xref: /illumos-gate/usr/src/uts/common/fs/zfs/spa.c (revision ec94d322)
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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
25  * Copyright (c) 2012 by Delphix. All rights reserved.
26  */
27 
28 /*
29  * This file contains all the routines used when modifying on-disk SPA state.
30  * This includes opening, importing, destroying, exporting a pool, and syncing a
31  * pool.
32  */
33 
34 #include <sys/zfs_context.h>
35 #include <sys/fm/fs/zfs.h>
36 #include <sys/spa_impl.h>
37 #include <sys/zio.h>
38 #include <sys/zio_checksum.h>
39 #include <sys/dmu.h>
40 #include <sys/dmu_tx.h>
41 #include <sys/zap.h>
42 #include <sys/zil.h>
43 #include <sys/ddt.h>
44 #include <sys/vdev_impl.h>
45 #include <sys/metaslab.h>
46 #include <sys/metaslab_impl.h>
47 #include <sys/uberblock_impl.h>
48 #include <sys/txg.h>
49 #include <sys/avl.h>
50 #include <sys/dmu_traverse.h>
51 #include <sys/dmu_objset.h>
52 #include <sys/unique.h>
53 #include <sys/dsl_pool.h>
54 #include <sys/dsl_dataset.h>
55 #include <sys/dsl_dir.h>
56 #include <sys/dsl_prop.h>
57 #include <sys/dsl_synctask.h>
58 #include <sys/fs/zfs.h>
59 #include <sys/arc.h>
60 #include <sys/callb.h>
61 #include <sys/systeminfo.h>
62 #include <sys/spa_boot.h>
63 #include <sys/zfs_ioctl.h>
64 #include <sys/dsl_scan.h>
65 #include <sys/zfeature.h>
66 
67 #ifdef	_KERNEL
68 #include <sys/bootprops.h>
69 #include <sys/callb.h>
70 #include <sys/cpupart.h>
71 #include <sys/pool.h>
72 #include <sys/sysdc.h>
73 #include <sys/zone.h>
74 #endif	/* _KERNEL */
75 
76 #include "zfs_prop.h"
77 #include "zfs_comutil.h"
78 
79 typedef enum zti_modes {
80 	ZTI_MODE_FIXED,			/* value is # of threads (min 1) */
81 	ZTI_MODE_ONLINE_PERCENT,	/* value is % of online CPUs */
82 	ZTI_MODE_BATCH,			/* cpu-intensive; value is ignored */
83 	ZTI_MODE_NULL,			/* don't create a taskq */
84 	ZTI_NMODES
85 } zti_modes_t;
86 
87 #define	ZTI_P(n, q)	{ ZTI_MODE_FIXED, (n), (q) }
88 #define	ZTI_PCT(n)	{ ZTI_MODE_ONLINE_PERCENT, (n), 1 }
89 #define	ZTI_BATCH	{ ZTI_MODE_BATCH, 0, 1 }
90 #define	ZTI_NULL	{ ZTI_MODE_NULL, 0, 0 }
91 
92 #define	ZTI_N(n)	ZTI_P(n, 1)
93 #define	ZTI_ONE		ZTI_N(1)
94 
95 typedef struct zio_taskq_info {
96 	zti_modes_t zti_mode;
97 	uint_t zti_value;
98 	uint_t zti_count;
99 } zio_taskq_info_t;
100 
101 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
102 	"issue", "issue_high", "intr", "intr_high"
103 };
104 
105 /*
106  * This table defines the taskq settings for each ZFS I/O type. When
107  * initializing a pool, we use this table to create an appropriately sized
108  * taskq. Some operations are low volume and therefore have a small, static
109  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
110  * macros. Other operations process a large amount of data; the ZTI_BATCH
111  * macro causes us to create a taskq oriented for throughput. Some operations
112  * are so high frequency and short-lived that the taskq itself can become a a
113  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
114  * additional degree of parallelism specified by the number of threads per-
115  * taskq and the number of taskqs; when dispatching an event in this case, the
116  * particular taskq is chosen at random.
117  *
118  * The different taskq priorities are to handle the different contexts (issue
119  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
120  * need to be handled with minimum delay.
121  */
122 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
123 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
124 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* NULL */
125 	{ ZTI_N(8),	ZTI_NULL,	ZTI_BATCH,	ZTI_NULL }, /* READ */
126 	{ ZTI_BATCH,	ZTI_N(5),	ZTI_N(8),	ZTI_N(5) }, /* WRITE */
127 	{ ZTI_P(12, 8),	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FREE */
128 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* CLAIM */
129 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* IOCTL */
130 };
131 
132 static dsl_syncfunc_t spa_sync_version;
133 static dsl_syncfunc_t spa_sync_props;
134 static dsl_checkfunc_t spa_change_guid_check;
135 static dsl_syncfunc_t spa_change_guid_sync;
136 static boolean_t spa_has_active_shared_spare(spa_t *spa);
137 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
138     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
139     char **ereport);
140 static void spa_vdev_resilver_done(spa_t *spa);
141 
142 uint_t		zio_taskq_batch_pct = 100;	/* 1 thread per cpu in pset */
143 id_t		zio_taskq_psrset_bind = PS_NONE;
144 boolean_t	zio_taskq_sysdc = B_TRUE;	/* use SDC scheduling class */
145 uint_t		zio_taskq_basedc = 80;		/* base duty cycle */
146 
147 boolean_t	spa_create_process = B_TRUE;	/* no process ==> no sysdc */
148 extern int	zfs_sync_pass_deferred_free;
149 
150 /*
151  * This (illegal) pool name is used when temporarily importing a spa_t in order
152  * to get the vdev stats associated with the imported devices.
153  */
154 #define	TRYIMPORT_NAME	"$import"
155 
156 /*
157  * ==========================================================================
158  * SPA properties routines
159  * ==========================================================================
160  */
161 
162 /*
163  * Add a (source=src, propname=propval) list to an nvlist.
164  */
165 static void
166 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
167     uint64_t intval, zprop_source_t src)
168 {
169 	const char *propname = zpool_prop_to_name(prop);
170 	nvlist_t *propval;
171 
172 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
173 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
174 
175 	if (strval != NULL)
176 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
177 	else
178 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
179 
180 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
181 	nvlist_free(propval);
182 }
183 
184 /*
185  * Get property values from the spa configuration.
186  */
187 static void
188 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
189 {
190 	vdev_t *rvd = spa->spa_root_vdev;
191 	dsl_pool_t *pool = spa->spa_dsl_pool;
192 	uint64_t size;
193 	uint64_t alloc;
194 	uint64_t space;
195 	uint64_t cap, version;
196 	zprop_source_t src = ZPROP_SRC_NONE;
197 	spa_config_dirent_t *dp;
198 
199 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
200 
201 	if (rvd != NULL) {
202 		alloc = metaslab_class_get_alloc(spa_normal_class(spa));
203 		size = metaslab_class_get_space(spa_normal_class(spa));
204 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
205 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
206 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
207 		spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
208 		    size - alloc, src);
209 
210 		space = 0;
211 		for (int c = 0; c < rvd->vdev_children; c++) {
212 			vdev_t *tvd = rvd->vdev_child[c];
213 			space += tvd->vdev_max_asize - tvd->vdev_asize;
214 		}
215 		spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
216 		    src);
217 
218 		spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
219 		    (spa_mode(spa) == FREAD), src);
220 
221 		cap = (size == 0) ? 0 : (alloc * 100 / size);
222 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
223 
224 		spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
225 		    ddt_get_pool_dedup_ratio(spa), src);
226 
227 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
228 		    rvd->vdev_state, src);
229 
230 		version = spa_version(spa);
231 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
232 			src = ZPROP_SRC_DEFAULT;
233 		else
234 			src = ZPROP_SRC_LOCAL;
235 		spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
236 	}
237 
238 	if (pool != NULL) {
239 		dsl_dir_t *freedir = pool->dp_free_dir;
240 
241 		/*
242 		 * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
243 		 * when opening pools before this version freedir will be NULL.
244 		 */
245 		if (freedir != NULL) {
246 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
247 			    freedir->dd_phys->dd_used_bytes, src);
248 		} else {
249 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
250 			    NULL, 0, src);
251 		}
252 	}
253 
254 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
255 
256 	if (spa->spa_comment != NULL) {
257 		spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
258 		    0, ZPROP_SRC_LOCAL);
259 	}
260 
261 	if (spa->spa_root != NULL)
262 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
263 		    0, ZPROP_SRC_LOCAL);
264 
265 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
266 		if (dp->scd_path == NULL) {
267 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
268 			    "none", 0, ZPROP_SRC_LOCAL);
269 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
270 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
271 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
272 		}
273 	}
274 }
275 
276 /*
277  * Get zpool property values.
278  */
279 int
280 spa_prop_get(spa_t *spa, nvlist_t **nvp)
281 {
282 	objset_t *mos = spa->spa_meta_objset;
283 	zap_cursor_t zc;
284 	zap_attribute_t za;
285 	int err;
286 
287 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
288 
289 	mutex_enter(&spa->spa_props_lock);
290 
291 	/*
292 	 * Get properties from the spa config.
293 	 */
294 	spa_prop_get_config(spa, nvp);
295 
296 	/* If no pool property object, no more prop to get. */
297 	if (mos == NULL || spa->spa_pool_props_object == 0) {
298 		mutex_exit(&spa->spa_props_lock);
299 		return (0);
300 	}
301 
302 	/*
303 	 * Get properties from the MOS pool property object.
304 	 */
305 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
306 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
307 	    zap_cursor_advance(&zc)) {
308 		uint64_t intval = 0;
309 		char *strval = NULL;
310 		zprop_source_t src = ZPROP_SRC_DEFAULT;
311 		zpool_prop_t prop;
312 
313 		if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
314 			continue;
315 
316 		switch (za.za_integer_length) {
317 		case 8:
318 			/* integer property */
319 			if (za.za_first_integer !=
320 			    zpool_prop_default_numeric(prop))
321 				src = ZPROP_SRC_LOCAL;
322 
323 			if (prop == ZPOOL_PROP_BOOTFS) {
324 				dsl_pool_t *dp;
325 				dsl_dataset_t *ds = NULL;
326 
327 				dp = spa_get_dsl(spa);
328 				rw_enter(&dp->dp_config_rwlock, RW_READER);
329 				if (err = dsl_dataset_hold_obj(dp,
330 				    za.za_first_integer, FTAG, &ds)) {
331 					rw_exit(&dp->dp_config_rwlock);
332 					break;
333 				}
334 
335 				strval = kmem_alloc(
336 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
337 				    KM_SLEEP);
338 				dsl_dataset_name(ds, strval);
339 				dsl_dataset_rele(ds, FTAG);
340 				rw_exit(&dp->dp_config_rwlock);
341 			} else {
342 				strval = NULL;
343 				intval = za.za_first_integer;
344 			}
345 
346 			spa_prop_add_list(*nvp, prop, strval, intval, src);
347 
348 			if (strval != NULL)
349 				kmem_free(strval,
350 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
351 
352 			break;
353 
354 		case 1:
355 			/* string property */
356 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
357 			err = zap_lookup(mos, spa->spa_pool_props_object,
358 			    za.za_name, 1, za.za_num_integers, strval);
359 			if (err) {
360 				kmem_free(strval, za.za_num_integers);
361 				break;
362 			}
363 			spa_prop_add_list(*nvp, prop, strval, 0, src);
364 			kmem_free(strval, za.za_num_integers);
365 			break;
366 
367 		default:
368 			break;
369 		}
370 	}
371 	zap_cursor_fini(&zc);
372 	mutex_exit(&spa->spa_props_lock);
373 out:
374 	if (err && err != ENOENT) {
375 		nvlist_free(*nvp);
376 		*nvp = NULL;
377 		return (err);
378 	}
379 
380 	return (0);
381 }
382 
383 /*
384  * Validate the given pool properties nvlist and modify the list
385  * for the property values to be set.
386  */
387 static int
388 spa_prop_validate(spa_t *spa, nvlist_t *props)
389 {
390 	nvpair_t *elem;
391 	int error = 0, reset_bootfs = 0;
392 	uint64_t objnum = 0;
393 	boolean_t has_feature = B_FALSE;
394 
395 	elem = NULL;
396 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
397 		uint64_t intval;
398 		char *strval, *slash, *check, *fname;
399 		const char *propname = nvpair_name(elem);
400 		zpool_prop_t prop = zpool_name_to_prop(propname);
401 
402 		switch (prop) {
403 		case ZPROP_INVAL:
404 			if (!zpool_prop_feature(propname)) {
405 				error = EINVAL;
406 				break;
407 			}
408 
409 			/*
410 			 * Sanitize the input.
411 			 */
412 			if (nvpair_type(elem) != DATA_TYPE_UINT64) {
413 				error = EINVAL;
414 				break;
415 			}
416 
417 			if (nvpair_value_uint64(elem, &intval) != 0) {
418 				error = EINVAL;
419 				break;
420 			}
421 
422 			if (intval != 0) {
423 				error = EINVAL;
424 				break;
425 			}
426 
427 			fname = strchr(propname, '@') + 1;
428 			if (zfeature_lookup_name(fname, NULL) != 0) {
429 				error = EINVAL;
430 				break;
431 			}
432 
433 			has_feature = B_TRUE;
434 			break;
435 
436 		case ZPOOL_PROP_VERSION:
437 			error = nvpair_value_uint64(elem, &intval);
438 			if (!error &&
439 			    (intval < spa_version(spa) ||
440 			    intval > SPA_VERSION_BEFORE_FEATURES ||
441 			    has_feature))
442 				error = EINVAL;
443 			break;
444 
445 		case ZPOOL_PROP_DELEGATION:
446 		case ZPOOL_PROP_AUTOREPLACE:
447 		case ZPOOL_PROP_LISTSNAPS:
448 		case ZPOOL_PROP_AUTOEXPAND:
449 			error = nvpair_value_uint64(elem, &intval);
450 			if (!error && intval > 1)
451 				error = EINVAL;
452 			break;
453 
454 		case ZPOOL_PROP_BOOTFS:
455 			/*
456 			 * If the pool version is less than SPA_VERSION_BOOTFS,
457 			 * or the pool is still being created (version == 0),
458 			 * the bootfs property cannot be set.
459 			 */
460 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
461 				error = ENOTSUP;
462 				break;
463 			}
464 
465 			/*
466 			 * Make sure the vdev config is bootable
467 			 */
468 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
469 				error = ENOTSUP;
470 				break;
471 			}
472 
473 			reset_bootfs = 1;
474 
475 			error = nvpair_value_string(elem, &strval);
476 
477 			if (!error) {
478 				objset_t *os;
479 				uint64_t compress;
480 
481 				if (strval == NULL || strval[0] == '\0') {
482 					objnum = zpool_prop_default_numeric(
483 					    ZPOOL_PROP_BOOTFS);
484 					break;
485 				}
486 
487 				if (error = dmu_objset_hold(strval, FTAG, &os))
488 					break;
489 
490 				/* Must be ZPL and not gzip compressed. */
491 
492 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
493 					error = ENOTSUP;
494 				} else if ((error = dsl_prop_get_integer(strval,
495 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
496 				    &compress, NULL)) == 0 &&
497 				    !BOOTFS_COMPRESS_VALID(compress)) {
498 					error = ENOTSUP;
499 				} else {
500 					objnum = dmu_objset_id(os);
501 				}
502 				dmu_objset_rele(os, FTAG);
503 			}
504 			break;
505 
506 		case ZPOOL_PROP_FAILUREMODE:
507 			error = nvpair_value_uint64(elem, &intval);
508 			if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
509 			    intval > ZIO_FAILURE_MODE_PANIC))
510 				error = EINVAL;
511 
512 			/*
513 			 * This is a special case which only occurs when
514 			 * the pool has completely failed. This allows
515 			 * the user to change the in-core failmode property
516 			 * without syncing it out to disk (I/Os might
517 			 * currently be blocked). We do this by returning
518 			 * EIO to the caller (spa_prop_set) to trick it
519 			 * into thinking we encountered a property validation
520 			 * error.
521 			 */
522 			if (!error && spa_suspended(spa)) {
523 				spa->spa_failmode = intval;
524 				error = EIO;
525 			}
526 			break;
527 
528 		case ZPOOL_PROP_CACHEFILE:
529 			if ((error = nvpair_value_string(elem, &strval)) != 0)
530 				break;
531 
532 			if (strval[0] == '\0')
533 				break;
534 
535 			if (strcmp(strval, "none") == 0)
536 				break;
537 
538 			if (strval[0] != '/') {
539 				error = EINVAL;
540 				break;
541 			}
542 
543 			slash = strrchr(strval, '/');
544 			ASSERT(slash != NULL);
545 
546 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
547 			    strcmp(slash, "/..") == 0)
548 				error = EINVAL;
549 			break;
550 
551 		case ZPOOL_PROP_COMMENT:
552 			if ((error = nvpair_value_string(elem, &strval)) != 0)
553 				break;
554 			for (check = strval; *check != '\0'; check++) {
555 				/*
556 				 * The kernel doesn't have an easy isprint()
557 				 * check.  For this kernel check, we merely
558 				 * check ASCII apart from DEL.  Fix this if
559 				 * there is an easy-to-use kernel isprint().
560 				 */
561 				if (*check >= 0x7f) {
562 					error = EINVAL;
563 					break;
564 				}
565 				check++;
566 			}
567 			if (strlen(strval) > ZPROP_MAX_COMMENT)
568 				error = E2BIG;
569 			break;
570 
571 		case ZPOOL_PROP_DEDUPDITTO:
572 			if (spa_version(spa) < SPA_VERSION_DEDUP)
573 				error = ENOTSUP;
574 			else
575 				error = nvpair_value_uint64(elem, &intval);
576 			if (error == 0 &&
577 			    intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
578 				error = EINVAL;
579 			break;
580 		}
581 
582 		if (error)
583 			break;
584 	}
585 
586 	if (!error && reset_bootfs) {
587 		error = nvlist_remove(props,
588 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
589 
590 		if (!error) {
591 			error = nvlist_add_uint64(props,
592 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
593 		}
594 	}
595 
596 	return (error);
597 }
598 
599 void
600 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
601 {
602 	char *cachefile;
603 	spa_config_dirent_t *dp;
604 
605 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
606 	    &cachefile) != 0)
607 		return;
608 
609 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
610 	    KM_SLEEP);
611 
612 	if (cachefile[0] == '\0')
613 		dp->scd_path = spa_strdup(spa_config_path);
614 	else if (strcmp(cachefile, "none") == 0)
615 		dp->scd_path = NULL;
616 	else
617 		dp->scd_path = spa_strdup(cachefile);
618 
619 	list_insert_head(&spa->spa_config_list, dp);
620 	if (need_sync)
621 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
622 }
623 
624 int
625 spa_prop_set(spa_t *spa, nvlist_t *nvp)
626 {
627 	int error;
628 	nvpair_t *elem = NULL;
629 	boolean_t need_sync = B_FALSE;
630 
631 	if ((error = spa_prop_validate(spa, nvp)) != 0)
632 		return (error);
633 
634 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
635 		zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
636 
637 		if (prop == ZPOOL_PROP_CACHEFILE ||
638 		    prop == ZPOOL_PROP_ALTROOT ||
639 		    prop == ZPOOL_PROP_READONLY)
640 			continue;
641 
642 		if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
643 			uint64_t ver;
644 
645 			if (prop == ZPOOL_PROP_VERSION) {
646 				VERIFY(nvpair_value_uint64(elem, &ver) == 0);
647 			} else {
648 				ASSERT(zpool_prop_feature(nvpair_name(elem)));
649 				ver = SPA_VERSION_FEATURES;
650 				need_sync = B_TRUE;
651 			}
652 
653 			/* Save time if the version is already set. */
654 			if (ver == spa_version(spa))
655 				continue;
656 
657 			/*
658 			 * In addition to the pool directory object, we might
659 			 * create the pool properties object, the features for
660 			 * read object, the features for write object, or the
661 			 * feature descriptions object.
662 			 */
663 			error = dsl_sync_task_do(spa_get_dsl(spa), NULL,
664 			    spa_sync_version, spa, &ver, 6);
665 			if (error)
666 				return (error);
667 			continue;
668 		}
669 
670 		need_sync = B_TRUE;
671 		break;
672 	}
673 
674 	if (need_sync) {
675 		return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_sync_props,
676 		    spa, nvp, 6));
677 	}
678 
679 	return (0);
680 }
681 
682 /*
683  * If the bootfs property value is dsobj, clear it.
684  */
685 void
686 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
687 {
688 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
689 		VERIFY(zap_remove(spa->spa_meta_objset,
690 		    spa->spa_pool_props_object,
691 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
692 		spa->spa_bootfs = 0;
693 	}
694 }
695 
696 /*ARGSUSED*/
697 static int
698 spa_change_guid_check(void *arg1, void *arg2, dmu_tx_t *tx)
699 {
700 	spa_t *spa = arg1;
701 	uint64_t *newguid = arg2;
702 	vdev_t *rvd = spa->spa_root_vdev;
703 	uint64_t vdev_state;
704 
705 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
706 	vdev_state = rvd->vdev_state;
707 	spa_config_exit(spa, SCL_STATE, FTAG);
708 
709 	if (vdev_state != VDEV_STATE_HEALTHY)
710 		return (ENXIO);
711 
712 	ASSERT3U(spa_guid(spa), !=, *newguid);
713 
714 	return (0);
715 }
716 
717 static void
718 spa_change_guid_sync(void *arg1, void *arg2, dmu_tx_t *tx)
719 {
720 	spa_t *spa = arg1;
721 	uint64_t *newguid = arg2;
722 	uint64_t oldguid;
723 	vdev_t *rvd = spa->spa_root_vdev;
724 
725 	oldguid = spa_guid(spa);
726 
727 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
728 	rvd->vdev_guid = *newguid;
729 	rvd->vdev_guid_sum += (*newguid - oldguid);
730 	vdev_config_dirty(rvd);
731 	spa_config_exit(spa, SCL_STATE, FTAG);
732 
733 	spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
734 	    oldguid, *newguid);
735 }
736 
737 /*
738  * Change the GUID for the pool.  This is done so that we can later
739  * re-import a pool built from a clone of our own vdevs.  We will modify
740  * the root vdev's guid, our own pool guid, and then mark all of our
741  * vdevs dirty.  Note that we must make sure that all our vdevs are
742  * online when we do this, or else any vdevs that weren't present
743  * would be orphaned from our pool.  We are also going to issue a
744  * sysevent to update any watchers.
745  */
746 int
747 spa_change_guid(spa_t *spa)
748 {
749 	int error;
750 	uint64_t guid;
751 
752 	mutex_enter(&spa_namespace_lock);
753 	guid = spa_generate_guid(NULL);
754 
755 	error = dsl_sync_task_do(spa_get_dsl(spa), spa_change_guid_check,
756 	    spa_change_guid_sync, spa, &guid, 5);
757 
758 	if (error == 0) {
759 		spa_config_sync(spa, B_FALSE, B_TRUE);
760 		spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
761 	}
762 
763 	mutex_exit(&spa_namespace_lock);
764 
765 	return (error);
766 }
767 
768 /*
769  * ==========================================================================
770  * SPA state manipulation (open/create/destroy/import/export)
771  * ==========================================================================
772  */
773 
774 static int
775 spa_error_entry_compare(const void *a, const void *b)
776 {
777 	spa_error_entry_t *sa = (spa_error_entry_t *)a;
778 	spa_error_entry_t *sb = (spa_error_entry_t *)b;
779 	int ret;
780 
781 	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
782 	    sizeof (zbookmark_t));
783 
784 	if (ret < 0)
785 		return (-1);
786 	else if (ret > 0)
787 		return (1);
788 	else
789 		return (0);
790 }
791 
792 /*
793  * Utility function which retrieves copies of the current logs and
794  * re-initializes them in the process.
795  */
796 void
797 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
798 {
799 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
800 
801 	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
802 	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
803 
804 	avl_create(&spa->spa_errlist_scrub,
805 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
806 	    offsetof(spa_error_entry_t, se_avl));
807 	avl_create(&spa->spa_errlist_last,
808 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
809 	    offsetof(spa_error_entry_t, se_avl));
810 }
811 
812 static void
813 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
814 {
815 	const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
816 	enum zti_modes mode = ztip->zti_mode;
817 	uint_t value = ztip->zti_value;
818 	uint_t count = ztip->zti_count;
819 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
820 	char name[32];
821 	uint_t flags = 0;
822 	boolean_t batch = B_FALSE;
823 
824 	if (mode == ZTI_MODE_NULL) {
825 		tqs->stqs_count = 0;
826 		tqs->stqs_taskq = NULL;
827 		return;
828 	}
829 
830 	ASSERT3U(count, >, 0);
831 
832 	tqs->stqs_count = count;
833 	tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
834 
835 	for (uint_t i = 0; i < count; i++) {
836 		taskq_t *tq;
837 
838 		switch (mode) {
839 		case ZTI_MODE_FIXED:
840 			ASSERT3U(value, >=, 1);
841 			value = MAX(value, 1);
842 			break;
843 
844 		case ZTI_MODE_BATCH:
845 			batch = B_TRUE;
846 			flags |= TASKQ_THREADS_CPU_PCT;
847 			value = zio_taskq_batch_pct;
848 			break;
849 
850 		case ZTI_MODE_ONLINE_PERCENT:
851 			flags |= TASKQ_THREADS_CPU_PCT;
852 			break;
853 
854 		default:
855 			panic("unrecognized mode for %s_%s taskq (%u:%u) in "
856 			    "spa_activate()",
857 			    zio_type_name[t], zio_taskq_types[q], mode, value);
858 			break;
859 		}
860 
861 		if (count > 1) {
862 			(void) snprintf(name, sizeof (name), "%s_%s_%u",
863 			    zio_type_name[t], zio_taskq_types[q], i);
864 		} else {
865 			(void) snprintf(name, sizeof (name), "%s_%s",
866 			    zio_type_name[t], zio_taskq_types[q]);
867 		}
868 
869 		if (zio_taskq_sysdc && spa->spa_proc != &p0) {
870 			if (batch)
871 				flags |= TASKQ_DC_BATCH;
872 
873 			tq = taskq_create_sysdc(name, value, 50, INT_MAX,
874 			    spa->spa_proc, zio_taskq_basedc, flags);
875 		} else {
876 			tq = taskq_create_proc(name, value, maxclsyspri, 50,
877 			    INT_MAX, spa->spa_proc, flags);
878 		}
879 
880 		tqs->stqs_taskq[i] = tq;
881 	}
882 }
883 
884 static void
885 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
886 {
887 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
888 
889 	if (tqs->stqs_taskq == NULL) {
890 		ASSERT0(tqs->stqs_count);
891 		return;
892 	}
893 
894 	for (uint_t i = 0; i < tqs->stqs_count; i++) {
895 		ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
896 		taskq_destroy(tqs->stqs_taskq[i]);
897 	}
898 
899 	kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
900 	tqs->stqs_taskq = NULL;
901 }
902 
903 /*
904  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
905  * Note that a type may have multiple discrete taskqs to avoid lock contention
906  * on the taskq itself. In that case we choose which taskq at random by using
907  * the low bits of gethrtime().
908  */
909 void
910 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
911     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
912 {
913 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
914 	taskq_t *tq;
915 
916 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
917 	ASSERT3U(tqs->stqs_count, !=, 0);
918 
919 	if (tqs->stqs_count == 1) {
920 		tq = tqs->stqs_taskq[0];
921 	} else {
922 		tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
923 	}
924 
925 	taskq_dispatch_ent(tq, func, arg, flags, ent);
926 }
927 
928 static void
929 spa_create_zio_taskqs(spa_t *spa)
930 {
931 	for (int t = 0; t < ZIO_TYPES; t++) {
932 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
933 			spa_taskqs_init(spa, t, q);
934 		}
935 	}
936 }
937 
938 #ifdef _KERNEL
939 static void
940 spa_thread(void *arg)
941 {
942 	callb_cpr_t cprinfo;
943 
944 	spa_t *spa = arg;
945 	user_t *pu = PTOU(curproc);
946 
947 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
948 	    spa->spa_name);
949 
950 	ASSERT(curproc != &p0);
951 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
952 	    "zpool-%s", spa->spa_name);
953 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
954 
955 	/* bind this thread to the requested psrset */
956 	if (zio_taskq_psrset_bind != PS_NONE) {
957 		pool_lock();
958 		mutex_enter(&cpu_lock);
959 		mutex_enter(&pidlock);
960 		mutex_enter(&curproc->p_lock);
961 
962 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
963 		    0, NULL, NULL) == 0)  {
964 			curthread->t_bind_pset = zio_taskq_psrset_bind;
965 		} else {
966 			cmn_err(CE_WARN,
967 			    "Couldn't bind process for zfs pool \"%s\" to "
968 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
969 		}
970 
971 		mutex_exit(&curproc->p_lock);
972 		mutex_exit(&pidlock);
973 		mutex_exit(&cpu_lock);
974 		pool_unlock();
975 	}
976 
977 	if (zio_taskq_sysdc) {
978 		sysdc_thread_enter(curthread, 100, 0);
979 	}
980 
981 	spa->spa_proc = curproc;
982 	spa->spa_did = curthread->t_did;
983 
984 	spa_create_zio_taskqs(spa);
985 
986 	mutex_enter(&spa->spa_proc_lock);
987 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
988 
989 	spa->spa_proc_state = SPA_PROC_ACTIVE;
990 	cv_broadcast(&spa->spa_proc_cv);
991 
992 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
993 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
994 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
995 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
996 
997 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
998 	spa->spa_proc_state = SPA_PROC_GONE;
999 	spa->spa_proc = &p0;
1000 	cv_broadcast(&spa->spa_proc_cv);
1001 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
1002 
1003 	mutex_enter(&curproc->p_lock);
1004 	lwp_exit();
1005 }
1006 #endif
1007 
1008 /*
1009  * Activate an uninitialized pool.
1010  */
1011 static void
1012 spa_activate(spa_t *spa, int mode)
1013 {
1014 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1015 
1016 	spa->spa_state = POOL_STATE_ACTIVE;
1017 	spa->spa_mode = mode;
1018 
1019 	spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1020 	spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1021 
1022 	/* Try to create a covering process */
1023 	mutex_enter(&spa->spa_proc_lock);
1024 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1025 	ASSERT(spa->spa_proc == &p0);
1026 	spa->spa_did = 0;
1027 
1028 	/* Only create a process if we're going to be around a while. */
1029 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1030 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1031 		    NULL, 0) == 0) {
1032 			spa->spa_proc_state = SPA_PROC_CREATED;
1033 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
1034 				cv_wait(&spa->spa_proc_cv,
1035 				    &spa->spa_proc_lock);
1036 			}
1037 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1038 			ASSERT(spa->spa_proc != &p0);
1039 			ASSERT(spa->spa_did != 0);
1040 		} else {
1041 #ifdef _KERNEL
1042 			cmn_err(CE_WARN,
1043 			    "Couldn't create process for zfs pool \"%s\"\n",
1044 			    spa->spa_name);
1045 #endif
1046 		}
1047 	}
1048 	mutex_exit(&spa->spa_proc_lock);
1049 
1050 	/* If we didn't create a process, we need to create our taskqs. */
1051 	if (spa->spa_proc == &p0) {
1052 		spa_create_zio_taskqs(spa);
1053 	}
1054 
1055 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1056 	    offsetof(vdev_t, vdev_config_dirty_node));
1057 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1058 	    offsetof(vdev_t, vdev_state_dirty_node));
1059 
1060 	txg_list_create(&spa->spa_vdev_txg_list,
1061 	    offsetof(struct vdev, vdev_txg_node));
1062 
1063 	avl_create(&spa->spa_errlist_scrub,
1064 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1065 	    offsetof(spa_error_entry_t, se_avl));
1066 	avl_create(&spa->spa_errlist_last,
1067 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1068 	    offsetof(spa_error_entry_t, se_avl));
1069 }
1070 
1071 /*
1072  * Opposite of spa_activate().
1073  */
1074 static void
1075 spa_deactivate(spa_t *spa)
1076 {
1077 	ASSERT(spa->spa_sync_on == B_FALSE);
1078 	ASSERT(spa->spa_dsl_pool == NULL);
1079 	ASSERT(spa->spa_root_vdev == NULL);
1080 	ASSERT(spa->spa_async_zio_root == NULL);
1081 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1082 
1083 	txg_list_destroy(&spa->spa_vdev_txg_list);
1084 
1085 	list_destroy(&spa->spa_config_dirty_list);
1086 	list_destroy(&spa->spa_state_dirty_list);
1087 
1088 	for (int t = 0; t < ZIO_TYPES; t++) {
1089 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1090 			spa_taskqs_fini(spa, t, q);
1091 		}
1092 	}
1093 
1094 	metaslab_class_destroy(spa->spa_normal_class);
1095 	spa->spa_normal_class = NULL;
1096 
1097 	metaslab_class_destroy(spa->spa_log_class);
1098 	spa->spa_log_class = NULL;
1099 
1100 	/*
1101 	 * If this was part of an import or the open otherwise failed, we may
1102 	 * still have errors left in the queues.  Empty them just in case.
1103 	 */
1104 	spa_errlog_drain(spa);
1105 
1106 	avl_destroy(&spa->spa_errlist_scrub);
1107 	avl_destroy(&spa->spa_errlist_last);
1108 
1109 	spa->spa_state = POOL_STATE_UNINITIALIZED;
1110 
1111 	mutex_enter(&spa->spa_proc_lock);
1112 	if (spa->spa_proc_state != SPA_PROC_NONE) {
1113 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1114 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1115 		cv_broadcast(&spa->spa_proc_cv);
1116 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1117 			ASSERT(spa->spa_proc != &p0);
1118 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1119 		}
1120 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1121 		spa->spa_proc_state = SPA_PROC_NONE;
1122 	}
1123 	ASSERT(spa->spa_proc == &p0);
1124 	mutex_exit(&spa->spa_proc_lock);
1125 
1126 	/*
1127 	 * We want to make sure spa_thread() has actually exited the ZFS
1128 	 * module, so that the module can't be unloaded out from underneath
1129 	 * it.
1130 	 */
1131 	if (spa->spa_did != 0) {
1132 		thread_join(spa->spa_did);
1133 		spa->spa_did = 0;
1134 	}
1135 }
1136 
1137 /*
1138  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1139  * will create all the necessary vdevs in the appropriate layout, with each vdev
1140  * in the CLOSED state.  This will prep the pool before open/creation/import.
1141  * All vdev validation is done by the vdev_alloc() routine.
1142  */
1143 static int
1144 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1145     uint_t id, int atype)
1146 {
1147 	nvlist_t **child;
1148 	uint_t children;
1149 	int error;
1150 
1151 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1152 		return (error);
1153 
1154 	if ((*vdp)->vdev_ops->vdev_op_leaf)
1155 		return (0);
1156 
1157 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1158 	    &child, &children);
1159 
1160 	if (error == ENOENT)
1161 		return (0);
1162 
1163 	if (error) {
1164 		vdev_free(*vdp);
1165 		*vdp = NULL;
1166 		return (EINVAL);
1167 	}
1168 
1169 	for (int c = 0; c < children; c++) {
1170 		vdev_t *vd;
1171 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1172 		    atype)) != 0) {
1173 			vdev_free(*vdp);
1174 			*vdp = NULL;
1175 			return (error);
1176 		}
1177 	}
1178 
1179 	ASSERT(*vdp != NULL);
1180 
1181 	return (0);
1182 }
1183 
1184 /*
1185  * Opposite of spa_load().
1186  */
1187 static void
1188 spa_unload(spa_t *spa)
1189 {
1190 	int i;
1191 
1192 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1193 
1194 	/*
1195 	 * Stop async tasks.
1196 	 */
1197 	spa_async_suspend(spa);
1198 
1199 	/*
1200 	 * Stop syncing.
1201 	 */
1202 	if (spa->spa_sync_on) {
1203 		txg_sync_stop(spa->spa_dsl_pool);
1204 		spa->spa_sync_on = B_FALSE;
1205 	}
1206 
1207 	/*
1208 	 * Wait for any outstanding async I/O to complete.
1209 	 */
1210 	if (spa->spa_async_zio_root != NULL) {
1211 		(void) zio_wait(spa->spa_async_zio_root);
1212 		spa->spa_async_zio_root = NULL;
1213 	}
1214 
1215 	bpobj_close(&spa->spa_deferred_bpobj);
1216 
1217 	/*
1218 	 * Close the dsl pool.
1219 	 */
1220 	if (spa->spa_dsl_pool) {
1221 		dsl_pool_close(spa->spa_dsl_pool);
1222 		spa->spa_dsl_pool = NULL;
1223 		spa->spa_meta_objset = NULL;
1224 	}
1225 
1226 	ddt_unload(spa);
1227 
1228 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1229 
1230 	/*
1231 	 * Drop and purge level 2 cache
1232 	 */
1233 	spa_l2cache_drop(spa);
1234 
1235 	/*
1236 	 * Close all vdevs.
1237 	 */
1238 	if (spa->spa_root_vdev)
1239 		vdev_free(spa->spa_root_vdev);
1240 	ASSERT(spa->spa_root_vdev == NULL);
1241 
1242 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1243 		vdev_free(spa->spa_spares.sav_vdevs[i]);
1244 	if (spa->spa_spares.sav_vdevs) {
1245 		kmem_free(spa->spa_spares.sav_vdevs,
1246 		    spa->spa_spares.sav_count * sizeof (void *));
1247 		spa->spa_spares.sav_vdevs = NULL;
1248 	}
1249 	if (spa->spa_spares.sav_config) {
1250 		nvlist_free(spa->spa_spares.sav_config);
1251 		spa->spa_spares.sav_config = NULL;
1252 	}
1253 	spa->spa_spares.sav_count = 0;
1254 
1255 	for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1256 		vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1257 		vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1258 	}
1259 	if (spa->spa_l2cache.sav_vdevs) {
1260 		kmem_free(spa->spa_l2cache.sav_vdevs,
1261 		    spa->spa_l2cache.sav_count * sizeof (void *));
1262 		spa->spa_l2cache.sav_vdevs = NULL;
1263 	}
1264 	if (spa->spa_l2cache.sav_config) {
1265 		nvlist_free(spa->spa_l2cache.sav_config);
1266 		spa->spa_l2cache.sav_config = NULL;
1267 	}
1268 	spa->spa_l2cache.sav_count = 0;
1269 
1270 	spa->spa_async_suspended = 0;
1271 
1272 	if (spa->spa_comment != NULL) {
1273 		spa_strfree(spa->spa_comment);
1274 		spa->spa_comment = NULL;
1275 	}
1276 
1277 	spa_config_exit(spa, SCL_ALL, FTAG);
1278 }
1279 
1280 /*
1281  * Load (or re-load) the current list of vdevs describing the active spares for
1282  * this pool.  When this is called, we have some form of basic information in
1283  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1284  * then re-generate a more complete list including status information.
1285  */
1286 static void
1287 spa_load_spares(spa_t *spa)
1288 {
1289 	nvlist_t **spares;
1290 	uint_t nspares;
1291 	int i;
1292 	vdev_t *vd, *tvd;
1293 
1294 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1295 
1296 	/*
1297 	 * First, close and free any existing spare vdevs.
1298 	 */
1299 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1300 		vd = spa->spa_spares.sav_vdevs[i];
1301 
1302 		/* Undo the call to spa_activate() below */
1303 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1304 		    B_FALSE)) != NULL && tvd->vdev_isspare)
1305 			spa_spare_remove(tvd);
1306 		vdev_close(vd);
1307 		vdev_free(vd);
1308 	}
1309 
1310 	if (spa->spa_spares.sav_vdevs)
1311 		kmem_free(spa->spa_spares.sav_vdevs,
1312 		    spa->spa_spares.sav_count * sizeof (void *));
1313 
1314 	if (spa->spa_spares.sav_config == NULL)
1315 		nspares = 0;
1316 	else
1317 		VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1318 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1319 
1320 	spa->spa_spares.sav_count = (int)nspares;
1321 	spa->spa_spares.sav_vdevs = NULL;
1322 
1323 	if (nspares == 0)
1324 		return;
1325 
1326 	/*
1327 	 * Construct the array of vdevs, opening them to get status in the
1328 	 * process.   For each spare, there is potentially two different vdev_t
1329 	 * structures associated with it: one in the list of spares (used only
1330 	 * for basic validation purposes) and one in the active vdev
1331 	 * configuration (if it's spared in).  During this phase we open and
1332 	 * validate each vdev on the spare list.  If the vdev also exists in the
1333 	 * active configuration, then we also mark this vdev as an active spare.
1334 	 */
1335 	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1336 	    KM_SLEEP);
1337 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1338 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1339 		    VDEV_ALLOC_SPARE) == 0);
1340 		ASSERT(vd != NULL);
1341 
1342 		spa->spa_spares.sav_vdevs[i] = vd;
1343 
1344 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1345 		    B_FALSE)) != NULL) {
1346 			if (!tvd->vdev_isspare)
1347 				spa_spare_add(tvd);
1348 
1349 			/*
1350 			 * We only mark the spare active if we were successfully
1351 			 * able to load the vdev.  Otherwise, importing a pool
1352 			 * with a bad active spare would result in strange
1353 			 * behavior, because multiple pool would think the spare
1354 			 * is actively in use.
1355 			 *
1356 			 * There is a vulnerability here to an equally bizarre
1357 			 * circumstance, where a dead active spare is later
1358 			 * brought back to life (onlined or otherwise).  Given
1359 			 * the rarity of this scenario, and the extra complexity
1360 			 * it adds, we ignore the possibility.
1361 			 */
1362 			if (!vdev_is_dead(tvd))
1363 				spa_spare_activate(tvd);
1364 		}
1365 
1366 		vd->vdev_top = vd;
1367 		vd->vdev_aux = &spa->spa_spares;
1368 
1369 		if (vdev_open(vd) != 0)
1370 			continue;
1371 
1372 		if (vdev_validate_aux(vd) == 0)
1373 			spa_spare_add(vd);
1374 	}
1375 
1376 	/*
1377 	 * Recompute the stashed list of spares, with status information
1378 	 * this time.
1379 	 */
1380 	VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1381 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1382 
1383 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1384 	    KM_SLEEP);
1385 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1386 		spares[i] = vdev_config_generate(spa,
1387 		    spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1388 	VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1389 	    ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1390 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1391 		nvlist_free(spares[i]);
1392 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1393 }
1394 
1395 /*
1396  * Load (or re-load) the current list of vdevs describing the active l2cache for
1397  * this pool.  When this is called, we have some form of basic information in
1398  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1399  * then re-generate a more complete list including status information.
1400  * Devices which are already active have their details maintained, and are
1401  * not re-opened.
1402  */
1403 static void
1404 spa_load_l2cache(spa_t *spa)
1405 {
1406 	nvlist_t **l2cache;
1407 	uint_t nl2cache;
1408 	int i, j, oldnvdevs;
1409 	uint64_t guid;
1410 	vdev_t *vd, **oldvdevs, **newvdevs;
1411 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1412 
1413 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1414 
1415 	if (sav->sav_config != NULL) {
1416 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1417 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1418 		newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1419 	} else {
1420 		nl2cache = 0;
1421 		newvdevs = NULL;
1422 	}
1423 
1424 	oldvdevs = sav->sav_vdevs;
1425 	oldnvdevs = sav->sav_count;
1426 	sav->sav_vdevs = NULL;
1427 	sav->sav_count = 0;
1428 
1429 	/*
1430 	 * Process new nvlist of vdevs.
1431 	 */
1432 	for (i = 0; i < nl2cache; i++) {
1433 		VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1434 		    &guid) == 0);
1435 
1436 		newvdevs[i] = NULL;
1437 		for (j = 0; j < oldnvdevs; j++) {
1438 			vd = oldvdevs[j];
1439 			if (vd != NULL && guid == vd->vdev_guid) {
1440 				/*
1441 				 * Retain previous vdev for add/remove ops.
1442 				 */
1443 				newvdevs[i] = vd;
1444 				oldvdevs[j] = NULL;
1445 				break;
1446 			}
1447 		}
1448 
1449 		if (newvdevs[i] == NULL) {
1450 			/*
1451 			 * Create new vdev
1452 			 */
1453 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1454 			    VDEV_ALLOC_L2CACHE) == 0);
1455 			ASSERT(vd != NULL);
1456 			newvdevs[i] = vd;
1457 
1458 			/*
1459 			 * Commit this vdev as an l2cache device,
1460 			 * even if it fails to open.
1461 			 */
1462 			spa_l2cache_add(vd);
1463 
1464 			vd->vdev_top = vd;
1465 			vd->vdev_aux = sav;
1466 
1467 			spa_l2cache_activate(vd);
1468 
1469 			if (vdev_open(vd) != 0)
1470 				continue;
1471 
1472 			(void) vdev_validate_aux(vd);
1473 
1474 			if (!vdev_is_dead(vd))
1475 				l2arc_add_vdev(spa, vd);
1476 		}
1477 	}
1478 
1479 	/*
1480 	 * Purge vdevs that were dropped
1481 	 */
1482 	for (i = 0; i < oldnvdevs; i++) {
1483 		uint64_t pool;
1484 
1485 		vd = oldvdevs[i];
1486 		if (vd != NULL) {
1487 			ASSERT(vd->vdev_isl2cache);
1488 
1489 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1490 			    pool != 0ULL && l2arc_vdev_present(vd))
1491 				l2arc_remove_vdev(vd);
1492 			vdev_clear_stats(vd);
1493 			vdev_free(vd);
1494 		}
1495 	}
1496 
1497 	if (oldvdevs)
1498 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1499 
1500 	if (sav->sav_config == NULL)
1501 		goto out;
1502 
1503 	sav->sav_vdevs = newvdevs;
1504 	sav->sav_count = (int)nl2cache;
1505 
1506 	/*
1507 	 * Recompute the stashed list of l2cache devices, with status
1508 	 * information this time.
1509 	 */
1510 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1511 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1512 
1513 	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1514 	for (i = 0; i < sav->sav_count; i++)
1515 		l2cache[i] = vdev_config_generate(spa,
1516 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1517 	VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1518 	    ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1519 out:
1520 	for (i = 0; i < sav->sav_count; i++)
1521 		nvlist_free(l2cache[i]);
1522 	if (sav->sav_count)
1523 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
1524 }
1525 
1526 static int
1527 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1528 {
1529 	dmu_buf_t *db;
1530 	char *packed = NULL;
1531 	size_t nvsize = 0;
1532 	int error;
1533 	*value = NULL;
1534 
1535 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1536 	nvsize = *(uint64_t *)db->db_data;
1537 	dmu_buf_rele(db, FTAG);
1538 
1539 	packed = kmem_alloc(nvsize, KM_SLEEP);
1540 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1541 	    DMU_READ_PREFETCH);
1542 	if (error == 0)
1543 		error = nvlist_unpack(packed, nvsize, value, 0);
1544 	kmem_free(packed, nvsize);
1545 
1546 	return (error);
1547 }
1548 
1549 /*
1550  * Checks to see if the given vdev could not be opened, in which case we post a
1551  * sysevent to notify the autoreplace code that the device has been removed.
1552  */
1553 static void
1554 spa_check_removed(vdev_t *vd)
1555 {
1556 	for (int c = 0; c < vd->vdev_children; c++)
1557 		spa_check_removed(vd->vdev_child[c]);
1558 
1559 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd)) {
1560 		zfs_post_autoreplace(vd->vdev_spa, vd);
1561 		spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1562 	}
1563 }
1564 
1565 /*
1566  * Validate the current config against the MOS config
1567  */
1568 static boolean_t
1569 spa_config_valid(spa_t *spa, nvlist_t *config)
1570 {
1571 	vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1572 	nvlist_t *nv;
1573 
1574 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1575 
1576 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1577 	VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1578 
1579 	ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1580 
1581 	/*
1582 	 * If we're doing a normal import, then build up any additional
1583 	 * diagnostic information about missing devices in this config.
1584 	 * We'll pass this up to the user for further processing.
1585 	 */
1586 	if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1587 		nvlist_t **child, *nv;
1588 		uint64_t idx = 0;
1589 
1590 		child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1591 		    KM_SLEEP);
1592 		VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1593 
1594 		for (int c = 0; c < rvd->vdev_children; c++) {
1595 			vdev_t *tvd = rvd->vdev_child[c];
1596 			vdev_t *mtvd  = mrvd->vdev_child[c];
1597 
1598 			if (tvd->vdev_ops == &vdev_missing_ops &&
1599 			    mtvd->vdev_ops != &vdev_missing_ops &&
1600 			    mtvd->vdev_islog)
1601 				child[idx++] = vdev_config_generate(spa, mtvd,
1602 				    B_FALSE, 0);
1603 		}
1604 
1605 		if (idx) {
1606 			VERIFY(nvlist_add_nvlist_array(nv,
1607 			    ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1608 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1609 			    ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1610 
1611 			for (int i = 0; i < idx; i++)
1612 				nvlist_free(child[i]);
1613 		}
1614 		nvlist_free(nv);
1615 		kmem_free(child, rvd->vdev_children * sizeof (char **));
1616 	}
1617 
1618 	/*
1619 	 * Compare the root vdev tree with the information we have
1620 	 * from the MOS config (mrvd). Check each top-level vdev
1621 	 * with the corresponding MOS config top-level (mtvd).
1622 	 */
1623 	for (int c = 0; c < rvd->vdev_children; c++) {
1624 		vdev_t *tvd = rvd->vdev_child[c];
1625 		vdev_t *mtvd  = mrvd->vdev_child[c];
1626 
1627 		/*
1628 		 * Resolve any "missing" vdevs in the current configuration.
1629 		 * If we find that the MOS config has more accurate information
1630 		 * about the top-level vdev then use that vdev instead.
1631 		 */
1632 		if (tvd->vdev_ops == &vdev_missing_ops &&
1633 		    mtvd->vdev_ops != &vdev_missing_ops) {
1634 
1635 			if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1636 				continue;
1637 
1638 			/*
1639 			 * Device specific actions.
1640 			 */
1641 			if (mtvd->vdev_islog) {
1642 				spa_set_log_state(spa, SPA_LOG_CLEAR);
1643 			} else {
1644 				/*
1645 				 * XXX - once we have 'readonly' pool
1646 				 * support we should be able to handle
1647 				 * missing data devices by transitioning
1648 				 * the pool to readonly.
1649 				 */
1650 				continue;
1651 			}
1652 
1653 			/*
1654 			 * Swap the missing vdev with the data we were
1655 			 * able to obtain from the MOS config.
1656 			 */
1657 			vdev_remove_child(rvd, tvd);
1658 			vdev_remove_child(mrvd, mtvd);
1659 
1660 			vdev_add_child(rvd, mtvd);
1661 			vdev_add_child(mrvd, tvd);
1662 
1663 			spa_config_exit(spa, SCL_ALL, FTAG);
1664 			vdev_load(mtvd);
1665 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1666 
1667 			vdev_reopen(rvd);
1668 		} else if (mtvd->vdev_islog) {
1669 			/*
1670 			 * Load the slog device's state from the MOS config
1671 			 * since it's possible that the label does not
1672 			 * contain the most up-to-date information.
1673 			 */
1674 			vdev_load_log_state(tvd, mtvd);
1675 			vdev_reopen(tvd);
1676 		}
1677 	}
1678 	vdev_free(mrvd);
1679 	spa_config_exit(spa, SCL_ALL, FTAG);
1680 
1681 	/*
1682 	 * Ensure we were able to validate the config.
1683 	 */
1684 	return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1685 }
1686 
1687 /*
1688  * Check for missing log devices
1689  */
1690 static int
1691 spa_check_logs(spa_t *spa)
1692 {
1693 	switch (spa->spa_log_state) {
1694 	case SPA_LOG_MISSING:
1695 		/* need to recheck in case slog has been restored */
1696 	case SPA_LOG_UNKNOWN:
1697 		if (dmu_objset_find(spa->spa_name, zil_check_log_chain, NULL,
1698 		    DS_FIND_CHILDREN)) {
1699 			spa_set_log_state(spa, SPA_LOG_MISSING);
1700 			return (1);
1701 		}
1702 		break;
1703 	}
1704 	return (0);
1705 }
1706 
1707 static boolean_t
1708 spa_passivate_log(spa_t *spa)
1709 {
1710 	vdev_t *rvd = spa->spa_root_vdev;
1711 	boolean_t slog_found = B_FALSE;
1712 
1713 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1714 
1715 	if (!spa_has_slogs(spa))
1716 		return (B_FALSE);
1717 
1718 	for (int c = 0; c < rvd->vdev_children; c++) {
1719 		vdev_t *tvd = rvd->vdev_child[c];
1720 		metaslab_group_t *mg = tvd->vdev_mg;
1721 
1722 		if (tvd->vdev_islog) {
1723 			metaslab_group_passivate(mg);
1724 			slog_found = B_TRUE;
1725 		}
1726 	}
1727 
1728 	return (slog_found);
1729 }
1730 
1731 static void
1732 spa_activate_log(spa_t *spa)
1733 {
1734 	vdev_t *rvd = spa->spa_root_vdev;
1735 
1736 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1737 
1738 	for (int c = 0; c < rvd->vdev_children; c++) {
1739 		vdev_t *tvd = rvd->vdev_child[c];
1740 		metaslab_group_t *mg = tvd->vdev_mg;
1741 
1742 		if (tvd->vdev_islog)
1743 			metaslab_group_activate(mg);
1744 	}
1745 }
1746 
1747 int
1748 spa_offline_log(spa_t *spa)
1749 {
1750 	int error = 0;
1751 
1752 	if ((error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1753 	    NULL, DS_FIND_CHILDREN)) == 0) {
1754 
1755 		/*
1756 		 * We successfully offlined the log device, sync out the
1757 		 * current txg so that the "stubby" block can be removed
1758 		 * by zil_sync().
1759 		 */
1760 		txg_wait_synced(spa->spa_dsl_pool, 0);
1761 	}
1762 	return (error);
1763 }
1764 
1765 static void
1766 spa_aux_check_removed(spa_aux_vdev_t *sav)
1767 {
1768 	for (int i = 0; i < sav->sav_count; i++)
1769 		spa_check_removed(sav->sav_vdevs[i]);
1770 }
1771 
1772 void
1773 spa_claim_notify(zio_t *zio)
1774 {
1775 	spa_t *spa = zio->io_spa;
1776 
1777 	if (zio->io_error)
1778 		return;
1779 
1780 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
1781 	if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1782 		spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1783 	mutex_exit(&spa->spa_props_lock);
1784 }
1785 
1786 typedef struct spa_load_error {
1787 	uint64_t	sle_meta_count;
1788 	uint64_t	sle_data_count;
1789 } spa_load_error_t;
1790 
1791 static void
1792 spa_load_verify_done(zio_t *zio)
1793 {
1794 	blkptr_t *bp = zio->io_bp;
1795 	spa_load_error_t *sle = zio->io_private;
1796 	dmu_object_type_t type = BP_GET_TYPE(bp);
1797 	int error = zio->io_error;
1798 
1799 	if (error) {
1800 		if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1801 		    type != DMU_OT_INTENT_LOG)
1802 			atomic_add_64(&sle->sle_meta_count, 1);
1803 		else
1804 			atomic_add_64(&sle->sle_data_count, 1);
1805 	}
1806 	zio_data_buf_free(zio->io_data, zio->io_size);
1807 }
1808 
1809 /*ARGSUSED*/
1810 static int
1811 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1812     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1813 {
1814 	if (bp != NULL) {
1815 		zio_t *rio = arg;
1816 		size_t size = BP_GET_PSIZE(bp);
1817 		void *data = zio_data_buf_alloc(size);
1818 
1819 		zio_nowait(zio_read(rio, spa, bp, data, size,
1820 		    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1821 		    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1822 		    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1823 	}
1824 	return (0);
1825 }
1826 
1827 static int
1828 spa_load_verify(spa_t *spa)
1829 {
1830 	zio_t *rio;
1831 	spa_load_error_t sle = { 0 };
1832 	zpool_rewind_policy_t policy;
1833 	boolean_t verify_ok = B_FALSE;
1834 	int error;
1835 
1836 	zpool_get_rewind_policy(spa->spa_config, &policy);
1837 
1838 	if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1839 		return (0);
1840 
1841 	rio = zio_root(spa, NULL, &sle,
1842 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1843 
1844 	error = traverse_pool(spa, spa->spa_verify_min_txg,
1845 	    TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1846 
1847 	(void) zio_wait(rio);
1848 
1849 	spa->spa_load_meta_errors = sle.sle_meta_count;
1850 	spa->spa_load_data_errors = sle.sle_data_count;
1851 
1852 	if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1853 	    sle.sle_data_count <= policy.zrp_maxdata) {
1854 		int64_t loss = 0;
1855 
1856 		verify_ok = B_TRUE;
1857 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1858 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1859 
1860 		loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1861 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1862 		    ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1863 		VERIFY(nvlist_add_int64(spa->spa_load_info,
1864 		    ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1865 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1866 		    ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1867 	} else {
1868 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1869 	}
1870 
1871 	if (error) {
1872 		if (error != ENXIO && error != EIO)
1873 			error = EIO;
1874 		return (error);
1875 	}
1876 
1877 	return (verify_ok ? 0 : EIO);
1878 }
1879 
1880 /*
1881  * Find a value in the pool props object.
1882  */
1883 static void
1884 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1885 {
1886 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1887 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1888 }
1889 
1890 /*
1891  * Find a value in the pool directory object.
1892  */
1893 static int
1894 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1895 {
1896 	return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1897 	    name, sizeof (uint64_t), 1, val));
1898 }
1899 
1900 static int
1901 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1902 {
1903 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1904 	return (err);
1905 }
1906 
1907 /*
1908  * Fix up config after a partly-completed split.  This is done with the
1909  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1910  * pool have that entry in their config, but only the splitting one contains
1911  * a list of all the guids of the vdevs that are being split off.
1912  *
1913  * This function determines what to do with that list: either rejoin
1914  * all the disks to the pool, or complete the splitting process.  To attempt
1915  * the rejoin, each disk that is offlined is marked online again, and
1916  * we do a reopen() call.  If the vdev label for every disk that was
1917  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1918  * then we call vdev_split() on each disk, and complete the split.
1919  *
1920  * Otherwise we leave the config alone, with all the vdevs in place in
1921  * the original pool.
1922  */
1923 static void
1924 spa_try_repair(spa_t *spa, nvlist_t *config)
1925 {
1926 	uint_t extracted;
1927 	uint64_t *glist;
1928 	uint_t i, gcount;
1929 	nvlist_t *nvl;
1930 	vdev_t **vd;
1931 	boolean_t attempt_reopen;
1932 
1933 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1934 		return;
1935 
1936 	/* check that the config is complete */
1937 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1938 	    &glist, &gcount) != 0)
1939 		return;
1940 
1941 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1942 
1943 	/* attempt to online all the vdevs & validate */
1944 	attempt_reopen = B_TRUE;
1945 	for (i = 0; i < gcount; i++) {
1946 		if (glist[i] == 0)	/* vdev is hole */
1947 			continue;
1948 
1949 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1950 		if (vd[i] == NULL) {
1951 			/*
1952 			 * Don't bother attempting to reopen the disks;
1953 			 * just do the split.
1954 			 */
1955 			attempt_reopen = B_FALSE;
1956 		} else {
1957 			/* attempt to re-online it */
1958 			vd[i]->vdev_offline = B_FALSE;
1959 		}
1960 	}
1961 
1962 	if (attempt_reopen) {
1963 		vdev_reopen(spa->spa_root_vdev);
1964 
1965 		/* check each device to see what state it's in */
1966 		for (extracted = 0, i = 0; i < gcount; i++) {
1967 			if (vd[i] != NULL &&
1968 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1969 				break;
1970 			++extracted;
1971 		}
1972 	}
1973 
1974 	/*
1975 	 * If every disk has been moved to the new pool, or if we never
1976 	 * even attempted to look at them, then we split them off for
1977 	 * good.
1978 	 */
1979 	if (!attempt_reopen || gcount == extracted) {
1980 		for (i = 0; i < gcount; i++)
1981 			if (vd[i] != NULL)
1982 				vdev_split(vd[i]);
1983 		vdev_reopen(spa->spa_root_vdev);
1984 	}
1985 
1986 	kmem_free(vd, gcount * sizeof (vdev_t *));
1987 }
1988 
1989 static int
1990 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
1991     boolean_t mosconfig)
1992 {
1993 	nvlist_t *config = spa->spa_config;
1994 	char *ereport = FM_EREPORT_ZFS_POOL;
1995 	char *comment;
1996 	int error;
1997 	uint64_t pool_guid;
1998 	nvlist_t *nvl;
1999 
2000 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2001 		return (EINVAL);
2002 
2003 	ASSERT(spa->spa_comment == NULL);
2004 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2005 		spa->spa_comment = spa_strdup(comment);
2006 
2007 	/*
2008 	 * Versioning wasn't explicitly added to the label until later, so if
2009 	 * it's not present treat it as the initial version.
2010 	 */
2011 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2012 	    &spa->spa_ubsync.ub_version) != 0)
2013 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2014 
2015 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2016 	    &spa->spa_config_txg);
2017 
2018 	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2019 	    spa_guid_exists(pool_guid, 0)) {
2020 		error = EEXIST;
2021 	} else {
2022 		spa->spa_config_guid = pool_guid;
2023 
2024 		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2025 		    &nvl) == 0) {
2026 			VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2027 			    KM_SLEEP) == 0);
2028 		}
2029 
2030 		nvlist_free(spa->spa_load_info);
2031 		spa->spa_load_info = fnvlist_alloc();
2032 
2033 		gethrestime(&spa->spa_loaded_ts);
2034 		error = spa_load_impl(spa, pool_guid, config, state, type,
2035 		    mosconfig, &ereport);
2036 	}
2037 
2038 	spa->spa_minref = refcount_count(&spa->spa_refcount);
2039 	if (error) {
2040 		if (error != EEXIST) {
2041 			spa->spa_loaded_ts.tv_sec = 0;
2042 			spa->spa_loaded_ts.tv_nsec = 0;
2043 		}
2044 		if (error != EBADF) {
2045 			zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2046 		}
2047 	}
2048 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2049 	spa->spa_ena = 0;
2050 
2051 	return (error);
2052 }
2053 
2054 /*
2055  * Load an existing storage pool, using the pool's builtin spa_config as a
2056  * source of configuration information.
2057  */
2058 static int
2059 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2060     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2061     char **ereport)
2062 {
2063 	int error = 0;
2064 	nvlist_t *nvroot = NULL;
2065 	nvlist_t *label;
2066 	vdev_t *rvd;
2067 	uberblock_t *ub = &spa->spa_uberblock;
2068 	uint64_t children, config_cache_txg = spa->spa_config_txg;
2069 	int orig_mode = spa->spa_mode;
2070 	int parse;
2071 	uint64_t obj;
2072 	boolean_t missing_feat_write = B_FALSE;
2073 
2074 	/*
2075 	 * If this is an untrusted config, access the pool in read-only mode.
2076 	 * This prevents things like resilvering recently removed devices.
2077 	 */
2078 	if (!mosconfig)
2079 		spa->spa_mode = FREAD;
2080 
2081 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
2082 
2083 	spa->spa_load_state = state;
2084 
2085 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2086 		return (EINVAL);
2087 
2088 	parse = (type == SPA_IMPORT_EXISTING ?
2089 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2090 
2091 	/*
2092 	 * Create "The Godfather" zio to hold all async IOs
2093 	 */
2094 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2095 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2096 
2097 	/*
2098 	 * Parse the configuration into a vdev tree.  We explicitly set the
2099 	 * value that will be returned by spa_version() since parsing the
2100 	 * configuration requires knowing the version number.
2101 	 */
2102 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2103 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2104 	spa_config_exit(spa, SCL_ALL, FTAG);
2105 
2106 	if (error != 0)
2107 		return (error);
2108 
2109 	ASSERT(spa->spa_root_vdev == rvd);
2110 
2111 	if (type != SPA_IMPORT_ASSEMBLE) {
2112 		ASSERT(spa_guid(spa) == pool_guid);
2113 	}
2114 
2115 	/*
2116 	 * Try to open all vdevs, loading each label in the process.
2117 	 */
2118 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2119 	error = vdev_open(rvd);
2120 	spa_config_exit(spa, SCL_ALL, FTAG);
2121 	if (error != 0)
2122 		return (error);
2123 
2124 	/*
2125 	 * We need to validate the vdev labels against the configuration that
2126 	 * we have in hand, which is dependent on the setting of mosconfig. If
2127 	 * mosconfig is true then we're validating the vdev labels based on
2128 	 * that config.  Otherwise, we're validating against the cached config
2129 	 * (zpool.cache) that was read when we loaded the zfs module, and then
2130 	 * later we will recursively call spa_load() and validate against
2131 	 * the vdev config.
2132 	 *
2133 	 * If we're assembling a new pool that's been split off from an
2134 	 * existing pool, the labels haven't yet been updated so we skip
2135 	 * validation for now.
2136 	 */
2137 	if (type != SPA_IMPORT_ASSEMBLE) {
2138 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2139 		error = vdev_validate(rvd, mosconfig);
2140 		spa_config_exit(spa, SCL_ALL, FTAG);
2141 
2142 		if (error != 0)
2143 			return (error);
2144 
2145 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2146 			return (ENXIO);
2147 	}
2148 
2149 	/*
2150 	 * Find the best uberblock.
2151 	 */
2152 	vdev_uberblock_load(rvd, ub, &label);
2153 
2154 	/*
2155 	 * If we weren't able to find a single valid uberblock, return failure.
2156 	 */
2157 	if (ub->ub_txg == 0) {
2158 		nvlist_free(label);
2159 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2160 	}
2161 
2162 	/*
2163 	 * If the pool has an unsupported version we can't open it.
2164 	 */
2165 	if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2166 		nvlist_free(label);
2167 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2168 	}
2169 
2170 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2171 		nvlist_t *features;
2172 
2173 		/*
2174 		 * If we weren't able to find what's necessary for reading the
2175 		 * MOS in the label, return failure.
2176 		 */
2177 		if (label == NULL || nvlist_lookup_nvlist(label,
2178 		    ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2179 			nvlist_free(label);
2180 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2181 			    ENXIO));
2182 		}
2183 
2184 		/*
2185 		 * Update our in-core representation with the definitive values
2186 		 * from the label.
2187 		 */
2188 		nvlist_free(spa->spa_label_features);
2189 		VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2190 	}
2191 
2192 	nvlist_free(label);
2193 
2194 	/*
2195 	 * Look through entries in the label nvlist's features_for_read. If
2196 	 * there is a feature listed there which we don't understand then we
2197 	 * cannot open a pool.
2198 	 */
2199 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2200 		nvlist_t *unsup_feat;
2201 
2202 		VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2203 		    0);
2204 
2205 		for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2206 		    NULL); nvp != NULL;
2207 		    nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2208 			if (!zfeature_is_supported(nvpair_name(nvp))) {
2209 				VERIFY(nvlist_add_string(unsup_feat,
2210 				    nvpair_name(nvp), "") == 0);
2211 			}
2212 		}
2213 
2214 		if (!nvlist_empty(unsup_feat)) {
2215 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2216 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2217 			nvlist_free(unsup_feat);
2218 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2219 			    ENOTSUP));
2220 		}
2221 
2222 		nvlist_free(unsup_feat);
2223 	}
2224 
2225 	/*
2226 	 * If the vdev guid sum doesn't match the uberblock, we have an
2227 	 * incomplete configuration.  We first check to see if the pool
2228 	 * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2229 	 * If it is, defer the vdev_guid_sum check till later so we
2230 	 * can handle missing vdevs.
2231 	 */
2232 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2233 	    &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2234 	    rvd->vdev_guid_sum != ub->ub_guid_sum)
2235 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2236 
2237 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2238 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2239 		spa_try_repair(spa, config);
2240 		spa_config_exit(spa, SCL_ALL, FTAG);
2241 		nvlist_free(spa->spa_config_splitting);
2242 		spa->spa_config_splitting = NULL;
2243 	}
2244 
2245 	/*
2246 	 * Initialize internal SPA structures.
2247 	 */
2248 	spa->spa_state = POOL_STATE_ACTIVE;
2249 	spa->spa_ubsync = spa->spa_uberblock;
2250 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2251 	    TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2252 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2253 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2254 	spa->spa_claim_max_txg = spa->spa_first_txg;
2255 	spa->spa_prev_software_version = ub->ub_software_version;
2256 
2257 	error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2258 	if (error)
2259 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2260 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2261 
2262 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2263 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2264 
2265 	if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2266 		boolean_t missing_feat_read = B_FALSE;
2267 		nvlist_t *unsup_feat, *enabled_feat;
2268 
2269 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2270 		    &spa->spa_feat_for_read_obj) != 0) {
2271 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2272 		}
2273 
2274 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2275 		    &spa->spa_feat_for_write_obj) != 0) {
2276 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2277 		}
2278 
2279 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2280 		    &spa->spa_feat_desc_obj) != 0) {
2281 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2282 		}
2283 
2284 		enabled_feat = fnvlist_alloc();
2285 		unsup_feat = fnvlist_alloc();
2286 
2287 		if (!feature_is_supported(spa->spa_meta_objset,
2288 		    spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
2289 		    unsup_feat, enabled_feat))
2290 			missing_feat_read = B_TRUE;
2291 
2292 		if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2293 			if (!feature_is_supported(spa->spa_meta_objset,
2294 			    spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
2295 			    unsup_feat, enabled_feat)) {
2296 				missing_feat_write = B_TRUE;
2297 			}
2298 		}
2299 
2300 		fnvlist_add_nvlist(spa->spa_load_info,
2301 		    ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2302 
2303 		if (!nvlist_empty(unsup_feat)) {
2304 			fnvlist_add_nvlist(spa->spa_load_info,
2305 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2306 		}
2307 
2308 		fnvlist_free(enabled_feat);
2309 		fnvlist_free(unsup_feat);
2310 
2311 		if (!missing_feat_read) {
2312 			fnvlist_add_boolean(spa->spa_load_info,
2313 			    ZPOOL_CONFIG_CAN_RDONLY);
2314 		}
2315 
2316 		/*
2317 		 * If the state is SPA_LOAD_TRYIMPORT, our objective is
2318 		 * twofold: to determine whether the pool is available for
2319 		 * import in read-write mode and (if it is not) whether the
2320 		 * pool is available for import in read-only mode. If the pool
2321 		 * is available for import in read-write mode, it is displayed
2322 		 * as available in userland; if it is not available for import
2323 		 * in read-only mode, it is displayed as unavailable in
2324 		 * userland. If the pool is available for import in read-only
2325 		 * mode but not read-write mode, it is displayed as unavailable
2326 		 * in userland with a special note that the pool is actually
2327 		 * available for open in read-only mode.
2328 		 *
2329 		 * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2330 		 * missing a feature for write, we must first determine whether
2331 		 * the pool can be opened read-only before returning to
2332 		 * userland in order to know whether to display the
2333 		 * abovementioned note.
2334 		 */
2335 		if (missing_feat_read || (missing_feat_write &&
2336 		    spa_writeable(spa))) {
2337 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2338 			    ENOTSUP));
2339 		}
2340 	}
2341 
2342 	spa->spa_is_initializing = B_TRUE;
2343 	error = dsl_pool_open(spa->spa_dsl_pool);
2344 	spa->spa_is_initializing = B_FALSE;
2345 	if (error != 0)
2346 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2347 
2348 	if (!mosconfig) {
2349 		uint64_t hostid;
2350 		nvlist_t *policy = NULL, *nvconfig;
2351 
2352 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2353 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2354 
2355 		if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2356 		    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2357 			char *hostname;
2358 			unsigned long myhostid = 0;
2359 
2360 			VERIFY(nvlist_lookup_string(nvconfig,
2361 			    ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2362 
2363 #ifdef	_KERNEL
2364 			myhostid = zone_get_hostid(NULL);
2365 #else	/* _KERNEL */
2366 			/*
2367 			 * We're emulating the system's hostid in userland, so
2368 			 * we can't use zone_get_hostid().
2369 			 */
2370 			(void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2371 #endif	/* _KERNEL */
2372 			if (hostid != 0 && myhostid != 0 &&
2373 			    hostid != myhostid) {
2374 				nvlist_free(nvconfig);
2375 				cmn_err(CE_WARN, "pool '%s' could not be "
2376 				    "loaded as it was last accessed by "
2377 				    "another system (host: %s hostid: 0x%lx). "
2378 				    "See: http://illumos.org/msg/ZFS-8000-EY",
2379 				    spa_name(spa), hostname,
2380 				    (unsigned long)hostid);
2381 				return (EBADF);
2382 			}
2383 		}
2384 		if (nvlist_lookup_nvlist(spa->spa_config,
2385 		    ZPOOL_REWIND_POLICY, &policy) == 0)
2386 			VERIFY(nvlist_add_nvlist(nvconfig,
2387 			    ZPOOL_REWIND_POLICY, policy) == 0);
2388 
2389 		spa_config_set(spa, nvconfig);
2390 		spa_unload(spa);
2391 		spa_deactivate(spa);
2392 		spa_activate(spa, orig_mode);
2393 
2394 		return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2395 	}
2396 
2397 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2398 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2399 	error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2400 	if (error != 0)
2401 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2402 
2403 	/*
2404 	 * Load the bit that tells us to use the new accounting function
2405 	 * (raid-z deflation).  If we have an older pool, this will not
2406 	 * be present.
2407 	 */
2408 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2409 	if (error != 0 && error != ENOENT)
2410 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2411 
2412 	error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2413 	    &spa->spa_creation_version);
2414 	if (error != 0 && error != ENOENT)
2415 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2416 
2417 	/*
2418 	 * Load the persistent error log.  If we have an older pool, this will
2419 	 * not be present.
2420 	 */
2421 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2422 	if (error != 0 && error != ENOENT)
2423 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2424 
2425 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2426 	    &spa->spa_errlog_scrub);
2427 	if (error != 0 && error != ENOENT)
2428 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2429 
2430 	/*
2431 	 * Load the history object.  If we have an older pool, this
2432 	 * will not be present.
2433 	 */
2434 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2435 	if (error != 0 && error != ENOENT)
2436 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2437 
2438 	/*
2439 	 * If we're assembling the pool from the split-off vdevs of
2440 	 * an existing pool, we don't want to attach the spares & cache
2441 	 * devices.
2442 	 */
2443 
2444 	/*
2445 	 * Load any hot spares for this pool.
2446 	 */
2447 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2448 	if (error != 0 && error != ENOENT)
2449 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2450 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2451 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2452 		if (load_nvlist(spa, spa->spa_spares.sav_object,
2453 		    &spa->spa_spares.sav_config) != 0)
2454 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2455 
2456 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2457 		spa_load_spares(spa);
2458 		spa_config_exit(spa, SCL_ALL, FTAG);
2459 	} else if (error == 0) {
2460 		spa->spa_spares.sav_sync = B_TRUE;
2461 	}
2462 
2463 	/*
2464 	 * Load any level 2 ARC devices for this pool.
2465 	 */
2466 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2467 	    &spa->spa_l2cache.sav_object);
2468 	if (error != 0 && error != ENOENT)
2469 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2470 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2471 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2472 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2473 		    &spa->spa_l2cache.sav_config) != 0)
2474 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2475 
2476 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2477 		spa_load_l2cache(spa);
2478 		spa_config_exit(spa, SCL_ALL, FTAG);
2479 	} else if (error == 0) {
2480 		spa->spa_l2cache.sav_sync = B_TRUE;
2481 	}
2482 
2483 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2484 
2485 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2486 	if (error && error != ENOENT)
2487 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2488 
2489 	if (error == 0) {
2490 		uint64_t autoreplace;
2491 
2492 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2493 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2494 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2495 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2496 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2497 		spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2498 		    &spa->spa_dedup_ditto);
2499 
2500 		spa->spa_autoreplace = (autoreplace != 0);
2501 	}
2502 
2503 	/*
2504 	 * If the 'autoreplace' property is set, then post a resource notifying
2505 	 * the ZFS DE that it should not issue any faults for unopenable
2506 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
2507 	 * unopenable vdevs so that the normal autoreplace handler can take
2508 	 * over.
2509 	 */
2510 	if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2511 		spa_check_removed(spa->spa_root_vdev);
2512 		/*
2513 		 * For the import case, this is done in spa_import(), because
2514 		 * at this point we're using the spare definitions from
2515 		 * the MOS config, not necessarily from the userland config.
2516 		 */
2517 		if (state != SPA_LOAD_IMPORT) {
2518 			spa_aux_check_removed(&spa->spa_spares);
2519 			spa_aux_check_removed(&spa->spa_l2cache);
2520 		}
2521 	}
2522 
2523 	/*
2524 	 * Load the vdev state for all toplevel vdevs.
2525 	 */
2526 	vdev_load(rvd);
2527 
2528 	/*
2529 	 * Propagate the leaf DTLs we just loaded all the way up the tree.
2530 	 */
2531 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2532 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2533 	spa_config_exit(spa, SCL_ALL, FTAG);
2534 
2535 	/*
2536 	 * Load the DDTs (dedup tables).
2537 	 */
2538 	error = ddt_load(spa);
2539 	if (error != 0)
2540 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2541 
2542 	spa_update_dspace(spa);
2543 
2544 	/*
2545 	 * Validate the config, using the MOS config to fill in any
2546 	 * information which might be missing.  If we fail to validate
2547 	 * the config then declare the pool unfit for use. If we're
2548 	 * assembling a pool from a split, the log is not transferred
2549 	 * over.
2550 	 */
2551 	if (type != SPA_IMPORT_ASSEMBLE) {
2552 		nvlist_t *nvconfig;
2553 
2554 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2555 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2556 
2557 		if (!spa_config_valid(spa, nvconfig)) {
2558 			nvlist_free(nvconfig);
2559 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2560 			    ENXIO));
2561 		}
2562 		nvlist_free(nvconfig);
2563 
2564 		/*
2565 		 * Now that we've validated the config, check the state of the
2566 		 * root vdev.  If it can't be opened, it indicates one or
2567 		 * more toplevel vdevs are faulted.
2568 		 */
2569 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2570 			return (ENXIO);
2571 
2572 		if (spa_check_logs(spa)) {
2573 			*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2574 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2575 		}
2576 	}
2577 
2578 	if (missing_feat_write) {
2579 		ASSERT(state == SPA_LOAD_TRYIMPORT);
2580 
2581 		/*
2582 		 * At this point, we know that we can open the pool in
2583 		 * read-only mode but not read-write mode. We now have enough
2584 		 * information and can return to userland.
2585 		 */
2586 		return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2587 	}
2588 
2589 	/*
2590 	 * We've successfully opened the pool, verify that we're ready
2591 	 * to start pushing transactions.
2592 	 */
2593 	if (state != SPA_LOAD_TRYIMPORT) {
2594 		if (error = spa_load_verify(spa))
2595 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2596 			    error));
2597 	}
2598 
2599 	if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2600 	    spa->spa_load_max_txg == UINT64_MAX)) {
2601 		dmu_tx_t *tx;
2602 		int need_update = B_FALSE;
2603 
2604 		ASSERT(state != SPA_LOAD_TRYIMPORT);
2605 
2606 		/*
2607 		 * Claim log blocks that haven't been committed yet.
2608 		 * This must all happen in a single txg.
2609 		 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2610 		 * invoked from zil_claim_log_block()'s i/o done callback.
2611 		 * Price of rollback is that we abandon the log.
2612 		 */
2613 		spa->spa_claiming = B_TRUE;
2614 
2615 		tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2616 		    spa_first_txg(spa));
2617 		(void) dmu_objset_find(spa_name(spa),
2618 		    zil_claim, tx, DS_FIND_CHILDREN);
2619 		dmu_tx_commit(tx);
2620 
2621 		spa->spa_claiming = B_FALSE;
2622 
2623 		spa_set_log_state(spa, SPA_LOG_GOOD);
2624 		spa->spa_sync_on = B_TRUE;
2625 		txg_sync_start(spa->spa_dsl_pool);
2626 
2627 		/*
2628 		 * Wait for all claims to sync.  We sync up to the highest
2629 		 * claimed log block birth time so that claimed log blocks
2630 		 * don't appear to be from the future.  spa_claim_max_txg
2631 		 * will have been set for us by either zil_check_log_chain()
2632 		 * (invoked from spa_check_logs()) or zil_claim() above.
2633 		 */
2634 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2635 
2636 		/*
2637 		 * If the config cache is stale, or we have uninitialized
2638 		 * metaslabs (see spa_vdev_add()), then update the config.
2639 		 *
2640 		 * If this is a verbatim import, trust the current
2641 		 * in-core spa_config and update the disk labels.
2642 		 */
2643 		if (config_cache_txg != spa->spa_config_txg ||
2644 		    state == SPA_LOAD_IMPORT ||
2645 		    state == SPA_LOAD_RECOVER ||
2646 		    (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2647 			need_update = B_TRUE;
2648 
2649 		for (int c = 0; c < rvd->vdev_children; c++)
2650 			if (rvd->vdev_child[c]->vdev_ms_array == 0)
2651 				need_update = B_TRUE;
2652 
2653 		/*
2654 		 * Update the config cache asychronously in case we're the
2655 		 * root pool, in which case the config cache isn't writable yet.
2656 		 */
2657 		if (need_update)
2658 			spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2659 
2660 		/*
2661 		 * Check all DTLs to see if anything needs resilvering.
2662 		 */
2663 		if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2664 		    vdev_resilver_needed(rvd, NULL, NULL))
2665 			spa_async_request(spa, SPA_ASYNC_RESILVER);
2666 
2667 		/*
2668 		 * Log the fact that we booted up (so that we can detect if
2669 		 * we rebooted in the middle of an operation).
2670 		 */
2671 		spa_history_log_version(spa, "open");
2672 
2673 		/*
2674 		 * Delete any inconsistent datasets.
2675 		 */
2676 		(void) dmu_objset_find(spa_name(spa),
2677 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2678 
2679 		/*
2680 		 * Clean up any stale temporary dataset userrefs.
2681 		 */
2682 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2683 	}
2684 
2685 	return (0);
2686 }
2687 
2688 static int
2689 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2690 {
2691 	int mode = spa->spa_mode;
2692 
2693 	spa_unload(spa);
2694 	spa_deactivate(spa);
2695 
2696 	spa->spa_load_max_txg--;
2697 
2698 	spa_activate(spa, mode);
2699 	spa_async_suspend(spa);
2700 
2701 	return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2702 }
2703 
2704 /*
2705  * If spa_load() fails this function will try loading prior txg's. If
2706  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2707  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2708  * function will not rewind the pool and will return the same error as
2709  * spa_load().
2710  */
2711 static int
2712 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2713     uint64_t max_request, int rewind_flags)
2714 {
2715 	nvlist_t *loadinfo = NULL;
2716 	nvlist_t *config = NULL;
2717 	int load_error, rewind_error;
2718 	uint64_t safe_rewind_txg;
2719 	uint64_t min_txg;
2720 
2721 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2722 		spa->spa_load_max_txg = spa->spa_load_txg;
2723 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2724 	} else {
2725 		spa->spa_load_max_txg = max_request;
2726 	}
2727 
2728 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2729 	    mosconfig);
2730 	if (load_error == 0)
2731 		return (0);
2732 
2733 	if (spa->spa_root_vdev != NULL)
2734 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2735 
2736 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2737 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2738 
2739 	if (rewind_flags & ZPOOL_NEVER_REWIND) {
2740 		nvlist_free(config);
2741 		return (load_error);
2742 	}
2743 
2744 	if (state == SPA_LOAD_RECOVER) {
2745 		/* Price of rolling back is discarding txgs, including log */
2746 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2747 	} else {
2748 		/*
2749 		 * If we aren't rolling back save the load info from our first
2750 		 * import attempt so that we can restore it after attempting
2751 		 * to rewind.
2752 		 */
2753 		loadinfo = spa->spa_load_info;
2754 		spa->spa_load_info = fnvlist_alloc();
2755 	}
2756 
2757 	spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2758 	safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2759 	min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2760 	    TXG_INITIAL : safe_rewind_txg;
2761 
2762 	/*
2763 	 * Continue as long as we're finding errors, we're still within
2764 	 * the acceptable rewind range, and we're still finding uberblocks
2765 	 */
2766 	while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2767 	    spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2768 		if (spa->spa_load_max_txg < safe_rewind_txg)
2769 			spa->spa_extreme_rewind = B_TRUE;
2770 		rewind_error = spa_load_retry(spa, state, mosconfig);
2771 	}
2772 
2773 	spa->spa_extreme_rewind = B_FALSE;
2774 	spa->spa_load_max_txg = UINT64_MAX;
2775 
2776 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2777 		spa_config_set(spa, config);
2778 
2779 	if (state == SPA_LOAD_RECOVER) {
2780 		ASSERT3P(loadinfo, ==, NULL);
2781 		return (rewind_error);
2782 	} else {
2783 		/* Store the rewind info as part of the initial load info */
2784 		fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2785 		    spa->spa_load_info);
2786 
2787 		/* Restore the initial load info */
2788 		fnvlist_free(spa->spa_load_info);
2789 		spa->spa_load_info = loadinfo;
2790 
2791 		return (load_error);
2792 	}
2793 }
2794 
2795 /*
2796  * Pool Open/Import
2797  *
2798  * The import case is identical to an open except that the configuration is sent
2799  * down from userland, instead of grabbed from the configuration cache.  For the
2800  * case of an open, the pool configuration will exist in the
2801  * POOL_STATE_UNINITIALIZED state.
2802  *
2803  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2804  * the same time open the pool, without having to keep around the spa_t in some
2805  * ambiguous state.
2806  */
2807 static int
2808 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2809     nvlist_t **config)
2810 {
2811 	spa_t *spa;
2812 	spa_load_state_t state = SPA_LOAD_OPEN;
2813 	int error;
2814 	int locked = B_FALSE;
2815 
2816 	*spapp = NULL;
2817 
2818 	/*
2819 	 * As disgusting as this is, we need to support recursive calls to this
2820 	 * function because dsl_dir_open() is called during spa_load(), and ends
2821 	 * up calling spa_open() again.  The real fix is to figure out how to
2822 	 * avoid dsl_dir_open() calling this in the first place.
2823 	 */
2824 	if (mutex_owner(&spa_namespace_lock) != curthread) {
2825 		mutex_enter(&spa_namespace_lock);
2826 		locked = B_TRUE;
2827 	}
2828 
2829 	if ((spa = spa_lookup(pool)) == NULL) {
2830 		if (locked)
2831 			mutex_exit(&spa_namespace_lock);
2832 		return (ENOENT);
2833 	}
2834 
2835 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2836 		zpool_rewind_policy_t policy;
2837 
2838 		zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2839 		    &policy);
2840 		if (policy.zrp_request & ZPOOL_DO_REWIND)
2841 			state = SPA_LOAD_RECOVER;
2842 
2843 		spa_activate(spa, spa_mode_global);
2844 
2845 		if (state != SPA_LOAD_RECOVER)
2846 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2847 
2848 		error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2849 		    policy.zrp_request);
2850 
2851 		if (error == EBADF) {
2852 			/*
2853 			 * If vdev_validate() returns failure (indicated by
2854 			 * EBADF), it indicates that one of the vdevs indicates
2855 			 * that the pool has been exported or destroyed.  If
2856 			 * this is the case, the config cache is out of sync and
2857 			 * we should remove the pool from the namespace.
2858 			 */
2859 			spa_unload(spa);
2860 			spa_deactivate(spa);
2861 			spa_config_sync(spa, B_TRUE, B_TRUE);
2862 			spa_remove(spa);
2863 			if (locked)
2864 				mutex_exit(&spa_namespace_lock);
2865 			return (ENOENT);
2866 		}
2867 
2868 		if (error) {
2869 			/*
2870 			 * We can't open the pool, but we still have useful
2871 			 * information: the state of each vdev after the
2872 			 * attempted vdev_open().  Return this to the user.
2873 			 */
2874 			if (config != NULL && spa->spa_config) {
2875 				VERIFY(nvlist_dup(spa->spa_config, config,
2876 				    KM_SLEEP) == 0);
2877 				VERIFY(nvlist_add_nvlist(*config,
2878 				    ZPOOL_CONFIG_LOAD_INFO,
2879 				    spa->spa_load_info) == 0);
2880 			}
2881 			spa_unload(spa);
2882 			spa_deactivate(spa);
2883 			spa->spa_last_open_failed = error;
2884 			if (locked)
2885 				mutex_exit(&spa_namespace_lock);
2886 			*spapp = NULL;
2887 			return (error);
2888 		}
2889 	}
2890 
2891 	spa_open_ref(spa, tag);
2892 
2893 	if (config != NULL)
2894 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2895 
2896 	/*
2897 	 * If we've recovered the pool, pass back any information we
2898 	 * gathered while doing the load.
2899 	 */
2900 	if (state == SPA_LOAD_RECOVER) {
2901 		VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2902 		    spa->spa_load_info) == 0);
2903 	}
2904 
2905 	if (locked) {
2906 		spa->spa_last_open_failed = 0;
2907 		spa->spa_last_ubsync_txg = 0;
2908 		spa->spa_load_txg = 0;
2909 		mutex_exit(&spa_namespace_lock);
2910 	}
2911 
2912 	*spapp = spa;
2913 
2914 	return (0);
2915 }
2916 
2917 int
2918 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2919     nvlist_t **config)
2920 {
2921 	return (spa_open_common(name, spapp, tag, policy, config));
2922 }
2923 
2924 int
2925 spa_open(const char *name, spa_t **spapp, void *tag)
2926 {
2927 	return (spa_open_common(name, spapp, tag, NULL, NULL));
2928 }
2929 
2930 /*
2931  * Lookup the given spa_t, incrementing the inject count in the process,
2932  * preventing it from being exported or destroyed.
2933  */
2934 spa_t *
2935 spa_inject_addref(char *name)
2936 {
2937 	spa_t *spa;
2938 
2939 	mutex_enter(&spa_namespace_lock);
2940 	if ((spa = spa_lookup(name)) == NULL) {
2941 		mutex_exit(&spa_namespace_lock);
2942 		return (NULL);
2943 	}
2944 	spa->spa_inject_ref++;
2945 	mutex_exit(&spa_namespace_lock);
2946 
2947 	return (spa);
2948 }
2949 
2950 void
2951 spa_inject_delref(spa_t *spa)
2952 {
2953 	mutex_enter(&spa_namespace_lock);
2954 	spa->spa_inject_ref--;
2955 	mutex_exit(&spa_namespace_lock);
2956 }
2957 
2958 /*
2959  * Add spares device information to the nvlist.
2960  */
2961 static void
2962 spa_add_spares(spa_t *spa, nvlist_t *config)
2963 {
2964 	nvlist_t **spares;
2965 	uint_t i, nspares;
2966 	nvlist_t *nvroot;
2967 	uint64_t guid;
2968 	vdev_stat_t *vs;
2969 	uint_t vsc;
2970 	uint64_t pool;
2971 
2972 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2973 
2974 	if (spa->spa_spares.sav_count == 0)
2975 		return;
2976 
2977 	VERIFY(nvlist_lookup_nvlist(config,
2978 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2979 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2980 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2981 	if (nspares != 0) {
2982 		VERIFY(nvlist_add_nvlist_array(nvroot,
2983 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2984 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
2985 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2986 
2987 		/*
2988 		 * Go through and find any spares which have since been
2989 		 * repurposed as an active spare.  If this is the case, update
2990 		 * their status appropriately.
2991 		 */
2992 		for (i = 0; i < nspares; i++) {
2993 			VERIFY(nvlist_lookup_uint64(spares[i],
2994 			    ZPOOL_CONFIG_GUID, &guid) == 0);
2995 			if (spa_spare_exists(guid, &pool, NULL) &&
2996 			    pool != 0ULL) {
2997 				VERIFY(nvlist_lookup_uint64_array(
2998 				    spares[i], ZPOOL_CONFIG_VDEV_STATS,
2999 				    (uint64_t **)&vs, &vsc) == 0);
3000 				vs->vs_state = VDEV_STATE_CANT_OPEN;
3001 				vs->vs_aux = VDEV_AUX_SPARED;
3002 			}
3003 		}
3004 	}
3005 }
3006 
3007 /*
3008  * Add l2cache device information to the nvlist, including vdev stats.
3009  */
3010 static void
3011 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3012 {
3013 	nvlist_t **l2cache;
3014 	uint_t i, j, nl2cache;
3015 	nvlist_t *nvroot;
3016 	uint64_t guid;
3017 	vdev_t *vd;
3018 	vdev_stat_t *vs;
3019 	uint_t vsc;
3020 
3021 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3022 
3023 	if (spa->spa_l2cache.sav_count == 0)
3024 		return;
3025 
3026 	VERIFY(nvlist_lookup_nvlist(config,
3027 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3028 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3029 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3030 	if (nl2cache != 0) {
3031 		VERIFY(nvlist_add_nvlist_array(nvroot,
3032 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3033 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
3034 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3035 
3036 		/*
3037 		 * Update level 2 cache device stats.
3038 		 */
3039 
3040 		for (i = 0; i < nl2cache; i++) {
3041 			VERIFY(nvlist_lookup_uint64(l2cache[i],
3042 			    ZPOOL_CONFIG_GUID, &guid) == 0);
3043 
3044 			vd = NULL;
3045 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3046 				if (guid ==
3047 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3048 					vd = spa->spa_l2cache.sav_vdevs[j];
3049 					break;
3050 				}
3051 			}
3052 			ASSERT(vd != NULL);
3053 
3054 			VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3055 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3056 			    == 0);
3057 			vdev_get_stats(vd, vs);
3058 		}
3059 	}
3060 }
3061 
3062 static void
3063 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3064 {
3065 	nvlist_t *features;
3066 	zap_cursor_t zc;
3067 	zap_attribute_t za;
3068 
3069 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3070 	VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3071 
3072 	if (spa->spa_feat_for_read_obj != 0) {
3073 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3074 		    spa->spa_feat_for_read_obj);
3075 		    zap_cursor_retrieve(&zc, &za) == 0;
3076 		    zap_cursor_advance(&zc)) {
3077 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3078 			    za.za_num_integers == 1);
3079 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3080 			    za.za_first_integer));
3081 		}
3082 		zap_cursor_fini(&zc);
3083 	}
3084 
3085 	if (spa->spa_feat_for_write_obj != 0) {
3086 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3087 		    spa->spa_feat_for_write_obj);
3088 		    zap_cursor_retrieve(&zc, &za) == 0;
3089 		    zap_cursor_advance(&zc)) {
3090 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3091 			    za.za_num_integers == 1);
3092 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3093 			    za.za_first_integer));
3094 		}
3095 		zap_cursor_fini(&zc);
3096 	}
3097 
3098 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3099 	    features) == 0);
3100 	nvlist_free(features);
3101 }
3102 
3103 int
3104 spa_get_stats(const char *name, nvlist_t **config,
3105     char *altroot, size_t buflen)
3106 {
3107 	int error;
3108 	spa_t *spa;
3109 
3110 	*config = NULL;
3111 	error = spa_open_common(name, &spa, FTAG, NULL, config);
3112 
3113 	if (spa != NULL) {
3114 		/*
3115 		 * This still leaves a window of inconsistency where the spares
3116 		 * or l2cache devices could change and the config would be
3117 		 * self-inconsistent.
3118 		 */
3119 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3120 
3121 		if (*config != NULL) {
3122 			uint64_t loadtimes[2];
3123 
3124 			loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3125 			loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3126 			VERIFY(nvlist_add_uint64_array(*config,
3127 			    ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3128 
3129 			VERIFY(nvlist_add_uint64(*config,
3130 			    ZPOOL_CONFIG_ERRCOUNT,
3131 			    spa_get_errlog_size(spa)) == 0);
3132 
3133 			if (spa_suspended(spa))
3134 				VERIFY(nvlist_add_uint64(*config,
3135 				    ZPOOL_CONFIG_SUSPENDED,
3136 				    spa->spa_failmode) == 0);
3137 
3138 			spa_add_spares(spa, *config);
3139 			spa_add_l2cache(spa, *config);
3140 			spa_add_feature_stats(spa, *config);
3141 		}
3142 	}
3143 
3144 	/*
3145 	 * We want to get the alternate root even for faulted pools, so we cheat
3146 	 * and call spa_lookup() directly.
3147 	 */
3148 	if (altroot) {
3149 		if (spa == NULL) {
3150 			mutex_enter(&spa_namespace_lock);
3151 			spa = spa_lookup(name);
3152 			if (spa)
3153 				spa_altroot(spa, altroot, buflen);
3154 			else
3155 				altroot[0] = '\0';
3156 			spa = NULL;
3157 			mutex_exit(&spa_namespace_lock);
3158 		} else {
3159 			spa_altroot(spa, altroot, buflen);
3160 		}
3161 	}
3162 
3163 	if (spa != NULL) {
3164 		spa_config_exit(spa, SCL_CONFIG, FTAG);
3165 		spa_close(spa, FTAG);
3166 	}
3167 
3168 	return (error);
3169 }
3170 
3171 /*
3172  * Validate that the auxiliary device array is well formed.  We must have an
3173  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3174  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3175  * specified, as long as they are well-formed.
3176  */
3177 static int
3178 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3179     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3180     vdev_labeltype_t label)
3181 {
3182 	nvlist_t **dev;
3183 	uint_t i, ndev;
3184 	vdev_t *vd;
3185 	int error;
3186 
3187 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3188 
3189 	/*
3190 	 * It's acceptable to have no devs specified.
3191 	 */
3192 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3193 		return (0);
3194 
3195 	if (ndev == 0)
3196 		return (EINVAL);
3197 
3198 	/*
3199 	 * Make sure the pool is formatted with a version that supports this
3200 	 * device type.
3201 	 */
3202 	if (spa_version(spa) < version)
3203 		return (ENOTSUP);
3204 
3205 	/*
3206 	 * Set the pending device list so we correctly handle device in-use
3207 	 * checking.
3208 	 */
3209 	sav->sav_pending = dev;
3210 	sav->sav_npending = ndev;
3211 
3212 	for (i = 0; i < ndev; i++) {
3213 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3214 		    mode)) != 0)
3215 			goto out;
3216 
3217 		if (!vd->vdev_ops->vdev_op_leaf) {
3218 			vdev_free(vd);
3219 			error = EINVAL;
3220 			goto out;
3221 		}
3222 
3223 		/*
3224 		 * The L2ARC currently only supports disk devices in
3225 		 * kernel context.  For user-level testing, we allow it.
3226 		 */
3227 #ifdef _KERNEL
3228 		if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3229 		    strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3230 			error = ENOTBLK;
3231 			vdev_free(vd);
3232 			goto out;
3233 		}
3234 #endif
3235 		vd->vdev_top = vd;
3236 
3237 		if ((error = vdev_open(vd)) == 0 &&
3238 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
3239 			VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3240 			    vd->vdev_guid) == 0);
3241 		}
3242 
3243 		vdev_free(vd);
3244 
3245 		if (error &&
3246 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3247 			goto out;
3248 		else
3249 			error = 0;
3250 	}
3251 
3252 out:
3253 	sav->sav_pending = NULL;
3254 	sav->sav_npending = 0;
3255 	return (error);
3256 }
3257 
3258 static int
3259 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3260 {
3261 	int error;
3262 
3263 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3264 
3265 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3266 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3267 	    VDEV_LABEL_SPARE)) != 0) {
3268 		return (error);
3269 	}
3270 
3271 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3272 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3273 	    VDEV_LABEL_L2CACHE));
3274 }
3275 
3276 static void
3277 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3278     const char *config)
3279 {
3280 	int i;
3281 
3282 	if (sav->sav_config != NULL) {
3283 		nvlist_t **olddevs;
3284 		uint_t oldndevs;
3285 		nvlist_t **newdevs;
3286 
3287 		/*
3288 		 * Generate new dev list by concatentating with the
3289 		 * current dev list.
3290 		 */
3291 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3292 		    &olddevs, &oldndevs) == 0);
3293 
3294 		newdevs = kmem_alloc(sizeof (void *) *
3295 		    (ndevs + oldndevs), KM_SLEEP);
3296 		for (i = 0; i < oldndevs; i++)
3297 			VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3298 			    KM_SLEEP) == 0);
3299 		for (i = 0; i < ndevs; i++)
3300 			VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3301 			    KM_SLEEP) == 0);
3302 
3303 		VERIFY(nvlist_remove(sav->sav_config, config,
3304 		    DATA_TYPE_NVLIST_ARRAY) == 0);
3305 
3306 		VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3307 		    config, newdevs, ndevs + oldndevs) == 0);
3308 		for (i = 0; i < oldndevs + ndevs; i++)
3309 			nvlist_free(newdevs[i]);
3310 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3311 	} else {
3312 		/*
3313 		 * Generate a new dev list.
3314 		 */
3315 		VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3316 		    KM_SLEEP) == 0);
3317 		VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3318 		    devs, ndevs) == 0);
3319 	}
3320 }
3321 
3322 /*
3323  * Stop and drop level 2 ARC devices
3324  */
3325 void
3326 spa_l2cache_drop(spa_t *spa)
3327 {
3328 	vdev_t *vd;
3329 	int i;
3330 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
3331 
3332 	for (i = 0; i < sav->sav_count; i++) {
3333 		uint64_t pool;
3334 
3335 		vd = sav->sav_vdevs[i];
3336 		ASSERT(vd != NULL);
3337 
3338 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3339 		    pool != 0ULL && l2arc_vdev_present(vd))
3340 			l2arc_remove_vdev(vd);
3341 	}
3342 }
3343 
3344 /*
3345  * Pool Creation
3346  */
3347 int
3348 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3349     nvlist_t *zplprops)
3350 {
3351 	spa_t *spa;
3352 	char *altroot = NULL;
3353 	vdev_t *rvd;
3354 	dsl_pool_t *dp;
3355 	dmu_tx_t *tx;
3356 	int error = 0;
3357 	uint64_t txg = TXG_INITIAL;
3358 	nvlist_t **spares, **l2cache;
3359 	uint_t nspares, nl2cache;
3360 	uint64_t version, obj;
3361 	boolean_t has_features;
3362 
3363 	/*
3364 	 * If this pool already exists, return failure.
3365 	 */
3366 	mutex_enter(&spa_namespace_lock);
3367 	if (spa_lookup(pool) != NULL) {
3368 		mutex_exit(&spa_namespace_lock);
3369 		return (EEXIST);
3370 	}
3371 
3372 	/*
3373 	 * Allocate a new spa_t structure.
3374 	 */
3375 	(void) nvlist_lookup_string(props,
3376 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3377 	spa = spa_add(pool, NULL, altroot);
3378 	spa_activate(spa, spa_mode_global);
3379 
3380 	if (props && (error = spa_prop_validate(spa, props))) {
3381 		spa_deactivate(spa);
3382 		spa_remove(spa);
3383 		mutex_exit(&spa_namespace_lock);
3384 		return (error);
3385 	}
3386 
3387 	has_features = B_FALSE;
3388 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3389 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3390 		if (zpool_prop_feature(nvpair_name(elem)))
3391 			has_features = B_TRUE;
3392 	}
3393 
3394 	if (has_features || nvlist_lookup_uint64(props,
3395 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3396 		version = SPA_VERSION;
3397 	}
3398 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3399 
3400 	spa->spa_first_txg = txg;
3401 	spa->spa_uberblock.ub_txg = txg - 1;
3402 	spa->spa_uberblock.ub_version = version;
3403 	spa->spa_ubsync = spa->spa_uberblock;
3404 
3405 	/*
3406 	 * Create "The Godfather" zio to hold all async IOs
3407 	 */
3408 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3409 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3410 
3411 	/*
3412 	 * Create the root vdev.
3413 	 */
3414 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3415 
3416 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3417 
3418 	ASSERT(error != 0 || rvd != NULL);
3419 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3420 
3421 	if (error == 0 && !zfs_allocatable_devs(nvroot))
3422 		error = EINVAL;
3423 
3424 	if (error == 0 &&
3425 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3426 	    (error = spa_validate_aux(spa, nvroot, txg,
3427 	    VDEV_ALLOC_ADD)) == 0) {
3428 		for (int c = 0; c < rvd->vdev_children; c++) {
3429 			vdev_metaslab_set_size(rvd->vdev_child[c]);
3430 			vdev_expand(rvd->vdev_child[c], txg);
3431 		}
3432 	}
3433 
3434 	spa_config_exit(spa, SCL_ALL, FTAG);
3435 
3436 	if (error != 0) {
3437 		spa_unload(spa);
3438 		spa_deactivate(spa);
3439 		spa_remove(spa);
3440 		mutex_exit(&spa_namespace_lock);
3441 		return (error);
3442 	}
3443 
3444 	/*
3445 	 * Get the list of spares, if specified.
3446 	 */
3447 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3448 	    &spares, &nspares) == 0) {
3449 		VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3450 		    KM_SLEEP) == 0);
3451 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3452 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3453 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3454 		spa_load_spares(spa);
3455 		spa_config_exit(spa, SCL_ALL, FTAG);
3456 		spa->spa_spares.sav_sync = B_TRUE;
3457 	}
3458 
3459 	/*
3460 	 * Get the list of level 2 cache devices, if specified.
3461 	 */
3462 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3463 	    &l2cache, &nl2cache) == 0) {
3464 		VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3465 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3466 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3467 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3468 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3469 		spa_load_l2cache(spa);
3470 		spa_config_exit(spa, SCL_ALL, FTAG);
3471 		spa->spa_l2cache.sav_sync = B_TRUE;
3472 	}
3473 
3474 	spa->spa_is_initializing = B_TRUE;
3475 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3476 	spa->spa_meta_objset = dp->dp_meta_objset;
3477 	spa->spa_is_initializing = B_FALSE;
3478 
3479 	/*
3480 	 * Create DDTs (dedup tables).
3481 	 */
3482 	ddt_create(spa);
3483 
3484 	spa_update_dspace(spa);
3485 
3486 	tx = dmu_tx_create_assigned(dp, txg);
3487 
3488 	/*
3489 	 * Create the pool config object.
3490 	 */
3491 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3492 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3493 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3494 
3495 	if (zap_add(spa->spa_meta_objset,
3496 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3497 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3498 		cmn_err(CE_PANIC, "failed to add pool config");
3499 	}
3500 
3501 	if (spa_version(spa) >= SPA_VERSION_FEATURES)
3502 		spa_feature_create_zap_objects(spa, tx);
3503 
3504 	if (zap_add(spa->spa_meta_objset,
3505 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3506 	    sizeof (uint64_t), 1, &version, tx) != 0) {
3507 		cmn_err(CE_PANIC, "failed to add pool version");
3508 	}
3509 
3510 	/* Newly created pools with the right version are always deflated. */
3511 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3512 		spa->spa_deflate = TRUE;
3513 		if (zap_add(spa->spa_meta_objset,
3514 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3515 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3516 			cmn_err(CE_PANIC, "failed to add deflate");
3517 		}
3518 	}
3519 
3520 	/*
3521 	 * Create the deferred-free bpobj.  Turn off compression
3522 	 * because sync-to-convergence takes longer if the blocksize
3523 	 * keeps changing.
3524 	 */
3525 	obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3526 	dmu_object_set_compress(spa->spa_meta_objset, obj,
3527 	    ZIO_COMPRESS_OFF, tx);
3528 	if (zap_add(spa->spa_meta_objset,
3529 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3530 	    sizeof (uint64_t), 1, &obj, tx) != 0) {
3531 		cmn_err(CE_PANIC, "failed to add bpobj");
3532 	}
3533 	VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3534 	    spa->spa_meta_objset, obj));
3535 
3536 	/*
3537 	 * Create the pool's history object.
3538 	 */
3539 	if (version >= SPA_VERSION_ZPOOL_HISTORY)
3540 		spa_history_create_obj(spa, tx);
3541 
3542 	/*
3543 	 * Set pool properties.
3544 	 */
3545 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3546 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3547 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3548 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3549 
3550 	if (props != NULL) {
3551 		spa_configfile_set(spa, props, B_FALSE);
3552 		spa_sync_props(spa, props, tx);
3553 	}
3554 
3555 	dmu_tx_commit(tx);
3556 
3557 	spa->spa_sync_on = B_TRUE;
3558 	txg_sync_start(spa->spa_dsl_pool);
3559 
3560 	/*
3561 	 * We explicitly wait for the first transaction to complete so that our
3562 	 * bean counters are appropriately updated.
3563 	 */
3564 	txg_wait_synced(spa->spa_dsl_pool, txg);
3565 
3566 	spa_config_sync(spa, B_FALSE, B_TRUE);
3567 
3568 	spa_history_log_version(spa, "create");
3569 
3570 	spa->spa_minref = refcount_count(&spa->spa_refcount);
3571 
3572 	mutex_exit(&spa_namespace_lock);
3573 
3574 	return (0);
3575 }
3576 
3577 #ifdef _KERNEL
3578 /*
3579  * Get the root pool information from the root disk, then import the root pool
3580  * during the system boot up time.
3581  */
3582 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3583 
3584 static nvlist_t *
3585 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3586 {
3587 	nvlist_t *config;
3588 	nvlist_t *nvtop, *nvroot;
3589 	uint64_t pgid;
3590 
3591 	if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3592 		return (NULL);
3593 
3594 	/*
3595 	 * Add this top-level vdev to the child array.
3596 	 */
3597 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3598 	    &nvtop) == 0);
3599 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3600 	    &pgid) == 0);
3601 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3602 
3603 	/*
3604 	 * Put this pool's top-level vdevs into a root vdev.
3605 	 */
3606 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3607 	VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3608 	    VDEV_TYPE_ROOT) == 0);
3609 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3610 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3611 	VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3612 	    &nvtop, 1) == 0);
3613 
3614 	/*
3615 	 * Replace the existing vdev_tree with the new root vdev in
3616 	 * this pool's configuration (remove the old, add the new).
3617 	 */
3618 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3619 	nvlist_free(nvroot);
3620 	return (config);
3621 }
3622 
3623 /*
3624  * Walk the vdev tree and see if we can find a device with "better"
3625  * configuration. A configuration is "better" if the label on that
3626  * device has a more recent txg.
3627  */
3628 static void
3629 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3630 {
3631 	for (int c = 0; c < vd->vdev_children; c++)
3632 		spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3633 
3634 	if (vd->vdev_ops->vdev_op_leaf) {
3635 		nvlist_t *label;
3636 		uint64_t label_txg;
3637 
3638 		if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3639 		    &label) != 0)
3640 			return;
3641 
3642 		VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3643 		    &label_txg) == 0);
3644 
3645 		/*
3646 		 * Do we have a better boot device?
3647 		 */
3648 		if (label_txg > *txg) {
3649 			*txg = label_txg;
3650 			*avd = vd;
3651 		}
3652 		nvlist_free(label);
3653 	}
3654 }
3655 
3656 /*
3657  * Import a root pool.
3658  *
3659  * For x86. devpath_list will consist of devid and/or physpath name of
3660  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3661  * The GRUB "findroot" command will return the vdev we should boot.
3662  *
3663  * For Sparc, devpath_list consists the physpath name of the booting device
3664  * no matter the rootpool is a single device pool or a mirrored pool.
3665  * e.g.
3666  *	"/pci@1f,0/ide@d/disk@0,0:a"
3667  */
3668 int
3669 spa_import_rootpool(char *devpath, char *devid)
3670 {
3671 	spa_t *spa;
3672 	vdev_t *rvd, *bvd, *avd = NULL;
3673 	nvlist_t *config, *nvtop;
3674 	uint64_t guid, txg;
3675 	char *pname;
3676 	int error;
3677 
3678 	/*
3679 	 * Read the label from the boot device and generate a configuration.
3680 	 */
3681 	config = spa_generate_rootconf(devpath, devid, &guid);
3682 #if defined(_OBP) && defined(_KERNEL)
3683 	if (config == NULL) {
3684 		if (strstr(devpath, "/iscsi/ssd") != NULL) {
3685 			/* iscsi boot */
3686 			get_iscsi_bootpath_phy(devpath);
3687 			config = spa_generate_rootconf(devpath, devid, &guid);
3688 		}
3689 	}
3690 #endif
3691 	if (config == NULL) {
3692 		cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3693 		    devpath);
3694 		return (EIO);
3695 	}
3696 
3697 	VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3698 	    &pname) == 0);
3699 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3700 
3701 	mutex_enter(&spa_namespace_lock);
3702 	if ((spa = spa_lookup(pname)) != NULL) {
3703 		/*
3704 		 * Remove the existing root pool from the namespace so that we
3705 		 * can replace it with the correct config we just read in.
3706 		 */
3707 		spa_remove(spa);
3708 	}
3709 
3710 	spa = spa_add(pname, config, NULL);
3711 	spa->spa_is_root = B_TRUE;
3712 	spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3713 
3714 	/*
3715 	 * Build up a vdev tree based on the boot device's label config.
3716 	 */
3717 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3718 	    &nvtop) == 0);
3719 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3720 	error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3721 	    VDEV_ALLOC_ROOTPOOL);
3722 	spa_config_exit(spa, SCL_ALL, FTAG);
3723 	if (error) {
3724 		mutex_exit(&spa_namespace_lock);
3725 		nvlist_free(config);
3726 		cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3727 		    pname);
3728 		return (error);
3729 	}
3730 
3731 	/*
3732 	 * Get the boot vdev.
3733 	 */
3734 	if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3735 		cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3736 		    (u_longlong_t)guid);
3737 		error = ENOENT;
3738 		goto out;
3739 	}
3740 
3741 	/*
3742 	 * Determine if there is a better boot device.
3743 	 */
3744 	avd = bvd;
3745 	spa_alt_rootvdev(rvd, &avd, &txg);
3746 	if (avd != bvd) {
3747 		cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3748 		    "try booting from '%s'", avd->vdev_path);
3749 		error = EINVAL;
3750 		goto out;
3751 	}
3752 
3753 	/*
3754 	 * If the boot device is part of a spare vdev then ensure that
3755 	 * we're booting off the active spare.
3756 	 */
3757 	if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3758 	    !bvd->vdev_isspare) {
3759 		cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3760 		    "try booting from '%s'",
3761 		    bvd->vdev_parent->
3762 		    vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3763 		error = EINVAL;
3764 		goto out;
3765 	}
3766 
3767 	error = 0;
3768 out:
3769 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3770 	vdev_free(rvd);
3771 	spa_config_exit(spa, SCL_ALL, FTAG);
3772 	mutex_exit(&spa_namespace_lock);
3773 
3774 	nvlist_free(config);
3775 	return (error);
3776 }
3777 
3778 #endif
3779 
3780 /*
3781  * Import a non-root pool into the system.
3782  */
3783 int
3784 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3785 {
3786 	spa_t *spa;
3787 	char *altroot = NULL;
3788 	spa_load_state_t state = SPA_LOAD_IMPORT;
3789 	zpool_rewind_policy_t policy;
3790 	uint64_t mode = spa_mode_global;
3791 	uint64_t readonly = B_FALSE;
3792 	int error;
3793 	nvlist_t *nvroot;
3794 	nvlist_t **spares, **l2cache;
3795 	uint_t nspares, nl2cache;
3796 
3797 	/*
3798 	 * If a pool with this name exists, return failure.
3799 	 */
3800 	mutex_enter(&spa_namespace_lock);
3801 	if (spa_lookup(pool) != NULL) {
3802 		mutex_exit(&spa_namespace_lock);
3803 		return (EEXIST);
3804 	}
3805 
3806 	/*
3807 	 * Create and initialize the spa structure.
3808 	 */
3809 	(void) nvlist_lookup_string(props,
3810 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3811 	(void) nvlist_lookup_uint64(props,
3812 	    zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3813 	if (readonly)
3814 		mode = FREAD;
3815 	spa = spa_add(pool, config, altroot);
3816 	spa->spa_import_flags = flags;
3817 
3818 	/*
3819 	 * Verbatim import - Take a pool and insert it into the namespace
3820 	 * as if it had been loaded at boot.
3821 	 */
3822 	if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3823 		if (props != NULL)
3824 			spa_configfile_set(spa, props, B_FALSE);
3825 
3826 		spa_config_sync(spa, B_FALSE, B_TRUE);
3827 
3828 		mutex_exit(&spa_namespace_lock);
3829 		spa_history_log_version(spa, "import");
3830 
3831 		return (0);
3832 	}
3833 
3834 	spa_activate(spa, mode);
3835 
3836 	/*
3837 	 * Don't start async tasks until we know everything is healthy.
3838 	 */
3839 	spa_async_suspend(spa);
3840 
3841 	zpool_get_rewind_policy(config, &policy);
3842 	if (policy.zrp_request & ZPOOL_DO_REWIND)
3843 		state = SPA_LOAD_RECOVER;
3844 
3845 	/*
3846 	 * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3847 	 * because the user-supplied config is actually the one to trust when
3848 	 * doing an import.
3849 	 */
3850 	if (state != SPA_LOAD_RECOVER)
3851 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3852 
3853 	error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3854 	    policy.zrp_request);
3855 
3856 	/*
3857 	 * Propagate anything learned while loading the pool and pass it
3858 	 * back to caller (i.e. rewind info, missing devices, etc).
3859 	 */
3860 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3861 	    spa->spa_load_info) == 0);
3862 
3863 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3864 	/*
3865 	 * Toss any existing sparelist, as it doesn't have any validity
3866 	 * anymore, and conflicts with spa_has_spare().
3867 	 */
3868 	if (spa->spa_spares.sav_config) {
3869 		nvlist_free(spa->spa_spares.sav_config);
3870 		spa->spa_spares.sav_config = NULL;
3871 		spa_load_spares(spa);
3872 	}
3873 	if (spa->spa_l2cache.sav_config) {
3874 		nvlist_free(spa->spa_l2cache.sav_config);
3875 		spa->spa_l2cache.sav_config = NULL;
3876 		spa_load_l2cache(spa);
3877 	}
3878 
3879 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3880 	    &nvroot) == 0);
3881 	if (error == 0)
3882 		error = spa_validate_aux(spa, nvroot, -1ULL,
3883 		    VDEV_ALLOC_SPARE);
3884 	if (error == 0)
3885 		error = spa_validate_aux(spa, nvroot, -1ULL,
3886 		    VDEV_ALLOC_L2CACHE);
3887 	spa_config_exit(spa, SCL_ALL, FTAG);
3888 
3889 	if (props != NULL)
3890 		spa_configfile_set(spa, props, B_FALSE);
3891 
3892 	if (error != 0 || (props && spa_writeable(spa) &&
3893 	    (error = spa_prop_set(spa, props)))) {
3894 		spa_unload(spa);
3895 		spa_deactivate(spa);
3896 		spa_remove(spa);
3897 		mutex_exit(&spa_namespace_lock);
3898 		return (error);
3899 	}
3900 
3901 	spa_async_resume(spa);
3902 
3903 	/*
3904 	 * Override any spares and level 2 cache devices as specified by
3905 	 * the user, as these may have correct device names/devids, etc.
3906 	 */
3907 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3908 	    &spares, &nspares) == 0) {
3909 		if (spa->spa_spares.sav_config)
3910 			VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3911 			    ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3912 		else
3913 			VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3914 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3915 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3916 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3917 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3918 		spa_load_spares(spa);
3919 		spa_config_exit(spa, SCL_ALL, FTAG);
3920 		spa->spa_spares.sav_sync = B_TRUE;
3921 	}
3922 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3923 	    &l2cache, &nl2cache) == 0) {
3924 		if (spa->spa_l2cache.sav_config)
3925 			VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3926 			    ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3927 		else
3928 			VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3929 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3930 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3931 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3932 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3933 		spa_load_l2cache(spa);
3934 		spa_config_exit(spa, SCL_ALL, FTAG);
3935 		spa->spa_l2cache.sav_sync = B_TRUE;
3936 	}
3937 
3938 	/*
3939 	 * Check for any removed devices.
3940 	 */
3941 	if (spa->spa_autoreplace) {
3942 		spa_aux_check_removed(&spa->spa_spares);
3943 		spa_aux_check_removed(&spa->spa_l2cache);
3944 	}
3945 
3946 	if (spa_writeable(spa)) {
3947 		/*
3948 		 * Update the config cache to include the newly-imported pool.
3949 		 */
3950 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3951 	}
3952 
3953 	/*
3954 	 * It's possible that the pool was expanded while it was exported.
3955 	 * We kick off an async task to handle this for us.
3956 	 */
3957 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3958 
3959 	mutex_exit(&spa_namespace_lock);
3960 	spa_history_log_version(spa, "import");
3961 
3962 	return (0);
3963 }
3964 
3965 nvlist_t *
3966 spa_tryimport(nvlist_t *tryconfig)
3967 {
3968 	nvlist_t *config = NULL;
3969 	char *poolname;
3970 	spa_t *spa;
3971 	uint64_t state;
3972 	int error;
3973 
3974 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3975 		return (NULL);
3976 
3977 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3978 		return (NULL);
3979 
3980 	/*
3981 	 * Create and initialize the spa structure.
3982 	 */
3983 	mutex_enter(&spa_namespace_lock);
3984 	spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3985 	spa_activate(spa, FREAD);
3986 
3987 	/*
3988 	 * Pass off the heavy lifting to spa_load().
3989 	 * Pass TRUE for mosconfig because the user-supplied config
3990 	 * is actually the one to trust when doing an import.
3991 	 */
3992 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
3993 
3994 	/*
3995 	 * If 'tryconfig' was at least parsable, return the current config.
3996 	 */
3997 	if (spa->spa_root_vdev != NULL) {
3998 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
3999 		VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4000 		    poolname) == 0);
4001 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4002 		    state) == 0);
4003 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4004 		    spa->spa_uberblock.ub_timestamp) == 0);
4005 		VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4006 		    spa->spa_load_info) == 0);
4007 
4008 		/*
4009 		 * If the bootfs property exists on this pool then we
4010 		 * copy it out so that external consumers can tell which
4011 		 * pools are bootable.
4012 		 */
4013 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
4014 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4015 
4016 			/*
4017 			 * We have to play games with the name since the
4018 			 * pool was opened as TRYIMPORT_NAME.
4019 			 */
4020 			if (dsl_dsobj_to_dsname(spa_name(spa),
4021 			    spa->spa_bootfs, tmpname) == 0) {
4022 				char *cp;
4023 				char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4024 
4025 				cp = strchr(tmpname, '/');
4026 				if (cp == NULL) {
4027 					(void) strlcpy(dsname, tmpname,
4028 					    MAXPATHLEN);
4029 				} else {
4030 					(void) snprintf(dsname, MAXPATHLEN,
4031 					    "%s/%s", poolname, ++cp);
4032 				}
4033 				VERIFY(nvlist_add_string(config,
4034 				    ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4035 				kmem_free(dsname, MAXPATHLEN);
4036 			}
4037 			kmem_free(tmpname, MAXPATHLEN);
4038 		}
4039 
4040 		/*
4041 		 * Add the list of hot spares and level 2 cache devices.
4042 		 */
4043 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4044 		spa_add_spares(spa, config);
4045 		spa_add_l2cache(spa, config);
4046 		spa_config_exit(spa, SCL_CONFIG, FTAG);
4047 	}
4048 
4049 	spa_unload(spa);
4050 	spa_deactivate(spa);
4051 	spa_remove(spa);
4052 	mutex_exit(&spa_namespace_lock);
4053 
4054 	return (config);
4055 }
4056 
4057 /*
4058  * Pool export/destroy
4059  *
4060  * The act of destroying or exporting a pool is very simple.  We make sure there
4061  * is no more pending I/O and any references to the pool are gone.  Then, we
4062  * update the pool state and sync all the labels to disk, removing the
4063  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4064  * we don't sync the labels or remove the configuration cache.
4065  */
4066 static int
4067 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4068     boolean_t force, boolean_t hardforce)
4069 {
4070 	spa_t *spa;
4071 
4072 	if (oldconfig)
4073 		*oldconfig = NULL;
4074 
4075 	if (!(spa_mode_global & FWRITE))
4076 		return (EROFS);
4077 
4078 	mutex_enter(&spa_namespace_lock);
4079 	if ((spa = spa_lookup(pool)) == NULL) {
4080 		mutex_exit(&spa_namespace_lock);
4081 		return (ENOENT);
4082 	}
4083 
4084 	/*
4085 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
4086 	 * reacquire the namespace lock, and see if we can export.
4087 	 */
4088 	spa_open_ref(spa, FTAG);
4089 	mutex_exit(&spa_namespace_lock);
4090 	spa_async_suspend(spa);
4091 	mutex_enter(&spa_namespace_lock);
4092 	spa_close(spa, FTAG);
4093 
4094 	/*
4095 	 * The pool will be in core if it's openable,
4096 	 * in which case we can modify its state.
4097 	 */
4098 	if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4099 		/*
4100 		 * Objsets may be open only because they're dirty, so we
4101 		 * have to force it to sync before checking spa_refcnt.
4102 		 */
4103 		txg_wait_synced(spa->spa_dsl_pool, 0);
4104 
4105 		/*
4106 		 * A pool cannot be exported or destroyed if there are active
4107 		 * references.  If we are resetting a pool, allow references by
4108 		 * fault injection handlers.
4109 		 */
4110 		if (!spa_refcount_zero(spa) ||
4111 		    (spa->spa_inject_ref != 0 &&
4112 		    new_state != POOL_STATE_UNINITIALIZED)) {
4113 			spa_async_resume(spa);
4114 			mutex_exit(&spa_namespace_lock);
4115 			return (EBUSY);
4116 		}
4117 
4118 		/*
4119 		 * A pool cannot be exported if it has an active shared spare.
4120 		 * This is to prevent other pools stealing the active spare
4121 		 * from an exported pool. At user's own will, such pool can
4122 		 * be forcedly exported.
4123 		 */
4124 		if (!force && new_state == POOL_STATE_EXPORTED &&
4125 		    spa_has_active_shared_spare(spa)) {
4126 			spa_async_resume(spa);
4127 			mutex_exit(&spa_namespace_lock);
4128 			return (EXDEV);
4129 		}
4130 
4131 		/*
4132 		 * We want this to be reflected on every label,
4133 		 * so mark them all dirty.  spa_unload() will do the
4134 		 * final sync that pushes these changes out.
4135 		 */
4136 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4137 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4138 			spa->spa_state = new_state;
4139 			spa->spa_final_txg = spa_last_synced_txg(spa) +
4140 			    TXG_DEFER_SIZE + 1;
4141 			vdev_config_dirty(spa->spa_root_vdev);
4142 			spa_config_exit(spa, SCL_ALL, FTAG);
4143 		}
4144 	}
4145 
4146 	spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4147 
4148 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4149 		spa_unload(spa);
4150 		spa_deactivate(spa);
4151 	}
4152 
4153 	if (oldconfig && spa->spa_config)
4154 		VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4155 
4156 	if (new_state != POOL_STATE_UNINITIALIZED) {
4157 		if (!hardforce)
4158 			spa_config_sync(spa, B_TRUE, B_TRUE);
4159 		spa_remove(spa);
4160 	}
4161 	mutex_exit(&spa_namespace_lock);
4162 
4163 	return (0);
4164 }
4165 
4166 /*
4167  * Destroy a storage pool.
4168  */
4169 int
4170 spa_destroy(char *pool)
4171 {
4172 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4173 	    B_FALSE, B_FALSE));
4174 }
4175 
4176 /*
4177  * Export a storage pool.
4178  */
4179 int
4180 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4181     boolean_t hardforce)
4182 {
4183 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4184 	    force, hardforce));
4185 }
4186 
4187 /*
4188  * Similar to spa_export(), this unloads the spa_t without actually removing it
4189  * from the namespace in any way.
4190  */
4191 int
4192 spa_reset(char *pool)
4193 {
4194 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4195 	    B_FALSE, B_FALSE));
4196 }
4197 
4198 /*
4199  * ==========================================================================
4200  * Device manipulation
4201  * ==========================================================================
4202  */
4203 
4204 /*
4205  * Add a device to a storage pool.
4206  */
4207 int
4208 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4209 {
4210 	uint64_t txg, id;
4211 	int error;
4212 	vdev_t *rvd = spa->spa_root_vdev;
4213 	vdev_t *vd, *tvd;
4214 	nvlist_t **spares, **l2cache;
4215 	uint_t nspares, nl2cache;
4216 
4217 	ASSERT(spa_writeable(spa));
4218 
4219 	txg = spa_vdev_enter(spa);
4220 
4221 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4222 	    VDEV_ALLOC_ADD)) != 0)
4223 		return (spa_vdev_exit(spa, NULL, txg, error));
4224 
4225 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
4226 
4227 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4228 	    &nspares) != 0)
4229 		nspares = 0;
4230 
4231 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4232 	    &nl2cache) != 0)
4233 		nl2cache = 0;
4234 
4235 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4236 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
4237 
4238 	if (vd->vdev_children != 0 &&
4239 	    (error = vdev_create(vd, txg, B_FALSE)) != 0)
4240 		return (spa_vdev_exit(spa, vd, txg, error));
4241 
4242 	/*
4243 	 * We must validate the spares and l2cache devices after checking the
4244 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4245 	 */
4246 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4247 		return (spa_vdev_exit(spa, vd, txg, error));
4248 
4249 	/*
4250 	 * Transfer each new top-level vdev from vd to rvd.
4251 	 */
4252 	for (int c = 0; c < vd->vdev_children; c++) {
4253 
4254 		/*
4255 		 * Set the vdev id to the first hole, if one exists.
4256 		 */
4257 		for (id = 0; id < rvd->vdev_children; id++) {
4258 			if (rvd->vdev_child[id]->vdev_ishole) {
4259 				vdev_free(rvd->vdev_child[id]);
4260 				break;
4261 			}
4262 		}
4263 		tvd = vd->vdev_child[c];
4264 		vdev_remove_child(vd, tvd);
4265 		tvd->vdev_id = id;
4266 		vdev_add_child(rvd, tvd);
4267 		vdev_config_dirty(tvd);
4268 	}
4269 
4270 	if (nspares != 0) {
4271 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4272 		    ZPOOL_CONFIG_SPARES);
4273 		spa_load_spares(spa);
4274 		spa->spa_spares.sav_sync = B_TRUE;
4275 	}
4276 
4277 	if (nl2cache != 0) {
4278 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4279 		    ZPOOL_CONFIG_L2CACHE);
4280 		spa_load_l2cache(spa);
4281 		spa->spa_l2cache.sav_sync = B_TRUE;
4282 	}
4283 
4284 	/*
4285 	 * We have to be careful when adding new vdevs to an existing pool.
4286 	 * If other threads start allocating from these vdevs before we
4287 	 * sync the config cache, and we lose power, then upon reboot we may
4288 	 * fail to open the pool because there are DVAs that the config cache
4289 	 * can't translate.  Therefore, we first add the vdevs without
4290 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4291 	 * and then let spa_config_update() initialize the new metaslabs.
4292 	 *
4293 	 * spa_load() checks for added-but-not-initialized vdevs, so that
4294 	 * if we lose power at any point in this sequence, the remaining
4295 	 * steps will be completed the next time we load the pool.
4296 	 */
4297 	(void) spa_vdev_exit(spa, vd, txg, 0);
4298 
4299 	mutex_enter(&spa_namespace_lock);
4300 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4301 	mutex_exit(&spa_namespace_lock);
4302 
4303 	return (0);
4304 }
4305 
4306 /*
4307  * Attach a device to a mirror.  The arguments are the path to any device
4308  * in the mirror, and the nvroot for the new device.  If the path specifies
4309  * a device that is not mirrored, we automatically insert the mirror vdev.
4310  *
4311  * If 'replacing' is specified, the new device is intended to replace the
4312  * existing device; in this case the two devices are made into their own
4313  * mirror using the 'replacing' vdev, which is functionally identical to
4314  * the mirror vdev (it actually reuses all the same ops) but has a few
4315  * extra rules: you can't attach to it after it's been created, and upon
4316  * completion of resilvering, the first disk (the one being replaced)
4317  * is automatically detached.
4318  */
4319 int
4320 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4321 {
4322 	uint64_t txg, dtl_max_txg;
4323 	vdev_t *rvd = spa->spa_root_vdev;
4324 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4325 	vdev_ops_t *pvops;
4326 	char *oldvdpath, *newvdpath;
4327 	int newvd_isspare;
4328 	int error;
4329 
4330 	ASSERT(spa_writeable(spa));
4331 
4332 	txg = spa_vdev_enter(spa);
4333 
4334 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4335 
4336 	if (oldvd == NULL)
4337 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4338 
4339 	if (!oldvd->vdev_ops->vdev_op_leaf)
4340 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4341 
4342 	pvd = oldvd->vdev_parent;
4343 
4344 	if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4345 	    VDEV_ALLOC_ATTACH)) != 0)
4346 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4347 
4348 	if (newrootvd->vdev_children != 1)
4349 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4350 
4351 	newvd = newrootvd->vdev_child[0];
4352 
4353 	if (!newvd->vdev_ops->vdev_op_leaf)
4354 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4355 
4356 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4357 		return (spa_vdev_exit(spa, newrootvd, txg, error));
4358 
4359 	/*
4360 	 * Spares can't replace logs
4361 	 */
4362 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4363 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4364 
4365 	if (!replacing) {
4366 		/*
4367 		 * For attach, the only allowable parent is a mirror or the root
4368 		 * vdev.
4369 		 */
4370 		if (pvd->vdev_ops != &vdev_mirror_ops &&
4371 		    pvd->vdev_ops != &vdev_root_ops)
4372 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4373 
4374 		pvops = &vdev_mirror_ops;
4375 	} else {
4376 		/*
4377 		 * Active hot spares can only be replaced by inactive hot
4378 		 * spares.
4379 		 */
4380 		if (pvd->vdev_ops == &vdev_spare_ops &&
4381 		    oldvd->vdev_isspare &&
4382 		    !spa_has_spare(spa, newvd->vdev_guid))
4383 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4384 
4385 		/*
4386 		 * If the source is a hot spare, and the parent isn't already a
4387 		 * spare, then we want to create a new hot spare.  Otherwise, we
4388 		 * want to create a replacing vdev.  The user is not allowed to
4389 		 * attach to a spared vdev child unless the 'isspare' state is
4390 		 * the same (spare replaces spare, non-spare replaces
4391 		 * non-spare).
4392 		 */
4393 		if (pvd->vdev_ops == &vdev_replacing_ops &&
4394 		    spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4395 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4396 		} else if (pvd->vdev_ops == &vdev_spare_ops &&
4397 		    newvd->vdev_isspare != oldvd->vdev_isspare) {
4398 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4399 		}
4400 
4401 		if (newvd->vdev_isspare)
4402 			pvops = &vdev_spare_ops;
4403 		else
4404 			pvops = &vdev_replacing_ops;
4405 	}
4406 
4407 	/*
4408 	 * Make sure the new device is big enough.
4409 	 */
4410 	if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4411 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4412 
4413 	/*
4414 	 * The new device cannot have a higher alignment requirement
4415 	 * than the top-level vdev.
4416 	 */
4417 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4418 		return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4419 
4420 	/*
4421 	 * If this is an in-place replacement, update oldvd's path and devid
4422 	 * to make it distinguishable from newvd, and unopenable from now on.
4423 	 */
4424 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4425 		spa_strfree(oldvd->vdev_path);
4426 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4427 		    KM_SLEEP);
4428 		(void) sprintf(oldvd->vdev_path, "%s/%s",
4429 		    newvd->vdev_path, "old");
4430 		if (oldvd->vdev_devid != NULL) {
4431 			spa_strfree(oldvd->vdev_devid);
4432 			oldvd->vdev_devid = NULL;
4433 		}
4434 	}
4435 
4436 	/* mark the device being resilvered */
4437 	newvd->vdev_resilvering = B_TRUE;
4438 
4439 	/*
4440 	 * If the parent is not a mirror, or if we're replacing, insert the new
4441 	 * mirror/replacing/spare vdev above oldvd.
4442 	 */
4443 	if (pvd->vdev_ops != pvops)
4444 		pvd = vdev_add_parent(oldvd, pvops);
4445 
4446 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
4447 	ASSERT(pvd->vdev_ops == pvops);
4448 	ASSERT(oldvd->vdev_parent == pvd);
4449 
4450 	/*
4451 	 * Extract the new device from its root and add it to pvd.
4452 	 */
4453 	vdev_remove_child(newrootvd, newvd);
4454 	newvd->vdev_id = pvd->vdev_children;
4455 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
4456 	vdev_add_child(pvd, newvd);
4457 
4458 	tvd = newvd->vdev_top;
4459 	ASSERT(pvd->vdev_top == tvd);
4460 	ASSERT(tvd->vdev_parent == rvd);
4461 
4462 	vdev_config_dirty(tvd);
4463 
4464 	/*
4465 	 * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4466 	 * for any dmu_sync-ed blocks.  It will propagate upward when
4467 	 * spa_vdev_exit() calls vdev_dtl_reassess().
4468 	 */
4469 	dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4470 
4471 	vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4472 	    dtl_max_txg - TXG_INITIAL);
4473 
4474 	if (newvd->vdev_isspare) {
4475 		spa_spare_activate(newvd);
4476 		spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4477 	}
4478 
4479 	oldvdpath = spa_strdup(oldvd->vdev_path);
4480 	newvdpath = spa_strdup(newvd->vdev_path);
4481 	newvd_isspare = newvd->vdev_isspare;
4482 
4483 	/*
4484 	 * Mark newvd's DTL dirty in this txg.
4485 	 */
4486 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
4487 
4488 	/*
4489 	 * Restart the resilver
4490 	 */
4491 	dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4492 
4493 	/*
4494 	 * Commit the config
4495 	 */
4496 	(void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4497 
4498 	spa_history_log_internal(spa, "vdev attach", NULL,
4499 	    "%s vdev=%s %s vdev=%s",
4500 	    replacing && newvd_isspare ? "spare in" :
4501 	    replacing ? "replace" : "attach", newvdpath,
4502 	    replacing ? "for" : "to", oldvdpath);
4503 
4504 	spa_strfree(oldvdpath);
4505 	spa_strfree(newvdpath);
4506 
4507 	if (spa->spa_bootfs)
4508 		spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4509 
4510 	return (0);
4511 }
4512 
4513 /*
4514  * Detach a device from a mirror or replacing vdev.
4515  * If 'replace_done' is specified, only detach if the parent
4516  * is a replacing vdev.
4517  */
4518 int
4519 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4520 {
4521 	uint64_t txg;
4522 	int error;
4523 	vdev_t *rvd = spa->spa_root_vdev;
4524 	vdev_t *vd, *pvd, *cvd, *tvd;
4525 	boolean_t unspare = B_FALSE;
4526 	uint64_t unspare_guid = 0;
4527 	char *vdpath;
4528 
4529 	ASSERT(spa_writeable(spa));
4530 
4531 	txg = spa_vdev_enter(spa);
4532 
4533 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4534 
4535 	if (vd == NULL)
4536 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4537 
4538 	if (!vd->vdev_ops->vdev_op_leaf)
4539 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4540 
4541 	pvd = vd->vdev_parent;
4542 
4543 	/*
4544 	 * If the parent/child relationship is not as expected, don't do it.
4545 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4546 	 * vdev that's replacing B with C.  The user's intent in replacing
4547 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4548 	 * the replace by detaching C, the expected behavior is to end up
4549 	 * M(A,B).  But suppose that right after deciding to detach C,
4550 	 * the replacement of B completes.  We would have M(A,C), and then
4551 	 * ask to detach C, which would leave us with just A -- not what
4552 	 * the user wanted.  To prevent this, we make sure that the
4553 	 * parent/child relationship hasn't changed -- in this example,
4554 	 * that C's parent is still the replacing vdev R.
4555 	 */
4556 	if (pvd->vdev_guid != pguid && pguid != 0)
4557 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4558 
4559 	/*
4560 	 * Only 'replacing' or 'spare' vdevs can be replaced.
4561 	 */
4562 	if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4563 	    pvd->vdev_ops != &vdev_spare_ops)
4564 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4565 
4566 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4567 	    spa_version(spa) >= SPA_VERSION_SPARES);
4568 
4569 	/*
4570 	 * Only mirror, replacing, and spare vdevs support detach.
4571 	 */
4572 	if (pvd->vdev_ops != &vdev_replacing_ops &&
4573 	    pvd->vdev_ops != &vdev_mirror_ops &&
4574 	    pvd->vdev_ops != &vdev_spare_ops)
4575 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4576 
4577 	/*
4578 	 * If this device has the only valid copy of some data,
4579 	 * we cannot safely detach it.
4580 	 */
4581 	if (vdev_dtl_required(vd))
4582 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4583 
4584 	ASSERT(pvd->vdev_children >= 2);
4585 
4586 	/*
4587 	 * If we are detaching the second disk from a replacing vdev, then
4588 	 * check to see if we changed the original vdev's path to have "/old"
4589 	 * at the end in spa_vdev_attach().  If so, undo that change now.
4590 	 */
4591 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4592 	    vd->vdev_path != NULL) {
4593 		size_t len = strlen(vd->vdev_path);
4594 
4595 		for (int c = 0; c < pvd->vdev_children; c++) {
4596 			cvd = pvd->vdev_child[c];
4597 
4598 			if (cvd == vd || cvd->vdev_path == NULL)
4599 				continue;
4600 
4601 			if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4602 			    strcmp(cvd->vdev_path + len, "/old") == 0) {
4603 				spa_strfree(cvd->vdev_path);
4604 				cvd->vdev_path = spa_strdup(vd->vdev_path);
4605 				break;
4606 			}
4607 		}
4608 	}
4609 
4610 	/*
4611 	 * If we are detaching the original disk from a spare, then it implies
4612 	 * that the spare should become a real disk, and be removed from the
4613 	 * active spare list for the pool.
4614 	 */
4615 	if (pvd->vdev_ops == &vdev_spare_ops &&
4616 	    vd->vdev_id == 0 &&
4617 	    pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4618 		unspare = B_TRUE;
4619 
4620 	/*
4621 	 * Erase the disk labels so the disk can be used for other things.
4622 	 * This must be done after all other error cases are handled,
4623 	 * but before we disembowel vd (so we can still do I/O to it).
4624 	 * But if we can't do it, don't treat the error as fatal --
4625 	 * it may be that the unwritability of the disk is the reason
4626 	 * it's being detached!
4627 	 */
4628 	error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4629 
4630 	/*
4631 	 * Remove vd from its parent and compact the parent's children.
4632 	 */
4633 	vdev_remove_child(pvd, vd);
4634 	vdev_compact_children(pvd);
4635 
4636 	/*
4637 	 * Remember one of the remaining children so we can get tvd below.
4638 	 */
4639 	cvd = pvd->vdev_child[pvd->vdev_children - 1];
4640 
4641 	/*
4642 	 * If we need to remove the remaining child from the list of hot spares,
4643 	 * do it now, marking the vdev as no longer a spare in the process.
4644 	 * We must do this before vdev_remove_parent(), because that can
4645 	 * change the GUID if it creates a new toplevel GUID.  For a similar
4646 	 * reason, we must remove the spare now, in the same txg as the detach;
4647 	 * otherwise someone could attach a new sibling, change the GUID, and
4648 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4649 	 */
4650 	if (unspare) {
4651 		ASSERT(cvd->vdev_isspare);
4652 		spa_spare_remove(cvd);
4653 		unspare_guid = cvd->vdev_guid;
4654 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4655 		cvd->vdev_unspare = B_TRUE;
4656 	}
4657 
4658 	/*
4659 	 * If the parent mirror/replacing vdev only has one child,
4660 	 * the parent is no longer needed.  Remove it from the tree.
4661 	 */
4662 	if (pvd->vdev_children == 1) {
4663 		if (pvd->vdev_ops == &vdev_spare_ops)
4664 			cvd->vdev_unspare = B_FALSE;
4665 		vdev_remove_parent(cvd);
4666 		cvd->vdev_resilvering = B_FALSE;
4667 	}
4668 
4669 
4670 	/*
4671 	 * We don't set tvd until now because the parent we just removed
4672 	 * may have been the previous top-level vdev.
4673 	 */
4674 	tvd = cvd->vdev_top;
4675 	ASSERT(tvd->vdev_parent == rvd);
4676 
4677 	/*
4678 	 * Reevaluate the parent vdev state.
4679 	 */
4680 	vdev_propagate_state(cvd);
4681 
4682 	/*
4683 	 * If the 'autoexpand' property is set on the pool then automatically
4684 	 * try to expand the size of the pool. For example if the device we
4685 	 * just detached was smaller than the others, it may be possible to
4686 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4687 	 * first so that we can obtain the updated sizes of the leaf vdevs.
4688 	 */
4689 	if (spa->spa_autoexpand) {
4690 		vdev_reopen(tvd);
4691 		vdev_expand(tvd, txg);
4692 	}
4693 
4694 	vdev_config_dirty(tvd);
4695 
4696 	/*
4697 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4698 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
4699 	 * But first make sure we're not on any *other* txg's DTL list, to
4700 	 * prevent vd from being accessed after it's freed.
4701 	 */
4702 	vdpath = spa_strdup(vd->vdev_path);
4703 	for (int t = 0; t < TXG_SIZE; t++)
4704 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4705 	vd->vdev_detached = B_TRUE;
4706 	vdev_dirty(tvd, VDD_DTL, vd, txg);
4707 
4708 	spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4709 
4710 	/* hang on to the spa before we release the lock */
4711 	spa_open_ref(spa, FTAG);
4712 
4713 	error = spa_vdev_exit(spa, vd, txg, 0);
4714 
4715 	spa_history_log_internal(spa, "detach", NULL,
4716 	    "vdev=%s", vdpath);
4717 	spa_strfree(vdpath);
4718 
4719 	/*
4720 	 * If this was the removal of the original device in a hot spare vdev,
4721 	 * then we want to go through and remove the device from the hot spare
4722 	 * list of every other pool.
4723 	 */
4724 	if (unspare) {
4725 		spa_t *altspa = NULL;
4726 
4727 		mutex_enter(&spa_namespace_lock);
4728 		while ((altspa = spa_next(altspa)) != NULL) {
4729 			if (altspa->spa_state != POOL_STATE_ACTIVE ||
4730 			    altspa == spa)
4731 				continue;
4732 
4733 			spa_open_ref(altspa, FTAG);
4734 			mutex_exit(&spa_namespace_lock);
4735 			(void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4736 			mutex_enter(&spa_namespace_lock);
4737 			spa_close(altspa, FTAG);
4738 		}
4739 		mutex_exit(&spa_namespace_lock);
4740 
4741 		/* search the rest of the vdevs for spares to remove */
4742 		spa_vdev_resilver_done(spa);
4743 	}
4744 
4745 	/* all done with the spa; OK to release */
4746 	mutex_enter(&spa_namespace_lock);
4747 	spa_close(spa, FTAG);
4748 	mutex_exit(&spa_namespace_lock);
4749 
4750 	return (error);
4751 }
4752 
4753 /*
4754  * Split a set of devices from their mirrors, and create a new pool from them.
4755  */
4756 int
4757 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4758     nvlist_t *props, boolean_t exp)
4759 {
4760 	int error = 0;
4761 	uint64_t txg, *glist;
4762 	spa_t *newspa;
4763 	uint_t c, children, lastlog;
4764 	nvlist_t **child, *nvl, *tmp;
4765 	dmu_tx_t *tx;
4766 	char *altroot = NULL;
4767 	vdev_t *rvd, **vml = NULL;			/* vdev modify list */
4768 	boolean_t activate_slog;
4769 
4770 	ASSERT(spa_writeable(spa));
4771 
4772 	txg = spa_vdev_enter(spa);
4773 
4774 	/* clear the log and flush everything up to now */
4775 	activate_slog = spa_passivate_log(spa);
4776 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4777 	error = spa_offline_log(spa);
4778 	txg = spa_vdev_config_enter(spa);
4779 
4780 	if (activate_slog)
4781 		spa_activate_log(spa);
4782 
4783 	if (error != 0)
4784 		return (spa_vdev_exit(spa, NULL, txg, error));
4785 
4786 	/* check new spa name before going any further */
4787 	if (spa_lookup(newname) != NULL)
4788 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4789 
4790 	/*
4791 	 * scan through all the children to ensure they're all mirrors
4792 	 */
4793 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4794 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4795 	    &children) != 0)
4796 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4797 
4798 	/* first, check to ensure we've got the right child count */
4799 	rvd = spa->spa_root_vdev;
4800 	lastlog = 0;
4801 	for (c = 0; c < rvd->vdev_children; c++) {
4802 		vdev_t *vd = rvd->vdev_child[c];
4803 
4804 		/* don't count the holes & logs as children */
4805 		if (vd->vdev_islog || vd->vdev_ishole) {
4806 			if (lastlog == 0)
4807 				lastlog = c;
4808 			continue;
4809 		}
4810 
4811 		lastlog = 0;
4812 	}
4813 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4814 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4815 
4816 	/* next, ensure no spare or cache devices are part of the split */
4817 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4818 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4819 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4820 
4821 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4822 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4823 
4824 	/* then, loop over each vdev and validate it */
4825 	for (c = 0; c < children; c++) {
4826 		uint64_t is_hole = 0;
4827 
4828 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4829 		    &is_hole);
4830 
4831 		if (is_hole != 0) {
4832 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4833 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4834 				continue;
4835 			} else {
4836 				error = EINVAL;
4837 				break;
4838 			}
4839 		}
4840 
4841 		/* which disk is going to be split? */
4842 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4843 		    &glist[c]) != 0) {
4844 			error = EINVAL;
4845 			break;
4846 		}
4847 
4848 		/* look it up in the spa */
4849 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4850 		if (vml[c] == NULL) {
4851 			error = ENODEV;
4852 			break;
4853 		}
4854 
4855 		/* make sure there's nothing stopping the split */
4856 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4857 		    vml[c]->vdev_islog ||
4858 		    vml[c]->vdev_ishole ||
4859 		    vml[c]->vdev_isspare ||
4860 		    vml[c]->vdev_isl2cache ||
4861 		    !vdev_writeable(vml[c]) ||
4862 		    vml[c]->vdev_children != 0 ||
4863 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4864 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4865 			error = EINVAL;
4866 			break;
4867 		}
4868 
4869 		if (vdev_dtl_required(vml[c])) {
4870 			error = EBUSY;
4871 			break;
4872 		}
4873 
4874 		/* we need certain info from the top level */
4875 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4876 		    vml[c]->vdev_top->vdev_ms_array) == 0);
4877 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4878 		    vml[c]->vdev_top->vdev_ms_shift) == 0);
4879 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4880 		    vml[c]->vdev_top->vdev_asize) == 0);
4881 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4882 		    vml[c]->vdev_top->vdev_ashift) == 0);
4883 	}
4884 
4885 	if (error != 0) {
4886 		kmem_free(vml, children * sizeof (vdev_t *));
4887 		kmem_free(glist, children * sizeof (uint64_t));
4888 		return (spa_vdev_exit(spa, NULL, txg, error));
4889 	}
4890 
4891 	/* stop writers from using the disks */
4892 	for (c = 0; c < children; c++) {
4893 		if (vml[c] != NULL)
4894 			vml[c]->vdev_offline = B_TRUE;
4895 	}
4896 	vdev_reopen(spa->spa_root_vdev);
4897 
4898 	/*
4899 	 * Temporarily record the splitting vdevs in the spa config.  This
4900 	 * will disappear once the config is regenerated.
4901 	 */
4902 	VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4903 	VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4904 	    glist, children) == 0);
4905 	kmem_free(glist, children * sizeof (uint64_t));
4906 
4907 	mutex_enter(&spa->spa_props_lock);
4908 	VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4909 	    nvl) == 0);
4910 	mutex_exit(&spa->spa_props_lock);
4911 	spa->spa_config_splitting = nvl;
4912 	vdev_config_dirty(spa->spa_root_vdev);
4913 
4914 	/* configure and create the new pool */
4915 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4916 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4917 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4918 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4919 	    spa_version(spa)) == 0);
4920 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4921 	    spa->spa_config_txg) == 0);
4922 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4923 	    spa_generate_guid(NULL)) == 0);
4924 	(void) nvlist_lookup_string(props,
4925 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4926 
4927 	/* add the new pool to the namespace */
4928 	newspa = spa_add(newname, config, altroot);
4929 	newspa->spa_config_txg = spa->spa_config_txg;
4930 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
4931 
4932 	/* release the spa config lock, retaining the namespace lock */
4933 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4934 
4935 	if (zio_injection_enabled)
4936 		zio_handle_panic_injection(spa, FTAG, 1);
4937 
4938 	spa_activate(newspa, spa_mode_global);
4939 	spa_async_suspend(newspa);
4940 
4941 	/* create the new pool from the disks of the original pool */
4942 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4943 	if (error)
4944 		goto out;
4945 
4946 	/* if that worked, generate a real config for the new pool */
4947 	if (newspa->spa_root_vdev != NULL) {
4948 		VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4949 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
4950 		VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4951 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4952 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4953 		    B_TRUE));
4954 	}
4955 
4956 	/* set the props */
4957 	if (props != NULL) {
4958 		spa_configfile_set(newspa, props, B_FALSE);
4959 		error = spa_prop_set(newspa, props);
4960 		if (error)
4961 			goto out;
4962 	}
4963 
4964 	/* flush everything */
4965 	txg = spa_vdev_config_enter(newspa);
4966 	vdev_config_dirty(newspa->spa_root_vdev);
4967 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4968 
4969 	if (zio_injection_enabled)
4970 		zio_handle_panic_injection(spa, FTAG, 2);
4971 
4972 	spa_async_resume(newspa);
4973 
4974 	/* finally, update the original pool's config */
4975 	txg = spa_vdev_config_enter(spa);
4976 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4977 	error = dmu_tx_assign(tx, TXG_WAIT);
4978 	if (error != 0)
4979 		dmu_tx_abort(tx);
4980 	for (c = 0; c < children; c++) {
4981 		if (vml[c] != NULL) {
4982 			vdev_split(vml[c]);
4983 			if (error == 0)
4984 				spa_history_log_internal(spa, "detach", tx,
4985 				    "vdev=%s", vml[c]->vdev_path);
4986 			vdev_free(vml[c]);
4987 		}
4988 	}
4989 	vdev_config_dirty(spa->spa_root_vdev);
4990 	spa->spa_config_splitting = NULL;
4991 	nvlist_free(nvl);
4992 	if (error == 0)
4993 		dmu_tx_commit(tx);
4994 	(void) spa_vdev_exit(spa, NULL, txg, 0);
4995 
4996 	if (zio_injection_enabled)
4997 		zio_handle_panic_injection(spa, FTAG, 3);
4998 
4999 	/* split is complete; log a history record */
5000 	spa_history_log_internal(newspa, "split", NULL,
5001 	    "from pool %s", spa_name(spa));
5002 
5003 	kmem_free(vml, children * sizeof (vdev_t *));
5004 
5005 	/* if we're not going to mount the filesystems in userland, export */
5006 	if (exp)
5007 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5008 		    B_FALSE, B_FALSE);
5009 
5010 	return (error);
5011 
5012 out:
5013 	spa_unload(newspa);
5014 	spa_deactivate(newspa);
5015 	spa_remove(newspa);
5016 
5017 	txg = spa_vdev_config_enter(spa);
5018 
5019 	/* re-online all offlined disks */
5020 	for (c = 0; c < children; c++) {
5021 		if (vml[c] != NULL)
5022 			vml[c]->vdev_offline = B_FALSE;
5023 	}
5024 	vdev_reopen(spa->spa_root_vdev);
5025 
5026 	nvlist_free(spa->spa_config_splitting);
5027 	spa->spa_config_splitting = NULL;
5028 	(void) spa_vdev_exit(spa, NULL, txg, error);
5029 
5030 	kmem_free(vml, children * sizeof (vdev_t *));
5031 	return (error);
5032 }
5033 
5034 static nvlist_t *
5035 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5036 {
5037 	for (int i = 0; i < count; i++) {
5038 		uint64_t guid;
5039 
5040 		VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5041 		    &guid) == 0);
5042 
5043 		if (guid == target_guid)
5044 			return (nvpp[i]);
5045 	}
5046 
5047 	return (NULL);
5048 }
5049 
5050 static void
5051 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5052 	nvlist_t *dev_to_remove)
5053 {
5054 	nvlist_t **newdev = NULL;
5055 
5056 	if (count > 1)
5057 		newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5058 
5059 	for (int i = 0, j = 0; i < count; i++) {
5060 		if (dev[i] == dev_to_remove)
5061 			continue;
5062 		VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5063 	}
5064 
5065 	VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5066 	VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5067 
5068 	for (int i = 0; i < count - 1; i++)
5069 		nvlist_free(newdev[i]);
5070 
5071 	if (count > 1)
5072 		kmem_free(newdev, (count - 1) * sizeof (void *));
5073 }
5074 
5075 /*
5076  * Evacuate the device.
5077  */
5078 static int
5079 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5080 {
5081 	uint64_t txg;
5082 	int error = 0;
5083 
5084 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5085 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5086 	ASSERT(vd == vd->vdev_top);
5087 
5088 	/*
5089 	 * Evacuate the device.  We don't hold the config lock as writer
5090 	 * since we need to do I/O but we do keep the
5091 	 * spa_namespace_lock held.  Once this completes the device
5092 	 * should no longer have any blocks allocated on it.
5093 	 */
5094 	if (vd->vdev_islog) {
5095 		if (vd->vdev_stat.vs_alloc != 0)
5096 			error = spa_offline_log(spa);
5097 	} else {
5098 		error = ENOTSUP;
5099 	}
5100 
5101 	if (error)
5102 		return (error);
5103 
5104 	/*
5105 	 * The evacuation succeeded.  Remove any remaining MOS metadata
5106 	 * associated with this vdev, and wait for these changes to sync.
5107 	 */
5108 	ASSERT0(vd->vdev_stat.vs_alloc);
5109 	txg = spa_vdev_config_enter(spa);
5110 	vd->vdev_removing = B_TRUE;
5111 	vdev_dirty(vd, 0, NULL, txg);
5112 	vdev_config_dirty(vd);
5113 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5114 
5115 	return (0);
5116 }
5117 
5118 /*
5119  * Complete the removal by cleaning up the namespace.
5120  */
5121 static void
5122 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5123 {
5124 	vdev_t *rvd = spa->spa_root_vdev;
5125 	uint64_t id = vd->vdev_id;
5126 	boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5127 
5128 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5129 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5130 	ASSERT(vd == vd->vdev_top);
5131 
5132 	/*
5133 	 * Only remove any devices which are empty.
5134 	 */
5135 	if (vd->vdev_stat.vs_alloc != 0)
5136 		return;
5137 
5138 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5139 
5140 	if (list_link_active(&vd->vdev_state_dirty_node))
5141 		vdev_state_clean(vd);
5142 	if (list_link_active(&vd->vdev_config_dirty_node))
5143 		vdev_config_clean(vd);
5144 
5145 	vdev_free(vd);
5146 
5147 	if (last_vdev) {
5148 		vdev_compact_children(rvd);
5149 	} else {
5150 		vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5151 		vdev_add_child(rvd, vd);
5152 	}
5153 	vdev_config_dirty(rvd);
5154 
5155 	/*
5156 	 * Reassess the health of our root vdev.
5157 	 */
5158 	vdev_reopen(rvd);
5159 }
5160 
5161 /*
5162  * Remove a device from the pool -
5163  *
5164  * Removing a device from the vdev namespace requires several steps
5165  * and can take a significant amount of time.  As a result we use
5166  * the spa_vdev_config_[enter/exit] functions which allow us to
5167  * grab and release the spa_config_lock while still holding the namespace
5168  * lock.  During each step the configuration is synced out.
5169  */
5170 
5171 /*
5172  * Remove a device from the pool.  Currently, this supports removing only hot
5173  * spares, slogs, and level 2 ARC devices.
5174  */
5175 int
5176 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5177 {
5178 	vdev_t *vd;
5179 	metaslab_group_t *mg;
5180 	nvlist_t **spares, **l2cache, *nv;
5181 	uint64_t txg = 0;
5182 	uint_t nspares, nl2cache;
5183 	int error = 0;
5184 	boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5185 
5186 	ASSERT(spa_writeable(spa));
5187 
5188 	if (!locked)
5189 		txg = spa_vdev_enter(spa);
5190 
5191 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5192 
5193 	if (spa->spa_spares.sav_vdevs != NULL &&
5194 	    nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5195 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5196 	    (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5197 		/*
5198 		 * Only remove the hot spare if it's not currently in use
5199 		 * in this pool.
5200 		 */
5201 		if (vd == NULL || unspare) {
5202 			spa_vdev_remove_aux(spa->spa_spares.sav_config,
5203 			    ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5204 			spa_load_spares(spa);
5205 			spa->spa_spares.sav_sync = B_TRUE;
5206 		} else {
5207 			error = EBUSY;
5208 		}
5209 	} else if (spa->spa_l2cache.sav_vdevs != NULL &&
5210 	    nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5211 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5212 	    (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5213 		/*
5214 		 * Cache devices can always be removed.
5215 		 */
5216 		spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5217 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5218 		spa_load_l2cache(spa);
5219 		spa->spa_l2cache.sav_sync = B_TRUE;
5220 	} else if (vd != NULL && vd->vdev_islog) {
5221 		ASSERT(!locked);
5222 		ASSERT(vd == vd->vdev_top);
5223 
5224 		/*
5225 		 * XXX - Once we have bp-rewrite this should
5226 		 * become the common case.
5227 		 */
5228 
5229 		mg = vd->vdev_mg;
5230 
5231 		/*
5232 		 * Stop allocating from this vdev.
5233 		 */
5234 		metaslab_group_passivate(mg);
5235 
5236 		/*
5237 		 * Wait for the youngest allocations and frees to sync,
5238 		 * and then wait for the deferral of those frees to finish.
5239 		 */
5240 		spa_vdev_config_exit(spa, NULL,
5241 		    txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5242 
5243 		/*
5244 		 * Attempt to evacuate the vdev.
5245 		 */
5246 		error = spa_vdev_remove_evacuate(spa, vd);
5247 
5248 		txg = spa_vdev_config_enter(spa);
5249 
5250 		/*
5251 		 * If we couldn't evacuate the vdev, unwind.
5252 		 */
5253 		if (error) {
5254 			metaslab_group_activate(mg);
5255 			return (spa_vdev_exit(spa, NULL, txg, error));
5256 		}
5257 
5258 		/*
5259 		 * Clean up the vdev namespace.
5260 		 */
5261 		spa_vdev_remove_from_namespace(spa, vd);
5262 
5263 	} else if (vd != NULL) {
5264 		/*
5265 		 * Normal vdevs cannot be removed (yet).
5266 		 */
5267 		error = ENOTSUP;
5268 	} else {
5269 		/*
5270 		 * There is no vdev of any kind with the specified guid.
5271 		 */
5272 		error = ENOENT;
5273 	}
5274 
5275 	if (!locked)
5276 		return (spa_vdev_exit(spa, NULL, txg, error));
5277 
5278 	return (error);
5279 }
5280 
5281 /*
5282  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5283  * current spared, so we can detach it.
5284  */
5285 static vdev_t *
5286 spa_vdev_resilver_done_hunt(vdev_t *vd)
5287 {
5288 	vdev_t *newvd, *oldvd;
5289 
5290 	for (int c = 0; c < vd->vdev_children; c++) {
5291 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5292 		if (oldvd != NULL)
5293 			return (oldvd);
5294 	}
5295 
5296 	/*
5297 	 * Check for a completed replacement.  We always consider the first
5298 	 * vdev in the list to be the oldest vdev, and the last one to be
5299 	 * the newest (see spa_vdev_attach() for how that works).  In
5300 	 * the case where the newest vdev is faulted, we will not automatically
5301 	 * remove it after a resilver completes.  This is OK as it will require
5302 	 * user intervention to determine which disk the admin wishes to keep.
5303 	 */
5304 	if (vd->vdev_ops == &vdev_replacing_ops) {
5305 		ASSERT(vd->vdev_children > 1);
5306 
5307 		newvd = vd->vdev_child[vd->vdev_children - 1];
5308 		oldvd = vd->vdev_child[0];
5309 
5310 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5311 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5312 		    !vdev_dtl_required(oldvd))
5313 			return (oldvd);
5314 	}
5315 
5316 	/*
5317 	 * Check for a completed resilver with the 'unspare' flag set.
5318 	 */
5319 	if (vd->vdev_ops == &vdev_spare_ops) {
5320 		vdev_t *first = vd->vdev_child[0];
5321 		vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5322 
5323 		if (last->vdev_unspare) {
5324 			oldvd = first;
5325 			newvd = last;
5326 		} else if (first->vdev_unspare) {
5327 			oldvd = last;
5328 			newvd = first;
5329 		} else {
5330 			oldvd = NULL;
5331 		}
5332 
5333 		if (oldvd != NULL &&
5334 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
5335 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5336 		    !vdev_dtl_required(oldvd))
5337 			return (oldvd);
5338 
5339 		/*
5340 		 * If there are more than two spares attached to a disk,
5341 		 * and those spares are not required, then we want to
5342 		 * attempt to free them up now so that they can be used
5343 		 * by other pools.  Once we're back down to a single
5344 		 * disk+spare, we stop removing them.
5345 		 */
5346 		if (vd->vdev_children > 2) {
5347 			newvd = vd->vdev_child[1];
5348 
5349 			if (newvd->vdev_isspare && last->vdev_isspare &&
5350 			    vdev_dtl_empty(last, DTL_MISSING) &&
5351 			    vdev_dtl_empty(last, DTL_OUTAGE) &&
5352 			    !vdev_dtl_required(newvd))
5353 				return (newvd);
5354 		}
5355 	}
5356 
5357 	return (NULL);
5358 }
5359 
5360 static void
5361 spa_vdev_resilver_done(spa_t *spa)
5362 {
5363 	vdev_t *vd, *pvd, *ppvd;
5364 	uint64_t guid, sguid, pguid, ppguid;
5365 
5366 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5367 
5368 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5369 		pvd = vd->vdev_parent;
5370 		ppvd = pvd->vdev_parent;
5371 		guid = vd->vdev_guid;
5372 		pguid = pvd->vdev_guid;
5373 		ppguid = ppvd->vdev_guid;
5374 		sguid = 0;
5375 		/*
5376 		 * If we have just finished replacing a hot spared device, then
5377 		 * we need to detach the parent's first child (the original hot
5378 		 * spare) as well.
5379 		 */
5380 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5381 		    ppvd->vdev_children == 2) {
5382 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5383 			sguid = ppvd->vdev_child[1]->vdev_guid;
5384 		}
5385 		spa_config_exit(spa, SCL_ALL, FTAG);
5386 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5387 			return;
5388 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5389 			return;
5390 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5391 	}
5392 
5393 	spa_config_exit(spa, SCL_ALL, FTAG);
5394 }
5395 
5396 /*
5397  * Update the stored path or FRU for this vdev.
5398  */
5399 int
5400 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5401     boolean_t ispath)
5402 {
5403 	vdev_t *vd;
5404 	boolean_t sync = B_FALSE;
5405 
5406 	ASSERT(spa_writeable(spa));
5407 
5408 	spa_vdev_state_enter(spa, SCL_ALL);
5409 
5410 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5411 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
5412 
5413 	if (!vd->vdev_ops->vdev_op_leaf)
5414 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5415 
5416 	if (ispath) {
5417 		if (strcmp(value, vd->vdev_path) != 0) {
5418 			spa_strfree(vd->vdev_path);
5419 			vd->vdev_path = spa_strdup(value);
5420 			sync = B_TRUE;
5421 		}
5422 	} else {
5423 		if (vd->vdev_fru == NULL) {
5424 			vd->vdev_fru = spa_strdup(value);
5425 			sync = B_TRUE;
5426 		} else if (strcmp(value, vd->vdev_fru) != 0) {
5427 			spa_strfree(vd->vdev_fru);
5428 			vd->vdev_fru = spa_strdup(value);
5429 			sync = B_TRUE;
5430 		}
5431 	}
5432 
5433 	return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5434 }
5435 
5436 int
5437 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5438 {
5439 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5440 }
5441 
5442 int
5443 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5444 {
5445 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5446 }
5447 
5448 /*
5449  * ==========================================================================
5450  * SPA Scanning
5451  * ==========================================================================
5452  */
5453 
5454 int
5455 spa_scan_stop(spa_t *spa)
5456 {
5457 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5458 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
5459 		return (EBUSY);
5460 	return (dsl_scan_cancel(spa->spa_dsl_pool));
5461 }
5462 
5463 int
5464 spa_scan(spa_t *spa, pool_scan_func_t func)
5465 {
5466 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5467 
5468 	if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5469 		return (ENOTSUP);
5470 
5471 	/*
5472 	 * If a resilver was requested, but there is no DTL on a
5473 	 * writeable leaf device, we have nothing to do.
5474 	 */
5475 	if (func == POOL_SCAN_RESILVER &&
5476 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5477 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5478 		return (0);
5479 	}
5480 
5481 	return (dsl_scan(spa->spa_dsl_pool, func));
5482 }
5483 
5484 /*
5485  * ==========================================================================
5486  * SPA async task processing
5487  * ==========================================================================
5488  */
5489 
5490 static void
5491 spa_async_remove(spa_t *spa, vdev_t *vd)
5492 {
5493 	if (vd->vdev_remove_wanted) {
5494 		vd->vdev_remove_wanted = B_FALSE;
5495 		vd->vdev_delayed_close = B_FALSE;
5496 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5497 
5498 		/*
5499 		 * We want to clear the stats, but we don't want to do a full
5500 		 * vdev_clear() as that will cause us to throw away
5501 		 * degraded/faulted state as well as attempt to reopen the
5502 		 * device, all of which is a waste.
5503 		 */
5504 		vd->vdev_stat.vs_read_errors = 0;
5505 		vd->vdev_stat.vs_write_errors = 0;
5506 		vd->vdev_stat.vs_checksum_errors = 0;
5507 
5508 		vdev_state_dirty(vd->vdev_top);
5509 	}
5510 
5511 	for (int c = 0; c < vd->vdev_children; c++)
5512 		spa_async_remove(spa, vd->vdev_child[c]);
5513 }
5514 
5515 static void
5516 spa_async_probe(spa_t *spa, vdev_t *vd)
5517 {
5518 	if (vd->vdev_probe_wanted) {
5519 		vd->vdev_probe_wanted = B_FALSE;
5520 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
5521 	}
5522 
5523 	for (int c = 0; c < vd->vdev_children; c++)
5524 		spa_async_probe(spa, vd->vdev_child[c]);
5525 }
5526 
5527 static void
5528 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5529 {
5530 	sysevent_id_t eid;
5531 	nvlist_t *attr;
5532 	char *physpath;
5533 
5534 	if (!spa->spa_autoexpand)
5535 		return;
5536 
5537 	for (int c = 0; c < vd->vdev_children; c++) {
5538 		vdev_t *cvd = vd->vdev_child[c];
5539 		spa_async_autoexpand(spa, cvd);
5540 	}
5541 
5542 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5543 		return;
5544 
5545 	physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5546 	(void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5547 
5548 	VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5549 	VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5550 
5551 	(void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5552 	    ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5553 
5554 	nvlist_free(attr);
5555 	kmem_free(physpath, MAXPATHLEN);
5556 }
5557 
5558 static void
5559 spa_async_thread(spa_t *spa)
5560 {
5561 	int tasks;
5562 
5563 	ASSERT(spa->spa_sync_on);
5564 
5565 	mutex_enter(&spa->spa_async_lock);
5566 	tasks = spa->spa_async_tasks;
5567 	spa->spa_async_tasks = 0;
5568 	mutex_exit(&spa->spa_async_lock);
5569 
5570 	/*
5571 	 * See if the config needs to be updated.
5572 	 */
5573 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5574 		uint64_t old_space, new_space;
5575 
5576 		mutex_enter(&spa_namespace_lock);
5577 		old_space = metaslab_class_get_space(spa_normal_class(spa));
5578 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5579 		new_space = metaslab_class_get_space(spa_normal_class(spa));
5580 		mutex_exit(&spa_namespace_lock);
5581 
5582 		/*
5583 		 * If the pool grew as a result of the config update,
5584 		 * then log an internal history event.
5585 		 */
5586 		if (new_space != old_space) {
5587 			spa_history_log_internal(spa, "vdev online", NULL,
5588 			    "pool '%s' size: %llu(+%llu)",
5589 			    spa_name(spa), new_space, new_space - old_space);
5590 		}
5591 	}
5592 
5593 	/*
5594 	 * See if any devices need to be marked REMOVED.
5595 	 */
5596 	if (tasks & SPA_ASYNC_REMOVE) {
5597 		spa_vdev_state_enter(spa, SCL_NONE);
5598 		spa_async_remove(spa, spa->spa_root_vdev);
5599 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5600 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5601 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
5602 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5603 		(void) spa_vdev_state_exit(spa, NULL, 0);
5604 	}
5605 
5606 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5607 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5608 		spa_async_autoexpand(spa, spa->spa_root_vdev);
5609 		spa_config_exit(spa, SCL_CONFIG, FTAG);
5610 	}
5611 
5612 	/*
5613 	 * See if any devices need to be probed.
5614 	 */
5615 	if (tasks & SPA_ASYNC_PROBE) {
5616 		spa_vdev_state_enter(spa, SCL_NONE);
5617 		spa_async_probe(spa, spa->spa_root_vdev);
5618 		(void) spa_vdev_state_exit(spa, NULL, 0);
5619 	}
5620 
5621 	/*
5622 	 * If any devices are done replacing, detach them.
5623 	 */
5624 	if (tasks & SPA_ASYNC_RESILVER_DONE)
5625 		spa_vdev_resilver_done(spa);
5626 
5627 	/*
5628 	 * Kick off a resilver.
5629 	 */
5630 	if (tasks & SPA_ASYNC_RESILVER)
5631 		dsl_resilver_restart(spa->spa_dsl_pool, 0);
5632 
5633 	/*
5634 	 * Let the world know that we're done.
5635 	 */
5636 	mutex_enter(&spa->spa_async_lock);
5637 	spa->spa_async_thread = NULL;
5638 	cv_broadcast(&spa->spa_async_cv);
5639 	mutex_exit(&spa->spa_async_lock);
5640 	thread_exit();
5641 }
5642 
5643 void
5644 spa_async_suspend(spa_t *spa)
5645 {
5646 	mutex_enter(&spa->spa_async_lock);
5647 	spa->spa_async_suspended++;
5648 	while (spa->spa_async_thread != NULL)
5649 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5650 	mutex_exit(&spa->spa_async_lock);
5651 }
5652 
5653 void
5654 spa_async_resume(spa_t *spa)
5655 {
5656 	mutex_enter(&spa->spa_async_lock);
5657 	ASSERT(spa->spa_async_suspended != 0);
5658 	spa->spa_async_suspended--;
5659 	mutex_exit(&spa->spa_async_lock);
5660 }
5661 
5662 static void
5663 spa_async_dispatch(spa_t *spa)
5664 {
5665 	mutex_enter(&spa->spa_async_lock);
5666 	if (spa->spa_async_tasks && !spa->spa_async_suspended &&
5667 	    spa->spa_async_thread == NULL &&
5668 	    rootdir != NULL && !vn_is_readonly(rootdir))
5669 		spa->spa_async_thread = thread_create(NULL, 0,
5670 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5671 	mutex_exit(&spa->spa_async_lock);
5672 }
5673 
5674 void
5675 spa_async_request(spa_t *spa, int task)
5676 {
5677 	zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5678 	mutex_enter(&spa->spa_async_lock);
5679 	spa->spa_async_tasks |= task;
5680 	mutex_exit(&spa->spa_async_lock);
5681 }
5682 
5683 /*
5684  * ==========================================================================
5685  * SPA syncing routines
5686  * ==========================================================================
5687  */
5688 
5689 static int
5690 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5691 {
5692 	bpobj_t *bpo = arg;
5693 	bpobj_enqueue(bpo, bp, tx);
5694 	return (0);
5695 }
5696 
5697 static int
5698 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5699 {
5700 	zio_t *zio = arg;
5701 
5702 	zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5703 	    zio->io_flags));
5704 	return (0);
5705 }
5706 
5707 static void
5708 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5709 {
5710 	char *packed = NULL;
5711 	size_t bufsize;
5712 	size_t nvsize = 0;
5713 	dmu_buf_t *db;
5714 
5715 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5716 
5717 	/*
5718 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5719 	 * information.  This avoids the dbuf_will_dirty() path and
5720 	 * saves us a pre-read to get data we don't actually care about.
5721 	 */
5722 	bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5723 	packed = kmem_alloc(bufsize, KM_SLEEP);
5724 
5725 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5726 	    KM_SLEEP) == 0);
5727 	bzero(packed + nvsize, bufsize - nvsize);
5728 
5729 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5730 
5731 	kmem_free(packed, bufsize);
5732 
5733 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5734 	dmu_buf_will_dirty(db, tx);
5735 	*(uint64_t *)db->db_data = nvsize;
5736 	dmu_buf_rele(db, FTAG);
5737 }
5738 
5739 static void
5740 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5741     const char *config, const char *entry)
5742 {
5743 	nvlist_t *nvroot;
5744 	nvlist_t **list;
5745 	int i;
5746 
5747 	if (!sav->sav_sync)
5748 		return;
5749 
5750 	/*
5751 	 * Update the MOS nvlist describing the list of available devices.
5752 	 * spa_validate_aux() will have already made sure this nvlist is
5753 	 * valid and the vdevs are labeled appropriately.
5754 	 */
5755 	if (sav->sav_object == 0) {
5756 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5757 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5758 		    sizeof (uint64_t), tx);
5759 		VERIFY(zap_update(spa->spa_meta_objset,
5760 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5761 		    &sav->sav_object, tx) == 0);
5762 	}
5763 
5764 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5765 	if (sav->sav_count == 0) {
5766 		VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5767 	} else {
5768 		list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5769 		for (i = 0; i < sav->sav_count; i++)
5770 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5771 			    B_FALSE, VDEV_CONFIG_L2CACHE);
5772 		VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5773 		    sav->sav_count) == 0);
5774 		for (i = 0; i < sav->sav_count; i++)
5775 			nvlist_free(list[i]);
5776 		kmem_free(list, sav->sav_count * sizeof (void *));
5777 	}
5778 
5779 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5780 	nvlist_free(nvroot);
5781 
5782 	sav->sav_sync = B_FALSE;
5783 }
5784 
5785 static void
5786 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5787 {
5788 	nvlist_t *config;
5789 
5790 	if (list_is_empty(&spa->spa_config_dirty_list))
5791 		return;
5792 
5793 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5794 
5795 	config = spa_config_generate(spa, spa->spa_root_vdev,
5796 	    dmu_tx_get_txg(tx), B_FALSE);
5797 
5798 	/*
5799 	 * If we're upgrading the spa version then make sure that
5800 	 * the config object gets updated with the correct version.
5801 	 */
5802 	if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5803 		fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5804 		    spa->spa_uberblock.ub_version);
5805 
5806 	spa_config_exit(spa, SCL_STATE, FTAG);
5807 
5808 	if (spa->spa_config_syncing)
5809 		nvlist_free(spa->spa_config_syncing);
5810 	spa->spa_config_syncing = config;
5811 
5812 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5813 }
5814 
5815 static void
5816 spa_sync_version(void *arg1, void *arg2, dmu_tx_t *tx)
5817 {
5818 	spa_t *spa = arg1;
5819 	uint64_t version = *(uint64_t *)arg2;
5820 
5821 	/*
5822 	 * Setting the version is special cased when first creating the pool.
5823 	 */
5824 	ASSERT(tx->tx_txg != TXG_INITIAL);
5825 
5826 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5827 	ASSERT(version >= spa_version(spa));
5828 
5829 	spa->spa_uberblock.ub_version = version;
5830 	vdev_config_dirty(spa->spa_root_vdev);
5831 	spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5832 }
5833 
5834 /*
5835  * Set zpool properties.
5836  */
5837 static void
5838 spa_sync_props(void *arg1, void *arg2, dmu_tx_t *tx)
5839 {
5840 	spa_t *spa = arg1;
5841 	objset_t *mos = spa->spa_meta_objset;
5842 	nvlist_t *nvp = arg2;
5843 	nvpair_t *elem = NULL;
5844 
5845 	mutex_enter(&spa->spa_props_lock);
5846 
5847 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
5848 		uint64_t intval;
5849 		char *strval, *fname;
5850 		zpool_prop_t prop;
5851 		const char *propname;
5852 		zprop_type_t proptype;
5853 		zfeature_info_t *feature;
5854 
5855 		switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5856 		case ZPROP_INVAL:
5857 			/*
5858 			 * We checked this earlier in spa_prop_validate().
5859 			 */
5860 			ASSERT(zpool_prop_feature(nvpair_name(elem)));
5861 
5862 			fname = strchr(nvpair_name(elem), '@') + 1;
5863 			VERIFY3U(0, ==, zfeature_lookup_name(fname, &feature));
5864 
5865 			spa_feature_enable(spa, feature, tx);
5866 			spa_history_log_internal(spa, "set", tx,
5867 			    "%s=enabled", nvpair_name(elem));
5868 			break;
5869 
5870 		case ZPOOL_PROP_VERSION:
5871 			VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5872 			/*
5873 			 * The version is synced seperatly before other
5874 			 * properties and should be correct by now.
5875 			 */
5876 			ASSERT3U(spa_version(spa), >=, intval);
5877 			break;
5878 
5879 		case ZPOOL_PROP_ALTROOT:
5880 			/*
5881 			 * 'altroot' is a non-persistent property. It should
5882 			 * have been set temporarily at creation or import time.
5883 			 */
5884 			ASSERT(spa->spa_root != NULL);
5885 			break;
5886 
5887 		case ZPOOL_PROP_READONLY:
5888 		case ZPOOL_PROP_CACHEFILE:
5889 			/*
5890 			 * 'readonly' and 'cachefile' are also non-persisitent
5891 			 * properties.
5892 			 */
5893 			break;
5894 		case ZPOOL_PROP_COMMENT:
5895 			VERIFY(nvpair_value_string(elem, &strval) == 0);
5896 			if (spa->spa_comment != NULL)
5897 				spa_strfree(spa->spa_comment);
5898 			spa->spa_comment = spa_strdup(strval);
5899 			/*
5900 			 * We need to dirty the configuration on all the vdevs
5901 			 * so that their labels get updated.  It's unnecessary
5902 			 * to do this for pool creation since the vdev's
5903 			 * configuratoin has already been dirtied.
5904 			 */
5905 			if (tx->tx_txg != TXG_INITIAL)
5906 				vdev_config_dirty(spa->spa_root_vdev);
5907 			spa_history_log_internal(spa, "set", tx,
5908 			    "%s=%s", nvpair_name(elem), strval);
5909 			break;
5910 		default:
5911 			/*
5912 			 * Set pool property values in the poolprops mos object.
5913 			 */
5914 			if (spa->spa_pool_props_object == 0) {
5915 				spa->spa_pool_props_object =
5916 				    zap_create_link(mos, DMU_OT_POOL_PROPS,
5917 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5918 				    tx);
5919 			}
5920 
5921 			/* normalize the property name */
5922 			propname = zpool_prop_to_name(prop);
5923 			proptype = zpool_prop_get_type(prop);
5924 
5925 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
5926 				ASSERT(proptype == PROP_TYPE_STRING);
5927 				VERIFY(nvpair_value_string(elem, &strval) == 0);
5928 				VERIFY(zap_update(mos,
5929 				    spa->spa_pool_props_object, propname,
5930 				    1, strlen(strval) + 1, strval, tx) == 0);
5931 				spa_history_log_internal(spa, "set", tx,
5932 				    "%s=%s", nvpair_name(elem), strval);
5933 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5934 				VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5935 
5936 				if (proptype == PROP_TYPE_INDEX) {
5937 					const char *unused;
5938 					VERIFY(zpool_prop_index_to_string(
5939 					    prop, intval, &unused) == 0);
5940 				}
5941 				VERIFY(zap_update(mos,
5942 				    spa->spa_pool_props_object, propname,
5943 				    8, 1, &intval, tx) == 0);
5944 				spa_history_log_internal(spa, "set", tx,
5945 				    "%s=%lld", nvpair_name(elem), intval);
5946 			} else {
5947 				ASSERT(0); /* not allowed */
5948 			}
5949 
5950 			switch (prop) {
5951 			case ZPOOL_PROP_DELEGATION:
5952 				spa->spa_delegation = intval;
5953 				break;
5954 			case ZPOOL_PROP_BOOTFS:
5955 				spa->spa_bootfs = intval;
5956 				break;
5957 			case ZPOOL_PROP_FAILUREMODE:
5958 				spa->spa_failmode = intval;
5959 				break;
5960 			case ZPOOL_PROP_AUTOEXPAND:
5961 				spa->spa_autoexpand = intval;
5962 				if (tx->tx_txg != TXG_INITIAL)
5963 					spa_async_request(spa,
5964 					    SPA_ASYNC_AUTOEXPAND);
5965 				break;
5966 			case ZPOOL_PROP_DEDUPDITTO:
5967 				spa->spa_dedup_ditto = intval;
5968 				break;
5969 			default:
5970 				break;
5971 			}
5972 		}
5973 
5974 	}
5975 
5976 	mutex_exit(&spa->spa_props_lock);
5977 }
5978 
5979 /*
5980  * Perform one-time upgrade on-disk changes.  spa_version() does not
5981  * reflect the new version this txg, so there must be no changes this
5982  * txg to anything that the upgrade code depends on after it executes.
5983  * Therefore this must be called after dsl_pool_sync() does the sync
5984  * tasks.
5985  */
5986 static void
5987 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
5988 {
5989 	dsl_pool_t *dp = spa->spa_dsl_pool;
5990 
5991 	ASSERT(spa->spa_sync_pass == 1);
5992 
5993 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
5994 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
5995 		dsl_pool_create_origin(dp, tx);
5996 
5997 		/* Keeping the origin open increases spa_minref */
5998 		spa->spa_minref += 3;
5999 	}
6000 
6001 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6002 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6003 		dsl_pool_upgrade_clones(dp, tx);
6004 	}
6005 
6006 	if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6007 	    spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6008 		dsl_pool_upgrade_dir_clones(dp, tx);
6009 
6010 		/* Keeping the freedir open increases spa_minref */
6011 		spa->spa_minref += 3;
6012 	}
6013 
6014 	if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6015 	    spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6016 		spa_feature_create_zap_objects(spa, tx);
6017 	}
6018 }
6019 
6020 /*
6021  * Sync the specified transaction group.  New blocks may be dirtied as
6022  * part of the process, so we iterate until it converges.
6023  */
6024 void
6025 spa_sync(spa_t *spa, uint64_t txg)
6026 {
6027 	dsl_pool_t *dp = spa->spa_dsl_pool;
6028 	objset_t *mos = spa->spa_meta_objset;
6029 	bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
6030 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6031 	vdev_t *rvd = spa->spa_root_vdev;
6032 	vdev_t *vd;
6033 	dmu_tx_t *tx;
6034 	int error;
6035 
6036 	VERIFY(spa_writeable(spa));
6037 
6038 	/*
6039 	 * Lock out configuration changes.
6040 	 */
6041 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6042 
6043 	spa->spa_syncing_txg = txg;
6044 	spa->spa_sync_pass = 0;
6045 
6046 	/*
6047 	 * If there are any pending vdev state changes, convert them
6048 	 * into config changes that go out with this transaction group.
6049 	 */
6050 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6051 	while (list_head(&spa->spa_state_dirty_list) != NULL) {
6052 		/*
6053 		 * We need the write lock here because, for aux vdevs,
6054 		 * calling vdev_config_dirty() modifies sav_config.
6055 		 * This is ugly and will become unnecessary when we
6056 		 * eliminate the aux vdev wart by integrating all vdevs
6057 		 * into the root vdev tree.
6058 		 */
6059 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6060 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6061 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6062 			vdev_state_clean(vd);
6063 			vdev_config_dirty(vd);
6064 		}
6065 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6066 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6067 	}
6068 	spa_config_exit(spa, SCL_STATE, FTAG);
6069 
6070 	tx = dmu_tx_create_assigned(dp, txg);
6071 
6072 	spa->spa_sync_starttime = gethrtime();
6073 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6074 	    spa->spa_sync_starttime + spa->spa_deadman_synctime));
6075 
6076 	/*
6077 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6078 	 * set spa_deflate if we have no raid-z vdevs.
6079 	 */
6080 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6081 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6082 		int i;
6083 
6084 		for (i = 0; i < rvd->vdev_children; i++) {
6085 			vd = rvd->vdev_child[i];
6086 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6087 				break;
6088 		}
6089 		if (i == rvd->vdev_children) {
6090 			spa->spa_deflate = TRUE;
6091 			VERIFY(0 == zap_add(spa->spa_meta_objset,
6092 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6093 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6094 		}
6095 	}
6096 
6097 	/*
6098 	 * If anything has changed in this txg, or if someone is waiting
6099 	 * for this txg to sync (eg, spa_vdev_remove()), push the
6100 	 * deferred frees from the previous txg.  If not, leave them
6101 	 * alone so that we don't generate work on an otherwise idle
6102 	 * system.
6103 	 */
6104 	if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6105 	    !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6106 	    !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6107 	    ((dsl_scan_active(dp->dp_scan) ||
6108 	    txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6109 		zio_t *zio = zio_root(spa, NULL, NULL, 0);
6110 		VERIFY3U(bpobj_iterate(defer_bpo,
6111 		    spa_free_sync_cb, zio, tx), ==, 0);
6112 		VERIFY0(zio_wait(zio));
6113 	}
6114 
6115 	/*
6116 	 * Iterate to convergence.
6117 	 */
6118 	do {
6119 		int pass = ++spa->spa_sync_pass;
6120 
6121 		spa_sync_config_object(spa, tx);
6122 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6123 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6124 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6125 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6126 		spa_errlog_sync(spa, txg);
6127 		dsl_pool_sync(dp, txg);
6128 
6129 		if (pass < zfs_sync_pass_deferred_free) {
6130 			zio_t *zio = zio_root(spa, NULL, NULL, 0);
6131 			bplist_iterate(free_bpl, spa_free_sync_cb,
6132 			    zio, tx);
6133 			VERIFY(zio_wait(zio) == 0);
6134 		} else {
6135 			bplist_iterate(free_bpl, bpobj_enqueue_cb,
6136 			    defer_bpo, tx);
6137 		}
6138 
6139 		ddt_sync(spa, txg);
6140 		dsl_scan_sync(dp, tx);
6141 
6142 		while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6143 			vdev_sync(vd, txg);
6144 
6145 		if (pass == 1)
6146 			spa_sync_upgrades(spa, tx);
6147 
6148 	} while (dmu_objset_is_dirty(mos, txg));
6149 
6150 	/*
6151 	 * Rewrite the vdev configuration (which includes the uberblock)
6152 	 * to commit the transaction group.
6153 	 *
6154 	 * If there are no dirty vdevs, we sync the uberblock to a few
6155 	 * random top-level vdevs that are known to be visible in the
6156 	 * config cache (see spa_vdev_add() for a complete description).
6157 	 * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6158 	 */
6159 	for (;;) {
6160 		/*
6161 		 * We hold SCL_STATE to prevent vdev open/close/etc.
6162 		 * while we're attempting to write the vdev labels.
6163 		 */
6164 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6165 
6166 		if (list_is_empty(&spa->spa_config_dirty_list)) {
6167 			vdev_t *svd[SPA_DVAS_PER_BP];
6168 			int svdcount = 0;
6169 			int children = rvd->vdev_children;
6170 			int c0 = spa_get_random(children);
6171 
6172 			for (int c = 0; c < children; c++) {
6173 				vd = rvd->vdev_child[(c0 + c) % children];
6174 				if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6175 					continue;
6176 				svd[svdcount++] = vd;
6177 				if (svdcount == SPA_DVAS_PER_BP)
6178 					break;
6179 			}
6180 			error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6181 			if (error != 0)
6182 				error = vdev_config_sync(svd, svdcount, txg,
6183 				    B_TRUE);
6184 		} else {
6185 			error = vdev_config_sync(rvd->vdev_child,
6186 			    rvd->vdev_children, txg, B_FALSE);
6187 			if (error != 0)
6188 				error = vdev_config_sync(rvd->vdev_child,
6189 				    rvd->vdev_children, txg, B_TRUE);
6190 		}
6191 
6192 		if (error == 0)
6193 			spa->spa_last_synced_guid = rvd->vdev_guid;
6194 
6195 		spa_config_exit(spa, SCL_STATE, FTAG);
6196 
6197 		if (error == 0)
6198 			break;
6199 		zio_suspend(spa, NULL);
6200 		zio_resume_wait(spa);
6201 	}
6202 	dmu_tx_commit(tx);
6203 
6204 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6205 
6206 	/*
6207 	 * Clear the dirty config list.
6208 	 */
6209 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6210 		vdev_config_clean(vd);
6211 
6212 	/*
6213 	 * Now that the new config has synced transactionally,
6214 	 * let it become visible to the config cache.
6215 	 */
6216 	if (spa->spa_config_syncing != NULL) {
6217 		spa_config_set(spa, spa->spa_config_syncing);
6218 		spa->spa_config_txg = txg;
6219 		spa->spa_config_syncing = NULL;
6220 	}
6221 
6222 	spa->spa_ubsync = spa->spa_uberblock;
6223 
6224 	dsl_pool_sync_done(dp, txg);
6225 
6226 	/*
6227 	 * Update usable space statistics.
6228 	 */
6229 	while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6230 		vdev_sync_done(vd, txg);
6231 
6232 	spa_update_dspace(spa);
6233 
6234 	/*
6235 	 * It had better be the case that we didn't dirty anything
6236 	 * since vdev_config_sync().
6237 	 */
6238 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6239 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6240 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6241 
6242 	spa->spa_sync_pass = 0;
6243 
6244 	spa_config_exit(spa, SCL_CONFIG, FTAG);
6245 
6246 	spa_handle_ignored_writes(spa);
6247 
6248 	/*
6249 	 * If any async tasks have been requested, kick them off.
6250 	 */
6251 	spa_async_dispatch(spa);
6252 }
6253 
6254 /*
6255  * Sync all pools.  We don't want to hold the namespace lock across these
6256  * operations, so we take a reference on the spa_t and drop the lock during the
6257  * sync.
6258  */
6259 void
6260 spa_sync_allpools(void)
6261 {
6262 	spa_t *spa = NULL;
6263 	mutex_enter(&spa_namespace_lock);
6264 	while ((spa = spa_next(spa)) != NULL) {
6265 		if (spa_state(spa) != POOL_STATE_ACTIVE ||
6266 		    !spa_writeable(spa) || spa_suspended(spa))
6267 			continue;
6268 		spa_open_ref(spa, FTAG);
6269 		mutex_exit(&spa_namespace_lock);
6270 		txg_wait_synced(spa_get_dsl(spa), 0);
6271 		mutex_enter(&spa_namespace_lock);
6272 		spa_close(spa, FTAG);
6273 	}
6274 	mutex_exit(&spa_namespace_lock);
6275 }
6276 
6277 /*
6278  * ==========================================================================
6279  * Miscellaneous routines
6280  * ==========================================================================
6281  */
6282 
6283 /*
6284  * Remove all pools in the system.
6285  */
6286 void
6287 spa_evict_all(void)
6288 {
6289 	spa_t *spa;
6290 
6291 	/*
6292 	 * Remove all cached state.  All pools should be closed now,
6293 	 * so every spa in the AVL tree should be unreferenced.
6294 	 */
6295 	mutex_enter(&spa_namespace_lock);
6296 	while ((spa = spa_next(NULL)) != NULL) {
6297 		/*
6298 		 * Stop async tasks.  The async thread may need to detach
6299 		 * a device that's been replaced, which requires grabbing
6300 		 * spa_namespace_lock, so we must drop it here.
6301 		 */
6302 		spa_open_ref(spa, FTAG);
6303 		mutex_exit(&spa_namespace_lock);
6304 		spa_async_suspend(spa);
6305 		mutex_enter(&spa_namespace_lock);
6306 		spa_close(spa, FTAG);
6307 
6308 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6309 			spa_unload(spa);
6310 			spa_deactivate(spa);
6311 		}
6312 		spa_remove(spa);
6313 	}
6314 	mutex_exit(&spa_namespace_lock);
6315 }
6316 
6317 vdev_t *
6318 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6319 {
6320 	vdev_t *vd;
6321 	int i;
6322 
6323 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6324 		return (vd);
6325 
6326 	if (aux) {
6327 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6328 			vd = spa->spa_l2cache.sav_vdevs[i];
6329 			if (vd->vdev_guid == guid)
6330 				return (vd);
6331 		}
6332 
6333 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
6334 			vd = spa->spa_spares.sav_vdevs[i];
6335 			if (vd->vdev_guid == guid)
6336 				return (vd);
6337 		}
6338 	}
6339 
6340 	return (NULL);
6341 }
6342 
6343 void
6344 spa_upgrade(spa_t *spa, uint64_t version)
6345 {
6346 	ASSERT(spa_writeable(spa));
6347 
6348 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6349 
6350 	/*
6351 	 * This should only be called for a non-faulted pool, and since a
6352 	 * future version would result in an unopenable pool, this shouldn't be
6353 	 * possible.
6354 	 */
6355 	ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6356 	ASSERT(version >= spa->spa_uberblock.ub_version);
6357 
6358 	spa->spa_uberblock.ub_version = version;
6359 	vdev_config_dirty(spa->spa_root_vdev);
6360 
6361 	spa_config_exit(spa, SCL_ALL, FTAG);
6362 
6363 	txg_wait_synced(spa_get_dsl(spa), 0);
6364 }
6365 
6366 boolean_t
6367 spa_has_spare(spa_t *spa, uint64_t guid)
6368 {
6369 	int i;
6370 	uint64_t spareguid;
6371 	spa_aux_vdev_t *sav = &spa->spa_spares;
6372 
6373 	for (i = 0; i < sav->sav_count; i++)
6374 		if (sav->sav_vdevs[i]->vdev_guid == guid)
6375 			return (B_TRUE);
6376 
6377 	for (i = 0; i < sav->sav_npending; i++) {
6378 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6379 		    &spareguid) == 0 && spareguid == guid)
6380 			return (B_TRUE);
6381 	}
6382 
6383 	return (B_FALSE);
6384 }
6385 
6386 /*
6387  * Check if a pool has an active shared spare device.
6388  * Note: reference count of an active spare is 2, as a spare and as a replace
6389  */
6390 static boolean_t
6391 spa_has_active_shared_spare(spa_t *spa)
6392 {
6393 	int i, refcnt;
6394 	uint64_t pool;
6395 	spa_aux_vdev_t *sav = &spa->spa_spares;
6396 
6397 	for (i = 0; i < sav->sav_count; i++) {
6398 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6399 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6400 		    refcnt > 2)
6401 			return (B_TRUE);
6402 	}
6403 
6404 	return (B_FALSE);
6405 }
6406 
6407 /*
6408  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6409  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6410  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6411  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6412  * or zdb as real changes.
6413  */
6414 void
6415 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6416 {
6417 #ifdef _KERNEL
6418 	sysevent_t		*ev;
6419 	sysevent_attr_list_t	*attr = NULL;
6420 	sysevent_value_t	value;
6421 	sysevent_id_t		eid;
6422 
6423 	ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6424 	    SE_SLEEP);
6425 
6426 	value.value_type = SE_DATA_TYPE_STRING;
6427 	value.value.sv_string = spa_name(spa);
6428 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6429 		goto done;
6430 
6431 	value.value_type = SE_DATA_TYPE_UINT64;
6432 	value.value.sv_uint64 = spa_guid(spa);
6433 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6434 		goto done;
6435 
6436 	if (vd) {
6437 		value.value_type = SE_DATA_TYPE_UINT64;
6438 		value.value.sv_uint64 = vd->vdev_guid;
6439 		if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6440 		    SE_SLEEP) != 0)
6441 			goto done;
6442 
6443 		if (vd->vdev_path) {
6444 			value.value_type = SE_DATA_TYPE_STRING;
6445 			value.value.sv_string = vd->vdev_path;
6446 			if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6447 			    &value, SE_SLEEP) != 0)
6448 				goto done;
6449 		}
6450 	}
6451 
6452 	if (sysevent_attach_attributes(ev, attr) != 0)
6453 		goto done;
6454 	attr = NULL;
6455 
6456 	(void) log_sysevent(ev, SE_SLEEP, &eid);
6457 
6458 done:
6459 	if (attr)
6460 		sysevent_free_attr(attr);
6461 	sysevent_free(ev);
6462 #endif
6463 }
6464