xref: /illumos-gate/usr/src/uts/common/fs/zfs/spa.c (revision 7f6f3ee7534143c5c719c28315b305ffa5e252b1)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * This file contains all the routines used when modifying on-disk SPA state.
29  * This includes opening, importing, destroying, exporting a pool, and syncing a
30  * pool.
31  */
32 
33 #include <sys/zfs_context.h>
34 #include <sys/fm/fs/zfs.h>
35 #include <sys/spa_impl.h>
36 #include <sys/zio.h>
37 #include <sys/zio_checksum.h>
38 #include <sys/dmu.h>
39 #include <sys/dmu_tx.h>
40 #include <sys/zap.h>
41 #include <sys/zil.h>
42 #include <sys/ddt.h>
43 #include <sys/vdev_impl.h>
44 #include <sys/metaslab.h>
45 #include <sys/metaslab_impl.h>
46 #include <sys/uberblock_impl.h>
47 #include <sys/txg.h>
48 #include <sys/avl.h>
49 #include <sys/dmu_traverse.h>
50 #include <sys/dmu_objset.h>
51 #include <sys/unique.h>
52 #include <sys/dsl_pool.h>
53 #include <sys/dsl_dataset.h>
54 #include <sys/dsl_dir.h>
55 #include <sys/dsl_prop.h>
56 #include <sys/dsl_synctask.h>
57 #include <sys/fs/zfs.h>
58 #include <sys/arc.h>
59 #include <sys/callb.h>
60 #include <sys/systeminfo.h>
61 #include <sys/spa_boot.h>
62 #include <sys/zfs_ioctl.h>
63 
64 #ifdef	_KERNEL
65 #include <sys/bootprops.h>
66 #include <sys/callb.h>
67 #include <sys/cpupart.h>
68 #include <sys/pool.h>
69 #include <sys/sysdc.h>
70 #include <sys/zone.h>
71 #endif	/* _KERNEL */
72 
73 #include "zfs_prop.h"
74 #include "zfs_comutil.h"
75 
76 typedef enum zti_modes {
77 	zti_mode_fixed,			/* value is # of threads (min 1) */
78 	zti_mode_online_percent,	/* value is % of online CPUs */
79 	zti_mode_batch,			/* cpu-intensive; value is ignored */
80 	zti_mode_null,			/* don't create a taskq */
81 	zti_nmodes
82 } zti_modes_t;
83 
84 #define	ZTI_FIX(n)	{ zti_mode_fixed, (n) }
85 #define	ZTI_PCT(n)	{ zti_mode_online_percent, (n) }
86 #define	ZTI_BATCH	{ zti_mode_batch, 0 }
87 #define	ZTI_NULL	{ zti_mode_null, 0 }
88 
89 #define	ZTI_ONE		ZTI_FIX(1)
90 
91 typedef struct zio_taskq_info {
92 	enum zti_modes zti_mode;
93 	uint_t zti_value;
94 } zio_taskq_info_t;
95 
96 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
97 	"issue", "issue_high", "intr", "intr_high"
98 };
99 
100 /*
101  * Define the taskq threads for the following I/O types:
102  * 	NULL, READ, WRITE, FREE, CLAIM, and IOCTL
103  */
104 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
105 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
106 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL },
107 	{ ZTI_FIX(8),	ZTI_NULL,	ZTI_BATCH,	ZTI_NULL },
108 	{ ZTI_BATCH,	ZTI_FIX(5),	ZTI_FIX(8),	ZTI_FIX(5) },
109 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL },
110 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL },
111 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL },
112 };
113 
114 static void spa_sync_props(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx);
115 static boolean_t spa_has_active_shared_spare(spa_t *spa);
116 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
117     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
118     char **ereport);
119 
120 uint_t		zio_taskq_batch_pct = 100;	/* 1 thread per cpu in pset */
121 id_t		zio_taskq_psrset_bind = PS_NONE;
122 boolean_t	zio_taskq_sysdc = B_TRUE;	/* use SDC scheduling class */
123 uint_t		zio_taskq_basedc = 80;		/* base duty cycle */
124 
125 boolean_t	spa_create_process = B_TRUE;	/* no process ==> no sysdc */
126 
127 /*
128  * This (illegal) pool name is used when temporarily importing a spa_t in order
129  * to get the vdev stats associated with the imported devices.
130  */
131 #define	TRYIMPORT_NAME	"$import"
132 
133 /*
134  * ==========================================================================
135  * SPA properties routines
136  * ==========================================================================
137  */
138 
139 /*
140  * Add a (source=src, propname=propval) list to an nvlist.
141  */
142 static void
143 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
144     uint64_t intval, zprop_source_t src)
145 {
146 	const char *propname = zpool_prop_to_name(prop);
147 	nvlist_t *propval;
148 
149 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
150 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
151 
152 	if (strval != NULL)
153 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
154 	else
155 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
156 
157 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
158 	nvlist_free(propval);
159 }
160 
161 /*
162  * Get property values from the spa configuration.
163  */
164 static void
165 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
166 {
167 	uint64_t size;
168 	uint64_t alloc;
169 	uint64_t cap, version;
170 	zprop_source_t src = ZPROP_SRC_NONE;
171 	spa_config_dirent_t *dp;
172 
173 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
174 
175 	if (spa->spa_root_vdev != NULL) {
176 		alloc = metaslab_class_get_alloc(spa_normal_class(spa));
177 		size = metaslab_class_get_space(spa_normal_class(spa));
178 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
179 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
180 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
181 		spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
182 		    size - alloc, src);
183 
184 		cap = (size == 0) ? 0 : (alloc * 100 / size);
185 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
186 
187 		spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
188 		    ddt_get_pool_dedup_ratio(spa), src);
189 
190 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
191 		    spa->spa_root_vdev->vdev_state, src);
192 
193 		version = spa_version(spa);
194 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
195 			src = ZPROP_SRC_DEFAULT;
196 		else
197 			src = ZPROP_SRC_LOCAL;
198 		spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
199 	}
200 
201 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
202 
203 	if (spa->spa_root != NULL)
204 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
205 		    0, ZPROP_SRC_LOCAL);
206 
207 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
208 		if (dp->scd_path == NULL) {
209 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
210 			    "none", 0, ZPROP_SRC_LOCAL);
211 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
212 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
213 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
214 		}
215 	}
216 }
217 
218 /*
219  * Get zpool property values.
220  */
221 int
222 spa_prop_get(spa_t *spa, nvlist_t **nvp)
223 {
224 	objset_t *mos = spa->spa_meta_objset;
225 	zap_cursor_t zc;
226 	zap_attribute_t za;
227 	int err;
228 
229 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
230 
231 	mutex_enter(&spa->spa_props_lock);
232 
233 	/*
234 	 * Get properties from the spa config.
235 	 */
236 	spa_prop_get_config(spa, nvp);
237 
238 	/* If no pool property object, no more prop to get. */
239 	if (mos == NULL || spa->spa_pool_props_object == 0) {
240 		mutex_exit(&spa->spa_props_lock);
241 		return (0);
242 	}
243 
244 	/*
245 	 * Get properties from the MOS pool property object.
246 	 */
247 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
248 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
249 	    zap_cursor_advance(&zc)) {
250 		uint64_t intval = 0;
251 		char *strval = NULL;
252 		zprop_source_t src = ZPROP_SRC_DEFAULT;
253 		zpool_prop_t prop;
254 
255 		if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
256 			continue;
257 
258 		switch (za.za_integer_length) {
259 		case 8:
260 			/* integer property */
261 			if (za.za_first_integer !=
262 			    zpool_prop_default_numeric(prop))
263 				src = ZPROP_SRC_LOCAL;
264 
265 			if (prop == ZPOOL_PROP_BOOTFS) {
266 				dsl_pool_t *dp;
267 				dsl_dataset_t *ds = NULL;
268 
269 				dp = spa_get_dsl(spa);
270 				rw_enter(&dp->dp_config_rwlock, RW_READER);
271 				if (err = dsl_dataset_hold_obj(dp,
272 				    za.za_first_integer, FTAG, &ds)) {
273 					rw_exit(&dp->dp_config_rwlock);
274 					break;
275 				}
276 
277 				strval = kmem_alloc(
278 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
279 				    KM_SLEEP);
280 				dsl_dataset_name(ds, strval);
281 				dsl_dataset_rele(ds, FTAG);
282 				rw_exit(&dp->dp_config_rwlock);
283 			} else {
284 				strval = NULL;
285 				intval = za.za_first_integer;
286 			}
287 
288 			spa_prop_add_list(*nvp, prop, strval, intval, src);
289 
290 			if (strval != NULL)
291 				kmem_free(strval,
292 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
293 
294 			break;
295 
296 		case 1:
297 			/* string property */
298 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
299 			err = zap_lookup(mos, spa->spa_pool_props_object,
300 			    za.za_name, 1, za.za_num_integers, strval);
301 			if (err) {
302 				kmem_free(strval, za.za_num_integers);
303 				break;
304 			}
305 			spa_prop_add_list(*nvp, prop, strval, 0, src);
306 			kmem_free(strval, za.za_num_integers);
307 			break;
308 
309 		default:
310 			break;
311 		}
312 	}
313 	zap_cursor_fini(&zc);
314 	mutex_exit(&spa->spa_props_lock);
315 out:
316 	if (err && err != ENOENT) {
317 		nvlist_free(*nvp);
318 		*nvp = NULL;
319 		return (err);
320 	}
321 
322 	return (0);
323 }
324 
325 /*
326  * Validate the given pool properties nvlist and modify the list
327  * for the property values to be set.
328  */
329 static int
330 spa_prop_validate(spa_t *spa, nvlist_t *props)
331 {
332 	nvpair_t *elem;
333 	int error = 0, reset_bootfs = 0;
334 	uint64_t objnum;
335 
336 	elem = NULL;
337 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
338 		zpool_prop_t prop;
339 		char *propname, *strval;
340 		uint64_t intval;
341 		objset_t *os;
342 		char *slash;
343 
344 		propname = nvpair_name(elem);
345 
346 		if ((prop = zpool_name_to_prop(propname)) == ZPROP_INVAL)
347 			return (EINVAL);
348 
349 		switch (prop) {
350 		case ZPOOL_PROP_VERSION:
351 			error = nvpair_value_uint64(elem, &intval);
352 			if (!error &&
353 			    (intval < spa_version(spa) || intval > SPA_VERSION))
354 				error = EINVAL;
355 			break;
356 
357 		case ZPOOL_PROP_DELEGATION:
358 		case ZPOOL_PROP_AUTOREPLACE:
359 		case ZPOOL_PROP_LISTSNAPS:
360 		case ZPOOL_PROP_AUTOEXPAND:
361 			error = nvpair_value_uint64(elem, &intval);
362 			if (!error && intval > 1)
363 				error = EINVAL;
364 			break;
365 
366 		case ZPOOL_PROP_BOOTFS:
367 			/*
368 			 * If the pool version is less than SPA_VERSION_BOOTFS,
369 			 * or the pool is still being created (version == 0),
370 			 * the bootfs property cannot be set.
371 			 */
372 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
373 				error = ENOTSUP;
374 				break;
375 			}
376 
377 			/*
378 			 * Make sure the vdev config is bootable
379 			 */
380 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
381 				error = ENOTSUP;
382 				break;
383 			}
384 
385 			reset_bootfs = 1;
386 
387 			error = nvpair_value_string(elem, &strval);
388 
389 			if (!error) {
390 				uint64_t compress;
391 
392 				if (strval == NULL || strval[0] == '\0') {
393 					objnum = zpool_prop_default_numeric(
394 					    ZPOOL_PROP_BOOTFS);
395 					break;
396 				}
397 
398 				if (error = dmu_objset_hold(strval, FTAG, &os))
399 					break;
400 
401 				/* Must be ZPL and not gzip compressed. */
402 
403 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
404 					error = ENOTSUP;
405 				} else if ((error = dsl_prop_get_integer(strval,
406 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
407 				    &compress, NULL)) == 0 &&
408 				    !BOOTFS_COMPRESS_VALID(compress)) {
409 					error = ENOTSUP;
410 				} else {
411 					objnum = dmu_objset_id(os);
412 				}
413 				dmu_objset_rele(os, FTAG);
414 			}
415 			break;
416 
417 		case ZPOOL_PROP_FAILUREMODE:
418 			error = nvpair_value_uint64(elem, &intval);
419 			if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
420 			    intval > ZIO_FAILURE_MODE_PANIC))
421 				error = EINVAL;
422 
423 			/*
424 			 * This is a special case which only occurs when
425 			 * the pool has completely failed. This allows
426 			 * the user to change the in-core failmode property
427 			 * without syncing it out to disk (I/Os might
428 			 * currently be blocked). We do this by returning
429 			 * EIO to the caller (spa_prop_set) to trick it
430 			 * into thinking we encountered a property validation
431 			 * error.
432 			 */
433 			if (!error && spa_suspended(spa)) {
434 				spa->spa_failmode = intval;
435 				error = EIO;
436 			}
437 			break;
438 
439 		case ZPOOL_PROP_CACHEFILE:
440 			if ((error = nvpair_value_string(elem, &strval)) != 0)
441 				break;
442 
443 			if (strval[0] == '\0')
444 				break;
445 
446 			if (strcmp(strval, "none") == 0)
447 				break;
448 
449 			if (strval[0] != '/') {
450 				error = EINVAL;
451 				break;
452 			}
453 
454 			slash = strrchr(strval, '/');
455 			ASSERT(slash != NULL);
456 
457 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
458 			    strcmp(slash, "/..") == 0)
459 				error = EINVAL;
460 			break;
461 
462 		case ZPOOL_PROP_DEDUPDITTO:
463 			if (spa_version(spa) < SPA_VERSION_DEDUP)
464 				error = ENOTSUP;
465 			else
466 				error = nvpair_value_uint64(elem, &intval);
467 			if (error == 0 &&
468 			    intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
469 				error = EINVAL;
470 			break;
471 		}
472 
473 		if (error)
474 			break;
475 	}
476 
477 	if (!error && reset_bootfs) {
478 		error = nvlist_remove(props,
479 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
480 
481 		if (!error) {
482 			error = nvlist_add_uint64(props,
483 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
484 		}
485 	}
486 
487 	return (error);
488 }
489 
490 void
491 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
492 {
493 	char *cachefile;
494 	spa_config_dirent_t *dp;
495 
496 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
497 	    &cachefile) != 0)
498 		return;
499 
500 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
501 	    KM_SLEEP);
502 
503 	if (cachefile[0] == '\0')
504 		dp->scd_path = spa_strdup(spa_config_path);
505 	else if (strcmp(cachefile, "none") == 0)
506 		dp->scd_path = NULL;
507 	else
508 		dp->scd_path = spa_strdup(cachefile);
509 
510 	list_insert_head(&spa->spa_config_list, dp);
511 	if (need_sync)
512 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
513 }
514 
515 int
516 spa_prop_set(spa_t *spa, nvlist_t *nvp)
517 {
518 	int error;
519 	nvpair_t *elem;
520 	boolean_t need_sync = B_FALSE;
521 	zpool_prop_t prop;
522 
523 	if ((error = spa_prop_validate(spa, nvp)) != 0)
524 		return (error);
525 
526 	elem = NULL;
527 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
528 		if ((prop = zpool_name_to_prop(
529 		    nvpair_name(elem))) == ZPROP_INVAL)
530 			return (EINVAL);
531 
532 		if (prop == ZPOOL_PROP_CACHEFILE || prop == ZPOOL_PROP_ALTROOT)
533 			continue;
534 
535 		need_sync = B_TRUE;
536 		break;
537 	}
538 
539 	if (need_sync)
540 		return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_sync_props,
541 		    spa, nvp, 3));
542 	else
543 		return (0);
544 }
545 
546 /*
547  * If the bootfs property value is dsobj, clear it.
548  */
549 void
550 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
551 {
552 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
553 		VERIFY(zap_remove(spa->spa_meta_objset,
554 		    spa->spa_pool_props_object,
555 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
556 		spa->spa_bootfs = 0;
557 	}
558 }
559 
560 /*
561  * ==========================================================================
562  * SPA state manipulation (open/create/destroy/import/export)
563  * ==========================================================================
564  */
565 
566 static int
567 spa_error_entry_compare(const void *a, const void *b)
568 {
569 	spa_error_entry_t *sa = (spa_error_entry_t *)a;
570 	spa_error_entry_t *sb = (spa_error_entry_t *)b;
571 	int ret;
572 
573 	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
574 	    sizeof (zbookmark_t));
575 
576 	if (ret < 0)
577 		return (-1);
578 	else if (ret > 0)
579 		return (1);
580 	else
581 		return (0);
582 }
583 
584 /*
585  * Utility function which retrieves copies of the current logs and
586  * re-initializes them in the process.
587  */
588 void
589 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
590 {
591 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
592 
593 	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
594 	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
595 
596 	avl_create(&spa->spa_errlist_scrub,
597 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
598 	    offsetof(spa_error_entry_t, se_avl));
599 	avl_create(&spa->spa_errlist_last,
600 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
601 	    offsetof(spa_error_entry_t, se_avl));
602 }
603 
604 static taskq_t *
605 spa_taskq_create(spa_t *spa, const char *name, enum zti_modes mode,
606     uint_t value)
607 {
608 	uint_t flags = TASKQ_PREPOPULATE;
609 	boolean_t batch = B_FALSE;
610 
611 	switch (mode) {
612 	case zti_mode_null:
613 		return (NULL);		/* no taskq needed */
614 
615 	case zti_mode_fixed:
616 		ASSERT3U(value, >=, 1);
617 		value = MAX(value, 1);
618 		break;
619 
620 	case zti_mode_batch:
621 		batch = B_TRUE;
622 		flags |= TASKQ_THREADS_CPU_PCT;
623 		value = zio_taskq_batch_pct;
624 		break;
625 
626 	case zti_mode_online_percent:
627 		flags |= TASKQ_THREADS_CPU_PCT;
628 		break;
629 
630 	default:
631 		panic("unrecognized mode for %s taskq (%u:%u) in "
632 		    "spa_activate()",
633 		    name, mode, value);
634 		break;
635 	}
636 
637 	if (zio_taskq_sysdc && spa->spa_proc != &p0) {
638 		if (batch)
639 			flags |= TASKQ_DC_BATCH;
640 
641 		return (taskq_create_sysdc(name, value, 50, INT_MAX,
642 		    spa->spa_proc, zio_taskq_basedc, flags));
643 	}
644 	return (taskq_create_proc(name, value, maxclsyspri, 50, INT_MAX,
645 	    spa->spa_proc, flags));
646 }
647 
648 static void
649 spa_create_zio_taskqs(spa_t *spa)
650 {
651 	for (int t = 0; t < ZIO_TYPES; t++) {
652 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
653 			const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
654 			enum zti_modes mode = ztip->zti_mode;
655 			uint_t value = ztip->zti_value;
656 			char name[32];
657 
658 			(void) snprintf(name, sizeof (name),
659 			    "%s_%s", zio_type_name[t], zio_taskq_types[q]);
660 
661 			spa->spa_zio_taskq[t][q] =
662 			    spa_taskq_create(spa, name, mode, value);
663 		}
664 	}
665 }
666 
667 #ifdef _KERNEL
668 static void
669 spa_thread(void *arg)
670 {
671 	callb_cpr_t cprinfo;
672 
673 	spa_t *spa = arg;
674 	user_t *pu = PTOU(curproc);
675 
676 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
677 	    spa->spa_name);
678 
679 	ASSERT(curproc != &p0);
680 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
681 	    "zpool-%s", spa->spa_name);
682 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
683 
684 	/* bind this thread to the requested psrset */
685 	if (zio_taskq_psrset_bind != PS_NONE) {
686 		pool_lock();
687 		mutex_enter(&cpu_lock);
688 		mutex_enter(&pidlock);
689 		mutex_enter(&curproc->p_lock);
690 
691 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
692 		    0, NULL, NULL) == 0)  {
693 			curthread->t_bind_pset = zio_taskq_psrset_bind;
694 		} else {
695 			cmn_err(CE_WARN,
696 			    "Couldn't bind process for zfs pool \"%s\" to "
697 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
698 		}
699 
700 		mutex_exit(&curproc->p_lock);
701 		mutex_exit(&pidlock);
702 		mutex_exit(&cpu_lock);
703 		pool_unlock();
704 	}
705 
706 	if (zio_taskq_sysdc) {
707 		sysdc_thread_enter(curthread, 100, 0);
708 	}
709 
710 	spa->spa_proc = curproc;
711 	spa->spa_did = curthread->t_did;
712 
713 	spa_create_zio_taskqs(spa);
714 
715 	mutex_enter(&spa->spa_proc_lock);
716 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
717 
718 	spa->spa_proc_state = SPA_PROC_ACTIVE;
719 	cv_broadcast(&spa->spa_proc_cv);
720 
721 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
722 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
723 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
724 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
725 
726 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
727 	spa->spa_proc_state = SPA_PROC_GONE;
728 	spa->spa_proc = &p0;
729 	cv_broadcast(&spa->spa_proc_cv);
730 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
731 
732 	mutex_enter(&curproc->p_lock);
733 	lwp_exit();
734 }
735 #endif
736 
737 /*
738  * Activate an uninitialized pool.
739  */
740 static void
741 spa_activate(spa_t *spa, int mode)
742 {
743 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
744 
745 	spa->spa_state = POOL_STATE_ACTIVE;
746 	spa->spa_mode = mode;
747 
748 	spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
749 	spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
750 
751 	/* Try to create a covering process */
752 	mutex_enter(&spa->spa_proc_lock);
753 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
754 	ASSERT(spa->spa_proc == &p0);
755 	spa->spa_did = 0;
756 
757 	/* Only create a process if we're going to be around a while. */
758 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
759 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
760 		    NULL, 0) == 0) {
761 			spa->spa_proc_state = SPA_PROC_CREATED;
762 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
763 				cv_wait(&spa->spa_proc_cv,
764 				    &spa->spa_proc_lock);
765 			}
766 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
767 			ASSERT(spa->spa_proc != &p0);
768 			ASSERT(spa->spa_did != 0);
769 		} else {
770 #ifdef _KERNEL
771 			cmn_err(CE_WARN,
772 			    "Couldn't create process for zfs pool \"%s\"\n",
773 			    spa->spa_name);
774 #endif
775 		}
776 	}
777 	mutex_exit(&spa->spa_proc_lock);
778 
779 	/* If we didn't create a process, we need to create our taskqs. */
780 	if (spa->spa_proc == &p0) {
781 		spa_create_zio_taskqs(spa);
782 	}
783 
784 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
785 	    offsetof(vdev_t, vdev_config_dirty_node));
786 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
787 	    offsetof(vdev_t, vdev_state_dirty_node));
788 
789 	txg_list_create(&spa->spa_vdev_txg_list,
790 	    offsetof(struct vdev, vdev_txg_node));
791 
792 	avl_create(&spa->spa_errlist_scrub,
793 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
794 	    offsetof(spa_error_entry_t, se_avl));
795 	avl_create(&spa->spa_errlist_last,
796 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
797 	    offsetof(spa_error_entry_t, se_avl));
798 }
799 
800 /*
801  * Opposite of spa_activate().
802  */
803 static void
804 spa_deactivate(spa_t *spa)
805 {
806 	ASSERT(spa->spa_sync_on == B_FALSE);
807 	ASSERT(spa->spa_dsl_pool == NULL);
808 	ASSERT(spa->spa_root_vdev == NULL);
809 	ASSERT(spa->spa_async_zio_root == NULL);
810 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
811 
812 	txg_list_destroy(&spa->spa_vdev_txg_list);
813 
814 	list_destroy(&spa->spa_config_dirty_list);
815 	list_destroy(&spa->spa_state_dirty_list);
816 
817 	for (int t = 0; t < ZIO_TYPES; t++) {
818 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
819 			if (spa->spa_zio_taskq[t][q] != NULL)
820 				taskq_destroy(spa->spa_zio_taskq[t][q]);
821 			spa->spa_zio_taskq[t][q] = NULL;
822 		}
823 	}
824 
825 	metaslab_class_destroy(spa->spa_normal_class);
826 	spa->spa_normal_class = NULL;
827 
828 	metaslab_class_destroy(spa->spa_log_class);
829 	spa->spa_log_class = NULL;
830 
831 	/*
832 	 * If this was part of an import or the open otherwise failed, we may
833 	 * still have errors left in the queues.  Empty them just in case.
834 	 */
835 	spa_errlog_drain(spa);
836 
837 	avl_destroy(&spa->spa_errlist_scrub);
838 	avl_destroy(&spa->spa_errlist_last);
839 
840 	spa->spa_state = POOL_STATE_UNINITIALIZED;
841 
842 	mutex_enter(&spa->spa_proc_lock);
843 	if (spa->spa_proc_state != SPA_PROC_NONE) {
844 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
845 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
846 		cv_broadcast(&spa->spa_proc_cv);
847 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
848 			ASSERT(spa->spa_proc != &p0);
849 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
850 		}
851 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
852 		spa->spa_proc_state = SPA_PROC_NONE;
853 	}
854 	ASSERT(spa->spa_proc == &p0);
855 	mutex_exit(&spa->spa_proc_lock);
856 
857 	/*
858 	 * We want to make sure spa_thread() has actually exited the ZFS
859 	 * module, so that the module can't be unloaded out from underneath
860 	 * it.
861 	 */
862 	if (spa->spa_did != 0) {
863 		thread_join(spa->spa_did);
864 		spa->spa_did = 0;
865 	}
866 }
867 
868 /*
869  * Verify a pool configuration, and construct the vdev tree appropriately.  This
870  * will create all the necessary vdevs in the appropriate layout, with each vdev
871  * in the CLOSED state.  This will prep the pool before open/creation/import.
872  * All vdev validation is done by the vdev_alloc() routine.
873  */
874 static int
875 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
876     uint_t id, int atype)
877 {
878 	nvlist_t **child;
879 	uint_t children;
880 	int error;
881 
882 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
883 		return (error);
884 
885 	if ((*vdp)->vdev_ops->vdev_op_leaf)
886 		return (0);
887 
888 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
889 	    &child, &children);
890 
891 	if (error == ENOENT)
892 		return (0);
893 
894 	if (error) {
895 		vdev_free(*vdp);
896 		*vdp = NULL;
897 		return (EINVAL);
898 	}
899 
900 	for (int c = 0; c < children; c++) {
901 		vdev_t *vd;
902 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
903 		    atype)) != 0) {
904 			vdev_free(*vdp);
905 			*vdp = NULL;
906 			return (error);
907 		}
908 	}
909 
910 	ASSERT(*vdp != NULL);
911 
912 	return (0);
913 }
914 
915 /*
916  * Opposite of spa_load().
917  */
918 static void
919 spa_unload(spa_t *spa)
920 {
921 	int i;
922 
923 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
924 
925 	/*
926 	 * Stop async tasks.
927 	 */
928 	spa_async_suspend(spa);
929 
930 	/*
931 	 * Stop syncing.
932 	 */
933 	if (spa->spa_sync_on) {
934 		txg_sync_stop(spa->spa_dsl_pool);
935 		spa->spa_sync_on = B_FALSE;
936 	}
937 
938 	/*
939 	 * Wait for any outstanding async I/O to complete.
940 	 */
941 	if (spa->spa_async_zio_root != NULL) {
942 		(void) zio_wait(spa->spa_async_zio_root);
943 		spa->spa_async_zio_root = NULL;
944 	}
945 
946 	/*
947 	 * Close the dsl pool.
948 	 */
949 	if (spa->spa_dsl_pool) {
950 		dsl_pool_close(spa->spa_dsl_pool);
951 		spa->spa_dsl_pool = NULL;
952 		spa->spa_meta_objset = NULL;
953 	}
954 
955 	ddt_unload(spa);
956 
957 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
958 
959 	/*
960 	 * Drop and purge level 2 cache
961 	 */
962 	spa_l2cache_drop(spa);
963 
964 	/*
965 	 * Close all vdevs.
966 	 */
967 	if (spa->spa_root_vdev)
968 		vdev_free(spa->spa_root_vdev);
969 	ASSERT(spa->spa_root_vdev == NULL);
970 
971 	for (i = 0; i < spa->spa_spares.sav_count; i++)
972 		vdev_free(spa->spa_spares.sav_vdevs[i]);
973 	if (spa->spa_spares.sav_vdevs) {
974 		kmem_free(spa->spa_spares.sav_vdevs,
975 		    spa->spa_spares.sav_count * sizeof (void *));
976 		spa->spa_spares.sav_vdevs = NULL;
977 	}
978 	if (spa->spa_spares.sav_config) {
979 		nvlist_free(spa->spa_spares.sav_config);
980 		spa->spa_spares.sav_config = NULL;
981 	}
982 	spa->spa_spares.sav_count = 0;
983 
984 	for (i = 0; i < spa->spa_l2cache.sav_count; i++)
985 		vdev_free(spa->spa_l2cache.sav_vdevs[i]);
986 	if (spa->spa_l2cache.sav_vdevs) {
987 		kmem_free(spa->spa_l2cache.sav_vdevs,
988 		    spa->spa_l2cache.sav_count * sizeof (void *));
989 		spa->spa_l2cache.sav_vdevs = NULL;
990 	}
991 	if (spa->spa_l2cache.sav_config) {
992 		nvlist_free(spa->spa_l2cache.sav_config);
993 		spa->spa_l2cache.sav_config = NULL;
994 	}
995 	spa->spa_l2cache.sav_count = 0;
996 
997 	spa->spa_async_suspended = 0;
998 
999 	spa_config_exit(spa, SCL_ALL, FTAG);
1000 }
1001 
1002 /*
1003  * Load (or re-load) the current list of vdevs describing the active spares for
1004  * this pool.  When this is called, we have some form of basic information in
1005  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1006  * then re-generate a more complete list including status information.
1007  */
1008 static void
1009 spa_load_spares(spa_t *spa)
1010 {
1011 	nvlist_t **spares;
1012 	uint_t nspares;
1013 	int i;
1014 	vdev_t *vd, *tvd;
1015 
1016 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1017 
1018 	/*
1019 	 * First, close and free any existing spare vdevs.
1020 	 */
1021 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1022 		vd = spa->spa_spares.sav_vdevs[i];
1023 
1024 		/* Undo the call to spa_activate() below */
1025 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1026 		    B_FALSE)) != NULL && tvd->vdev_isspare)
1027 			spa_spare_remove(tvd);
1028 		vdev_close(vd);
1029 		vdev_free(vd);
1030 	}
1031 
1032 	if (spa->spa_spares.sav_vdevs)
1033 		kmem_free(spa->spa_spares.sav_vdevs,
1034 		    spa->spa_spares.sav_count * sizeof (void *));
1035 
1036 	if (spa->spa_spares.sav_config == NULL)
1037 		nspares = 0;
1038 	else
1039 		VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1040 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1041 
1042 	spa->spa_spares.sav_count = (int)nspares;
1043 	spa->spa_spares.sav_vdevs = NULL;
1044 
1045 	if (nspares == 0)
1046 		return;
1047 
1048 	/*
1049 	 * Construct the array of vdevs, opening them to get status in the
1050 	 * process.   For each spare, there is potentially two different vdev_t
1051 	 * structures associated with it: one in the list of spares (used only
1052 	 * for basic validation purposes) and one in the active vdev
1053 	 * configuration (if it's spared in).  During this phase we open and
1054 	 * validate each vdev on the spare list.  If the vdev also exists in the
1055 	 * active configuration, then we also mark this vdev as an active spare.
1056 	 */
1057 	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1058 	    KM_SLEEP);
1059 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1060 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1061 		    VDEV_ALLOC_SPARE) == 0);
1062 		ASSERT(vd != NULL);
1063 
1064 		spa->spa_spares.sav_vdevs[i] = vd;
1065 
1066 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1067 		    B_FALSE)) != NULL) {
1068 			if (!tvd->vdev_isspare)
1069 				spa_spare_add(tvd);
1070 
1071 			/*
1072 			 * We only mark the spare active if we were successfully
1073 			 * able to load the vdev.  Otherwise, importing a pool
1074 			 * with a bad active spare would result in strange
1075 			 * behavior, because multiple pool would think the spare
1076 			 * is actively in use.
1077 			 *
1078 			 * There is a vulnerability here to an equally bizarre
1079 			 * circumstance, where a dead active spare is later
1080 			 * brought back to life (onlined or otherwise).  Given
1081 			 * the rarity of this scenario, and the extra complexity
1082 			 * it adds, we ignore the possibility.
1083 			 */
1084 			if (!vdev_is_dead(tvd))
1085 				spa_spare_activate(tvd);
1086 		}
1087 
1088 		vd->vdev_top = vd;
1089 		vd->vdev_aux = &spa->spa_spares;
1090 
1091 		if (vdev_open(vd) != 0)
1092 			continue;
1093 
1094 		if (vdev_validate_aux(vd) == 0)
1095 			spa_spare_add(vd);
1096 	}
1097 
1098 	/*
1099 	 * Recompute the stashed list of spares, with status information
1100 	 * this time.
1101 	 */
1102 	VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1103 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1104 
1105 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1106 	    KM_SLEEP);
1107 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1108 		spares[i] = vdev_config_generate(spa,
1109 		    spa->spa_spares.sav_vdevs[i], B_TRUE, B_TRUE, B_FALSE);
1110 	VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1111 	    ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1112 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1113 		nvlist_free(spares[i]);
1114 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1115 }
1116 
1117 /*
1118  * Load (or re-load) the current list of vdevs describing the active l2cache for
1119  * this pool.  When this is called, we have some form of basic information in
1120  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1121  * then re-generate a more complete list including status information.
1122  * Devices which are already active have their details maintained, and are
1123  * not re-opened.
1124  */
1125 static void
1126 spa_load_l2cache(spa_t *spa)
1127 {
1128 	nvlist_t **l2cache;
1129 	uint_t nl2cache;
1130 	int i, j, oldnvdevs;
1131 	uint64_t guid;
1132 	vdev_t *vd, **oldvdevs, **newvdevs;
1133 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1134 
1135 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1136 
1137 	if (sav->sav_config != NULL) {
1138 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1139 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1140 		newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1141 	} else {
1142 		nl2cache = 0;
1143 	}
1144 
1145 	oldvdevs = sav->sav_vdevs;
1146 	oldnvdevs = sav->sav_count;
1147 	sav->sav_vdevs = NULL;
1148 	sav->sav_count = 0;
1149 
1150 	/*
1151 	 * Process new nvlist of vdevs.
1152 	 */
1153 	for (i = 0; i < nl2cache; i++) {
1154 		VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1155 		    &guid) == 0);
1156 
1157 		newvdevs[i] = NULL;
1158 		for (j = 0; j < oldnvdevs; j++) {
1159 			vd = oldvdevs[j];
1160 			if (vd != NULL && guid == vd->vdev_guid) {
1161 				/*
1162 				 * Retain previous vdev for add/remove ops.
1163 				 */
1164 				newvdevs[i] = vd;
1165 				oldvdevs[j] = NULL;
1166 				break;
1167 			}
1168 		}
1169 
1170 		if (newvdevs[i] == NULL) {
1171 			/*
1172 			 * Create new vdev
1173 			 */
1174 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1175 			    VDEV_ALLOC_L2CACHE) == 0);
1176 			ASSERT(vd != NULL);
1177 			newvdevs[i] = vd;
1178 
1179 			/*
1180 			 * Commit this vdev as an l2cache device,
1181 			 * even if it fails to open.
1182 			 */
1183 			spa_l2cache_add(vd);
1184 
1185 			vd->vdev_top = vd;
1186 			vd->vdev_aux = sav;
1187 
1188 			spa_l2cache_activate(vd);
1189 
1190 			if (vdev_open(vd) != 0)
1191 				continue;
1192 
1193 			(void) vdev_validate_aux(vd);
1194 
1195 			if (!vdev_is_dead(vd))
1196 				l2arc_add_vdev(spa, vd);
1197 		}
1198 	}
1199 
1200 	/*
1201 	 * Purge vdevs that were dropped
1202 	 */
1203 	for (i = 0; i < oldnvdevs; i++) {
1204 		uint64_t pool;
1205 
1206 		vd = oldvdevs[i];
1207 		if (vd != NULL) {
1208 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1209 			    pool != 0ULL && l2arc_vdev_present(vd))
1210 				l2arc_remove_vdev(vd);
1211 			(void) vdev_close(vd);
1212 			spa_l2cache_remove(vd);
1213 		}
1214 	}
1215 
1216 	if (oldvdevs)
1217 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1218 
1219 	if (sav->sav_config == NULL)
1220 		goto out;
1221 
1222 	sav->sav_vdevs = newvdevs;
1223 	sav->sav_count = (int)nl2cache;
1224 
1225 	/*
1226 	 * Recompute the stashed list of l2cache devices, with status
1227 	 * information this time.
1228 	 */
1229 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1230 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1231 
1232 	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1233 	for (i = 0; i < sav->sav_count; i++)
1234 		l2cache[i] = vdev_config_generate(spa,
1235 		    sav->sav_vdevs[i], B_TRUE, B_FALSE, B_TRUE);
1236 	VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1237 	    ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1238 out:
1239 	for (i = 0; i < sav->sav_count; i++)
1240 		nvlist_free(l2cache[i]);
1241 	if (sav->sav_count)
1242 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
1243 }
1244 
1245 static int
1246 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1247 {
1248 	dmu_buf_t *db;
1249 	char *packed = NULL;
1250 	size_t nvsize = 0;
1251 	int error;
1252 	*value = NULL;
1253 
1254 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1255 	nvsize = *(uint64_t *)db->db_data;
1256 	dmu_buf_rele(db, FTAG);
1257 
1258 	packed = kmem_alloc(nvsize, KM_SLEEP);
1259 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1260 	    DMU_READ_PREFETCH);
1261 	if (error == 0)
1262 		error = nvlist_unpack(packed, nvsize, value, 0);
1263 	kmem_free(packed, nvsize);
1264 
1265 	return (error);
1266 }
1267 
1268 /*
1269  * Checks to see if the given vdev could not be opened, in which case we post a
1270  * sysevent to notify the autoreplace code that the device has been removed.
1271  */
1272 static void
1273 spa_check_removed(vdev_t *vd)
1274 {
1275 	for (int c = 0; c < vd->vdev_children; c++)
1276 		spa_check_removed(vd->vdev_child[c]);
1277 
1278 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd)) {
1279 		zfs_post_autoreplace(vd->vdev_spa, vd);
1280 		spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1281 	}
1282 }
1283 
1284 /*
1285  * Load the slog device state from the config object since it's possible
1286  * that the label does not contain the most up-to-date information.
1287  */
1288 void
1289 spa_load_log_state(spa_t *spa, nvlist_t *nv)
1290 {
1291 	vdev_t *ovd, *rvd = spa->spa_root_vdev;
1292 
1293 	/*
1294 	 * Load the original root vdev tree from the passed config.
1295 	 */
1296 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1297 	VERIFY(spa_config_parse(spa, &ovd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1298 
1299 	for (int c = 0; c < rvd->vdev_children; c++) {
1300 		vdev_t *cvd = rvd->vdev_child[c];
1301 		if (cvd->vdev_islog)
1302 			vdev_load_log_state(cvd, ovd->vdev_child[c]);
1303 	}
1304 	vdev_free(ovd);
1305 	spa_config_exit(spa, SCL_ALL, FTAG);
1306 }
1307 
1308 /*
1309  * Check for missing log devices
1310  */
1311 int
1312 spa_check_logs(spa_t *spa)
1313 {
1314 	switch (spa->spa_log_state) {
1315 	case SPA_LOG_MISSING:
1316 		/* need to recheck in case slog has been restored */
1317 	case SPA_LOG_UNKNOWN:
1318 		if (dmu_objset_find(spa->spa_name, zil_check_log_chain, NULL,
1319 		    DS_FIND_CHILDREN)) {
1320 			spa_set_log_state(spa, SPA_LOG_MISSING);
1321 			return (1);
1322 		}
1323 		break;
1324 	}
1325 	return (0);
1326 }
1327 
1328 static boolean_t
1329 spa_passivate_log(spa_t *spa)
1330 {
1331 	vdev_t *rvd = spa->spa_root_vdev;
1332 	boolean_t slog_found = B_FALSE;
1333 
1334 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1335 
1336 	if (!spa_has_slogs(spa))
1337 		return (B_FALSE);
1338 
1339 	for (int c = 0; c < rvd->vdev_children; c++) {
1340 		vdev_t *tvd = rvd->vdev_child[c];
1341 		metaslab_group_t *mg = tvd->vdev_mg;
1342 
1343 		if (tvd->vdev_islog) {
1344 			metaslab_group_passivate(mg);
1345 			slog_found = B_TRUE;
1346 		}
1347 	}
1348 
1349 	return (slog_found);
1350 }
1351 
1352 static void
1353 spa_activate_log(spa_t *spa)
1354 {
1355 	vdev_t *rvd = spa->spa_root_vdev;
1356 
1357 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1358 
1359 	for (int c = 0; c < rvd->vdev_children; c++) {
1360 		vdev_t *tvd = rvd->vdev_child[c];
1361 		metaslab_group_t *mg = tvd->vdev_mg;
1362 
1363 		if (tvd->vdev_islog)
1364 			metaslab_group_activate(mg);
1365 	}
1366 }
1367 
1368 int
1369 spa_offline_log(spa_t *spa)
1370 {
1371 	int error = 0;
1372 
1373 	if ((error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1374 	    NULL, DS_FIND_CHILDREN)) == 0) {
1375 
1376 		/*
1377 		 * We successfully offlined the log device, sync out the
1378 		 * current txg so that the "stubby" block can be removed
1379 		 * by zil_sync().
1380 		 */
1381 		txg_wait_synced(spa->spa_dsl_pool, 0);
1382 	}
1383 	return (error);
1384 }
1385 
1386 static void
1387 spa_aux_check_removed(spa_aux_vdev_t *sav)
1388 {
1389 	for (int i = 0; i < sav->sav_count; i++)
1390 		spa_check_removed(sav->sav_vdevs[i]);
1391 }
1392 
1393 void
1394 spa_claim_notify(zio_t *zio)
1395 {
1396 	spa_t *spa = zio->io_spa;
1397 
1398 	if (zio->io_error)
1399 		return;
1400 
1401 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
1402 	if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1403 		spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1404 	mutex_exit(&spa->spa_props_lock);
1405 }
1406 
1407 typedef struct spa_load_error {
1408 	uint64_t	sle_metadata_count;
1409 	uint64_t	sle_data_count;
1410 } spa_load_error_t;
1411 
1412 static void
1413 spa_load_verify_done(zio_t *zio)
1414 {
1415 	blkptr_t *bp = zio->io_bp;
1416 	spa_load_error_t *sle = zio->io_private;
1417 	dmu_object_type_t type = BP_GET_TYPE(bp);
1418 	int error = zio->io_error;
1419 
1420 	if (error) {
1421 		if ((BP_GET_LEVEL(bp) != 0 || dmu_ot[type].ot_metadata) &&
1422 		    type != DMU_OT_INTENT_LOG)
1423 			atomic_add_64(&sle->sle_metadata_count, 1);
1424 		else
1425 			atomic_add_64(&sle->sle_data_count, 1);
1426 	}
1427 	zio_data_buf_free(zio->io_data, zio->io_size);
1428 }
1429 
1430 /*ARGSUSED*/
1431 static int
1432 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1433     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1434 {
1435 	if (bp != NULL) {
1436 		zio_t *rio = arg;
1437 		size_t size = BP_GET_PSIZE(bp);
1438 		void *data = zio_data_buf_alloc(size);
1439 
1440 		zio_nowait(zio_read(rio, spa, bp, data, size,
1441 		    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1442 		    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1443 		    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1444 	}
1445 	return (0);
1446 }
1447 
1448 static int
1449 spa_load_verify(spa_t *spa)
1450 {
1451 	zio_t *rio;
1452 	spa_load_error_t sle = { 0 };
1453 	zpool_rewind_policy_t policy;
1454 	boolean_t verify_ok = B_FALSE;
1455 	int error;
1456 
1457 	rio = zio_root(spa, NULL, &sle,
1458 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1459 
1460 	error = traverse_pool(spa, spa->spa_verify_min_txg,
1461 	    TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1462 
1463 	(void) zio_wait(rio);
1464 
1465 	zpool_get_rewind_policy(spa->spa_config, &policy);
1466 
1467 	spa->spa_load_meta_errors = sle.sle_metadata_count;
1468 	spa->spa_load_data_errors = sle.sle_data_count;
1469 
1470 	if (!error && sle.sle_metadata_count <= policy.zrp_maxmeta &&
1471 	    sle.sle_data_count <= policy.zrp_maxdata) {
1472 		verify_ok = B_TRUE;
1473 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1474 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1475 	} else {
1476 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1477 	}
1478 
1479 	if (error) {
1480 		if (error != ENXIO && error != EIO)
1481 			error = EIO;
1482 		return (error);
1483 	}
1484 
1485 	return (verify_ok ? 0 : EIO);
1486 }
1487 
1488 /*
1489  * Find a value in the pool props object.
1490  */
1491 static void
1492 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1493 {
1494 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1495 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1496 }
1497 
1498 /*
1499  * Find a value in the pool directory object.
1500  */
1501 static int
1502 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1503 {
1504 	return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1505 	    name, sizeof (uint64_t), 1, val));
1506 }
1507 
1508 static int
1509 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1510 {
1511 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1512 	return (err);
1513 }
1514 
1515 /*
1516  * Fix up config after a partly-completed split.  This is done with the
1517  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1518  * pool have that entry in their config, but only the splitting one contains
1519  * a list of all the guids of the vdevs that are being split off.
1520  *
1521  * This function determines what to do with that list: either rejoin
1522  * all the disks to the pool, or complete the splitting process.  To attempt
1523  * the rejoin, each disk that is offlined is marked online again, and
1524  * we do a reopen() call.  If the vdev label for every disk that was
1525  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1526  * then we call vdev_split() on each disk, and complete the split.
1527  *
1528  * Otherwise we leave the config alone, with all the vdevs in place in
1529  * the original pool.
1530  */
1531 static void
1532 spa_try_repair(spa_t *spa, nvlist_t *config)
1533 {
1534 	uint_t extracted;
1535 	uint64_t *glist;
1536 	uint_t i, gcount;
1537 	nvlist_t *nvl;
1538 	vdev_t **vd;
1539 	boolean_t attempt_reopen;
1540 
1541 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1542 		return;
1543 
1544 	/* check that the config is complete */
1545 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1546 	    &glist, &gcount) != 0)
1547 		return;
1548 
1549 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1550 
1551 	/* attempt to online all the vdevs & validate */
1552 	attempt_reopen = B_TRUE;
1553 	for (i = 0; i < gcount; i++) {
1554 		if (glist[i] == 0)	/* vdev is hole */
1555 			continue;
1556 
1557 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1558 		if (vd[i] == NULL) {
1559 			/*
1560 			 * Don't bother attempting to reopen the disks;
1561 			 * just do the split.
1562 			 */
1563 			attempt_reopen = B_FALSE;
1564 		} else {
1565 			/* attempt to re-online it */
1566 			vd[i]->vdev_offline = B_FALSE;
1567 		}
1568 	}
1569 
1570 	if (attempt_reopen) {
1571 		vdev_reopen(spa->spa_root_vdev);
1572 
1573 		/* check each device to see what state it's in */
1574 		for (extracted = 0, i = 0; i < gcount; i++) {
1575 			if (vd[i] != NULL &&
1576 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1577 				break;
1578 			++extracted;
1579 		}
1580 	}
1581 
1582 	/*
1583 	 * If every disk has been moved to the new pool, or if we never
1584 	 * even attempted to look at them, then we split them off for
1585 	 * good.
1586 	 */
1587 	if (!attempt_reopen || gcount == extracted) {
1588 		for (i = 0; i < gcount; i++)
1589 			if (vd[i] != NULL)
1590 				vdev_split(vd[i]);
1591 		vdev_reopen(spa->spa_root_vdev);
1592 	}
1593 
1594 	kmem_free(vd, gcount * sizeof (vdev_t *));
1595 }
1596 
1597 static int
1598 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
1599     boolean_t mosconfig)
1600 {
1601 	nvlist_t *config = spa->spa_config;
1602 	char *ereport = FM_EREPORT_ZFS_POOL;
1603 	int error;
1604 	uint64_t pool_guid;
1605 	nvlist_t *nvl;
1606 
1607 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
1608 		return (EINVAL);
1609 
1610 	/*
1611 	 * Versioning wasn't explicitly added to the label until later, so if
1612 	 * it's not present treat it as the initial version.
1613 	 */
1614 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
1615 	    &spa->spa_ubsync.ub_version) != 0)
1616 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
1617 
1618 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
1619 	    &spa->spa_config_txg);
1620 
1621 	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
1622 	    spa_guid_exists(pool_guid, 0)) {
1623 		error = EEXIST;
1624 	} else {
1625 		spa->spa_load_guid = pool_guid;
1626 
1627 		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
1628 		    &nvl) == 0) {
1629 			VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
1630 			    KM_SLEEP) == 0);
1631 		}
1632 
1633 		error = spa_load_impl(spa, pool_guid, config, state, type,
1634 		    mosconfig, &ereport);
1635 	}
1636 
1637 	spa->spa_minref = refcount_count(&spa->spa_refcount);
1638 	if (error && error != EBADF)
1639 		zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
1640 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
1641 	spa->spa_ena = 0;
1642 
1643 	return (error);
1644 }
1645 
1646 /*
1647  * Load an existing storage pool, using the pool's builtin spa_config as a
1648  * source of configuration information.
1649  */
1650 static int
1651 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
1652     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
1653     char **ereport)
1654 {
1655 	int error = 0;
1656 	nvlist_t *nvconfig, *nvroot = NULL;
1657 	vdev_t *rvd;
1658 	uberblock_t *ub = &spa->spa_uberblock;
1659 	uint64_t config_cache_txg = spa->spa_config_txg;
1660 	int orig_mode = spa->spa_mode;
1661 	int parse;
1662 
1663 	/*
1664 	 * If this is an untrusted config, access the pool in read-only mode.
1665 	 * This prevents things like resilvering recently removed devices.
1666 	 */
1667 	if (!mosconfig)
1668 		spa->spa_mode = FREAD;
1669 
1670 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1671 
1672 	spa->spa_load_state = state;
1673 
1674 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
1675 		return (EINVAL);
1676 
1677 	parse = (type == SPA_IMPORT_EXISTING ?
1678 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
1679 
1680 	/*
1681 	 * Create "The Godfather" zio to hold all async IOs
1682 	 */
1683 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
1684 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
1685 
1686 	/*
1687 	 * Parse the configuration into a vdev tree.  We explicitly set the
1688 	 * value that will be returned by spa_version() since parsing the
1689 	 * configuration requires knowing the version number.
1690 	 */
1691 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1692 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
1693 	spa_config_exit(spa, SCL_ALL, FTAG);
1694 
1695 	if (error != 0)
1696 		return (error);
1697 
1698 	ASSERT(spa->spa_root_vdev == rvd);
1699 
1700 	if (type != SPA_IMPORT_ASSEMBLE) {
1701 		ASSERT(spa_guid(spa) == pool_guid);
1702 	}
1703 
1704 	/*
1705 	 * Try to open all vdevs, loading each label in the process.
1706 	 */
1707 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1708 	error = vdev_open(rvd);
1709 	spa_config_exit(spa, SCL_ALL, FTAG);
1710 	if (error != 0)
1711 		return (error);
1712 
1713 	/*
1714 	 * We need to validate the vdev labels against the configuration that
1715 	 * we have in hand, which is dependent on the setting of mosconfig. If
1716 	 * mosconfig is true then we're validating the vdev labels based on
1717 	 * that config.  Otherwise, we're validating against the cached config
1718 	 * (zpool.cache) that was read when we loaded the zfs module, and then
1719 	 * later we will recursively call spa_load() and validate against
1720 	 * the vdev config.
1721 	 *
1722 	 * If we're assembling a new pool that's been split off from an
1723 	 * existing pool, the labels haven't yet been updated so we skip
1724 	 * validation for now.
1725 	 */
1726 	if (type != SPA_IMPORT_ASSEMBLE) {
1727 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1728 		error = vdev_validate(rvd);
1729 		spa_config_exit(spa, SCL_ALL, FTAG);
1730 
1731 		if (error != 0)
1732 			return (error);
1733 
1734 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
1735 			return (ENXIO);
1736 	}
1737 
1738 	/*
1739 	 * Find the best uberblock.
1740 	 */
1741 	vdev_uberblock_load(NULL, rvd, ub);
1742 
1743 	/*
1744 	 * If we weren't able to find a single valid uberblock, return failure.
1745 	 */
1746 	if (ub->ub_txg == 0)
1747 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
1748 
1749 	/*
1750 	 * If the pool is newer than the code, we can't open it.
1751 	 */
1752 	if (ub->ub_version > SPA_VERSION)
1753 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
1754 
1755 	/*
1756 	 * If the vdev guid sum doesn't match the uberblock, we have an
1757 	 * incomplete configuration.
1758 	 */
1759 	if (mosconfig && type != SPA_IMPORT_ASSEMBLE &&
1760 	    rvd->vdev_guid_sum != ub->ub_guid_sum)
1761 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
1762 
1763 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
1764 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1765 		spa_try_repair(spa, config);
1766 		spa_config_exit(spa, SCL_ALL, FTAG);
1767 		nvlist_free(spa->spa_config_splitting);
1768 		spa->spa_config_splitting = NULL;
1769 	}
1770 
1771 	/*
1772 	 * Initialize internal SPA structures.
1773 	 */
1774 	spa->spa_state = POOL_STATE_ACTIVE;
1775 	spa->spa_ubsync = spa->spa_uberblock;
1776 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
1777 	    TXG_INITIAL : spa_last_synced_txg(spa) - TXG_DEFER_SIZE;
1778 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
1779 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
1780 	spa->spa_claim_max_txg = spa->spa_first_txg;
1781 
1782 	error = dsl_pool_open(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
1783 	if (error)
1784 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1785 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
1786 
1787 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
1788 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1789 
1790 	if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
1791 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1792 
1793 	if (!mosconfig) {
1794 		uint64_t hostid;
1795 
1796 		if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
1797 		    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
1798 			char *hostname;
1799 			unsigned long myhostid = 0;
1800 
1801 			VERIFY(nvlist_lookup_string(nvconfig,
1802 			    ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
1803 
1804 #ifdef	_KERNEL
1805 			myhostid = zone_get_hostid(NULL);
1806 #else	/* _KERNEL */
1807 			/*
1808 			 * We're emulating the system's hostid in userland, so
1809 			 * we can't use zone_get_hostid().
1810 			 */
1811 			(void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
1812 #endif	/* _KERNEL */
1813 			if (hostid != 0 && myhostid != 0 &&
1814 			    hostid != myhostid) {
1815 				cmn_err(CE_WARN, "pool '%s' could not be "
1816 				    "loaded as it was last accessed by "
1817 				    "another system (host: %s hostid: 0x%lx). "
1818 				    "See: http://www.sun.com/msg/ZFS-8000-EY",
1819 				    spa_name(spa), hostname,
1820 				    (unsigned long)hostid);
1821 				return (EBADF);
1822 			}
1823 		}
1824 
1825 		spa_config_set(spa, nvconfig);
1826 		spa_unload(spa);
1827 		spa_deactivate(spa);
1828 		spa_activate(spa, orig_mode);
1829 
1830 		return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
1831 	}
1832 
1833 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPLIST,
1834 	    &spa->spa_deferred_bplist_obj) != 0)
1835 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1836 
1837 	/*
1838 	 * Load the bit that tells us to use the new accounting function
1839 	 * (raid-z deflation).  If we have an older pool, this will not
1840 	 * be present.
1841 	 */
1842 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
1843 	if (error != 0 && error != ENOENT)
1844 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1845 
1846 	/*
1847 	 * Load the persistent error log.  If we have an older pool, this will
1848 	 * not be present.
1849 	 */
1850 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
1851 	if (error != 0 && error != ENOENT)
1852 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1853 
1854 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
1855 	    &spa->spa_errlog_scrub);
1856 	if (error != 0 && error != ENOENT)
1857 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1858 
1859 	/*
1860 	 * Load the history object.  If we have an older pool, this
1861 	 * will not be present.
1862 	 */
1863 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
1864 	if (error != 0 && error != ENOENT)
1865 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1866 
1867 	/*
1868 	 * If we're assembling the pool from the split-off vdevs of
1869 	 * an existing pool, we don't want to attach the spares & cache
1870 	 * devices.
1871 	 */
1872 
1873 	/*
1874 	 * Load any hot spares for this pool.
1875 	 */
1876 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
1877 	if (error != 0 && error != ENOENT)
1878 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1879 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
1880 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
1881 		if (load_nvlist(spa, spa->spa_spares.sav_object,
1882 		    &spa->spa_spares.sav_config) != 0)
1883 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1884 
1885 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1886 		spa_load_spares(spa);
1887 		spa_config_exit(spa, SCL_ALL, FTAG);
1888 	} else if (error == 0) {
1889 		spa->spa_spares.sav_sync = B_TRUE;
1890 	}
1891 
1892 	/*
1893 	 * Load any level 2 ARC devices for this pool.
1894 	 */
1895 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
1896 	    &spa->spa_l2cache.sav_object);
1897 	if (error != 0 && error != ENOENT)
1898 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1899 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
1900 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
1901 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
1902 		    &spa->spa_l2cache.sav_config) != 0)
1903 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1904 
1905 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1906 		spa_load_l2cache(spa);
1907 		spa_config_exit(spa, SCL_ALL, FTAG);
1908 	} else if (error == 0) {
1909 		spa->spa_l2cache.sav_sync = B_TRUE;
1910 	}
1911 
1912 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
1913 
1914 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
1915 	if (error && error != ENOENT)
1916 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1917 
1918 	if (error == 0) {
1919 		uint64_t autoreplace;
1920 
1921 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
1922 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
1923 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
1924 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
1925 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
1926 		spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
1927 		    &spa->spa_dedup_ditto);
1928 
1929 		spa->spa_autoreplace = (autoreplace != 0);
1930 	}
1931 
1932 	/*
1933 	 * If the 'autoreplace' property is set, then post a resource notifying
1934 	 * the ZFS DE that it should not issue any faults for unopenable
1935 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
1936 	 * unopenable vdevs so that the normal autoreplace handler can take
1937 	 * over.
1938 	 */
1939 	if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
1940 		spa_check_removed(spa->spa_root_vdev);
1941 		/*
1942 		 * For the import case, this is done in spa_import(), because
1943 		 * at this point we're using the spare definitions from
1944 		 * the MOS config, not necessarily from the userland config.
1945 		 */
1946 		if (state != SPA_LOAD_IMPORT) {
1947 			spa_aux_check_removed(&spa->spa_spares);
1948 			spa_aux_check_removed(&spa->spa_l2cache);
1949 		}
1950 	}
1951 
1952 	/*
1953 	 * Load the vdev state for all toplevel vdevs.
1954 	 */
1955 	vdev_load(rvd);
1956 
1957 	/*
1958 	 * Propagate the leaf DTLs we just loaded all the way up the tree.
1959 	 */
1960 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1961 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
1962 	spa_config_exit(spa, SCL_ALL, FTAG);
1963 
1964 	/*
1965 	 * Check the state of the root vdev.  If it can't be opened, it
1966 	 * indicates one or more toplevel vdevs are faulted.
1967 	 */
1968 	if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
1969 		return (ENXIO);
1970 
1971 	/*
1972 	 * Load the DDTs (dedup tables).
1973 	 */
1974 	error = ddt_load(spa);
1975 	if (error != 0)
1976 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
1977 
1978 	spa_update_dspace(spa);
1979 
1980 	if (state != SPA_LOAD_TRYIMPORT) {
1981 		error = spa_load_verify(spa);
1982 		if (error)
1983 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
1984 			    error));
1985 	}
1986 
1987 	/*
1988 	 * Load the intent log state and check log integrity.  If we're
1989 	 * assembling a pool from a split, the log is not transferred over.
1990 	 */
1991 	if (type != SPA_IMPORT_ASSEMBLE) {
1992 		VERIFY(nvlist_lookup_nvlist(nvconfig, ZPOOL_CONFIG_VDEV_TREE,
1993 		    &nvroot) == 0);
1994 		spa_load_log_state(spa, nvroot);
1995 		nvlist_free(nvconfig);
1996 
1997 		if (spa_check_logs(spa)) {
1998 			*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
1999 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2000 		}
2001 	}
2002 
2003 	if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2004 	    spa->spa_load_max_txg == UINT64_MAX)) {
2005 		dmu_tx_t *tx;
2006 		int need_update = B_FALSE;
2007 
2008 		ASSERT(state != SPA_LOAD_TRYIMPORT);
2009 
2010 		/*
2011 		 * Claim log blocks that haven't been committed yet.
2012 		 * This must all happen in a single txg.
2013 		 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2014 		 * invoked from zil_claim_log_block()'s i/o done callback.
2015 		 * Price of rollback is that we abandon the log.
2016 		 */
2017 		spa->spa_claiming = B_TRUE;
2018 
2019 		tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2020 		    spa_first_txg(spa));
2021 		(void) dmu_objset_find(spa_name(spa),
2022 		    zil_claim, tx, DS_FIND_CHILDREN);
2023 		dmu_tx_commit(tx);
2024 
2025 		spa->spa_claiming = B_FALSE;
2026 
2027 		spa_set_log_state(spa, SPA_LOG_GOOD);
2028 		spa->spa_sync_on = B_TRUE;
2029 		txg_sync_start(spa->spa_dsl_pool);
2030 
2031 		/*
2032 		 * Wait for all claims to sync.  We sync up to the highest
2033 		 * claimed log block birth time so that claimed log blocks
2034 		 * don't appear to be from the future.  spa_claim_max_txg
2035 		 * will have been set for us by either zil_check_log_chain()
2036 		 * (invoked from spa_check_logs()) or zil_claim() above.
2037 		 */
2038 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2039 
2040 		/*
2041 		 * If the config cache is stale, or we have uninitialized
2042 		 * metaslabs (see spa_vdev_add()), then update the config.
2043 		 *
2044 		 * If spa_load_verbatim is true, trust the current
2045 		 * in-core spa_config and update the disk labels.
2046 		 */
2047 		if (config_cache_txg != spa->spa_config_txg ||
2048 		    state == SPA_LOAD_IMPORT || spa->spa_load_verbatim ||
2049 		    state == SPA_LOAD_RECOVER)
2050 			need_update = B_TRUE;
2051 
2052 		for (int c = 0; c < rvd->vdev_children; c++)
2053 			if (rvd->vdev_child[c]->vdev_ms_array == 0)
2054 				need_update = B_TRUE;
2055 
2056 		/*
2057 		 * Update the config cache asychronously in case we're the
2058 		 * root pool, in which case the config cache isn't writable yet.
2059 		 */
2060 		if (need_update)
2061 			spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2062 
2063 		/*
2064 		 * Check all DTLs to see if anything needs resilvering.
2065 		 */
2066 		if (vdev_resilver_needed(rvd, NULL, NULL))
2067 			spa_async_request(spa, SPA_ASYNC_RESILVER);
2068 
2069 		/*
2070 		 * Delete any inconsistent datasets.
2071 		 */
2072 		(void) dmu_objset_find(spa_name(spa),
2073 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2074 
2075 		/*
2076 		 * Clean up any stale temporary dataset userrefs.
2077 		 */
2078 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2079 	}
2080 
2081 	return (0);
2082 }
2083 
2084 static int
2085 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2086 {
2087 	spa_unload(spa);
2088 	spa_deactivate(spa);
2089 
2090 	spa->spa_load_max_txg--;
2091 
2092 	spa_activate(spa, spa_mode_global);
2093 	spa_async_suspend(spa);
2094 
2095 	return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2096 }
2097 
2098 static int
2099 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2100     uint64_t max_request, boolean_t extreme)
2101 {
2102 	nvlist_t *config = NULL;
2103 	int load_error, rewind_error;
2104 	uint64_t safe_rollback_txg;
2105 	uint64_t min_txg;
2106 
2107 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2108 		spa->spa_load_max_txg = spa->spa_load_txg;
2109 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2110 	} else {
2111 		spa->spa_load_max_txg = max_request;
2112 	}
2113 
2114 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2115 	    mosconfig);
2116 	if (load_error == 0)
2117 		return (0);
2118 
2119 	if (spa->spa_root_vdev != NULL)
2120 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2121 
2122 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2123 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2124 
2125 	/* specific txg requested */
2126 	if (spa->spa_load_max_txg != UINT64_MAX && !extreme) {
2127 		nvlist_free(config);
2128 		return (load_error);
2129 	}
2130 
2131 	/* Price of rolling back is discarding txgs, including log */
2132 	if (state == SPA_LOAD_RECOVER)
2133 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2134 
2135 	spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
2136 	safe_rollback_txg = spa->spa_uberblock.ub_txg - TXG_DEFER_SIZE;
2137 
2138 	min_txg = extreme ? TXG_INITIAL : safe_rollback_txg;
2139 	while (rewind_error && (spa->spa_uberblock.ub_txg >= min_txg)) {
2140 		if (spa->spa_load_max_txg < safe_rollback_txg)
2141 			spa->spa_extreme_rewind = B_TRUE;
2142 		rewind_error = spa_load_retry(spa, state, mosconfig);
2143 	}
2144 
2145 	if (config)
2146 		spa_rewind_data_to_nvlist(spa, config);
2147 
2148 	spa->spa_extreme_rewind = B_FALSE;
2149 	spa->spa_load_max_txg = UINT64_MAX;
2150 
2151 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2152 		spa_config_set(spa, config);
2153 
2154 	return (state == SPA_LOAD_RECOVER ? rewind_error : load_error);
2155 }
2156 
2157 /*
2158  * Pool Open/Import
2159  *
2160  * The import case is identical to an open except that the configuration is sent
2161  * down from userland, instead of grabbed from the configuration cache.  For the
2162  * case of an open, the pool configuration will exist in the
2163  * POOL_STATE_UNINITIALIZED state.
2164  *
2165  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2166  * the same time open the pool, without having to keep around the spa_t in some
2167  * ambiguous state.
2168  */
2169 static int
2170 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2171     nvlist_t **config)
2172 {
2173 	spa_t *spa;
2174 	boolean_t norewind;
2175 	boolean_t extreme;
2176 	zpool_rewind_policy_t policy;
2177 	spa_load_state_t state = SPA_LOAD_OPEN;
2178 	int error;
2179 	int locked = B_FALSE;
2180 
2181 	*spapp = NULL;
2182 
2183 	zpool_get_rewind_policy(nvpolicy, &policy);
2184 	if (policy.zrp_request & ZPOOL_DO_REWIND)
2185 		state = SPA_LOAD_RECOVER;
2186 	norewind = (policy.zrp_request == ZPOOL_NO_REWIND);
2187 	extreme = ((policy.zrp_request & ZPOOL_EXTREME_REWIND) != 0);
2188 
2189 	/*
2190 	 * As disgusting as this is, we need to support recursive calls to this
2191 	 * function because dsl_dir_open() is called during spa_load(), and ends
2192 	 * up calling spa_open() again.  The real fix is to figure out how to
2193 	 * avoid dsl_dir_open() calling this in the first place.
2194 	 */
2195 	if (mutex_owner(&spa_namespace_lock) != curthread) {
2196 		mutex_enter(&spa_namespace_lock);
2197 		locked = B_TRUE;
2198 	}
2199 
2200 	if ((spa = spa_lookup(pool)) == NULL) {
2201 		if (locked)
2202 			mutex_exit(&spa_namespace_lock);
2203 		return (ENOENT);
2204 	}
2205 
2206 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2207 
2208 		spa_activate(spa, spa_mode_global);
2209 
2210 		if (spa->spa_last_open_failed && norewind) {
2211 			if (config != NULL && spa->spa_config)
2212 				VERIFY(nvlist_dup(spa->spa_config,
2213 				    config, KM_SLEEP) == 0);
2214 			spa_deactivate(spa);
2215 			if (locked)
2216 				mutex_exit(&spa_namespace_lock);
2217 			return (spa->spa_last_open_failed);
2218 		}
2219 
2220 		if (state != SPA_LOAD_RECOVER)
2221 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2222 
2223 		error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2224 		    extreme);
2225 
2226 		if (error == EBADF) {
2227 			/*
2228 			 * If vdev_validate() returns failure (indicated by
2229 			 * EBADF), it indicates that one of the vdevs indicates
2230 			 * that the pool has been exported or destroyed.  If
2231 			 * this is the case, the config cache is out of sync and
2232 			 * we should remove the pool from the namespace.
2233 			 */
2234 			spa_unload(spa);
2235 			spa_deactivate(spa);
2236 			spa_config_sync(spa, B_TRUE, B_TRUE);
2237 			spa_remove(spa);
2238 			if (locked)
2239 				mutex_exit(&spa_namespace_lock);
2240 			return (ENOENT);
2241 		}
2242 
2243 		if (error) {
2244 			/*
2245 			 * We can't open the pool, but we still have useful
2246 			 * information: the state of each vdev after the
2247 			 * attempted vdev_open().  Return this to the user.
2248 			 */
2249 			if (config != NULL && spa->spa_config)
2250 				VERIFY(nvlist_dup(spa->spa_config, config,
2251 				    KM_SLEEP) == 0);
2252 			spa_unload(spa);
2253 			spa_deactivate(spa);
2254 			spa->spa_last_open_failed = error;
2255 			if (locked)
2256 				mutex_exit(&spa_namespace_lock);
2257 			*spapp = NULL;
2258 			return (error);
2259 		}
2260 
2261 	}
2262 
2263 	spa_open_ref(spa, tag);
2264 
2265 
2266 	if (config != NULL)
2267 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2268 
2269 	if (locked) {
2270 		spa->spa_last_open_failed = 0;
2271 		spa->spa_last_ubsync_txg = 0;
2272 		spa->spa_load_txg = 0;
2273 		mutex_exit(&spa_namespace_lock);
2274 	}
2275 
2276 	*spapp = spa;
2277 
2278 	return (0);
2279 }
2280 
2281 int
2282 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2283     nvlist_t **config)
2284 {
2285 	return (spa_open_common(name, spapp, tag, policy, config));
2286 }
2287 
2288 int
2289 spa_open(const char *name, spa_t **spapp, void *tag)
2290 {
2291 	return (spa_open_common(name, spapp, tag, NULL, NULL));
2292 }
2293 
2294 /*
2295  * Lookup the given spa_t, incrementing the inject count in the process,
2296  * preventing it from being exported or destroyed.
2297  */
2298 spa_t *
2299 spa_inject_addref(char *name)
2300 {
2301 	spa_t *spa;
2302 
2303 	mutex_enter(&spa_namespace_lock);
2304 	if ((spa = spa_lookup(name)) == NULL) {
2305 		mutex_exit(&spa_namespace_lock);
2306 		return (NULL);
2307 	}
2308 	spa->spa_inject_ref++;
2309 	mutex_exit(&spa_namespace_lock);
2310 
2311 	return (spa);
2312 }
2313 
2314 void
2315 spa_inject_delref(spa_t *spa)
2316 {
2317 	mutex_enter(&spa_namespace_lock);
2318 	spa->spa_inject_ref--;
2319 	mutex_exit(&spa_namespace_lock);
2320 }
2321 
2322 /*
2323  * Add spares device information to the nvlist.
2324  */
2325 static void
2326 spa_add_spares(spa_t *spa, nvlist_t *config)
2327 {
2328 	nvlist_t **spares;
2329 	uint_t i, nspares;
2330 	nvlist_t *nvroot;
2331 	uint64_t guid;
2332 	vdev_stat_t *vs;
2333 	uint_t vsc;
2334 	uint64_t pool;
2335 
2336 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2337 
2338 	if (spa->spa_spares.sav_count == 0)
2339 		return;
2340 
2341 	VERIFY(nvlist_lookup_nvlist(config,
2342 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2343 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2344 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2345 	if (nspares != 0) {
2346 		VERIFY(nvlist_add_nvlist_array(nvroot,
2347 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2348 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
2349 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2350 
2351 		/*
2352 		 * Go through and find any spares which have since been
2353 		 * repurposed as an active spare.  If this is the case, update
2354 		 * their status appropriately.
2355 		 */
2356 		for (i = 0; i < nspares; i++) {
2357 			VERIFY(nvlist_lookup_uint64(spares[i],
2358 			    ZPOOL_CONFIG_GUID, &guid) == 0);
2359 			if (spa_spare_exists(guid, &pool, NULL) &&
2360 			    pool != 0ULL) {
2361 				VERIFY(nvlist_lookup_uint64_array(
2362 				    spares[i], ZPOOL_CONFIG_STATS,
2363 				    (uint64_t **)&vs, &vsc) == 0);
2364 				vs->vs_state = VDEV_STATE_CANT_OPEN;
2365 				vs->vs_aux = VDEV_AUX_SPARED;
2366 			}
2367 		}
2368 	}
2369 }
2370 
2371 /*
2372  * Add l2cache device information to the nvlist, including vdev stats.
2373  */
2374 static void
2375 spa_add_l2cache(spa_t *spa, nvlist_t *config)
2376 {
2377 	nvlist_t **l2cache;
2378 	uint_t i, j, nl2cache;
2379 	nvlist_t *nvroot;
2380 	uint64_t guid;
2381 	vdev_t *vd;
2382 	vdev_stat_t *vs;
2383 	uint_t vsc;
2384 
2385 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2386 
2387 	if (spa->spa_l2cache.sav_count == 0)
2388 		return;
2389 
2390 	VERIFY(nvlist_lookup_nvlist(config,
2391 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2392 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
2393 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2394 	if (nl2cache != 0) {
2395 		VERIFY(nvlist_add_nvlist_array(nvroot,
2396 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2397 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
2398 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
2399 
2400 		/*
2401 		 * Update level 2 cache device stats.
2402 		 */
2403 
2404 		for (i = 0; i < nl2cache; i++) {
2405 			VERIFY(nvlist_lookup_uint64(l2cache[i],
2406 			    ZPOOL_CONFIG_GUID, &guid) == 0);
2407 
2408 			vd = NULL;
2409 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
2410 				if (guid ==
2411 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
2412 					vd = spa->spa_l2cache.sav_vdevs[j];
2413 					break;
2414 				}
2415 			}
2416 			ASSERT(vd != NULL);
2417 
2418 			VERIFY(nvlist_lookup_uint64_array(l2cache[i],
2419 			    ZPOOL_CONFIG_STATS, (uint64_t **)&vs, &vsc) == 0);
2420 			vdev_get_stats(vd, vs);
2421 		}
2422 	}
2423 }
2424 
2425 int
2426 spa_get_stats(const char *name, nvlist_t **config, char *altroot, size_t buflen)
2427 {
2428 	int error;
2429 	spa_t *spa;
2430 
2431 	*config = NULL;
2432 	error = spa_open_common(name, &spa, FTAG, NULL, config);
2433 
2434 	if (spa != NULL) {
2435 		/*
2436 		 * This still leaves a window of inconsistency where the spares
2437 		 * or l2cache devices could change and the config would be
2438 		 * self-inconsistent.
2439 		 */
2440 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
2441 
2442 		if (*config != NULL) {
2443 			VERIFY(nvlist_add_uint64(*config,
2444 			    ZPOOL_CONFIG_ERRCOUNT,
2445 			    spa_get_errlog_size(spa)) == 0);
2446 
2447 			if (spa_suspended(spa))
2448 				VERIFY(nvlist_add_uint64(*config,
2449 				    ZPOOL_CONFIG_SUSPENDED,
2450 				    spa->spa_failmode) == 0);
2451 
2452 			spa_add_spares(spa, *config);
2453 			spa_add_l2cache(spa, *config);
2454 		}
2455 	}
2456 
2457 	/*
2458 	 * We want to get the alternate root even for faulted pools, so we cheat
2459 	 * and call spa_lookup() directly.
2460 	 */
2461 	if (altroot) {
2462 		if (spa == NULL) {
2463 			mutex_enter(&spa_namespace_lock);
2464 			spa = spa_lookup(name);
2465 			if (spa)
2466 				spa_altroot(spa, altroot, buflen);
2467 			else
2468 				altroot[0] = '\0';
2469 			spa = NULL;
2470 			mutex_exit(&spa_namespace_lock);
2471 		} else {
2472 			spa_altroot(spa, altroot, buflen);
2473 		}
2474 	}
2475 
2476 	if (spa != NULL) {
2477 		spa_config_exit(spa, SCL_CONFIG, FTAG);
2478 		spa_close(spa, FTAG);
2479 	}
2480 
2481 	return (error);
2482 }
2483 
2484 /*
2485  * Validate that the auxiliary device array is well formed.  We must have an
2486  * array of nvlists, each which describes a valid leaf vdev.  If this is an
2487  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
2488  * specified, as long as they are well-formed.
2489  */
2490 static int
2491 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
2492     spa_aux_vdev_t *sav, const char *config, uint64_t version,
2493     vdev_labeltype_t label)
2494 {
2495 	nvlist_t **dev;
2496 	uint_t i, ndev;
2497 	vdev_t *vd;
2498 	int error;
2499 
2500 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2501 
2502 	/*
2503 	 * It's acceptable to have no devs specified.
2504 	 */
2505 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
2506 		return (0);
2507 
2508 	if (ndev == 0)
2509 		return (EINVAL);
2510 
2511 	/*
2512 	 * Make sure the pool is formatted with a version that supports this
2513 	 * device type.
2514 	 */
2515 	if (spa_version(spa) < version)
2516 		return (ENOTSUP);
2517 
2518 	/*
2519 	 * Set the pending device list so we correctly handle device in-use
2520 	 * checking.
2521 	 */
2522 	sav->sav_pending = dev;
2523 	sav->sav_npending = ndev;
2524 
2525 	for (i = 0; i < ndev; i++) {
2526 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
2527 		    mode)) != 0)
2528 			goto out;
2529 
2530 		if (!vd->vdev_ops->vdev_op_leaf) {
2531 			vdev_free(vd);
2532 			error = EINVAL;
2533 			goto out;
2534 		}
2535 
2536 		/*
2537 		 * The L2ARC currently only supports disk devices in
2538 		 * kernel context.  For user-level testing, we allow it.
2539 		 */
2540 #ifdef _KERNEL
2541 		if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
2542 		    strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
2543 			error = ENOTBLK;
2544 			goto out;
2545 		}
2546 #endif
2547 		vd->vdev_top = vd;
2548 
2549 		if ((error = vdev_open(vd)) == 0 &&
2550 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
2551 			VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
2552 			    vd->vdev_guid) == 0);
2553 		}
2554 
2555 		vdev_free(vd);
2556 
2557 		if (error &&
2558 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
2559 			goto out;
2560 		else
2561 			error = 0;
2562 	}
2563 
2564 out:
2565 	sav->sav_pending = NULL;
2566 	sav->sav_npending = 0;
2567 	return (error);
2568 }
2569 
2570 static int
2571 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
2572 {
2573 	int error;
2574 
2575 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
2576 
2577 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
2578 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
2579 	    VDEV_LABEL_SPARE)) != 0) {
2580 		return (error);
2581 	}
2582 
2583 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
2584 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
2585 	    VDEV_LABEL_L2CACHE));
2586 }
2587 
2588 static void
2589 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
2590     const char *config)
2591 {
2592 	int i;
2593 
2594 	if (sav->sav_config != NULL) {
2595 		nvlist_t **olddevs;
2596 		uint_t oldndevs;
2597 		nvlist_t **newdevs;
2598 
2599 		/*
2600 		 * Generate new dev list by concatentating with the
2601 		 * current dev list.
2602 		 */
2603 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
2604 		    &olddevs, &oldndevs) == 0);
2605 
2606 		newdevs = kmem_alloc(sizeof (void *) *
2607 		    (ndevs + oldndevs), KM_SLEEP);
2608 		for (i = 0; i < oldndevs; i++)
2609 			VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
2610 			    KM_SLEEP) == 0);
2611 		for (i = 0; i < ndevs; i++)
2612 			VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
2613 			    KM_SLEEP) == 0);
2614 
2615 		VERIFY(nvlist_remove(sav->sav_config, config,
2616 		    DATA_TYPE_NVLIST_ARRAY) == 0);
2617 
2618 		VERIFY(nvlist_add_nvlist_array(sav->sav_config,
2619 		    config, newdevs, ndevs + oldndevs) == 0);
2620 		for (i = 0; i < oldndevs + ndevs; i++)
2621 			nvlist_free(newdevs[i]);
2622 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
2623 	} else {
2624 		/*
2625 		 * Generate a new dev list.
2626 		 */
2627 		VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
2628 		    KM_SLEEP) == 0);
2629 		VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
2630 		    devs, ndevs) == 0);
2631 	}
2632 }
2633 
2634 /*
2635  * Stop and drop level 2 ARC devices
2636  */
2637 void
2638 spa_l2cache_drop(spa_t *spa)
2639 {
2640 	vdev_t *vd;
2641 	int i;
2642 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
2643 
2644 	for (i = 0; i < sav->sav_count; i++) {
2645 		uint64_t pool;
2646 
2647 		vd = sav->sav_vdevs[i];
2648 		ASSERT(vd != NULL);
2649 
2650 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
2651 		    pool != 0ULL && l2arc_vdev_present(vd))
2652 			l2arc_remove_vdev(vd);
2653 		if (vd->vdev_isl2cache)
2654 			spa_l2cache_remove(vd);
2655 		vdev_clear_stats(vd);
2656 		(void) vdev_close(vd);
2657 	}
2658 }
2659 
2660 /*
2661  * Pool Creation
2662  */
2663 int
2664 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
2665     const char *history_str, nvlist_t *zplprops)
2666 {
2667 	spa_t *spa;
2668 	char *altroot = NULL;
2669 	vdev_t *rvd;
2670 	dsl_pool_t *dp;
2671 	dmu_tx_t *tx;
2672 	int error = 0;
2673 	uint64_t txg = TXG_INITIAL;
2674 	nvlist_t **spares, **l2cache;
2675 	uint_t nspares, nl2cache;
2676 	uint64_t version;
2677 
2678 	/*
2679 	 * If this pool already exists, return failure.
2680 	 */
2681 	mutex_enter(&spa_namespace_lock);
2682 	if (spa_lookup(pool) != NULL) {
2683 		mutex_exit(&spa_namespace_lock);
2684 		return (EEXIST);
2685 	}
2686 
2687 	/*
2688 	 * Allocate a new spa_t structure.
2689 	 */
2690 	(void) nvlist_lookup_string(props,
2691 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
2692 	spa = spa_add(pool, NULL, altroot);
2693 	spa_activate(spa, spa_mode_global);
2694 
2695 	if (props && (error = spa_prop_validate(spa, props))) {
2696 		spa_deactivate(spa);
2697 		spa_remove(spa);
2698 		mutex_exit(&spa_namespace_lock);
2699 		return (error);
2700 	}
2701 
2702 	if (nvlist_lookup_uint64(props, zpool_prop_to_name(ZPOOL_PROP_VERSION),
2703 	    &version) != 0)
2704 		version = SPA_VERSION;
2705 	ASSERT(version <= SPA_VERSION);
2706 
2707 	spa->spa_first_txg = txg;
2708 	spa->spa_uberblock.ub_txg = txg - 1;
2709 	spa->spa_uberblock.ub_version = version;
2710 	spa->spa_ubsync = spa->spa_uberblock;
2711 
2712 	/*
2713 	 * Create "The Godfather" zio to hold all async IOs
2714 	 */
2715 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2716 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2717 
2718 	/*
2719 	 * Create the root vdev.
2720 	 */
2721 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2722 
2723 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
2724 
2725 	ASSERT(error != 0 || rvd != NULL);
2726 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
2727 
2728 	if (error == 0 && !zfs_allocatable_devs(nvroot))
2729 		error = EINVAL;
2730 
2731 	if (error == 0 &&
2732 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
2733 	    (error = spa_validate_aux(spa, nvroot, txg,
2734 	    VDEV_ALLOC_ADD)) == 0) {
2735 		for (int c = 0; c < rvd->vdev_children; c++) {
2736 			vdev_metaslab_set_size(rvd->vdev_child[c]);
2737 			vdev_expand(rvd->vdev_child[c], txg);
2738 		}
2739 	}
2740 
2741 	spa_config_exit(spa, SCL_ALL, FTAG);
2742 
2743 	if (error != 0) {
2744 		spa_unload(spa);
2745 		spa_deactivate(spa);
2746 		spa_remove(spa);
2747 		mutex_exit(&spa_namespace_lock);
2748 		return (error);
2749 	}
2750 
2751 	/*
2752 	 * Get the list of spares, if specified.
2753 	 */
2754 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
2755 	    &spares, &nspares) == 0) {
2756 		VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
2757 		    KM_SLEEP) == 0);
2758 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
2759 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2760 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2761 		spa_load_spares(spa);
2762 		spa_config_exit(spa, SCL_ALL, FTAG);
2763 		spa->spa_spares.sav_sync = B_TRUE;
2764 	}
2765 
2766 	/*
2767 	 * Get the list of level 2 cache devices, if specified.
2768 	 */
2769 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
2770 	    &l2cache, &nl2cache) == 0) {
2771 		VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
2772 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
2773 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
2774 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2775 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2776 		spa_load_l2cache(spa);
2777 		spa_config_exit(spa, SCL_ALL, FTAG);
2778 		spa->spa_l2cache.sav_sync = B_TRUE;
2779 	}
2780 
2781 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
2782 	spa->spa_meta_objset = dp->dp_meta_objset;
2783 
2784 	/*
2785 	 * Create DDTs (dedup tables).
2786 	 */
2787 	ddt_create(spa);
2788 
2789 	spa_update_dspace(spa);
2790 
2791 	tx = dmu_tx_create_assigned(dp, txg);
2792 
2793 	/*
2794 	 * Create the pool config object.
2795 	 */
2796 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
2797 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
2798 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
2799 
2800 	if (zap_add(spa->spa_meta_objset,
2801 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
2802 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
2803 		cmn_err(CE_PANIC, "failed to add pool config");
2804 	}
2805 
2806 	/* Newly created pools with the right version are always deflated. */
2807 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
2808 		spa->spa_deflate = TRUE;
2809 		if (zap_add(spa->spa_meta_objset,
2810 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
2811 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
2812 			cmn_err(CE_PANIC, "failed to add deflate");
2813 		}
2814 	}
2815 
2816 	/*
2817 	 * Create the deferred-free bplist object.  Turn off compression
2818 	 * because sync-to-convergence takes longer if the blocksize
2819 	 * keeps changing.
2820 	 */
2821 	spa->spa_deferred_bplist_obj = bplist_create(spa->spa_meta_objset,
2822 	    1 << 14, tx);
2823 	dmu_object_set_compress(spa->spa_meta_objset,
2824 	    spa->spa_deferred_bplist_obj, ZIO_COMPRESS_OFF, tx);
2825 
2826 	if (zap_add(spa->spa_meta_objset,
2827 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPLIST,
2828 	    sizeof (uint64_t), 1, &spa->spa_deferred_bplist_obj, tx) != 0) {
2829 		cmn_err(CE_PANIC, "failed to add bplist");
2830 	}
2831 
2832 	/*
2833 	 * Create the pool's history object.
2834 	 */
2835 	if (version >= SPA_VERSION_ZPOOL_HISTORY)
2836 		spa_history_create_obj(spa, tx);
2837 
2838 	/*
2839 	 * Set pool properties.
2840 	 */
2841 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
2842 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2843 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
2844 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
2845 
2846 	if (props != NULL) {
2847 		spa_configfile_set(spa, props, B_FALSE);
2848 		spa_sync_props(spa, props, CRED(), tx);
2849 	}
2850 
2851 	dmu_tx_commit(tx);
2852 
2853 	spa->spa_sync_on = B_TRUE;
2854 	txg_sync_start(spa->spa_dsl_pool);
2855 
2856 	/*
2857 	 * We explicitly wait for the first transaction to complete so that our
2858 	 * bean counters are appropriately updated.
2859 	 */
2860 	txg_wait_synced(spa->spa_dsl_pool, txg);
2861 
2862 	spa_config_sync(spa, B_FALSE, B_TRUE);
2863 
2864 	if (version >= SPA_VERSION_ZPOOL_HISTORY && history_str != NULL)
2865 		(void) spa_history_log(spa, history_str, LOG_CMD_POOL_CREATE);
2866 	spa_history_log_version(spa, LOG_POOL_CREATE);
2867 
2868 	spa->spa_minref = refcount_count(&spa->spa_refcount);
2869 
2870 	mutex_exit(&spa_namespace_lock);
2871 
2872 	return (0);
2873 }
2874 
2875 #ifdef _KERNEL
2876 /*
2877  * Get the root pool information from the root disk, then import the root pool
2878  * during the system boot up time.
2879  */
2880 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
2881 
2882 static nvlist_t *
2883 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
2884 {
2885 	nvlist_t *config;
2886 	nvlist_t *nvtop, *nvroot;
2887 	uint64_t pgid;
2888 
2889 	if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
2890 		return (NULL);
2891 
2892 	/*
2893 	 * Add this top-level vdev to the child array.
2894 	 */
2895 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
2896 	    &nvtop) == 0);
2897 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
2898 	    &pgid) == 0);
2899 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
2900 
2901 	/*
2902 	 * Put this pool's top-level vdevs into a root vdev.
2903 	 */
2904 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2905 	VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
2906 	    VDEV_TYPE_ROOT) == 0);
2907 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
2908 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
2909 	VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
2910 	    &nvtop, 1) == 0);
2911 
2912 	/*
2913 	 * Replace the existing vdev_tree with the new root vdev in
2914 	 * this pool's configuration (remove the old, add the new).
2915 	 */
2916 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
2917 	nvlist_free(nvroot);
2918 	return (config);
2919 }
2920 
2921 /*
2922  * Walk the vdev tree and see if we can find a device with "better"
2923  * configuration. A configuration is "better" if the label on that
2924  * device has a more recent txg.
2925  */
2926 static void
2927 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
2928 {
2929 	for (int c = 0; c < vd->vdev_children; c++)
2930 		spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
2931 
2932 	if (vd->vdev_ops->vdev_op_leaf) {
2933 		nvlist_t *label;
2934 		uint64_t label_txg;
2935 
2936 		if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
2937 		    &label) != 0)
2938 			return;
2939 
2940 		VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
2941 		    &label_txg) == 0);
2942 
2943 		/*
2944 		 * Do we have a better boot device?
2945 		 */
2946 		if (label_txg > *txg) {
2947 			*txg = label_txg;
2948 			*avd = vd;
2949 		}
2950 		nvlist_free(label);
2951 	}
2952 }
2953 
2954 /*
2955  * Import a root pool.
2956  *
2957  * For x86. devpath_list will consist of devid and/or physpath name of
2958  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
2959  * The GRUB "findroot" command will return the vdev we should boot.
2960  *
2961  * For Sparc, devpath_list consists the physpath name of the booting device
2962  * no matter the rootpool is a single device pool or a mirrored pool.
2963  * e.g.
2964  *	"/pci@1f,0/ide@d/disk@0,0:a"
2965  */
2966 int
2967 spa_import_rootpool(char *devpath, char *devid)
2968 {
2969 	spa_t *spa;
2970 	vdev_t *rvd, *bvd, *avd = NULL;
2971 	nvlist_t *config, *nvtop;
2972 	uint64_t guid, txg;
2973 	char *pname;
2974 	int error;
2975 
2976 	/*
2977 	 * Read the label from the boot device and generate a configuration.
2978 	 */
2979 	config = spa_generate_rootconf(devpath, devid, &guid);
2980 #if defined(_OBP) && defined(_KERNEL)
2981 	if (config == NULL) {
2982 		if (strstr(devpath, "/iscsi/ssd") != NULL) {
2983 			/* iscsi boot */
2984 			get_iscsi_bootpath_phy(devpath);
2985 			config = spa_generate_rootconf(devpath, devid, &guid);
2986 		}
2987 	}
2988 #endif
2989 	if (config == NULL) {
2990 		cmn_err(CE_NOTE, "Can not read the pool label from '%s'",
2991 		    devpath);
2992 		return (EIO);
2993 	}
2994 
2995 	VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
2996 	    &pname) == 0);
2997 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
2998 
2999 	mutex_enter(&spa_namespace_lock);
3000 	if ((spa = spa_lookup(pname)) != NULL) {
3001 		/*
3002 		 * Remove the existing root pool from the namespace so that we
3003 		 * can replace it with the correct config we just read in.
3004 		 */
3005 		spa_remove(spa);
3006 	}
3007 
3008 	spa = spa_add(pname, config, NULL);
3009 	spa->spa_is_root = B_TRUE;
3010 	spa->spa_load_verbatim = B_TRUE;
3011 
3012 	/*
3013 	 * Build up a vdev tree based on the boot device's label config.
3014 	 */
3015 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3016 	    &nvtop) == 0);
3017 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3018 	error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3019 	    VDEV_ALLOC_ROOTPOOL);
3020 	spa_config_exit(spa, SCL_ALL, FTAG);
3021 	if (error) {
3022 		mutex_exit(&spa_namespace_lock);
3023 		nvlist_free(config);
3024 		cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3025 		    pname);
3026 		return (error);
3027 	}
3028 
3029 	/*
3030 	 * Get the boot vdev.
3031 	 */
3032 	if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3033 		cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3034 		    (u_longlong_t)guid);
3035 		error = ENOENT;
3036 		goto out;
3037 	}
3038 
3039 	/*
3040 	 * Determine if there is a better boot device.
3041 	 */
3042 	avd = bvd;
3043 	spa_alt_rootvdev(rvd, &avd, &txg);
3044 	if (avd != bvd) {
3045 		cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3046 		    "try booting from '%s'", avd->vdev_path);
3047 		error = EINVAL;
3048 		goto out;
3049 	}
3050 
3051 	/*
3052 	 * If the boot device is part of a spare vdev then ensure that
3053 	 * we're booting off the active spare.
3054 	 */
3055 	if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3056 	    !bvd->vdev_isspare) {
3057 		cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3058 		    "try booting from '%s'",
3059 		    bvd->vdev_parent->vdev_child[1]->vdev_path);
3060 		error = EINVAL;
3061 		goto out;
3062 	}
3063 
3064 	error = 0;
3065 	spa_history_log_version(spa, LOG_POOL_IMPORT);
3066 out:
3067 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3068 	vdev_free(rvd);
3069 	spa_config_exit(spa, SCL_ALL, FTAG);
3070 	mutex_exit(&spa_namespace_lock);
3071 
3072 	nvlist_free(config);
3073 	return (error);
3074 }
3075 
3076 #endif
3077 
3078 /*
3079  * Take a pool and insert it into the namespace as if it had been loaded at
3080  * boot.
3081  */
3082 int
3083 spa_import_verbatim(const char *pool, nvlist_t *config, nvlist_t *props)
3084 {
3085 	spa_t *spa;
3086 	zpool_rewind_policy_t policy;
3087 	char *altroot = NULL;
3088 
3089 	mutex_enter(&spa_namespace_lock);
3090 	if (spa_lookup(pool) != NULL) {
3091 		mutex_exit(&spa_namespace_lock);
3092 		return (EEXIST);
3093 	}
3094 
3095 	(void) nvlist_lookup_string(props,
3096 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3097 	spa = spa_add(pool, config, altroot);
3098 
3099 	zpool_get_rewind_policy(config, &policy);
3100 	spa->spa_load_max_txg = policy.zrp_txg;
3101 
3102 	spa->spa_load_verbatim = B_TRUE;
3103 
3104 	if (props != NULL)
3105 		spa_configfile_set(spa, props, B_FALSE);
3106 
3107 	spa_config_sync(spa, B_FALSE, B_TRUE);
3108 
3109 	mutex_exit(&spa_namespace_lock);
3110 	spa_history_log_version(spa, LOG_POOL_IMPORT);
3111 
3112 	return (0);
3113 }
3114 
3115 /*
3116  * Import a non-root pool into the system.
3117  */
3118 int
3119 spa_import(const char *pool, nvlist_t *config, nvlist_t *props)
3120 {
3121 	spa_t *spa;
3122 	char *altroot = NULL;
3123 	spa_load_state_t state = SPA_LOAD_IMPORT;
3124 	zpool_rewind_policy_t policy;
3125 	int error;
3126 	nvlist_t *nvroot;
3127 	nvlist_t **spares, **l2cache;
3128 	uint_t nspares, nl2cache;
3129 
3130 	/*
3131 	 * If a pool with this name exists, return failure.
3132 	 */
3133 	mutex_enter(&spa_namespace_lock);
3134 	if (spa_lookup(pool) != NULL) {
3135 		mutex_exit(&spa_namespace_lock);
3136 		return (EEXIST);
3137 	}
3138 
3139 	zpool_get_rewind_policy(config, &policy);
3140 	if (policy.zrp_request & ZPOOL_DO_REWIND)
3141 		state = SPA_LOAD_RECOVER;
3142 
3143 	/*
3144 	 * Create and initialize the spa structure.
3145 	 */
3146 	(void) nvlist_lookup_string(props,
3147 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3148 	spa = spa_add(pool, config, altroot);
3149 	spa_activate(spa, spa_mode_global);
3150 
3151 	/*
3152 	 * Don't start async tasks until we know everything is healthy.
3153 	 */
3154 	spa_async_suspend(spa);
3155 
3156 	/*
3157 	 * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3158 	 * because the user-supplied config is actually the one to trust when
3159 	 * doing an import.
3160 	 */
3161 	if (state != SPA_LOAD_RECOVER)
3162 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3163 	error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3164 	    ((policy.zrp_request & ZPOOL_EXTREME_REWIND) != 0));
3165 
3166 	/*
3167 	 * Propagate anything learned about failing or best txgs
3168 	 * back to caller
3169 	 */
3170 	spa_rewind_data_to_nvlist(spa, config);
3171 
3172 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3173 	/*
3174 	 * Toss any existing sparelist, as it doesn't have any validity
3175 	 * anymore, and conflicts with spa_has_spare().
3176 	 */
3177 	if (spa->spa_spares.sav_config) {
3178 		nvlist_free(spa->spa_spares.sav_config);
3179 		spa->spa_spares.sav_config = NULL;
3180 		spa_load_spares(spa);
3181 	}
3182 	if (spa->spa_l2cache.sav_config) {
3183 		nvlist_free(spa->spa_l2cache.sav_config);
3184 		spa->spa_l2cache.sav_config = NULL;
3185 		spa_load_l2cache(spa);
3186 	}
3187 
3188 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3189 	    &nvroot) == 0);
3190 	if (error == 0)
3191 		error = spa_validate_aux(spa, nvroot, -1ULL,
3192 		    VDEV_ALLOC_SPARE);
3193 	if (error == 0)
3194 		error = spa_validate_aux(spa, nvroot, -1ULL,
3195 		    VDEV_ALLOC_L2CACHE);
3196 	spa_config_exit(spa, SCL_ALL, FTAG);
3197 
3198 	if (props != NULL)
3199 		spa_configfile_set(spa, props, B_FALSE);
3200 
3201 	if (error != 0 || (props && spa_writeable(spa) &&
3202 	    (error = spa_prop_set(spa, props)))) {
3203 		spa_unload(spa);
3204 		spa_deactivate(spa);
3205 		spa_remove(spa);
3206 		mutex_exit(&spa_namespace_lock);
3207 		return (error);
3208 	}
3209 
3210 	spa_async_resume(spa);
3211 
3212 	/*
3213 	 * Override any spares and level 2 cache devices as specified by
3214 	 * the user, as these may have correct device names/devids, etc.
3215 	 */
3216 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3217 	    &spares, &nspares) == 0) {
3218 		if (spa->spa_spares.sav_config)
3219 			VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3220 			    ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3221 		else
3222 			VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3223 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3224 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3225 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3226 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3227 		spa_load_spares(spa);
3228 		spa_config_exit(spa, SCL_ALL, FTAG);
3229 		spa->spa_spares.sav_sync = B_TRUE;
3230 	}
3231 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3232 	    &l2cache, &nl2cache) == 0) {
3233 		if (spa->spa_l2cache.sav_config)
3234 			VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3235 			    ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3236 		else
3237 			VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3238 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3239 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3240 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3241 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3242 		spa_load_l2cache(spa);
3243 		spa_config_exit(spa, SCL_ALL, FTAG);
3244 		spa->spa_l2cache.sav_sync = B_TRUE;
3245 	}
3246 
3247 	/*
3248 	 * Check for any removed devices.
3249 	 */
3250 	if (spa->spa_autoreplace) {
3251 		spa_aux_check_removed(&spa->spa_spares);
3252 		spa_aux_check_removed(&spa->spa_l2cache);
3253 	}
3254 
3255 	if (spa_writeable(spa)) {
3256 		/*
3257 		 * Update the config cache to include the newly-imported pool.
3258 		 */
3259 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3260 	}
3261 
3262 	/*
3263 	 * It's possible that the pool was expanded while it was exported.
3264 	 * We kick off an async task to handle this for us.
3265 	 */
3266 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3267 
3268 	mutex_exit(&spa_namespace_lock);
3269 	spa_history_log_version(spa, LOG_POOL_IMPORT);
3270 
3271 	return (0);
3272 }
3273 
3274 nvlist_t *
3275 spa_tryimport(nvlist_t *tryconfig)
3276 {
3277 	nvlist_t *config = NULL;
3278 	char *poolname;
3279 	spa_t *spa;
3280 	uint64_t state;
3281 	int error;
3282 
3283 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3284 		return (NULL);
3285 
3286 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3287 		return (NULL);
3288 
3289 	/*
3290 	 * Create and initialize the spa structure.
3291 	 */
3292 	mutex_enter(&spa_namespace_lock);
3293 	spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3294 	spa_activate(spa, FREAD);
3295 
3296 	/*
3297 	 * Pass off the heavy lifting to spa_load().
3298 	 * Pass TRUE for mosconfig because the user-supplied config
3299 	 * is actually the one to trust when doing an import.
3300 	 */
3301 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
3302 
3303 	/*
3304 	 * If 'tryconfig' was at least parsable, return the current config.
3305 	 */
3306 	if (spa->spa_root_vdev != NULL) {
3307 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3308 		VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
3309 		    poolname) == 0);
3310 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
3311 		    state) == 0);
3312 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
3313 		    spa->spa_uberblock.ub_timestamp) == 0);
3314 
3315 		/*
3316 		 * If the bootfs property exists on this pool then we
3317 		 * copy it out so that external consumers can tell which
3318 		 * pools are bootable.
3319 		 */
3320 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
3321 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3322 
3323 			/*
3324 			 * We have to play games with the name since the
3325 			 * pool was opened as TRYIMPORT_NAME.
3326 			 */
3327 			if (dsl_dsobj_to_dsname(spa_name(spa),
3328 			    spa->spa_bootfs, tmpname) == 0) {
3329 				char *cp;
3330 				char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
3331 
3332 				cp = strchr(tmpname, '/');
3333 				if (cp == NULL) {
3334 					(void) strlcpy(dsname, tmpname,
3335 					    MAXPATHLEN);
3336 				} else {
3337 					(void) snprintf(dsname, MAXPATHLEN,
3338 					    "%s/%s", poolname, ++cp);
3339 				}
3340 				VERIFY(nvlist_add_string(config,
3341 				    ZPOOL_CONFIG_BOOTFS, dsname) == 0);
3342 				kmem_free(dsname, MAXPATHLEN);
3343 			}
3344 			kmem_free(tmpname, MAXPATHLEN);
3345 		}
3346 
3347 		/*
3348 		 * Add the list of hot spares and level 2 cache devices.
3349 		 */
3350 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3351 		spa_add_spares(spa, config);
3352 		spa_add_l2cache(spa, config);
3353 		spa_config_exit(spa, SCL_CONFIG, FTAG);
3354 	}
3355 
3356 	spa_unload(spa);
3357 	spa_deactivate(spa);
3358 	spa_remove(spa);
3359 	mutex_exit(&spa_namespace_lock);
3360 
3361 	return (config);
3362 }
3363 
3364 /*
3365  * Pool export/destroy
3366  *
3367  * The act of destroying or exporting a pool is very simple.  We make sure there
3368  * is no more pending I/O and any references to the pool are gone.  Then, we
3369  * update the pool state and sync all the labels to disk, removing the
3370  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
3371  * we don't sync the labels or remove the configuration cache.
3372  */
3373 static int
3374 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
3375     boolean_t force, boolean_t hardforce)
3376 {
3377 	spa_t *spa;
3378 
3379 	if (oldconfig)
3380 		*oldconfig = NULL;
3381 
3382 	if (!(spa_mode_global & FWRITE))
3383 		return (EROFS);
3384 
3385 	mutex_enter(&spa_namespace_lock);
3386 	if ((spa = spa_lookup(pool)) == NULL) {
3387 		mutex_exit(&spa_namespace_lock);
3388 		return (ENOENT);
3389 	}
3390 
3391 	/*
3392 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
3393 	 * reacquire the namespace lock, and see if we can export.
3394 	 */
3395 	spa_open_ref(spa, FTAG);
3396 	mutex_exit(&spa_namespace_lock);
3397 	spa_async_suspend(spa);
3398 	mutex_enter(&spa_namespace_lock);
3399 	spa_close(spa, FTAG);
3400 
3401 	/*
3402 	 * The pool will be in core if it's openable,
3403 	 * in which case we can modify its state.
3404 	 */
3405 	if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
3406 		/*
3407 		 * Objsets may be open only because they're dirty, so we
3408 		 * have to force it to sync before checking spa_refcnt.
3409 		 */
3410 		txg_wait_synced(spa->spa_dsl_pool, 0);
3411 
3412 		/*
3413 		 * A pool cannot be exported or destroyed if there are active
3414 		 * references.  If we are resetting a pool, allow references by
3415 		 * fault injection handlers.
3416 		 */
3417 		if (!spa_refcount_zero(spa) ||
3418 		    (spa->spa_inject_ref != 0 &&
3419 		    new_state != POOL_STATE_UNINITIALIZED)) {
3420 			spa_async_resume(spa);
3421 			mutex_exit(&spa_namespace_lock);
3422 			return (EBUSY);
3423 		}
3424 
3425 		/*
3426 		 * A pool cannot be exported if it has an active shared spare.
3427 		 * This is to prevent other pools stealing the active spare
3428 		 * from an exported pool. At user's own will, such pool can
3429 		 * be forcedly exported.
3430 		 */
3431 		if (!force && new_state == POOL_STATE_EXPORTED &&
3432 		    spa_has_active_shared_spare(spa)) {
3433 			spa_async_resume(spa);
3434 			mutex_exit(&spa_namespace_lock);
3435 			return (EXDEV);
3436 		}
3437 
3438 		/*
3439 		 * We want this to be reflected on every label,
3440 		 * so mark them all dirty.  spa_unload() will do the
3441 		 * final sync that pushes these changes out.
3442 		 */
3443 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
3444 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3445 			spa->spa_state = new_state;
3446 			spa->spa_final_txg = spa_last_synced_txg(spa) + 1;
3447 			vdev_config_dirty(spa->spa_root_vdev);
3448 			spa_config_exit(spa, SCL_ALL, FTAG);
3449 		}
3450 	}
3451 
3452 	spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
3453 
3454 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
3455 		spa_unload(spa);
3456 		spa_deactivate(spa);
3457 	}
3458 
3459 	if (oldconfig && spa->spa_config)
3460 		VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
3461 
3462 	if (new_state != POOL_STATE_UNINITIALIZED) {
3463 		if (!hardforce)
3464 			spa_config_sync(spa, B_TRUE, B_TRUE);
3465 		spa_remove(spa);
3466 	}
3467 	mutex_exit(&spa_namespace_lock);
3468 
3469 	return (0);
3470 }
3471 
3472 /*
3473  * Destroy a storage pool.
3474  */
3475 int
3476 spa_destroy(char *pool)
3477 {
3478 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
3479 	    B_FALSE, B_FALSE));
3480 }
3481 
3482 /*
3483  * Export a storage pool.
3484  */
3485 int
3486 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
3487     boolean_t hardforce)
3488 {
3489 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
3490 	    force, hardforce));
3491 }
3492 
3493 /*
3494  * Similar to spa_export(), this unloads the spa_t without actually removing it
3495  * from the namespace in any way.
3496  */
3497 int
3498 spa_reset(char *pool)
3499 {
3500 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
3501 	    B_FALSE, B_FALSE));
3502 }
3503 
3504 /*
3505  * ==========================================================================
3506  * Device manipulation
3507  * ==========================================================================
3508  */
3509 
3510 /*
3511  * Add a device to a storage pool.
3512  */
3513 int
3514 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
3515 {
3516 	uint64_t txg, id;
3517 	int error;
3518 	vdev_t *rvd = spa->spa_root_vdev;
3519 	vdev_t *vd, *tvd;
3520 	nvlist_t **spares, **l2cache;
3521 	uint_t nspares, nl2cache;
3522 
3523 	txg = spa_vdev_enter(spa);
3524 
3525 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
3526 	    VDEV_ALLOC_ADD)) != 0)
3527 		return (spa_vdev_exit(spa, NULL, txg, error));
3528 
3529 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
3530 
3531 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
3532 	    &nspares) != 0)
3533 		nspares = 0;
3534 
3535 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
3536 	    &nl2cache) != 0)
3537 		nl2cache = 0;
3538 
3539 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
3540 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
3541 
3542 	if (vd->vdev_children != 0 &&
3543 	    (error = vdev_create(vd, txg, B_FALSE)) != 0)
3544 		return (spa_vdev_exit(spa, vd, txg, error));
3545 
3546 	/*
3547 	 * We must validate the spares and l2cache devices after checking the
3548 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
3549 	 */
3550 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
3551 		return (spa_vdev_exit(spa, vd, txg, error));
3552 
3553 	/*
3554 	 * Transfer each new top-level vdev from vd to rvd.
3555 	 */
3556 	for (int c = 0; c < vd->vdev_children; c++) {
3557 
3558 		/*
3559 		 * Set the vdev id to the first hole, if one exists.
3560 		 */
3561 		for (id = 0; id < rvd->vdev_children; id++) {
3562 			if (rvd->vdev_child[id]->vdev_ishole) {
3563 				vdev_free(rvd->vdev_child[id]);
3564 				break;
3565 			}
3566 		}
3567 		tvd = vd->vdev_child[c];
3568 		vdev_remove_child(vd, tvd);
3569 		tvd->vdev_id = id;
3570 		vdev_add_child(rvd, tvd);
3571 		vdev_config_dirty(tvd);
3572 	}
3573 
3574 	if (nspares != 0) {
3575 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
3576 		    ZPOOL_CONFIG_SPARES);
3577 		spa_load_spares(spa);
3578 		spa->spa_spares.sav_sync = B_TRUE;
3579 	}
3580 
3581 	if (nl2cache != 0) {
3582 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
3583 		    ZPOOL_CONFIG_L2CACHE);
3584 		spa_load_l2cache(spa);
3585 		spa->spa_l2cache.sav_sync = B_TRUE;
3586 	}
3587 
3588 	/*
3589 	 * We have to be careful when adding new vdevs to an existing pool.
3590 	 * If other threads start allocating from these vdevs before we
3591 	 * sync the config cache, and we lose power, then upon reboot we may
3592 	 * fail to open the pool because there are DVAs that the config cache
3593 	 * can't translate.  Therefore, we first add the vdevs without
3594 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
3595 	 * and then let spa_config_update() initialize the new metaslabs.
3596 	 *
3597 	 * spa_load() checks for added-but-not-initialized vdevs, so that
3598 	 * if we lose power at any point in this sequence, the remaining
3599 	 * steps will be completed the next time we load the pool.
3600 	 */
3601 	(void) spa_vdev_exit(spa, vd, txg, 0);
3602 
3603 	mutex_enter(&spa_namespace_lock);
3604 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3605 	mutex_exit(&spa_namespace_lock);
3606 
3607 	return (0);
3608 }
3609 
3610 /*
3611  * Attach a device to a mirror.  The arguments are the path to any device
3612  * in the mirror, and the nvroot for the new device.  If the path specifies
3613  * a device that is not mirrored, we automatically insert the mirror vdev.
3614  *
3615  * If 'replacing' is specified, the new device is intended to replace the
3616  * existing device; in this case the two devices are made into their own
3617  * mirror using the 'replacing' vdev, which is functionally identical to
3618  * the mirror vdev (it actually reuses all the same ops) but has a few
3619  * extra rules: you can't attach to it after it's been created, and upon
3620  * completion of resilvering, the first disk (the one being replaced)
3621  * is automatically detached.
3622  */
3623 int
3624 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
3625 {
3626 	uint64_t txg, open_txg;
3627 	vdev_t *rvd = spa->spa_root_vdev;
3628 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
3629 	vdev_ops_t *pvops;
3630 	char *oldvdpath, *newvdpath;
3631 	int newvd_isspare;
3632 	int error;
3633 
3634 	txg = spa_vdev_enter(spa);
3635 
3636 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
3637 
3638 	if (oldvd == NULL)
3639 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
3640 
3641 	if (!oldvd->vdev_ops->vdev_op_leaf)
3642 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3643 
3644 	pvd = oldvd->vdev_parent;
3645 
3646 	if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
3647 	    VDEV_ALLOC_ADD)) != 0)
3648 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
3649 
3650 	if (newrootvd->vdev_children != 1)
3651 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
3652 
3653 	newvd = newrootvd->vdev_child[0];
3654 
3655 	if (!newvd->vdev_ops->vdev_op_leaf)
3656 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
3657 
3658 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
3659 		return (spa_vdev_exit(spa, newrootvd, txg, error));
3660 
3661 	/*
3662 	 * Spares can't replace logs
3663 	 */
3664 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
3665 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3666 
3667 	if (!replacing) {
3668 		/*
3669 		 * For attach, the only allowable parent is a mirror or the root
3670 		 * vdev.
3671 		 */
3672 		if (pvd->vdev_ops != &vdev_mirror_ops &&
3673 		    pvd->vdev_ops != &vdev_root_ops)
3674 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3675 
3676 		pvops = &vdev_mirror_ops;
3677 	} else {
3678 		/*
3679 		 * Active hot spares can only be replaced by inactive hot
3680 		 * spares.
3681 		 */
3682 		if (pvd->vdev_ops == &vdev_spare_ops &&
3683 		    pvd->vdev_child[1] == oldvd &&
3684 		    !spa_has_spare(spa, newvd->vdev_guid))
3685 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3686 
3687 		/*
3688 		 * If the source is a hot spare, and the parent isn't already a
3689 		 * spare, then we want to create a new hot spare.  Otherwise, we
3690 		 * want to create a replacing vdev.  The user is not allowed to
3691 		 * attach to a spared vdev child unless the 'isspare' state is
3692 		 * the same (spare replaces spare, non-spare replaces
3693 		 * non-spare).
3694 		 */
3695 		if (pvd->vdev_ops == &vdev_replacing_ops)
3696 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3697 		else if (pvd->vdev_ops == &vdev_spare_ops &&
3698 		    newvd->vdev_isspare != oldvd->vdev_isspare)
3699 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
3700 		else if (pvd->vdev_ops != &vdev_spare_ops &&
3701 		    newvd->vdev_isspare)
3702 			pvops = &vdev_spare_ops;
3703 		else
3704 			pvops = &vdev_replacing_ops;
3705 	}
3706 
3707 	/*
3708 	 * Make sure the new device is big enough.
3709 	 */
3710 	if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
3711 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
3712 
3713 	/*
3714 	 * The new device cannot have a higher alignment requirement
3715 	 * than the top-level vdev.
3716 	 */
3717 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
3718 		return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
3719 
3720 	/*
3721 	 * If this is an in-place replacement, update oldvd's path and devid
3722 	 * to make it distinguishable from newvd, and unopenable from now on.
3723 	 */
3724 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
3725 		spa_strfree(oldvd->vdev_path);
3726 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
3727 		    KM_SLEEP);
3728 		(void) sprintf(oldvd->vdev_path, "%s/%s",
3729 		    newvd->vdev_path, "old");
3730 		if (oldvd->vdev_devid != NULL) {
3731 			spa_strfree(oldvd->vdev_devid);
3732 			oldvd->vdev_devid = NULL;
3733 		}
3734 	}
3735 
3736 	/*
3737 	 * If the parent is not a mirror, or if we're replacing, insert the new
3738 	 * mirror/replacing/spare vdev above oldvd.
3739 	 */
3740 	if (pvd->vdev_ops != pvops)
3741 		pvd = vdev_add_parent(oldvd, pvops);
3742 
3743 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
3744 	ASSERT(pvd->vdev_ops == pvops);
3745 	ASSERT(oldvd->vdev_parent == pvd);
3746 
3747 	/*
3748 	 * Extract the new device from its root and add it to pvd.
3749 	 */
3750 	vdev_remove_child(newrootvd, newvd);
3751 	newvd->vdev_id = pvd->vdev_children;
3752 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
3753 	vdev_add_child(pvd, newvd);
3754 
3755 	tvd = newvd->vdev_top;
3756 	ASSERT(pvd->vdev_top == tvd);
3757 	ASSERT(tvd->vdev_parent == rvd);
3758 
3759 	vdev_config_dirty(tvd);
3760 
3761 	/*
3762 	 * Set newvd's DTL to [TXG_INITIAL, open_txg].  It will propagate
3763 	 * upward when spa_vdev_exit() calls vdev_dtl_reassess().
3764 	 */
3765 	open_txg = txg + TXG_CONCURRENT_STATES - 1;
3766 
3767 	vdev_dtl_dirty(newvd, DTL_MISSING,
3768 	    TXG_INITIAL, open_txg - TXG_INITIAL + 1);
3769 
3770 	if (newvd->vdev_isspare) {
3771 		spa_spare_activate(newvd);
3772 		spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
3773 	}
3774 
3775 	oldvdpath = spa_strdup(oldvd->vdev_path);
3776 	newvdpath = spa_strdup(newvd->vdev_path);
3777 	newvd_isspare = newvd->vdev_isspare;
3778 
3779 	/*
3780 	 * Mark newvd's DTL dirty in this txg.
3781 	 */
3782 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
3783 
3784 	(void) spa_vdev_exit(spa, newrootvd, open_txg, 0);
3785 
3786 	spa_history_internal_log(LOG_POOL_VDEV_ATTACH, spa, NULL,
3787 	    CRED(),  "%s vdev=%s %s vdev=%s",
3788 	    replacing && newvd_isspare ? "spare in" :
3789 	    replacing ? "replace" : "attach", newvdpath,
3790 	    replacing ? "for" : "to", oldvdpath);
3791 
3792 	spa_strfree(oldvdpath);
3793 	spa_strfree(newvdpath);
3794 
3795 	/*
3796 	 * Kick off a resilver to update newvd.
3797 	 */
3798 	VERIFY3U(spa_scrub(spa, POOL_SCRUB_RESILVER), ==, 0);
3799 
3800 	return (0);
3801 }
3802 
3803 /*
3804  * Detach a device from a mirror or replacing vdev.
3805  * If 'replace_done' is specified, only detach if the parent
3806  * is a replacing vdev.
3807  */
3808 int
3809 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
3810 {
3811 	uint64_t txg;
3812 	int error;
3813 	vdev_t *rvd = spa->spa_root_vdev;
3814 	vdev_t *vd, *pvd, *cvd, *tvd;
3815 	boolean_t unspare = B_FALSE;
3816 	uint64_t unspare_guid;
3817 	size_t len;
3818 	char *vdpath;
3819 
3820 	txg = spa_vdev_enter(spa);
3821 
3822 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
3823 
3824 	if (vd == NULL)
3825 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
3826 
3827 	if (!vd->vdev_ops->vdev_op_leaf)
3828 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3829 
3830 	pvd = vd->vdev_parent;
3831 
3832 	/*
3833 	 * If the parent/child relationship is not as expected, don't do it.
3834 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
3835 	 * vdev that's replacing B with C.  The user's intent in replacing
3836 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
3837 	 * the replace by detaching C, the expected behavior is to end up
3838 	 * M(A,B).  But suppose that right after deciding to detach C,
3839 	 * the replacement of B completes.  We would have M(A,C), and then
3840 	 * ask to detach C, which would leave us with just A -- not what
3841 	 * the user wanted.  To prevent this, we make sure that the
3842 	 * parent/child relationship hasn't changed -- in this example,
3843 	 * that C's parent is still the replacing vdev R.
3844 	 */
3845 	if (pvd->vdev_guid != pguid && pguid != 0)
3846 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
3847 
3848 	/*
3849 	 * If replace_done is specified, only remove this device if it's
3850 	 * the first child of a replacing vdev.  For the 'spare' vdev, either
3851 	 * disk can be removed.
3852 	 */
3853 	if (replace_done) {
3854 		if (pvd->vdev_ops == &vdev_replacing_ops) {
3855 			if (vd->vdev_id != 0)
3856 				return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3857 		} else if (pvd->vdev_ops != &vdev_spare_ops) {
3858 			return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3859 		}
3860 	}
3861 
3862 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
3863 	    spa_version(spa) >= SPA_VERSION_SPARES);
3864 
3865 	/*
3866 	 * Only mirror, replacing, and spare vdevs support detach.
3867 	 */
3868 	if (pvd->vdev_ops != &vdev_replacing_ops &&
3869 	    pvd->vdev_ops != &vdev_mirror_ops &&
3870 	    pvd->vdev_ops != &vdev_spare_ops)
3871 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3872 
3873 	/*
3874 	 * If this device has the only valid copy of some data,
3875 	 * we cannot safely detach it.
3876 	 */
3877 	if (vdev_dtl_required(vd))
3878 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
3879 
3880 	ASSERT(pvd->vdev_children >= 2);
3881 
3882 	/*
3883 	 * If we are detaching the second disk from a replacing vdev, then
3884 	 * check to see if we changed the original vdev's path to have "/old"
3885 	 * at the end in spa_vdev_attach().  If so, undo that change now.
3886 	 */
3887 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id == 1 &&
3888 	    pvd->vdev_child[0]->vdev_path != NULL &&
3889 	    pvd->vdev_child[1]->vdev_path != NULL) {
3890 		ASSERT(pvd->vdev_child[1] == vd);
3891 		cvd = pvd->vdev_child[0];
3892 		len = strlen(vd->vdev_path);
3893 		if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
3894 		    strcmp(cvd->vdev_path + len, "/old") == 0) {
3895 			spa_strfree(cvd->vdev_path);
3896 			cvd->vdev_path = spa_strdup(vd->vdev_path);
3897 		}
3898 	}
3899 
3900 	/*
3901 	 * If we are detaching the original disk from a spare, then it implies
3902 	 * that the spare should become a real disk, and be removed from the
3903 	 * active spare list for the pool.
3904 	 */
3905 	if (pvd->vdev_ops == &vdev_spare_ops &&
3906 	    vd->vdev_id == 0 && pvd->vdev_child[1]->vdev_isspare)
3907 		unspare = B_TRUE;
3908 
3909 	/*
3910 	 * Erase the disk labels so the disk can be used for other things.
3911 	 * This must be done after all other error cases are handled,
3912 	 * but before we disembowel vd (so we can still do I/O to it).
3913 	 * But if we can't do it, don't treat the error as fatal --
3914 	 * it may be that the unwritability of the disk is the reason
3915 	 * it's being detached!
3916 	 */
3917 	error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
3918 
3919 	/*
3920 	 * Remove vd from its parent and compact the parent's children.
3921 	 */
3922 	vdev_remove_child(pvd, vd);
3923 	vdev_compact_children(pvd);
3924 
3925 	/*
3926 	 * Remember one of the remaining children so we can get tvd below.
3927 	 */
3928 	cvd = pvd->vdev_child[0];
3929 
3930 	/*
3931 	 * If we need to remove the remaining child from the list of hot spares,
3932 	 * do it now, marking the vdev as no longer a spare in the process.
3933 	 * We must do this before vdev_remove_parent(), because that can
3934 	 * change the GUID if it creates a new toplevel GUID.  For a similar
3935 	 * reason, we must remove the spare now, in the same txg as the detach;
3936 	 * otherwise someone could attach a new sibling, change the GUID, and
3937 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
3938 	 */
3939 	if (unspare) {
3940 		ASSERT(cvd->vdev_isspare);
3941 		spa_spare_remove(cvd);
3942 		unspare_guid = cvd->vdev_guid;
3943 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
3944 	}
3945 
3946 	/*
3947 	 * If the parent mirror/replacing vdev only has one child,
3948 	 * the parent is no longer needed.  Remove it from the tree.
3949 	 */
3950 	if (pvd->vdev_children == 1)
3951 		vdev_remove_parent(cvd);
3952 
3953 	/*
3954 	 * We don't set tvd until now because the parent we just removed
3955 	 * may have been the previous top-level vdev.
3956 	 */
3957 	tvd = cvd->vdev_top;
3958 	ASSERT(tvd->vdev_parent == rvd);
3959 
3960 	/*
3961 	 * Reevaluate the parent vdev state.
3962 	 */
3963 	vdev_propagate_state(cvd);
3964 
3965 	/*
3966 	 * If the 'autoexpand' property is set on the pool then automatically
3967 	 * try to expand the size of the pool. For example if the device we
3968 	 * just detached was smaller than the others, it may be possible to
3969 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
3970 	 * first so that we can obtain the updated sizes of the leaf vdevs.
3971 	 */
3972 	if (spa->spa_autoexpand) {
3973 		vdev_reopen(tvd);
3974 		vdev_expand(tvd, txg);
3975 	}
3976 
3977 	vdev_config_dirty(tvd);
3978 
3979 	/*
3980 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
3981 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
3982 	 * But first make sure we're not on any *other* txg's DTL list, to
3983 	 * prevent vd from being accessed after it's freed.
3984 	 */
3985 	vdpath = spa_strdup(vd->vdev_path);
3986 	for (int t = 0; t < TXG_SIZE; t++)
3987 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
3988 	vd->vdev_detached = B_TRUE;
3989 	vdev_dirty(tvd, VDD_DTL, vd, txg);
3990 
3991 	spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
3992 
3993 	error = spa_vdev_exit(spa, vd, txg, 0);
3994 
3995 	spa_history_internal_log(LOG_POOL_VDEV_DETACH, spa, NULL, CRED(),
3996 	    "vdev=%s", vdpath);
3997 	spa_strfree(vdpath);
3998 
3999 	/*
4000 	 * If this was the removal of the original device in a hot spare vdev,
4001 	 * then we want to go through and remove the device from the hot spare
4002 	 * list of every other pool.
4003 	 */
4004 	if (unspare) {
4005 		spa_t *myspa = spa;
4006 		spa = NULL;
4007 		mutex_enter(&spa_namespace_lock);
4008 		while ((spa = spa_next(spa)) != NULL) {
4009 			if (spa->spa_state != POOL_STATE_ACTIVE)
4010 				continue;
4011 			if (spa == myspa)
4012 				continue;
4013 			spa_open_ref(spa, FTAG);
4014 			mutex_exit(&spa_namespace_lock);
4015 			(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4016 			mutex_enter(&spa_namespace_lock);
4017 			spa_close(spa, FTAG);
4018 		}
4019 		mutex_exit(&spa_namespace_lock);
4020 	}
4021 
4022 	return (error);
4023 }
4024 
4025 /*
4026  * Split a set of devices from their mirrors, and create a new pool from them.
4027  */
4028 int
4029 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4030     nvlist_t *props, boolean_t exp)
4031 {
4032 	int error = 0;
4033 	uint64_t txg, *glist;
4034 	spa_t *newspa;
4035 	uint_t c, children, lastlog;
4036 	nvlist_t **child, *nvl, *tmp;
4037 	dmu_tx_t *tx;
4038 	char *altroot = NULL;
4039 	vdev_t *rvd, **vml = NULL;			/* vdev modify list */
4040 	boolean_t activate_slog;
4041 
4042 	if (!spa_writeable(spa))
4043 		return (EROFS);
4044 
4045 	txg = spa_vdev_enter(spa);
4046 
4047 	/* clear the log and flush everything up to now */
4048 	activate_slog = spa_passivate_log(spa);
4049 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4050 	error = spa_offline_log(spa);
4051 	txg = spa_vdev_config_enter(spa);
4052 
4053 	if (activate_slog)
4054 		spa_activate_log(spa);
4055 
4056 	if (error != 0)
4057 		return (spa_vdev_exit(spa, NULL, txg, error));
4058 
4059 	/* check new spa name before going any further */
4060 	if (spa_lookup(newname) != NULL)
4061 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4062 
4063 	/*
4064 	 * scan through all the children to ensure they're all mirrors
4065 	 */
4066 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4067 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4068 	    &children) != 0)
4069 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4070 
4071 	/* first, check to ensure we've got the right child count */
4072 	rvd = spa->spa_root_vdev;
4073 	lastlog = 0;
4074 	for (c = 0; c < rvd->vdev_children; c++) {
4075 		vdev_t *vd = rvd->vdev_child[c];
4076 
4077 		/* don't count the holes & logs as children */
4078 		if (vd->vdev_islog || vd->vdev_ishole) {
4079 			if (lastlog == 0)
4080 				lastlog = c;
4081 			continue;
4082 		}
4083 
4084 		lastlog = 0;
4085 	}
4086 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4087 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4088 
4089 	/* next, ensure no spare or cache devices are part of the split */
4090 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4091 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4092 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4093 
4094 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4095 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4096 
4097 	/* then, loop over each vdev and validate it */
4098 	for (c = 0; c < children; c++) {
4099 		uint64_t is_hole = 0;
4100 
4101 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4102 		    &is_hole);
4103 
4104 		if (is_hole != 0) {
4105 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4106 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4107 				continue;
4108 			} else {
4109 				error = EINVAL;
4110 				break;
4111 			}
4112 		}
4113 
4114 		/* which disk is going to be split? */
4115 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4116 		    &glist[c]) != 0) {
4117 			error = EINVAL;
4118 			break;
4119 		}
4120 
4121 		/* look it up in the spa */
4122 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4123 		if (vml[c] == NULL) {
4124 			error = ENODEV;
4125 			break;
4126 		}
4127 
4128 		/* make sure there's nothing stopping the split */
4129 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4130 		    vml[c]->vdev_islog ||
4131 		    vml[c]->vdev_ishole ||
4132 		    vml[c]->vdev_isspare ||
4133 		    vml[c]->vdev_isl2cache ||
4134 		    !vdev_writeable(vml[c]) ||
4135 		    vml[c]->vdev_children != 0 ||
4136 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4137 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4138 			error = EINVAL;
4139 			break;
4140 		}
4141 
4142 		if (vdev_dtl_required(vml[c])) {
4143 			error = EBUSY;
4144 			break;
4145 		}
4146 
4147 		/* we need certain info from the top level */
4148 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4149 		    vml[c]->vdev_top->vdev_ms_array) == 0);
4150 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4151 		    vml[c]->vdev_top->vdev_ms_shift) == 0);
4152 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4153 		    vml[c]->vdev_top->vdev_asize) == 0);
4154 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4155 		    vml[c]->vdev_top->vdev_ashift) == 0);
4156 	}
4157 
4158 	if (error != 0) {
4159 		kmem_free(vml, children * sizeof (vdev_t *));
4160 		kmem_free(glist, children * sizeof (uint64_t));
4161 		return (spa_vdev_exit(spa, NULL, txg, error));
4162 	}
4163 
4164 	/* stop writers from using the disks */
4165 	for (c = 0; c < children; c++) {
4166 		if (vml[c] != NULL)
4167 			vml[c]->vdev_offline = B_TRUE;
4168 	}
4169 	vdev_reopen(spa->spa_root_vdev);
4170 
4171 	/*
4172 	 * Temporarily record the splitting vdevs in the spa config.  This
4173 	 * will disappear once the config is regenerated.
4174 	 */
4175 	VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4176 	VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4177 	    glist, children) == 0);
4178 	kmem_free(glist, children * sizeof (uint64_t));
4179 
4180 	VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4181 	    nvl) == 0);
4182 	spa->spa_config_splitting = nvl;
4183 	vdev_config_dirty(spa->spa_root_vdev);
4184 
4185 	/* configure and create the new pool */
4186 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4187 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4188 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4189 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4190 	    spa_version(spa)) == 0);
4191 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4192 	    spa->spa_config_txg) == 0);
4193 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4194 	    spa_generate_guid(NULL)) == 0);
4195 	(void) nvlist_lookup_string(props,
4196 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4197 
4198 	/* add the new pool to the namespace */
4199 	newspa = spa_add(newname, config, altroot);
4200 	newspa->spa_config_txg = spa->spa_config_txg;
4201 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
4202 
4203 	/* release the spa config lock, retaining the namespace lock */
4204 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4205 
4206 	if (zio_injection_enabled)
4207 		zio_handle_panic_injection(spa, FTAG, 1);
4208 
4209 	spa_activate(newspa, spa_mode_global);
4210 	spa_async_suspend(newspa);
4211 
4212 	/* create the new pool from the disks of the original pool */
4213 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4214 	if (error)
4215 		goto out;
4216 
4217 	/* if that worked, generate a real config for the new pool */
4218 	if (newspa->spa_root_vdev != NULL) {
4219 		VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4220 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
4221 		VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4222 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4223 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4224 		    B_TRUE));
4225 	}
4226 
4227 	/* set the props */
4228 	if (props != NULL) {
4229 		spa_configfile_set(newspa, props, B_FALSE);
4230 		error = spa_prop_set(newspa, props);
4231 		if (error)
4232 			goto out;
4233 	}
4234 
4235 	/* flush everything */
4236 	txg = spa_vdev_config_enter(newspa);
4237 	vdev_config_dirty(newspa->spa_root_vdev);
4238 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4239 
4240 	if (zio_injection_enabled)
4241 		zio_handle_panic_injection(spa, FTAG, 2);
4242 
4243 	spa_async_resume(newspa);
4244 
4245 	/* finally, update the original pool's config */
4246 	txg = spa_vdev_config_enter(spa);
4247 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4248 	error = dmu_tx_assign(tx, TXG_WAIT);
4249 	if (error != 0)
4250 		dmu_tx_abort(tx);
4251 	for (c = 0; c < children; c++) {
4252 		if (vml[c] != NULL) {
4253 			vdev_split(vml[c]);
4254 			if (error == 0)
4255 				spa_history_internal_log(LOG_POOL_VDEV_DETACH,
4256 				    spa, tx, CRED(), "vdev=%s",
4257 				    vml[c]->vdev_path);
4258 			vdev_free(vml[c]);
4259 		}
4260 	}
4261 	vdev_config_dirty(spa->spa_root_vdev);
4262 	spa->spa_config_splitting = NULL;
4263 	nvlist_free(nvl);
4264 	if (error == 0)
4265 		dmu_tx_commit(tx);
4266 	(void) spa_vdev_exit(spa, NULL, txg, 0);
4267 
4268 	if (zio_injection_enabled)
4269 		zio_handle_panic_injection(spa, FTAG, 3);
4270 
4271 	/* split is complete; log a history record */
4272 	spa_history_internal_log(LOG_POOL_SPLIT, newspa, NULL, CRED(),
4273 	    "split new pool %s from pool %s", newname, spa_name(spa));
4274 
4275 	kmem_free(vml, children * sizeof (vdev_t *));
4276 
4277 	/* if we're not going to mount the filesystems in userland, export */
4278 	if (exp)
4279 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
4280 		    B_FALSE, B_FALSE);
4281 
4282 	return (error);
4283 
4284 out:
4285 	spa_unload(newspa);
4286 	spa_deactivate(newspa);
4287 	spa_remove(newspa);
4288 
4289 	txg = spa_vdev_config_enter(spa);
4290 	nvlist_free(spa->spa_config_splitting);
4291 	spa->spa_config_splitting = NULL;
4292 	(void) spa_vdev_exit(spa, NULL, txg, error);
4293 
4294 	kmem_free(vml, children * sizeof (vdev_t *));
4295 	return (error);
4296 }
4297 
4298 static nvlist_t *
4299 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
4300 {
4301 	for (int i = 0; i < count; i++) {
4302 		uint64_t guid;
4303 
4304 		VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
4305 		    &guid) == 0);
4306 
4307 		if (guid == target_guid)
4308 			return (nvpp[i]);
4309 	}
4310 
4311 	return (NULL);
4312 }
4313 
4314 static void
4315 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
4316 	nvlist_t *dev_to_remove)
4317 {
4318 	nvlist_t **newdev = NULL;
4319 
4320 	if (count > 1)
4321 		newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
4322 
4323 	for (int i = 0, j = 0; i < count; i++) {
4324 		if (dev[i] == dev_to_remove)
4325 			continue;
4326 		VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
4327 	}
4328 
4329 	VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
4330 	VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
4331 
4332 	for (int i = 0; i < count - 1; i++)
4333 		nvlist_free(newdev[i]);
4334 
4335 	if (count > 1)
4336 		kmem_free(newdev, (count - 1) * sizeof (void *));
4337 }
4338 
4339 /*
4340  * Removing a device from the vdev namespace requires several steps
4341  * and can take a significant amount of time.  As a result we use
4342  * the spa_vdev_config_[enter/exit] functions which allow us to
4343  * grab and release the spa_config_lock while still holding the namespace
4344  * lock.  During each step the configuration is synced out.
4345  */
4346 
4347 /*
4348  * Evacuate the device.
4349  */
4350 int
4351 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
4352 {
4353 	int error = 0;
4354 	uint64_t txg;
4355 
4356 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4357 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4358 	ASSERT(vd == vd->vdev_top);
4359 
4360 	/*
4361 	 * Evacuate the device.  We don't hold the config lock as writer
4362 	 * since we need to do I/O but we do keep the
4363 	 * spa_namespace_lock held.  Once this completes the device
4364 	 * should no longer have any blocks allocated on it.
4365 	 */
4366 	if (vd->vdev_islog) {
4367 		error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
4368 		    NULL, DS_FIND_CHILDREN);
4369 	} else {
4370 		error = ENOTSUP;	/* until we have bp rewrite */
4371 	}
4372 
4373 	txg_wait_synced(spa_get_dsl(spa), 0);
4374 
4375 	if (error)
4376 		return (error);
4377 
4378 	/*
4379 	 * The evacuation succeeded.  Remove any remaining MOS metadata
4380 	 * associated with this vdev, and wait for these changes to sync.
4381 	 */
4382 	txg = spa_vdev_config_enter(spa);
4383 	vd->vdev_removing = B_TRUE;
4384 	vdev_dirty(vd, 0, NULL, txg);
4385 	vdev_config_dirty(vd);
4386 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4387 
4388 	return (0);
4389 }
4390 
4391 /*
4392  * Complete the removal by cleaning up the namespace.
4393  */
4394 void
4395 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
4396 {
4397 	vdev_t *rvd = spa->spa_root_vdev;
4398 	uint64_t id = vd->vdev_id;
4399 	boolean_t last_vdev = (id == (rvd->vdev_children - 1));
4400 
4401 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
4402 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
4403 	ASSERT(vd == vd->vdev_top);
4404 
4405 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4406 
4407 	if (list_link_active(&vd->vdev_state_dirty_node))
4408 		vdev_state_clean(vd);
4409 	if (list_link_active(&vd->vdev_config_dirty_node))
4410 		vdev_config_clean(vd);
4411 
4412 	vdev_free(vd);
4413 
4414 	if (last_vdev) {
4415 		vdev_compact_children(rvd);
4416 	} else {
4417 		vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
4418 		vdev_add_child(rvd, vd);
4419 	}
4420 	vdev_config_dirty(rvd);
4421 
4422 	/*
4423 	 * Reassess the health of our root vdev.
4424 	 */
4425 	vdev_reopen(rvd);
4426 }
4427 
4428 /*
4429  * Remove a device from the pool.  Currently, this supports removing only hot
4430  * spares, slogs, and level 2 ARC devices.
4431  */
4432 int
4433 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
4434 {
4435 	vdev_t *vd;
4436 	metaslab_group_t *mg;
4437 	nvlist_t **spares, **l2cache, *nv;
4438 	uint64_t txg = 0;
4439 	uint_t nspares, nl2cache;
4440 	int error = 0;
4441 	boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
4442 
4443 	if (!locked)
4444 		txg = spa_vdev_enter(spa);
4445 
4446 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4447 
4448 	if (spa->spa_spares.sav_vdevs != NULL &&
4449 	    nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
4450 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
4451 	    (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
4452 		/*
4453 		 * Only remove the hot spare if it's not currently in use
4454 		 * in this pool.
4455 		 */
4456 		if (vd == NULL || unspare) {
4457 			spa_vdev_remove_aux(spa->spa_spares.sav_config,
4458 			    ZPOOL_CONFIG_SPARES, spares, nspares, nv);
4459 			spa_load_spares(spa);
4460 			spa->spa_spares.sav_sync = B_TRUE;
4461 		} else {
4462 			error = EBUSY;
4463 		}
4464 	} else if (spa->spa_l2cache.sav_vdevs != NULL &&
4465 	    nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
4466 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
4467 	    (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
4468 		/*
4469 		 * Cache devices can always be removed.
4470 		 */
4471 		spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
4472 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
4473 		spa_load_l2cache(spa);
4474 		spa->spa_l2cache.sav_sync = B_TRUE;
4475 	} else if (vd != NULL && vd->vdev_islog) {
4476 		ASSERT(!locked);
4477 		ASSERT(vd == vd->vdev_top);
4478 
4479 		/*
4480 		 * XXX - Once we have bp-rewrite this should
4481 		 * become the common case.
4482 		 */
4483 
4484 		mg = vd->vdev_mg;
4485 
4486 		/*
4487 		 * Stop allocating from this vdev.
4488 		 */
4489 		metaslab_group_passivate(mg);
4490 
4491 		/*
4492 		 * Wait for the youngest allocations and frees to sync,
4493 		 * and then wait for the deferral of those frees to finish.
4494 		 */
4495 		spa_vdev_config_exit(spa, NULL,
4496 		    txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
4497 
4498 		/*
4499 		 * Attempt to evacuate the vdev.
4500 		 */
4501 		error = spa_vdev_remove_evacuate(spa, vd);
4502 
4503 		txg = spa_vdev_config_enter(spa);
4504 
4505 		/*
4506 		 * If we couldn't evacuate the vdev, unwind.
4507 		 */
4508 		if (error) {
4509 			metaslab_group_activate(mg);
4510 			return (spa_vdev_exit(spa, NULL, txg, error));
4511 		}
4512 
4513 		/*
4514 		 * Clean up the vdev namespace.
4515 		 */
4516 		spa_vdev_remove_from_namespace(spa, vd);
4517 
4518 	} else if (vd != NULL) {
4519 		/*
4520 		 * Normal vdevs cannot be removed (yet).
4521 		 */
4522 		error = ENOTSUP;
4523 	} else {
4524 		/*
4525 		 * There is no vdev of any kind with the specified guid.
4526 		 */
4527 		error = ENOENT;
4528 	}
4529 
4530 	if (!locked)
4531 		return (spa_vdev_exit(spa, NULL, txg, error));
4532 
4533 	return (error);
4534 }
4535 
4536 /*
4537  * Find any device that's done replacing, or a vdev marked 'unspare' that's
4538  * current spared, so we can detach it.
4539  */
4540 static vdev_t *
4541 spa_vdev_resilver_done_hunt(vdev_t *vd)
4542 {
4543 	vdev_t *newvd, *oldvd;
4544 
4545 	for (int c = 0; c < vd->vdev_children; c++) {
4546 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
4547 		if (oldvd != NULL)
4548 			return (oldvd);
4549 	}
4550 
4551 	/*
4552 	 * Check for a completed replacement.
4553 	 */
4554 	if (vd->vdev_ops == &vdev_replacing_ops && vd->vdev_children == 2) {
4555 		oldvd = vd->vdev_child[0];
4556 		newvd = vd->vdev_child[1];
4557 
4558 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
4559 		    !vdev_dtl_required(oldvd))
4560 			return (oldvd);
4561 	}
4562 
4563 	/*
4564 	 * Check for a completed resilver with the 'unspare' flag set.
4565 	 */
4566 	if (vd->vdev_ops == &vdev_spare_ops && vd->vdev_children == 2) {
4567 		newvd = vd->vdev_child[0];
4568 		oldvd = vd->vdev_child[1];
4569 
4570 		if (newvd->vdev_unspare &&
4571 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
4572 		    !vdev_dtl_required(oldvd)) {
4573 			newvd->vdev_unspare = 0;
4574 			return (oldvd);
4575 		}
4576 	}
4577 
4578 	return (NULL);
4579 }
4580 
4581 static void
4582 spa_vdev_resilver_done(spa_t *spa)
4583 {
4584 	vdev_t *vd, *pvd, *ppvd;
4585 	uint64_t guid, sguid, pguid, ppguid;
4586 
4587 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4588 
4589 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
4590 		pvd = vd->vdev_parent;
4591 		ppvd = pvd->vdev_parent;
4592 		guid = vd->vdev_guid;
4593 		pguid = pvd->vdev_guid;
4594 		ppguid = ppvd->vdev_guid;
4595 		sguid = 0;
4596 		/*
4597 		 * If we have just finished replacing a hot spared device, then
4598 		 * we need to detach the parent's first child (the original hot
4599 		 * spare) as well.
4600 		 */
4601 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0) {
4602 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
4603 			ASSERT(ppvd->vdev_children == 2);
4604 			sguid = ppvd->vdev_child[1]->vdev_guid;
4605 		}
4606 		spa_config_exit(spa, SCL_ALL, FTAG);
4607 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
4608 			return;
4609 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
4610 			return;
4611 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4612 	}
4613 
4614 	spa_config_exit(spa, SCL_ALL, FTAG);
4615 }
4616 
4617 /*
4618  * Update the stored path or FRU for this vdev.
4619  */
4620 int
4621 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
4622     boolean_t ispath)
4623 {
4624 	vdev_t *vd;
4625 
4626 	spa_vdev_state_enter(spa, SCL_ALL);
4627 
4628 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
4629 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
4630 
4631 	if (!vd->vdev_ops->vdev_op_leaf)
4632 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
4633 
4634 	if (ispath) {
4635 		spa_strfree(vd->vdev_path);
4636 		vd->vdev_path = spa_strdup(value);
4637 	} else {
4638 		if (vd->vdev_fru != NULL)
4639 			spa_strfree(vd->vdev_fru);
4640 		vd->vdev_fru = spa_strdup(value);
4641 	}
4642 
4643 	return (spa_vdev_state_exit(spa, vd, 0));
4644 }
4645 
4646 int
4647 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
4648 {
4649 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
4650 }
4651 
4652 int
4653 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
4654 {
4655 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
4656 }
4657 
4658 /*
4659  * ==========================================================================
4660  * SPA Scrubbing
4661  * ==========================================================================
4662  */
4663 
4664 int
4665 spa_scrub(spa_t *spa, pool_scrub_type_t type)
4666 {
4667 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
4668 
4669 	if ((uint_t)type >= POOL_SCRUB_TYPES)
4670 		return (ENOTSUP);
4671 
4672 	/*
4673 	 * If a resilver was requested, but there is no DTL on a
4674 	 * writeable leaf device, we have nothing to do.
4675 	 */
4676 	if (type == POOL_SCRUB_RESILVER &&
4677 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
4678 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
4679 		return (0);
4680 	}
4681 
4682 	if (type == POOL_SCRUB_EVERYTHING &&
4683 	    spa->spa_dsl_pool->dp_scrub_func != SCRUB_FUNC_NONE &&
4684 	    spa->spa_dsl_pool->dp_scrub_isresilver)
4685 		return (EBUSY);
4686 
4687 	if (type == POOL_SCRUB_EVERYTHING || type == POOL_SCRUB_RESILVER) {
4688 		return (dsl_pool_scrub_clean(spa->spa_dsl_pool));
4689 	} else if (type == POOL_SCRUB_NONE) {
4690 		return (dsl_pool_scrub_cancel(spa->spa_dsl_pool));
4691 	} else {
4692 		return (EINVAL);
4693 	}
4694 }
4695 
4696 /*
4697  * ==========================================================================
4698  * SPA async task processing
4699  * ==========================================================================
4700  */
4701 
4702 static void
4703 spa_async_remove(spa_t *spa, vdev_t *vd)
4704 {
4705 	if (vd->vdev_remove_wanted) {
4706 		vd->vdev_remove_wanted = 0;
4707 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
4708 
4709 		/*
4710 		 * We want to clear the stats, but we don't want to do a full
4711 		 * vdev_clear() as that will cause us to throw away
4712 		 * degraded/faulted state as well as attempt to reopen the
4713 		 * device, all of which is a waste.
4714 		 */
4715 		vd->vdev_stat.vs_read_errors = 0;
4716 		vd->vdev_stat.vs_write_errors = 0;
4717 		vd->vdev_stat.vs_checksum_errors = 0;
4718 
4719 		vdev_state_dirty(vd->vdev_top);
4720 	}
4721 
4722 	for (int c = 0; c < vd->vdev_children; c++)
4723 		spa_async_remove(spa, vd->vdev_child[c]);
4724 }
4725 
4726 static void
4727 spa_async_probe(spa_t *spa, vdev_t *vd)
4728 {
4729 	if (vd->vdev_probe_wanted) {
4730 		vd->vdev_probe_wanted = 0;
4731 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
4732 	}
4733 
4734 	for (int c = 0; c < vd->vdev_children; c++)
4735 		spa_async_probe(spa, vd->vdev_child[c]);
4736 }
4737 
4738 static void
4739 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
4740 {
4741 	sysevent_id_t eid;
4742 	nvlist_t *attr;
4743 	char *physpath;
4744 
4745 	if (!spa->spa_autoexpand)
4746 		return;
4747 
4748 	for (int c = 0; c < vd->vdev_children; c++) {
4749 		vdev_t *cvd = vd->vdev_child[c];
4750 		spa_async_autoexpand(spa, cvd);
4751 	}
4752 
4753 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
4754 		return;
4755 
4756 	physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
4757 	(void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
4758 
4759 	VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4760 	VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
4761 
4762 	(void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
4763 	    ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
4764 
4765 	nvlist_free(attr);
4766 	kmem_free(physpath, MAXPATHLEN);
4767 }
4768 
4769 static void
4770 spa_async_thread(spa_t *spa)
4771 {
4772 	int tasks;
4773 
4774 	ASSERT(spa->spa_sync_on);
4775 
4776 	mutex_enter(&spa->spa_async_lock);
4777 	tasks = spa->spa_async_tasks;
4778 	spa->spa_async_tasks = 0;
4779 	mutex_exit(&spa->spa_async_lock);
4780 
4781 	/*
4782 	 * See if the config needs to be updated.
4783 	 */
4784 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
4785 		uint64_t old_space, new_space;
4786 
4787 		mutex_enter(&spa_namespace_lock);
4788 		old_space = metaslab_class_get_space(spa_normal_class(spa));
4789 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4790 		new_space = metaslab_class_get_space(spa_normal_class(spa));
4791 		mutex_exit(&spa_namespace_lock);
4792 
4793 		/*
4794 		 * If the pool grew as a result of the config update,
4795 		 * then log an internal history event.
4796 		 */
4797 		if (new_space != old_space) {
4798 			spa_history_internal_log(LOG_POOL_VDEV_ONLINE,
4799 			    spa, NULL, CRED(),
4800 			    "pool '%s' size: %llu(+%llu)",
4801 			    spa_name(spa), new_space, new_space - old_space);
4802 		}
4803 	}
4804 
4805 	/*
4806 	 * See if any devices need to be marked REMOVED.
4807 	 */
4808 	if (tasks & SPA_ASYNC_REMOVE) {
4809 		spa_vdev_state_enter(spa, SCL_NONE);
4810 		spa_async_remove(spa, spa->spa_root_vdev);
4811 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
4812 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
4813 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
4814 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
4815 		(void) spa_vdev_state_exit(spa, NULL, 0);
4816 	}
4817 
4818 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
4819 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4820 		spa_async_autoexpand(spa, spa->spa_root_vdev);
4821 		spa_config_exit(spa, SCL_CONFIG, FTAG);
4822 	}
4823 
4824 	/*
4825 	 * See if any devices need to be probed.
4826 	 */
4827 	if (tasks & SPA_ASYNC_PROBE) {
4828 		spa_vdev_state_enter(spa, SCL_NONE);
4829 		spa_async_probe(spa, spa->spa_root_vdev);
4830 		(void) spa_vdev_state_exit(spa, NULL, 0);
4831 	}
4832 
4833 	/*
4834 	 * If any devices are done replacing, detach them.
4835 	 */
4836 	if (tasks & SPA_ASYNC_RESILVER_DONE)
4837 		spa_vdev_resilver_done(spa);
4838 
4839 	/*
4840 	 * Kick off a resilver.
4841 	 */
4842 	if (tasks & SPA_ASYNC_RESILVER)
4843 		VERIFY(spa_scrub(spa, POOL_SCRUB_RESILVER) == 0);
4844 
4845 	/*
4846 	 * Let the world know that we're done.
4847 	 */
4848 	mutex_enter(&spa->spa_async_lock);
4849 	spa->spa_async_thread = NULL;
4850 	cv_broadcast(&spa->spa_async_cv);
4851 	mutex_exit(&spa->spa_async_lock);
4852 	thread_exit();
4853 }
4854 
4855 void
4856 spa_async_suspend(spa_t *spa)
4857 {
4858 	mutex_enter(&spa->spa_async_lock);
4859 	spa->spa_async_suspended++;
4860 	while (spa->spa_async_thread != NULL)
4861 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
4862 	mutex_exit(&spa->spa_async_lock);
4863 }
4864 
4865 void
4866 spa_async_resume(spa_t *spa)
4867 {
4868 	mutex_enter(&spa->spa_async_lock);
4869 	ASSERT(spa->spa_async_suspended != 0);
4870 	spa->spa_async_suspended--;
4871 	mutex_exit(&spa->spa_async_lock);
4872 }
4873 
4874 static void
4875 spa_async_dispatch(spa_t *spa)
4876 {
4877 	mutex_enter(&spa->spa_async_lock);
4878 	if (spa->spa_async_tasks && !spa->spa_async_suspended &&
4879 	    spa->spa_async_thread == NULL &&
4880 	    rootdir != NULL && !vn_is_readonly(rootdir))
4881 		spa->spa_async_thread = thread_create(NULL, 0,
4882 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
4883 	mutex_exit(&spa->spa_async_lock);
4884 }
4885 
4886 void
4887 spa_async_request(spa_t *spa, int task)
4888 {
4889 	mutex_enter(&spa->spa_async_lock);
4890 	spa->spa_async_tasks |= task;
4891 	mutex_exit(&spa->spa_async_lock);
4892 }
4893 
4894 /*
4895  * ==========================================================================
4896  * SPA syncing routines
4897  * ==========================================================================
4898  */
4899 static void
4900 spa_sync_deferred_bplist(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx, uint64_t txg)
4901 {
4902 	blkptr_t blk;
4903 	uint64_t itor = 0;
4904 	uint8_t c = 1;
4905 
4906 	while (bplist_iterate(bpl, &itor, &blk) == 0) {
4907 		ASSERT(blk.blk_birth < txg);
4908 		zio_free(spa, txg, &blk);
4909 	}
4910 
4911 	bplist_vacate(bpl, tx);
4912 
4913 	/*
4914 	 * Pre-dirty the first block so we sync to convergence faster.
4915 	 * (Usually only the first block is needed.)
4916 	 */
4917 	dmu_write(bpl->bpl_mos, spa->spa_deferred_bplist_obj, 0, 1, &c, tx);
4918 }
4919 
4920 static void
4921 spa_sync_free(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
4922 {
4923 	zio_t *zio = arg;
4924 
4925 	zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
4926 	    zio->io_flags));
4927 }
4928 
4929 static void
4930 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
4931 {
4932 	char *packed = NULL;
4933 	size_t bufsize;
4934 	size_t nvsize = 0;
4935 	dmu_buf_t *db;
4936 
4937 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
4938 
4939 	/*
4940 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
4941 	 * information.  This avoids the dbuf_will_dirty() path and
4942 	 * saves us a pre-read to get data we don't actually care about.
4943 	 */
4944 	bufsize = P2ROUNDUP(nvsize, SPA_CONFIG_BLOCKSIZE);
4945 	packed = kmem_alloc(bufsize, KM_SLEEP);
4946 
4947 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
4948 	    KM_SLEEP) == 0);
4949 	bzero(packed + nvsize, bufsize - nvsize);
4950 
4951 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
4952 
4953 	kmem_free(packed, bufsize);
4954 
4955 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
4956 	dmu_buf_will_dirty(db, tx);
4957 	*(uint64_t *)db->db_data = nvsize;
4958 	dmu_buf_rele(db, FTAG);
4959 }
4960 
4961 static void
4962 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
4963     const char *config, const char *entry)
4964 {
4965 	nvlist_t *nvroot;
4966 	nvlist_t **list;
4967 	int i;
4968 
4969 	if (!sav->sav_sync)
4970 		return;
4971 
4972 	/*
4973 	 * Update the MOS nvlist describing the list of available devices.
4974 	 * spa_validate_aux() will have already made sure this nvlist is
4975 	 * valid and the vdevs are labeled appropriately.
4976 	 */
4977 	if (sav->sav_object == 0) {
4978 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
4979 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
4980 		    sizeof (uint64_t), tx);
4981 		VERIFY(zap_update(spa->spa_meta_objset,
4982 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
4983 		    &sav->sav_object, tx) == 0);
4984 	}
4985 
4986 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4987 	if (sav->sav_count == 0) {
4988 		VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
4989 	} else {
4990 		list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
4991 		for (i = 0; i < sav->sav_count; i++)
4992 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
4993 			    B_FALSE, B_FALSE, B_TRUE);
4994 		VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
4995 		    sav->sav_count) == 0);
4996 		for (i = 0; i < sav->sav_count; i++)
4997 			nvlist_free(list[i]);
4998 		kmem_free(list, sav->sav_count * sizeof (void *));
4999 	}
5000 
5001 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5002 	nvlist_free(nvroot);
5003 
5004 	sav->sav_sync = B_FALSE;
5005 }
5006 
5007 static void
5008 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5009 {
5010 	nvlist_t *config;
5011 
5012 	if (list_is_empty(&spa->spa_config_dirty_list))
5013 		return;
5014 
5015 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5016 
5017 	config = spa_config_generate(spa, spa->spa_root_vdev,
5018 	    dmu_tx_get_txg(tx), B_FALSE);
5019 
5020 	spa_config_exit(spa, SCL_STATE, FTAG);
5021 
5022 	if (spa->spa_config_syncing)
5023 		nvlist_free(spa->spa_config_syncing);
5024 	spa->spa_config_syncing = config;
5025 
5026 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5027 }
5028 
5029 /*
5030  * Set zpool properties.
5031  */
5032 static void
5033 spa_sync_props(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
5034 {
5035 	spa_t *spa = arg1;
5036 	objset_t *mos = spa->spa_meta_objset;
5037 	nvlist_t *nvp = arg2;
5038 	nvpair_t *elem;
5039 	uint64_t intval;
5040 	char *strval;
5041 	zpool_prop_t prop;
5042 	const char *propname;
5043 	zprop_type_t proptype;
5044 
5045 	mutex_enter(&spa->spa_props_lock);
5046 
5047 	elem = NULL;
5048 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
5049 		switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5050 		case ZPOOL_PROP_VERSION:
5051 			/*
5052 			 * Only set version for non-zpool-creation cases
5053 			 * (set/import). spa_create() needs special care
5054 			 * for version setting.
5055 			 */
5056 			if (tx->tx_txg != TXG_INITIAL) {
5057 				VERIFY(nvpair_value_uint64(elem,
5058 				    &intval) == 0);
5059 				ASSERT(intval <= SPA_VERSION);
5060 				ASSERT(intval >= spa_version(spa));
5061 				spa->spa_uberblock.ub_version = intval;
5062 				vdev_config_dirty(spa->spa_root_vdev);
5063 			}
5064 			break;
5065 
5066 		case ZPOOL_PROP_ALTROOT:
5067 			/*
5068 			 * 'altroot' is a non-persistent property. It should
5069 			 * have been set temporarily at creation or import time.
5070 			 */
5071 			ASSERT(spa->spa_root != NULL);
5072 			break;
5073 
5074 		case ZPOOL_PROP_CACHEFILE:
5075 			/*
5076 			 * 'cachefile' is also a non-persisitent property.
5077 			 */
5078 			break;
5079 		default:
5080 			/*
5081 			 * Set pool property values in the poolprops mos object.
5082 			 */
5083 			if (spa->spa_pool_props_object == 0) {
5084 				VERIFY((spa->spa_pool_props_object =
5085 				    zap_create(mos, DMU_OT_POOL_PROPS,
5086 				    DMU_OT_NONE, 0, tx)) > 0);
5087 
5088 				VERIFY(zap_update(mos,
5089 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5090 				    8, 1, &spa->spa_pool_props_object, tx)
5091 				    == 0);
5092 			}
5093 
5094 			/* normalize the property name */
5095 			propname = zpool_prop_to_name(prop);
5096 			proptype = zpool_prop_get_type(prop);
5097 
5098 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
5099 				ASSERT(proptype == PROP_TYPE_STRING);
5100 				VERIFY(nvpair_value_string(elem, &strval) == 0);
5101 				VERIFY(zap_update(mos,
5102 				    spa->spa_pool_props_object, propname,
5103 				    1, strlen(strval) + 1, strval, tx) == 0);
5104 
5105 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5106 				VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5107 
5108 				if (proptype == PROP_TYPE_INDEX) {
5109 					const char *unused;
5110 					VERIFY(zpool_prop_index_to_string(
5111 					    prop, intval, &unused) == 0);
5112 				}
5113 				VERIFY(zap_update(mos,
5114 				    spa->spa_pool_props_object, propname,
5115 				    8, 1, &intval, tx) == 0);
5116 			} else {
5117 				ASSERT(0); /* not allowed */
5118 			}
5119 
5120 			switch (prop) {
5121 			case ZPOOL_PROP_DELEGATION:
5122 				spa->spa_delegation = intval;
5123 				break;
5124 			case ZPOOL_PROP_BOOTFS:
5125 				spa->spa_bootfs = intval;
5126 				break;
5127 			case ZPOOL_PROP_FAILUREMODE:
5128 				spa->spa_failmode = intval;
5129 				break;
5130 			case ZPOOL_PROP_AUTOEXPAND:
5131 				spa->spa_autoexpand = intval;
5132 				spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
5133 				break;
5134 			case ZPOOL_PROP_DEDUPDITTO:
5135 				spa->spa_dedup_ditto = intval;
5136 				break;
5137 			default:
5138 				break;
5139 			}
5140 		}
5141 
5142 		/* log internal history if this is not a zpool create */
5143 		if (spa_version(spa) >= SPA_VERSION_ZPOOL_HISTORY &&
5144 		    tx->tx_txg != TXG_INITIAL) {
5145 			spa_history_internal_log(LOG_POOL_PROPSET,
5146 			    spa, tx, cr, "%s %lld %s",
5147 			    nvpair_name(elem), intval, spa_name(spa));
5148 		}
5149 	}
5150 
5151 	mutex_exit(&spa->spa_props_lock);
5152 }
5153 
5154 /*
5155  * Sync the specified transaction group.  New blocks may be dirtied as
5156  * part of the process, so we iterate until it converges.
5157  */
5158 void
5159 spa_sync(spa_t *spa, uint64_t txg)
5160 {
5161 	dsl_pool_t *dp = spa->spa_dsl_pool;
5162 	objset_t *mos = spa->spa_meta_objset;
5163 	bplist_t *defer_bpl = &spa->spa_deferred_bplist;
5164 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
5165 	vdev_t *rvd = spa->spa_root_vdev;
5166 	vdev_t *vd;
5167 	dmu_tx_t *tx;
5168 	int error;
5169 
5170 	/*
5171 	 * Lock out configuration changes.
5172 	 */
5173 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5174 
5175 	spa->spa_syncing_txg = txg;
5176 	spa->spa_sync_pass = 0;
5177 
5178 	/*
5179 	 * If there are any pending vdev state changes, convert them
5180 	 * into config changes that go out with this transaction group.
5181 	 */
5182 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5183 	while (list_head(&spa->spa_state_dirty_list) != NULL) {
5184 		/*
5185 		 * We need the write lock here because, for aux vdevs,
5186 		 * calling vdev_config_dirty() modifies sav_config.
5187 		 * This is ugly and will become unnecessary when we
5188 		 * eliminate the aux vdev wart by integrating all vdevs
5189 		 * into the root vdev tree.
5190 		 */
5191 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5192 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
5193 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
5194 			vdev_state_clean(vd);
5195 			vdev_config_dirty(vd);
5196 		}
5197 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
5198 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
5199 	}
5200 	spa_config_exit(spa, SCL_STATE, FTAG);
5201 
5202 	VERIFY(0 == bplist_open(defer_bpl, mos, spa->spa_deferred_bplist_obj));
5203 
5204 	tx = dmu_tx_create_assigned(dp, txg);
5205 
5206 	/*
5207 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
5208 	 * set spa_deflate if we have no raid-z vdevs.
5209 	 */
5210 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
5211 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
5212 		int i;
5213 
5214 		for (i = 0; i < rvd->vdev_children; i++) {
5215 			vd = rvd->vdev_child[i];
5216 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
5217 				break;
5218 		}
5219 		if (i == rvd->vdev_children) {
5220 			spa->spa_deflate = TRUE;
5221 			VERIFY(0 == zap_add(spa->spa_meta_objset,
5222 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
5223 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
5224 		}
5225 	}
5226 
5227 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
5228 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
5229 		dsl_pool_create_origin(dp, tx);
5230 
5231 		/* Keeping the origin open increases spa_minref */
5232 		spa->spa_minref += 3;
5233 	}
5234 
5235 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
5236 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
5237 		dsl_pool_upgrade_clones(dp, tx);
5238 	}
5239 
5240 	/*
5241 	 * If anything has changed in this txg, push the deferred frees
5242 	 * from the previous txg.  If not, leave them alone so that we
5243 	 * don't generate work on an otherwise idle system.
5244 	 */
5245 	if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
5246 	    !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
5247 	    !txg_list_empty(&dp->dp_sync_tasks, txg))
5248 		spa_sync_deferred_bplist(spa, defer_bpl, tx, txg);
5249 
5250 	/*
5251 	 * Iterate to convergence.
5252 	 */
5253 	do {
5254 		int pass = ++spa->spa_sync_pass;
5255 
5256 		spa_sync_config_object(spa, tx);
5257 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
5258 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
5259 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
5260 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
5261 		spa_errlog_sync(spa, txg);
5262 		dsl_pool_sync(dp, txg);
5263 
5264 		if (pass <= SYNC_PASS_DEFERRED_FREE) {
5265 			zio_t *zio = zio_root(spa, NULL, NULL, 0);
5266 			bplist_sync(free_bpl, spa_sync_free, zio, tx);
5267 			VERIFY(zio_wait(zio) == 0);
5268 		} else {
5269 			bplist_sync(free_bpl, bplist_enqueue_cb, defer_bpl, tx);
5270 		}
5271 
5272 		ddt_sync(spa, txg);
5273 
5274 		mutex_enter(&spa->spa_scrub_lock);
5275 		while (spa->spa_scrub_inflight > 0)
5276 			cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock);
5277 		mutex_exit(&spa->spa_scrub_lock);
5278 
5279 		while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
5280 			vdev_sync(vd, txg);
5281 
5282 	} while (dmu_objset_is_dirty(mos, txg));
5283 
5284 	ASSERT(free_bpl->bpl_queue == NULL);
5285 
5286 	bplist_close(defer_bpl);
5287 
5288 	/*
5289 	 * Rewrite the vdev configuration (which includes the uberblock)
5290 	 * to commit the transaction group.
5291 	 *
5292 	 * If there are no dirty vdevs, we sync the uberblock to a few
5293 	 * random top-level vdevs that are known to be visible in the
5294 	 * config cache (see spa_vdev_add() for a complete description).
5295 	 * If there *are* dirty vdevs, sync the uberblock to all vdevs.
5296 	 */
5297 	for (;;) {
5298 		/*
5299 		 * We hold SCL_STATE to prevent vdev open/close/etc.
5300 		 * while we're attempting to write the vdev labels.
5301 		 */
5302 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5303 
5304 		if (list_is_empty(&spa->spa_config_dirty_list)) {
5305 			vdev_t *svd[SPA_DVAS_PER_BP];
5306 			int svdcount = 0;
5307 			int children = rvd->vdev_children;
5308 			int c0 = spa_get_random(children);
5309 
5310 			for (int c = 0; c < children; c++) {
5311 				vd = rvd->vdev_child[(c0 + c) % children];
5312 				if (vd->vdev_ms_array == 0 || vd->vdev_islog)
5313 					continue;
5314 				svd[svdcount++] = vd;
5315 				if (svdcount == SPA_DVAS_PER_BP)
5316 					break;
5317 			}
5318 			error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
5319 			if (error != 0)
5320 				error = vdev_config_sync(svd, svdcount, txg,
5321 				    B_TRUE);
5322 		} else {
5323 			error = vdev_config_sync(rvd->vdev_child,
5324 			    rvd->vdev_children, txg, B_FALSE);
5325 			if (error != 0)
5326 				error = vdev_config_sync(rvd->vdev_child,
5327 				    rvd->vdev_children, txg, B_TRUE);
5328 		}
5329 
5330 		spa_config_exit(spa, SCL_STATE, FTAG);
5331 
5332 		if (error == 0)
5333 			break;
5334 		zio_suspend(spa, NULL);
5335 		zio_resume_wait(spa);
5336 	}
5337 	dmu_tx_commit(tx);
5338 
5339 	/*
5340 	 * Clear the dirty config list.
5341 	 */
5342 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
5343 		vdev_config_clean(vd);
5344 
5345 	/*
5346 	 * Now that the new config has synced transactionally,
5347 	 * let it become visible to the config cache.
5348 	 */
5349 	if (spa->spa_config_syncing != NULL) {
5350 		spa_config_set(spa, spa->spa_config_syncing);
5351 		spa->spa_config_txg = txg;
5352 		spa->spa_config_syncing = NULL;
5353 	}
5354 
5355 	spa->spa_ubsync = spa->spa_uberblock;
5356 
5357 	dsl_pool_sync_done(dp, txg);
5358 
5359 	/*
5360 	 * Update usable space statistics.
5361 	 */
5362 	while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
5363 		vdev_sync_done(vd, txg);
5364 
5365 	spa_update_dspace(spa);
5366 
5367 	/*
5368 	 * It had better be the case that we didn't dirty anything
5369 	 * since vdev_config_sync().
5370 	 */
5371 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
5372 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
5373 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
5374 	ASSERT(defer_bpl->bpl_queue == NULL);
5375 	ASSERT(free_bpl->bpl_queue == NULL);
5376 
5377 	spa->spa_sync_pass = 0;
5378 
5379 	spa_config_exit(spa, SCL_CONFIG, FTAG);
5380 
5381 	spa_handle_ignored_writes(spa);
5382 
5383 	/*
5384 	 * If any async tasks have been requested, kick them off.
5385 	 */
5386 	spa_async_dispatch(spa);
5387 }
5388 
5389 /*
5390  * Sync all pools.  We don't want to hold the namespace lock across these
5391  * operations, so we take a reference on the spa_t and drop the lock during the
5392  * sync.
5393  */
5394 void
5395 spa_sync_allpools(void)
5396 {
5397 	spa_t *spa = NULL;
5398 	mutex_enter(&spa_namespace_lock);
5399 	while ((spa = spa_next(spa)) != NULL) {
5400 		if (spa_state(spa) != POOL_STATE_ACTIVE || spa_suspended(spa))
5401 			continue;
5402 		spa_open_ref(spa, FTAG);
5403 		mutex_exit(&spa_namespace_lock);
5404 		txg_wait_synced(spa_get_dsl(spa), 0);
5405 		mutex_enter(&spa_namespace_lock);
5406 		spa_close(spa, FTAG);
5407 	}
5408 	mutex_exit(&spa_namespace_lock);
5409 }
5410 
5411 /*
5412  * ==========================================================================
5413  * Miscellaneous routines
5414  * ==========================================================================
5415  */
5416 
5417 /*
5418  * Remove all pools in the system.
5419  */
5420 void
5421 spa_evict_all(void)
5422 {
5423 	spa_t *spa;
5424 
5425 	/*
5426 	 * Remove all cached state.  All pools should be closed now,
5427 	 * so every spa in the AVL tree should be unreferenced.
5428 	 */
5429 	mutex_enter(&spa_namespace_lock);
5430 	while ((spa = spa_next(NULL)) != NULL) {
5431 		/*
5432 		 * Stop async tasks.  The async thread may need to detach
5433 		 * a device that's been replaced, which requires grabbing
5434 		 * spa_namespace_lock, so we must drop it here.
5435 		 */
5436 		spa_open_ref(spa, FTAG);
5437 		mutex_exit(&spa_namespace_lock);
5438 		spa_async_suspend(spa);
5439 		mutex_enter(&spa_namespace_lock);
5440 		spa_close(spa, FTAG);
5441 
5442 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
5443 			spa_unload(spa);
5444 			spa_deactivate(spa);
5445 		}
5446 		spa_remove(spa);
5447 	}
5448 	mutex_exit(&spa_namespace_lock);
5449 }
5450 
5451 vdev_t *
5452 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
5453 {
5454 	vdev_t *vd;
5455 	int i;
5456 
5457 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
5458 		return (vd);
5459 
5460 	if (aux) {
5461 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
5462 			vd = spa->spa_l2cache.sav_vdevs[i];
5463 			if (vd->vdev_guid == guid)
5464 				return (vd);
5465 		}
5466 
5467 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
5468 			vd = spa->spa_spares.sav_vdevs[i];
5469 			if (vd->vdev_guid == guid)
5470 				return (vd);
5471 		}
5472 	}
5473 
5474 	return (NULL);
5475 }
5476 
5477 void
5478 spa_upgrade(spa_t *spa, uint64_t version)
5479 {
5480 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5481 
5482 	/*
5483 	 * This should only be called for a non-faulted pool, and since a
5484 	 * future version would result in an unopenable pool, this shouldn't be
5485 	 * possible.
5486 	 */
5487 	ASSERT(spa->spa_uberblock.ub_version <= SPA_VERSION);
5488 	ASSERT(version >= spa->spa_uberblock.ub_version);
5489 
5490 	spa->spa_uberblock.ub_version = version;
5491 	vdev_config_dirty(spa->spa_root_vdev);
5492 
5493 	spa_config_exit(spa, SCL_ALL, FTAG);
5494 
5495 	txg_wait_synced(spa_get_dsl(spa), 0);
5496 }
5497 
5498 boolean_t
5499 spa_has_spare(spa_t *spa, uint64_t guid)
5500 {
5501 	int i;
5502 	uint64_t spareguid;
5503 	spa_aux_vdev_t *sav = &spa->spa_spares;
5504 
5505 	for (i = 0; i < sav->sav_count; i++)
5506 		if (sav->sav_vdevs[i]->vdev_guid == guid)
5507 			return (B_TRUE);
5508 
5509 	for (i = 0; i < sav->sav_npending; i++) {
5510 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
5511 		    &spareguid) == 0 && spareguid == guid)
5512 			return (B_TRUE);
5513 	}
5514 
5515 	return (B_FALSE);
5516 }
5517 
5518 /*
5519  * Check if a pool has an active shared spare device.
5520  * Note: reference count of an active spare is 2, as a spare and as a replace
5521  */
5522 static boolean_t
5523 spa_has_active_shared_spare(spa_t *spa)
5524 {
5525 	int i, refcnt;
5526 	uint64_t pool;
5527 	spa_aux_vdev_t *sav = &spa->spa_spares;
5528 
5529 	for (i = 0; i < sav->sav_count; i++) {
5530 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
5531 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
5532 		    refcnt > 2)
5533 			return (B_TRUE);
5534 	}
5535 
5536 	return (B_FALSE);
5537 }
5538 
5539 /*
5540  * Post a sysevent corresponding to the given event.  The 'name' must be one of
5541  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
5542  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
5543  * in the userland libzpool, as we don't want consumers to misinterpret ztest
5544  * or zdb as real changes.
5545  */
5546 void
5547 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
5548 {
5549 #ifdef _KERNEL
5550 	sysevent_t		*ev;
5551 	sysevent_attr_list_t	*attr = NULL;
5552 	sysevent_value_t	value;
5553 	sysevent_id_t		eid;
5554 
5555 	ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
5556 	    SE_SLEEP);
5557 
5558 	value.value_type = SE_DATA_TYPE_STRING;
5559 	value.value.sv_string = spa_name(spa);
5560 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
5561 		goto done;
5562 
5563 	value.value_type = SE_DATA_TYPE_UINT64;
5564 	value.value.sv_uint64 = spa_guid(spa);
5565 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
5566 		goto done;
5567 
5568 	if (vd) {
5569 		value.value_type = SE_DATA_TYPE_UINT64;
5570 		value.value.sv_uint64 = vd->vdev_guid;
5571 		if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
5572 		    SE_SLEEP) != 0)
5573 			goto done;
5574 
5575 		if (vd->vdev_path) {
5576 			value.value_type = SE_DATA_TYPE_STRING;
5577 			value.value.sv_string = vd->vdev_path;
5578 			if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
5579 			    &value, SE_SLEEP) != 0)
5580 				goto done;
5581 		}
5582 	}
5583 
5584 	if (sysevent_attach_attributes(ev, attr) != 0)
5585 		goto done;
5586 	attr = NULL;
5587 
5588 	(void) log_sysevent(ev, SE_SLEEP, &eid);
5589 
5590 done:
5591 	if (attr)
5592 		sysevent_free_attr(attr);
5593 	sysevent_free(ev);
5594 #endif
5595 }
5596