xref: /freebsd/sys/contrib/openzfs/module/zfs/spa.c (revision ea9075959bf3a6e98d9638467500a690267f3947)
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 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
25  * Copyright (c) 2018, Nexenta Systems, Inc.  All rights reserved.
26  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
27  * Copyright 2013 Saso Kiselkov. All rights reserved.
28  * Copyright (c) 2014 Integros [integros.com]
29  * Copyright 2016 Toomas Soome <tsoome@me.com>
30  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
31  * Copyright 2018 Joyent, Inc.
32  * Copyright (c) 2017, 2019, Datto Inc. All rights reserved.
33  * Copyright 2017 Joyent, Inc.
34  * Copyright (c) 2017, Intel Corporation.
35  * Copyright (c) 2021, Colm Buckley <colm@tuatha.org>
36  */
37 
38 /*
39  * SPA: Storage Pool Allocator
40  *
41  * This file contains all the routines used when modifying on-disk SPA state.
42  * This includes opening, importing, destroying, exporting a pool, and syncing a
43  * pool.
44  */
45 
46 #include <sys/zfs_context.h>
47 #include <sys/fm/fs/zfs.h>
48 #include <sys/spa_impl.h>
49 #include <sys/zio.h>
50 #include <sys/zio_checksum.h>
51 #include <sys/dmu.h>
52 #include <sys/dmu_tx.h>
53 #include <sys/zap.h>
54 #include <sys/zil.h>
55 #include <sys/brt.h>
56 #include <sys/ddt.h>
57 #include <sys/vdev_impl.h>
58 #include <sys/vdev_removal.h>
59 #include <sys/vdev_indirect_mapping.h>
60 #include <sys/vdev_indirect_births.h>
61 #include <sys/vdev_initialize.h>
62 #include <sys/vdev_rebuild.h>
63 #include <sys/vdev_trim.h>
64 #include <sys/vdev_disk.h>
65 #include <sys/vdev_draid.h>
66 #include <sys/metaslab.h>
67 #include <sys/metaslab_impl.h>
68 #include <sys/mmp.h>
69 #include <sys/uberblock_impl.h>
70 #include <sys/txg.h>
71 #include <sys/avl.h>
72 #include <sys/bpobj.h>
73 #include <sys/dmu_traverse.h>
74 #include <sys/dmu_objset.h>
75 #include <sys/unique.h>
76 #include <sys/dsl_pool.h>
77 #include <sys/dsl_dataset.h>
78 #include <sys/dsl_dir.h>
79 #include <sys/dsl_prop.h>
80 #include <sys/dsl_synctask.h>
81 #include <sys/fs/zfs.h>
82 #include <sys/arc.h>
83 #include <sys/callb.h>
84 #include <sys/systeminfo.h>
85 #include <sys/zfs_ioctl.h>
86 #include <sys/dsl_scan.h>
87 #include <sys/zfeature.h>
88 #include <sys/dsl_destroy.h>
89 #include <sys/zvol.h>
90 
91 #ifdef	_KERNEL
92 #include <sys/fm/protocol.h>
93 #include <sys/fm/util.h>
94 #include <sys/callb.h>
95 #include <sys/zone.h>
96 #include <sys/vmsystm.h>
97 #endif	/* _KERNEL */
98 
99 #include "zfs_prop.h"
100 #include "zfs_comutil.h"
101 
102 /*
103  * The interval, in seconds, at which failed configuration cache file writes
104  * should be retried.
105  */
106 int zfs_ccw_retry_interval = 300;
107 
108 typedef enum zti_modes {
109 	ZTI_MODE_FIXED,			/* value is # of threads (min 1) */
110 	ZTI_MODE_BATCH,			/* cpu-intensive; value is ignored */
111 	ZTI_MODE_SCALE,			/* Taskqs scale with CPUs. */
112 	ZTI_MODE_NULL,			/* don't create a taskq */
113 	ZTI_NMODES
114 } zti_modes_t;
115 
116 #define	ZTI_P(n, q)	{ ZTI_MODE_FIXED, (n), (q) }
117 #define	ZTI_PCT(n)	{ ZTI_MODE_ONLINE_PERCENT, (n), 1 }
118 #define	ZTI_BATCH	{ ZTI_MODE_BATCH, 0, 1 }
119 #define	ZTI_SCALE	{ ZTI_MODE_SCALE, 0, 1 }
120 #define	ZTI_NULL	{ ZTI_MODE_NULL, 0, 0 }
121 
122 #define	ZTI_N(n)	ZTI_P(n, 1)
123 #define	ZTI_ONE		ZTI_N(1)
124 
125 typedef struct zio_taskq_info {
126 	zti_modes_t zti_mode;
127 	uint_t zti_value;
128 	uint_t zti_count;
129 } zio_taskq_info_t;
130 
131 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
132 	"iss", "iss_h", "int", "int_h"
133 };
134 
135 /*
136  * This table defines the taskq settings for each ZFS I/O type. When
137  * initializing a pool, we use this table to create an appropriately sized
138  * taskq. Some operations are low volume and therefore have a small, static
139  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
140  * macros. Other operations process a large amount of data; the ZTI_BATCH
141  * macro causes us to create a taskq oriented for throughput. Some operations
142  * are so high frequency and short-lived that the taskq itself can become a
143  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
144  * additional degree of parallelism specified by the number of threads per-
145  * taskq and the number of taskqs; when dispatching an event in this case, the
146  * particular taskq is chosen at random. ZTI_SCALE is similar to ZTI_BATCH,
147  * but with number of taskqs also scaling with number of CPUs.
148  *
149  * The different taskq priorities are to handle the different contexts (issue
150  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
151  * need to be handled with minimum delay.
152  */
153 static const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
154 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
155 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* NULL */
156 	{ ZTI_N(8),	ZTI_NULL,	ZTI_SCALE,	ZTI_NULL }, /* READ */
157 	{ ZTI_BATCH,	ZTI_N(5),	ZTI_SCALE,	ZTI_N(5) }, /* WRITE */
158 	{ ZTI_SCALE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FREE */
159 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* CLAIM */
160 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* IOCTL */
161 	{ ZTI_N(4),	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* TRIM */
162 };
163 
164 static void spa_sync_version(void *arg, dmu_tx_t *tx);
165 static void spa_sync_props(void *arg, dmu_tx_t *tx);
166 static boolean_t spa_has_active_shared_spare(spa_t *spa);
167 static int spa_load_impl(spa_t *spa, spa_import_type_t type,
168     const char **ereport);
169 static void spa_vdev_resilver_done(spa_t *spa);
170 
171 static uint_t	zio_taskq_batch_pct = 80;	  /* 1 thread per cpu in pset */
172 static uint_t	zio_taskq_batch_tpq;		  /* threads per taskq */
173 static const boolean_t	zio_taskq_sysdc = B_TRUE; /* use SDC scheduling class */
174 static const uint_t	zio_taskq_basedc = 80;	  /* base duty cycle */
175 
176 static const boolean_t spa_create_process = B_TRUE; /* no process => no sysdc */
177 
178 /*
179  * Report any spa_load_verify errors found, but do not fail spa_load.
180  * This is used by zdb to analyze non-idle pools.
181  */
182 boolean_t	spa_load_verify_dryrun = B_FALSE;
183 
184 /*
185  * Allow read spacemaps in case of readonly import (spa_mode == SPA_MODE_READ).
186  * This is used by zdb for spacemaps verification.
187  */
188 boolean_t	spa_mode_readable_spacemaps = B_FALSE;
189 
190 /*
191  * This (illegal) pool name is used when temporarily importing a spa_t in order
192  * to get the vdev stats associated with the imported devices.
193  */
194 #define	TRYIMPORT_NAME	"$import"
195 
196 /*
197  * For debugging purposes: print out vdev tree during pool import.
198  */
199 static int		spa_load_print_vdev_tree = B_FALSE;
200 
201 /*
202  * A non-zero value for zfs_max_missing_tvds means that we allow importing
203  * pools with missing top-level vdevs. This is strictly intended for advanced
204  * pool recovery cases since missing data is almost inevitable. Pools with
205  * missing devices can only be imported read-only for safety reasons, and their
206  * fail-mode will be automatically set to "continue".
207  *
208  * With 1 missing vdev we should be able to import the pool and mount all
209  * datasets. User data that was not modified after the missing device has been
210  * added should be recoverable. This means that snapshots created prior to the
211  * addition of that device should be completely intact.
212  *
213  * With 2 missing vdevs, some datasets may fail to mount since there are
214  * dataset statistics that are stored as regular metadata. Some data might be
215  * recoverable if those vdevs were added recently.
216  *
217  * With 3 or more missing vdevs, the pool is severely damaged and MOS entries
218  * may be missing entirely. Chances of data recovery are very low. Note that
219  * there are also risks of performing an inadvertent rewind as we might be
220  * missing all the vdevs with the latest uberblocks.
221  */
222 uint64_t	zfs_max_missing_tvds = 0;
223 
224 /*
225  * The parameters below are similar to zfs_max_missing_tvds but are only
226  * intended for a preliminary open of the pool with an untrusted config which
227  * might be incomplete or out-dated.
228  *
229  * We are more tolerant for pools opened from a cachefile since we could have
230  * an out-dated cachefile where a device removal was not registered.
231  * We could have set the limit arbitrarily high but in the case where devices
232  * are really missing we would want to return the proper error codes; we chose
233  * SPA_DVAS_PER_BP - 1 so that some copies of the MOS would still be available
234  * and we get a chance to retrieve the trusted config.
235  */
236 uint64_t	zfs_max_missing_tvds_cachefile = SPA_DVAS_PER_BP - 1;
237 
238 /*
239  * In the case where config was assembled by scanning device paths (/dev/dsks
240  * by default) we are less tolerant since all the existing devices should have
241  * been detected and we want spa_load to return the right error codes.
242  */
243 uint64_t	zfs_max_missing_tvds_scan = 0;
244 
245 /*
246  * Debugging aid that pauses spa_sync() towards the end.
247  */
248 static const boolean_t	zfs_pause_spa_sync = B_FALSE;
249 
250 /*
251  * Variables to indicate the livelist condense zthr func should wait at certain
252  * points for the livelist to be removed - used to test condense/destroy races
253  */
254 static int zfs_livelist_condense_zthr_pause = 0;
255 static int zfs_livelist_condense_sync_pause = 0;
256 
257 /*
258  * Variables to track whether or not condense cancellation has been
259  * triggered in testing.
260  */
261 static int zfs_livelist_condense_sync_cancel = 0;
262 static int zfs_livelist_condense_zthr_cancel = 0;
263 
264 /*
265  * Variable to track whether or not extra ALLOC blkptrs were added to a
266  * livelist entry while it was being condensed (caused by the way we track
267  * remapped blkptrs in dbuf_remap_impl)
268  */
269 static int zfs_livelist_condense_new_alloc = 0;
270 
271 /*
272  * ==========================================================================
273  * SPA properties routines
274  * ==========================================================================
275  */
276 
277 /*
278  * Add a (source=src, propname=propval) list to an nvlist.
279  */
280 static void
281 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, const char *strval,
282     uint64_t intval, zprop_source_t src)
283 {
284 	const char *propname = zpool_prop_to_name(prop);
285 	nvlist_t *propval;
286 
287 	propval = fnvlist_alloc();
288 	fnvlist_add_uint64(propval, ZPROP_SOURCE, src);
289 
290 	if (strval != NULL)
291 		fnvlist_add_string(propval, ZPROP_VALUE, strval);
292 	else
293 		fnvlist_add_uint64(propval, ZPROP_VALUE, intval);
294 
295 	fnvlist_add_nvlist(nvl, propname, propval);
296 	nvlist_free(propval);
297 }
298 
299 /*
300  * Add a user property (source=src, propname=propval) to an nvlist.
301  */
302 static void
303 spa_prop_add_user(nvlist_t *nvl, const char *propname, char *strval,
304     zprop_source_t src)
305 {
306 	nvlist_t *propval;
307 
308 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
309 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
310 	VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
311 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
312 	nvlist_free(propval);
313 }
314 
315 /*
316  * Get property values from the spa configuration.
317  */
318 static void
319 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
320 {
321 	vdev_t *rvd = spa->spa_root_vdev;
322 	dsl_pool_t *pool = spa->spa_dsl_pool;
323 	uint64_t size, alloc, cap, version;
324 	const zprop_source_t src = ZPROP_SRC_NONE;
325 	spa_config_dirent_t *dp;
326 	metaslab_class_t *mc = spa_normal_class(spa);
327 
328 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
329 
330 	if (rvd != NULL) {
331 		alloc = metaslab_class_get_alloc(mc);
332 		alloc += metaslab_class_get_alloc(spa_special_class(spa));
333 		alloc += metaslab_class_get_alloc(spa_dedup_class(spa));
334 		alloc += metaslab_class_get_alloc(spa_embedded_log_class(spa));
335 
336 		size = metaslab_class_get_space(mc);
337 		size += metaslab_class_get_space(spa_special_class(spa));
338 		size += metaslab_class_get_space(spa_dedup_class(spa));
339 		size += metaslab_class_get_space(spa_embedded_log_class(spa));
340 
341 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
342 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
343 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
344 		spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
345 		    size - alloc, src);
346 		spa_prop_add_list(*nvp, ZPOOL_PROP_CHECKPOINT, NULL,
347 		    spa->spa_checkpoint_info.sci_dspace, src);
348 
349 		spa_prop_add_list(*nvp, ZPOOL_PROP_FRAGMENTATION, NULL,
350 		    metaslab_class_fragmentation(mc), src);
351 		spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL,
352 		    metaslab_class_expandable_space(mc), src);
353 		spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
354 		    (spa_mode(spa) == SPA_MODE_READ), src);
355 
356 		cap = (size == 0) ? 0 : (alloc * 100 / size);
357 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
358 
359 		spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
360 		    ddt_get_pool_dedup_ratio(spa), src);
361 		spa_prop_add_list(*nvp, ZPOOL_PROP_BCLONEUSED, NULL,
362 		    brt_get_used(spa), src);
363 		spa_prop_add_list(*nvp, ZPOOL_PROP_BCLONESAVED, NULL,
364 		    brt_get_saved(spa), src);
365 		spa_prop_add_list(*nvp, ZPOOL_PROP_BCLONERATIO, NULL,
366 		    brt_get_ratio(spa), src);
367 
368 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
369 		    rvd->vdev_state, src);
370 
371 		version = spa_version(spa);
372 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION)) {
373 			spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL,
374 			    version, ZPROP_SRC_DEFAULT);
375 		} else {
376 			spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL,
377 			    version, ZPROP_SRC_LOCAL);
378 		}
379 		spa_prop_add_list(*nvp, ZPOOL_PROP_LOAD_GUID,
380 		    NULL, spa_load_guid(spa), src);
381 	}
382 
383 	if (pool != NULL) {
384 		/*
385 		 * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
386 		 * when opening pools before this version freedir will be NULL.
387 		 */
388 		if (pool->dp_free_dir != NULL) {
389 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
390 			    dsl_dir_phys(pool->dp_free_dir)->dd_used_bytes,
391 			    src);
392 		} else {
393 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
394 			    NULL, 0, src);
395 		}
396 
397 		if (pool->dp_leak_dir != NULL) {
398 			spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED, NULL,
399 			    dsl_dir_phys(pool->dp_leak_dir)->dd_used_bytes,
400 			    src);
401 		} else {
402 			spa_prop_add_list(*nvp, ZPOOL_PROP_LEAKED,
403 			    NULL, 0, src);
404 		}
405 	}
406 
407 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
408 
409 	if (spa->spa_comment != NULL) {
410 		spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
411 		    0, ZPROP_SRC_LOCAL);
412 	}
413 
414 	if (spa->spa_compatibility != NULL) {
415 		spa_prop_add_list(*nvp, ZPOOL_PROP_COMPATIBILITY,
416 		    spa->spa_compatibility, 0, ZPROP_SRC_LOCAL);
417 	}
418 
419 	if (spa->spa_root != NULL)
420 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
421 		    0, ZPROP_SRC_LOCAL);
422 
423 	if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) {
424 		spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
425 		    MIN(zfs_max_recordsize, SPA_MAXBLOCKSIZE), ZPROP_SRC_NONE);
426 	} else {
427 		spa_prop_add_list(*nvp, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
428 		    SPA_OLD_MAXBLOCKSIZE, ZPROP_SRC_NONE);
429 	}
430 
431 	if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_DNODE)) {
432 		spa_prop_add_list(*nvp, ZPOOL_PROP_MAXDNODESIZE, NULL,
433 		    DNODE_MAX_SIZE, ZPROP_SRC_NONE);
434 	} else {
435 		spa_prop_add_list(*nvp, ZPOOL_PROP_MAXDNODESIZE, NULL,
436 		    DNODE_MIN_SIZE, ZPROP_SRC_NONE);
437 	}
438 
439 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
440 		if (dp->scd_path == NULL) {
441 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
442 			    "none", 0, ZPROP_SRC_LOCAL);
443 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
444 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
445 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
446 		}
447 	}
448 }
449 
450 /*
451  * Get zpool property values.
452  */
453 int
454 spa_prop_get(spa_t *spa, nvlist_t **nvp)
455 {
456 	objset_t *mos = spa->spa_meta_objset;
457 	zap_cursor_t zc;
458 	zap_attribute_t za;
459 	dsl_pool_t *dp;
460 	int err;
461 
462 	err = nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP);
463 	if (err)
464 		return (err);
465 
466 	dp = spa_get_dsl(spa);
467 	dsl_pool_config_enter(dp, FTAG);
468 	mutex_enter(&spa->spa_props_lock);
469 
470 	/*
471 	 * Get properties from the spa config.
472 	 */
473 	spa_prop_get_config(spa, nvp);
474 
475 	/* If no pool property object, no more prop to get. */
476 	if (mos == NULL || spa->spa_pool_props_object == 0)
477 		goto out;
478 
479 	/*
480 	 * Get properties from the MOS pool property object.
481 	 */
482 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
483 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
484 	    zap_cursor_advance(&zc)) {
485 		uint64_t intval = 0;
486 		char *strval = NULL;
487 		zprop_source_t src = ZPROP_SRC_DEFAULT;
488 		zpool_prop_t prop;
489 
490 		if ((prop = zpool_name_to_prop(za.za_name)) ==
491 		    ZPOOL_PROP_INVAL && !zfs_prop_user(za.za_name))
492 			continue;
493 
494 		switch (za.za_integer_length) {
495 		case 8:
496 			/* integer property */
497 			if (za.za_first_integer !=
498 			    zpool_prop_default_numeric(prop))
499 				src = ZPROP_SRC_LOCAL;
500 
501 			if (prop == ZPOOL_PROP_BOOTFS) {
502 				dsl_dataset_t *ds = NULL;
503 
504 				err = dsl_dataset_hold_obj(dp,
505 				    za.za_first_integer, FTAG, &ds);
506 				if (err != 0)
507 					break;
508 
509 				strval = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN,
510 				    KM_SLEEP);
511 				dsl_dataset_name(ds, strval);
512 				dsl_dataset_rele(ds, FTAG);
513 			} else {
514 				strval = NULL;
515 				intval = za.za_first_integer;
516 			}
517 
518 			spa_prop_add_list(*nvp, prop, strval, intval, src);
519 
520 			if (strval != NULL)
521 				kmem_free(strval, ZFS_MAX_DATASET_NAME_LEN);
522 
523 			break;
524 
525 		case 1:
526 			/* string property */
527 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
528 			err = zap_lookup(mos, spa->spa_pool_props_object,
529 			    za.za_name, 1, za.za_num_integers, strval);
530 			if (err) {
531 				kmem_free(strval, za.za_num_integers);
532 				break;
533 			}
534 			if (prop != ZPOOL_PROP_INVAL) {
535 				spa_prop_add_list(*nvp, prop, strval, 0, src);
536 			} else {
537 				src = ZPROP_SRC_LOCAL;
538 				spa_prop_add_user(*nvp, za.za_name, strval,
539 				    src);
540 			}
541 			kmem_free(strval, za.za_num_integers);
542 			break;
543 
544 		default:
545 			break;
546 		}
547 	}
548 	zap_cursor_fini(&zc);
549 out:
550 	mutex_exit(&spa->spa_props_lock);
551 	dsl_pool_config_exit(dp, FTAG);
552 	if (err && err != ENOENT) {
553 		nvlist_free(*nvp);
554 		*nvp = NULL;
555 		return (err);
556 	}
557 
558 	return (0);
559 }
560 
561 /*
562  * Validate the given pool properties nvlist and modify the list
563  * for the property values to be set.
564  */
565 static int
566 spa_prop_validate(spa_t *spa, nvlist_t *props)
567 {
568 	nvpair_t *elem;
569 	int error = 0, reset_bootfs = 0;
570 	uint64_t objnum = 0;
571 	boolean_t has_feature = B_FALSE;
572 
573 	elem = NULL;
574 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
575 		uint64_t intval;
576 		const char *strval, *slash, *check, *fname;
577 		const char *propname = nvpair_name(elem);
578 		zpool_prop_t prop = zpool_name_to_prop(propname);
579 
580 		switch (prop) {
581 		case ZPOOL_PROP_INVAL:
582 			/*
583 			 * Sanitize the input.
584 			 */
585 			if (zfs_prop_user(propname)) {
586 				if (strlen(propname) >= ZAP_MAXNAMELEN) {
587 					error = SET_ERROR(ENAMETOOLONG);
588 					break;
589 				}
590 
591 				if (strlen(fnvpair_value_string(elem)) >=
592 				    ZAP_MAXVALUELEN) {
593 					error = SET_ERROR(E2BIG);
594 					break;
595 				}
596 			} else if (zpool_prop_feature(propname)) {
597 				if (nvpair_type(elem) != DATA_TYPE_UINT64) {
598 					error = SET_ERROR(EINVAL);
599 					break;
600 				}
601 
602 				if (nvpair_value_uint64(elem, &intval) != 0) {
603 					error = SET_ERROR(EINVAL);
604 					break;
605 				}
606 
607 				if (intval != 0) {
608 					error = SET_ERROR(EINVAL);
609 					break;
610 				}
611 
612 				fname = strchr(propname, '@') + 1;
613 				if (zfeature_lookup_name(fname, NULL) != 0) {
614 					error = SET_ERROR(EINVAL);
615 					break;
616 				}
617 
618 				has_feature = B_TRUE;
619 			} else {
620 				error = SET_ERROR(EINVAL);
621 				break;
622 			}
623 			break;
624 
625 		case ZPOOL_PROP_VERSION:
626 			error = nvpair_value_uint64(elem, &intval);
627 			if (!error &&
628 			    (intval < spa_version(spa) ||
629 			    intval > SPA_VERSION_BEFORE_FEATURES ||
630 			    has_feature))
631 				error = SET_ERROR(EINVAL);
632 			break;
633 
634 		case ZPOOL_PROP_DELEGATION:
635 		case ZPOOL_PROP_AUTOREPLACE:
636 		case ZPOOL_PROP_LISTSNAPS:
637 		case ZPOOL_PROP_AUTOEXPAND:
638 		case ZPOOL_PROP_AUTOTRIM:
639 			error = nvpair_value_uint64(elem, &intval);
640 			if (!error && intval > 1)
641 				error = SET_ERROR(EINVAL);
642 			break;
643 
644 		case ZPOOL_PROP_MULTIHOST:
645 			error = nvpair_value_uint64(elem, &intval);
646 			if (!error && intval > 1)
647 				error = SET_ERROR(EINVAL);
648 
649 			if (!error) {
650 				uint32_t hostid = zone_get_hostid(NULL);
651 				if (hostid)
652 					spa->spa_hostid = hostid;
653 				else
654 					error = SET_ERROR(ENOTSUP);
655 			}
656 
657 			break;
658 
659 		case ZPOOL_PROP_BOOTFS:
660 			/*
661 			 * If the pool version is less than SPA_VERSION_BOOTFS,
662 			 * or the pool is still being created (version == 0),
663 			 * the bootfs property cannot be set.
664 			 */
665 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
666 				error = SET_ERROR(ENOTSUP);
667 				break;
668 			}
669 
670 			/*
671 			 * Make sure the vdev config is bootable
672 			 */
673 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
674 				error = SET_ERROR(ENOTSUP);
675 				break;
676 			}
677 
678 			reset_bootfs = 1;
679 
680 			error = nvpair_value_string(elem, &strval);
681 
682 			if (!error) {
683 				objset_t *os;
684 
685 				if (strval == NULL || strval[0] == '\0') {
686 					objnum = zpool_prop_default_numeric(
687 					    ZPOOL_PROP_BOOTFS);
688 					break;
689 				}
690 
691 				error = dmu_objset_hold(strval, FTAG, &os);
692 				if (error != 0)
693 					break;
694 
695 				/* Must be ZPL. */
696 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
697 					error = SET_ERROR(ENOTSUP);
698 				} else {
699 					objnum = dmu_objset_id(os);
700 				}
701 				dmu_objset_rele(os, FTAG);
702 			}
703 			break;
704 
705 		case ZPOOL_PROP_FAILUREMODE:
706 			error = nvpair_value_uint64(elem, &intval);
707 			if (!error && intval > ZIO_FAILURE_MODE_PANIC)
708 				error = SET_ERROR(EINVAL);
709 
710 			/*
711 			 * This is a special case which only occurs when
712 			 * the pool has completely failed. This allows
713 			 * the user to change the in-core failmode property
714 			 * without syncing it out to disk (I/Os might
715 			 * currently be blocked). We do this by returning
716 			 * EIO to the caller (spa_prop_set) to trick it
717 			 * into thinking we encountered a property validation
718 			 * error.
719 			 */
720 			if (!error && spa_suspended(spa)) {
721 				spa->spa_failmode = intval;
722 				error = SET_ERROR(EIO);
723 			}
724 			break;
725 
726 		case ZPOOL_PROP_CACHEFILE:
727 			if ((error = nvpair_value_string(elem, &strval)) != 0)
728 				break;
729 
730 			if (strval[0] == '\0')
731 				break;
732 
733 			if (strcmp(strval, "none") == 0)
734 				break;
735 
736 			if (strval[0] != '/') {
737 				error = SET_ERROR(EINVAL);
738 				break;
739 			}
740 
741 			slash = strrchr(strval, '/');
742 			ASSERT(slash != NULL);
743 
744 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
745 			    strcmp(slash, "/..") == 0)
746 				error = SET_ERROR(EINVAL);
747 			break;
748 
749 		case ZPOOL_PROP_COMMENT:
750 			if ((error = nvpair_value_string(elem, &strval)) != 0)
751 				break;
752 			for (check = strval; *check != '\0'; check++) {
753 				if (!isprint(*check)) {
754 					error = SET_ERROR(EINVAL);
755 					break;
756 				}
757 			}
758 			if (strlen(strval) > ZPROP_MAX_COMMENT)
759 				error = SET_ERROR(E2BIG);
760 			break;
761 
762 		default:
763 			break;
764 		}
765 
766 		if (error)
767 			break;
768 	}
769 
770 	(void) nvlist_remove_all(props,
771 	    zpool_prop_to_name(ZPOOL_PROP_DEDUPDITTO));
772 
773 	if (!error && reset_bootfs) {
774 		error = nvlist_remove(props,
775 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
776 
777 		if (!error) {
778 			error = nvlist_add_uint64(props,
779 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
780 		}
781 	}
782 
783 	return (error);
784 }
785 
786 void
787 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
788 {
789 	const char *cachefile;
790 	spa_config_dirent_t *dp;
791 
792 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
793 	    &cachefile) != 0)
794 		return;
795 
796 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
797 	    KM_SLEEP);
798 
799 	if (cachefile[0] == '\0')
800 		dp->scd_path = spa_strdup(spa_config_path);
801 	else if (strcmp(cachefile, "none") == 0)
802 		dp->scd_path = NULL;
803 	else
804 		dp->scd_path = spa_strdup(cachefile);
805 
806 	list_insert_head(&spa->spa_config_list, dp);
807 	if (need_sync)
808 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
809 }
810 
811 int
812 spa_prop_set(spa_t *spa, nvlist_t *nvp)
813 {
814 	int error;
815 	nvpair_t *elem = NULL;
816 	boolean_t need_sync = B_FALSE;
817 
818 	if ((error = spa_prop_validate(spa, nvp)) != 0)
819 		return (error);
820 
821 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
822 		zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
823 
824 		if (prop == ZPOOL_PROP_CACHEFILE ||
825 		    prop == ZPOOL_PROP_ALTROOT ||
826 		    prop == ZPOOL_PROP_READONLY)
827 			continue;
828 
829 		if (prop == ZPOOL_PROP_INVAL &&
830 		    zfs_prop_user(nvpair_name(elem))) {
831 			need_sync = B_TRUE;
832 			break;
833 		}
834 
835 		if (prop == ZPOOL_PROP_VERSION || prop == ZPOOL_PROP_INVAL) {
836 			uint64_t ver = 0;
837 
838 			if (prop == ZPOOL_PROP_VERSION) {
839 				VERIFY(nvpair_value_uint64(elem, &ver) == 0);
840 			} else {
841 				ASSERT(zpool_prop_feature(nvpair_name(elem)));
842 				ver = SPA_VERSION_FEATURES;
843 				need_sync = B_TRUE;
844 			}
845 
846 			/* Save time if the version is already set. */
847 			if (ver == spa_version(spa))
848 				continue;
849 
850 			/*
851 			 * In addition to the pool directory object, we might
852 			 * create the pool properties object, the features for
853 			 * read object, the features for write object, or the
854 			 * feature descriptions object.
855 			 */
856 			error = dsl_sync_task(spa->spa_name, NULL,
857 			    spa_sync_version, &ver,
858 			    6, ZFS_SPACE_CHECK_RESERVED);
859 			if (error)
860 				return (error);
861 			continue;
862 		}
863 
864 		need_sync = B_TRUE;
865 		break;
866 	}
867 
868 	if (need_sync) {
869 		return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
870 		    nvp, 6, ZFS_SPACE_CHECK_RESERVED));
871 	}
872 
873 	return (0);
874 }
875 
876 /*
877  * If the bootfs property value is dsobj, clear it.
878  */
879 void
880 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
881 {
882 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
883 		VERIFY(zap_remove(spa->spa_meta_objset,
884 		    spa->spa_pool_props_object,
885 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
886 		spa->spa_bootfs = 0;
887 	}
888 }
889 
890 static int
891 spa_change_guid_check(void *arg, dmu_tx_t *tx)
892 {
893 	uint64_t *newguid __maybe_unused = arg;
894 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
895 	vdev_t *rvd = spa->spa_root_vdev;
896 	uint64_t vdev_state;
897 
898 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
899 		int error = (spa_has_checkpoint(spa)) ?
900 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
901 		return (SET_ERROR(error));
902 	}
903 
904 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
905 	vdev_state = rvd->vdev_state;
906 	spa_config_exit(spa, SCL_STATE, FTAG);
907 
908 	if (vdev_state != VDEV_STATE_HEALTHY)
909 		return (SET_ERROR(ENXIO));
910 
911 	ASSERT3U(spa_guid(spa), !=, *newguid);
912 
913 	return (0);
914 }
915 
916 static void
917 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
918 {
919 	uint64_t *newguid = arg;
920 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
921 	uint64_t oldguid;
922 	vdev_t *rvd = spa->spa_root_vdev;
923 
924 	oldguid = spa_guid(spa);
925 
926 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
927 	rvd->vdev_guid = *newguid;
928 	rvd->vdev_guid_sum += (*newguid - oldguid);
929 	vdev_config_dirty(rvd);
930 	spa_config_exit(spa, SCL_STATE, FTAG);
931 
932 	spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
933 	    (u_longlong_t)oldguid, (u_longlong_t)*newguid);
934 }
935 
936 /*
937  * Change the GUID for the pool.  This is done so that we can later
938  * re-import a pool built from a clone of our own vdevs.  We will modify
939  * the root vdev's guid, our own pool guid, and then mark all of our
940  * vdevs dirty.  Note that we must make sure that all our vdevs are
941  * online when we do this, or else any vdevs that weren't present
942  * would be orphaned from our pool.  We are also going to issue a
943  * sysevent to update any watchers.
944  */
945 int
946 spa_change_guid(spa_t *spa)
947 {
948 	int error;
949 	uint64_t guid;
950 
951 	mutex_enter(&spa->spa_vdev_top_lock);
952 	mutex_enter(&spa_namespace_lock);
953 	guid = spa_generate_guid(NULL);
954 
955 	error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
956 	    spa_change_guid_sync, &guid, 5, ZFS_SPACE_CHECK_RESERVED);
957 
958 	if (error == 0) {
959 		/*
960 		 * Clear the kobj flag from all the vdevs to allow
961 		 * vdev_cache_process_kobj_evt() to post events to all the
962 		 * vdevs since GUID is updated.
963 		 */
964 		vdev_clear_kobj_evt(spa->spa_root_vdev);
965 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
966 			vdev_clear_kobj_evt(spa->spa_l2cache.sav_vdevs[i]);
967 
968 		spa_write_cachefile(spa, B_FALSE, B_TRUE, B_TRUE);
969 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_REGUID);
970 	}
971 
972 	mutex_exit(&spa_namespace_lock);
973 	mutex_exit(&spa->spa_vdev_top_lock);
974 
975 	return (error);
976 }
977 
978 /*
979  * ==========================================================================
980  * SPA state manipulation (open/create/destroy/import/export)
981  * ==========================================================================
982  */
983 
984 static int
985 spa_error_entry_compare(const void *a, const void *b)
986 {
987 	const spa_error_entry_t *sa = (const spa_error_entry_t *)a;
988 	const spa_error_entry_t *sb = (const spa_error_entry_t *)b;
989 	int ret;
990 
991 	ret = memcmp(&sa->se_bookmark, &sb->se_bookmark,
992 	    sizeof (zbookmark_phys_t));
993 
994 	return (TREE_ISIGN(ret));
995 }
996 
997 /*
998  * Utility function which retrieves copies of the current logs and
999  * re-initializes them in the process.
1000  */
1001 void
1002 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
1003 {
1004 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
1005 
1006 	memcpy(last, &spa->spa_errlist_last, sizeof (avl_tree_t));
1007 	memcpy(scrub, &spa->spa_errlist_scrub, sizeof (avl_tree_t));
1008 
1009 	avl_create(&spa->spa_errlist_scrub,
1010 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1011 	    offsetof(spa_error_entry_t, se_avl));
1012 	avl_create(&spa->spa_errlist_last,
1013 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1014 	    offsetof(spa_error_entry_t, se_avl));
1015 }
1016 
1017 static void
1018 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
1019 {
1020 	const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
1021 	enum zti_modes mode = ztip->zti_mode;
1022 	uint_t value = ztip->zti_value;
1023 	uint_t count = ztip->zti_count;
1024 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1025 	uint_t cpus, flags = TASKQ_DYNAMIC;
1026 	boolean_t batch = B_FALSE;
1027 
1028 	switch (mode) {
1029 	case ZTI_MODE_FIXED:
1030 		ASSERT3U(value, >, 0);
1031 		break;
1032 
1033 	case ZTI_MODE_BATCH:
1034 		batch = B_TRUE;
1035 		flags |= TASKQ_THREADS_CPU_PCT;
1036 		value = MIN(zio_taskq_batch_pct, 100);
1037 		break;
1038 
1039 	case ZTI_MODE_SCALE:
1040 		flags |= TASKQ_THREADS_CPU_PCT;
1041 		/*
1042 		 * We want more taskqs to reduce lock contention, but we want
1043 		 * less for better request ordering and CPU utilization.
1044 		 */
1045 		cpus = MAX(1, boot_ncpus * zio_taskq_batch_pct / 100);
1046 		if (zio_taskq_batch_tpq > 0) {
1047 			count = MAX(1, (cpus + zio_taskq_batch_tpq / 2) /
1048 			    zio_taskq_batch_tpq);
1049 		} else {
1050 			/*
1051 			 * Prefer 6 threads per taskq, but no more taskqs
1052 			 * than threads in them on large systems. For 80%:
1053 			 *
1054 			 *                 taskq   taskq   total
1055 			 * cpus    taskqs  percent threads threads
1056 			 * ------- ------- ------- ------- -------
1057 			 * 1       1       80%     1       1
1058 			 * 2       1       80%     1       1
1059 			 * 4       1       80%     3       3
1060 			 * 8       2       40%     3       6
1061 			 * 16      3       27%     4       12
1062 			 * 32      5       16%     5       25
1063 			 * 64      7       11%     7       49
1064 			 * 128     10      8%      10      100
1065 			 * 256     14      6%      15      210
1066 			 */
1067 			count = 1 + cpus / 6;
1068 			while (count * count > cpus)
1069 				count--;
1070 		}
1071 		/* Limit each taskq within 100% to not trigger assertion. */
1072 		count = MAX(count, (zio_taskq_batch_pct + 99) / 100);
1073 		value = (zio_taskq_batch_pct + count / 2) / count;
1074 		break;
1075 
1076 	case ZTI_MODE_NULL:
1077 		tqs->stqs_count = 0;
1078 		tqs->stqs_taskq = NULL;
1079 		return;
1080 
1081 	default:
1082 		panic("unrecognized mode for %s_%s taskq (%u:%u) in "
1083 		    "spa_activate()",
1084 		    zio_type_name[t], zio_taskq_types[q], mode, value);
1085 		break;
1086 	}
1087 
1088 	ASSERT3U(count, >, 0);
1089 	tqs->stqs_count = count;
1090 	tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
1091 
1092 	for (uint_t i = 0; i < count; i++) {
1093 		taskq_t *tq;
1094 		char name[32];
1095 
1096 		if (count > 1)
1097 			(void) snprintf(name, sizeof (name), "%s_%s_%u",
1098 			    zio_type_name[t], zio_taskq_types[q], i);
1099 		else
1100 			(void) snprintf(name, sizeof (name), "%s_%s",
1101 			    zio_type_name[t], zio_taskq_types[q]);
1102 
1103 		if (zio_taskq_sysdc && spa->spa_proc != &p0) {
1104 			if (batch)
1105 				flags |= TASKQ_DC_BATCH;
1106 
1107 			(void) zio_taskq_basedc;
1108 			tq = taskq_create_sysdc(name, value, 50, INT_MAX,
1109 			    spa->spa_proc, zio_taskq_basedc, flags);
1110 		} else {
1111 			pri_t pri = maxclsyspri;
1112 			/*
1113 			 * The write issue taskq can be extremely CPU
1114 			 * intensive.  Run it at slightly less important
1115 			 * priority than the other taskqs.
1116 			 *
1117 			 * Under Linux and FreeBSD this means incrementing
1118 			 * the priority value as opposed to platforms like
1119 			 * illumos where it should be decremented.
1120 			 *
1121 			 * On FreeBSD, if priorities divided by four (RQ_PPQ)
1122 			 * are equal then a difference between them is
1123 			 * insignificant.
1124 			 */
1125 			if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE) {
1126 #if defined(__linux__)
1127 				pri++;
1128 #elif defined(__FreeBSD__)
1129 				pri += 4;
1130 #else
1131 #error "unknown OS"
1132 #endif
1133 			}
1134 			tq = taskq_create_proc(name, value, pri, 50,
1135 			    INT_MAX, spa->spa_proc, flags);
1136 		}
1137 
1138 		tqs->stqs_taskq[i] = tq;
1139 	}
1140 }
1141 
1142 static void
1143 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
1144 {
1145 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1146 
1147 	if (tqs->stqs_taskq == NULL) {
1148 		ASSERT3U(tqs->stqs_count, ==, 0);
1149 		return;
1150 	}
1151 
1152 	for (uint_t i = 0; i < tqs->stqs_count; i++) {
1153 		ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
1154 		taskq_destroy(tqs->stqs_taskq[i]);
1155 	}
1156 
1157 	kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
1158 	tqs->stqs_taskq = NULL;
1159 }
1160 
1161 /*
1162  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
1163  * Note that a type may have multiple discrete taskqs to avoid lock contention
1164  * on the taskq itself. In that case we choose which taskq at random by using
1165  * the low bits of gethrtime().
1166  */
1167 void
1168 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
1169     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
1170 {
1171 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1172 	taskq_t *tq;
1173 
1174 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
1175 	ASSERT3U(tqs->stqs_count, !=, 0);
1176 
1177 	if (tqs->stqs_count == 1) {
1178 		tq = tqs->stqs_taskq[0];
1179 	} else {
1180 		tq = tqs->stqs_taskq[((uint64_t)gethrtime()) % tqs->stqs_count];
1181 	}
1182 
1183 	taskq_dispatch_ent(tq, func, arg, flags, ent);
1184 }
1185 
1186 /*
1187  * Same as spa_taskq_dispatch_ent() but block on the task until completion.
1188  */
1189 void
1190 spa_taskq_dispatch_sync(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
1191     task_func_t *func, void *arg, uint_t flags)
1192 {
1193 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1194 	taskq_t *tq;
1195 	taskqid_t id;
1196 
1197 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
1198 	ASSERT3U(tqs->stqs_count, !=, 0);
1199 
1200 	if (tqs->stqs_count == 1) {
1201 		tq = tqs->stqs_taskq[0];
1202 	} else {
1203 		tq = tqs->stqs_taskq[((uint64_t)gethrtime()) % tqs->stqs_count];
1204 	}
1205 
1206 	id = taskq_dispatch(tq, func, arg, flags);
1207 	if (id)
1208 		taskq_wait_id(tq, id);
1209 }
1210 
1211 static void
1212 spa_create_zio_taskqs(spa_t *spa)
1213 {
1214 	for (int t = 0; t < ZIO_TYPES; t++) {
1215 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1216 			spa_taskqs_init(spa, t, q);
1217 		}
1218 	}
1219 }
1220 
1221 /*
1222  * Disabled until spa_thread() can be adapted for Linux.
1223  */
1224 #undef HAVE_SPA_THREAD
1225 
1226 #if defined(_KERNEL) && defined(HAVE_SPA_THREAD)
1227 static void
1228 spa_thread(void *arg)
1229 {
1230 	psetid_t zio_taskq_psrset_bind = PS_NONE;
1231 	callb_cpr_t cprinfo;
1232 
1233 	spa_t *spa = arg;
1234 	user_t *pu = PTOU(curproc);
1235 
1236 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
1237 	    spa->spa_name);
1238 
1239 	ASSERT(curproc != &p0);
1240 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
1241 	    "zpool-%s", spa->spa_name);
1242 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
1243 
1244 	/* bind this thread to the requested psrset */
1245 	if (zio_taskq_psrset_bind != PS_NONE) {
1246 		pool_lock();
1247 		mutex_enter(&cpu_lock);
1248 		mutex_enter(&pidlock);
1249 		mutex_enter(&curproc->p_lock);
1250 
1251 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
1252 		    0, NULL, NULL) == 0)  {
1253 			curthread->t_bind_pset = zio_taskq_psrset_bind;
1254 		} else {
1255 			cmn_err(CE_WARN,
1256 			    "Couldn't bind process for zfs pool \"%s\" to "
1257 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
1258 		}
1259 
1260 		mutex_exit(&curproc->p_lock);
1261 		mutex_exit(&pidlock);
1262 		mutex_exit(&cpu_lock);
1263 		pool_unlock();
1264 	}
1265 
1266 	if (zio_taskq_sysdc) {
1267 		sysdc_thread_enter(curthread, 100, 0);
1268 	}
1269 
1270 	spa->spa_proc = curproc;
1271 	spa->spa_did = curthread->t_did;
1272 
1273 	spa_create_zio_taskqs(spa);
1274 
1275 	mutex_enter(&spa->spa_proc_lock);
1276 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1277 
1278 	spa->spa_proc_state = SPA_PROC_ACTIVE;
1279 	cv_broadcast(&spa->spa_proc_cv);
1280 
1281 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
1282 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1283 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1284 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1285 
1286 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1287 	spa->spa_proc_state = SPA_PROC_GONE;
1288 	spa->spa_proc = &p0;
1289 	cv_broadcast(&spa->spa_proc_cv);
1290 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
1291 
1292 	mutex_enter(&curproc->p_lock);
1293 	lwp_exit();
1294 }
1295 #endif
1296 
1297 /*
1298  * Activate an uninitialized pool.
1299  */
1300 static void
1301 spa_activate(spa_t *spa, spa_mode_t mode)
1302 {
1303 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1304 
1305 	spa->spa_state = POOL_STATE_ACTIVE;
1306 	spa->spa_mode = mode;
1307 	spa->spa_read_spacemaps = spa_mode_readable_spacemaps;
1308 
1309 	spa->spa_normal_class = metaslab_class_create(spa, &zfs_metaslab_ops);
1310 	spa->spa_log_class = metaslab_class_create(spa, &zfs_metaslab_ops);
1311 	spa->spa_embedded_log_class =
1312 	    metaslab_class_create(spa, &zfs_metaslab_ops);
1313 	spa->spa_special_class = metaslab_class_create(spa, &zfs_metaslab_ops);
1314 	spa->spa_dedup_class = metaslab_class_create(spa, &zfs_metaslab_ops);
1315 
1316 	/* Try to create a covering process */
1317 	mutex_enter(&spa->spa_proc_lock);
1318 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1319 	ASSERT(spa->spa_proc == &p0);
1320 	spa->spa_did = 0;
1321 
1322 	(void) spa_create_process;
1323 #ifdef HAVE_SPA_THREAD
1324 	/* Only create a process if we're going to be around a while. */
1325 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1326 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1327 		    NULL, 0) == 0) {
1328 			spa->spa_proc_state = SPA_PROC_CREATED;
1329 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
1330 				cv_wait(&spa->spa_proc_cv,
1331 				    &spa->spa_proc_lock);
1332 			}
1333 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1334 			ASSERT(spa->spa_proc != &p0);
1335 			ASSERT(spa->spa_did != 0);
1336 		} else {
1337 #ifdef _KERNEL
1338 			cmn_err(CE_WARN,
1339 			    "Couldn't create process for zfs pool \"%s\"\n",
1340 			    spa->spa_name);
1341 #endif
1342 		}
1343 	}
1344 #endif /* HAVE_SPA_THREAD */
1345 	mutex_exit(&spa->spa_proc_lock);
1346 
1347 	/* If we didn't create a process, we need to create our taskqs. */
1348 	if (spa->spa_proc == &p0) {
1349 		spa_create_zio_taskqs(spa);
1350 	}
1351 
1352 	for (size_t i = 0; i < TXG_SIZE; i++) {
1353 		spa->spa_txg_zio[i] = zio_root(spa, NULL, NULL,
1354 		    ZIO_FLAG_CANFAIL);
1355 	}
1356 
1357 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1358 	    offsetof(vdev_t, vdev_config_dirty_node));
1359 	list_create(&spa->spa_evicting_os_list, sizeof (objset_t),
1360 	    offsetof(objset_t, os_evicting_node));
1361 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1362 	    offsetof(vdev_t, vdev_state_dirty_node));
1363 
1364 	txg_list_create(&spa->spa_vdev_txg_list, spa,
1365 	    offsetof(struct vdev, vdev_txg_node));
1366 
1367 	avl_create(&spa->spa_errlist_scrub,
1368 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1369 	    offsetof(spa_error_entry_t, se_avl));
1370 	avl_create(&spa->spa_errlist_last,
1371 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1372 	    offsetof(spa_error_entry_t, se_avl));
1373 	avl_create(&spa->spa_errlist_healed,
1374 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1375 	    offsetof(spa_error_entry_t, se_avl));
1376 
1377 	spa_activate_os(spa);
1378 
1379 	spa_keystore_init(&spa->spa_keystore);
1380 
1381 	/*
1382 	 * This taskq is used to perform zvol-minor-related tasks
1383 	 * asynchronously. This has several advantages, including easy
1384 	 * resolution of various deadlocks.
1385 	 *
1386 	 * The taskq must be single threaded to ensure tasks are always
1387 	 * processed in the order in which they were dispatched.
1388 	 *
1389 	 * A taskq per pool allows one to keep the pools independent.
1390 	 * This way if one pool is suspended, it will not impact another.
1391 	 *
1392 	 * The preferred location to dispatch a zvol minor task is a sync
1393 	 * task. In this context, there is easy access to the spa_t and minimal
1394 	 * error handling is required because the sync task must succeed.
1395 	 */
1396 	spa->spa_zvol_taskq = taskq_create("z_zvol", 1, defclsyspri,
1397 	    1, INT_MAX, 0);
1398 
1399 	/*
1400 	 * Taskq dedicated to prefetcher threads: this is used to prevent the
1401 	 * pool traverse code from monopolizing the global (and limited)
1402 	 * system_taskq by inappropriately scheduling long running tasks on it.
1403 	 */
1404 	spa->spa_prefetch_taskq = taskq_create("z_prefetch", 100,
1405 	    defclsyspri, 1, INT_MAX, TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT);
1406 
1407 	/*
1408 	 * The taskq to upgrade datasets in this pool. Currently used by
1409 	 * feature SPA_FEATURE_USEROBJ_ACCOUNTING/SPA_FEATURE_PROJECT_QUOTA.
1410 	 */
1411 	spa->spa_upgrade_taskq = taskq_create("z_upgrade", 100,
1412 	    defclsyspri, 1, INT_MAX, TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT);
1413 }
1414 
1415 /*
1416  * Opposite of spa_activate().
1417  */
1418 static void
1419 spa_deactivate(spa_t *spa)
1420 {
1421 	ASSERT(spa->spa_sync_on == B_FALSE);
1422 	ASSERT(spa->spa_dsl_pool == NULL);
1423 	ASSERT(spa->spa_root_vdev == NULL);
1424 	ASSERT(spa->spa_async_zio_root == NULL);
1425 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1426 
1427 	spa_evicting_os_wait(spa);
1428 
1429 	if (spa->spa_zvol_taskq) {
1430 		taskq_destroy(spa->spa_zvol_taskq);
1431 		spa->spa_zvol_taskq = NULL;
1432 	}
1433 
1434 	if (spa->spa_prefetch_taskq) {
1435 		taskq_destroy(spa->spa_prefetch_taskq);
1436 		spa->spa_prefetch_taskq = NULL;
1437 	}
1438 
1439 	if (spa->spa_upgrade_taskq) {
1440 		taskq_destroy(spa->spa_upgrade_taskq);
1441 		spa->spa_upgrade_taskq = NULL;
1442 	}
1443 
1444 	txg_list_destroy(&spa->spa_vdev_txg_list);
1445 
1446 	list_destroy(&spa->spa_config_dirty_list);
1447 	list_destroy(&spa->spa_evicting_os_list);
1448 	list_destroy(&spa->spa_state_dirty_list);
1449 
1450 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
1451 
1452 	for (int t = 0; t < ZIO_TYPES; t++) {
1453 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1454 			spa_taskqs_fini(spa, t, q);
1455 		}
1456 	}
1457 
1458 	for (size_t i = 0; i < TXG_SIZE; i++) {
1459 		ASSERT3P(spa->spa_txg_zio[i], !=, NULL);
1460 		VERIFY0(zio_wait(spa->spa_txg_zio[i]));
1461 		spa->spa_txg_zio[i] = NULL;
1462 	}
1463 
1464 	metaslab_class_destroy(spa->spa_normal_class);
1465 	spa->spa_normal_class = NULL;
1466 
1467 	metaslab_class_destroy(spa->spa_log_class);
1468 	spa->spa_log_class = NULL;
1469 
1470 	metaslab_class_destroy(spa->spa_embedded_log_class);
1471 	spa->spa_embedded_log_class = NULL;
1472 
1473 	metaslab_class_destroy(spa->spa_special_class);
1474 	spa->spa_special_class = NULL;
1475 
1476 	metaslab_class_destroy(spa->spa_dedup_class);
1477 	spa->spa_dedup_class = NULL;
1478 
1479 	/*
1480 	 * If this was part of an import or the open otherwise failed, we may
1481 	 * still have errors left in the queues.  Empty them just in case.
1482 	 */
1483 	spa_errlog_drain(spa);
1484 	avl_destroy(&spa->spa_errlist_scrub);
1485 	avl_destroy(&spa->spa_errlist_last);
1486 	avl_destroy(&spa->spa_errlist_healed);
1487 
1488 	spa_keystore_fini(&spa->spa_keystore);
1489 
1490 	spa->spa_state = POOL_STATE_UNINITIALIZED;
1491 
1492 	mutex_enter(&spa->spa_proc_lock);
1493 	if (spa->spa_proc_state != SPA_PROC_NONE) {
1494 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1495 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1496 		cv_broadcast(&spa->spa_proc_cv);
1497 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1498 			ASSERT(spa->spa_proc != &p0);
1499 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1500 		}
1501 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1502 		spa->spa_proc_state = SPA_PROC_NONE;
1503 	}
1504 	ASSERT(spa->spa_proc == &p0);
1505 	mutex_exit(&spa->spa_proc_lock);
1506 
1507 	/*
1508 	 * We want to make sure spa_thread() has actually exited the ZFS
1509 	 * module, so that the module can't be unloaded out from underneath
1510 	 * it.
1511 	 */
1512 	if (spa->spa_did != 0) {
1513 		thread_join(spa->spa_did);
1514 		spa->spa_did = 0;
1515 	}
1516 
1517 	spa_deactivate_os(spa);
1518 
1519 }
1520 
1521 /*
1522  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1523  * will create all the necessary vdevs in the appropriate layout, with each vdev
1524  * in the CLOSED state.  This will prep the pool before open/creation/import.
1525  * All vdev validation is done by the vdev_alloc() routine.
1526  */
1527 int
1528 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1529     uint_t id, int atype)
1530 {
1531 	nvlist_t **child;
1532 	uint_t children;
1533 	int error;
1534 
1535 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1536 		return (error);
1537 
1538 	if ((*vdp)->vdev_ops->vdev_op_leaf)
1539 		return (0);
1540 
1541 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1542 	    &child, &children);
1543 
1544 	if (error == ENOENT)
1545 		return (0);
1546 
1547 	if (error) {
1548 		vdev_free(*vdp);
1549 		*vdp = NULL;
1550 		return (SET_ERROR(EINVAL));
1551 	}
1552 
1553 	for (int c = 0; c < children; c++) {
1554 		vdev_t *vd;
1555 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1556 		    atype)) != 0) {
1557 			vdev_free(*vdp);
1558 			*vdp = NULL;
1559 			return (error);
1560 		}
1561 	}
1562 
1563 	ASSERT(*vdp != NULL);
1564 
1565 	return (0);
1566 }
1567 
1568 static boolean_t
1569 spa_should_flush_logs_on_unload(spa_t *spa)
1570 {
1571 	if (!spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))
1572 		return (B_FALSE);
1573 
1574 	if (!spa_writeable(spa))
1575 		return (B_FALSE);
1576 
1577 	if (!spa->spa_sync_on)
1578 		return (B_FALSE);
1579 
1580 	if (spa_state(spa) != POOL_STATE_EXPORTED)
1581 		return (B_FALSE);
1582 
1583 	if (zfs_keep_log_spacemaps_at_export)
1584 		return (B_FALSE);
1585 
1586 	return (B_TRUE);
1587 }
1588 
1589 /*
1590  * Opens a transaction that will set the flag that will instruct
1591  * spa_sync to attempt to flush all the metaslabs for that txg.
1592  */
1593 static void
1594 spa_unload_log_sm_flush_all(spa_t *spa)
1595 {
1596 	dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
1597 	VERIFY0(dmu_tx_assign(tx, TXG_WAIT));
1598 
1599 	ASSERT3U(spa->spa_log_flushall_txg, ==, 0);
1600 	spa->spa_log_flushall_txg = dmu_tx_get_txg(tx);
1601 
1602 	dmu_tx_commit(tx);
1603 	txg_wait_synced(spa_get_dsl(spa), spa->spa_log_flushall_txg);
1604 }
1605 
1606 static void
1607 spa_unload_log_sm_metadata(spa_t *spa)
1608 {
1609 	void *cookie = NULL;
1610 	spa_log_sm_t *sls;
1611 	while ((sls = avl_destroy_nodes(&spa->spa_sm_logs_by_txg,
1612 	    &cookie)) != NULL) {
1613 		VERIFY0(sls->sls_mscount);
1614 		kmem_free(sls, sizeof (spa_log_sm_t));
1615 	}
1616 
1617 	for (log_summary_entry_t *e = list_head(&spa->spa_log_summary);
1618 	    e != NULL; e = list_head(&spa->spa_log_summary)) {
1619 		VERIFY0(e->lse_mscount);
1620 		list_remove(&spa->spa_log_summary, e);
1621 		kmem_free(e, sizeof (log_summary_entry_t));
1622 	}
1623 
1624 	spa->spa_unflushed_stats.sus_nblocks = 0;
1625 	spa->spa_unflushed_stats.sus_memused = 0;
1626 	spa->spa_unflushed_stats.sus_blocklimit = 0;
1627 }
1628 
1629 static void
1630 spa_destroy_aux_threads(spa_t *spa)
1631 {
1632 	if (spa->spa_condense_zthr != NULL) {
1633 		zthr_destroy(spa->spa_condense_zthr);
1634 		spa->spa_condense_zthr = NULL;
1635 	}
1636 	if (spa->spa_checkpoint_discard_zthr != NULL) {
1637 		zthr_destroy(spa->spa_checkpoint_discard_zthr);
1638 		spa->spa_checkpoint_discard_zthr = NULL;
1639 	}
1640 	if (spa->spa_livelist_delete_zthr != NULL) {
1641 		zthr_destroy(spa->spa_livelist_delete_zthr);
1642 		spa->spa_livelist_delete_zthr = NULL;
1643 	}
1644 	if (spa->spa_livelist_condense_zthr != NULL) {
1645 		zthr_destroy(spa->spa_livelist_condense_zthr);
1646 		spa->spa_livelist_condense_zthr = NULL;
1647 	}
1648 }
1649 
1650 /*
1651  * Opposite of spa_load().
1652  */
1653 static void
1654 spa_unload(spa_t *spa)
1655 {
1656 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1657 	ASSERT(spa_state(spa) != POOL_STATE_UNINITIALIZED);
1658 
1659 	spa_import_progress_remove(spa_guid(spa));
1660 	spa_load_note(spa, "UNLOADING");
1661 
1662 	spa_wake_waiters(spa);
1663 
1664 	/*
1665 	 * If we have set the spa_final_txg, we have already performed the
1666 	 * tasks below in spa_export_common(). We should not redo it here since
1667 	 * we delay the final TXGs beyond what spa_final_txg is set at.
1668 	 */
1669 	if (spa->spa_final_txg == UINT64_MAX) {
1670 		/*
1671 		 * If the log space map feature is enabled and the pool is
1672 		 * getting exported (but not destroyed), we want to spend some
1673 		 * time flushing as many metaslabs as we can in an attempt to
1674 		 * destroy log space maps and save import time.
1675 		 */
1676 		if (spa_should_flush_logs_on_unload(spa))
1677 			spa_unload_log_sm_flush_all(spa);
1678 
1679 		/*
1680 		 * Stop async tasks.
1681 		 */
1682 		spa_async_suspend(spa);
1683 
1684 		if (spa->spa_root_vdev) {
1685 			vdev_t *root_vdev = spa->spa_root_vdev;
1686 			vdev_initialize_stop_all(root_vdev,
1687 			    VDEV_INITIALIZE_ACTIVE);
1688 			vdev_trim_stop_all(root_vdev, VDEV_TRIM_ACTIVE);
1689 			vdev_autotrim_stop_all(spa);
1690 			vdev_rebuild_stop_all(spa);
1691 		}
1692 	}
1693 
1694 	/*
1695 	 * Stop syncing.
1696 	 */
1697 	if (spa->spa_sync_on) {
1698 		txg_sync_stop(spa->spa_dsl_pool);
1699 		spa->spa_sync_on = B_FALSE;
1700 	}
1701 
1702 	/*
1703 	 * This ensures that there is no async metaslab prefetching
1704 	 * while we attempt to unload the spa.
1705 	 */
1706 	if (spa->spa_root_vdev != NULL) {
1707 		for (int c = 0; c < spa->spa_root_vdev->vdev_children; c++) {
1708 			vdev_t *vc = spa->spa_root_vdev->vdev_child[c];
1709 			if (vc->vdev_mg != NULL)
1710 				taskq_wait(vc->vdev_mg->mg_taskq);
1711 		}
1712 	}
1713 
1714 	if (spa->spa_mmp.mmp_thread)
1715 		mmp_thread_stop(spa);
1716 
1717 	/*
1718 	 * Wait for any outstanding async I/O to complete.
1719 	 */
1720 	if (spa->spa_async_zio_root != NULL) {
1721 		for (int i = 0; i < max_ncpus; i++)
1722 			(void) zio_wait(spa->spa_async_zio_root[i]);
1723 		kmem_free(spa->spa_async_zio_root, max_ncpus * sizeof (void *));
1724 		spa->spa_async_zio_root = NULL;
1725 	}
1726 
1727 	if (spa->spa_vdev_removal != NULL) {
1728 		spa_vdev_removal_destroy(spa->spa_vdev_removal);
1729 		spa->spa_vdev_removal = NULL;
1730 	}
1731 
1732 	spa_destroy_aux_threads(spa);
1733 
1734 	spa_condense_fini(spa);
1735 
1736 	bpobj_close(&spa->spa_deferred_bpobj);
1737 
1738 	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
1739 
1740 	/*
1741 	 * Close all vdevs.
1742 	 */
1743 	if (spa->spa_root_vdev)
1744 		vdev_free(spa->spa_root_vdev);
1745 	ASSERT(spa->spa_root_vdev == NULL);
1746 
1747 	/*
1748 	 * Close the dsl pool.
1749 	 */
1750 	if (spa->spa_dsl_pool) {
1751 		dsl_pool_close(spa->spa_dsl_pool);
1752 		spa->spa_dsl_pool = NULL;
1753 		spa->spa_meta_objset = NULL;
1754 	}
1755 
1756 	ddt_unload(spa);
1757 	brt_unload(spa);
1758 	spa_unload_log_sm_metadata(spa);
1759 
1760 	/*
1761 	 * Drop and purge level 2 cache
1762 	 */
1763 	spa_l2cache_drop(spa);
1764 
1765 	if (spa->spa_spares.sav_vdevs) {
1766 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
1767 			vdev_free(spa->spa_spares.sav_vdevs[i]);
1768 		kmem_free(spa->spa_spares.sav_vdevs,
1769 		    spa->spa_spares.sav_count * sizeof (void *));
1770 		spa->spa_spares.sav_vdevs = NULL;
1771 	}
1772 	if (spa->spa_spares.sav_config) {
1773 		nvlist_free(spa->spa_spares.sav_config);
1774 		spa->spa_spares.sav_config = NULL;
1775 	}
1776 	spa->spa_spares.sav_count = 0;
1777 
1778 	if (spa->spa_l2cache.sav_vdevs) {
1779 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++) {
1780 			vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1781 			vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1782 		}
1783 		kmem_free(spa->spa_l2cache.sav_vdevs,
1784 		    spa->spa_l2cache.sav_count * sizeof (void *));
1785 		spa->spa_l2cache.sav_vdevs = NULL;
1786 	}
1787 	if (spa->spa_l2cache.sav_config) {
1788 		nvlist_free(spa->spa_l2cache.sav_config);
1789 		spa->spa_l2cache.sav_config = NULL;
1790 	}
1791 	spa->spa_l2cache.sav_count = 0;
1792 
1793 	spa->spa_async_suspended = 0;
1794 
1795 	spa->spa_indirect_vdevs_loaded = B_FALSE;
1796 
1797 	if (spa->spa_comment != NULL) {
1798 		spa_strfree(spa->spa_comment);
1799 		spa->spa_comment = NULL;
1800 	}
1801 	if (spa->spa_compatibility != NULL) {
1802 		spa_strfree(spa->spa_compatibility);
1803 		spa->spa_compatibility = NULL;
1804 	}
1805 
1806 	spa_config_exit(spa, SCL_ALL, spa);
1807 }
1808 
1809 /*
1810  * Load (or re-load) the current list of vdevs describing the active spares for
1811  * this pool.  When this is called, we have some form of basic information in
1812  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1813  * then re-generate a more complete list including status information.
1814  */
1815 void
1816 spa_load_spares(spa_t *spa)
1817 {
1818 	nvlist_t **spares;
1819 	uint_t nspares;
1820 	int i;
1821 	vdev_t *vd, *tvd;
1822 
1823 #ifndef _KERNEL
1824 	/*
1825 	 * zdb opens both the current state of the pool and the
1826 	 * checkpointed state (if present), with a different spa_t.
1827 	 *
1828 	 * As spare vdevs are shared among open pools, we skip loading
1829 	 * them when we load the checkpointed state of the pool.
1830 	 */
1831 	if (!spa_writeable(spa))
1832 		return;
1833 #endif
1834 
1835 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1836 
1837 	/*
1838 	 * First, close and free any existing spare vdevs.
1839 	 */
1840 	if (spa->spa_spares.sav_vdevs) {
1841 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
1842 			vd = spa->spa_spares.sav_vdevs[i];
1843 
1844 			/* Undo the call to spa_activate() below */
1845 			if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1846 			    B_FALSE)) != NULL && tvd->vdev_isspare)
1847 				spa_spare_remove(tvd);
1848 			vdev_close(vd);
1849 			vdev_free(vd);
1850 		}
1851 
1852 		kmem_free(spa->spa_spares.sav_vdevs,
1853 		    spa->spa_spares.sav_count * sizeof (void *));
1854 	}
1855 
1856 	if (spa->spa_spares.sav_config == NULL)
1857 		nspares = 0;
1858 	else
1859 		VERIFY0(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1860 		    ZPOOL_CONFIG_SPARES, &spares, &nspares));
1861 
1862 	spa->spa_spares.sav_count = (int)nspares;
1863 	spa->spa_spares.sav_vdevs = NULL;
1864 
1865 	if (nspares == 0)
1866 		return;
1867 
1868 	/*
1869 	 * Construct the array of vdevs, opening them to get status in the
1870 	 * process.   For each spare, there is potentially two different vdev_t
1871 	 * structures associated with it: one in the list of spares (used only
1872 	 * for basic validation purposes) and one in the active vdev
1873 	 * configuration (if it's spared in).  During this phase we open and
1874 	 * validate each vdev on the spare list.  If the vdev also exists in the
1875 	 * active configuration, then we also mark this vdev as an active spare.
1876 	 */
1877 	spa->spa_spares.sav_vdevs = kmem_zalloc(nspares * sizeof (void *),
1878 	    KM_SLEEP);
1879 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1880 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1881 		    VDEV_ALLOC_SPARE) == 0);
1882 		ASSERT(vd != NULL);
1883 
1884 		spa->spa_spares.sav_vdevs[i] = vd;
1885 
1886 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1887 		    B_FALSE)) != NULL) {
1888 			if (!tvd->vdev_isspare)
1889 				spa_spare_add(tvd);
1890 
1891 			/*
1892 			 * We only mark the spare active if we were successfully
1893 			 * able to load the vdev.  Otherwise, importing a pool
1894 			 * with a bad active spare would result in strange
1895 			 * behavior, because multiple pool would think the spare
1896 			 * is actively in use.
1897 			 *
1898 			 * There is a vulnerability here to an equally bizarre
1899 			 * circumstance, where a dead active spare is later
1900 			 * brought back to life (onlined or otherwise).  Given
1901 			 * the rarity of this scenario, and the extra complexity
1902 			 * it adds, we ignore the possibility.
1903 			 */
1904 			if (!vdev_is_dead(tvd))
1905 				spa_spare_activate(tvd);
1906 		}
1907 
1908 		vd->vdev_top = vd;
1909 		vd->vdev_aux = &spa->spa_spares;
1910 
1911 		if (vdev_open(vd) != 0)
1912 			continue;
1913 
1914 		if (vdev_validate_aux(vd) == 0)
1915 			spa_spare_add(vd);
1916 	}
1917 
1918 	/*
1919 	 * Recompute the stashed list of spares, with status information
1920 	 * this time.
1921 	 */
1922 	fnvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES);
1923 
1924 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1925 	    KM_SLEEP);
1926 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1927 		spares[i] = vdev_config_generate(spa,
1928 		    spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1929 	fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
1930 	    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
1931 	    spa->spa_spares.sav_count);
1932 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1933 		nvlist_free(spares[i]);
1934 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1935 }
1936 
1937 /*
1938  * Load (or re-load) the current list of vdevs describing the active l2cache for
1939  * this pool.  When this is called, we have some form of basic information in
1940  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1941  * then re-generate a more complete list including status information.
1942  * Devices which are already active have their details maintained, and are
1943  * not re-opened.
1944  */
1945 void
1946 spa_load_l2cache(spa_t *spa)
1947 {
1948 	nvlist_t **l2cache = NULL;
1949 	uint_t nl2cache;
1950 	int i, j, oldnvdevs;
1951 	uint64_t guid;
1952 	vdev_t *vd, **oldvdevs, **newvdevs;
1953 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1954 
1955 #ifndef _KERNEL
1956 	/*
1957 	 * zdb opens both the current state of the pool and the
1958 	 * checkpointed state (if present), with a different spa_t.
1959 	 *
1960 	 * As L2 caches are part of the ARC which is shared among open
1961 	 * pools, we skip loading them when we load the checkpointed
1962 	 * state of the pool.
1963 	 */
1964 	if (!spa_writeable(spa))
1965 		return;
1966 #endif
1967 
1968 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1969 
1970 	oldvdevs = sav->sav_vdevs;
1971 	oldnvdevs = sav->sav_count;
1972 	sav->sav_vdevs = NULL;
1973 	sav->sav_count = 0;
1974 
1975 	if (sav->sav_config == NULL) {
1976 		nl2cache = 0;
1977 		newvdevs = NULL;
1978 		goto out;
1979 	}
1980 
1981 	VERIFY0(nvlist_lookup_nvlist_array(sav->sav_config,
1982 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache));
1983 	newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1984 
1985 	/*
1986 	 * Process new nvlist of vdevs.
1987 	 */
1988 	for (i = 0; i < nl2cache; i++) {
1989 		guid = fnvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID);
1990 
1991 		newvdevs[i] = NULL;
1992 		for (j = 0; j < oldnvdevs; j++) {
1993 			vd = oldvdevs[j];
1994 			if (vd != NULL && guid == vd->vdev_guid) {
1995 				/*
1996 				 * Retain previous vdev for add/remove ops.
1997 				 */
1998 				newvdevs[i] = vd;
1999 				oldvdevs[j] = NULL;
2000 				break;
2001 			}
2002 		}
2003 
2004 		if (newvdevs[i] == NULL) {
2005 			/*
2006 			 * Create new vdev
2007 			 */
2008 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
2009 			    VDEV_ALLOC_L2CACHE) == 0);
2010 			ASSERT(vd != NULL);
2011 			newvdevs[i] = vd;
2012 
2013 			/*
2014 			 * Commit this vdev as an l2cache device,
2015 			 * even if it fails to open.
2016 			 */
2017 			spa_l2cache_add(vd);
2018 
2019 			vd->vdev_top = vd;
2020 			vd->vdev_aux = sav;
2021 
2022 			spa_l2cache_activate(vd);
2023 
2024 			if (vdev_open(vd) != 0)
2025 				continue;
2026 
2027 			(void) vdev_validate_aux(vd);
2028 
2029 			if (!vdev_is_dead(vd))
2030 				l2arc_add_vdev(spa, vd);
2031 
2032 			/*
2033 			 * Upon cache device addition to a pool or pool
2034 			 * creation with a cache device or if the header
2035 			 * of the device is invalid we issue an async
2036 			 * TRIM command for the whole device which will
2037 			 * execute if l2arc_trim_ahead > 0.
2038 			 */
2039 			spa_async_request(spa, SPA_ASYNC_L2CACHE_TRIM);
2040 		}
2041 	}
2042 
2043 	sav->sav_vdevs = newvdevs;
2044 	sav->sav_count = (int)nl2cache;
2045 
2046 	/*
2047 	 * Recompute the stashed list of l2cache devices, with status
2048 	 * information this time.
2049 	 */
2050 	fnvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE);
2051 
2052 	if (sav->sav_count > 0)
2053 		l2cache = kmem_alloc(sav->sav_count * sizeof (void *),
2054 		    KM_SLEEP);
2055 	for (i = 0; i < sav->sav_count; i++)
2056 		l2cache[i] = vdev_config_generate(spa,
2057 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
2058 	fnvlist_add_nvlist_array(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
2059 	    (const nvlist_t * const *)l2cache, sav->sav_count);
2060 
2061 out:
2062 	/*
2063 	 * Purge vdevs that were dropped
2064 	 */
2065 	if (oldvdevs) {
2066 		for (i = 0; i < oldnvdevs; i++) {
2067 			uint64_t pool;
2068 
2069 			vd = oldvdevs[i];
2070 			if (vd != NULL) {
2071 				ASSERT(vd->vdev_isl2cache);
2072 
2073 				if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
2074 				    pool != 0ULL && l2arc_vdev_present(vd))
2075 					l2arc_remove_vdev(vd);
2076 				vdev_clear_stats(vd);
2077 				vdev_free(vd);
2078 			}
2079 		}
2080 
2081 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
2082 	}
2083 
2084 	for (i = 0; i < sav->sav_count; i++)
2085 		nvlist_free(l2cache[i]);
2086 	if (sav->sav_count)
2087 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
2088 }
2089 
2090 static int
2091 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
2092 {
2093 	dmu_buf_t *db;
2094 	char *packed = NULL;
2095 	size_t nvsize = 0;
2096 	int error;
2097 	*value = NULL;
2098 
2099 	error = dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db);
2100 	if (error)
2101 		return (error);
2102 
2103 	nvsize = *(uint64_t *)db->db_data;
2104 	dmu_buf_rele(db, FTAG);
2105 
2106 	packed = vmem_alloc(nvsize, KM_SLEEP);
2107 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
2108 	    DMU_READ_PREFETCH);
2109 	if (error == 0)
2110 		error = nvlist_unpack(packed, nvsize, value, 0);
2111 	vmem_free(packed, nvsize);
2112 
2113 	return (error);
2114 }
2115 
2116 /*
2117  * Concrete top-level vdevs that are not missing and are not logs. At every
2118  * spa_sync we write new uberblocks to at least SPA_SYNC_MIN_VDEVS core tvds.
2119  */
2120 static uint64_t
2121 spa_healthy_core_tvds(spa_t *spa)
2122 {
2123 	vdev_t *rvd = spa->spa_root_vdev;
2124 	uint64_t tvds = 0;
2125 
2126 	for (uint64_t i = 0; i < rvd->vdev_children; i++) {
2127 		vdev_t *vd = rvd->vdev_child[i];
2128 		if (vd->vdev_islog)
2129 			continue;
2130 		if (vdev_is_concrete(vd) && !vdev_is_dead(vd))
2131 			tvds++;
2132 	}
2133 
2134 	return (tvds);
2135 }
2136 
2137 /*
2138  * Checks to see if the given vdev could not be opened, in which case we post a
2139  * sysevent to notify the autoreplace code that the device has been removed.
2140  */
2141 static void
2142 spa_check_removed(vdev_t *vd)
2143 {
2144 	for (uint64_t c = 0; c < vd->vdev_children; c++)
2145 		spa_check_removed(vd->vdev_child[c]);
2146 
2147 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
2148 	    vdev_is_concrete(vd)) {
2149 		zfs_post_autoreplace(vd->vdev_spa, vd);
2150 		spa_event_notify(vd->vdev_spa, vd, NULL, ESC_ZFS_VDEV_CHECK);
2151 	}
2152 }
2153 
2154 static int
2155 spa_check_for_missing_logs(spa_t *spa)
2156 {
2157 	vdev_t *rvd = spa->spa_root_vdev;
2158 
2159 	/*
2160 	 * If we're doing a normal import, then build up any additional
2161 	 * diagnostic information about missing log devices.
2162 	 * We'll pass this up to the user for further processing.
2163 	 */
2164 	if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
2165 		nvlist_t **child, *nv;
2166 		uint64_t idx = 0;
2167 
2168 		child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t *),
2169 		    KM_SLEEP);
2170 		nv = fnvlist_alloc();
2171 
2172 		for (uint64_t c = 0; c < rvd->vdev_children; c++) {
2173 			vdev_t *tvd = rvd->vdev_child[c];
2174 
2175 			/*
2176 			 * We consider a device as missing only if it failed
2177 			 * to open (i.e. offline or faulted is not considered
2178 			 * as missing).
2179 			 */
2180 			if (tvd->vdev_islog &&
2181 			    tvd->vdev_state == VDEV_STATE_CANT_OPEN) {
2182 				child[idx++] = vdev_config_generate(spa, tvd,
2183 				    B_FALSE, VDEV_CONFIG_MISSING);
2184 			}
2185 		}
2186 
2187 		if (idx > 0) {
2188 			fnvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
2189 			    (const nvlist_t * const *)child, idx);
2190 			fnvlist_add_nvlist(spa->spa_load_info,
2191 			    ZPOOL_CONFIG_MISSING_DEVICES, nv);
2192 
2193 			for (uint64_t i = 0; i < idx; i++)
2194 				nvlist_free(child[i]);
2195 		}
2196 		nvlist_free(nv);
2197 		kmem_free(child, rvd->vdev_children * sizeof (char **));
2198 
2199 		if (idx > 0) {
2200 			spa_load_failed(spa, "some log devices are missing");
2201 			vdev_dbgmsg_print_tree(rvd, 2);
2202 			return (SET_ERROR(ENXIO));
2203 		}
2204 	} else {
2205 		for (uint64_t c = 0; c < rvd->vdev_children; c++) {
2206 			vdev_t *tvd = rvd->vdev_child[c];
2207 
2208 			if (tvd->vdev_islog &&
2209 			    tvd->vdev_state == VDEV_STATE_CANT_OPEN) {
2210 				spa_set_log_state(spa, SPA_LOG_CLEAR);
2211 				spa_load_note(spa, "some log devices are "
2212 				    "missing, ZIL is dropped.");
2213 				vdev_dbgmsg_print_tree(rvd, 2);
2214 				break;
2215 			}
2216 		}
2217 	}
2218 
2219 	return (0);
2220 }
2221 
2222 /*
2223  * Check for missing log devices
2224  */
2225 static boolean_t
2226 spa_check_logs(spa_t *spa)
2227 {
2228 	boolean_t rv = B_FALSE;
2229 	dsl_pool_t *dp = spa_get_dsl(spa);
2230 
2231 	switch (spa->spa_log_state) {
2232 	default:
2233 		break;
2234 	case SPA_LOG_MISSING:
2235 		/* need to recheck in case slog has been restored */
2236 	case SPA_LOG_UNKNOWN:
2237 		rv = (dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
2238 		    zil_check_log_chain, NULL, DS_FIND_CHILDREN) != 0);
2239 		if (rv)
2240 			spa_set_log_state(spa, SPA_LOG_MISSING);
2241 		break;
2242 	}
2243 	return (rv);
2244 }
2245 
2246 /*
2247  * Passivate any log vdevs (note, does not apply to embedded log metaslabs).
2248  */
2249 static boolean_t
2250 spa_passivate_log(spa_t *spa)
2251 {
2252 	vdev_t *rvd = spa->spa_root_vdev;
2253 	boolean_t slog_found = B_FALSE;
2254 
2255 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
2256 
2257 	for (int c = 0; c < rvd->vdev_children; c++) {
2258 		vdev_t *tvd = rvd->vdev_child[c];
2259 
2260 		if (tvd->vdev_islog) {
2261 			ASSERT3P(tvd->vdev_log_mg, ==, NULL);
2262 			metaslab_group_passivate(tvd->vdev_mg);
2263 			slog_found = B_TRUE;
2264 		}
2265 	}
2266 
2267 	return (slog_found);
2268 }
2269 
2270 /*
2271  * Activate any log vdevs (note, does not apply to embedded log metaslabs).
2272  */
2273 static void
2274 spa_activate_log(spa_t *spa)
2275 {
2276 	vdev_t *rvd = spa->spa_root_vdev;
2277 
2278 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
2279 
2280 	for (int c = 0; c < rvd->vdev_children; c++) {
2281 		vdev_t *tvd = rvd->vdev_child[c];
2282 
2283 		if (tvd->vdev_islog) {
2284 			ASSERT3P(tvd->vdev_log_mg, ==, NULL);
2285 			metaslab_group_activate(tvd->vdev_mg);
2286 		}
2287 	}
2288 }
2289 
2290 int
2291 spa_reset_logs(spa_t *spa)
2292 {
2293 	int error;
2294 
2295 	error = dmu_objset_find(spa_name(spa), zil_reset,
2296 	    NULL, DS_FIND_CHILDREN);
2297 	if (error == 0) {
2298 		/*
2299 		 * We successfully offlined the log device, sync out the
2300 		 * current txg so that the "stubby" block can be removed
2301 		 * by zil_sync().
2302 		 */
2303 		txg_wait_synced(spa->spa_dsl_pool, 0);
2304 	}
2305 	return (error);
2306 }
2307 
2308 static void
2309 spa_aux_check_removed(spa_aux_vdev_t *sav)
2310 {
2311 	for (int i = 0; i < sav->sav_count; i++)
2312 		spa_check_removed(sav->sav_vdevs[i]);
2313 }
2314 
2315 void
2316 spa_claim_notify(zio_t *zio)
2317 {
2318 	spa_t *spa = zio->io_spa;
2319 
2320 	if (zio->io_error)
2321 		return;
2322 
2323 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
2324 	if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
2325 		spa->spa_claim_max_txg = zio->io_bp->blk_birth;
2326 	mutex_exit(&spa->spa_props_lock);
2327 }
2328 
2329 typedef struct spa_load_error {
2330 	boolean_t	sle_verify_data;
2331 	uint64_t	sle_meta_count;
2332 	uint64_t	sle_data_count;
2333 } spa_load_error_t;
2334 
2335 static void
2336 spa_load_verify_done(zio_t *zio)
2337 {
2338 	blkptr_t *bp = zio->io_bp;
2339 	spa_load_error_t *sle = zio->io_private;
2340 	dmu_object_type_t type = BP_GET_TYPE(bp);
2341 	int error = zio->io_error;
2342 	spa_t *spa = zio->io_spa;
2343 
2344 	abd_free(zio->io_abd);
2345 	if (error) {
2346 		if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
2347 		    type != DMU_OT_INTENT_LOG)
2348 			atomic_inc_64(&sle->sle_meta_count);
2349 		else
2350 			atomic_inc_64(&sle->sle_data_count);
2351 	}
2352 
2353 	mutex_enter(&spa->spa_scrub_lock);
2354 	spa->spa_load_verify_bytes -= BP_GET_PSIZE(bp);
2355 	cv_broadcast(&spa->spa_scrub_io_cv);
2356 	mutex_exit(&spa->spa_scrub_lock);
2357 }
2358 
2359 /*
2360  * Maximum number of inflight bytes is the log2 fraction of the arc size.
2361  * By default, we set it to 1/16th of the arc.
2362  */
2363 static uint_t spa_load_verify_shift = 4;
2364 static int spa_load_verify_metadata = B_TRUE;
2365 static int spa_load_verify_data = B_TRUE;
2366 
2367 static int
2368 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
2369     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
2370 {
2371 	zio_t *rio = arg;
2372 	spa_load_error_t *sle = rio->io_private;
2373 
2374 	(void) zilog, (void) dnp;
2375 
2376 	/*
2377 	 * Note: normally this routine will not be called if
2378 	 * spa_load_verify_metadata is not set.  However, it may be useful
2379 	 * to manually set the flag after the traversal has begun.
2380 	 */
2381 	if (!spa_load_verify_metadata)
2382 		return (0);
2383 
2384 	/*
2385 	 * Sanity check the block pointer in order to detect obvious damage
2386 	 * before using the contents in subsequent checks or in zio_read().
2387 	 * When damaged consider it to be a metadata error since we cannot
2388 	 * trust the BP_GET_TYPE and BP_GET_LEVEL values.
2389 	 */
2390 	if (!zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_LOG)) {
2391 		atomic_inc_64(&sle->sle_meta_count);
2392 		return (0);
2393 	}
2394 
2395 	if (zb->zb_level == ZB_DNODE_LEVEL || BP_IS_HOLE(bp) ||
2396 	    BP_IS_EMBEDDED(bp) || BP_IS_REDACTED(bp))
2397 		return (0);
2398 
2399 	if (!BP_IS_METADATA(bp) &&
2400 	    (!spa_load_verify_data || !sle->sle_verify_data))
2401 		return (0);
2402 
2403 	uint64_t maxinflight_bytes =
2404 	    arc_target_bytes() >> spa_load_verify_shift;
2405 	size_t size = BP_GET_PSIZE(bp);
2406 
2407 	mutex_enter(&spa->spa_scrub_lock);
2408 	while (spa->spa_load_verify_bytes >= maxinflight_bytes)
2409 		cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
2410 	spa->spa_load_verify_bytes += size;
2411 	mutex_exit(&spa->spa_scrub_lock);
2412 
2413 	zio_nowait(zio_read(rio, spa, bp, abd_alloc_for_io(size, B_FALSE), size,
2414 	    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
2415 	    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
2416 	    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
2417 	return (0);
2418 }
2419 
2420 static int
2421 verify_dataset_name_len(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
2422 {
2423 	(void) dp, (void) arg;
2424 
2425 	if (dsl_dataset_namelen(ds) >= ZFS_MAX_DATASET_NAME_LEN)
2426 		return (SET_ERROR(ENAMETOOLONG));
2427 
2428 	return (0);
2429 }
2430 
2431 static int
2432 spa_load_verify(spa_t *spa)
2433 {
2434 	zio_t *rio;
2435 	spa_load_error_t sle = { 0 };
2436 	zpool_load_policy_t policy;
2437 	boolean_t verify_ok = B_FALSE;
2438 	int error = 0;
2439 
2440 	zpool_get_load_policy(spa->spa_config, &policy);
2441 
2442 	if (policy.zlp_rewind & ZPOOL_NEVER_REWIND ||
2443 	    policy.zlp_maxmeta == UINT64_MAX)
2444 		return (0);
2445 
2446 	dsl_pool_config_enter(spa->spa_dsl_pool, FTAG);
2447 	error = dmu_objset_find_dp(spa->spa_dsl_pool,
2448 	    spa->spa_dsl_pool->dp_root_dir_obj, verify_dataset_name_len, NULL,
2449 	    DS_FIND_CHILDREN);
2450 	dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
2451 	if (error != 0)
2452 		return (error);
2453 
2454 	/*
2455 	 * Verify data only if we are rewinding or error limit was set.
2456 	 * Otherwise nothing except dbgmsg care about it to waste time.
2457 	 */
2458 	sle.sle_verify_data = (policy.zlp_rewind & ZPOOL_REWIND_MASK) ||
2459 	    (policy.zlp_maxdata < UINT64_MAX);
2460 
2461 	rio = zio_root(spa, NULL, &sle,
2462 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
2463 
2464 	if (spa_load_verify_metadata) {
2465 		if (spa->spa_extreme_rewind) {
2466 			spa_load_note(spa, "performing a complete scan of the "
2467 			    "pool since extreme rewind is on. This may take "
2468 			    "a very long time.\n  (spa_load_verify_data=%u, "
2469 			    "spa_load_verify_metadata=%u)",
2470 			    spa_load_verify_data, spa_load_verify_metadata);
2471 		}
2472 
2473 		error = traverse_pool(spa, spa->spa_verify_min_txg,
2474 		    TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA |
2475 		    TRAVERSE_NO_DECRYPT, spa_load_verify_cb, rio);
2476 	}
2477 
2478 	(void) zio_wait(rio);
2479 	ASSERT0(spa->spa_load_verify_bytes);
2480 
2481 	spa->spa_load_meta_errors = sle.sle_meta_count;
2482 	spa->spa_load_data_errors = sle.sle_data_count;
2483 
2484 	if (sle.sle_meta_count != 0 || sle.sle_data_count != 0) {
2485 		spa_load_note(spa, "spa_load_verify found %llu metadata errors "
2486 		    "and %llu data errors", (u_longlong_t)sle.sle_meta_count,
2487 		    (u_longlong_t)sle.sle_data_count);
2488 	}
2489 
2490 	if (spa_load_verify_dryrun ||
2491 	    (!error && sle.sle_meta_count <= policy.zlp_maxmeta &&
2492 	    sle.sle_data_count <= policy.zlp_maxdata)) {
2493 		int64_t loss = 0;
2494 
2495 		verify_ok = B_TRUE;
2496 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
2497 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
2498 
2499 		loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
2500 		fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_LOAD_TIME,
2501 		    spa->spa_load_txg_ts);
2502 		fnvlist_add_int64(spa->spa_load_info, ZPOOL_CONFIG_REWIND_TIME,
2503 		    loss);
2504 		fnvlist_add_uint64(spa->spa_load_info,
2505 		    ZPOOL_CONFIG_LOAD_META_ERRORS, sle.sle_meta_count);
2506 		fnvlist_add_uint64(spa->spa_load_info,
2507 		    ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count);
2508 	} else {
2509 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
2510 	}
2511 
2512 	if (spa_load_verify_dryrun)
2513 		return (0);
2514 
2515 	if (error) {
2516 		if (error != ENXIO && error != EIO)
2517 			error = SET_ERROR(EIO);
2518 		return (error);
2519 	}
2520 
2521 	return (verify_ok ? 0 : EIO);
2522 }
2523 
2524 /*
2525  * Find a value in the pool props object.
2526  */
2527 static void
2528 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
2529 {
2530 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
2531 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
2532 }
2533 
2534 /*
2535  * Find a value in the pool directory object.
2536  */
2537 static int
2538 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val, boolean_t log_enoent)
2539 {
2540 	int error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
2541 	    name, sizeof (uint64_t), 1, val);
2542 
2543 	if (error != 0 && (error != ENOENT || log_enoent)) {
2544 		spa_load_failed(spa, "couldn't get '%s' value in MOS directory "
2545 		    "[error=%d]", name, error);
2546 	}
2547 
2548 	return (error);
2549 }
2550 
2551 static int
2552 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
2553 {
2554 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
2555 	return (SET_ERROR(err));
2556 }
2557 
2558 boolean_t
2559 spa_livelist_delete_check(spa_t *spa)
2560 {
2561 	return (spa->spa_livelists_to_delete != 0);
2562 }
2563 
2564 static boolean_t
2565 spa_livelist_delete_cb_check(void *arg, zthr_t *z)
2566 {
2567 	(void) z;
2568 	spa_t *spa = arg;
2569 	return (spa_livelist_delete_check(spa));
2570 }
2571 
2572 static int
2573 delete_blkptr_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
2574 {
2575 	spa_t *spa = arg;
2576 	zio_free(spa, tx->tx_txg, bp);
2577 	dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD,
2578 	    -bp_get_dsize_sync(spa, bp),
2579 	    -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx);
2580 	return (0);
2581 }
2582 
2583 static int
2584 dsl_get_next_livelist_obj(objset_t *os, uint64_t zap_obj, uint64_t *llp)
2585 {
2586 	int err;
2587 	zap_cursor_t zc;
2588 	zap_attribute_t za;
2589 	zap_cursor_init(&zc, os, zap_obj);
2590 	err = zap_cursor_retrieve(&zc, &za);
2591 	zap_cursor_fini(&zc);
2592 	if (err == 0)
2593 		*llp = za.za_first_integer;
2594 	return (err);
2595 }
2596 
2597 /*
2598  * Components of livelist deletion that must be performed in syncing
2599  * context: freeing block pointers and updating the pool-wide data
2600  * structures to indicate how much work is left to do
2601  */
2602 typedef struct sublist_delete_arg {
2603 	spa_t *spa;
2604 	dsl_deadlist_t *ll;
2605 	uint64_t key;
2606 	bplist_t *to_free;
2607 } sublist_delete_arg_t;
2608 
2609 static void
2610 sublist_delete_sync(void *arg, dmu_tx_t *tx)
2611 {
2612 	sublist_delete_arg_t *sda = arg;
2613 	spa_t *spa = sda->spa;
2614 	dsl_deadlist_t *ll = sda->ll;
2615 	uint64_t key = sda->key;
2616 	bplist_t *to_free = sda->to_free;
2617 
2618 	bplist_iterate(to_free, delete_blkptr_cb, spa, tx);
2619 	dsl_deadlist_remove_entry(ll, key, tx);
2620 }
2621 
2622 typedef struct livelist_delete_arg {
2623 	spa_t *spa;
2624 	uint64_t ll_obj;
2625 	uint64_t zap_obj;
2626 } livelist_delete_arg_t;
2627 
2628 static void
2629 livelist_delete_sync(void *arg, dmu_tx_t *tx)
2630 {
2631 	livelist_delete_arg_t *lda = arg;
2632 	spa_t *spa = lda->spa;
2633 	uint64_t ll_obj = lda->ll_obj;
2634 	uint64_t zap_obj = lda->zap_obj;
2635 	objset_t *mos = spa->spa_meta_objset;
2636 	uint64_t count;
2637 
2638 	/* free the livelist and decrement the feature count */
2639 	VERIFY0(zap_remove_int(mos, zap_obj, ll_obj, tx));
2640 	dsl_deadlist_free(mos, ll_obj, tx);
2641 	spa_feature_decr(spa, SPA_FEATURE_LIVELIST, tx);
2642 	VERIFY0(zap_count(mos, zap_obj, &count));
2643 	if (count == 0) {
2644 		/* no more livelists to delete */
2645 		VERIFY0(zap_remove(mos, DMU_POOL_DIRECTORY_OBJECT,
2646 		    DMU_POOL_DELETED_CLONES, tx));
2647 		VERIFY0(zap_destroy(mos, zap_obj, tx));
2648 		spa->spa_livelists_to_delete = 0;
2649 		spa_notify_waiters(spa);
2650 	}
2651 }
2652 
2653 /*
2654  * Load in the value for the livelist to be removed and open it. Then,
2655  * load its first sublist and determine which block pointers should actually
2656  * be freed. Then, call a synctask which performs the actual frees and updates
2657  * the pool-wide livelist data.
2658  */
2659 static void
2660 spa_livelist_delete_cb(void *arg, zthr_t *z)
2661 {
2662 	spa_t *spa = arg;
2663 	uint64_t ll_obj = 0, count;
2664 	objset_t *mos = spa->spa_meta_objset;
2665 	uint64_t zap_obj = spa->spa_livelists_to_delete;
2666 	/*
2667 	 * Determine the next livelist to delete. This function should only
2668 	 * be called if there is at least one deleted clone.
2669 	 */
2670 	VERIFY0(dsl_get_next_livelist_obj(mos, zap_obj, &ll_obj));
2671 	VERIFY0(zap_count(mos, ll_obj, &count));
2672 	if (count > 0) {
2673 		dsl_deadlist_t *ll;
2674 		dsl_deadlist_entry_t *dle;
2675 		bplist_t to_free;
2676 		ll = kmem_zalloc(sizeof (dsl_deadlist_t), KM_SLEEP);
2677 		dsl_deadlist_open(ll, mos, ll_obj);
2678 		dle = dsl_deadlist_first(ll);
2679 		ASSERT3P(dle, !=, NULL);
2680 		bplist_create(&to_free);
2681 		int err = dsl_process_sub_livelist(&dle->dle_bpobj, &to_free,
2682 		    z, NULL);
2683 		if (err == 0) {
2684 			sublist_delete_arg_t sync_arg = {
2685 			    .spa = spa,
2686 			    .ll = ll,
2687 			    .key = dle->dle_mintxg,
2688 			    .to_free = &to_free
2689 			};
2690 			zfs_dbgmsg("deleting sublist (id %llu) from"
2691 			    " livelist %llu, %lld remaining",
2692 			    (u_longlong_t)dle->dle_bpobj.bpo_object,
2693 			    (u_longlong_t)ll_obj, (longlong_t)count - 1);
2694 			VERIFY0(dsl_sync_task(spa_name(spa), NULL,
2695 			    sublist_delete_sync, &sync_arg, 0,
2696 			    ZFS_SPACE_CHECK_DESTROY));
2697 		} else {
2698 			VERIFY3U(err, ==, EINTR);
2699 		}
2700 		bplist_clear(&to_free);
2701 		bplist_destroy(&to_free);
2702 		dsl_deadlist_close(ll);
2703 		kmem_free(ll, sizeof (dsl_deadlist_t));
2704 	} else {
2705 		livelist_delete_arg_t sync_arg = {
2706 		    .spa = spa,
2707 		    .ll_obj = ll_obj,
2708 		    .zap_obj = zap_obj
2709 		};
2710 		zfs_dbgmsg("deletion of livelist %llu completed",
2711 		    (u_longlong_t)ll_obj);
2712 		VERIFY0(dsl_sync_task(spa_name(spa), NULL, livelist_delete_sync,
2713 		    &sync_arg, 0, ZFS_SPACE_CHECK_DESTROY));
2714 	}
2715 }
2716 
2717 static void
2718 spa_start_livelist_destroy_thread(spa_t *spa)
2719 {
2720 	ASSERT3P(spa->spa_livelist_delete_zthr, ==, NULL);
2721 	spa->spa_livelist_delete_zthr =
2722 	    zthr_create("z_livelist_destroy",
2723 	    spa_livelist_delete_cb_check, spa_livelist_delete_cb, spa,
2724 	    minclsyspri);
2725 }
2726 
2727 typedef struct livelist_new_arg {
2728 	bplist_t *allocs;
2729 	bplist_t *frees;
2730 } livelist_new_arg_t;
2731 
2732 static int
2733 livelist_track_new_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
2734     dmu_tx_t *tx)
2735 {
2736 	ASSERT(tx == NULL);
2737 	livelist_new_arg_t *lna = arg;
2738 	if (bp_freed) {
2739 		bplist_append(lna->frees, bp);
2740 	} else {
2741 		bplist_append(lna->allocs, bp);
2742 		zfs_livelist_condense_new_alloc++;
2743 	}
2744 	return (0);
2745 }
2746 
2747 typedef struct livelist_condense_arg {
2748 	spa_t *spa;
2749 	bplist_t to_keep;
2750 	uint64_t first_size;
2751 	uint64_t next_size;
2752 } livelist_condense_arg_t;
2753 
2754 static void
2755 spa_livelist_condense_sync(void *arg, dmu_tx_t *tx)
2756 {
2757 	livelist_condense_arg_t *lca = arg;
2758 	spa_t *spa = lca->spa;
2759 	bplist_t new_frees;
2760 	dsl_dataset_t *ds = spa->spa_to_condense.ds;
2761 
2762 	/* Have we been cancelled? */
2763 	if (spa->spa_to_condense.cancelled) {
2764 		zfs_livelist_condense_sync_cancel++;
2765 		goto out;
2766 	}
2767 
2768 	dsl_deadlist_entry_t *first = spa->spa_to_condense.first;
2769 	dsl_deadlist_entry_t *next = spa->spa_to_condense.next;
2770 	dsl_deadlist_t *ll = &ds->ds_dir->dd_livelist;
2771 
2772 	/*
2773 	 * It's possible that the livelist was changed while the zthr was
2774 	 * running. Therefore, we need to check for new blkptrs in the two
2775 	 * entries being condensed and continue to track them in the livelist.
2776 	 * Because of the way we handle remapped blkptrs (see dbuf_remap_impl),
2777 	 * it's possible that the newly added blkptrs are FREEs or ALLOCs so
2778 	 * we need to sort them into two different bplists.
2779 	 */
2780 	uint64_t first_obj = first->dle_bpobj.bpo_object;
2781 	uint64_t next_obj = next->dle_bpobj.bpo_object;
2782 	uint64_t cur_first_size = first->dle_bpobj.bpo_phys->bpo_num_blkptrs;
2783 	uint64_t cur_next_size = next->dle_bpobj.bpo_phys->bpo_num_blkptrs;
2784 
2785 	bplist_create(&new_frees);
2786 	livelist_new_arg_t new_bps = {
2787 	    .allocs = &lca->to_keep,
2788 	    .frees = &new_frees,
2789 	};
2790 
2791 	if (cur_first_size > lca->first_size) {
2792 		VERIFY0(livelist_bpobj_iterate_from_nofree(&first->dle_bpobj,
2793 		    livelist_track_new_cb, &new_bps, lca->first_size));
2794 	}
2795 	if (cur_next_size > lca->next_size) {
2796 		VERIFY0(livelist_bpobj_iterate_from_nofree(&next->dle_bpobj,
2797 		    livelist_track_new_cb, &new_bps, lca->next_size));
2798 	}
2799 
2800 	dsl_deadlist_clear_entry(first, ll, tx);
2801 	ASSERT(bpobj_is_empty(&first->dle_bpobj));
2802 	dsl_deadlist_remove_entry(ll, next->dle_mintxg, tx);
2803 
2804 	bplist_iterate(&lca->to_keep, dsl_deadlist_insert_alloc_cb, ll, tx);
2805 	bplist_iterate(&new_frees, dsl_deadlist_insert_free_cb, ll, tx);
2806 	bplist_destroy(&new_frees);
2807 
2808 	char dsname[ZFS_MAX_DATASET_NAME_LEN];
2809 	dsl_dataset_name(ds, dsname);
2810 	zfs_dbgmsg("txg %llu condensing livelist of %s (id %llu), bpobj %llu "
2811 	    "(%llu blkptrs) and bpobj %llu (%llu blkptrs) -> bpobj %llu "
2812 	    "(%llu blkptrs)", (u_longlong_t)tx->tx_txg, dsname,
2813 	    (u_longlong_t)ds->ds_object, (u_longlong_t)first_obj,
2814 	    (u_longlong_t)cur_first_size, (u_longlong_t)next_obj,
2815 	    (u_longlong_t)cur_next_size,
2816 	    (u_longlong_t)first->dle_bpobj.bpo_object,
2817 	    (u_longlong_t)first->dle_bpobj.bpo_phys->bpo_num_blkptrs);
2818 out:
2819 	dmu_buf_rele(ds->ds_dbuf, spa);
2820 	spa->spa_to_condense.ds = NULL;
2821 	bplist_clear(&lca->to_keep);
2822 	bplist_destroy(&lca->to_keep);
2823 	kmem_free(lca, sizeof (livelist_condense_arg_t));
2824 	spa->spa_to_condense.syncing = B_FALSE;
2825 }
2826 
2827 static void
2828 spa_livelist_condense_cb(void *arg, zthr_t *t)
2829 {
2830 	while (zfs_livelist_condense_zthr_pause &&
2831 	    !(zthr_has_waiters(t) || zthr_iscancelled(t)))
2832 		delay(1);
2833 
2834 	spa_t *spa = arg;
2835 	dsl_deadlist_entry_t *first = spa->spa_to_condense.first;
2836 	dsl_deadlist_entry_t *next = spa->spa_to_condense.next;
2837 	uint64_t first_size, next_size;
2838 
2839 	livelist_condense_arg_t *lca =
2840 	    kmem_alloc(sizeof (livelist_condense_arg_t), KM_SLEEP);
2841 	bplist_create(&lca->to_keep);
2842 
2843 	/*
2844 	 * Process the livelists (matching FREEs and ALLOCs) in open context
2845 	 * so we have minimal work in syncing context to condense.
2846 	 *
2847 	 * We save bpobj sizes (first_size and next_size) to use later in
2848 	 * syncing context to determine if entries were added to these sublists
2849 	 * while in open context. This is possible because the clone is still
2850 	 * active and open for normal writes and we want to make sure the new,
2851 	 * unprocessed blockpointers are inserted into the livelist normally.
2852 	 *
2853 	 * Note that dsl_process_sub_livelist() both stores the size number of
2854 	 * blockpointers and iterates over them while the bpobj's lock held, so
2855 	 * the sizes returned to us are consistent which what was actually
2856 	 * processed.
2857 	 */
2858 	int err = dsl_process_sub_livelist(&first->dle_bpobj, &lca->to_keep, t,
2859 	    &first_size);
2860 	if (err == 0)
2861 		err = dsl_process_sub_livelist(&next->dle_bpobj, &lca->to_keep,
2862 		    t, &next_size);
2863 
2864 	if (err == 0) {
2865 		while (zfs_livelist_condense_sync_pause &&
2866 		    !(zthr_has_waiters(t) || zthr_iscancelled(t)))
2867 			delay(1);
2868 
2869 		dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
2870 		dmu_tx_mark_netfree(tx);
2871 		dmu_tx_hold_space(tx, 1);
2872 		err = dmu_tx_assign(tx, TXG_NOWAIT | TXG_NOTHROTTLE);
2873 		if (err == 0) {
2874 			/*
2875 			 * Prevent the condense zthr restarting before
2876 			 * the synctask completes.
2877 			 */
2878 			spa->spa_to_condense.syncing = B_TRUE;
2879 			lca->spa = spa;
2880 			lca->first_size = first_size;
2881 			lca->next_size = next_size;
2882 			dsl_sync_task_nowait(spa_get_dsl(spa),
2883 			    spa_livelist_condense_sync, lca, tx);
2884 			dmu_tx_commit(tx);
2885 			return;
2886 		}
2887 	}
2888 	/*
2889 	 * Condensing can not continue: either it was externally stopped or
2890 	 * we were unable to assign to a tx because the pool has run out of
2891 	 * space. In the second case, we'll just end up trying to condense
2892 	 * again in a later txg.
2893 	 */
2894 	ASSERT(err != 0);
2895 	bplist_clear(&lca->to_keep);
2896 	bplist_destroy(&lca->to_keep);
2897 	kmem_free(lca, sizeof (livelist_condense_arg_t));
2898 	dmu_buf_rele(spa->spa_to_condense.ds->ds_dbuf, spa);
2899 	spa->spa_to_condense.ds = NULL;
2900 	if (err == EINTR)
2901 		zfs_livelist_condense_zthr_cancel++;
2902 }
2903 
2904 /*
2905  * Check that there is something to condense but that a condense is not
2906  * already in progress and that condensing has not been cancelled.
2907  */
2908 static boolean_t
2909 spa_livelist_condense_cb_check(void *arg, zthr_t *z)
2910 {
2911 	(void) z;
2912 	spa_t *spa = arg;
2913 	if ((spa->spa_to_condense.ds != NULL) &&
2914 	    (spa->spa_to_condense.syncing == B_FALSE) &&
2915 	    (spa->spa_to_condense.cancelled == B_FALSE)) {
2916 		return (B_TRUE);
2917 	}
2918 	return (B_FALSE);
2919 }
2920 
2921 static void
2922 spa_start_livelist_condensing_thread(spa_t *spa)
2923 {
2924 	spa->spa_to_condense.ds = NULL;
2925 	spa->spa_to_condense.first = NULL;
2926 	spa->spa_to_condense.next = NULL;
2927 	spa->spa_to_condense.syncing = B_FALSE;
2928 	spa->spa_to_condense.cancelled = B_FALSE;
2929 
2930 	ASSERT3P(spa->spa_livelist_condense_zthr, ==, NULL);
2931 	spa->spa_livelist_condense_zthr =
2932 	    zthr_create("z_livelist_condense",
2933 	    spa_livelist_condense_cb_check,
2934 	    spa_livelist_condense_cb, spa, minclsyspri);
2935 }
2936 
2937 static void
2938 spa_spawn_aux_threads(spa_t *spa)
2939 {
2940 	ASSERT(spa_writeable(spa));
2941 
2942 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
2943 
2944 	spa_start_indirect_condensing_thread(spa);
2945 	spa_start_livelist_destroy_thread(spa);
2946 	spa_start_livelist_condensing_thread(spa);
2947 
2948 	ASSERT3P(spa->spa_checkpoint_discard_zthr, ==, NULL);
2949 	spa->spa_checkpoint_discard_zthr =
2950 	    zthr_create("z_checkpoint_discard",
2951 	    spa_checkpoint_discard_thread_check,
2952 	    spa_checkpoint_discard_thread, spa, minclsyspri);
2953 }
2954 
2955 /*
2956  * Fix up config after a partly-completed split.  This is done with the
2957  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
2958  * pool have that entry in their config, but only the splitting one contains
2959  * a list of all the guids of the vdevs that are being split off.
2960  *
2961  * This function determines what to do with that list: either rejoin
2962  * all the disks to the pool, or complete the splitting process.  To attempt
2963  * the rejoin, each disk that is offlined is marked online again, and
2964  * we do a reopen() call.  If the vdev label for every disk that was
2965  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
2966  * then we call vdev_split() on each disk, and complete the split.
2967  *
2968  * Otherwise we leave the config alone, with all the vdevs in place in
2969  * the original pool.
2970  */
2971 static void
2972 spa_try_repair(spa_t *spa, nvlist_t *config)
2973 {
2974 	uint_t extracted;
2975 	uint64_t *glist;
2976 	uint_t i, gcount;
2977 	nvlist_t *nvl;
2978 	vdev_t **vd;
2979 	boolean_t attempt_reopen;
2980 
2981 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
2982 		return;
2983 
2984 	/* check that the config is complete */
2985 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
2986 	    &glist, &gcount) != 0)
2987 		return;
2988 
2989 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
2990 
2991 	/* attempt to online all the vdevs & validate */
2992 	attempt_reopen = B_TRUE;
2993 	for (i = 0; i < gcount; i++) {
2994 		if (glist[i] == 0)	/* vdev is hole */
2995 			continue;
2996 
2997 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
2998 		if (vd[i] == NULL) {
2999 			/*
3000 			 * Don't bother attempting to reopen the disks;
3001 			 * just do the split.
3002 			 */
3003 			attempt_reopen = B_FALSE;
3004 		} else {
3005 			/* attempt to re-online it */
3006 			vd[i]->vdev_offline = B_FALSE;
3007 		}
3008 	}
3009 
3010 	if (attempt_reopen) {
3011 		vdev_reopen(spa->spa_root_vdev);
3012 
3013 		/* check each device to see what state it's in */
3014 		for (extracted = 0, i = 0; i < gcount; i++) {
3015 			if (vd[i] != NULL &&
3016 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
3017 				break;
3018 			++extracted;
3019 		}
3020 	}
3021 
3022 	/*
3023 	 * If every disk has been moved to the new pool, or if we never
3024 	 * even attempted to look at them, then we split them off for
3025 	 * good.
3026 	 */
3027 	if (!attempt_reopen || gcount == extracted) {
3028 		for (i = 0; i < gcount; i++)
3029 			if (vd[i] != NULL)
3030 				vdev_split(vd[i]);
3031 		vdev_reopen(spa->spa_root_vdev);
3032 	}
3033 
3034 	kmem_free(vd, gcount * sizeof (vdev_t *));
3035 }
3036 
3037 static int
3038 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type)
3039 {
3040 	const char *ereport = FM_EREPORT_ZFS_POOL;
3041 	int error;
3042 
3043 	spa->spa_load_state = state;
3044 	(void) spa_import_progress_set_state(spa_guid(spa),
3045 	    spa_load_state(spa));
3046 
3047 	gethrestime(&spa->spa_loaded_ts);
3048 	error = spa_load_impl(spa, type, &ereport);
3049 
3050 	/*
3051 	 * Don't count references from objsets that are already closed
3052 	 * and are making their way through the eviction process.
3053 	 */
3054 	spa_evicting_os_wait(spa);
3055 	spa->spa_minref = zfs_refcount_count(&spa->spa_refcount);
3056 	if (error) {
3057 		if (error != EEXIST) {
3058 			spa->spa_loaded_ts.tv_sec = 0;
3059 			spa->spa_loaded_ts.tv_nsec = 0;
3060 		}
3061 		if (error != EBADF) {
3062 			(void) zfs_ereport_post(ereport, spa,
3063 			    NULL, NULL, NULL, 0);
3064 		}
3065 	}
3066 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
3067 	spa->spa_ena = 0;
3068 
3069 	(void) spa_import_progress_set_state(spa_guid(spa),
3070 	    spa_load_state(spa));
3071 
3072 	return (error);
3073 }
3074 
3075 #ifdef ZFS_DEBUG
3076 /*
3077  * Count the number of per-vdev ZAPs associated with all of the vdevs in the
3078  * vdev tree rooted in the given vd, and ensure that each ZAP is present in the
3079  * spa's per-vdev ZAP list.
3080  */
3081 static uint64_t
3082 vdev_count_verify_zaps(vdev_t *vd)
3083 {
3084 	spa_t *spa = vd->vdev_spa;
3085 	uint64_t total = 0;
3086 
3087 	if (vd->vdev_top_zap != 0) {
3088 		total++;
3089 		ASSERT0(zap_lookup_int(spa->spa_meta_objset,
3090 		    spa->spa_all_vdev_zaps, vd->vdev_top_zap));
3091 	}
3092 	if (vd->vdev_leaf_zap != 0) {
3093 		total++;
3094 		ASSERT0(zap_lookup_int(spa->spa_meta_objset,
3095 		    spa->spa_all_vdev_zaps, vd->vdev_leaf_zap));
3096 	}
3097 
3098 	for (uint64_t i = 0; i < vd->vdev_children; i++) {
3099 		total += vdev_count_verify_zaps(vd->vdev_child[i]);
3100 	}
3101 
3102 	return (total);
3103 }
3104 #else
3105 #define	vdev_count_verify_zaps(vd) ((void) sizeof (vd), 0)
3106 #endif
3107 
3108 /*
3109  * Determine whether the activity check is required.
3110  */
3111 static boolean_t
3112 spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
3113     nvlist_t *config)
3114 {
3115 	uint64_t state = 0;
3116 	uint64_t hostid = 0;
3117 	uint64_t tryconfig_txg = 0;
3118 	uint64_t tryconfig_timestamp = 0;
3119 	uint16_t tryconfig_mmp_seq = 0;
3120 	nvlist_t *nvinfo;
3121 
3122 	if (nvlist_exists(config, ZPOOL_CONFIG_LOAD_INFO)) {
3123 		nvinfo = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_LOAD_INFO);
3124 		(void) nvlist_lookup_uint64(nvinfo, ZPOOL_CONFIG_MMP_TXG,
3125 		    &tryconfig_txg);
3126 		(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
3127 		    &tryconfig_timestamp);
3128 		(void) nvlist_lookup_uint16(nvinfo, ZPOOL_CONFIG_MMP_SEQ,
3129 		    &tryconfig_mmp_seq);
3130 	}
3131 
3132 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE, &state);
3133 
3134 	/*
3135 	 * Disable the MMP activity check - This is used by zdb which
3136 	 * is intended to be used on potentially active pools.
3137 	 */
3138 	if (spa->spa_import_flags & ZFS_IMPORT_SKIP_MMP)
3139 		return (B_FALSE);
3140 
3141 	/*
3142 	 * Skip the activity check when the MMP feature is disabled.
3143 	 */
3144 	if (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay == 0)
3145 		return (B_FALSE);
3146 
3147 	/*
3148 	 * If the tryconfig_ values are nonzero, they are the results of an
3149 	 * earlier tryimport.  If they all match the uberblock we just found,
3150 	 * then the pool has not changed and we return false so we do not test
3151 	 * a second time.
3152 	 */
3153 	if (tryconfig_txg && tryconfig_txg == ub->ub_txg &&
3154 	    tryconfig_timestamp && tryconfig_timestamp == ub->ub_timestamp &&
3155 	    tryconfig_mmp_seq && tryconfig_mmp_seq ==
3156 	    (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0))
3157 		return (B_FALSE);
3158 
3159 	/*
3160 	 * Allow the activity check to be skipped when importing the pool
3161 	 * on the same host which last imported it.  Since the hostid from
3162 	 * configuration may be stale use the one read from the label.
3163 	 */
3164 	if (nvlist_exists(label, ZPOOL_CONFIG_HOSTID))
3165 		hostid = fnvlist_lookup_uint64(label, ZPOOL_CONFIG_HOSTID);
3166 
3167 	if (hostid == spa_get_hostid(spa))
3168 		return (B_FALSE);
3169 
3170 	/*
3171 	 * Skip the activity test when the pool was cleanly exported.
3172 	 */
3173 	if (state != POOL_STATE_ACTIVE)
3174 		return (B_FALSE);
3175 
3176 	return (B_TRUE);
3177 }
3178 
3179 /*
3180  * Nanoseconds the activity check must watch for changes on-disk.
3181  */
3182 static uint64_t
3183 spa_activity_check_duration(spa_t *spa, uberblock_t *ub)
3184 {
3185 	uint64_t import_intervals = MAX(zfs_multihost_import_intervals, 1);
3186 	uint64_t multihost_interval = MSEC2NSEC(
3187 	    MMP_INTERVAL_OK(zfs_multihost_interval));
3188 	uint64_t import_delay = MAX(NANOSEC, import_intervals *
3189 	    multihost_interval);
3190 
3191 	/*
3192 	 * Local tunables determine a minimum duration except for the case
3193 	 * where we know when the remote host will suspend the pool if MMP
3194 	 * writes do not land.
3195 	 *
3196 	 * See Big Theory comment at the top of mmp.c for the reasoning behind
3197 	 * these cases and times.
3198 	 */
3199 
3200 	ASSERT(MMP_IMPORT_SAFETY_FACTOR >= 100);
3201 
3202 	if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
3203 	    MMP_FAIL_INT(ub) > 0) {
3204 
3205 		/* MMP on remote host will suspend pool after failed writes */
3206 		import_delay = MMP_FAIL_INT(ub) * MSEC2NSEC(MMP_INTERVAL(ub)) *
3207 		    MMP_IMPORT_SAFETY_FACTOR / 100;
3208 
3209 		zfs_dbgmsg("fail_intvals>0 import_delay=%llu ub_mmp "
3210 		    "mmp_fails=%llu ub_mmp mmp_interval=%llu "
3211 		    "import_intervals=%llu", (u_longlong_t)import_delay,
3212 		    (u_longlong_t)MMP_FAIL_INT(ub),
3213 		    (u_longlong_t)MMP_INTERVAL(ub),
3214 		    (u_longlong_t)import_intervals);
3215 
3216 	} else if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
3217 	    MMP_FAIL_INT(ub) == 0) {
3218 
3219 		/* MMP on remote host will never suspend pool */
3220 		import_delay = MAX(import_delay, (MSEC2NSEC(MMP_INTERVAL(ub)) +
3221 		    ub->ub_mmp_delay) * import_intervals);
3222 
3223 		zfs_dbgmsg("fail_intvals=0 import_delay=%llu ub_mmp "
3224 		    "mmp_interval=%llu ub_mmp_delay=%llu "
3225 		    "import_intervals=%llu", (u_longlong_t)import_delay,
3226 		    (u_longlong_t)MMP_INTERVAL(ub),
3227 		    (u_longlong_t)ub->ub_mmp_delay,
3228 		    (u_longlong_t)import_intervals);
3229 
3230 	} else if (MMP_VALID(ub)) {
3231 		/*
3232 		 * zfs-0.7 compatibility case
3233 		 */
3234 
3235 		import_delay = MAX(import_delay, (multihost_interval +
3236 		    ub->ub_mmp_delay) * import_intervals);
3237 
3238 		zfs_dbgmsg("import_delay=%llu ub_mmp_delay=%llu "
3239 		    "import_intervals=%llu leaves=%u",
3240 		    (u_longlong_t)import_delay,
3241 		    (u_longlong_t)ub->ub_mmp_delay,
3242 		    (u_longlong_t)import_intervals,
3243 		    vdev_count_leaves(spa));
3244 	} else {
3245 		/* Using local tunings is the only reasonable option */
3246 		zfs_dbgmsg("pool last imported on non-MMP aware "
3247 		    "host using import_delay=%llu multihost_interval=%llu "
3248 		    "import_intervals=%llu", (u_longlong_t)import_delay,
3249 		    (u_longlong_t)multihost_interval,
3250 		    (u_longlong_t)import_intervals);
3251 	}
3252 
3253 	return (import_delay);
3254 }
3255 
3256 /*
3257  * Perform the import activity check.  If the user canceled the import or
3258  * we detected activity then fail.
3259  */
3260 static int
3261 spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
3262 {
3263 	uint64_t txg = ub->ub_txg;
3264 	uint64_t timestamp = ub->ub_timestamp;
3265 	uint64_t mmp_config = ub->ub_mmp_config;
3266 	uint16_t mmp_seq = MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0;
3267 	uint64_t import_delay;
3268 	hrtime_t import_expire;
3269 	nvlist_t *mmp_label = NULL;
3270 	vdev_t *rvd = spa->spa_root_vdev;
3271 	kcondvar_t cv;
3272 	kmutex_t mtx;
3273 	int error = 0;
3274 
3275 	cv_init(&cv, NULL, CV_DEFAULT, NULL);
3276 	mutex_init(&mtx, NULL, MUTEX_DEFAULT, NULL);
3277 	mutex_enter(&mtx);
3278 
3279 	/*
3280 	 * If ZPOOL_CONFIG_MMP_TXG is present an activity check was performed
3281 	 * during the earlier tryimport.  If the txg recorded there is 0 then
3282 	 * the pool is known to be active on another host.
3283 	 *
3284 	 * Otherwise, the pool might be in use on another host.  Check for
3285 	 * changes in the uberblocks on disk if necessary.
3286 	 */
3287 	if (nvlist_exists(config, ZPOOL_CONFIG_LOAD_INFO)) {
3288 		nvlist_t *nvinfo = fnvlist_lookup_nvlist(config,
3289 		    ZPOOL_CONFIG_LOAD_INFO);
3290 
3291 		if (nvlist_exists(nvinfo, ZPOOL_CONFIG_MMP_TXG) &&
3292 		    fnvlist_lookup_uint64(nvinfo, ZPOOL_CONFIG_MMP_TXG) == 0) {
3293 			vdev_uberblock_load(rvd, ub, &mmp_label);
3294 			error = SET_ERROR(EREMOTEIO);
3295 			goto out;
3296 		}
3297 	}
3298 
3299 	import_delay = spa_activity_check_duration(spa, ub);
3300 
3301 	/* Add a small random factor in case of simultaneous imports (0-25%) */
3302 	import_delay += import_delay * random_in_range(250) / 1000;
3303 
3304 	import_expire = gethrtime() + import_delay;
3305 
3306 	while (gethrtime() < import_expire) {
3307 		(void) spa_import_progress_set_mmp_check(spa_guid(spa),
3308 		    NSEC2SEC(import_expire - gethrtime()));
3309 
3310 		vdev_uberblock_load(rvd, ub, &mmp_label);
3311 
3312 		if (txg != ub->ub_txg || timestamp != ub->ub_timestamp ||
3313 		    mmp_seq != (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0)) {
3314 			zfs_dbgmsg("multihost activity detected "
3315 			    "txg %llu ub_txg  %llu "
3316 			    "timestamp %llu ub_timestamp  %llu "
3317 			    "mmp_config %#llx ub_mmp_config %#llx",
3318 			    (u_longlong_t)txg, (u_longlong_t)ub->ub_txg,
3319 			    (u_longlong_t)timestamp,
3320 			    (u_longlong_t)ub->ub_timestamp,
3321 			    (u_longlong_t)mmp_config,
3322 			    (u_longlong_t)ub->ub_mmp_config);
3323 
3324 			error = SET_ERROR(EREMOTEIO);
3325 			break;
3326 		}
3327 
3328 		if (mmp_label) {
3329 			nvlist_free(mmp_label);
3330 			mmp_label = NULL;
3331 		}
3332 
3333 		error = cv_timedwait_sig(&cv, &mtx, ddi_get_lbolt() + hz);
3334 		if (error != -1) {
3335 			error = SET_ERROR(EINTR);
3336 			break;
3337 		}
3338 		error = 0;
3339 	}
3340 
3341 out:
3342 	mutex_exit(&mtx);
3343 	mutex_destroy(&mtx);
3344 	cv_destroy(&cv);
3345 
3346 	/*
3347 	 * If the pool is determined to be active store the status in the
3348 	 * spa->spa_load_info nvlist.  If the remote hostname or hostid are
3349 	 * available from configuration read from disk store them as well.
3350 	 * This allows 'zpool import' to generate a more useful message.
3351 	 *
3352 	 * ZPOOL_CONFIG_MMP_STATE    - observed pool status (mandatory)
3353 	 * ZPOOL_CONFIG_MMP_HOSTNAME - hostname from the active pool
3354 	 * ZPOOL_CONFIG_MMP_HOSTID   - hostid from the active pool
3355 	 */
3356 	if (error == EREMOTEIO) {
3357 		const char *hostname = "<unknown>";
3358 		uint64_t hostid = 0;
3359 
3360 		if (mmp_label) {
3361 			if (nvlist_exists(mmp_label, ZPOOL_CONFIG_HOSTNAME)) {
3362 				hostname = fnvlist_lookup_string(mmp_label,
3363 				    ZPOOL_CONFIG_HOSTNAME);
3364 				fnvlist_add_string(spa->spa_load_info,
3365 				    ZPOOL_CONFIG_MMP_HOSTNAME, hostname);
3366 			}
3367 
3368 			if (nvlist_exists(mmp_label, ZPOOL_CONFIG_HOSTID)) {
3369 				hostid = fnvlist_lookup_uint64(mmp_label,
3370 				    ZPOOL_CONFIG_HOSTID);
3371 				fnvlist_add_uint64(spa->spa_load_info,
3372 				    ZPOOL_CONFIG_MMP_HOSTID, hostid);
3373 			}
3374 		}
3375 
3376 		fnvlist_add_uint64(spa->spa_load_info,
3377 		    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_ACTIVE);
3378 		fnvlist_add_uint64(spa->spa_load_info,
3379 		    ZPOOL_CONFIG_MMP_TXG, 0);
3380 
3381 		error = spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO);
3382 	}
3383 
3384 	if (mmp_label)
3385 		nvlist_free(mmp_label);
3386 
3387 	return (error);
3388 }
3389 
3390 static int
3391 spa_verify_host(spa_t *spa, nvlist_t *mos_config)
3392 {
3393 	uint64_t hostid;
3394 	const char *hostname;
3395 	uint64_t myhostid = 0;
3396 
3397 	if (!spa_is_root(spa) && nvlist_lookup_uint64(mos_config,
3398 	    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
3399 		hostname = fnvlist_lookup_string(mos_config,
3400 		    ZPOOL_CONFIG_HOSTNAME);
3401 
3402 		myhostid = zone_get_hostid(NULL);
3403 
3404 		if (hostid != 0 && myhostid != 0 && hostid != myhostid) {
3405 			cmn_err(CE_WARN, "pool '%s' could not be "
3406 			    "loaded as it was last accessed by "
3407 			    "another system (host: %s hostid: 0x%llx). "
3408 			    "See: https://openzfs.github.io/openzfs-docs/msg/"
3409 			    "ZFS-8000-EY",
3410 			    spa_name(spa), hostname, (u_longlong_t)hostid);
3411 			spa_load_failed(spa, "hostid verification failed: pool "
3412 			    "last accessed by host: %s (hostid: 0x%llx)",
3413 			    hostname, (u_longlong_t)hostid);
3414 			return (SET_ERROR(EBADF));
3415 		}
3416 	}
3417 
3418 	return (0);
3419 }
3420 
3421 static int
3422 spa_ld_parse_config(spa_t *spa, spa_import_type_t type)
3423 {
3424 	int error = 0;
3425 	nvlist_t *nvtree, *nvl, *config = spa->spa_config;
3426 	int parse;
3427 	vdev_t *rvd;
3428 	uint64_t pool_guid;
3429 	const char *comment;
3430 	const char *compatibility;
3431 
3432 	/*
3433 	 * Versioning wasn't explicitly added to the label until later, so if
3434 	 * it's not present treat it as the initial version.
3435 	 */
3436 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
3437 	    &spa->spa_ubsync.ub_version) != 0)
3438 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
3439 
3440 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid)) {
3441 		spa_load_failed(spa, "invalid config provided: '%s' missing",
3442 		    ZPOOL_CONFIG_POOL_GUID);
3443 		return (SET_ERROR(EINVAL));
3444 	}
3445 
3446 	/*
3447 	 * If we are doing an import, ensure that the pool is not already
3448 	 * imported by checking if its pool guid already exists in the
3449 	 * spa namespace.
3450 	 *
3451 	 * The only case that we allow an already imported pool to be
3452 	 * imported again, is when the pool is checkpointed and we want to
3453 	 * look at its checkpointed state from userland tools like zdb.
3454 	 */
3455 #ifdef _KERNEL
3456 	if ((spa->spa_load_state == SPA_LOAD_IMPORT ||
3457 	    spa->spa_load_state == SPA_LOAD_TRYIMPORT) &&
3458 	    spa_guid_exists(pool_guid, 0)) {
3459 #else
3460 	if ((spa->spa_load_state == SPA_LOAD_IMPORT ||
3461 	    spa->spa_load_state == SPA_LOAD_TRYIMPORT) &&
3462 	    spa_guid_exists(pool_guid, 0) &&
3463 	    !spa_importing_readonly_checkpoint(spa)) {
3464 #endif
3465 		spa_load_failed(spa, "a pool with guid %llu is already open",
3466 		    (u_longlong_t)pool_guid);
3467 		return (SET_ERROR(EEXIST));
3468 	}
3469 
3470 	spa->spa_config_guid = pool_guid;
3471 
3472 	nvlist_free(spa->spa_load_info);
3473 	spa->spa_load_info = fnvlist_alloc();
3474 
3475 	ASSERT(spa->spa_comment == NULL);
3476 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
3477 		spa->spa_comment = spa_strdup(comment);
3478 
3479 	ASSERT(spa->spa_compatibility == NULL);
3480 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMPATIBILITY,
3481 	    &compatibility) == 0)
3482 		spa->spa_compatibility = spa_strdup(compatibility);
3483 
3484 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
3485 	    &spa->spa_config_txg);
3486 
3487 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) == 0)
3488 		spa->spa_config_splitting = fnvlist_dup(nvl);
3489 
3490 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvtree)) {
3491 		spa_load_failed(spa, "invalid config provided: '%s' missing",
3492 		    ZPOOL_CONFIG_VDEV_TREE);
3493 		return (SET_ERROR(EINVAL));
3494 	}
3495 
3496 	/*
3497 	 * Create "The Godfather" zio to hold all async IOs
3498 	 */
3499 	spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
3500 	    KM_SLEEP);
3501 	for (int i = 0; i < max_ncpus; i++) {
3502 		spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
3503 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
3504 		    ZIO_FLAG_GODFATHER);
3505 	}
3506 
3507 	/*
3508 	 * Parse the configuration into a vdev tree.  We explicitly set the
3509 	 * value that will be returned by spa_version() since parsing the
3510 	 * configuration requires knowing the version number.
3511 	 */
3512 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3513 	parse = (type == SPA_IMPORT_EXISTING ?
3514 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
3515 	error = spa_config_parse(spa, &rvd, nvtree, NULL, 0, parse);
3516 	spa_config_exit(spa, SCL_ALL, FTAG);
3517 
3518 	if (error != 0) {
3519 		spa_load_failed(spa, "unable to parse config [error=%d]",
3520 		    error);
3521 		return (error);
3522 	}
3523 
3524 	ASSERT(spa->spa_root_vdev == rvd);
3525 	ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT);
3526 	ASSERT3U(spa->spa_max_ashift, <=, SPA_MAXBLOCKSHIFT);
3527 
3528 	if (type != SPA_IMPORT_ASSEMBLE) {
3529 		ASSERT(spa_guid(spa) == pool_guid);
3530 	}
3531 
3532 	return (0);
3533 }
3534 
3535 /*
3536  * Recursively open all vdevs in the vdev tree. This function is called twice:
3537  * first with the untrusted config, then with the trusted config.
3538  */
3539 static int
3540 spa_ld_open_vdevs(spa_t *spa)
3541 {
3542 	int error = 0;
3543 
3544 	/*
3545 	 * spa_missing_tvds_allowed defines how many top-level vdevs can be
3546 	 * missing/unopenable for the root vdev to be still considered openable.
3547 	 */
3548 	if (spa->spa_trust_config) {
3549 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds;
3550 	} else if (spa->spa_config_source == SPA_CONFIG_SRC_CACHEFILE) {
3551 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds_cachefile;
3552 	} else if (spa->spa_config_source == SPA_CONFIG_SRC_SCAN) {
3553 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds_scan;
3554 	} else {
3555 		spa->spa_missing_tvds_allowed = 0;
3556 	}
3557 
3558 	spa->spa_missing_tvds_allowed =
3559 	    MAX(zfs_max_missing_tvds, spa->spa_missing_tvds_allowed);
3560 
3561 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3562 	error = vdev_open(spa->spa_root_vdev);
3563 	spa_config_exit(spa, SCL_ALL, FTAG);
3564 
3565 	if (spa->spa_missing_tvds != 0) {
3566 		spa_load_note(spa, "vdev tree has %lld missing top-level "
3567 		    "vdevs.", (u_longlong_t)spa->spa_missing_tvds);
3568 		if (spa->spa_trust_config && (spa->spa_mode & SPA_MODE_WRITE)) {
3569 			/*
3570 			 * Although theoretically we could allow users to open
3571 			 * incomplete pools in RW mode, we'd need to add a lot
3572 			 * of extra logic (e.g. adjust pool space to account
3573 			 * for missing vdevs).
3574 			 * This limitation also prevents users from accidentally
3575 			 * opening the pool in RW mode during data recovery and
3576 			 * damaging it further.
3577 			 */
3578 			spa_load_note(spa, "pools with missing top-level "
3579 			    "vdevs can only be opened in read-only mode.");
3580 			error = SET_ERROR(ENXIO);
3581 		} else {
3582 			spa_load_note(spa, "current settings allow for maximum "
3583 			    "%lld missing top-level vdevs at this stage.",
3584 			    (u_longlong_t)spa->spa_missing_tvds_allowed);
3585 		}
3586 	}
3587 	if (error != 0) {
3588 		spa_load_failed(spa, "unable to open vdev tree [error=%d]",
3589 		    error);
3590 	}
3591 	if (spa->spa_missing_tvds != 0 || error != 0)
3592 		vdev_dbgmsg_print_tree(spa->spa_root_vdev, 2);
3593 
3594 	return (error);
3595 }
3596 
3597 /*
3598  * We need to validate the vdev labels against the configuration that
3599  * we have in hand. This function is called twice: first with an untrusted
3600  * config, then with a trusted config. The validation is more strict when the
3601  * config is trusted.
3602  */
3603 static int
3604 spa_ld_validate_vdevs(spa_t *spa)
3605 {
3606 	int error = 0;
3607 	vdev_t *rvd = spa->spa_root_vdev;
3608 
3609 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3610 	error = vdev_validate(rvd);
3611 	spa_config_exit(spa, SCL_ALL, FTAG);
3612 
3613 	if (error != 0) {
3614 		spa_load_failed(spa, "vdev_validate failed [error=%d]", error);
3615 		return (error);
3616 	}
3617 
3618 	if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN) {
3619 		spa_load_failed(spa, "cannot open vdev tree after invalidating "
3620 		    "some vdevs");
3621 		vdev_dbgmsg_print_tree(rvd, 2);
3622 		return (SET_ERROR(ENXIO));
3623 	}
3624 
3625 	return (0);
3626 }
3627 
3628 static void
3629 spa_ld_select_uberblock_done(spa_t *spa, uberblock_t *ub)
3630 {
3631 	spa->spa_state = POOL_STATE_ACTIVE;
3632 	spa->spa_ubsync = spa->spa_uberblock;
3633 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
3634 	    TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
3635 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
3636 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
3637 	spa->spa_claim_max_txg = spa->spa_first_txg;
3638 	spa->spa_prev_software_version = ub->ub_software_version;
3639 }
3640 
3641 static int
3642 spa_ld_select_uberblock(spa_t *spa, spa_import_type_t type)
3643 {
3644 	vdev_t *rvd = spa->spa_root_vdev;
3645 	nvlist_t *label;
3646 	uberblock_t *ub = &spa->spa_uberblock;
3647 	boolean_t activity_check = B_FALSE;
3648 
3649 	/*
3650 	 * If we are opening the checkpointed state of the pool by
3651 	 * rewinding to it, at this point we will have written the
3652 	 * checkpointed uberblock to the vdev labels, so searching
3653 	 * the labels will find the right uberblock.  However, if
3654 	 * we are opening the checkpointed state read-only, we have
3655 	 * not modified the labels. Therefore, we must ignore the
3656 	 * labels and continue using the spa_uberblock that was set
3657 	 * by spa_ld_checkpoint_rewind.
3658 	 *
3659 	 * Note that it would be fine to ignore the labels when
3660 	 * rewinding (opening writeable) as well. However, if we
3661 	 * crash just after writing the labels, we will end up
3662 	 * searching the labels. Doing so in the common case means
3663 	 * that this code path gets exercised normally, rather than
3664 	 * just in the edge case.
3665 	 */
3666 	if (ub->ub_checkpoint_txg != 0 &&
3667 	    spa_importing_readonly_checkpoint(spa)) {
3668 		spa_ld_select_uberblock_done(spa, ub);
3669 		return (0);
3670 	}
3671 
3672 	/*
3673 	 * Find the best uberblock.
3674 	 */
3675 	vdev_uberblock_load(rvd, ub, &label);
3676 
3677 	/*
3678 	 * If we weren't able to find a single valid uberblock, return failure.
3679 	 */
3680 	if (ub->ub_txg == 0) {
3681 		nvlist_free(label);
3682 		spa_load_failed(spa, "no valid uberblock found");
3683 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
3684 	}
3685 
3686 	if (spa->spa_load_max_txg != UINT64_MAX) {
3687 		(void) spa_import_progress_set_max_txg(spa_guid(spa),
3688 		    (u_longlong_t)spa->spa_load_max_txg);
3689 	}
3690 	spa_load_note(spa, "using uberblock with txg=%llu",
3691 	    (u_longlong_t)ub->ub_txg);
3692 
3693 
3694 	/*
3695 	 * For pools which have the multihost property on determine if the
3696 	 * pool is truly inactive and can be safely imported.  Prevent
3697 	 * hosts which don't have a hostid set from importing the pool.
3698 	 */
3699 	activity_check = spa_activity_check_required(spa, ub, label,
3700 	    spa->spa_config);
3701 	if (activity_check) {
3702 		if (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay &&
3703 		    spa_get_hostid(spa) == 0) {
3704 			nvlist_free(label);
3705 			fnvlist_add_uint64(spa->spa_load_info,
3706 			    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_NO_HOSTID);
3707 			return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
3708 		}
3709 
3710 		int error = spa_activity_check(spa, ub, spa->spa_config);
3711 		if (error) {
3712 			nvlist_free(label);
3713 			return (error);
3714 		}
3715 
3716 		fnvlist_add_uint64(spa->spa_load_info,
3717 		    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_INACTIVE);
3718 		fnvlist_add_uint64(spa->spa_load_info,
3719 		    ZPOOL_CONFIG_MMP_TXG, ub->ub_txg);
3720 		fnvlist_add_uint16(spa->spa_load_info,
3721 		    ZPOOL_CONFIG_MMP_SEQ,
3722 		    (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0));
3723 	}
3724 
3725 	/*
3726 	 * If the pool has an unsupported version we can't open it.
3727 	 */
3728 	if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
3729 		nvlist_free(label);
3730 		spa_load_failed(spa, "version %llu is not supported",
3731 		    (u_longlong_t)ub->ub_version);
3732 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
3733 	}
3734 
3735 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
3736 		nvlist_t *features;
3737 
3738 		/*
3739 		 * If we weren't able to find what's necessary for reading the
3740 		 * MOS in the label, return failure.
3741 		 */
3742 		if (label == NULL) {
3743 			spa_load_failed(spa, "label config unavailable");
3744 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
3745 			    ENXIO));
3746 		}
3747 
3748 		if (nvlist_lookup_nvlist(label, ZPOOL_CONFIG_FEATURES_FOR_READ,
3749 		    &features) != 0) {
3750 			nvlist_free(label);
3751 			spa_load_failed(spa, "invalid label: '%s' missing",
3752 			    ZPOOL_CONFIG_FEATURES_FOR_READ);
3753 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
3754 			    ENXIO));
3755 		}
3756 
3757 		/*
3758 		 * Update our in-core representation with the definitive values
3759 		 * from the label.
3760 		 */
3761 		nvlist_free(spa->spa_label_features);
3762 		spa->spa_label_features = fnvlist_dup(features);
3763 	}
3764 
3765 	nvlist_free(label);
3766 
3767 	/*
3768 	 * Look through entries in the label nvlist's features_for_read. If
3769 	 * there is a feature listed there which we don't understand then we
3770 	 * cannot open a pool.
3771 	 */
3772 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
3773 		nvlist_t *unsup_feat;
3774 
3775 		unsup_feat = fnvlist_alloc();
3776 
3777 		for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
3778 		    NULL); nvp != NULL;
3779 		    nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
3780 			if (!zfeature_is_supported(nvpair_name(nvp))) {
3781 				fnvlist_add_string(unsup_feat,
3782 				    nvpair_name(nvp), "");
3783 			}
3784 		}
3785 
3786 		if (!nvlist_empty(unsup_feat)) {
3787 			fnvlist_add_nvlist(spa->spa_load_info,
3788 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
3789 			nvlist_free(unsup_feat);
3790 			spa_load_failed(spa, "some features are unsupported");
3791 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
3792 			    ENOTSUP));
3793 		}
3794 
3795 		nvlist_free(unsup_feat);
3796 	}
3797 
3798 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
3799 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3800 		spa_try_repair(spa, spa->spa_config);
3801 		spa_config_exit(spa, SCL_ALL, FTAG);
3802 		nvlist_free(spa->spa_config_splitting);
3803 		spa->spa_config_splitting = NULL;
3804 	}
3805 
3806 	/*
3807 	 * Initialize internal SPA structures.
3808 	 */
3809 	spa_ld_select_uberblock_done(spa, ub);
3810 
3811 	return (0);
3812 }
3813 
3814 static int
3815 spa_ld_open_rootbp(spa_t *spa)
3816 {
3817 	int error = 0;
3818 	vdev_t *rvd = spa->spa_root_vdev;
3819 
3820 	error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
3821 	if (error != 0) {
3822 		spa_load_failed(spa, "unable to open rootbp in dsl_pool_init "
3823 		    "[error=%d]", error);
3824 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
3825 	}
3826 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
3827 
3828 	return (0);
3829 }
3830 
3831 static int
3832 spa_ld_trusted_config(spa_t *spa, spa_import_type_t type,
3833     boolean_t reloading)
3834 {
3835 	vdev_t *mrvd, *rvd = spa->spa_root_vdev;
3836 	nvlist_t *nv, *mos_config, *policy;
3837 	int error = 0, copy_error;
3838 	uint64_t healthy_tvds, healthy_tvds_mos;
3839 	uint64_t mos_config_txg;
3840 
3841 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object, B_TRUE)
3842 	    != 0)
3843 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
3844 
3845 	/*
3846 	 * If we're assembling a pool from a split, the config provided is
3847 	 * already trusted so there is nothing to do.
3848 	 */
3849 	if (type == SPA_IMPORT_ASSEMBLE)
3850 		return (0);
3851 
3852 	healthy_tvds = spa_healthy_core_tvds(spa);
3853 
3854 	if (load_nvlist(spa, spa->spa_config_object, &mos_config)
3855 	    != 0) {
3856 		spa_load_failed(spa, "unable to retrieve MOS config");
3857 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
3858 	}
3859 
3860 	/*
3861 	 * If we are doing an open, pool owner wasn't verified yet, thus do
3862 	 * the verification here.
3863 	 */
3864 	if (spa->spa_load_state == SPA_LOAD_OPEN) {
3865 		error = spa_verify_host(spa, mos_config);
3866 		if (error != 0) {
3867 			nvlist_free(mos_config);
3868 			return (error);
3869 		}
3870 	}
3871 
3872 	nv = fnvlist_lookup_nvlist(mos_config, ZPOOL_CONFIG_VDEV_TREE);
3873 
3874 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3875 
3876 	/*
3877 	 * Build a new vdev tree from the trusted config
3878 	 */
3879 	error = spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD);
3880 	if (error != 0) {
3881 		nvlist_free(mos_config);
3882 		spa_config_exit(spa, SCL_ALL, FTAG);
3883 		spa_load_failed(spa, "spa_config_parse failed [error=%d]",
3884 		    error);
3885 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
3886 	}
3887 
3888 	/*
3889 	 * Vdev paths in the MOS may be obsolete. If the untrusted config was
3890 	 * obtained by scanning /dev/dsk, then it will have the right vdev
3891 	 * paths. We update the trusted MOS config with this information.
3892 	 * We first try to copy the paths with vdev_copy_path_strict, which
3893 	 * succeeds only when both configs have exactly the same vdev tree.
3894 	 * If that fails, we fall back to a more flexible method that has a
3895 	 * best effort policy.
3896 	 */
3897 	copy_error = vdev_copy_path_strict(rvd, mrvd);
3898 	if (copy_error != 0 || spa_load_print_vdev_tree) {
3899 		spa_load_note(spa, "provided vdev tree:");
3900 		vdev_dbgmsg_print_tree(rvd, 2);
3901 		spa_load_note(spa, "MOS vdev tree:");
3902 		vdev_dbgmsg_print_tree(mrvd, 2);
3903 	}
3904 	if (copy_error != 0) {
3905 		spa_load_note(spa, "vdev_copy_path_strict failed, falling "
3906 		    "back to vdev_copy_path_relaxed");
3907 		vdev_copy_path_relaxed(rvd, mrvd);
3908 	}
3909 
3910 	vdev_close(rvd);
3911 	vdev_free(rvd);
3912 	spa->spa_root_vdev = mrvd;
3913 	rvd = mrvd;
3914 	spa_config_exit(spa, SCL_ALL, FTAG);
3915 
3916 	/*
3917 	 * We will use spa_config if we decide to reload the spa or if spa_load
3918 	 * fails and we rewind. We must thus regenerate the config using the
3919 	 * MOS information with the updated paths. ZPOOL_LOAD_POLICY is used to
3920 	 * pass settings on how to load the pool and is not stored in the MOS.
3921 	 * We copy it over to our new, trusted config.
3922 	 */
3923 	mos_config_txg = fnvlist_lookup_uint64(mos_config,
3924 	    ZPOOL_CONFIG_POOL_TXG);
3925 	nvlist_free(mos_config);
3926 	mos_config = spa_config_generate(spa, NULL, mos_config_txg, B_FALSE);
3927 	if (nvlist_lookup_nvlist(spa->spa_config, ZPOOL_LOAD_POLICY,
3928 	    &policy) == 0)
3929 		fnvlist_add_nvlist(mos_config, ZPOOL_LOAD_POLICY, policy);
3930 	spa_config_set(spa, mos_config);
3931 	spa->spa_config_source = SPA_CONFIG_SRC_MOS;
3932 
3933 	/*
3934 	 * Now that we got the config from the MOS, we should be more strict
3935 	 * in checking blkptrs and can make assumptions about the consistency
3936 	 * of the vdev tree. spa_trust_config must be set to true before opening
3937 	 * vdevs in order for them to be writeable.
3938 	 */
3939 	spa->spa_trust_config = B_TRUE;
3940 
3941 	/*
3942 	 * Open and validate the new vdev tree
3943 	 */
3944 	error = spa_ld_open_vdevs(spa);
3945 	if (error != 0)
3946 		return (error);
3947 
3948 	error = spa_ld_validate_vdevs(spa);
3949 	if (error != 0)
3950 		return (error);
3951 
3952 	if (copy_error != 0 || spa_load_print_vdev_tree) {
3953 		spa_load_note(spa, "final vdev tree:");
3954 		vdev_dbgmsg_print_tree(rvd, 2);
3955 	}
3956 
3957 	if (spa->spa_load_state != SPA_LOAD_TRYIMPORT &&
3958 	    !spa->spa_extreme_rewind && zfs_max_missing_tvds == 0) {
3959 		/*
3960 		 * Sanity check to make sure that we are indeed loading the
3961 		 * latest uberblock. If we missed SPA_SYNC_MIN_VDEVS tvds
3962 		 * in the config provided and they happened to be the only ones
3963 		 * to have the latest uberblock, we could involuntarily perform
3964 		 * an extreme rewind.
3965 		 */
3966 		healthy_tvds_mos = spa_healthy_core_tvds(spa);
3967 		if (healthy_tvds_mos - healthy_tvds >=
3968 		    SPA_SYNC_MIN_VDEVS) {
3969 			spa_load_note(spa, "config provided misses too many "
3970 			    "top-level vdevs compared to MOS (%lld vs %lld). ",
3971 			    (u_longlong_t)healthy_tvds,
3972 			    (u_longlong_t)healthy_tvds_mos);
3973 			spa_load_note(spa, "vdev tree:");
3974 			vdev_dbgmsg_print_tree(rvd, 2);
3975 			if (reloading) {
3976 				spa_load_failed(spa, "config was already "
3977 				    "provided from MOS. Aborting.");
3978 				return (spa_vdev_err(rvd,
3979 				    VDEV_AUX_CORRUPT_DATA, EIO));
3980 			}
3981 			spa_load_note(spa, "spa must be reloaded using MOS "
3982 			    "config");
3983 			return (SET_ERROR(EAGAIN));
3984 		}
3985 	}
3986 
3987 	error = spa_check_for_missing_logs(spa);
3988 	if (error != 0)
3989 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
3990 
3991 	if (rvd->vdev_guid_sum != spa->spa_uberblock.ub_guid_sum) {
3992 		spa_load_failed(spa, "uberblock guid sum doesn't match MOS "
3993 		    "guid sum (%llu != %llu)",
3994 		    (u_longlong_t)spa->spa_uberblock.ub_guid_sum,
3995 		    (u_longlong_t)rvd->vdev_guid_sum);
3996 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
3997 		    ENXIO));
3998 	}
3999 
4000 	return (0);
4001 }
4002 
4003 static int
4004 spa_ld_open_indirect_vdev_metadata(spa_t *spa)
4005 {
4006 	int error = 0;
4007 	vdev_t *rvd = spa->spa_root_vdev;
4008 
4009 	/*
4010 	 * Everything that we read before spa_remove_init() must be stored
4011 	 * on concreted vdevs.  Therefore we do this as early as possible.
4012 	 */
4013 	error = spa_remove_init(spa);
4014 	if (error != 0) {
4015 		spa_load_failed(spa, "spa_remove_init failed [error=%d]",
4016 		    error);
4017 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4018 	}
4019 
4020 	/*
4021 	 * Retrieve information needed to condense indirect vdev mappings.
4022 	 */
4023 	error = spa_condense_init(spa);
4024 	if (error != 0) {
4025 		spa_load_failed(spa, "spa_condense_init failed [error=%d]",
4026 		    error);
4027 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
4028 	}
4029 
4030 	return (0);
4031 }
4032 
4033 static int
4034 spa_ld_check_features(spa_t *spa, boolean_t *missing_feat_writep)
4035 {
4036 	int error = 0;
4037 	vdev_t *rvd = spa->spa_root_vdev;
4038 
4039 	if (spa_version(spa) >= SPA_VERSION_FEATURES) {
4040 		boolean_t missing_feat_read = B_FALSE;
4041 		nvlist_t *unsup_feat, *enabled_feat;
4042 
4043 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
4044 		    &spa->spa_feat_for_read_obj, B_TRUE) != 0) {
4045 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4046 		}
4047 
4048 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
4049 		    &spa->spa_feat_for_write_obj, B_TRUE) != 0) {
4050 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4051 		}
4052 
4053 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
4054 		    &spa->spa_feat_desc_obj, B_TRUE) != 0) {
4055 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4056 		}
4057 
4058 		enabled_feat = fnvlist_alloc();
4059 		unsup_feat = fnvlist_alloc();
4060 
4061 		if (!spa_features_check(spa, B_FALSE,
4062 		    unsup_feat, enabled_feat))
4063 			missing_feat_read = B_TRUE;
4064 
4065 		if (spa_writeable(spa) ||
4066 		    spa->spa_load_state == SPA_LOAD_TRYIMPORT) {
4067 			if (!spa_features_check(spa, B_TRUE,
4068 			    unsup_feat, enabled_feat)) {
4069 				*missing_feat_writep = B_TRUE;
4070 			}
4071 		}
4072 
4073 		fnvlist_add_nvlist(spa->spa_load_info,
4074 		    ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
4075 
4076 		if (!nvlist_empty(unsup_feat)) {
4077 			fnvlist_add_nvlist(spa->spa_load_info,
4078 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
4079 		}
4080 
4081 		fnvlist_free(enabled_feat);
4082 		fnvlist_free(unsup_feat);
4083 
4084 		if (!missing_feat_read) {
4085 			fnvlist_add_boolean(spa->spa_load_info,
4086 			    ZPOOL_CONFIG_CAN_RDONLY);
4087 		}
4088 
4089 		/*
4090 		 * If the state is SPA_LOAD_TRYIMPORT, our objective is
4091 		 * twofold: to determine whether the pool is available for
4092 		 * import in read-write mode and (if it is not) whether the
4093 		 * pool is available for import in read-only mode. If the pool
4094 		 * is available for import in read-write mode, it is displayed
4095 		 * as available in userland; if it is not available for import
4096 		 * in read-only mode, it is displayed as unavailable in
4097 		 * userland. If the pool is available for import in read-only
4098 		 * mode but not read-write mode, it is displayed as unavailable
4099 		 * in userland with a special note that the pool is actually
4100 		 * available for open in read-only mode.
4101 		 *
4102 		 * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
4103 		 * missing a feature for write, we must first determine whether
4104 		 * the pool can be opened read-only before returning to
4105 		 * userland in order to know whether to display the
4106 		 * abovementioned note.
4107 		 */
4108 		if (missing_feat_read || (*missing_feat_writep &&
4109 		    spa_writeable(spa))) {
4110 			spa_load_failed(spa, "pool uses unsupported features");
4111 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
4112 			    ENOTSUP));
4113 		}
4114 
4115 		/*
4116 		 * Load refcounts for ZFS features from disk into an in-memory
4117 		 * cache during SPA initialization.
4118 		 */
4119 		for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
4120 			uint64_t refcount;
4121 
4122 			error = feature_get_refcount_from_disk(spa,
4123 			    &spa_feature_table[i], &refcount);
4124 			if (error == 0) {
4125 				spa->spa_feat_refcount_cache[i] = refcount;
4126 			} else if (error == ENOTSUP) {
4127 				spa->spa_feat_refcount_cache[i] =
4128 				    SPA_FEATURE_DISABLED;
4129 			} else {
4130 				spa_load_failed(spa, "error getting refcount "
4131 				    "for feature %s [error=%d]",
4132 				    spa_feature_table[i].fi_guid, error);
4133 				return (spa_vdev_err(rvd,
4134 				    VDEV_AUX_CORRUPT_DATA, EIO));
4135 			}
4136 		}
4137 	}
4138 
4139 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
4140 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
4141 		    &spa->spa_feat_enabled_txg_obj, B_TRUE) != 0)
4142 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4143 	}
4144 
4145 	/*
4146 	 * Encryption was added before bookmark_v2, even though bookmark_v2
4147 	 * is now a dependency. If this pool has encryption enabled without
4148 	 * bookmark_v2, trigger an errata message.
4149 	 */
4150 	if (spa_feature_is_enabled(spa, SPA_FEATURE_ENCRYPTION) &&
4151 	    !spa_feature_is_enabled(spa, SPA_FEATURE_BOOKMARK_V2)) {
4152 		spa->spa_errata = ZPOOL_ERRATA_ZOL_8308_ENCRYPTION;
4153 	}
4154 
4155 	return (0);
4156 }
4157 
4158 static int
4159 spa_ld_load_special_directories(spa_t *spa)
4160 {
4161 	int error = 0;
4162 	vdev_t *rvd = spa->spa_root_vdev;
4163 
4164 	spa->spa_is_initializing = B_TRUE;
4165 	error = dsl_pool_open(spa->spa_dsl_pool);
4166 	spa->spa_is_initializing = B_FALSE;
4167 	if (error != 0) {
4168 		spa_load_failed(spa, "dsl_pool_open failed [error=%d]", error);
4169 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4170 	}
4171 
4172 	return (0);
4173 }
4174 
4175 static int
4176 spa_ld_get_props(spa_t *spa)
4177 {
4178 	int error = 0;
4179 	uint64_t obj;
4180 	vdev_t *rvd = spa->spa_root_vdev;
4181 
4182 	/* Grab the checksum salt from the MOS. */
4183 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
4184 	    DMU_POOL_CHECKSUM_SALT, 1,
4185 	    sizeof (spa->spa_cksum_salt.zcs_bytes),
4186 	    spa->spa_cksum_salt.zcs_bytes);
4187 	if (error == ENOENT) {
4188 		/* Generate a new salt for subsequent use */
4189 		(void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
4190 		    sizeof (spa->spa_cksum_salt.zcs_bytes));
4191 	} else if (error != 0) {
4192 		spa_load_failed(spa, "unable to retrieve checksum salt from "
4193 		    "MOS [error=%d]", error);
4194 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4195 	}
4196 
4197 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj, B_TRUE) != 0)
4198 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4199 	error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
4200 	if (error != 0) {
4201 		spa_load_failed(spa, "error opening deferred-frees bpobj "
4202 		    "[error=%d]", error);
4203 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4204 	}
4205 
4206 	/*
4207 	 * Load the bit that tells us to use the new accounting function
4208 	 * (raid-z deflation).  If we have an older pool, this will not
4209 	 * be present.
4210 	 */
4211 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate, B_FALSE);
4212 	if (error != 0 && error != ENOENT)
4213 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4214 
4215 	error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
4216 	    &spa->spa_creation_version, B_FALSE);
4217 	if (error != 0 && error != ENOENT)
4218 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4219 
4220 	/*
4221 	 * Load the persistent error log.  If we have an older pool, this will
4222 	 * not be present.
4223 	 */
4224 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last,
4225 	    B_FALSE);
4226 	if (error != 0 && error != ENOENT)
4227 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4228 
4229 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
4230 	    &spa->spa_errlog_scrub, B_FALSE);
4231 	if (error != 0 && error != ENOENT)
4232 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4233 
4234 	/*
4235 	 * Load the livelist deletion field. If a livelist is queued for
4236 	 * deletion, indicate that in the spa
4237 	 */
4238 	error = spa_dir_prop(spa, DMU_POOL_DELETED_CLONES,
4239 	    &spa->spa_livelists_to_delete, B_FALSE);
4240 	if (error != 0 && error != ENOENT)
4241 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4242 
4243 	/*
4244 	 * Load the history object.  If we have an older pool, this
4245 	 * will not be present.
4246 	 */
4247 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history, B_FALSE);
4248 	if (error != 0 && error != ENOENT)
4249 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4250 
4251 	/*
4252 	 * Load the per-vdev ZAP map. If we have an older pool, this will not
4253 	 * be present; in this case, defer its creation to a later time to
4254 	 * avoid dirtying the MOS this early / out of sync context. See
4255 	 * spa_sync_config_object.
4256 	 */
4257 
4258 	/* The sentinel is only available in the MOS config. */
4259 	nvlist_t *mos_config;
4260 	if (load_nvlist(spa, spa->spa_config_object, &mos_config) != 0) {
4261 		spa_load_failed(spa, "unable to retrieve MOS config");
4262 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4263 	}
4264 
4265 	error = spa_dir_prop(spa, DMU_POOL_VDEV_ZAP_MAP,
4266 	    &spa->spa_all_vdev_zaps, B_FALSE);
4267 
4268 	if (error == ENOENT) {
4269 		VERIFY(!nvlist_exists(mos_config,
4270 		    ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS));
4271 		spa->spa_avz_action = AVZ_ACTION_INITIALIZE;
4272 		ASSERT0(vdev_count_verify_zaps(spa->spa_root_vdev));
4273 	} else if (error != 0) {
4274 		nvlist_free(mos_config);
4275 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4276 	} else if (!nvlist_exists(mos_config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS)) {
4277 		/*
4278 		 * An older version of ZFS overwrote the sentinel value, so
4279 		 * we have orphaned per-vdev ZAPs in the MOS. Defer their
4280 		 * destruction to later; see spa_sync_config_object.
4281 		 */
4282 		spa->spa_avz_action = AVZ_ACTION_DESTROY;
4283 		/*
4284 		 * We're assuming that no vdevs have had their ZAPs created
4285 		 * before this. Better be sure of it.
4286 		 */
4287 		ASSERT0(vdev_count_verify_zaps(spa->spa_root_vdev));
4288 	}
4289 	nvlist_free(mos_config);
4290 
4291 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
4292 
4293 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object,
4294 	    B_FALSE);
4295 	if (error && error != ENOENT)
4296 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4297 
4298 	if (error == 0) {
4299 		uint64_t autoreplace = 0;
4300 
4301 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
4302 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
4303 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
4304 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
4305 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
4306 		spa_prop_find(spa, ZPOOL_PROP_MULTIHOST, &spa->spa_multihost);
4307 		spa_prop_find(spa, ZPOOL_PROP_AUTOTRIM, &spa->spa_autotrim);
4308 		spa->spa_autoreplace = (autoreplace != 0);
4309 	}
4310 
4311 	/*
4312 	 * If we are importing a pool with missing top-level vdevs,
4313 	 * we enforce that the pool doesn't panic or get suspended on
4314 	 * error since the likelihood of missing data is extremely high.
4315 	 */
4316 	if (spa->spa_missing_tvds > 0 &&
4317 	    spa->spa_failmode != ZIO_FAILURE_MODE_CONTINUE &&
4318 	    spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
4319 		spa_load_note(spa, "forcing failmode to 'continue' "
4320 		    "as some top level vdevs are missing");
4321 		spa->spa_failmode = ZIO_FAILURE_MODE_CONTINUE;
4322 	}
4323 
4324 	return (0);
4325 }
4326 
4327 static int
4328 spa_ld_open_aux_vdevs(spa_t *spa, spa_import_type_t type)
4329 {
4330 	int error = 0;
4331 	vdev_t *rvd = spa->spa_root_vdev;
4332 
4333 	/*
4334 	 * If we're assembling the pool from the split-off vdevs of
4335 	 * an existing pool, we don't want to attach the spares & cache
4336 	 * devices.
4337 	 */
4338 
4339 	/*
4340 	 * Load any hot spares for this pool.
4341 	 */
4342 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object,
4343 	    B_FALSE);
4344 	if (error != 0 && error != ENOENT)
4345 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4346 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
4347 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
4348 		if (load_nvlist(spa, spa->spa_spares.sav_object,
4349 		    &spa->spa_spares.sav_config) != 0) {
4350 			spa_load_failed(spa, "error loading spares nvlist");
4351 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4352 		}
4353 
4354 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4355 		spa_load_spares(spa);
4356 		spa_config_exit(spa, SCL_ALL, FTAG);
4357 	} else if (error == 0) {
4358 		spa->spa_spares.sav_sync = B_TRUE;
4359 	}
4360 
4361 	/*
4362 	 * Load any level 2 ARC devices for this pool.
4363 	 */
4364 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
4365 	    &spa->spa_l2cache.sav_object, B_FALSE);
4366 	if (error != 0 && error != ENOENT)
4367 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4368 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
4369 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
4370 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
4371 		    &spa->spa_l2cache.sav_config) != 0) {
4372 			spa_load_failed(spa, "error loading l2cache nvlist");
4373 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4374 		}
4375 
4376 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4377 		spa_load_l2cache(spa);
4378 		spa_config_exit(spa, SCL_ALL, FTAG);
4379 	} else if (error == 0) {
4380 		spa->spa_l2cache.sav_sync = B_TRUE;
4381 	}
4382 
4383 	return (0);
4384 }
4385 
4386 static int
4387 spa_ld_load_vdev_metadata(spa_t *spa)
4388 {
4389 	int error = 0;
4390 	vdev_t *rvd = spa->spa_root_vdev;
4391 
4392 	/*
4393 	 * If the 'multihost' property is set, then never allow a pool to
4394 	 * be imported when the system hostid is zero.  The exception to
4395 	 * this rule is zdb which is always allowed to access pools.
4396 	 */
4397 	if (spa_multihost(spa) && spa_get_hostid(spa) == 0 &&
4398 	    (spa->spa_import_flags & ZFS_IMPORT_SKIP_MMP) == 0) {
4399 		fnvlist_add_uint64(spa->spa_load_info,
4400 		    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_NO_HOSTID);
4401 		return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
4402 	}
4403 
4404 	/*
4405 	 * If the 'autoreplace' property is set, then post a resource notifying
4406 	 * the ZFS DE that it should not issue any faults for unopenable
4407 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
4408 	 * unopenable vdevs so that the normal autoreplace handler can take
4409 	 * over.
4410 	 */
4411 	if (spa->spa_autoreplace && spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
4412 		spa_check_removed(spa->spa_root_vdev);
4413 		/*
4414 		 * For the import case, this is done in spa_import(), because
4415 		 * at this point we're using the spare definitions from
4416 		 * the MOS config, not necessarily from the userland config.
4417 		 */
4418 		if (spa->spa_load_state != SPA_LOAD_IMPORT) {
4419 			spa_aux_check_removed(&spa->spa_spares);
4420 			spa_aux_check_removed(&spa->spa_l2cache);
4421 		}
4422 	}
4423 
4424 	/*
4425 	 * Load the vdev metadata such as metaslabs, DTLs, spacemap object, etc.
4426 	 */
4427 	error = vdev_load(rvd);
4428 	if (error != 0) {
4429 		spa_load_failed(spa, "vdev_load failed [error=%d]", error);
4430 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
4431 	}
4432 
4433 	error = spa_ld_log_spacemaps(spa);
4434 	if (error != 0) {
4435 		spa_load_failed(spa, "spa_ld_log_spacemaps failed [error=%d]",
4436 		    error);
4437 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
4438 	}
4439 
4440 	/*
4441 	 * Propagate the leaf DTLs we just loaded all the way up the vdev tree.
4442 	 */
4443 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4444 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE, B_FALSE);
4445 	spa_config_exit(spa, SCL_ALL, FTAG);
4446 
4447 	return (0);
4448 }
4449 
4450 static int
4451 spa_ld_load_dedup_tables(spa_t *spa)
4452 {
4453 	int error = 0;
4454 	vdev_t *rvd = spa->spa_root_vdev;
4455 
4456 	error = ddt_load(spa);
4457 	if (error != 0) {
4458 		spa_load_failed(spa, "ddt_load failed [error=%d]", error);
4459 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4460 	}
4461 
4462 	return (0);
4463 }
4464 
4465 static int
4466 spa_ld_load_brt(spa_t *spa)
4467 {
4468 	int error = 0;
4469 	vdev_t *rvd = spa->spa_root_vdev;
4470 
4471 	error = brt_load(spa);
4472 	if (error != 0) {
4473 		spa_load_failed(spa, "brt_load failed [error=%d]", error);
4474 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
4475 	}
4476 
4477 	return (0);
4478 }
4479 
4480 static int
4481 spa_ld_verify_logs(spa_t *spa, spa_import_type_t type, const char **ereport)
4482 {
4483 	vdev_t *rvd = spa->spa_root_vdev;
4484 
4485 	if (type != SPA_IMPORT_ASSEMBLE && spa_writeable(spa)) {
4486 		boolean_t missing = spa_check_logs(spa);
4487 		if (missing) {
4488 			if (spa->spa_missing_tvds != 0) {
4489 				spa_load_note(spa, "spa_check_logs failed "
4490 				    "so dropping the logs");
4491 			} else {
4492 				*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
4493 				spa_load_failed(spa, "spa_check_logs failed");
4494 				return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG,
4495 				    ENXIO));
4496 			}
4497 		}
4498 	}
4499 
4500 	return (0);
4501 }
4502 
4503 static int
4504 spa_ld_verify_pool_data(spa_t *spa)
4505 {
4506 	int error = 0;
4507 	vdev_t *rvd = spa->spa_root_vdev;
4508 
4509 	/*
4510 	 * We've successfully opened the pool, verify that we're ready
4511 	 * to start pushing transactions.
4512 	 */
4513 	if (spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
4514 		error = spa_load_verify(spa);
4515 		if (error != 0) {
4516 			spa_load_failed(spa, "spa_load_verify failed "
4517 			    "[error=%d]", error);
4518 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
4519 			    error));
4520 		}
4521 	}
4522 
4523 	return (0);
4524 }
4525 
4526 static void
4527 spa_ld_claim_log_blocks(spa_t *spa)
4528 {
4529 	dmu_tx_t *tx;
4530 	dsl_pool_t *dp = spa_get_dsl(spa);
4531 
4532 	/*
4533 	 * Claim log blocks that haven't been committed yet.
4534 	 * This must all happen in a single txg.
4535 	 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
4536 	 * invoked from zil_claim_log_block()'s i/o done callback.
4537 	 * Price of rollback is that we abandon the log.
4538 	 */
4539 	spa->spa_claiming = B_TRUE;
4540 
4541 	tx = dmu_tx_create_assigned(dp, spa_first_txg(spa));
4542 	(void) dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
4543 	    zil_claim, tx, DS_FIND_CHILDREN);
4544 	dmu_tx_commit(tx);
4545 
4546 	spa->spa_claiming = B_FALSE;
4547 
4548 	spa_set_log_state(spa, SPA_LOG_GOOD);
4549 }
4550 
4551 static void
4552 spa_ld_check_for_config_update(spa_t *spa, uint64_t config_cache_txg,
4553     boolean_t update_config_cache)
4554 {
4555 	vdev_t *rvd = spa->spa_root_vdev;
4556 	int need_update = B_FALSE;
4557 
4558 	/*
4559 	 * If the config cache is stale, or we have uninitialized
4560 	 * metaslabs (see spa_vdev_add()), then update the config.
4561 	 *
4562 	 * If this is a verbatim import, trust the current
4563 	 * in-core spa_config and update the disk labels.
4564 	 */
4565 	if (update_config_cache || config_cache_txg != spa->spa_config_txg ||
4566 	    spa->spa_load_state == SPA_LOAD_IMPORT ||
4567 	    spa->spa_load_state == SPA_LOAD_RECOVER ||
4568 	    (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
4569 		need_update = B_TRUE;
4570 
4571 	for (int c = 0; c < rvd->vdev_children; c++)
4572 		if (rvd->vdev_child[c]->vdev_ms_array == 0)
4573 			need_update = B_TRUE;
4574 
4575 	/*
4576 	 * Update the config cache asynchronously in case we're the
4577 	 * root pool, in which case the config cache isn't writable yet.
4578 	 */
4579 	if (need_update)
4580 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
4581 }
4582 
4583 static void
4584 spa_ld_prepare_for_reload(spa_t *spa)
4585 {
4586 	spa_mode_t mode = spa->spa_mode;
4587 	int async_suspended = spa->spa_async_suspended;
4588 
4589 	spa_unload(spa);
4590 	spa_deactivate(spa);
4591 	spa_activate(spa, mode);
4592 
4593 	/*
4594 	 * We save the value of spa_async_suspended as it gets reset to 0 by
4595 	 * spa_unload(). We want to restore it back to the original value before
4596 	 * returning as we might be calling spa_async_resume() later.
4597 	 */
4598 	spa->spa_async_suspended = async_suspended;
4599 }
4600 
4601 static int
4602 spa_ld_read_checkpoint_txg(spa_t *spa)
4603 {
4604 	uberblock_t checkpoint;
4605 	int error = 0;
4606 
4607 	ASSERT0(spa->spa_checkpoint_txg);
4608 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4609 
4610 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
4611 	    DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
4612 	    sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);
4613 
4614 	if (error == ENOENT)
4615 		return (0);
4616 
4617 	if (error != 0)
4618 		return (error);
4619 
4620 	ASSERT3U(checkpoint.ub_txg, !=, 0);
4621 	ASSERT3U(checkpoint.ub_checkpoint_txg, !=, 0);
4622 	ASSERT3U(checkpoint.ub_timestamp, !=, 0);
4623 	spa->spa_checkpoint_txg = checkpoint.ub_txg;
4624 	spa->spa_checkpoint_info.sci_timestamp = checkpoint.ub_timestamp;
4625 
4626 	return (0);
4627 }
4628 
4629 static int
4630 spa_ld_mos_init(spa_t *spa, spa_import_type_t type)
4631 {
4632 	int error = 0;
4633 
4634 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4635 	ASSERT(spa->spa_config_source != SPA_CONFIG_SRC_NONE);
4636 
4637 	/*
4638 	 * Never trust the config that is provided unless we are assembling
4639 	 * a pool following a split.
4640 	 * This means don't trust blkptrs and the vdev tree in general. This
4641 	 * also effectively puts the spa in read-only mode since
4642 	 * spa_writeable() checks for spa_trust_config to be true.
4643 	 * We will later load a trusted config from the MOS.
4644 	 */
4645 	if (type != SPA_IMPORT_ASSEMBLE)
4646 		spa->spa_trust_config = B_FALSE;
4647 
4648 	/*
4649 	 * Parse the config provided to create a vdev tree.
4650 	 */
4651 	error = spa_ld_parse_config(spa, type);
4652 	if (error != 0)
4653 		return (error);
4654 
4655 	spa_import_progress_add(spa);
4656 
4657 	/*
4658 	 * Now that we have the vdev tree, try to open each vdev. This involves
4659 	 * opening the underlying physical device, retrieving its geometry and
4660 	 * probing the vdev with a dummy I/O. The state of each vdev will be set
4661 	 * based on the success of those operations. After this we'll be ready
4662 	 * to read from the vdevs.
4663 	 */
4664 	error = spa_ld_open_vdevs(spa);
4665 	if (error != 0)
4666 		return (error);
4667 
4668 	/*
4669 	 * Read the label of each vdev and make sure that the GUIDs stored
4670 	 * there match the GUIDs in the config provided.
4671 	 * If we're assembling a new pool that's been split off from an
4672 	 * existing pool, the labels haven't yet been updated so we skip
4673 	 * validation for now.
4674 	 */
4675 	if (type != SPA_IMPORT_ASSEMBLE) {
4676 		error = spa_ld_validate_vdevs(spa);
4677 		if (error != 0)
4678 			return (error);
4679 	}
4680 
4681 	/*
4682 	 * Read all vdev labels to find the best uberblock (i.e. latest,
4683 	 * unless spa_load_max_txg is set) and store it in spa_uberblock. We
4684 	 * get the list of features required to read blkptrs in the MOS from
4685 	 * the vdev label with the best uberblock and verify that our version
4686 	 * of zfs supports them all.
4687 	 */
4688 	error = spa_ld_select_uberblock(spa, type);
4689 	if (error != 0)
4690 		return (error);
4691 
4692 	/*
4693 	 * Pass that uberblock to the dsl_pool layer which will open the root
4694 	 * blkptr. This blkptr points to the latest version of the MOS and will
4695 	 * allow us to read its contents.
4696 	 */
4697 	error = spa_ld_open_rootbp(spa);
4698 	if (error != 0)
4699 		return (error);
4700 
4701 	return (0);
4702 }
4703 
4704 static int
4705 spa_ld_checkpoint_rewind(spa_t *spa)
4706 {
4707 	uberblock_t checkpoint;
4708 	int error = 0;
4709 
4710 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4711 	ASSERT(spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
4712 
4713 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
4714 	    DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
4715 	    sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);
4716 
4717 	if (error != 0) {
4718 		spa_load_failed(spa, "unable to retrieve checkpointed "
4719 		    "uberblock from the MOS config [error=%d]", error);
4720 
4721 		if (error == ENOENT)
4722 			error = ZFS_ERR_NO_CHECKPOINT;
4723 
4724 		return (error);
4725 	}
4726 
4727 	ASSERT3U(checkpoint.ub_txg, <, spa->spa_uberblock.ub_txg);
4728 	ASSERT3U(checkpoint.ub_txg, ==, checkpoint.ub_checkpoint_txg);
4729 
4730 	/*
4731 	 * We need to update the txg and timestamp of the checkpointed
4732 	 * uberblock to be higher than the latest one. This ensures that
4733 	 * the checkpointed uberblock is selected if we were to close and
4734 	 * reopen the pool right after we've written it in the vdev labels.
4735 	 * (also see block comment in vdev_uberblock_compare)
4736 	 */
4737 	checkpoint.ub_txg = spa->spa_uberblock.ub_txg + 1;
4738 	checkpoint.ub_timestamp = gethrestime_sec();
4739 
4740 	/*
4741 	 * Set current uberblock to be the checkpointed uberblock.
4742 	 */
4743 	spa->spa_uberblock = checkpoint;
4744 
4745 	/*
4746 	 * If we are doing a normal rewind, then the pool is open for
4747 	 * writing and we sync the "updated" checkpointed uberblock to
4748 	 * disk. Once this is done, we've basically rewound the whole
4749 	 * pool and there is no way back.
4750 	 *
4751 	 * There are cases when we don't want to attempt and sync the
4752 	 * checkpointed uberblock to disk because we are opening a
4753 	 * pool as read-only. Specifically, verifying the checkpointed
4754 	 * state with zdb, and importing the checkpointed state to get
4755 	 * a "preview" of its content.
4756 	 */
4757 	if (spa_writeable(spa)) {
4758 		vdev_t *rvd = spa->spa_root_vdev;
4759 
4760 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4761 		vdev_t *svd[SPA_SYNC_MIN_VDEVS] = { NULL };
4762 		int svdcount = 0;
4763 		int children = rvd->vdev_children;
4764 		int c0 = random_in_range(children);
4765 
4766 		for (int c = 0; c < children; c++) {
4767 			vdev_t *vd = rvd->vdev_child[(c0 + c) % children];
4768 
4769 			/* Stop when revisiting the first vdev */
4770 			if (c > 0 && svd[0] == vd)
4771 				break;
4772 
4773 			if (vd->vdev_ms_array == 0 || vd->vdev_islog ||
4774 			    !vdev_is_concrete(vd))
4775 				continue;
4776 
4777 			svd[svdcount++] = vd;
4778 			if (svdcount == SPA_SYNC_MIN_VDEVS)
4779 				break;
4780 		}
4781 		error = vdev_config_sync(svd, svdcount, spa->spa_first_txg);
4782 		if (error == 0)
4783 			spa->spa_last_synced_guid = rvd->vdev_guid;
4784 		spa_config_exit(spa, SCL_ALL, FTAG);
4785 
4786 		if (error != 0) {
4787 			spa_load_failed(spa, "failed to write checkpointed "
4788 			    "uberblock to the vdev labels [error=%d]", error);
4789 			return (error);
4790 		}
4791 	}
4792 
4793 	return (0);
4794 }
4795 
4796 static int
4797 spa_ld_mos_with_trusted_config(spa_t *spa, spa_import_type_t type,
4798     boolean_t *update_config_cache)
4799 {
4800 	int error;
4801 
4802 	/*
4803 	 * Parse the config for pool, open and validate vdevs,
4804 	 * select an uberblock, and use that uberblock to open
4805 	 * the MOS.
4806 	 */
4807 	error = spa_ld_mos_init(spa, type);
4808 	if (error != 0)
4809 		return (error);
4810 
4811 	/*
4812 	 * Retrieve the trusted config stored in the MOS and use it to create
4813 	 * a new, exact version of the vdev tree, then reopen all vdevs.
4814 	 */
4815 	error = spa_ld_trusted_config(spa, type, B_FALSE);
4816 	if (error == EAGAIN) {
4817 		if (update_config_cache != NULL)
4818 			*update_config_cache = B_TRUE;
4819 
4820 		/*
4821 		 * Redo the loading process with the trusted config if it is
4822 		 * too different from the untrusted config.
4823 		 */
4824 		spa_ld_prepare_for_reload(spa);
4825 		spa_load_note(spa, "RELOADING");
4826 		error = spa_ld_mos_init(spa, type);
4827 		if (error != 0)
4828 			return (error);
4829 
4830 		error = spa_ld_trusted_config(spa, type, B_TRUE);
4831 		if (error != 0)
4832 			return (error);
4833 
4834 	} else if (error != 0) {
4835 		return (error);
4836 	}
4837 
4838 	return (0);
4839 }
4840 
4841 /*
4842  * Load an existing storage pool, using the config provided. This config
4843  * describes which vdevs are part of the pool and is later validated against
4844  * partial configs present in each vdev's label and an entire copy of the
4845  * config stored in the MOS.
4846  */
4847 static int
4848 spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
4849 {
4850 	int error = 0;
4851 	boolean_t missing_feat_write = B_FALSE;
4852 	boolean_t checkpoint_rewind =
4853 	    (spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
4854 	boolean_t update_config_cache = B_FALSE;
4855 
4856 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4857 	ASSERT(spa->spa_config_source != SPA_CONFIG_SRC_NONE);
4858 
4859 	spa_load_note(spa, "LOADING");
4860 
4861 	error = spa_ld_mos_with_trusted_config(spa, type, &update_config_cache);
4862 	if (error != 0)
4863 		return (error);
4864 
4865 	/*
4866 	 * If we are rewinding to the checkpoint then we need to repeat
4867 	 * everything we've done so far in this function but this time
4868 	 * selecting the checkpointed uberblock and using that to open
4869 	 * the MOS.
4870 	 */
4871 	if (checkpoint_rewind) {
4872 		/*
4873 		 * If we are rewinding to the checkpoint update config cache
4874 		 * anyway.
4875 		 */
4876 		update_config_cache = B_TRUE;
4877 
4878 		/*
4879 		 * Extract the checkpointed uberblock from the current MOS
4880 		 * and use this as the pool's uberblock from now on. If the
4881 		 * pool is imported as writeable we also write the checkpoint
4882 		 * uberblock to the labels, making the rewind permanent.
4883 		 */
4884 		error = spa_ld_checkpoint_rewind(spa);
4885 		if (error != 0)
4886 			return (error);
4887 
4888 		/*
4889 		 * Redo the loading process again with the
4890 		 * checkpointed uberblock.
4891 		 */
4892 		spa_ld_prepare_for_reload(spa);
4893 		spa_load_note(spa, "LOADING checkpointed uberblock");
4894 		error = spa_ld_mos_with_trusted_config(spa, type, NULL);
4895 		if (error != 0)
4896 			return (error);
4897 	}
4898 
4899 	/*
4900 	 * Retrieve the checkpoint txg if the pool has a checkpoint.
4901 	 */
4902 	error = spa_ld_read_checkpoint_txg(spa);
4903 	if (error != 0)
4904 		return (error);
4905 
4906 	/*
4907 	 * Retrieve the mapping of indirect vdevs. Those vdevs were removed
4908 	 * from the pool and their contents were re-mapped to other vdevs. Note
4909 	 * that everything that we read before this step must have been
4910 	 * rewritten on concrete vdevs after the last device removal was
4911 	 * initiated. Otherwise we could be reading from indirect vdevs before
4912 	 * we have loaded their mappings.
4913 	 */
4914 	error = spa_ld_open_indirect_vdev_metadata(spa);
4915 	if (error != 0)
4916 		return (error);
4917 
4918 	/*
4919 	 * Retrieve the full list of active features from the MOS and check if
4920 	 * they are all supported.
4921 	 */
4922 	error = spa_ld_check_features(spa, &missing_feat_write);
4923 	if (error != 0)
4924 		return (error);
4925 
4926 	/*
4927 	 * Load several special directories from the MOS needed by the dsl_pool
4928 	 * layer.
4929 	 */
4930 	error = spa_ld_load_special_directories(spa);
4931 	if (error != 0)
4932 		return (error);
4933 
4934 	/*
4935 	 * Retrieve pool properties from the MOS.
4936 	 */
4937 	error = spa_ld_get_props(spa);
4938 	if (error != 0)
4939 		return (error);
4940 
4941 	/*
4942 	 * Retrieve the list of auxiliary devices - cache devices and spares -
4943 	 * and open them.
4944 	 */
4945 	error = spa_ld_open_aux_vdevs(spa, type);
4946 	if (error != 0)
4947 		return (error);
4948 
4949 	/*
4950 	 * Load the metadata for all vdevs. Also check if unopenable devices
4951 	 * should be autoreplaced.
4952 	 */
4953 	error = spa_ld_load_vdev_metadata(spa);
4954 	if (error != 0)
4955 		return (error);
4956 
4957 	error = spa_ld_load_dedup_tables(spa);
4958 	if (error != 0)
4959 		return (error);
4960 
4961 	error = spa_ld_load_brt(spa);
4962 	if (error != 0)
4963 		return (error);
4964 
4965 	/*
4966 	 * Verify the logs now to make sure we don't have any unexpected errors
4967 	 * when we claim log blocks later.
4968 	 */
4969 	error = spa_ld_verify_logs(spa, type, ereport);
4970 	if (error != 0)
4971 		return (error);
4972 
4973 	if (missing_feat_write) {
4974 		ASSERT(spa->spa_load_state == SPA_LOAD_TRYIMPORT);
4975 
4976 		/*
4977 		 * At this point, we know that we can open the pool in
4978 		 * read-only mode but not read-write mode. We now have enough
4979 		 * information and can return to userland.
4980 		 */
4981 		return (spa_vdev_err(spa->spa_root_vdev, VDEV_AUX_UNSUP_FEAT,
4982 		    ENOTSUP));
4983 	}
4984 
4985 	/*
4986 	 * Traverse the last txgs to make sure the pool was left off in a safe
4987 	 * state. When performing an extreme rewind, we verify the whole pool,
4988 	 * which can take a very long time.
4989 	 */
4990 	error = spa_ld_verify_pool_data(spa);
4991 	if (error != 0)
4992 		return (error);
4993 
4994 	/*
4995 	 * Calculate the deflated space for the pool. This must be done before
4996 	 * we write anything to the pool because we'd need to update the space
4997 	 * accounting using the deflated sizes.
4998 	 */
4999 	spa_update_dspace(spa);
5000 
5001 	/*
5002 	 * We have now retrieved all the information we needed to open the
5003 	 * pool. If we are importing the pool in read-write mode, a few
5004 	 * additional steps must be performed to finish the import.
5005 	 */
5006 	if (spa_writeable(spa) && (spa->spa_load_state == SPA_LOAD_RECOVER ||
5007 	    spa->spa_load_max_txg == UINT64_MAX)) {
5008 		uint64_t config_cache_txg = spa->spa_config_txg;
5009 
5010 		ASSERT(spa->spa_load_state != SPA_LOAD_TRYIMPORT);
5011 
5012 		/*
5013 		 * In case of a checkpoint rewind, log the original txg
5014 		 * of the checkpointed uberblock.
5015 		 */
5016 		if (checkpoint_rewind) {
5017 			spa_history_log_internal(spa, "checkpoint rewind",
5018 			    NULL, "rewound state to txg=%llu",
5019 			    (u_longlong_t)spa->spa_uberblock.ub_checkpoint_txg);
5020 		}
5021 
5022 		/*
5023 		 * Traverse the ZIL and claim all blocks.
5024 		 */
5025 		spa_ld_claim_log_blocks(spa);
5026 
5027 		/*
5028 		 * Kick-off the syncing thread.
5029 		 */
5030 		spa->spa_sync_on = B_TRUE;
5031 		txg_sync_start(spa->spa_dsl_pool);
5032 		mmp_thread_start(spa);
5033 
5034 		/*
5035 		 * Wait for all claims to sync.  We sync up to the highest
5036 		 * claimed log block birth time so that claimed log blocks
5037 		 * don't appear to be from the future.  spa_claim_max_txg
5038 		 * will have been set for us by ZIL traversal operations
5039 		 * performed above.
5040 		 */
5041 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
5042 
5043 		/*
5044 		 * Check if we need to request an update of the config. On the
5045 		 * next sync, we would update the config stored in vdev labels
5046 		 * and the cachefile (by default /etc/zfs/zpool.cache).
5047 		 */
5048 		spa_ld_check_for_config_update(spa, config_cache_txg,
5049 		    update_config_cache);
5050 
5051 		/*
5052 		 * Check if a rebuild was in progress and if so resume it.
5053 		 * Then check all DTLs to see if anything needs resilvering.
5054 		 * The resilver will be deferred if a rebuild was started.
5055 		 */
5056 		if (vdev_rebuild_active(spa->spa_root_vdev)) {
5057 			vdev_rebuild_restart(spa);
5058 		} else if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
5059 		    vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5060 			spa_async_request(spa, SPA_ASYNC_RESILVER);
5061 		}
5062 
5063 		/*
5064 		 * Log the fact that we booted up (so that we can detect if
5065 		 * we rebooted in the middle of an operation).
5066 		 */
5067 		spa_history_log_version(spa, "open", NULL);
5068 
5069 		spa_restart_removal(spa);
5070 		spa_spawn_aux_threads(spa);
5071 
5072 		/*
5073 		 * Delete any inconsistent datasets.
5074 		 *
5075 		 * Note:
5076 		 * Since we may be issuing deletes for clones here,
5077 		 * we make sure to do so after we've spawned all the
5078 		 * auxiliary threads above (from which the livelist
5079 		 * deletion zthr is part of).
5080 		 */
5081 		(void) dmu_objset_find(spa_name(spa),
5082 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
5083 
5084 		/*
5085 		 * Clean up any stale temporary dataset userrefs.
5086 		 */
5087 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
5088 
5089 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5090 		vdev_initialize_restart(spa->spa_root_vdev);
5091 		vdev_trim_restart(spa->spa_root_vdev);
5092 		vdev_autotrim_restart(spa);
5093 		spa_config_exit(spa, SCL_CONFIG, FTAG);
5094 	}
5095 
5096 	spa_import_progress_remove(spa_guid(spa));
5097 	spa_async_request(spa, SPA_ASYNC_L2CACHE_REBUILD);
5098 
5099 	spa_load_note(spa, "LOADED");
5100 
5101 	return (0);
5102 }
5103 
5104 static int
5105 spa_load_retry(spa_t *spa, spa_load_state_t state)
5106 {
5107 	spa_mode_t mode = spa->spa_mode;
5108 
5109 	spa_unload(spa);
5110 	spa_deactivate(spa);
5111 
5112 	spa->spa_load_max_txg = spa->spa_uberblock.ub_txg - 1;
5113 
5114 	spa_activate(spa, mode);
5115 	spa_async_suspend(spa);
5116 
5117 	spa_load_note(spa, "spa_load_retry: rewind, max txg: %llu",
5118 	    (u_longlong_t)spa->spa_load_max_txg);
5119 
5120 	return (spa_load(spa, state, SPA_IMPORT_EXISTING));
5121 }
5122 
5123 /*
5124  * If spa_load() fails this function will try loading prior txg's. If
5125  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
5126  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
5127  * function will not rewind the pool and will return the same error as
5128  * spa_load().
5129  */
5130 static int
5131 spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
5132     int rewind_flags)
5133 {
5134 	nvlist_t *loadinfo = NULL;
5135 	nvlist_t *config = NULL;
5136 	int load_error, rewind_error;
5137 	uint64_t safe_rewind_txg;
5138 	uint64_t min_txg;
5139 
5140 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
5141 		spa->spa_load_max_txg = spa->spa_load_txg;
5142 		spa_set_log_state(spa, SPA_LOG_CLEAR);
5143 	} else {
5144 		spa->spa_load_max_txg = max_request;
5145 		if (max_request != UINT64_MAX)
5146 			spa->spa_extreme_rewind = B_TRUE;
5147 	}
5148 
5149 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING);
5150 	if (load_error == 0)
5151 		return (0);
5152 	if (load_error == ZFS_ERR_NO_CHECKPOINT) {
5153 		/*
5154 		 * When attempting checkpoint-rewind on a pool with no
5155 		 * checkpoint, we should not attempt to load uberblocks
5156 		 * from previous txgs when spa_load fails.
5157 		 */
5158 		ASSERT(spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
5159 		spa_import_progress_remove(spa_guid(spa));
5160 		return (load_error);
5161 	}
5162 
5163 	if (spa->spa_root_vdev != NULL)
5164 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
5165 
5166 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
5167 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
5168 
5169 	if (rewind_flags & ZPOOL_NEVER_REWIND) {
5170 		nvlist_free(config);
5171 		spa_import_progress_remove(spa_guid(spa));
5172 		return (load_error);
5173 	}
5174 
5175 	if (state == SPA_LOAD_RECOVER) {
5176 		/* Price of rolling back is discarding txgs, including log */
5177 		spa_set_log_state(spa, SPA_LOG_CLEAR);
5178 	} else {
5179 		/*
5180 		 * If we aren't rolling back save the load info from our first
5181 		 * import attempt so that we can restore it after attempting
5182 		 * to rewind.
5183 		 */
5184 		loadinfo = spa->spa_load_info;
5185 		spa->spa_load_info = fnvlist_alloc();
5186 	}
5187 
5188 	spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
5189 	safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
5190 	min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
5191 	    TXG_INITIAL : safe_rewind_txg;
5192 
5193 	/*
5194 	 * Continue as long as we're finding errors, we're still within
5195 	 * the acceptable rewind range, and we're still finding uberblocks
5196 	 */
5197 	while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
5198 	    spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
5199 		if (spa->spa_load_max_txg < safe_rewind_txg)
5200 			spa->spa_extreme_rewind = B_TRUE;
5201 		rewind_error = spa_load_retry(spa, state);
5202 	}
5203 
5204 	spa->spa_extreme_rewind = B_FALSE;
5205 	spa->spa_load_max_txg = UINT64_MAX;
5206 
5207 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
5208 		spa_config_set(spa, config);
5209 	else
5210 		nvlist_free(config);
5211 
5212 	if (state == SPA_LOAD_RECOVER) {
5213 		ASSERT3P(loadinfo, ==, NULL);
5214 		spa_import_progress_remove(spa_guid(spa));
5215 		return (rewind_error);
5216 	} else {
5217 		/* Store the rewind info as part of the initial load info */
5218 		fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
5219 		    spa->spa_load_info);
5220 
5221 		/* Restore the initial load info */
5222 		fnvlist_free(spa->spa_load_info);
5223 		spa->spa_load_info = loadinfo;
5224 
5225 		spa_import_progress_remove(spa_guid(spa));
5226 		return (load_error);
5227 	}
5228 }
5229 
5230 /*
5231  * Pool Open/Import
5232  *
5233  * The import case is identical to an open except that the configuration is sent
5234  * down from userland, instead of grabbed from the configuration cache.  For the
5235  * case of an open, the pool configuration will exist in the
5236  * POOL_STATE_UNINITIALIZED state.
5237  *
5238  * The stats information (gen/count/ustats) is used to gather vdev statistics at
5239  * the same time open the pool, without having to keep around the spa_t in some
5240  * ambiguous state.
5241  */
5242 static int
5243 spa_open_common(const char *pool, spa_t **spapp, const void *tag,
5244     nvlist_t *nvpolicy, nvlist_t **config)
5245 {
5246 	spa_t *spa;
5247 	spa_load_state_t state = SPA_LOAD_OPEN;
5248 	int error;
5249 	int locked = B_FALSE;
5250 	int firstopen = B_FALSE;
5251 
5252 	*spapp = NULL;
5253 
5254 	/*
5255 	 * As disgusting as this is, we need to support recursive calls to this
5256 	 * function because dsl_dir_open() is called during spa_load(), and ends
5257 	 * up calling spa_open() again.  The real fix is to figure out how to
5258 	 * avoid dsl_dir_open() calling this in the first place.
5259 	 */
5260 	if (MUTEX_NOT_HELD(&spa_namespace_lock)) {
5261 		mutex_enter(&spa_namespace_lock);
5262 		locked = B_TRUE;
5263 	}
5264 
5265 	if ((spa = spa_lookup(pool)) == NULL) {
5266 		if (locked)
5267 			mutex_exit(&spa_namespace_lock);
5268 		return (SET_ERROR(ENOENT));
5269 	}
5270 
5271 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
5272 		zpool_load_policy_t policy;
5273 
5274 		firstopen = B_TRUE;
5275 
5276 		zpool_get_load_policy(nvpolicy ? nvpolicy : spa->spa_config,
5277 		    &policy);
5278 		if (policy.zlp_rewind & ZPOOL_DO_REWIND)
5279 			state = SPA_LOAD_RECOVER;
5280 
5281 		spa_activate(spa, spa_mode_global);
5282 
5283 		if (state != SPA_LOAD_RECOVER)
5284 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
5285 		spa->spa_config_source = SPA_CONFIG_SRC_CACHEFILE;
5286 
5287 		zfs_dbgmsg("spa_open_common: opening %s", pool);
5288 		error = spa_load_best(spa, state, policy.zlp_txg,
5289 		    policy.zlp_rewind);
5290 
5291 		if (error == EBADF) {
5292 			/*
5293 			 * If vdev_validate() returns failure (indicated by
5294 			 * EBADF), it indicates that one of the vdevs indicates
5295 			 * that the pool has been exported or destroyed.  If
5296 			 * this is the case, the config cache is out of sync and
5297 			 * we should remove the pool from the namespace.
5298 			 */
5299 			spa_unload(spa);
5300 			spa_deactivate(spa);
5301 			spa_write_cachefile(spa, B_TRUE, B_TRUE, B_FALSE);
5302 			spa_remove(spa);
5303 			if (locked)
5304 				mutex_exit(&spa_namespace_lock);
5305 			return (SET_ERROR(ENOENT));
5306 		}
5307 
5308 		if (error) {
5309 			/*
5310 			 * We can't open the pool, but we still have useful
5311 			 * information: the state of each vdev after the
5312 			 * attempted vdev_open().  Return this to the user.
5313 			 */
5314 			if (config != NULL && spa->spa_config) {
5315 				*config = fnvlist_dup(spa->spa_config);
5316 				fnvlist_add_nvlist(*config,
5317 				    ZPOOL_CONFIG_LOAD_INFO,
5318 				    spa->spa_load_info);
5319 			}
5320 			spa_unload(spa);
5321 			spa_deactivate(spa);
5322 			spa->spa_last_open_failed = error;
5323 			if (locked)
5324 				mutex_exit(&spa_namespace_lock);
5325 			*spapp = NULL;
5326 			return (error);
5327 		}
5328 	}
5329 
5330 	spa_open_ref(spa, tag);
5331 
5332 	if (config != NULL)
5333 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
5334 
5335 	/*
5336 	 * If we've recovered the pool, pass back any information we
5337 	 * gathered while doing the load.
5338 	 */
5339 	if (state == SPA_LOAD_RECOVER && config != NULL) {
5340 		fnvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
5341 		    spa->spa_load_info);
5342 	}
5343 
5344 	if (locked) {
5345 		spa->spa_last_open_failed = 0;
5346 		spa->spa_last_ubsync_txg = 0;
5347 		spa->spa_load_txg = 0;
5348 		mutex_exit(&spa_namespace_lock);
5349 	}
5350 
5351 	if (firstopen)
5352 		zvol_create_minors_recursive(spa_name(spa));
5353 
5354 	*spapp = spa;
5355 
5356 	return (0);
5357 }
5358 
5359 int
5360 spa_open_rewind(const char *name, spa_t **spapp, const void *tag,
5361     nvlist_t *policy, nvlist_t **config)
5362 {
5363 	return (spa_open_common(name, spapp, tag, policy, config));
5364 }
5365 
5366 int
5367 spa_open(const char *name, spa_t **spapp, const void *tag)
5368 {
5369 	return (spa_open_common(name, spapp, tag, NULL, NULL));
5370 }
5371 
5372 /*
5373  * Lookup the given spa_t, incrementing the inject count in the process,
5374  * preventing it from being exported or destroyed.
5375  */
5376 spa_t *
5377 spa_inject_addref(char *name)
5378 {
5379 	spa_t *spa;
5380 
5381 	mutex_enter(&spa_namespace_lock);
5382 	if ((spa = spa_lookup(name)) == NULL) {
5383 		mutex_exit(&spa_namespace_lock);
5384 		return (NULL);
5385 	}
5386 	spa->spa_inject_ref++;
5387 	mutex_exit(&spa_namespace_lock);
5388 
5389 	return (spa);
5390 }
5391 
5392 void
5393 spa_inject_delref(spa_t *spa)
5394 {
5395 	mutex_enter(&spa_namespace_lock);
5396 	spa->spa_inject_ref--;
5397 	mutex_exit(&spa_namespace_lock);
5398 }
5399 
5400 /*
5401  * Add spares device information to the nvlist.
5402  */
5403 static void
5404 spa_add_spares(spa_t *spa, nvlist_t *config)
5405 {
5406 	nvlist_t **spares;
5407 	uint_t i, nspares;
5408 	nvlist_t *nvroot;
5409 	uint64_t guid;
5410 	vdev_stat_t *vs;
5411 	uint_t vsc;
5412 	uint64_t pool;
5413 
5414 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
5415 
5416 	if (spa->spa_spares.sav_count == 0)
5417 		return;
5418 
5419 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
5420 	VERIFY0(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5421 	    ZPOOL_CONFIG_SPARES, &spares, &nspares));
5422 	if (nspares != 0) {
5423 		fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
5424 		    (const nvlist_t * const *)spares, nspares);
5425 		VERIFY0(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
5426 		    &spares, &nspares));
5427 
5428 		/*
5429 		 * Go through and find any spares which have since been
5430 		 * repurposed as an active spare.  If this is the case, update
5431 		 * their status appropriately.
5432 		 */
5433 		for (i = 0; i < nspares; i++) {
5434 			guid = fnvlist_lookup_uint64(spares[i],
5435 			    ZPOOL_CONFIG_GUID);
5436 			VERIFY0(nvlist_lookup_uint64_array(spares[i],
5437 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc));
5438 			if (spa_spare_exists(guid, &pool, NULL) &&
5439 			    pool != 0ULL) {
5440 				vs->vs_state = VDEV_STATE_CANT_OPEN;
5441 				vs->vs_aux = VDEV_AUX_SPARED;
5442 			} else {
5443 				vs->vs_state =
5444 				    spa->spa_spares.sav_vdevs[i]->vdev_state;
5445 			}
5446 		}
5447 	}
5448 }
5449 
5450 /*
5451  * Add l2cache device information to the nvlist, including vdev stats.
5452  */
5453 static void
5454 spa_add_l2cache(spa_t *spa, nvlist_t *config)
5455 {
5456 	nvlist_t **l2cache;
5457 	uint_t i, j, nl2cache;
5458 	nvlist_t *nvroot;
5459 	uint64_t guid;
5460 	vdev_t *vd;
5461 	vdev_stat_t *vs;
5462 	uint_t vsc;
5463 
5464 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
5465 
5466 	if (spa->spa_l2cache.sav_count == 0)
5467 		return;
5468 
5469 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
5470 	VERIFY0(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5471 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache));
5472 	if (nl2cache != 0) {
5473 		fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
5474 		    (const nvlist_t * const *)l2cache, nl2cache);
5475 		VERIFY0(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
5476 		    &l2cache, &nl2cache));
5477 
5478 		/*
5479 		 * Update level 2 cache device stats.
5480 		 */
5481 
5482 		for (i = 0; i < nl2cache; i++) {
5483 			guid = fnvlist_lookup_uint64(l2cache[i],
5484 			    ZPOOL_CONFIG_GUID);
5485 
5486 			vd = NULL;
5487 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
5488 				if (guid ==
5489 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
5490 					vd = spa->spa_l2cache.sav_vdevs[j];
5491 					break;
5492 				}
5493 			}
5494 			ASSERT(vd != NULL);
5495 
5496 			VERIFY0(nvlist_lookup_uint64_array(l2cache[i],
5497 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc));
5498 			vdev_get_stats(vd, vs);
5499 			vdev_config_generate_stats(vd, l2cache[i]);
5500 
5501 		}
5502 	}
5503 }
5504 
5505 static void
5506 spa_feature_stats_from_disk(spa_t *spa, nvlist_t *features)
5507 {
5508 	zap_cursor_t zc;
5509 	zap_attribute_t za;
5510 
5511 	if (spa->spa_feat_for_read_obj != 0) {
5512 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
5513 		    spa->spa_feat_for_read_obj);
5514 		    zap_cursor_retrieve(&zc, &za) == 0;
5515 		    zap_cursor_advance(&zc)) {
5516 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
5517 			    za.za_num_integers == 1);
5518 			VERIFY0(nvlist_add_uint64(features, za.za_name,
5519 			    za.za_first_integer));
5520 		}
5521 		zap_cursor_fini(&zc);
5522 	}
5523 
5524 	if (spa->spa_feat_for_write_obj != 0) {
5525 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
5526 		    spa->spa_feat_for_write_obj);
5527 		    zap_cursor_retrieve(&zc, &za) == 0;
5528 		    zap_cursor_advance(&zc)) {
5529 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
5530 			    za.za_num_integers == 1);
5531 			VERIFY0(nvlist_add_uint64(features, za.za_name,
5532 			    za.za_first_integer));
5533 		}
5534 		zap_cursor_fini(&zc);
5535 	}
5536 }
5537 
5538 static void
5539 spa_feature_stats_from_cache(spa_t *spa, nvlist_t *features)
5540 {
5541 	int i;
5542 
5543 	for (i = 0; i < SPA_FEATURES; i++) {
5544 		zfeature_info_t feature = spa_feature_table[i];
5545 		uint64_t refcount;
5546 
5547 		if (feature_get_refcount(spa, &feature, &refcount) != 0)
5548 			continue;
5549 
5550 		VERIFY0(nvlist_add_uint64(features, feature.fi_guid, refcount));
5551 	}
5552 }
5553 
5554 /*
5555  * Store a list of pool features and their reference counts in the
5556  * config.
5557  *
5558  * The first time this is called on a spa, allocate a new nvlist, fetch
5559  * the pool features and reference counts from disk, then save the list
5560  * in the spa. In subsequent calls on the same spa use the saved nvlist
5561  * and refresh its values from the cached reference counts.  This
5562  * ensures we don't block here on I/O on a suspended pool so 'zpool
5563  * clear' can resume the pool.
5564  */
5565 static void
5566 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
5567 {
5568 	nvlist_t *features;
5569 
5570 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
5571 
5572 	mutex_enter(&spa->spa_feat_stats_lock);
5573 	features = spa->spa_feat_stats;
5574 
5575 	if (features != NULL) {
5576 		spa_feature_stats_from_cache(spa, features);
5577 	} else {
5578 		VERIFY0(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP));
5579 		spa->spa_feat_stats = features;
5580 		spa_feature_stats_from_disk(spa, features);
5581 	}
5582 
5583 	VERIFY0(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
5584 	    features));
5585 
5586 	mutex_exit(&spa->spa_feat_stats_lock);
5587 }
5588 
5589 int
5590 spa_get_stats(const char *name, nvlist_t **config,
5591     char *altroot, size_t buflen)
5592 {
5593 	int error;
5594 	spa_t *spa;
5595 
5596 	*config = NULL;
5597 	error = spa_open_common(name, &spa, FTAG, NULL, config);
5598 
5599 	if (spa != NULL) {
5600 		/*
5601 		 * This still leaves a window of inconsistency where the spares
5602 		 * or l2cache devices could change and the config would be
5603 		 * self-inconsistent.
5604 		 */
5605 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5606 
5607 		if (*config != NULL) {
5608 			uint64_t loadtimes[2];
5609 
5610 			loadtimes[0] = spa->spa_loaded_ts.tv_sec;
5611 			loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
5612 			fnvlist_add_uint64_array(*config,
5613 			    ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2);
5614 
5615 			fnvlist_add_uint64(*config,
5616 			    ZPOOL_CONFIG_ERRCOUNT,
5617 			    spa_approx_errlog_size(spa));
5618 
5619 			if (spa_suspended(spa)) {
5620 				fnvlist_add_uint64(*config,
5621 				    ZPOOL_CONFIG_SUSPENDED,
5622 				    spa->spa_failmode);
5623 				fnvlist_add_uint64(*config,
5624 				    ZPOOL_CONFIG_SUSPENDED_REASON,
5625 				    spa->spa_suspended);
5626 			}
5627 
5628 			spa_add_spares(spa, *config);
5629 			spa_add_l2cache(spa, *config);
5630 			spa_add_feature_stats(spa, *config);
5631 		}
5632 	}
5633 
5634 	/*
5635 	 * We want to get the alternate root even for faulted pools, so we cheat
5636 	 * and call spa_lookup() directly.
5637 	 */
5638 	if (altroot) {
5639 		if (spa == NULL) {
5640 			mutex_enter(&spa_namespace_lock);
5641 			spa = spa_lookup(name);
5642 			if (spa)
5643 				spa_altroot(spa, altroot, buflen);
5644 			else
5645 				altroot[0] = '\0';
5646 			spa = NULL;
5647 			mutex_exit(&spa_namespace_lock);
5648 		} else {
5649 			spa_altroot(spa, altroot, buflen);
5650 		}
5651 	}
5652 
5653 	if (spa != NULL) {
5654 		spa_config_exit(spa, SCL_CONFIG, FTAG);
5655 		spa_close(spa, FTAG);
5656 	}
5657 
5658 	return (error);
5659 }
5660 
5661 /*
5662  * Validate that the auxiliary device array is well formed.  We must have an
5663  * array of nvlists, each which describes a valid leaf vdev.  If this is an
5664  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
5665  * specified, as long as they are well-formed.
5666  */
5667 static int
5668 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
5669     spa_aux_vdev_t *sav, const char *config, uint64_t version,
5670     vdev_labeltype_t label)
5671 {
5672 	nvlist_t **dev;
5673 	uint_t i, ndev;
5674 	vdev_t *vd;
5675 	int error;
5676 
5677 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5678 
5679 	/*
5680 	 * It's acceptable to have no devs specified.
5681 	 */
5682 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
5683 		return (0);
5684 
5685 	if (ndev == 0)
5686 		return (SET_ERROR(EINVAL));
5687 
5688 	/*
5689 	 * Make sure the pool is formatted with a version that supports this
5690 	 * device type.
5691 	 */
5692 	if (spa_version(spa) < version)
5693 		return (SET_ERROR(ENOTSUP));
5694 
5695 	/*
5696 	 * Set the pending device list so we correctly handle device in-use
5697 	 * checking.
5698 	 */
5699 	sav->sav_pending = dev;
5700 	sav->sav_npending = ndev;
5701 
5702 	for (i = 0; i < ndev; i++) {
5703 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
5704 		    mode)) != 0)
5705 			goto out;
5706 
5707 		if (!vd->vdev_ops->vdev_op_leaf) {
5708 			vdev_free(vd);
5709 			error = SET_ERROR(EINVAL);
5710 			goto out;
5711 		}
5712 
5713 		vd->vdev_top = vd;
5714 
5715 		if ((error = vdev_open(vd)) == 0 &&
5716 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
5717 			fnvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
5718 			    vd->vdev_guid);
5719 		}
5720 
5721 		vdev_free(vd);
5722 
5723 		if (error &&
5724 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
5725 			goto out;
5726 		else
5727 			error = 0;
5728 	}
5729 
5730 out:
5731 	sav->sav_pending = NULL;
5732 	sav->sav_npending = 0;
5733 	return (error);
5734 }
5735 
5736 static int
5737 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
5738 {
5739 	int error;
5740 
5741 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5742 
5743 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
5744 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
5745 	    VDEV_LABEL_SPARE)) != 0) {
5746 		return (error);
5747 	}
5748 
5749 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
5750 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
5751 	    VDEV_LABEL_L2CACHE));
5752 }
5753 
5754 static void
5755 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
5756     const char *config)
5757 {
5758 	int i;
5759 
5760 	if (sav->sav_config != NULL) {
5761 		nvlist_t **olddevs;
5762 		uint_t oldndevs;
5763 		nvlist_t **newdevs;
5764 
5765 		/*
5766 		 * Generate new dev list by concatenating with the
5767 		 * current dev list.
5768 		 */
5769 		VERIFY0(nvlist_lookup_nvlist_array(sav->sav_config, config,
5770 		    &olddevs, &oldndevs));
5771 
5772 		newdevs = kmem_alloc(sizeof (void *) *
5773 		    (ndevs + oldndevs), KM_SLEEP);
5774 		for (i = 0; i < oldndevs; i++)
5775 			newdevs[i] = fnvlist_dup(olddevs[i]);
5776 		for (i = 0; i < ndevs; i++)
5777 			newdevs[i + oldndevs] = fnvlist_dup(devs[i]);
5778 
5779 		fnvlist_remove(sav->sav_config, config);
5780 
5781 		fnvlist_add_nvlist_array(sav->sav_config, config,
5782 		    (const nvlist_t * const *)newdevs, ndevs + oldndevs);
5783 		for (i = 0; i < oldndevs + ndevs; i++)
5784 			nvlist_free(newdevs[i]);
5785 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
5786 	} else {
5787 		/*
5788 		 * Generate a new dev list.
5789 		 */
5790 		sav->sav_config = fnvlist_alloc();
5791 		fnvlist_add_nvlist_array(sav->sav_config, config,
5792 		    (const nvlist_t * const *)devs, ndevs);
5793 	}
5794 }
5795 
5796 /*
5797  * Stop and drop level 2 ARC devices
5798  */
5799 void
5800 spa_l2cache_drop(spa_t *spa)
5801 {
5802 	vdev_t *vd;
5803 	int i;
5804 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
5805 
5806 	for (i = 0; i < sav->sav_count; i++) {
5807 		uint64_t pool;
5808 
5809 		vd = sav->sav_vdevs[i];
5810 		ASSERT(vd != NULL);
5811 
5812 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
5813 		    pool != 0ULL && l2arc_vdev_present(vd))
5814 			l2arc_remove_vdev(vd);
5815 	}
5816 }
5817 
5818 /*
5819  * Verify encryption parameters for spa creation. If we are encrypting, we must
5820  * have the encryption feature flag enabled.
5821  */
5822 static int
5823 spa_create_check_encryption_params(dsl_crypto_params_t *dcp,
5824     boolean_t has_encryption)
5825 {
5826 	if (dcp->cp_crypt != ZIO_CRYPT_OFF &&
5827 	    dcp->cp_crypt != ZIO_CRYPT_INHERIT &&
5828 	    !has_encryption)
5829 		return (SET_ERROR(ENOTSUP));
5830 
5831 	return (dmu_objset_create_crypt_check(NULL, dcp, NULL));
5832 }
5833 
5834 /*
5835  * Pool Creation
5836  */
5837 int
5838 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
5839     nvlist_t *zplprops, dsl_crypto_params_t *dcp)
5840 {
5841 	spa_t *spa;
5842 	const char *altroot = NULL;
5843 	vdev_t *rvd;
5844 	dsl_pool_t *dp;
5845 	dmu_tx_t *tx;
5846 	int error = 0;
5847 	uint64_t txg = TXG_INITIAL;
5848 	nvlist_t **spares, **l2cache;
5849 	uint_t nspares, nl2cache;
5850 	uint64_t version, obj, ndraid = 0;
5851 	boolean_t has_features;
5852 	boolean_t has_encryption;
5853 	boolean_t has_allocclass;
5854 	spa_feature_t feat;
5855 	const char *feat_name;
5856 	const char *poolname;
5857 	nvlist_t *nvl;
5858 
5859 	if (props == NULL ||
5860 	    nvlist_lookup_string(props, "tname", &poolname) != 0)
5861 		poolname = (char *)pool;
5862 
5863 	/*
5864 	 * If this pool already exists, return failure.
5865 	 */
5866 	mutex_enter(&spa_namespace_lock);
5867 	if (spa_lookup(poolname) != NULL) {
5868 		mutex_exit(&spa_namespace_lock);
5869 		return (SET_ERROR(EEXIST));
5870 	}
5871 
5872 	/*
5873 	 * Allocate a new spa_t structure.
5874 	 */
5875 	nvl = fnvlist_alloc();
5876 	fnvlist_add_string(nvl, ZPOOL_CONFIG_POOL_NAME, pool);
5877 	(void) nvlist_lookup_string(props,
5878 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
5879 	spa = spa_add(poolname, nvl, altroot);
5880 	fnvlist_free(nvl);
5881 	spa_activate(spa, spa_mode_global);
5882 
5883 	if (props && (error = spa_prop_validate(spa, props))) {
5884 		spa_deactivate(spa);
5885 		spa_remove(spa);
5886 		mutex_exit(&spa_namespace_lock);
5887 		return (error);
5888 	}
5889 
5890 	/*
5891 	 * Temporary pool names should never be written to disk.
5892 	 */
5893 	if (poolname != pool)
5894 		spa->spa_import_flags |= ZFS_IMPORT_TEMP_NAME;
5895 
5896 	has_features = B_FALSE;
5897 	has_encryption = B_FALSE;
5898 	has_allocclass = B_FALSE;
5899 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
5900 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
5901 		if (zpool_prop_feature(nvpair_name(elem))) {
5902 			has_features = B_TRUE;
5903 
5904 			feat_name = strchr(nvpair_name(elem), '@') + 1;
5905 			VERIFY0(zfeature_lookup_name(feat_name, &feat));
5906 			if (feat == SPA_FEATURE_ENCRYPTION)
5907 				has_encryption = B_TRUE;
5908 			if (feat == SPA_FEATURE_ALLOCATION_CLASSES)
5909 				has_allocclass = B_TRUE;
5910 		}
5911 	}
5912 
5913 	/* verify encryption params, if they were provided */
5914 	if (dcp != NULL) {
5915 		error = spa_create_check_encryption_params(dcp, has_encryption);
5916 		if (error != 0) {
5917 			spa_deactivate(spa);
5918 			spa_remove(spa);
5919 			mutex_exit(&spa_namespace_lock);
5920 			return (error);
5921 		}
5922 	}
5923 	if (!has_allocclass && zfs_special_devs(nvroot, NULL)) {
5924 		spa_deactivate(spa);
5925 		spa_remove(spa);
5926 		mutex_exit(&spa_namespace_lock);
5927 		return (ENOTSUP);
5928 	}
5929 
5930 	if (has_features || nvlist_lookup_uint64(props,
5931 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
5932 		version = SPA_VERSION;
5933 	}
5934 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5935 
5936 	spa->spa_first_txg = txg;
5937 	spa->spa_uberblock.ub_txg = txg - 1;
5938 	spa->spa_uberblock.ub_version = version;
5939 	spa->spa_ubsync = spa->spa_uberblock;
5940 	spa->spa_load_state = SPA_LOAD_CREATE;
5941 	spa->spa_removing_phys.sr_state = DSS_NONE;
5942 	spa->spa_removing_phys.sr_removing_vdev = -1;
5943 	spa->spa_removing_phys.sr_prev_indirect_vdev = -1;
5944 	spa->spa_indirect_vdevs_loaded = B_TRUE;
5945 
5946 	/*
5947 	 * Create "The Godfather" zio to hold all async IOs
5948 	 */
5949 	spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
5950 	    KM_SLEEP);
5951 	for (int i = 0; i < max_ncpus; i++) {
5952 		spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
5953 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
5954 		    ZIO_FLAG_GODFATHER);
5955 	}
5956 
5957 	/*
5958 	 * Create the root vdev.
5959 	 */
5960 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5961 
5962 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
5963 
5964 	ASSERT(error != 0 || rvd != NULL);
5965 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
5966 
5967 	if (error == 0 && !zfs_allocatable_devs(nvroot))
5968 		error = SET_ERROR(EINVAL);
5969 
5970 	if (error == 0 &&
5971 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
5972 	    (error = vdev_draid_spare_create(nvroot, rvd, &ndraid, 0)) == 0 &&
5973 	    (error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) == 0) {
5974 		/*
5975 		 * instantiate the metaslab groups (this will dirty the vdevs)
5976 		 * we can no longer error exit past this point
5977 		 */
5978 		for (int c = 0; error == 0 && c < rvd->vdev_children; c++) {
5979 			vdev_t *vd = rvd->vdev_child[c];
5980 
5981 			vdev_metaslab_set_size(vd);
5982 			vdev_expand(vd, txg);
5983 		}
5984 	}
5985 
5986 	spa_config_exit(spa, SCL_ALL, FTAG);
5987 
5988 	if (error != 0) {
5989 		spa_unload(spa);
5990 		spa_deactivate(spa);
5991 		spa_remove(spa);
5992 		mutex_exit(&spa_namespace_lock);
5993 		return (error);
5994 	}
5995 
5996 	/*
5997 	 * Get the list of spares, if specified.
5998 	 */
5999 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
6000 	    &spares, &nspares) == 0) {
6001 		spa->spa_spares.sav_config = fnvlist_alloc();
6002 		fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
6003 		    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
6004 		    nspares);
6005 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6006 		spa_load_spares(spa);
6007 		spa_config_exit(spa, SCL_ALL, FTAG);
6008 		spa->spa_spares.sav_sync = B_TRUE;
6009 	}
6010 
6011 	/*
6012 	 * Get the list of level 2 cache devices, if specified.
6013 	 */
6014 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
6015 	    &l2cache, &nl2cache) == 0) {
6016 		VERIFY0(nvlist_alloc(&spa->spa_l2cache.sav_config,
6017 		    NV_UNIQUE_NAME, KM_SLEEP));
6018 		fnvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
6019 		    ZPOOL_CONFIG_L2CACHE, (const nvlist_t * const *)l2cache,
6020 		    nl2cache);
6021 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6022 		spa_load_l2cache(spa);
6023 		spa_config_exit(spa, SCL_ALL, FTAG);
6024 		spa->spa_l2cache.sav_sync = B_TRUE;
6025 	}
6026 
6027 	spa->spa_is_initializing = B_TRUE;
6028 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, dcp, txg);
6029 	spa->spa_is_initializing = B_FALSE;
6030 
6031 	/*
6032 	 * Create DDTs (dedup tables).
6033 	 */
6034 	ddt_create(spa);
6035 	/*
6036 	 * Create BRT table and BRT table object.
6037 	 */
6038 	brt_create(spa);
6039 
6040 	spa_update_dspace(spa);
6041 
6042 	tx = dmu_tx_create_assigned(dp, txg);
6043 
6044 	/*
6045 	 * Create the pool's history object.
6046 	 */
6047 	if (version >= SPA_VERSION_ZPOOL_HISTORY && !spa->spa_history)
6048 		spa_history_create_obj(spa, tx);
6049 
6050 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_CREATE);
6051 	spa_history_log_version(spa, "create", tx);
6052 
6053 	/*
6054 	 * Create the pool config object.
6055 	 */
6056 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
6057 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
6058 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
6059 
6060 	if (zap_add(spa->spa_meta_objset,
6061 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
6062 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
6063 		cmn_err(CE_PANIC, "failed to add pool config");
6064 	}
6065 
6066 	if (zap_add(spa->spa_meta_objset,
6067 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
6068 	    sizeof (uint64_t), 1, &version, tx) != 0) {
6069 		cmn_err(CE_PANIC, "failed to add pool version");
6070 	}
6071 
6072 	/* Newly created pools with the right version are always deflated. */
6073 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
6074 		spa->spa_deflate = TRUE;
6075 		if (zap_add(spa->spa_meta_objset,
6076 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6077 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
6078 			cmn_err(CE_PANIC, "failed to add deflate");
6079 		}
6080 	}
6081 
6082 	/*
6083 	 * Create the deferred-free bpobj.  Turn off compression
6084 	 * because sync-to-convergence takes longer if the blocksize
6085 	 * keeps changing.
6086 	 */
6087 	obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
6088 	dmu_object_set_compress(spa->spa_meta_objset, obj,
6089 	    ZIO_COMPRESS_OFF, tx);
6090 	if (zap_add(spa->spa_meta_objset,
6091 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
6092 	    sizeof (uint64_t), 1, &obj, tx) != 0) {
6093 		cmn_err(CE_PANIC, "failed to add bpobj");
6094 	}
6095 	VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
6096 	    spa->spa_meta_objset, obj));
6097 
6098 	/*
6099 	 * Generate some random noise for salted checksums to operate on.
6100 	 */
6101 	(void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
6102 	    sizeof (spa->spa_cksum_salt.zcs_bytes));
6103 
6104 	/*
6105 	 * Set pool properties.
6106 	 */
6107 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
6108 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
6109 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
6110 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
6111 	spa->spa_multihost = zpool_prop_default_numeric(ZPOOL_PROP_MULTIHOST);
6112 	spa->spa_autotrim = zpool_prop_default_numeric(ZPOOL_PROP_AUTOTRIM);
6113 
6114 	if (props != NULL) {
6115 		spa_configfile_set(spa, props, B_FALSE);
6116 		spa_sync_props(props, tx);
6117 	}
6118 
6119 	for (int i = 0; i < ndraid; i++)
6120 		spa_feature_incr(spa, SPA_FEATURE_DRAID, tx);
6121 
6122 	dmu_tx_commit(tx);
6123 
6124 	spa->spa_sync_on = B_TRUE;
6125 	txg_sync_start(dp);
6126 	mmp_thread_start(spa);
6127 	txg_wait_synced(dp, txg);
6128 
6129 	spa_spawn_aux_threads(spa);
6130 
6131 	spa_write_cachefile(spa, B_FALSE, B_TRUE, B_TRUE);
6132 
6133 	/*
6134 	 * Don't count references from objsets that are already closed
6135 	 * and are making their way through the eviction process.
6136 	 */
6137 	spa_evicting_os_wait(spa);
6138 	spa->spa_minref = zfs_refcount_count(&spa->spa_refcount);
6139 	spa->spa_load_state = SPA_LOAD_NONE;
6140 
6141 	spa_import_os(spa);
6142 
6143 	mutex_exit(&spa_namespace_lock);
6144 
6145 	return (0);
6146 }
6147 
6148 /*
6149  * Import a non-root pool into the system.
6150  */
6151 int
6152 spa_import(char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
6153 {
6154 	spa_t *spa;
6155 	const char *altroot = NULL;
6156 	spa_load_state_t state = SPA_LOAD_IMPORT;
6157 	zpool_load_policy_t policy;
6158 	spa_mode_t mode = spa_mode_global;
6159 	uint64_t readonly = B_FALSE;
6160 	int error;
6161 	nvlist_t *nvroot;
6162 	nvlist_t **spares, **l2cache;
6163 	uint_t nspares, nl2cache;
6164 
6165 	/*
6166 	 * If a pool with this name exists, return failure.
6167 	 */
6168 	mutex_enter(&spa_namespace_lock);
6169 	if (spa_lookup(pool) != NULL) {
6170 		mutex_exit(&spa_namespace_lock);
6171 		return (SET_ERROR(EEXIST));
6172 	}
6173 
6174 	/*
6175 	 * Create and initialize the spa structure.
6176 	 */
6177 	(void) nvlist_lookup_string(props,
6178 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
6179 	(void) nvlist_lookup_uint64(props,
6180 	    zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
6181 	if (readonly)
6182 		mode = SPA_MODE_READ;
6183 	spa = spa_add(pool, config, altroot);
6184 	spa->spa_import_flags = flags;
6185 
6186 	/*
6187 	 * Verbatim import - Take a pool and insert it into the namespace
6188 	 * as if it had been loaded at boot.
6189 	 */
6190 	if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
6191 		if (props != NULL)
6192 			spa_configfile_set(spa, props, B_FALSE);
6193 
6194 		spa_write_cachefile(spa, B_FALSE, B_TRUE, B_FALSE);
6195 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_IMPORT);
6196 		zfs_dbgmsg("spa_import: verbatim import of %s", pool);
6197 		mutex_exit(&spa_namespace_lock);
6198 		return (0);
6199 	}
6200 
6201 	spa_activate(spa, mode);
6202 
6203 	/*
6204 	 * Don't start async tasks until we know everything is healthy.
6205 	 */
6206 	spa_async_suspend(spa);
6207 
6208 	zpool_get_load_policy(config, &policy);
6209 	if (policy.zlp_rewind & ZPOOL_DO_REWIND)
6210 		state = SPA_LOAD_RECOVER;
6211 
6212 	spa->spa_config_source = SPA_CONFIG_SRC_TRYIMPORT;
6213 
6214 	if (state != SPA_LOAD_RECOVER) {
6215 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
6216 		zfs_dbgmsg("spa_import: importing %s", pool);
6217 	} else {
6218 		zfs_dbgmsg("spa_import: importing %s, max_txg=%lld "
6219 		    "(RECOVERY MODE)", pool, (longlong_t)policy.zlp_txg);
6220 	}
6221 	error = spa_load_best(spa, state, policy.zlp_txg, policy.zlp_rewind);
6222 
6223 	/*
6224 	 * Propagate anything learned while loading the pool and pass it
6225 	 * back to caller (i.e. rewind info, missing devices, etc).
6226 	 */
6227 	fnvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, spa->spa_load_info);
6228 
6229 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6230 	/*
6231 	 * Toss any existing sparelist, as it doesn't have any validity
6232 	 * anymore, and conflicts with spa_has_spare().
6233 	 */
6234 	if (spa->spa_spares.sav_config) {
6235 		nvlist_free(spa->spa_spares.sav_config);
6236 		spa->spa_spares.sav_config = NULL;
6237 		spa_load_spares(spa);
6238 	}
6239 	if (spa->spa_l2cache.sav_config) {
6240 		nvlist_free(spa->spa_l2cache.sav_config);
6241 		spa->spa_l2cache.sav_config = NULL;
6242 		spa_load_l2cache(spa);
6243 	}
6244 
6245 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
6246 	spa_config_exit(spa, SCL_ALL, FTAG);
6247 
6248 	if (props != NULL)
6249 		spa_configfile_set(spa, props, B_FALSE);
6250 
6251 	if (error != 0 || (props && spa_writeable(spa) &&
6252 	    (error = spa_prop_set(spa, props)))) {
6253 		spa_unload(spa);
6254 		spa_deactivate(spa);
6255 		spa_remove(spa);
6256 		mutex_exit(&spa_namespace_lock);
6257 		return (error);
6258 	}
6259 
6260 	spa_async_resume(spa);
6261 
6262 	/*
6263 	 * Override any spares and level 2 cache devices as specified by
6264 	 * the user, as these may have correct device names/devids, etc.
6265 	 */
6266 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
6267 	    &spares, &nspares) == 0) {
6268 		if (spa->spa_spares.sav_config)
6269 			fnvlist_remove(spa->spa_spares.sav_config,
6270 			    ZPOOL_CONFIG_SPARES);
6271 		else
6272 			spa->spa_spares.sav_config = fnvlist_alloc();
6273 		fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
6274 		    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
6275 		    nspares);
6276 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6277 		spa_load_spares(spa);
6278 		spa_config_exit(spa, SCL_ALL, FTAG);
6279 		spa->spa_spares.sav_sync = B_TRUE;
6280 	}
6281 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
6282 	    &l2cache, &nl2cache) == 0) {
6283 		if (spa->spa_l2cache.sav_config)
6284 			fnvlist_remove(spa->spa_l2cache.sav_config,
6285 			    ZPOOL_CONFIG_L2CACHE);
6286 		else
6287 			spa->spa_l2cache.sav_config = fnvlist_alloc();
6288 		fnvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
6289 		    ZPOOL_CONFIG_L2CACHE, (const nvlist_t * const *)l2cache,
6290 		    nl2cache);
6291 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6292 		spa_load_l2cache(spa);
6293 		spa_config_exit(spa, SCL_ALL, FTAG);
6294 		spa->spa_l2cache.sav_sync = B_TRUE;
6295 	}
6296 
6297 	/*
6298 	 * Check for any removed devices.
6299 	 */
6300 	if (spa->spa_autoreplace) {
6301 		spa_aux_check_removed(&spa->spa_spares);
6302 		spa_aux_check_removed(&spa->spa_l2cache);
6303 	}
6304 
6305 	if (spa_writeable(spa)) {
6306 		/*
6307 		 * Update the config cache to include the newly-imported pool.
6308 		 */
6309 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
6310 	}
6311 
6312 	/*
6313 	 * It's possible that the pool was expanded while it was exported.
6314 	 * We kick off an async task to handle this for us.
6315 	 */
6316 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
6317 
6318 	spa_history_log_version(spa, "import", NULL);
6319 
6320 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_IMPORT);
6321 
6322 	mutex_exit(&spa_namespace_lock);
6323 
6324 	zvol_create_minors_recursive(pool);
6325 
6326 	spa_import_os(spa);
6327 
6328 	return (0);
6329 }
6330 
6331 nvlist_t *
6332 spa_tryimport(nvlist_t *tryconfig)
6333 {
6334 	nvlist_t *config = NULL;
6335 	const char *poolname, *cachefile;
6336 	spa_t *spa;
6337 	uint64_t state;
6338 	int error;
6339 	zpool_load_policy_t policy;
6340 
6341 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
6342 		return (NULL);
6343 
6344 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
6345 		return (NULL);
6346 
6347 	/*
6348 	 * Create and initialize the spa structure.
6349 	 */
6350 	mutex_enter(&spa_namespace_lock);
6351 	spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
6352 	spa_activate(spa, SPA_MODE_READ);
6353 
6354 	/*
6355 	 * Rewind pool if a max txg was provided.
6356 	 */
6357 	zpool_get_load_policy(spa->spa_config, &policy);
6358 	if (policy.zlp_txg != UINT64_MAX) {
6359 		spa->spa_load_max_txg = policy.zlp_txg;
6360 		spa->spa_extreme_rewind = B_TRUE;
6361 		zfs_dbgmsg("spa_tryimport: importing %s, max_txg=%lld",
6362 		    poolname, (longlong_t)policy.zlp_txg);
6363 	} else {
6364 		zfs_dbgmsg("spa_tryimport: importing %s", poolname);
6365 	}
6366 
6367 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_CACHEFILE, &cachefile)
6368 	    == 0) {
6369 		zfs_dbgmsg("spa_tryimport: using cachefile '%s'", cachefile);
6370 		spa->spa_config_source = SPA_CONFIG_SRC_CACHEFILE;
6371 	} else {
6372 		spa->spa_config_source = SPA_CONFIG_SRC_SCAN;
6373 	}
6374 
6375 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING);
6376 
6377 	/*
6378 	 * If 'tryconfig' was at least parsable, return the current config.
6379 	 */
6380 	if (spa->spa_root_vdev != NULL) {
6381 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
6382 		fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, poolname);
6383 		fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, state);
6384 		fnvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
6385 		    spa->spa_uberblock.ub_timestamp);
6386 		fnvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
6387 		    spa->spa_load_info);
6388 		fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA,
6389 		    spa->spa_errata);
6390 
6391 		/*
6392 		 * If the bootfs property exists on this pool then we
6393 		 * copy it out so that external consumers can tell which
6394 		 * pools are bootable.
6395 		 */
6396 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
6397 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
6398 
6399 			/*
6400 			 * We have to play games with the name since the
6401 			 * pool was opened as TRYIMPORT_NAME.
6402 			 */
6403 			if (dsl_dsobj_to_dsname(spa_name(spa),
6404 			    spa->spa_bootfs, tmpname) == 0) {
6405 				char *cp;
6406 				char *dsname;
6407 
6408 				dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
6409 
6410 				cp = strchr(tmpname, '/');
6411 				if (cp == NULL) {
6412 					(void) strlcpy(dsname, tmpname,
6413 					    MAXPATHLEN);
6414 				} else {
6415 					(void) snprintf(dsname, MAXPATHLEN,
6416 					    "%s/%s", poolname, ++cp);
6417 				}
6418 				fnvlist_add_string(config, ZPOOL_CONFIG_BOOTFS,
6419 				    dsname);
6420 				kmem_free(dsname, MAXPATHLEN);
6421 			}
6422 			kmem_free(tmpname, MAXPATHLEN);
6423 		}
6424 
6425 		/*
6426 		 * Add the list of hot spares and level 2 cache devices.
6427 		 */
6428 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6429 		spa_add_spares(spa, config);
6430 		spa_add_l2cache(spa, config);
6431 		spa_config_exit(spa, SCL_CONFIG, FTAG);
6432 	}
6433 
6434 	spa_unload(spa);
6435 	spa_deactivate(spa);
6436 	spa_remove(spa);
6437 	mutex_exit(&spa_namespace_lock);
6438 
6439 	return (config);
6440 }
6441 
6442 /*
6443  * Pool export/destroy
6444  *
6445  * The act of destroying or exporting a pool is very simple.  We make sure there
6446  * is no more pending I/O and any references to the pool are gone.  Then, we
6447  * update the pool state and sync all the labels to disk, removing the
6448  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
6449  * we don't sync the labels or remove the configuration cache.
6450  */
6451 static int
6452 spa_export_common(const char *pool, int new_state, nvlist_t **oldconfig,
6453     boolean_t force, boolean_t hardforce)
6454 {
6455 	int error;
6456 	spa_t *spa;
6457 
6458 	if (oldconfig)
6459 		*oldconfig = NULL;
6460 
6461 	if (!(spa_mode_global & SPA_MODE_WRITE))
6462 		return (SET_ERROR(EROFS));
6463 
6464 	mutex_enter(&spa_namespace_lock);
6465 	if ((spa = spa_lookup(pool)) == NULL) {
6466 		mutex_exit(&spa_namespace_lock);
6467 		return (SET_ERROR(ENOENT));
6468 	}
6469 
6470 	if (spa->spa_is_exporting) {
6471 		/* the pool is being exported by another thread */
6472 		mutex_exit(&spa_namespace_lock);
6473 		return (SET_ERROR(ZFS_ERR_EXPORT_IN_PROGRESS));
6474 	}
6475 	spa->spa_is_exporting = B_TRUE;
6476 
6477 	/*
6478 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
6479 	 * reacquire the namespace lock, and see if we can export.
6480 	 */
6481 	spa_open_ref(spa, FTAG);
6482 	mutex_exit(&spa_namespace_lock);
6483 	spa_async_suspend(spa);
6484 	if (spa->spa_zvol_taskq) {
6485 		zvol_remove_minors(spa, spa_name(spa), B_TRUE);
6486 		taskq_wait(spa->spa_zvol_taskq);
6487 	}
6488 	mutex_enter(&spa_namespace_lock);
6489 	spa_close(spa, FTAG);
6490 
6491 	if (spa->spa_state == POOL_STATE_UNINITIALIZED)
6492 		goto export_spa;
6493 	/*
6494 	 * The pool will be in core if it's openable, in which case we can
6495 	 * modify its state.  Objsets may be open only because they're dirty,
6496 	 * so we have to force it to sync before checking spa_refcnt.
6497 	 */
6498 	if (spa->spa_sync_on) {
6499 		txg_wait_synced(spa->spa_dsl_pool, 0);
6500 		spa_evicting_os_wait(spa);
6501 	}
6502 
6503 	/*
6504 	 * A pool cannot be exported or destroyed if there are active
6505 	 * references.  If we are resetting a pool, allow references by
6506 	 * fault injection handlers.
6507 	 */
6508 	if (!spa_refcount_zero(spa) || (spa->spa_inject_ref != 0)) {
6509 		error = SET_ERROR(EBUSY);
6510 		goto fail;
6511 	}
6512 
6513 	if (spa->spa_sync_on) {
6514 		vdev_t *rvd = spa->spa_root_vdev;
6515 		/*
6516 		 * A pool cannot be exported if it has an active shared spare.
6517 		 * This is to prevent other pools stealing the active spare
6518 		 * from an exported pool. At user's own will, such pool can
6519 		 * be forcedly exported.
6520 		 */
6521 		if (!force && new_state == POOL_STATE_EXPORTED &&
6522 		    spa_has_active_shared_spare(spa)) {
6523 			error = SET_ERROR(EXDEV);
6524 			goto fail;
6525 		}
6526 
6527 		/*
6528 		 * We're about to export or destroy this pool. Make sure
6529 		 * we stop all initialization and trim activity here before
6530 		 * we set the spa_final_txg. This will ensure that all
6531 		 * dirty data resulting from the initialization is
6532 		 * committed to disk before we unload the pool.
6533 		 */
6534 		vdev_initialize_stop_all(rvd, VDEV_INITIALIZE_ACTIVE);
6535 		vdev_trim_stop_all(rvd, VDEV_TRIM_ACTIVE);
6536 		vdev_autotrim_stop_all(spa);
6537 		vdev_rebuild_stop_all(spa);
6538 
6539 		/*
6540 		 * We want this to be reflected on every label,
6541 		 * so mark them all dirty.  spa_unload() will do the
6542 		 * final sync that pushes these changes out.
6543 		 */
6544 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
6545 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6546 			spa->spa_state = new_state;
6547 			vdev_config_dirty(rvd);
6548 			spa_config_exit(spa, SCL_ALL, FTAG);
6549 		}
6550 
6551 		/*
6552 		 * If the log space map feature is enabled and the pool is
6553 		 * getting exported (but not destroyed), we want to spend some
6554 		 * time flushing as many metaslabs as we can in an attempt to
6555 		 * destroy log space maps and save import time. This has to be
6556 		 * done before we set the spa_final_txg, otherwise
6557 		 * spa_sync() -> spa_flush_metaslabs() may dirty the final TXGs.
6558 		 * spa_should_flush_logs_on_unload() should be called after
6559 		 * spa_state has been set to the new_state.
6560 		 */
6561 		if (spa_should_flush_logs_on_unload(spa))
6562 			spa_unload_log_sm_flush_all(spa);
6563 
6564 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
6565 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6566 			spa->spa_final_txg = spa_last_synced_txg(spa) +
6567 			    TXG_DEFER_SIZE + 1;
6568 			spa_config_exit(spa, SCL_ALL, FTAG);
6569 		}
6570 	}
6571 
6572 export_spa:
6573 	spa_export_os(spa);
6574 
6575 	if (new_state == POOL_STATE_DESTROYED)
6576 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_DESTROY);
6577 	else if (new_state == POOL_STATE_EXPORTED)
6578 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_EXPORT);
6579 
6580 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6581 		spa_unload(spa);
6582 		spa_deactivate(spa);
6583 	}
6584 
6585 	if (oldconfig && spa->spa_config)
6586 		*oldconfig = fnvlist_dup(spa->spa_config);
6587 
6588 	if (new_state != POOL_STATE_UNINITIALIZED) {
6589 		if (!hardforce)
6590 			spa_write_cachefile(spa, B_TRUE, B_TRUE, B_FALSE);
6591 		spa_remove(spa);
6592 	} else {
6593 		/*
6594 		 * If spa_remove() is not called for this spa_t and
6595 		 * there is any possibility that it can be reused,
6596 		 * we make sure to reset the exporting flag.
6597 		 */
6598 		spa->spa_is_exporting = B_FALSE;
6599 	}
6600 
6601 	mutex_exit(&spa_namespace_lock);
6602 	return (0);
6603 
6604 fail:
6605 	spa->spa_is_exporting = B_FALSE;
6606 	spa_async_resume(spa);
6607 	mutex_exit(&spa_namespace_lock);
6608 	return (error);
6609 }
6610 
6611 /*
6612  * Destroy a storage pool.
6613  */
6614 int
6615 spa_destroy(const char *pool)
6616 {
6617 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
6618 	    B_FALSE, B_FALSE));
6619 }
6620 
6621 /*
6622  * Export a storage pool.
6623  */
6624 int
6625 spa_export(const char *pool, nvlist_t **oldconfig, boolean_t force,
6626     boolean_t hardforce)
6627 {
6628 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
6629 	    force, hardforce));
6630 }
6631 
6632 /*
6633  * Similar to spa_export(), this unloads the spa_t without actually removing it
6634  * from the namespace in any way.
6635  */
6636 int
6637 spa_reset(const char *pool)
6638 {
6639 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
6640 	    B_FALSE, B_FALSE));
6641 }
6642 
6643 /*
6644  * ==========================================================================
6645  * Device manipulation
6646  * ==========================================================================
6647  */
6648 
6649 /*
6650  * This is called as a synctask to increment the draid feature flag
6651  */
6652 static void
6653 spa_draid_feature_incr(void *arg, dmu_tx_t *tx)
6654 {
6655 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
6656 	int draid = (int)(uintptr_t)arg;
6657 
6658 	for (int c = 0; c < draid; c++)
6659 		spa_feature_incr(spa, SPA_FEATURE_DRAID, tx);
6660 }
6661 
6662 /*
6663  * Add a device to a storage pool.
6664  */
6665 int
6666 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
6667 {
6668 	uint64_t txg, ndraid = 0;
6669 	int error;
6670 	vdev_t *rvd = spa->spa_root_vdev;
6671 	vdev_t *vd, *tvd;
6672 	nvlist_t **spares, **l2cache;
6673 	uint_t nspares, nl2cache;
6674 
6675 	ASSERT(spa_writeable(spa));
6676 
6677 	txg = spa_vdev_enter(spa);
6678 
6679 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
6680 	    VDEV_ALLOC_ADD)) != 0)
6681 		return (spa_vdev_exit(spa, NULL, txg, error));
6682 
6683 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
6684 
6685 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
6686 	    &nspares) != 0)
6687 		nspares = 0;
6688 
6689 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
6690 	    &nl2cache) != 0)
6691 		nl2cache = 0;
6692 
6693 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
6694 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
6695 
6696 	if (vd->vdev_children != 0 &&
6697 	    (error = vdev_create(vd, txg, B_FALSE)) != 0) {
6698 		return (spa_vdev_exit(spa, vd, txg, error));
6699 	}
6700 
6701 	/*
6702 	 * The virtual dRAID spares must be added after vdev tree is created
6703 	 * and the vdev guids are generated.  The guid of their associated
6704 	 * dRAID is stored in the config and used when opening the spare.
6705 	 */
6706 	if ((error = vdev_draid_spare_create(nvroot, vd, &ndraid,
6707 	    rvd->vdev_children)) == 0) {
6708 		if (ndraid > 0 && nvlist_lookup_nvlist_array(nvroot,
6709 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) != 0)
6710 			nspares = 0;
6711 	} else {
6712 		return (spa_vdev_exit(spa, vd, txg, error));
6713 	}
6714 
6715 	/*
6716 	 * We must validate the spares and l2cache devices after checking the
6717 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
6718 	 */
6719 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
6720 		return (spa_vdev_exit(spa, vd, txg, error));
6721 
6722 	/*
6723 	 * If we are in the middle of a device removal, we can only add
6724 	 * devices which match the existing devices in the pool.
6725 	 * If we are in the middle of a removal, or have some indirect
6726 	 * vdevs, we can not add raidz or dRAID top levels.
6727 	 */
6728 	if (spa->spa_vdev_removal != NULL ||
6729 	    spa->spa_removing_phys.sr_prev_indirect_vdev != -1) {
6730 		for (int c = 0; c < vd->vdev_children; c++) {
6731 			tvd = vd->vdev_child[c];
6732 			if (spa->spa_vdev_removal != NULL &&
6733 			    tvd->vdev_ashift != spa->spa_max_ashift) {
6734 				return (spa_vdev_exit(spa, vd, txg, EINVAL));
6735 			}
6736 			/* Fail if top level vdev is raidz or a dRAID */
6737 			if (vdev_get_nparity(tvd) != 0)
6738 				return (spa_vdev_exit(spa, vd, txg, EINVAL));
6739 
6740 			/*
6741 			 * Need the top level mirror to be
6742 			 * a mirror of leaf vdevs only
6743 			 */
6744 			if (tvd->vdev_ops == &vdev_mirror_ops) {
6745 				for (uint64_t cid = 0;
6746 				    cid < tvd->vdev_children; cid++) {
6747 					vdev_t *cvd = tvd->vdev_child[cid];
6748 					if (!cvd->vdev_ops->vdev_op_leaf) {
6749 						return (spa_vdev_exit(spa, vd,
6750 						    txg, EINVAL));
6751 					}
6752 				}
6753 			}
6754 		}
6755 	}
6756 
6757 	for (int c = 0; c < vd->vdev_children; c++) {
6758 		tvd = vd->vdev_child[c];
6759 		vdev_remove_child(vd, tvd);
6760 		tvd->vdev_id = rvd->vdev_children;
6761 		vdev_add_child(rvd, tvd);
6762 		vdev_config_dirty(tvd);
6763 	}
6764 
6765 	if (nspares != 0) {
6766 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
6767 		    ZPOOL_CONFIG_SPARES);
6768 		spa_load_spares(spa);
6769 		spa->spa_spares.sav_sync = B_TRUE;
6770 	}
6771 
6772 	if (nl2cache != 0) {
6773 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
6774 		    ZPOOL_CONFIG_L2CACHE);
6775 		spa_load_l2cache(spa);
6776 		spa->spa_l2cache.sav_sync = B_TRUE;
6777 	}
6778 
6779 	/*
6780 	 * We can't increment a feature while holding spa_vdev so we
6781 	 * have to do it in a synctask.
6782 	 */
6783 	if (ndraid != 0) {
6784 		dmu_tx_t *tx;
6785 
6786 		tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
6787 		dsl_sync_task_nowait(spa->spa_dsl_pool, spa_draid_feature_incr,
6788 		    (void *)(uintptr_t)ndraid, tx);
6789 		dmu_tx_commit(tx);
6790 	}
6791 
6792 	/*
6793 	 * We have to be careful when adding new vdevs to an existing pool.
6794 	 * If other threads start allocating from these vdevs before we
6795 	 * sync the config cache, and we lose power, then upon reboot we may
6796 	 * fail to open the pool because there are DVAs that the config cache
6797 	 * can't translate.  Therefore, we first add the vdevs without
6798 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
6799 	 * and then let spa_config_update() initialize the new metaslabs.
6800 	 *
6801 	 * spa_load() checks for added-but-not-initialized vdevs, so that
6802 	 * if we lose power at any point in this sequence, the remaining
6803 	 * steps will be completed the next time we load the pool.
6804 	 */
6805 	(void) spa_vdev_exit(spa, vd, txg, 0);
6806 
6807 	mutex_enter(&spa_namespace_lock);
6808 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
6809 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_VDEV_ADD);
6810 	mutex_exit(&spa_namespace_lock);
6811 
6812 	return (0);
6813 }
6814 
6815 /*
6816  * Attach a device to a mirror.  The arguments are the path to any device
6817  * in the mirror, and the nvroot for the new device.  If the path specifies
6818  * a device that is not mirrored, we automatically insert the mirror vdev.
6819  *
6820  * If 'replacing' is specified, the new device is intended to replace the
6821  * existing device; in this case the two devices are made into their own
6822  * mirror using the 'replacing' vdev, which is functionally identical to
6823  * the mirror vdev (it actually reuses all the same ops) but has a few
6824  * extra rules: you can't attach to it after it's been created, and upon
6825  * completion of resilvering, the first disk (the one being replaced)
6826  * is automatically detached.
6827  *
6828  * If 'rebuild' is specified, then sequential reconstruction (a.ka. rebuild)
6829  * should be performed instead of traditional healing reconstruction.  From
6830  * an administrators perspective these are both resilver operations.
6831  */
6832 int
6833 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing,
6834     int rebuild)
6835 {
6836 	uint64_t txg, dtl_max_txg;
6837 	vdev_t *rvd = spa->spa_root_vdev;
6838 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
6839 	vdev_ops_t *pvops;
6840 	char *oldvdpath, *newvdpath;
6841 	int newvd_isspare;
6842 	int error;
6843 
6844 	ASSERT(spa_writeable(spa));
6845 
6846 	txg = spa_vdev_enter(spa);
6847 
6848 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
6849 
6850 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
6851 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
6852 		error = (spa_has_checkpoint(spa)) ?
6853 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
6854 		return (spa_vdev_exit(spa, NULL, txg, error));
6855 	}
6856 
6857 	if (rebuild) {
6858 		if (!spa_feature_is_enabled(spa, SPA_FEATURE_DEVICE_REBUILD))
6859 			return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
6860 
6861 		if (dsl_scan_resilvering(spa_get_dsl(spa)))
6862 			return (spa_vdev_exit(spa, NULL, txg,
6863 			    ZFS_ERR_RESILVER_IN_PROGRESS));
6864 	} else {
6865 		if (vdev_rebuild_active(rvd))
6866 			return (spa_vdev_exit(spa, NULL, txg,
6867 			    ZFS_ERR_REBUILD_IN_PROGRESS));
6868 	}
6869 
6870 	if (spa->spa_vdev_removal != NULL)
6871 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
6872 
6873 	if (oldvd == NULL)
6874 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
6875 
6876 	if (!oldvd->vdev_ops->vdev_op_leaf)
6877 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
6878 
6879 	pvd = oldvd->vdev_parent;
6880 
6881 	if (spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
6882 	    VDEV_ALLOC_ATTACH) != 0)
6883 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
6884 
6885 	if (newrootvd->vdev_children != 1)
6886 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
6887 
6888 	newvd = newrootvd->vdev_child[0];
6889 
6890 	if (!newvd->vdev_ops->vdev_op_leaf)
6891 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
6892 
6893 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
6894 		return (spa_vdev_exit(spa, newrootvd, txg, error));
6895 
6896 	/*
6897 	 * log, dedup and special vdevs should not be replaced by spares.
6898 	 */
6899 	if ((oldvd->vdev_top->vdev_alloc_bias != VDEV_BIAS_NONE ||
6900 	    oldvd->vdev_top->vdev_islog) && newvd->vdev_isspare) {
6901 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6902 	}
6903 
6904 	/*
6905 	 * A dRAID spare can only replace a child of its parent dRAID vdev.
6906 	 */
6907 	if (newvd->vdev_ops == &vdev_draid_spare_ops &&
6908 	    oldvd->vdev_top != vdev_draid_spare_get_parent(newvd)) {
6909 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6910 	}
6911 
6912 	if (rebuild) {
6913 		/*
6914 		 * For rebuilds, the top vdev must support reconstruction
6915 		 * using only space maps.  This means the only allowable
6916 		 * vdevs types are the root vdev, a mirror, or dRAID.
6917 		 */
6918 		tvd = pvd;
6919 		if (pvd->vdev_top != NULL)
6920 			tvd = pvd->vdev_top;
6921 
6922 		if (tvd->vdev_ops != &vdev_mirror_ops &&
6923 		    tvd->vdev_ops != &vdev_root_ops &&
6924 		    tvd->vdev_ops != &vdev_draid_ops) {
6925 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6926 		}
6927 	}
6928 
6929 	if (!replacing) {
6930 		/*
6931 		 * For attach, the only allowable parent is a mirror or the root
6932 		 * vdev.
6933 		 */
6934 		if (pvd->vdev_ops != &vdev_mirror_ops &&
6935 		    pvd->vdev_ops != &vdev_root_ops)
6936 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6937 
6938 		pvops = &vdev_mirror_ops;
6939 	} else {
6940 		/*
6941 		 * Active hot spares can only be replaced by inactive hot
6942 		 * spares.
6943 		 */
6944 		if (pvd->vdev_ops == &vdev_spare_ops &&
6945 		    oldvd->vdev_isspare &&
6946 		    !spa_has_spare(spa, newvd->vdev_guid))
6947 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6948 
6949 		/*
6950 		 * If the source is a hot spare, and the parent isn't already a
6951 		 * spare, then we want to create a new hot spare.  Otherwise, we
6952 		 * want to create a replacing vdev.  The user is not allowed to
6953 		 * attach to a spared vdev child unless the 'isspare' state is
6954 		 * the same (spare replaces spare, non-spare replaces
6955 		 * non-spare).
6956 		 */
6957 		if (pvd->vdev_ops == &vdev_replacing_ops &&
6958 		    spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
6959 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6960 		} else if (pvd->vdev_ops == &vdev_spare_ops &&
6961 		    newvd->vdev_isspare != oldvd->vdev_isspare) {
6962 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6963 		}
6964 
6965 		if (newvd->vdev_isspare)
6966 			pvops = &vdev_spare_ops;
6967 		else
6968 			pvops = &vdev_replacing_ops;
6969 	}
6970 
6971 	/*
6972 	 * Make sure the new device is big enough.
6973 	 */
6974 	if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
6975 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
6976 
6977 	/*
6978 	 * The new device cannot have a higher alignment requirement
6979 	 * than the top-level vdev.
6980 	 */
6981 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
6982 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
6983 
6984 	/*
6985 	 * If this is an in-place replacement, update oldvd's path and devid
6986 	 * to make it distinguishable from newvd, and unopenable from now on.
6987 	 */
6988 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
6989 		spa_strfree(oldvd->vdev_path);
6990 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
6991 		    KM_SLEEP);
6992 		(void) snprintf(oldvd->vdev_path, strlen(newvd->vdev_path) + 5,
6993 		    "%s/%s", newvd->vdev_path, "old");
6994 		if (oldvd->vdev_devid != NULL) {
6995 			spa_strfree(oldvd->vdev_devid);
6996 			oldvd->vdev_devid = NULL;
6997 		}
6998 	}
6999 
7000 	/*
7001 	 * If the parent is not a mirror, or if we're replacing, insert the new
7002 	 * mirror/replacing/spare vdev above oldvd.
7003 	 */
7004 	if (pvd->vdev_ops != pvops)
7005 		pvd = vdev_add_parent(oldvd, pvops);
7006 
7007 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
7008 	ASSERT(pvd->vdev_ops == pvops);
7009 	ASSERT(oldvd->vdev_parent == pvd);
7010 
7011 	/*
7012 	 * Extract the new device from its root and add it to pvd.
7013 	 */
7014 	vdev_remove_child(newrootvd, newvd);
7015 	newvd->vdev_id = pvd->vdev_children;
7016 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
7017 	vdev_add_child(pvd, newvd);
7018 
7019 	/*
7020 	 * Reevaluate the parent vdev state.
7021 	 */
7022 	vdev_propagate_state(pvd);
7023 
7024 	tvd = newvd->vdev_top;
7025 	ASSERT(pvd->vdev_top == tvd);
7026 	ASSERT(tvd->vdev_parent == rvd);
7027 
7028 	vdev_config_dirty(tvd);
7029 
7030 	/*
7031 	 * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
7032 	 * for any dmu_sync-ed blocks.  It will propagate upward when
7033 	 * spa_vdev_exit() calls vdev_dtl_reassess().
7034 	 */
7035 	dtl_max_txg = txg + TXG_CONCURRENT_STATES;
7036 
7037 	vdev_dtl_dirty(newvd, DTL_MISSING,
7038 	    TXG_INITIAL, dtl_max_txg - TXG_INITIAL);
7039 
7040 	if (newvd->vdev_isspare) {
7041 		spa_spare_activate(newvd);
7042 		spa_event_notify(spa, newvd, NULL, ESC_ZFS_VDEV_SPARE);
7043 	}
7044 
7045 	oldvdpath = spa_strdup(oldvd->vdev_path);
7046 	newvdpath = spa_strdup(newvd->vdev_path);
7047 	newvd_isspare = newvd->vdev_isspare;
7048 
7049 	/*
7050 	 * Mark newvd's DTL dirty in this txg.
7051 	 */
7052 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
7053 
7054 	/*
7055 	 * Schedule the resilver or rebuild to restart in the future. We do
7056 	 * this to ensure that dmu_sync-ed blocks have been stitched into the
7057 	 * respective datasets.
7058 	 */
7059 	if (rebuild) {
7060 		newvd->vdev_rebuild_txg = txg;
7061 
7062 		vdev_rebuild(tvd);
7063 	} else {
7064 		newvd->vdev_resilver_txg = txg;
7065 
7066 		if (dsl_scan_resilvering(spa_get_dsl(spa)) &&
7067 		    spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER)) {
7068 			vdev_defer_resilver(newvd);
7069 		} else {
7070 			dsl_scan_restart_resilver(spa->spa_dsl_pool,
7071 			    dtl_max_txg);
7072 		}
7073 	}
7074 
7075 	if (spa->spa_bootfs)
7076 		spa_event_notify(spa, newvd, NULL, ESC_ZFS_BOOTFS_VDEV_ATTACH);
7077 
7078 	spa_event_notify(spa, newvd, NULL, ESC_ZFS_VDEV_ATTACH);
7079 
7080 	/*
7081 	 * Commit the config
7082 	 */
7083 	(void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
7084 
7085 	spa_history_log_internal(spa, "vdev attach", NULL,
7086 	    "%s vdev=%s %s vdev=%s",
7087 	    replacing && newvd_isspare ? "spare in" :
7088 	    replacing ? "replace" : "attach", newvdpath,
7089 	    replacing ? "for" : "to", oldvdpath);
7090 
7091 	spa_strfree(oldvdpath);
7092 	spa_strfree(newvdpath);
7093 
7094 	return (0);
7095 }
7096 
7097 /*
7098  * Detach a device from a mirror or replacing vdev.
7099  *
7100  * If 'replace_done' is specified, only detach if the parent
7101  * is a replacing vdev.
7102  */
7103 int
7104 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
7105 {
7106 	uint64_t txg;
7107 	int error;
7108 	vdev_t *rvd __maybe_unused = spa->spa_root_vdev;
7109 	vdev_t *vd, *pvd, *cvd, *tvd;
7110 	boolean_t unspare = B_FALSE;
7111 	uint64_t unspare_guid = 0;
7112 	char *vdpath;
7113 
7114 	ASSERT(spa_writeable(spa));
7115 
7116 	txg = spa_vdev_detach_enter(spa, guid);
7117 
7118 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
7119 
7120 	/*
7121 	 * Besides being called directly from the userland through the
7122 	 * ioctl interface, spa_vdev_detach() can be potentially called
7123 	 * at the end of spa_vdev_resilver_done().
7124 	 *
7125 	 * In the regular case, when we have a checkpoint this shouldn't
7126 	 * happen as we never empty the DTLs of a vdev during the scrub
7127 	 * [see comment in dsl_scan_done()]. Thus spa_vdev_resilvering_done()
7128 	 * should never get here when we have a checkpoint.
7129 	 *
7130 	 * That said, even in a case when we checkpoint the pool exactly
7131 	 * as spa_vdev_resilver_done() calls this function everything
7132 	 * should be fine as the resilver will return right away.
7133 	 */
7134 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
7135 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
7136 		error = (spa_has_checkpoint(spa)) ?
7137 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
7138 		return (spa_vdev_exit(spa, NULL, txg, error));
7139 	}
7140 
7141 	if (vd == NULL)
7142 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
7143 
7144 	if (!vd->vdev_ops->vdev_op_leaf)
7145 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
7146 
7147 	pvd = vd->vdev_parent;
7148 
7149 	/*
7150 	 * If the parent/child relationship is not as expected, don't do it.
7151 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
7152 	 * vdev that's replacing B with C.  The user's intent in replacing
7153 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
7154 	 * the replace by detaching C, the expected behavior is to end up
7155 	 * M(A,B).  But suppose that right after deciding to detach C,
7156 	 * the replacement of B completes.  We would have M(A,C), and then
7157 	 * ask to detach C, which would leave us with just A -- not what
7158 	 * the user wanted.  To prevent this, we make sure that the
7159 	 * parent/child relationship hasn't changed -- in this example,
7160 	 * that C's parent is still the replacing vdev R.
7161 	 */
7162 	if (pvd->vdev_guid != pguid && pguid != 0)
7163 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
7164 
7165 	/*
7166 	 * Only 'replacing' or 'spare' vdevs can be replaced.
7167 	 */
7168 	if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
7169 	    pvd->vdev_ops != &vdev_spare_ops)
7170 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
7171 
7172 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
7173 	    spa_version(spa) >= SPA_VERSION_SPARES);
7174 
7175 	/*
7176 	 * Only mirror, replacing, and spare vdevs support detach.
7177 	 */
7178 	if (pvd->vdev_ops != &vdev_replacing_ops &&
7179 	    pvd->vdev_ops != &vdev_mirror_ops &&
7180 	    pvd->vdev_ops != &vdev_spare_ops)
7181 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
7182 
7183 	/*
7184 	 * If this device has the only valid copy of some data,
7185 	 * we cannot safely detach it.
7186 	 */
7187 	if (vdev_dtl_required(vd))
7188 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
7189 
7190 	ASSERT(pvd->vdev_children >= 2);
7191 
7192 	/*
7193 	 * If we are detaching the second disk from a replacing vdev, then
7194 	 * check to see if we changed the original vdev's path to have "/old"
7195 	 * at the end in spa_vdev_attach().  If so, undo that change now.
7196 	 */
7197 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
7198 	    vd->vdev_path != NULL) {
7199 		size_t len = strlen(vd->vdev_path);
7200 
7201 		for (int c = 0; c < pvd->vdev_children; c++) {
7202 			cvd = pvd->vdev_child[c];
7203 
7204 			if (cvd == vd || cvd->vdev_path == NULL)
7205 				continue;
7206 
7207 			if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
7208 			    strcmp(cvd->vdev_path + len, "/old") == 0) {
7209 				spa_strfree(cvd->vdev_path);
7210 				cvd->vdev_path = spa_strdup(vd->vdev_path);
7211 				break;
7212 			}
7213 		}
7214 	}
7215 
7216 	/*
7217 	 * If we are detaching the original disk from a normal spare, then it
7218 	 * implies that the spare should become a real disk, and be removed
7219 	 * from the active spare list for the pool.  dRAID spares on the
7220 	 * other hand are coupled to the pool and thus should never be removed
7221 	 * from the spares list.
7222 	 */
7223 	if (pvd->vdev_ops == &vdev_spare_ops && vd->vdev_id == 0) {
7224 		vdev_t *last_cvd = pvd->vdev_child[pvd->vdev_children - 1];
7225 
7226 		if (last_cvd->vdev_isspare &&
7227 		    last_cvd->vdev_ops != &vdev_draid_spare_ops) {
7228 			unspare = B_TRUE;
7229 		}
7230 	}
7231 
7232 	/*
7233 	 * Erase the disk labels so the disk can be used for other things.
7234 	 * This must be done after all other error cases are handled,
7235 	 * but before we disembowel vd (so we can still do I/O to it).
7236 	 * But if we can't do it, don't treat the error as fatal --
7237 	 * it may be that the unwritability of the disk is the reason
7238 	 * it's being detached!
7239 	 */
7240 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
7241 
7242 	/*
7243 	 * Remove vd from its parent and compact the parent's children.
7244 	 */
7245 	vdev_remove_child(pvd, vd);
7246 	vdev_compact_children(pvd);
7247 
7248 	/*
7249 	 * Remember one of the remaining children so we can get tvd below.
7250 	 */
7251 	cvd = pvd->vdev_child[pvd->vdev_children - 1];
7252 
7253 	/*
7254 	 * If we need to remove the remaining child from the list of hot spares,
7255 	 * do it now, marking the vdev as no longer a spare in the process.
7256 	 * We must do this before vdev_remove_parent(), because that can
7257 	 * change the GUID if it creates a new toplevel GUID.  For a similar
7258 	 * reason, we must remove the spare now, in the same txg as the detach;
7259 	 * otherwise someone could attach a new sibling, change the GUID, and
7260 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
7261 	 */
7262 	if (unspare) {
7263 		ASSERT(cvd->vdev_isspare);
7264 		spa_spare_remove(cvd);
7265 		unspare_guid = cvd->vdev_guid;
7266 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
7267 		cvd->vdev_unspare = B_TRUE;
7268 	}
7269 
7270 	/*
7271 	 * If the parent mirror/replacing vdev only has one child,
7272 	 * the parent is no longer needed.  Remove it from the tree.
7273 	 */
7274 	if (pvd->vdev_children == 1) {
7275 		if (pvd->vdev_ops == &vdev_spare_ops)
7276 			cvd->vdev_unspare = B_FALSE;
7277 		vdev_remove_parent(cvd);
7278 	}
7279 
7280 	/*
7281 	 * We don't set tvd until now because the parent we just removed
7282 	 * may have been the previous top-level vdev.
7283 	 */
7284 	tvd = cvd->vdev_top;
7285 	ASSERT(tvd->vdev_parent == rvd);
7286 
7287 	/*
7288 	 * Reevaluate the parent vdev state.
7289 	 */
7290 	vdev_propagate_state(cvd);
7291 
7292 	/*
7293 	 * If the 'autoexpand' property is set on the pool then automatically
7294 	 * try to expand the size of the pool. For example if the device we
7295 	 * just detached was smaller than the others, it may be possible to
7296 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
7297 	 * first so that we can obtain the updated sizes of the leaf vdevs.
7298 	 */
7299 	if (spa->spa_autoexpand) {
7300 		vdev_reopen(tvd);
7301 		vdev_expand(tvd, txg);
7302 	}
7303 
7304 	vdev_config_dirty(tvd);
7305 
7306 	/*
7307 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
7308 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
7309 	 * But first make sure we're not on any *other* txg's DTL list, to
7310 	 * prevent vd from being accessed after it's freed.
7311 	 */
7312 	vdpath = spa_strdup(vd->vdev_path ? vd->vdev_path : "none");
7313 	for (int t = 0; t < TXG_SIZE; t++)
7314 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
7315 	vd->vdev_detached = B_TRUE;
7316 	vdev_dirty(tvd, VDD_DTL, vd, txg);
7317 
7318 	spa_event_notify(spa, vd, NULL, ESC_ZFS_VDEV_REMOVE);
7319 	spa_notify_waiters(spa);
7320 
7321 	/* hang on to the spa before we release the lock */
7322 	spa_open_ref(spa, FTAG);
7323 
7324 	error = spa_vdev_exit(spa, vd, txg, 0);
7325 
7326 	spa_history_log_internal(spa, "detach", NULL,
7327 	    "vdev=%s", vdpath);
7328 	spa_strfree(vdpath);
7329 
7330 	/*
7331 	 * If this was the removal of the original device in a hot spare vdev,
7332 	 * then we want to go through and remove the device from the hot spare
7333 	 * list of every other pool.
7334 	 */
7335 	if (unspare) {
7336 		spa_t *altspa = NULL;
7337 
7338 		mutex_enter(&spa_namespace_lock);
7339 		while ((altspa = spa_next(altspa)) != NULL) {
7340 			if (altspa->spa_state != POOL_STATE_ACTIVE ||
7341 			    altspa == spa)
7342 				continue;
7343 
7344 			spa_open_ref(altspa, FTAG);
7345 			mutex_exit(&spa_namespace_lock);
7346 			(void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
7347 			mutex_enter(&spa_namespace_lock);
7348 			spa_close(altspa, FTAG);
7349 		}
7350 		mutex_exit(&spa_namespace_lock);
7351 
7352 		/* search the rest of the vdevs for spares to remove */
7353 		spa_vdev_resilver_done(spa);
7354 	}
7355 
7356 	/* all done with the spa; OK to release */
7357 	mutex_enter(&spa_namespace_lock);
7358 	spa_close(spa, FTAG);
7359 	mutex_exit(&spa_namespace_lock);
7360 
7361 	return (error);
7362 }
7363 
7364 static int
7365 spa_vdev_initialize_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
7366     list_t *vd_list)
7367 {
7368 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
7369 
7370 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
7371 
7372 	/* Look up vdev and ensure it's a leaf. */
7373 	vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
7374 	if (vd == NULL || vd->vdev_detached) {
7375 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7376 		return (SET_ERROR(ENODEV));
7377 	} else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
7378 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7379 		return (SET_ERROR(EINVAL));
7380 	} else if (!vdev_writeable(vd)) {
7381 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7382 		return (SET_ERROR(EROFS));
7383 	}
7384 	mutex_enter(&vd->vdev_initialize_lock);
7385 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7386 
7387 	/*
7388 	 * When we activate an initialize action we check to see
7389 	 * if the vdev_initialize_thread is NULL. We do this instead
7390 	 * of using the vdev_initialize_state since there might be
7391 	 * a previous initialization process which has completed but
7392 	 * the thread is not exited.
7393 	 */
7394 	if (cmd_type == POOL_INITIALIZE_START &&
7395 	    (vd->vdev_initialize_thread != NULL ||
7396 	    vd->vdev_top->vdev_removing)) {
7397 		mutex_exit(&vd->vdev_initialize_lock);
7398 		return (SET_ERROR(EBUSY));
7399 	} else if (cmd_type == POOL_INITIALIZE_CANCEL &&
7400 	    (vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE &&
7401 	    vd->vdev_initialize_state != VDEV_INITIALIZE_SUSPENDED)) {
7402 		mutex_exit(&vd->vdev_initialize_lock);
7403 		return (SET_ERROR(ESRCH));
7404 	} else if (cmd_type == POOL_INITIALIZE_SUSPEND &&
7405 	    vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE) {
7406 		mutex_exit(&vd->vdev_initialize_lock);
7407 		return (SET_ERROR(ESRCH));
7408 	}
7409 
7410 	switch (cmd_type) {
7411 	case POOL_INITIALIZE_START:
7412 		vdev_initialize(vd);
7413 		break;
7414 	case POOL_INITIALIZE_CANCEL:
7415 		vdev_initialize_stop(vd, VDEV_INITIALIZE_CANCELED, vd_list);
7416 		break;
7417 	case POOL_INITIALIZE_SUSPEND:
7418 		vdev_initialize_stop(vd, VDEV_INITIALIZE_SUSPENDED, vd_list);
7419 		break;
7420 	default:
7421 		panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
7422 	}
7423 	mutex_exit(&vd->vdev_initialize_lock);
7424 
7425 	return (0);
7426 }
7427 
7428 int
7429 spa_vdev_initialize(spa_t *spa, nvlist_t *nv, uint64_t cmd_type,
7430     nvlist_t *vdev_errlist)
7431 {
7432 	int total_errors = 0;
7433 	list_t vd_list;
7434 
7435 	list_create(&vd_list, sizeof (vdev_t),
7436 	    offsetof(vdev_t, vdev_initialize_node));
7437 
7438 	/*
7439 	 * We hold the namespace lock through the whole function
7440 	 * to prevent any changes to the pool while we're starting or
7441 	 * stopping initialization. The config and state locks are held so that
7442 	 * we can properly assess the vdev state before we commit to
7443 	 * the initializing operation.
7444 	 */
7445 	mutex_enter(&spa_namespace_lock);
7446 
7447 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
7448 	    pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
7449 		uint64_t vdev_guid = fnvpair_value_uint64(pair);
7450 
7451 		int error = spa_vdev_initialize_impl(spa, vdev_guid, cmd_type,
7452 		    &vd_list);
7453 		if (error != 0) {
7454 			char guid_as_str[MAXNAMELEN];
7455 
7456 			(void) snprintf(guid_as_str, sizeof (guid_as_str),
7457 			    "%llu", (unsigned long long)vdev_guid);
7458 			fnvlist_add_int64(vdev_errlist, guid_as_str, error);
7459 			total_errors++;
7460 		}
7461 	}
7462 
7463 	/* Wait for all initialize threads to stop. */
7464 	vdev_initialize_stop_wait(spa, &vd_list);
7465 
7466 	/* Sync out the initializing state */
7467 	txg_wait_synced(spa->spa_dsl_pool, 0);
7468 	mutex_exit(&spa_namespace_lock);
7469 
7470 	list_destroy(&vd_list);
7471 
7472 	return (total_errors);
7473 }
7474 
7475 static int
7476 spa_vdev_trim_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
7477     uint64_t rate, boolean_t partial, boolean_t secure, list_t *vd_list)
7478 {
7479 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
7480 
7481 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
7482 
7483 	/* Look up vdev and ensure it's a leaf. */
7484 	vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
7485 	if (vd == NULL || vd->vdev_detached) {
7486 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7487 		return (SET_ERROR(ENODEV));
7488 	} else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
7489 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7490 		return (SET_ERROR(EINVAL));
7491 	} else if (!vdev_writeable(vd)) {
7492 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7493 		return (SET_ERROR(EROFS));
7494 	} else if (!vd->vdev_has_trim) {
7495 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7496 		return (SET_ERROR(EOPNOTSUPP));
7497 	} else if (secure && !vd->vdev_has_securetrim) {
7498 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7499 		return (SET_ERROR(EOPNOTSUPP));
7500 	}
7501 	mutex_enter(&vd->vdev_trim_lock);
7502 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
7503 
7504 	/*
7505 	 * When we activate a TRIM action we check to see if the
7506 	 * vdev_trim_thread is NULL. We do this instead of using the
7507 	 * vdev_trim_state since there might be a previous TRIM process
7508 	 * which has completed but the thread is not exited.
7509 	 */
7510 	if (cmd_type == POOL_TRIM_START &&
7511 	    (vd->vdev_trim_thread != NULL || vd->vdev_top->vdev_removing)) {
7512 		mutex_exit(&vd->vdev_trim_lock);
7513 		return (SET_ERROR(EBUSY));
7514 	} else if (cmd_type == POOL_TRIM_CANCEL &&
7515 	    (vd->vdev_trim_state != VDEV_TRIM_ACTIVE &&
7516 	    vd->vdev_trim_state != VDEV_TRIM_SUSPENDED)) {
7517 		mutex_exit(&vd->vdev_trim_lock);
7518 		return (SET_ERROR(ESRCH));
7519 	} else if (cmd_type == POOL_TRIM_SUSPEND &&
7520 	    vd->vdev_trim_state != VDEV_TRIM_ACTIVE) {
7521 		mutex_exit(&vd->vdev_trim_lock);
7522 		return (SET_ERROR(ESRCH));
7523 	}
7524 
7525 	switch (cmd_type) {
7526 	case POOL_TRIM_START:
7527 		vdev_trim(vd, rate, partial, secure);
7528 		break;
7529 	case POOL_TRIM_CANCEL:
7530 		vdev_trim_stop(vd, VDEV_TRIM_CANCELED, vd_list);
7531 		break;
7532 	case POOL_TRIM_SUSPEND:
7533 		vdev_trim_stop(vd, VDEV_TRIM_SUSPENDED, vd_list);
7534 		break;
7535 	default:
7536 		panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
7537 	}
7538 	mutex_exit(&vd->vdev_trim_lock);
7539 
7540 	return (0);
7541 }
7542 
7543 /*
7544  * Initiates a manual TRIM for the requested vdevs. This kicks off individual
7545  * TRIM threads for each child vdev.  These threads pass over all of the free
7546  * space in the vdev's metaslabs and issues TRIM commands for that space.
7547  */
7548 int
7549 spa_vdev_trim(spa_t *spa, nvlist_t *nv, uint64_t cmd_type, uint64_t rate,
7550     boolean_t partial, boolean_t secure, nvlist_t *vdev_errlist)
7551 {
7552 	int total_errors = 0;
7553 	list_t vd_list;
7554 
7555 	list_create(&vd_list, sizeof (vdev_t),
7556 	    offsetof(vdev_t, vdev_trim_node));
7557 
7558 	/*
7559 	 * We hold the namespace lock through the whole function
7560 	 * to prevent any changes to the pool while we're starting or
7561 	 * stopping TRIM. The config and state locks are held so that
7562 	 * we can properly assess the vdev state before we commit to
7563 	 * the TRIM operation.
7564 	 */
7565 	mutex_enter(&spa_namespace_lock);
7566 
7567 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
7568 	    pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
7569 		uint64_t vdev_guid = fnvpair_value_uint64(pair);
7570 
7571 		int error = spa_vdev_trim_impl(spa, vdev_guid, cmd_type,
7572 		    rate, partial, secure, &vd_list);
7573 		if (error != 0) {
7574 			char guid_as_str[MAXNAMELEN];
7575 
7576 			(void) snprintf(guid_as_str, sizeof (guid_as_str),
7577 			    "%llu", (unsigned long long)vdev_guid);
7578 			fnvlist_add_int64(vdev_errlist, guid_as_str, error);
7579 			total_errors++;
7580 		}
7581 	}
7582 
7583 	/* Wait for all TRIM threads to stop. */
7584 	vdev_trim_stop_wait(spa, &vd_list);
7585 
7586 	/* Sync out the TRIM state */
7587 	txg_wait_synced(spa->spa_dsl_pool, 0);
7588 	mutex_exit(&spa_namespace_lock);
7589 
7590 	list_destroy(&vd_list);
7591 
7592 	return (total_errors);
7593 }
7594 
7595 /*
7596  * Split a set of devices from their mirrors, and create a new pool from them.
7597  */
7598 int
7599 spa_vdev_split_mirror(spa_t *spa, const char *newname, nvlist_t *config,
7600     nvlist_t *props, boolean_t exp)
7601 {
7602 	int error = 0;
7603 	uint64_t txg, *glist;
7604 	spa_t *newspa;
7605 	uint_t c, children, lastlog;
7606 	nvlist_t **child, *nvl, *tmp;
7607 	dmu_tx_t *tx;
7608 	const char *altroot = NULL;
7609 	vdev_t *rvd, **vml = NULL;			/* vdev modify list */
7610 	boolean_t activate_slog;
7611 
7612 	ASSERT(spa_writeable(spa));
7613 
7614 	txg = spa_vdev_enter(spa);
7615 
7616 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
7617 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
7618 		error = (spa_has_checkpoint(spa)) ?
7619 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
7620 		return (spa_vdev_exit(spa, NULL, txg, error));
7621 	}
7622 
7623 	/* clear the log and flush everything up to now */
7624 	activate_slog = spa_passivate_log(spa);
7625 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
7626 	error = spa_reset_logs(spa);
7627 	txg = spa_vdev_config_enter(spa);
7628 
7629 	if (activate_slog)
7630 		spa_activate_log(spa);
7631 
7632 	if (error != 0)
7633 		return (spa_vdev_exit(spa, NULL, txg, error));
7634 
7635 	/* check new spa name before going any further */
7636 	if (spa_lookup(newname) != NULL)
7637 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
7638 
7639 	/*
7640 	 * scan through all the children to ensure they're all mirrors
7641 	 */
7642 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
7643 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
7644 	    &children) != 0)
7645 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
7646 
7647 	/* first, check to ensure we've got the right child count */
7648 	rvd = spa->spa_root_vdev;
7649 	lastlog = 0;
7650 	for (c = 0; c < rvd->vdev_children; c++) {
7651 		vdev_t *vd = rvd->vdev_child[c];
7652 
7653 		/* don't count the holes & logs as children */
7654 		if (vd->vdev_islog || (vd->vdev_ops != &vdev_indirect_ops &&
7655 		    !vdev_is_concrete(vd))) {
7656 			if (lastlog == 0)
7657 				lastlog = c;
7658 			continue;
7659 		}
7660 
7661 		lastlog = 0;
7662 	}
7663 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
7664 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
7665 
7666 	/* next, ensure no spare or cache devices are part of the split */
7667 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
7668 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
7669 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
7670 
7671 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
7672 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
7673 
7674 	/* then, loop over each vdev and validate it */
7675 	for (c = 0; c < children; c++) {
7676 		uint64_t is_hole = 0;
7677 
7678 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
7679 		    &is_hole);
7680 
7681 		if (is_hole != 0) {
7682 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
7683 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
7684 				continue;
7685 			} else {
7686 				error = SET_ERROR(EINVAL);
7687 				break;
7688 			}
7689 		}
7690 
7691 		/* deal with indirect vdevs */
7692 		if (spa->spa_root_vdev->vdev_child[c]->vdev_ops ==
7693 		    &vdev_indirect_ops)
7694 			continue;
7695 
7696 		/* which disk is going to be split? */
7697 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
7698 		    &glist[c]) != 0) {
7699 			error = SET_ERROR(EINVAL);
7700 			break;
7701 		}
7702 
7703 		/* look it up in the spa */
7704 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
7705 		if (vml[c] == NULL) {
7706 			error = SET_ERROR(ENODEV);
7707 			break;
7708 		}
7709 
7710 		/* make sure there's nothing stopping the split */
7711 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
7712 		    vml[c]->vdev_islog ||
7713 		    !vdev_is_concrete(vml[c]) ||
7714 		    vml[c]->vdev_isspare ||
7715 		    vml[c]->vdev_isl2cache ||
7716 		    !vdev_writeable(vml[c]) ||
7717 		    vml[c]->vdev_children != 0 ||
7718 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
7719 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
7720 			error = SET_ERROR(EINVAL);
7721 			break;
7722 		}
7723 
7724 		if (vdev_dtl_required(vml[c]) ||
7725 		    vdev_resilver_needed(vml[c], NULL, NULL)) {
7726 			error = SET_ERROR(EBUSY);
7727 			break;
7728 		}
7729 
7730 		/* we need certain info from the top level */
7731 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
7732 		    vml[c]->vdev_top->vdev_ms_array);
7733 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
7734 		    vml[c]->vdev_top->vdev_ms_shift);
7735 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
7736 		    vml[c]->vdev_top->vdev_asize);
7737 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
7738 		    vml[c]->vdev_top->vdev_ashift);
7739 
7740 		/* transfer per-vdev ZAPs */
7741 		ASSERT3U(vml[c]->vdev_leaf_zap, !=, 0);
7742 		VERIFY0(nvlist_add_uint64(child[c],
7743 		    ZPOOL_CONFIG_VDEV_LEAF_ZAP, vml[c]->vdev_leaf_zap));
7744 
7745 		ASSERT3U(vml[c]->vdev_top->vdev_top_zap, !=, 0);
7746 		VERIFY0(nvlist_add_uint64(child[c],
7747 		    ZPOOL_CONFIG_VDEV_TOP_ZAP,
7748 		    vml[c]->vdev_parent->vdev_top_zap));
7749 	}
7750 
7751 	if (error != 0) {
7752 		kmem_free(vml, children * sizeof (vdev_t *));
7753 		kmem_free(glist, children * sizeof (uint64_t));
7754 		return (spa_vdev_exit(spa, NULL, txg, error));
7755 	}
7756 
7757 	/* stop writers from using the disks */
7758 	for (c = 0; c < children; c++) {
7759 		if (vml[c] != NULL)
7760 			vml[c]->vdev_offline = B_TRUE;
7761 	}
7762 	vdev_reopen(spa->spa_root_vdev);
7763 
7764 	/*
7765 	 * Temporarily record the splitting vdevs in the spa config.  This
7766 	 * will disappear once the config is regenerated.
7767 	 */
7768 	nvl = fnvlist_alloc();
7769 	fnvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST, glist, children);
7770 	kmem_free(glist, children * sizeof (uint64_t));
7771 
7772 	mutex_enter(&spa->spa_props_lock);
7773 	fnvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT, nvl);
7774 	mutex_exit(&spa->spa_props_lock);
7775 	spa->spa_config_splitting = nvl;
7776 	vdev_config_dirty(spa->spa_root_vdev);
7777 
7778 	/* configure and create the new pool */
7779 	fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname);
7780 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
7781 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE);
7782 	fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
7783 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, spa->spa_config_txg);
7784 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
7785 	    spa_generate_guid(NULL));
7786 	VERIFY0(nvlist_add_boolean(config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS));
7787 	(void) nvlist_lookup_string(props,
7788 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
7789 
7790 	/* add the new pool to the namespace */
7791 	newspa = spa_add(newname, config, altroot);
7792 	newspa->spa_avz_action = AVZ_ACTION_REBUILD;
7793 	newspa->spa_config_txg = spa->spa_config_txg;
7794 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
7795 
7796 	/* release the spa config lock, retaining the namespace lock */
7797 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
7798 
7799 	if (zio_injection_enabled)
7800 		zio_handle_panic_injection(spa, FTAG, 1);
7801 
7802 	spa_activate(newspa, spa_mode_global);
7803 	spa_async_suspend(newspa);
7804 
7805 	/*
7806 	 * Temporarily stop the initializing and TRIM activity.  We set the
7807 	 * state to ACTIVE so that we know to resume initializing or TRIM
7808 	 * once the split has completed.
7809 	 */
7810 	list_t vd_initialize_list;
7811 	list_create(&vd_initialize_list, sizeof (vdev_t),
7812 	    offsetof(vdev_t, vdev_initialize_node));
7813 
7814 	list_t vd_trim_list;
7815 	list_create(&vd_trim_list, sizeof (vdev_t),
7816 	    offsetof(vdev_t, vdev_trim_node));
7817 
7818 	for (c = 0; c < children; c++) {
7819 		if (vml[c] != NULL && vml[c]->vdev_ops != &vdev_indirect_ops) {
7820 			mutex_enter(&vml[c]->vdev_initialize_lock);
7821 			vdev_initialize_stop(vml[c],
7822 			    VDEV_INITIALIZE_ACTIVE, &vd_initialize_list);
7823 			mutex_exit(&vml[c]->vdev_initialize_lock);
7824 
7825 			mutex_enter(&vml[c]->vdev_trim_lock);
7826 			vdev_trim_stop(vml[c], VDEV_TRIM_ACTIVE, &vd_trim_list);
7827 			mutex_exit(&vml[c]->vdev_trim_lock);
7828 		}
7829 	}
7830 
7831 	vdev_initialize_stop_wait(spa, &vd_initialize_list);
7832 	vdev_trim_stop_wait(spa, &vd_trim_list);
7833 
7834 	list_destroy(&vd_initialize_list);
7835 	list_destroy(&vd_trim_list);
7836 
7837 	newspa->spa_config_source = SPA_CONFIG_SRC_SPLIT;
7838 	newspa->spa_is_splitting = B_TRUE;
7839 
7840 	/* create the new pool from the disks of the original pool */
7841 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE);
7842 	if (error)
7843 		goto out;
7844 
7845 	/* if that worked, generate a real config for the new pool */
7846 	if (newspa->spa_root_vdev != NULL) {
7847 		newspa->spa_config_splitting = fnvlist_alloc();
7848 		fnvlist_add_uint64(newspa->spa_config_splitting,
7849 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa));
7850 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
7851 		    B_TRUE));
7852 	}
7853 
7854 	/* set the props */
7855 	if (props != NULL) {
7856 		spa_configfile_set(newspa, props, B_FALSE);
7857 		error = spa_prop_set(newspa, props);
7858 		if (error)
7859 			goto out;
7860 	}
7861 
7862 	/* flush everything */
7863 	txg = spa_vdev_config_enter(newspa);
7864 	vdev_config_dirty(newspa->spa_root_vdev);
7865 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
7866 
7867 	if (zio_injection_enabled)
7868 		zio_handle_panic_injection(spa, FTAG, 2);
7869 
7870 	spa_async_resume(newspa);
7871 
7872 	/* finally, update the original pool's config */
7873 	txg = spa_vdev_config_enter(spa);
7874 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
7875 	error = dmu_tx_assign(tx, TXG_WAIT);
7876 	if (error != 0)
7877 		dmu_tx_abort(tx);
7878 	for (c = 0; c < children; c++) {
7879 		if (vml[c] != NULL && vml[c]->vdev_ops != &vdev_indirect_ops) {
7880 			vdev_t *tvd = vml[c]->vdev_top;
7881 
7882 			/*
7883 			 * Need to be sure the detachable VDEV is not
7884 			 * on any *other* txg's DTL list to prevent it
7885 			 * from being accessed after it's freed.
7886 			 */
7887 			for (int t = 0; t < TXG_SIZE; t++) {
7888 				(void) txg_list_remove_this(
7889 				    &tvd->vdev_dtl_list, vml[c], t);
7890 			}
7891 
7892 			vdev_split(vml[c]);
7893 			if (error == 0)
7894 				spa_history_log_internal(spa, "detach", tx,
7895 				    "vdev=%s", vml[c]->vdev_path);
7896 
7897 			vdev_free(vml[c]);
7898 		}
7899 	}
7900 	spa->spa_avz_action = AVZ_ACTION_REBUILD;
7901 	vdev_config_dirty(spa->spa_root_vdev);
7902 	spa->spa_config_splitting = NULL;
7903 	nvlist_free(nvl);
7904 	if (error == 0)
7905 		dmu_tx_commit(tx);
7906 	(void) spa_vdev_exit(spa, NULL, txg, 0);
7907 
7908 	if (zio_injection_enabled)
7909 		zio_handle_panic_injection(spa, FTAG, 3);
7910 
7911 	/* split is complete; log a history record */
7912 	spa_history_log_internal(newspa, "split", NULL,
7913 	    "from pool %s", spa_name(spa));
7914 
7915 	newspa->spa_is_splitting = B_FALSE;
7916 	kmem_free(vml, children * sizeof (vdev_t *));
7917 
7918 	/* if we're not going to mount the filesystems in userland, export */
7919 	if (exp)
7920 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
7921 		    B_FALSE, B_FALSE);
7922 
7923 	return (error);
7924 
7925 out:
7926 	spa_unload(newspa);
7927 	spa_deactivate(newspa);
7928 	spa_remove(newspa);
7929 
7930 	txg = spa_vdev_config_enter(spa);
7931 
7932 	/* re-online all offlined disks */
7933 	for (c = 0; c < children; c++) {
7934 		if (vml[c] != NULL)
7935 			vml[c]->vdev_offline = B_FALSE;
7936 	}
7937 
7938 	/* restart initializing or trimming disks as necessary */
7939 	spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART);
7940 	spa_async_request(spa, SPA_ASYNC_TRIM_RESTART);
7941 	spa_async_request(spa, SPA_ASYNC_AUTOTRIM_RESTART);
7942 
7943 	vdev_reopen(spa->spa_root_vdev);
7944 
7945 	nvlist_free(spa->spa_config_splitting);
7946 	spa->spa_config_splitting = NULL;
7947 	(void) spa_vdev_exit(spa, NULL, txg, error);
7948 
7949 	kmem_free(vml, children * sizeof (vdev_t *));
7950 	return (error);
7951 }
7952 
7953 /*
7954  * Find any device that's done replacing, or a vdev marked 'unspare' that's
7955  * currently spared, so we can detach it.
7956  */
7957 static vdev_t *
7958 spa_vdev_resilver_done_hunt(vdev_t *vd)
7959 {
7960 	vdev_t *newvd, *oldvd;
7961 
7962 	for (int c = 0; c < vd->vdev_children; c++) {
7963 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
7964 		if (oldvd != NULL)
7965 			return (oldvd);
7966 	}
7967 
7968 	/*
7969 	 * Check for a completed replacement.  We always consider the first
7970 	 * vdev in the list to be the oldest vdev, and the last one to be
7971 	 * the newest (see spa_vdev_attach() for how that works).  In
7972 	 * the case where the newest vdev is faulted, we will not automatically
7973 	 * remove it after a resilver completes.  This is OK as it will require
7974 	 * user intervention to determine which disk the admin wishes to keep.
7975 	 */
7976 	if (vd->vdev_ops == &vdev_replacing_ops) {
7977 		ASSERT(vd->vdev_children > 1);
7978 
7979 		newvd = vd->vdev_child[vd->vdev_children - 1];
7980 		oldvd = vd->vdev_child[0];
7981 
7982 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
7983 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
7984 		    !vdev_dtl_required(oldvd))
7985 			return (oldvd);
7986 	}
7987 
7988 	/*
7989 	 * Check for a completed resilver with the 'unspare' flag set.
7990 	 * Also potentially update faulted state.
7991 	 */
7992 	if (vd->vdev_ops == &vdev_spare_ops) {
7993 		vdev_t *first = vd->vdev_child[0];
7994 		vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
7995 
7996 		if (last->vdev_unspare) {
7997 			oldvd = first;
7998 			newvd = last;
7999 		} else if (first->vdev_unspare) {
8000 			oldvd = last;
8001 			newvd = first;
8002 		} else {
8003 			oldvd = NULL;
8004 		}
8005 
8006 		if (oldvd != NULL &&
8007 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
8008 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
8009 		    !vdev_dtl_required(oldvd))
8010 			return (oldvd);
8011 
8012 		vdev_propagate_state(vd);
8013 
8014 		/*
8015 		 * If there are more than two spares attached to a disk,
8016 		 * and those spares are not required, then we want to
8017 		 * attempt to free them up now so that they can be used
8018 		 * by other pools.  Once we're back down to a single
8019 		 * disk+spare, we stop removing them.
8020 		 */
8021 		if (vd->vdev_children > 2) {
8022 			newvd = vd->vdev_child[1];
8023 
8024 			if (newvd->vdev_isspare && last->vdev_isspare &&
8025 			    vdev_dtl_empty(last, DTL_MISSING) &&
8026 			    vdev_dtl_empty(last, DTL_OUTAGE) &&
8027 			    !vdev_dtl_required(newvd))
8028 				return (newvd);
8029 		}
8030 	}
8031 
8032 	return (NULL);
8033 }
8034 
8035 static void
8036 spa_vdev_resilver_done(spa_t *spa)
8037 {
8038 	vdev_t *vd, *pvd, *ppvd;
8039 	uint64_t guid, sguid, pguid, ppguid;
8040 
8041 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
8042 
8043 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
8044 		pvd = vd->vdev_parent;
8045 		ppvd = pvd->vdev_parent;
8046 		guid = vd->vdev_guid;
8047 		pguid = pvd->vdev_guid;
8048 		ppguid = ppvd->vdev_guid;
8049 		sguid = 0;
8050 		/*
8051 		 * If we have just finished replacing a hot spared device, then
8052 		 * we need to detach the parent's first child (the original hot
8053 		 * spare) as well.
8054 		 */
8055 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
8056 		    ppvd->vdev_children == 2) {
8057 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
8058 			sguid = ppvd->vdev_child[1]->vdev_guid;
8059 		}
8060 		ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
8061 
8062 		spa_config_exit(spa, SCL_ALL, FTAG);
8063 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
8064 			return;
8065 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
8066 			return;
8067 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
8068 	}
8069 
8070 	spa_config_exit(spa, SCL_ALL, FTAG);
8071 
8072 	/*
8073 	 * If a detach was not performed above replace waiters will not have
8074 	 * been notified.  In which case we must do so now.
8075 	 */
8076 	spa_notify_waiters(spa);
8077 }
8078 
8079 /*
8080  * Update the stored path or FRU for this vdev.
8081  */
8082 static int
8083 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
8084     boolean_t ispath)
8085 {
8086 	vdev_t *vd;
8087 	boolean_t sync = B_FALSE;
8088 
8089 	ASSERT(spa_writeable(spa));
8090 
8091 	spa_vdev_state_enter(spa, SCL_ALL);
8092 
8093 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
8094 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
8095 
8096 	if (!vd->vdev_ops->vdev_op_leaf)
8097 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
8098 
8099 	if (ispath) {
8100 		if (strcmp(value, vd->vdev_path) != 0) {
8101 			spa_strfree(vd->vdev_path);
8102 			vd->vdev_path = spa_strdup(value);
8103 			sync = B_TRUE;
8104 		}
8105 	} else {
8106 		if (vd->vdev_fru == NULL) {
8107 			vd->vdev_fru = spa_strdup(value);
8108 			sync = B_TRUE;
8109 		} else if (strcmp(value, vd->vdev_fru) != 0) {
8110 			spa_strfree(vd->vdev_fru);
8111 			vd->vdev_fru = spa_strdup(value);
8112 			sync = B_TRUE;
8113 		}
8114 	}
8115 
8116 	return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
8117 }
8118 
8119 int
8120 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
8121 {
8122 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
8123 }
8124 
8125 int
8126 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
8127 {
8128 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
8129 }
8130 
8131 /*
8132  * ==========================================================================
8133  * SPA Scanning
8134  * ==========================================================================
8135  */
8136 int
8137 spa_scrub_pause_resume(spa_t *spa, pool_scrub_cmd_t cmd)
8138 {
8139 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
8140 
8141 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
8142 		return (SET_ERROR(EBUSY));
8143 
8144 	return (dsl_scrub_set_pause_resume(spa->spa_dsl_pool, cmd));
8145 }
8146 
8147 int
8148 spa_scan_stop(spa_t *spa)
8149 {
8150 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
8151 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
8152 		return (SET_ERROR(EBUSY));
8153 	return (dsl_scan_cancel(spa->spa_dsl_pool));
8154 }
8155 
8156 int
8157 spa_scan(spa_t *spa, pool_scan_func_t func)
8158 {
8159 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
8160 
8161 	if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
8162 		return (SET_ERROR(ENOTSUP));
8163 
8164 	if (func == POOL_SCAN_RESILVER &&
8165 	    !spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER))
8166 		return (SET_ERROR(ENOTSUP));
8167 
8168 	/*
8169 	 * If a resilver was requested, but there is no DTL on a
8170 	 * writeable leaf device, we have nothing to do.
8171 	 */
8172 	if (func == POOL_SCAN_RESILVER &&
8173 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
8174 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
8175 		return (0);
8176 	}
8177 
8178 	return (dsl_scan(spa->spa_dsl_pool, func));
8179 }
8180 
8181 /*
8182  * ==========================================================================
8183  * SPA async task processing
8184  * ==========================================================================
8185  */
8186 
8187 static void
8188 spa_async_remove(spa_t *spa, vdev_t *vd)
8189 {
8190 	if (vd->vdev_remove_wanted) {
8191 		vd->vdev_remove_wanted = B_FALSE;
8192 		vd->vdev_delayed_close = B_FALSE;
8193 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
8194 
8195 		/*
8196 		 * We want to clear the stats, but we don't want to do a full
8197 		 * vdev_clear() as that will cause us to throw away
8198 		 * degraded/faulted state as well as attempt to reopen the
8199 		 * device, all of which is a waste.
8200 		 */
8201 		vd->vdev_stat.vs_read_errors = 0;
8202 		vd->vdev_stat.vs_write_errors = 0;
8203 		vd->vdev_stat.vs_checksum_errors = 0;
8204 
8205 		vdev_state_dirty(vd->vdev_top);
8206 
8207 		/* Tell userspace that the vdev is gone. */
8208 		zfs_post_remove(spa, vd);
8209 	}
8210 
8211 	for (int c = 0; c < vd->vdev_children; c++)
8212 		spa_async_remove(spa, vd->vdev_child[c]);
8213 }
8214 
8215 static void
8216 spa_async_probe(spa_t *spa, vdev_t *vd)
8217 {
8218 	if (vd->vdev_probe_wanted) {
8219 		vd->vdev_probe_wanted = B_FALSE;
8220 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
8221 	}
8222 
8223 	for (int c = 0; c < vd->vdev_children; c++)
8224 		spa_async_probe(spa, vd->vdev_child[c]);
8225 }
8226 
8227 static void
8228 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
8229 {
8230 	if (!spa->spa_autoexpand)
8231 		return;
8232 
8233 	for (int c = 0; c < vd->vdev_children; c++) {
8234 		vdev_t *cvd = vd->vdev_child[c];
8235 		spa_async_autoexpand(spa, cvd);
8236 	}
8237 
8238 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
8239 		return;
8240 
8241 	spa_event_notify(vd->vdev_spa, vd, NULL, ESC_ZFS_VDEV_AUTOEXPAND);
8242 }
8243 
8244 static __attribute__((noreturn)) void
8245 spa_async_thread(void *arg)
8246 {
8247 	spa_t *spa = (spa_t *)arg;
8248 	dsl_pool_t *dp = spa->spa_dsl_pool;
8249 	int tasks;
8250 
8251 	ASSERT(spa->spa_sync_on);
8252 
8253 	mutex_enter(&spa->spa_async_lock);
8254 	tasks = spa->spa_async_tasks;
8255 	spa->spa_async_tasks = 0;
8256 	mutex_exit(&spa->spa_async_lock);
8257 
8258 	/*
8259 	 * See if the config needs to be updated.
8260 	 */
8261 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
8262 		uint64_t old_space, new_space;
8263 
8264 		mutex_enter(&spa_namespace_lock);
8265 		old_space = metaslab_class_get_space(spa_normal_class(spa));
8266 		old_space += metaslab_class_get_space(spa_special_class(spa));
8267 		old_space += metaslab_class_get_space(spa_dedup_class(spa));
8268 		old_space += metaslab_class_get_space(
8269 		    spa_embedded_log_class(spa));
8270 
8271 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
8272 
8273 		new_space = metaslab_class_get_space(spa_normal_class(spa));
8274 		new_space += metaslab_class_get_space(spa_special_class(spa));
8275 		new_space += metaslab_class_get_space(spa_dedup_class(spa));
8276 		new_space += metaslab_class_get_space(
8277 		    spa_embedded_log_class(spa));
8278 		mutex_exit(&spa_namespace_lock);
8279 
8280 		/*
8281 		 * If the pool grew as a result of the config update,
8282 		 * then log an internal history event.
8283 		 */
8284 		if (new_space != old_space) {
8285 			spa_history_log_internal(spa, "vdev online", NULL,
8286 			    "pool '%s' size: %llu(+%llu)",
8287 			    spa_name(spa), (u_longlong_t)new_space,
8288 			    (u_longlong_t)(new_space - old_space));
8289 		}
8290 	}
8291 
8292 	/*
8293 	 * See if any devices need to be marked REMOVED.
8294 	 */
8295 	if (tasks & SPA_ASYNC_REMOVE) {
8296 		spa_vdev_state_enter(spa, SCL_NONE);
8297 		spa_async_remove(spa, spa->spa_root_vdev);
8298 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
8299 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
8300 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
8301 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
8302 		(void) spa_vdev_state_exit(spa, NULL, 0);
8303 	}
8304 
8305 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
8306 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
8307 		spa_async_autoexpand(spa, spa->spa_root_vdev);
8308 		spa_config_exit(spa, SCL_CONFIG, FTAG);
8309 	}
8310 
8311 	/*
8312 	 * See if any devices need to be probed.
8313 	 */
8314 	if (tasks & SPA_ASYNC_PROBE) {
8315 		spa_vdev_state_enter(spa, SCL_NONE);
8316 		spa_async_probe(spa, spa->spa_root_vdev);
8317 		(void) spa_vdev_state_exit(spa, NULL, 0);
8318 	}
8319 
8320 	/*
8321 	 * If any devices are done replacing, detach them.
8322 	 */
8323 	if (tasks & SPA_ASYNC_RESILVER_DONE ||
8324 	    tasks & SPA_ASYNC_REBUILD_DONE) {
8325 		spa_vdev_resilver_done(spa);
8326 	}
8327 
8328 	/*
8329 	 * Kick off a resilver.
8330 	 */
8331 	if (tasks & SPA_ASYNC_RESILVER &&
8332 	    !vdev_rebuild_active(spa->spa_root_vdev) &&
8333 	    (!dsl_scan_resilvering(dp) ||
8334 	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_RESILVER_DEFER)))
8335 		dsl_scan_restart_resilver(dp, 0);
8336 
8337 	if (tasks & SPA_ASYNC_INITIALIZE_RESTART) {
8338 		mutex_enter(&spa_namespace_lock);
8339 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
8340 		vdev_initialize_restart(spa->spa_root_vdev);
8341 		spa_config_exit(spa, SCL_CONFIG, FTAG);
8342 		mutex_exit(&spa_namespace_lock);
8343 	}
8344 
8345 	if (tasks & SPA_ASYNC_TRIM_RESTART) {
8346 		mutex_enter(&spa_namespace_lock);
8347 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
8348 		vdev_trim_restart(spa->spa_root_vdev);
8349 		spa_config_exit(spa, SCL_CONFIG, FTAG);
8350 		mutex_exit(&spa_namespace_lock);
8351 	}
8352 
8353 	if (tasks & SPA_ASYNC_AUTOTRIM_RESTART) {
8354 		mutex_enter(&spa_namespace_lock);
8355 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
8356 		vdev_autotrim_restart(spa);
8357 		spa_config_exit(spa, SCL_CONFIG, FTAG);
8358 		mutex_exit(&spa_namespace_lock);
8359 	}
8360 
8361 	/*
8362 	 * Kick off L2 cache whole device TRIM.
8363 	 */
8364 	if (tasks & SPA_ASYNC_L2CACHE_TRIM) {
8365 		mutex_enter(&spa_namespace_lock);
8366 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
8367 		vdev_trim_l2arc(spa);
8368 		spa_config_exit(spa, SCL_CONFIG, FTAG);
8369 		mutex_exit(&spa_namespace_lock);
8370 	}
8371 
8372 	/*
8373 	 * Kick off L2 cache rebuilding.
8374 	 */
8375 	if (tasks & SPA_ASYNC_L2CACHE_REBUILD) {
8376 		mutex_enter(&spa_namespace_lock);
8377 		spa_config_enter(spa, SCL_L2ARC, FTAG, RW_READER);
8378 		l2arc_spa_rebuild_start(spa);
8379 		spa_config_exit(spa, SCL_L2ARC, FTAG);
8380 		mutex_exit(&spa_namespace_lock);
8381 	}
8382 
8383 	/*
8384 	 * Let the world know that we're done.
8385 	 */
8386 	mutex_enter(&spa->spa_async_lock);
8387 	spa->spa_async_thread = NULL;
8388 	cv_broadcast(&spa->spa_async_cv);
8389 	mutex_exit(&spa->spa_async_lock);
8390 	thread_exit();
8391 }
8392 
8393 void
8394 spa_async_suspend(spa_t *spa)
8395 {
8396 	mutex_enter(&spa->spa_async_lock);
8397 	spa->spa_async_suspended++;
8398 	while (spa->spa_async_thread != NULL)
8399 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
8400 	mutex_exit(&spa->spa_async_lock);
8401 
8402 	spa_vdev_remove_suspend(spa);
8403 
8404 	zthr_t *condense_thread = spa->spa_condense_zthr;
8405 	if (condense_thread != NULL)
8406 		zthr_cancel(condense_thread);
8407 
8408 	zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
8409 	if (discard_thread != NULL)
8410 		zthr_cancel(discard_thread);
8411 
8412 	zthr_t *ll_delete_thread = spa->spa_livelist_delete_zthr;
8413 	if (ll_delete_thread != NULL)
8414 		zthr_cancel(ll_delete_thread);
8415 
8416 	zthr_t *ll_condense_thread = spa->spa_livelist_condense_zthr;
8417 	if (ll_condense_thread != NULL)
8418 		zthr_cancel(ll_condense_thread);
8419 }
8420 
8421 void
8422 spa_async_resume(spa_t *spa)
8423 {
8424 	mutex_enter(&spa->spa_async_lock);
8425 	ASSERT(spa->spa_async_suspended != 0);
8426 	spa->spa_async_suspended--;
8427 	mutex_exit(&spa->spa_async_lock);
8428 	spa_restart_removal(spa);
8429 
8430 	zthr_t *condense_thread = spa->spa_condense_zthr;
8431 	if (condense_thread != NULL)
8432 		zthr_resume(condense_thread);
8433 
8434 	zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
8435 	if (discard_thread != NULL)
8436 		zthr_resume(discard_thread);
8437 
8438 	zthr_t *ll_delete_thread = spa->spa_livelist_delete_zthr;
8439 	if (ll_delete_thread != NULL)
8440 		zthr_resume(ll_delete_thread);
8441 
8442 	zthr_t *ll_condense_thread = spa->spa_livelist_condense_zthr;
8443 	if (ll_condense_thread != NULL)
8444 		zthr_resume(ll_condense_thread);
8445 }
8446 
8447 static boolean_t
8448 spa_async_tasks_pending(spa_t *spa)
8449 {
8450 	uint_t non_config_tasks;
8451 	uint_t config_task;
8452 	boolean_t config_task_suspended;
8453 
8454 	non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
8455 	config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
8456 	if (spa->spa_ccw_fail_time == 0) {
8457 		config_task_suspended = B_FALSE;
8458 	} else {
8459 		config_task_suspended =
8460 		    (gethrtime() - spa->spa_ccw_fail_time) <
8461 		    ((hrtime_t)zfs_ccw_retry_interval * NANOSEC);
8462 	}
8463 
8464 	return (non_config_tasks || (config_task && !config_task_suspended));
8465 }
8466 
8467 static void
8468 spa_async_dispatch(spa_t *spa)
8469 {
8470 	mutex_enter(&spa->spa_async_lock);
8471 	if (spa_async_tasks_pending(spa) &&
8472 	    !spa->spa_async_suspended &&
8473 	    spa->spa_async_thread == NULL)
8474 		spa->spa_async_thread = thread_create(NULL, 0,
8475 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
8476 	mutex_exit(&spa->spa_async_lock);
8477 }
8478 
8479 void
8480 spa_async_request(spa_t *spa, int task)
8481 {
8482 	zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
8483 	mutex_enter(&spa->spa_async_lock);
8484 	spa->spa_async_tasks |= task;
8485 	mutex_exit(&spa->spa_async_lock);
8486 }
8487 
8488 int
8489 spa_async_tasks(spa_t *spa)
8490 {
8491 	return (spa->spa_async_tasks);
8492 }
8493 
8494 /*
8495  * ==========================================================================
8496  * SPA syncing routines
8497  * ==========================================================================
8498  */
8499 
8500 
8501 static int
8502 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
8503     dmu_tx_t *tx)
8504 {
8505 	bpobj_t *bpo = arg;
8506 	bpobj_enqueue(bpo, bp, bp_freed, tx);
8507 	return (0);
8508 }
8509 
8510 int
8511 bpobj_enqueue_alloc_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
8512 {
8513 	return (bpobj_enqueue_cb(arg, bp, B_FALSE, tx));
8514 }
8515 
8516 int
8517 bpobj_enqueue_free_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
8518 {
8519 	return (bpobj_enqueue_cb(arg, bp, B_TRUE, tx));
8520 }
8521 
8522 static int
8523 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
8524 {
8525 	zio_t *pio = arg;
8526 
8527 	zio_nowait(zio_free_sync(pio, pio->io_spa, dmu_tx_get_txg(tx), bp,
8528 	    pio->io_flags));
8529 	return (0);
8530 }
8531 
8532 static int
8533 bpobj_spa_free_sync_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
8534     dmu_tx_t *tx)
8535 {
8536 	ASSERT(!bp_freed);
8537 	return (spa_free_sync_cb(arg, bp, tx));
8538 }
8539 
8540 /*
8541  * Note: this simple function is not inlined to make it easier to dtrace the
8542  * amount of time spent syncing frees.
8543  */
8544 static void
8545 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
8546 {
8547 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
8548 	bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
8549 	VERIFY(zio_wait(zio) == 0);
8550 }
8551 
8552 /*
8553  * Note: this simple function is not inlined to make it easier to dtrace the
8554  * amount of time spent syncing deferred frees.
8555  */
8556 static void
8557 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
8558 {
8559 	if (spa_sync_pass(spa) != 1)
8560 		return;
8561 
8562 	/*
8563 	 * Note:
8564 	 * If the log space map feature is active, we stop deferring
8565 	 * frees to the next TXG and therefore running this function
8566 	 * would be considered a no-op as spa_deferred_bpobj should
8567 	 * not have any entries.
8568 	 *
8569 	 * That said we run this function anyway (instead of returning
8570 	 * immediately) for the edge-case scenario where we just
8571 	 * activated the log space map feature in this TXG but we have
8572 	 * deferred frees from the previous TXG.
8573 	 */
8574 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
8575 	VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
8576 	    bpobj_spa_free_sync_cb, zio, tx), ==, 0);
8577 	VERIFY0(zio_wait(zio));
8578 }
8579 
8580 static void
8581 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
8582 {
8583 	char *packed = NULL;
8584 	size_t bufsize;
8585 	size_t nvsize = 0;
8586 	dmu_buf_t *db;
8587 
8588 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
8589 
8590 	/*
8591 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
8592 	 * information.  This avoids the dmu_buf_will_dirty() path and
8593 	 * saves us a pre-read to get data we don't actually care about.
8594 	 */
8595 	bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
8596 	packed = vmem_alloc(bufsize, KM_SLEEP);
8597 
8598 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
8599 	    KM_SLEEP) == 0);
8600 	memset(packed + nvsize, 0, bufsize - nvsize);
8601 
8602 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
8603 
8604 	vmem_free(packed, bufsize);
8605 
8606 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
8607 	dmu_buf_will_dirty(db, tx);
8608 	*(uint64_t *)db->db_data = nvsize;
8609 	dmu_buf_rele(db, FTAG);
8610 }
8611 
8612 static void
8613 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
8614     const char *config, const char *entry)
8615 {
8616 	nvlist_t *nvroot;
8617 	nvlist_t **list;
8618 	int i;
8619 
8620 	if (!sav->sav_sync)
8621 		return;
8622 
8623 	/*
8624 	 * Update the MOS nvlist describing the list of available devices.
8625 	 * spa_validate_aux() will have already made sure this nvlist is
8626 	 * valid and the vdevs are labeled appropriately.
8627 	 */
8628 	if (sav->sav_object == 0) {
8629 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
8630 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
8631 		    sizeof (uint64_t), tx);
8632 		VERIFY(zap_update(spa->spa_meta_objset,
8633 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
8634 		    &sav->sav_object, tx) == 0);
8635 	}
8636 
8637 	nvroot = fnvlist_alloc();
8638 	if (sav->sav_count == 0) {
8639 		fnvlist_add_nvlist_array(nvroot, config,
8640 		    (const nvlist_t * const *)NULL, 0);
8641 	} else {
8642 		list = kmem_alloc(sav->sav_count*sizeof (void *), KM_SLEEP);
8643 		for (i = 0; i < sav->sav_count; i++)
8644 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
8645 			    B_FALSE, VDEV_CONFIG_L2CACHE);
8646 		fnvlist_add_nvlist_array(nvroot, config,
8647 		    (const nvlist_t * const *)list, sav->sav_count);
8648 		for (i = 0; i < sav->sav_count; i++)
8649 			nvlist_free(list[i]);
8650 		kmem_free(list, sav->sav_count * sizeof (void *));
8651 	}
8652 
8653 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
8654 	nvlist_free(nvroot);
8655 
8656 	sav->sav_sync = B_FALSE;
8657 }
8658 
8659 /*
8660  * Rebuild spa's all-vdev ZAP from the vdev ZAPs indicated in each vdev_t.
8661  * The all-vdev ZAP must be empty.
8662  */
8663 static void
8664 spa_avz_build(vdev_t *vd, uint64_t avz, dmu_tx_t *tx)
8665 {
8666 	spa_t *spa = vd->vdev_spa;
8667 
8668 	if (vd->vdev_top_zap != 0) {
8669 		VERIFY0(zap_add_int(spa->spa_meta_objset, avz,
8670 		    vd->vdev_top_zap, tx));
8671 	}
8672 	if (vd->vdev_leaf_zap != 0) {
8673 		VERIFY0(zap_add_int(spa->spa_meta_objset, avz,
8674 		    vd->vdev_leaf_zap, tx));
8675 	}
8676 	for (uint64_t i = 0; i < vd->vdev_children; i++) {
8677 		spa_avz_build(vd->vdev_child[i], avz, tx);
8678 	}
8679 }
8680 
8681 static void
8682 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
8683 {
8684 	nvlist_t *config;
8685 
8686 	/*
8687 	 * If the pool is being imported from a pre-per-vdev-ZAP version of ZFS,
8688 	 * its config may not be dirty but we still need to build per-vdev ZAPs.
8689 	 * Similarly, if the pool is being assembled (e.g. after a split), we
8690 	 * need to rebuild the AVZ although the config may not be dirty.
8691 	 */
8692 	if (list_is_empty(&spa->spa_config_dirty_list) &&
8693 	    spa->spa_avz_action == AVZ_ACTION_NONE)
8694 		return;
8695 
8696 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
8697 
8698 	ASSERT(spa->spa_avz_action == AVZ_ACTION_NONE ||
8699 	    spa->spa_avz_action == AVZ_ACTION_INITIALIZE ||
8700 	    spa->spa_all_vdev_zaps != 0);
8701 
8702 	if (spa->spa_avz_action == AVZ_ACTION_REBUILD) {
8703 		/* Make and build the new AVZ */
8704 		uint64_t new_avz = zap_create(spa->spa_meta_objset,
8705 		    DMU_OTN_ZAP_METADATA, DMU_OT_NONE, 0, tx);
8706 		spa_avz_build(spa->spa_root_vdev, new_avz, tx);
8707 
8708 		/* Diff old AVZ with new one */
8709 		zap_cursor_t zc;
8710 		zap_attribute_t za;
8711 
8712 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
8713 		    spa->spa_all_vdev_zaps);
8714 		    zap_cursor_retrieve(&zc, &za) == 0;
8715 		    zap_cursor_advance(&zc)) {
8716 			uint64_t vdzap = za.za_first_integer;
8717 			if (zap_lookup_int(spa->spa_meta_objset, new_avz,
8718 			    vdzap) == ENOENT) {
8719 				/*
8720 				 * ZAP is listed in old AVZ but not in new one;
8721 				 * destroy it
8722 				 */
8723 				VERIFY0(zap_destroy(spa->spa_meta_objset, vdzap,
8724 				    tx));
8725 			}
8726 		}
8727 
8728 		zap_cursor_fini(&zc);
8729 
8730 		/* Destroy the old AVZ */
8731 		VERIFY0(zap_destroy(spa->spa_meta_objset,
8732 		    spa->spa_all_vdev_zaps, tx));
8733 
8734 		/* Replace the old AVZ in the dir obj with the new one */
8735 		VERIFY0(zap_update(spa->spa_meta_objset,
8736 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_VDEV_ZAP_MAP,
8737 		    sizeof (new_avz), 1, &new_avz, tx));
8738 
8739 		spa->spa_all_vdev_zaps = new_avz;
8740 	} else if (spa->spa_avz_action == AVZ_ACTION_DESTROY) {
8741 		zap_cursor_t zc;
8742 		zap_attribute_t za;
8743 
8744 		/* Walk through the AVZ and destroy all listed ZAPs */
8745 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
8746 		    spa->spa_all_vdev_zaps);
8747 		    zap_cursor_retrieve(&zc, &za) == 0;
8748 		    zap_cursor_advance(&zc)) {
8749 			uint64_t zap = za.za_first_integer;
8750 			VERIFY0(zap_destroy(spa->spa_meta_objset, zap, tx));
8751 		}
8752 
8753 		zap_cursor_fini(&zc);
8754 
8755 		/* Destroy and unlink the AVZ itself */
8756 		VERIFY0(zap_destroy(spa->spa_meta_objset,
8757 		    spa->spa_all_vdev_zaps, tx));
8758 		VERIFY0(zap_remove(spa->spa_meta_objset,
8759 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_VDEV_ZAP_MAP, tx));
8760 		spa->spa_all_vdev_zaps = 0;
8761 	}
8762 
8763 	if (spa->spa_all_vdev_zaps == 0) {
8764 		spa->spa_all_vdev_zaps = zap_create_link(spa->spa_meta_objset,
8765 		    DMU_OTN_ZAP_METADATA, DMU_POOL_DIRECTORY_OBJECT,
8766 		    DMU_POOL_VDEV_ZAP_MAP, tx);
8767 	}
8768 	spa->spa_avz_action = AVZ_ACTION_NONE;
8769 
8770 	/* Create ZAPs for vdevs that don't have them. */
8771 	vdev_construct_zaps(spa->spa_root_vdev, tx);
8772 
8773 	config = spa_config_generate(spa, spa->spa_root_vdev,
8774 	    dmu_tx_get_txg(tx), B_FALSE);
8775 
8776 	/*
8777 	 * If we're upgrading the spa version then make sure that
8778 	 * the config object gets updated with the correct version.
8779 	 */
8780 	if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
8781 		fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
8782 		    spa->spa_uberblock.ub_version);
8783 
8784 	spa_config_exit(spa, SCL_STATE, FTAG);
8785 
8786 	nvlist_free(spa->spa_config_syncing);
8787 	spa->spa_config_syncing = config;
8788 
8789 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
8790 }
8791 
8792 static void
8793 spa_sync_version(void *arg, dmu_tx_t *tx)
8794 {
8795 	uint64_t *versionp = arg;
8796 	uint64_t version = *versionp;
8797 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
8798 
8799 	/*
8800 	 * Setting the version is special cased when first creating the pool.
8801 	 */
8802 	ASSERT(tx->tx_txg != TXG_INITIAL);
8803 
8804 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
8805 	ASSERT(version >= spa_version(spa));
8806 
8807 	spa->spa_uberblock.ub_version = version;
8808 	vdev_config_dirty(spa->spa_root_vdev);
8809 	spa_history_log_internal(spa, "set", tx, "version=%lld",
8810 	    (longlong_t)version);
8811 }
8812 
8813 /*
8814  * Set zpool properties.
8815  */
8816 static void
8817 spa_sync_props(void *arg, dmu_tx_t *tx)
8818 {
8819 	nvlist_t *nvp = arg;
8820 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
8821 	objset_t *mos = spa->spa_meta_objset;
8822 	nvpair_t *elem = NULL;
8823 
8824 	mutex_enter(&spa->spa_props_lock);
8825 
8826 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
8827 		uint64_t intval;
8828 		const char *strval, *fname;
8829 		zpool_prop_t prop;
8830 		const char *propname;
8831 		const char *elemname = nvpair_name(elem);
8832 		zprop_type_t proptype;
8833 		spa_feature_t fid;
8834 
8835 		switch (prop = zpool_name_to_prop(elemname)) {
8836 		case ZPOOL_PROP_VERSION:
8837 			intval = fnvpair_value_uint64(elem);
8838 			/*
8839 			 * The version is synced separately before other
8840 			 * properties and should be correct by now.
8841 			 */
8842 			ASSERT3U(spa_version(spa), >=, intval);
8843 			break;
8844 
8845 		case ZPOOL_PROP_ALTROOT:
8846 			/*
8847 			 * 'altroot' is a non-persistent property. It should
8848 			 * have been set temporarily at creation or import time.
8849 			 */
8850 			ASSERT(spa->spa_root != NULL);
8851 			break;
8852 
8853 		case ZPOOL_PROP_READONLY:
8854 		case ZPOOL_PROP_CACHEFILE:
8855 			/*
8856 			 * 'readonly' and 'cachefile' are also non-persistent
8857 			 * properties.
8858 			 */
8859 			break;
8860 		case ZPOOL_PROP_COMMENT:
8861 			strval = fnvpair_value_string(elem);
8862 			if (spa->spa_comment != NULL)
8863 				spa_strfree(spa->spa_comment);
8864 			spa->spa_comment = spa_strdup(strval);
8865 			/*
8866 			 * We need to dirty the configuration on all the vdevs
8867 			 * so that their labels get updated.  We also need to
8868 			 * update the cache file to keep it in sync with the
8869 			 * MOS version. It's unnecessary to do this for pool
8870 			 * creation since the vdev's configuration has already
8871 			 * been dirtied.
8872 			 */
8873 			if (tx->tx_txg != TXG_INITIAL) {
8874 				vdev_config_dirty(spa->spa_root_vdev);
8875 				spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
8876 			}
8877 			spa_history_log_internal(spa, "set", tx,
8878 			    "%s=%s", elemname, strval);
8879 			break;
8880 		case ZPOOL_PROP_COMPATIBILITY:
8881 			strval = fnvpair_value_string(elem);
8882 			if (spa->spa_compatibility != NULL)
8883 				spa_strfree(spa->spa_compatibility);
8884 			spa->spa_compatibility = spa_strdup(strval);
8885 			/*
8886 			 * Dirty the configuration on vdevs as above.
8887 			 */
8888 			if (tx->tx_txg != TXG_INITIAL) {
8889 				vdev_config_dirty(spa->spa_root_vdev);
8890 				spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
8891 			}
8892 
8893 			spa_history_log_internal(spa, "set", tx,
8894 			    "%s=%s", nvpair_name(elem), strval);
8895 			break;
8896 
8897 		case ZPOOL_PROP_INVAL:
8898 			if (zpool_prop_feature(elemname)) {
8899 				fname = strchr(elemname, '@') + 1;
8900 				VERIFY0(zfeature_lookup_name(fname, &fid));
8901 
8902 				spa_feature_enable(spa, fid, tx);
8903 				spa_history_log_internal(spa, "set", tx,
8904 				    "%s=enabled", elemname);
8905 				break;
8906 			} else if (!zfs_prop_user(elemname)) {
8907 				ASSERT(zpool_prop_feature(elemname));
8908 				break;
8909 			}
8910 			zfs_fallthrough;
8911 		default:
8912 			/*
8913 			 * Set pool property values in the poolprops mos object.
8914 			 */
8915 			if (spa->spa_pool_props_object == 0) {
8916 				spa->spa_pool_props_object =
8917 				    zap_create_link(mos, DMU_OT_POOL_PROPS,
8918 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
8919 				    tx);
8920 			}
8921 
8922 			/* normalize the property name */
8923 			propname = zpool_prop_to_name(prop);
8924 			proptype = zpool_prop_get_type(prop);
8925 			if (prop == ZPOOL_PROP_INVAL &&
8926 			    zfs_prop_user(elemname)) {
8927 				propname = elemname;
8928 				proptype = PROP_TYPE_STRING;
8929 			}
8930 
8931 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
8932 				ASSERT(proptype == PROP_TYPE_STRING);
8933 				strval = fnvpair_value_string(elem);
8934 				VERIFY0(zap_update(mos,
8935 				    spa->spa_pool_props_object, propname,
8936 				    1, strlen(strval) + 1, strval, tx));
8937 				spa_history_log_internal(spa, "set", tx,
8938 				    "%s=%s", elemname, strval);
8939 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
8940 				intval = fnvpair_value_uint64(elem);
8941 
8942 				if (proptype == PROP_TYPE_INDEX) {
8943 					const char *unused;
8944 					VERIFY0(zpool_prop_index_to_string(
8945 					    prop, intval, &unused));
8946 				}
8947 				VERIFY0(zap_update(mos,
8948 				    spa->spa_pool_props_object, propname,
8949 				    8, 1, &intval, tx));
8950 				spa_history_log_internal(spa, "set", tx,
8951 				    "%s=%lld", elemname,
8952 				    (longlong_t)intval);
8953 
8954 				switch (prop) {
8955 				case ZPOOL_PROP_DELEGATION:
8956 					spa->spa_delegation = intval;
8957 					break;
8958 				case ZPOOL_PROP_BOOTFS:
8959 					spa->spa_bootfs = intval;
8960 					break;
8961 				case ZPOOL_PROP_FAILUREMODE:
8962 					spa->spa_failmode = intval;
8963 					break;
8964 				case ZPOOL_PROP_AUTOTRIM:
8965 					spa->spa_autotrim = intval;
8966 					spa_async_request(spa,
8967 					    SPA_ASYNC_AUTOTRIM_RESTART);
8968 					break;
8969 				case ZPOOL_PROP_AUTOEXPAND:
8970 					spa->spa_autoexpand = intval;
8971 					if (tx->tx_txg != TXG_INITIAL)
8972 						spa_async_request(spa,
8973 						    SPA_ASYNC_AUTOEXPAND);
8974 					break;
8975 				case ZPOOL_PROP_MULTIHOST:
8976 					spa->spa_multihost = intval;
8977 					break;
8978 				default:
8979 					break;
8980 				}
8981 			} else {
8982 				ASSERT(0); /* not allowed */
8983 			}
8984 		}
8985 
8986 	}
8987 
8988 	mutex_exit(&spa->spa_props_lock);
8989 }
8990 
8991 /*
8992  * Perform one-time upgrade on-disk changes.  spa_version() does not
8993  * reflect the new version this txg, so there must be no changes this
8994  * txg to anything that the upgrade code depends on after it executes.
8995  * Therefore this must be called after dsl_pool_sync() does the sync
8996  * tasks.
8997  */
8998 static void
8999 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
9000 {
9001 	if (spa_sync_pass(spa) != 1)
9002 		return;
9003 
9004 	dsl_pool_t *dp = spa->spa_dsl_pool;
9005 	rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
9006 
9007 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
9008 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
9009 		dsl_pool_create_origin(dp, tx);
9010 
9011 		/* Keeping the origin open increases spa_minref */
9012 		spa->spa_minref += 3;
9013 	}
9014 
9015 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
9016 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
9017 		dsl_pool_upgrade_clones(dp, tx);
9018 	}
9019 
9020 	if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
9021 	    spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
9022 		dsl_pool_upgrade_dir_clones(dp, tx);
9023 
9024 		/* Keeping the freedir open increases spa_minref */
9025 		spa->spa_minref += 3;
9026 	}
9027 
9028 	if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
9029 	    spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
9030 		spa_feature_create_zap_objects(spa, tx);
9031 	}
9032 
9033 	/*
9034 	 * LZ4_COMPRESS feature's behaviour was changed to activate_on_enable
9035 	 * when possibility to use lz4 compression for metadata was added
9036 	 * Old pools that have this feature enabled must be upgraded to have
9037 	 * this feature active
9038 	 */
9039 	if (spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
9040 		boolean_t lz4_en = spa_feature_is_enabled(spa,
9041 		    SPA_FEATURE_LZ4_COMPRESS);
9042 		boolean_t lz4_ac = spa_feature_is_active(spa,
9043 		    SPA_FEATURE_LZ4_COMPRESS);
9044 
9045 		if (lz4_en && !lz4_ac)
9046 			spa_feature_incr(spa, SPA_FEATURE_LZ4_COMPRESS, tx);
9047 	}
9048 
9049 	/*
9050 	 * If we haven't written the salt, do so now.  Note that the
9051 	 * feature may not be activated yet, but that's fine since
9052 	 * the presence of this ZAP entry is backwards compatible.
9053 	 */
9054 	if (zap_contains(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
9055 	    DMU_POOL_CHECKSUM_SALT) == ENOENT) {
9056 		VERIFY0(zap_add(spa->spa_meta_objset,
9057 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CHECKSUM_SALT, 1,
9058 		    sizeof (spa->spa_cksum_salt.zcs_bytes),
9059 		    spa->spa_cksum_salt.zcs_bytes, tx));
9060 	}
9061 
9062 	rrw_exit(&dp->dp_config_rwlock, FTAG);
9063 }
9064 
9065 static void
9066 vdev_indirect_state_sync_verify(vdev_t *vd)
9067 {
9068 	vdev_indirect_mapping_t *vim __maybe_unused = vd->vdev_indirect_mapping;
9069 	vdev_indirect_births_t *vib __maybe_unused = vd->vdev_indirect_births;
9070 
9071 	if (vd->vdev_ops == &vdev_indirect_ops) {
9072 		ASSERT(vim != NULL);
9073 		ASSERT(vib != NULL);
9074 	}
9075 
9076 	uint64_t obsolete_sm_object = 0;
9077 	ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
9078 	if (obsolete_sm_object != 0) {
9079 		ASSERT(vd->vdev_obsolete_sm != NULL);
9080 		ASSERT(vd->vdev_removing ||
9081 		    vd->vdev_ops == &vdev_indirect_ops);
9082 		ASSERT(vdev_indirect_mapping_num_entries(vim) > 0);
9083 		ASSERT(vdev_indirect_mapping_bytes_mapped(vim) > 0);
9084 		ASSERT3U(obsolete_sm_object, ==,
9085 		    space_map_object(vd->vdev_obsolete_sm));
9086 		ASSERT3U(vdev_indirect_mapping_bytes_mapped(vim), >=,
9087 		    space_map_allocated(vd->vdev_obsolete_sm));
9088 	}
9089 	ASSERT(vd->vdev_obsolete_segments != NULL);
9090 
9091 	/*
9092 	 * Since frees / remaps to an indirect vdev can only
9093 	 * happen in syncing context, the obsolete segments
9094 	 * tree must be empty when we start syncing.
9095 	 */
9096 	ASSERT0(range_tree_space(vd->vdev_obsolete_segments));
9097 }
9098 
9099 /*
9100  * Set the top-level vdev's max queue depth. Evaluate each top-level's
9101  * async write queue depth in case it changed. The max queue depth will
9102  * not change in the middle of syncing out this txg.
9103  */
9104 static void
9105 spa_sync_adjust_vdev_max_queue_depth(spa_t *spa)
9106 {
9107 	ASSERT(spa_writeable(spa));
9108 
9109 	vdev_t *rvd = spa->spa_root_vdev;
9110 	uint32_t max_queue_depth = zfs_vdev_async_write_max_active *
9111 	    zfs_vdev_queue_depth_pct / 100;
9112 	metaslab_class_t *normal = spa_normal_class(spa);
9113 	metaslab_class_t *special = spa_special_class(spa);
9114 	metaslab_class_t *dedup = spa_dedup_class(spa);
9115 
9116 	uint64_t slots_per_allocator = 0;
9117 	for (int c = 0; c < rvd->vdev_children; c++) {
9118 		vdev_t *tvd = rvd->vdev_child[c];
9119 
9120 		metaslab_group_t *mg = tvd->vdev_mg;
9121 		if (mg == NULL || !metaslab_group_initialized(mg))
9122 			continue;
9123 
9124 		metaslab_class_t *mc = mg->mg_class;
9125 		if (mc != normal && mc != special && mc != dedup)
9126 			continue;
9127 
9128 		/*
9129 		 * It is safe to do a lock-free check here because only async
9130 		 * allocations look at mg_max_alloc_queue_depth, and async
9131 		 * allocations all happen from spa_sync().
9132 		 */
9133 		for (int i = 0; i < mg->mg_allocators; i++) {
9134 			ASSERT0(zfs_refcount_count(
9135 			    &(mg->mg_allocator[i].mga_alloc_queue_depth)));
9136 		}
9137 		mg->mg_max_alloc_queue_depth = max_queue_depth;
9138 
9139 		for (int i = 0; i < mg->mg_allocators; i++) {
9140 			mg->mg_allocator[i].mga_cur_max_alloc_queue_depth =
9141 			    zfs_vdev_def_queue_depth;
9142 		}
9143 		slots_per_allocator += zfs_vdev_def_queue_depth;
9144 	}
9145 
9146 	for (int i = 0; i < spa->spa_alloc_count; i++) {
9147 		ASSERT0(zfs_refcount_count(&normal->mc_allocator[i].
9148 		    mca_alloc_slots));
9149 		ASSERT0(zfs_refcount_count(&special->mc_allocator[i].
9150 		    mca_alloc_slots));
9151 		ASSERT0(zfs_refcount_count(&dedup->mc_allocator[i].
9152 		    mca_alloc_slots));
9153 		normal->mc_allocator[i].mca_alloc_max_slots =
9154 		    slots_per_allocator;
9155 		special->mc_allocator[i].mca_alloc_max_slots =
9156 		    slots_per_allocator;
9157 		dedup->mc_allocator[i].mca_alloc_max_slots =
9158 		    slots_per_allocator;
9159 	}
9160 	normal->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
9161 	special->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
9162 	dedup->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
9163 }
9164 
9165 static void
9166 spa_sync_condense_indirect(spa_t *spa, dmu_tx_t *tx)
9167 {
9168 	ASSERT(spa_writeable(spa));
9169 
9170 	vdev_t *rvd = spa->spa_root_vdev;
9171 	for (int c = 0; c < rvd->vdev_children; c++) {
9172 		vdev_t *vd = rvd->vdev_child[c];
9173 		vdev_indirect_state_sync_verify(vd);
9174 
9175 		if (vdev_indirect_should_condense(vd)) {
9176 			spa_condense_indirect_start_sync(vd, tx);
9177 			break;
9178 		}
9179 	}
9180 }
9181 
9182 static void
9183 spa_sync_iterate_to_convergence(spa_t *spa, dmu_tx_t *tx)
9184 {
9185 	objset_t *mos = spa->spa_meta_objset;
9186 	dsl_pool_t *dp = spa->spa_dsl_pool;
9187 	uint64_t txg = tx->tx_txg;
9188 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
9189 
9190 	do {
9191 		int pass = ++spa->spa_sync_pass;
9192 
9193 		spa_sync_config_object(spa, tx);
9194 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
9195 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
9196 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
9197 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
9198 		spa_errlog_sync(spa, txg);
9199 		dsl_pool_sync(dp, txg);
9200 
9201 		if (pass < zfs_sync_pass_deferred_free ||
9202 		    spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP)) {
9203 			/*
9204 			 * If the log space map feature is active we don't
9205 			 * care about deferred frees and the deferred bpobj
9206 			 * as the log space map should effectively have the
9207 			 * same results (i.e. appending only to one object).
9208 			 */
9209 			spa_sync_frees(spa, free_bpl, tx);
9210 		} else {
9211 			/*
9212 			 * We can not defer frees in pass 1, because
9213 			 * we sync the deferred frees later in pass 1.
9214 			 */
9215 			ASSERT3U(pass, >, 1);
9216 			bplist_iterate(free_bpl, bpobj_enqueue_alloc_cb,
9217 			    &spa->spa_deferred_bpobj, tx);
9218 		}
9219 
9220 		brt_sync(spa, txg);
9221 		ddt_sync(spa, txg);
9222 		dsl_scan_sync(dp, tx);
9223 		svr_sync(spa, tx);
9224 		spa_sync_upgrades(spa, tx);
9225 
9226 		spa_flush_metaslabs(spa, tx);
9227 
9228 		vdev_t *vd = NULL;
9229 		while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
9230 		    != NULL)
9231 			vdev_sync(vd, txg);
9232 
9233 		/*
9234 		 * Note: We need to check if the MOS is dirty because we could
9235 		 * have marked the MOS dirty without updating the uberblock
9236 		 * (e.g. if we have sync tasks but no dirty user data). We need
9237 		 * to check the uberblock's rootbp because it is updated if we
9238 		 * have synced out dirty data (though in this case the MOS will
9239 		 * most likely also be dirty due to second order effects, we
9240 		 * don't want to rely on that here).
9241 		 */
9242 		if (pass == 1 &&
9243 		    spa->spa_uberblock.ub_rootbp.blk_birth < txg &&
9244 		    !dmu_objset_is_dirty(mos, txg)) {
9245 			/*
9246 			 * Nothing changed on the first pass, therefore this
9247 			 * TXG is a no-op. Avoid syncing deferred frees, so
9248 			 * that we can keep this TXG as a no-op.
9249 			 */
9250 			ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
9251 			ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
9252 			ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
9253 			ASSERT(txg_list_empty(&dp->dp_early_sync_tasks, txg));
9254 			break;
9255 		}
9256 
9257 		spa_sync_deferred_frees(spa, tx);
9258 	} while (dmu_objset_is_dirty(mos, txg));
9259 }
9260 
9261 /*
9262  * Rewrite the vdev configuration (which includes the uberblock) to
9263  * commit the transaction group.
9264  *
9265  * If there are no dirty vdevs, we sync the uberblock to a few random
9266  * top-level vdevs that are known to be visible in the config cache
9267  * (see spa_vdev_add() for a complete description). If there *are* dirty
9268  * vdevs, sync the uberblock to all vdevs.
9269  */
9270 static void
9271 spa_sync_rewrite_vdev_config(spa_t *spa, dmu_tx_t *tx)
9272 {
9273 	vdev_t *rvd = spa->spa_root_vdev;
9274 	uint64_t txg = tx->tx_txg;
9275 
9276 	for (;;) {
9277 		int error = 0;
9278 
9279 		/*
9280 		 * We hold SCL_STATE to prevent vdev open/close/etc.
9281 		 * while we're attempting to write the vdev labels.
9282 		 */
9283 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
9284 
9285 		if (list_is_empty(&spa->spa_config_dirty_list)) {
9286 			vdev_t *svd[SPA_SYNC_MIN_VDEVS] = { NULL };
9287 			int svdcount = 0;
9288 			int children = rvd->vdev_children;
9289 			int c0 = random_in_range(children);
9290 
9291 			for (int c = 0; c < children; c++) {
9292 				vdev_t *vd =
9293 				    rvd->vdev_child[(c0 + c) % children];
9294 
9295 				/* Stop when revisiting the first vdev */
9296 				if (c > 0 && svd[0] == vd)
9297 					break;
9298 
9299 				if (vd->vdev_ms_array == 0 ||
9300 				    vd->vdev_islog ||
9301 				    !vdev_is_concrete(vd))
9302 					continue;
9303 
9304 				svd[svdcount++] = vd;
9305 				if (svdcount == SPA_SYNC_MIN_VDEVS)
9306 					break;
9307 			}
9308 			error = vdev_config_sync(svd, svdcount, txg);
9309 		} else {
9310 			error = vdev_config_sync(rvd->vdev_child,
9311 			    rvd->vdev_children, txg);
9312 		}
9313 
9314 		if (error == 0)
9315 			spa->spa_last_synced_guid = rvd->vdev_guid;
9316 
9317 		spa_config_exit(spa, SCL_STATE, FTAG);
9318 
9319 		if (error == 0)
9320 			break;
9321 		zio_suspend(spa, NULL, ZIO_SUSPEND_IOERR);
9322 		zio_resume_wait(spa);
9323 	}
9324 }
9325 
9326 /*
9327  * Sync the specified transaction group.  New blocks may be dirtied as
9328  * part of the process, so we iterate until it converges.
9329  */
9330 void
9331 spa_sync(spa_t *spa, uint64_t txg)
9332 {
9333 	vdev_t *vd = NULL;
9334 
9335 	VERIFY(spa_writeable(spa));
9336 
9337 	/*
9338 	 * Wait for i/os issued in open context that need to complete
9339 	 * before this txg syncs.
9340 	 */
9341 	(void) zio_wait(spa->spa_txg_zio[txg & TXG_MASK]);
9342 	spa->spa_txg_zio[txg & TXG_MASK] = zio_root(spa, NULL, NULL,
9343 	    ZIO_FLAG_CANFAIL);
9344 
9345 	/*
9346 	 * Now that there can be no more cloning in this transaction group,
9347 	 * but we are still before issuing frees, we can process pending BRT
9348 	 * updates.
9349 	 */
9350 	brt_pending_apply(spa, txg);
9351 
9352 	/*
9353 	 * Lock out configuration changes.
9354 	 */
9355 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
9356 
9357 	spa->spa_syncing_txg = txg;
9358 	spa->spa_sync_pass = 0;
9359 
9360 	for (int i = 0; i < spa->spa_alloc_count; i++) {
9361 		mutex_enter(&spa->spa_allocs[i].spaa_lock);
9362 		VERIFY0(avl_numnodes(&spa->spa_allocs[i].spaa_tree));
9363 		mutex_exit(&spa->spa_allocs[i].spaa_lock);
9364 	}
9365 
9366 	/*
9367 	 * If there are any pending vdev state changes, convert them
9368 	 * into config changes that go out with this transaction group.
9369 	 */
9370 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
9371 	while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
9372 		/* Avoid holding the write lock unless actually necessary */
9373 		if (vd->vdev_aux == NULL) {
9374 			vdev_state_clean(vd);
9375 			vdev_config_dirty(vd);
9376 			continue;
9377 		}
9378 		/*
9379 		 * We need the write lock here because, for aux vdevs,
9380 		 * calling vdev_config_dirty() modifies sav_config.
9381 		 * This is ugly and will become unnecessary when we
9382 		 * eliminate the aux vdev wart by integrating all vdevs
9383 		 * into the root vdev tree.
9384 		 */
9385 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9386 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
9387 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
9388 			vdev_state_clean(vd);
9389 			vdev_config_dirty(vd);
9390 		}
9391 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9392 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
9393 	}
9394 	spa_config_exit(spa, SCL_STATE, FTAG);
9395 
9396 	dsl_pool_t *dp = spa->spa_dsl_pool;
9397 	dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
9398 
9399 	spa->spa_sync_starttime = gethrtime();
9400 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
9401 	spa->spa_deadman_tqid = taskq_dispatch_delay(system_delay_taskq,
9402 	    spa_deadman, spa, TQ_SLEEP, ddi_get_lbolt() +
9403 	    NSEC_TO_TICK(spa->spa_deadman_synctime));
9404 
9405 	/*
9406 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
9407 	 * set spa_deflate if we have no raid-z vdevs.
9408 	 */
9409 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
9410 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
9411 		vdev_t *rvd = spa->spa_root_vdev;
9412 
9413 		int i;
9414 		for (i = 0; i < rvd->vdev_children; i++) {
9415 			vd = rvd->vdev_child[i];
9416 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
9417 				break;
9418 		}
9419 		if (i == rvd->vdev_children) {
9420 			spa->spa_deflate = TRUE;
9421 			VERIFY0(zap_add(spa->spa_meta_objset,
9422 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
9423 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
9424 		}
9425 	}
9426 
9427 	spa_sync_adjust_vdev_max_queue_depth(spa);
9428 
9429 	spa_sync_condense_indirect(spa, tx);
9430 
9431 	spa_sync_iterate_to_convergence(spa, tx);
9432 
9433 #ifdef ZFS_DEBUG
9434 	if (!list_is_empty(&spa->spa_config_dirty_list)) {
9435 	/*
9436 	 * Make sure that the number of ZAPs for all the vdevs matches
9437 	 * the number of ZAPs in the per-vdev ZAP list. This only gets
9438 	 * called if the config is dirty; otherwise there may be
9439 	 * outstanding AVZ operations that weren't completed in
9440 	 * spa_sync_config_object.
9441 	 */
9442 		uint64_t all_vdev_zap_entry_count;
9443 		ASSERT0(zap_count(spa->spa_meta_objset,
9444 		    spa->spa_all_vdev_zaps, &all_vdev_zap_entry_count));
9445 		ASSERT3U(vdev_count_verify_zaps(spa->spa_root_vdev), ==,
9446 		    all_vdev_zap_entry_count);
9447 	}
9448 #endif
9449 
9450 	if (spa->spa_vdev_removal != NULL) {
9451 		ASSERT0(spa->spa_vdev_removal->svr_bytes_done[txg & TXG_MASK]);
9452 	}
9453 
9454 	spa_sync_rewrite_vdev_config(spa, tx);
9455 	dmu_tx_commit(tx);
9456 
9457 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
9458 	spa->spa_deadman_tqid = 0;
9459 
9460 	/*
9461 	 * Clear the dirty config list.
9462 	 */
9463 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
9464 		vdev_config_clean(vd);
9465 
9466 	/*
9467 	 * Now that the new config has synced transactionally,
9468 	 * let it become visible to the config cache.
9469 	 */
9470 	if (spa->spa_config_syncing != NULL) {
9471 		spa_config_set(spa, spa->spa_config_syncing);
9472 		spa->spa_config_txg = txg;
9473 		spa->spa_config_syncing = NULL;
9474 	}
9475 
9476 	dsl_pool_sync_done(dp, txg);
9477 
9478 	for (int i = 0; i < spa->spa_alloc_count; i++) {
9479 		mutex_enter(&spa->spa_allocs[i].spaa_lock);
9480 		VERIFY0(avl_numnodes(&spa->spa_allocs[i].spaa_tree));
9481 		mutex_exit(&spa->spa_allocs[i].spaa_lock);
9482 	}
9483 
9484 	/*
9485 	 * Update usable space statistics.
9486 	 */
9487 	while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
9488 	    != NULL)
9489 		vdev_sync_done(vd, txg);
9490 
9491 	metaslab_class_evict_old(spa->spa_normal_class, txg);
9492 	metaslab_class_evict_old(spa->spa_log_class, txg);
9493 
9494 	spa_sync_close_syncing_log_sm(spa);
9495 
9496 	spa_update_dspace(spa);
9497 
9498 	if (spa_get_autotrim(spa) == SPA_AUTOTRIM_ON)
9499 		vdev_autotrim_kick(spa);
9500 
9501 	/*
9502 	 * It had better be the case that we didn't dirty anything
9503 	 * since vdev_config_sync().
9504 	 */
9505 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
9506 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
9507 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
9508 
9509 	while (zfs_pause_spa_sync)
9510 		delay(1);
9511 
9512 	spa->spa_sync_pass = 0;
9513 
9514 	/*
9515 	 * Update the last synced uberblock here. We want to do this at
9516 	 * the end of spa_sync() so that consumers of spa_last_synced_txg()
9517 	 * will be guaranteed that all the processing associated with
9518 	 * that txg has been completed.
9519 	 */
9520 	spa->spa_ubsync = spa->spa_uberblock;
9521 	spa_config_exit(spa, SCL_CONFIG, FTAG);
9522 
9523 	spa_handle_ignored_writes(spa);
9524 
9525 	/*
9526 	 * If any async tasks have been requested, kick them off.
9527 	 */
9528 	spa_async_dispatch(spa);
9529 }
9530 
9531 /*
9532  * Sync all pools.  We don't want to hold the namespace lock across these
9533  * operations, so we take a reference on the spa_t and drop the lock during the
9534  * sync.
9535  */
9536 void
9537 spa_sync_allpools(void)
9538 {
9539 	spa_t *spa = NULL;
9540 	mutex_enter(&spa_namespace_lock);
9541 	while ((spa = spa_next(spa)) != NULL) {
9542 		if (spa_state(spa) != POOL_STATE_ACTIVE ||
9543 		    !spa_writeable(spa) || spa_suspended(spa))
9544 			continue;
9545 		spa_open_ref(spa, FTAG);
9546 		mutex_exit(&spa_namespace_lock);
9547 		txg_wait_synced(spa_get_dsl(spa), 0);
9548 		mutex_enter(&spa_namespace_lock);
9549 		spa_close(spa, FTAG);
9550 	}
9551 	mutex_exit(&spa_namespace_lock);
9552 }
9553 
9554 /*
9555  * ==========================================================================
9556  * Miscellaneous routines
9557  * ==========================================================================
9558  */
9559 
9560 /*
9561  * Remove all pools in the system.
9562  */
9563 void
9564 spa_evict_all(void)
9565 {
9566 	spa_t *spa;
9567 
9568 	/*
9569 	 * Remove all cached state.  All pools should be closed now,
9570 	 * so every spa in the AVL tree should be unreferenced.
9571 	 */
9572 	mutex_enter(&spa_namespace_lock);
9573 	while ((spa = spa_next(NULL)) != NULL) {
9574 		/*
9575 		 * Stop async tasks.  The async thread may need to detach
9576 		 * a device that's been replaced, which requires grabbing
9577 		 * spa_namespace_lock, so we must drop it here.
9578 		 */
9579 		spa_open_ref(spa, FTAG);
9580 		mutex_exit(&spa_namespace_lock);
9581 		spa_async_suspend(spa);
9582 		mutex_enter(&spa_namespace_lock);
9583 		spa_close(spa, FTAG);
9584 
9585 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
9586 			spa_unload(spa);
9587 			spa_deactivate(spa);
9588 		}
9589 		spa_remove(spa);
9590 	}
9591 	mutex_exit(&spa_namespace_lock);
9592 }
9593 
9594 vdev_t *
9595 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
9596 {
9597 	vdev_t *vd;
9598 	int i;
9599 
9600 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
9601 		return (vd);
9602 
9603 	if (aux) {
9604 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
9605 			vd = spa->spa_l2cache.sav_vdevs[i];
9606 			if (vd->vdev_guid == guid)
9607 				return (vd);
9608 		}
9609 
9610 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
9611 			vd = spa->spa_spares.sav_vdevs[i];
9612 			if (vd->vdev_guid == guid)
9613 				return (vd);
9614 		}
9615 	}
9616 
9617 	return (NULL);
9618 }
9619 
9620 void
9621 spa_upgrade(spa_t *spa, uint64_t version)
9622 {
9623 	ASSERT(spa_writeable(spa));
9624 
9625 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
9626 
9627 	/*
9628 	 * This should only be called for a non-faulted pool, and since a
9629 	 * future version would result in an unopenable pool, this shouldn't be
9630 	 * possible.
9631 	 */
9632 	ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
9633 	ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
9634 
9635 	spa->spa_uberblock.ub_version = version;
9636 	vdev_config_dirty(spa->spa_root_vdev);
9637 
9638 	spa_config_exit(spa, SCL_ALL, FTAG);
9639 
9640 	txg_wait_synced(spa_get_dsl(spa), 0);
9641 }
9642 
9643 static boolean_t
9644 spa_has_aux_vdev(spa_t *spa, uint64_t guid, spa_aux_vdev_t *sav)
9645 {
9646 	(void) spa;
9647 	int i;
9648 	uint64_t vdev_guid;
9649 
9650 	for (i = 0; i < sav->sav_count; i++)
9651 		if (sav->sav_vdevs[i]->vdev_guid == guid)
9652 			return (B_TRUE);
9653 
9654 	for (i = 0; i < sav->sav_npending; i++) {
9655 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
9656 		    &vdev_guid) == 0 && vdev_guid == guid)
9657 			return (B_TRUE);
9658 	}
9659 
9660 	return (B_FALSE);
9661 }
9662 
9663 boolean_t
9664 spa_has_l2cache(spa_t *spa, uint64_t guid)
9665 {
9666 	return (spa_has_aux_vdev(spa, guid, &spa->spa_l2cache));
9667 }
9668 
9669 boolean_t
9670 spa_has_spare(spa_t *spa, uint64_t guid)
9671 {
9672 	return (spa_has_aux_vdev(spa, guid, &spa->spa_spares));
9673 }
9674 
9675 /*
9676  * Check if a pool has an active shared spare device.
9677  * Note: reference count of an active spare is 2, as a spare and as a replace
9678  */
9679 static boolean_t
9680 spa_has_active_shared_spare(spa_t *spa)
9681 {
9682 	int i, refcnt;
9683 	uint64_t pool;
9684 	spa_aux_vdev_t *sav = &spa->spa_spares;
9685 
9686 	for (i = 0; i < sav->sav_count; i++) {
9687 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
9688 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
9689 		    refcnt > 2)
9690 			return (B_TRUE);
9691 	}
9692 
9693 	return (B_FALSE);
9694 }
9695 
9696 uint64_t
9697 spa_total_metaslabs(spa_t *spa)
9698 {
9699 	vdev_t *rvd = spa->spa_root_vdev;
9700 
9701 	uint64_t m = 0;
9702 	for (uint64_t c = 0; c < rvd->vdev_children; c++) {
9703 		vdev_t *vd = rvd->vdev_child[c];
9704 		if (!vdev_is_concrete(vd))
9705 			continue;
9706 		m += vd->vdev_ms_count;
9707 	}
9708 	return (m);
9709 }
9710 
9711 /*
9712  * Notify any waiting threads that some activity has switched from being in-
9713  * progress to not-in-progress so that the thread can wake up and determine
9714  * whether it is finished waiting.
9715  */
9716 void
9717 spa_notify_waiters(spa_t *spa)
9718 {
9719 	/*
9720 	 * Acquiring spa_activities_lock here prevents the cv_broadcast from
9721 	 * happening between the waiting thread's check and cv_wait.
9722 	 */
9723 	mutex_enter(&spa->spa_activities_lock);
9724 	cv_broadcast(&spa->spa_activities_cv);
9725 	mutex_exit(&spa->spa_activities_lock);
9726 }
9727 
9728 /*
9729  * Notify any waiting threads that the pool is exporting, and then block until
9730  * they are finished using the spa_t.
9731  */
9732 void
9733 spa_wake_waiters(spa_t *spa)
9734 {
9735 	mutex_enter(&spa->spa_activities_lock);
9736 	spa->spa_waiters_cancel = B_TRUE;
9737 	cv_broadcast(&spa->spa_activities_cv);
9738 	while (spa->spa_waiters != 0)
9739 		cv_wait(&spa->spa_waiters_cv, &spa->spa_activities_lock);
9740 	spa->spa_waiters_cancel = B_FALSE;
9741 	mutex_exit(&spa->spa_activities_lock);
9742 }
9743 
9744 /* Whether the vdev or any of its descendants are being initialized/trimmed. */
9745 static boolean_t
9746 spa_vdev_activity_in_progress_impl(vdev_t *vd, zpool_wait_activity_t activity)
9747 {
9748 	spa_t *spa = vd->vdev_spa;
9749 
9750 	ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER));
9751 	ASSERT(MUTEX_HELD(&spa->spa_activities_lock));
9752 	ASSERT(activity == ZPOOL_WAIT_INITIALIZE ||
9753 	    activity == ZPOOL_WAIT_TRIM);
9754 
9755 	kmutex_t *lock = activity == ZPOOL_WAIT_INITIALIZE ?
9756 	    &vd->vdev_initialize_lock : &vd->vdev_trim_lock;
9757 
9758 	mutex_exit(&spa->spa_activities_lock);
9759 	mutex_enter(lock);
9760 	mutex_enter(&spa->spa_activities_lock);
9761 
9762 	boolean_t in_progress = (activity == ZPOOL_WAIT_INITIALIZE) ?
9763 	    (vd->vdev_initialize_state == VDEV_INITIALIZE_ACTIVE) :
9764 	    (vd->vdev_trim_state == VDEV_TRIM_ACTIVE);
9765 	mutex_exit(lock);
9766 
9767 	if (in_progress)
9768 		return (B_TRUE);
9769 
9770 	for (int i = 0; i < vd->vdev_children; i++) {
9771 		if (spa_vdev_activity_in_progress_impl(vd->vdev_child[i],
9772 		    activity))
9773 			return (B_TRUE);
9774 	}
9775 
9776 	return (B_FALSE);
9777 }
9778 
9779 /*
9780  * If use_guid is true, this checks whether the vdev specified by guid is
9781  * being initialized/trimmed. Otherwise, it checks whether any vdev in the pool
9782  * is being initialized/trimmed. The caller must hold the config lock and
9783  * spa_activities_lock.
9784  */
9785 static int
9786 spa_vdev_activity_in_progress(spa_t *spa, boolean_t use_guid, uint64_t guid,
9787     zpool_wait_activity_t activity, boolean_t *in_progress)
9788 {
9789 	mutex_exit(&spa->spa_activities_lock);
9790 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
9791 	mutex_enter(&spa->spa_activities_lock);
9792 
9793 	vdev_t *vd;
9794 	if (use_guid) {
9795 		vd = spa_lookup_by_guid(spa, guid, B_FALSE);
9796 		if (vd == NULL || !vd->vdev_ops->vdev_op_leaf) {
9797 			spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9798 			return (EINVAL);
9799 		}
9800 	} else {
9801 		vd = spa->spa_root_vdev;
9802 	}
9803 
9804 	*in_progress = spa_vdev_activity_in_progress_impl(vd, activity);
9805 
9806 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9807 	return (0);
9808 }
9809 
9810 /*
9811  * Locking for waiting threads
9812  * ---------------------------
9813  *
9814  * Waiting threads need a way to check whether a given activity is in progress,
9815  * and then, if it is, wait for it to complete. Each activity will have some
9816  * in-memory representation of the relevant on-disk state which can be used to
9817  * determine whether or not the activity is in progress. The in-memory state and
9818  * the locking used to protect it will be different for each activity, and may
9819  * not be suitable for use with a cvar (e.g., some state is protected by the
9820  * config lock). To allow waiting threads to wait without any races, another
9821  * lock, spa_activities_lock, is used.
9822  *
9823  * When the state is checked, both the activity-specific lock (if there is one)
9824  * and spa_activities_lock are held. In some cases, the activity-specific lock
9825  * is acquired explicitly (e.g. the config lock). In others, the locking is
9826  * internal to some check (e.g. bpobj_is_empty). After checking, the waiting
9827  * thread releases the activity-specific lock and, if the activity is in
9828  * progress, then cv_waits using spa_activities_lock.
9829  *
9830  * The waiting thread is woken when another thread, one completing some
9831  * activity, updates the state of the activity and then calls
9832  * spa_notify_waiters, which will cv_broadcast. This 'completing' thread only
9833  * needs to hold its activity-specific lock when updating the state, and this
9834  * lock can (but doesn't have to) be dropped before calling spa_notify_waiters.
9835  *
9836  * Because spa_notify_waiters acquires spa_activities_lock before broadcasting,
9837  * and because it is held when the waiting thread checks the state of the
9838  * activity, it can never be the case that the completing thread both updates
9839  * the activity state and cv_broadcasts in between the waiting thread's check
9840  * and cv_wait. Thus, a waiting thread can never miss a wakeup.
9841  *
9842  * In order to prevent deadlock, when the waiting thread does its check, in some
9843  * cases it will temporarily drop spa_activities_lock in order to acquire the
9844  * activity-specific lock. The order in which spa_activities_lock and the
9845  * activity specific lock are acquired in the waiting thread is determined by
9846  * the order in which they are acquired in the completing thread; if the
9847  * completing thread calls spa_notify_waiters with the activity-specific lock
9848  * held, then the waiting thread must also acquire the activity-specific lock
9849  * first.
9850  */
9851 
9852 static int
9853 spa_activity_in_progress(spa_t *spa, zpool_wait_activity_t activity,
9854     boolean_t use_tag, uint64_t tag, boolean_t *in_progress)
9855 {
9856 	int error = 0;
9857 
9858 	ASSERT(MUTEX_HELD(&spa->spa_activities_lock));
9859 
9860 	switch (activity) {
9861 	case ZPOOL_WAIT_CKPT_DISCARD:
9862 		*in_progress =
9863 		    (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT) &&
9864 		    zap_contains(spa_meta_objset(spa),
9865 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ZPOOL_CHECKPOINT) ==
9866 		    ENOENT);
9867 		break;
9868 	case ZPOOL_WAIT_FREE:
9869 		*in_progress = ((spa_version(spa) >= SPA_VERSION_DEADLISTS &&
9870 		    !bpobj_is_empty(&spa->spa_dsl_pool->dp_free_bpobj)) ||
9871 		    spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY) ||
9872 		    spa_livelist_delete_check(spa));
9873 		break;
9874 	case ZPOOL_WAIT_INITIALIZE:
9875 	case ZPOOL_WAIT_TRIM:
9876 		error = spa_vdev_activity_in_progress(spa, use_tag, tag,
9877 		    activity, in_progress);
9878 		break;
9879 	case ZPOOL_WAIT_REPLACE:
9880 		mutex_exit(&spa->spa_activities_lock);
9881 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
9882 		mutex_enter(&spa->spa_activities_lock);
9883 
9884 		*in_progress = vdev_replace_in_progress(spa->spa_root_vdev);
9885 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9886 		break;
9887 	case ZPOOL_WAIT_REMOVE:
9888 		*in_progress = (spa->spa_removing_phys.sr_state ==
9889 		    DSS_SCANNING);
9890 		break;
9891 	case ZPOOL_WAIT_RESILVER:
9892 		if ((*in_progress = vdev_rebuild_active(spa->spa_root_vdev)))
9893 			break;
9894 		zfs_fallthrough;
9895 	case ZPOOL_WAIT_SCRUB:
9896 	{
9897 		boolean_t scanning, paused, is_scrub;
9898 		dsl_scan_t *scn =  spa->spa_dsl_pool->dp_scan;
9899 
9900 		is_scrub = (scn->scn_phys.scn_func == POOL_SCAN_SCRUB);
9901 		scanning = (scn->scn_phys.scn_state == DSS_SCANNING);
9902 		paused = dsl_scan_is_paused_scrub(scn);
9903 		*in_progress = (scanning && !paused &&
9904 		    is_scrub == (activity == ZPOOL_WAIT_SCRUB));
9905 		break;
9906 	}
9907 	default:
9908 		panic("unrecognized value for activity %d", activity);
9909 	}
9910 
9911 	return (error);
9912 }
9913 
9914 static int
9915 spa_wait_common(const char *pool, zpool_wait_activity_t activity,
9916     boolean_t use_tag, uint64_t tag, boolean_t *waited)
9917 {
9918 	/*
9919 	 * The tag is used to distinguish between instances of an activity.
9920 	 * 'initialize' and 'trim' are the only activities that we use this for.
9921 	 * The other activities can only have a single instance in progress in a
9922 	 * pool at one time, making the tag unnecessary.
9923 	 *
9924 	 * There can be multiple devices being replaced at once, but since they
9925 	 * all finish once resilvering finishes, we don't bother keeping track
9926 	 * of them individually, we just wait for them all to finish.
9927 	 */
9928 	if (use_tag && activity != ZPOOL_WAIT_INITIALIZE &&
9929 	    activity != ZPOOL_WAIT_TRIM)
9930 		return (EINVAL);
9931 
9932 	if (activity < 0 || activity >= ZPOOL_WAIT_NUM_ACTIVITIES)
9933 		return (EINVAL);
9934 
9935 	spa_t *spa;
9936 	int error = spa_open(pool, &spa, FTAG);
9937 	if (error != 0)
9938 		return (error);
9939 
9940 	/*
9941 	 * Increment the spa's waiter count so that we can call spa_close and
9942 	 * still ensure that the spa_t doesn't get freed before this thread is
9943 	 * finished with it when the pool is exported. We want to call spa_close
9944 	 * before we start waiting because otherwise the additional ref would
9945 	 * prevent the pool from being exported or destroyed throughout the
9946 	 * potentially long wait.
9947 	 */
9948 	mutex_enter(&spa->spa_activities_lock);
9949 	spa->spa_waiters++;
9950 	spa_close(spa, FTAG);
9951 
9952 	*waited = B_FALSE;
9953 	for (;;) {
9954 		boolean_t in_progress;
9955 		error = spa_activity_in_progress(spa, activity, use_tag, tag,
9956 		    &in_progress);
9957 
9958 		if (error || !in_progress || spa->spa_waiters_cancel)
9959 			break;
9960 
9961 		*waited = B_TRUE;
9962 
9963 		if (cv_wait_sig(&spa->spa_activities_cv,
9964 		    &spa->spa_activities_lock) == 0) {
9965 			error = EINTR;
9966 			break;
9967 		}
9968 	}
9969 
9970 	spa->spa_waiters--;
9971 	cv_signal(&spa->spa_waiters_cv);
9972 	mutex_exit(&spa->spa_activities_lock);
9973 
9974 	return (error);
9975 }
9976 
9977 /*
9978  * Wait for a particular instance of the specified activity to complete, where
9979  * the instance is identified by 'tag'
9980  */
9981 int
9982 spa_wait_tag(const char *pool, zpool_wait_activity_t activity, uint64_t tag,
9983     boolean_t *waited)
9984 {
9985 	return (spa_wait_common(pool, activity, B_TRUE, tag, waited));
9986 }
9987 
9988 /*
9989  * Wait for all instances of the specified activity complete
9990  */
9991 int
9992 spa_wait(const char *pool, zpool_wait_activity_t activity, boolean_t *waited)
9993 {
9994 
9995 	return (spa_wait_common(pool, activity, B_FALSE, 0, waited));
9996 }
9997 
9998 sysevent_t *
9999 spa_event_create(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl, const char *name)
10000 {
10001 	sysevent_t *ev = NULL;
10002 #ifdef _KERNEL
10003 	nvlist_t *resource;
10004 
10005 	resource = zfs_event_create(spa, vd, FM_SYSEVENT_CLASS, name, hist_nvl);
10006 	if (resource) {
10007 		ev = kmem_alloc(sizeof (sysevent_t), KM_SLEEP);
10008 		ev->resource = resource;
10009 	}
10010 #else
10011 	(void) spa, (void) vd, (void) hist_nvl, (void) name;
10012 #endif
10013 	return (ev);
10014 }
10015 
10016 void
10017 spa_event_post(sysevent_t *ev)
10018 {
10019 #ifdef _KERNEL
10020 	if (ev) {
10021 		zfs_zevent_post(ev->resource, NULL, zfs_zevent_post_cb);
10022 		kmem_free(ev, sizeof (*ev));
10023 	}
10024 #else
10025 	(void) ev;
10026 #endif
10027 }
10028 
10029 /*
10030  * Post a zevent corresponding to the given sysevent.   The 'name' must be one
10031  * of the event definitions in sys/sysevent/eventdefs.h.  The payload will be
10032  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
10033  * in the userland libzpool, as we don't want consumers to misinterpret ztest
10034  * or zdb as real changes.
10035  */
10036 void
10037 spa_event_notify(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl, const char *name)
10038 {
10039 	spa_event_post(spa_event_create(spa, vd, hist_nvl, name));
10040 }
10041 
10042 /* state manipulation functions */
10043 EXPORT_SYMBOL(spa_open);
10044 EXPORT_SYMBOL(spa_open_rewind);
10045 EXPORT_SYMBOL(spa_get_stats);
10046 EXPORT_SYMBOL(spa_create);
10047 EXPORT_SYMBOL(spa_import);
10048 EXPORT_SYMBOL(spa_tryimport);
10049 EXPORT_SYMBOL(spa_destroy);
10050 EXPORT_SYMBOL(spa_export);
10051 EXPORT_SYMBOL(spa_reset);
10052 EXPORT_SYMBOL(spa_async_request);
10053 EXPORT_SYMBOL(spa_async_suspend);
10054 EXPORT_SYMBOL(spa_async_resume);
10055 EXPORT_SYMBOL(spa_inject_addref);
10056 EXPORT_SYMBOL(spa_inject_delref);
10057 EXPORT_SYMBOL(spa_scan_stat_init);
10058 EXPORT_SYMBOL(spa_scan_get_stats);
10059 
10060 /* device manipulation */
10061 EXPORT_SYMBOL(spa_vdev_add);
10062 EXPORT_SYMBOL(spa_vdev_attach);
10063 EXPORT_SYMBOL(spa_vdev_detach);
10064 EXPORT_SYMBOL(spa_vdev_setpath);
10065 EXPORT_SYMBOL(spa_vdev_setfru);
10066 EXPORT_SYMBOL(spa_vdev_split_mirror);
10067 
10068 /* spare statech is global across all pools) */
10069 EXPORT_SYMBOL(spa_spare_add);
10070 EXPORT_SYMBOL(spa_spare_remove);
10071 EXPORT_SYMBOL(spa_spare_exists);
10072 EXPORT_SYMBOL(spa_spare_activate);
10073 
10074 /* L2ARC statech is global across all pools) */
10075 EXPORT_SYMBOL(spa_l2cache_add);
10076 EXPORT_SYMBOL(spa_l2cache_remove);
10077 EXPORT_SYMBOL(spa_l2cache_exists);
10078 EXPORT_SYMBOL(spa_l2cache_activate);
10079 EXPORT_SYMBOL(spa_l2cache_drop);
10080 
10081 /* scanning */
10082 EXPORT_SYMBOL(spa_scan);
10083 EXPORT_SYMBOL(spa_scan_stop);
10084 
10085 /* spa syncing */
10086 EXPORT_SYMBOL(spa_sync); /* only for DMU use */
10087 EXPORT_SYMBOL(spa_sync_allpools);
10088 
10089 /* properties */
10090 EXPORT_SYMBOL(spa_prop_set);
10091 EXPORT_SYMBOL(spa_prop_get);
10092 EXPORT_SYMBOL(spa_prop_clear_bootfs);
10093 
10094 /* asynchronous event notification */
10095 EXPORT_SYMBOL(spa_event_notify);
10096 
10097 /* BEGIN CSTYLED */
10098 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_shift, UINT, ZMOD_RW,
10099 	"log2 fraction of arc that can be used by inflight I/Os when "
10100 	"verifying pool during import");
10101 /* END CSTYLED */
10102 
10103 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_metadata, INT, ZMOD_RW,
10104 	"Set to traverse metadata on pool import");
10105 
10106 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_data, INT, ZMOD_RW,
10107 	"Set to traverse data on pool import");
10108 
10109 ZFS_MODULE_PARAM(zfs_spa, spa_, load_print_vdev_tree, INT, ZMOD_RW,
10110 	"Print vdev tree to zfs_dbgmsg during pool import");
10111 
10112 ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_pct, UINT, ZMOD_RD,
10113 	"Percentage of CPUs to run an IO worker thread");
10114 
10115 ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_tpq, UINT, ZMOD_RD,
10116 	"Number of threads per IO worker taskqueue");
10117 
10118 /* BEGIN CSTYLED */
10119 ZFS_MODULE_PARAM(zfs, zfs_, max_missing_tvds, U64, ZMOD_RW,
10120 	"Allow importing pool with up to this number of missing top-level "
10121 	"vdevs (in read-only mode)");
10122 /* END CSTYLED */
10123 
10124 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, zthr_pause, INT,
10125 	ZMOD_RW, "Set the livelist condense zthr to pause");
10126 
10127 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, sync_pause, INT,
10128 	ZMOD_RW, "Set the livelist condense synctask to pause");
10129 
10130 /* BEGIN CSTYLED */
10131 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, sync_cancel,
10132 	INT, ZMOD_RW,
10133 	"Whether livelist condensing was canceled in the synctask");
10134 
10135 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, zthr_cancel,
10136 	INT, ZMOD_RW,
10137 	"Whether livelist condensing was canceled in the zthr function");
10138 
10139 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, new_alloc, INT,
10140 	ZMOD_RW,
10141 	"Whether extra ALLOC blkptrs were added to a livelist entry while it "
10142 	"was being condensed");
10143 /* END CSTYLED */
10144