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 https://opensource.org/licenses/CDDL-1.0.
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) 2011, 2024 by Delphix. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
26  * Copyright 2013 Saso Kiselkov. All rights reserved.
27  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
28  * Copyright (c) 2017, Intel Corporation.
29  * Copyright (c) 2019 Datto Inc.
30  */
31 
32 #ifndef _SYS_SPA_IMPL_H
33 #define	_SYS_SPA_IMPL_H
34 
35 #include <sys/spa.h>
36 #include <sys/spa_checkpoint.h>
37 #include <sys/spa_log_spacemap.h>
38 #include <sys/vdev.h>
39 #include <sys/vdev_rebuild.h>
40 #include <sys/vdev_removal.h>
41 #include <sys/vdev_raidz.h>
42 #include <sys/metaslab.h>
43 #include <sys/dmu.h>
44 #include <sys/dsl_pool.h>
45 #include <sys/uberblock_impl.h>
46 #include <sys/zfs_context.h>
47 #include <sys/avl.h>
48 #include <sys/zfs_refcount.h>
49 #include <sys/bplist.h>
50 #include <sys/bpobj.h>
51 #include <sys/dsl_crypt.h>
52 #include <sys/zfeature.h>
53 #include <sys/zthr.h>
54 #include <sys/dsl_deadlist.h>
55 #include <zfeature_common.h>
56 
57 #ifdef	__cplusplus
58 extern "C" {
59 #endif
60 
61 typedef struct spa_alloc {
62 	kmutex_t	spaa_lock;
63 	avl_tree_t	spaa_tree;
64 } ____cacheline_aligned spa_alloc_t;
65 
66 typedef struct spa_allocs_use {
67 	kmutex_t	sau_lock;
68 	uint_t		sau_rotor;
69 	boolean_t	sau_inuse[];
70 } spa_allocs_use_t;
71 
72 typedef struct spa_error_entry {
73 	zbookmark_phys_t	se_bookmark;
74 	char			*se_name;
75 	avl_node_t		se_avl;
76 	zbookmark_err_phys_t	se_zep;		/* not accounted in avl_find */
77 } spa_error_entry_t;
78 
79 typedef struct spa_history_phys {
80 	uint64_t sh_pool_create_len;	/* ending offset of zpool create */
81 	uint64_t sh_phys_max_off;	/* physical EOF */
82 	uint64_t sh_bof;		/* logical BOF */
83 	uint64_t sh_eof;		/* logical EOF */
84 	uint64_t sh_records_lost;	/* num of records overwritten */
85 } spa_history_phys_t;
86 
87 /*
88  * All members must be uint64_t, for byteswap purposes.
89  */
90 typedef struct spa_removing_phys {
91 	uint64_t sr_state; /* dsl_scan_state_t */
92 
93 	/*
94 	 * The vdev ID that we most recently attempted to remove,
95 	 * or -1 if no removal has been attempted.
96 	 */
97 	uint64_t sr_removing_vdev;
98 
99 	/*
100 	 * The vdev ID that we most recently successfully removed,
101 	 * or -1 if no devices have been removed.
102 	 */
103 	uint64_t sr_prev_indirect_vdev;
104 
105 	uint64_t sr_start_time;
106 	uint64_t sr_end_time;
107 
108 	/*
109 	 * Note that we can not use the space map's or indirect mapping's
110 	 * accounting as a substitute for these values, because we need to
111 	 * count frees of not-yet-copied data as though it did the copy.
112 	 * Otherwise, we could get into a situation where copied > to_copy,
113 	 * or we complete before copied == to_copy.
114 	 */
115 	uint64_t sr_to_copy; /* bytes that need to be copied */
116 	uint64_t sr_copied; /* bytes that have been copied or freed */
117 } spa_removing_phys_t;
118 
119 /*
120  * This struct is stored as an entry in the DMU_POOL_DIRECTORY_OBJECT
121  * (with key DMU_POOL_CONDENSING_INDIRECT).  It is present if a condense
122  * of an indirect vdev's mapping object is in progress.
123  */
124 typedef struct spa_condensing_indirect_phys {
125 	/*
126 	 * The vdev ID of the indirect vdev whose indirect mapping is
127 	 * being condensed.
128 	 */
129 	uint64_t	scip_vdev;
130 
131 	/*
132 	 * The vdev's old obsolete spacemap.  This spacemap's contents are
133 	 * being integrated into the new mapping.
134 	 */
135 	uint64_t	scip_prev_obsolete_sm_object;
136 
137 	/*
138 	 * The new mapping object that is being created.
139 	 */
140 	uint64_t	scip_next_mapping_object;
141 } spa_condensing_indirect_phys_t;
142 
143 struct spa_aux_vdev {
144 	uint64_t	sav_object;		/* MOS object for device list */
145 	nvlist_t	*sav_config;		/* cached device config */
146 	vdev_t		**sav_vdevs;		/* devices */
147 	int		sav_count;		/* number devices */
148 	boolean_t	sav_sync;		/* sync the device list */
149 	boolean_t	sav_label_sync;		/* sync aux labels */
150 	nvlist_t	**sav_pending;		/* pending device additions */
151 	uint_t		sav_npending;		/* # pending devices */
152 };
153 
154 typedef struct spa_config_lock {
155 	kmutex_t	scl_lock;
156 	kthread_t	*scl_writer;
157 	int		scl_write_wanted;
158 	int		scl_count;
159 	kcondvar_t	scl_cv;
160 } ____cacheline_aligned spa_config_lock_t;
161 
162 typedef struct spa_config_dirent {
163 	list_node_t	scd_link;
164 	char		*scd_path;
165 } spa_config_dirent_t;
166 
167 typedef enum zio_taskq_type {
168 	ZIO_TASKQ_ISSUE = 0,
169 	ZIO_TASKQ_ISSUE_HIGH,
170 	ZIO_TASKQ_INTERRUPT,
171 	ZIO_TASKQ_INTERRUPT_HIGH,
172 	ZIO_TASKQ_TYPES
173 } zio_taskq_type_t;
174 
175 /*
176  * State machine for the zpool-poolname process.  The states transitions
177  * are done as follows:
178  *
179  *	From		   To			Routine
180  *	PROC_NONE	-> PROC_CREATED		spa_activate()
181  *	PROC_CREATED	-> PROC_ACTIVE		spa_thread()
182  *	PROC_ACTIVE	-> PROC_DEACTIVATE	spa_deactivate()
183  *	PROC_DEACTIVATE	-> PROC_GONE		spa_thread()
184  *	PROC_GONE	-> PROC_NONE		spa_deactivate()
185  */
186 typedef enum spa_proc_state {
187 	SPA_PROC_NONE,		/* spa_proc = &p0, no process created */
188 	SPA_PROC_CREATED,	/* spa_activate() has proc, is waiting */
189 	SPA_PROC_ACTIVE,	/* taskqs created, spa_proc set */
190 	SPA_PROC_DEACTIVATE,	/* spa_deactivate() requests process exit */
191 	SPA_PROC_GONE		/* spa_thread() is exiting, spa_proc = &p0 */
192 } spa_proc_state_t;
193 
194 typedef struct spa_taskqs {
195 	uint_t stqs_count;
196 	taskq_t **stqs_taskq;
197 } spa_taskqs_t;
198 
199 /* one for each thread in the spa sync taskq */
200 typedef struct spa_syncthread_info {
201 	kthread_t	*sti_thread;
202 	uint_t		sti_allocator;
203 } spa_syncthread_info_t;
204 
205 typedef enum spa_all_vdev_zap_action {
206 	AVZ_ACTION_NONE = 0,
207 	AVZ_ACTION_DESTROY,	/* Destroy all per-vdev ZAPs and the AVZ. */
208 	AVZ_ACTION_REBUILD,	/* Populate the new AVZ, see spa_avz_rebuild */
209 	AVZ_ACTION_INITIALIZE
210 } spa_avz_action_t;
211 
212 typedef enum spa_config_source {
213 	SPA_CONFIG_SRC_NONE = 0,
214 	SPA_CONFIG_SRC_SCAN,		/* scan of path (default: /dev/dsk) */
215 	SPA_CONFIG_SRC_CACHEFILE,	/* any cachefile */
216 	SPA_CONFIG_SRC_TRYIMPORT,	/* returned from call to tryimport */
217 	SPA_CONFIG_SRC_SPLIT,		/* new pool in a pool split */
218 	SPA_CONFIG_SRC_MOS		/* MOS, but not always from right txg */
219 } spa_config_source_t;
220 
221 struct spa {
222 	/*
223 	 * Fields protected by spa_namespace_lock.
224 	 */
225 	char		spa_name[ZFS_MAX_DATASET_NAME_LEN];	/* pool name */
226 	char		*spa_comment;		/* comment */
227 	avl_node_t	spa_avl;		/* node in spa_namespace_avl */
228 	nvlist_t	*spa_config;		/* last synced config */
229 	nvlist_t	*spa_config_syncing;	/* currently syncing config */
230 	nvlist_t	*spa_config_splitting;	/* config for splitting */
231 	nvlist_t	*spa_load_info;		/* info and errors from load */
232 	uint64_t	spa_config_txg;		/* txg of last config change */
233 	uint32_t	spa_sync_pass;		/* iterate-to-convergence */
234 	pool_state_t	spa_state;		/* pool state */
235 	int		spa_inject_ref;		/* injection references */
236 	uint8_t		spa_sync_on;		/* sync threads are running */
237 	spa_load_state_t spa_load_state;	/* current load operation */
238 	boolean_t	spa_indirect_vdevs_loaded; /* mappings loaded? */
239 	boolean_t	spa_trust_config;	/* do we trust vdev tree? */
240 	boolean_t	spa_is_splitting;	/* in the middle of a split? */
241 	spa_config_source_t spa_config_source;	/* where config comes from? */
242 	uint64_t	spa_import_flags;	/* import specific flags */
243 	spa_taskqs_t	spa_zio_taskq[ZIO_TYPES][ZIO_TASKQ_TYPES];
244 	dsl_pool_t	*spa_dsl_pool;
245 	boolean_t	spa_is_initializing;	/* true while opening pool */
246 	boolean_t	spa_is_exporting;	/* true while exporting pool */
247 	kthread_t	*spa_export_thread;	/* valid during pool export */
248 	kthread_t	*spa_load_thread;	/* loading, no namespace lock */
249 	metaslab_class_t *spa_normal_class;	/* normal data class */
250 	metaslab_class_t *spa_log_class;	/* intent log data class */
251 	metaslab_class_t *spa_embedded_log_class; /* log on normal vdevs */
252 	metaslab_class_t *spa_special_class;	/* special allocation class */
253 	metaslab_class_t *spa_dedup_class;	/* dedup allocation class */
254 	uint64_t	spa_first_txg;		/* first txg after spa_open() */
255 	uint64_t	spa_final_txg;		/* txg of export/destroy */
256 	uint64_t	spa_freeze_txg;		/* freeze pool at this txg */
257 	uint64_t	spa_load_max_txg;	/* best initial ub_txg */
258 	uint64_t	spa_claim_max_txg;	/* highest claimed birth txg */
259 	inode_timespec_t spa_loaded_ts;		/* 1st successful open time */
260 	objset_t	*spa_meta_objset;	/* copy of dp->dp_meta_objset */
261 	kmutex_t	spa_evicting_os_lock;	/* Evicting objset list lock */
262 	list_t		spa_evicting_os_list;	/* Objsets being evicted. */
263 	kcondvar_t	spa_evicting_os_cv;	/* Objset Eviction Completion */
264 	txg_list_t	spa_vdev_txg_list;	/* per-txg dirty vdev list */
265 	vdev_t		*spa_root_vdev;		/* top-level vdev container */
266 	uint64_t	spa_min_ashift;		/* of vdevs in normal class */
267 	uint64_t	spa_max_ashift;		/* of vdevs in normal class */
268 	uint64_t	spa_min_alloc;		/* of vdevs in normal class */
269 	uint64_t	spa_gcd_alloc;		/* of vdevs in normal class */
270 	uint64_t	spa_config_guid;	/* config pool guid */
271 	uint64_t	spa_load_guid;		/* spa_load initialized guid */
272 	uint64_t	spa_last_synced_guid;	/* last synced guid */
273 	list_t		spa_config_dirty_list;	/* vdevs with dirty config */
274 	list_t		spa_state_dirty_list;	/* vdevs with dirty state */
275 	/*
276 	 * spa_allocs is an array, whose lengths is stored in spa_alloc_count.
277 	 * There is one tree and one lock for each allocator, to help improve
278 	 * allocation performance in write-heavy workloads.
279 	 */
280 	spa_alloc_t	*spa_allocs;
281 	spa_allocs_use_t *spa_allocs_use;
282 	int		spa_alloc_count;
283 	int		spa_active_allocator;	/* selectable allocator */
284 
285 	/* per-allocator sync thread taskqs */
286 	taskq_t		*spa_sync_tq;
287 	spa_syncthread_info_t *spa_syncthreads;
288 
289 	spa_aux_vdev_t	spa_spares;		/* hot spares */
290 	spa_aux_vdev_t	spa_l2cache;		/* L2ARC cache devices */
291 	boolean_t	spa_aux_sync_uber;	/* need to sync aux uber */
292 	nvlist_t	*spa_label_features;	/* Features for reading MOS */
293 	uint64_t	spa_config_object;	/* MOS object for pool config */
294 	uint64_t	spa_config_generation;	/* config generation number */
295 	uint64_t	spa_syncing_txg;	/* txg currently syncing */
296 	bpobj_t		spa_deferred_bpobj;	/* deferred-free bplist */
297 	bplist_t	spa_free_bplist[TXG_SIZE]; /* bplist of stuff to free */
298 	zio_cksum_salt_t spa_cksum_salt;	/* secret salt for cksum */
299 	/* checksum context templates */
300 	kmutex_t	spa_cksum_tmpls_lock;
301 	void		*spa_cksum_tmpls[ZIO_CHECKSUM_FUNCTIONS];
302 	uberblock_t	spa_ubsync;		/* last synced uberblock */
303 	uberblock_t	spa_uberblock;		/* current uberblock */
304 	boolean_t	spa_extreme_rewind;	/* rewind past deferred frees */
305 	kmutex_t	spa_scrub_lock;		/* resilver/scrub lock */
306 	uint64_t	spa_scrub_inflight;	/* in-flight scrub bytes */
307 
308 	/* in-flight verification bytes */
309 	uint64_t	spa_load_verify_bytes;
310 	kcondvar_t	spa_scrub_io_cv;	/* scrub I/O completion */
311 	uint8_t		spa_scrub_active;	/* active or suspended? */
312 	uint8_t		spa_scrub_type;		/* type of scrub we're doing */
313 	uint8_t		spa_scrub_finished;	/* indicator to rotate logs */
314 	uint8_t		spa_scrub_started;	/* started since last boot */
315 	uint8_t		spa_scrub_reopen;	/* scrub doing vdev_reopen */
316 	uint64_t	spa_scan_pass_start;	/* start time per pass/reboot */
317 	uint64_t	spa_scan_pass_scrub_pause; /* scrub pause time */
318 	uint64_t	spa_scan_pass_scrub_spent_paused; /* total paused */
319 	uint64_t	spa_scan_pass_exam;	/* examined bytes per pass */
320 	uint64_t	spa_scan_pass_issued;	/* issued bytes per pass */
321 
322 	/* error scrub pause time in milliseconds */
323 	uint64_t	spa_scan_pass_errorscrub_pause;
324 	/* total error scrub paused time in milliseconds */
325 	uint64_t	spa_scan_pass_errorscrub_spent_paused;
326 	/*
327 	 * We are in the middle of a resilver, and another resilver
328 	 * is needed once this one completes. This is set iff any
329 	 * vdev_resilver_deferred is set.
330 	 */
331 	boolean_t	spa_resilver_deferred;
332 	kmutex_t	spa_async_lock;		/* protect async state */
333 	kthread_t	*spa_async_thread;	/* thread doing async task */
334 	int		spa_async_suspended;	/* async tasks suspended */
335 	kcondvar_t	spa_async_cv;		/* wait for thread_exit() */
336 	uint16_t	spa_async_tasks;	/* async task mask */
337 	uint64_t	spa_missing_tvds;	/* unopenable tvds on load */
338 	uint64_t	spa_missing_tvds_allowed; /* allow loading spa? */
339 
340 	uint64_t	spa_nonallocating_dspace;
341 	spa_removing_phys_t spa_removing_phys;
342 	spa_vdev_removal_t *spa_vdev_removal;
343 
344 	spa_condensing_indirect_phys_t	spa_condensing_indirect_phys;
345 	spa_condensing_indirect_t	*spa_condensing_indirect;
346 	zthr_t		*spa_condense_zthr;	/* zthr doing condense. */
347 
348 	vdev_raidz_expand_t	*spa_raidz_expand;
349 	zthr_t		*spa_raidz_expand_zthr;
350 
351 	uint64_t	spa_checkpoint_txg;	/* the txg of the checkpoint */
352 	spa_checkpoint_info_t spa_checkpoint_info; /* checkpoint accounting */
353 	zthr_t		*spa_checkpoint_discard_zthr;
354 
355 	space_map_t	*spa_syncing_log_sm;	/* current log space map */
356 	avl_tree_t	spa_sm_logs_by_txg;
357 	kmutex_t	spa_flushed_ms_lock;	/* for metaslabs_by_flushed */
358 	avl_tree_t	spa_metaslabs_by_flushed;
359 	spa_unflushed_stats_t	spa_unflushed_stats;
360 	list_t		spa_log_summary;
361 	uint64_t	spa_log_flushall_txg;
362 
363 	zthr_t		*spa_livelist_delete_zthr; /* deleting livelists */
364 	zthr_t		*spa_livelist_condense_zthr; /* condensing livelists */
365 	uint64_t	spa_livelists_to_delete; /* set of livelists to free */
366 	livelist_condense_entry_t	spa_to_condense; /* next to condense */
367 
368 	char		*spa_root;		/* alternate root directory */
369 	uint64_t	spa_ena;		/* spa-wide ereport ENA */
370 	int		spa_last_open_failed;	/* error if last open failed */
371 	uint64_t	spa_last_ubsync_txg;	/* "best" uberblock txg */
372 	uint64_t	spa_last_ubsync_txg_ts;	/* timestamp from that ub */
373 	uint64_t	spa_load_txg;		/* ub txg that loaded */
374 	uint64_t	spa_load_txg_ts;	/* timestamp from that ub */
375 	uint64_t	spa_load_meta_errors;	/* verify metadata err count */
376 	uint64_t	spa_load_data_errors;	/* verify data err count */
377 	uint64_t	spa_verify_min_txg;	/* start txg of verify scrub */
378 	kmutex_t	spa_errlog_lock;	/* error log lock */
379 	uint64_t	spa_errlog_last;	/* last error log object */
380 	uint64_t	spa_errlog_scrub;	/* scrub error log object */
381 	kmutex_t	spa_errlist_lock;	/* error list/ereport lock */
382 	avl_tree_t	spa_errlist_last;	/* last error list */
383 	avl_tree_t	spa_errlist_scrub;	/* scrub error list */
384 	avl_tree_t	spa_errlist_healed;	/* list of healed blocks */
385 	uint64_t	spa_deflate;		/* should we deflate? */
386 	uint64_t	spa_history;		/* history object */
387 	kmutex_t	spa_history_lock;	/* history lock */
388 	vdev_t		*spa_pending_vdev;	/* pending vdev additions */
389 	kmutex_t	spa_props_lock;		/* property lock */
390 	uint64_t	spa_pool_props_object;	/* object for properties */
391 	uint64_t	spa_bootfs;		/* default boot filesystem */
392 	uint64_t	spa_failmode;		/* failure mode for the pool */
393 	uint64_t	spa_deadman_failmode;	/* failure mode for deadman */
394 	uint64_t	spa_delegation;		/* delegation on/off */
395 	list_t		spa_config_list;	/* previous cache file(s) */
396 	/* per-CPU array of root of async I/O: */
397 	zio_t		**spa_async_zio_root;
398 	zio_t		*spa_suspend_zio_root;	/* root of all suspended I/O */
399 	zio_t		*spa_txg_zio[TXG_SIZE]; /* spa_sync() waits for this */
400 	kmutex_t	spa_suspend_lock;	/* protects suspend_zio_root */
401 	kcondvar_t	spa_suspend_cv;		/* notification of resume */
402 	zio_suspend_reason_t	spa_suspended;	/* pool is suspended */
403 	uint8_t		spa_claiming;		/* pool is doing zil_claim() */
404 	boolean_t	spa_is_root;		/* pool is root */
405 	int		spa_minref;		/* num refs when first opened */
406 	spa_mode_t	spa_mode;		/* SPA_MODE_{READ|WRITE} */
407 	boolean_t	spa_read_spacemaps;	/* spacemaps available if ro */
408 	spa_log_state_t spa_log_state;		/* log state */
409 	uint64_t	spa_autoexpand;		/* lun expansion on/off */
410 	ddt_t		*spa_ddt[ZIO_CHECKSUM_FUNCTIONS]; /* in-core DDTs */
411 	uint64_t	spa_ddt_stat_object;	/* DDT statistics */
412 	uint64_t	spa_dedup_dspace;	/* Cache get_dedup_dspace() */
413 	uint64_t	spa_dedup_checksum;	/* default dedup checksum */
414 	uint64_t	spa_dspace;		/* dspace in normal class */
415 	boolean_t	spa_active_ddt_prune;	/* ddt prune process active */
416 	struct brt	*spa_brt;		/* in-core BRT */
417 	kmutex_t	spa_vdev_top_lock;	/* dueling offline/remove */
418 	kmutex_t	spa_proc_lock;		/* protects spa_proc* */
419 	kcondvar_t	spa_proc_cv;		/* spa_proc_state transitions */
420 	spa_proc_state_t spa_proc_state;	/* see definition */
421 	proc_t		*spa_proc;		/* "zpool-poolname" process */
422 	uintptr_t	spa_did;		/* if procp != p0, did of t1 */
423 	boolean_t	spa_autoreplace;	/* autoreplace set in open */
424 	int		spa_vdev_locks;		/* locks grabbed */
425 	uint64_t	spa_creation_version;	/* version at pool creation */
426 	uint64_t	spa_prev_software_version; /* See ub_software_version */
427 	uint64_t	spa_feat_for_write_obj;	/* required to write to pool */
428 	uint64_t	spa_feat_for_read_obj;	/* required to read from pool */
429 	uint64_t	spa_feat_desc_obj;	/* Feature descriptions */
430 	uint64_t	spa_feat_enabled_txg_obj; /* Feature enabled txg */
431 	kmutex_t	spa_feat_stats_lock;	/* protects spa_feat_stats */
432 	nvlist_t	*spa_feat_stats;	/* Cache of enabled features */
433 	/* cache feature refcounts */
434 	uint64_t	spa_feat_refcount_cache[SPA_FEATURES];
435 	taskqid_t	spa_deadman_tqid;	/* Task id */
436 	uint64_t	spa_deadman_calls;	/* number of deadman calls */
437 	hrtime_t	spa_sync_starttime;	/* starting time of spa_sync */
438 	uint64_t	spa_deadman_synctime;	/* deadman sync expiration */
439 	uint64_t	spa_deadman_ziotime;	/* deadman zio expiration */
440 	uint64_t	spa_all_vdev_zaps;	/* ZAP of per-vd ZAP obj #s */
441 	spa_avz_action_t	spa_avz_action;	/* destroy/rebuild AVZ? */
442 	uint64_t	spa_autotrim;		/* automatic background trim? */
443 	uint64_t	spa_errata;		/* errata issues detected */
444 	spa_stats_t	spa_stats;		/* assorted spa statistics */
445 	spa_keystore_t	spa_keystore;		/* loaded crypto keys */
446 
447 	/* arc_memory_throttle() parameters during low memory condition */
448 	uint64_t	spa_lowmem_page_load;	/* memory load during txg */
449 	uint64_t	spa_lowmem_last_txg;	/* txg window start */
450 
451 	hrtime_t	spa_ccw_fail_time;	/* Conf cache write fail time */
452 	taskq_t		*spa_zvol_taskq;	/* Taskq for minor management */
453 	taskq_t		*spa_metaslab_taskq;	/* Taskq for metaslab preload */
454 	taskq_t		*spa_prefetch_taskq;	/* Taskq for prefetch threads */
455 	taskq_t		*spa_upgrade_taskq;	/* Taskq for upgrade jobs */
456 	uint64_t	spa_multihost;		/* multihost aware (mmp) */
457 	mmp_thread_t	spa_mmp;		/* multihost mmp thread */
458 	list_t		spa_leaf_list;		/* list of leaf vdevs */
459 	uint64_t	spa_leaf_list_gen;	/* track leaf_list changes */
460 	uint32_t	spa_hostid;		/* cached system hostid */
461 
462 	/* synchronization for threads in spa_wait */
463 	kmutex_t	spa_activities_lock;
464 	kcondvar_t	spa_activities_cv;
465 	kcondvar_t	spa_waiters_cv;
466 	int		spa_waiters;		/* number of waiting threads */
467 	boolean_t	spa_waiters_cancel;	/* waiters should return */
468 
469 	char		*spa_compatibility;	/* compatibility file(s) */
470 	uint64_t	spa_dedup_table_quota;	/* property DDT maximum size */
471 	uint64_t	spa_dedup_dsize;	/* cached on-disk size of DDT */
472 	uint64_t	spa_dedup_class_full_txg; /* txg dedup class was full */
473 
474 	/*
475 	 * spa_refcount & spa_config_lock must be the last elements
476 	 * because zfs_refcount_t changes size based on compilation options.
477 	 * In order for the MDB module to function correctly, the other
478 	 * fields must remain in the same location.
479 	 */
480 	spa_config_lock_t spa_config_lock[SCL_LOCKS]; /* config changes */
481 	zfs_refcount_t	spa_refcount;		/* number of opens */
482 };
483 
484 extern char *spa_config_path;
485 extern const char *zfs_deadman_failmode;
486 extern uint_t spa_slop_shift;
487 extern void spa_taskq_dispatch(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
488     task_func_t *func, zio_t *zio, boolean_t cutinline);
489 extern void spa_load_spares(spa_t *spa);
490 extern void spa_load_l2cache(spa_t *spa);
491 extern sysevent_t *spa_event_create(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl,
492     const char *name);
493 extern void spa_event_post(sysevent_t *ev);
494 extern int param_set_deadman_failmode_common(const char *val);
495 extern void spa_set_deadman_synctime(hrtime_t ns);
496 extern void spa_set_deadman_ziotime(hrtime_t ns);
497 extern const char *spa_history_zone(void);
498 extern const char *zfs_active_allocator;
499 extern int param_set_active_allocator_common(const char *val);
500 
501 #ifdef	__cplusplus
502 }
503 #endif
504 
505 #endif	/* _SYS_SPA_IMPL_H */
506