spa_misc.c revision 0713e232b7712cd27d99e1e935ebb8d5de61c57d
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25 */
26
27#include <sys/zfs_context.h>
28#include <sys/spa_impl.h>
29#include <sys/spa_boot.h>
30#include <sys/zio.h>
31#include <sys/zio_checksum.h>
32#include <sys/zio_compress.h>
33#include <sys/dmu.h>
34#include <sys/dmu_tx.h>
35#include <sys/zap.h>
36#include <sys/zil.h>
37#include <sys/vdev_impl.h>
38#include <sys/metaslab.h>
39#include <sys/uberblock_impl.h>
40#include <sys/txg.h>
41#include <sys/avl.h>
42#include <sys/unique.h>
43#include <sys/dsl_pool.h>
44#include <sys/dsl_dir.h>
45#include <sys/dsl_prop.h>
46#include <sys/dsl_scan.h>
47#include <sys/fs/zfs.h>
48#include <sys/metaslab_impl.h>
49#include <sys/arc.h>
50#include <sys/ddt.h>
51#include "zfs_prop.h"
52#include "zfeature_common.h"
53
54/*
55 * SPA locking
56 *
57 * There are four basic locks for managing spa_t structures:
58 *
59 * spa_namespace_lock (global mutex)
60 *
61 *	This lock must be acquired to do any of the following:
62 *
63 *		- Lookup a spa_t by name
64 *		- Add or remove a spa_t from the namespace
65 *		- Increase spa_refcount from non-zero
66 *		- Check if spa_refcount is zero
67 *		- Rename a spa_t
68 *		- add/remove/attach/detach devices
69 *		- Held for the duration of create/destroy/import/export
70 *
71 *	It does not need to handle recursion.  A create or destroy may
72 *	reference objects (files or zvols) in other pools, but by
73 *	definition they must have an existing reference, and will never need
74 *	to lookup a spa_t by name.
75 *
76 * spa_refcount (per-spa refcount_t protected by mutex)
77 *
78 *	This reference count keep track of any active users of the spa_t.  The
79 *	spa_t cannot be destroyed or freed while this is non-zero.  Internally,
80 *	the refcount is never really 'zero' - opening a pool implicitly keeps
81 *	some references in the DMU.  Internally we check against spa_minref, but
82 *	present the image of a zero/non-zero value to consumers.
83 *
84 * spa_config_lock[] (per-spa array of rwlocks)
85 *
86 *	This protects the spa_t from config changes, and must be held in
87 *	the following circumstances:
88 *
89 *		- RW_READER to perform I/O to the spa
90 *		- RW_WRITER to change the vdev config
91 *
92 * The locking order is fairly straightforward:
93 *
94 *		spa_namespace_lock	->	spa_refcount
95 *
96 *	The namespace lock must be acquired to increase the refcount from 0
97 *	or to check if it is zero.
98 *
99 *		spa_refcount		->	spa_config_lock[]
100 *
101 *	There must be at least one valid reference on the spa_t to acquire
102 *	the config lock.
103 *
104 *		spa_namespace_lock	->	spa_config_lock[]
105 *
106 *	The namespace lock must always be taken before the config lock.
107 *
108 *
109 * The spa_namespace_lock can be acquired directly and is globally visible.
110 *
111 * The namespace is manipulated using the following functions, all of which
112 * require the spa_namespace_lock to be held.
113 *
114 *	spa_lookup()		Lookup a spa_t by name.
115 *
116 *	spa_add()		Create a new spa_t in the namespace.
117 *
118 *	spa_remove()		Remove a spa_t from the namespace.  This also
119 *				frees up any memory associated with the spa_t.
120 *
121 *	spa_next()		Returns the next spa_t in the system, or the
122 *				first if NULL is passed.
123 *
124 *	spa_evict_all()		Shutdown and remove all spa_t structures in
125 *				the system.
126 *
127 *	spa_guid_exists()	Determine whether a pool/device guid exists.
128 *
129 * The spa_refcount is manipulated using the following functions:
130 *
131 *	spa_open_ref()		Adds a reference to the given spa_t.  Must be
132 *				called with spa_namespace_lock held if the
133 *				refcount is currently zero.
134 *
135 *	spa_close()		Remove a reference from the spa_t.  This will
136 *				not free the spa_t or remove it from the
137 *				namespace.  No locking is required.
138 *
139 *	spa_refcount_zero()	Returns true if the refcount is currently
140 *				zero.  Must be called with spa_namespace_lock
141 *				held.
142 *
143 * The spa_config_lock[] is an array of rwlocks, ordered as follows:
144 * SCL_CONFIG > SCL_STATE > SCL_ALLOC > SCL_ZIO > SCL_FREE > SCL_VDEV.
145 * spa_config_lock[] is manipulated with spa_config_{enter,exit,held}().
146 *
147 * To read the configuration, it suffices to hold one of these locks as reader.
148 * To modify the configuration, you must hold all locks as writer.  To modify
149 * vdev state without altering the vdev tree's topology (e.g. online/offline),
150 * you must hold SCL_STATE and SCL_ZIO as writer.
151 *
152 * We use these distinct config locks to avoid recursive lock entry.
153 * For example, spa_sync() (which holds SCL_CONFIG as reader) induces
154 * block allocations (SCL_ALLOC), which may require reading space maps
155 * from disk (dmu_read() -> zio_read() -> SCL_ZIO).
156 *
157 * The spa config locks cannot be normal rwlocks because we need the
158 * ability to hand off ownership.  For example, SCL_ZIO is acquired
159 * by the issuing thread and later released by an interrupt thread.
160 * They do, however, obey the usual write-wanted semantics to prevent
161 * writer (i.e. system administrator) starvation.
162 *
163 * The lock acquisition rules are as follows:
164 *
165 * SCL_CONFIG
166 *	Protects changes to the vdev tree topology, such as vdev
167 *	add/remove/attach/detach.  Protects the dirty config list
168 *	(spa_config_dirty_list) and the set of spares and l2arc devices.
169 *
170 * SCL_STATE
171 *	Protects changes to pool state and vdev state, such as vdev
172 *	online/offline/fault/degrade/clear.  Protects the dirty state list
173 *	(spa_state_dirty_list) and global pool state (spa_state).
174 *
175 * SCL_ALLOC
176 *	Protects changes to metaslab groups and classes.
177 *	Held as reader by metaslab_alloc() and metaslab_claim().
178 *
179 * SCL_ZIO
180 *	Held by bp-level zios (those which have no io_vd upon entry)
181 *	to prevent changes to the vdev tree.  The bp-level zio implicitly
182 *	protects all of its vdev child zios, which do not hold SCL_ZIO.
183 *
184 * SCL_FREE
185 *	Protects changes to metaslab groups and classes.
186 *	Held as reader by metaslab_free().  SCL_FREE is distinct from
187 *	SCL_ALLOC, and lower than SCL_ZIO, so that we can safely free
188 *	blocks in zio_done() while another i/o that holds either
189 *	SCL_ALLOC or SCL_ZIO is waiting for this i/o to complete.
190 *
191 * SCL_VDEV
192 *	Held as reader to prevent changes to the vdev tree during trivial
193 *	inquiries such as bp_get_dsize().  SCL_VDEV is distinct from the
194 *	other locks, and lower than all of them, to ensure that it's safe
195 *	to acquire regardless of caller context.
196 *
197 * In addition, the following rules apply:
198 *
199 * (a)	spa_props_lock protects pool properties, spa_config and spa_config_list.
200 *	The lock ordering is SCL_CONFIG > spa_props_lock.
201 *
202 * (b)	I/O operations on leaf vdevs.  For any zio operation that takes
203 *	an explicit vdev_t argument -- such as zio_ioctl(), zio_read_phys(),
204 *	or zio_write_phys() -- the caller must ensure that the config cannot
205 *	cannot change in the interim, and that the vdev cannot be reopened.
206 *	SCL_STATE as reader suffices for both.
207 *
208 * The vdev configuration is protected by spa_vdev_enter() / spa_vdev_exit().
209 *
210 *	spa_vdev_enter()	Acquire the namespace lock and the config lock
211 *				for writing.
212 *
213 *	spa_vdev_exit()		Release the config lock, wait for all I/O
214 *				to complete, sync the updated configs to the
215 *				cache, and release the namespace lock.
216 *
217 * vdev state is protected by spa_vdev_state_enter() / spa_vdev_state_exit().
218 * Like spa_vdev_enter/exit, these are convenience wrappers -- the actual
219 * locking is, always, based on spa_namespace_lock and spa_config_lock[].
220 *
221 * spa_rename() is also implemented within this file since it requires
222 * manipulation of the namespace.
223 */
224
225static avl_tree_t spa_namespace_avl;
226kmutex_t spa_namespace_lock;
227static kcondvar_t spa_namespace_cv;
228static int spa_active_count;
229int spa_max_replication_override = SPA_DVAS_PER_BP;
230
231static kmutex_t spa_spare_lock;
232static avl_tree_t spa_spare_avl;
233static kmutex_t spa_l2cache_lock;
234static avl_tree_t spa_l2cache_avl;
235
236kmem_cache_t *spa_buffer_pool;
237int spa_mode_global;
238
239#ifdef ZFS_DEBUG
240/* Everything except dprintf and spa is on by default in debug builds */
241int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA);
242#else
243int zfs_flags = 0;
244#endif
245
246/*
247 * zfs_recover can be set to nonzero to attempt to recover from
248 * otherwise-fatal errors, typically caused by on-disk corruption.  When
249 * set, calls to zfs_panic_recover() will turn into warning messages.
250 */
251int zfs_recover = 0;
252
253/*
254 * Expiration time in milliseconds. This value has two meanings. First it is
255 * used to determine when the spa_deadman() logic should fire. By default the
256 * spa_deadman() will fire if spa_sync() has not completed in 1000 seconds.
257 * Secondly, the value determines if an I/O is considered "hung". Any I/O that
258 * has not completed in zfs_deadman_synctime_ms is considered "hung" resulting
259 * in a system panic.
260 */
261uint64_t zfs_deadman_synctime_ms = 1000000ULL;
262
263/*
264 * Check time in milliseconds. This defines the frequency at which we check
265 * for hung I/O.
266 */
267uint64_t zfs_deadman_checktime_ms = 5000ULL;
268
269/*
270 * Override the zfs deadman behavior via /etc/system. By default the
271 * deadman is enabled except on VMware and sparc deployments.
272 */
273int zfs_deadman_enabled = -1;
274
275/*
276 * The worst case is single-sector max-parity RAID-Z blocks, in which
277 * case the space requirement is exactly (VDEV_RAIDZ_MAXPARITY + 1)
278 * times the size; so just assume that.  Add to this the fact that
279 * we can have up to 3 DVAs per bp, and one more factor of 2 because
280 * the block may be dittoed with up to 3 DVAs by ddt_sync().  All together,
281 * the worst case is:
282 *     (VDEV_RAIDZ_MAXPARITY + 1) * SPA_DVAS_PER_BP * 2 == 24
283 */
284int spa_asize_inflation = 24;
285
286/*
287 * ==========================================================================
288 * SPA config locking
289 * ==========================================================================
290 */
291static void
292spa_config_lock_init(spa_t *spa)
293{
294	for (int i = 0; i < SCL_LOCKS; i++) {
295		spa_config_lock_t *scl = &spa->spa_config_lock[i];
296		mutex_init(&scl->scl_lock, NULL, MUTEX_DEFAULT, NULL);
297		cv_init(&scl->scl_cv, NULL, CV_DEFAULT, NULL);
298		refcount_create_untracked(&scl->scl_count);
299		scl->scl_writer = NULL;
300		scl->scl_write_wanted = 0;
301	}
302}
303
304static void
305spa_config_lock_destroy(spa_t *spa)
306{
307	for (int i = 0; i < SCL_LOCKS; i++) {
308		spa_config_lock_t *scl = &spa->spa_config_lock[i];
309		mutex_destroy(&scl->scl_lock);
310		cv_destroy(&scl->scl_cv);
311		refcount_destroy(&scl->scl_count);
312		ASSERT(scl->scl_writer == NULL);
313		ASSERT(scl->scl_write_wanted == 0);
314	}
315}
316
317int
318spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
319{
320	for (int i = 0; i < SCL_LOCKS; i++) {
321		spa_config_lock_t *scl = &spa->spa_config_lock[i];
322		if (!(locks & (1 << i)))
323			continue;
324		mutex_enter(&scl->scl_lock);
325		if (rw == RW_READER) {
326			if (scl->scl_writer || scl->scl_write_wanted) {
327				mutex_exit(&scl->scl_lock);
328				spa_config_exit(spa, locks ^ (1 << i), tag);
329				return (0);
330			}
331		} else {
332			ASSERT(scl->scl_writer != curthread);
333			if (!refcount_is_zero(&scl->scl_count)) {
334				mutex_exit(&scl->scl_lock);
335				spa_config_exit(spa, locks ^ (1 << i), tag);
336				return (0);
337			}
338			scl->scl_writer = curthread;
339		}
340		(void) refcount_add(&scl->scl_count, tag);
341		mutex_exit(&scl->scl_lock);
342	}
343	return (1);
344}
345
346void
347spa_config_enter(spa_t *spa, int locks, void *tag, krw_t rw)
348{
349	int wlocks_held = 0;
350
351	ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
352
353	for (int i = 0; i < SCL_LOCKS; i++) {
354		spa_config_lock_t *scl = &spa->spa_config_lock[i];
355		if (scl->scl_writer == curthread)
356			wlocks_held |= (1 << i);
357		if (!(locks & (1 << i)))
358			continue;
359		mutex_enter(&scl->scl_lock);
360		if (rw == RW_READER) {
361			while (scl->scl_writer || scl->scl_write_wanted) {
362				cv_wait(&scl->scl_cv, &scl->scl_lock);
363			}
364		} else {
365			ASSERT(scl->scl_writer != curthread);
366			while (!refcount_is_zero(&scl->scl_count)) {
367				scl->scl_write_wanted++;
368				cv_wait(&scl->scl_cv, &scl->scl_lock);
369				scl->scl_write_wanted--;
370			}
371			scl->scl_writer = curthread;
372		}
373		(void) refcount_add(&scl->scl_count, tag);
374		mutex_exit(&scl->scl_lock);
375	}
376	ASSERT(wlocks_held <= locks);
377}
378
379void
380spa_config_exit(spa_t *spa, int locks, void *tag)
381{
382	for (int i = SCL_LOCKS - 1; i >= 0; i--) {
383		spa_config_lock_t *scl = &spa->spa_config_lock[i];
384		if (!(locks & (1 << i)))
385			continue;
386		mutex_enter(&scl->scl_lock);
387		ASSERT(!refcount_is_zero(&scl->scl_count));
388		if (refcount_remove(&scl->scl_count, tag) == 0) {
389			ASSERT(scl->scl_writer == NULL ||
390			    scl->scl_writer == curthread);
391			scl->scl_writer = NULL;	/* OK in either case */
392			cv_broadcast(&scl->scl_cv);
393		}
394		mutex_exit(&scl->scl_lock);
395	}
396}
397
398int
399spa_config_held(spa_t *spa, int locks, krw_t rw)
400{
401	int locks_held = 0;
402
403	for (int i = 0; i < SCL_LOCKS; i++) {
404		spa_config_lock_t *scl = &spa->spa_config_lock[i];
405		if (!(locks & (1 << i)))
406			continue;
407		if ((rw == RW_READER && !refcount_is_zero(&scl->scl_count)) ||
408		    (rw == RW_WRITER && scl->scl_writer == curthread))
409			locks_held |= 1 << i;
410	}
411
412	return (locks_held);
413}
414
415/*
416 * ==========================================================================
417 * SPA namespace functions
418 * ==========================================================================
419 */
420
421/*
422 * Lookup the named spa_t in the AVL tree.  The spa_namespace_lock must be held.
423 * Returns NULL if no matching spa_t is found.
424 */
425spa_t *
426spa_lookup(const char *name)
427{
428	static spa_t search;	/* spa_t is large; don't allocate on stack */
429	spa_t *spa;
430	avl_index_t where;
431	char *cp;
432
433	ASSERT(MUTEX_HELD(&spa_namespace_lock));
434
435	(void) strlcpy(search.spa_name, name, sizeof (search.spa_name));
436
437	/*
438	 * If it's a full dataset name, figure out the pool name and
439	 * just use that.
440	 */
441	cp = strpbrk(search.spa_name, "/@");
442	if (cp != NULL)
443		*cp = '\0';
444
445	spa = avl_find(&spa_namespace_avl, &search, &where);
446
447	return (spa);
448}
449
450/*
451 * Fires when spa_sync has not completed within zfs_deadman_synctime_ms.
452 * If the zfs_deadman_enabled flag is set then it inspects all vdev queues
453 * looking for potentially hung I/Os.
454 */
455void
456spa_deadman(void *arg)
457{
458	spa_t *spa = arg;
459
460	/*
461	 * Disable the deadman timer if the pool is suspended.
462	 */
463	if (spa_suspended(spa)) {
464		VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
465		return;
466	}
467
468	zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
469	    (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
470	    ++spa->spa_deadman_calls);
471	if (zfs_deadman_enabled)
472		vdev_deadman(spa->spa_root_vdev);
473}
474
475/*
476 * Create an uninitialized spa_t with the given name.  Requires
477 * spa_namespace_lock.  The caller must ensure that the spa_t doesn't already
478 * exist by calling spa_lookup() first.
479 */
480spa_t *
481spa_add(const char *name, nvlist_t *config, const char *altroot)
482{
483	spa_t *spa;
484	spa_config_dirent_t *dp;
485	cyc_handler_t hdlr;
486	cyc_time_t when;
487
488	ASSERT(MUTEX_HELD(&spa_namespace_lock));
489
490	spa = kmem_zalloc(sizeof (spa_t), KM_SLEEP);
491
492	mutex_init(&spa->spa_async_lock, NULL, MUTEX_DEFAULT, NULL);
493	mutex_init(&spa->spa_errlist_lock, NULL, MUTEX_DEFAULT, NULL);
494	mutex_init(&spa->spa_errlog_lock, NULL, MUTEX_DEFAULT, NULL);
495	mutex_init(&spa->spa_history_lock, NULL, MUTEX_DEFAULT, NULL);
496	mutex_init(&spa->spa_proc_lock, NULL, MUTEX_DEFAULT, NULL);
497	mutex_init(&spa->spa_props_lock, NULL, MUTEX_DEFAULT, NULL);
498	mutex_init(&spa->spa_scrub_lock, NULL, MUTEX_DEFAULT, NULL);
499	mutex_init(&spa->spa_suspend_lock, NULL, MUTEX_DEFAULT, NULL);
500	mutex_init(&spa->spa_vdev_top_lock, NULL, MUTEX_DEFAULT, NULL);
501	mutex_init(&spa->spa_iokstat_lock, NULL, MUTEX_DEFAULT, NULL);
502
503	cv_init(&spa->spa_async_cv, NULL, CV_DEFAULT, NULL);
504	cv_init(&spa->spa_proc_cv, NULL, CV_DEFAULT, NULL);
505	cv_init(&spa->spa_scrub_io_cv, NULL, CV_DEFAULT, NULL);
506	cv_init(&spa->spa_suspend_cv, NULL, CV_DEFAULT, NULL);
507
508	for (int t = 0; t < TXG_SIZE; t++)
509		bplist_create(&spa->spa_free_bplist[t]);
510
511	(void) strlcpy(spa->spa_name, name, sizeof (spa->spa_name));
512	spa->spa_state = POOL_STATE_UNINITIALIZED;
513	spa->spa_freeze_txg = UINT64_MAX;
514	spa->spa_final_txg = UINT64_MAX;
515	spa->spa_load_max_txg = UINT64_MAX;
516	spa->spa_proc = &p0;
517	spa->spa_proc_state = SPA_PROC_NONE;
518
519	hdlr.cyh_func = spa_deadman;
520	hdlr.cyh_arg = spa;
521	hdlr.cyh_level = CY_LOW_LEVEL;
522
523	spa->spa_deadman_synctime = MSEC2NSEC(zfs_deadman_synctime_ms);
524
525	/*
526	 * This determines how often we need to check for hung I/Os after
527	 * the cyclic has already fired. Since checking for hung I/Os is
528	 * an expensive operation we don't want to check too frequently.
529	 * Instead wait for 5 seconds before checking again.
530	 */
531	when.cyt_interval = MSEC2NSEC(zfs_deadman_checktime_ms);
532	when.cyt_when = CY_INFINITY;
533	mutex_enter(&cpu_lock);
534	spa->spa_deadman_cycid = cyclic_add(&hdlr, &when);
535	mutex_exit(&cpu_lock);
536
537	refcount_create(&spa->spa_refcount);
538	spa_config_lock_init(spa);
539
540	avl_add(&spa_namespace_avl, spa);
541
542	/*
543	 * Set the alternate root, if there is one.
544	 */
545	if (altroot) {
546		spa->spa_root = spa_strdup(altroot);
547		spa_active_count++;
548	}
549
550	/*
551	 * Every pool starts with the default cachefile
552	 */
553	list_create(&spa->spa_config_list, sizeof (spa_config_dirent_t),
554	    offsetof(spa_config_dirent_t, scd_link));
555
556	dp = kmem_zalloc(sizeof (spa_config_dirent_t), KM_SLEEP);
557	dp->scd_path = altroot ? NULL : spa_strdup(spa_config_path);
558	list_insert_head(&spa->spa_config_list, dp);
559
560	VERIFY(nvlist_alloc(&spa->spa_load_info, NV_UNIQUE_NAME,
561	    KM_SLEEP) == 0);
562
563	if (config != NULL) {
564		nvlist_t *features;
565
566		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_FEATURES_FOR_READ,
567		    &features) == 0) {
568			VERIFY(nvlist_dup(features, &spa->spa_label_features,
569			    0) == 0);
570		}
571
572		VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
573	}
574
575	if (spa->spa_label_features == NULL) {
576		VERIFY(nvlist_alloc(&spa->spa_label_features, NV_UNIQUE_NAME,
577		    KM_SLEEP) == 0);
578	}
579
580	spa->spa_iokstat = kstat_create("zfs", 0, name,
581	    "disk", KSTAT_TYPE_IO, 1, 0);
582	if (spa->spa_iokstat) {
583		spa->spa_iokstat->ks_lock = &spa->spa_iokstat_lock;
584		kstat_install(spa->spa_iokstat);
585	}
586
587	spa->spa_debug = ((zfs_flags & ZFS_DEBUG_SPA) != 0);
588
589	return (spa);
590}
591
592/*
593 * Removes a spa_t from the namespace, freeing up any memory used.  Requires
594 * spa_namespace_lock.  This is called only after the spa_t has been closed and
595 * deactivated.
596 */
597void
598spa_remove(spa_t *spa)
599{
600	spa_config_dirent_t *dp;
601
602	ASSERT(MUTEX_HELD(&spa_namespace_lock));
603	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
604
605	nvlist_free(spa->spa_config_splitting);
606
607	avl_remove(&spa_namespace_avl, spa);
608	cv_broadcast(&spa_namespace_cv);
609
610	if (spa->spa_root) {
611		spa_strfree(spa->spa_root);
612		spa_active_count--;
613	}
614
615	while ((dp = list_head(&spa->spa_config_list)) != NULL) {
616		list_remove(&spa->spa_config_list, dp);
617		if (dp->scd_path != NULL)
618			spa_strfree(dp->scd_path);
619		kmem_free(dp, sizeof (spa_config_dirent_t));
620	}
621
622	list_destroy(&spa->spa_config_list);
623
624	nvlist_free(spa->spa_label_features);
625	nvlist_free(spa->spa_load_info);
626	spa_config_set(spa, NULL);
627
628	mutex_enter(&cpu_lock);
629	if (spa->spa_deadman_cycid != CYCLIC_NONE)
630		cyclic_remove(spa->spa_deadman_cycid);
631	mutex_exit(&cpu_lock);
632	spa->spa_deadman_cycid = CYCLIC_NONE;
633
634	refcount_destroy(&spa->spa_refcount);
635
636	spa_config_lock_destroy(spa);
637
638	kstat_delete(spa->spa_iokstat);
639	spa->spa_iokstat = NULL;
640
641	for (int t = 0; t < TXG_SIZE; t++)
642		bplist_destroy(&spa->spa_free_bplist[t]);
643
644	cv_destroy(&spa->spa_async_cv);
645	cv_destroy(&spa->spa_proc_cv);
646	cv_destroy(&spa->spa_scrub_io_cv);
647	cv_destroy(&spa->spa_suspend_cv);
648
649	mutex_destroy(&spa->spa_async_lock);
650	mutex_destroy(&spa->spa_errlist_lock);
651	mutex_destroy(&spa->spa_errlog_lock);
652	mutex_destroy(&spa->spa_history_lock);
653	mutex_destroy(&spa->spa_proc_lock);
654	mutex_destroy(&spa->spa_props_lock);
655	mutex_destroy(&spa->spa_scrub_lock);
656	mutex_destroy(&spa->spa_suspend_lock);
657	mutex_destroy(&spa->spa_vdev_top_lock);
658	mutex_destroy(&spa->spa_iokstat_lock);
659
660	kmem_free(spa, sizeof (spa_t));
661}
662
663/*
664 * Given a pool, return the next pool in the namespace, or NULL if there is
665 * none.  If 'prev' is NULL, return the first pool.
666 */
667spa_t *
668spa_next(spa_t *prev)
669{
670	ASSERT(MUTEX_HELD(&spa_namespace_lock));
671
672	if (prev)
673		return (AVL_NEXT(&spa_namespace_avl, prev));
674	else
675		return (avl_first(&spa_namespace_avl));
676}
677
678/*
679 * ==========================================================================
680 * SPA refcount functions
681 * ==========================================================================
682 */
683
684/*
685 * Add a reference to the given spa_t.  Must have at least one reference, or
686 * have the namespace lock held.
687 */
688void
689spa_open_ref(spa_t *spa, void *tag)
690{
691	ASSERT(refcount_count(&spa->spa_refcount) >= spa->spa_minref ||
692	    MUTEX_HELD(&spa_namespace_lock));
693	(void) refcount_add(&spa->spa_refcount, tag);
694}
695
696/*
697 * Remove a reference to the given spa_t.  Must have at least one reference, or
698 * have the namespace lock held.
699 */
700void
701spa_close(spa_t *spa, void *tag)
702{
703	ASSERT(refcount_count(&spa->spa_refcount) > spa->spa_minref ||
704	    MUTEX_HELD(&spa_namespace_lock));
705	(void) refcount_remove(&spa->spa_refcount, tag);
706}
707
708/*
709 * Check to see if the spa refcount is zero.  Must be called with
710 * spa_namespace_lock held.  We really compare against spa_minref, which is the
711 * number of references acquired when opening a pool
712 */
713boolean_t
714spa_refcount_zero(spa_t *spa)
715{
716	ASSERT(MUTEX_HELD(&spa_namespace_lock));
717
718	return (refcount_count(&spa->spa_refcount) == spa->spa_minref);
719}
720
721/*
722 * ==========================================================================
723 * SPA spare and l2cache tracking
724 * ==========================================================================
725 */
726
727/*
728 * Hot spares and cache devices are tracked using the same code below,
729 * for 'auxiliary' devices.
730 */
731
732typedef struct spa_aux {
733	uint64_t	aux_guid;
734	uint64_t	aux_pool;
735	avl_node_t	aux_avl;
736	int		aux_count;
737} spa_aux_t;
738
739static int
740spa_aux_compare(const void *a, const void *b)
741{
742	const spa_aux_t *sa = a;
743	const spa_aux_t *sb = b;
744
745	if (sa->aux_guid < sb->aux_guid)
746		return (-1);
747	else if (sa->aux_guid > sb->aux_guid)
748		return (1);
749	else
750		return (0);
751}
752
753void
754spa_aux_add(vdev_t *vd, avl_tree_t *avl)
755{
756	avl_index_t where;
757	spa_aux_t search;
758	spa_aux_t *aux;
759
760	search.aux_guid = vd->vdev_guid;
761	if ((aux = avl_find(avl, &search, &where)) != NULL) {
762		aux->aux_count++;
763	} else {
764		aux = kmem_zalloc(sizeof (spa_aux_t), KM_SLEEP);
765		aux->aux_guid = vd->vdev_guid;
766		aux->aux_count = 1;
767		avl_insert(avl, aux, where);
768	}
769}
770
771void
772spa_aux_remove(vdev_t *vd, avl_tree_t *avl)
773{
774	spa_aux_t search;
775	spa_aux_t *aux;
776	avl_index_t where;
777
778	search.aux_guid = vd->vdev_guid;
779	aux = avl_find(avl, &search, &where);
780
781	ASSERT(aux != NULL);
782
783	if (--aux->aux_count == 0) {
784		avl_remove(avl, aux);
785		kmem_free(aux, sizeof (spa_aux_t));
786	} else if (aux->aux_pool == spa_guid(vd->vdev_spa)) {
787		aux->aux_pool = 0ULL;
788	}
789}
790
791boolean_t
792spa_aux_exists(uint64_t guid, uint64_t *pool, int *refcnt, avl_tree_t *avl)
793{
794	spa_aux_t search, *found;
795
796	search.aux_guid = guid;
797	found = avl_find(avl, &search, NULL);
798
799	if (pool) {
800		if (found)
801			*pool = found->aux_pool;
802		else
803			*pool = 0ULL;
804	}
805
806	if (refcnt) {
807		if (found)
808			*refcnt = found->aux_count;
809		else
810			*refcnt = 0;
811	}
812
813	return (found != NULL);
814}
815
816void
817spa_aux_activate(vdev_t *vd, avl_tree_t *avl)
818{
819	spa_aux_t search, *found;
820	avl_index_t where;
821
822	search.aux_guid = vd->vdev_guid;
823	found = avl_find(avl, &search, &where);
824	ASSERT(found != NULL);
825	ASSERT(found->aux_pool == 0ULL);
826
827	found->aux_pool = spa_guid(vd->vdev_spa);
828}
829
830/*
831 * Spares are tracked globally due to the following constraints:
832 *
833 * 	- A spare may be part of multiple pools.
834 * 	- A spare may be added to a pool even if it's actively in use within
835 *	  another pool.
836 * 	- A spare in use in any pool can only be the source of a replacement if
837 *	  the target is a spare in the same pool.
838 *
839 * We keep track of all spares on the system through the use of a reference
840 * counted AVL tree.  When a vdev is added as a spare, or used as a replacement
841 * spare, then we bump the reference count in the AVL tree.  In addition, we set
842 * the 'vdev_isspare' member to indicate that the device is a spare (active or
843 * inactive).  When a spare is made active (used to replace a device in the
844 * pool), we also keep track of which pool its been made a part of.
845 *
846 * The 'spa_spare_lock' protects the AVL tree.  These functions are normally
847 * called under the spa_namespace lock as part of vdev reconfiguration.  The
848 * separate spare lock exists for the status query path, which does not need to
849 * be completely consistent with respect to other vdev configuration changes.
850 */
851
852static int
853spa_spare_compare(const void *a, const void *b)
854{
855	return (spa_aux_compare(a, b));
856}
857
858void
859spa_spare_add(vdev_t *vd)
860{
861	mutex_enter(&spa_spare_lock);
862	ASSERT(!vd->vdev_isspare);
863	spa_aux_add(vd, &spa_spare_avl);
864	vd->vdev_isspare = B_TRUE;
865	mutex_exit(&spa_spare_lock);
866}
867
868void
869spa_spare_remove(vdev_t *vd)
870{
871	mutex_enter(&spa_spare_lock);
872	ASSERT(vd->vdev_isspare);
873	spa_aux_remove(vd, &spa_spare_avl);
874	vd->vdev_isspare = B_FALSE;
875	mutex_exit(&spa_spare_lock);
876}
877
878boolean_t
879spa_spare_exists(uint64_t guid, uint64_t *pool, int *refcnt)
880{
881	boolean_t found;
882
883	mutex_enter(&spa_spare_lock);
884	found = spa_aux_exists(guid, pool, refcnt, &spa_spare_avl);
885	mutex_exit(&spa_spare_lock);
886
887	return (found);
888}
889
890void
891spa_spare_activate(vdev_t *vd)
892{
893	mutex_enter(&spa_spare_lock);
894	ASSERT(vd->vdev_isspare);
895	spa_aux_activate(vd, &spa_spare_avl);
896	mutex_exit(&spa_spare_lock);
897}
898
899/*
900 * Level 2 ARC devices are tracked globally for the same reasons as spares.
901 * Cache devices currently only support one pool per cache device, and so
902 * for these devices the aux reference count is currently unused beyond 1.
903 */
904
905static int
906spa_l2cache_compare(const void *a, const void *b)
907{
908	return (spa_aux_compare(a, b));
909}
910
911void
912spa_l2cache_add(vdev_t *vd)
913{
914	mutex_enter(&spa_l2cache_lock);
915	ASSERT(!vd->vdev_isl2cache);
916	spa_aux_add(vd, &spa_l2cache_avl);
917	vd->vdev_isl2cache = B_TRUE;
918	mutex_exit(&spa_l2cache_lock);
919}
920
921void
922spa_l2cache_remove(vdev_t *vd)
923{
924	mutex_enter(&spa_l2cache_lock);
925	ASSERT(vd->vdev_isl2cache);
926	spa_aux_remove(vd, &spa_l2cache_avl);
927	vd->vdev_isl2cache = B_FALSE;
928	mutex_exit(&spa_l2cache_lock);
929}
930
931boolean_t
932spa_l2cache_exists(uint64_t guid, uint64_t *pool)
933{
934	boolean_t found;
935
936	mutex_enter(&spa_l2cache_lock);
937	found = spa_aux_exists(guid, pool, NULL, &spa_l2cache_avl);
938	mutex_exit(&spa_l2cache_lock);
939
940	return (found);
941}
942
943void
944spa_l2cache_activate(vdev_t *vd)
945{
946	mutex_enter(&spa_l2cache_lock);
947	ASSERT(vd->vdev_isl2cache);
948	spa_aux_activate(vd, &spa_l2cache_avl);
949	mutex_exit(&spa_l2cache_lock);
950}
951
952/*
953 * ==========================================================================
954 * SPA vdev locking
955 * ==========================================================================
956 */
957
958/*
959 * Lock the given spa_t for the purpose of adding or removing a vdev.
960 * Grabs the global spa_namespace_lock plus the spa config lock for writing.
961 * It returns the next transaction group for the spa_t.
962 */
963uint64_t
964spa_vdev_enter(spa_t *spa)
965{
966	mutex_enter(&spa->spa_vdev_top_lock);
967	mutex_enter(&spa_namespace_lock);
968	return (spa_vdev_config_enter(spa));
969}
970
971/*
972 * Internal implementation for spa_vdev_enter().  Used when a vdev
973 * operation requires multiple syncs (i.e. removing a device) while
974 * keeping the spa_namespace_lock held.
975 */
976uint64_t
977spa_vdev_config_enter(spa_t *spa)
978{
979	ASSERT(MUTEX_HELD(&spa_namespace_lock));
980
981	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
982
983	return (spa_last_synced_txg(spa) + 1);
984}
985
986/*
987 * Used in combination with spa_vdev_config_enter() to allow the syncing
988 * of multiple transactions without releasing the spa_namespace_lock.
989 */
990void
991spa_vdev_config_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error, char *tag)
992{
993	ASSERT(MUTEX_HELD(&spa_namespace_lock));
994
995	int config_changed = B_FALSE;
996
997	ASSERT(txg > spa_last_synced_txg(spa));
998
999	spa->spa_pending_vdev = NULL;
1000
1001	/*
1002	 * Reassess the DTLs.
1003	 */
1004	vdev_dtl_reassess(spa->spa_root_vdev, 0, 0, B_FALSE);
1005
1006	if (error == 0 && !list_is_empty(&spa->spa_config_dirty_list)) {
1007		config_changed = B_TRUE;
1008		spa->spa_config_generation++;
1009	}
1010
1011	/*
1012	 * Verify the metaslab classes.
1013	 */
1014	ASSERT(metaslab_class_validate(spa_normal_class(spa)) == 0);
1015	ASSERT(metaslab_class_validate(spa_log_class(spa)) == 0);
1016
1017	spa_config_exit(spa, SCL_ALL, spa);
1018
1019	/*
1020	 * Panic the system if the specified tag requires it.  This
1021	 * is useful for ensuring that configurations are updated
1022	 * transactionally.
1023	 */
1024	if (zio_injection_enabled)
1025		zio_handle_panic_injection(spa, tag, 0);
1026
1027	/*
1028	 * Note: this txg_wait_synced() is important because it ensures
1029	 * that there won't be more than one config change per txg.
1030	 * This allows us to use the txg as the generation number.
1031	 */
1032	if (error == 0)
1033		txg_wait_synced(spa->spa_dsl_pool, txg);
1034
1035	if (vd != NULL) {
1036		ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
1037		spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1038		vdev_free(vd);
1039		spa_config_exit(spa, SCL_ALL, spa);
1040	}
1041
1042	/*
1043	 * If the config changed, update the config cache.
1044	 */
1045	if (config_changed)
1046		spa_config_sync(spa, B_FALSE, B_TRUE);
1047}
1048
1049/*
1050 * Unlock the spa_t after adding or removing a vdev.  Besides undoing the
1051 * locking of spa_vdev_enter(), we also want make sure the transactions have
1052 * synced to disk, and then update the global configuration cache with the new
1053 * information.
1054 */
1055int
1056spa_vdev_exit(spa_t *spa, vdev_t *vd, uint64_t txg, int error)
1057{
1058	spa_vdev_config_exit(spa, vd, txg, error, FTAG);
1059	mutex_exit(&spa_namespace_lock);
1060	mutex_exit(&spa->spa_vdev_top_lock);
1061
1062	return (error);
1063}
1064
1065/*
1066 * Lock the given spa_t for the purpose of changing vdev state.
1067 */
1068void
1069spa_vdev_state_enter(spa_t *spa, int oplocks)
1070{
1071	int locks = SCL_STATE_ALL | oplocks;
1072
1073	/*
1074	 * Root pools may need to read of the underlying devfs filesystem
1075	 * when opening up a vdev.  Unfortunately if we're holding the
1076	 * SCL_ZIO lock it will result in a deadlock when we try to issue
1077	 * the read from the root filesystem.  Instead we "prefetch"
1078	 * the associated vnodes that we need prior to opening the
1079	 * underlying devices and cache them so that we can prevent
1080	 * any I/O when we are doing the actual open.
1081	 */
1082	if (spa_is_root(spa)) {
1083		int low = locks & ~(SCL_ZIO - 1);
1084		int high = locks & ~low;
1085
1086		spa_config_enter(spa, high, spa, RW_WRITER);
1087		vdev_hold(spa->spa_root_vdev);
1088		spa_config_enter(spa, low, spa, RW_WRITER);
1089	} else {
1090		spa_config_enter(spa, locks, spa, RW_WRITER);
1091	}
1092	spa->spa_vdev_locks = locks;
1093}
1094
1095int
1096spa_vdev_state_exit(spa_t *spa, vdev_t *vd, int error)
1097{
1098	boolean_t config_changed = B_FALSE;
1099
1100	if (vd != NULL || error == 0)
1101		vdev_dtl_reassess(vd ? vd->vdev_top : spa->spa_root_vdev,
1102		    0, 0, B_FALSE);
1103
1104	if (vd != NULL) {
1105		vdev_state_dirty(vd->vdev_top);
1106		config_changed = B_TRUE;
1107		spa->spa_config_generation++;
1108	}
1109
1110	if (spa_is_root(spa))
1111		vdev_rele(spa->spa_root_vdev);
1112
1113	ASSERT3U(spa->spa_vdev_locks, >=, SCL_STATE_ALL);
1114	spa_config_exit(spa, spa->spa_vdev_locks, spa);
1115
1116	/*
1117	 * If anything changed, wait for it to sync.  This ensures that,
1118	 * from the system administrator's perspective, zpool(1M) commands
1119	 * are synchronous.  This is important for things like zpool offline:
1120	 * when the command completes, you expect no further I/O from ZFS.
1121	 */
1122	if (vd != NULL)
1123		txg_wait_synced(spa->spa_dsl_pool, 0);
1124
1125	/*
1126	 * If the config changed, update the config cache.
1127	 */
1128	if (config_changed) {
1129		mutex_enter(&spa_namespace_lock);
1130		spa_config_sync(spa, B_FALSE, B_TRUE);
1131		mutex_exit(&spa_namespace_lock);
1132	}
1133
1134	return (error);
1135}
1136
1137/*
1138 * ==========================================================================
1139 * Miscellaneous functions
1140 * ==========================================================================
1141 */
1142
1143void
1144spa_activate_mos_feature(spa_t *spa, const char *feature)
1145{
1146	(void) nvlist_add_boolean(spa->spa_label_features, feature);
1147	vdev_config_dirty(spa->spa_root_vdev);
1148}
1149
1150void
1151spa_deactivate_mos_feature(spa_t *spa, const char *feature)
1152{
1153	(void) nvlist_remove_all(spa->spa_label_features, feature);
1154	vdev_config_dirty(spa->spa_root_vdev);
1155}
1156
1157/*
1158 * Rename a spa_t.
1159 */
1160int
1161spa_rename(const char *name, const char *newname)
1162{
1163	spa_t *spa;
1164	int err;
1165
1166	/*
1167	 * Lookup the spa_t and grab the config lock for writing.  We need to
1168	 * actually open the pool so that we can sync out the necessary labels.
1169	 * It's OK to call spa_open() with the namespace lock held because we
1170	 * allow recursive calls for other reasons.
1171	 */
1172	mutex_enter(&spa_namespace_lock);
1173	if ((err = spa_open(name, &spa, FTAG)) != 0) {
1174		mutex_exit(&spa_namespace_lock);
1175		return (err);
1176	}
1177
1178	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1179
1180	avl_remove(&spa_namespace_avl, spa);
1181	(void) strlcpy(spa->spa_name, newname, sizeof (spa->spa_name));
1182	avl_add(&spa_namespace_avl, spa);
1183
1184	/*
1185	 * Sync all labels to disk with the new names by marking the root vdev
1186	 * dirty and waiting for it to sync.  It will pick up the new pool name
1187	 * during the sync.
1188	 */
1189	vdev_config_dirty(spa->spa_root_vdev);
1190
1191	spa_config_exit(spa, SCL_ALL, FTAG);
1192
1193	txg_wait_synced(spa->spa_dsl_pool, 0);
1194
1195	/*
1196	 * Sync the updated config cache.
1197	 */
1198	spa_config_sync(spa, B_FALSE, B_TRUE);
1199
1200	spa_close(spa, FTAG);
1201
1202	mutex_exit(&spa_namespace_lock);
1203
1204	return (0);
1205}
1206
1207/*
1208 * Return the spa_t associated with given pool_guid, if it exists.  If
1209 * device_guid is non-zero, determine whether the pool exists *and* contains
1210 * a device with the specified device_guid.
1211 */
1212spa_t *
1213spa_by_guid(uint64_t pool_guid, uint64_t device_guid)
1214{
1215	spa_t *spa;
1216	avl_tree_t *t = &spa_namespace_avl;
1217
1218	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1219
1220	for (spa = avl_first(t); spa != NULL; spa = AVL_NEXT(t, spa)) {
1221		if (spa->spa_state == POOL_STATE_UNINITIALIZED)
1222			continue;
1223		if (spa->spa_root_vdev == NULL)
1224			continue;
1225		if (spa_guid(spa) == pool_guid) {
1226			if (device_guid == 0)
1227				break;
1228
1229			if (vdev_lookup_by_guid(spa->spa_root_vdev,
1230			    device_guid) != NULL)
1231				break;
1232
1233			/*
1234			 * Check any devices we may be in the process of adding.
1235			 */
1236			if (spa->spa_pending_vdev) {
1237				if (vdev_lookup_by_guid(spa->spa_pending_vdev,
1238				    device_guid) != NULL)
1239					break;
1240			}
1241		}
1242	}
1243
1244	return (spa);
1245}
1246
1247/*
1248 * Determine whether a pool with the given pool_guid exists.
1249 */
1250boolean_t
1251spa_guid_exists(uint64_t pool_guid, uint64_t device_guid)
1252{
1253	return (spa_by_guid(pool_guid, device_guid) != NULL);
1254}
1255
1256char *
1257spa_strdup(const char *s)
1258{
1259	size_t len;
1260	char *new;
1261
1262	len = strlen(s);
1263	new = kmem_alloc(len + 1, KM_SLEEP);
1264	bcopy(s, new, len);
1265	new[len] = '\0';
1266
1267	return (new);
1268}
1269
1270void
1271spa_strfree(char *s)
1272{
1273	kmem_free(s, strlen(s) + 1);
1274}
1275
1276uint64_t
1277spa_get_random(uint64_t range)
1278{
1279	uint64_t r;
1280
1281	ASSERT(range != 0);
1282
1283	(void) random_get_pseudo_bytes((void *)&r, sizeof (uint64_t));
1284
1285	return (r % range);
1286}
1287
1288uint64_t
1289spa_generate_guid(spa_t *spa)
1290{
1291	uint64_t guid = spa_get_random(-1ULL);
1292
1293	if (spa != NULL) {
1294		while (guid == 0 || spa_guid_exists(spa_guid(spa), guid))
1295			guid = spa_get_random(-1ULL);
1296	} else {
1297		while (guid == 0 || spa_guid_exists(guid, 0))
1298			guid = spa_get_random(-1ULL);
1299	}
1300
1301	return (guid);
1302}
1303
1304void
1305sprintf_blkptr(char *buf, const blkptr_t *bp)
1306{
1307	char type[256];
1308	char *checksum = NULL;
1309	char *compress = NULL;
1310
1311	if (bp != NULL) {
1312		if (BP_GET_TYPE(bp) & DMU_OT_NEWTYPE) {
1313			dmu_object_byteswap_t bswap =
1314			    DMU_OT_BYTESWAP(BP_GET_TYPE(bp));
1315			(void) snprintf(type, sizeof (type), "bswap %s %s",
1316			    DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) ?
1317			    "metadata" : "data",
1318			    dmu_ot_byteswap[bswap].ob_name);
1319		} else {
1320			(void) strlcpy(type, dmu_ot[BP_GET_TYPE(bp)].ot_name,
1321			    sizeof (type));
1322		}
1323		checksum = zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_name;
1324		compress = zio_compress_table[BP_GET_COMPRESS(bp)].ci_name;
1325	}
1326
1327	SPRINTF_BLKPTR(snprintf, ' ', buf, bp, type, checksum, compress);
1328}
1329
1330void
1331spa_freeze(spa_t *spa)
1332{
1333	uint64_t freeze_txg = 0;
1334
1335	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1336	if (spa->spa_freeze_txg == UINT64_MAX) {
1337		freeze_txg = spa_last_synced_txg(spa) + TXG_SIZE;
1338		spa->spa_freeze_txg = freeze_txg;
1339	}
1340	spa_config_exit(spa, SCL_ALL, FTAG);
1341	if (freeze_txg != 0)
1342		txg_wait_synced(spa_get_dsl(spa), freeze_txg);
1343}
1344
1345void
1346zfs_panic_recover(const char *fmt, ...)
1347{
1348	va_list adx;
1349
1350	va_start(adx, fmt);
1351	vcmn_err(zfs_recover ? CE_WARN : CE_PANIC, fmt, adx);
1352	va_end(adx);
1353}
1354
1355/*
1356 * This is a stripped-down version of strtoull, suitable only for converting
1357 * lowercase hexadecimal numbers that don't overflow.
1358 */
1359uint64_t
1360strtonum(const char *str, char **nptr)
1361{
1362	uint64_t val = 0;
1363	char c;
1364	int digit;
1365
1366	while ((c = *str) != '\0') {
1367		if (c >= '0' && c <= '9')
1368			digit = c - '0';
1369		else if (c >= 'a' && c <= 'f')
1370			digit = 10 + c - 'a';
1371		else
1372			break;
1373
1374		val *= 16;
1375		val += digit;
1376
1377		str++;
1378	}
1379
1380	if (nptr)
1381		*nptr = (char *)str;
1382
1383	return (val);
1384}
1385
1386/*
1387 * ==========================================================================
1388 * Accessor functions
1389 * ==========================================================================
1390 */
1391
1392boolean_t
1393spa_shutting_down(spa_t *spa)
1394{
1395	return (spa->spa_async_suspended);
1396}
1397
1398dsl_pool_t *
1399spa_get_dsl(spa_t *spa)
1400{
1401	return (spa->spa_dsl_pool);
1402}
1403
1404boolean_t
1405spa_is_initializing(spa_t *spa)
1406{
1407	return (spa->spa_is_initializing);
1408}
1409
1410blkptr_t *
1411spa_get_rootblkptr(spa_t *spa)
1412{
1413	return (&spa->spa_ubsync.ub_rootbp);
1414}
1415
1416void
1417spa_set_rootblkptr(spa_t *spa, const blkptr_t *bp)
1418{
1419	spa->spa_uberblock.ub_rootbp = *bp;
1420}
1421
1422void
1423spa_altroot(spa_t *spa, char *buf, size_t buflen)
1424{
1425	if (spa->spa_root == NULL)
1426		buf[0] = '\0';
1427	else
1428		(void) strncpy(buf, spa->spa_root, buflen);
1429}
1430
1431int
1432spa_sync_pass(spa_t *spa)
1433{
1434	return (spa->spa_sync_pass);
1435}
1436
1437char *
1438spa_name(spa_t *spa)
1439{
1440	return (spa->spa_name);
1441}
1442
1443uint64_t
1444spa_guid(spa_t *spa)
1445{
1446	dsl_pool_t *dp = spa_get_dsl(spa);
1447	uint64_t guid;
1448
1449	/*
1450	 * If we fail to parse the config during spa_load(), we can go through
1451	 * the error path (which posts an ereport) and end up here with no root
1452	 * vdev.  We stash the original pool guid in 'spa_config_guid' to handle
1453	 * this case.
1454	 */
1455	if (spa->spa_root_vdev == NULL)
1456		return (spa->spa_config_guid);
1457
1458	guid = spa->spa_last_synced_guid != 0 ?
1459	    spa->spa_last_synced_guid : spa->spa_root_vdev->vdev_guid;
1460
1461	/*
1462	 * Return the most recently synced out guid unless we're
1463	 * in syncing context.
1464	 */
1465	if (dp && dsl_pool_sync_context(dp))
1466		return (spa->spa_root_vdev->vdev_guid);
1467	else
1468		return (guid);
1469}
1470
1471uint64_t
1472spa_load_guid(spa_t *spa)
1473{
1474	/*
1475	 * This is a GUID that exists solely as a reference for the
1476	 * purposes of the arc.  It is generated at load time, and
1477	 * is never written to persistent storage.
1478	 */
1479	return (spa->spa_load_guid);
1480}
1481
1482uint64_t
1483spa_last_synced_txg(spa_t *spa)
1484{
1485	return (spa->spa_ubsync.ub_txg);
1486}
1487
1488uint64_t
1489spa_first_txg(spa_t *spa)
1490{
1491	return (spa->spa_first_txg);
1492}
1493
1494uint64_t
1495spa_syncing_txg(spa_t *spa)
1496{
1497	return (spa->spa_syncing_txg);
1498}
1499
1500pool_state_t
1501spa_state(spa_t *spa)
1502{
1503	return (spa->spa_state);
1504}
1505
1506spa_load_state_t
1507spa_load_state(spa_t *spa)
1508{
1509	return (spa->spa_load_state);
1510}
1511
1512uint64_t
1513spa_freeze_txg(spa_t *spa)
1514{
1515	return (spa->spa_freeze_txg);
1516}
1517
1518/* ARGSUSED */
1519uint64_t
1520spa_get_asize(spa_t *spa, uint64_t lsize)
1521{
1522	return (lsize * spa_asize_inflation);
1523}
1524
1525uint64_t
1526spa_get_dspace(spa_t *spa)
1527{
1528	return (spa->spa_dspace);
1529}
1530
1531void
1532spa_update_dspace(spa_t *spa)
1533{
1534	spa->spa_dspace = metaslab_class_get_dspace(spa_normal_class(spa)) +
1535	    ddt_get_dedup_dspace(spa);
1536}
1537
1538/*
1539 * Return the failure mode that has been set to this pool. The default
1540 * behavior will be to block all I/Os when a complete failure occurs.
1541 */
1542uint8_t
1543spa_get_failmode(spa_t *spa)
1544{
1545	return (spa->spa_failmode);
1546}
1547
1548boolean_t
1549spa_suspended(spa_t *spa)
1550{
1551	return (spa->spa_suspended);
1552}
1553
1554uint64_t
1555spa_version(spa_t *spa)
1556{
1557	return (spa->spa_ubsync.ub_version);
1558}
1559
1560boolean_t
1561spa_deflate(spa_t *spa)
1562{
1563	return (spa->spa_deflate);
1564}
1565
1566metaslab_class_t *
1567spa_normal_class(spa_t *spa)
1568{
1569	return (spa->spa_normal_class);
1570}
1571
1572metaslab_class_t *
1573spa_log_class(spa_t *spa)
1574{
1575	return (spa->spa_log_class);
1576}
1577
1578int
1579spa_max_replication(spa_t *spa)
1580{
1581	/*
1582	 * As of SPA_VERSION == SPA_VERSION_DITTO_BLOCKS, we are able to
1583	 * handle BPs with more than one DVA allocated.  Set our max
1584	 * replication level accordingly.
1585	 */
1586	if (spa_version(spa) < SPA_VERSION_DITTO_BLOCKS)
1587		return (1);
1588	return (MIN(SPA_DVAS_PER_BP, spa_max_replication_override));
1589}
1590
1591int
1592spa_prev_software_version(spa_t *spa)
1593{
1594	return (spa->spa_prev_software_version);
1595}
1596
1597uint64_t
1598spa_deadman_synctime(spa_t *spa)
1599{
1600	return (spa->spa_deadman_synctime);
1601}
1602
1603uint64_t
1604dva_get_dsize_sync(spa_t *spa, const dva_t *dva)
1605{
1606	uint64_t asize = DVA_GET_ASIZE(dva);
1607	uint64_t dsize = asize;
1608
1609	ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0);
1610
1611	if (asize != 0 && spa->spa_deflate) {
1612		vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva));
1613		dsize = (asize >> SPA_MINBLOCKSHIFT) * vd->vdev_deflate_ratio;
1614	}
1615
1616	return (dsize);
1617}
1618
1619uint64_t
1620bp_get_dsize_sync(spa_t *spa, const blkptr_t *bp)
1621{
1622	uint64_t dsize = 0;
1623
1624	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1625		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1626
1627	return (dsize);
1628}
1629
1630uint64_t
1631bp_get_dsize(spa_t *spa, const blkptr_t *bp)
1632{
1633	uint64_t dsize = 0;
1634
1635	spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
1636
1637	for (int d = 0; d < SPA_DVAS_PER_BP; d++)
1638		dsize += dva_get_dsize_sync(spa, &bp->blk_dva[d]);
1639
1640	spa_config_exit(spa, SCL_VDEV, FTAG);
1641
1642	return (dsize);
1643}
1644
1645/*
1646 * ==========================================================================
1647 * Initialization and Termination
1648 * ==========================================================================
1649 */
1650
1651static int
1652spa_name_compare(const void *a1, const void *a2)
1653{
1654	const spa_t *s1 = a1;
1655	const spa_t *s2 = a2;
1656	int s;
1657
1658	s = strcmp(s1->spa_name, s2->spa_name);
1659	if (s > 0)
1660		return (1);
1661	if (s < 0)
1662		return (-1);
1663	return (0);
1664}
1665
1666int
1667spa_busy(void)
1668{
1669	return (spa_active_count);
1670}
1671
1672void
1673spa_boot_init()
1674{
1675	spa_config_load();
1676}
1677
1678void
1679spa_init(int mode)
1680{
1681	mutex_init(&spa_namespace_lock, NULL, MUTEX_DEFAULT, NULL);
1682	mutex_init(&spa_spare_lock, NULL, MUTEX_DEFAULT, NULL);
1683	mutex_init(&spa_l2cache_lock, NULL, MUTEX_DEFAULT, NULL);
1684	cv_init(&spa_namespace_cv, NULL, CV_DEFAULT, NULL);
1685
1686	avl_create(&spa_namespace_avl, spa_name_compare, sizeof (spa_t),
1687	    offsetof(spa_t, spa_avl));
1688
1689	avl_create(&spa_spare_avl, spa_spare_compare, sizeof (spa_aux_t),
1690	    offsetof(spa_aux_t, aux_avl));
1691
1692	avl_create(&spa_l2cache_avl, spa_l2cache_compare, sizeof (spa_aux_t),
1693	    offsetof(spa_aux_t, aux_avl));
1694
1695	spa_mode_global = mode;
1696
1697#ifdef _KERNEL
1698	spa_arch_init();
1699#else
1700	if (spa_mode_global != FREAD && dprintf_find_string("watch")) {
1701		arc_procfd = open("/proc/self/ctl", O_WRONLY);
1702		if (arc_procfd == -1) {
1703			perror("could not enable watchpoints: "
1704			    "opening /proc/self/ctl failed: ");
1705		} else {
1706			arc_watch = B_TRUE;
1707		}
1708	}
1709#endif
1710
1711	refcount_init();
1712	unique_init();
1713	range_tree_init();
1714	zio_init();
1715	dmu_init();
1716	zil_init();
1717	vdev_cache_stat_init();
1718	zfs_prop_init();
1719	zpool_prop_init();
1720	zpool_feature_init();
1721	spa_config_load();
1722	l2arc_start();
1723}
1724
1725void
1726spa_fini(void)
1727{
1728	l2arc_stop();
1729
1730	spa_evict_all();
1731
1732	vdev_cache_stat_fini();
1733	zil_fini();
1734	dmu_fini();
1735	zio_fini();
1736	range_tree_fini();
1737	unique_fini();
1738	refcount_fini();
1739
1740	avl_destroy(&spa_namespace_avl);
1741	avl_destroy(&spa_spare_avl);
1742	avl_destroy(&spa_l2cache_avl);
1743
1744	cv_destroy(&spa_namespace_cv);
1745	mutex_destroy(&spa_namespace_lock);
1746	mutex_destroy(&spa_spare_lock);
1747	mutex_destroy(&spa_l2cache_lock);
1748}
1749
1750/*
1751 * Return whether this pool has slogs. No locking needed.
1752 * It's not a problem if the wrong answer is returned as it's only for
1753 * performance and not correctness
1754 */
1755boolean_t
1756spa_has_slogs(spa_t *spa)
1757{
1758	return (spa->spa_log_class->mc_rotor != NULL);
1759}
1760
1761spa_log_state_t
1762spa_get_log_state(spa_t *spa)
1763{
1764	return (spa->spa_log_state);
1765}
1766
1767void
1768spa_set_log_state(spa_t *spa, spa_log_state_t state)
1769{
1770	spa->spa_log_state = state;
1771}
1772
1773boolean_t
1774spa_is_root(spa_t *spa)
1775{
1776	return (spa->spa_is_root);
1777}
1778
1779boolean_t
1780spa_writeable(spa_t *spa)
1781{
1782	return (!!(spa->spa_mode & FWRITE));
1783}
1784
1785int
1786spa_mode(spa_t *spa)
1787{
1788	return (spa->spa_mode);
1789}
1790
1791uint64_t
1792spa_bootfs(spa_t *spa)
1793{
1794	return (spa->spa_bootfs);
1795}
1796
1797uint64_t
1798spa_delegation(spa_t *spa)
1799{
1800	return (spa->spa_delegation);
1801}
1802
1803objset_t *
1804spa_meta_objset(spa_t *spa)
1805{
1806	return (spa->spa_meta_objset);
1807}
1808
1809enum zio_checksum
1810spa_dedup_checksum(spa_t *spa)
1811{
1812	return (spa->spa_dedup_checksum);
1813}
1814
1815/*
1816 * Reset pool scan stat per scan pass (or reboot).
1817 */
1818void
1819spa_scan_stat_init(spa_t *spa)
1820{
1821	/* data not stored on disk */
1822	spa->spa_scan_pass_start = gethrestime_sec();
1823	spa->spa_scan_pass_exam = 0;
1824	vdev_scan_stat_init(spa->spa_root_vdev);
1825}
1826
1827/*
1828 * Get scan stats for zpool status reports
1829 */
1830int
1831spa_scan_get_stats(spa_t *spa, pool_scan_stat_t *ps)
1832{
1833	dsl_scan_t *scn = spa->spa_dsl_pool ? spa->spa_dsl_pool->dp_scan : NULL;
1834
1835	if (scn == NULL || scn->scn_phys.scn_func == POOL_SCAN_NONE)
1836		return (SET_ERROR(ENOENT));
1837	bzero(ps, sizeof (pool_scan_stat_t));
1838
1839	/* data stored on disk */
1840	ps->pss_func = scn->scn_phys.scn_func;
1841	ps->pss_start_time = scn->scn_phys.scn_start_time;
1842	ps->pss_end_time = scn->scn_phys.scn_end_time;
1843	ps->pss_to_examine = scn->scn_phys.scn_to_examine;
1844	ps->pss_examined = scn->scn_phys.scn_examined;
1845	ps->pss_to_process = scn->scn_phys.scn_to_process;
1846	ps->pss_processed = scn->scn_phys.scn_processed;
1847	ps->pss_errors = scn->scn_phys.scn_errors;
1848	ps->pss_state = scn->scn_phys.scn_state;
1849
1850	/* data not stored on disk */
1851	ps->pss_pass_start = spa->spa_scan_pass_start;
1852	ps->pss_pass_exam = spa->spa_scan_pass_exam;
1853
1854	return (0);
1855}
1856
1857boolean_t
1858spa_debug_enabled(spa_t *spa)
1859{
1860	return (spa->spa_debug);
1861}
1862