xref: /freebsd/sys/contrib/openzfs/module/zfs/spa.c (revision 2f10ffc003be396f3fc23cd2888023896560252b)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * This file and its contents are supplied under the terms of the
4  * Common Development and Distribution License ("CDDL"), version 1.0.
5  * You may only use this file in accordance with the terms of version
6  * 1.0 of the CDDL.
7  *
8  * A full copy of the text of the CDDL should have accompanied this
9  * source.  A copy of the CDDL is also available via the Internet at
10  * https://opensource.org/license/CDDL-1.0.
11  */
12 
13 /*
14  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
15  * Copyright (c) 2011, 2024 by Delphix. All rights reserved.
16  * Copyright (c) 2018, Nexenta Systems, Inc.  All rights reserved.
17  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
18  * Copyright 2013 Saso Kiselkov. All rights reserved.
19  * Copyright (c) 2014 Integros [integros.com]
20  * Copyright 2016 Toomas Soome <tsoome@me.com>
21  * Copyright (c) 2016 Actifio, Inc. All rights reserved.
22  * Copyright 2018 Joyent, Inc.
23  * Copyright (c) 2017, 2019, Datto Inc. All rights reserved.
24  * Copyright 2017 Joyent, Inc.
25  * Copyright (c) 2017, Intel Corporation.
26  * Copyright (c) 2021, Colm Buckley <colm@tuatha.org>
27  * Copyright (c) 2023 Hewlett Packard Enterprise Development LP.
28  * Copyright (c) 2023-2026, Klara, Inc.
29  * Copyright (c) 2026, TrueNAS.
30  * Copyright 2026 Edgecast Cloud LLC.
31  */
32 
33 /*
34  * SPA: Storage Pool Allocator
35  *
36  * This file contains all the routines used when modifying on-disk SPA state.
37  * This includes opening, importing, destroying, exporting a pool, and syncing a
38  * pool.
39  */
40 
41 #include <sys/zfs_context.h>
42 #include <sys/fm/fs/zfs.h>
43 #include <sys/spa_impl.h>
44 #include <sys/zio.h>
45 #include <sys/zio_checksum.h>
46 #include <sys/dmu.h>
47 #include <sys/dmu_tx.h>
48 #include <sys/zap.h>
49 #include <sys/zil.h>
50 #include <sys/brt.h>
51 #include <sys/ddt.h>
52 #include <sys/vdev_impl.h>
53 #include <sys/vdev_removal.h>
54 #include <sys/vdev_indirect_mapping.h>
55 #include <sys/vdev_indirect_births.h>
56 #include <sys/vdev_initialize.h>
57 #include <sys/vdev_rebuild.h>
58 #include <sys/vdev_trim.h>
59 #include <sys/vdev_disk.h>
60 #include <sys/vdev_raidz.h>
61 #include <sys/vdev_draid.h>
62 #include <sys/metaslab.h>
63 #include <sys/metaslab_impl.h>
64 #include <sys/mmp.h>
65 #include <sys/uberblock_impl.h>
66 #include <sys/txg.h>
67 #include <sys/avl.h>
68 #include <sys/bpobj.h>
69 #include <sys/dmu_traverse.h>
70 #include <sys/dmu_objset.h>
71 #include <sys/unique.h>
72 #include <sys/dsl_pool.h>
73 #include <sys/dsl_dataset.h>
74 #include <sys/dsl_dir.h>
75 #include <sys/dsl_prop.h>
76 #include <sys/dsl_synctask.h>
77 #include <sys/fs/zfs.h>
78 #include <sys/arc.h>
79 #include <sys/callb.h>
80 #include <sys/systeminfo.h>
81 #include <sys/zfs_ioctl.h>
82 #include <sys/dsl_scan.h>
83 #include <sys/zfeature.h>
84 #include <sys/dsl_destroy.h>
85 #include <sys/zvol.h>
86 
87 #ifdef	_KERNEL
88 #include <sys/fm/protocol.h>
89 #include <sys/fm/util.h>
90 #include <sys/callb.h>
91 #include <sys/zone.h>
92 #include <sys/vmsystm.h>
93 #endif	/* _KERNEL */
94 
95 #include "zfs_crrd.h"
96 #include "zfs_prop.h"
97 #include "zfs_comutil.h"
98 #include <cityhash.h>
99 
100 /*
101  * spa_thread() existed on Illumos as a parent thread for the various worker
102  * threads that actually run the pool, as a way to both reference the entire
103  * pool work as a single object, and to share properties like scheduling
104  * options. It has not yet been adapted to Linux or FreeBSD. This define is
105  * used to mark related parts of the code to make things easier for the reader,
106  * and to compile this code out. It can be removed when someone implements it,
107  * moves it to some Illumos-specific place, or removes it entirely.
108  */
109 #undef HAVE_SPA_THREAD
110 
111 /*
112  * The "System Duty Cycle" scheduling class is an Illumos feature to help
113  * prevent CPU-intensive kernel threads from affecting latency on interactive
114  * threads. It doesn't exist on Linux or FreeBSD, so the supporting code is
115  * gated behind a define. On Illumos SDC depends on spa_thread(), but
116  * spa_thread() also has other uses, so this is a separate define.
117  */
118 #undef HAVE_SYSDC
119 
120 /*
121  * The interval, in seconds, at which failed configuration cache file writes
122  * should be retried.
123  */
124 int zfs_ccw_retry_interval = 300;
125 
126 typedef enum zti_modes {
127 	ZTI_MODE_FIXED,			/* value is # of threads (min 1) */
128 	ZTI_MODE_SCALE,			/* Taskqs scale with CPUs. */
129 	ZTI_MODE_SYNC,			/* sync thread assigned */
130 	ZTI_MODE_NULL,			/* don't create a taskq */
131 	ZTI_NMODES
132 } zti_modes_t;
133 
134 #define	ZTI_P(n, q)	{ ZTI_MODE_FIXED, (n), (q) }
135 #define	ZTI_PCT(n)	{ ZTI_MODE_ONLINE_PERCENT, (n), 1 }
136 #define	ZTI_SCALE(min)	{ ZTI_MODE_SCALE, (min), 1 }
137 #define	ZTI_SYNC	{ ZTI_MODE_SYNC, 0, 1 }
138 #define	ZTI_NULL	{ ZTI_MODE_NULL, 0, 0 }
139 
140 #define	ZTI_N(n)	ZTI_P(n, 1)
141 #define	ZTI_ONE		ZTI_N(1)
142 
143 typedef struct zio_taskq_info {
144 	zti_modes_t zti_mode;
145 	uint_t zti_value;
146 	uint_t zti_count;
147 } zio_taskq_info_t;
148 
149 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
150 	"iss", "iss_h", "int", "int_h"
151 };
152 
153 /*
154  * This table defines the taskq settings for each ZFS I/O type. When
155  * initializing a pool, we use this table to create an appropriately sized
156  * taskq. Some operations are low volume and therefore have a small, static
157  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
158  * macros. Other operations process a large amount of data; the ZTI_SCALE
159  * macro causes us to create a taskq oriented for throughput. Some operations
160  * are so high frequency and short-lived that the taskq itself can become a
161  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
162  * additional degree of parallelism specified by the number of threads per-
163  * taskq and the number of taskqs; when dispatching an event in this case, the
164  * particular taskq is chosen at random. ZTI_SCALE uses a number of taskqs
165  * that scales with the number of CPUs.
166  *
167  * The different taskq priorities are to handle the different contexts (issue
168  * and interrupt) and then to reserve threads for high priority I/Os that
169  * need to be handled with minimum delay.  Illumos taskq has unfair TQ_FRONT
170  * implementation, so separate high priority threads are used there.
171  */
172 static zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
173 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
174 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* NULL */
175 	{ ZTI_N(8),	ZTI_NULL,	ZTI_SCALE(0),	ZTI_NULL }, /* READ */
176 #ifdef illumos
177 	{ ZTI_SYNC,	ZTI_N(5),	ZTI_SCALE(0),	ZTI_N(5) }, /* WRITE */
178 #else
179 	{ ZTI_SYNC,	ZTI_NULL,	ZTI_SCALE(0),	ZTI_NULL }, /* WRITE */
180 #endif
181 	{ ZTI_SCALE(32), ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FREE */
182 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* CLAIM */
183 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FLUSH */
184 	{ ZTI_N(4),	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* TRIM */
185 };
186 
187 static void spa_sync_version(void *arg, dmu_tx_t *tx);
188 static void spa_sync_props(void *arg, dmu_tx_t *tx);
189 static boolean_t spa_has_active_shared_spare(spa_t *spa);
190 static int spa_load_impl(spa_t *spa, spa_import_type_t type,
191     const char **ereport);
192 static void spa_vdev_resilver_done(spa_t *spa);
193 
194 /*
195  * Percentage of all CPUs that can be used by the metaslab preload taskq.
196  */
197 static uint_t metaslab_preload_pct = 50;
198 
199 static uint_t	zio_taskq_batch_pct = 80;	  /* 1 thread per cpu in pset */
200 static uint_t	zio_taskq_batch_tpq;		  /* threads per taskq */
201 
202 #ifdef HAVE_SYSDC
203 static const boolean_t	zio_taskq_sysdc = B_TRUE; /* use SDC scheduling class */
204 static const uint_t	zio_taskq_basedc = 80;	  /* base duty cycle */
205 #endif
206 
207 #ifdef HAVE_SPA_THREAD
208 static const boolean_t spa_create_process = B_TRUE; /* no process => no sysdc */
209 #endif
210 
211 static uint_t	zio_taskq_write_tpq = 16;
212 
213 /*
214  * Report any spa_load_verify errors found, but do not fail spa_load.
215  * This is used by zdb to analyze non-idle pools.
216  */
217 boolean_t	spa_load_verify_dryrun = B_FALSE;
218 
219 /*
220  * Allow read spacemaps in case of readonly import (spa_mode == SPA_MODE_READ).
221  * This is used by zdb for spacemaps verification.
222  */
223 boolean_t	spa_mode_readable_spacemaps = B_FALSE;
224 
225 /*
226  * This (illegal) pool name is used when temporarily importing a spa_t in order
227  * to get the vdev stats associated with the imported devices.
228  */
229 #define	TRYIMPORT_NAME	"$import"
230 
231 /*
232  * For debugging purposes: print out vdev tree during pool import.
233  */
234 static int		spa_load_print_vdev_tree = B_FALSE;
235 
236 /*
237  * A non-zero value for zfs_max_missing_tvds means that we allow importing
238  * pools with missing top-level vdevs. This is strictly intended for advanced
239  * pool recovery cases since missing data is almost inevitable. Pools with
240  * missing devices can only be imported read-only for safety reasons, and their
241  * fail-mode will be automatically set to "continue".
242  *
243  * With 1 missing vdev we should be able to import the pool and mount all
244  * datasets. User data that was not modified after the missing device has been
245  * added should be recoverable. This means that snapshots created prior to the
246  * addition of that device should be completely intact.
247  *
248  * With 2 missing vdevs, some datasets may fail to mount since there are
249  * dataset statistics that are stored as regular metadata. Some data might be
250  * recoverable if those vdevs were added recently.
251  *
252  * With 3 or more missing vdevs, the pool is severely damaged and MOS entries
253  * may be missing entirely. Chances of data recovery are very low. Note that
254  * there are also risks of performing an inadvertent rewind as we might be
255  * missing all the vdevs with the latest uberblocks.
256  */
257 uint64_t	zfs_max_missing_tvds = 0;
258 
259 /*
260  * The parameters below are similar to zfs_max_missing_tvds but are only
261  * intended for a preliminary open of the pool with an untrusted config which
262  * might be incomplete or out-dated.
263  *
264  * We are more tolerant for pools opened from a cachefile since we could have
265  * an out-dated cachefile where a device removal was not registered.
266  * We could have set the limit arbitrarily high but in the case where devices
267  * are really missing we would want to return the proper error codes; we chose
268  * SPA_DVAS_PER_BP - 1 so that some copies of the MOS would still be available
269  * and we get a chance to retrieve the trusted config.
270  */
271 uint64_t	zfs_max_missing_tvds_cachefile = SPA_DVAS_PER_BP - 1;
272 
273 /*
274  * In the case where config was assembled by scanning device paths (/dev/dsks
275  * by default) we are less tolerant since all the existing devices should have
276  * been detected and we want spa_load to return the right error codes.
277  */
278 uint64_t	zfs_max_missing_tvds_scan = 0;
279 
280 /*
281  * Debugging aid that pauses spa_sync() towards the end.
282  */
283 static const boolean_t	zfs_pause_spa_sync = B_FALSE;
284 
285 /*
286  * Variables to indicate the livelist condense zthr func should wait at certain
287  * points for the livelist to be removed - used to test condense/destroy races
288  */
289 static int zfs_livelist_condense_zthr_pause = 0;
290 static int zfs_livelist_condense_sync_pause = 0;
291 
292 /*
293  * Variables to track whether or not condense cancellation has been
294  * triggered in testing.
295  */
296 static int zfs_livelist_condense_sync_cancel = 0;
297 static int zfs_livelist_condense_zthr_cancel = 0;
298 
299 /*
300  * Variable to track whether or not extra ALLOC blkptrs were added to a
301  * livelist entry while it was being condensed (caused by the way we track
302  * remapped blkptrs in dbuf_remap_impl)
303  */
304 static int zfs_livelist_condense_new_alloc = 0;
305 
306 /*
307  * Time variable to decide how often the txg should be added into the
308  * database (in seconds).
309  * The smallest available resolution is in minutes, which means an update occurs
310  * each time we reach `spa_note_txg_time` and the txg has changed. We provide
311  * a 256-slot ring buffer for minute-level resolution. The number is limited by
312  * the size of the structure we use and the maximum amount of bytes we can write
313  * into ZAP. Setting `spa_note_txg_time` to 10 minutes results in approximately
314  * 144 records per day. Given the 256 slots, this provides roughly 1.5 days of
315  * high-resolution data.
316  *
317  * The user can decrease `spa_note_txg_time` to increase resolution within
318  * a day, at the cost of retaining fewer days of data. Alternatively, increasing
319  * the interval allows storing data over a longer period, but with lower
320  * frequency.
321  *
322  * This parameter does not affect the daily or monthly databases, as those only
323  * store one record per day and per month, respectively.
324  */
325 static uint_t spa_note_txg_time = 10 * 60;
326 
327 /*
328  * How often flush txg database to a disk (in seconds).
329  * We flush data every time we write to it, making it the most reliable option.
330  * Since this happens every 10 minutes, it shouldn't introduce any noticeable
331  * overhead for the system. In case of failure, we will always have an
332  * up-to-date version of the database.
333  *
334  * The user can adjust the flush interval to a lower value, but it probably
335  * doesn't make sense to flush more often than the database is updated.
336  * The user can also increase the interval if they're concerned about the
337  * performance of writing the entire database to disk.
338  */
339 static uint_t spa_flush_txg_time = 10 * 60;
340 
341 /*
342  * ==========================================================================
343  * SPA properties routines
344  * ==========================================================================
345  */
346 
347 /*
348  * Add a (source=src, propname=propval) list to an nvlist.
349  */
350 static void
351 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, const char *strval,
352     uint64_t intval, zprop_source_t src)
353 {
354 	const char *propname = zpool_prop_to_name(prop);
355 	nvlist_t *propval;
356 
357 	propval = fnvlist_alloc();
358 	fnvlist_add_uint64(propval, ZPROP_SOURCE, src);
359 
360 	if (strval != NULL)
361 		fnvlist_add_string(propval, ZPROP_VALUE, strval);
362 	else
363 		fnvlist_add_uint64(propval, ZPROP_VALUE, intval);
364 
365 	fnvlist_add_nvlist(nvl, propname, propval);
366 	nvlist_free(propval);
367 }
368 
369 static int
370 spa_prop_add(spa_t *spa, const char *propname, nvlist_t *outnvl)
371 {
372 	zpool_prop_t prop = zpool_name_to_prop(propname);
373 	zprop_source_t src = ZPROP_SRC_NONE;
374 	uint64_t intval;
375 	int err;
376 
377 	/*
378 	 * NB: Not all properties lookups via this API require
379 	 * the spa props lock, so they must explicitly grab it here.
380 	 */
381 	switch (prop) {
382 	case ZPOOL_PROP_DEDUPCACHED:
383 		err = ddt_get_pool_dedup_cached(spa, &intval);
384 		if (err != 0)
385 			return (SET_ERROR(err));
386 		break;
387 	default:
388 		return (SET_ERROR(EINVAL));
389 	}
390 
391 	spa_prop_add_list(outnvl, prop, NULL, intval, src);
392 
393 	return (0);
394 }
395 
396 int
397 spa_prop_get_nvlist(spa_t *spa, char **props, unsigned int n_props,
398     nvlist_t *outnvl)
399 {
400 	int err = 0;
401 
402 	if (props == NULL)
403 		return (0);
404 
405 	for (unsigned int i = 0; i < n_props && err == 0; i++) {
406 		err = spa_prop_add(spa, props[i], outnvl);
407 	}
408 
409 	return (err);
410 }
411 
412 /*
413  * Add metaslab class properties to an nvlist.
414  */
415 static void
416 spa_prop_add_metaslab_class(nvlist_t *nv, metaslab_class_t *mc,
417     zpool_mc_props_t mcp, uint64_t *sizep, uint64_t *allocp, uint64_t *usablep,
418     uint64_t *usedp)
419 {
420 	uint64_t size = metaslab_class_get_space(mc);
421 	uint64_t alloc = metaslab_class_get_alloc(mc);
422 	uint64_t dsize = metaslab_class_get_dspace(mc);
423 	uint64_t dalloc = metaslab_class_get_dalloc(mc);
424 	uint64_t cap = (size == 0) ? 0 : (alloc * 100 / size);
425 	const zprop_source_t src = ZPROP_SRC_NONE;
426 
427 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_SIZE, NULL, size, src);
428 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_ALLOCATED, NULL, alloc, src);
429 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_USABLE, NULL, dsize, src);
430 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_USED, NULL, dalloc, src);
431 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_FRAGMENTATION, NULL,
432 	    metaslab_class_fragmentation(mc), src);
433 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_EXPANDSZ, NULL,
434 	    metaslab_class_expandable_space(mc), src);
435 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_FREE, NULL, size - alloc,
436 	    src);
437 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_AVAILABLE, NULL,
438 	    dsize - dalloc, src);
439 	spa_prop_add_list(nv, mcp + ZPOOL_MC_PROP_CAPACITY, NULL, cap, src);
440 	if (sizep != NULL)
441 		*sizep += size;
442 	if (allocp != NULL)
443 		*allocp += alloc;
444 	if (usablep != NULL)
445 		*usablep += dsize;
446 	if (usedp != NULL)
447 		*usedp += dalloc;
448 }
449 
450 /*
451  * Add a user property (source=src, propname=propval) to an nvlist.
452  */
453 static void
454 spa_prop_add_user(nvlist_t *nvl, const char *propname, char *strval,
455     zprop_source_t src)
456 {
457 	nvlist_t *propval;
458 
459 	VERIFY0(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP));
460 	VERIFY0(nvlist_add_uint64(propval, ZPROP_SOURCE, src));
461 	VERIFY0(nvlist_add_string(propval, ZPROP_VALUE, strval));
462 	VERIFY0(nvlist_add_nvlist(nvl, propname, propval));
463 	nvlist_free(propval);
464 }
465 
466 /*
467  * Get property values from the spa configuration.
468  */
469 static void
470 spa_prop_get_config(spa_t *spa, nvlist_t *nv)
471 {
472 	vdev_t *rvd = spa->spa_root_vdev;
473 	dsl_pool_t *pool = spa->spa_dsl_pool;
474 	uint64_t size, alloc, usable, used, cap, version;
475 	const zprop_source_t src = ZPROP_SRC_NONE;
476 	spa_config_dirent_t *dp;
477 	metaslab_class_t *mc = spa_normal_class(spa);
478 
479 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
480 
481 	if (rvd != NULL) {
482 		spa_prop_add_list(nv, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
483 
484 		size = alloc = usable = used = 0;
485 		spa_prop_add_metaslab_class(nv, mc, ZPOOL_MC_PROPS_NORMAL,
486 		    &size, &alloc, &usable, &used);
487 		spa_prop_add_metaslab_class(nv, spa_special_class(spa),
488 		    ZPOOL_MC_PROPS_SPECIAL, &size, &alloc, &usable, &used);
489 		spa_prop_add_metaslab_class(nv, spa_dedup_class(spa),
490 		    ZPOOL_MC_PROPS_DEDUP, &size, &alloc, &usable, &used);
491 		spa_prop_add_metaslab_class(nv, spa_log_class(spa),
492 		    ZPOOL_MC_PROPS_LOG, NULL, NULL, NULL, NULL);
493 		spa_prop_add_metaslab_class(nv, spa_embedded_log_class(spa),
494 		    ZPOOL_MC_PROPS_ELOG, &size, &alloc, &usable, &used);
495 		spa_prop_add_metaslab_class(nv,
496 		    spa_special_embedded_log_class(spa), ZPOOL_MC_PROPS_SELOG,
497 		    &size, &alloc, &usable, &used);
498 
499 		spa_prop_add_list(nv, ZPOOL_PROP_SIZE, NULL, size, src);
500 		spa_prop_add_list(nv, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
501 		spa_prop_add_list(nv, ZPOOL_PROP_FREE, NULL,
502 		    size - alloc, src);
503 		spa_prop_add_list(nv, ZPOOL_PROP_FRAGMENTATION, NULL,
504 		    metaslab_class_fragmentation(mc), src);
505 		spa_prop_add_list(nv, ZPOOL_PROP_EXPANDSZ, NULL,
506 		    metaslab_class_expandable_space(mc), src);
507 		cap = (size == 0) ? 0 : (alloc * 100 / size);
508 		spa_prop_add_list(nv, ZPOOL_PROP_CAPACITY, NULL, cap, src);
509 		spa_prop_add_list(nv, ZPOOL_PROP_AVAILABLE, NULL, usable - used,
510 		    src);
511 		spa_prop_add_list(nv, ZPOOL_PROP_USABLE, NULL, usable, src);
512 		spa_prop_add_list(nv, ZPOOL_PROP_USED, NULL, used, src);
513 
514 		spa_prop_add_list(nv, ZPOOL_PROP_CHECKPOINT, NULL,
515 		    spa->spa_checkpoint_info.sci_dspace, src);
516 		spa_prop_add_list(nv, ZPOOL_PROP_READONLY, NULL,
517 		    (spa_mode(spa) == SPA_MODE_READ), src);
518 
519 		spa_prop_add_list(nv, ZPOOL_PROP_DEDUPRATIO, NULL,
520 		    ddt_get_pool_dedup_ratio(spa), src);
521 		spa_prop_add_list(nv, ZPOOL_PROP_DEDUPUSED, NULL,
522 		    ddt_get_dedup_used(spa), src);
523 		spa_prop_add_list(nv, ZPOOL_PROP_DEDUPSAVED, NULL,
524 		    ddt_get_dedup_saved(spa), src);
525 		spa_prop_add_list(nv, ZPOOL_PROP_BCLONEUSED, NULL,
526 		    brt_get_used(spa), src);
527 		spa_prop_add_list(nv, ZPOOL_PROP_BCLONESAVED, NULL,
528 		    brt_get_saved(spa), src);
529 		spa_prop_add_list(nv, ZPOOL_PROP_BCLONERATIO, NULL,
530 		    brt_get_ratio(spa), src);
531 
532 		spa_prop_add_list(nv, ZPOOL_PROP_DEDUP_TABLE_SIZE, NULL,
533 		    ddt_get_ddt_dsize(spa), src);
534 		spa_prop_add_list(nv, ZPOOL_PROP_HEALTH, NULL,
535 		    rvd->vdev_state, src);
536 		spa_prop_add_list(nv, ZPOOL_PROP_LAST_SCRUBBED_TXG, NULL,
537 		    spa_get_last_scrubbed_txg(spa), src);
538 
539 		version = spa_version(spa);
540 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION)) {
541 			spa_prop_add_list(nv, ZPOOL_PROP_VERSION, NULL,
542 			    version, ZPROP_SRC_DEFAULT);
543 		} else {
544 			spa_prop_add_list(nv, ZPOOL_PROP_VERSION, NULL,
545 			    version, ZPROP_SRC_LOCAL);
546 		}
547 		spa_prop_add_list(nv, ZPOOL_PROP_LOAD_GUID,
548 		    NULL, spa_load_guid(spa), src);
549 	}
550 
551 	if (pool != NULL) {
552 		/*
553 		 * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
554 		 * when opening pools before this version freedir will be NULL.
555 		 */
556 		if (pool->dp_free_dir != NULL) {
557 			spa_prop_add_list(nv, ZPOOL_PROP_FREEING, NULL,
558 			    dsl_dir_phys(pool->dp_free_dir)->dd_used_bytes,
559 			    src);
560 		} else {
561 			spa_prop_add_list(nv, ZPOOL_PROP_FREEING,
562 			    NULL, 0, src);
563 		}
564 
565 		if (pool->dp_leak_dir != NULL) {
566 			spa_prop_add_list(nv, ZPOOL_PROP_LEAKED, NULL,
567 			    dsl_dir_phys(pool->dp_leak_dir)->dd_used_bytes,
568 			    src);
569 		} else {
570 			spa_prop_add_list(nv, ZPOOL_PROP_LEAKED,
571 			    NULL, 0, src);
572 		}
573 	}
574 
575 	spa_prop_add_list(nv, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
576 
577 	if (spa->spa_comment != NULL) {
578 		spa_prop_add_list(nv, ZPOOL_PROP_COMMENT, spa->spa_comment,
579 		    0, ZPROP_SRC_LOCAL);
580 	}
581 
582 	if (spa->spa_compatibility != NULL) {
583 		spa_prop_add_list(nv, ZPOOL_PROP_COMPATIBILITY,
584 		    spa->spa_compatibility, 0, ZPROP_SRC_LOCAL);
585 	}
586 
587 	if (spa->spa_root != NULL)
588 		spa_prop_add_list(nv, ZPOOL_PROP_ALTROOT, spa->spa_root,
589 		    0, ZPROP_SRC_LOCAL);
590 
591 	if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_BLOCKS)) {
592 		spa_prop_add_list(nv, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
593 		    MIN(zfs_max_recordsize, SPA_MAXBLOCKSIZE), ZPROP_SRC_NONE);
594 	} else {
595 		spa_prop_add_list(nv, ZPOOL_PROP_MAXBLOCKSIZE, NULL,
596 		    SPA_OLD_MAXBLOCKSIZE, ZPROP_SRC_NONE);
597 	}
598 
599 	if (spa_feature_is_enabled(spa, SPA_FEATURE_LARGE_DNODE)) {
600 		spa_prop_add_list(nv, ZPOOL_PROP_MAXDNODESIZE, NULL,
601 		    DNODE_MAX_SIZE, ZPROP_SRC_NONE);
602 	} else {
603 		spa_prop_add_list(nv, ZPOOL_PROP_MAXDNODESIZE, NULL,
604 		    DNODE_MIN_SIZE, ZPROP_SRC_NONE);
605 	}
606 
607 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
608 		if (dp->scd_path == NULL) {
609 			spa_prop_add_list(nv, ZPOOL_PROP_CACHEFILE,
610 			    "none", 0, ZPROP_SRC_LOCAL);
611 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
612 			spa_prop_add_list(nv, ZPOOL_PROP_CACHEFILE,
613 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
614 		}
615 	}
616 }
617 
618 /*
619  * Get zpool property values.
620  */
621 int
622 spa_prop_get(spa_t *spa, nvlist_t *nv)
623 {
624 	objset_t *mos = spa->spa_meta_objset;
625 	zap_cursor_t zc;
626 	zap_attribute_t *za;
627 	dsl_pool_t *dp;
628 	int err = 0;
629 
630 	dp = spa_get_dsl(spa);
631 	dsl_pool_config_enter(dp, FTAG);
632 	za = zap_attribute_alloc();
633 	mutex_enter(&spa->spa_props_lock);
634 
635 	/*
636 	 * Get properties from the spa config.
637 	 */
638 	spa_prop_get_config(spa, nv);
639 
640 	/* If no pool property object, no more prop to get. */
641 	if (mos == NULL || spa->spa_pool_props_object == 0)
642 		goto out;
643 
644 	/*
645 	 * Get properties from the MOS pool property object.
646 	 */
647 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
648 	    (err = zap_cursor_retrieve(&zc, za)) == 0;
649 	    zap_cursor_advance(&zc)) {
650 		uint64_t intval = 0;
651 		char *strval = NULL;
652 		zprop_source_t src = ZPROP_SRC_DEFAULT;
653 		zpool_prop_t prop;
654 
655 		if ((prop = zpool_name_to_prop(za->za_name)) ==
656 		    ZPOOL_PROP_INVAL && !zfs_prop_user(za->za_name))
657 			continue;
658 
659 		switch (za->za_integer_length) {
660 		case 8:
661 			/* integer property */
662 			if (za->za_first_integer !=
663 			    zpool_prop_default_numeric(prop))
664 				src = ZPROP_SRC_LOCAL;
665 
666 			if (prop == ZPOOL_PROP_BOOTFS) {
667 				dsl_dataset_t *ds = NULL;
668 
669 				err = dsl_dataset_hold_obj(dp,
670 				    za->za_first_integer, FTAG, &ds);
671 				if (err != 0)
672 					break;
673 
674 				strval = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN,
675 				    KM_SLEEP);
676 				dsl_dataset_name(ds, strval);
677 				dsl_dataset_rele(ds, FTAG);
678 			} else {
679 				strval = NULL;
680 				intval = za->za_first_integer;
681 			}
682 
683 			spa_prop_add_list(nv, prop, strval, intval, src);
684 
685 			if (strval != NULL)
686 				kmem_free(strval, ZFS_MAX_DATASET_NAME_LEN);
687 
688 			break;
689 
690 		case 1:
691 			/* string property */
692 			strval = kmem_alloc(za->za_num_integers, KM_SLEEP);
693 			err = zap_lookup(mos, spa->spa_pool_props_object,
694 			    za->za_name, 1, za->za_num_integers, strval);
695 			if (err) {
696 				kmem_free(strval, za->za_num_integers);
697 				break;
698 			}
699 			if (prop != ZPOOL_PROP_INVAL) {
700 				spa_prop_add_list(nv, prop, strval, 0, src);
701 			} else {
702 				src = ZPROP_SRC_LOCAL;
703 				spa_prop_add_user(nv, za->za_name, strval,
704 				    src);
705 			}
706 			kmem_free(strval, za->za_num_integers);
707 			break;
708 
709 		default:
710 			break;
711 		}
712 	}
713 	zap_cursor_fini(&zc);
714 out:
715 	mutex_exit(&spa->spa_props_lock);
716 	dsl_pool_config_exit(dp, FTAG);
717 	zap_attribute_free(za);
718 
719 	if (err && err != ENOENT)
720 		return (err);
721 
722 	return (0);
723 }
724 
725 /*
726  * Validate the given pool properties nvlist and modify the list
727  * for the property values to be set.
728  */
729 static int
730 spa_prop_validate(spa_t *spa, nvlist_t *props)
731 {
732 	nvpair_t *elem;
733 	int error = 0, reset_bootfs = 0;
734 	uint64_t objnum = 0;
735 	boolean_t has_feature = B_FALSE;
736 
737 	elem = NULL;
738 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
739 		uint64_t intval;
740 		const char *strval, *slash, *check, *fname;
741 		const char *propname = nvpair_name(elem);
742 		zpool_prop_t prop = zpool_name_to_prop(propname);
743 
744 		switch (prop) {
745 		case ZPOOL_PROP_INVAL:
746 			/*
747 			 * Sanitize the input.
748 			 */
749 			if (zfs_prop_user(propname)) {
750 				if (strlen(propname) >= ZAP_MAXNAMELEN) {
751 					error = SET_ERROR(ENAMETOOLONG);
752 					break;
753 				}
754 
755 				if (strlen(fnvpair_value_string(elem)) >=
756 				    ZAP_MAXVALUELEN) {
757 					error = SET_ERROR(E2BIG);
758 					break;
759 				}
760 			} else if (zpool_prop_feature(propname)) {
761 				if (nvpair_type(elem) != DATA_TYPE_UINT64) {
762 					error = SET_ERROR(EINVAL);
763 					break;
764 				}
765 
766 				if (nvpair_value_uint64(elem, &intval) != 0) {
767 					error = SET_ERROR(EINVAL);
768 					break;
769 				}
770 
771 				if (intval != 0) {
772 					error = SET_ERROR(EINVAL);
773 					break;
774 				}
775 
776 				fname = strchr(propname, '@') + 1;
777 				if (zfeature_lookup_name(fname, NULL) != 0) {
778 					error = SET_ERROR(EINVAL);
779 					break;
780 				}
781 
782 				has_feature = B_TRUE;
783 			} else {
784 				error = SET_ERROR(EINVAL);
785 				break;
786 			}
787 			break;
788 
789 		case ZPOOL_PROP_VERSION:
790 			error = nvpair_value_uint64(elem, &intval);
791 			if (!error &&
792 			    (intval < spa_version(spa) ||
793 			    intval > SPA_VERSION_BEFORE_FEATURES ||
794 			    has_feature))
795 				error = SET_ERROR(EINVAL);
796 			break;
797 
798 		case ZPOOL_PROP_DEDUP_TABLE_QUOTA:
799 			error = nvpair_value_uint64(elem, &intval);
800 			break;
801 
802 		case ZPOOL_PROP_DELEGATION:
803 		case ZPOOL_PROP_AUTOREPLACE:
804 		case ZPOOL_PROP_LISTSNAPS:
805 		case ZPOOL_PROP_AUTOEXPAND:
806 		case ZPOOL_PROP_AUTOTRIM:
807 			error = nvpair_value_uint64(elem, &intval);
808 			if (!error && intval > 1)
809 				error = SET_ERROR(EINVAL);
810 			break;
811 
812 		case ZPOOL_PROP_MULTIHOST:
813 			error = nvpair_value_uint64(elem, &intval);
814 			if (!error && intval > 1)
815 				error = SET_ERROR(EINVAL);
816 
817 			if (!error) {
818 				uint32_t hostid = zone_get_hostid(NULL);
819 				if (hostid)
820 					spa->spa_hostid = hostid;
821 				else
822 					error = SET_ERROR(ENOTSUP);
823 			}
824 
825 			break;
826 
827 		case ZPOOL_PROP_BOOTFS:
828 			/*
829 			 * If the pool version is less than SPA_VERSION_BOOTFS,
830 			 * or the pool is still being created (version == 0),
831 			 * the bootfs property cannot be set.
832 			 */
833 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
834 				error = SET_ERROR(ENOTSUP);
835 				break;
836 			}
837 
838 			/*
839 			 * Make sure the vdev config is bootable
840 			 */
841 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
842 				error = SET_ERROR(ENOTSUP);
843 				break;
844 			}
845 
846 			reset_bootfs = 1;
847 
848 			error = nvpair_value_string(elem, &strval);
849 
850 			if (!error) {
851 				objset_t *os;
852 
853 				if (strval == NULL || strval[0] == '\0') {
854 					objnum = zpool_prop_default_numeric(
855 					    ZPOOL_PROP_BOOTFS);
856 					break;
857 				}
858 
859 				error = dmu_objset_hold(strval, FTAG, &os);
860 				if (error != 0)
861 					break;
862 
863 				/* Must be ZPL. */
864 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
865 					error = SET_ERROR(ENOTSUP);
866 				} else {
867 					objnum = dmu_objset_id(os);
868 				}
869 				dmu_objset_rele(os, FTAG);
870 			}
871 			break;
872 
873 		case ZPOOL_PROP_FAILUREMODE:
874 			error = nvpair_value_uint64(elem, &intval);
875 			if (!error && intval > ZIO_FAILURE_MODE_PANIC)
876 				error = SET_ERROR(EINVAL);
877 
878 			/*
879 			 * This is a special case which only occurs when
880 			 * the pool has completely failed. This allows
881 			 * the user to change the in-core failmode property
882 			 * without syncing it out to disk (I/Os might
883 			 * currently be blocked). We do this by returning
884 			 * EIO to the caller (spa_prop_set) to trick it
885 			 * into thinking we encountered a property validation
886 			 * error.
887 			 */
888 			if (!error && spa_suspended(spa)) {
889 				spa->spa_failmode = intval;
890 				error = SET_ERROR(EIO);
891 			}
892 			break;
893 
894 		case ZPOOL_PROP_CACHEFILE:
895 			if ((error = nvpair_value_string(elem, &strval)) != 0)
896 				break;
897 
898 			if (strval[0] == '\0')
899 				break;
900 
901 			if (strcmp(strval, "none") == 0)
902 				break;
903 
904 			if (strval[0] != '/') {
905 				error = SET_ERROR(EINVAL);
906 				break;
907 			}
908 
909 			slash = strrchr(strval, '/');
910 			ASSERT(slash != NULL);
911 
912 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
913 			    strcmp(slash, "/..") == 0)
914 				error = SET_ERROR(EINVAL);
915 			break;
916 
917 		case ZPOOL_PROP_COMMENT:
918 			if ((error = nvpair_value_string(elem, &strval)) != 0)
919 				break;
920 			for (check = strval; *check != '\0'; check++) {
921 				if (!isprint(*check)) {
922 					error = SET_ERROR(EINVAL);
923 					break;
924 				}
925 			}
926 			if (strlen(strval) > ZPROP_MAX_COMMENT)
927 				error = SET_ERROR(E2BIG);
928 			break;
929 
930 		default:
931 			break;
932 		}
933 
934 		if (error)
935 			break;
936 	}
937 
938 	(void) nvlist_remove_all(props,
939 	    zpool_prop_to_name(ZPOOL_PROP_DEDUPDITTO));
940 
941 	if (!error && reset_bootfs) {
942 		error = nvlist_remove(props,
943 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
944 
945 		if (!error) {
946 			error = nvlist_add_uint64(props,
947 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
948 		}
949 	}
950 
951 	return (error);
952 }
953 
954 void
955 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
956 {
957 	const char *cachefile;
958 	spa_config_dirent_t *dp;
959 
960 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
961 	    &cachefile) != 0)
962 		return;
963 
964 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
965 	    KM_SLEEP);
966 
967 	if (cachefile[0] == '\0')
968 		dp->scd_path = spa_strdup(spa_config_path);
969 	else if (strcmp(cachefile, "none") == 0)
970 		dp->scd_path = NULL;
971 	else
972 		dp->scd_path = spa_strdup(cachefile);
973 
974 	list_insert_head(&spa->spa_config_list, dp);
975 	if (need_sync)
976 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
977 }
978 
979 int
980 spa_prop_set(spa_t *spa, nvlist_t *nvp)
981 {
982 	int error;
983 	nvpair_t *elem = NULL;
984 	boolean_t need_sync = B_FALSE;
985 
986 	if ((error = spa_prop_validate(spa, nvp)) != 0)
987 		return (error);
988 
989 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
990 		zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
991 
992 		if (prop == ZPOOL_PROP_CACHEFILE ||
993 		    prop == ZPOOL_PROP_ALTROOT ||
994 		    prop == ZPOOL_PROP_READONLY)
995 			continue;
996 
997 		if (prop == ZPOOL_PROP_INVAL &&
998 		    zfs_prop_user(nvpair_name(elem))) {
999 			need_sync = B_TRUE;
1000 			break;
1001 		}
1002 
1003 		if (prop == ZPOOL_PROP_VERSION || prop == ZPOOL_PROP_INVAL) {
1004 			uint64_t ver = 0;
1005 
1006 			if (prop == ZPOOL_PROP_VERSION) {
1007 				VERIFY0(nvpair_value_uint64(elem, &ver));
1008 			} else {
1009 				ASSERT(zpool_prop_feature(nvpair_name(elem)));
1010 				ver = SPA_VERSION_FEATURES;
1011 				need_sync = B_TRUE;
1012 			}
1013 
1014 			/* Save time if the version is already set. */
1015 			if (ver == spa_version(spa))
1016 				continue;
1017 
1018 			/*
1019 			 * In addition to the pool directory object, we might
1020 			 * create the pool properties object, the features for
1021 			 * read object, the features for write object, or the
1022 			 * feature descriptions object.
1023 			 */
1024 			error = dsl_sync_task(spa->spa_name, NULL,
1025 			    spa_sync_version, &ver,
1026 			    6, ZFS_SPACE_CHECK_RESERVED);
1027 			if (error)
1028 				return (error);
1029 			continue;
1030 		}
1031 
1032 		need_sync = B_TRUE;
1033 		break;
1034 	}
1035 
1036 	if (need_sync) {
1037 		return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
1038 		    nvp, 6, ZFS_SPACE_CHECK_RESERVED));
1039 	}
1040 
1041 	return (0);
1042 }
1043 
1044 /*
1045  * If the bootfs property value is dsobj, clear it.
1046  */
1047 void
1048 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
1049 {
1050 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
1051 		VERIFY(zap_remove(spa->spa_meta_objset,
1052 		    spa->spa_pool_props_object,
1053 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
1054 		spa->spa_bootfs = 0;
1055 	}
1056 }
1057 
1058 static int
1059 spa_change_guid_check(void *arg, dmu_tx_t *tx)
1060 {
1061 	uint64_t *newguid __maybe_unused = arg;
1062 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1063 	vdev_t *rvd = spa->spa_root_vdev;
1064 	uint64_t vdev_state;
1065 
1066 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
1067 		int error = (spa_has_checkpoint(spa)) ?
1068 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
1069 		return (SET_ERROR(error));
1070 	}
1071 
1072 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1073 	vdev_state = rvd->vdev_state;
1074 	spa_config_exit(spa, SCL_STATE, FTAG);
1075 
1076 	if (vdev_state != VDEV_STATE_HEALTHY)
1077 		return (SET_ERROR(ENXIO));
1078 
1079 	ASSERT3U(spa_guid(spa), !=, *newguid);
1080 
1081 	return (0);
1082 }
1083 
1084 static void
1085 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
1086 {
1087 	uint64_t *newguid = arg;
1088 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1089 	uint64_t oldguid;
1090 	vdev_t *rvd = spa->spa_root_vdev;
1091 
1092 	oldguid = spa_guid(spa);
1093 
1094 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1095 	rvd->vdev_guid = *newguid;
1096 	rvd->vdev_guid_sum += (*newguid - oldguid);
1097 	vdev_config_dirty(rvd);
1098 	spa_config_exit(spa, SCL_STATE, FTAG);
1099 
1100 	spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
1101 	    (u_longlong_t)oldguid, (u_longlong_t)*newguid);
1102 }
1103 
1104 /*
1105  * Change the GUID for the pool.  This is done so that we can later
1106  * re-import a pool built from a clone of our own vdevs.  We will modify
1107  * the root vdev's guid, our own pool guid, and then mark all of our
1108  * vdevs dirty.  Note that we must make sure that all our vdevs are
1109  * online when we do this, or else any vdevs that weren't present
1110  * would be orphaned from our pool.  We are also going to issue a
1111  * sysevent to update any watchers.
1112  *
1113  * The GUID of the pool will be changed to the value pointed to by guidp.
1114  * The GUID may not be set to the reserverd value of 0.
1115  * The new GUID will be generated if guidp is NULL.
1116  */
1117 int
1118 spa_change_guid(spa_t *spa, const uint64_t *guidp)
1119 {
1120 	uint64_t guid;
1121 	int error;
1122 
1123 	mutex_enter(&spa->spa_vdev_top_lock);
1124 	spa_namespace_enter(FTAG);
1125 
1126 	if (guidp != NULL) {
1127 		guid = *guidp;
1128 		if (guid == 0) {
1129 			error = SET_ERROR(EINVAL);
1130 			goto out;
1131 		}
1132 
1133 		if (spa_guid_exists(guid, 0)) {
1134 			error = SET_ERROR(EEXIST);
1135 			goto out;
1136 		}
1137 	} else {
1138 		guid = spa_generate_guid(NULL);
1139 	}
1140 
1141 	error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
1142 	    spa_change_guid_sync, &guid, 5, ZFS_SPACE_CHECK_RESERVED);
1143 
1144 	if (error == 0) {
1145 		/*
1146 		 * Clear the kobj flag from all the vdevs to allow
1147 		 * vdev_cache_process_kobj_evt() to post events to all the
1148 		 * vdevs since GUID is updated.
1149 		 */
1150 		vdev_clear_kobj_evt(spa->spa_root_vdev);
1151 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
1152 			vdev_clear_kobj_evt(spa->spa_l2cache.sav_vdevs[i]);
1153 
1154 		spa_write_cachefile(spa, B_FALSE, B_TRUE, B_TRUE);
1155 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_REGUID);
1156 	}
1157 
1158 out:
1159 	spa_namespace_exit(FTAG);
1160 	mutex_exit(&spa->spa_vdev_top_lock);
1161 
1162 	return (error);
1163 }
1164 
1165 /*
1166  * ==========================================================================
1167  * SPA state manipulation (open/create/destroy/import/export)
1168  * ==========================================================================
1169  */
1170 
1171 static int
1172 spa_error_entry_compare(const void *a, const void *b)
1173 {
1174 	const spa_error_entry_t *sa = (const spa_error_entry_t *)a;
1175 	const spa_error_entry_t *sb = (const spa_error_entry_t *)b;
1176 	int ret;
1177 
1178 	ret = memcmp(&sa->se_bookmark, &sb->se_bookmark,
1179 	    sizeof (zbookmark_phys_t));
1180 
1181 	return (TREE_ISIGN(ret));
1182 }
1183 
1184 /*
1185  * Utility function which retrieves copies of the current logs and
1186  * re-initializes them in the process.
1187  */
1188 void
1189 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
1190 {
1191 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
1192 
1193 	memcpy(last, &spa->spa_errlist_last, sizeof (avl_tree_t));
1194 	memcpy(scrub, &spa->spa_errlist_scrub, sizeof (avl_tree_t));
1195 
1196 	avl_create(&spa->spa_errlist_scrub,
1197 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1198 	    offsetof(spa_error_entry_t, se_avl));
1199 	avl_create(&spa->spa_errlist_last,
1200 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1201 	    offsetof(spa_error_entry_t, se_avl));
1202 }
1203 
1204 static void
1205 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
1206 {
1207 	const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
1208 	enum zti_modes mode = ztip->zti_mode;
1209 	uint_t value = ztip->zti_value;
1210 	uint_t count = ztip->zti_count;
1211 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1212 	uint_t cpus, threads, flags = TASKQ_DYNAMIC;
1213 
1214 	switch (mode) {
1215 	case ZTI_MODE_FIXED:
1216 		ASSERT3U(value, >, 0);
1217 		break;
1218 
1219 	case ZTI_MODE_SYNC:
1220 
1221 		/*
1222 		 * Create one wr_iss taskq for every 'zio_taskq_write_tpq' CPUs,
1223 		 * not to exceed the number of spa allocators, and align to it.
1224 		 */
1225 		threads = MAX(1, boot_ncpus * zio_taskq_batch_pct / 100);
1226 		count = MAX(1, threads / MAX(1, zio_taskq_write_tpq));
1227 		count = MAX(count, (zio_taskq_batch_pct + 99) / 100);
1228 		count = MIN(count, spa->spa_alloc_count);
1229 		while (spa->spa_alloc_count % count != 0 &&
1230 		    spa->spa_alloc_count < count * 2)
1231 			count--;
1232 
1233 		/*
1234 		 * zio_taskq_batch_pct is unbounded and may exceed 100%, but no
1235 		 * single taskq may have more threads than 100% of online cpus.
1236 		 */
1237 		value = (zio_taskq_batch_pct + count / 2) / count;
1238 		value = MIN(value, 100);
1239 		flags |= TASKQ_THREADS_CPU_PCT;
1240 		break;
1241 
1242 	case ZTI_MODE_SCALE:
1243 		/*
1244 		 * We want more taskqs to reduce lock contention, but we want
1245 		 * less for better request ordering and CPU utilization.
1246 		 */
1247 		threads = MAX(1, boot_ncpus * zio_taskq_batch_pct / 100);
1248 		threads = MAX(threads, value);
1249 		if (zio_taskq_batch_tpq > 0) {
1250 			count = MAX(1, (threads + zio_taskq_batch_tpq / 2) /
1251 			    zio_taskq_batch_tpq);
1252 		} else {
1253 			/*
1254 			 * Prefer 6 threads per taskq, but no more taskqs
1255 			 * than threads in them on large systems. For 80%:
1256 			 *
1257 			 *                 taskq   taskq   total
1258 			 * cpus    taskqs  percent threads threads
1259 			 * ------- ------- ------- ------- -------
1260 			 * 1       1       80%     1       1
1261 			 * 2       1       80%     1       1
1262 			 * 4       1       80%     3       3
1263 			 * 8       2       40%     3       6
1264 			 * 16      3       27%     4       12
1265 			 * 32      5       16%     5       25
1266 			 * 64      7       11%     7       49
1267 			 * 128     10      8%      10      100
1268 			 * 256     14      6%      15      210
1269 			 */
1270 			cpus = MIN(threads, boot_ncpus);
1271 			count = 1 + threads / 6;
1272 			while (count * count > cpus)
1273 				count--;
1274 		}
1275 
1276 		/*
1277 		 * Try to represent the number of threads per taskq as percent
1278 		 * of online CPUs to allow scaling with later online/offline.
1279 		 * Fall back to absolute numbers if can't.
1280 		 */
1281 		value = (threads * 100 + boot_ncpus * count / 2) /
1282 		    (boot_ncpus * count);
1283 		if (value < 5 || value > 100)
1284 			value = MAX(1, (threads + count / 2) / count);
1285 		else
1286 			flags |= TASKQ_THREADS_CPU_PCT;
1287 		break;
1288 
1289 	case ZTI_MODE_NULL:
1290 		tqs->stqs_count = 0;
1291 		tqs->stqs_taskq = NULL;
1292 		return;
1293 
1294 	default:
1295 		panic("unrecognized mode for %s_%s taskq (%u:%u) in "
1296 		    "spa_taskqs_init()",
1297 		    zio_type_name[t], zio_taskq_types[q], mode, value);
1298 		break;
1299 	}
1300 
1301 	ASSERT3U(count, >, 0);
1302 	tqs->stqs_count = count;
1303 	tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
1304 
1305 	for (uint_t i = 0; i < count; i++) {
1306 		taskq_t *tq;
1307 		char name[32];
1308 
1309 		if (count > 1)
1310 			(void) snprintf(name, sizeof (name), "%s_%s_%u",
1311 			    zio_type_name[t], zio_taskq_types[q], i);
1312 		else
1313 			(void) snprintf(name, sizeof (name), "%s_%s",
1314 			    zio_type_name[t], zio_taskq_types[q]);
1315 
1316 #ifdef HAVE_SYSDC
1317 		if (zio_taskq_sysdc && spa->spa_proc != &p0) {
1318 			(void) zio_taskq_basedc;
1319 			tq = taskq_create_sysdc(name, value, 50, INT_MAX,
1320 			    spa->spa_proc, zio_taskq_basedc, flags);
1321 		} else {
1322 #endif
1323 			/*
1324 			 * The write issue taskq can be extremely CPU
1325 			 * intensive.  Run it at slightly less important
1326 			 * priority than the other taskqs.
1327 			 */
1328 			const pri_t pri = (t == ZIO_TYPE_WRITE &&
1329 			    q == ZIO_TASKQ_ISSUE) ?
1330 			    wtqclsyspri : maxclsyspri;
1331 			tq = taskq_create_proc(name, value, pri, 50,
1332 			    INT_MAX, spa->spa_proc, flags);
1333 #ifdef HAVE_SYSDC
1334 		}
1335 #endif
1336 
1337 		tqs->stqs_taskq[i] = tq;
1338 	}
1339 }
1340 
1341 static void
1342 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
1343 {
1344 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1345 
1346 	if (tqs->stqs_taskq == NULL) {
1347 		ASSERT0(tqs->stqs_count);
1348 		return;
1349 	}
1350 
1351 	for (uint_t i = 0; i < tqs->stqs_count; i++) {
1352 		ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
1353 		taskq_destroy(tqs->stqs_taskq[i]);
1354 	}
1355 
1356 	kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
1357 	tqs->stqs_taskq = NULL;
1358 }
1359 
1360 #ifdef _KERNEL
1361 /*
1362  * The READ and WRITE rows of zio_taskqs are configurable at module load time
1363  * by setting zio_taskq_read or zio_taskq_write.
1364  *
1365  * Example (the defaults for READ and WRITE)
1366  *   zio_taskq_read='fixed,1,8 null scale null'
1367  *   zio_taskq_write='sync null scale null'
1368  *
1369  * Each sets the entire row at a time.
1370  *
1371  * 'fixed' is parameterised: fixed,Q,T where Q is number of taskqs, T is number
1372  * of threads per taskq.
1373  *
1374  * 'null' can only be set on the high-priority queues (queue selection for
1375  * high-priority queues will fall back to the regular queue if the high-pri
1376  * is NULL.
1377  */
1378 static const char *const modes[ZTI_NMODES] = {
1379 	"fixed", "scale", "sync", "null"
1380 };
1381 
1382 /* Parse the incoming config string. Modifies cfg */
1383 static int
1384 spa_taskq_param_set(zio_type_t t, char *cfg)
1385 {
1386 	int err = 0;
1387 
1388 	zio_taskq_info_t row[ZIO_TASKQ_TYPES] = {{0}};
1389 
1390 	char *next = cfg, *tok, *c;
1391 
1392 	/*
1393 	 * Parse out each element from the string and fill `row`. The entire
1394 	 * row has to be set at once, so any errors are flagged by just
1395 	 * breaking out of this loop early.
1396 	 */
1397 	uint_t q;
1398 	for (q = 0; q < ZIO_TASKQ_TYPES; q++) {
1399 		/* `next` is the start of the config */
1400 		if (next == NULL)
1401 			break;
1402 
1403 		/* Eat up leading space */
1404 		while (isspace(*next))
1405 			next++;
1406 		if (*next == '\0')
1407 			break;
1408 
1409 		/* Mode ends at space or end of string */
1410 		tok = next;
1411 		next = strchr(tok, ' ');
1412 		if (next != NULL) *next++ = '\0';
1413 
1414 		/* Parameters start after a comma */
1415 		c = strchr(tok, ',');
1416 		if (c != NULL) *c++ = '\0';
1417 
1418 		/* Match mode string */
1419 		uint_t mode;
1420 		for (mode = 0; mode < ZTI_NMODES; mode++)
1421 			if (strcmp(tok, modes[mode]) == 0)
1422 				break;
1423 		if (mode == ZTI_NMODES)
1424 			break;
1425 
1426 		/* Invalid canary */
1427 		row[q].zti_mode = ZTI_NMODES;
1428 
1429 		/* Per-mode setup */
1430 		switch (mode) {
1431 
1432 		/*
1433 		 * FIXED is parameterised: number of queues, and number of
1434 		 * threads per queue.
1435 		 */
1436 		case ZTI_MODE_FIXED: {
1437 			/* No parameters? */
1438 			if (c == NULL || *c == '\0')
1439 				break;
1440 
1441 			/* Find next parameter */
1442 			tok = c;
1443 			c = strchr(tok, ',');
1444 			if (c == NULL)
1445 				break;
1446 
1447 			/* Take digits and convert */
1448 			unsigned long long nq;
1449 			if (!(isdigit(*tok)))
1450 				break;
1451 			err = ddi_strtoull(tok, &tok, 10, &nq);
1452 			/* Must succeed and also end at the next param sep */
1453 			if (err != 0 || tok != c)
1454 				break;
1455 
1456 			/* Move past the comma */
1457 			tok++;
1458 			/* Need another number */
1459 			if (!(isdigit(*tok)))
1460 				break;
1461 			/* Remember start to make sure we moved */
1462 			c = tok;
1463 
1464 			/* Take digits */
1465 			unsigned long long ntpq;
1466 			err = ddi_strtoull(tok, &tok, 10, &ntpq);
1467 			/* Must succeed, and moved forward */
1468 			if (err != 0 || tok == c || *tok != '\0')
1469 				break;
1470 
1471 			/*
1472 			 * sanity; zero queues/threads make no sense, and
1473 			 * 16K is almost certainly more than anyone will ever
1474 			 * need and avoids silly numbers like UINT32_MAX
1475 			 */
1476 			if (nq == 0 || nq >= 16384 ||
1477 			    ntpq == 0 || ntpq >= 16384)
1478 				break;
1479 
1480 			const zio_taskq_info_t zti = ZTI_P(ntpq, nq);
1481 			row[q] = zti;
1482 			break;
1483 		}
1484 
1485 		/*
1486 		 * SCALE is optionally parameterised by minimum number of
1487 		 * threads.
1488 		 */
1489 		case ZTI_MODE_SCALE: {
1490 			unsigned long long mint = 0;
1491 			if (c != NULL && *c != '\0') {
1492 				/* Need a number */
1493 				if (!(isdigit(*c)))
1494 					break;
1495 				tok = c;
1496 
1497 				/* Take digits */
1498 				err = ddi_strtoull(tok, &tok, 10, &mint);
1499 				/* Must succeed, and moved forward */
1500 				if (err != 0 || tok == c || *tok != '\0')
1501 					break;
1502 
1503 				/* Sanity check */
1504 				if (mint >= 16384)
1505 					break;
1506 			}
1507 
1508 			const zio_taskq_info_t zti = ZTI_SCALE(mint);
1509 			row[q] = zti;
1510 			break;
1511 		}
1512 
1513 		case ZTI_MODE_SYNC: {
1514 			const zio_taskq_info_t zti = ZTI_SYNC;
1515 			row[q] = zti;
1516 			break;
1517 		}
1518 
1519 		case ZTI_MODE_NULL: {
1520 			/*
1521 			 * Can only null the high-priority queues; the general-
1522 			 * purpose ones have to exist.
1523 			 */
1524 			if (q != ZIO_TASKQ_ISSUE_HIGH &&
1525 			    q != ZIO_TASKQ_INTERRUPT_HIGH)
1526 				break;
1527 
1528 			const zio_taskq_info_t zti = ZTI_NULL;
1529 			row[q] = zti;
1530 			break;
1531 		}
1532 
1533 		default:
1534 			break;
1535 		}
1536 
1537 		/* Ensure we set a mode */
1538 		if (row[q].zti_mode == ZTI_NMODES)
1539 			break;
1540 	}
1541 
1542 	/* Didn't get a full row, fail */
1543 	if (q < ZIO_TASKQ_TYPES)
1544 		return (SET_ERROR(EINVAL));
1545 
1546 	/* Eat trailing space */
1547 	if (next != NULL)
1548 		while (isspace(*next))
1549 			next++;
1550 
1551 	/* If there's anything left over then fail */
1552 	if (next != NULL && *next != '\0')
1553 		return (SET_ERROR(EINVAL));
1554 
1555 	/* Success! Copy it into the real config */
1556 	for (q = 0; q < ZIO_TASKQ_TYPES; q++)
1557 		zio_taskqs[t][q] = row[q];
1558 
1559 	return (0);
1560 }
1561 
1562 static int
1563 spa_taskq_param_get(zio_type_t t, char *buf, boolean_t add_newline)
1564 {
1565 	int pos = 0;
1566 
1567 	/* Build paramater string from live config */
1568 	const char *sep = "";
1569 	for (uint_t q = 0; q < ZIO_TASKQ_TYPES; q++) {
1570 		const zio_taskq_info_t *zti = &zio_taskqs[t][q];
1571 		if (zti->zti_mode == ZTI_MODE_FIXED)
1572 			pos += sprintf(&buf[pos], "%s%s,%u,%u", sep,
1573 			    modes[zti->zti_mode], zti->zti_count,
1574 			    zti->zti_value);
1575 		else if (zti->zti_mode == ZTI_MODE_SCALE && zti->zti_value > 0)
1576 			pos += sprintf(&buf[pos], "%s%s,%u", sep,
1577 			    modes[zti->zti_mode], zti->zti_value);
1578 		else
1579 			pos += sprintf(&buf[pos], "%s%s", sep,
1580 			    modes[zti->zti_mode]);
1581 		sep = " ";
1582 	}
1583 
1584 	if (add_newline)
1585 		buf[pos++] = '\n';
1586 	buf[pos] = '\0';
1587 
1588 	return (pos);
1589 }
1590 
1591 #ifdef __linux__
1592 static int
1593 spa_taskq_read_param_set(const char *val, zfs_kernel_param_t *kp)
1594 {
1595 	char *cfg = kmem_strdup(val);
1596 	int err = spa_taskq_param_set(ZIO_TYPE_READ, cfg);
1597 	kmem_strfree(cfg);
1598 	return (-err);
1599 }
1600 
1601 static int
1602 spa_taskq_read_param_get(char *buf, zfs_kernel_param_t *kp)
1603 {
1604 	return (spa_taskq_param_get(ZIO_TYPE_READ, buf, TRUE));
1605 }
1606 
1607 static int
1608 spa_taskq_write_param_set(const char *val, zfs_kernel_param_t *kp)
1609 {
1610 	char *cfg = kmem_strdup(val);
1611 	int err = spa_taskq_param_set(ZIO_TYPE_WRITE, cfg);
1612 	kmem_strfree(cfg);
1613 	return (-err);
1614 }
1615 
1616 static int
1617 spa_taskq_write_param_get(char *buf, zfs_kernel_param_t *kp)
1618 {
1619 	return (spa_taskq_param_get(ZIO_TYPE_WRITE, buf, TRUE));
1620 }
1621 
1622 static int
1623 spa_taskq_free_param_set(const char *val, zfs_kernel_param_t *kp)
1624 {
1625 	char *cfg = kmem_strdup(val);
1626 	int err = spa_taskq_param_set(ZIO_TYPE_FREE, cfg);
1627 	kmem_strfree(cfg);
1628 	return (-err);
1629 }
1630 
1631 static int
1632 spa_taskq_free_param_get(char *buf, zfs_kernel_param_t *kp)
1633 {
1634 	return (spa_taskq_param_get(ZIO_TYPE_FREE, buf, TRUE));
1635 }
1636 #else
1637 /*
1638  * On FreeBSD load-time parameters can be set up before malloc() is available,
1639  * so we have to do all the parsing work on the stack.
1640  */
1641 #define	SPA_TASKQ_PARAM_MAX	(128)
1642 
1643 static int
1644 spa_taskq_read_param(ZFS_MODULE_PARAM_ARGS)
1645 {
1646 	char buf[SPA_TASKQ_PARAM_MAX];
1647 	int err;
1648 
1649 	(void) spa_taskq_param_get(ZIO_TYPE_READ, buf, FALSE);
1650 	err = sysctl_handle_string(oidp, buf, sizeof (buf), req);
1651 	if (err || req->newptr == NULL)
1652 		return (err);
1653 	return (spa_taskq_param_set(ZIO_TYPE_READ, buf));
1654 }
1655 
1656 static int
1657 spa_taskq_write_param(ZFS_MODULE_PARAM_ARGS)
1658 {
1659 	char buf[SPA_TASKQ_PARAM_MAX];
1660 	int err;
1661 
1662 	(void) spa_taskq_param_get(ZIO_TYPE_WRITE, buf, FALSE);
1663 	err = sysctl_handle_string(oidp, buf, sizeof (buf), req);
1664 	if (err || req->newptr == NULL)
1665 		return (err);
1666 	return (spa_taskq_param_set(ZIO_TYPE_WRITE, buf));
1667 }
1668 
1669 static int
1670 spa_taskq_free_param(ZFS_MODULE_PARAM_ARGS)
1671 {
1672 	char buf[SPA_TASKQ_PARAM_MAX];
1673 	int err;
1674 
1675 	(void) spa_taskq_param_get(ZIO_TYPE_FREE, buf, FALSE);
1676 	err = sysctl_handle_string(oidp, buf, sizeof (buf), req);
1677 	if (err || req->newptr == NULL)
1678 		return (err);
1679 	return (spa_taskq_param_set(ZIO_TYPE_FREE, buf));
1680 }
1681 #endif
1682 #endif /* _KERNEL */
1683 
1684 /*
1685  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
1686  * Note that a type may have multiple discrete taskqs to avoid lock contention
1687  * on the taskq itself.
1688  */
1689 void
1690 spa_taskq_dispatch(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
1691     task_func_t *func, zio_t *zio, boolean_t cutinline)
1692 {
1693 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1694 	taskq_t *tq;
1695 
1696 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
1697 	ASSERT3U(tqs->stqs_count, !=, 0);
1698 
1699 	/*
1700 	 * NB: We are assuming that the zio can only be dispatched
1701 	 * to a single taskq at a time.  It would be a grievous error
1702 	 * to dispatch the zio to another taskq at the same time.
1703 	 */
1704 	ASSERT(zio);
1705 	ASSERT(taskq_empty_ent(&zio->io_tqent));
1706 
1707 	if (tqs->stqs_count == 1) {
1708 		tq = tqs->stqs_taskq[0];
1709 	} else if ((t == ZIO_TYPE_WRITE) && (q == ZIO_TASKQ_ISSUE) &&
1710 	    ZIO_HAS_ALLOCATOR(zio)) {
1711 		tq = tqs->stqs_taskq[zio->io_allocator % tqs->stqs_count];
1712 	} else {
1713 		tq = tqs->stqs_taskq[((uint64_t)gethrtime()) % tqs->stqs_count];
1714 	}
1715 
1716 	taskq_dispatch_ent(tq, func, zio, cutinline ? TQ_FRONT : 0,
1717 	    &zio->io_tqent);
1718 }
1719 
1720 static void
1721 spa_create_zio_taskqs(spa_t *spa)
1722 {
1723 	for (int t = 0; t < ZIO_TYPES; t++) {
1724 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1725 			spa_taskqs_init(spa, t, q);
1726 		}
1727 	}
1728 }
1729 
1730 #if defined(_KERNEL) && defined(HAVE_SPA_THREAD)
1731 static void
1732 spa_thread(void *arg)
1733 {
1734 	psetid_t zio_taskq_psrset_bind = PS_NONE;
1735 	callb_cpr_t cprinfo;
1736 
1737 	spa_t *spa = arg;
1738 	user_t *pu = PTOU(curproc);
1739 
1740 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
1741 	    spa->spa_name);
1742 
1743 	ASSERT(curproc != &p0);
1744 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
1745 	    "zpool-%s", spa->spa_name);
1746 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
1747 
1748 	/* bind this thread to the requested psrset */
1749 	if (zio_taskq_psrset_bind != PS_NONE) {
1750 		pool_lock();
1751 		mutex_enter(&cpu_lock);
1752 		mutex_enter(&pidlock);
1753 		mutex_enter(&curproc->p_lock);
1754 
1755 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
1756 		    0, NULL, NULL) == 0)  {
1757 			curthread->t_bind_pset = zio_taskq_psrset_bind;
1758 		} else {
1759 			cmn_err(CE_WARN,
1760 			    "Couldn't bind process for zfs pool \"%s\" to "
1761 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
1762 		}
1763 
1764 		mutex_exit(&curproc->p_lock);
1765 		mutex_exit(&pidlock);
1766 		mutex_exit(&cpu_lock);
1767 		pool_unlock();
1768 	}
1769 
1770 #ifdef HAVE_SYSDC
1771 	if (zio_taskq_sysdc) {
1772 		sysdc_thread_enter(curthread, 100, 0);
1773 	}
1774 #endif
1775 
1776 	spa->spa_proc = curproc;
1777 	spa->spa_did = curthread->t_did;
1778 
1779 	spa_create_zio_taskqs(spa);
1780 
1781 	mutex_enter(&spa->spa_proc_lock);
1782 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1783 
1784 	spa->spa_proc_state = SPA_PROC_ACTIVE;
1785 	cv_broadcast(&spa->spa_proc_cv);
1786 
1787 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
1788 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1789 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1790 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1791 
1792 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1793 	spa->spa_proc_state = SPA_PROC_GONE;
1794 	spa->spa_proc = &p0;
1795 	cv_broadcast(&spa->spa_proc_cv);
1796 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
1797 
1798 	mutex_enter(&curproc->p_lock);
1799 	lwp_exit();
1800 }
1801 #endif
1802 
1803 extern metaslab_ops_t *metaslab_allocator(spa_t *spa);
1804 
1805 /*
1806  * Activate an uninitialized pool.
1807  */
1808 static void
1809 spa_activate(spa_t *spa, spa_mode_t mode)
1810 {
1811 	metaslab_ops_t *msp = metaslab_allocator(spa);
1812 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1813 
1814 	spa->spa_state = POOL_STATE_ACTIVE;
1815 	spa->spa_final_txg = UINT64_MAX;
1816 	spa->spa_mode = mode;
1817 	spa->spa_read_spacemaps = spa_mode_readable_spacemaps;
1818 
1819 	spa->spa_normal_class = metaslab_class_create(spa, "normal",
1820 	    msp, B_FALSE);
1821 	spa->spa_log_class = metaslab_class_create(spa, "log", msp, B_TRUE);
1822 	spa->spa_embedded_log_class = metaslab_class_create(spa,
1823 	    "embedded_log", msp, B_TRUE);
1824 	spa->spa_special_class = metaslab_class_create(spa, "special",
1825 	    msp, B_FALSE);
1826 	spa->spa_special_embedded_log_class = metaslab_class_create(spa,
1827 	    "special_embedded_log", msp, B_TRUE);
1828 	spa->spa_dedup_class = metaslab_class_create(spa, "dedup",
1829 	    msp, B_FALSE);
1830 
1831 	/* Try to create a covering process */
1832 	mutex_enter(&spa->spa_proc_lock);
1833 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1834 	ASSERT(spa->spa_proc == &p0);
1835 	spa->spa_did = 0;
1836 
1837 #ifdef HAVE_SPA_THREAD
1838 	/* Only create a process if we're going to be around a while. */
1839 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1840 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1841 		    NULL, 0) == 0) {
1842 			spa->spa_proc_state = SPA_PROC_CREATED;
1843 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
1844 				cv_wait(&spa->spa_proc_cv,
1845 				    &spa->spa_proc_lock);
1846 			}
1847 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1848 			ASSERT(spa->spa_proc != &p0);
1849 			ASSERT(spa->spa_did != 0);
1850 		} else {
1851 #ifdef _KERNEL
1852 			cmn_err(CE_WARN,
1853 			    "Couldn't create process for zfs pool \"%s\"\n",
1854 			    spa->spa_name);
1855 #endif
1856 		}
1857 	}
1858 #endif /* HAVE_SPA_THREAD */
1859 	mutex_exit(&spa->spa_proc_lock);
1860 
1861 	/* If we didn't create a process, we need to create our taskqs. */
1862 	if (spa->spa_proc == &p0) {
1863 		spa_create_zio_taskqs(spa);
1864 	}
1865 
1866 	for (size_t i = 0; i < TXG_SIZE; i++) {
1867 		spa->spa_txg_zio[i] = zio_root(spa, NULL, NULL,
1868 		    ZIO_FLAG_CANFAIL);
1869 	}
1870 
1871 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1872 	    offsetof(vdev_t, vdev_config_dirty_node));
1873 	list_create(&spa->spa_evicting_os_list, sizeof (objset_t),
1874 	    offsetof(objset_t, os_evicting_node));
1875 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1876 	    offsetof(vdev_t, vdev_state_dirty_node));
1877 
1878 	txg_list_create(&spa->spa_vdev_txg_list, spa,
1879 	    offsetof(struct vdev, vdev_txg_node));
1880 
1881 	avl_create(&spa->spa_errlist_scrub,
1882 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1883 	    offsetof(spa_error_entry_t, se_avl));
1884 	avl_create(&spa->spa_errlist_last,
1885 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1886 	    offsetof(spa_error_entry_t, se_avl));
1887 	avl_create(&spa->spa_errlist_healed,
1888 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1889 	    offsetof(spa_error_entry_t, se_avl));
1890 
1891 	spa_activate_os(spa);
1892 
1893 	spa_keystore_init(&spa->spa_keystore);
1894 
1895 	/*
1896 	 * This taskq is used to perform zvol-minor-related tasks
1897 	 * asynchronously. This has several advantages, including easy
1898 	 * resolution of various deadlocks.
1899 	 *
1900 	 * The taskq must be single threaded to ensure tasks are always
1901 	 * processed in the order in which they were dispatched.
1902 	 *
1903 	 * A taskq per pool allows one to keep the pools independent.
1904 	 * This way if one pool is suspended, it will not impact another.
1905 	 *
1906 	 * The preferred location to dispatch a zvol minor task is a sync
1907 	 * task. In this context, there is easy access to the spa_t and minimal
1908 	 * error handling is required because the sync task must succeed.
1909 	 */
1910 	spa->spa_zvol_taskq = taskq_create("z_zvol", 1, defclsyspri,
1911 	    1, INT_MAX, 0);
1912 
1913 	/*
1914 	 * The taskq to preload metaslabs.
1915 	 */
1916 	spa->spa_metaslab_taskq = taskq_create("z_metaslab",
1917 	    metaslab_preload_pct, maxclsyspri, 1, INT_MAX,
1918 	    TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT);
1919 
1920 	/*
1921 	 * Taskq dedicated to prefetcher threads: this is used to prevent the
1922 	 * pool traverse code from monopolizing the global (and limited)
1923 	 * system_taskq by inappropriately scheduling long running tasks on it.
1924 	 */
1925 	spa->spa_prefetch_taskq = taskq_create("z_prefetch", 100,
1926 	    defclsyspri, 1, INT_MAX, TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT);
1927 
1928 	/*
1929 	 * The taskq to upgrade datasets in this pool. Currently used by
1930 	 * feature SPA_FEATURE_USEROBJ_ACCOUNTING/SPA_FEATURE_PROJECT_QUOTA.
1931 	 */
1932 	spa->spa_upgrade_taskq = taskq_create("z_upgrade", 100,
1933 	    defclsyspri, 1, INT_MAX, TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT);
1934 }
1935 
1936 /*
1937  * Opposite of spa_activate().
1938  */
1939 static void
1940 spa_deactivate(spa_t *spa)
1941 {
1942 	if (spa->spa_create_info != NULL) {
1943 		nvlist_free(spa->spa_create_info);
1944 		spa->spa_create_info = NULL;
1945 	}
1946 	ASSERT(spa->spa_sync_on == B_FALSE);
1947 	ASSERT0P(spa->spa_dsl_pool);
1948 	ASSERT0P(spa->spa_root_vdev);
1949 	ASSERT0P(spa->spa_async_zio_root);
1950 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1951 
1952 	spa_evicting_os_wait(spa);
1953 
1954 	if (spa->spa_zvol_taskq) {
1955 		taskq_destroy(spa->spa_zvol_taskq);
1956 		spa->spa_zvol_taskq = NULL;
1957 	}
1958 
1959 	if (spa->spa_metaslab_taskq) {
1960 		taskq_destroy(spa->spa_metaslab_taskq);
1961 		spa->spa_metaslab_taskq = NULL;
1962 	}
1963 
1964 	if (spa->spa_prefetch_taskq) {
1965 		taskq_destroy(spa->spa_prefetch_taskq);
1966 		spa->spa_prefetch_taskq = NULL;
1967 	}
1968 
1969 	if (spa->spa_upgrade_taskq) {
1970 		taskq_destroy(spa->spa_upgrade_taskq);
1971 		spa->spa_upgrade_taskq = NULL;
1972 	}
1973 
1974 	txg_list_destroy(&spa->spa_vdev_txg_list);
1975 
1976 	list_destroy(&spa->spa_config_dirty_list);
1977 	list_destroy(&spa->spa_evicting_os_list);
1978 	list_destroy(&spa->spa_state_dirty_list);
1979 
1980 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid, B_TRUE);
1981 
1982 	for (int t = 0; t < ZIO_TYPES; t++) {
1983 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1984 			spa_taskqs_fini(spa, t, q);
1985 		}
1986 	}
1987 
1988 	for (size_t i = 0; i < TXG_SIZE; i++) {
1989 		ASSERT3P(spa->spa_txg_zio[i], !=, NULL);
1990 		VERIFY0(zio_wait(spa->spa_txg_zio[i]));
1991 		spa->spa_txg_zio[i] = NULL;
1992 	}
1993 
1994 	metaslab_class_destroy(spa->spa_normal_class);
1995 	spa->spa_normal_class = NULL;
1996 
1997 	metaslab_class_destroy(spa->spa_log_class);
1998 	spa->spa_log_class = NULL;
1999 
2000 	metaslab_class_destroy(spa->spa_embedded_log_class);
2001 	spa->spa_embedded_log_class = NULL;
2002 
2003 	metaslab_class_destroy(spa->spa_special_class);
2004 	spa->spa_special_class = NULL;
2005 
2006 	metaslab_class_destroy(spa->spa_special_embedded_log_class);
2007 	spa->spa_special_embedded_log_class = NULL;
2008 
2009 	metaslab_class_destroy(spa->spa_dedup_class);
2010 	spa->spa_dedup_class = NULL;
2011 
2012 	/*
2013 	 * If this was part of an import or the open otherwise failed, we may
2014 	 * still have errors left in the queues.  Empty them just in case.
2015 	 */
2016 	spa_errlog_drain(spa);
2017 	avl_destroy(&spa->spa_errlist_scrub);
2018 	avl_destroy(&spa->spa_errlist_last);
2019 	avl_destroy(&spa->spa_errlist_healed);
2020 
2021 	spa_keystore_fini(&spa->spa_keystore);
2022 
2023 	spa->spa_state = POOL_STATE_UNINITIALIZED;
2024 
2025 	mutex_enter(&spa->spa_proc_lock);
2026 	if (spa->spa_proc_state != SPA_PROC_NONE) {
2027 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
2028 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
2029 		cv_broadcast(&spa->spa_proc_cv);
2030 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
2031 			ASSERT(spa->spa_proc != &p0);
2032 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
2033 		}
2034 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
2035 		spa->spa_proc_state = SPA_PROC_NONE;
2036 	}
2037 	ASSERT(spa->spa_proc == &p0);
2038 	mutex_exit(&spa->spa_proc_lock);
2039 
2040 	/*
2041 	 * We want to make sure spa_thread() has actually exited the ZFS
2042 	 * module, so that the module can't be unloaded out from underneath
2043 	 * it.
2044 	 */
2045 	if (spa->spa_did != 0) {
2046 		thread_join(spa->spa_did);
2047 		spa->spa_did = 0;
2048 	}
2049 
2050 	spa_deactivate_os(spa);
2051 
2052 }
2053 
2054 /*
2055  * Verify a pool configuration, and construct the vdev tree appropriately.  This
2056  * will create all the necessary vdevs in the appropriate layout, with each vdev
2057  * in the CLOSED state.  This will prep the pool before open/creation/import.
2058  * All vdev validation is done by the vdev_alloc() routine.
2059  */
2060 int
2061 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
2062     uint_t id, int atype)
2063 {
2064 	nvlist_t **child;
2065 	uint_t children;
2066 	int error;
2067 
2068 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
2069 		return (error);
2070 
2071 	if ((*vdp)->vdev_ops->vdev_op_leaf)
2072 		return (0);
2073 
2074 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
2075 	    &child, &children);
2076 
2077 	if (error == ENOENT)
2078 		return (0);
2079 
2080 	if (error) {
2081 		vdev_free(*vdp);
2082 		*vdp = NULL;
2083 		return (SET_ERROR(EINVAL));
2084 	}
2085 
2086 	for (int c = 0; c < children; c++) {
2087 		vdev_t *vd;
2088 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
2089 		    atype)) != 0) {
2090 			vdev_free(*vdp);
2091 			*vdp = NULL;
2092 			return (error);
2093 		}
2094 	}
2095 
2096 	ASSERT(*vdp != NULL);
2097 
2098 	return (0);
2099 }
2100 
2101 static boolean_t
2102 spa_should_flush_logs_on_unload(spa_t *spa)
2103 {
2104 	if (!spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))
2105 		return (B_FALSE);
2106 
2107 	if (!spa_writeable(spa))
2108 		return (B_FALSE);
2109 
2110 	if (!spa->spa_sync_on)
2111 		return (B_FALSE);
2112 
2113 	if (spa_state(spa) != POOL_STATE_EXPORTED)
2114 		return (B_FALSE);
2115 
2116 	if (zfs_keep_log_spacemaps_at_export)
2117 		return (B_FALSE);
2118 
2119 	return (B_TRUE);
2120 }
2121 
2122 /*
2123  * Opens a transaction that will set the flag that will instruct
2124  * spa_sync to attempt to flush all the metaslabs for that txg.
2125  */
2126 static void
2127 spa_unload_log_sm_flush_all(spa_t *spa)
2128 {
2129 	dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
2130 	VERIFY0(dmu_tx_assign(tx, DMU_TX_WAIT | DMU_TX_SUSPEND));
2131 
2132 	spa_log_flushall_start(spa, SPA_LOG_FLUSHALL_EXPORT,
2133 	    dmu_tx_get_txg(tx));
2134 
2135 	dmu_tx_commit(tx);
2136 	txg_wait_synced(spa_get_dsl(spa), spa->spa_log_flushall_txg);
2137 }
2138 
2139 static void
2140 spa_unload_log_sm_metadata(spa_t *spa)
2141 {
2142 	void *cookie = NULL;
2143 	spa_log_sm_t *sls;
2144 	log_summary_entry_t *e;
2145 
2146 	while ((sls = avl_destroy_nodes(&spa->spa_sm_logs_by_txg,
2147 	    &cookie)) != NULL) {
2148 		VERIFY0(sls->sls_mscount);
2149 		kmem_free(sls, sizeof (spa_log_sm_t));
2150 	}
2151 
2152 	while ((e = list_remove_head(&spa->spa_log_summary)) != NULL) {
2153 		VERIFY0(e->lse_mscount);
2154 		kmem_free(e, sizeof (log_summary_entry_t));
2155 	}
2156 
2157 	spa->spa_unflushed_stats.sus_nblocks = 0;
2158 	spa->spa_unflushed_stats.sus_memused = 0;
2159 	spa->spa_unflushed_stats.sus_blocklimit = 0;
2160 	spa->spa_unflushed_stats.sus_nmetaslabs = 0;
2161 
2162 	spa_log_sm_stats_update(spa);
2163 }
2164 
2165 static void
2166 spa_destroy_aux_threads(spa_t *spa)
2167 {
2168 	if (spa->spa_condense_zthr != NULL) {
2169 		zthr_destroy(spa->spa_condense_zthr);
2170 		spa->spa_condense_zthr = NULL;
2171 	}
2172 	if (spa->spa_checkpoint_discard_zthr != NULL) {
2173 		zthr_destroy(spa->spa_checkpoint_discard_zthr);
2174 		spa->spa_checkpoint_discard_zthr = NULL;
2175 	}
2176 	if (spa->spa_livelist_delete_zthr != NULL) {
2177 		zthr_destroy(spa->spa_livelist_delete_zthr);
2178 		spa->spa_livelist_delete_zthr = NULL;
2179 	}
2180 	if (spa->spa_livelist_condense_zthr != NULL) {
2181 		zthr_destroy(spa->spa_livelist_condense_zthr);
2182 		spa->spa_livelist_condense_zthr = NULL;
2183 	}
2184 	if (spa->spa_raidz_expand_zthr != NULL) {
2185 		zthr_destroy(spa->spa_raidz_expand_zthr);
2186 		spa->spa_raidz_expand_zthr = NULL;
2187 	}
2188 }
2189 
2190 static void
2191 spa_sync_time_logger(spa_t *spa, uint64_t txg, boolean_t force)
2192 {
2193 	uint64_t curtime, dirty;
2194 	dmu_tx_t *tx;
2195 	dsl_pool_t *dp = spa->spa_dsl_pool;
2196 	uint64_t idx = txg & TXG_MASK;
2197 
2198 	if (!spa_writeable(spa)) {
2199 		return;
2200 	}
2201 
2202 	curtime = gethrestime_sec();
2203 	if (txg > spa->spa_last_noted_txg &&
2204 	    (force ||
2205 	    curtime >= spa->spa_last_noted_txg_time + spa_note_txg_time)) {
2206 		spa->spa_last_noted_txg_time = curtime;
2207 		spa->spa_last_noted_txg = txg;
2208 
2209 		mutex_enter(&spa->spa_txg_log_time_lock);
2210 		dbrrd_add(&spa->spa_txg_log_time, curtime, txg);
2211 		mutex_exit(&spa->spa_txg_log_time_lock);
2212 	}
2213 
2214 	if (!force &&
2215 	    curtime < spa->spa_last_flush_txg_time + spa_flush_txg_time) {
2216 		return;
2217 	}
2218 	if (txg > spa_final_dirty_txg(spa)) {
2219 		return;
2220 	}
2221 	spa->spa_last_flush_txg_time = curtime;
2222 
2223 	mutex_enter(&dp->dp_lock);
2224 	dirty = dp->dp_dirty_pertxg[idx];
2225 	mutex_exit(&dp->dp_lock);
2226 	if (!force && dirty == 0) {
2227 		return;
2228 	}
2229 
2230 	spa->spa_last_flush_txg_time = curtime;
2231 	tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
2232 
2233 	VERIFY0(zap_update(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
2234 	    DMU_POOL_TXG_LOG_TIME_MINUTES, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2235 	    &spa->spa_txg_log_time.dbr_minutes, tx));
2236 	VERIFY0(zap_update(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
2237 	    DMU_POOL_TXG_LOG_TIME_DAYS, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2238 	    &spa->spa_txg_log_time.dbr_days, tx));
2239 	VERIFY0(zap_update(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
2240 	    DMU_POOL_TXG_LOG_TIME_MONTHS, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2241 	    &spa->spa_txg_log_time.dbr_months, tx));
2242 	dmu_tx_commit(tx);
2243 }
2244 
2245 static void
2246 spa_unload_sync_time_logger(spa_t *spa)
2247 {
2248 	uint64_t txg;
2249 	dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
2250 	VERIFY0(dmu_tx_assign(tx, DMU_TX_WAIT));
2251 
2252 	txg = dmu_tx_get_txg(tx);
2253 	spa_sync_time_logger(spa, txg, B_TRUE);
2254 
2255 	dmu_tx_commit(tx);
2256 }
2257 
2258 static void
2259 spa_load_txg_log_time(spa_t *spa)
2260 {
2261 	int error;
2262 
2263 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
2264 	    DMU_POOL_TXG_LOG_TIME_MINUTES, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2265 	    &spa->spa_txg_log_time.dbr_minutes);
2266 	if (error != 0 && error != ENOENT) {
2267 		spa_load_note(spa, "unable to load a txg time database with "
2268 		    "minute resolution [error=%d]", error);
2269 	}
2270 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
2271 	    DMU_POOL_TXG_LOG_TIME_DAYS, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2272 	    &spa->spa_txg_log_time.dbr_days);
2273 	if (error != 0 && error != ENOENT) {
2274 		spa_load_note(spa, "unable to load a txg time database with "
2275 		    "day resolution [error=%d]", error);
2276 	}
2277 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
2278 	    DMU_POOL_TXG_LOG_TIME_MONTHS, RRD_ENTRY_SIZE, RRD_STRUCT_ELEM,
2279 	    &spa->spa_txg_log_time.dbr_months);
2280 	if (error != 0 && error != ENOENT) {
2281 		spa_load_note(spa, "unable to load a txg time database with "
2282 		    "month resolution [error=%d]", error);
2283 	}
2284 }
2285 
2286 static boolean_t
2287 spa_should_sync_time_logger_on_unload(spa_t *spa)
2288 {
2289 
2290 	if (!spa_writeable(spa))
2291 		return (B_FALSE);
2292 
2293 	if (!spa->spa_sync_on)
2294 		return (B_FALSE);
2295 
2296 	if (spa_state(spa) != POOL_STATE_EXPORTED)
2297 		return (B_FALSE);
2298 
2299 	if (spa->spa_last_noted_txg == 0)
2300 		return (B_FALSE);
2301 
2302 	return (B_TRUE);
2303 }
2304 
2305 
2306 /*
2307  * Opposite of spa_load().
2308  */
2309 static void
2310 spa_unload(spa_t *spa)
2311 {
2312 	ASSERT(spa_namespace_held() ||
2313 	    spa->spa_export_thread == curthread);
2314 	ASSERT(spa_state(spa) != POOL_STATE_UNINITIALIZED);
2315 
2316 	spa_import_progress_remove(spa_guid(spa));
2317 	spa_load_note(spa, "UNLOADING");
2318 
2319 	spa_wake_waiters(spa);
2320 
2321 	/*
2322 	 * If we have set the spa_final_txg, we have already performed the
2323 	 * tasks below in spa_export_common(). We should not redo it here since
2324 	 * we delay the final TXGs beyond what spa_final_txg is set at.
2325 	 */
2326 	if (spa->spa_final_txg == UINT64_MAX) {
2327 		if (spa_should_sync_time_logger_on_unload(spa))
2328 			spa_unload_sync_time_logger(spa);
2329 
2330 		/*
2331 		 * If the log space map feature is enabled and the pool is
2332 		 * getting exported (but not destroyed), we want to spend some
2333 		 * time flushing as many metaslabs as we can in an attempt to
2334 		 * destroy log space maps and save import time.
2335 		 */
2336 		if (spa_should_flush_logs_on_unload(spa))
2337 			spa_unload_log_sm_flush_all(spa);
2338 		else
2339 			spa_log_flushall_done(spa);
2340 
2341 		/*
2342 		 * Stop async tasks.
2343 		 */
2344 		spa_async_suspend(spa);
2345 
2346 		if (spa->spa_root_vdev) {
2347 			vdev_t *root_vdev = spa->spa_root_vdev;
2348 			vdev_initialize_stop_all(root_vdev,
2349 			    VDEV_INITIALIZE_ACTIVE);
2350 			vdev_trim_stop_all(root_vdev, VDEV_TRIM_ACTIVE);
2351 			vdev_autotrim_stop_all(spa);
2352 			vdev_rebuild_stop_all(spa);
2353 			l2arc_spa_rebuild_stop(spa);
2354 		}
2355 
2356 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2357 		spa->spa_final_txg = spa_last_synced_txg(spa) +
2358 		    TXG_DEFER_SIZE + 1;
2359 		spa_config_exit(spa, SCL_ALL, FTAG);
2360 	}
2361 
2362 	/*
2363 	 * Stop syncing.
2364 	 */
2365 	if (spa->spa_sync_on) {
2366 		txg_sync_stop(spa->spa_dsl_pool);
2367 		spa->spa_sync_on = B_FALSE;
2368 	}
2369 
2370 	/*
2371 	 * This ensures that there is no async metaslab prefetching
2372 	 * while we attempt to unload the spa.
2373 	 */
2374 	taskq_wait(spa->spa_metaslab_taskq);
2375 
2376 	if (spa->spa_mmp.mmp_thread)
2377 		mmp_thread_stop(spa);
2378 
2379 	/*
2380 	 * Wait for any outstanding async I/O to complete.
2381 	 */
2382 	if (spa->spa_async_zio_root != NULL) {
2383 		for (int i = 0; i < max_ncpus; i++)
2384 			(void) zio_wait(spa->spa_async_zio_root[i]);
2385 		kmem_free(spa->spa_async_zio_root, max_ncpus * sizeof (void *));
2386 		spa->spa_async_zio_root = NULL;
2387 	}
2388 
2389 	if (spa->spa_vdev_removal != NULL) {
2390 		spa_vdev_removal_destroy(spa->spa_vdev_removal);
2391 		spa->spa_vdev_removal = NULL;
2392 	}
2393 
2394 	spa_destroy_aux_threads(spa);
2395 
2396 	spa_condense_fini(spa);
2397 
2398 	bpobj_close(&spa->spa_deferred_bpobj);
2399 
2400 	spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
2401 
2402 	/*
2403 	 * Close all vdevs.
2404 	 */
2405 	if (spa->spa_root_vdev)
2406 		vdev_free(spa->spa_root_vdev);
2407 	ASSERT0P(spa->spa_root_vdev);
2408 
2409 	/*
2410 	 * Close the dsl pool.
2411 	 */
2412 	if (spa->spa_dsl_pool) {
2413 		dsl_pool_close(spa->spa_dsl_pool);
2414 		spa->spa_dsl_pool = NULL;
2415 		spa->spa_meta_objset = NULL;
2416 	}
2417 
2418 	ddt_unload(spa);
2419 	brt_unload(spa);
2420 	spa_unload_log_sm_metadata(spa);
2421 
2422 	/*
2423 	 * Drop and purge level 2 cache
2424 	 */
2425 	spa_l2cache_drop(spa);
2426 
2427 	if (spa->spa_spares.sav_vdevs) {
2428 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
2429 			vdev_free(spa->spa_spares.sav_vdevs[i]);
2430 		kmem_free(spa->spa_spares.sav_vdevs,
2431 		    spa->spa_spares.sav_count * sizeof (void *));
2432 		spa->spa_spares.sav_vdevs = NULL;
2433 	}
2434 	if (spa->spa_spares.sav_config) {
2435 		nvlist_free(spa->spa_spares.sav_config);
2436 		spa->spa_spares.sav_config = NULL;
2437 	}
2438 	spa->spa_spares.sav_count = 0;
2439 
2440 	if (spa->spa_l2cache.sav_vdevs) {
2441 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++) {
2442 			vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
2443 			vdev_free(spa->spa_l2cache.sav_vdevs[i]);
2444 		}
2445 		kmem_free(spa->spa_l2cache.sav_vdevs,
2446 		    spa->spa_l2cache.sav_count * sizeof (void *));
2447 		spa->spa_l2cache.sav_vdevs = NULL;
2448 	}
2449 	if (spa->spa_l2cache.sav_config) {
2450 		nvlist_free(spa->spa_l2cache.sav_config);
2451 		spa->spa_l2cache.sav_config = NULL;
2452 	}
2453 	spa->spa_l2cache.sav_count = 0;
2454 
2455 	spa->spa_async_suspended = 0;
2456 
2457 	spa->spa_indirect_vdevs_loaded = B_FALSE;
2458 
2459 	if (spa->spa_comment != NULL) {
2460 		spa_strfree(spa->spa_comment);
2461 		spa->spa_comment = NULL;
2462 	}
2463 	if (spa->spa_compatibility != NULL) {
2464 		spa_strfree(spa->spa_compatibility);
2465 		spa->spa_compatibility = NULL;
2466 	}
2467 
2468 	spa->spa_raidz_expand = NULL;
2469 	spa->spa_checkpoint_txg = 0;
2470 
2471 	spa_config_exit(spa, SCL_ALL, spa);
2472 }
2473 
2474 /*
2475  * Load (or re-load) the current list of vdevs describing the active spares for
2476  * this pool.  When this is called, we have some form of basic information in
2477  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
2478  * then re-generate a more complete list including status information.
2479  */
2480 void
2481 spa_load_spares(spa_t *spa)
2482 {
2483 	nvlist_t **spares;
2484 	uint_t nspares;
2485 	int i;
2486 	vdev_t *vd, *tvd;
2487 
2488 #ifndef _KERNEL
2489 	/*
2490 	 * zdb opens both the current state of the pool and the
2491 	 * checkpointed state (if present), with a different spa_t.
2492 	 *
2493 	 * As spare vdevs are shared among open pools, we skip loading
2494 	 * them when we load the checkpointed state of the pool.
2495 	 */
2496 	if (!spa_writeable(spa))
2497 		return;
2498 #endif
2499 
2500 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2501 
2502 	/*
2503 	 * First, close and free any existing spare vdevs.
2504 	 */
2505 	if (spa->spa_spares.sav_vdevs) {
2506 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
2507 			vd = spa->spa_spares.sav_vdevs[i];
2508 
2509 			/* Undo the call to spa_activate() below */
2510 			if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
2511 			    B_FALSE)) != NULL && tvd->vdev_isspare)
2512 				spa_spare_remove(tvd);
2513 			vdev_close(vd);
2514 			vdev_free(vd);
2515 		}
2516 
2517 		kmem_free(spa->spa_spares.sav_vdevs,
2518 		    spa->spa_spares.sav_count * sizeof (void *));
2519 	}
2520 
2521 	if (spa->spa_spares.sav_config == NULL)
2522 		nspares = 0;
2523 	else
2524 		VERIFY0(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2525 		    ZPOOL_CONFIG_SPARES, &spares, &nspares));
2526 
2527 	spa->spa_spares.sav_count = (int)nspares;
2528 	spa->spa_spares.sav_vdevs = NULL;
2529 
2530 	if (nspares == 0)
2531 		return;
2532 
2533 	/*
2534 	 * Construct the array of vdevs, opening them to get status in the
2535 	 * process.   For each spare, there is potentially two different vdev_t
2536 	 * structures associated with it: one in the list of spares (used only
2537 	 * for basic validation purposes) and one in the active vdev
2538 	 * configuration (if it's spared in).  During this phase we open and
2539 	 * validate each vdev on the spare list.  If the vdev also exists in the
2540 	 * active configuration, then we also mark this vdev as an active spare.
2541 	 */
2542 	spa->spa_spares.sav_vdevs = kmem_zalloc(nspares * sizeof (void *),
2543 	    KM_SLEEP);
2544 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
2545 		VERIFY0(spa_config_parse(spa, &vd, spares[i], NULL, 0,
2546 		    VDEV_ALLOC_SPARE));
2547 		ASSERT(vd != NULL);
2548 
2549 		spa->spa_spares.sav_vdevs[i] = vd;
2550 
2551 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
2552 		    B_FALSE)) != NULL) {
2553 			if (!tvd->vdev_isspare)
2554 				spa_spare_add(tvd);
2555 
2556 			/*
2557 			 * We only mark the spare active if we were successfully
2558 			 * able to load the vdev.  Otherwise, importing a pool
2559 			 * with a bad active spare would result in strange
2560 			 * behavior, because multiple pool would think the spare
2561 			 * is actively in use.
2562 			 *
2563 			 * There is a vulnerability here to an equally bizarre
2564 			 * circumstance, where a dead active spare is later
2565 			 * brought back to life (onlined or otherwise).  Given
2566 			 * the rarity of this scenario, and the extra complexity
2567 			 * it adds, we ignore the possibility.
2568 			 */
2569 			if (!vdev_is_dead(tvd))
2570 				spa_spare_activate(tvd);
2571 		}
2572 
2573 		vd->vdev_top = vd;
2574 		vd->vdev_aux = &spa->spa_spares;
2575 
2576 		if (vdev_open(vd, CRED()) != 0)
2577 			continue;
2578 
2579 		if (vdev_validate_aux(vd) == 0)
2580 			spa_spare_add(vd);
2581 	}
2582 
2583 	/*
2584 	 * Recompute the stashed list of spares, with status information
2585 	 * this time.
2586 	 */
2587 	fnvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES);
2588 
2589 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
2590 	    KM_SLEEP);
2591 	for (i = 0; i < spa->spa_spares.sav_count; i++)
2592 		spares[i] = vdev_config_generate(spa,
2593 		    spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
2594 	fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
2595 	    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
2596 	    spa->spa_spares.sav_count);
2597 	for (i = 0; i < spa->spa_spares.sav_count; i++)
2598 		nvlist_free(spares[i]);
2599 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
2600 }
2601 
2602 /*
2603  * Load (or re-load) the current list of vdevs describing the active l2cache for
2604  * this pool.  When this is called, we have some form of basic information in
2605  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
2606  * then re-generate a more complete list including status information.
2607  * Devices which are already active have their details maintained, and are
2608  * not re-opened.
2609  */
2610 void
2611 spa_load_l2cache(spa_t *spa)
2612 {
2613 	nvlist_t **l2cache = NULL;
2614 	uint_t nl2cache;
2615 	int i, j, oldnvdevs;
2616 	uint64_t guid;
2617 	vdev_t *vd, **oldvdevs, **newvdevs;
2618 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
2619 
2620 #ifndef _KERNEL
2621 	/*
2622 	 * zdb opens both the current state of the pool and the
2623 	 * checkpointed state (if present), with a different spa_t.
2624 	 *
2625 	 * As L2 caches are part of the ARC which is shared among open
2626 	 * pools, we skip loading them when we load the checkpointed
2627 	 * state of the pool.
2628 	 */
2629 	if (!spa_writeable(spa))
2630 		return;
2631 #endif
2632 
2633 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2634 
2635 	oldvdevs = sav->sav_vdevs;
2636 	oldnvdevs = sav->sav_count;
2637 	sav->sav_vdevs = NULL;
2638 	sav->sav_count = 0;
2639 
2640 	if (sav->sav_config == NULL) {
2641 		nl2cache = 0;
2642 		newvdevs = NULL;
2643 		goto out;
2644 	}
2645 
2646 	VERIFY0(nvlist_lookup_nvlist_array(sav->sav_config,
2647 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache));
2648 	newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
2649 
2650 	/*
2651 	 * Process new nvlist of vdevs.
2652 	 */
2653 	for (i = 0; i < nl2cache; i++) {
2654 		guid = fnvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID);
2655 
2656 		newvdevs[i] = NULL;
2657 		for (j = 0; j < oldnvdevs; j++) {
2658 			vd = oldvdevs[j];
2659 			if (vd != NULL && guid == vd->vdev_guid) {
2660 				/*
2661 				 * Retain previous vdev for add/remove ops.
2662 				 */
2663 				newvdevs[i] = vd;
2664 				oldvdevs[j] = NULL;
2665 				break;
2666 			}
2667 		}
2668 
2669 		if (newvdevs[i] == NULL) {
2670 			/*
2671 			 * Create new vdev
2672 			 */
2673 			VERIFY0(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
2674 			    VDEV_ALLOC_L2CACHE));
2675 			ASSERT(vd != NULL);
2676 			newvdevs[i] = vd;
2677 
2678 			/*
2679 			 * Commit this vdev as an l2cache device,
2680 			 * even if it fails to open.
2681 			 */
2682 			spa_l2cache_add(vd);
2683 
2684 			vd->vdev_top = vd;
2685 			vd->vdev_aux = sav;
2686 
2687 			spa_l2cache_activate(vd);
2688 
2689 			if (vdev_open(vd, CRED()) != 0)
2690 				continue;
2691 
2692 			(void) vdev_validate_aux(vd);
2693 
2694 			if (!vdev_is_dead(vd))
2695 				l2arc_add_vdev(spa, vd);
2696 
2697 			/*
2698 			 * Upon cache device addition to a pool or pool
2699 			 * creation with a cache device or if the header
2700 			 * of the device is invalid we issue an async
2701 			 * TRIM command for the whole device which will
2702 			 * execute if l2arc_trim_ahead > 0.
2703 			 */
2704 			spa_async_request(spa, SPA_ASYNC_L2CACHE_TRIM);
2705 		}
2706 	}
2707 
2708 	sav->sav_vdevs = newvdevs;
2709 	sav->sav_count = (int)nl2cache;
2710 
2711 	/*
2712 	 * Recompute the stashed list of l2cache devices, with status
2713 	 * information this time.
2714 	 */
2715 	fnvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE);
2716 
2717 	if (sav->sav_count > 0)
2718 		l2cache = kmem_alloc(sav->sav_count * sizeof (void *),
2719 		    KM_SLEEP);
2720 	for (i = 0; i < sav->sav_count; i++)
2721 		l2cache[i] = vdev_config_generate(spa,
2722 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
2723 	fnvlist_add_nvlist_array(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
2724 	    (const nvlist_t * const *)l2cache, sav->sav_count);
2725 
2726 out:
2727 	/*
2728 	 * Purge vdevs that were dropped
2729 	 */
2730 	if (oldvdevs) {
2731 		for (i = 0; i < oldnvdevs; i++) {
2732 			uint64_t pool;
2733 
2734 			vd = oldvdevs[i];
2735 			if (vd != NULL) {
2736 				ASSERT(vd->vdev_isl2cache);
2737 
2738 				if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
2739 				    pool != 0ULL && l2arc_vdev_present(vd))
2740 					l2arc_remove_vdev(vd);
2741 				vdev_clear_stats(vd);
2742 				vdev_free(vd);
2743 			}
2744 		}
2745 
2746 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
2747 	}
2748 
2749 	for (i = 0; i < sav->sav_count; i++)
2750 		nvlist_free(l2cache[i]);
2751 	if (sav->sav_count)
2752 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
2753 }
2754 
2755 static int
2756 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
2757 {
2758 	dmu_buf_t *db;
2759 	char *packed = NULL;
2760 	size_t nvsize = 0;
2761 	int error;
2762 	*value = NULL;
2763 
2764 	error = dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db);
2765 	if (error)
2766 		return (error);
2767 
2768 	nvsize = *(uint64_t *)db->db_data;
2769 	dmu_buf_rele(db, FTAG);
2770 
2771 	packed = vmem_alloc(nvsize, KM_SLEEP);
2772 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
2773 	    DMU_READ_PREFETCH);
2774 	if (error == 0)
2775 		error = nvlist_unpack(packed, nvsize, value, 0);
2776 	vmem_free(packed, nvsize);
2777 
2778 	return (error);
2779 }
2780 
2781 /*
2782  * Concrete top-level vdevs that are not missing and are not logs. At every
2783  * spa_sync we write new uberblocks to at least SPA_SYNC_MIN_VDEVS core tvds.
2784  */
2785 static uint64_t
2786 spa_healthy_core_tvds(spa_t *spa)
2787 {
2788 	vdev_t *rvd = spa->spa_root_vdev;
2789 	uint64_t tvds = 0;
2790 
2791 	for (uint64_t i = 0; i < rvd->vdev_children; i++) {
2792 		vdev_t *vd = rvd->vdev_child[i];
2793 		if (vd->vdev_islog)
2794 			continue;
2795 		if (vdev_is_concrete(vd) && !vdev_is_dead(vd))
2796 			tvds++;
2797 	}
2798 
2799 	return (tvds);
2800 }
2801 
2802 /*
2803  * Checks to see if the given vdev could not be opened, in which case we post a
2804  * sysevent to notify the autoreplace code that the device has been removed.
2805  */
2806 static void
2807 spa_check_removed(vdev_t *vd)
2808 {
2809 	for (uint64_t c = 0; c < vd->vdev_children; c++)
2810 		spa_check_removed(vd->vdev_child[c]);
2811 
2812 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
2813 	    vdev_is_concrete(vd)) {
2814 		zfs_post_autoreplace(vd->vdev_spa, vd);
2815 		spa_event_notify(vd->vdev_spa, vd, NULL, ESC_ZFS_VDEV_CHECK);
2816 	}
2817 }
2818 
2819 static int
2820 spa_check_for_missing_logs(spa_t *spa)
2821 {
2822 	vdev_t *rvd = spa->spa_root_vdev;
2823 
2824 	/*
2825 	 * If we're doing a normal import, then build up any additional
2826 	 * diagnostic information about missing log devices.
2827 	 * We'll pass this up to the user for further processing.
2828 	 */
2829 	if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
2830 		nvlist_t **child, *nv;
2831 		uint64_t idx = 0;
2832 
2833 		child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t *),
2834 		    KM_SLEEP);
2835 		nv = fnvlist_alloc();
2836 
2837 		for (uint64_t c = 0; c < rvd->vdev_children; c++) {
2838 			vdev_t *tvd = rvd->vdev_child[c];
2839 
2840 			/*
2841 			 * We consider a device as missing only if it failed
2842 			 * to open (i.e. offline or faulted is not considered
2843 			 * as missing).
2844 			 */
2845 			if (tvd->vdev_islog &&
2846 			    tvd->vdev_state == VDEV_STATE_CANT_OPEN) {
2847 				child[idx++] = vdev_config_generate(spa, tvd,
2848 				    B_FALSE, VDEV_CONFIG_MISSING);
2849 			}
2850 		}
2851 
2852 		if (idx > 0) {
2853 			fnvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
2854 			    (const nvlist_t * const *)child, idx);
2855 			fnvlist_add_nvlist(spa->spa_load_info,
2856 			    ZPOOL_CONFIG_MISSING_DEVICES, nv);
2857 
2858 			for (uint64_t i = 0; i < idx; i++)
2859 				nvlist_free(child[i]);
2860 		}
2861 		nvlist_free(nv);
2862 		kmem_free(child, rvd->vdev_children * sizeof (char **));
2863 
2864 		if (idx > 0) {
2865 			spa_load_failed(spa, "some log devices are missing");
2866 			vdev_dbgmsg_print_tree(rvd, 2);
2867 			return (SET_ERROR(ENXIO));
2868 		}
2869 	} else {
2870 		for (uint64_t c = 0; c < rvd->vdev_children; c++) {
2871 			vdev_t *tvd = rvd->vdev_child[c];
2872 
2873 			if (tvd->vdev_islog &&
2874 			    tvd->vdev_state == VDEV_STATE_CANT_OPEN) {
2875 				spa_set_log_state(spa, SPA_LOG_CLEAR);
2876 				spa_load_note(spa, "some log devices are "
2877 				    "missing, ZIL is dropped.");
2878 				vdev_dbgmsg_print_tree(rvd, 2);
2879 				break;
2880 			}
2881 		}
2882 	}
2883 
2884 	return (0);
2885 }
2886 
2887 /*
2888  * Check for missing log devices
2889  */
2890 static boolean_t
2891 spa_check_logs(spa_t *spa)
2892 {
2893 	boolean_t rv = B_FALSE;
2894 	dsl_pool_t *dp = spa_get_dsl(spa);
2895 
2896 	switch (spa->spa_log_state) {
2897 	default:
2898 		break;
2899 	case SPA_LOG_MISSING:
2900 		/* need to recheck in case slog has been restored */
2901 	case SPA_LOG_UNKNOWN:
2902 		rv = (dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
2903 		    zil_check_log_chain, NULL, DS_FIND_CHILDREN) != 0);
2904 		if (rv)
2905 			spa_set_log_state(spa, SPA_LOG_MISSING);
2906 		break;
2907 	}
2908 	return (rv);
2909 }
2910 
2911 /*
2912  * Passivate any log vdevs (note, does not apply to embedded log metaslabs).
2913  */
2914 static boolean_t
2915 spa_passivate_log(spa_t *spa)
2916 {
2917 	vdev_t *rvd = spa->spa_root_vdev;
2918 	boolean_t slog_found = B_FALSE;
2919 
2920 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
2921 
2922 	for (int c = 0; c < rvd->vdev_children; c++) {
2923 		vdev_t *tvd = rvd->vdev_child[c];
2924 
2925 		if (tvd->vdev_islog) {
2926 			ASSERT0P(tvd->vdev_log_mg);
2927 			metaslab_group_passivate(tvd->vdev_mg);
2928 			slog_found = B_TRUE;
2929 		}
2930 	}
2931 
2932 	return (slog_found);
2933 }
2934 
2935 /*
2936  * Activate any log vdevs (note, does not apply to embedded log metaslabs).
2937  */
2938 static void
2939 spa_activate_log(spa_t *spa)
2940 {
2941 	vdev_t *rvd = spa->spa_root_vdev;
2942 
2943 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
2944 
2945 	for (int c = 0; c < rvd->vdev_children; c++) {
2946 		vdev_t *tvd = rvd->vdev_child[c];
2947 
2948 		if (tvd->vdev_islog) {
2949 			ASSERT0P(tvd->vdev_log_mg);
2950 			metaslab_group_activate(tvd->vdev_mg);
2951 		}
2952 	}
2953 }
2954 
2955 int
2956 spa_reset_logs(spa_t *spa)
2957 {
2958 	int error;
2959 
2960 	error = dmu_objset_find(spa_name(spa), zil_reset,
2961 	    NULL, DS_FIND_CHILDREN);
2962 	if (error == 0) {
2963 		/*
2964 		 * We successfully offlined the log device, sync out the
2965 		 * current txg so that the "stubby" block can be removed
2966 		 * by zil_sync().
2967 		 */
2968 		txg_wait_synced(spa->spa_dsl_pool, 0);
2969 	}
2970 	return (error);
2971 }
2972 
2973 static void
2974 spa_aux_check_removed(spa_aux_vdev_t *sav)
2975 {
2976 	for (int i = 0; i < sav->sav_count; i++)
2977 		spa_check_removed(sav->sav_vdevs[i]);
2978 }
2979 
2980 void
2981 spa_claim_notify(zio_t *zio)
2982 {
2983 	spa_t *spa = zio->io_spa;
2984 
2985 	if (zio->io_error)
2986 		return;
2987 
2988 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
2989 	if (spa->spa_claim_max_txg < BP_GET_BIRTH(zio->io_bp))
2990 		spa->spa_claim_max_txg = BP_GET_BIRTH(zio->io_bp);
2991 	mutex_exit(&spa->spa_props_lock);
2992 }
2993 
2994 typedef struct spa_load_error {
2995 	boolean_t	sle_verify_data;
2996 	boolean_t	sle_relaxmeta;	/* tolerate non-critical meta-data */
2997 	uint64_t	sle_maxmeta;	/* max acceptable meta-data errors */
2998 	uint64_t	sle_maxdata;	/* max acceptable data errors */
2999 	uint64_t	sle_meta_count;
3000 	uint64_t	sle_data_count;
3001 } spa_load_error_t;
3002 
3003 static void
3004 spa_load_verify_done(zio_t *zio)
3005 {
3006 	blkptr_t *bp = zio->io_bp;
3007 	spa_load_error_t *sle = zio->io_private;
3008 	dmu_object_type_t type = BP_GET_TYPE(bp);
3009 	int error = zio->io_error;
3010 	spa_t *spa = zio->io_spa;
3011 
3012 	abd_free(zio->io_abd);
3013 	if (error) {
3014 		boolean_t meta;
3015 
3016 		if (type == DMU_OT_INTENT_LOG) {
3017 			meta = B_FALSE;
3018 		} else if (zio->io_bookmark.zb_objset == DMU_META_OBJSET) {
3019 			meta = B_TRUE;
3020 		} else if (sle->sle_relaxmeta) {
3021 			/*
3022 			 * Losing a file or a directory costs us the affected
3023 			 * objects, but the pool as a whole remains operable.
3024 			 */
3025 			meta = DMU_OT_IS_CRITICAL(type, BP_GET_LEVEL(bp));
3026 		} else {
3027 			meta = BP_GET_LEVEL(bp) != 0 ||
3028 			    DMU_OT_IS_METADATA(type);
3029 		}
3030 		if (meta)
3031 			atomic_inc_64(&sle->sle_meta_count);
3032 		else
3033 			atomic_inc_64(&sle->sle_data_count);
3034 	}
3035 
3036 	mutex_enter(&spa->spa_scrub_lock);
3037 	spa->spa_load_verify_bytes -= BP_GET_PSIZE(bp);
3038 	cv_broadcast(&spa->spa_scrub_io_cv);
3039 	mutex_exit(&spa->spa_scrub_lock);
3040 }
3041 
3042 /*
3043  * Maximum number of inflight bytes is the log2 fraction of the arc size.
3044  * By default, we set it to 1/16th of the arc.
3045  */
3046 static uint_t spa_load_verify_shift = 4;
3047 static int spa_load_verify_metadata = B_TRUE;
3048 static int spa_load_verify_data = B_TRUE;
3049 
3050 static int
3051 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
3052     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
3053 {
3054 	zio_t *rio = arg;
3055 	spa_load_error_t *sle = rio->io_private;
3056 
3057 	(void) zilog, (void) dnp;
3058 
3059 	/*
3060 	 * Note: normally this routine will not be called if
3061 	 * spa_load_verify_metadata is not set.  However, it may be useful
3062 	 * to manually set the flag after the traversal has begun.
3063 	 */
3064 	if (!spa_load_verify_metadata)
3065 		return (0);
3066 
3067 	/*
3068 	 * Stop the traversal as soon as the verdict is known, there is no
3069 	 * point in counting the errors we are not going to tolerate anyway.
3070 	 */
3071 	if (sle->sle_meta_count > sle->sle_maxmeta ||
3072 	    sle->sle_data_count > sle->sle_maxdata)
3073 		return (SET_ERROR(ECANCELED));
3074 
3075 	/*
3076 	 * Sanity check the block pointer in order to detect obvious damage
3077 	 * before using the contents in subsequent checks or in zio_read().
3078 	 * When damaged consider it to be a metadata error since we cannot
3079 	 * trust the BP_GET_TYPE and BP_GET_LEVEL values.
3080 	 */
3081 	if (zfs_blkptr_verify(spa, bp, BLK_CONFIG_NEEDED, BLK_VERIFY_LOG)) {
3082 		atomic_inc_64(&sle->sle_meta_count);
3083 		return (0);
3084 	}
3085 
3086 	if (zb->zb_level == ZB_DNODE_LEVEL || BP_IS_HOLE(bp) ||
3087 	    BP_IS_EMBEDDED(bp) || BP_IS_REDACTED(bp))
3088 		return (0);
3089 
3090 	if (!BP_IS_METADATA(bp) &&
3091 	    (!spa_load_verify_data || !sle->sle_verify_data))
3092 		return (0);
3093 
3094 	uint64_t maxinflight_bytes =
3095 	    arc_target_bytes() >> spa_load_verify_shift;
3096 	size_t size = BP_GET_PSIZE(bp);
3097 
3098 	mutex_enter(&spa->spa_scrub_lock);
3099 	while (spa->spa_load_verify_bytes >= maxinflight_bytes)
3100 		cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
3101 	spa->spa_load_verify_bytes += size;
3102 	mutex_exit(&spa->spa_scrub_lock);
3103 
3104 	zio_nowait(zio_read(rio, spa, bp, abd_alloc_for_io(size, B_FALSE), size,
3105 	    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
3106 	    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
3107 	    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
3108 	return (0);
3109 }
3110 
3111 static int
3112 verify_dataset_name_len(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
3113 {
3114 	(void) dp, (void) arg;
3115 
3116 	if (dsl_dataset_namelen(ds) >= ZFS_MAX_DATASET_NAME_LEN)
3117 		return (SET_ERROR(ENAMETOOLONG));
3118 
3119 	return (0);
3120 }
3121 
3122 static int
3123 spa_load_verify(spa_t *spa)
3124 {
3125 	zio_t *rio;
3126 	spa_load_error_t sle = { 0 };
3127 	zpool_load_policy_t policy;
3128 	boolean_t verify_ok = B_FALSE, aborted = B_FALSE;
3129 	int error = 0;
3130 
3131 	zpool_get_load_policy(spa->spa_config, &policy);
3132 
3133 	if (policy.zlp_rewind & ZPOOL_NEVER_REWIND ||
3134 	    policy.zlp_maxmeta == UINT64_MAX)
3135 		return (0);
3136 
3137 	dsl_pool_config_enter(spa->spa_dsl_pool, FTAG);
3138 	error = dmu_objset_find_dp(spa->spa_dsl_pool,
3139 	    spa->spa_dsl_pool->dp_root_dir_obj, verify_dataset_name_len, NULL,
3140 	    DS_FIND_CHILDREN);
3141 	dsl_pool_config_exit(spa->spa_dsl_pool, FTAG);
3142 	if (error != 0)
3143 		return (error);
3144 
3145 	/*
3146 	 * Verify data only if somebody is going to look at the error count:
3147 	 * either the caller set a limit for it, or we are only searching for
3148 	 * the best txg without rewinding to it (zpool import -nF), which
3149 	 * reports the count back to the user.
3150 	 */
3151 	sle.sle_verify_data = policy.zlp_maxdata < UINT64_MAX ||
3152 	    ((policy.zlp_rewind & ZPOOL_REWIND_MASK) &&
3153 	    (spa_load_verify_dryrun ||
3154 	    spa->spa_load_state != SPA_LOAD_RECOVER));
3155 
3156 	sle.sle_relaxmeta = policy.zlp_relaxmeta;
3157 
3158 	/*
3159 	 * Dry run reports the errors instead of acting on them, so it needs
3160 	 * the complete counts.  Otherwise stop counting once the thresholds
3161 	 * are exceeded, since the result can not change after that.
3162 	 */
3163 	if (spa_load_verify_dryrun) {
3164 		sle.sle_maxmeta = sle.sle_maxdata = UINT64_MAX;
3165 	} else {
3166 		sle.sle_maxmeta = policy.zlp_maxmeta;
3167 		sle.sle_maxdata = policy.zlp_maxdata;
3168 	}
3169 
3170 	rio = zio_root(spa, NULL, &sle,
3171 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
3172 
3173 	if (spa_load_verify_metadata) {
3174 		if (spa->spa_extreme_rewind) {
3175 			spa_load_note(spa, "performing a complete scan of the "
3176 			    "pool since extreme rewind is on. This may take "
3177 			    "a very long time.\n  (verifying metadata=%u, "
3178 			    "data=%u)", spa_load_verify_metadata,
3179 			    spa_load_verify_data && sle.sle_verify_data);
3180 		}
3181 
3182 		error = traverse_pool(spa, spa->spa_verify_min_txg,
3183 		    TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA |
3184 		    TRAVERSE_NO_DECRYPT | TRAVERSE_HARD,
3185 		    spa_load_verify_cb, rio);
3186 
3187 		/*
3188 		 * We aborted the traversal ourselves, so this is not a real
3189 		 * error, only the error counts below are now lower bounds.
3190 		 */
3191 		if (error == ECANCELED) {
3192 			error = 0;
3193 			aborted = B_TRUE;
3194 		}
3195 	}
3196 
3197 	(void) zio_wait(rio);
3198 	ASSERT0(spa->spa_load_verify_bytes);
3199 
3200 	spa->spa_load_meta_errors = sle.sle_meta_count;
3201 	spa->spa_load_data_errors = sle.sle_data_count;
3202 
3203 	if (sle.sle_meta_count != 0 || sle.sle_data_count != 0) {
3204 		spa_load_note(spa, "spa_load_verify found %s%llu metadata "
3205 		    "errors and %llu data errors",
3206 		    aborted ? "at least " : "",
3207 		    (u_longlong_t)sle.sle_meta_count,
3208 		    (u_longlong_t)sle.sle_data_count);
3209 	}
3210 
3211 	if (spa_load_verify_dryrun ||
3212 	    (!error && sle.sle_meta_count <= policy.zlp_maxmeta &&
3213 	    sle.sle_data_count <= policy.zlp_maxdata)) {
3214 		verify_ok = B_TRUE;
3215 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
3216 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
3217 
3218 		fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_LOAD_TXG,
3219 		    spa->spa_load_txg);
3220 		fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_LOAD_TIME,
3221 		    spa->spa_load_txg_ts);
3222 		/*
3223 		 * The loss makes sense only for a fallback to an older
3224 		 * uberblock, which is the only case we know the newest one in.
3225 		 */
3226 		if (spa->spa_last_ubsync_txg_ts != 0) {
3227 			fnvlist_add_int64(spa->spa_load_info,
3228 			    ZPOOL_CONFIG_REWIND_TIME,
3229 			    spa->spa_last_ubsync_txg_ts -
3230 			    spa->spa_load_txg_ts);
3231 		}
3232 		fnvlist_add_uint64(spa->spa_load_info,
3233 		    ZPOOL_CONFIG_LOAD_META_ERRORS, sle.sle_meta_count);
3234 		fnvlist_add_uint64(spa->spa_load_info,
3235 		    ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count);
3236 	} else {
3237 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
3238 	}
3239 
3240 	if (spa_load_verify_dryrun)
3241 		return (0);
3242 
3243 	if (error) {
3244 		if (error != ENXIO && error != EIO)
3245 			error = SET_ERROR(EIO);
3246 		return (error);
3247 	}
3248 
3249 	return (verify_ok ? 0 : EIO);
3250 }
3251 
3252 /*
3253  * Find a value in the pool props object.
3254  */
3255 static void
3256 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
3257 {
3258 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
3259 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
3260 }
3261 
3262 /*
3263  * Find a value in the pool directory object.
3264  */
3265 static int
3266 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val, boolean_t log_enoent)
3267 {
3268 	int error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
3269 	    name, sizeof (uint64_t), 1, val);
3270 
3271 	if (error != 0 && (error != ENOENT || log_enoent)) {
3272 		spa_load_failed(spa, "couldn't get '%s' value in MOS directory "
3273 		    "[error=%d]", name, error);
3274 	}
3275 
3276 	return (error);
3277 }
3278 
3279 static int
3280 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
3281 {
3282 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
3283 	return (SET_ERROR(err));
3284 }
3285 
3286 boolean_t
3287 spa_livelist_delete_check(spa_t *spa)
3288 {
3289 	return (spa->spa_livelists_to_delete != 0);
3290 }
3291 
3292 static boolean_t
3293 spa_livelist_delete_cb_check(void *arg, zthr_t *z)
3294 {
3295 	(void) z;
3296 	spa_t *spa = arg;
3297 	return (spa_livelist_delete_check(spa));
3298 }
3299 
3300 static int
3301 delete_blkptr_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
3302 {
3303 	spa_t *spa = arg;
3304 	zio_free(spa, tx->tx_txg, bp);
3305 	dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD,
3306 	    -bp_get_dsize_sync(spa, bp),
3307 	    -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx);
3308 	return (0);
3309 }
3310 
3311 static int
3312 dsl_get_next_livelist_obj(objset_t *os, uint64_t zap_obj, uint64_t *llp)
3313 {
3314 	int err;
3315 	zap_cursor_t zc;
3316 	zap_attribute_t *za = zap_attribute_alloc();
3317 	zap_cursor_init(&zc, os, zap_obj);
3318 	err = zap_cursor_retrieve(&zc, za);
3319 	zap_cursor_fini(&zc);
3320 	if (err == 0)
3321 		*llp = za->za_first_integer;
3322 	zap_attribute_free(za);
3323 	return (err);
3324 }
3325 
3326 /*
3327  * Components of livelist deletion that must be performed in syncing
3328  * context: freeing block pointers and updating the pool-wide data
3329  * structures to indicate how much work is left to do
3330  */
3331 typedef struct sublist_delete_arg {
3332 	spa_t *spa;
3333 	dsl_deadlist_t *ll;
3334 	uint64_t key;
3335 	bplist_t *to_free;
3336 } sublist_delete_arg_t;
3337 
3338 static void
3339 sublist_delete_sync(void *arg, dmu_tx_t *tx)
3340 {
3341 	sublist_delete_arg_t *sda = arg;
3342 	spa_t *spa = sda->spa;
3343 	dsl_deadlist_t *ll = sda->ll;
3344 	uint64_t key = sda->key;
3345 	bplist_t *to_free = sda->to_free;
3346 
3347 	bplist_iterate(to_free, delete_blkptr_cb, spa, tx);
3348 	dsl_deadlist_remove_entry(ll, key, tx);
3349 }
3350 
3351 typedef struct livelist_delete_arg {
3352 	spa_t *spa;
3353 	uint64_t ll_obj;
3354 	uint64_t zap_obj;
3355 } livelist_delete_arg_t;
3356 
3357 static void
3358 livelist_delete_sync(void *arg, dmu_tx_t *tx)
3359 {
3360 	livelist_delete_arg_t *lda = arg;
3361 	spa_t *spa = lda->spa;
3362 	uint64_t ll_obj = lda->ll_obj;
3363 	uint64_t zap_obj = lda->zap_obj;
3364 	objset_t *mos = spa->spa_meta_objset;
3365 	uint64_t count;
3366 
3367 	/* free the livelist and decrement the feature count */
3368 	VERIFY0(zap_remove_int(mos, zap_obj, ll_obj, tx));
3369 	dsl_deadlist_free(mos, ll_obj, tx);
3370 	spa_feature_decr(spa, SPA_FEATURE_LIVELIST, tx);
3371 	VERIFY0(zap_count(mos, zap_obj, &count));
3372 	if (count == 0) {
3373 		/* no more livelists to delete */
3374 		VERIFY0(zap_remove(mos, DMU_POOL_DIRECTORY_OBJECT,
3375 		    DMU_POOL_DELETED_CLONES, tx));
3376 		VERIFY0(zap_destroy(mos, zap_obj, tx));
3377 		spa->spa_livelists_to_delete = 0;
3378 		spa_notify_waiters(spa);
3379 	}
3380 }
3381 
3382 /*
3383  * Load in the value for the livelist to be removed and open it. Then,
3384  * load its first sublist and determine which block pointers should actually
3385  * be freed. Then, call a synctask which performs the actual frees and updates
3386  * the pool-wide livelist data.
3387  */
3388 static void
3389 spa_livelist_delete_cb(void *arg, zthr_t *z)
3390 {
3391 	spa_t *spa = arg;
3392 	uint64_t ll_obj = 0, count;
3393 	objset_t *mos = spa->spa_meta_objset;
3394 	uint64_t zap_obj = spa->spa_livelists_to_delete;
3395 	/*
3396 	 * Determine the next livelist to delete. This function should only
3397 	 * be called if there is at least one deleted clone.
3398 	 */
3399 	VERIFY0(dsl_get_next_livelist_obj(mos, zap_obj, &ll_obj));
3400 	VERIFY0(zap_count(mos, ll_obj, &count));
3401 	if (count > 0) {
3402 		dsl_deadlist_t *ll;
3403 		dsl_deadlist_entry_t *dle;
3404 		bplist_t to_free;
3405 		ll = kmem_zalloc(sizeof (dsl_deadlist_t), KM_SLEEP);
3406 		VERIFY0(dsl_deadlist_open(ll, mos, ll_obj));
3407 		dle = dsl_deadlist_first(ll);
3408 		ASSERT3P(dle, !=, NULL);
3409 		bplist_create(&to_free);
3410 		int err = dsl_process_sub_livelist(&dle->dle_bpobj, &to_free,
3411 		    z, NULL);
3412 		if (err == 0) {
3413 			sublist_delete_arg_t sync_arg = {
3414 			    .spa = spa,
3415 			    .ll = ll,
3416 			    .key = dle->dle_mintxg,
3417 			    .to_free = &to_free
3418 			};
3419 			zfs_dbgmsg("deleting sublist (id %llu) from"
3420 			    " livelist %llu, %lld remaining",
3421 			    (u_longlong_t)dle->dle_bpobj.bpo_object,
3422 			    (u_longlong_t)ll_obj, (longlong_t)count - 1);
3423 			VERIFY0(dsl_sync_task(spa_name(spa), NULL,
3424 			    sublist_delete_sync, &sync_arg, 0,
3425 			    ZFS_SPACE_CHECK_DESTROY));
3426 		} else {
3427 			VERIFY3U(err, ==, EINTR);
3428 		}
3429 		bplist_clear(&to_free);
3430 		bplist_destroy(&to_free);
3431 		dsl_deadlist_close(ll);
3432 		kmem_free(ll, sizeof (dsl_deadlist_t));
3433 	} else {
3434 		livelist_delete_arg_t sync_arg = {
3435 		    .spa = spa,
3436 		    .ll_obj = ll_obj,
3437 		    .zap_obj = zap_obj
3438 		};
3439 		zfs_dbgmsg("deletion of livelist %llu completed",
3440 		    (u_longlong_t)ll_obj);
3441 		VERIFY0(dsl_sync_task(spa_name(spa), NULL, livelist_delete_sync,
3442 		    &sync_arg, 0, ZFS_SPACE_CHECK_DESTROY));
3443 	}
3444 }
3445 
3446 static void
3447 spa_start_livelist_destroy_thread(spa_t *spa)
3448 {
3449 	ASSERT0P(spa->spa_livelist_delete_zthr);
3450 	spa->spa_livelist_delete_zthr =
3451 	    zthr_create("z_livelist_destroy",
3452 	    spa_livelist_delete_cb_check, spa_livelist_delete_cb, spa,
3453 	    minclsyspri);
3454 }
3455 
3456 typedef struct livelist_new_arg {
3457 	bplist_t *allocs;
3458 	bplist_t *frees;
3459 } livelist_new_arg_t;
3460 
3461 static int
3462 livelist_track_new_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
3463     dmu_tx_t *tx)
3464 {
3465 	ASSERT0P(tx);
3466 	livelist_new_arg_t *lna = arg;
3467 	if (bp_freed) {
3468 		bplist_append(lna->frees, bp);
3469 	} else {
3470 		bplist_append(lna->allocs, bp);
3471 		zfs_livelist_condense_new_alloc++;
3472 	}
3473 	return (0);
3474 }
3475 
3476 typedef struct livelist_condense_arg {
3477 	spa_t *spa;
3478 	bplist_t to_keep;
3479 	uint64_t first_size;
3480 	uint64_t next_size;
3481 } livelist_condense_arg_t;
3482 
3483 static void
3484 spa_livelist_condense_sync(void *arg, dmu_tx_t *tx)
3485 {
3486 	livelist_condense_arg_t *lca = arg;
3487 	spa_t *spa = lca->spa;
3488 	bplist_t new_frees;
3489 	dsl_dataset_t *ds = spa->spa_to_condense.ds;
3490 
3491 	/* Have we been cancelled? */
3492 	if (spa->spa_to_condense.cancelled) {
3493 		zfs_livelist_condense_sync_cancel++;
3494 		goto out;
3495 	}
3496 
3497 	dsl_deadlist_entry_t *first = spa->spa_to_condense.first;
3498 	dsl_deadlist_entry_t *next = spa->spa_to_condense.next;
3499 	dsl_deadlist_t *ll = &ds->ds_dir->dd_livelist;
3500 
3501 	/*
3502 	 * It's possible that the livelist was changed while the zthr was
3503 	 * running. Therefore, we need to check for new blkptrs in the two
3504 	 * entries being condensed and continue to track them in the livelist.
3505 	 * Because of the way we handle remapped blkptrs (see dbuf_remap_impl),
3506 	 * it's possible that the newly added blkptrs are FREEs or ALLOCs so
3507 	 * we need to sort them into two different bplists.
3508 	 */
3509 	uint64_t first_obj = first->dle_bpobj.bpo_object;
3510 	uint64_t next_obj = next->dle_bpobj.bpo_object;
3511 	uint64_t cur_first_size = first->dle_bpobj.bpo_phys->bpo_num_blkptrs;
3512 	uint64_t cur_next_size = next->dle_bpobj.bpo_phys->bpo_num_blkptrs;
3513 
3514 	bplist_create(&new_frees);
3515 	livelist_new_arg_t new_bps = {
3516 	    .allocs = &lca->to_keep,
3517 	    .frees = &new_frees,
3518 	};
3519 
3520 	if (cur_first_size > lca->first_size) {
3521 		VERIFY0(livelist_bpobj_iterate_from_nofree(&first->dle_bpobj,
3522 		    livelist_track_new_cb, &new_bps, lca->first_size));
3523 	}
3524 	if (cur_next_size > lca->next_size) {
3525 		VERIFY0(livelist_bpobj_iterate_from_nofree(&next->dle_bpobj,
3526 		    livelist_track_new_cb, &new_bps, lca->next_size));
3527 	}
3528 
3529 	dsl_deadlist_clear_entry(first, ll, tx);
3530 	ASSERT(bpobj_is_empty(&first->dle_bpobj));
3531 	dsl_deadlist_remove_entry(ll, next->dle_mintxg, tx);
3532 
3533 	bplist_iterate(&lca->to_keep, dsl_deadlist_insert_alloc_cb, ll, tx);
3534 	bplist_iterate(&new_frees, dsl_deadlist_insert_free_cb, ll, tx);
3535 	bplist_destroy(&new_frees);
3536 
3537 	char dsname[ZFS_MAX_DATASET_NAME_LEN];
3538 	dsl_dataset_name(ds, dsname);
3539 	zfs_dbgmsg("txg %llu condensing livelist of %s (id %llu), bpobj %llu "
3540 	    "(%llu blkptrs) and bpobj %llu (%llu blkptrs) -> bpobj %llu "
3541 	    "(%llu blkptrs)", (u_longlong_t)tx->tx_txg, dsname,
3542 	    (u_longlong_t)ds->ds_object, (u_longlong_t)first_obj,
3543 	    (u_longlong_t)cur_first_size, (u_longlong_t)next_obj,
3544 	    (u_longlong_t)cur_next_size,
3545 	    (u_longlong_t)first->dle_bpobj.bpo_object,
3546 	    (u_longlong_t)first->dle_bpobj.bpo_phys->bpo_num_blkptrs);
3547 out:
3548 	dmu_buf_rele(ds->ds_dbuf, spa);
3549 	spa->spa_to_condense.ds = NULL;
3550 	bplist_clear(&lca->to_keep);
3551 	bplist_destroy(&lca->to_keep);
3552 	kmem_free(lca, sizeof (livelist_condense_arg_t));
3553 	spa->spa_to_condense.syncing = B_FALSE;
3554 }
3555 
3556 static void
3557 spa_livelist_condense_cb(void *arg, zthr_t *t)
3558 {
3559 	while (zfs_livelist_condense_zthr_pause &&
3560 	    !(zthr_has_waiters(t) || zthr_iscancelled(t)))
3561 		delay(1);
3562 
3563 	spa_t *spa = arg;
3564 	dsl_deadlist_entry_t *first = spa->spa_to_condense.first;
3565 	dsl_deadlist_entry_t *next = spa->spa_to_condense.next;
3566 	uint64_t first_size, next_size;
3567 
3568 	livelist_condense_arg_t *lca =
3569 	    kmem_alloc(sizeof (livelist_condense_arg_t), KM_SLEEP);
3570 	bplist_create(&lca->to_keep);
3571 
3572 	/*
3573 	 * Process the livelists (matching FREEs and ALLOCs) in open context
3574 	 * so we have minimal work in syncing context to condense.
3575 	 *
3576 	 * We save bpobj sizes (first_size and next_size) to use later in
3577 	 * syncing context to determine if entries were added to these sublists
3578 	 * while in open context. This is possible because the clone is still
3579 	 * active and open for normal writes and we want to make sure the new,
3580 	 * unprocessed blockpointers are inserted into the livelist normally.
3581 	 *
3582 	 * Note that dsl_process_sub_livelist() both stores the size number of
3583 	 * blockpointers and iterates over them while the bpobj's lock held, so
3584 	 * the sizes returned to us are consistent which what was actually
3585 	 * processed.
3586 	 */
3587 	int err = dsl_process_sub_livelist(&first->dle_bpobj, &lca->to_keep, t,
3588 	    &first_size);
3589 	if (err == 0)
3590 		err = dsl_process_sub_livelist(&next->dle_bpobj, &lca->to_keep,
3591 		    t, &next_size);
3592 
3593 	if (err == 0) {
3594 		while (zfs_livelist_condense_sync_pause &&
3595 		    !(zthr_has_waiters(t) || zthr_iscancelled(t)))
3596 			delay(1);
3597 
3598 		dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
3599 		dmu_tx_mark_netfree(tx);
3600 		dmu_tx_hold_space(tx, 1);
3601 		err = dmu_tx_assign(tx, DMU_TX_NOWAIT | DMU_TX_NOTHROTTLE);
3602 		if (err == 0) {
3603 			/*
3604 			 * Prevent the condense zthr restarting before
3605 			 * the synctask completes.
3606 			 */
3607 			spa->spa_to_condense.syncing = B_TRUE;
3608 			lca->spa = spa;
3609 			lca->first_size = first_size;
3610 			lca->next_size = next_size;
3611 			dsl_sync_task_nowait(spa_get_dsl(spa),
3612 			    spa_livelist_condense_sync, lca, tx);
3613 			dmu_tx_commit(tx);
3614 			return;
3615 		}
3616 	}
3617 	/*
3618 	 * Condensing can not continue: either it was externally stopped or
3619 	 * we were unable to assign to a tx because the pool has run out of
3620 	 * space. In the second case, we'll just end up trying to condense
3621 	 * again in a later txg.
3622 	 */
3623 	ASSERT(err != 0);
3624 	bplist_clear(&lca->to_keep);
3625 	bplist_destroy(&lca->to_keep);
3626 	kmem_free(lca, sizeof (livelist_condense_arg_t));
3627 	dmu_buf_rele(spa->spa_to_condense.ds->ds_dbuf, spa);
3628 	spa->spa_to_condense.ds = NULL;
3629 	if (err == EINTR)
3630 		zfs_livelist_condense_zthr_cancel++;
3631 }
3632 
3633 /*
3634  * Check that there is something to condense but that a condense is not
3635  * already in progress and that condensing has not been cancelled.
3636  */
3637 static boolean_t
3638 spa_livelist_condense_cb_check(void *arg, zthr_t *z)
3639 {
3640 	(void) z;
3641 	spa_t *spa = arg;
3642 	if ((spa->spa_to_condense.ds != NULL) &&
3643 	    (spa->spa_to_condense.syncing == B_FALSE) &&
3644 	    (spa->spa_to_condense.cancelled == B_FALSE)) {
3645 		return (B_TRUE);
3646 	}
3647 	return (B_FALSE);
3648 }
3649 
3650 static void
3651 spa_start_livelist_condensing_thread(spa_t *spa)
3652 {
3653 	spa->spa_to_condense.ds = NULL;
3654 	spa->spa_to_condense.first = NULL;
3655 	spa->spa_to_condense.next = NULL;
3656 	spa->spa_to_condense.syncing = B_FALSE;
3657 	spa->spa_to_condense.cancelled = B_FALSE;
3658 
3659 	ASSERT0P(spa->spa_livelist_condense_zthr);
3660 	spa->spa_livelist_condense_zthr =
3661 	    zthr_create("z_livelist_condense",
3662 	    spa_livelist_condense_cb_check,
3663 	    spa_livelist_condense_cb, spa, minclsyspri);
3664 }
3665 
3666 static void
3667 spa_spawn_aux_threads(spa_t *spa)
3668 {
3669 	ASSERT(spa_writeable(spa));
3670 
3671 	spa_start_raidz_expansion_thread(spa);
3672 	spa_start_indirect_condensing_thread(spa);
3673 	spa_start_livelist_destroy_thread(spa);
3674 	spa_start_livelist_condensing_thread(spa);
3675 
3676 	ASSERT0P(spa->spa_checkpoint_discard_zthr);
3677 	spa->spa_checkpoint_discard_zthr =
3678 	    zthr_create("z_checkpoint_discard",
3679 	    spa_checkpoint_discard_thread_check,
3680 	    spa_checkpoint_discard_thread, spa, minclsyspri);
3681 }
3682 
3683 /*
3684  * Fix up config after a partly-completed split.  This is done with the
3685  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
3686  * pool have that entry in their config, but only the splitting one contains
3687  * a list of all the guids of the vdevs that are being split off.
3688  *
3689  * This function determines what to do with that list: either rejoin
3690  * all the disks to the pool, or complete the splitting process.  To attempt
3691  * the rejoin, each disk that is offlined is marked online again, and
3692  * we do a reopen() call.  If the vdev label for every disk that was
3693  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
3694  * then we call vdev_split() on each disk, and complete the split.
3695  *
3696  * Otherwise we leave the config alone, with all the vdevs in place in
3697  * the original pool.
3698  */
3699 static void
3700 spa_try_repair(spa_t *spa, nvlist_t *config)
3701 {
3702 	uint_t extracted;
3703 	uint64_t *glist;
3704 	uint_t i, gcount;
3705 	nvlist_t *nvl;
3706 	vdev_t **vd;
3707 	boolean_t attempt_reopen;
3708 
3709 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
3710 		return;
3711 
3712 	/* check that the config is complete */
3713 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
3714 	    &glist, &gcount) != 0)
3715 		return;
3716 
3717 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
3718 
3719 	/* attempt to online all the vdevs & validate */
3720 	attempt_reopen = B_TRUE;
3721 	for (i = 0; i < gcount; i++) {
3722 		if (glist[i] == 0)	/* vdev is hole */
3723 			continue;
3724 
3725 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
3726 		if (vd[i] == NULL) {
3727 			/*
3728 			 * Don't bother attempting to reopen the disks;
3729 			 * just do the split.
3730 			 */
3731 			attempt_reopen = B_FALSE;
3732 		} else {
3733 			/* attempt to re-online it */
3734 			vd[i]->vdev_offline = B_FALSE;
3735 		}
3736 	}
3737 
3738 	if (attempt_reopen) {
3739 		vdev_reopen(spa->spa_root_vdev);
3740 
3741 		/* check each device to see what state it's in */
3742 		for (extracted = 0, i = 0; i < gcount; i++) {
3743 			if (vd[i] != NULL &&
3744 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
3745 				break;
3746 			++extracted;
3747 		}
3748 	}
3749 
3750 	/*
3751 	 * If every disk has been moved to the new pool, or if we never
3752 	 * even attempted to look at them, then we split them off for
3753 	 * good.
3754 	 */
3755 	if (!attempt_reopen || gcount == extracted) {
3756 		for (i = 0; i < gcount; i++)
3757 			if (vd[i] != NULL)
3758 				vdev_split(vd[i]);
3759 		vdev_reopen(spa->spa_root_vdev);
3760 	}
3761 
3762 	kmem_free(vd, gcount * sizeof (vdev_t *));
3763 }
3764 
3765 static int
3766 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type)
3767 {
3768 	const char *ereport = FM_EREPORT_ZFS_POOL;
3769 	int error;
3770 
3771 	spa->spa_load_state = state;
3772 	(void) spa_import_progress_set_state(spa_guid(spa),
3773 	    spa_load_state(spa));
3774 	spa_import_progress_set_notes(spa, "spa_load()");
3775 
3776 	gethrestime(&spa->spa_loaded_ts);
3777 	error = spa_load_impl(spa, type, &ereport);
3778 
3779 	/*
3780 	 * Don't count references from objsets that are already closed
3781 	 * and are making their way through the eviction process.
3782 	 */
3783 	spa_evicting_os_wait(spa);
3784 	spa->spa_minref = zfs_refcount_count(&spa->spa_refcount);
3785 	if (error) {
3786 		if (error != EEXIST) {
3787 			spa->spa_loaded_ts.tv_sec = 0;
3788 			spa->spa_loaded_ts.tv_nsec = 0;
3789 		}
3790 		if (error != EBADF) {
3791 			(void) zfs_ereport_post(ereport, spa,
3792 			    NULL, NULL, NULL, 0);
3793 		}
3794 	}
3795 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
3796 	spa->spa_ena = 0;
3797 
3798 	(void) spa_import_progress_set_state(spa_guid(spa),
3799 	    spa_load_state(spa));
3800 
3801 	return (error);
3802 }
3803 
3804 #ifdef ZFS_DEBUG
3805 /*
3806  * Count the number of per-vdev ZAPs associated with all of the vdevs in the
3807  * vdev tree rooted in the given vd, and ensure that each ZAP is present in the
3808  * spa's per-vdev ZAP list.
3809  */
3810 static uint64_t
3811 vdev_count_verify_zaps(vdev_t *vd)
3812 {
3813 	spa_t *spa = vd->vdev_spa;
3814 	uint64_t total = 0;
3815 
3816 	if (spa_feature_is_active(vd->vdev_spa, SPA_FEATURE_AVZ_V2) &&
3817 	    vd->vdev_root_zap != 0) {
3818 		total++;
3819 		ASSERT0(zap_lookup_int(spa->spa_meta_objset,
3820 		    spa->spa_all_vdev_zaps, vd->vdev_root_zap));
3821 	}
3822 	if (vd->vdev_top_zap != 0) {
3823 		total++;
3824 		ASSERT0(zap_lookup_int(spa->spa_meta_objset,
3825 		    spa->spa_all_vdev_zaps, vd->vdev_top_zap));
3826 	}
3827 	if (vd->vdev_leaf_zap != 0) {
3828 		total++;
3829 		ASSERT0(zap_lookup_int(spa->spa_meta_objset,
3830 		    spa->spa_all_vdev_zaps, vd->vdev_leaf_zap));
3831 	}
3832 
3833 	for (uint64_t i = 0; i < vd->vdev_children; i++) {
3834 		total += vdev_count_verify_zaps(vd->vdev_child[i]);
3835 	}
3836 
3837 	return (total);
3838 }
3839 #else
3840 #define	vdev_count_verify_zaps(vd) ((void) sizeof (vd), 0)
3841 #endif
3842 
3843 /*
3844  * Check the results load_info results from previous tryimport.
3845  *
3846  * error results:
3847  *          0 - Pool remains in an idle state
3848  *  EREMOTEIO - Pool was known to be active on the other host
3849  *     ENOENT - The config does not contain complete tryimport info
3850  */
3851 static int
3852 spa_activity_verify_config(spa_t *spa, uberblock_t *ub)
3853 {
3854 	uint64_t tryconfig_mmp_state = MMP_STATE_ACTIVE;
3855 	uint64_t tryconfig_txg = 0;
3856 	uint64_t tryconfig_timestamp = 0;
3857 	uint16_t tryconfig_mmp_seq = 0;
3858 	nvlist_t *nvinfo, *config = spa->spa_config;
3859 	int error;
3860 
3861 	/* Simply a non-zero value to indicate the verify was done. */
3862 	spa->spa_mmp.mmp_import_ns = 1000;
3863 
3864 	error = nvlist_lookup_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, &nvinfo);
3865 	if (error)
3866 		return (SET_ERROR(ENOENT));
3867 
3868 	/*
3869 	 * If ZPOOL_CONFIG_MMP_STATE is present an activity check was performed
3870 	 * during the earlier tryimport.  If the state recorded there isn't
3871 	 * MMP_STATE_INACTIVE the pool is known to be active on another host.
3872 	 */
3873 	error = nvlist_lookup_uint64(nvinfo, ZPOOL_CONFIG_MMP_STATE,
3874 	    &tryconfig_mmp_state);
3875 	if (error)
3876 		return (SET_ERROR(ENOENT));
3877 
3878 	if (tryconfig_mmp_state != MMP_STATE_INACTIVE) {
3879 		spa_load_failed(spa, "mmp: pool is active on remote host, "
3880 		    "state=%llu", (u_longlong_t)tryconfig_mmp_state);
3881 		return (SET_ERROR(EREMOTEIO));
3882 	}
3883 
3884 	/*
3885 	 * If ZPOOL_CONFIG_MMP_TXG is present an activity check was performed
3886 	 * during the earlier tryimport.  If the txg recorded there is 0 then
3887 	 * the pool is known to be active on another host.
3888 	 */
3889 	error = nvlist_lookup_uint64(nvinfo, ZPOOL_CONFIG_MMP_TXG,
3890 	    &tryconfig_txg);
3891 	if (error)
3892 		return (SET_ERROR(ENOENT));
3893 
3894 	if (tryconfig_txg == 0) {
3895 		spa_load_failed(spa, "mmp: pool is active on remote host, "
3896 		    "tryconfig_txg=%llu", (u_longlong_t)tryconfig_txg);
3897 		return (SET_ERROR(EREMOTEIO));
3898 	}
3899 
3900 	error = nvlist_lookup_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
3901 	    &tryconfig_timestamp);
3902 	if (error)
3903 		return (SET_ERROR(ENOENT));
3904 
3905 	error = nvlist_lookup_uint16(nvinfo, ZPOOL_CONFIG_MMP_SEQ,
3906 	    &tryconfig_mmp_seq);
3907 	if (error)
3908 		return (SET_ERROR(ENOENT));
3909 
3910 	if (tryconfig_timestamp == ub->ub_timestamp &&
3911 	    tryconfig_txg == ub->ub_txg &&
3912 	    MMP_SEQ_VALID(ub) && tryconfig_mmp_seq == MMP_SEQ(ub)) {
3913 		zfs_dbgmsg("mmp: verified pool mmp tryimport config, "
3914 		    "spa=%s", spa_load_name(spa));
3915 		return (0);
3916 	}
3917 
3918 	spa_load_failed(spa, "mmp: pool is active on remote host, "
3919 	    "tc_timestamp=%llu ub_timestamp=%llu "
3920 	    "tc_txg=%llu ub_txg=%llu tc_seq=%llu ub_seq=%llu",
3921 	    (u_longlong_t)tryconfig_timestamp, (u_longlong_t)ub->ub_timestamp,
3922 	    (u_longlong_t)tryconfig_txg, (u_longlong_t)ub->ub_txg,
3923 	    (u_longlong_t)tryconfig_mmp_seq, (u_longlong_t)MMP_SEQ(ub));
3924 
3925 	return (SET_ERROR(EREMOTEIO));
3926 }
3927 
3928 /*
3929  * Determine whether the activity check is required.
3930  */
3931 static boolean_t
3932 spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label)
3933 {
3934 	nvlist_t *config = spa->spa_config;
3935 	uint64_t state = POOL_STATE_ACTIVE;
3936 	uint64_t hostid = 0;
3937 
3938 	/*
3939 	 * Disable the MMP activity check - This is used by zdb which
3940 	 * is always read-only and intended to be used on potentially
3941 	 * active pools.
3942 	 */
3943 	if (spa->spa_import_flags & ZFS_IMPORT_SKIP_MMP) {
3944 		zfs_dbgmsg("mmp: skipping check ZFS_IMPORT_SKIP_MMP is set, "
3945 		    "spa=%s", spa_load_name(spa));
3946 		return (B_FALSE);
3947 	}
3948 
3949 	/*
3950 	 * Skip the activity check when the MMP feature is disabled.
3951 	 * - MMP_MAGIC not set - Legacy pool predates the MMP feature, or
3952 	 * - MMP_MAGIC set && mmp_delay == 0 - MMP feature is disabled.
3953 	 */
3954 	if ((ub->ub_mmp_magic != MMP_MAGIC) ||
3955 	    (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay == 0)) {
3956 		zfs_dbgmsg("mmp: skipping check: feature is disabled, "
3957 		    "spa=%s", spa_load_name(spa));
3958 		return (B_FALSE);
3959 	}
3960 
3961 	/*
3962 	 * Allow the activity check to be skipped when importing a cleanly
3963 	 * exported pool on the same host which last imported it.  Since the
3964 	 * hostid from configuration may be stale use the one read from the
3965 	 * label.  Imports from other hostids must perform the activity check.
3966 	 */
3967 	if (label != NULL) {
3968 		if (nvlist_exists(label, ZPOOL_CONFIG_HOSTID))
3969 			hostid = fnvlist_lookup_uint64(label,
3970 			    ZPOOL_CONFIG_HOSTID);
3971 
3972 		if (nvlist_exists(config, ZPOOL_CONFIG_POOL_STATE))
3973 			state = fnvlist_lookup_uint64(config,
3974 			    ZPOOL_CONFIG_POOL_STATE);
3975 
3976 		if (spa_get_hostid(spa) && hostid == spa_get_hostid(spa) &&
3977 		    state == POOL_STATE_EXPORTED) {
3978 			zfs_dbgmsg("mmp: skipping check: hostid matches "
3979 			    "and pool is exported, spa=%s, hostid=%llx",
3980 			    spa_load_name(spa), (u_longlong_t)hostid);
3981 			return (B_FALSE);
3982 		}
3983 
3984 		if (state == POOL_STATE_DESTROYED) {
3985 			zfs_dbgmsg("mmp: skipping check: intentionally "
3986 			    "destroyed pool, spa=%s", spa_load_name(spa));
3987 			return (B_FALSE);
3988 		}
3989 	}
3990 
3991 	return (B_TRUE);
3992 }
3993 
3994 /*
3995  * Nanoseconds the activity check must watch for changes on-disk.
3996  */
3997 static uint64_t
3998 spa_activity_check_duration(spa_t *spa, uberblock_t *ub)
3999 {
4000 	uint64_t import_intervals = MAX(zfs_multihost_import_intervals, 1);
4001 	uint64_t multihost_interval = MSEC2NSEC(
4002 	    MMP_INTERVAL_OK(zfs_multihost_interval));
4003 	uint64_t import_delay = MAX(NANOSEC, import_intervals *
4004 	    multihost_interval);
4005 
4006 	/*
4007 	 * Local tunables determine a minimum duration except for the case
4008 	 * where we know when the remote host will suspend the pool if MMP
4009 	 * writes do not land.
4010 	 *
4011 	 * See Big Theory comment at the top of mmp.c for the reasoning behind
4012 	 * these cases and times.
4013 	 */
4014 
4015 	ASSERT(MMP_IMPORT_SAFETY_FACTOR >= 100);
4016 
4017 	if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
4018 	    MMP_FAIL_INT(ub) > 0) {
4019 
4020 		/* MMP on remote host will suspend pool after failed writes */
4021 		import_delay = MMP_FAIL_INT(ub) * MSEC2NSEC(MMP_INTERVAL(ub)) *
4022 		    MMP_IMPORT_SAFETY_FACTOR / 100;
4023 
4024 		zfs_dbgmsg("mmp: settings spa=%s fail_intvals>0 "
4025 		    "import_delay=%llu mmp_fails=%llu mmp_interval=%llu "
4026 		    "import_intervals=%llu", spa_load_name(spa),
4027 		    (u_longlong_t)import_delay,
4028 		    (u_longlong_t)MMP_FAIL_INT(ub),
4029 		    (u_longlong_t)MMP_INTERVAL(ub),
4030 		    (u_longlong_t)import_intervals);
4031 
4032 	} else if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
4033 	    MMP_FAIL_INT(ub) == 0) {
4034 
4035 		/* MMP on remote host will never suspend pool */
4036 		import_delay = MAX(import_delay, (MSEC2NSEC(MMP_INTERVAL(ub)) +
4037 		    ub->ub_mmp_delay) * import_intervals);
4038 
4039 		zfs_dbgmsg("mmp: settings spa=%s fail_intvals=0 "
4040 		    "import_delay=%llu mmp_interval=%llu ub_mmp_delay=%llu "
4041 		    "import_intervals=%llu", spa_load_name(spa),
4042 		    (u_longlong_t)import_delay,
4043 		    (u_longlong_t)MMP_INTERVAL(ub),
4044 		    (u_longlong_t)ub->ub_mmp_delay,
4045 		    (u_longlong_t)import_intervals);
4046 
4047 	} else if (MMP_VALID(ub)) {
4048 		/*
4049 		 * zfs-0.7 compatibility case
4050 		 */
4051 
4052 		import_delay = MAX(import_delay, (multihost_interval +
4053 		    ub->ub_mmp_delay) * import_intervals);
4054 
4055 		zfs_dbgmsg("mmp: settings spa=%s import_delay=%llu "
4056 		    "ub_mmp_delay=%llu import_intervals=%llu leaves=%u",
4057 		    spa_load_name(spa), (u_longlong_t)import_delay,
4058 		    (u_longlong_t)ub->ub_mmp_delay,
4059 		    (u_longlong_t)import_intervals,
4060 		    vdev_count_leaves(spa));
4061 	} else {
4062 		/* Using local tunings is the only reasonable option */
4063 		zfs_dbgmsg("mmp: pool last imported on non-MMP aware "
4064 		    "host using settings spa=%s import_delay=%llu "
4065 		    "multihost_interval=%llu import_intervals=%llu",
4066 		    spa_load_name(spa), (u_longlong_t)import_delay,
4067 		    (u_longlong_t)multihost_interval,
4068 		    (u_longlong_t)import_intervals);
4069 	}
4070 
4071 	return (import_delay);
4072 }
4073 
4074 /*
4075  * Store the observed pool status in spa->spa_load_info nvlist.  If the
4076  * remote hostname or hostid are available from configuration read from
4077  * disk store them as well.  Additionally, provide some diagnostic info
4078  * for which activity checks were run and their duration.  This allows
4079  * 'zpool import' to generate a more useful message.
4080  *
4081  * Mandatory observed pool status
4082  * - ZPOOL_CONFIG_MMP_STATE        - observed pool status (active/inactive)
4083  * - ZPOOL_CONFIG_MMP_TXG          - observed pool txg number
4084  * - ZPOOL_CONFIG_MMP_SEQ          - observed pool sequence id
4085  *
4086  * Optional information for detailed reporting
4087  * - ZPOOL_CONFIG_MMP_HOSTNAME     - hostname from the active pool
4088  * - ZPOOL_CONFIG_MMP_HOSTID       - hostid from the active pool
4089  * - ZPOOL_CONFIG_MMP_RESULT	 - set to result of activity check
4090  * - ZPOOL_CONFIG_MMP_TRYIMPORT_NS - tryimport duration in nanosec
4091  * - ZPOOL_CONFIG_MMP_IMPORT_NS    - import duration in nanosec
4092  * - ZPOOL_CONFIG_MMP_CLAIM_NS     - claim duration in nanosec
4093  *
4094  * ZPOOL_CONFIG_MMP_RESULT can be set to:
4095  * - ENXIO	- system hostid not set
4096  * - ESRCH	- activity check skipped
4097  * - EREMOTEIO	- activity check detected active pool
4098  * - ENODEV	- claim could not be written to a device the config expects
4099  * - EIO	- claim writes were issued to present devices and failed
4100  * - EINTR	- activity check interrupted
4101  * - 0		- activity check detected no activity
4102  *
4103  * ENODEV and EIO are reported with ZPOOL_CONFIG_MMP_STATE set to
4104  * MMP_STATE_ACTIVE even though no remote host was seen.  Nothing is actually
4105  * active in either case, but an older zpool(8) knows only the two existing
4106  * states and reaches zfs_error_aux() with an uninitialized buffer for any
4107  * other value, so the state is kept as one it understands and the real cause
4108  * travels in the result.
4109  */
4110 static void
4111 spa_activity_set_load_info(spa_t *spa, nvlist_t *label, mmp_state_t state,
4112     uint64_t txg, uint16_t seq, int error)
4113 {
4114 	mmp_thread_t *mmp = &spa->spa_mmp;
4115 	const char *hostname = NULL;
4116 	uint64_t hostid = 0;
4117 
4118 	/* Always report a zero txg and seq id for active pools. */
4119 	if (state == MMP_STATE_ACTIVE) {
4120 		ASSERT0(txg);
4121 		ASSERT0(seq);
4122 	}
4123 
4124 	if (label) {
4125 		if (nvlist_exists(label, ZPOOL_CONFIG_HOSTNAME)) {
4126 			hostname = fnvlist_lookup_string(label,
4127 			    ZPOOL_CONFIG_HOSTNAME);
4128 			fnvlist_add_string(spa->spa_load_info,
4129 			    ZPOOL_CONFIG_MMP_HOSTNAME, hostname);
4130 		}
4131 
4132 		if (nvlist_exists(label, ZPOOL_CONFIG_HOSTID)) {
4133 			hostid = fnvlist_lookup_uint64(label,
4134 			    ZPOOL_CONFIG_HOSTID);
4135 			fnvlist_add_uint64(spa->spa_load_info,
4136 			    ZPOOL_CONFIG_MMP_HOSTID, hostid);
4137 		}
4138 	}
4139 
4140 	fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_MMP_STATE, state);
4141 	fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_MMP_TXG, txg);
4142 	fnvlist_add_uint16(spa->spa_load_info, ZPOOL_CONFIG_MMP_SEQ, seq);
4143 	fnvlist_add_uint32(spa->spa_load_info, ZPOOL_CONFIG_MMP_RESULT, error);
4144 
4145 	if (mmp->mmp_tryimport_ns > 0) {
4146 		fnvlist_add_uint64(spa->spa_load_info,
4147 		    ZPOOL_CONFIG_MMP_TRYIMPORT_NS, mmp->mmp_tryimport_ns);
4148 	}
4149 
4150 	if (mmp->mmp_import_ns > 0) {
4151 		fnvlist_add_uint64(spa->spa_load_info,
4152 		    ZPOOL_CONFIG_MMP_IMPORT_NS, mmp->mmp_import_ns);
4153 	}
4154 
4155 	if (mmp->mmp_claim_ns > 0) {
4156 		fnvlist_add_uint64(spa->spa_load_info,
4157 		    ZPOOL_CONFIG_MMP_CLAIM_NS, mmp->mmp_claim_ns);
4158 	}
4159 
4160 	zfs_dbgmsg("mmp: set spa_load_info, spa=%s hostname=%s hostid=%llx "
4161 	    "state=%d txg=%llu seq=%llu tryimport_ns=%lld import_ns=%lld "
4162 	    "claim_ns=%lld", spa_load_name(spa),
4163 	    hostname != NULL ? hostname : "none", (u_longlong_t)hostid,
4164 	    (int)state, (u_longlong_t)txg, (u_longlong_t)seq,
4165 	    (longlong_t)mmp->mmp_tryimport_ns, (longlong_t)mmp->mmp_import_ns,
4166 	    (longlong_t)mmp->mmp_claim_ns);
4167 }
4168 
4169 static int
4170 spa_ld_activity_result(spa_t *spa, int error, const char *state)
4171 {
4172 	switch (error) {
4173 	case ENXIO:
4174 		cmn_err(CE_WARN, "pool '%s' system hostid not set, "
4175 		    "aborted import during %s", spa_load_name(spa), state);
4176 		/* Userspace expects EREMOTEIO for no system hostid */
4177 		error = EREMOTEIO;
4178 		break;
4179 	case ENODEV:
4180 		cmn_err(CE_WARN, "pool '%s' could not claim every device the "
4181 		    "config expects present, aborted import during %s; if a "
4182 		    "device is permanently gone see 'zhack mmp reclaim'",
4183 		    spa_load_name(spa), state);
4184 		/* Userspace expects EREMOTEIO for a failed claim */
4185 		error = EREMOTEIO;
4186 		break;
4187 	case EIO:
4188 		cmn_err(CE_WARN, "pool '%s' had I/O errors writing the claim, "
4189 		    "aborted import during %s", spa_load_name(spa), state);
4190 		/* Userspace expects EREMOTEIO for a failed claim */
4191 		error = EREMOTEIO;
4192 		break;
4193 	case EREMOTEIO:
4194 		cmn_err(CE_WARN, "pool '%s' activity detected, aborted "
4195 		    "import during %s", spa_load_name(spa), state);
4196 		break;
4197 	case EINTR:
4198 		cmn_err(CE_WARN, "pool '%s' activity check, interrupted "
4199 		    "import during %s", spa_load_name(spa), state);
4200 		break;
4201 	case 0:
4202 		cmn_err(CE_NOTE, "pool '%s' activity check completed "
4203 		    "successfully", spa_load_name(spa));
4204 		break;
4205 	}
4206 
4207 	return (error);
4208 }
4209 
4210 
4211 /*
4212  * Remote host activity check.  Performed during tryimport when the pool
4213  * has passed on the basic sanity check and is open read-only.
4214  *
4215  * error results:
4216  *          0 - no activity detected
4217  *  EREMOTEIO - remote activity detected
4218  *      EINTR - user canceled the operation
4219  */
4220 static int
4221 spa_activity_check_tryimport(spa_t *spa, uberblock_t *spa_ub,
4222     boolean_t importing)
4223 {
4224 	kcondvar_t cv;
4225 	kmutex_t mtx;
4226 	int error = 0;
4227 
4228 	cv_init(&cv, NULL, CV_DEFAULT, NULL);
4229 	mutex_init(&mtx, NULL, MUTEX_DEFAULT, NULL);
4230 	mutex_enter(&mtx);
4231 
4232 	uint64_t import_delay = spa_activity_check_duration(spa, spa_ub);
4233 	hrtime_t start_time = gethrtime();
4234 
4235 	/* Add a small random factor in case of simultaneous imports (0-25%) */
4236 	import_delay += import_delay * random_in_range(250) / 1000;
4237 	hrtime_t import_expire = gethrtime() + import_delay;
4238 
4239 	if (importing) {
4240 		/* Console message includes tryimport and claim time */
4241 		hrtime_t extra_delay = MMP_IMPORT_VERIFY_ITERS *
4242 		    MSEC2NSEC(MMP_INTERVAL_VALID(spa_ub) ?
4243 		    MMP_INTERVAL(spa_ub) : MMP_MIN_INTERVAL);
4244 		cmn_err(CE_NOTE, "pool '%s' activity check required, "
4245 		    "%llu seconds remaining", spa_load_name(spa),
4246 		    (u_longlong_t)MAX(NSEC2SEC(import_delay + extra_delay), 1));
4247 		spa_import_progress_set_notes(spa, "Checking MMP activity, "
4248 		    "waiting %llu ms", (u_longlong_t)NSEC2MSEC(import_delay));
4249 	}
4250 
4251 	hrtime_t now;
4252 	nvlist_t *mmp_label = NULL;
4253 
4254 	while ((now = gethrtime()) < import_expire) {
4255 		vdev_t *rvd = spa->spa_root_vdev;
4256 		uberblock_t mmp_ub;
4257 
4258 		if (importing) {
4259 			(void) spa_import_progress_set_mmp_check(spa_guid(spa),
4260 			    NSEC2SEC(import_expire - gethrtime()));
4261 		}
4262 
4263 		vdev_uberblock_load(rvd, &mmp_ub, &mmp_label);
4264 
4265 		if (vdev_uberblock_compare(spa_ub, &mmp_ub)) {
4266 			spa_load_failed(spa, "mmp: activity detected during "
4267 			    "tryimport, spa_ub_txg=%llu mmp_ub_txg=%llu "
4268 			    "spa_ub_seq=%llu mmp_ub_seq=%llu "
4269 			    "spa_ub_timestamp=%llu mmp_ub_timestamp=%llu "
4270 			    "spa_ub_config=%#llx mmp_ub_config=%#llx",
4271 			    (u_longlong_t)spa_ub->ub_txg,
4272 			    (u_longlong_t)mmp_ub.ub_txg,
4273 			    (u_longlong_t)(MMP_SEQ_VALID(spa_ub) ?
4274 			    MMP_SEQ(spa_ub) : 0),
4275 			    (u_longlong_t)(MMP_SEQ_VALID(&mmp_ub) ?
4276 			    MMP_SEQ(&mmp_ub) : 0),
4277 			    (u_longlong_t)spa_ub->ub_timestamp,
4278 			    (u_longlong_t)mmp_ub.ub_timestamp,
4279 			    (u_longlong_t)spa_ub->ub_mmp_config,
4280 			    (u_longlong_t)mmp_ub.ub_mmp_config);
4281 			error = SET_ERROR(EREMOTEIO);
4282 			break;
4283 		}
4284 
4285 		if (mmp_label) {
4286 			nvlist_free(mmp_label);
4287 			mmp_label = NULL;
4288 		}
4289 
4290 		error = cv_timedwait_sig(&cv, &mtx, ddi_get_lbolt() + hz);
4291 		if (error != -1) {
4292 			error = SET_ERROR(EINTR);
4293 			break;
4294 		}
4295 		error = 0;
4296 	}
4297 
4298 	mutex_exit(&mtx);
4299 	mutex_destroy(&mtx);
4300 	cv_destroy(&cv);
4301 
4302 	if (mmp_label)
4303 		nvlist_free(mmp_label);
4304 
4305 	if (spa->spa_load_state == SPA_LOAD_IMPORT ||
4306 	    spa->spa_load_state == SPA_LOAD_OPEN) {
4307 		spa->spa_mmp.mmp_import_ns = gethrtime() - start_time;
4308 	} else {
4309 		spa->spa_mmp.mmp_tryimport_ns = gethrtime() - start_time;
4310 	}
4311 
4312 	return (error);
4313 }
4314 
4315 /*
4316  * Remote host activity check.  Performed during import when the pool has
4317  * passed most sanity check and has been reopened read/write.
4318  *
4319  * error results:
4320  *          0 - no activity detected
4321  *  EREMOTEIO - remote activity detected
4322  *     ENODEV - the claim could not be written to a device the config
4323  *              expects to be present
4324  *        EIO - the claim writes were issued to present devices and failed
4325  *      EINTR - user canceled the operation
4326  */
4327 static int
4328 spa_activity_check_claim(spa_t *spa)
4329 {
4330 	vdev_t *rvd = spa->spa_root_vdev;
4331 	nvlist_t *mmp_label;
4332 	uberblock_t spa_ub;
4333 	kcondvar_t cv;
4334 	kmutex_t mtx;
4335 	int error = 0;
4336 
4337 	cv_init(&cv, NULL, CV_DEFAULT, NULL);
4338 	mutex_init(&mtx, NULL, MUTEX_DEFAULT, NULL);
4339 	mutex_enter(&mtx);
4340 
4341 	hrtime_t start_time = gethrtime();
4342 
4343 	/*
4344 	 * Load the best uberblock and verify it matches the uberblock already
4345 	 * identified and stored as spa->spa_uberblock to verify the pool has
4346 	 * not changed.
4347 	 */
4348 	vdev_uberblock_load(rvd, &spa_ub, &mmp_label);
4349 
4350 	if (memcmp(&spa->spa_uberblock, &spa_ub, sizeof (uberblock_t))) {
4351 		spa_load_failed(spa, "mmp: uberblock changed on disk");
4352 		error = SET_ERROR(EREMOTEIO);
4353 		goto out;
4354 	}
4355 
4356 	if (!MMP_VALID(&spa_ub) || !MMP_INTERVAL_VALID(&spa_ub) ||
4357 	    !MMP_SEQ_VALID(&spa_ub) || !MMP_FAIL_INT_VALID(&spa_ub)) {
4358 		spa_load_failed(spa, "mmp: is not enabled in spa uberblock");
4359 		error = SET_ERROR(EREMOTEIO);
4360 		goto out;
4361 	}
4362 
4363 	nvlist_free(mmp_label);
4364 	mmp_label = NULL;
4365 
4366 	uint64_t spa_ub_interval = MMP_INTERVAL(&spa_ub);
4367 	uint16_t spa_ub_seq = MMP_SEQ(&spa_ub);
4368 
4369 	/*
4370 	 * In the highly unlikely event the sequence numbers have been
4371 	 * exhaused reset the sequence to zero.  As long as the MMP
4372 	 * uberblock is updated on all of the vdevs the activity will
4373 	 * still be detected.
4374 	 */
4375 	if (MMP_SEQ_MAX == spa_ub_seq)
4376 		spa_ub_seq = 0;
4377 
4378 	spa_import_progress_set_notes(spa,
4379 	    "Establishing MMP claim, waiting %llu ms",
4380 	    (u_longlong_t)(MMP_IMPORT_VERIFY_ITERS * spa_ub_interval));
4381 
4382 	/*
4383 	 * Repeatedly sync out an MMP uberblock with a randomly selected
4384 	 * sequence number, then read it back after the MMP interval.  This
4385 	 * random value acts as a claim token and is visible on other hosts.
4386 	 * If the same random value is read back we can be certain no other
4387 	 * pool is attempting to import the pool.
4388 	 */
4389 	for (int i = MMP_IMPORT_VERIFY_ITERS; i > 0; i--) {
4390 		uberblock_t set_ub, mmp_ub;
4391 		uint16_t mmp_seq;
4392 
4393 		(void) spa_import_progress_set_mmp_check(spa_guid(spa),
4394 		    NSEC2SEC(i * MSEC2NSEC(spa_ub_interval)));
4395 
4396 		set_ub = spa_ub;
4397 		mmp_seq = spa_ub_seq + 1 +
4398 		    random_in_range(MMP_SEQ_MAX - spa_ub_seq);
4399 		MMP_SEQ_CLEAR(&set_ub);
4400 		set_ub.ub_mmp_config |= MMP_SEQ_SET(mmp_seq);
4401 
4402 		error = mmp_claim_uberblock(spa, rvd, &set_ub);
4403 		if (error) {
4404 			spa_load_failed(spa, "mmp: uberblock claim "
4405 			    "failed, error=%d", error);
4406 			/*
4407 			 * ENODEV and EIO are both kept distinct from the
4408 			 * EREMOTEIO returned when another host is seen below.
4409 			 * Failing to write the claim is not evidence of a
4410 			 * remote host, and only the ENODEV case has a
4411 			 * recovery.
4412 			 */
4413 			break;
4414 		}
4415 
4416 		error = cv_timedwait_sig(&cv, &mtx, ddi_get_lbolt() +
4417 		    MSEC_TO_TICK(spa_ub_interval));
4418 		if (error != -1) {
4419 			error = SET_ERROR(EINTR);
4420 			break;
4421 		}
4422 
4423 		vdev_uberblock_load(rvd, &mmp_ub, &mmp_label);
4424 
4425 		if (vdev_uberblock_compare(&set_ub, &mmp_ub)) {
4426 			spa_load_failed(spa, "mmp: activity detected during "
4427 			    "claim, set_ub_txg=%llu mmp_ub_txg=%llu "
4428 			    "set_ub_seq=%llu mmp_ub_seq=%llu "
4429 			    "set_ub_timestamp=%llu mmp_ub_timestamp=%llu "
4430 			    "set_ub_config=%#llx mmp_ub_config=%#llx",
4431 			    (u_longlong_t)set_ub.ub_txg,
4432 			    (u_longlong_t)mmp_ub.ub_txg,
4433 			    (u_longlong_t)(MMP_SEQ_VALID(&set_ub) ?
4434 			    MMP_SEQ(&set_ub) : 0),
4435 			    (u_longlong_t)(MMP_SEQ_VALID(&mmp_ub) ?
4436 			    MMP_SEQ(&mmp_ub) : 0),
4437 			    (u_longlong_t)set_ub.ub_timestamp,
4438 			    (u_longlong_t)mmp_ub.ub_timestamp,
4439 			    (u_longlong_t)set_ub.ub_mmp_config,
4440 			    (u_longlong_t)mmp_ub.ub_mmp_config);
4441 			error = SET_ERROR(EREMOTEIO);
4442 			break;
4443 		}
4444 
4445 		if (mmp_label) {
4446 			nvlist_free(mmp_label);
4447 			mmp_label = NULL;
4448 		}
4449 
4450 		error = 0;
4451 	}
4452 out:
4453 	spa->spa_mmp.mmp_claim_ns = gethrtime() - start_time;
4454 	(void) spa_import_progress_set_mmp_check(spa_guid(spa), 0);
4455 
4456 	/*
4457 	 * A claim shortfall reaches userspace as EREMOTEIO exactly as remote
4458 	 * activity does, so an older zpool(8) sees no change.  The cause
4459 	 * travels in the result for a zpool(8) which knows to read it.
4460 	 */
4461 	if (error == EREMOTEIO || error == ENODEV || error == EIO) {
4462 		spa_activity_set_load_info(spa, mmp_label,
4463 		    MMP_STATE_ACTIVE, 0, 0, error);
4464 	} else {
4465 		spa_activity_set_load_info(spa, mmp_label,
4466 		    MMP_STATE_INACTIVE, spa_ub.ub_txg, MMP_SEQ(&spa_ub), 0);
4467 	}
4468 
4469 	/*
4470 	 * Restore the original sequence, this allows us to retry the
4471 	 * import procedure if a subsequent step fails during import.
4472 	 * Failure to restore it reduces the available sequence ids for
4473 	 * the next import but shouldn't be considered fatal.
4474 	 */
4475 	int restore_error = mmp_claim_uberblock(spa, rvd, &spa_ub);
4476 	if (restore_error) {
4477 		zfs_dbgmsg("mmp: uberblock restore failed, spa=%s error=%d",
4478 		    spa_load_name(spa), restore_error);
4479 	}
4480 
4481 	if (mmp_label)
4482 		nvlist_free(mmp_label);
4483 
4484 	mutex_exit(&mtx);
4485 	mutex_destroy(&mtx);
4486 	cv_destroy(&cv);
4487 
4488 	return (error);
4489 }
4490 
4491 static int
4492 spa_ld_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *label)
4493 {
4494 	vdev_t *rvd = spa->spa_root_vdev;
4495 	int error;
4496 
4497 	if (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay &&
4498 	    spa_get_hostid(spa) == 0) {
4499 		spa_activity_set_load_info(spa, label, MMP_STATE_NO_HOSTID,
4500 		    ub->ub_txg, MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0, ENXIO);
4501 		zfs_dbgmsg("mmp: system hostid not set, ub_mmp_magic=%llx "
4502 		    "ub_mmp_delay=%llu hostid=%llx",
4503 		    (u_longlong_t)ub->ub_mmp_magic,
4504 		    (u_longlong_t)ub->ub_mmp_delay,
4505 		    (u_longlong_t)spa_get_hostid(spa));
4506 		return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, ENXIO));
4507 	}
4508 
4509 	switch (spa->spa_load_state) {
4510 	case SPA_LOAD_TRYIMPORT:
4511 tryimport:
4512 		error = spa_activity_check_tryimport(spa, ub, B_TRUE);
4513 		if (error == EREMOTEIO) {
4514 			spa_activity_set_load_info(spa, label,
4515 			    MMP_STATE_ACTIVE, 0, 0, EREMOTEIO);
4516 			return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
4517 		} else if (error) {
4518 			ASSERT3S(error, ==, EINTR);
4519 			spa_activity_set_load_info(spa, label,
4520 			    MMP_STATE_ACTIVE, 0, 0, EINTR);
4521 			return (error);
4522 		}
4523 
4524 		spa_activity_set_load_info(spa, label, MMP_STATE_INACTIVE,
4525 		    ub->ub_txg, MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0, 0);
4526 
4527 		break;
4528 
4529 	case SPA_LOAD_IMPORT:
4530 	case SPA_LOAD_OPEN:
4531 		error = spa_activity_verify_config(spa, ub);
4532 		if (error == EREMOTEIO) {
4533 			spa_activity_set_load_info(spa, label,
4534 			    MMP_STATE_ACTIVE, 0, 0, EREMOTEIO);
4535 			return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
4536 		} else if (error) {
4537 			ASSERT3S(error, ==, ENOENT);
4538 			goto tryimport;
4539 		}
4540 
4541 		/* Load info set in spa_activity_check_claim() */
4542 
4543 		break;
4544 
4545 	case SPA_LOAD_RECOVER:
4546 		zfs_dbgmsg("mmp: skipping mmp check for rewind, spa=%s",
4547 		    spa_load_name(spa));
4548 		break;
4549 
4550 	default:
4551 		spa_activity_set_load_info(spa, label, MMP_STATE_ACTIVE,
4552 		    0, 0, EREMOTEIO);
4553 		zfs_dbgmsg("mmp: unreachable, spa=%s spa_load_state=%d",
4554 		    spa_load_name(spa), spa->spa_load_state);
4555 		return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
4556 	}
4557 
4558 	return (0);
4559 }
4560 
4561 /*
4562  * Called from zfs_ioc_clear for a pool that was suspended
4563  * after failing mmp write checks.
4564  */
4565 boolean_t
4566 spa_mmp_remote_host_activity(spa_t *spa)
4567 {
4568 	ASSERT(spa_multihost(spa) && spa_suspended(spa));
4569 
4570 	nvlist_t *best_label;
4571 	uberblock_t best_ub;
4572 
4573 	/*
4574 	 * Locate the best uberblock on disk
4575 	 */
4576 	vdev_uberblock_load(spa->spa_root_vdev, &best_ub, &best_label);
4577 	if (best_label) {
4578 		/*
4579 		 * confirm that the best hostid matches our hostid
4580 		 */
4581 		if (nvlist_exists(best_label, ZPOOL_CONFIG_HOSTID) &&
4582 		    spa_get_hostid(spa) !=
4583 		    fnvlist_lookup_uint64(best_label, ZPOOL_CONFIG_HOSTID)) {
4584 			nvlist_free(best_label);
4585 			return (B_TRUE);
4586 		}
4587 		nvlist_free(best_label);
4588 	} else {
4589 		return (B_TRUE);
4590 	}
4591 
4592 	if (!MMP_VALID(&best_ub) ||
4593 	    !MMP_FAIL_INT_VALID(&best_ub) ||
4594 	    MMP_FAIL_INT(&best_ub) == 0) {
4595 		return (B_TRUE);
4596 	}
4597 
4598 	if (best_ub.ub_txg != spa->spa_uberblock.ub_txg ||
4599 	    best_ub.ub_timestamp != spa->spa_uberblock.ub_timestamp) {
4600 		zfs_dbgmsg("mmp: txg mismatch detected during pool clear, "
4601 		    "spa=%s txg=%llu ub_txg=%llu timestamp=%llu "
4602 		    "ub_timestamp=%llu", spa_name(spa),
4603 		    (u_longlong_t)spa->spa_uberblock.ub_txg,
4604 		    (u_longlong_t)best_ub.ub_txg,
4605 		    (u_longlong_t)spa->spa_uberblock.ub_timestamp,
4606 		    (u_longlong_t)best_ub.ub_timestamp);
4607 		return (B_TRUE);
4608 	}
4609 
4610 	/*
4611 	 * Perform an activity check looking for any remote writer
4612 	 */
4613 	return (spa_activity_check_tryimport(spa, &best_ub, B_FALSE) != 0);
4614 }
4615 
4616 static int
4617 spa_verify_host(spa_t *spa, nvlist_t *mos_config)
4618 {
4619 	uint64_t hostid;
4620 	const char *hostname;
4621 	uint64_t myhostid = 0;
4622 
4623 	if (!spa_is_root(spa) && nvlist_lookup_uint64(mos_config,
4624 	    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
4625 		hostname = fnvlist_lookup_string(mos_config,
4626 		    ZPOOL_CONFIG_HOSTNAME);
4627 
4628 		myhostid = zone_get_hostid(NULL);
4629 
4630 		if (hostid != 0 && myhostid != 0 && hostid != myhostid) {
4631 			cmn_err(CE_WARN, "pool '%s' could not be "
4632 			    "loaded as it was last accessed by "
4633 			    "another system (host: %s hostid: 0x%llx). "
4634 			    "See: https://openzfs.github.io/openzfs-docs/msg/"
4635 			    "ZFS-8000-EY",
4636 			    spa_name(spa), hostname, (u_longlong_t)hostid);
4637 			spa_load_failed(spa, "hostid verification failed: pool "
4638 			    "last accessed by host: %s (hostid: 0x%llx)",
4639 			    hostname, (u_longlong_t)hostid);
4640 			return (SET_ERROR(EBADF));
4641 		}
4642 	}
4643 
4644 	return (0);
4645 }
4646 
4647 static int
4648 spa_ld_parse_config(spa_t *spa, spa_import_type_t type)
4649 {
4650 	int error = 0;
4651 	nvlist_t *nvtree, *nvl, *config = spa->spa_config;
4652 	int parse;
4653 	vdev_t *rvd;
4654 	uint64_t pool_guid;
4655 	const char *comment;
4656 	const char *compatibility;
4657 
4658 	/*
4659 	 * Versioning wasn't explicitly added to the label until later, so if
4660 	 * it's not present treat it as the initial version.
4661 	 */
4662 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
4663 	    &spa->spa_ubsync.ub_version) != 0)
4664 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
4665 
4666 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid)) {
4667 		spa_load_failed(spa, "invalid config provided: '%s' missing",
4668 		    ZPOOL_CONFIG_POOL_GUID);
4669 		return (SET_ERROR(EINVAL));
4670 	}
4671 
4672 	/*
4673 	 * If we are doing an import, ensure that the pool is not already
4674 	 * imported by checking if its pool guid already exists in the
4675 	 * spa namespace.
4676 	 *
4677 	 * The only case that we allow an already imported pool to be
4678 	 * imported again, is when the pool is checkpointed and we want to
4679 	 * look at its checkpointed state from userland tools like zdb.
4680 	 */
4681 #ifdef _KERNEL
4682 	if ((spa->spa_load_state == SPA_LOAD_IMPORT ||
4683 	    spa->spa_load_state == SPA_LOAD_TRYIMPORT) &&
4684 	    spa_guid_exists(pool_guid, 0)) {
4685 #else
4686 	if ((spa->spa_load_state == SPA_LOAD_IMPORT ||
4687 	    spa->spa_load_state == SPA_LOAD_TRYIMPORT) &&
4688 	    spa_guid_exists(pool_guid, 0) &&
4689 	    !spa_importing_readonly_checkpoint(spa)) {
4690 #endif
4691 		spa_load_failed(spa, "a pool with guid %llu is already open",
4692 		    (u_longlong_t)pool_guid);
4693 		return (SET_ERROR(EEXIST));
4694 	}
4695 
4696 	spa->spa_config_guid = pool_guid;
4697 
4698 	nvlist_free(spa->spa_load_info);
4699 	spa->spa_load_info = fnvlist_alloc();
4700 
4701 	ASSERT0P(spa->spa_comment);
4702 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
4703 		spa->spa_comment = spa_strdup(comment);
4704 
4705 	ASSERT0P(spa->spa_compatibility);
4706 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMPATIBILITY,
4707 	    &compatibility) == 0)
4708 		spa->spa_compatibility = spa_strdup(compatibility);
4709 
4710 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4711 	    &spa->spa_config_txg);
4712 
4713 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) == 0)
4714 		spa->spa_config_splitting = fnvlist_dup(nvl);
4715 
4716 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvtree)) {
4717 		spa_load_failed(spa, "invalid config provided: '%s' missing",
4718 		    ZPOOL_CONFIG_VDEV_TREE);
4719 		return (SET_ERROR(EINVAL));
4720 	}
4721 
4722 	/*
4723 	 * Create "The Godfather" zio to hold all async IOs
4724 	 */
4725 	spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
4726 	    KM_SLEEP);
4727 	for (int i = 0; i < max_ncpus; i++) {
4728 		spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
4729 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
4730 		    ZIO_FLAG_GODFATHER);
4731 	}
4732 
4733 	/*
4734 	 * Parse the configuration into a vdev tree.  We explicitly set the
4735 	 * value that will be returned by spa_version() since parsing the
4736 	 * configuration requires knowing the version number.
4737 	 */
4738 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4739 	parse = (type == SPA_IMPORT_EXISTING ?
4740 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
4741 	error = spa_config_parse(spa, &rvd, nvtree, NULL, 0, parse);
4742 	spa_config_exit(spa, SCL_ALL, FTAG);
4743 
4744 	if (error != 0) {
4745 		spa_load_failed(spa, "unable to parse config [error=%d]",
4746 		    error);
4747 		return (error);
4748 	}
4749 
4750 	ASSERT(spa->spa_root_vdev == rvd);
4751 	ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT);
4752 	ASSERT3U(spa->spa_max_ashift, <=, SPA_MAXBLOCKSHIFT);
4753 
4754 	if (type != SPA_IMPORT_ASSEMBLE) {
4755 		ASSERT(spa_guid(spa) == pool_guid);
4756 	}
4757 
4758 	return (0);
4759 }
4760 
4761 /*
4762  * Recursively open all vdevs in the vdev tree. This function is called twice:
4763  * first with the untrusted config, then with the trusted config.
4764  */
4765 static int
4766 spa_ld_open_vdevs(spa_t *spa)
4767 {
4768 	int error = 0;
4769 
4770 	/*
4771 	 * spa_missing_tvds_allowed defines how many top-level vdevs can be
4772 	 * missing/unopenable for the root vdev to be still considered openable.
4773 	 */
4774 	if (spa->spa_trust_config) {
4775 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds;
4776 	} else if (spa->spa_config_source == SPA_CONFIG_SRC_CACHEFILE) {
4777 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds_cachefile;
4778 	} else if (spa->spa_config_source == SPA_CONFIG_SRC_SCAN) {
4779 		spa->spa_missing_tvds_allowed = zfs_max_missing_tvds_scan;
4780 	} else {
4781 		spa->spa_missing_tvds_allowed = 0;
4782 	}
4783 
4784 	spa->spa_missing_tvds_allowed =
4785 	    MAX(zfs_max_missing_tvds, spa->spa_missing_tvds_allowed);
4786 
4787 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4788 	error = vdev_open(spa->spa_root_vdev, CRED());
4789 	spa_config_exit(spa, SCL_ALL, FTAG);
4790 
4791 	if (spa->spa_missing_tvds != 0) {
4792 		spa_load_note(spa, "vdev tree has %lld missing top-level "
4793 		    "vdevs.", (u_longlong_t)spa->spa_missing_tvds);
4794 		if (spa->spa_trust_config && (spa->spa_mode & SPA_MODE_WRITE)) {
4795 			/*
4796 			 * Although theoretically we could allow users to open
4797 			 * incomplete pools in RW mode, we'd need to add a lot
4798 			 * of extra logic (e.g. adjust pool space to account
4799 			 * for missing vdevs).
4800 			 * This limitation also prevents users from accidentally
4801 			 * opening the pool in RW mode during data recovery and
4802 			 * damaging it further.
4803 			 */
4804 			spa_load_note(spa, "pools with missing top-level "
4805 			    "vdevs can only be opened in read-only mode.");
4806 			error = SET_ERROR(ENXIO);
4807 		} else {
4808 			spa_load_note(spa, "current settings allow for maximum "
4809 			    "%lld missing top-level vdevs at this stage.",
4810 			    (u_longlong_t)spa->spa_missing_tvds_allowed);
4811 		}
4812 	}
4813 	if (error != 0) {
4814 		spa_load_failed(spa, "unable to open vdev tree [error=%d]",
4815 		    error);
4816 	}
4817 	if (spa->spa_missing_tvds != 0 || error != 0)
4818 		vdev_dbgmsg_print_tree(spa->spa_root_vdev, 2);
4819 
4820 	return (error);
4821 }
4822 
4823 /*
4824  * We need to validate the vdev labels against the configuration that
4825  * we have in hand. This function is called twice: first with an untrusted
4826  * config, then with a trusted config. The validation is more strict when the
4827  * config is trusted.
4828  */
4829 static int
4830 spa_ld_validate_vdevs(spa_t *spa)
4831 {
4832 	int error = 0;
4833 	vdev_t *rvd = spa->spa_root_vdev;
4834 
4835 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4836 	error = vdev_validate(rvd);
4837 	spa_config_exit(spa, SCL_ALL, FTAG);
4838 
4839 	if (error != 0) {
4840 		spa_load_failed(spa, "vdev_validate failed [error=%d]", error);
4841 		return (error);
4842 	}
4843 
4844 	if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN) {
4845 		spa_load_failed(spa, "cannot open vdev tree after invalidating "
4846 		    "some vdevs");
4847 		vdev_dbgmsg_print_tree(rvd, 2);
4848 		return (SET_ERROR(ENXIO));
4849 	}
4850 
4851 	return (0);
4852 }
4853 
4854 static void
4855 spa_ld_select_uberblock_done(spa_t *spa, uberblock_t *ub)
4856 {
4857 	spa->spa_state = POOL_STATE_ACTIVE;
4858 	spa->spa_ubsync = spa->spa_uberblock;
4859 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
4860 	    TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
4861 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
4862 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
4863 	spa->spa_claim_max_txg = spa->spa_first_txg;
4864 	spa->spa_prev_software_version = ub->ub_software_version;
4865 }
4866 
4867 static int
4868 spa_ld_select_uberblock(spa_t *spa, spa_import_type_t type)
4869 {
4870 	vdev_t *rvd = spa->spa_root_vdev;
4871 	nvlist_t *label;
4872 	uberblock_t *ub = &spa->spa_uberblock;
4873 
4874 	/*
4875 	 * If we are opening the checkpointed state of the pool by
4876 	 * rewinding to it, at this point we will have written the
4877 	 * checkpointed uberblock to the vdev labels, so searching
4878 	 * the labels will find the right uberblock.  However, if
4879 	 * we are opening the checkpointed state read-only, we have
4880 	 * not modified the labels. Therefore, we must ignore the
4881 	 * labels and continue using the spa_uberblock that was set
4882 	 * by spa_ld_checkpoint_rewind.
4883 	 *
4884 	 * Note that it would be fine to ignore the labels when
4885 	 * rewinding (opening writeable) as well. However, if we
4886 	 * crash just after writing the labels, we will end up
4887 	 * searching the labels. Doing so in the common case means
4888 	 * that this code path gets exercised normally, rather than
4889 	 * just in the edge case.
4890 	 */
4891 	if (ub->ub_checkpoint_txg != 0 &&
4892 	    spa_importing_readonly_checkpoint(spa)) {
4893 		spa_ld_select_uberblock_done(spa, ub);
4894 		return (0);
4895 	}
4896 
4897 	/*
4898 	 * Find the best uberblock.
4899 	 */
4900 	vdev_uberblock_load(rvd, ub, &label);
4901 
4902 	/*
4903 	 * If we weren't able to find a single valid uberblock, return failure.
4904 	 */
4905 	if (ub->ub_txg == 0) {
4906 		nvlist_free(label);
4907 		spa_load_failed(spa, "no valid uberblock found");
4908 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
4909 	}
4910 
4911 	if (spa->spa_load_max_txg != UINT64_MAX) {
4912 		(void) spa_import_progress_set_max_txg(spa_guid(spa),
4913 		    (u_longlong_t)spa->spa_load_max_txg);
4914 	}
4915 	spa_load_note(spa, "using uberblock with txg=%llu",
4916 	    (u_longlong_t)ub->ub_txg);
4917 	if (ub->ub_raidz_reflow_info != 0) {
4918 		spa_load_note(spa, "uberblock raidz_reflow_info: "
4919 		    "state=%u offset=%llu",
4920 		    (int)RRSS_GET_STATE(ub),
4921 		    (u_longlong_t)RRSS_GET_OFFSET(ub));
4922 	}
4923 
4924 	/*
4925 	 * For pools which have the multihost property on determine if the
4926 	 * pool is truly inactive and can be safely imported.  Prevent
4927 	 * hosts which don't have a hostid set from importing the pool.
4928 	 */
4929 	spa->spa_activity_check = spa_activity_check_required(spa, ub, label);
4930 	if (spa->spa_activity_check) {
4931 		int error = spa_ld_activity_check(spa, ub, label);
4932 		if (error) {
4933 			spa_load_state_t state = spa->spa_load_state;
4934 			error = spa_ld_activity_result(spa, error,
4935 			    state == SPA_LOAD_TRYIMPORT ? "tryimport" :
4936 			    state == SPA_LOAD_IMPORT ? "import" : "open");
4937 			nvlist_free(label);
4938 			return (error);
4939 		}
4940 	} else {
4941 		fnvlist_add_uint32(spa->spa_load_info,
4942 		    ZPOOL_CONFIG_MMP_RESULT, ESRCH);
4943 	}
4944 
4945 	/*
4946 	 * If the pool has an unsupported version we can't open it.
4947 	 */
4948 	if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
4949 		nvlist_free(label);
4950 		spa_load_failed(spa, "version %llu is not supported",
4951 		    (u_longlong_t)ub->ub_version);
4952 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
4953 	}
4954 
4955 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
4956 		nvlist_t *features;
4957 
4958 		/*
4959 		 * If we weren't able to find what's necessary for reading the
4960 		 * MOS in the label, return failure.
4961 		 */
4962 		if (label == NULL) {
4963 			spa_load_failed(spa, "label config unavailable");
4964 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
4965 			    ENXIO));
4966 		}
4967 
4968 		if (nvlist_lookup_nvlist(label, ZPOOL_CONFIG_FEATURES_FOR_READ,
4969 		    &features) != 0) {
4970 			nvlist_free(label);
4971 			spa_load_failed(spa, "invalid label: '%s' missing",
4972 			    ZPOOL_CONFIG_FEATURES_FOR_READ);
4973 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
4974 			    ENXIO));
4975 		}
4976 
4977 		/*
4978 		 * Update our in-core representation with the definitive values
4979 		 * from the label.
4980 		 */
4981 		nvlist_free(spa->spa_label_features);
4982 		spa->spa_label_features = fnvlist_dup(features);
4983 	}
4984 
4985 	nvlist_free(label);
4986 
4987 	/*
4988 	 * Look through entries in the label nvlist's features_for_read. If
4989 	 * there is a feature listed there which we don't understand then we
4990 	 * cannot open a pool.
4991 	 */
4992 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
4993 		nvlist_t *unsup_feat;
4994 
4995 		unsup_feat = fnvlist_alloc();
4996 
4997 		for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
4998 		    NULL); nvp != NULL;
4999 		    nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
5000 			if (!zfeature_is_supported(nvpair_name(nvp))) {
5001 				fnvlist_add_string(unsup_feat,
5002 				    nvpair_name(nvp), "");
5003 			}
5004 		}
5005 
5006 		if (!nvlist_empty(unsup_feat)) {
5007 			fnvlist_add_nvlist(spa->spa_load_info,
5008 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
5009 			nvlist_free(unsup_feat);
5010 			spa_load_failed(spa, "some features are unsupported");
5011 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
5012 			    ENOTSUP));
5013 		}
5014 
5015 		nvlist_free(unsup_feat);
5016 	}
5017 
5018 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
5019 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5020 		spa_try_repair(spa, spa->spa_config);
5021 		spa_config_exit(spa, SCL_ALL, FTAG);
5022 		nvlist_free(spa->spa_config_splitting);
5023 		spa->spa_config_splitting = NULL;
5024 	}
5025 
5026 	/*
5027 	 * Initialize internal SPA structures.
5028 	 */
5029 	spa_ld_select_uberblock_done(spa, ub);
5030 
5031 	return (0);
5032 }
5033 
5034 static int
5035 spa_ld_open_rootbp(spa_t *spa)
5036 {
5037 	int error = 0;
5038 	vdev_t *rvd = spa->spa_root_vdev;
5039 
5040 	error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
5041 	if (error != 0) {
5042 		spa_load_failed(spa, "unable to open rootbp in dsl_pool_init "
5043 		    "[error=%d]", error);
5044 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5045 	}
5046 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
5047 
5048 	return (0);
5049 }
5050 
5051 static int
5052 spa_ld_trusted_config(spa_t *spa, spa_import_type_t type,
5053     boolean_t reloading)
5054 {
5055 	vdev_t *mrvd, *rvd = spa->spa_root_vdev;
5056 	nvlist_t *nv, *mos_config, *policy;
5057 	int error = 0, copy_error;
5058 	uint64_t healthy_tvds, healthy_tvds_mos;
5059 	uint64_t mos_config_txg;
5060 
5061 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object, B_TRUE)
5062 	    != 0)
5063 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5064 
5065 	/*
5066 	 * If we're assembling a pool from a split, the config provided is
5067 	 * already trusted so there is nothing to do.
5068 	 */
5069 	if (type == SPA_IMPORT_ASSEMBLE)
5070 		return (0);
5071 
5072 	healthy_tvds = spa_healthy_core_tvds(spa);
5073 
5074 	if (load_nvlist(spa, spa->spa_config_object, &mos_config)
5075 	    != 0) {
5076 		spa_load_failed(spa, "unable to retrieve MOS config");
5077 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5078 	}
5079 
5080 	/*
5081 	 * If we are doing an open, pool owner wasn't verified yet, thus do
5082 	 * the verification here.
5083 	 */
5084 	if (spa->spa_load_state == SPA_LOAD_OPEN) {
5085 		error = spa_verify_host(spa, mos_config);
5086 		if (error != 0) {
5087 			nvlist_free(mos_config);
5088 			return (error);
5089 		}
5090 	}
5091 
5092 	nv = fnvlist_lookup_nvlist(mos_config, ZPOOL_CONFIG_VDEV_TREE);
5093 
5094 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5095 
5096 	/*
5097 	 * Build a new vdev tree from the trusted config
5098 	 */
5099 	error = spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD);
5100 	if (error != 0) {
5101 		nvlist_free(mos_config);
5102 		spa_config_exit(spa, SCL_ALL, FTAG);
5103 		spa_load_failed(spa, "spa_config_parse failed [error=%d]",
5104 		    error);
5105 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
5106 	}
5107 
5108 	/*
5109 	 * Vdev paths in the MOS may be obsolete. If the untrusted config was
5110 	 * obtained by scanning /dev/dsk, then it will have the right vdev
5111 	 * paths. We update the trusted MOS config with this information.
5112 	 * We first try to copy the paths with vdev_copy_path_strict, which
5113 	 * succeeds only when both configs have exactly the same vdev tree.
5114 	 * If that fails, we fall back to a more flexible method that has a
5115 	 * best effort policy.
5116 	 */
5117 	copy_error = vdev_copy_path_strict(rvd, mrvd);
5118 	if (copy_error != 0 || spa_load_print_vdev_tree) {
5119 		spa_load_note(spa, "provided vdev tree:");
5120 		vdev_dbgmsg_print_tree(rvd, 2);
5121 		spa_load_note(spa, "MOS vdev tree:");
5122 		vdev_dbgmsg_print_tree(mrvd, 2);
5123 	}
5124 	if (copy_error != 0) {
5125 		spa_load_note(spa, "vdev_copy_path_strict failed, falling "
5126 		    "back to vdev_copy_path_relaxed");
5127 		vdev_copy_path_relaxed(rvd, mrvd);
5128 	}
5129 
5130 	vdev_close(rvd);
5131 	vdev_free(rvd);
5132 	spa->spa_root_vdev = mrvd;
5133 	rvd = mrvd;
5134 	spa_config_exit(spa, SCL_ALL, FTAG);
5135 
5136 	/*
5137 	 * If 'zpool import' used a cached config, then the on-disk hostid and
5138 	 * hostname may be different to the cached config in ways that should
5139 	 * prevent import.  Userspace can't discover this without a scan, but
5140 	 * we know, so we add these values to LOAD_INFO so the caller can know
5141 	 * the difference.
5142 	 *
5143 	 * Note that we have to do this before the config is regenerated,
5144 	 * because the new config will have the hostid and hostname for this
5145 	 * host, in readiness for import.
5146 	 */
5147 	if (nvlist_exists(mos_config, ZPOOL_CONFIG_HOSTID))
5148 		fnvlist_add_uint64(spa->spa_load_info, ZPOOL_CONFIG_HOSTID,
5149 		    fnvlist_lookup_uint64(mos_config, ZPOOL_CONFIG_HOSTID));
5150 	if (nvlist_exists(mos_config, ZPOOL_CONFIG_HOSTNAME))
5151 		fnvlist_add_string(spa->spa_load_info, ZPOOL_CONFIG_HOSTNAME,
5152 		    fnvlist_lookup_string(mos_config, ZPOOL_CONFIG_HOSTNAME));
5153 
5154 	/*
5155 	 * We will use spa_config if we decide to reload the spa or if spa_load
5156 	 * fails and we rewind. We must thus regenerate the config using the
5157 	 * MOS information with the updated paths. ZPOOL_LOAD_POLICY is used to
5158 	 * pass settings on how to load the pool and is not stored in the MOS.
5159 	 * We copy it over to our new, trusted config.
5160 	 */
5161 	mos_config_txg = fnvlist_lookup_uint64(mos_config,
5162 	    ZPOOL_CONFIG_POOL_TXG);
5163 	nvlist_free(mos_config);
5164 	mos_config = spa_config_generate(spa, NULL, mos_config_txg, B_FALSE);
5165 	if (nvlist_lookup_nvlist(spa->spa_config, ZPOOL_LOAD_POLICY,
5166 	    &policy) == 0)
5167 		fnvlist_add_nvlist(mos_config, ZPOOL_LOAD_POLICY, policy);
5168 	spa_config_set(spa, mos_config);
5169 	spa->spa_config_source = SPA_CONFIG_SRC_MOS;
5170 
5171 	/*
5172 	 * Now that we got the config from the MOS, we should be more strict
5173 	 * in checking blkptrs and can make assumptions about the consistency
5174 	 * of the vdev tree. spa_trust_config must be set to true before opening
5175 	 * vdevs in order for them to be writeable.
5176 	 */
5177 	spa->spa_trust_config = B_TRUE;
5178 
5179 	/*
5180 	 * Open and validate the new vdev tree
5181 	 */
5182 	error = spa_ld_open_vdevs(spa);
5183 	if (error != 0)
5184 		return (error);
5185 
5186 	error = spa_ld_validate_vdevs(spa);
5187 	if (error != 0)
5188 		return (error);
5189 
5190 	if (copy_error != 0 || spa_load_print_vdev_tree) {
5191 		spa_load_note(spa, "final vdev tree:");
5192 		vdev_dbgmsg_print_tree(rvd, 2);
5193 	}
5194 
5195 	if (spa->spa_load_state != SPA_LOAD_TRYIMPORT &&
5196 	    !spa->spa_extreme_rewind && zfs_max_missing_tvds == 0) {
5197 		/*
5198 		 * Sanity check to make sure that we are indeed loading the
5199 		 * latest uberblock. If we missed SPA_SYNC_MIN_VDEVS tvds
5200 		 * in the config provided and they happened to be the only ones
5201 		 * to have the latest uberblock, we could involuntarily perform
5202 		 * an extreme rewind.
5203 		 */
5204 		healthy_tvds_mos = spa_healthy_core_tvds(spa);
5205 		if (healthy_tvds_mos - healthy_tvds >=
5206 		    SPA_SYNC_MIN_VDEVS) {
5207 			spa_load_note(spa, "config provided misses too many "
5208 			    "top-level vdevs compared to MOS (%lld vs %lld). ",
5209 			    (u_longlong_t)healthy_tvds,
5210 			    (u_longlong_t)healthy_tvds_mos);
5211 			spa_load_note(spa, "vdev tree:");
5212 			vdev_dbgmsg_print_tree(rvd, 2);
5213 			if (reloading) {
5214 				spa_load_failed(spa, "config was already "
5215 				    "provided from MOS. Aborting.");
5216 				return (spa_vdev_err(rvd,
5217 				    VDEV_AUX_CORRUPT_DATA, EIO));
5218 			}
5219 			spa_load_note(spa, "spa must be reloaded using MOS "
5220 			    "config");
5221 			return (SET_ERROR(EAGAIN));
5222 		}
5223 	}
5224 
5225 	/*
5226 	 * Final sanity check for multihost pools that no other host is
5227 	 * accessing the pool.  All of the read-only check have passed at
5228 	 * this point, perform targetted updates to the mmp uberblocks to
5229 	 * safely force a visible change.
5230 	 */
5231 	if (spa->spa_load_state != SPA_LOAD_TRYIMPORT &&
5232 	    !spa->spa_extreme_rewind && spa->spa_activity_check) {
5233 
5234 		error = spa_activity_check_claim(spa);
5235 		error = spa_ld_activity_result(spa, error, "claim");
5236 
5237 		if (error == EREMOTEIO)
5238 			return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
5239 		else if (error)
5240 			return (error);
5241 	}
5242 
5243 	error = spa_check_for_missing_logs(spa);
5244 	if (error != 0)
5245 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
5246 
5247 	if (rvd->vdev_guid_sum != spa->spa_uberblock.ub_guid_sum) {
5248 		spa_load_failed(spa, "uberblock guid sum doesn't match MOS "
5249 		    "guid sum (%llu != %llu)",
5250 		    (u_longlong_t)spa->spa_uberblock.ub_guid_sum,
5251 		    (u_longlong_t)rvd->vdev_guid_sum);
5252 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
5253 		    ENXIO));
5254 	}
5255 
5256 	return (0);
5257 }
5258 
5259 static int
5260 spa_ld_open_indirect_vdev_metadata(spa_t *spa)
5261 {
5262 	int error = 0;
5263 	vdev_t *rvd = spa->spa_root_vdev;
5264 
5265 	/*
5266 	 * Everything that we read before spa_remove_init() must be stored
5267 	 * on concreted vdevs.  Therefore we do this as early as possible.
5268 	 */
5269 	error = spa_remove_init(spa);
5270 	if (error != 0) {
5271 		spa_load_failed(spa, "spa_remove_init failed [error=%d]",
5272 		    error);
5273 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5274 	}
5275 
5276 	/*
5277 	 * Retrieve information needed to condense indirect vdev mappings.
5278 	 */
5279 	error = spa_condense_init(spa);
5280 	if (error != 0) {
5281 		spa_load_failed(spa, "spa_condense_init failed [error=%d]",
5282 		    error);
5283 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
5284 	}
5285 
5286 	return (0);
5287 }
5288 
5289 static int
5290 spa_ld_check_features(spa_t *spa, boolean_t *missing_feat_writep)
5291 {
5292 	int error = 0;
5293 	vdev_t *rvd = spa->spa_root_vdev;
5294 
5295 	if (spa_version(spa) >= SPA_VERSION_FEATURES) {
5296 		boolean_t missing_feat_read = B_FALSE;
5297 		nvlist_t *unsup_feat, *enabled_feat;
5298 
5299 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
5300 		    &spa->spa_feat_for_read_obj, B_TRUE) != 0) {
5301 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5302 		}
5303 
5304 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
5305 		    &spa->spa_feat_for_write_obj, B_TRUE) != 0) {
5306 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5307 		}
5308 
5309 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
5310 		    &spa->spa_feat_desc_obj, B_TRUE) != 0) {
5311 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5312 		}
5313 
5314 		enabled_feat = fnvlist_alloc();
5315 		unsup_feat = fnvlist_alloc();
5316 
5317 		if (!spa_features_check(spa, B_FALSE,
5318 		    unsup_feat, enabled_feat))
5319 			missing_feat_read = B_TRUE;
5320 
5321 		if (spa_writeable(spa) ||
5322 		    spa->spa_load_state == SPA_LOAD_TRYIMPORT) {
5323 			if (!spa_features_check(spa, B_TRUE,
5324 			    unsup_feat, enabled_feat)) {
5325 				*missing_feat_writep = B_TRUE;
5326 			}
5327 		}
5328 
5329 		fnvlist_add_nvlist(spa->spa_load_info,
5330 		    ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
5331 
5332 		if (!nvlist_empty(unsup_feat)) {
5333 			fnvlist_add_nvlist(spa->spa_load_info,
5334 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
5335 		}
5336 
5337 		fnvlist_free(enabled_feat);
5338 		fnvlist_free(unsup_feat);
5339 
5340 		if (!missing_feat_read) {
5341 			fnvlist_add_boolean(spa->spa_load_info,
5342 			    ZPOOL_CONFIG_CAN_RDONLY);
5343 		}
5344 
5345 		/*
5346 		 * If the state is SPA_LOAD_TRYIMPORT, our objective is
5347 		 * twofold: to determine whether the pool is available for
5348 		 * import in read-write mode and (if it is not) whether the
5349 		 * pool is available for import in read-only mode. If the pool
5350 		 * is available for import in read-write mode, it is displayed
5351 		 * as available in userland; if it is not available for import
5352 		 * in read-only mode, it is displayed as unavailable in
5353 		 * userland. If the pool is available for import in read-only
5354 		 * mode but not read-write mode, it is displayed as unavailable
5355 		 * in userland with a special note that the pool is actually
5356 		 * available for open in read-only mode.
5357 		 *
5358 		 * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
5359 		 * missing a feature for write, we must first determine whether
5360 		 * the pool can be opened read-only before returning to
5361 		 * userland in order to know whether to display the
5362 		 * abovementioned note.
5363 		 */
5364 		if (missing_feat_read || (*missing_feat_writep &&
5365 		    spa_writeable(spa))) {
5366 			spa_load_failed(spa, "pool uses unsupported features");
5367 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
5368 			    ENOTSUP));
5369 		}
5370 
5371 		/*
5372 		 * Load refcounts for ZFS features from disk into an in-memory
5373 		 * cache during SPA initialization.
5374 		 */
5375 		for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
5376 			uint64_t refcount;
5377 
5378 			error = feature_get_refcount_from_disk(spa,
5379 			    &spa_feature_table[i], &refcount);
5380 			if (error == 0) {
5381 				spa->spa_feat_refcount_cache[i] = refcount;
5382 			} else if (error == ENOTSUP) {
5383 				spa->spa_feat_refcount_cache[i] =
5384 				    SPA_FEATURE_DISABLED;
5385 			} else {
5386 				spa_load_failed(spa, "error getting refcount "
5387 				    "for feature %s [error=%d]",
5388 				    spa_feature_table[i].fi_guid, error);
5389 				return (spa_vdev_err(rvd,
5390 				    VDEV_AUX_CORRUPT_DATA, EIO));
5391 			}
5392 		}
5393 	}
5394 
5395 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
5396 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
5397 		    &spa->spa_feat_enabled_txg_obj, B_TRUE) != 0)
5398 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5399 	}
5400 
5401 	/*
5402 	 * Encryption was added before bookmark_v2, even though bookmark_v2
5403 	 * is now a dependency. If this pool has encryption enabled without
5404 	 * bookmark_v2, trigger an errata message.
5405 	 */
5406 	if (spa_feature_is_enabled(spa, SPA_FEATURE_ENCRYPTION) &&
5407 	    !spa_feature_is_enabled(spa, SPA_FEATURE_BOOKMARK_V2)) {
5408 		spa->spa_errata = ZPOOL_ERRATA_ZOL_8308_ENCRYPTION;
5409 	}
5410 
5411 	return (0);
5412 }
5413 
5414 static int
5415 spa_ld_load_special_directories(spa_t *spa)
5416 {
5417 	int error = 0;
5418 	vdev_t *rvd = spa->spa_root_vdev;
5419 
5420 	spa->spa_is_initializing = B_TRUE;
5421 	error = dsl_pool_open(spa->spa_dsl_pool);
5422 	spa->spa_is_initializing = B_FALSE;
5423 	if (error != 0) {
5424 		spa_load_failed(spa, "dsl_pool_open failed [error=%d]", error);
5425 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5426 	}
5427 
5428 	return (0);
5429 }
5430 
5431 static int
5432 spa_ld_get_props(spa_t *spa)
5433 {
5434 	int error = 0;
5435 	uint64_t obj;
5436 	vdev_t *rvd = spa->spa_root_vdev;
5437 
5438 	/* Grab the checksum salt from the MOS. */
5439 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
5440 	    DMU_POOL_CHECKSUM_SALT, 1,
5441 	    sizeof (spa->spa_cksum_salt.zcs_bytes),
5442 	    spa->spa_cksum_salt.zcs_bytes);
5443 	if (error == ENOENT) {
5444 		/* Generate a new salt for subsequent use */
5445 		(void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
5446 		    sizeof (spa->spa_cksum_salt.zcs_bytes));
5447 	} else if (error != 0) {
5448 		spa_load_failed(spa, "unable to retrieve checksum salt from "
5449 		    "MOS [error=%d]", error);
5450 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5451 	}
5452 
5453 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj, B_TRUE) != 0)
5454 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5455 	error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
5456 	if (error != 0) {
5457 		spa_load_failed(spa, "error opening deferred-frees bpobj "
5458 		    "[error=%d]", error);
5459 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5460 	}
5461 
5462 	/*
5463 	 * Load the bit that tells us to use the new accounting function
5464 	 * (raid-z deflation).  If we have an older pool, this will not
5465 	 * be present.
5466 	 */
5467 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate, B_FALSE);
5468 	if (error != 0 && error != ENOENT)
5469 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5470 
5471 	error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
5472 	    &spa->spa_creation_version, B_FALSE);
5473 	if (error != 0 && error != ENOENT)
5474 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5475 
5476 	/* Load time log */
5477 	spa_load_txg_log_time(spa);
5478 
5479 	/*
5480 	 * Load the persistent error log.  If we have an older pool, this will
5481 	 * not be present.
5482 	 */
5483 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last,
5484 	    B_FALSE);
5485 	if (error != 0 && error != ENOENT)
5486 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5487 
5488 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
5489 	    &spa->spa_errlog_scrub, B_FALSE);
5490 	if (error != 0 && error != ENOENT)
5491 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5492 
5493 	/* Load the last scrubbed txg. */
5494 	error = spa_dir_prop(spa, DMU_POOL_LAST_SCRUBBED_TXG,
5495 	    &spa->spa_scrubbed_last_txg, B_FALSE);
5496 	if (error != 0 && error != ENOENT)
5497 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5498 
5499 	/*
5500 	 * Load the livelist deletion field. If a livelist is queued for
5501 	 * deletion, indicate that in the spa
5502 	 */
5503 	error = spa_dir_prop(spa, DMU_POOL_DELETED_CLONES,
5504 	    &spa->spa_livelists_to_delete, B_FALSE);
5505 	if (error != 0 && error != ENOENT)
5506 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5507 
5508 	/*
5509 	 * Load the history object.  If we have an older pool, this
5510 	 * will not be present.
5511 	 */
5512 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history, B_FALSE);
5513 	if (error != 0 && error != ENOENT)
5514 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5515 
5516 	/*
5517 	 * Load the per-vdev ZAP map. If we have an older pool, this will not
5518 	 * be present; in this case, defer its creation to a later time to
5519 	 * avoid dirtying the MOS this early / out of sync context. See
5520 	 * spa_sync_config_object.
5521 	 */
5522 
5523 	/* The sentinel is only available in the MOS config. */
5524 	nvlist_t *mos_config;
5525 	if (load_nvlist(spa, spa->spa_config_object, &mos_config) != 0) {
5526 		spa_load_failed(spa, "unable to retrieve MOS config");
5527 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5528 	}
5529 
5530 	error = spa_dir_prop(spa, DMU_POOL_VDEV_ZAP_MAP,
5531 	    &spa->spa_all_vdev_zaps, B_FALSE);
5532 
5533 	if (error == ENOENT) {
5534 		VERIFY(!nvlist_exists(mos_config,
5535 		    ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS));
5536 		spa->spa_avz_action = AVZ_ACTION_INITIALIZE;
5537 		ASSERT0(vdev_count_verify_zaps(spa->spa_root_vdev));
5538 	} else if (error != 0) {
5539 		nvlist_free(mos_config);
5540 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5541 	} else if (!nvlist_exists(mos_config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS)) {
5542 		/*
5543 		 * An older version of ZFS overwrote the sentinel value, so
5544 		 * we have orphaned per-vdev ZAPs in the MOS. Defer their
5545 		 * destruction to later; see spa_sync_config_object.
5546 		 */
5547 		spa->spa_avz_action = AVZ_ACTION_DESTROY;
5548 		/*
5549 		 * We're assuming that no vdevs have had their ZAPs created
5550 		 * before this. Better be sure of it.
5551 		 */
5552 		ASSERT0(vdev_count_verify_zaps(spa->spa_root_vdev));
5553 	}
5554 	nvlist_free(mos_config);
5555 
5556 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
5557 
5558 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object,
5559 	    B_FALSE);
5560 	if (error && error != ENOENT)
5561 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5562 
5563 	if (error == 0) {
5564 		uint64_t autoreplace = 0;
5565 
5566 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
5567 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
5568 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
5569 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
5570 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
5571 		spa_prop_find(spa, ZPOOL_PROP_DEDUP_TABLE_QUOTA,
5572 		    &spa->spa_dedup_table_quota);
5573 		spa_prop_find(spa, ZPOOL_PROP_MULTIHOST, &spa->spa_multihost);
5574 		spa_prop_find(spa, ZPOOL_PROP_AUTOTRIM, &spa->spa_autotrim);
5575 		spa->spa_autoreplace = (autoreplace != 0);
5576 	}
5577 
5578 	/*
5579 	 * If we are importing a pool with missing top-level vdevs,
5580 	 * we enforce that the pool doesn't panic or get suspended on
5581 	 * error since the likelihood of missing data is extremely high.
5582 	 */
5583 	if (spa->spa_missing_tvds > 0 &&
5584 	    spa->spa_failmode != ZIO_FAILURE_MODE_CONTINUE &&
5585 	    spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
5586 		spa_load_note(spa, "forcing failmode to 'continue' "
5587 		    "as some top level vdevs are missing");
5588 		spa->spa_failmode = ZIO_FAILURE_MODE_CONTINUE;
5589 	}
5590 
5591 	return (0);
5592 }
5593 
5594 static int
5595 spa_ld_open_aux_vdevs(spa_t *spa, spa_import_type_t type)
5596 {
5597 	int error = 0;
5598 	vdev_t *rvd = spa->spa_root_vdev;
5599 
5600 	/*
5601 	 * If we're assembling the pool from the split-off vdevs of
5602 	 * an existing pool, we don't want to attach the spares & cache
5603 	 * devices.
5604 	 */
5605 
5606 	/*
5607 	 * Load any hot spares for this pool.
5608 	 */
5609 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object,
5610 	    B_FALSE);
5611 	if (error != 0 && error != ENOENT)
5612 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5613 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
5614 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
5615 		error = load_nvlist(spa, spa->spa_spares.sav_object,
5616 		    &spa->spa_spares.sav_config);
5617 		if (error != 0) {
5618 			if (!zfs_recover && spa_writeable(spa)) {
5619 				spa_load_failed(spa, "error loading spares "
5620 				    "nvlist [error=%d]", error);
5621 				return (spa_vdev_err(rvd,
5622 				    VDEV_AUX_CORRUPT_DATA, EIO));
5623 			}
5624 			spa_load_note(spa, "ignoring spares nvlist "
5625 			    "[error=%d], no spares will be available", error);
5626 			/* Leak the object, its dnode may be unreadable. */
5627 			spa->spa_spares.sav_object = 0;
5628 			spa->spa_spares.sav_sync = B_TRUE;
5629 		} else {
5630 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5631 			spa_load_spares(spa);
5632 			spa_config_exit(spa, SCL_ALL, FTAG);
5633 		}
5634 	} else if (error == 0) {
5635 		spa->spa_spares.sav_sync = B_TRUE;
5636 	}
5637 
5638 	/*
5639 	 * Load any level 2 ARC devices for this pool.
5640 	 */
5641 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
5642 	    &spa->spa_l2cache.sav_object, B_FALSE);
5643 	if (error != 0 && error != ENOENT)
5644 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5645 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
5646 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
5647 		error = load_nvlist(spa, spa->spa_l2cache.sav_object,
5648 		    &spa->spa_l2cache.sav_config);
5649 		if (error != 0) {
5650 			if (!zfs_recover && spa_writeable(spa)) {
5651 				spa_load_failed(spa, "error loading l2cache "
5652 				    "nvlist [error=%d]", error);
5653 				return (spa_vdev_err(rvd,
5654 				    VDEV_AUX_CORRUPT_DATA, EIO));
5655 			}
5656 			spa_load_note(spa, "ignoring l2cache nvlist "
5657 			    "[error=%d], no l2cache will be available", error);
5658 			/* Leak the object, its dnode may be unreadable. */
5659 			spa->spa_l2cache.sav_object = 0;
5660 			spa->spa_l2cache.sav_sync = B_TRUE;
5661 		} else {
5662 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5663 			spa_load_l2cache(spa);
5664 			spa_config_exit(spa, SCL_ALL, FTAG);
5665 		}
5666 	} else if (error == 0) {
5667 		spa->spa_l2cache.sav_sync = B_TRUE;
5668 	}
5669 
5670 	return (0);
5671 }
5672 
5673 static int
5674 spa_ld_load_vdev_metadata(spa_t *spa)
5675 {
5676 	int error = 0;
5677 	vdev_t *rvd = spa->spa_root_vdev;
5678 
5679 	/*
5680 	 * If the 'multihost' property is set, then never allow a pool to
5681 	 * be imported when the system hostid is zero.  The exception to
5682 	 * this rule is zdb which is always allowed to access pools.
5683 	 */
5684 	if (spa_multihost(spa) && spa_get_hostid(spa) == 0 &&
5685 	    (spa->spa_import_flags & ZFS_IMPORT_SKIP_MMP) == 0) {
5686 		fnvlist_add_uint64(spa->spa_load_info,
5687 		    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_NO_HOSTID);
5688 		return (spa_vdev_err(rvd, VDEV_AUX_ACTIVE, EREMOTEIO));
5689 	}
5690 
5691 	/*
5692 	 * If the 'autoreplace' property is set, then post a resource notifying
5693 	 * the ZFS DE that it should not issue any faults for unopenable
5694 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
5695 	 * unopenable vdevs so that the normal autoreplace handler can take
5696 	 * over.
5697 	 */
5698 	if (spa->spa_autoreplace && spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
5699 		spa_check_removed(spa->spa_root_vdev);
5700 		/*
5701 		 * For the import case, this is done in spa_import(), because
5702 		 * at this point we're using the spare definitions from
5703 		 * the MOS config, not necessarily from the userland config.
5704 		 */
5705 		if (spa->spa_load_state != SPA_LOAD_IMPORT) {
5706 			spa_aux_check_removed(&spa->spa_spares);
5707 			spa_aux_check_removed(&spa->spa_l2cache);
5708 		}
5709 	}
5710 
5711 	/*
5712 	 * Load the vdev metadata such as metaslabs, DTLs, spacemap object, etc.
5713 	 */
5714 	error = vdev_load(rvd);
5715 	if (error != 0) {
5716 		spa_load_failed(spa, "vdev_load failed [error=%d]", error);
5717 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
5718 	}
5719 
5720 	error = spa_ld_log_spacemaps(spa);
5721 	if (error != 0) {
5722 		spa_load_failed(spa, "spa_ld_log_spacemaps failed [error=%d]",
5723 		    error);
5724 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, error));
5725 	}
5726 
5727 	/*
5728 	 * Propagate the leaf DTLs we just loaded all the way up the vdev tree.
5729 	 */
5730 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5731 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE, B_FALSE);
5732 	spa_config_exit(spa, SCL_ALL, FTAG);
5733 
5734 	return (0);
5735 }
5736 
5737 static int
5738 spa_ld_load_dedup_tables(spa_t *spa)
5739 {
5740 	int error = 0;
5741 	vdev_t *rvd = spa->spa_root_vdev;
5742 
5743 	error = ddt_load(spa);
5744 	if (error != 0) {
5745 		spa_load_failed(spa, "ddt_load failed [error=%d]", error);
5746 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5747 	}
5748 
5749 	return (0);
5750 }
5751 
5752 static int
5753 spa_ld_load_brt(spa_t *spa)
5754 {
5755 	int error = 0;
5756 	vdev_t *rvd = spa->spa_root_vdev;
5757 
5758 	error = brt_load(spa);
5759 	if (error != 0) {
5760 		spa_load_failed(spa, "brt_load failed [error=%d]", error);
5761 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
5762 	}
5763 
5764 	return (0);
5765 }
5766 
5767 static int
5768 spa_ld_verify_logs(spa_t *spa, spa_import_type_t type, const char **ereport)
5769 {
5770 	vdev_t *rvd = spa->spa_root_vdev;
5771 
5772 	if (type != SPA_IMPORT_ASSEMBLE && spa_writeable(spa)) {
5773 		boolean_t missing = spa_check_logs(spa);
5774 		if (missing) {
5775 			if (spa->spa_missing_tvds != 0) {
5776 				spa_load_note(spa, "spa_check_logs failed "
5777 				    "so dropping the logs");
5778 			} else {
5779 				*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
5780 				spa_load_failed(spa, "spa_check_logs failed");
5781 				return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG,
5782 				    ENXIO));
5783 			}
5784 		}
5785 	}
5786 
5787 	return (0);
5788 }
5789 
5790 static int
5791 spa_ld_verify_pool_data(spa_t *spa)
5792 {
5793 	int error = 0;
5794 	vdev_t *rvd = spa->spa_root_vdev;
5795 
5796 	/*
5797 	 * We've successfully opened the pool, verify that we're ready
5798 	 * to start pushing transactions.
5799 	 */
5800 	if (spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
5801 		error = spa_load_verify(spa);
5802 		if (error != 0) {
5803 			spa_load_failed(spa, "spa_load_verify failed "
5804 			    "[error=%d]", error);
5805 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
5806 			    error));
5807 		}
5808 	}
5809 
5810 	return (0);
5811 }
5812 
5813 static void
5814 spa_ld_claim_log_blocks(spa_t *spa)
5815 {
5816 	dmu_tx_t *tx;
5817 	dsl_pool_t *dp = spa_get_dsl(spa);
5818 
5819 	/*
5820 	 * Claim log blocks that haven't been committed yet.
5821 	 * This must all happen in a single txg.
5822 	 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
5823 	 * invoked from zil_claim_log_block()'s i/o done callback.
5824 	 * Price of rollback is that we abandon the log.
5825 	 */
5826 	spa->spa_claiming = B_TRUE;
5827 
5828 	tx = dmu_tx_create_assigned(dp, spa_first_txg(spa));
5829 	(void) dmu_objset_find_dp(dp, dp->dp_root_dir_obj,
5830 	    zil_claim, tx, DS_FIND_CHILDREN);
5831 	dmu_tx_commit(tx);
5832 
5833 	spa->spa_claiming = B_FALSE;
5834 
5835 	spa_set_log_state(spa, SPA_LOG_GOOD);
5836 }
5837 
5838 static void
5839 spa_ld_check_for_config_update(spa_t *spa, uint64_t config_cache_txg,
5840     boolean_t update_config_cache)
5841 {
5842 	vdev_t *rvd = spa->spa_root_vdev;
5843 	int need_update = B_FALSE;
5844 
5845 	/*
5846 	 * If the config cache is stale, or we have uninitialized
5847 	 * metaslabs (see spa_vdev_add()), then update the config.
5848 	 *
5849 	 * If this is a verbatim import, trust the current
5850 	 * in-core spa_config and update the disk labels.
5851 	 */
5852 	if (update_config_cache || config_cache_txg != spa->spa_config_txg ||
5853 	    spa->spa_load_state == SPA_LOAD_IMPORT ||
5854 	    spa->spa_load_state == SPA_LOAD_RECOVER ||
5855 	    (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
5856 		need_update = B_TRUE;
5857 
5858 	for (int c = 0; c < rvd->vdev_children; c++)
5859 		if (rvd->vdev_child[c]->vdev_ms_array == 0)
5860 			need_update = B_TRUE;
5861 
5862 	/*
5863 	 * Update the config cache asynchronously in case we're the
5864 	 * root pool, in which case the config cache isn't writable yet.
5865 	 */
5866 	if (need_update)
5867 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
5868 }
5869 
5870 static void
5871 spa_ld_prepare_for_reload(spa_t *spa)
5872 {
5873 	spa_mode_t mode = spa->spa_mode;
5874 	int async_suspended = spa->spa_async_suspended;
5875 
5876 	spa_unload(spa);
5877 	spa_deactivate(spa);
5878 	spa_activate(spa, mode);
5879 
5880 	/*
5881 	 * We save the value of spa_async_suspended as it gets reset to 0 by
5882 	 * spa_unload(). We want to restore it back to the original value before
5883 	 * returning as we might be calling spa_async_resume() later.
5884 	 */
5885 	spa->spa_async_suspended = async_suspended;
5886 }
5887 
5888 static int
5889 spa_ld_read_checkpoint_txg(spa_t *spa)
5890 {
5891 	uberblock_t checkpoint;
5892 	int error = 0;
5893 
5894 	ASSERT0(spa->spa_checkpoint_txg);
5895 	ASSERT(spa_namespace_held() ||
5896 	    spa->spa_load_thread == curthread);
5897 
5898 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
5899 	    DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
5900 	    sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);
5901 
5902 	if (error == ENOENT)
5903 		return (0);
5904 
5905 	if (error != 0)
5906 		return (error);
5907 
5908 	ASSERT3U(checkpoint.ub_txg, !=, 0);
5909 	ASSERT3U(checkpoint.ub_checkpoint_txg, !=, 0);
5910 	ASSERT3U(checkpoint.ub_timestamp, !=, 0);
5911 	spa->spa_checkpoint_txg = checkpoint.ub_txg;
5912 	spa->spa_checkpoint_info.sci_timestamp = checkpoint.ub_timestamp;
5913 
5914 	return (0);
5915 }
5916 
5917 static int
5918 spa_ld_mos_init(spa_t *spa, spa_import_type_t type)
5919 {
5920 	int error = 0;
5921 
5922 	ASSERT(spa_namespace_held());
5923 	ASSERT(spa->spa_config_source != SPA_CONFIG_SRC_NONE);
5924 
5925 	/*
5926 	 * Never trust the config that is provided unless we are assembling
5927 	 * a pool following a split.
5928 	 * This means don't trust blkptrs and the vdev tree in general. This
5929 	 * also effectively puts the spa in read-only mode since
5930 	 * spa_writeable() checks for spa_trust_config to be true.
5931 	 * We will later load a trusted config from the MOS.
5932 	 */
5933 	if (type != SPA_IMPORT_ASSEMBLE)
5934 		spa->spa_trust_config = B_FALSE;
5935 
5936 	/*
5937 	 * Parse the config provided to create a vdev tree.
5938 	 */
5939 	error = spa_ld_parse_config(spa, type);
5940 	if (error != 0)
5941 		return (error);
5942 
5943 	spa_import_progress_add(spa);
5944 
5945 	/*
5946 	 * Now that we have the vdev tree, try to open each vdev. This involves
5947 	 * opening the underlying physical device, retrieving its geometry and
5948 	 * probing the vdev with a dummy I/O. The state of each vdev will be set
5949 	 * based on the success of those operations. After this we'll be ready
5950 	 * to read from the vdevs.
5951 	 */
5952 	error = spa_ld_open_vdevs(spa);
5953 	if (error != 0)
5954 		return (error);
5955 
5956 	/*
5957 	 * Read the label of each vdev and make sure that the GUIDs stored
5958 	 * there match the GUIDs in the config provided.
5959 	 * If we're assembling a new pool that's been split off from an
5960 	 * existing pool, the labels haven't yet been updated so we skip
5961 	 * validation for now.
5962 	 */
5963 	if (type != SPA_IMPORT_ASSEMBLE) {
5964 		error = spa_ld_validate_vdevs(spa);
5965 		if (error != 0)
5966 			return (error);
5967 	}
5968 
5969 	/*
5970 	 * Read all vdev labels to find the best uberblock (i.e. latest,
5971 	 * unless spa_load_max_txg is set) and store it in spa_uberblock. We
5972 	 * get the list of features required to read blkptrs in the MOS from
5973 	 * the vdev label with the best uberblock and verify that our version
5974 	 * of zfs supports them all.
5975 	 */
5976 	error = spa_ld_select_uberblock(spa, type);
5977 	if (error != 0)
5978 		return (error);
5979 
5980 	/*
5981 	 * Pass that uberblock to the dsl_pool layer which will open the root
5982 	 * blkptr. This blkptr points to the latest version of the MOS and will
5983 	 * allow us to read its contents.
5984 	 */
5985 	error = spa_ld_open_rootbp(spa);
5986 	if (error != 0)
5987 		return (error);
5988 
5989 	return (0);
5990 }
5991 
5992 static int
5993 spa_ld_checkpoint_rewind(spa_t *spa)
5994 {
5995 	uberblock_t checkpoint;
5996 	int error = 0;
5997 
5998 	ASSERT(spa_namespace_held());
5999 	ASSERT(spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
6000 
6001 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
6002 	    DMU_POOL_ZPOOL_CHECKPOINT, sizeof (uint64_t),
6003 	    sizeof (uberblock_t) / sizeof (uint64_t), &checkpoint);
6004 
6005 	if (error != 0) {
6006 		spa_load_failed(spa, "unable to retrieve checkpointed "
6007 		    "uberblock from the MOS config [error=%d]", error);
6008 
6009 		if (error == ENOENT)
6010 			error = ZFS_ERR_NO_CHECKPOINT;
6011 
6012 		return (error);
6013 	}
6014 
6015 	ASSERT3U(checkpoint.ub_txg, <, spa->spa_uberblock.ub_txg);
6016 	ASSERT3U(checkpoint.ub_txg, ==, checkpoint.ub_checkpoint_txg);
6017 
6018 	/*
6019 	 * We need to update the txg and timestamp of the checkpointed
6020 	 * uberblock to be higher than the latest one. This ensures that
6021 	 * the checkpointed uberblock is selected if we were to close and
6022 	 * reopen the pool right after we've written it in the vdev labels.
6023 	 * (also see block comment in vdev_uberblock_compare)
6024 	 */
6025 	checkpoint.ub_txg = spa->spa_uberblock.ub_txg + 1;
6026 	checkpoint.ub_timestamp = gethrestime_sec();
6027 
6028 	/*
6029 	 * Set current uberblock to be the checkpointed uberblock.
6030 	 */
6031 	spa->spa_uberblock = checkpoint;
6032 
6033 	/*
6034 	 * If we are doing a normal rewind, then the pool is open for
6035 	 * writing and we sync the "updated" checkpointed uberblock to
6036 	 * disk. Once this is done, we've basically rewound the whole
6037 	 * pool and there is no way back.
6038 	 *
6039 	 * There are cases when we don't want to attempt and sync the
6040 	 * checkpointed uberblock to disk because we are opening a
6041 	 * pool as read-only. Specifically, verifying the checkpointed
6042 	 * state with zdb, and importing the checkpointed state to get
6043 	 * a "preview" of its content.
6044 	 */
6045 	if (spa_writeable(spa)) {
6046 		vdev_t *rvd = spa->spa_root_vdev;
6047 
6048 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6049 		vdev_t *svd[SPA_SYNC_MIN_VDEVS] = { NULL };
6050 		int svdcount = 0;
6051 		int children = rvd->vdev_children;
6052 		int c0 = random_in_range(children);
6053 
6054 		for (int c = 0; c < children; c++) {
6055 			vdev_t *vd = rvd->vdev_child[(c0 + c) % children];
6056 
6057 			/* Stop when revisiting the first vdev */
6058 			if (c > 0 && svd[0] == vd)
6059 				break;
6060 
6061 			if (vd->vdev_ms_array == 0 || vd->vdev_islog ||
6062 			    !vdev_is_concrete(vd))
6063 				continue;
6064 
6065 			svd[svdcount++] = vd;
6066 			if (svdcount == SPA_SYNC_MIN_VDEVS)
6067 				break;
6068 		}
6069 		error = vdev_config_sync(spa, svd, svdcount,
6070 		    spa->spa_first_txg);
6071 		if (error == 0)
6072 			spa->spa_last_synced_guid = rvd->vdev_guid;
6073 		spa_config_exit(spa, SCL_ALL, FTAG);
6074 
6075 		if (error != 0) {
6076 			spa_load_failed(spa, "failed to write checkpointed "
6077 			    "uberblock to the vdev labels [error=%d]", error);
6078 			return (error);
6079 		}
6080 	}
6081 
6082 	return (0);
6083 }
6084 
6085 static int
6086 spa_ld_mos_with_trusted_config(spa_t *spa, spa_import_type_t type,
6087     boolean_t *update_config_cache)
6088 {
6089 	int error;
6090 
6091 	/*
6092 	 * Parse the config for pool, open and validate vdevs,
6093 	 * select an uberblock, and use that uberblock to open
6094 	 * the MOS.
6095 	 */
6096 	error = spa_ld_mos_init(spa, type);
6097 	if (error != 0)
6098 		return (error);
6099 
6100 	/*
6101 	 * Retrieve the trusted config stored in the MOS and use it to create
6102 	 * a new, exact version of the vdev tree, then reopen all vdevs.
6103 	 */
6104 	error = spa_ld_trusted_config(spa, type, B_FALSE);
6105 	if (error == EAGAIN) {
6106 		if (update_config_cache != NULL)
6107 			*update_config_cache = B_TRUE;
6108 
6109 		/*
6110 		 * Redo the loading process with the trusted config if it is
6111 		 * too different from the untrusted config.
6112 		 */
6113 		spa_ld_prepare_for_reload(spa);
6114 		spa_load_note(spa, "RELOADING");
6115 		error = spa_ld_mos_init(spa, type);
6116 		if (error != 0)
6117 			return (error);
6118 
6119 		error = spa_ld_trusted_config(spa, type, B_TRUE);
6120 		if (error != 0)
6121 			return (error);
6122 
6123 	} else if (error != 0) {
6124 		return (error);
6125 	}
6126 
6127 	return (0);
6128 }
6129 
6130 /*
6131  * Load an existing storage pool, using the config provided. This config
6132  * describes which vdevs are part of the pool and is later validated against
6133  * partial configs present in each vdev's label and an entire copy of the
6134  * config stored in the MOS.
6135  */
6136 static int
6137 spa_load_impl(spa_t *spa, spa_import_type_t type, const char **ereport)
6138 {
6139 	int error = 0;
6140 	boolean_t missing_feat_write = B_FALSE;
6141 	boolean_t checkpoint_rewind =
6142 	    (spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
6143 	boolean_t update_config_cache = B_FALSE;
6144 	hrtime_t load_start = gethrtime();
6145 
6146 	ASSERT(spa_namespace_held());
6147 	ASSERT(spa->spa_config_source != SPA_CONFIG_SRC_NONE);
6148 
6149 	spa_load_note(spa, "LOADING");
6150 
6151 	error = spa_ld_mos_with_trusted_config(spa, type, &update_config_cache);
6152 	if (error != 0)
6153 		return (error);
6154 
6155 	/*
6156 	 * If we are rewinding to the checkpoint then we need to repeat
6157 	 * everything we've done so far in this function but this time
6158 	 * selecting the checkpointed uberblock and using that to open
6159 	 * the MOS.
6160 	 */
6161 	if (checkpoint_rewind) {
6162 		/*
6163 		 * If we are rewinding to the checkpoint update config cache
6164 		 * anyway.
6165 		 */
6166 		update_config_cache = B_TRUE;
6167 
6168 		/*
6169 		 * Extract the checkpointed uberblock from the current MOS
6170 		 * and use this as the pool's uberblock from now on. If the
6171 		 * pool is imported as writeable we also write the checkpoint
6172 		 * uberblock to the labels, making the rewind permanent.
6173 		 */
6174 		error = spa_ld_checkpoint_rewind(spa);
6175 		if (error != 0)
6176 			return (error);
6177 
6178 		/*
6179 		 * Redo the loading process again with the
6180 		 * checkpointed uberblock.
6181 		 */
6182 		spa_ld_prepare_for_reload(spa);
6183 		spa_load_note(spa, "LOADING checkpointed uberblock");
6184 		error = spa_ld_mos_with_trusted_config(spa, type, NULL);
6185 		if (error != 0)
6186 			return (error);
6187 	}
6188 
6189 	/*
6190 	 * Drop the namespace lock for the rest of the function.
6191 	 */
6192 	spa->spa_load_thread = curthread;
6193 	spa_namespace_exit(FTAG);
6194 
6195 	/*
6196 	 * Retrieve the checkpoint txg if the pool has a checkpoint.
6197 	 */
6198 	spa_import_progress_set_notes(spa, "Loading checkpoint txg");
6199 	error = spa_ld_read_checkpoint_txg(spa);
6200 	if (error != 0)
6201 		goto fail;
6202 
6203 	/*
6204 	 * Retrieve the mapping of indirect vdevs. Those vdevs were removed
6205 	 * from the pool and their contents were re-mapped to other vdevs. Note
6206 	 * that everything that we read before this step must have been
6207 	 * rewritten on concrete vdevs after the last device removal was
6208 	 * initiated. Otherwise we could be reading from indirect vdevs before
6209 	 * we have loaded their mappings.
6210 	 */
6211 	spa_import_progress_set_notes(spa, "Loading indirect vdev metadata");
6212 	error = spa_ld_open_indirect_vdev_metadata(spa);
6213 	if (error != 0)
6214 		goto fail;
6215 
6216 	/*
6217 	 * Retrieve the full list of active features from the MOS and check if
6218 	 * they are all supported.
6219 	 */
6220 	spa_import_progress_set_notes(spa, "Checking feature flags");
6221 	error = spa_ld_check_features(spa, &missing_feat_write);
6222 	if (error != 0)
6223 		goto fail;
6224 
6225 	/*
6226 	 * Load several special directories from the MOS needed by the dsl_pool
6227 	 * layer.
6228 	 */
6229 	spa_import_progress_set_notes(spa, "Loading special MOS directories");
6230 	error = spa_ld_load_special_directories(spa);
6231 	if (error != 0)
6232 		goto fail;
6233 
6234 	/*
6235 	 * Retrieve pool properties from the MOS.
6236 	 */
6237 	spa_import_progress_set_notes(spa, "Loading properties");
6238 	error = spa_ld_get_props(spa);
6239 	if (error != 0)
6240 		goto fail;
6241 
6242 	/*
6243 	 * Retrieve the list of auxiliary devices - cache devices and spares -
6244 	 * and open them.
6245 	 */
6246 	spa_import_progress_set_notes(spa, "Loading AUX vdevs");
6247 	error = spa_ld_open_aux_vdevs(spa, type);
6248 	if (error != 0)
6249 		goto fail;
6250 
6251 	/*
6252 	 * Load the metadata for all vdevs. Also check if unopenable devices
6253 	 * should be autoreplaced.
6254 	 */
6255 	spa_import_progress_set_notes(spa, "Loading vdev metadata");
6256 	error = spa_ld_load_vdev_metadata(spa);
6257 	if (error != 0)
6258 		goto fail;
6259 
6260 	spa_import_progress_set_notes(spa, "Loading dedup tables");
6261 	error = spa_ld_load_dedup_tables(spa);
6262 	if (error != 0)
6263 		goto fail;
6264 
6265 	spa_import_progress_set_notes(spa, "Loading BRT");
6266 	error = spa_ld_load_brt(spa);
6267 	if (error != 0)
6268 		goto fail;
6269 
6270 	/*
6271 	 * Verify the logs now to make sure we don't have any unexpected errors
6272 	 * when we claim log blocks later.
6273 	 */
6274 	spa_import_progress_set_notes(spa, "Verifying Log Devices");
6275 	error = spa_ld_verify_logs(spa, type, ereport);
6276 	if (error != 0)
6277 		goto fail;
6278 
6279 	if (missing_feat_write) {
6280 		ASSERT(spa->spa_load_state == SPA_LOAD_TRYIMPORT);
6281 
6282 		/*
6283 		 * At this point, we know that we can open the pool in
6284 		 * read-only mode but not read-write mode. We now have enough
6285 		 * information and can return to userland.
6286 		 */
6287 		error = spa_vdev_err(spa->spa_root_vdev, VDEV_AUX_UNSUP_FEAT,
6288 		    ENOTSUP);
6289 		goto fail;
6290 	}
6291 
6292 	/*
6293 	 * Traverse the last txgs to make sure the pool was left off in a safe
6294 	 * state. When performing an extreme rewind, we verify the whole pool,
6295 	 * which can take a very long time.
6296 	 */
6297 	spa_import_progress_set_notes(spa, "Verifying pool data");
6298 	error = spa_ld_verify_pool_data(spa);
6299 	if (error != 0)
6300 		goto fail;
6301 
6302 	/*
6303 	 * Calculate the deflated space for the pool. This must be done before
6304 	 * we write anything to the pool because we'd need to update the space
6305 	 * accounting using the deflated sizes.
6306 	 */
6307 	spa_import_progress_set_notes(spa, "Calculating deflated space");
6308 	spa_update_dspace(spa);
6309 
6310 	/*
6311 	 * We have now retrieved all the information we needed to open the
6312 	 * pool. If we are importing the pool in read-write mode, a few
6313 	 * additional steps must be performed to finish the import.
6314 	 */
6315 	if (spa_writeable(spa) && (spa->spa_load_state == SPA_LOAD_RECOVER ||
6316 	    spa->spa_load_max_txg == UINT64_MAX)) {
6317 		uint64_t config_cache_txg = spa->spa_config_txg;
6318 
6319 		spa_import_progress_set_notes(spa, "Starting import");
6320 
6321 		ASSERT(spa->spa_load_state != SPA_LOAD_TRYIMPORT);
6322 
6323 		/*
6324 		 * Before we do any zio_write's, complete the raidz expansion
6325 		 * scratch space copying, if necessary.
6326 		 */
6327 		if (RRSS_GET_STATE(&spa->spa_uberblock) == RRSS_SCRATCH_VALID)
6328 			vdev_raidz_reflow_copy_scratch(spa);
6329 
6330 		/*
6331 		 * In case of a checkpoint rewind, log the original txg
6332 		 * of the checkpointed uberblock.
6333 		 */
6334 		if (checkpoint_rewind) {
6335 			spa_history_log_internal(spa, "checkpoint rewind",
6336 			    NULL, "rewound state to txg=%llu",
6337 			    (u_longlong_t)spa->spa_uberblock.ub_checkpoint_txg);
6338 		}
6339 
6340 		spa_import_progress_set_notes(spa, "Claiming ZIL blocks");
6341 		/*
6342 		 * Traverse the ZIL and claim all blocks.
6343 		 */
6344 		spa_ld_claim_log_blocks(spa);
6345 
6346 		/*
6347 		 * Kick-off the syncing thread.
6348 		 */
6349 		spa->spa_sync_on = B_TRUE;
6350 		txg_sync_start(spa->spa_dsl_pool);
6351 		mmp_thread_start(spa);
6352 
6353 		/*
6354 		 * Wait for all claims to sync.  We sync up to the highest
6355 		 * claimed log block birth time so that claimed log blocks
6356 		 * don't appear to be from the future.  spa_claim_max_txg
6357 		 * will have been set for us by ZIL traversal operations
6358 		 * performed above.
6359 		 */
6360 		spa_import_progress_set_notes(spa, "Syncing ZIL claims");
6361 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
6362 
6363 		/*
6364 		 * Check if we need to request an update of the config. On the
6365 		 * next sync, we would update the config stored in vdev labels
6366 		 * and the cachefile (by default /etc/zfs/zpool.cache).
6367 		 */
6368 		spa_import_progress_set_notes(spa, "Updating configs");
6369 		spa_ld_check_for_config_update(spa, config_cache_txg,
6370 		    update_config_cache);
6371 
6372 		/*
6373 		 * Check if a rebuild was in progress and if so resume it.
6374 		 * Then check all DTLs to see if anything needs resilvering.
6375 		 * The resilver will be deferred if a rebuild was started.
6376 		 */
6377 		spa_import_progress_set_notes(spa, "Starting resilvers");
6378 		if (vdev_rebuild_active(spa->spa_root_vdev)) {
6379 			vdev_rebuild_restart(spa);
6380 		} else if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
6381 		    vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
6382 			spa_async_request(spa, SPA_ASYNC_RESILVER);
6383 		}
6384 
6385 		/*
6386 		 * Log the fact that we booted up (so that we can detect if
6387 		 * we rebooted in the middle of an operation).
6388 		 */
6389 		spa_history_log_version(spa, "open", NULL);
6390 
6391 		spa_import_progress_set_notes(spa,
6392 		    "Restarting device removals");
6393 		spa_restart_removal(spa);
6394 		spa_spawn_aux_threads(spa);
6395 
6396 		/*
6397 		 * Delete any inconsistent datasets.
6398 		 *
6399 		 * Note:
6400 		 * Since we may be issuing deletes for clones here,
6401 		 * we make sure to do so after we've spawned all the
6402 		 * auxiliary threads above (from which the livelist
6403 		 * deletion zthr is part of).
6404 		 */
6405 		spa_import_progress_set_notes(spa,
6406 		    "Cleaning up inconsistent objsets");
6407 		(void) dmu_objset_find(spa_name(spa),
6408 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
6409 
6410 		/*
6411 		 * Clean up any stale temporary dataset userrefs.
6412 		 */
6413 		spa_import_progress_set_notes(spa,
6414 		    "Cleaning up temporary userrefs");
6415 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
6416 
6417 		/*
6418 		 * Anything still marked for deferred destruction because a
6419 		 * mount was holding it was left that way by a crash or an
6420 		 * export, and nothing is holding it now.  The sweep walks
6421 		 * every snapshot, so leave it to the async thread rather than
6422 		 * spending import time on it.
6423 		 */
6424 		spa_async_request(spa, SPA_ASYNC_DEFER_DESTROY);
6425 
6426 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6427 		spa_import_progress_set_notes(spa, "Restarting initialize");
6428 		vdev_initialize_restart(spa->spa_root_vdev);
6429 		spa_import_progress_set_notes(spa, "Restarting TRIM");
6430 		vdev_trim_restart(spa->spa_root_vdev);
6431 		vdev_autotrim_restart(spa);
6432 		spa_config_exit(spa, SCL_CONFIG, FTAG);
6433 		spa_import_progress_set_notes(spa, "Finished importing");
6434 	}
6435 	zio_handle_import_delay(spa, gethrtime() - load_start);
6436 
6437 	spa_import_progress_remove(spa_guid(spa));
6438 	spa_async_request(spa, SPA_ASYNC_L2CACHE_REBUILD);
6439 
6440 	spa_load_note(spa, "LOADED");
6441 fail:
6442 	spa_namespace_enter(FTAG);
6443 	spa->spa_load_thread = NULL;
6444 	spa_namespace_broadcast();
6445 
6446 	return (error);
6447 
6448 }
6449 
6450 static int
6451 spa_load_retry(spa_t *spa, spa_load_state_t state)
6452 {
6453 	spa_mode_t mode = spa->spa_mode;
6454 
6455 	spa_unload(spa);
6456 	spa_deactivate(spa);
6457 
6458 	spa->spa_load_max_txg = spa->spa_uberblock.ub_txg - 1;
6459 
6460 	spa_activate(spa, mode);
6461 	spa_async_suspend(spa);
6462 
6463 	spa_load_note(spa, "spa_load_retry: rewind, max txg: %llu",
6464 	    (u_longlong_t)spa->spa_load_max_txg);
6465 
6466 	return (spa_load(spa, state, SPA_IMPORT_EXISTING));
6467 }
6468 
6469 /*
6470  * If spa_load() fails this function will try loading prior txg's. If
6471  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
6472  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
6473  * function will not rewind the pool and will return the same error as
6474  * spa_load(), or ECANCELED if the load only probed the requested txg
6475  * instead of bringing the pool up.
6476  */
6477 static int
6478 spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
6479     int rewind_flags)
6480 {
6481 	nvlist_t *loadinfo = NULL;
6482 	nvlist_t *config = NULL;
6483 	int load_error, rewind_error;
6484 	uint64_t safe_rewind_txg;
6485 	uint64_t min_txg;
6486 
6487 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
6488 		spa->spa_load_max_txg = spa->spa_load_txg;
6489 		spa_set_log_state(spa, SPA_LOG_CLEAR);
6490 	} else {
6491 		spa->spa_load_max_txg = max_request;
6492 		if (max_request != UINT64_MAX)
6493 			spa->spa_extreme_rewind = B_TRUE;
6494 	}
6495 
6496 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING);
6497 	if (load_error == 0) {
6498 		/*
6499 		 * A load of an explicitly requested txg may only probe
6500 		 * whether that txg is usable, finishing without a syncing
6501 		 * thread.  Such a pool is not functional, so it can not be
6502 		 * handed to the caller no matter how well it loaded.  Report
6503 		 * the probed txg the same way an actual rewind would.
6504 		 */
6505 		if (spa_writeable(spa) && !spa->spa_sync_on) {
6506 			loadinfo = fnvlist_alloc();
6507 			fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
6508 			    spa->spa_load_info);
6509 			fnvlist_free(spa->spa_load_info);
6510 			spa->spa_load_info = loadinfo;
6511 			spa_import_progress_remove(spa_guid(spa));
6512 			return (SET_ERROR(ECANCELED));
6513 		}
6514 		return (0);
6515 	}
6516 
6517 	/* Do not attempt to load uberblocks from previous txgs when: */
6518 	switch (load_error) {
6519 	case ZFS_ERR_NO_CHECKPOINT:
6520 		/* Attempting checkpoint-rewind on a pool with no checkpoint */
6521 		ASSERT(spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
6522 		zfs_fallthrough;
6523 	case EREMOTEIO:
6524 		/* MMP determines the pool is active on another host */
6525 		zfs_fallthrough;
6526 	case EBADF:
6527 		/* The config cache is out of sync (vdevs or hostid) */
6528 		zfs_fallthrough;
6529 	case EINTR:
6530 		/* The user interactively interrupted the import */
6531 		spa_import_progress_remove(spa_guid(spa));
6532 		return (load_error);
6533 	}
6534 
6535 	if (spa->spa_root_vdev != NULL)
6536 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
6537 
6538 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
6539 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
6540 
6541 	if (rewind_flags & ZPOOL_NEVER_REWIND) {
6542 		nvlist_free(config);
6543 		spa_import_progress_remove(spa_guid(spa));
6544 		return (load_error);
6545 	}
6546 
6547 	if (state == SPA_LOAD_RECOVER) {
6548 		/* Price of rolling back is discarding txgs, including log */
6549 		spa_set_log_state(spa, SPA_LOG_CLEAR);
6550 	} else {
6551 		/*
6552 		 * If we aren't rolling back save the load info from our first
6553 		 * import attempt so that we can restore it after attempting
6554 		 * to rewind.
6555 		 */
6556 		loadinfo = spa->spa_load_info;
6557 		spa->spa_load_info = fnvlist_alloc();
6558 	}
6559 
6560 	spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
6561 	safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
6562 	min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
6563 	    TXG_INITIAL : safe_rewind_txg;
6564 
6565 	/*
6566 	 * Continue as long as we're finding errors, we're still within
6567 	 * the acceptable rewind range, and we're still finding uberblocks
6568 	 */
6569 	while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
6570 	    spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
6571 		if (spa->spa_load_max_txg < safe_rewind_txg)
6572 			spa->spa_extreme_rewind = B_TRUE;
6573 		rewind_error = spa_load_retry(spa, state);
6574 	}
6575 
6576 	spa->spa_extreme_rewind = B_FALSE;
6577 	spa->spa_load_max_txg = UINT64_MAX;
6578 
6579 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
6580 		spa_config_set(spa, config);
6581 	else
6582 		nvlist_free(config);
6583 
6584 	if (state == SPA_LOAD_RECOVER) {
6585 		ASSERT0P(loadinfo);
6586 		spa_import_progress_remove(spa_guid(spa));
6587 		return (rewind_error);
6588 	} else {
6589 		/* Store the rewind info as part of the initial load info */
6590 		fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
6591 		    spa->spa_load_info);
6592 
6593 		/* Restore the initial load info */
6594 		fnvlist_free(spa->spa_load_info);
6595 		spa->spa_load_info = loadinfo;
6596 
6597 		spa_import_progress_remove(spa_guid(spa));
6598 		return (load_error);
6599 	}
6600 }
6601 
6602 /*
6603  * Pool Open/Import
6604  *
6605  * The import case is identical to an open except that the configuration is sent
6606  * down from userland, instead of grabbed from the configuration cache.  For the
6607  * case of an open, the pool configuration will exist in the
6608  * POOL_STATE_UNINITIALIZED state.
6609  *
6610  * The stats information (gen/count/ustats) is used to gather vdev statistics at
6611  * the same time open the pool, without having to keep around the spa_t in some
6612  * ambiguous state.
6613  */
6614 static int
6615 spa_open_common(const char *pool, spa_t **spapp, const void *tag,
6616     nvlist_t *nvpolicy, nvlist_t **config)
6617 {
6618 	spa_t *spa;
6619 	spa_load_state_t state = SPA_LOAD_OPEN;
6620 	int error;
6621 	int locked = B_FALSE;
6622 	int firstopen = B_FALSE;
6623 
6624 	*spapp = NULL;
6625 
6626 	/*
6627 	 * As disgusting as this is, we need to support recursive calls to this
6628 	 * function because dsl_dir_open() is called during spa_load(), and ends
6629 	 * up calling spa_open() again.  The real fix is to figure out how to
6630 	 * avoid dsl_dir_open() calling this in the first place.
6631 	 */
6632 	if (!spa_namespace_held()) {
6633 		spa_namespace_enter(FTAG);
6634 		locked = B_TRUE;
6635 	}
6636 
6637 	if ((spa = spa_lookup(pool)) == NULL) {
6638 		if (locked)
6639 			spa_namespace_exit(FTAG);
6640 		return (SET_ERROR(ENOENT));
6641 	}
6642 
6643 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
6644 		zpool_load_policy_t policy;
6645 
6646 		firstopen = B_TRUE;
6647 
6648 		zpool_get_load_policy(nvpolicy ? nvpolicy : spa->spa_config,
6649 		    &policy);
6650 		if (policy.zlp_rewind & ZPOOL_DO_REWIND)
6651 			state = SPA_LOAD_RECOVER;
6652 
6653 		spa_activate(spa, spa_mode_global);
6654 
6655 		if (state != SPA_LOAD_RECOVER)
6656 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
6657 		spa->spa_config_source = SPA_CONFIG_SRC_CACHEFILE;
6658 
6659 		zfs_dbgmsg("spa_open_common: opening %s", pool);
6660 		error = spa_load_best(spa, state, policy.zlp_txg,
6661 		    policy.zlp_rewind);
6662 
6663 		if (error == EBADF) {
6664 			/*
6665 			 * If vdev_validate() returns failure (indicated by
6666 			 * EBADF), it indicates that one of the vdevs indicates
6667 			 * that the pool has been exported or destroyed.  If
6668 			 * this is the case, the config cache is out of sync and
6669 			 * we should remove the pool from the namespace.
6670 			 */
6671 			spa_unload(spa);
6672 			spa_deactivate(spa);
6673 			spa_write_cachefile(spa, B_TRUE, B_TRUE, B_FALSE);
6674 			spa_remove(spa);
6675 			if (locked)
6676 				spa_namespace_exit(FTAG);
6677 			return (SET_ERROR(ENOENT));
6678 		}
6679 
6680 		if (error) {
6681 			/*
6682 			 * We can't open the pool, but we still have useful
6683 			 * information: the state of each vdev after the
6684 			 * attempted vdev_open().  Return this to the user.
6685 			 */
6686 			if (config != NULL && spa->spa_config) {
6687 				*config = fnvlist_dup(spa->spa_config);
6688 				fnvlist_add_nvlist(*config,
6689 				    ZPOOL_CONFIG_LOAD_INFO,
6690 				    spa->spa_load_info);
6691 			}
6692 			spa_unload(spa);
6693 			spa_deactivate(spa);
6694 			spa->spa_last_open_failed = error;
6695 			if (locked)
6696 				spa_namespace_exit(FTAG);
6697 			*spapp = NULL;
6698 			return (error);
6699 		}
6700 	}
6701 
6702 	spa_open_ref(spa, tag);
6703 
6704 	if (config != NULL)
6705 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
6706 
6707 	/*
6708 	 * If we've recovered the pool, pass back any information we
6709 	 * gathered while doing the load.
6710 	 */
6711 	if (state == SPA_LOAD_RECOVER && config != NULL) {
6712 		fnvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
6713 		    spa->spa_load_info);
6714 	}
6715 
6716 	if (locked) {
6717 		spa->spa_last_open_failed = 0;
6718 		spa->spa_last_ubsync_txg = 0;
6719 		spa->spa_load_txg = 0;
6720 		spa_namespace_exit(FTAG);
6721 	}
6722 
6723 	if (firstopen)
6724 		zvol_create_minors(spa_name(spa));
6725 
6726 	*spapp = spa;
6727 
6728 	return (0);
6729 }
6730 
6731 int
6732 spa_open_rewind(const char *name, spa_t **spapp, const void *tag,
6733     nvlist_t *policy, nvlist_t **config)
6734 {
6735 	return (spa_open_common(name, spapp, tag, policy, config));
6736 }
6737 
6738 int
6739 spa_open(const char *name, spa_t **spapp, const void *tag)
6740 {
6741 	return (spa_open_common(name, spapp, tag, NULL, NULL));
6742 }
6743 
6744 /*
6745  * Lookup the given spa_t, incrementing the inject count in the process,
6746  * preventing it from being exported or destroyed.
6747  */
6748 spa_t *
6749 spa_inject_addref(char *name)
6750 {
6751 	spa_t *spa;
6752 
6753 	spa_namespace_enter(FTAG);
6754 	if ((spa = spa_lookup(name)) == NULL) {
6755 		spa_namespace_exit(FTAG);
6756 		return (NULL);
6757 	}
6758 	spa->spa_inject_ref++;
6759 	spa_namespace_exit(FTAG);
6760 
6761 	return (spa);
6762 }
6763 
6764 void
6765 spa_inject_delref(spa_t *spa)
6766 {
6767 	spa_namespace_enter(FTAG);
6768 	spa->spa_inject_ref--;
6769 	spa_namespace_exit(FTAG);
6770 }
6771 
6772 /*
6773  * Add spares device information to the nvlist.
6774  */
6775 static void
6776 spa_add_spares(spa_t *spa, nvlist_t *config)
6777 {
6778 	nvlist_t **spares;
6779 	uint_t i, nspares;
6780 	nvlist_t *nvroot;
6781 	uint64_t guid;
6782 	vdev_stat_t *vs;
6783 	uint_t vsc;
6784 	uint64_t pool;
6785 
6786 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
6787 
6788 	if (spa->spa_spares.sav_count == 0)
6789 		return;
6790 
6791 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
6792 	VERIFY0(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
6793 	    ZPOOL_CONFIG_SPARES, &spares, &nspares));
6794 	if (nspares != 0) {
6795 		fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
6796 		    (const nvlist_t * const *)spares, nspares);
6797 		VERIFY0(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
6798 		    &spares, &nspares));
6799 
6800 		/*
6801 		 * Go through and find any spares which have since been
6802 		 * repurposed as an active spare.  If this is the case, update
6803 		 * their status appropriately.
6804 		 */
6805 		for (i = 0; i < nspares; i++) {
6806 			guid = fnvlist_lookup_uint64(spares[i],
6807 			    ZPOOL_CONFIG_GUID);
6808 			VERIFY0(nvlist_lookup_uint64_array(spares[i],
6809 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc));
6810 			if (spa_spare_exists(guid, &pool, NULL) &&
6811 			    pool != 0ULL) {
6812 				vs->vs_state = VDEV_STATE_CANT_OPEN;
6813 				vs->vs_aux = VDEV_AUX_SPARED;
6814 			} else {
6815 				vs->vs_state =
6816 				    spa->spa_spares.sav_vdevs[i]->vdev_state;
6817 			}
6818 		}
6819 	}
6820 }
6821 
6822 /*
6823  * Add l2cache device information to the nvlist, including vdev stats.
6824  */
6825 static void
6826 spa_add_l2cache(spa_t *spa, nvlist_t *config)
6827 {
6828 	nvlist_t **l2cache;
6829 	uint_t i, j, nl2cache;
6830 	nvlist_t *nvroot;
6831 	uint64_t guid;
6832 	vdev_t *vd;
6833 	vdev_stat_t *vs;
6834 	uint_t vsc;
6835 
6836 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
6837 
6838 	if (spa->spa_l2cache.sav_count == 0)
6839 		return;
6840 
6841 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
6842 	VERIFY0(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
6843 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache));
6844 	if (nl2cache != 0) {
6845 		fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
6846 		    (const nvlist_t * const *)l2cache, nl2cache);
6847 		VERIFY0(nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
6848 		    &l2cache, &nl2cache));
6849 
6850 		/*
6851 		 * Update level 2 cache device stats.
6852 		 */
6853 
6854 		for (i = 0; i < nl2cache; i++) {
6855 			guid = fnvlist_lookup_uint64(l2cache[i],
6856 			    ZPOOL_CONFIG_GUID);
6857 
6858 			vd = NULL;
6859 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
6860 				if (guid ==
6861 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
6862 					vd = spa->spa_l2cache.sav_vdevs[j];
6863 					break;
6864 				}
6865 			}
6866 			ASSERT(vd != NULL);
6867 
6868 			VERIFY0(nvlist_lookup_uint64_array(l2cache[i],
6869 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc));
6870 			vdev_get_stats(vd, vs);
6871 			vdev_config_generate_stats(vd, l2cache[i]);
6872 
6873 		}
6874 	}
6875 }
6876 
6877 static void
6878 spa_feature_stats_from_disk(spa_t *spa, nvlist_t *features)
6879 {
6880 	zap_cursor_t zc;
6881 	zap_attribute_t *za = zap_attribute_alloc();
6882 
6883 	if (spa->spa_feat_for_read_obj != 0) {
6884 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
6885 		    spa->spa_feat_for_read_obj);
6886 		    zap_cursor_retrieve(&zc, za) == 0;
6887 		    zap_cursor_advance(&zc)) {
6888 			ASSERT(za->za_integer_length == sizeof (uint64_t) &&
6889 			    za->za_num_integers == 1);
6890 			VERIFY0(nvlist_add_uint64(features, za->za_name,
6891 			    za->za_first_integer));
6892 		}
6893 		zap_cursor_fini(&zc);
6894 	}
6895 
6896 	if (spa->spa_feat_for_write_obj != 0) {
6897 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
6898 		    spa->spa_feat_for_write_obj);
6899 		    zap_cursor_retrieve(&zc, za) == 0;
6900 		    zap_cursor_advance(&zc)) {
6901 			ASSERT(za->za_integer_length == sizeof (uint64_t) &&
6902 			    za->za_num_integers == 1);
6903 			VERIFY0(nvlist_add_uint64(features, za->za_name,
6904 			    za->za_first_integer));
6905 		}
6906 		zap_cursor_fini(&zc);
6907 	}
6908 	zap_attribute_free(za);
6909 }
6910 
6911 static void
6912 spa_feature_stats_from_cache(spa_t *spa, nvlist_t *features)
6913 {
6914 	int i;
6915 
6916 	for (i = 0; i < SPA_FEATURES; i++) {
6917 		zfeature_info_t feature = spa_feature_table[i];
6918 		uint64_t refcount;
6919 
6920 		if (feature_get_refcount(spa, &feature, &refcount) != 0)
6921 			continue;
6922 
6923 		VERIFY0(nvlist_add_uint64(features, feature.fi_guid, refcount));
6924 	}
6925 }
6926 
6927 /*
6928  * Store a list of pool features and their reference counts in the
6929  * config.
6930  *
6931  * The first time this is called on a spa, allocate a new nvlist, fetch
6932  * the pool features and reference counts from disk, then save the list
6933  * in the spa. In subsequent calls on the same spa use the saved nvlist
6934  * and refresh its values from the cached reference counts.  This
6935  * ensures we don't block here on I/O on a suspended pool so 'zpool
6936  * clear' can resume the pool.
6937  */
6938 static void
6939 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
6940 {
6941 	nvlist_t *features;
6942 
6943 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
6944 
6945 	mutex_enter(&spa->spa_feat_stats_lock);
6946 	features = spa->spa_feat_stats;
6947 
6948 	if (features != NULL) {
6949 		spa_feature_stats_from_cache(spa, features);
6950 	} else {
6951 		VERIFY0(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP));
6952 		spa->spa_feat_stats = features;
6953 		spa_feature_stats_from_disk(spa, features);
6954 	}
6955 
6956 	VERIFY0(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
6957 	    features));
6958 
6959 	mutex_exit(&spa->spa_feat_stats_lock);
6960 }
6961 
6962 int
6963 spa_get_stats(const char *name, nvlist_t **config,
6964     char *altroot, size_t buflen)
6965 {
6966 	int error;
6967 	spa_t *spa;
6968 
6969 	*config = NULL;
6970 	error = spa_open_common(name, &spa, FTAG, NULL, config);
6971 
6972 	if (spa != NULL) {
6973 		/*
6974 		 * This still leaves a window of inconsistency where the spares
6975 		 * or l2cache devices could change and the config would be
6976 		 * self-inconsistent.
6977 		 */
6978 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6979 
6980 		if (*config != NULL) {
6981 			uint64_t loadtimes[2];
6982 
6983 			loadtimes[0] = spa->spa_loaded_ts.tv_sec;
6984 			loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
6985 			fnvlist_add_uint64_array(*config,
6986 			    ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2);
6987 
6988 			fnvlist_add_uint64(*config,
6989 			    ZPOOL_CONFIG_ERRCOUNT,
6990 			    spa_approx_errlog_size(spa));
6991 
6992 			if (spa_suspended(spa)) {
6993 				fnvlist_add_uint64(*config,
6994 				    ZPOOL_CONFIG_SUSPENDED,
6995 				    spa->spa_failmode);
6996 				fnvlist_add_uint64(*config,
6997 				    ZPOOL_CONFIG_SUSPENDED_REASON,
6998 				    spa->spa_suspended);
6999 			}
7000 
7001 			spa_add_spares(spa, *config);
7002 			spa_add_l2cache(spa, *config);
7003 			spa_add_feature_stats(spa, *config);
7004 		}
7005 	}
7006 
7007 	/*
7008 	 * We want to get the alternate root even for faulted pools, so we cheat
7009 	 * and call spa_lookup() directly.
7010 	 */
7011 	if (altroot) {
7012 		if (spa == NULL) {
7013 			spa_namespace_enter(FTAG);
7014 			spa = spa_lookup(name);
7015 			if (spa)
7016 				spa_altroot(spa, altroot, buflen);
7017 			else
7018 				altroot[0] = '\0';
7019 			spa = NULL;
7020 			spa_namespace_exit(FTAG);
7021 		} else {
7022 			spa_altroot(spa, altroot, buflen);
7023 		}
7024 	}
7025 
7026 	if (spa != NULL) {
7027 		spa_config_exit(spa, SCL_CONFIG, FTAG);
7028 		spa_close(spa, FTAG);
7029 	}
7030 
7031 	return (error);
7032 }
7033 
7034 /*
7035  * Validate that the auxiliary device array is well formed.  We must have an
7036  * array of nvlists, each which describes a valid leaf vdev.  If this is an
7037  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
7038  * specified, as long as they are well-formed.
7039  */
7040 static int
7041 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
7042     spa_aux_vdev_t *sav, const char *config, uint64_t version,
7043     vdev_labeltype_t label)
7044 {
7045 	nvlist_t **dev;
7046 	uint_t i, ndev;
7047 	vdev_t *vd;
7048 	int error;
7049 
7050 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
7051 
7052 	/*
7053 	 * It's acceptable to have no devs specified.
7054 	 */
7055 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
7056 		return (0);
7057 
7058 	if (ndev == 0)
7059 		return (SET_ERROR(EINVAL));
7060 
7061 	/*
7062 	 * Make sure the pool is formatted with a version that supports this
7063 	 * device type.
7064 	 */
7065 	if (spa_version(spa) < version)
7066 		return (SET_ERROR(ENOTSUP));
7067 
7068 	/*
7069 	 * Set the pending device list so we correctly handle device in-use
7070 	 * checking.
7071 	 */
7072 	sav->sav_pending = dev;
7073 	sav->sav_npending = ndev;
7074 
7075 	for (i = 0; i < ndev; i++) {
7076 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
7077 		    mode)) != 0)
7078 			goto out;
7079 
7080 		if (!vd->vdev_ops->vdev_op_leaf) {
7081 			vdev_free(vd);
7082 			error = SET_ERROR(EINVAL);
7083 			goto out;
7084 		}
7085 
7086 		vd->vdev_top = vd;
7087 
7088 		if ((error = vdev_open(vd, CRED())) == 0 &&
7089 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
7090 			fnvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
7091 			    vd->vdev_guid);
7092 		}
7093 
7094 		vdev_free(vd);
7095 
7096 		if (error &&
7097 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
7098 			goto out;
7099 		else
7100 			error = 0;
7101 	}
7102 
7103 out:
7104 	sav->sav_pending = NULL;
7105 	sav->sav_npending = 0;
7106 	return (error);
7107 }
7108 
7109 static int
7110 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
7111 {
7112 	int error;
7113 
7114 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
7115 
7116 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
7117 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
7118 	    VDEV_LABEL_SPARE)) != 0) {
7119 		return (error);
7120 	}
7121 
7122 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
7123 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
7124 	    VDEV_LABEL_L2CACHE));
7125 }
7126 
7127 static void
7128 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
7129     const char *config)
7130 {
7131 	int i;
7132 
7133 	if (sav->sav_config != NULL) {
7134 		nvlist_t **olddevs;
7135 		uint_t oldndevs;
7136 		nvlist_t **newdevs;
7137 
7138 		/*
7139 		 * Generate new dev list by concatenating with the
7140 		 * current dev list.
7141 		 */
7142 		VERIFY0(nvlist_lookup_nvlist_array(sav->sav_config, config,
7143 		    &olddevs, &oldndevs));
7144 
7145 		newdevs = kmem_alloc(sizeof (void *) *
7146 		    (ndevs + oldndevs), KM_SLEEP);
7147 		for (i = 0; i < oldndevs; i++)
7148 			newdevs[i] = fnvlist_dup(olddevs[i]);
7149 		for (i = 0; i < ndevs; i++)
7150 			newdevs[i + oldndevs] = fnvlist_dup(devs[i]);
7151 
7152 		fnvlist_remove(sav->sav_config, config);
7153 
7154 		fnvlist_add_nvlist_array(sav->sav_config, config,
7155 		    (const nvlist_t * const *)newdevs, ndevs + oldndevs);
7156 		for (i = 0; i < oldndevs + ndevs; i++)
7157 			nvlist_free(newdevs[i]);
7158 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
7159 	} else {
7160 		/*
7161 		 * Generate a new dev list.
7162 		 */
7163 		sav->sav_config = fnvlist_alloc();
7164 		fnvlist_add_nvlist_array(sav->sav_config, config,
7165 		    (const nvlist_t * const *)devs, ndevs);
7166 	}
7167 }
7168 
7169 /*
7170  * Stop and drop level 2 ARC devices
7171  */
7172 void
7173 spa_l2cache_drop(spa_t *spa)
7174 {
7175 	vdev_t *vd;
7176 	int i;
7177 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
7178 
7179 	for (i = 0; i < sav->sav_count; i++) {
7180 		uint64_t pool;
7181 
7182 		vd = sav->sav_vdevs[i];
7183 		ASSERT(vd != NULL);
7184 
7185 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
7186 		    pool != 0ULL && l2arc_vdev_present(vd))
7187 			l2arc_remove_vdev(vd);
7188 	}
7189 }
7190 
7191 /*
7192  * Verify encryption parameters for spa creation. If we are encrypting, we must
7193  * have the encryption feature flag enabled.
7194  */
7195 static int
7196 spa_create_check_encryption_params(dsl_crypto_params_t *dcp,
7197     boolean_t has_encryption)
7198 {
7199 	if (dcp->cp_crypt != ZIO_CRYPT_OFF &&
7200 	    dcp->cp_crypt != ZIO_CRYPT_INHERIT &&
7201 	    !has_encryption)
7202 		return (SET_ERROR(ENOTSUP));
7203 
7204 	return (dmu_objset_create_crypt_check(NULL, dcp, NULL));
7205 }
7206 
7207 /*
7208  * Pool Creation
7209  */
7210 int
7211 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
7212     nvlist_t *zplprops, dsl_crypto_params_t *dcp, nvlist_t **errinfo)
7213 {
7214 	spa_t *spa;
7215 	const char *altroot = NULL;
7216 	vdev_t *rvd;
7217 	dsl_pool_t *dp;
7218 	dmu_tx_t *tx;
7219 	int error = 0;
7220 	uint64_t txg = TXG_INITIAL;
7221 	nvlist_t **spares, **l2cache;
7222 	uint_t nspares, nl2cache;
7223 	uint64_t version, obj, ndraid = 0, draid_nfgroup = 0;
7224 	boolean_t has_features;
7225 	boolean_t has_encryption;
7226 	boolean_t has_allocclass;
7227 	boolean_t has_draid;
7228 	boolean_t has_draid_fdomains;
7229 	spa_feature_t feat;
7230 	const char *feat_name;
7231 	const char *poolname;
7232 	nvlist_t *nvl;
7233 
7234 	if (props == NULL ||
7235 	    nvlist_lookup_string(props,
7236 	    zpool_prop_to_name(ZPOOL_PROP_TNAME), &poolname) != 0)
7237 		poolname = (char *)pool;
7238 
7239 	/*
7240 	 * If this pool already exists, return failure.
7241 	 */
7242 	spa_namespace_enter(FTAG);
7243 	if (spa_lookup(poolname) != NULL) {
7244 		spa_namespace_exit(FTAG);
7245 		return (SET_ERROR(EEXIST));
7246 	}
7247 
7248 	/*
7249 	 * Allocate a new spa_t structure.
7250 	 */
7251 	nvl = fnvlist_alloc();
7252 	fnvlist_add_string(nvl, ZPOOL_CONFIG_POOL_NAME, pool);
7253 	(void) nvlist_lookup_string(props,
7254 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
7255 	spa = spa_add(poolname, nvl, altroot);
7256 	fnvlist_free(nvl);
7257 	spa_activate(spa, spa_mode_global);
7258 
7259 	if (props && (error = spa_prop_validate(spa, props))) {
7260 		spa_deactivate(spa);
7261 		spa_remove(spa);
7262 		spa_namespace_exit(FTAG);
7263 		return (error);
7264 	}
7265 
7266 	/*
7267 	 * Temporary pool names should never be written to disk.
7268 	 */
7269 	if (poolname != pool)
7270 		spa->spa_import_flags |= ZFS_IMPORT_TEMP_NAME;
7271 
7272 	has_features = B_FALSE;
7273 	has_encryption = B_FALSE;
7274 	has_allocclass = B_FALSE;
7275 	has_draid = B_FALSE;
7276 	has_draid_fdomains = B_FALSE;
7277 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
7278 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
7279 		if (zpool_prop_feature(nvpair_name(elem))) {
7280 			has_features = B_TRUE;
7281 
7282 			feat_name = strchr(nvpair_name(elem), '@') + 1;
7283 			VERIFY0(zfeature_lookup_name(feat_name, &feat));
7284 			if (feat == SPA_FEATURE_ENCRYPTION)
7285 				has_encryption = B_TRUE;
7286 			if (feat == SPA_FEATURE_ALLOCATION_CLASSES)
7287 				has_allocclass = B_TRUE;
7288 			if (feat == SPA_FEATURE_DRAID)
7289 				has_draid = B_TRUE;
7290 			if (feat == SPA_FEATURE_DRAID_FAIL_DOMAINS)
7291 				has_draid_fdomains = B_TRUE;
7292 		}
7293 	}
7294 
7295 	/* verify encryption params, if they were provided */
7296 	if (dcp != NULL) {
7297 		error = spa_create_check_encryption_params(dcp, has_encryption);
7298 		if (error != 0) {
7299 			spa_deactivate(spa);
7300 			spa_remove(spa);
7301 			spa_namespace_exit(FTAG);
7302 			return (error);
7303 		}
7304 	}
7305 	if (!has_allocclass && zfs_special_devs(nvroot, NULL)) {
7306 		spa_deactivate(spa);
7307 		spa_remove(spa);
7308 		spa_namespace_exit(FTAG);
7309 		return (ENOTSUP);
7310 	}
7311 
7312 	if (has_features || nvlist_lookup_uint64(props,
7313 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
7314 		version = SPA_VERSION;
7315 	}
7316 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
7317 
7318 	spa->spa_first_txg = txg;
7319 	spa->spa_uberblock.ub_txg = txg - 1;
7320 	spa->spa_uberblock.ub_version = version;
7321 	spa->spa_ubsync = spa->spa_uberblock;
7322 	spa->spa_load_state = SPA_LOAD_CREATE;
7323 	spa->spa_removing_phys.sr_state = DSS_NONE;
7324 	spa->spa_removing_phys.sr_removing_vdev = -1;
7325 	spa->spa_removing_phys.sr_prev_indirect_vdev = -1;
7326 	spa->spa_indirect_vdevs_loaded = B_TRUE;
7327 	spa->spa_deflate = (version >= SPA_VERSION_RAIDZ_DEFLATE);
7328 
7329 	/*
7330 	 * Create "The Godfather" zio to hold all async IOs
7331 	 */
7332 	spa->spa_async_zio_root = kmem_alloc(max_ncpus * sizeof (void *),
7333 	    KM_SLEEP);
7334 	for (int i = 0; i < max_ncpus; i++) {
7335 		spa->spa_async_zio_root[i] = zio_root(spa, NULL, NULL,
7336 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
7337 		    ZIO_FLAG_GODFATHER);
7338 	}
7339 
7340 	/*
7341 	 * Create the root vdev.
7342 	 */
7343 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7344 
7345 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
7346 
7347 	ASSERT(error != 0 || rvd != NULL);
7348 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
7349 
7350 	if (error == 0 && !zfs_allocatable_devs(nvroot))
7351 		error = SET_ERROR(EINVAL);
7352 
7353 	if (error == 0 &&
7354 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
7355 	    (error = vdev_draid_spare_create(nvroot, rvd, &ndraid,
7356 	    &draid_nfgroup, 0)) == 0 &&
7357 	    (ndraid == 0 || has_draid || (error = SET_ERROR(ENOTSUP))) &&
7358 	    (draid_nfgroup == 0 || has_draid_fdomains ||
7359 	    (error = SET_ERROR(ENOTSUP))) && error == 0 &&
7360 	    (error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) == 0) {
7361 		/*
7362 		 * instantiate the metaslab groups (this will dirty the vdevs)
7363 		 * we can no longer error exit past this point
7364 		 */
7365 		for (int c = 0; error == 0 && c < rvd->vdev_children; c++) {
7366 			vdev_t *vd = rvd->vdev_child[c];
7367 
7368 			vdev_metaslab_set_size(vd);
7369 			vdev_expand(vd, txg);
7370 		}
7371 	}
7372 
7373 	spa_config_exit(spa, SCL_ALL, FTAG);
7374 
7375 	if (error != 0) {
7376 		if (errinfo != NULL) {
7377 			*errinfo = spa->spa_create_info;
7378 			spa->spa_create_info = NULL;
7379 		}
7380 		spa_unload(spa);
7381 		spa_deactivate(spa);
7382 		spa_remove(spa);
7383 		spa_namespace_exit(FTAG);
7384 		return (error);
7385 	}
7386 
7387 	/*
7388 	 * Get the list of spares, if specified.
7389 	 */
7390 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
7391 	    &spares, &nspares) == 0) {
7392 		spa->spa_spares.sav_config = fnvlist_alloc();
7393 		fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
7394 		    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
7395 		    nspares);
7396 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7397 		spa_load_spares(spa);
7398 		spa_config_exit(spa, SCL_ALL, FTAG);
7399 		spa->spa_spares.sav_sync = B_TRUE;
7400 	}
7401 
7402 	/*
7403 	 * Get the list of level 2 cache devices, if specified.
7404 	 */
7405 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
7406 	    &l2cache, &nl2cache) == 0) {
7407 		VERIFY0(nvlist_alloc(&spa->spa_l2cache.sav_config,
7408 		    NV_UNIQUE_NAME, KM_SLEEP));
7409 		fnvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
7410 		    ZPOOL_CONFIG_L2CACHE, (const nvlist_t * const *)l2cache,
7411 		    nl2cache);
7412 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7413 		spa_load_l2cache(spa);
7414 		spa_config_exit(spa, SCL_ALL, FTAG);
7415 		spa->spa_l2cache.sav_sync = B_TRUE;
7416 	}
7417 
7418 	spa->spa_is_initializing = B_TRUE;
7419 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, dcp, txg);
7420 	spa->spa_is_initializing = B_FALSE;
7421 
7422 	/*
7423 	 * Create DDTs (dedup tables).
7424 	 */
7425 	ddt_create(spa);
7426 	/*
7427 	 * Create BRT table and BRT table object.
7428 	 */
7429 	brt_create(spa);
7430 
7431 	spa_update_dspace(spa);
7432 
7433 	tx = dmu_tx_create_assigned(dp, txg);
7434 
7435 	/*
7436 	 * Create the pool's history object.
7437 	 */
7438 	if (version >= SPA_VERSION_ZPOOL_HISTORY && !spa->spa_history)
7439 		spa_history_create_obj(spa, tx);
7440 
7441 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_CREATE);
7442 	spa_history_log_version(spa, "create", tx);
7443 
7444 	/*
7445 	 * Create the pool config object.
7446 	 */
7447 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
7448 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
7449 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
7450 
7451 	if (zap_add(spa->spa_meta_objset,
7452 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
7453 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
7454 		cmn_err(CE_PANIC, "failed to add pool config");
7455 	}
7456 
7457 	if (zap_add(spa->spa_meta_objset,
7458 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
7459 	    sizeof (uint64_t), 1, &version, tx) != 0) {
7460 		cmn_err(CE_PANIC, "failed to add pool version");
7461 	}
7462 
7463 	/* Newly created pools with the right version are always deflated. */
7464 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
7465 		if (zap_add(spa->spa_meta_objset,
7466 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
7467 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
7468 			cmn_err(CE_PANIC, "failed to add deflate");
7469 		}
7470 	}
7471 
7472 	/*
7473 	 * Create the deferred-free bpobj.  Turn off compression
7474 	 * because sync-to-convergence takes longer if the blocksize
7475 	 * keeps changing.
7476 	 */
7477 	obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
7478 	dmu_object_set_compress(spa->spa_meta_objset, obj,
7479 	    ZIO_COMPRESS_OFF, tx);
7480 	if (zap_add(spa->spa_meta_objset,
7481 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
7482 	    sizeof (uint64_t), 1, &obj, tx) != 0) {
7483 		cmn_err(CE_PANIC, "failed to add bpobj");
7484 	}
7485 	VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
7486 	    spa->spa_meta_objset, obj));
7487 
7488 	/*
7489 	 * Generate some random noise for salted checksums to operate on.
7490 	 */
7491 	(void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
7492 	    sizeof (spa->spa_cksum_salt.zcs_bytes));
7493 
7494 	/*
7495 	 * Set pool properties.
7496 	 */
7497 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
7498 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
7499 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
7500 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
7501 	spa->spa_multihost = zpool_prop_default_numeric(ZPOOL_PROP_MULTIHOST);
7502 	spa->spa_autotrim = zpool_prop_default_numeric(ZPOOL_PROP_AUTOTRIM);
7503 	spa->spa_dedup_table_quota =
7504 	    zpool_prop_default_numeric(ZPOOL_PROP_DEDUP_TABLE_QUOTA);
7505 
7506 	if (props != NULL) {
7507 		spa_configfile_set(spa, props, B_FALSE);
7508 		spa_sync_props(props, tx);
7509 	}
7510 
7511 	for (int i = 0; i < ndraid; i++)
7512 		spa_feature_incr(spa, SPA_FEATURE_DRAID, tx);
7513 
7514 	for (int i = 0; i < draid_nfgroup; i++)
7515 		spa_feature_incr(spa, SPA_FEATURE_DRAID_FAIL_DOMAINS, tx);
7516 
7517 	dmu_tx_commit(tx);
7518 
7519 	spa->spa_sync_on = B_TRUE;
7520 	txg_sync_start(dp);
7521 	mmp_thread_start(spa);
7522 	txg_wait_synced(dp, txg);
7523 
7524 	spa_spawn_aux_threads(spa);
7525 
7526 	spa_write_cachefile(spa, B_FALSE, B_TRUE, B_TRUE);
7527 
7528 	/*
7529 	 * Don't count references from objsets that are already closed
7530 	 * and are making their way through the eviction process.
7531 	 */
7532 	spa_evicting_os_wait(spa);
7533 	spa->spa_minref = zfs_refcount_count(&spa->spa_refcount);
7534 	spa->spa_load_state = SPA_LOAD_NONE;
7535 
7536 	spa_import_os(spa);
7537 
7538 	spa_namespace_exit(FTAG);
7539 
7540 	return (0);
7541 }
7542 
7543 /*
7544  * Import a non-root pool into the system.
7545  */
7546 int
7547 spa_import(char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
7548 {
7549 	spa_t *spa;
7550 	const char *altroot = NULL;
7551 	spa_load_state_t state = SPA_LOAD_IMPORT;
7552 	zpool_load_policy_t policy;
7553 	spa_mode_t mode = spa_mode_global;
7554 	uint64_t readonly = B_FALSE;
7555 	int error;
7556 	nvlist_t *nvroot;
7557 	nvlist_t **spares, **l2cache;
7558 	uint_t nspares, nl2cache;
7559 
7560 	/*
7561 	 * If a pool with this name exists, return failure.
7562 	 */
7563 	spa_namespace_enter(FTAG);
7564 	if (spa_lookup(pool) != NULL) {
7565 		spa_namespace_exit(FTAG);
7566 		return (SET_ERROR(EEXIST));
7567 	}
7568 
7569 	/*
7570 	 * Create and initialize the spa structure.
7571 	 */
7572 	(void) nvlist_lookup_string(props,
7573 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
7574 	(void) nvlist_lookup_uint64(props,
7575 	    zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
7576 	if (readonly)
7577 		mode = SPA_MODE_READ;
7578 	spa = spa_add(pool, config, altroot);
7579 	spa->spa_import_flags = flags;
7580 
7581 	/*
7582 	 * Verbatim import - Take a pool and insert it into the namespace
7583 	 * as if it had been loaded at boot.
7584 	 */
7585 	if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
7586 		if (props != NULL)
7587 			spa_configfile_set(spa, props, B_FALSE);
7588 
7589 		spa_write_cachefile(spa, B_FALSE, B_TRUE, B_FALSE);
7590 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_IMPORT);
7591 		zfs_dbgmsg("spa_import: verbatim import of %s", pool);
7592 		spa_namespace_exit(FTAG);
7593 		return (0);
7594 	}
7595 
7596 	spa_activate(spa, mode);
7597 
7598 	/*
7599 	 * Don't start async tasks until we know everything is healthy.
7600 	 */
7601 	spa_async_suspend(spa);
7602 
7603 	zpool_get_load_policy(config, &policy);
7604 	if (policy.zlp_rewind & ZPOOL_DO_REWIND)
7605 		state = SPA_LOAD_RECOVER;
7606 
7607 	spa->spa_config_source = SPA_CONFIG_SRC_TRYIMPORT;
7608 
7609 	if (state != SPA_LOAD_RECOVER) {
7610 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
7611 		zfs_dbgmsg("spa_import: importing %s", pool);
7612 	} else {
7613 		zfs_dbgmsg("spa_import: importing %s, max_txg=%lld "
7614 		    "(RECOVERY MODE)", pool, (longlong_t)policy.zlp_txg);
7615 	}
7616 	error = spa_load_best(spa, state, policy.zlp_txg, policy.zlp_rewind);
7617 
7618 	/*
7619 	 * Propagate anything learned while loading the pool and pass it
7620 	 * back to caller (i.e. rewind info, missing devices, etc).
7621 	 */
7622 	fnvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO, spa->spa_load_info);
7623 
7624 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7625 	/*
7626 	 * Toss any existing sparelist, as it doesn't have any validity
7627 	 * anymore, and conflicts with spa_has_spare().
7628 	 */
7629 	if (spa->spa_spares.sav_config) {
7630 		nvlist_free(spa->spa_spares.sav_config);
7631 		spa->spa_spares.sav_config = NULL;
7632 		spa_load_spares(spa);
7633 	}
7634 	if (spa->spa_l2cache.sav_config) {
7635 		nvlist_free(spa->spa_l2cache.sav_config);
7636 		spa->spa_l2cache.sav_config = NULL;
7637 		spa_load_l2cache(spa);
7638 	}
7639 
7640 	nvroot = fnvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE);
7641 	spa_config_exit(spa, SCL_ALL, FTAG);
7642 
7643 	if (props != NULL)
7644 		spa_configfile_set(spa, props, B_FALSE);
7645 
7646 	if (error != 0 || (props && spa_writeable(spa) &&
7647 	    (error = spa_prop_set(spa, props)))) {
7648 		spa_unload(spa);
7649 		spa_deactivate(spa);
7650 		spa_remove(spa);
7651 		spa_namespace_exit(FTAG);
7652 		return (error);
7653 	}
7654 
7655 	spa_async_resume(spa);
7656 
7657 	/*
7658 	 * Override any spares and level 2 cache devices as specified by
7659 	 * the user, as these may have correct device names/devids, etc.
7660 	 */
7661 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
7662 	    &spares, &nspares) == 0) {
7663 		if (spa->spa_spares.sav_config)
7664 			fnvlist_remove(spa->spa_spares.sav_config,
7665 			    ZPOOL_CONFIG_SPARES);
7666 		else
7667 			spa->spa_spares.sav_config = fnvlist_alloc();
7668 		fnvlist_add_nvlist_array(spa->spa_spares.sav_config,
7669 		    ZPOOL_CONFIG_SPARES, (const nvlist_t * const *)spares,
7670 		    nspares);
7671 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7672 		spa_load_spares(spa);
7673 		spa_config_exit(spa, SCL_ALL, FTAG);
7674 		spa->spa_spares.sav_sync = B_TRUE;
7675 		spa->spa_spares.sav_label_sync = B_TRUE;
7676 	}
7677 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
7678 	    &l2cache, &nl2cache) == 0) {
7679 		if (spa->spa_l2cache.sav_config)
7680 			fnvlist_remove(spa->spa_l2cache.sav_config,
7681 			    ZPOOL_CONFIG_L2CACHE);
7682 		else
7683 			spa->spa_l2cache.sav_config = fnvlist_alloc();
7684 		fnvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
7685 		    ZPOOL_CONFIG_L2CACHE, (const nvlist_t * const *)l2cache,
7686 		    nl2cache);
7687 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7688 		spa_load_l2cache(spa);
7689 		spa_config_exit(spa, SCL_ALL, FTAG);
7690 		spa->spa_l2cache.sav_sync = B_TRUE;
7691 		spa->spa_l2cache.sav_label_sync = B_TRUE;
7692 	}
7693 
7694 	/*
7695 	 * Check for any removed devices.
7696 	 */
7697 	if (spa->spa_autoreplace) {
7698 		spa_aux_check_removed(&spa->spa_spares);
7699 		spa_aux_check_removed(&spa->spa_l2cache);
7700 	}
7701 
7702 	if (spa_writeable(spa)) {
7703 		/*
7704 		 * Update the config cache to include the newly-imported pool.
7705 		 */
7706 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
7707 	}
7708 
7709 	/*
7710 	 * It's possible that the pool was expanded while it was exported.
7711 	 * We kick off an async task to handle this for us.
7712 	 */
7713 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
7714 
7715 	spa_history_log_version(spa, "import", NULL);
7716 
7717 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_IMPORT);
7718 
7719 	spa_namespace_exit(FTAG);
7720 
7721 	zvol_create_minors(pool);
7722 
7723 	spa_import_os(spa);
7724 
7725 	return (0);
7726 }
7727 
7728 nvlist_t *
7729 spa_tryimport(nvlist_t *tryconfig)
7730 {
7731 	nvlist_t *config = NULL;
7732 	const char *poolname, *cachefile;
7733 	spa_t *spa;
7734 	uint64_t state;
7735 	int error;
7736 	zpool_load_policy_t policy;
7737 
7738 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
7739 		return (NULL);
7740 
7741 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
7742 		return (NULL);
7743 
7744 	/*
7745 	 * Create and initialize the spa structure.
7746 	 */
7747 	char *name = kmem_alloc(MAXPATHLEN, KM_SLEEP);
7748 	(void) snprintf(name, MAXPATHLEN, "%s-%llx-%s",
7749 	    TRYIMPORT_NAME, (u_longlong_t)(uintptr_t)curthread, poolname);
7750 
7751 	spa_namespace_enter(FTAG);
7752 	spa = spa_add(name, tryconfig, NULL);
7753 	spa_activate(spa, SPA_MODE_READ);
7754 	kmem_free(name, MAXPATHLEN);
7755 
7756 	spa->spa_load_name = spa_strdup(poolname);
7757 
7758 	/*
7759 	 * Rewind pool if a max txg was provided.
7760 	 */
7761 	zpool_get_load_policy(spa->spa_config, &policy);
7762 	if (policy.zlp_txg != UINT64_MAX) {
7763 		spa->spa_load_max_txg = policy.zlp_txg;
7764 		spa->spa_extreme_rewind = B_TRUE;
7765 		zfs_dbgmsg("spa_tryimport: importing %s, max_txg=%lld",
7766 		    spa_load_name(spa), (longlong_t)policy.zlp_txg);
7767 	} else {
7768 		zfs_dbgmsg("spa_tryimport: importing %s", spa_load_name(spa));
7769 	}
7770 
7771 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_CACHEFILE, &cachefile)
7772 	    == 0) {
7773 		zfs_dbgmsg("spa_tryimport: using cachefile '%s'", cachefile);
7774 		spa->spa_config_source = SPA_CONFIG_SRC_CACHEFILE;
7775 	} else {
7776 		spa->spa_config_source = SPA_CONFIG_SRC_SCAN;
7777 	}
7778 
7779 	/*
7780 	 * spa_import() relies on a pool config fetched by spa_try_import()
7781 	 * for spare/cache devices. Import flags are not passed to
7782 	 * spa_tryimport(), which makes it return early due to a missing log
7783 	 * device and missing retrieving the cache device and spare eventually.
7784 	 * Passing ZFS_IMPORT_MISSING_LOG to spa_tryimport() makes it fetch
7785 	 * the correct configuration regardless of the missing log device.
7786 	 */
7787 	spa->spa_import_flags |= ZFS_IMPORT_MISSING_LOG;
7788 
7789 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING);
7790 
7791 	/*
7792 	 * If 'tryconfig' was at least parsable, return the current config.
7793 	 */
7794 	if (spa->spa_root_vdev != NULL) {
7795 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
7796 		fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
7797 		    spa_load_name(spa));
7798 		fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE, state);
7799 		fnvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
7800 		    spa->spa_uberblock.ub_timestamp);
7801 		fnvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
7802 		    spa->spa_load_info);
7803 		fnvlist_add_uint64(config, ZPOOL_CONFIG_ERRATA,
7804 		    spa->spa_errata);
7805 
7806 		/*
7807 		 * If the bootfs property exists on this pool then we
7808 		 * copy it out so that external consumers can tell which
7809 		 * pools are bootable.
7810 		 */
7811 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
7812 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
7813 
7814 			/*
7815 			 * We have to play games with the name since the
7816 			 * pool was opened as TRYIMPORT_NAME.
7817 			 */
7818 			if (dsl_dsobj_to_dsname(spa_name(spa),
7819 			    spa->spa_bootfs, tmpname) == 0) {
7820 				char *cp;
7821 				char *dsname;
7822 
7823 				dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
7824 
7825 				cp = strchr(tmpname, '/');
7826 				if (cp == NULL) {
7827 					(void) strlcpy(dsname, tmpname,
7828 					    MAXPATHLEN);
7829 				} else {
7830 					(void) snprintf(dsname, MAXPATHLEN,
7831 					    "%s/%s", spa_load_name(spa), ++cp);
7832 				}
7833 				fnvlist_add_string(config, ZPOOL_CONFIG_BOOTFS,
7834 				    dsname);
7835 				kmem_free(dsname, MAXPATHLEN);
7836 			}
7837 			kmem_free(tmpname, MAXPATHLEN);
7838 		}
7839 
7840 		/*
7841 		 * Add the list of hot spares and level 2 cache devices.
7842 		 */
7843 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
7844 		spa_add_spares(spa, config);
7845 		spa_add_l2cache(spa, config);
7846 		spa_config_exit(spa, SCL_CONFIG, FTAG);
7847 	}
7848 
7849 	spa_unload(spa);
7850 	spa_deactivate(spa);
7851 	spa_remove(spa);
7852 	spa_namespace_exit(FTAG);
7853 
7854 	return (config);
7855 }
7856 
7857 /*
7858  * Pool export/destroy
7859  *
7860  * The act of destroying or exporting a pool is very simple.  We make sure there
7861  * is no more pending I/O and any references to the pool are gone.  Then, we
7862  * update the pool state and sync all the labels to disk, removing the
7863  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
7864  * we don't sync the labels or remove the configuration cache.
7865  */
7866 static int
7867 spa_export_common(const char *pool, int new_state, nvlist_t **oldconfig,
7868     boolean_t force, boolean_t hardforce)
7869 {
7870 	int error = 0;
7871 	spa_t *spa;
7872 	hrtime_t export_start = gethrtime();
7873 
7874 	if (oldconfig)
7875 		*oldconfig = NULL;
7876 
7877 	if (!(spa_mode_global & SPA_MODE_WRITE))
7878 		return (SET_ERROR(EROFS));
7879 
7880 	spa_namespace_enter(FTAG);
7881 	if ((spa = spa_lookup(pool)) == NULL) {
7882 		spa_namespace_exit(FTAG);
7883 		return (SET_ERROR(ENOENT));
7884 	}
7885 
7886 	if (spa->spa_is_exporting) {
7887 		/* the pool is being exported by another thread */
7888 		spa_namespace_exit(FTAG);
7889 		return (SET_ERROR(ZFS_ERR_EXPORT_IN_PROGRESS));
7890 	}
7891 	spa->spa_is_exporting = B_TRUE;
7892 
7893 	/*
7894 	 * Put a hold on the pool, drop the namespace lock, stop async tasks
7895 	 * and see if we can export.
7896 	 */
7897 	spa_open_ref(spa, FTAG);
7898 	spa_namespace_exit(FTAG);
7899 #ifdef ZFS_DEBUG
7900 	spa_condense_debug_cancel(spa);
7901 #endif
7902 	spa_async_suspend(spa);
7903 
7904 	spa_namespace_enter(FTAG);
7905 	spa->spa_export_thread = curthread;
7906 	spa_close(spa, FTAG);
7907 
7908 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
7909 		spa_namespace_exit(FTAG);
7910 		goto export_spa;
7911 	}
7912 
7913 	/*
7914 	 * The pool will be in core if it's openable, in which case we can
7915 	 * modify its state.  Objsets may be open only because they're dirty,
7916 	 * so we have to force it to sync before checking spa_refcnt.
7917 	 */
7918 	if (spa->spa_sync_on) {
7919 		txg_wait_synced(spa->spa_dsl_pool, 0);
7920 		spa_evicting_os_wait(spa);
7921 	}
7922 
7923 	/*
7924 	 * A pool cannot be exported or destroyed if there are active
7925 	 * references.  If we are resetting a pool, allow references by
7926 	 * fault injection handlers.
7927 	 */
7928 	if (!spa_refcount_zero(spa) || (spa->spa_inject_ref != 0)) {
7929 		error = SET_ERROR(EBUSY);
7930 		goto fail;
7931 	}
7932 
7933 	spa_namespace_exit(FTAG);
7934 	/*
7935 	 * At this point we no longer hold the spa_namespace_lock and
7936 	 * there were no references on the spa. Future spa_lookups will
7937 	 * notice the spa->spa_export_thread and wait until we signal
7938 	 * that we are finshed.
7939 	 */
7940 
7941 	if (spa->spa_zvol_taskq) {
7942 		zvol_remove_minors(spa, spa_name(spa), B_TRUE);
7943 		taskq_wait(spa->spa_zvol_taskq);
7944 	}
7945 
7946 	if (spa->spa_sync_on) {
7947 		vdev_t *rvd = spa->spa_root_vdev;
7948 		/*
7949 		 * A pool cannot be exported if it has an active shared spare.
7950 		 * This is to prevent other pools stealing the active spare
7951 		 * from an exported pool. At user's own will, such pool can
7952 		 * be forcedly exported.
7953 		 */
7954 		if (!force && new_state == POOL_STATE_EXPORTED &&
7955 		    spa_has_active_shared_spare(spa)) {
7956 			error = SET_ERROR(EXDEV);
7957 			spa_namespace_enter(FTAG);
7958 			goto fail;
7959 		}
7960 
7961 		/*
7962 		 * We're about to export or destroy this pool. Make sure
7963 		 * we stop all initialization and trim activity here before
7964 		 * we set the spa_final_txg. This will ensure that all
7965 		 * dirty data resulting from the initialization is
7966 		 * committed to disk before we unload the pool.
7967 		 */
7968 		vdev_initialize_stop_all(rvd, VDEV_INITIALIZE_ACTIVE);
7969 		vdev_trim_stop_all(rvd, VDEV_TRIM_ACTIVE);
7970 		vdev_autotrim_stop_all(spa);
7971 		vdev_rebuild_stop_all(spa);
7972 		l2arc_spa_rebuild_stop(spa);
7973 
7974 		/*
7975 		 * We want this to be reflected on every label,
7976 		 * so mark them all dirty.  spa_unload() will do the
7977 		 * final sync that pushes these changes out.
7978 		 */
7979 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
7980 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
7981 			spa->spa_state = new_state;
7982 			vdev_config_dirty(rvd);
7983 			spa_config_exit(spa, SCL_ALL, FTAG);
7984 		}
7985 
7986 		if (spa_should_sync_time_logger_on_unload(spa))
7987 			spa_unload_sync_time_logger(spa);
7988 
7989 		/*
7990 		 * If the log space map feature is enabled and the pool is
7991 		 * getting exported (but not destroyed), we want to spend some
7992 		 * time flushing as many metaslabs as we can in an attempt to
7993 		 * destroy log space maps and save import time. This has to be
7994 		 * done before we set the spa_final_txg, otherwise
7995 		 * spa_sync() -> spa_flush_metaslabs() may dirty the final TXGs.
7996 		 * spa_should_flush_logs_on_unload() should be called after
7997 		 * spa_state has been set to the new_state.
7998 		 */
7999 		if (spa_should_flush_logs_on_unload(spa))
8000 			spa_unload_log_sm_flush_all(spa);
8001 
8002 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
8003 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
8004 			spa->spa_final_txg = spa_last_synced_txg(spa) +
8005 			    TXG_DEFER_SIZE + 1;
8006 			spa_config_exit(spa, SCL_ALL, FTAG);
8007 		}
8008 	}
8009 
8010 export_spa:
8011 	spa_export_os(spa);
8012 
8013 	if (new_state == POOL_STATE_DESTROYED)
8014 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_DESTROY);
8015 	else if (new_state == POOL_STATE_EXPORTED)
8016 		spa_event_notify(spa, NULL, NULL, ESC_ZFS_POOL_EXPORT);
8017 
8018 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
8019 		spa_unload(spa);
8020 		spa_deactivate(spa);
8021 	}
8022 
8023 	if (oldconfig && spa->spa_config)
8024 		*oldconfig = fnvlist_dup(spa->spa_config);
8025 
8026 	if (new_state == POOL_STATE_EXPORTED)
8027 		zio_handle_export_delay(spa, gethrtime() - export_start);
8028 
8029 	/*
8030 	 * Take the namespace lock for the actual spa_t removal
8031 	 */
8032 	spa_namespace_enter(FTAG);
8033 	if (new_state != POOL_STATE_UNINITIALIZED) {
8034 		if (!hardforce)
8035 			spa_write_cachefile(spa, B_TRUE, B_TRUE, B_FALSE);
8036 		spa_remove(spa);
8037 	} else {
8038 		/*
8039 		 * If spa_remove() is not called for this spa_t and
8040 		 * there is any possibility that it can be reused,
8041 		 * we make sure to reset the exporting flag.
8042 		 */
8043 		spa->spa_is_exporting = B_FALSE;
8044 		spa->spa_export_thread = NULL;
8045 	}
8046 
8047 	/*
8048 	 * Wake up any waiters in spa_lookup()
8049 	 */
8050 	spa_namespace_broadcast();
8051 	spa_namespace_exit(FTAG);
8052 	return (0);
8053 
8054 fail:
8055 	spa->spa_is_exporting = B_FALSE;
8056 	spa->spa_export_thread = NULL;
8057 
8058 	spa_async_resume(spa);
8059 	/*
8060 	 * Wake up any waiters in spa_lookup()
8061 	 */
8062 	spa_namespace_broadcast();
8063 	spa_namespace_exit(FTAG);
8064 	return (error);
8065 }
8066 
8067 /*
8068  * Destroy a storage pool.
8069  */
8070 int
8071 spa_destroy(const char *pool)
8072 {
8073 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
8074 	    B_FALSE, B_FALSE));
8075 }
8076 
8077 /*
8078  * Export a storage pool.
8079  */
8080 int
8081 spa_export(const char *pool, nvlist_t **oldconfig, boolean_t force,
8082     boolean_t hardforce)
8083 {
8084 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
8085 	    force, hardforce));
8086 }
8087 
8088 /*
8089  * Similar to spa_export(), this unloads the spa_t without actually removing it
8090  * from the namespace in any way.
8091  */
8092 int
8093 spa_reset(const char *pool)
8094 {
8095 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
8096 	    B_FALSE, B_FALSE));
8097 }
8098 
8099 /*
8100  * ==========================================================================
8101  * Device manipulation
8102  * ==========================================================================
8103  */
8104 
8105 /*
8106  * This is called as a synctask to increment the draid feature flag
8107  */
8108 static void
8109 spa_draid_feature_incr(void *arg, dmu_tx_t *tx)
8110 {
8111 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
8112 	int draid = (int)(uintptr_t)arg;
8113 
8114 	for (int c = 0; c < draid; c++)
8115 		spa_feature_incr(spa, SPA_FEATURE_DRAID, tx);
8116 }
8117 
8118 /*
8119  * This is called as a synctask to increment the draid_fail_domains feature flag
8120  */
8121 static void
8122 spa_draid_fdomains_feature_incr(void *arg, dmu_tx_t *tx)
8123 {
8124 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
8125 	int nfgrp = (int)(uintptr_t)arg;
8126 
8127 	for (int c = 0; c < nfgrp; c++)
8128 		spa_feature_incr(spa, SPA_FEATURE_DRAID_FAIL_DOMAINS, tx);
8129 }
8130 
8131 /*
8132  * Add a device to a storage pool.
8133  */
8134 int
8135 spa_vdev_add(spa_t *spa, nvlist_t *nvroot, boolean_t check_ashift)
8136 {
8137 	uint64_t txg, ndraid = 0, draid_nfgroup = 0;
8138 	int error;
8139 	vdev_t *rvd = spa->spa_root_vdev;
8140 	vdev_t *vd, *tvd;
8141 	nvlist_t **spares, **l2cache;
8142 	uint_t nspares, nl2cache;
8143 
8144 	ASSERT(spa_writeable(spa));
8145 
8146 	txg = spa_vdev_enter(spa);
8147 
8148 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
8149 	    VDEV_ALLOC_ADD)) != 0)
8150 		return (spa_vdev_exit(spa, NULL, txg, error));
8151 
8152 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
8153 
8154 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
8155 	    &nspares) != 0)
8156 		nspares = 0;
8157 
8158 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
8159 	    &nl2cache) != 0)
8160 		nl2cache = 0;
8161 
8162 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
8163 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
8164 
8165 	if (vd->vdev_children != 0 &&
8166 	    (error = vdev_create(vd, txg, B_FALSE)) != 0) {
8167 		return (spa_vdev_exit(spa, vd, txg, error));
8168 	}
8169 
8170 	/*
8171 	 * The virtual dRAID spares must be added after vdev tree is created
8172 	 * and the vdev guids are generated.  The guid of their associated
8173 	 * dRAID is stored in the config and used when opening the spare.
8174 	 */
8175 	if ((error = vdev_draid_spare_create(nvroot, vd, &ndraid,
8176 	    &draid_nfgroup, rvd->vdev_children)) == 0) {
8177 
8178 		if (ndraid > 0 && nvlist_lookup_nvlist_array(nvroot,
8179 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) != 0)
8180 			nspares = 0;
8181 
8182 		if (draid_nfgroup > 0 && !spa_feature_is_enabled(spa,
8183 		    SPA_FEATURE_DRAID_FAIL_DOMAINS))
8184 			return (spa_vdev_exit(spa, vd, txg, ENOTSUP));
8185 	} else {
8186 		return (spa_vdev_exit(spa, vd, txg, error));
8187 	}
8188 
8189 	/*
8190 	 * We must validate the spares and l2cache devices after checking the
8191 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
8192 	 */
8193 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
8194 		return (spa_vdev_exit(spa, vd, txg, error));
8195 
8196 	/*
8197 	 * If we are in the middle of a device removal, we can only add
8198 	 * devices which match the existing devices in the pool.
8199 	 * If we are in the middle of a removal, or have some indirect
8200 	 * vdevs, we can not add raidz or dRAID top levels.
8201 	 */
8202 	if (spa->spa_vdev_removal != NULL ||
8203 	    spa->spa_removing_phys.sr_prev_indirect_vdev != -1) {
8204 		for (int c = 0; c < vd->vdev_children; c++) {
8205 			tvd = vd->vdev_child[c];
8206 			if (spa->spa_vdev_removal != NULL &&
8207 			    tvd->vdev_ashift != spa->spa_max_ashift) {
8208 				return (spa_vdev_exit(spa, vd, txg, EINVAL));
8209 			}
8210 			/* Fail if top level vdev is raidz or a dRAID */
8211 			if (vdev_get_nparity(tvd) != 0)
8212 				return (spa_vdev_exit(spa, vd, txg, EINVAL));
8213 
8214 			/*
8215 			 * Need the top level mirror to be
8216 			 * a mirror of leaf vdevs only
8217 			 */
8218 			if (tvd->vdev_ops == &vdev_mirror_ops) {
8219 				for (uint64_t cid = 0;
8220 				    cid < tvd->vdev_children; cid++) {
8221 					vdev_t *cvd = tvd->vdev_child[cid];
8222 					if (!cvd->vdev_ops->vdev_op_leaf) {
8223 						return (spa_vdev_exit(spa, vd,
8224 						    txg, EINVAL));
8225 					}
8226 				}
8227 			}
8228 		}
8229 	}
8230 
8231 	if (check_ashift && spa->spa_max_ashift == spa->spa_min_ashift) {
8232 		for (int c = 0; c < vd->vdev_children; c++) {
8233 			tvd = vd->vdev_child[c];
8234 			if (tvd->vdev_ashift != spa->spa_max_ashift) {
8235 				return (spa_vdev_exit(spa, vd, txg,
8236 				    ZFS_ERR_ASHIFT_MISMATCH));
8237 			}
8238 		}
8239 	}
8240 
8241 	for (int c = 0; c < vd->vdev_children; c++) {
8242 		tvd = vd->vdev_child[c];
8243 		vdev_remove_child(vd, tvd);
8244 		tvd->vdev_id = rvd->vdev_children;
8245 		vdev_add_child(rvd, tvd);
8246 		vdev_config_dirty(tvd);
8247 	}
8248 
8249 	if (nspares != 0) {
8250 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
8251 		    ZPOOL_CONFIG_SPARES);
8252 		spa_load_spares(spa);
8253 		spa->spa_spares.sav_sync = B_TRUE;
8254 	}
8255 
8256 	if (nl2cache != 0) {
8257 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
8258 		    ZPOOL_CONFIG_L2CACHE);
8259 		spa_load_l2cache(spa);
8260 		spa->spa_l2cache.sav_sync = B_TRUE;
8261 	}
8262 
8263 	/*
8264 	 * We can't increment a feature while holding spa_vdev so we
8265 	 * have to do it in a synctask.
8266 	 */
8267 	if (ndraid != 0) {
8268 		dmu_tx_t *tx;
8269 
8270 		tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
8271 
8272 		dsl_sync_task_nowait(spa->spa_dsl_pool, spa_draid_feature_incr,
8273 		    (void *)(uintptr_t)ndraid, tx);
8274 
8275 		if (draid_nfgroup > 0)
8276 			dsl_sync_task_nowait(spa->spa_dsl_pool,
8277 			    spa_draid_fdomains_feature_incr,
8278 			    (void *)(uintptr_t)draid_nfgroup, tx);
8279 
8280 		dmu_tx_commit(tx);
8281 	}
8282 
8283 	/*
8284 	 * We have to be careful when adding new vdevs to an existing pool.
8285 	 * If other threads start allocating from these vdevs before we
8286 	 * sync the config cache, and we lose power, then upon reboot we may
8287 	 * fail to open the pool because there are DVAs that the config cache
8288 	 * can't translate.  Therefore, we first add the vdevs without
8289 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
8290 	 * and then let spa_config_update() initialize the new metaslabs.
8291 	 *
8292 	 * spa_load() checks for added-but-not-initialized vdevs, so that
8293 	 * if we lose power at any point in this sequence, the remaining
8294 	 * steps will be completed the next time we load the pool.
8295 	 */
8296 	(void) spa_vdev_exit(spa, vd, txg, 0);
8297 
8298 	spa_namespace_enter(FTAG);
8299 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
8300 	spa_event_notify(spa, NULL, NULL, ESC_ZFS_VDEV_ADD);
8301 	spa_namespace_exit(FTAG);
8302 
8303 	return (0);
8304 }
8305 
8306 /*
8307  * Given a vdev to be replaced and its parent, check for a possible
8308  * "double spare" condition if a vdev is to be replaced by a spare.  When this
8309  * happens, you can get two spares assigned to one failed vdev.
8310  *
8311  * To trigger a double spare condition:
8312  *
8313  * 1. disk1 fails
8314  * 2. 1st spare is kicked in for disk1 and it resilvers
8315  * 3. Someone replaces disk1 with a new blank disk
8316  * 4. New blank disk starts resilvering
8317  * 5. While resilvering, new blank disk has IO errors and faults
8318  * 6. 2nd spare is kicked in for new blank disk
8319  * 7. At this point two spares are kicked in for the original disk1.
8320  *
8321  * It looks like this:
8322  *
8323  * NAME                                            STATE     READ WRITE CKSUM
8324  * tank2                                           DEGRADED     0     0     0
8325  *   draid2:6d:10c:2s-0                            DEGRADED     0     0     0
8326  *     scsi-0QEMU_QEMU_HARDDISK_d1                 ONLINE       0     0     0
8327  *     scsi-0QEMU_QEMU_HARDDISK_d2                 ONLINE       0     0     0
8328  *     scsi-0QEMU_QEMU_HARDDISK_d3                 ONLINE       0     0     0
8329  *     scsi-0QEMU_QEMU_HARDDISK_d4                 ONLINE       0     0     0
8330  *     scsi-0QEMU_QEMU_HARDDISK_d5                 ONLINE       0     0     0
8331  *     scsi-0QEMU_QEMU_HARDDISK_d6                 ONLINE       0     0     0
8332  *     scsi-0QEMU_QEMU_HARDDISK_d7                 ONLINE       0     0     0
8333  *     scsi-0QEMU_QEMU_HARDDISK_d8                 ONLINE       0     0     0
8334  *     scsi-0QEMU_QEMU_HARDDISK_d9                 ONLINE       0     0     0
8335  *     spare-9                                     DEGRADED     0     0     0
8336  *       replacing-0                               DEGRADED     0    93     0
8337  *         scsi-0QEMU_QEMU_HARDDISK_d10-part1/old  UNAVAIL      0     0     0
8338  *         spare-1                                 DEGRADED     0     0     0
8339  *           scsi-0QEMU_QEMU_HARDDISK_d10          REMOVED      0     0     0
8340  *           draid2-0-0                            ONLINE       0     0     0
8341  *       draid2-0-1                                ONLINE       0     0     0
8342  * spares
8343  *   draid2-0-0                                    INUSE     currently in use
8344  *   draid2-0-1                                    INUSE     currently in use
8345  *
8346  * ARGS:
8347  *
8348  * newvd:  New spare disk
8349  * pvd:    Parent vdev_t the spare should attach to
8350  *
8351  * This function returns B_TRUE if adding the new vdev would create a double
8352  * spare condition, B_FALSE otherwise.
8353  */
8354 static boolean_t
8355 spa_vdev_new_spare_would_cause_double_spares(vdev_t *newvd, vdev_t *pvd)
8356 {
8357 	vdev_t *ppvd;
8358 
8359 	ppvd = pvd->vdev_parent;
8360 	if (ppvd == NULL)
8361 		return (B_FALSE);
8362 
8363 	/*
8364 	 * To determine if this configuration would cause a double spare, we
8365 	 * look at the vdev_op of the parent vdev, and of the parent's parent
8366 	 * vdev.  We also look at vdev_isspare on the new disk.  A double spare
8367 	 * condition looks like this:
8368 	 *
8369 	 * 1. parent of parent's op is a spare or draid spare
8370 	 * 2. parent's op is replacing
8371 	 * 3. new disk is a spare
8372 	 */
8373 	if ((ppvd->vdev_ops == &vdev_spare_ops) ||
8374 	    (ppvd->vdev_ops == &vdev_draid_spare_ops))
8375 		if (pvd->vdev_ops == &vdev_replacing_ops)
8376 			if (newvd->vdev_isspare)
8377 				return (B_TRUE);
8378 
8379 	return (B_FALSE);
8380 }
8381 
8382 /*
8383  * Attach a device to a vdev specified by its guid.  The vdev type can be
8384  * a mirror, a raidz, or a leaf device that is also a top-level (e.g. a
8385  * single device). When the vdev is a single device, a mirror vdev will be
8386  * automatically inserted.
8387  *
8388  * If 'replacing' is specified, the new device is intended to replace the
8389  * existing device; in this case the two devices are made into their own
8390  * mirror using the 'replacing' vdev, which is functionally identical to
8391  * the mirror vdev (it actually reuses all the same ops) but has a few
8392  * extra rules: you can't attach to it after it's been created, and upon
8393  * completion of resilvering, the first disk (the one being replaced)
8394  * is automatically detached.
8395  *
8396  * If 'rebuild' is specified, then sequential reconstruction (a.ka. rebuild)
8397  * should be performed instead of traditional healing reconstruction.  From
8398  * an administrators perspective these are both resilver operations.
8399  */
8400 int
8401 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing,
8402     int rebuild)
8403 {
8404 	uint64_t txg, dtl_max_txg;
8405 	vdev_t *rvd = spa->spa_root_vdev;
8406 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
8407 	vdev_ops_t *pvops;
8408 	char *oldvdpath, *newvdpath;
8409 	int newvd_isspare = B_FALSE;
8410 	int error;
8411 
8412 	ASSERT(spa_writeable(spa));
8413 
8414 	txg = spa_vdev_enter(spa);
8415 
8416 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
8417 
8418 	ASSERT(spa_namespace_held());
8419 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
8420 		error = (spa_has_checkpoint(spa)) ?
8421 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
8422 		return (spa_vdev_exit(spa, NULL, txg, error));
8423 	}
8424 
8425 	if (rebuild) {
8426 		if (!spa_feature_is_enabled(spa, SPA_FEATURE_DEVICE_REBUILD))
8427 			return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8428 
8429 		if (dsl_scan_resilvering(spa_get_dsl(spa)) ||
8430 		    dsl_scan_resilver_scheduled(spa_get_dsl(spa))) {
8431 			return (spa_vdev_exit(spa, NULL, txg,
8432 			    ZFS_ERR_RESILVER_IN_PROGRESS));
8433 		}
8434 	} else {
8435 		if (vdev_rebuild_active(rvd))
8436 			return (spa_vdev_exit(spa, NULL, txg,
8437 			    ZFS_ERR_REBUILD_IN_PROGRESS));
8438 	}
8439 
8440 	if (spa->spa_vdev_removal != NULL) {
8441 		return (spa_vdev_exit(spa, NULL, txg,
8442 		    ZFS_ERR_DEVRM_IN_PROGRESS));
8443 	}
8444 
8445 	if (oldvd == NULL)
8446 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
8447 
8448 	boolean_t raidz = oldvd->vdev_ops == &vdev_raidz_ops;
8449 
8450 	if (raidz) {
8451 		if (!spa_feature_is_enabled(spa, SPA_FEATURE_RAIDZ_EXPANSION))
8452 			return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8453 
8454 		/*
8455 		 * Can't expand a raidz while prior expand is in progress.
8456 		 */
8457 		if (spa->spa_raidz_expand != NULL) {
8458 			return (spa_vdev_exit(spa, NULL, txg,
8459 			    ZFS_ERR_RAIDZ_EXPAND_IN_PROGRESS));
8460 		}
8461 	} else if (!oldvd->vdev_ops->vdev_op_leaf) {
8462 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8463 	}
8464 
8465 	if (raidz)
8466 		pvd = oldvd;
8467 	else
8468 		pvd = oldvd->vdev_parent;
8469 
8470 	if (spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
8471 	    VDEV_ALLOC_ATTACH) != 0)
8472 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
8473 
8474 	if (newrootvd->vdev_children != 1)
8475 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
8476 
8477 	newvd = newrootvd->vdev_child[0];
8478 
8479 	if (!newvd->vdev_ops->vdev_op_leaf)
8480 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
8481 
8482 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
8483 		return (spa_vdev_exit(spa, newrootvd, txg, error));
8484 
8485 	/*
8486 	 * Spares can't replace logs
8487 	 */
8488 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
8489 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8490 
8491 	/*
8492 	 * For special and dedup vdevs a spare must have matching rotational
8493 	 * characteristics.  A rotating spare replacing a non-rotating vdev
8494 	 * would silently degrade pool performance, so we reject the mismatch.
8495 	 */
8496 	if (newvd->vdev_isspare &&
8497 	    oldvd->vdev_top->vdev_alloc_bias != VDEV_BIAS_NONE &&
8498 	    newvd->vdev_nonrot != oldvd->vdev_nonrot)
8499 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8500 
8501 	/*
8502 	 * A dRAID spare can only replace a child of its parent dRAID vdev.
8503 	 */
8504 	if (newvd->vdev_ops == &vdev_draid_spare_ops &&
8505 	    oldvd->vdev_top != vdev_draid_spare_get_parent(newvd)) {
8506 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8507 	}
8508 
8509 	if (rebuild) {
8510 		/*
8511 		 * For rebuilds, the top vdev must support reconstruction
8512 		 * using only space maps.  This means the only allowable
8513 		 * vdevs types are the root vdev, a mirror, or dRAID.
8514 		 */
8515 		tvd = pvd;
8516 		if (pvd->vdev_top != NULL)
8517 			tvd = pvd->vdev_top;
8518 
8519 		if (tvd->vdev_ops != &vdev_mirror_ops &&
8520 		    tvd->vdev_ops != &vdev_root_ops &&
8521 		    tvd->vdev_ops != &vdev_draid_ops) {
8522 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8523 		}
8524 	}
8525 
8526 	if (!replacing) {
8527 		/*
8528 		 * For attach, the only allowable parent is a mirror or
8529 		 * the root vdev. A raidz vdev can be attached to, but
8530 		 * you cannot attach to a raidz child.
8531 		 */
8532 		if (pvd->vdev_ops != &vdev_mirror_ops &&
8533 		    pvd->vdev_ops != &vdev_root_ops &&
8534 		    !raidz)
8535 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8536 
8537 		pvops = &vdev_mirror_ops;
8538 	} else {
8539 		/*
8540 		 * Active hot spares can only be replaced by inactive hot
8541 		 * spares.
8542 		 */
8543 		if (pvd->vdev_ops == &vdev_spare_ops &&
8544 		    oldvd->vdev_isspare &&
8545 		    !spa_has_spare(spa, newvd->vdev_guid))
8546 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8547 
8548 		/*
8549 		 * If the source is a hot spare, and the parent isn't already a
8550 		 * spare, then we want to create a new hot spare.  Otherwise, we
8551 		 * want to create a replacing vdev.  The user is not allowed to
8552 		 * attach to a spared vdev child unless the 'isspare' state is
8553 		 * the same (spare replaces spare, non-spare replaces
8554 		 * non-spare).
8555 		 */
8556 		if (pvd->vdev_ops == &vdev_replacing_ops &&
8557 		    spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
8558 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8559 		} else if (pvd->vdev_ops == &vdev_spare_ops &&
8560 		    newvd->vdev_isspare != oldvd->vdev_isspare) {
8561 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8562 		}
8563 
8564 		if (spa_vdev_new_spare_would_cause_double_spares(newvd, pvd)) {
8565 			vdev_dbgmsg(newvd,
8566 			    "disk would create double spares, ignore.");
8567 			return (spa_vdev_exit(spa, newrootvd, txg, EEXIST));
8568 		}
8569 
8570 		if (newvd->vdev_isspare)
8571 			pvops = &vdev_spare_ops;
8572 		else
8573 			pvops = &vdev_replacing_ops;
8574 	}
8575 
8576 	/*
8577 	 * Make sure the new device is big enough.
8578 	 */
8579 	vdev_t *min_vdev = raidz ? oldvd->vdev_child[0] : oldvd;
8580 	if (newvd->vdev_asize < vdev_get_min_asize(min_vdev))
8581 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
8582 
8583 	/*
8584 	 * The new device cannot have a higher alignment requirement
8585 	 * than the top-level vdev.
8586 	 */
8587 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift) {
8588 		return (spa_vdev_exit(spa, newrootvd, txg,
8589 		    ZFS_ERR_ASHIFT_MISMATCH));
8590 	}
8591 
8592 	/*
8593 	 * RAIDZ-expansion-specific checks.
8594 	 */
8595 	if (raidz) {
8596 		if (vdev_raidz_attach_check(newvd) != 0)
8597 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
8598 
8599 		/*
8600 		 * Fail early if a child is not healthy or being replaced
8601 		 */
8602 		for (int i = 0; i < oldvd->vdev_children; i++) {
8603 			if (vdev_is_dead(oldvd->vdev_child[i]) ||
8604 			    !oldvd->vdev_child[i]->vdev_ops->vdev_op_leaf) {
8605 				return (spa_vdev_exit(spa, newrootvd, txg,
8606 				    ENXIO));
8607 			}
8608 			/* Also fail if reserved boot area is in-use */
8609 			if (vdev_check_boot_reserve(spa, oldvd->vdev_child[i])
8610 			    != 0) {
8611 				return (spa_vdev_exit(spa, newrootvd, txg,
8612 				    EADDRINUSE));
8613 			}
8614 		}
8615 	}
8616 
8617 	if (raidz) {
8618 		/*
8619 		 * Note: oldvdpath is freed by spa_strfree(),  but
8620 		 * kmem_asprintf() is freed by kmem_strfree(), so we have to
8621 		 * move it to a spa_strdup-ed string.
8622 		 */
8623 		char *tmp = kmem_asprintf("raidz%u-%u",
8624 		    (uint_t)vdev_get_nparity(oldvd), (uint_t)oldvd->vdev_id);
8625 		oldvdpath = spa_strdup(tmp);
8626 		kmem_strfree(tmp);
8627 	} else {
8628 		oldvdpath = spa_strdup(oldvd->vdev_path);
8629 	}
8630 	newvdpath = spa_strdup(newvd->vdev_path);
8631 
8632 	/*
8633 	 * If this is an in-place replacement, update oldvd's path and devid
8634 	 * to make it distinguishable from newvd, and unopenable from now on.
8635 	 */
8636 	if (strcmp(oldvdpath, newvdpath) == 0) {
8637 		spa_strfree(oldvd->vdev_path);
8638 		oldvd->vdev_path = kmem_alloc(strlen(newvdpath) + 5,
8639 		    KM_SLEEP);
8640 		(void) sprintf(oldvd->vdev_path, "%s/old",
8641 		    newvdpath);
8642 		if (oldvd->vdev_devid != NULL) {
8643 			spa_strfree(oldvd->vdev_devid);
8644 			oldvd->vdev_devid = NULL;
8645 		}
8646 		spa_strfree(oldvdpath);
8647 		oldvdpath = spa_strdup(oldvd->vdev_path);
8648 	}
8649 
8650 	/*
8651 	 * If the parent is not a mirror, or if we're replacing, insert the new
8652 	 * mirror/replacing/spare vdev above oldvd.
8653 	 */
8654 	if (!raidz && pvd->vdev_ops != pvops) {
8655 		pvd = vdev_add_parent(oldvd, pvops);
8656 		ASSERT(pvd->vdev_ops == pvops);
8657 		ASSERT(oldvd->vdev_parent == pvd);
8658 	}
8659 
8660 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
8661 
8662 	/*
8663 	 * Extract the new device from its root and add it to pvd.
8664 	 */
8665 	vdev_remove_child(newrootvd, newvd);
8666 	newvd->vdev_id = pvd->vdev_children;
8667 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
8668 	vdev_add_child(pvd, newvd);
8669 
8670 	/*
8671 	 * Reevaluate the parent vdev state.
8672 	 */
8673 	vdev_propagate_state(pvd);
8674 
8675 	tvd = newvd->vdev_top;
8676 	ASSERT(pvd->vdev_top == tvd);
8677 	ASSERT(tvd->vdev_parent == rvd);
8678 
8679 	vdev_config_dirty(tvd);
8680 
8681 	/*
8682 	 * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
8683 	 * for any dmu_sync-ed blocks.  It will propagate upward when
8684 	 * spa_vdev_exit() calls vdev_dtl_reassess().
8685 	 */
8686 	dtl_max_txg = txg + TXG_CONCURRENT_STATES;
8687 
8688 	if (raidz) {
8689 		dmu_tx_t *tx = dmu_tx_create_assigned(spa->spa_dsl_pool,
8690 		    txg);
8691 		dsl_sync_task_nowait(spa->spa_dsl_pool, vdev_raidz_attach_sync,
8692 		    newvd, tx);
8693 		dmu_tx_commit(tx);
8694 
8695 		/*
8696 		 * Wait for the youngest allocations and frees to sync,
8697 		 * and then wait for the deferral of those frees to finish.
8698 		 */
8699 		spa_vdev_config_exit(spa, NULL,
8700 		    txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
8701 
8702 		vdev_initialize_stop_all(tvd, VDEV_INITIALIZE_ACTIVE);
8703 		vdev_trim_stop_all(tvd, VDEV_TRIM_ACTIVE);
8704 		vdev_autotrim_stop_wait(tvd);
8705 
8706 		dtl_max_txg = spa_vdev_config_enter(spa);
8707 
8708 		tvd->vdev_rz_expanding = B_TRUE;
8709 
8710 		vdev_dirty_leaves(tvd, VDD_DTL, dtl_max_txg);
8711 		vdev_config_dirty(tvd);
8712 		zthr_wakeup(spa->spa_raidz_expand_zthr);
8713 	} else {
8714 		vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
8715 		    dtl_max_txg - TXG_INITIAL);
8716 
8717 		if (newvd->vdev_isspare) {
8718 			spa_spare_activate(newvd);
8719 			spa_event_notify(spa, newvd, NULL, ESC_ZFS_VDEV_SPARE);
8720 		}
8721 
8722 		newvd_isspare = newvd->vdev_isspare;
8723 
8724 		/*
8725 		 * Mark newvd's DTL dirty in this txg.
8726 		 */
8727 		vdev_dirty(tvd, VDD_DTL, newvd, txg);
8728 
8729 		/*
8730 		 * Schedule the resilver or rebuild to restart in the future.
8731 		 * We do this to ensure that dmu_sync-ed blocks have been
8732 		 * stitched into the respective datasets.
8733 		 */
8734 		if (rebuild) {
8735 			newvd->vdev_rebuild_txg = txg;
8736 
8737 			vdev_rebuild(tvd, txg);
8738 		} else {
8739 			newvd->vdev_resilver_txg = txg;
8740 
8741 			if (dsl_scan_resilvering(spa_get_dsl(spa)) &&
8742 			    spa_feature_is_enabled(spa,
8743 			    SPA_FEATURE_RESILVER_DEFER)) {
8744 				vdev_defer_resilver(newvd);
8745 			} else {
8746 				dsl_scan_restart_resilver(spa->spa_dsl_pool,
8747 				    dtl_max_txg);
8748 			}
8749 		}
8750 	}
8751 
8752 	if (spa->spa_bootfs)
8753 		spa_event_notify(spa, newvd, NULL, ESC_ZFS_BOOTFS_VDEV_ATTACH);
8754 
8755 	spa_event_notify(spa, newvd, NULL, ESC_ZFS_VDEV_ATTACH);
8756 
8757 	/*
8758 	 * Commit the config
8759 	 */
8760 	(void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
8761 
8762 	spa_history_log_internal(spa, "vdev attach", NULL,
8763 	    "%s vdev=%s %s vdev=%s",
8764 	    replacing && newvd_isspare ? "spare in" :
8765 	    replacing ? "replace" : "attach", newvdpath,
8766 	    replacing ? "for" : "to", oldvdpath);
8767 
8768 	spa_strfree(oldvdpath);
8769 	spa_strfree(newvdpath);
8770 
8771 	return (0);
8772 }
8773 
8774 /*
8775  * Detach a device from a mirror or replacing vdev.
8776  *
8777  * If 'replace_done' is specified, only detach if the parent
8778  * is a replacing or a spare vdev.
8779  */
8780 int
8781 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
8782 {
8783 	uint64_t txg;
8784 	int error;
8785 	vdev_t *rvd __maybe_unused = spa->spa_root_vdev;
8786 	vdev_t *vd, *pvd, *cvd, *tvd;
8787 	boolean_t unspare = B_FALSE;
8788 	uint64_t unspare_guid = 0;
8789 	char *vdpath;
8790 
8791 	ASSERT(spa_writeable(spa));
8792 
8793 	txg = spa_vdev_detach_enter(spa, guid);
8794 
8795 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
8796 
8797 	/*
8798 	 * Besides being called directly from the userland through the
8799 	 * ioctl interface, spa_vdev_detach() can be potentially called
8800 	 * at the end of spa_vdev_resilver_done().
8801 	 *
8802 	 * In the regular case, when we have a checkpoint this shouldn't
8803 	 * happen as we never empty the DTLs of a vdev during the scrub
8804 	 * [see comment in dsl_scan_done()]. Thus spa_vdev_resilvering_done()
8805 	 * should never get here when we have a checkpoint.
8806 	 *
8807 	 * That said, even in a case when we checkpoint the pool exactly
8808 	 * as spa_vdev_resilver_done() calls this function everything
8809 	 * should be fine as the resilver will return right away.
8810 	 */
8811 	ASSERT(spa_namespace_held());
8812 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
8813 		error = (spa_has_checkpoint(spa)) ?
8814 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
8815 		return (spa_vdev_exit(spa, NULL, txg, error));
8816 	}
8817 
8818 	if (vd == NULL)
8819 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
8820 
8821 	if (!vd->vdev_ops->vdev_op_leaf)
8822 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8823 
8824 	pvd = vd->vdev_parent;
8825 
8826 	/*
8827 	 * If the parent/child relationship is not as expected, don't do it.
8828 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
8829 	 * vdev that's replacing B with C.  The user's intent in replacing
8830 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
8831 	 * the replace by detaching C, the expected behavior is to end up
8832 	 * M(A,B).  But suppose that right after deciding to detach C,
8833 	 * the replacement of B completes.  We would have M(A,C), and then
8834 	 * ask to detach C, which would leave us with just A -- not what
8835 	 * the user wanted.  To prevent this, we make sure that the
8836 	 * parent/child relationship hasn't changed -- in this example,
8837 	 * that C's parent is still the replacing vdev R.
8838 	 */
8839 	if (pvd->vdev_guid != pguid && pguid != 0)
8840 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
8841 
8842 	/*
8843 	 * Only 'replacing' or 'spare' vdevs can be replaced.
8844 	 */
8845 	if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
8846 	    pvd->vdev_ops != &vdev_spare_ops)
8847 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8848 
8849 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
8850 	    spa_version(spa) >= SPA_VERSION_SPARES);
8851 
8852 	/*
8853 	 * Only mirror, replacing, and spare vdevs support detach.
8854 	 */
8855 	if (pvd->vdev_ops != &vdev_replacing_ops &&
8856 	    pvd->vdev_ops != &vdev_mirror_ops &&
8857 	    pvd->vdev_ops != &vdev_spare_ops)
8858 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
8859 
8860 	/*
8861 	 * If this device has the only valid copy of some data,
8862 	 * we cannot safely detach it.
8863 	 */
8864 	if (vdev_dtl_required(vd))
8865 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
8866 
8867 	ASSERT(pvd->vdev_children >= 2);
8868 
8869 	/*
8870 	 * If we are detaching the second disk from a replacing vdev, then
8871 	 * check to see if we changed the original vdev's path to have "/old"
8872 	 * at the end in spa_vdev_attach().  If so, undo that change now.
8873 	 */
8874 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
8875 	    vd->vdev_path != NULL) {
8876 		size_t len = strlen(vd->vdev_path);
8877 
8878 		for (int c = 0; c < pvd->vdev_children; c++) {
8879 			cvd = pvd->vdev_child[c];
8880 
8881 			if (cvd == vd || cvd->vdev_path == NULL)
8882 				continue;
8883 
8884 			if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
8885 			    strcmp(cvd->vdev_path + len, "/old") == 0) {
8886 				spa_strfree(cvd->vdev_path);
8887 				cvd->vdev_path = spa_strdup(vd->vdev_path);
8888 				break;
8889 			}
8890 		}
8891 	}
8892 
8893 	/*
8894 	 * If we are detaching the original disk from a normal spare, then it
8895 	 * implies that the spare should become a real disk, and be removed
8896 	 * from the active spare list for the pool.  dRAID spares on the
8897 	 * other hand are coupled to the pool and thus should never be removed
8898 	 * from the spares list.
8899 	 */
8900 	if (pvd->vdev_ops == &vdev_spare_ops && vd->vdev_id == 0) {
8901 		vdev_t *last_cvd = pvd->vdev_child[pvd->vdev_children - 1];
8902 
8903 		if (last_cvd->vdev_isspare &&
8904 		    last_cvd->vdev_ops != &vdev_draid_spare_ops) {
8905 			unspare = B_TRUE;
8906 		}
8907 	}
8908 
8909 	/*
8910 	 * Erase the disk labels so the disk can be used for other things.
8911 	 * This must be done after all other error cases are handled,
8912 	 * but before we disembowel vd (so we can still do I/O to it).
8913 	 * But if we can't do it, don't treat the error as fatal --
8914 	 * it may be that the unwritability of the disk is the reason
8915 	 * it's being detached!
8916 	 */
8917 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
8918 
8919 	/*
8920 	 * Remove vd from its parent and compact the parent's children.
8921 	 */
8922 	vdev_remove_child(pvd, vd);
8923 	vdev_compact_children(pvd);
8924 
8925 	/*
8926 	 * Remember one of the remaining children so we can get tvd below.
8927 	 */
8928 	cvd = pvd->vdev_child[pvd->vdev_children - 1];
8929 
8930 	/*
8931 	 * If we need to remove the remaining child from the list of hot spares,
8932 	 * do it now, marking the vdev as no longer a spare in the process.
8933 	 * We must do this before vdev_remove_parent(), because that can
8934 	 * change the GUID if it creates a new toplevel GUID.  For a similar
8935 	 * reason, we must remove the spare now, in the same txg as the detach;
8936 	 * otherwise someone could attach a new sibling, change the GUID, and
8937 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
8938 	 */
8939 	if (unspare) {
8940 		ASSERT(cvd->vdev_isspare);
8941 		spa_spare_remove(cvd);
8942 		unspare_guid = cvd->vdev_guid;
8943 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
8944 		cvd->vdev_unspare = B_TRUE;
8945 	}
8946 
8947 	/*
8948 	 * If the parent mirror/replacing vdev only has one child,
8949 	 * the parent is no longer needed.  Remove it from the tree.
8950 	 */
8951 	if (pvd->vdev_children == 1) {
8952 		if (pvd->vdev_ops == &vdev_spare_ops)
8953 			cvd->vdev_unspare = B_FALSE;
8954 		vdev_remove_parent(cvd);
8955 	}
8956 
8957 	/*
8958 	 * We don't set tvd until now because the parent we just removed
8959 	 * may have been the previous top-level vdev.
8960 	 */
8961 	tvd = cvd->vdev_top;
8962 	ASSERT(tvd->vdev_parent == rvd);
8963 
8964 	/*
8965 	 * Reevaluate the parent vdev state.
8966 	 */
8967 	vdev_propagate_state(cvd);
8968 
8969 	/*
8970 	 * If the 'autoexpand' property is set on the pool then automatically
8971 	 * try to expand the size of the pool. For example if the device we
8972 	 * just detached was smaller than the others, it may be possible to
8973 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
8974 	 * first so that we can obtain the updated sizes of the leaf vdevs.
8975 	 */
8976 	if (spa->spa_autoexpand) {
8977 		vdev_reopen(tvd);
8978 		vdev_expand(tvd, txg);
8979 	}
8980 
8981 	vdev_config_dirty(tvd);
8982 
8983 	/*
8984 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
8985 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
8986 	 * But first make sure we're not on any *other* txg's DTL list, to
8987 	 * prevent vd from being accessed after it's freed.
8988 	 */
8989 	vdpath = spa_strdup(vd->vdev_path ? vd->vdev_path : "none");
8990 	for (int t = 0; t < TXG_SIZE; t++)
8991 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
8992 	vd->vdev_detached = B_TRUE;
8993 	vdev_dirty(tvd, VDD_DTL, vd, txg);
8994 
8995 	spa_event_notify(spa, vd, NULL, ESC_ZFS_VDEV_REMOVE);
8996 	spa_notify_waiters(spa);
8997 
8998 	/* hang on to the spa before we release the lock */
8999 	spa_open_ref(spa, FTAG);
9000 
9001 	error = spa_vdev_exit(spa, vd, txg, 0);
9002 
9003 	spa_history_log_internal(spa, "detach", NULL,
9004 	    "vdev=%s", vdpath);
9005 	spa_strfree(vdpath);
9006 
9007 	/*
9008 	 * If this was the removal of the original device in a hot spare vdev,
9009 	 * then we want to go through and remove the device from the hot spare
9010 	 * list of every other pool.
9011 	 */
9012 	if (unspare) {
9013 		spa_t *altspa = NULL;
9014 
9015 		spa_namespace_enter(FTAG);
9016 		while ((altspa = spa_next(altspa)) != NULL) {
9017 			if (altspa->spa_state != POOL_STATE_ACTIVE ||
9018 			    altspa == spa)
9019 				continue;
9020 
9021 			spa_open_ref(altspa, FTAG);
9022 			spa_namespace_exit(FTAG);
9023 			(void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
9024 			spa_namespace_enter(FTAG);
9025 			spa_close(altspa, FTAG);
9026 		}
9027 		spa_namespace_exit(FTAG);
9028 
9029 		/* search the rest of the vdevs for spares to remove */
9030 		spa_vdev_resilver_done(spa);
9031 	}
9032 
9033 	/* all done with the spa; OK to release */
9034 	spa_namespace_enter(FTAG);
9035 	spa_close(spa, FTAG);
9036 	spa_namespace_exit(FTAG);
9037 
9038 	return (error);
9039 }
9040 
9041 static int
9042 spa_vdev_initialize_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
9043     uint64_t value, boolean_t value_provided, list_t *vd_list)
9044 {
9045 	ASSERT(spa_namespace_held());
9046 
9047 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
9048 
9049 	/* Look up vdev and ensure it's a leaf. */
9050 	vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
9051 	if (vd == NULL || vd->vdev_detached) {
9052 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9053 		return (SET_ERROR(ENODEV));
9054 	} else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
9055 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9056 		return (SET_ERROR(EINVAL));
9057 	} else if (!vdev_writeable(vd)) {
9058 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9059 		return (SET_ERROR(EROFS));
9060 	}
9061 	mutex_enter(&vd->vdev_initialize_lock);
9062 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9063 
9064 	/*
9065 	 * When we activate an initialize action we check to see
9066 	 * if the vdev_initialize_thread is NULL. We do this instead
9067 	 * of using the vdev_initialize_state since there might be
9068 	 * a previous initialization process which has completed but
9069 	 * the thread is not exited.
9070 	 */
9071 	if (cmd_type == POOL_INITIALIZE_START &&
9072 	    (vd->vdev_initialize_thread != NULL ||
9073 	    vd->vdev_top->vdev_removing || vd->vdev_top->vdev_rz_expanding)) {
9074 		mutex_exit(&vd->vdev_initialize_lock);
9075 		return (SET_ERROR(EBUSY));
9076 	} else if (cmd_type == POOL_INITIALIZE_CANCEL &&
9077 	    (vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE &&
9078 	    vd->vdev_initialize_state != VDEV_INITIALIZE_SUSPENDED)) {
9079 		mutex_exit(&vd->vdev_initialize_lock);
9080 		return (SET_ERROR(ESRCH));
9081 	} else if (cmd_type == POOL_INITIALIZE_SUSPEND &&
9082 	    vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE) {
9083 		mutex_exit(&vd->vdev_initialize_lock);
9084 		return (SET_ERROR(ESRCH));
9085 	} else if (cmd_type == POOL_INITIALIZE_UNINIT &&
9086 	    vd->vdev_initialize_thread != NULL) {
9087 		mutex_exit(&vd->vdev_initialize_lock);
9088 		return (SET_ERROR(EBUSY));
9089 	}
9090 
9091 	switch (cmd_type) {
9092 	case POOL_INITIALIZE_START:
9093 		vdev_initialize(vd, value, value_provided);
9094 		break;
9095 	case POOL_INITIALIZE_CANCEL:
9096 		vdev_initialize_stop(vd, VDEV_INITIALIZE_CANCELED, vd_list);
9097 		break;
9098 	case POOL_INITIALIZE_SUSPEND:
9099 		vdev_initialize_stop(vd, VDEV_INITIALIZE_SUSPENDED, vd_list);
9100 		break;
9101 	case POOL_INITIALIZE_UNINIT:
9102 		vdev_uninitialize(vd);
9103 		break;
9104 	default:
9105 		panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
9106 	}
9107 	mutex_exit(&vd->vdev_initialize_lock);
9108 
9109 	return (0);
9110 }
9111 
9112 int
9113 spa_vdev_initialize(spa_t *spa, nvlist_t *nv, uint64_t cmd_type,
9114     uint64_t value, boolean_t value_provided, nvlist_t *vdev_errlist)
9115 {
9116 	int total_errors = 0;
9117 	list_t vd_list;
9118 
9119 	list_create(&vd_list, sizeof (vdev_t),
9120 	    offsetof(vdev_t, vdev_initialize_node));
9121 
9122 	/*
9123 	 * We hold the namespace lock through the whole function
9124 	 * to prevent any changes to the pool while we're starting or
9125 	 * stopping initialization. The config and state locks are held so that
9126 	 * we can properly assess the vdev state before we commit to
9127 	 * the initializing operation.
9128 	 */
9129 	spa_namespace_enter(FTAG);
9130 
9131 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
9132 	    pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
9133 		uint64_t vdev_guid = fnvpair_value_uint64(pair);
9134 
9135 		int error = spa_vdev_initialize_impl(spa, vdev_guid, cmd_type,
9136 		    value, value_provided, &vd_list);
9137 		if (error != 0) {
9138 			char guid_as_str[MAXNAMELEN];
9139 
9140 			(void) snprintf(guid_as_str, sizeof (guid_as_str),
9141 			    "%llu", (unsigned long long)vdev_guid);
9142 			fnvlist_add_int64(vdev_errlist, guid_as_str, error);
9143 			total_errors++;
9144 		}
9145 	}
9146 
9147 	/* Wait for all initialize threads to stop. */
9148 	vdev_initialize_stop_wait(spa, &vd_list);
9149 
9150 	/* Sync out the initializing state */
9151 	txg_wait_synced(spa->spa_dsl_pool, 0);
9152 	spa_namespace_exit(FTAG);
9153 
9154 	list_destroy(&vd_list);
9155 
9156 	return (total_errors);
9157 }
9158 
9159 static int
9160 spa_vdev_trim_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
9161     uint64_t rate, boolean_t partial, boolean_t secure, list_t *vd_list)
9162 {
9163 	ASSERT(spa_namespace_held());
9164 
9165 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
9166 
9167 	/* Look up vdev and ensure it's a leaf. */
9168 	vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
9169 	if (vd == NULL || vd->vdev_detached) {
9170 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9171 		return (SET_ERROR(ENODEV));
9172 	} else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
9173 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9174 		return (SET_ERROR(EINVAL));
9175 	} else if (!vdev_writeable(vd)) {
9176 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9177 		return (SET_ERROR(EROFS));
9178 	} else if (!vd->vdev_has_trim) {
9179 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9180 		return (SET_ERROR(EOPNOTSUPP));
9181 	} else if (secure && !vd->vdev_has_securetrim) {
9182 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9183 		return (SET_ERROR(EOPNOTSUPP));
9184 	}
9185 	mutex_enter(&vd->vdev_trim_lock);
9186 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
9187 
9188 	/*
9189 	 * When we activate a TRIM action we check to see if the
9190 	 * vdev_trim_thread is NULL. We do this instead of using the
9191 	 * vdev_trim_state since there might be a previous TRIM process
9192 	 * which has completed but the thread is not exited.
9193 	 */
9194 	if (cmd_type == POOL_TRIM_START &&
9195 	    (vd->vdev_trim_thread != NULL || vd->vdev_top->vdev_removing ||
9196 	    vd->vdev_top->vdev_rz_expanding)) {
9197 		mutex_exit(&vd->vdev_trim_lock);
9198 		return (SET_ERROR(EBUSY));
9199 	} else if (cmd_type == POOL_TRIM_CANCEL &&
9200 	    (vd->vdev_trim_state != VDEV_TRIM_ACTIVE &&
9201 	    vd->vdev_trim_state != VDEV_TRIM_SUSPENDED)) {
9202 		mutex_exit(&vd->vdev_trim_lock);
9203 		return (SET_ERROR(ESRCH));
9204 	} else if (cmd_type == POOL_TRIM_SUSPEND &&
9205 	    vd->vdev_trim_state != VDEV_TRIM_ACTIVE) {
9206 		mutex_exit(&vd->vdev_trim_lock);
9207 		return (SET_ERROR(ESRCH));
9208 	}
9209 
9210 	switch (cmd_type) {
9211 	case POOL_TRIM_START:
9212 		vdev_trim(vd, rate, partial, secure);
9213 		break;
9214 	case POOL_TRIM_CANCEL:
9215 		vdev_trim_stop(vd, VDEV_TRIM_CANCELED, vd_list);
9216 		break;
9217 	case POOL_TRIM_SUSPEND:
9218 		vdev_trim_stop(vd, VDEV_TRIM_SUSPENDED, vd_list);
9219 		break;
9220 	default:
9221 		panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
9222 	}
9223 	mutex_exit(&vd->vdev_trim_lock);
9224 
9225 	return (0);
9226 }
9227 
9228 /*
9229  * Initiates a manual TRIM for the requested vdevs. This kicks off individual
9230  * TRIM threads for each child vdev.  These threads pass over all of the free
9231  * space in the vdev's metaslabs and issues TRIM commands for that space.
9232  */
9233 int
9234 spa_vdev_trim(spa_t *spa, nvlist_t *nv, uint64_t cmd_type, uint64_t rate,
9235     boolean_t partial, boolean_t secure, nvlist_t *vdev_errlist)
9236 {
9237 	int total_errors = 0;
9238 	list_t vd_list;
9239 
9240 	list_create(&vd_list, sizeof (vdev_t),
9241 	    offsetof(vdev_t, vdev_trim_node));
9242 
9243 	/*
9244 	 * We hold the namespace lock through the whole function
9245 	 * to prevent any changes to the pool while we're starting or
9246 	 * stopping TRIM. The config and state locks are held so that
9247 	 * we can properly assess the vdev state before we commit to
9248 	 * the TRIM operation.
9249 	 */
9250 	spa_namespace_enter(FTAG);
9251 
9252 	for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
9253 	    pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
9254 		uint64_t vdev_guid = fnvpair_value_uint64(pair);
9255 
9256 		int error = spa_vdev_trim_impl(spa, vdev_guid, cmd_type,
9257 		    rate, partial, secure, &vd_list);
9258 		if (error != 0) {
9259 			char guid_as_str[MAXNAMELEN];
9260 
9261 			(void) snprintf(guid_as_str, sizeof (guid_as_str),
9262 			    "%llu", (unsigned long long)vdev_guid);
9263 			fnvlist_add_int64(vdev_errlist, guid_as_str, error);
9264 			total_errors++;
9265 		}
9266 	}
9267 
9268 	/* Wait for all TRIM threads to stop. */
9269 	vdev_trim_stop_wait(spa, &vd_list);
9270 
9271 	/* Sync out the TRIM state */
9272 	txg_wait_synced(spa->spa_dsl_pool, 0);
9273 	spa_namespace_exit(FTAG);
9274 
9275 	list_destroy(&vd_list);
9276 
9277 	return (total_errors);
9278 }
9279 
9280 typedef struct spa_split_dtl_arg {
9281 	spa_t		*ssda_spa;	/* the new pool */
9282 	uint64_t	*ssda_objs;	/* original DTL space map objects */
9283 	uint_t		ssda_count;	/* nitems in ssda_objs */
9284 } spa_split_dtl_arg_t;
9285 
9286 /*
9287  * Record the DTL space map object of every leaf that has one into objs[],
9288  * advancing *idxp. These are the objects that will be carried, via the
9289  * copied MOS, onto the split disks.
9290  */
9291 static void
9292 spa_split_collect_dtl(vdev_t *vd, uint64_t *objs, uint_t *idxp)
9293 {
9294 	if (vd->vdev_ops->vdev_op_leaf) {
9295 		if (vd->vdev_dtl_sm != NULL)
9296 			objs[(*idxp)++] = space_map_object(vd->vdev_dtl_sm);
9297 		return;
9298 	}
9299 	for (uint64_t c = 0; c < vd->vdev_children; c++)
9300 		spa_split_collect_dtl(vd->vdev_child[c], objs, idxp);
9301 }
9302 
9303 /*
9304  * Callback that frees the inherited DTL space map objects from the new
9305  * pool MOS. The new pool MOS is a byte copy of the original pool, so it
9306  * contains a DTL space map object for every leaf of the original pool.
9307  * The new pool references none of them because split leaves
9308  * start with an empty DTL and allocate their own on demand.
9309  */
9310 static void
9311 spa_split_dtl_free_sync(void *arg, dmu_tx_t *tx)
9312 {
9313 	spa_split_dtl_arg_t *ssda = arg;
9314 	objset_t *mos = ssda->ssda_spa->spa_meta_objset;
9315 
9316 	for (uint_t i = 0; i < ssda->ssda_count; i++)
9317 		space_map_free_obj(mos, ssda->ssda_objs[i], tx);
9318 }
9319 
9320 /*
9321  * Split a set of devices from their mirrors, and create a new pool from them.
9322  */
9323 int
9324 spa_vdev_split_mirror(spa_t *spa, const char *newname, nvlist_t *config,
9325     nvlist_t *props, boolean_t exp)
9326 {
9327 	int error = 0;
9328 	uint64_t txg, *glist;
9329 	spa_t *newspa;
9330 	uint_t c, children, lastlog;
9331 	nvlist_t **child, *nvl, *tmp;
9332 	dmu_tx_t *tx;
9333 	const char *altroot = NULL;
9334 	vdev_t *rvd, **vml = NULL;	/* vdev modify list */
9335 	uint64_t *dtl_objs = NULL;	/* DTL objs from original pool */
9336 	uint_t ndtl = 0, nleaves;
9337 	boolean_t activate_slog;
9338 
9339 	ASSERT(spa_writeable(spa));
9340 
9341 	txg = spa_vdev_enter(spa);
9342 
9343 	ASSERT(spa_namespace_held());
9344 	if (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT)) {
9345 		error = (spa_has_checkpoint(spa)) ?
9346 		    ZFS_ERR_CHECKPOINT_EXISTS : ZFS_ERR_DISCARDING_CHECKPOINT;
9347 		return (spa_vdev_exit(spa, NULL, txg, error));
9348 	}
9349 
9350 	/* clear the log and flush everything up to now */
9351 	activate_slog = spa_passivate_log(spa);
9352 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
9353 	error = spa_reset_logs(spa);
9354 	txg = spa_vdev_config_enter(spa);
9355 
9356 	if (activate_slog)
9357 		spa_activate_log(spa);
9358 
9359 	if (error != 0)
9360 		return (spa_vdev_exit(spa, NULL, txg, error));
9361 
9362 	/* check new spa name before going any further */
9363 	if (spa_lookup(newname) != NULL)
9364 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
9365 
9366 	/*
9367 	 * scan through all the children to ensure they're all mirrors
9368 	 */
9369 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
9370 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
9371 	    &children) != 0)
9372 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
9373 
9374 	/* first, check to ensure we've got the right child count */
9375 	rvd = spa->spa_root_vdev;
9376 	lastlog = 0;
9377 	for (c = 0; c < rvd->vdev_children; c++) {
9378 		vdev_t *vd = rvd->vdev_child[c];
9379 
9380 		/* don't count the holes & logs as children */
9381 		if (vd->vdev_islog || (vd->vdev_ops != &vdev_indirect_ops &&
9382 		    !vdev_is_concrete(vd))) {
9383 			if (lastlog == 0)
9384 				lastlog = c;
9385 			continue;
9386 		}
9387 
9388 		lastlog = 0;
9389 	}
9390 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
9391 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
9392 
9393 	/* next, ensure no spare or cache devices are part of the split */
9394 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
9395 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
9396 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
9397 
9398 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
9399 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
9400 
9401 	/* then, loop over each vdev and validate it */
9402 	for (c = 0; c < children; c++) {
9403 		uint64_t is_hole = 0;
9404 
9405 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
9406 		    &is_hole);
9407 
9408 		if (is_hole != 0) {
9409 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
9410 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
9411 				continue;
9412 			} else {
9413 				error = SET_ERROR(EINVAL);
9414 				break;
9415 			}
9416 		}
9417 
9418 		/* deal with indirect vdevs */
9419 		if (spa->spa_root_vdev->vdev_child[c]->vdev_ops ==
9420 		    &vdev_indirect_ops)
9421 			continue;
9422 
9423 		/* which disk is going to be split? */
9424 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
9425 		    &glist[c]) != 0) {
9426 			error = SET_ERROR(EINVAL);
9427 			break;
9428 		}
9429 
9430 		/* look it up in the spa */
9431 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
9432 		if (vml[c] == NULL) {
9433 			error = SET_ERROR(ENODEV);
9434 			break;
9435 		}
9436 
9437 		/* make sure there's nothing stopping the split */
9438 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
9439 		    vml[c]->vdev_islog ||
9440 		    !vdev_is_concrete(vml[c]) ||
9441 		    vml[c]->vdev_isspare ||
9442 		    vml[c]->vdev_isl2cache ||
9443 		    !vdev_writeable(vml[c]) ||
9444 		    vml[c]->vdev_children != 0 ||
9445 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
9446 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
9447 			error = SET_ERROR(EINVAL);
9448 			break;
9449 		}
9450 
9451 		if (vdev_dtl_required(vml[c]) ||
9452 		    vdev_resilver_needed(vml[c], NULL, NULL)) {
9453 			error = SET_ERROR(EBUSY);
9454 			break;
9455 		}
9456 
9457 		/* we need certain info from the top level */
9458 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
9459 		    vml[c]->vdev_top->vdev_ms_array);
9460 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
9461 		    vml[c]->vdev_top->vdev_ms_shift);
9462 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
9463 		    vml[c]->vdev_top->vdev_asize);
9464 		fnvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
9465 		    vml[c]->vdev_top->vdev_ashift);
9466 
9467 		/* transfer per-vdev ZAPs */
9468 		ASSERT3U(vml[c]->vdev_leaf_zap, !=, 0);
9469 		VERIFY0(nvlist_add_uint64(child[c],
9470 		    ZPOOL_CONFIG_VDEV_LEAF_ZAP, vml[c]->vdev_leaf_zap));
9471 
9472 		ASSERT3U(vml[c]->vdev_top->vdev_top_zap, !=, 0);
9473 		VERIFY0(nvlist_add_uint64(child[c],
9474 		    ZPOOL_CONFIG_VDEV_TOP_ZAP,
9475 		    vml[c]->vdev_parent->vdev_top_zap));
9476 	}
9477 
9478 	if (error != 0) {
9479 		kmem_free(vml, children * sizeof (vdev_t *));
9480 		kmem_free(glist, children * sizeof (uint64_t));
9481 		return (spa_vdev_exit(spa, NULL, txg, error));
9482 	}
9483 
9484 	/* Create array of DTL objects. */
9485 	nleaves = vdev_count_leaves(spa);
9486 	dtl_objs = kmem_zalloc(nleaves * sizeof (uint64_t), KM_SLEEP);
9487 	spa_split_collect_dtl(spa->spa_root_vdev, dtl_objs, &ndtl);
9488 
9489 	/* stop writers from using the disks */
9490 	for (c = 0; c < children; c++) {
9491 		if (vml[c] != NULL)
9492 			vml[c]->vdev_offline = B_TRUE;
9493 	}
9494 	vdev_reopen(spa->spa_root_vdev);
9495 
9496 	/*
9497 	 * Temporarily record the splitting vdevs in the spa config.  This
9498 	 * will disappear once the config is regenerated.
9499 	 */
9500 	nvl = fnvlist_alloc();
9501 	fnvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST, glist, children);
9502 	kmem_free(glist, children * sizeof (uint64_t));
9503 
9504 	mutex_enter(&spa->spa_props_lock);
9505 	fnvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT, nvl);
9506 	mutex_exit(&spa->spa_props_lock);
9507 	spa->spa_config_splitting = nvl;
9508 	vdev_config_dirty(spa->spa_root_vdev);
9509 
9510 	/* configure and create the new pool */
9511 	fnvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname);
9512 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
9513 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE);
9514 	fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION, spa_version(spa));
9515 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG, spa->spa_config_txg);
9516 	fnvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
9517 	    spa_generate_guid(NULL));
9518 	VERIFY0(nvlist_add_boolean(config, ZPOOL_CONFIG_HAS_PER_VDEV_ZAPS));
9519 	(void) nvlist_lookup_string(props,
9520 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
9521 
9522 	/* add the new pool to the namespace */
9523 	newspa = spa_add(newname, config, altroot);
9524 	newspa->spa_avz_action = AVZ_ACTION_REBUILD;
9525 	newspa->spa_config_txg = spa->spa_config_txg;
9526 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
9527 
9528 	/* release the spa config lock, retaining the namespace lock */
9529 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
9530 
9531 	if (zio_injection_enabled)
9532 		zio_handle_panic_injection(spa, FTAG, 1);
9533 
9534 	spa_activate(newspa, spa_mode_global);
9535 	spa_async_suspend(newspa);
9536 
9537 	/*
9538 	 * Temporarily stop the initializing and TRIM activity.  We set the
9539 	 * state to ACTIVE so that we know to resume initializing or TRIM
9540 	 * once the split has completed.
9541 	 */
9542 	list_t vd_initialize_list;
9543 	list_create(&vd_initialize_list, sizeof (vdev_t),
9544 	    offsetof(vdev_t, vdev_initialize_node));
9545 
9546 	list_t vd_trim_list;
9547 	list_create(&vd_trim_list, sizeof (vdev_t),
9548 	    offsetof(vdev_t, vdev_trim_node));
9549 
9550 	for (c = 0; c < children; c++) {
9551 		if (vml[c] != NULL && vml[c]->vdev_ops != &vdev_indirect_ops) {
9552 			mutex_enter(&vml[c]->vdev_initialize_lock);
9553 			vdev_initialize_stop(vml[c],
9554 			    VDEV_INITIALIZE_ACTIVE, &vd_initialize_list);
9555 			mutex_exit(&vml[c]->vdev_initialize_lock);
9556 
9557 			mutex_enter(&vml[c]->vdev_trim_lock);
9558 			vdev_trim_stop(vml[c], VDEV_TRIM_ACTIVE, &vd_trim_list);
9559 			mutex_exit(&vml[c]->vdev_trim_lock);
9560 		}
9561 	}
9562 
9563 	vdev_initialize_stop_wait(spa, &vd_initialize_list);
9564 	vdev_trim_stop_wait(spa, &vd_trim_list);
9565 
9566 	list_destroy(&vd_initialize_list);
9567 	list_destroy(&vd_trim_list);
9568 
9569 	newspa->spa_config_source = SPA_CONFIG_SRC_SPLIT;
9570 	newspa->spa_is_splitting = B_TRUE;
9571 
9572 	/* create the new pool from the disks of the original pool */
9573 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE);
9574 	if (error)
9575 		goto out;
9576 
9577 	/* if that worked, generate a real config for the new pool */
9578 	if (newspa->spa_root_vdev != NULL) {
9579 		newspa->spa_config_splitting = fnvlist_alloc();
9580 		fnvlist_add_uint64(newspa->spa_config_splitting,
9581 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa));
9582 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
9583 		    B_TRUE));
9584 	}
9585 
9586 	/*
9587 	 * Free the DTL space map objects inherited from the original pool
9588 	 * MOS so we won't leak them.
9589 	 */
9590 	if (ndtl != 0) {
9591 		spa_split_dtl_arg_t ssda;
9592 
9593 		ssda.ssda_spa = newspa;
9594 		ssda.ssda_objs = dtl_objs;
9595 		ssda.ssda_count = ndtl;
9596 		VERIFY0(dsl_sync_task(spa_name(newspa), NULL,
9597 		    spa_split_dtl_free_sync, &ssda, 0, ZFS_SPACE_CHECK_NONE));
9598 	}
9599 
9600 	/* set the props */
9601 	if (props != NULL) {
9602 		spa_configfile_set(newspa, props, B_FALSE);
9603 		error = spa_prop_set(newspa, props);
9604 		if (error)
9605 			goto out;
9606 	}
9607 
9608 	/* flush everything */
9609 	txg = spa_vdev_config_enter(newspa);
9610 	vdev_config_dirty(newspa->spa_root_vdev);
9611 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
9612 
9613 	if (zio_injection_enabled)
9614 		zio_handle_panic_injection(spa, FTAG, 2);
9615 
9616 	spa_async_resume(newspa);
9617 
9618 	/* finally, update the original pool's config */
9619 	txg = spa_vdev_config_enter(spa);
9620 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
9621 	error = dmu_tx_assign(tx, DMU_TX_WAIT);
9622 	if (error != 0)
9623 		dmu_tx_abort(tx);
9624 	for (c = 0; c < children; c++) {
9625 		if (vml[c] != NULL && vml[c]->vdev_ops != &vdev_indirect_ops) {
9626 			vdev_t *tvd = vml[c]->vdev_top;
9627 
9628 			/*
9629 			 * Need to be sure the detachable VDEV is not
9630 			 * on any *other* txg's DTL list to prevent it
9631 			 * from being accessed after it's freed.
9632 			 */
9633 			for (int t = 0; t < TXG_SIZE; t++) {
9634 				(void) txg_list_remove_this(
9635 				    &tvd->vdev_dtl_list, vml[c], t);
9636 			}
9637 
9638 			vdev_split(vml[c]);
9639 
9640 			/*
9641 			 * As in spa_vdev_detach(), mark the vdev detached
9642 			 * and dirty its DTL, so that vdev_dtl_sync() frees
9643 			 * the leaf's DTL space map object.
9644 			 */
9645 			vml[c]->vdev_detached = B_TRUE;
9646 
9647 			/*
9648 			 * The leaf ZAP was transferred to the new pool
9649 			 * and this pool's copy is destroyed by the AVZ
9650 			 * rebuild below, so clear it to keep
9651 			 * vdev_dtl_sync() from destroying it again.
9652 			 */
9653 			vml[c]->vdev_leaf_zap = 0;
9654 
9655 			/*
9656 			 * vml[c]->vdev_top may be stale; the
9657 			 * surviving top-level vdev is rvd->vdev_child[c].
9658 			 */
9659 			if (vml[c]->vdev_dtl_sm != NULL)
9660 				vdev_dirty(rvd->vdev_child[c], VDD_DTL,
9661 				    vml[c], txg);
9662 
9663 			if (error == 0)
9664 				spa_history_log_internal(spa, "detach", tx,
9665 				    "vdev=%s", vml[c]->vdev_path);
9666 		}
9667 	}
9668 	spa->spa_avz_action = AVZ_ACTION_REBUILD;
9669 	vdev_config_dirty(spa->spa_root_vdev);
9670 	spa->spa_config_splitting = NULL;
9671 	nvlist_free(nvl);
9672 	if (error == 0)
9673 		dmu_tx_commit(tx);
9674 	(void) spa_vdev_exit(spa, NULL, txg, 0);
9675 
9676 	/*
9677 	 * txg is synced, free vdevs.
9678 	 */
9679 	spa_config_enter(spa, SCL_STATE_ALL, spa, RW_WRITER);
9680 	for (c = 0; c < children; c++) {
9681 		if (vml[c] != NULL && vml[c]->vdev_ops != &vdev_indirect_ops) {
9682 			ASSERT0P(vml[c]->vdev_dtl_sm);
9683 			vdev_free(vml[c]);
9684 		}
9685 	}
9686 	spa_config_exit(spa, SCL_STATE_ALL, spa);
9687 
9688 	if (zio_injection_enabled)
9689 		zio_handle_panic_injection(spa, FTAG, 3);
9690 
9691 	/* split is complete; log a history record */
9692 	spa_history_log_internal(newspa, "split", NULL,
9693 	    "from pool %s", spa_name(spa));
9694 
9695 	newspa->spa_is_splitting = B_FALSE;
9696 	kmem_free(vml, children * sizeof (vdev_t *));
9697 	if (dtl_objs != NULL)
9698 		kmem_free(dtl_objs, nleaves * sizeof (uint64_t));
9699 
9700 	/* if we're not going to mount the filesystems in userland, export */
9701 	if (exp)
9702 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
9703 		    B_FALSE, B_FALSE);
9704 
9705 	return (error);
9706 
9707 out:
9708 	spa_unload(newspa);
9709 	spa_deactivate(newspa);
9710 	spa_remove(newspa);
9711 
9712 	txg = spa_vdev_config_enter(spa);
9713 
9714 	/* re-online all offlined disks */
9715 	for (c = 0; c < children; c++) {
9716 		if (vml[c] != NULL)
9717 			vml[c]->vdev_offline = B_FALSE;
9718 	}
9719 
9720 	/* restart initializing or trimming disks as necessary */
9721 	spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART);
9722 	spa_async_request(spa, SPA_ASYNC_TRIM_RESTART);
9723 	spa_async_request(spa, SPA_ASYNC_AUTOTRIM_RESTART);
9724 
9725 	vdev_reopen(spa->spa_root_vdev);
9726 
9727 	nvlist_free(spa->spa_config_splitting);
9728 	spa->spa_config_splitting = NULL;
9729 	(void) spa_vdev_exit(spa, NULL, txg, error);
9730 
9731 	kmem_free(vml, children * sizeof (vdev_t *));
9732 	if (dtl_objs != NULL)
9733 		kmem_free(dtl_objs, nleaves * sizeof (uint64_t));
9734 
9735 	return (error);
9736 }
9737 
9738 /*
9739  * Find any device that's done replacing, or a vdev marked 'unspare' that's
9740  * currently spared, so we can detach it.
9741  */
9742 static vdev_t *
9743 spa_vdev_resilver_done_hunt(vdev_t *vd)
9744 {
9745 	vdev_t *newvd, *oldvd;
9746 
9747 	for (int c = 0; c < vd->vdev_children; c++) {
9748 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
9749 		if (oldvd != NULL)
9750 			return (oldvd);
9751 	}
9752 
9753 	/*
9754 	 * Check for a completed replacement.  We always consider the first
9755 	 * vdev in the list to be the oldest vdev, and the last one to be
9756 	 * the newest (see spa_vdev_attach() for how that works).  In
9757 	 * the case where the newest vdev is faulted, we will not automatically
9758 	 * remove it after a resilver completes.  This is OK as it will require
9759 	 * user intervention to determine which disk the admin wishes to keep.
9760 	 */
9761 	if (vd->vdev_ops == &vdev_replacing_ops) {
9762 		ASSERT(vd->vdev_children > 1);
9763 
9764 		newvd = vd->vdev_child[vd->vdev_children - 1];
9765 		oldvd = vd->vdev_child[0];
9766 
9767 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
9768 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
9769 		    !vdev_dtl_required(oldvd))
9770 			return (oldvd);
9771 	}
9772 
9773 	/*
9774 	 * Check for a completed resilver with the 'unspare' flag set.
9775 	 * Also potentially update faulted state.
9776 	 */
9777 	if (vd->vdev_ops == &vdev_spare_ops) {
9778 		vdev_t *first = vd->vdev_child[0];
9779 		vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
9780 
9781 		if (last->vdev_unspare) {
9782 			oldvd = first;
9783 			newvd = last;
9784 		} else if (first->vdev_unspare) {
9785 			oldvd = last;
9786 			newvd = first;
9787 		} else {
9788 			oldvd = NULL;
9789 		}
9790 
9791 		if (oldvd != NULL &&
9792 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
9793 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
9794 		    !vdev_dtl_required(oldvd))
9795 			return (oldvd);
9796 
9797 		vdev_propagate_state(vd);
9798 
9799 		/*
9800 		 * If there are more than two spares attached to a disk,
9801 		 * and those spares are not required, then we want to
9802 		 * attempt to free them up now so that they can be used
9803 		 * by other pools.  Once we're back down to a single
9804 		 * disk+spare, we stop removing them.
9805 		 */
9806 		if (vd->vdev_children > 2) {
9807 			newvd = vd->vdev_child[1];
9808 
9809 			if (newvd->vdev_isspare && last->vdev_isspare &&
9810 			    vdev_dtl_empty(last, DTL_MISSING) &&
9811 			    vdev_dtl_empty(last, DTL_OUTAGE) &&
9812 			    !vdev_dtl_required(newvd))
9813 				return (newvd);
9814 		}
9815 	}
9816 
9817 	return (NULL);
9818 }
9819 
9820 static void
9821 spa_vdev_resilver_done(spa_t *spa)
9822 {
9823 	vdev_t *vd, *pvd, *ppvd;
9824 	uint64_t guid, sguid, pguid, ppguid;
9825 
9826 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
9827 
9828 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
9829 		pvd = vd->vdev_parent;
9830 		ppvd = pvd->vdev_parent;
9831 		guid = vd->vdev_guid;
9832 		pguid = pvd->vdev_guid;
9833 		ppguid = ppvd->vdev_guid;
9834 		sguid = 0;
9835 		/*
9836 		 * If we have just finished replacing a hot spared device, then
9837 		 * we need to detach the parent's first child (the original hot
9838 		 * spare) as well.
9839 		 */
9840 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
9841 		    ppvd->vdev_children == 2) {
9842 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
9843 			sguid = ppvd->vdev_child[1]->vdev_guid;
9844 		}
9845 		ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
9846 
9847 		spa_config_exit(spa, SCL_ALL, FTAG);
9848 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
9849 			return;
9850 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
9851 			return;
9852 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
9853 	}
9854 
9855 	spa_config_exit(spa, SCL_ALL, FTAG);
9856 
9857 	/*
9858 	 * If a detach was not performed above replace waiters will not have
9859 	 * been notified.  In which case we must do so now.
9860 	 */
9861 	spa_notify_waiters(spa);
9862 }
9863 
9864 /*
9865  * Update the stored path or FRU for this vdev.
9866  */
9867 static int
9868 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
9869     boolean_t ispath)
9870 {
9871 	vdev_t *vd;
9872 	boolean_t sync = B_FALSE;
9873 
9874 	ASSERT(spa_writeable(spa));
9875 
9876 	spa_vdev_state_enter(spa, SCL_ALL);
9877 
9878 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
9879 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
9880 
9881 	if (!vd->vdev_ops->vdev_op_leaf)
9882 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
9883 
9884 	if (ispath) {
9885 		if (strcmp(value, vd->vdev_path) != 0) {
9886 			spa_strfree(vd->vdev_path);
9887 			vd->vdev_path = spa_strdup(value);
9888 			sync = B_TRUE;
9889 		}
9890 	} else {
9891 		if (vd->vdev_fru == NULL) {
9892 			vd->vdev_fru = spa_strdup(value);
9893 			sync = B_TRUE;
9894 		} else if (strcmp(value, vd->vdev_fru) != 0) {
9895 			spa_strfree(vd->vdev_fru);
9896 			vd->vdev_fru = spa_strdup(value);
9897 			sync = B_TRUE;
9898 		}
9899 	}
9900 
9901 	return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
9902 }
9903 
9904 int
9905 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
9906 {
9907 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
9908 }
9909 
9910 int
9911 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
9912 {
9913 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
9914 }
9915 
9916 /*
9917  * ==========================================================================
9918  * SPA Scanning
9919  * ==========================================================================
9920  */
9921 int
9922 spa_scrub_pause_resume(spa_t *spa, pool_scrub_cmd_t cmd)
9923 {
9924 	ASSERT0(spa_config_held(spa, SCL_ALL, RW_WRITER));
9925 
9926 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
9927 		return (SET_ERROR(EBUSY));
9928 
9929 	return (dsl_scrub_set_pause_resume(spa->spa_dsl_pool, cmd));
9930 }
9931 
9932 int
9933 spa_scan_stop(spa_t *spa)
9934 {
9935 	ASSERT0(spa_config_held(spa, SCL_ALL, RW_WRITER));
9936 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
9937 		return (SET_ERROR(EBUSY));
9938 
9939 	return (dsl_scan_cancel(spa->spa_dsl_pool));
9940 }
9941 
9942 int
9943 spa_scan(spa_t *spa, pool_scan_func_t func, pool_scrub_flags_t flags)
9944 {
9945 	return (spa_scan_range(spa, func, 0, 0, flags));
9946 }
9947 
9948 int
9949 spa_scan_range(spa_t *spa, pool_scan_func_t func, uint64_t txgstart,
9950     uint64_t txgend, pool_scrub_flags_t flags)
9951 {
9952 	dsl_scan_flags_t dsl_flags = 0;
9953 
9954 	ASSERT0(spa_config_held(spa, SCL_ALL, RW_WRITER));
9955 
9956 	if (flags & POOL_SCRUB_THOROUGH)
9957 		dsl_flags |= DSF_SCRUB_THOROUGH;
9958 
9959 	if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
9960 		return (SET_ERROR(ENOTSUP));
9961 
9962 	if (func == POOL_SCAN_RESILVER &&
9963 	    !spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER))
9964 		return (SET_ERROR(ENOTSUP));
9965 
9966 	if (func != POOL_SCAN_SCRUB && (txgstart != 0 || txgend != 0))
9967 		return (SET_ERROR(ENOTSUP));
9968 
9969 	/*
9970 	 * If a resilver was requested, but there is no DTL on a
9971 	 * writeable leaf device, we have nothing to do.
9972 	 */
9973 	if (func == POOL_SCAN_RESILVER &&
9974 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
9975 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
9976 		return (0);
9977 	}
9978 
9979 	if (func == POOL_SCAN_ERRORSCRUB &&
9980 	    !spa_feature_is_enabled(spa, SPA_FEATURE_HEAD_ERRLOG))
9981 		return (SET_ERROR(ENOTSUP));
9982 
9983 	return (dsl_scan(spa->spa_dsl_pool, func, txgstart, txgend, dsl_flags));
9984 }
9985 
9986 /*
9987  * ==========================================================================
9988  * SPA async task processing
9989  * ==========================================================================
9990  */
9991 
9992 static void
9993 spa_async_remove(spa_t *spa, vdev_t *vd, boolean_t by_kernel)
9994 {
9995 	if (vd->vdev_remove_wanted) {
9996 		vd->vdev_remove_wanted = B_FALSE;
9997 		vd->vdev_delayed_close = B_FALSE;
9998 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
9999 
10000 		/*
10001 		 * We want to clear the stats, but we don't want to do a full
10002 		 * vdev_clear() as that will cause us to throw away
10003 		 * degraded/faulted state as well as attempt to reopen the
10004 		 * device, all of which is a waste.
10005 		 */
10006 		vd->vdev_stat.vs_read_errors = 0;
10007 		vd->vdev_stat.vs_write_errors = 0;
10008 		vd->vdev_stat.vs_checksum_errors = 0;
10009 
10010 		vdev_state_dirty(vd->vdev_top);
10011 
10012 		/* Tell userspace that the vdev is gone. */
10013 		zfs_post_remove(spa, vd, by_kernel);
10014 	}
10015 
10016 	for (int c = 0; c < vd->vdev_children; c++)
10017 		spa_async_remove(spa, vd->vdev_child[c], by_kernel);
10018 }
10019 
10020 static void
10021 spa_async_fault_vdev(vdev_t *vd, boolean_t *suspend)
10022 {
10023 	if (vd->vdev_fault_wanted) {
10024 		vdev_state_t newstate = VDEV_STATE_FAULTED;
10025 		vd->vdev_fault_wanted = B_FALSE;
10026 
10027 		/*
10028 		 * If this device has the only valid copy of the data, then
10029 		 * back off and simply mark the vdev as degraded instead.
10030 		 */
10031 		if (!vd->vdev_top->vdev_islog && vd->vdev_aux == NULL &&
10032 		    vdev_dtl_required(vd)) {
10033 			newstate = VDEV_STATE_DEGRADED;
10034 			/* A required disk is missing so suspend the pool */
10035 			*suspend = B_TRUE;
10036 		}
10037 		vdev_set_state(vd, B_TRUE, newstate, VDEV_AUX_ERR_EXCEEDED);
10038 	}
10039 	for (int c = 0; c < vd->vdev_children; c++)
10040 		spa_async_fault_vdev(vd->vdev_child[c], suspend);
10041 }
10042 
10043 static void
10044 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
10045 {
10046 	if (!spa->spa_autoexpand)
10047 		return;
10048 
10049 	for (int c = 0; c < vd->vdev_children; c++) {
10050 		vdev_t *cvd = vd->vdev_child[c];
10051 		spa_async_autoexpand(spa, cvd);
10052 	}
10053 
10054 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
10055 		return;
10056 
10057 	spa_event_notify(vd->vdev_spa, vd, NULL, ESC_ZFS_VDEV_AUTOEXPAND);
10058 }
10059 
10060 static __attribute__((noreturn)) void
10061 spa_async_thread(void *arg)
10062 {
10063 	spa_t *spa = (spa_t *)arg;
10064 	dsl_pool_t *dp = spa->spa_dsl_pool;
10065 	uint32_t tasks;
10066 
10067 	ASSERT(spa->spa_sync_on);
10068 
10069 	mutex_enter(&spa->spa_async_lock);
10070 	tasks = spa->spa_async_tasks;
10071 	spa->spa_async_tasks = 0;
10072 	mutex_exit(&spa->spa_async_lock);
10073 
10074 	/*
10075 	 * See if the config needs to be updated.
10076 	 */
10077 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
10078 		uint64_t old_space, new_space;
10079 
10080 		spa_namespace_enter(FTAG);
10081 		old_space = metaslab_class_get_space(spa_normal_class(spa));
10082 		old_space += metaslab_class_get_space(spa_special_class(spa));
10083 		old_space += metaslab_class_get_space(spa_dedup_class(spa));
10084 		old_space += metaslab_class_get_space(
10085 		    spa_embedded_log_class(spa));
10086 		old_space += metaslab_class_get_space(
10087 		    spa_special_embedded_log_class(spa));
10088 
10089 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
10090 
10091 		new_space = metaslab_class_get_space(spa_normal_class(spa));
10092 		new_space += metaslab_class_get_space(spa_special_class(spa));
10093 		new_space += metaslab_class_get_space(spa_dedup_class(spa));
10094 		new_space += metaslab_class_get_space(
10095 		    spa_embedded_log_class(spa));
10096 		new_space += metaslab_class_get_space(
10097 		    spa_special_embedded_log_class(spa));
10098 		spa_namespace_exit(FTAG);
10099 
10100 		/*
10101 		 * If the pool grew as a result of the config update,
10102 		 * then log an internal history event.
10103 		 */
10104 		if (new_space != old_space) {
10105 			spa_history_log_internal(spa, "vdev online", NULL,
10106 			    "pool '%s' size: %llu(+%llu)",
10107 			    spa_name(spa), (u_longlong_t)new_space,
10108 			    (u_longlong_t)(new_space - old_space));
10109 		}
10110 	}
10111 
10112 	/*
10113 	 * See if any devices need to be marked REMOVED.
10114 	 */
10115 	if (tasks & (SPA_ASYNC_REMOVE | SPA_ASYNC_REMOVE_BY_USER)) {
10116 		boolean_t by_kernel = B_TRUE;
10117 		if (tasks & SPA_ASYNC_REMOVE_BY_USER)
10118 			by_kernel = B_FALSE;
10119 		spa_vdev_state_enter(spa, SCL_NONE);
10120 		spa_async_remove(spa, spa->spa_root_vdev, by_kernel);
10121 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
10122 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i],
10123 			    by_kernel);
10124 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
10125 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i],
10126 			    by_kernel);
10127 		(void) spa_vdev_state_exit(spa, NULL, 0);
10128 	}
10129 
10130 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
10131 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
10132 		spa_async_autoexpand(spa, spa->spa_root_vdev);
10133 		spa_config_exit(spa, SCL_CONFIG, FTAG);
10134 	}
10135 
10136 	/*
10137 	 * See if any devices need to be marked faulted.
10138 	 */
10139 	if (tasks & SPA_ASYNC_FAULT_VDEV) {
10140 		spa_vdev_state_enter(spa, SCL_NONE);
10141 		boolean_t suspend = B_FALSE;
10142 		spa_async_fault_vdev(spa->spa_root_vdev, &suspend);
10143 		(void) spa_vdev_state_exit(spa, NULL, 0);
10144 		if (suspend)
10145 			zio_suspend(spa, NULL, ZIO_SUSPEND_IOERR);
10146 	}
10147 
10148 	/*
10149 	 * If any devices are done replacing, detach them.
10150 	 */
10151 	if (tasks & SPA_ASYNC_RESILVER_DONE ||
10152 	    tasks & SPA_ASYNC_REBUILD_DONE ||
10153 	    tasks & SPA_ASYNC_DETACH_SPARE) {
10154 		spa_vdev_resilver_done(spa);
10155 	}
10156 
10157 	/*
10158 	 * Kick off a resilver.
10159 	 */
10160 	if (tasks & SPA_ASYNC_RESILVER &&
10161 	    !vdev_rebuild_active(spa->spa_root_vdev) &&
10162 	    (!dsl_scan_resilvering(dp) ||
10163 	    !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_RESILVER_DEFER)))
10164 		dsl_scan_restart_resilver(dp, 0);
10165 
10166 	if (tasks & SPA_ASYNC_INITIALIZE_RESTART) {
10167 		spa_namespace_enter(FTAG);
10168 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
10169 		vdev_initialize_restart(spa->spa_root_vdev);
10170 		spa_config_exit(spa, SCL_CONFIG, FTAG);
10171 		spa_namespace_exit(FTAG);
10172 	}
10173 
10174 	if (tasks & SPA_ASYNC_TRIM_RESTART) {
10175 		spa_namespace_enter(FTAG);
10176 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
10177 		vdev_trim_restart(spa->spa_root_vdev);
10178 		spa_config_exit(spa, SCL_CONFIG, FTAG);
10179 		spa_namespace_exit(FTAG);
10180 	}
10181 
10182 	if (tasks & SPA_ASYNC_AUTOTRIM_RESTART) {
10183 		spa_namespace_enter(FTAG);
10184 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
10185 		vdev_autotrim_restart(spa);
10186 		spa_config_exit(spa, SCL_CONFIG, FTAG);
10187 		spa_namespace_exit(FTAG);
10188 	}
10189 
10190 	/*
10191 	 * Kick off L2 cache whole device TRIM.
10192 	 */
10193 	if (tasks & SPA_ASYNC_L2CACHE_TRIM) {
10194 		spa_namespace_enter(FTAG);
10195 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
10196 		vdev_trim_l2arc(spa);
10197 		spa_config_exit(spa, SCL_CONFIG, FTAG);
10198 		spa_namespace_exit(FTAG);
10199 	}
10200 
10201 	/*
10202 	 * Kick off L2 cache rebuilding.
10203 	 */
10204 	if (tasks & SPA_ASYNC_L2CACHE_REBUILD) {
10205 		spa_namespace_enter(FTAG);
10206 		spa_config_enter(spa, SCL_L2ARC, FTAG, RW_READER);
10207 		l2arc_spa_rebuild_start(spa);
10208 		spa_config_exit(spa, SCL_L2ARC, FTAG);
10209 		spa_namespace_exit(FTAG);
10210 	}
10211 
10212 	/*
10213 	 * Finish off snapshots whose deferred destruction was waiting on
10214 	 * something that has since let go of them.  The destroy is a sync
10215 	 * task, which a suspended pool would never come back from, and the
10216 	 * export path waits on this thread, so leave the mark where it is
10217 	 * and pick it up on the next request or at the next import.
10218 	 */
10219 	if ((tasks & SPA_ASYNC_DEFER_DESTROY) && spa_writeable(spa) &&
10220 	    !spa_suspended(spa))
10221 		dsl_destroy_snapshot_deferred(spa_name(spa));
10222 
10223 	/*
10224 	 * Let the world know that we're done.
10225 	 */
10226 	mutex_enter(&spa->spa_async_lock);
10227 	spa->spa_async_thread = NULL;
10228 	cv_broadcast(&spa->spa_async_cv);
10229 	mutex_exit(&spa->spa_async_lock);
10230 	thread_exit();
10231 }
10232 
10233 void
10234 spa_async_suspend(spa_t *spa)
10235 {
10236 	mutex_enter(&spa->spa_async_lock);
10237 	spa->spa_async_suspended++;
10238 	while (spa->spa_async_thread != NULL)
10239 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
10240 	mutex_exit(&spa->spa_async_lock);
10241 
10242 	spa_vdev_remove_suspend(spa);
10243 
10244 	zthr_t *condense_thread = spa->spa_condense_zthr;
10245 	if (condense_thread != NULL)
10246 		zthr_cancel(condense_thread);
10247 
10248 	zthr_t *raidz_expand_thread = spa->spa_raidz_expand_zthr;
10249 	if (raidz_expand_thread != NULL)
10250 		zthr_cancel(raidz_expand_thread);
10251 
10252 	zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
10253 	if (discard_thread != NULL)
10254 		zthr_cancel(discard_thread);
10255 
10256 	zthr_t *ll_delete_thread = spa->spa_livelist_delete_zthr;
10257 	if (ll_delete_thread != NULL)
10258 		zthr_cancel(ll_delete_thread);
10259 
10260 	zthr_t *ll_condense_thread = spa->spa_livelist_condense_zthr;
10261 	if (ll_condense_thread != NULL)
10262 		zthr_cancel(ll_condense_thread);
10263 }
10264 
10265 void
10266 spa_async_resume(spa_t *spa)
10267 {
10268 	mutex_enter(&spa->spa_async_lock);
10269 	ASSERT(spa->spa_async_suspended != 0);
10270 	spa->spa_async_suspended--;
10271 	mutex_exit(&spa->spa_async_lock);
10272 	spa_restart_removal(spa);
10273 
10274 	zthr_t *condense_thread = spa->spa_condense_zthr;
10275 	if (condense_thread != NULL)
10276 		zthr_resume(condense_thread);
10277 
10278 	zthr_t *raidz_expand_thread = spa->spa_raidz_expand_zthr;
10279 	if (raidz_expand_thread != NULL)
10280 		zthr_resume(raidz_expand_thread);
10281 
10282 	zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
10283 	if (discard_thread != NULL)
10284 		zthr_resume(discard_thread);
10285 
10286 	zthr_t *ll_delete_thread = spa->spa_livelist_delete_zthr;
10287 	if (ll_delete_thread != NULL)
10288 		zthr_resume(ll_delete_thread);
10289 
10290 	zthr_t *ll_condense_thread = spa->spa_livelist_condense_zthr;
10291 	if (ll_condense_thread != NULL)
10292 		zthr_resume(ll_condense_thread);
10293 }
10294 
10295 static boolean_t
10296 spa_async_tasks_pending(spa_t *spa)
10297 {
10298 	uint_t non_config_tasks;
10299 	uint_t config_task;
10300 	boolean_t config_task_suspended;
10301 
10302 	non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
10303 	config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
10304 	if (spa->spa_ccw_fail_time == 0) {
10305 		config_task_suspended = B_FALSE;
10306 	} else {
10307 		config_task_suspended =
10308 		    (gethrtime() - spa->spa_ccw_fail_time) <
10309 		    ((hrtime_t)zfs_ccw_retry_interval * NANOSEC);
10310 	}
10311 
10312 	return (non_config_tasks || (config_task && !config_task_suspended));
10313 }
10314 
10315 static void
10316 spa_async_dispatch(spa_t *spa)
10317 {
10318 	mutex_enter(&spa->spa_async_lock);
10319 	if (spa_async_tasks_pending(spa) &&
10320 	    !spa->spa_async_suspended &&
10321 	    spa->spa_async_thread == NULL)
10322 		spa->spa_async_thread = thread_create(NULL, 0,
10323 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
10324 	mutex_exit(&spa->spa_async_lock);
10325 }
10326 
10327 void
10328 spa_async_request(spa_t *spa, int task)
10329 {
10330 	zfs_dbgmsg("spa=%s async request task=%u", spa_load_name(spa), task);
10331 	mutex_enter(&spa->spa_async_lock);
10332 	spa->spa_async_tasks |= task;
10333 	mutex_exit(&spa->spa_async_lock);
10334 }
10335 
10336 int
10337 spa_async_tasks(spa_t *spa)
10338 {
10339 	return (spa->spa_async_tasks);
10340 }
10341 
10342 /*
10343  * ==========================================================================
10344  * SPA syncing routines
10345  * ==========================================================================
10346  */
10347 
10348 
10349 static int
10350 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
10351     dmu_tx_t *tx)
10352 {
10353 	bpobj_t *bpo = arg;
10354 	bpobj_enqueue(bpo, bp, bp_freed, tx);
10355 	return (0);
10356 }
10357 
10358 int
10359 bpobj_enqueue_alloc_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
10360 {
10361 	return (bpobj_enqueue_cb(arg, bp, B_FALSE, tx));
10362 }
10363 
10364 int
10365 bpobj_enqueue_free_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
10366 {
10367 	return (bpobj_enqueue_cb(arg, bp, B_TRUE, tx));
10368 }
10369 
10370 static int
10371 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
10372 {
10373 	zio_t *pio = arg;
10374 
10375 	zio_nowait(zio_free_sync(pio, pio->io_spa, dmu_tx_get_txg(tx), bp,
10376 	    pio->io_flags));
10377 	return (0);
10378 }
10379 
10380 static int
10381 bpobj_spa_free_sync_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
10382     dmu_tx_t *tx)
10383 {
10384 	ASSERT(!bp_freed);
10385 	return (spa_free_sync_cb(arg, bp, tx));
10386 }
10387 
10388 /*
10389  * Note: this simple function is not inlined to make it easier to dtrace the
10390  * amount of time spent syncing frees.
10391  */
10392 static void
10393 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
10394 {
10395 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
10396 	bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
10397 	VERIFY0(zio_wait(zio));
10398 }
10399 
10400 /*
10401  * Note: this simple function is not inlined to make it easier to dtrace the
10402  * amount of time spent syncing deferred frees.
10403  */
10404 static void
10405 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
10406 {
10407 	if (spa_sync_pass(spa) != 1)
10408 		return;
10409 
10410 	/*
10411 	 * Note:
10412 	 * If the log space map feature is active, we stop deferring
10413 	 * frees to the next TXG and therefore running this function
10414 	 * would be considered a no-op as spa_deferred_bpobj should
10415 	 * not have any entries.
10416 	 *
10417 	 * That said we run this function anyway (instead of returning
10418 	 * immediately) for the edge-case scenario where we just
10419 	 * activated the log space map feature in this TXG but we have
10420 	 * deferred frees from the previous TXG.
10421 	 */
10422 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
10423 	VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
10424 	    bpobj_spa_free_sync_cb, zio, tx), ==, 0);
10425 	VERIFY0(zio_wait(zio));
10426 }
10427 
10428 static void
10429 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
10430 {
10431 	char *packed = NULL;
10432 	size_t bufsize;
10433 	size_t nvsize = 0;
10434 	dmu_buf_t *db;
10435 
10436 	VERIFY0(nvlist_size(nv, &nvsize, NV_ENCODE_XDR));
10437 
10438 	/*
10439 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
10440 	 * information.  This avoids the dmu_buf_will_dirty() path and
10441 	 * saves us a pre-read to get data we don't actually care about.
10442 	 */
10443 	bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
10444 	packed = vmem_alloc(bufsize, KM_SLEEP);
10445 
10446 	VERIFY0(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
10447 	    KM_SLEEP));
10448 	memset(packed + nvsize, 0, bufsize - nvsize);
10449 
10450 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx,
10451 	    DMU_READ_NO_PREFETCH);
10452 
10453 	vmem_free(packed, bufsize);
10454 
10455 	VERIFY0(dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
10456 	dmu_buf_will_dirty(db, tx);
10457 	*(uint64_t *)db->db_data = nvsize;
10458 	dmu_buf_rele(db, FTAG);
10459 }
10460 
10461 static void
10462 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
10463     const char *config, const char *entry)
10464 {
10465 	nvlist_t *nvroot;
10466 	nvlist_t **list;
10467 	int i;
10468 
10469 	if (!sav->sav_sync)
10470 		return;
10471 
10472 	/*
10473 	 * Update the MOS nvlist describing the list of available devices.
10474 	 * spa_validate_aux() will have already made sure this nvlist is
10475 	 * valid and the vdevs are labeled appropriately.
10476 	 */
10477 	if (sav->sav_object == 0) {
10478 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
10479 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
10480 		    sizeof (uint64_t), tx);
10481 		VERIFY(zap_update(spa->spa_meta_objset,
10482 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
10483 		    &sav->sav_object, tx) == 0);
10484 	}
10485 
10486 	nvroot = fnvlist_alloc();
10487 	if (sav->sav_count == 0) {
10488 		fnvlist_add_nvlist_array(nvroot, config,
10489 		    (const nvlist_t * const *)NULL, 0);
10490 	} else {
10491 		list = kmem_alloc(sav->sav_count*sizeof (void *), KM_SLEEP);
10492 		for (i = 0; i < sav->sav_count; i++)
10493 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
10494 			    B_FALSE, VDEV_CONFIG_L2CACHE);
10495 		fnvlist_add_nvlist_array(nvroot, config,
10496 		    (const nvlist_t * const *)list, sav->sav_count);
10497 		for (i = 0; i < sav->sav_count; i++)
10498 			nvlist_free(list[i]);
10499 		kmem_free(list, sav->sav_count * sizeof (void *));
10500 	}
10501 
10502 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
10503 	nvlist_free(nvroot);
10504 
10505 	sav->sav_sync = B_FALSE;
10506 }
10507 
10508 /*
10509  * Rebuild spa's all-vdev ZAP from the vdev ZAPs indicated in each vdev_t.
10510  * The all-vdev ZAP must be empty.
10511  */
10512 static void
10513 spa_avz_build(vdev_t *vd, uint64_t avz, dmu_tx_t *tx)
10514 {
10515 	spa_t *spa = vd->vdev_spa;
10516 
10517 	if (vd->vdev_root_zap != 0 &&
10518 	    spa_feature_is_active(spa, SPA_FEATURE_AVZ_V2)) {
10519 		VERIFY0(zap_add_int(spa->spa_meta_objset, avz,
10520 		    vd->vdev_root_zap, tx));
10521 	}
10522 	if (vd->vdev_top_zap != 0) {
10523 		VERIFY0(zap_add_int(spa->spa_meta_objset, avz,
10524 		    vd->vdev_top_zap, tx));
10525 	}
10526 	if (vd->vdev_leaf_zap != 0) {
10527 		VERIFY0(zap_add_int(spa->spa_meta_objset, avz,
10528 		    vd->vdev_leaf_zap, tx));
10529 	}
10530 	for (uint64_t i = 0; i < vd->vdev_children; i++) {
10531 		spa_avz_build(vd->vdev_child[i], avz, tx);
10532 	}
10533 }
10534 
10535 static void
10536 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
10537 {
10538 	nvlist_t *config;
10539 
10540 	/*
10541 	 * If the pool is being imported from a pre-per-vdev-ZAP version of ZFS,
10542 	 * its config may not be dirty but we still need to build per-vdev ZAPs.
10543 	 * Similarly, if the pool is being assembled (e.g. after a split), we
10544 	 * need to rebuild the AVZ although the config may not be dirty.
10545 	 */
10546 	if (list_is_empty(&spa->spa_config_dirty_list) &&
10547 	    spa->spa_avz_action == AVZ_ACTION_NONE)
10548 		return;
10549 
10550 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
10551 
10552 	ASSERT(spa->spa_avz_action == AVZ_ACTION_NONE ||
10553 	    spa->spa_avz_action == AVZ_ACTION_INITIALIZE ||
10554 	    spa->spa_all_vdev_zaps != 0);
10555 
10556 	if (spa->spa_avz_action == AVZ_ACTION_REBUILD) {
10557 		/* Make and build the new AVZ */
10558 		uint64_t new_avz = zap_create(spa->spa_meta_objset,
10559 		    DMU_OTN_ZAP_METADATA, DMU_OT_NONE, 0, tx);
10560 		spa_avz_build(spa->spa_root_vdev, new_avz, tx);
10561 
10562 		/* Diff old AVZ with new one */
10563 		zap_cursor_t zc;
10564 		zap_attribute_t *za = zap_attribute_alloc();
10565 
10566 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
10567 		    spa->spa_all_vdev_zaps);
10568 		    zap_cursor_retrieve(&zc, za) == 0;
10569 		    zap_cursor_advance(&zc)) {
10570 			uint64_t vdzap = za->za_first_integer;
10571 			if (zap_lookup_int(spa->spa_meta_objset, new_avz,
10572 			    vdzap) == ENOENT) {
10573 				/*
10574 				 * ZAP is listed in old AVZ but not in new one;
10575 				 * destroy it
10576 				 */
10577 				VERIFY0(zap_destroy(spa->spa_meta_objset, vdzap,
10578 				    tx));
10579 			}
10580 		}
10581 
10582 		zap_cursor_fini(&zc);
10583 		zap_attribute_free(za);
10584 
10585 		/* Destroy the old AVZ */
10586 		VERIFY0(zap_destroy(spa->spa_meta_objset,
10587 		    spa->spa_all_vdev_zaps, tx));
10588 
10589 		/* Replace the old AVZ in the dir obj with the new one */
10590 		VERIFY0(zap_update(spa->spa_meta_objset,
10591 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_VDEV_ZAP_MAP,
10592 		    sizeof (new_avz), 1, &new_avz, tx));
10593 
10594 		spa->spa_all_vdev_zaps = new_avz;
10595 	} else if (spa->spa_avz_action == AVZ_ACTION_DESTROY) {
10596 		zap_cursor_t zc;
10597 		zap_attribute_t *za = zap_attribute_alloc();
10598 
10599 		/* Walk through the AVZ and destroy all listed ZAPs */
10600 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
10601 		    spa->spa_all_vdev_zaps);
10602 		    zap_cursor_retrieve(&zc, za) == 0;
10603 		    zap_cursor_advance(&zc)) {
10604 			uint64_t zap = za->za_first_integer;
10605 			VERIFY0(zap_destroy(spa->spa_meta_objset, zap, tx));
10606 		}
10607 
10608 		zap_cursor_fini(&zc);
10609 		zap_attribute_free(za);
10610 
10611 		/* Destroy and unlink the AVZ itself */
10612 		VERIFY0(zap_destroy(spa->spa_meta_objset,
10613 		    spa->spa_all_vdev_zaps, tx));
10614 		VERIFY0(zap_remove(spa->spa_meta_objset,
10615 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_VDEV_ZAP_MAP, tx));
10616 		spa->spa_all_vdev_zaps = 0;
10617 	}
10618 
10619 	if (spa->spa_all_vdev_zaps == 0) {
10620 		spa->spa_all_vdev_zaps = zap_create_link(spa->spa_meta_objset,
10621 		    DMU_OTN_ZAP_METADATA, DMU_POOL_DIRECTORY_OBJECT,
10622 		    DMU_POOL_VDEV_ZAP_MAP, tx);
10623 	}
10624 	spa->spa_avz_action = AVZ_ACTION_NONE;
10625 
10626 	/* Create ZAPs for vdevs that don't have them. */
10627 	vdev_construct_zaps(spa->spa_root_vdev, tx);
10628 
10629 	config = spa_config_generate(spa, spa->spa_root_vdev,
10630 	    dmu_tx_get_txg(tx), B_FALSE);
10631 
10632 	/*
10633 	 * If we're upgrading the spa version then make sure that
10634 	 * the config object gets updated with the correct version.
10635 	 */
10636 	if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
10637 		fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
10638 		    spa->spa_uberblock.ub_version);
10639 
10640 	spa_config_exit(spa, SCL_STATE, FTAG);
10641 
10642 	nvlist_free(spa->spa_config_syncing);
10643 	spa->spa_config_syncing = config;
10644 
10645 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
10646 }
10647 
10648 static void
10649 spa_sync_version(void *arg, dmu_tx_t *tx)
10650 {
10651 	uint64_t *versionp = arg;
10652 	uint64_t version = *versionp;
10653 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
10654 
10655 	/*
10656 	 * Setting the version is special cased when first creating the pool.
10657 	 */
10658 	ASSERT(tx->tx_txg != TXG_INITIAL);
10659 
10660 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
10661 	ASSERT(version >= spa_version(spa));
10662 
10663 	spa->spa_uberblock.ub_version = version;
10664 	vdev_config_dirty(spa->spa_root_vdev);
10665 	spa_history_log_internal(spa, "set", tx, "version=%lld",
10666 	    (longlong_t)version);
10667 }
10668 
10669 /*
10670  * Set zpool properties.
10671  */
10672 static void
10673 spa_sync_props(void *arg, dmu_tx_t *tx)
10674 {
10675 	nvlist_t *nvp = arg;
10676 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
10677 	objset_t *mos = spa->spa_meta_objset;
10678 	nvpair_t *elem = NULL;
10679 
10680 	mutex_enter(&spa->spa_props_lock);
10681 
10682 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
10683 		uint64_t intval;
10684 		const char *strval, *fname;
10685 		zpool_prop_t prop;
10686 		const char *propname;
10687 		const char *elemname = nvpair_name(elem);
10688 		zprop_type_t proptype;
10689 		spa_feature_t fid;
10690 
10691 		switch (prop = zpool_name_to_prop(elemname)) {
10692 		case ZPOOL_PROP_VERSION:
10693 			intval = fnvpair_value_uint64(elem);
10694 			/*
10695 			 * The version is synced separately before other
10696 			 * properties and should be correct by now.
10697 			 */
10698 			ASSERT3U(spa_version(spa), >=, intval);
10699 			break;
10700 
10701 		case ZPOOL_PROP_ALTROOT:
10702 			/*
10703 			 * 'altroot' is a non-persistent property. It should
10704 			 * have been set temporarily at creation or import time.
10705 			 */
10706 			ASSERT(spa->spa_root != NULL);
10707 			break;
10708 
10709 		case ZPOOL_PROP_READONLY:
10710 		case ZPOOL_PROP_CACHEFILE:
10711 			/*
10712 			 * 'readonly' and 'cachefile' are also non-persistent
10713 			 * properties.
10714 			 */
10715 			break;
10716 		case ZPOOL_PROP_COMMENT:
10717 			strval = fnvpair_value_string(elem);
10718 			if (spa->spa_comment != NULL)
10719 				spa_strfree(spa->spa_comment);
10720 			spa->spa_comment = spa_strdup(strval);
10721 			/*
10722 			 * We need to dirty the configuration on all the vdevs
10723 			 * so that their labels get updated.  We also need to
10724 			 * update the cache file to keep it in sync with the
10725 			 * MOS version. It's unnecessary to do this for pool
10726 			 * creation since the vdev's configuration has already
10727 			 * been dirtied.
10728 			 */
10729 			if (tx->tx_txg != TXG_INITIAL) {
10730 				vdev_config_dirty(spa->spa_root_vdev);
10731 				spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
10732 			}
10733 			spa_history_log_internal(spa, "set", tx,
10734 			    "%s=%s", elemname, strval);
10735 			break;
10736 		case ZPOOL_PROP_COMPATIBILITY:
10737 			strval = fnvpair_value_string(elem);
10738 			if (spa->spa_compatibility != NULL)
10739 				spa_strfree(spa->spa_compatibility);
10740 			spa->spa_compatibility = spa_strdup(strval);
10741 			/*
10742 			 * Dirty the configuration on vdevs as above.
10743 			 */
10744 			if (tx->tx_txg != TXG_INITIAL) {
10745 				vdev_config_dirty(spa->spa_root_vdev);
10746 				spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
10747 			}
10748 
10749 			spa_history_log_internal(spa, "set", tx,
10750 			    "%s=%s", nvpair_name(elem), strval);
10751 			break;
10752 
10753 		case ZPOOL_PROP_INVAL:
10754 			if (zpool_prop_feature(elemname)) {
10755 				fname = strchr(elemname, '@') + 1;
10756 				VERIFY0(zfeature_lookup_name(fname, &fid));
10757 
10758 				spa_feature_enable(spa, fid, tx);
10759 				spa_history_log_internal(spa, "set", tx,
10760 				    "%s=enabled", elemname);
10761 				break;
10762 			} else if (!zfs_prop_user(elemname)) {
10763 				ASSERT(zpool_prop_feature(elemname));
10764 				break;
10765 			}
10766 			zfs_fallthrough;
10767 		default:
10768 			/*
10769 			 * Set pool property values in the poolprops mos object.
10770 			 */
10771 			if (spa->spa_pool_props_object == 0) {
10772 				spa->spa_pool_props_object =
10773 				    zap_create_link(mos, DMU_OT_POOL_PROPS,
10774 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
10775 				    tx);
10776 			}
10777 
10778 			/* normalize the property name */
10779 			if (prop == ZPOOL_PROP_INVAL) {
10780 				propname = elemname;
10781 				proptype = PROP_TYPE_STRING;
10782 			} else {
10783 				propname = zpool_prop_to_name(prop);
10784 				proptype = zpool_prop_get_type(prop);
10785 			}
10786 
10787 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
10788 				ASSERT(proptype == PROP_TYPE_STRING);
10789 				strval = fnvpair_value_string(elem);
10790 				if (strlen(strval) == 0) {
10791 					/* remove the property if value == "" */
10792 					(void) zap_remove(mos,
10793 					    spa->spa_pool_props_object,
10794 					    propname, tx);
10795 				} else {
10796 					VERIFY0(zap_update(mos,
10797 					    spa->spa_pool_props_object,
10798 					    propname, 1, strlen(strval) + 1,
10799 					    strval, tx));
10800 				}
10801 				spa_history_log_internal(spa, "set", tx,
10802 				    "%s=%s", elemname, strval);
10803 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
10804 				intval = fnvpair_value_uint64(elem);
10805 
10806 				if (proptype == PROP_TYPE_INDEX) {
10807 					const char *unused;
10808 					VERIFY0(zpool_prop_index_to_string(
10809 					    prop, intval, &unused));
10810 				}
10811 				VERIFY0(zap_update(mos,
10812 				    spa->spa_pool_props_object, propname,
10813 				    8, 1, &intval, tx));
10814 				spa_history_log_internal(spa, "set", tx,
10815 				    "%s=%lld", elemname,
10816 				    (longlong_t)intval);
10817 
10818 				switch (prop) {
10819 				case ZPOOL_PROP_DELEGATION:
10820 					spa->spa_delegation = intval;
10821 					break;
10822 				case ZPOOL_PROP_BOOTFS:
10823 					spa->spa_bootfs = intval;
10824 					break;
10825 				case ZPOOL_PROP_FAILUREMODE:
10826 					spa->spa_failmode = intval;
10827 					break;
10828 				case ZPOOL_PROP_AUTOTRIM:
10829 					spa->spa_autotrim = intval;
10830 					spa_async_request(spa,
10831 					    SPA_ASYNC_AUTOTRIM_RESTART);
10832 					break;
10833 				case ZPOOL_PROP_AUTOEXPAND:
10834 					spa->spa_autoexpand = intval;
10835 					if (tx->tx_txg != TXG_INITIAL)
10836 						spa_async_request(spa,
10837 						    SPA_ASYNC_AUTOEXPAND);
10838 					break;
10839 				case ZPOOL_PROP_MULTIHOST:
10840 					spa->spa_multihost = intval;
10841 					break;
10842 				case ZPOOL_PROP_DEDUP_TABLE_QUOTA:
10843 					spa->spa_dedup_table_quota = intval;
10844 					break;
10845 				default:
10846 					break;
10847 				}
10848 			} else {
10849 				ASSERT(0); /* not allowed */
10850 			}
10851 		}
10852 
10853 	}
10854 
10855 	mutex_exit(&spa->spa_props_lock);
10856 }
10857 
10858 /*
10859  * Perform one-time upgrade on-disk changes.  spa_version() does not
10860  * reflect the new version this txg, so there must be no changes this
10861  * txg to anything that the upgrade code depends on after it executes.
10862  * Therefore this must be called after dsl_pool_sync() does the sync
10863  * tasks.
10864  */
10865 static void
10866 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
10867 {
10868 	if (spa_sync_pass(spa) != 1)
10869 		return;
10870 
10871 	uint64_t oldver = spa->spa_ubsync.ub_version;
10872 	uint64_t newver = spa->spa_uberblock.ub_version;
10873 
10874 	/*
10875 	 * These upgrades change DSL namespace, so they need the
10876 	 * writer lock.
10877 	 */
10878 	boolean_t need_origin = oldver < SPA_VERSION_ORIGIN &&
10879 	    newver >= SPA_VERSION_ORIGIN;
10880 	boolean_t need_clones = oldver < SPA_VERSION_NEXT_CLONES &&
10881 	    newver >= SPA_VERSION_NEXT_CLONES;
10882 	boolean_t need_dir_clones = oldver < SPA_VERSION_DIR_CLONES &&
10883 	    newver >= SPA_VERSION_DIR_CLONES;
10884 
10885 	if (need_origin || need_clones || need_dir_clones) {
10886 		dsl_pool_t *dp = spa->spa_dsl_pool;
10887 
10888 		rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
10889 
10890 		if (need_origin) {
10891 			dsl_pool_create_origin(dp, tx);
10892 
10893 			/* Keeping the origin open increases spa_minref */
10894 			spa->spa_minref += 3;
10895 		}
10896 
10897 		if (need_clones) {
10898 			dsl_pool_upgrade_clones(dp, tx);
10899 		}
10900 
10901 		if (need_dir_clones) {
10902 			dsl_pool_upgrade_dir_clones(dp, tx);
10903 
10904 			/* Keeping the freedir open increases spa_minref */
10905 			spa->spa_minref += 3;
10906 		}
10907 
10908 		rrw_exit(&dp->dp_config_rwlock, FTAG);
10909 	}
10910 
10911 	/* Remaining upgrades do not need dp_config_rwlock */
10912 
10913 	if (oldver < SPA_VERSION_FEATURES && newver >= SPA_VERSION_FEATURES) {
10914 		spa_feature_create_zap_objects(spa, tx);
10915 	}
10916 
10917 	/*
10918 	 * LZ4_COMPRESS feature's behaviour was changed to activate_on_enable
10919 	 * when possibility to use lz4 compression for metadata was added
10920 	 * Old pools that have this feature enabled must be upgraded to have
10921 	 * this feature active
10922 	 */
10923 	if (newver >= SPA_VERSION_FEATURES) {
10924 		boolean_t lz4_en = spa_feature_is_enabled(spa,
10925 		    SPA_FEATURE_LZ4_COMPRESS);
10926 		boolean_t lz4_ac = spa_feature_is_active(spa,
10927 		    SPA_FEATURE_LZ4_COMPRESS);
10928 
10929 		if (lz4_en && !lz4_ac)
10930 			spa_feature_incr(spa, SPA_FEATURE_LZ4_COMPRESS, tx);
10931 	}
10932 
10933 	/*
10934 	 * If we haven't written the salt, do so now.  Note that the
10935 	 * feature may not be activated yet, but that's fine since
10936 	 * the presence of this ZAP entry is backwards compatible.
10937 	 */
10938 	if (zap_contains(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
10939 	    DMU_POOL_CHECKSUM_SALT) == ENOENT) {
10940 		VERIFY0(zap_add(spa->spa_meta_objset,
10941 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CHECKSUM_SALT, 1,
10942 		    sizeof (spa->spa_cksum_salt.zcs_bytes),
10943 		    spa->spa_cksum_salt.zcs_bytes, tx));
10944 	}
10945 }
10946 
10947 static void
10948 vdev_indirect_state_sync_verify(vdev_t *vd)
10949 {
10950 	vdev_indirect_mapping_t *vim __maybe_unused = vd->vdev_indirect_mapping;
10951 	vdev_indirect_births_t *vib __maybe_unused = vd->vdev_indirect_births;
10952 
10953 	if (vd->vdev_ops == &vdev_indirect_ops) {
10954 		ASSERT(vim != NULL);
10955 		ASSERT(vib != NULL);
10956 	}
10957 
10958 	uint64_t obsolete_sm_object = 0;
10959 	ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
10960 	if (obsolete_sm_object != 0) {
10961 		ASSERT(vd->vdev_obsolete_sm != NULL);
10962 		ASSERT(vd->vdev_removing ||
10963 		    vd->vdev_ops == &vdev_indirect_ops);
10964 		ASSERT(vdev_indirect_mapping_num_entries(vim) > 0);
10965 		ASSERT(vdev_indirect_mapping_bytes_mapped(vim) > 0);
10966 		ASSERT3U(obsolete_sm_object, ==,
10967 		    space_map_object(vd->vdev_obsolete_sm));
10968 		ASSERT3U(vdev_indirect_mapping_bytes_mapped(vim), >=,
10969 		    space_map_allocated(vd->vdev_obsolete_sm));
10970 	}
10971 	ASSERT(vd->vdev_obsolete_segments != NULL);
10972 
10973 	/*
10974 	 * Since frees / remaps to an indirect vdev can only
10975 	 * happen in syncing context, the obsolete segments
10976 	 * tree must be empty when we start syncing.
10977 	 */
10978 	ASSERT0(zfs_range_tree_space(vd->vdev_obsolete_segments));
10979 }
10980 
10981 /*
10982  * Set the top-level vdev's max queue depth. Evaluate each top-level's
10983  * async write queue depth in case it changed. The max queue depth will
10984  * not change in the middle of syncing out this txg.
10985  */
10986 static void
10987 spa_sync_adjust_vdev_max_queue_depth(spa_t *spa)
10988 {
10989 	ASSERT(spa_writeable(spa));
10990 
10991 	metaslab_class_balance(spa_normal_class(spa), B_TRUE);
10992 	metaslab_class_balance(spa_special_class(spa), B_TRUE);
10993 	metaslab_class_balance(spa_dedup_class(spa), B_TRUE);
10994 }
10995 
10996 static void
10997 spa_sync_condense_indirect(spa_t *spa, dmu_tx_t *tx)
10998 {
10999 	ASSERT(spa_writeable(spa));
11000 
11001 	vdev_t *rvd = spa->spa_root_vdev;
11002 	for (int c = 0; c < rvd->vdev_children; c++) {
11003 		vdev_t *vd = rvd->vdev_child[c];
11004 		vdev_indirect_state_sync_verify(vd);
11005 
11006 		if (vdev_indirect_should_condense(vd)) {
11007 			spa_condense_indirect_start_sync(vd, tx);
11008 			break;
11009 		}
11010 	}
11011 }
11012 
11013 static void
11014 spa_sync_iterate_to_convergence(spa_t *spa, dmu_tx_t *tx)
11015 {
11016 	objset_t *mos = spa->spa_meta_objset;
11017 	dsl_pool_t *dp = spa->spa_dsl_pool;
11018 	uint64_t txg = tx->tx_txg;
11019 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
11020 
11021 	do {
11022 		int pass = ++spa->spa_sync_pass;
11023 
11024 		spa_sync_config_object(spa, tx);
11025 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
11026 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
11027 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
11028 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
11029 		spa_errlog_sync(spa, txg);
11030 		dsl_pool_sync(dp, txg);
11031 
11032 		if (pass < zfs_sync_pass_deferred_free ||
11033 		    spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP)) {
11034 			/*
11035 			 * If the log space map feature is active we don't
11036 			 * care about deferred frees and the deferred bpobj
11037 			 * as the log space map should effectively have the
11038 			 * same results (i.e. appending only to one object).
11039 			 */
11040 			spa_sync_frees(spa, free_bpl, tx);
11041 		} else {
11042 			/*
11043 			 * We can not defer frees in pass 1, because
11044 			 * we sync the deferred frees later in pass 1.
11045 			 */
11046 			ASSERT3U(pass, >, 1);
11047 			bplist_iterate(free_bpl, bpobj_enqueue_alloc_cb,
11048 			    &spa->spa_deferred_bpobj, tx);
11049 		}
11050 
11051 		brt_sync(spa, txg);
11052 		ddt_sync(spa, txg);
11053 		dsl_scan_sync(dp, tx);
11054 		dsl_errorscrub_sync(dp, tx);
11055 		svr_sync(spa, tx);
11056 		spa_sync_upgrades(spa, tx);
11057 
11058 		spa_flush_metaslabs(spa, tx);
11059 
11060 		vdev_t *vd = NULL;
11061 		while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
11062 		    != NULL)
11063 			vdev_sync(vd, txg);
11064 
11065 		if (pass == 1) {
11066 			/*
11067 			 * dsl_pool_sync() -> dp_sync_tasks may have dirtied
11068 			 * the config. If that happens, this txg should not
11069 			 * be a no-op. So we must sync the config to the MOS
11070 			 * before checking for no-op.
11071 			 *
11072 			 * Note that when the config is dirty, it will
11073 			 * be written to the MOS (i.e. the MOS will be
11074 			 * dirtied) every time we call spa_sync_config_object()
11075 			 * in this txg.  Therefore we can't call this after
11076 			 * dsl_pool_sync() every pass, because it would
11077 			 * prevent us from converging, since we'd dirty
11078 			 * the MOS every pass.
11079 			 *
11080 			 * Sync tasks can only be processed in pass 1, so
11081 			 * there's no need to do this in later passes.
11082 			 */
11083 			spa_sync_config_object(spa, tx);
11084 		}
11085 
11086 		/*
11087 		 * Note: We need to check if the MOS is dirty because we could
11088 		 * have marked the MOS dirty without updating the uberblock
11089 		 * (e.g. if we have sync tasks but no dirty user data). We need
11090 		 * to check the uberblock's rootbp because it is updated if we
11091 		 * have synced out dirty data (though in this case the MOS will
11092 		 * most likely also be dirty due to second order effects, we
11093 		 * don't want to rely on that here).
11094 		 */
11095 		if (pass == 1 &&
11096 		    BP_GET_LOGICAL_BIRTH(&spa->spa_uberblock.ub_rootbp) < txg &&
11097 		    !dmu_objset_is_dirty(mos, txg)) {
11098 			/*
11099 			 * Nothing changed on the first pass, therefore this
11100 			 * TXG is a no-op. Avoid syncing deferred frees, so
11101 			 * that we can keep this TXG as a no-op.
11102 			 */
11103 			ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
11104 			ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
11105 			ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
11106 			ASSERT(txg_list_empty(&dp->dp_early_sync_tasks, txg));
11107 			break;
11108 		}
11109 
11110 		spa_sync_deferred_frees(spa, tx);
11111 	} while (dmu_objset_is_dirty(mos, txg));
11112 }
11113 
11114 /*
11115  * Select up to SPA_SYNC_MIN_VDEVS top-level vdevs to write the uberblock to.
11116  * First take the ones written during this txg, so that the idle ones may stay
11117  * asleep.  If there are not enough, top up from special and dedup vdevs, which
11118  * are expected to have no seek penalty.  Pools having none of those keep the
11119  * old behavior of topping up from any vdev.
11120  */
11121 static int
11122 spa_select_uberblock_vdevs(spa_t *spa, vdev_t **svd, uint64_t txg)
11123 {
11124 	vdev_t *rvd = spa->spa_root_vdev;
11125 	uint64_t children = rvd->vdev_children;
11126 	uint64_t c0 = random_in_range(children);
11127 	boolean_t tiered = spa_has_special(spa) || spa_has_dedup(spa);
11128 	int svdcount = 0;
11129 
11130 	for (int pass = 0; pass < 3; pass++) {
11131 		if (pass == 2 && svdcount > 0 && tiered)
11132 			break;
11133 
11134 		for (uint64_t c = 0; c < children &&
11135 		    svdcount < SPA_SYNC_MIN_VDEVS; c++) {
11136 			vdev_t *vd = rvd->vdev_child[(c0 + c) % children];
11137 			boolean_t dup = B_FALSE;
11138 
11139 			if (vd->vdev_ms_array == 0 || vd->vdev_islog ||
11140 			    !vdev_is_concrete(vd))
11141 				continue;
11142 
11143 			if (pass == 0 && !txg_list_member(
11144 			    &spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg)))
11145 				continue;
11146 
11147 			if (pass == 1) {
11148 				metaslab_class_t *mc = vd->vdev_mg != NULL ?
11149 				    vd->vdev_mg->mg_class : NULL;
11150 				if (mc != spa_special_class(spa) &&
11151 				    mc != spa_dedup_class(spa))
11152 					continue;
11153 			}
11154 
11155 			for (int i = 0; i < svdcount; i++)
11156 				dup |= (svd[i] == vd);
11157 			if (dup)
11158 				continue;
11159 
11160 			svd[svdcount++] = vd;
11161 		}
11162 	}
11163 
11164 	return (svdcount);
11165 }
11166 
11167 /*
11168  * Rewrite the vdev configuration (which includes the uberblock) to
11169  * commit the transaction group.
11170  *
11171  * If there are no dirty vdevs, we sync the uberblock to a few random
11172  * top-level vdevs that are known to be visible in the config cache
11173  * (see spa_vdev_add() for a complete description). If there *are* dirty
11174  * vdevs, sync the uberblock to all vdevs.
11175  */
11176 static void
11177 spa_sync_rewrite_vdev_config(spa_t *spa, dmu_tx_t *tx)
11178 {
11179 	vdev_t *rvd = spa->spa_root_vdev;
11180 	uint64_t txg = tx->tx_txg;
11181 
11182 	for (;;) {
11183 		int error = 0;
11184 
11185 		/*
11186 		 * We hold SCL_STATE to prevent vdev open/close/etc.
11187 		 * while we're attempting to write the vdev labels.
11188 		 */
11189 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
11190 
11191 		if (list_is_empty(&spa->spa_config_dirty_list)) {
11192 			vdev_t *svd[SPA_SYNC_MIN_VDEVS] = { NULL };
11193 			int svdcount = spa_select_uberblock_vdevs(spa, svd,
11194 			    txg);
11195 
11196 			error = vdev_config_sync(spa, svd, svdcount, txg);
11197 		} else {
11198 			error = vdev_config_sync(spa, rvd->vdev_child,
11199 			    rvd->vdev_children, txg);
11200 		}
11201 
11202 		if (error == 0)
11203 			spa->spa_last_synced_guid = rvd->vdev_guid;
11204 
11205 		spa_config_exit(spa, SCL_STATE, FTAG);
11206 
11207 		if (error == 0)
11208 			break;
11209 		zio_suspend(spa, NULL, ZIO_SUSPEND_IOERR);
11210 		zio_resume_wait(spa);
11211 	}
11212 }
11213 
11214 /*
11215  * Sync the specified transaction group.  New blocks may be dirtied as
11216  * part of the process, so we iterate until it converges.
11217  */
11218 void
11219 spa_sync(spa_t *spa, uint64_t txg)
11220 {
11221 	vdev_t *vd = NULL;
11222 
11223 	VERIFY(spa_writeable(spa));
11224 
11225 	/*
11226 	 * Wait for i/os issued in open context that need to complete
11227 	 * before this txg syncs.
11228 	 */
11229 	(void) zio_wait(spa->spa_txg_zio[txg & TXG_MASK]);
11230 	spa->spa_txg_zio[txg & TXG_MASK] = zio_root(spa, NULL, NULL,
11231 	    ZIO_FLAG_CANFAIL);
11232 
11233 	/*
11234 	 * Now that there can be no more cloning in this transaction group,
11235 	 * but we are still before issuing frees, we can process pending BRT
11236 	 * updates.
11237 	 */
11238 	brt_pending_apply(spa, txg);
11239 
11240 	spa_sync_time_logger(spa, txg, B_FALSE);
11241 
11242 	/*
11243 	 * Lock out configuration changes.
11244 	 */
11245 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
11246 
11247 	spa->spa_syncing_txg = txg;
11248 	spa->spa_sync_pass = 0;
11249 
11250 	/*
11251 	 * If there are any pending vdev state changes, convert them
11252 	 * into config changes that go out with this transaction group.
11253 	 */
11254 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
11255 	while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
11256 		/* Avoid holding the write lock unless actually necessary */
11257 		if (vd->vdev_aux == NULL) {
11258 			vdev_state_clean(vd);
11259 			vdev_config_dirty(vd);
11260 			continue;
11261 		}
11262 		/*
11263 		 * We need the write lock here because, for aux vdevs,
11264 		 * calling vdev_config_dirty() modifies sav_config.
11265 		 * This is ugly and will become unnecessary when we
11266 		 * eliminate the aux vdev wart by integrating all vdevs
11267 		 * into the root vdev tree.
11268 		 */
11269 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
11270 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
11271 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
11272 			vdev_state_clean(vd);
11273 			vdev_config_dirty(vd);
11274 		}
11275 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
11276 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
11277 	}
11278 	spa_config_exit(spa, SCL_STATE, FTAG);
11279 
11280 	dsl_pool_t *dp = spa->spa_dsl_pool;
11281 	dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
11282 
11283 	spa->spa_sync_starttime = getlrtime();
11284 
11285 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid, B_TRUE);
11286 	spa->spa_deadman_tqid = taskq_dispatch_delay(system_delay_taskq,
11287 	    spa_deadman, spa, TQ_SLEEP, ddi_get_lbolt() +
11288 	    NSEC_TO_TICK(spa->spa_deadman_synctime));
11289 
11290 	/*
11291 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
11292 	 * set spa_deflate if we have no raid-z vdevs.
11293 	 */
11294 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
11295 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
11296 		vdev_t *rvd = spa->spa_root_vdev;
11297 
11298 		int i;
11299 		for (i = 0; i < rvd->vdev_children; i++) {
11300 			vd = rvd->vdev_child[i];
11301 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
11302 				break;
11303 		}
11304 		if (i == rvd->vdev_children) {
11305 			spa->spa_deflate = TRUE;
11306 			VERIFY0(zap_add(spa->spa_meta_objset,
11307 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
11308 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
11309 		}
11310 	}
11311 
11312 	spa_sync_adjust_vdev_max_queue_depth(spa);
11313 
11314 	spa_sync_condense_indirect(spa, tx);
11315 
11316 	spa_sync_iterate_to_convergence(spa, tx);
11317 
11318 #ifdef ZFS_DEBUG
11319 	if (!list_is_empty(&spa->spa_config_dirty_list)) {
11320 	/*
11321 	 * Make sure that the number of ZAPs for all the vdevs matches
11322 	 * the number of ZAPs in the per-vdev ZAP list. This only gets
11323 	 * called if the config is dirty; otherwise there may be
11324 	 * outstanding AVZ operations that weren't completed in
11325 	 * spa_sync_config_object.
11326 	 */
11327 		uint64_t all_vdev_zap_entry_count;
11328 		ASSERT0(zap_count(spa->spa_meta_objset,
11329 		    spa->spa_all_vdev_zaps, &all_vdev_zap_entry_count));
11330 		ASSERT3U(vdev_count_verify_zaps(spa->spa_root_vdev), ==,
11331 		    all_vdev_zap_entry_count);
11332 	}
11333 #endif
11334 
11335 	if (spa->spa_vdev_removal != NULL) {
11336 		ASSERT0(spa->spa_vdev_removal->svr_bytes_done[txg & TXG_MASK]);
11337 	}
11338 
11339 	for (vd = txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd;
11340 	    vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg)))
11341 		vdev_sync_dispatch(vd, txg);
11342 
11343 	spa_sync_rewrite_vdev_config(spa, tx);
11344 	dmu_tx_commit(tx);
11345 
11346 	taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid, B_TRUE);
11347 	spa->spa_deadman_tqid = 0;
11348 
11349 	/*
11350 	 * Clear the dirty config list.
11351 	 */
11352 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
11353 		vdev_config_clean(vd);
11354 
11355 	/*
11356 	 * Now that the new config has synced transactionally,
11357 	 * let it become visible to the config cache.
11358 	 */
11359 	if (spa->spa_config_syncing != NULL) {
11360 		spa_config_set(spa, spa->spa_config_syncing);
11361 		spa->spa_config_txg = txg;
11362 		spa->spa_config_syncing = NULL;
11363 	}
11364 
11365 	dsl_pool_sync_done(dp, txg);
11366 
11367 	while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
11368 	    != NULL)
11369 		vdev_sync_done(vd, txg);
11370 
11371 	metaslab_class_evict_old(spa->spa_normal_class, txg);
11372 	metaslab_class_evict_old(spa->spa_log_class, txg);
11373 	/* Embedded log classes have only one metaslab per vdev. */
11374 	metaslab_class_evict_old(spa->spa_special_class, txg);
11375 	metaslab_class_evict_old(spa->spa_dedup_class, txg);
11376 
11377 	spa_sync_close_syncing_log_sm(spa);
11378 
11379 	spa_update_dspace(spa);
11380 	spa_log_sm_stats_update(spa);
11381 
11382 	if (spa_get_autotrim(spa) == SPA_AUTOTRIM_ON)
11383 		vdev_autotrim_kick(spa);
11384 
11385 	/*
11386 	 * It had better be the case that we didn't dirty anything
11387 	 * since vdev_config_sync().
11388 	 */
11389 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
11390 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
11391 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
11392 
11393 	while (zfs_pause_spa_sync)
11394 		delay(1);
11395 
11396 	spa->spa_sync_pass = 0;
11397 
11398 	/*
11399 	 * Update the last synced uberblock here. We want to do this at
11400 	 * the end of spa_sync() so that consumers of spa_last_synced_txg()
11401 	 * will be guaranteed that all the processing associated with
11402 	 * that txg has been completed.
11403 	 */
11404 	spa->spa_ubsync = spa->spa_uberblock;
11405 	spa_config_exit(spa, SCL_CONFIG, FTAG);
11406 
11407 	/*
11408 	 * An activity that ended in this txg is only over for a reader of
11409 	 * the pool now that the txg is on disk, so let the waiters look
11410 	 * again (see spa_activity_in_progress()).
11411 	 */
11412 	spa_notify_waiters(spa);
11413 
11414 	spa_handle_ignored_writes(spa);
11415 
11416 	/*
11417 	 * If any async tasks have been requested, kick them off.
11418 	 */
11419 	spa_async_dispatch(spa);
11420 }
11421 
11422 /*
11423  * Sync all pools.  We don't want to hold the namespace lock across these
11424  * operations, so we take a reference on the spa_t and drop the lock during the
11425  * sync.
11426  */
11427 void
11428 spa_sync_allpools(void)
11429 {
11430 	spa_t *spa = NULL;
11431 	spa_namespace_enter(FTAG);
11432 	while ((spa = spa_next(spa)) != NULL) {
11433 		if (spa_state(spa) != POOL_STATE_ACTIVE ||
11434 		    !spa_writeable(spa) || spa_suspended(spa))
11435 			continue;
11436 		spa_open_ref(spa, FTAG);
11437 		spa_namespace_exit(FTAG);
11438 		txg_wait_synced(spa_get_dsl(spa), 0);
11439 		spa_namespace_enter(FTAG);
11440 		spa_close(spa, FTAG);
11441 	}
11442 	spa_namespace_exit(FTAG);
11443 }
11444 
11445 taskq_t *
11446 spa_sync_tq_create(spa_t *spa, const char *name)
11447 {
11448 	kthread_t **kthreads;
11449 
11450 	ASSERT0P(spa->spa_sync_tq);
11451 	ASSERT3S(spa->spa_alloc_count, <=, boot_ncpus);
11452 
11453 	/*
11454 	 * - do not allow more allocators than cpus.
11455 	 * - there may be more cpus than allocators.
11456 	 * - do not allow more sync taskq threads than allocators or cpus.
11457 	 */
11458 	int nthreads = spa->spa_alloc_count;
11459 	spa->spa_syncthreads = kmem_zalloc(sizeof (spa_syncthread_info_t) *
11460 	    nthreads, KM_SLEEP);
11461 
11462 	spa->spa_sync_tq = taskq_create_synced(name, nthreads, minclsyspri,
11463 	    nthreads, INT_MAX, TASKQ_PREPOPULATE, &kthreads);
11464 	VERIFY(spa->spa_sync_tq != NULL);
11465 	VERIFY(kthreads != NULL);
11466 
11467 	spa_syncthread_info_t *ti = spa->spa_syncthreads;
11468 	for (int i = 0; i < nthreads; i++, ti++) {
11469 		ti->sti_thread = kthreads[i];
11470 		ti->sti_allocator = i;
11471 	}
11472 
11473 	kmem_free(kthreads, sizeof (*kthreads) * nthreads);
11474 	return (spa->spa_sync_tq);
11475 }
11476 
11477 void
11478 spa_sync_tq_destroy(spa_t *spa)
11479 {
11480 	ASSERT(spa->spa_sync_tq != NULL);
11481 
11482 	taskq_wait(spa->spa_sync_tq);
11483 	taskq_destroy(spa->spa_sync_tq);
11484 	kmem_free(spa->spa_syncthreads,
11485 	    sizeof (spa_syncthread_info_t) * spa->spa_alloc_count);
11486 	spa->spa_sync_tq = NULL;
11487 }
11488 
11489 uint_t
11490 spa_acq_allocator(spa_t *spa)
11491 {
11492 	int i;
11493 
11494 	if (spa->spa_alloc_count == 1)
11495 		return (0);
11496 
11497 	mutex_enter(&spa->spa_allocs_use->sau_lock);
11498 	uint_t r = spa->spa_allocs_use->sau_rotor;
11499 	do {
11500 		if (++r == spa->spa_alloc_count)
11501 			r = 0;
11502 	} while (spa->spa_allocs_use->sau_inuse[r]);
11503 	spa->spa_allocs_use->sau_inuse[r] = B_TRUE;
11504 	spa->spa_allocs_use->sau_rotor = r;
11505 	mutex_exit(&spa->spa_allocs_use->sau_lock);
11506 
11507 	spa_syncthread_info_t *ti = spa->spa_syncthreads;
11508 	for (i = 0; i < spa->spa_alloc_count; i++, ti++) {
11509 		if (ti->sti_thread == curthread) {
11510 			ti->sti_allocator = r;
11511 			break;
11512 		}
11513 	}
11514 	ASSERT3S(i, <, spa->spa_alloc_count);
11515 	return (r);
11516 }
11517 
11518 void
11519 spa_rel_allocator(spa_t *spa, uint_t allocator)
11520 {
11521 	if (spa->spa_alloc_count > 1)
11522 		spa->spa_allocs_use->sau_inuse[allocator] = B_FALSE;
11523 }
11524 
11525 void
11526 spa_select_allocator(zio_t *zio)
11527 {
11528 	zbookmark_phys_t *bm = &zio->io_bookmark;
11529 	spa_t *spa = zio->io_spa;
11530 
11531 	ASSERT(zio->io_type == ZIO_TYPE_WRITE);
11532 
11533 	/*
11534 	 * A gang block (for example) may have inherited its parent's
11535 	 * allocator, in which case there is nothing further to do here.
11536 	 */
11537 	if (ZIO_HAS_ALLOCATOR(zio))
11538 		return;
11539 
11540 	ASSERT(spa != NULL);
11541 	ASSERT(bm != NULL);
11542 
11543 	/*
11544 	 * First try to use an allocator assigned to the syncthread, and set
11545 	 * the corresponding write issue taskq for the allocator.
11546 	 * Note, we must have an open pool to do this.
11547 	 */
11548 	if (spa->spa_sync_tq != NULL) {
11549 		spa_syncthread_info_t *ti = spa->spa_syncthreads;
11550 		for (int i = 0; i < spa->spa_alloc_count; i++, ti++) {
11551 			if (ti->sti_thread == curthread) {
11552 				zio->io_allocator = ti->sti_allocator;
11553 				return;
11554 			}
11555 		}
11556 	}
11557 
11558 	/*
11559 	 * We want to try to use as many allocators as possible to help improve
11560 	 * performance, but we also want logically adjacent IOs to be physically
11561 	 * adjacent to improve sequential read performance. We chunk each object
11562 	 * into 2^20 block regions, and then hash based on the objset, object,
11563 	 * level, and region to accomplish both of these goals.
11564 	 */
11565 	uint64_t hv = cityhash4(bm->zb_objset, bm->zb_object, bm->zb_level,
11566 	    bm->zb_blkid >> 20);
11567 
11568 	zio->io_allocator = (uint_t)hv % spa->spa_alloc_count;
11569 }
11570 
11571 /*
11572  * ==========================================================================
11573  * Miscellaneous routines
11574  * ==========================================================================
11575  */
11576 
11577 /*
11578  * Remove all pools in the system.
11579  */
11580 void
11581 spa_evict_all(void)
11582 {
11583 	spa_t *spa;
11584 
11585 	/*
11586 	 * Remove all cached state.  All pools should be closed now,
11587 	 * so every spa in the AVL tree should be unreferenced.
11588 	 */
11589 	spa_namespace_enter(FTAG);
11590 	while ((spa = spa_next(NULL)) != NULL) {
11591 		/*
11592 		 * Stop async tasks.  The async thread may need to detach
11593 		 * a device that's been replaced, which requires grabbing
11594 		 * spa_namespace_lock, so we must drop it here.
11595 		 */
11596 		spa_open_ref(spa, FTAG);
11597 		spa_namespace_exit(FTAG);
11598 		spa_async_suspend(spa);
11599 		spa_namespace_enter(FTAG);
11600 		spa_close(spa, FTAG);
11601 
11602 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
11603 			spa_unload(spa);
11604 			spa_deactivate(spa);
11605 		}
11606 		spa_remove(spa);
11607 	}
11608 	spa_namespace_exit(FTAG);
11609 }
11610 
11611 vdev_t *
11612 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
11613 {
11614 	vdev_t *vd;
11615 	int i;
11616 
11617 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
11618 		return (vd);
11619 
11620 	if (aux) {
11621 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
11622 			vd = spa->spa_l2cache.sav_vdevs[i];
11623 			if (vd->vdev_guid == guid)
11624 				return (vd);
11625 		}
11626 
11627 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
11628 			vd = spa->spa_spares.sav_vdevs[i];
11629 			if (vd->vdev_guid == guid)
11630 				return (vd);
11631 		}
11632 	}
11633 
11634 	return (NULL);
11635 }
11636 
11637 void
11638 spa_upgrade(spa_t *spa, uint64_t version)
11639 {
11640 	ASSERT(spa_writeable(spa));
11641 
11642 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
11643 
11644 	/*
11645 	 * This should only be called for a non-faulted pool, and since a
11646 	 * future version would result in an unopenable pool, this shouldn't be
11647 	 * possible.
11648 	 */
11649 	ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
11650 	ASSERT3U(version, >=, spa->spa_uberblock.ub_version);
11651 
11652 	spa->spa_uberblock.ub_version = version;
11653 	vdev_config_dirty(spa->spa_root_vdev);
11654 
11655 	spa_config_exit(spa, SCL_ALL, FTAG);
11656 
11657 	txg_wait_synced(spa_get_dsl(spa), 0);
11658 }
11659 
11660 static boolean_t
11661 spa_has_aux_vdev(spa_t *spa, uint64_t guid, spa_aux_vdev_t *sav)
11662 {
11663 	(void) spa;
11664 	int i;
11665 	uint64_t vdev_guid;
11666 
11667 	for (i = 0; i < sav->sav_count; i++)
11668 		if (sav->sav_vdevs[i]->vdev_guid == guid)
11669 			return (B_TRUE);
11670 
11671 	for (i = 0; i < sav->sav_npending; i++) {
11672 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
11673 		    &vdev_guid) == 0 && vdev_guid == guid)
11674 			return (B_TRUE);
11675 	}
11676 
11677 	return (B_FALSE);
11678 }
11679 
11680 boolean_t
11681 spa_has_l2cache(spa_t *spa, uint64_t guid)
11682 {
11683 	return (spa_has_aux_vdev(spa, guid, &spa->spa_l2cache));
11684 }
11685 
11686 boolean_t
11687 spa_has_spare(spa_t *spa, uint64_t guid)
11688 {
11689 	return (spa_has_aux_vdev(spa, guid, &spa->spa_spares));
11690 }
11691 
11692 /*
11693  * Check if a pool has an active shared spare device.
11694  * Note: reference count of an active spare is 2, as a spare and as a replace
11695  */
11696 static boolean_t
11697 spa_has_active_shared_spare(spa_t *spa)
11698 {
11699 	int i, refcnt;
11700 	uint64_t pool;
11701 	spa_aux_vdev_t *sav = &spa->spa_spares;
11702 
11703 	for (i = 0; i < sav->sav_count; i++) {
11704 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
11705 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
11706 		    refcnt > 2)
11707 			return (B_TRUE);
11708 	}
11709 
11710 	return (B_FALSE);
11711 }
11712 
11713 uint64_t
11714 spa_total_metaslabs(spa_t *spa)
11715 {
11716 	vdev_t *rvd = spa->spa_root_vdev;
11717 
11718 	uint64_t m = 0;
11719 	for (uint64_t c = 0; c < rvd->vdev_children; c++) {
11720 		vdev_t *vd = rvd->vdev_child[c];
11721 		if (!vdev_is_concrete(vd))
11722 			continue;
11723 		m += vd->vdev_ms_count;
11724 	}
11725 	return (m);
11726 }
11727 
11728 /*
11729  * Notify any waiting threads that some activity has switched from being in-
11730  * progress to not-in-progress so that the thread can wake up and determine
11731  * whether it is finished waiting.
11732  */
11733 void
11734 spa_notify_waiters(spa_t *spa)
11735 {
11736 	/*
11737 	 * Acquiring spa_activities_lock here prevents the cv_broadcast from
11738 	 * happening between the waiting thread's check and cv_wait.
11739 	 */
11740 	mutex_enter(&spa->spa_activities_lock);
11741 	cv_broadcast(&spa->spa_activities_cv);
11742 	mutex_exit(&spa->spa_activities_lock);
11743 }
11744 
11745 /*
11746  * Notify any waiting threads that the pool is exporting, and then block until
11747  * they are finished using the spa_t.
11748  */
11749 void
11750 spa_wake_waiters(spa_t *spa)
11751 {
11752 	mutex_enter(&spa->spa_activities_lock);
11753 	spa->spa_waiters_cancel = B_TRUE;
11754 	cv_broadcast(&spa->spa_activities_cv);
11755 	while (spa->spa_waiters != 0)
11756 		cv_wait(&spa->spa_waiters_cv, &spa->spa_activities_lock);
11757 	spa->spa_waiters_cancel = B_FALSE;
11758 	mutex_exit(&spa->spa_activities_lock);
11759 }
11760 
11761 /* Whether the vdev or any of its descendants are being initialized/trimmed. */
11762 static boolean_t
11763 spa_vdev_activity_in_progress_impl(vdev_t *vd, zpool_wait_activity_t activity)
11764 {
11765 	spa_t *spa = vd->vdev_spa;
11766 
11767 	ASSERT(spa_config_held(spa, SCL_CONFIG | SCL_STATE, RW_READER));
11768 	ASSERT(MUTEX_HELD(&spa->spa_activities_lock));
11769 	ASSERT(activity == ZPOOL_WAIT_INITIALIZE ||
11770 	    activity == ZPOOL_WAIT_TRIM);
11771 
11772 	kmutex_t *lock = activity == ZPOOL_WAIT_INITIALIZE ?
11773 	    &vd->vdev_initialize_lock : &vd->vdev_trim_lock;
11774 
11775 	mutex_exit(&spa->spa_activities_lock);
11776 	mutex_enter(lock);
11777 	mutex_enter(&spa->spa_activities_lock);
11778 
11779 	/*
11780 	 * A thread that has finished still has to sync out the new state
11781 	 * before it exits, and until it does the vdev cannot be initialized
11782 	 * or trimmed again.  Wait for the thread itself, not just the state,
11783 	 * so that a command issued after the wait returns does not fail with
11784 	 * EBUSY.
11785 	 */
11786 	boolean_t in_progress = (activity == ZPOOL_WAIT_INITIALIZE) ?
11787 	    (vd->vdev_initialize_state == VDEV_INITIALIZE_ACTIVE ||
11788 	    vd->vdev_initialize_thread != NULL) :
11789 	    (vd->vdev_trim_state == VDEV_TRIM_ACTIVE ||
11790 	    vd->vdev_trim_thread != NULL);
11791 	mutex_exit(lock);
11792 
11793 	if (in_progress)
11794 		return (B_TRUE);
11795 
11796 	for (int i = 0; i < vd->vdev_children; i++) {
11797 		if (spa_vdev_activity_in_progress_impl(vd->vdev_child[i],
11798 		    activity))
11799 			return (B_TRUE);
11800 	}
11801 
11802 	return (B_FALSE);
11803 }
11804 
11805 /*
11806  * If use_guid is true, this checks whether the vdev specified by guid is
11807  * being initialized/trimmed. Otherwise, it checks whether any vdev in the pool
11808  * is being initialized/trimmed. The caller must hold the config lock and
11809  * spa_activities_lock.
11810  */
11811 static int
11812 spa_vdev_activity_in_progress(spa_t *spa, boolean_t use_guid, uint64_t guid,
11813     zpool_wait_activity_t activity, boolean_t *in_progress)
11814 {
11815 	mutex_exit(&spa->spa_activities_lock);
11816 	spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
11817 	mutex_enter(&spa->spa_activities_lock);
11818 
11819 	vdev_t *vd;
11820 	if (use_guid) {
11821 		vd = spa_lookup_by_guid(spa, guid, B_FALSE);
11822 		if (vd == NULL || !vd->vdev_ops->vdev_op_leaf) {
11823 			spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
11824 			return (EINVAL);
11825 		}
11826 	} else {
11827 		vd = spa->spa_root_vdev;
11828 	}
11829 
11830 	*in_progress = spa_vdev_activity_in_progress_impl(vd, activity);
11831 
11832 	spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
11833 	return (0);
11834 }
11835 
11836 /*
11837  * Locking for waiting threads
11838  * ---------------------------
11839  *
11840  * Waiting threads need a way to check whether a given activity is in progress,
11841  * and then, if it is, wait for it to complete. Each activity will have some
11842  * in-memory representation of the relevant on-disk state which can be used to
11843  * determine whether or not the activity is in progress. The in-memory state and
11844  * the locking used to protect it will be different for each activity, and may
11845  * not be suitable for use with a cvar (e.g., some state is protected by the
11846  * config lock). To allow waiting threads to wait without any races, another
11847  * lock, spa_activities_lock, is used.
11848  *
11849  * When the state is checked, both the activity-specific lock (if there is one)
11850  * and spa_activities_lock are held. In some cases, the activity-specific lock
11851  * is acquired explicitly (e.g. the config lock). In others, the locking is
11852  * internal to some check (e.g. bpobj_is_empty). After checking, the waiting
11853  * thread releases the activity-specific lock and, if the activity is in
11854  * progress, then cv_waits using spa_activities_lock.
11855  *
11856  * The waiting thread is woken when another thread, one completing some
11857  * activity, updates the state of the activity and then calls
11858  * spa_notify_waiters, which will cv_broadcast. This 'completing' thread only
11859  * needs to hold its activity-specific lock when updating the state, and this
11860  * lock can (but doesn't have to) be dropped before calling spa_notify_waiters.
11861  *
11862  * Because spa_notify_waiters acquires spa_activities_lock before broadcasting,
11863  * and because it is held when the waiting thread checks the state of the
11864  * activity, it can never be the case that the completing thread both updates
11865  * the activity state and cv_broadcasts in between the waiting thread's check
11866  * and cv_wait. Thus, a waiting thread can never miss a wakeup.
11867  *
11868  * In order to prevent deadlock, when the waiting thread does its check, in some
11869  * cases it will temporarily drop spa_activities_lock in order to acquire the
11870  * activity-specific lock. The order in which spa_activities_lock and the
11871  * activity specific lock are acquired in the waiting thread is determined by
11872  * the order in which they are acquired in the completing thread; if the
11873  * completing thread calls spa_notify_waiters with the activity-specific lock
11874  * held, then the waiting thread must also acquire the activity-specific lock
11875  * first.
11876  */
11877 
11878 static int
11879 spa_activity_in_progress(spa_t *spa, zpool_wait_activity_t activity,
11880     boolean_t use_tag, uint64_t tag, boolean_t *in_progress)
11881 {
11882 	int error = 0;
11883 
11884 	ASSERT(MUTEX_HELD(&spa->spa_activities_lock));
11885 
11886 	switch (activity) {
11887 	case ZPOOL_WAIT_CKPT_DISCARD:
11888 		*in_progress =
11889 		    (spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT) &&
11890 		    zap_contains(spa_meta_objset(spa),
11891 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ZPOOL_CHECKPOINT) ==
11892 		    ENOENT);
11893 		break;
11894 	case ZPOOL_WAIT_FREE:
11895 		*in_progress = ((spa_version(spa) >= SPA_VERSION_DEADLISTS &&
11896 		    !bpobj_is_empty(&spa->spa_dsl_pool->dp_free_bpobj)) ||
11897 		    spa_feature_is_active(spa, SPA_FEATURE_ASYNC_DESTROY) ||
11898 		    spa_livelist_delete_check(spa));
11899 		break;
11900 	case ZPOOL_WAIT_INITIALIZE:
11901 	case ZPOOL_WAIT_TRIM:
11902 		error = spa_vdev_activity_in_progress(spa, use_tag, tag,
11903 		    activity, in_progress);
11904 		break;
11905 	case ZPOOL_WAIT_REPLACE:
11906 		mutex_exit(&spa->spa_activities_lock);
11907 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
11908 		mutex_enter(&spa->spa_activities_lock);
11909 
11910 		*in_progress = vdev_replace_in_progress(spa->spa_root_vdev);
11911 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
11912 		break;
11913 	case ZPOOL_WAIT_REMOVE:
11914 		*in_progress = (spa->spa_removing_phys.sr_state ==
11915 		    DSS_SCANNING);
11916 		break;
11917 	case ZPOOL_WAIT_RESILVER:
11918 		*in_progress = vdev_rebuild_active(spa->spa_root_vdev);
11919 		if (*in_progress)
11920 			break;
11921 		zfs_fallthrough;
11922 	case ZPOOL_WAIT_SCRUB:
11923 	{
11924 		boolean_t scanning, paused, is_scrub, finishing;
11925 		dsl_scan_t *scn =  spa->spa_dsl_pool->dp_scan;
11926 
11927 		is_scrub = (scn->scn_phys.scn_func == POOL_SCAN_SCRUB);
11928 		scanning = (scn->scn_phys.scn_state == DSS_SCANNING);
11929 		paused = dsl_scan_is_paused_scrub(scn);
11930 
11931 		/*
11932 		 * dsl_scan_done() marks the scan finished in syncing
11933 		 * context, ahead of the config and label writes that the
11934 		 * same txg carries, so the scan is not over for anyone
11935 		 * reading the pool until that txg has synced.  Keep
11936 		 * reporting it as in progress until then, the way the
11937 		 * initialize and trim waits cover the whole operation.
11938 		 */
11939 		finishing = (scn->scn_finished_txg != 0 &&
11940 		    spa_last_synced_txg(spa) < scn->scn_finished_txg);
11941 
11942 		*in_progress = ((scanning || finishing) && !paused &&
11943 		    is_scrub == (activity == ZPOOL_WAIT_SCRUB));
11944 		break;
11945 	}
11946 	case ZPOOL_WAIT_RAIDZ_EXPAND:
11947 	{
11948 		vdev_raidz_expand_t *vre = spa->spa_raidz_expand;
11949 		*in_progress = (vre != NULL && vre->vre_state == DSS_SCANNING);
11950 		break;
11951 	}
11952 	case ZPOOL_WAIT_CONDENSE: {
11953 		*in_progress = B_FALSE;
11954 		spa_condense_stat_t *scns;
11955 
11956 		for (spa_condense_type_t type = 0;
11957 		    type < SPA_CONDENSE_TYPES; type++) {
11958 			scns = &spa->spa_condense_stats[type];
11959 			if (scns->scns_start_time > 0 &&
11960 			    scns->scns_end_time == 0) {
11961 				*in_progress = B_TRUE;
11962 				break;
11963 			}
11964 		}
11965 		break;
11966 	}
11967 	default:
11968 		panic("unrecognized value for activity %d", activity);
11969 	}
11970 
11971 	return (error);
11972 }
11973 
11974 static int
11975 spa_wait_common(const char *pool, zpool_wait_activity_t activity,
11976     boolean_t use_tag, uint64_t tag, boolean_t *waited)
11977 {
11978 	/*
11979 	 * The tag is used to distinguish between instances of an activity.
11980 	 * 'initialize' and 'trim' are the only activities that we use this for.
11981 	 * The other activities can only have a single instance in progress in a
11982 	 * pool at one time, making the tag unnecessary.
11983 	 *
11984 	 * There can be multiple devices being replaced at once, but since they
11985 	 * all finish once resilvering finishes, we don't bother keeping track
11986 	 * of them individually, we just wait for them all to finish.
11987 	 */
11988 	if (use_tag && activity != ZPOOL_WAIT_INITIALIZE &&
11989 	    activity != ZPOOL_WAIT_TRIM)
11990 		return (EINVAL);
11991 
11992 	if (activity < 0 || activity >= ZPOOL_WAIT_NUM_ACTIVITIES)
11993 		return (EINVAL);
11994 
11995 	spa_t *spa;
11996 	int error = spa_open(pool, &spa, FTAG);
11997 	if (error != 0)
11998 		return (error);
11999 
12000 	/*
12001 	 * Increment the spa's waiter count so that we can call spa_close and
12002 	 * still ensure that the spa_t doesn't get freed before this thread is
12003 	 * finished with it when the pool is exported. We want to call spa_close
12004 	 * before we start waiting because otherwise the additional ref would
12005 	 * prevent the pool from being exported or destroyed throughout the
12006 	 * potentially long wait.
12007 	 */
12008 	mutex_enter(&spa->spa_activities_lock);
12009 	spa->spa_waiters++;
12010 	spa_close(spa, FTAG);
12011 
12012 	*waited = B_FALSE;
12013 	for (;;) {
12014 		boolean_t in_progress;
12015 		error = spa_activity_in_progress(spa, activity, use_tag, tag,
12016 		    &in_progress);
12017 
12018 		if (error || !in_progress || spa->spa_waiters_cancel)
12019 			break;
12020 
12021 		*waited = B_TRUE;
12022 
12023 		if (cv_wait_sig(&spa->spa_activities_cv,
12024 		    &spa->spa_activities_lock) == 0) {
12025 			error = EINTR;
12026 			break;
12027 		}
12028 	}
12029 
12030 	spa->spa_waiters--;
12031 	cv_signal(&spa->spa_waiters_cv);
12032 	mutex_exit(&spa->spa_activities_lock);
12033 
12034 	return (error);
12035 }
12036 
12037 /*
12038  * Wait for a particular instance of the specified activity to complete, where
12039  * the instance is identified by 'tag'
12040  */
12041 int
12042 spa_wait_tag(const char *pool, zpool_wait_activity_t activity, uint64_t tag,
12043     boolean_t *waited)
12044 {
12045 	return (spa_wait_common(pool, activity, B_TRUE, tag, waited));
12046 }
12047 
12048 /*
12049  * Wait for all instances of the specified activity complete
12050  */
12051 int
12052 spa_wait(const char *pool, zpool_wait_activity_t activity, boolean_t *waited)
12053 {
12054 
12055 	return (spa_wait_common(pool, activity, B_FALSE, 0, waited));
12056 }
12057 
12058 sysevent_t *
12059 spa_event_create(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl, const char *name)
12060 {
12061 	sysevent_t *ev = NULL;
12062 #ifdef _KERNEL
12063 	nvlist_t *resource;
12064 
12065 	resource = zfs_event_create(spa, vd, FM_SYSEVENT_CLASS, name, hist_nvl);
12066 	if (resource) {
12067 		ev = kmem_alloc(sizeof (sysevent_t), KM_SLEEP);
12068 		ev->resource = resource;
12069 	}
12070 #else
12071 	(void) spa, (void) vd, (void) hist_nvl, (void) name;
12072 #endif
12073 	return (ev);
12074 }
12075 
12076 void
12077 spa_event_post(sysevent_t *ev)
12078 {
12079 #ifdef _KERNEL
12080 	if (ev) {
12081 		zfs_zevent_post(ev->resource, NULL, zfs_zevent_post_cb);
12082 		kmem_free(ev, sizeof (*ev));
12083 	}
12084 #else
12085 	(void) ev;
12086 #endif
12087 }
12088 
12089 /*
12090  * Post a zevent corresponding to the given sysevent.   The 'name' must be one
12091  * of the event definitions in sys/sysevent/eventdefs.h.  The payload will be
12092  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
12093  * in the userland libzpool, as we don't want consumers to misinterpret ztest
12094  * or zdb as real changes.
12095  */
12096 void
12097 spa_event_notify(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl, const char *name)
12098 {
12099 	spa_event_post(spa_event_create(spa, vd, hist_nvl, name));
12100 }
12101 
12102 #ifdef ZFS_DEBUG
12103 /*
12104  * This runs the "debug" condense type, which does nothing, just updates the
12105  * condense counters every second for ten seconds. This exists entirely for
12106  * testing and debugging the condense system itself, which is why it is
12107  * compiled out of production builds.
12108  */
12109 #define	SPA_CONDENSE_DEBUG_STEP	(10)
12110 
12111 static void
12112 spa_condense_debug_task(void *arg)
12113 {
12114 	spa_t *spa = arg;
12115 	spa_condense_stat_t *scns =
12116 	    &spa->spa_condense_stats[SPA_CONDENSE_DEBUG];
12117 
12118 	mutex_enter(&spa->spa_condense_stats_lock);
12119 
12120 	if (spa->spa_condense_debug_tqid == TASKQID_INVALID) {
12121 		/*
12122 		 * Task no longer required, probably cancelled by
12123 		 * spa_condense_debug_cancel(). Just exit.
12124 		 */
12125 		mutex_exit(&spa->spa_condense_stats_lock);
12126 		return;
12127 	}
12128 
12129 	spa->spa_condense_debug_tqid = TASKQID_INVALID;
12130 
12131 	/* Move the condense progress along a bit. */
12132 	scns->scns_processed = MIN(scns->scns_total, scns->scns_processed +
12133 	    (scns->scns_total / SPA_CONDENSE_DEBUG_STEP));
12134 	if (scns->scns_processed == scns->scns_total) {
12135 		/*
12136 		 * Reached the end. Set the end time to "complete" the
12137 		 * condense, signal waiters, release resources and we're done.
12138 		 */
12139 		scns->scns_end_time = gethrestime_sec();
12140 		mutex_exit(&spa->spa_condense_stats_lock);
12141 		spa_notify_waiters(spa);
12142 		spa_close(spa, scns);
12143 		return;
12144 	}
12145 
12146 	/* More to do, re-arm the timer for another round. */
12147 	spa->spa_condense_debug_tqid = taskq_dispatch_delay(system_delay_taskq,
12148 	    spa_condense_debug_task, spa, TQ_SLEEP,
12149 	    ddi_get_lbolt() + SEC_TO_TICK(1));
12150 	mutex_exit(&spa->spa_condense_stats_lock);
12151 }
12152 
12153 void
12154 spa_condense_debug_start(spa_t *spa)
12155 {
12156 	uint32_t nitems = 10 + random_in_range(90) * SPA_CONDENSE_DEBUG_STEP;
12157 
12158 	spa_condense_stat_t *scns =
12159 	    &spa->spa_condense_stats[SPA_CONDENSE_DEBUG];
12160 
12161 	mutex_enter(&spa->spa_condense_stats_lock);
12162 
12163 	if (scns->scns_start_time == 0 || scns->scns_end_time > 0) {
12164 		/* Previous run finished, or no previous run. Start fresh. */
12165 		scns->scns_start_time = gethrestime_sec();
12166 		scns->scns_end_time = 0;
12167 		scns->scns_processed = 0;
12168 		scns->scns_total = nitems;
12169 	} else {
12170 		/* In progress, just add some more work. */
12171 		scns->scns_total += nitems;
12172 	}
12173 
12174 	if (spa->spa_condense_debug_tqid == TASKQID_INVALID) {
12175 		spa_open_ref(spa, scns);
12176 		spa->spa_condense_debug_tqid = taskq_dispatch_delay(
12177 		    system_delay_taskq, spa_condense_debug_task, spa, TQ_SLEEP,
12178 		    ddi_get_lbolt() + SEC_TO_TICK(1));
12179 	}
12180 
12181 	mutex_exit(&spa->spa_condense_stats_lock);
12182 }
12183 
12184 void
12185 spa_condense_debug_cancel(spa_t *spa)
12186 {
12187 	spa_condense_stat_t *scns =
12188 	    &spa->spa_condense_stats[SPA_CONDENSE_DEBUG];
12189 
12190 	mutex_enter(&spa->spa_condense_stats_lock);
12191 
12192 	/* "Cancel" by just setting the end time. */
12193 	if (scns->scns_end_time == 0)
12194 		scns->scns_end_time = gethrestime_sec();
12195 
12196 	if (spa->spa_condense_debug_tqid == TASKQID_INVALID) {
12197 		/* No task, so nothing else to do. */
12198 		mutex_exit(&spa->spa_condense_stats_lock);
12199 		spa_notify_waiters(spa);
12200 		return;
12201 	}
12202 
12203 	/*
12204 	 * Task is either waiting to run, or running and waiting to take
12205 	 * spa_condense_stats_lock. Clear the tqid, so if it does run after we
12206 	 * drop the lock, it will immediately exit.
12207 	 */
12208 	taskqid_t tqid = spa->spa_condense_debug_tqid;
12209 	spa->spa_condense_debug_tqid = TASKQID_INVALID;
12210 
12211 	mutex_exit(&spa->spa_condense_stats_lock);
12212 
12213 	/*
12214 	 * Cancel the task. If its running, wait for it to complete (ie do
12215 	 * nothing, per above).
12216 	 */
12217 	taskq_cancel_id(system_delay_taskq, tqid, B_TRUE);
12218 
12219 	/*
12220 	 * Task didn't run or aborted, so it never cleaned up. We do it on its
12221 	 * behalf.
12222 	 */
12223 	spa_notify_waiters(spa);
12224 	spa_close(spa, scns);
12225 }
12226 #endif
12227 
12228 /* state manipulation functions */
12229 EXPORT_SYMBOL(spa_open);
12230 EXPORT_SYMBOL(spa_open_rewind);
12231 EXPORT_SYMBOL(spa_get_stats);
12232 EXPORT_SYMBOL(spa_create);
12233 EXPORT_SYMBOL(spa_import);
12234 EXPORT_SYMBOL(spa_tryimport);
12235 EXPORT_SYMBOL(spa_destroy);
12236 EXPORT_SYMBOL(spa_export);
12237 EXPORT_SYMBOL(spa_reset);
12238 EXPORT_SYMBOL(spa_async_request);
12239 EXPORT_SYMBOL(spa_async_suspend);
12240 EXPORT_SYMBOL(spa_async_resume);
12241 EXPORT_SYMBOL(spa_inject_addref);
12242 EXPORT_SYMBOL(spa_inject_delref);
12243 EXPORT_SYMBOL(spa_scan_stat_init);
12244 EXPORT_SYMBOL(spa_scan_get_stats);
12245 
12246 /* device manipulation */
12247 EXPORT_SYMBOL(spa_vdev_add);
12248 EXPORT_SYMBOL(spa_vdev_attach);
12249 EXPORT_SYMBOL(spa_vdev_detach);
12250 EXPORT_SYMBOL(spa_vdev_setpath);
12251 EXPORT_SYMBOL(spa_vdev_setfru);
12252 EXPORT_SYMBOL(spa_vdev_split_mirror);
12253 
12254 /* spare statech is global across all pools) */
12255 EXPORT_SYMBOL(spa_spare_add);
12256 EXPORT_SYMBOL(spa_spare_remove);
12257 EXPORT_SYMBOL(spa_spare_exists);
12258 EXPORT_SYMBOL(spa_spare_activate);
12259 
12260 /* L2ARC statech is global across all pools) */
12261 EXPORT_SYMBOL(spa_l2cache_add);
12262 EXPORT_SYMBOL(spa_l2cache_remove);
12263 EXPORT_SYMBOL(spa_l2cache_exists);
12264 EXPORT_SYMBOL(spa_l2cache_activate);
12265 EXPORT_SYMBOL(spa_l2cache_drop);
12266 
12267 /* scanning */
12268 EXPORT_SYMBOL(spa_scan);
12269 EXPORT_SYMBOL(spa_scan_range);
12270 EXPORT_SYMBOL(spa_scan_stop);
12271 
12272 /* spa syncing */
12273 EXPORT_SYMBOL(spa_sync); /* only for DMU use */
12274 EXPORT_SYMBOL(spa_sync_allpools);
12275 
12276 /* properties */
12277 EXPORT_SYMBOL(spa_prop_set);
12278 EXPORT_SYMBOL(spa_prop_get);
12279 EXPORT_SYMBOL(spa_prop_clear_bootfs);
12280 
12281 /* asynchronous event notification */
12282 EXPORT_SYMBOL(spa_event_notify);
12283 
12284 ZFS_MODULE_PARAM(zfs_metaslab, metaslab_, preload_pct, UINT, ZMOD_RW,
12285 	"Percentage of CPUs to run a metaslab preload taskq");
12286 
12287 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_shift, UINT, ZMOD_RW,
12288 	"log2 fraction of arc that can be used by inflight I/Os when "
12289 	"verifying pool during import");
12290 
12291 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_metadata, INT, ZMOD_RW,
12292 	"Set to traverse metadata on pool import");
12293 
12294 ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_data, INT, ZMOD_RW,
12295 	"Set to traverse data on pool import");
12296 
12297 ZFS_MODULE_PARAM(zfs_spa, spa_, load_print_vdev_tree, INT, ZMOD_RW,
12298 	"Print vdev tree to zfs_dbgmsg during pool import");
12299 
12300 ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_pct, UINT, ZMOD_RW,
12301 	"Percentage of CPUs to run an IO worker thread");
12302 
12303 ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_tpq, UINT, ZMOD_RW,
12304 	"Number of threads per IO worker taskqueue");
12305 
12306 ZFS_MODULE_PARAM(zfs, zfs_, max_missing_tvds, U64, ZMOD_RW,
12307 	"Allow importing pool with up to this number of missing top-level "
12308 	"vdevs (in read-only mode)");
12309 
12310 ZFS_MODULE_PARAM(zfs, zfs_, max_missing_tvds_cachefile, U64, ZMOD_RW,
12311 	"Allow importing pools with missing top-level vdevs in cache file");
12312 
12313 ZFS_MODULE_PARAM(zfs, zfs_, max_missing_tvds_scan, U64, ZMOD_RW,
12314 	"Allow importing pools with missing top-level vdevs during scan");
12315 
12316 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, zthr_pause, INT,
12317 	ZMOD_RW, "Set the livelist condense zthr to pause");
12318 
12319 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, sync_pause, INT,
12320 	ZMOD_RW, "Set the livelist condense synctask to pause");
12321 
12322 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, sync_cancel,
12323 	INT, ZMOD_RW,
12324 	"Whether livelist condensing was canceled in the synctask");
12325 
12326 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, zthr_cancel,
12327 	INT, ZMOD_RW,
12328 	"Whether livelist condensing was canceled in the zthr function");
12329 
12330 ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, new_alloc, INT,
12331 	ZMOD_RW,
12332 	"Whether extra ALLOC blkptrs were added to a livelist entry while it "
12333 	"was being condensed");
12334 
12335 ZFS_MODULE_PARAM(zfs_spa, spa_, note_txg_time, UINT, ZMOD_RW,
12336 	"How frequently TXG timestamps are stored internally (in seconds)");
12337 
12338 ZFS_MODULE_PARAM(zfs_spa, spa_, flush_txg_time, UINT, ZMOD_RW,
12339 	"How frequently the TXG timestamps database should be flushed "
12340 	"to disk (in seconds)");
12341 
12342 #ifdef _KERNEL
12343 ZFS_MODULE_VIRTUAL_PARAM_CALL(zfs_zio, zio_, taskq_read,
12344 	spa_taskq_read_param_set, spa_taskq_read_param_get, ZMOD_RW,
12345 	"Configure IO queues for read IO");
12346 ZFS_MODULE_VIRTUAL_PARAM_CALL(zfs_zio, zio_, taskq_write,
12347 	spa_taskq_write_param_set, spa_taskq_write_param_get, ZMOD_RW,
12348 	"Configure IO queues for write IO");
12349 ZFS_MODULE_VIRTUAL_PARAM_CALL(zfs_zio, zio_, taskq_free,
12350 	spa_taskq_free_param_set, spa_taskq_free_param_get, ZMOD_RW,
12351 	"Configure IO queues for free IO");
12352 #endif
12353 
12354 ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_write_tpq, UINT, ZMOD_RW,
12355 	"Number of CPUs per write issue taskq");
12356 
12357 ZFS_MODULE_PARAM(zfs, zfs_, ccw_retry_interval, INT, ZMOD_RW,
12358 	"Configuration cache file write, retry after failure, interval "
12359 	"(seconds)");
12360