1582{
1583	return (spa->spa_dedup_checksum);
1584}
1585