xref: /titanic_41/usr/src/uts/common/fs/zfs/spa.c (revision 8878595fcb30298d8ee1db0aee6e69e4dc15b318)
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 (c) 2013 by Delphix. All rights reserved.
25  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
26  */
27 
28 /*
29  * SPA: Storage Pool Allocator
30  *
31  * This file contains all the routines used when modifying on-disk SPA state.
32  * This includes opening, importing, destroying, exporting a pool, and syncing a
33  * pool.
34  */
35 
36 #include <sys/zfs_context.h>
37 #include <sys/fm/fs/zfs.h>
38 #include <sys/spa_impl.h>
39 #include <sys/zio.h>
40 #include <sys/zio_checksum.h>
41 #include <sys/dmu.h>
42 #include <sys/dmu_tx.h>
43 #include <sys/zap.h>
44 #include <sys/zil.h>
45 #include <sys/ddt.h>
46 #include <sys/vdev_impl.h>
47 #include <sys/metaslab.h>
48 #include <sys/metaslab_impl.h>
49 #include <sys/uberblock_impl.h>
50 #include <sys/txg.h>
51 #include <sys/avl.h>
52 #include <sys/dmu_traverse.h>
53 #include <sys/dmu_objset.h>
54 #include <sys/unique.h>
55 #include <sys/dsl_pool.h>
56 #include <sys/dsl_dataset.h>
57 #include <sys/dsl_dir.h>
58 #include <sys/dsl_prop.h>
59 #include <sys/dsl_synctask.h>
60 #include <sys/fs/zfs.h>
61 #include <sys/arc.h>
62 #include <sys/callb.h>
63 #include <sys/systeminfo.h>
64 #include <sys/spa_boot.h>
65 #include <sys/zfs_ioctl.h>
66 #include <sys/dsl_scan.h>
67 #include <sys/zfeature.h>
68 #include <sys/dsl_destroy.h>
69 
70 #ifdef	_KERNEL
71 #include <sys/bootprops.h>
72 #include <sys/callb.h>
73 #include <sys/cpupart.h>
74 #include <sys/pool.h>
75 #include <sys/sysdc.h>
76 #include <sys/zone.h>
77 #endif	/* _KERNEL */
78 
79 #include "zfs_prop.h"
80 #include "zfs_comutil.h"
81 
82 /*
83  * The interval, in seconds, at which failed configuration cache file writes
84  * should be retried.
85  */
86 static int zfs_ccw_retry_interval = 300;
87 
88 typedef enum zti_modes {
89 	ZTI_MODE_FIXED,			/* value is # of threads (min 1) */
90 	ZTI_MODE_ONLINE_PERCENT,	/* value is % of online CPUs */
91 	ZTI_MODE_BATCH,			/* cpu-intensive; value is ignored */
92 	ZTI_MODE_NULL,			/* don't create a taskq */
93 	ZTI_NMODES
94 } zti_modes_t;
95 
96 #define	ZTI_P(n, q)	{ ZTI_MODE_FIXED, (n), (q) }
97 #define	ZTI_PCT(n)	{ ZTI_MODE_ONLINE_PERCENT, (n), 1 }
98 #define	ZTI_BATCH	{ ZTI_MODE_BATCH, 0, 1 }
99 #define	ZTI_NULL	{ ZTI_MODE_NULL, 0, 0 }
100 
101 #define	ZTI_N(n)	ZTI_P(n, 1)
102 #define	ZTI_ONE		ZTI_N(1)
103 
104 typedef struct zio_taskq_info {
105 	zti_modes_t zti_mode;
106 	uint_t zti_value;
107 	uint_t zti_count;
108 } zio_taskq_info_t;
109 
110 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
111 	"issue", "issue_high", "intr", "intr_high"
112 };
113 
114 /*
115  * This table defines the taskq settings for each ZFS I/O type. When
116  * initializing a pool, we use this table to create an appropriately sized
117  * taskq. Some operations are low volume and therefore have a small, static
118  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
119  * macros. Other operations process a large amount of data; the ZTI_BATCH
120  * macro causes us to create a taskq oriented for throughput. Some operations
121  * are so high frequency and short-lived that the taskq itself can become a a
122  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
123  * additional degree of parallelism specified by the number of threads per-
124  * taskq and the number of taskqs; when dispatching an event in this case, the
125  * particular taskq is chosen at random.
126  *
127  * The different taskq priorities are to handle the different contexts (issue
128  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
129  * need to be handled with minimum delay.
130  */
131 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
132 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
133 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* NULL */
134 	{ ZTI_N(8),	ZTI_NULL,	ZTI_BATCH,	ZTI_NULL }, /* READ */
135 	{ ZTI_BATCH,	ZTI_N(5),	ZTI_N(8),	ZTI_N(5) }, /* WRITE */
136 	{ ZTI_P(12, 8),	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FREE */
137 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* CLAIM */
138 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* IOCTL */
139 };
140 
141 static void spa_sync_version(void *arg, dmu_tx_t *tx);
142 static void spa_sync_props(void *arg, dmu_tx_t *tx);
143 static boolean_t spa_has_active_shared_spare(spa_t *spa);
144 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
145     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
146     char **ereport);
147 static void spa_vdev_resilver_done(spa_t *spa);
148 
149 uint_t		zio_taskq_batch_pct = 100;	/* 1 thread per cpu in pset */
150 id_t		zio_taskq_psrset_bind = PS_NONE;
151 boolean_t	zio_taskq_sysdc = B_TRUE;	/* use SDC scheduling class */
152 uint_t		zio_taskq_basedc = 80;		/* base duty cycle */
153 
154 boolean_t	spa_create_process = B_TRUE;	/* no process ==> no sysdc */
155 extern int	zfs_sync_pass_deferred_free;
156 
157 /*
158  * This (illegal) pool name is used when temporarily importing a spa_t in order
159  * to get the vdev stats associated with the imported devices.
160  */
161 #define	TRYIMPORT_NAME	"$import"
162 
163 /*
164  * ==========================================================================
165  * SPA properties routines
166  * ==========================================================================
167  */
168 
169 /*
170  * Add a (source=src, propname=propval) list to an nvlist.
171  */
172 static void
173 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
174     uint64_t intval, zprop_source_t src)
175 {
176 	const char *propname = zpool_prop_to_name(prop);
177 	nvlist_t *propval;
178 
179 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
180 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
181 
182 	if (strval != NULL)
183 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
184 	else
185 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
186 
187 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
188 	nvlist_free(propval);
189 }
190 
191 /*
192  * Get property values from the spa configuration.
193  */
194 static void
195 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
196 {
197 	vdev_t *rvd = spa->spa_root_vdev;
198 	dsl_pool_t *pool = spa->spa_dsl_pool;
199 	uint64_t size;
200 	uint64_t alloc;
201 	uint64_t space;
202 	uint64_t cap, version;
203 	zprop_source_t src = ZPROP_SRC_NONE;
204 	spa_config_dirent_t *dp;
205 
206 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
207 
208 	if (rvd != NULL) {
209 		alloc = metaslab_class_get_alloc(spa_normal_class(spa));
210 		size = metaslab_class_get_space(spa_normal_class(spa));
211 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
212 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
213 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
214 		spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
215 		    size - alloc, src);
216 
217 		space = 0;
218 		for (int c = 0; c < rvd->vdev_children; c++) {
219 			vdev_t *tvd = rvd->vdev_child[c];
220 			space += tvd->vdev_max_asize - tvd->vdev_asize;
221 		}
222 		spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
223 		    src);
224 
225 		spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
226 		    (spa_mode(spa) == FREAD), src);
227 
228 		cap = (size == 0) ? 0 : (alloc * 100 / size);
229 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
230 
231 		spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
232 		    ddt_get_pool_dedup_ratio(spa), src);
233 
234 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
235 		    rvd->vdev_state, src);
236 
237 		version = spa_version(spa);
238 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
239 			src = ZPROP_SRC_DEFAULT;
240 		else
241 			src = ZPROP_SRC_LOCAL;
242 		spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
243 	}
244 
245 	if (pool != NULL) {
246 		dsl_dir_t *freedir = pool->dp_free_dir;
247 
248 		/*
249 		 * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
250 		 * when opening pools before this version freedir will be NULL.
251 		 */
252 		if (freedir != NULL) {
253 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
254 			    freedir->dd_phys->dd_used_bytes, src);
255 		} else {
256 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
257 			    NULL, 0, src);
258 		}
259 	}
260 
261 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
262 
263 	if (spa->spa_comment != NULL) {
264 		spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
265 		    0, ZPROP_SRC_LOCAL);
266 	}
267 
268 	if (spa->spa_root != NULL)
269 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
270 		    0, ZPROP_SRC_LOCAL);
271 
272 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
273 		if (dp->scd_path == NULL) {
274 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
275 			    "none", 0, ZPROP_SRC_LOCAL);
276 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
277 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
278 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
279 		}
280 	}
281 }
282 
283 /*
284  * Get zpool property values.
285  */
286 int
287 spa_prop_get(spa_t *spa, nvlist_t **nvp)
288 {
289 	objset_t *mos = spa->spa_meta_objset;
290 	zap_cursor_t zc;
291 	zap_attribute_t za;
292 	int err;
293 
294 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
295 
296 	mutex_enter(&spa->spa_props_lock);
297 
298 	/*
299 	 * Get properties from the spa config.
300 	 */
301 	spa_prop_get_config(spa, nvp);
302 
303 	/* If no pool property object, no more prop to get. */
304 	if (mos == NULL || spa->spa_pool_props_object == 0) {
305 		mutex_exit(&spa->spa_props_lock);
306 		return (0);
307 	}
308 
309 	/*
310 	 * Get properties from the MOS pool property object.
311 	 */
312 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
313 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
314 	    zap_cursor_advance(&zc)) {
315 		uint64_t intval = 0;
316 		char *strval = NULL;
317 		zprop_source_t src = ZPROP_SRC_DEFAULT;
318 		zpool_prop_t prop;
319 
320 		if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
321 			continue;
322 
323 		switch (za.za_integer_length) {
324 		case 8:
325 			/* integer property */
326 			if (za.za_first_integer !=
327 			    zpool_prop_default_numeric(prop))
328 				src = ZPROP_SRC_LOCAL;
329 
330 			if (prop == ZPOOL_PROP_BOOTFS) {
331 				dsl_pool_t *dp;
332 				dsl_dataset_t *ds = NULL;
333 
334 				dp = spa_get_dsl(spa);
335 				dsl_pool_config_enter(dp, FTAG);
336 				if (err = dsl_dataset_hold_obj(dp,
337 				    za.za_first_integer, FTAG, &ds)) {
338 					dsl_pool_config_exit(dp, FTAG);
339 					break;
340 				}
341 
342 				strval = kmem_alloc(
343 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
344 				    KM_SLEEP);
345 				dsl_dataset_name(ds, strval);
346 				dsl_dataset_rele(ds, FTAG);
347 				dsl_pool_config_exit(dp, FTAG);
348 			} else {
349 				strval = NULL;
350 				intval = za.za_first_integer;
351 			}
352 
353 			spa_prop_add_list(*nvp, prop, strval, intval, src);
354 
355 			if (strval != NULL)
356 				kmem_free(strval,
357 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
358 
359 			break;
360 
361 		case 1:
362 			/* string property */
363 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
364 			err = zap_lookup(mos, spa->spa_pool_props_object,
365 			    za.za_name, 1, za.za_num_integers, strval);
366 			if (err) {
367 				kmem_free(strval, za.za_num_integers);
368 				break;
369 			}
370 			spa_prop_add_list(*nvp, prop, strval, 0, src);
371 			kmem_free(strval, za.za_num_integers);
372 			break;
373 
374 		default:
375 			break;
376 		}
377 	}
378 	zap_cursor_fini(&zc);
379 	mutex_exit(&spa->spa_props_lock);
380 out:
381 	if (err && err != ENOENT) {
382 		nvlist_free(*nvp);
383 		*nvp = NULL;
384 		return (err);
385 	}
386 
387 	return (0);
388 }
389 
390 /*
391  * Validate the given pool properties nvlist and modify the list
392  * for the property values to be set.
393  */
394 static int
395 spa_prop_validate(spa_t *spa, nvlist_t *props)
396 {
397 	nvpair_t *elem;
398 	int error = 0, reset_bootfs = 0;
399 	uint64_t objnum = 0;
400 	boolean_t has_feature = B_FALSE;
401 
402 	elem = NULL;
403 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
404 		uint64_t intval;
405 		char *strval, *slash, *check, *fname;
406 		const char *propname = nvpair_name(elem);
407 		zpool_prop_t prop = zpool_name_to_prop(propname);
408 
409 		switch (prop) {
410 		case ZPROP_INVAL:
411 			if (!zpool_prop_feature(propname)) {
412 				error = SET_ERROR(EINVAL);
413 				break;
414 			}
415 
416 			/*
417 			 * Sanitize the input.
418 			 */
419 			if (nvpair_type(elem) != DATA_TYPE_UINT64) {
420 				error = SET_ERROR(EINVAL);
421 				break;
422 			}
423 
424 			if (nvpair_value_uint64(elem, &intval) != 0) {
425 				error = SET_ERROR(EINVAL);
426 				break;
427 			}
428 
429 			if (intval != 0) {
430 				error = SET_ERROR(EINVAL);
431 				break;
432 			}
433 
434 			fname = strchr(propname, '@') + 1;
435 			if (zfeature_lookup_name(fname, NULL) != 0) {
436 				error = SET_ERROR(EINVAL);
437 				break;
438 			}
439 
440 			has_feature = B_TRUE;
441 			break;
442 
443 		case ZPOOL_PROP_VERSION:
444 			error = nvpair_value_uint64(elem, &intval);
445 			if (!error &&
446 			    (intval < spa_version(spa) ||
447 			    intval > SPA_VERSION_BEFORE_FEATURES ||
448 			    has_feature))
449 				error = SET_ERROR(EINVAL);
450 			break;
451 
452 		case ZPOOL_PROP_DELEGATION:
453 		case ZPOOL_PROP_AUTOREPLACE:
454 		case ZPOOL_PROP_LISTSNAPS:
455 		case ZPOOL_PROP_AUTOEXPAND:
456 			error = nvpair_value_uint64(elem, &intval);
457 			if (!error && intval > 1)
458 				error = SET_ERROR(EINVAL);
459 			break;
460 
461 		case ZPOOL_PROP_BOOTFS:
462 			/*
463 			 * If the pool version is less than SPA_VERSION_BOOTFS,
464 			 * or the pool is still being created (version == 0),
465 			 * the bootfs property cannot be set.
466 			 */
467 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
468 				error = SET_ERROR(ENOTSUP);
469 				break;
470 			}
471 
472 			/*
473 			 * Make sure the vdev config is bootable
474 			 */
475 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
476 				error = SET_ERROR(ENOTSUP);
477 				break;
478 			}
479 
480 			reset_bootfs = 1;
481 
482 			error = nvpair_value_string(elem, &strval);
483 
484 			if (!error) {
485 				objset_t *os;
486 				uint64_t compress;
487 
488 				if (strval == NULL || strval[0] == '\0') {
489 					objnum = zpool_prop_default_numeric(
490 					    ZPOOL_PROP_BOOTFS);
491 					break;
492 				}
493 
494 				if (error = dmu_objset_hold(strval, FTAG, &os))
495 					break;
496 
497 				/* Must be ZPL and not gzip compressed. */
498 
499 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
500 					error = SET_ERROR(ENOTSUP);
501 				} else if ((error =
502 				    dsl_prop_get_int_ds(dmu_objset_ds(os),
503 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
504 				    &compress)) == 0 &&
505 				    !BOOTFS_COMPRESS_VALID(compress)) {
506 					error = SET_ERROR(ENOTSUP);
507 				} else {
508 					objnum = dmu_objset_id(os);
509 				}
510 				dmu_objset_rele(os, FTAG);
511 			}
512 			break;
513 
514 		case ZPOOL_PROP_FAILUREMODE:
515 			error = nvpair_value_uint64(elem, &intval);
516 			if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
517 			    intval > ZIO_FAILURE_MODE_PANIC))
518 				error = SET_ERROR(EINVAL);
519 
520 			/*
521 			 * This is a special case which only occurs when
522 			 * the pool has completely failed. This allows
523 			 * the user to change the in-core failmode property
524 			 * without syncing it out to disk (I/Os might
525 			 * currently be blocked). We do this by returning
526 			 * EIO to the caller (spa_prop_set) to trick it
527 			 * into thinking we encountered a property validation
528 			 * error.
529 			 */
530 			if (!error && spa_suspended(spa)) {
531 				spa->spa_failmode = intval;
532 				error = SET_ERROR(EIO);
533 			}
534 			break;
535 
536 		case ZPOOL_PROP_CACHEFILE:
537 			if ((error = nvpair_value_string(elem, &strval)) != 0)
538 				break;
539 
540 			if (strval[0] == '\0')
541 				break;
542 
543 			if (strcmp(strval, "none") == 0)
544 				break;
545 
546 			if (strval[0] != '/') {
547 				error = SET_ERROR(EINVAL);
548 				break;
549 			}
550 
551 			slash = strrchr(strval, '/');
552 			ASSERT(slash != NULL);
553 
554 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
555 			    strcmp(slash, "/..") == 0)
556 				error = SET_ERROR(EINVAL);
557 			break;
558 
559 		case ZPOOL_PROP_COMMENT:
560 			if ((error = nvpair_value_string(elem, &strval)) != 0)
561 				break;
562 			for (check = strval; *check != '\0'; check++) {
563 				/*
564 				 * The kernel doesn't have an easy isprint()
565 				 * check.  For this kernel check, we merely
566 				 * check ASCII apart from DEL.  Fix this if
567 				 * there is an easy-to-use kernel isprint().
568 				 */
569 				if (*check >= 0x7f) {
570 					error = SET_ERROR(EINVAL);
571 					break;
572 				}
573 				check++;
574 			}
575 			if (strlen(strval) > ZPROP_MAX_COMMENT)
576 				error = E2BIG;
577 			break;
578 
579 		case ZPOOL_PROP_DEDUPDITTO:
580 			if (spa_version(spa) < SPA_VERSION_DEDUP)
581 				error = SET_ERROR(ENOTSUP);
582 			else
583 				error = nvpair_value_uint64(elem, &intval);
584 			if (error == 0 &&
585 			    intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
586 				error = SET_ERROR(EINVAL);
587 			break;
588 		}
589 
590 		if (error)
591 			break;
592 	}
593 
594 	if (!error && reset_bootfs) {
595 		error = nvlist_remove(props,
596 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
597 
598 		if (!error) {
599 			error = nvlist_add_uint64(props,
600 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
601 		}
602 	}
603 
604 	return (error);
605 }
606 
607 void
608 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
609 {
610 	char *cachefile;
611 	spa_config_dirent_t *dp;
612 
613 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
614 	    &cachefile) != 0)
615 		return;
616 
617 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
618 	    KM_SLEEP);
619 
620 	if (cachefile[0] == '\0')
621 		dp->scd_path = spa_strdup(spa_config_path);
622 	else if (strcmp(cachefile, "none") == 0)
623 		dp->scd_path = NULL;
624 	else
625 		dp->scd_path = spa_strdup(cachefile);
626 
627 	list_insert_head(&spa->spa_config_list, dp);
628 	if (need_sync)
629 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
630 }
631 
632 int
633 spa_prop_set(spa_t *spa, nvlist_t *nvp)
634 {
635 	int error;
636 	nvpair_t *elem = NULL;
637 	boolean_t need_sync = B_FALSE;
638 
639 	if ((error = spa_prop_validate(spa, nvp)) != 0)
640 		return (error);
641 
642 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
643 		zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
644 
645 		if (prop == ZPOOL_PROP_CACHEFILE ||
646 		    prop == ZPOOL_PROP_ALTROOT ||
647 		    prop == ZPOOL_PROP_READONLY)
648 			continue;
649 
650 		if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
651 			uint64_t ver;
652 
653 			if (prop == ZPOOL_PROP_VERSION) {
654 				VERIFY(nvpair_value_uint64(elem, &ver) == 0);
655 			} else {
656 				ASSERT(zpool_prop_feature(nvpair_name(elem)));
657 				ver = SPA_VERSION_FEATURES;
658 				need_sync = B_TRUE;
659 			}
660 
661 			/* Save time if the version is already set. */
662 			if (ver == spa_version(spa))
663 				continue;
664 
665 			/*
666 			 * In addition to the pool directory object, we might
667 			 * create the pool properties object, the features for
668 			 * read object, the features for write object, or the
669 			 * feature descriptions object.
670 			 */
671 			error = dsl_sync_task(spa->spa_name, NULL,
672 			    spa_sync_version, &ver, 6);
673 			if (error)
674 				return (error);
675 			continue;
676 		}
677 
678 		need_sync = B_TRUE;
679 		break;
680 	}
681 
682 	if (need_sync) {
683 		return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
684 		    nvp, 6));
685 	}
686 
687 	return (0);
688 }
689 
690 /*
691  * If the bootfs property value is dsobj, clear it.
692  */
693 void
694 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
695 {
696 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
697 		VERIFY(zap_remove(spa->spa_meta_objset,
698 		    spa->spa_pool_props_object,
699 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
700 		spa->spa_bootfs = 0;
701 	}
702 }
703 
704 /*ARGSUSED*/
705 static int
706 spa_change_guid_check(void *arg, dmu_tx_t *tx)
707 {
708 	uint64_t *newguid = arg;
709 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
710 	vdev_t *rvd = spa->spa_root_vdev;
711 	uint64_t vdev_state;
712 
713 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
714 	vdev_state = rvd->vdev_state;
715 	spa_config_exit(spa, SCL_STATE, FTAG);
716 
717 	if (vdev_state != VDEV_STATE_HEALTHY)
718 		return (SET_ERROR(ENXIO));
719 
720 	ASSERT3U(spa_guid(spa), !=, *newguid);
721 
722 	return (0);
723 }
724 
725 static void
726 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
727 {
728 	uint64_t *newguid = arg;
729 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
730 	uint64_t oldguid;
731 	vdev_t *rvd = spa->spa_root_vdev;
732 
733 	oldguid = spa_guid(spa);
734 
735 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
736 	rvd->vdev_guid = *newguid;
737 	rvd->vdev_guid_sum += (*newguid - oldguid);
738 	vdev_config_dirty(rvd);
739 	spa_config_exit(spa, SCL_STATE, FTAG);
740 
741 	spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
742 	    oldguid, *newguid);
743 }
744 
745 /*
746  * Change the GUID for the pool.  This is done so that we can later
747  * re-import a pool built from a clone of our own vdevs.  We will modify
748  * the root vdev's guid, our own pool guid, and then mark all of our
749  * vdevs dirty.  Note that we must make sure that all our vdevs are
750  * online when we do this, or else any vdevs that weren't present
751  * would be orphaned from our pool.  We are also going to issue a
752  * sysevent to update any watchers.
753  */
754 int
755 spa_change_guid(spa_t *spa)
756 {
757 	int error;
758 	uint64_t guid;
759 
760 	mutex_enter(&spa->spa_vdev_top_lock);
761 	mutex_enter(&spa_namespace_lock);
762 	guid = spa_generate_guid(NULL);
763 
764 	error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
765 	    spa_change_guid_sync, &guid, 5);
766 
767 	if (error == 0) {
768 		spa_config_sync(spa, B_FALSE, B_TRUE);
769 		spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
770 	}
771 
772 	mutex_exit(&spa_namespace_lock);
773 	mutex_exit(&spa->spa_vdev_top_lock);
774 
775 	return (error);
776 }
777 
778 /*
779  * ==========================================================================
780  * SPA state manipulation (open/create/destroy/import/export)
781  * ==========================================================================
782  */
783 
784 static int
785 spa_error_entry_compare(const void *a, const void *b)
786 {
787 	spa_error_entry_t *sa = (spa_error_entry_t *)a;
788 	spa_error_entry_t *sb = (spa_error_entry_t *)b;
789 	int ret;
790 
791 	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
792 	    sizeof (zbookmark_t));
793 
794 	if (ret < 0)
795 		return (-1);
796 	else if (ret > 0)
797 		return (1);
798 	else
799 		return (0);
800 }
801 
802 /*
803  * Utility function which retrieves copies of the current logs and
804  * re-initializes them in the process.
805  */
806 void
807 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
808 {
809 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
810 
811 	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
812 	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
813 
814 	avl_create(&spa->spa_errlist_scrub,
815 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
816 	    offsetof(spa_error_entry_t, se_avl));
817 	avl_create(&spa->spa_errlist_last,
818 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
819 	    offsetof(spa_error_entry_t, se_avl));
820 }
821 
822 static void
823 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
824 {
825 	const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
826 	enum zti_modes mode = ztip->zti_mode;
827 	uint_t value = ztip->zti_value;
828 	uint_t count = ztip->zti_count;
829 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
830 	char name[32];
831 	uint_t flags = 0;
832 	boolean_t batch = B_FALSE;
833 
834 	if (mode == ZTI_MODE_NULL) {
835 		tqs->stqs_count = 0;
836 		tqs->stqs_taskq = NULL;
837 		return;
838 	}
839 
840 	ASSERT3U(count, >, 0);
841 
842 	tqs->stqs_count = count;
843 	tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
844 
845 	for (uint_t i = 0; i < count; i++) {
846 		taskq_t *tq;
847 
848 		switch (mode) {
849 		case ZTI_MODE_FIXED:
850 			ASSERT3U(value, >=, 1);
851 			value = MAX(value, 1);
852 			break;
853 
854 		case ZTI_MODE_BATCH:
855 			batch = B_TRUE;
856 			flags |= TASKQ_THREADS_CPU_PCT;
857 			value = zio_taskq_batch_pct;
858 			break;
859 
860 		case ZTI_MODE_ONLINE_PERCENT:
861 			flags |= TASKQ_THREADS_CPU_PCT;
862 			break;
863 
864 		default:
865 			panic("unrecognized mode for %s_%s taskq (%u:%u) in "
866 			    "spa_activate()",
867 			    zio_type_name[t], zio_taskq_types[q], mode, value);
868 			break;
869 		}
870 
871 		if (count > 1) {
872 			(void) snprintf(name, sizeof (name), "%s_%s_%u",
873 			    zio_type_name[t], zio_taskq_types[q], i);
874 		} else {
875 			(void) snprintf(name, sizeof (name), "%s_%s",
876 			    zio_type_name[t], zio_taskq_types[q]);
877 		}
878 
879 		if (zio_taskq_sysdc && spa->spa_proc != &p0) {
880 			if (batch)
881 				flags |= TASKQ_DC_BATCH;
882 
883 			tq = taskq_create_sysdc(name, value, 50, INT_MAX,
884 			    spa->spa_proc, zio_taskq_basedc, flags);
885 		} else {
886 			tq = taskq_create_proc(name, value, maxclsyspri, 50,
887 			    INT_MAX, spa->spa_proc, flags);
888 		}
889 
890 		tqs->stqs_taskq[i] = tq;
891 	}
892 }
893 
894 static void
895 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
896 {
897 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
898 
899 	if (tqs->stqs_taskq == NULL) {
900 		ASSERT0(tqs->stqs_count);
901 		return;
902 	}
903 
904 	for (uint_t i = 0; i < tqs->stqs_count; i++) {
905 		ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
906 		taskq_destroy(tqs->stqs_taskq[i]);
907 	}
908 
909 	kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
910 	tqs->stqs_taskq = NULL;
911 }
912 
913 /*
914  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
915  * Note that a type may have multiple discrete taskqs to avoid lock contention
916  * on the taskq itself. In that case we choose which taskq at random by using
917  * the low bits of gethrtime().
918  */
919 void
920 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
921     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
922 {
923 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
924 	taskq_t *tq;
925 
926 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
927 	ASSERT3U(tqs->stqs_count, !=, 0);
928 
929 	if (tqs->stqs_count == 1) {
930 		tq = tqs->stqs_taskq[0];
931 	} else {
932 		tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
933 	}
934 
935 	taskq_dispatch_ent(tq, func, arg, flags, ent);
936 }
937 
938 static void
939 spa_create_zio_taskqs(spa_t *spa)
940 {
941 	for (int t = 0; t < ZIO_TYPES; t++) {
942 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
943 			spa_taskqs_init(spa, t, q);
944 		}
945 	}
946 }
947 
948 #ifdef _KERNEL
949 static void
950 spa_thread(void *arg)
951 {
952 	callb_cpr_t cprinfo;
953 
954 	spa_t *spa = arg;
955 	user_t *pu = PTOU(curproc);
956 
957 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
958 	    spa->spa_name);
959 
960 	ASSERT(curproc != &p0);
961 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
962 	    "zpool-%s", spa->spa_name);
963 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
964 
965 	/* bind this thread to the requested psrset */
966 	if (zio_taskq_psrset_bind != PS_NONE) {
967 		pool_lock();
968 		mutex_enter(&cpu_lock);
969 		mutex_enter(&pidlock);
970 		mutex_enter(&curproc->p_lock);
971 
972 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
973 		    0, NULL, NULL) == 0)  {
974 			curthread->t_bind_pset = zio_taskq_psrset_bind;
975 		} else {
976 			cmn_err(CE_WARN,
977 			    "Couldn't bind process for zfs pool \"%s\" to "
978 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
979 		}
980 
981 		mutex_exit(&curproc->p_lock);
982 		mutex_exit(&pidlock);
983 		mutex_exit(&cpu_lock);
984 		pool_unlock();
985 	}
986 
987 	if (zio_taskq_sysdc) {
988 		sysdc_thread_enter(curthread, 100, 0);
989 	}
990 
991 	spa->spa_proc = curproc;
992 	spa->spa_did = curthread->t_did;
993 
994 	spa_create_zio_taskqs(spa);
995 
996 	mutex_enter(&spa->spa_proc_lock);
997 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
998 
999 	spa->spa_proc_state = SPA_PROC_ACTIVE;
1000 	cv_broadcast(&spa->spa_proc_cv);
1001 
1002 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
1003 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1004 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1005 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1006 
1007 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1008 	spa->spa_proc_state = SPA_PROC_GONE;
1009 	spa->spa_proc = &p0;
1010 	cv_broadcast(&spa->spa_proc_cv);
1011 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
1012 
1013 	mutex_enter(&curproc->p_lock);
1014 	lwp_exit();
1015 }
1016 #endif
1017 
1018 /*
1019  * Activate an uninitialized pool.
1020  */
1021 static void
1022 spa_activate(spa_t *spa, int mode)
1023 {
1024 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1025 
1026 	spa->spa_state = POOL_STATE_ACTIVE;
1027 	spa->spa_mode = mode;
1028 
1029 	spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1030 	spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1031 
1032 	/* Try to create a covering process */
1033 	mutex_enter(&spa->spa_proc_lock);
1034 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1035 	ASSERT(spa->spa_proc == &p0);
1036 	spa->spa_did = 0;
1037 
1038 	/* Only create a process if we're going to be around a while. */
1039 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1040 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1041 		    NULL, 0) == 0) {
1042 			spa->spa_proc_state = SPA_PROC_CREATED;
1043 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
1044 				cv_wait(&spa->spa_proc_cv,
1045 				    &spa->spa_proc_lock);
1046 			}
1047 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1048 			ASSERT(spa->spa_proc != &p0);
1049 			ASSERT(spa->spa_did != 0);
1050 		} else {
1051 #ifdef _KERNEL
1052 			cmn_err(CE_WARN,
1053 			    "Couldn't create process for zfs pool \"%s\"\n",
1054 			    spa->spa_name);
1055 #endif
1056 		}
1057 	}
1058 	mutex_exit(&spa->spa_proc_lock);
1059 
1060 	/* If we didn't create a process, we need to create our taskqs. */
1061 	if (spa->spa_proc == &p0) {
1062 		spa_create_zio_taskqs(spa);
1063 	}
1064 
1065 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1066 	    offsetof(vdev_t, vdev_config_dirty_node));
1067 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1068 	    offsetof(vdev_t, vdev_state_dirty_node));
1069 
1070 	txg_list_create(&spa->spa_vdev_txg_list,
1071 	    offsetof(struct vdev, vdev_txg_node));
1072 
1073 	avl_create(&spa->spa_errlist_scrub,
1074 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1075 	    offsetof(spa_error_entry_t, se_avl));
1076 	avl_create(&spa->spa_errlist_last,
1077 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1078 	    offsetof(spa_error_entry_t, se_avl));
1079 }
1080 
1081 /*
1082  * Opposite of spa_activate().
1083  */
1084 static void
1085 spa_deactivate(spa_t *spa)
1086 {
1087 	ASSERT(spa->spa_sync_on == B_FALSE);
1088 	ASSERT(spa->spa_dsl_pool == NULL);
1089 	ASSERT(spa->spa_root_vdev == NULL);
1090 	ASSERT(spa->spa_async_zio_root == NULL);
1091 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1092 
1093 	txg_list_destroy(&spa->spa_vdev_txg_list);
1094 
1095 	list_destroy(&spa->spa_config_dirty_list);
1096 	list_destroy(&spa->spa_state_dirty_list);
1097 
1098 	for (int t = 0; t < ZIO_TYPES; t++) {
1099 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1100 			spa_taskqs_fini(spa, t, q);
1101 		}
1102 	}
1103 
1104 	metaslab_class_destroy(spa->spa_normal_class);
1105 	spa->spa_normal_class = NULL;
1106 
1107 	metaslab_class_destroy(spa->spa_log_class);
1108 	spa->spa_log_class = NULL;
1109 
1110 	/*
1111 	 * If this was part of an import or the open otherwise failed, we may
1112 	 * still have errors left in the queues.  Empty them just in case.
1113 	 */
1114 	spa_errlog_drain(spa);
1115 
1116 	avl_destroy(&spa->spa_errlist_scrub);
1117 	avl_destroy(&spa->spa_errlist_last);
1118 
1119 	spa->spa_state = POOL_STATE_UNINITIALIZED;
1120 
1121 	mutex_enter(&spa->spa_proc_lock);
1122 	if (spa->spa_proc_state != SPA_PROC_NONE) {
1123 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1124 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1125 		cv_broadcast(&spa->spa_proc_cv);
1126 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1127 			ASSERT(spa->spa_proc != &p0);
1128 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1129 		}
1130 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1131 		spa->spa_proc_state = SPA_PROC_NONE;
1132 	}
1133 	ASSERT(spa->spa_proc == &p0);
1134 	mutex_exit(&spa->spa_proc_lock);
1135 
1136 	/*
1137 	 * We want to make sure spa_thread() has actually exited the ZFS
1138 	 * module, so that the module can't be unloaded out from underneath
1139 	 * it.
1140 	 */
1141 	if (spa->spa_did != 0) {
1142 		thread_join(spa->spa_did);
1143 		spa->spa_did = 0;
1144 	}
1145 }
1146 
1147 /*
1148  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1149  * will create all the necessary vdevs in the appropriate layout, with each vdev
1150  * in the CLOSED state.  This will prep the pool before open/creation/import.
1151  * All vdev validation is done by the vdev_alloc() routine.
1152  */
1153 static int
1154 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1155     uint_t id, int atype)
1156 {
1157 	nvlist_t **child;
1158 	uint_t children;
1159 	int error;
1160 
1161 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1162 		return (error);
1163 
1164 	if ((*vdp)->vdev_ops->vdev_op_leaf)
1165 		return (0);
1166 
1167 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1168 	    &child, &children);
1169 
1170 	if (error == ENOENT)
1171 		return (0);
1172 
1173 	if (error) {
1174 		vdev_free(*vdp);
1175 		*vdp = NULL;
1176 		return (SET_ERROR(EINVAL));
1177 	}
1178 
1179 	for (int c = 0; c < children; c++) {
1180 		vdev_t *vd;
1181 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1182 		    atype)) != 0) {
1183 			vdev_free(*vdp);
1184 			*vdp = NULL;
1185 			return (error);
1186 		}
1187 	}
1188 
1189 	ASSERT(*vdp != NULL);
1190 
1191 	return (0);
1192 }
1193 
1194 /*
1195  * Opposite of spa_load().
1196  */
1197 static void
1198 spa_unload(spa_t *spa)
1199 {
1200 	int i;
1201 
1202 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1203 
1204 	/*
1205 	 * Stop async tasks.
1206 	 */
1207 	spa_async_suspend(spa);
1208 
1209 	/*
1210 	 * Stop syncing.
1211 	 */
1212 	if (spa->spa_sync_on) {
1213 		txg_sync_stop(spa->spa_dsl_pool);
1214 		spa->spa_sync_on = B_FALSE;
1215 	}
1216 
1217 	/*
1218 	 * Wait for any outstanding async I/O to complete.
1219 	 */
1220 	if (spa->spa_async_zio_root != NULL) {
1221 		(void) zio_wait(spa->spa_async_zio_root);
1222 		spa->spa_async_zio_root = NULL;
1223 	}
1224 
1225 	bpobj_close(&spa->spa_deferred_bpobj);
1226 
1227 	/*
1228 	 * Close the dsl pool.
1229 	 */
1230 	if (spa->spa_dsl_pool) {
1231 		dsl_pool_close(spa->spa_dsl_pool);
1232 		spa->spa_dsl_pool = NULL;
1233 		spa->spa_meta_objset = NULL;
1234 	}
1235 
1236 	ddt_unload(spa);
1237 
1238 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1239 
1240 	/*
1241 	 * Drop and purge level 2 cache
1242 	 */
1243 	spa_l2cache_drop(spa);
1244 
1245 	/*
1246 	 * Close all vdevs.
1247 	 */
1248 	if (spa->spa_root_vdev)
1249 		vdev_free(spa->spa_root_vdev);
1250 	ASSERT(spa->spa_root_vdev == NULL);
1251 
1252 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1253 		vdev_free(spa->spa_spares.sav_vdevs[i]);
1254 	if (spa->spa_spares.sav_vdevs) {
1255 		kmem_free(spa->spa_spares.sav_vdevs,
1256 		    spa->spa_spares.sav_count * sizeof (void *));
1257 		spa->spa_spares.sav_vdevs = NULL;
1258 	}
1259 	if (spa->spa_spares.sav_config) {
1260 		nvlist_free(spa->spa_spares.sav_config);
1261 		spa->spa_spares.sav_config = NULL;
1262 	}
1263 	spa->spa_spares.sav_count = 0;
1264 
1265 	for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1266 		vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1267 		vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1268 	}
1269 	if (spa->spa_l2cache.sav_vdevs) {
1270 		kmem_free(spa->spa_l2cache.sav_vdevs,
1271 		    spa->spa_l2cache.sav_count * sizeof (void *));
1272 		spa->spa_l2cache.sav_vdevs = NULL;
1273 	}
1274 	if (spa->spa_l2cache.sav_config) {
1275 		nvlist_free(spa->spa_l2cache.sav_config);
1276 		spa->spa_l2cache.sav_config = NULL;
1277 	}
1278 	spa->spa_l2cache.sav_count = 0;
1279 
1280 	spa->spa_async_suspended = 0;
1281 
1282 	if (spa->spa_comment != NULL) {
1283 		spa_strfree(spa->spa_comment);
1284 		spa->spa_comment = NULL;
1285 	}
1286 
1287 	spa_config_exit(spa, SCL_ALL, FTAG);
1288 }
1289 
1290 /*
1291  * Load (or re-load) the current list of vdevs describing the active spares for
1292  * this pool.  When this is called, we have some form of basic information in
1293  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1294  * then re-generate a more complete list including status information.
1295  */
1296 static void
1297 spa_load_spares(spa_t *spa)
1298 {
1299 	nvlist_t **spares;
1300 	uint_t nspares;
1301 	int i;
1302 	vdev_t *vd, *tvd;
1303 
1304 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1305 
1306 	/*
1307 	 * First, close and free any existing spare vdevs.
1308 	 */
1309 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1310 		vd = spa->spa_spares.sav_vdevs[i];
1311 
1312 		/* Undo the call to spa_activate() below */
1313 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1314 		    B_FALSE)) != NULL && tvd->vdev_isspare)
1315 			spa_spare_remove(tvd);
1316 		vdev_close(vd);
1317 		vdev_free(vd);
1318 	}
1319 
1320 	if (spa->spa_spares.sav_vdevs)
1321 		kmem_free(spa->spa_spares.sav_vdevs,
1322 		    spa->spa_spares.sav_count * sizeof (void *));
1323 
1324 	if (spa->spa_spares.sav_config == NULL)
1325 		nspares = 0;
1326 	else
1327 		VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1328 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1329 
1330 	spa->spa_spares.sav_count = (int)nspares;
1331 	spa->spa_spares.sav_vdevs = NULL;
1332 
1333 	if (nspares == 0)
1334 		return;
1335 
1336 	/*
1337 	 * Construct the array of vdevs, opening them to get status in the
1338 	 * process.   For each spare, there is potentially two different vdev_t
1339 	 * structures associated with it: one in the list of spares (used only
1340 	 * for basic validation purposes) and one in the active vdev
1341 	 * configuration (if it's spared in).  During this phase we open and
1342 	 * validate each vdev on the spare list.  If the vdev also exists in the
1343 	 * active configuration, then we also mark this vdev as an active spare.
1344 	 */
1345 	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1346 	    KM_SLEEP);
1347 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1348 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1349 		    VDEV_ALLOC_SPARE) == 0);
1350 		ASSERT(vd != NULL);
1351 
1352 		spa->spa_spares.sav_vdevs[i] = vd;
1353 
1354 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1355 		    B_FALSE)) != NULL) {
1356 			if (!tvd->vdev_isspare)
1357 				spa_spare_add(tvd);
1358 
1359 			/*
1360 			 * We only mark the spare active if we were successfully
1361 			 * able to load the vdev.  Otherwise, importing a pool
1362 			 * with a bad active spare would result in strange
1363 			 * behavior, because multiple pool would think the spare
1364 			 * is actively in use.
1365 			 *
1366 			 * There is a vulnerability here to an equally bizarre
1367 			 * circumstance, where a dead active spare is later
1368 			 * brought back to life (onlined or otherwise).  Given
1369 			 * the rarity of this scenario, and the extra complexity
1370 			 * it adds, we ignore the possibility.
1371 			 */
1372 			if (!vdev_is_dead(tvd))
1373 				spa_spare_activate(tvd);
1374 		}
1375 
1376 		vd->vdev_top = vd;
1377 		vd->vdev_aux = &spa->spa_spares;
1378 
1379 		if (vdev_open(vd) != 0)
1380 			continue;
1381 
1382 		if (vdev_validate_aux(vd) == 0)
1383 			spa_spare_add(vd);
1384 	}
1385 
1386 	/*
1387 	 * Recompute the stashed list of spares, with status information
1388 	 * this time.
1389 	 */
1390 	VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1391 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1392 
1393 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1394 	    KM_SLEEP);
1395 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1396 		spares[i] = vdev_config_generate(spa,
1397 		    spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1398 	VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1399 	    ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1400 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1401 		nvlist_free(spares[i]);
1402 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1403 }
1404 
1405 /*
1406  * Load (or re-load) the current list of vdevs describing the active l2cache for
1407  * this pool.  When this is called, we have some form of basic information in
1408  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1409  * then re-generate a more complete list including status information.
1410  * Devices which are already active have their details maintained, and are
1411  * not re-opened.
1412  */
1413 static void
1414 spa_load_l2cache(spa_t *spa)
1415 {
1416 	nvlist_t **l2cache;
1417 	uint_t nl2cache;
1418 	int i, j, oldnvdevs;
1419 	uint64_t guid;
1420 	vdev_t *vd, **oldvdevs, **newvdevs;
1421 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1422 
1423 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1424 
1425 	if (sav->sav_config != NULL) {
1426 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1427 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1428 		newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1429 	} else {
1430 		nl2cache = 0;
1431 		newvdevs = NULL;
1432 	}
1433 
1434 	oldvdevs = sav->sav_vdevs;
1435 	oldnvdevs = sav->sav_count;
1436 	sav->sav_vdevs = NULL;
1437 	sav->sav_count = 0;
1438 
1439 	/*
1440 	 * Process new nvlist of vdevs.
1441 	 */
1442 	for (i = 0; i < nl2cache; i++) {
1443 		VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1444 		    &guid) == 0);
1445 
1446 		newvdevs[i] = NULL;
1447 		for (j = 0; j < oldnvdevs; j++) {
1448 			vd = oldvdevs[j];
1449 			if (vd != NULL && guid == vd->vdev_guid) {
1450 				/*
1451 				 * Retain previous vdev for add/remove ops.
1452 				 */
1453 				newvdevs[i] = vd;
1454 				oldvdevs[j] = NULL;
1455 				break;
1456 			}
1457 		}
1458 
1459 		if (newvdevs[i] == NULL) {
1460 			/*
1461 			 * Create new vdev
1462 			 */
1463 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1464 			    VDEV_ALLOC_L2CACHE) == 0);
1465 			ASSERT(vd != NULL);
1466 			newvdevs[i] = vd;
1467 
1468 			/*
1469 			 * Commit this vdev as an l2cache device,
1470 			 * even if it fails to open.
1471 			 */
1472 			spa_l2cache_add(vd);
1473 
1474 			vd->vdev_top = vd;
1475 			vd->vdev_aux = sav;
1476 
1477 			spa_l2cache_activate(vd);
1478 
1479 			if (vdev_open(vd) != 0)
1480 				continue;
1481 
1482 			(void) vdev_validate_aux(vd);
1483 
1484 			if (!vdev_is_dead(vd))
1485 				l2arc_add_vdev(spa, vd);
1486 		}
1487 	}
1488 
1489 	/*
1490 	 * Purge vdevs that were dropped
1491 	 */
1492 	for (i = 0; i < oldnvdevs; i++) {
1493 		uint64_t pool;
1494 
1495 		vd = oldvdevs[i];
1496 		if (vd != NULL) {
1497 			ASSERT(vd->vdev_isl2cache);
1498 
1499 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1500 			    pool != 0ULL && l2arc_vdev_present(vd))
1501 				l2arc_remove_vdev(vd);
1502 			vdev_clear_stats(vd);
1503 			vdev_free(vd);
1504 		}
1505 	}
1506 
1507 	if (oldvdevs)
1508 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1509 
1510 	if (sav->sav_config == NULL)
1511 		goto out;
1512 
1513 	sav->sav_vdevs = newvdevs;
1514 	sav->sav_count = (int)nl2cache;
1515 
1516 	/*
1517 	 * Recompute the stashed list of l2cache devices, with status
1518 	 * information this time.
1519 	 */
1520 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1521 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1522 
1523 	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1524 	for (i = 0; i < sav->sav_count; i++)
1525 		l2cache[i] = vdev_config_generate(spa,
1526 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1527 	VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1528 	    ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1529 out:
1530 	for (i = 0; i < sav->sav_count; i++)
1531 		nvlist_free(l2cache[i]);
1532 	if (sav->sav_count)
1533 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
1534 }
1535 
1536 static int
1537 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1538 {
1539 	dmu_buf_t *db;
1540 	char *packed = NULL;
1541 	size_t nvsize = 0;
1542 	int error;
1543 	*value = NULL;
1544 
1545 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1546 	nvsize = *(uint64_t *)db->db_data;
1547 	dmu_buf_rele(db, FTAG);
1548 
1549 	packed = kmem_alloc(nvsize, KM_SLEEP);
1550 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1551 	    DMU_READ_PREFETCH);
1552 	if (error == 0)
1553 		error = nvlist_unpack(packed, nvsize, value, 0);
1554 	kmem_free(packed, nvsize);
1555 
1556 	return (error);
1557 }
1558 
1559 /*
1560  * Checks to see if the given vdev could not be opened, in which case we post a
1561  * sysevent to notify the autoreplace code that the device has been removed.
1562  */
1563 static void
1564 spa_check_removed(vdev_t *vd)
1565 {
1566 	for (int c = 0; c < vd->vdev_children; c++)
1567 		spa_check_removed(vd->vdev_child[c]);
1568 
1569 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1570 	    !vd->vdev_ishole) {
1571 		zfs_post_autoreplace(vd->vdev_spa, vd);
1572 		spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1573 	}
1574 }
1575 
1576 /*
1577  * Validate the current config against the MOS config
1578  */
1579 static boolean_t
1580 spa_config_valid(spa_t *spa, nvlist_t *config)
1581 {
1582 	vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1583 	nvlist_t *nv;
1584 
1585 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1586 
1587 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1588 	VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1589 
1590 	ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1591 
1592 	/*
1593 	 * If we're doing a normal import, then build up any additional
1594 	 * diagnostic information about missing devices in this config.
1595 	 * We'll pass this up to the user for further processing.
1596 	 */
1597 	if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1598 		nvlist_t **child, *nv;
1599 		uint64_t idx = 0;
1600 
1601 		child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1602 		    KM_SLEEP);
1603 		VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1604 
1605 		for (int c = 0; c < rvd->vdev_children; c++) {
1606 			vdev_t *tvd = rvd->vdev_child[c];
1607 			vdev_t *mtvd  = mrvd->vdev_child[c];
1608 
1609 			if (tvd->vdev_ops == &vdev_missing_ops &&
1610 			    mtvd->vdev_ops != &vdev_missing_ops &&
1611 			    mtvd->vdev_islog)
1612 				child[idx++] = vdev_config_generate(spa, mtvd,
1613 				    B_FALSE, 0);
1614 		}
1615 
1616 		if (idx) {
1617 			VERIFY(nvlist_add_nvlist_array(nv,
1618 			    ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1619 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1620 			    ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1621 
1622 			for (int i = 0; i < idx; i++)
1623 				nvlist_free(child[i]);
1624 		}
1625 		nvlist_free(nv);
1626 		kmem_free(child, rvd->vdev_children * sizeof (char **));
1627 	}
1628 
1629 	/*
1630 	 * Compare the root vdev tree with the information we have
1631 	 * from the MOS config (mrvd). Check each top-level vdev
1632 	 * with the corresponding MOS config top-level (mtvd).
1633 	 */
1634 	for (int c = 0; c < rvd->vdev_children; c++) {
1635 		vdev_t *tvd = rvd->vdev_child[c];
1636 		vdev_t *mtvd  = mrvd->vdev_child[c];
1637 
1638 		/*
1639 		 * Resolve any "missing" vdevs in the current configuration.
1640 		 * If we find that the MOS config has more accurate information
1641 		 * about the top-level vdev then use that vdev instead.
1642 		 */
1643 		if (tvd->vdev_ops == &vdev_missing_ops &&
1644 		    mtvd->vdev_ops != &vdev_missing_ops) {
1645 
1646 			if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1647 				continue;
1648 
1649 			/*
1650 			 * Device specific actions.
1651 			 */
1652 			if (mtvd->vdev_islog) {
1653 				spa_set_log_state(spa, SPA_LOG_CLEAR);
1654 			} else {
1655 				/*
1656 				 * XXX - once we have 'readonly' pool
1657 				 * support we should be able to handle
1658 				 * missing data devices by transitioning
1659 				 * the pool to readonly.
1660 				 */
1661 				continue;
1662 			}
1663 
1664 			/*
1665 			 * Swap the missing vdev with the data we were
1666 			 * able to obtain from the MOS config.
1667 			 */
1668 			vdev_remove_child(rvd, tvd);
1669 			vdev_remove_child(mrvd, mtvd);
1670 
1671 			vdev_add_child(rvd, mtvd);
1672 			vdev_add_child(mrvd, tvd);
1673 
1674 			spa_config_exit(spa, SCL_ALL, FTAG);
1675 			vdev_load(mtvd);
1676 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1677 
1678 			vdev_reopen(rvd);
1679 		} else if (mtvd->vdev_islog) {
1680 			/*
1681 			 * Load the slog device's state from the MOS config
1682 			 * since it's possible that the label does not
1683 			 * contain the most up-to-date information.
1684 			 */
1685 			vdev_load_log_state(tvd, mtvd);
1686 			vdev_reopen(tvd);
1687 		}
1688 	}
1689 	vdev_free(mrvd);
1690 	spa_config_exit(spa, SCL_ALL, FTAG);
1691 
1692 	/*
1693 	 * Ensure we were able to validate the config.
1694 	 */
1695 	return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1696 }
1697 
1698 /*
1699  * Check for missing log devices
1700  */
1701 static boolean_t
1702 spa_check_logs(spa_t *spa)
1703 {
1704 	boolean_t rv = B_FALSE;
1705 
1706 	switch (spa->spa_log_state) {
1707 	case SPA_LOG_MISSING:
1708 		/* need to recheck in case slog has been restored */
1709 	case SPA_LOG_UNKNOWN:
1710 		rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1711 		    NULL, DS_FIND_CHILDREN) != 0);
1712 		if (rv)
1713 			spa_set_log_state(spa, SPA_LOG_MISSING);
1714 		break;
1715 	}
1716 	return (rv);
1717 }
1718 
1719 static boolean_t
1720 spa_passivate_log(spa_t *spa)
1721 {
1722 	vdev_t *rvd = spa->spa_root_vdev;
1723 	boolean_t slog_found = B_FALSE;
1724 
1725 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1726 
1727 	if (!spa_has_slogs(spa))
1728 		return (B_FALSE);
1729 
1730 	for (int c = 0; c < rvd->vdev_children; c++) {
1731 		vdev_t *tvd = rvd->vdev_child[c];
1732 		metaslab_group_t *mg = tvd->vdev_mg;
1733 
1734 		if (tvd->vdev_islog) {
1735 			metaslab_group_passivate(mg);
1736 			slog_found = B_TRUE;
1737 		}
1738 	}
1739 
1740 	return (slog_found);
1741 }
1742 
1743 static void
1744 spa_activate_log(spa_t *spa)
1745 {
1746 	vdev_t *rvd = spa->spa_root_vdev;
1747 
1748 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1749 
1750 	for (int c = 0; c < rvd->vdev_children; c++) {
1751 		vdev_t *tvd = rvd->vdev_child[c];
1752 		metaslab_group_t *mg = tvd->vdev_mg;
1753 
1754 		if (tvd->vdev_islog)
1755 			metaslab_group_activate(mg);
1756 	}
1757 }
1758 
1759 int
1760 spa_offline_log(spa_t *spa)
1761 {
1762 	int error;
1763 
1764 	error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1765 	    NULL, DS_FIND_CHILDREN);
1766 	if (error == 0) {
1767 		/*
1768 		 * We successfully offlined the log device, sync out the
1769 		 * current txg so that the "stubby" block can be removed
1770 		 * by zil_sync().
1771 		 */
1772 		txg_wait_synced(spa->spa_dsl_pool, 0);
1773 	}
1774 	return (error);
1775 }
1776 
1777 static void
1778 spa_aux_check_removed(spa_aux_vdev_t *sav)
1779 {
1780 	for (int i = 0; i < sav->sav_count; i++)
1781 		spa_check_removed(sav->sav_vdevs[i]);
1782 }
1783 
1784 void
1785 spa_claim_notify(zio_t *zio)
1786 {
1787 	spa_t *spa = zio->io_spa;
1788 
1789 	if (zio->io_error)
1790 		return;
1791 
1792 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
1793 	if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1794 		spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1795 	mutex_exit(&spa->spa_props_lock);
1796 }
1797 
1798 typedef struct spa_load_error {
1799 	uint64_t	sle_meta_count;
1800 	uint64_t	sle_data_count;
1801 } spa_load_error_t;
1802 
1803 static void
1804 spa_load_verify_done(zio_t *zio)
1805 {
1806 	blkptr_t *bp = zio->io_bp;
1807 	spa_load_error_t *sle = zio->io_private;
1808 	dmu_object_type_t type = BP_GET_TYPE(bp);
1809 	int error = zio->io_error;
1810 
1811 	if (error) {
1812 		if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1813 		    type != DMU_OT_INTENT_LOG)
1814 			atomic_add_64(&sle->sle_meta_count, 1);
1815 		else
1816 			atomic_add_64(&sle->sle_data_count, 1);
1817 	}
1818 	zio_data_buf_free(zio->io_data, zio->io_size);
1819 }
1820 
1821 /*ARGSUSED*/
1822 static int
1823 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1824     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1825 {
1826 	if (bp != NULL) {
1827 		zio_t *rio = arg;
1828 		size_t size = BP_GET_PSIZE(bp);
1829 		void *data = zio_data_buf_alloc(size);
1830 
1831 		zio_nowait(zio_read(rio, spa, bp, data, size,
1832 		    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1833 		    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1834 		    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1835 	}
1836 	return (0);
1837 }
1838 
1839 static int
1840 spa_load_verify(spa_t *spa)
1841 {
1842 	zio_t *rio;
1843 	spa_load_error_t sle = { 0 };
1844 	zpool_rewind_policy_t policy;
1845 	boolean_t verify_ok = B_FALSE;
1846 	int error;
1847 
1848 	zpool_get_rewind_policy(spa->spa_config, &policy);
1849 
1850 	if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1851 		return (0);
1852 
1853 	rio = zio_root(spa, NULL, &sle,
1854 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1855 
1856 	error = traverse_pool(spa, spa->spa_verify_min_txg,
1857 	    TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1858 
1859 	(void) zio_wait(rio);
1860 
1861 	spa->spa_load_meta_errors = sle.sle_meta_count;
1862 	spa->spa_load_data_errors = sle.sle_data_count;
1863 
1864 	if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1865 	    sle.sle_data_count <= policy.zrp_maxdata) {
1866 		int64_t loss = 0;
1867 
1868 		verify_ok = B_TRUE;
1869 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1870 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1871 
1872 		loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1873 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1874 		    ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1875 		VERIFY(nvlist_add_int64(spa->spa_load_info,
1876 		    ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1877 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1878 		    ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1879 	} else {
1880 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1881 	}
1882 
1883 	if (error) {
1884 		if (error != ENXIO && error != EIO)
1885 			error = SET_ERROR(EIO);
1886 		return (error);
1887 	}
1888 
1889 	return (verify_ok ? 0 : EIO);
1890 }
1891 
1892 /*
1893  * Find a value in the pool props object.
1894  */
1895 static void
1896 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1897 {
1898 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1899 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1900 }
1901 
1902 /*
1903  * Find a value in the pool directory object.
1904  */
1905 static int
1906 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1907 {
1908 	return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1909 	    name, sizeof (uint64_t), 1, val));
1910 }
1911 
1912 static int
1913 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1914 {
1915 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1916 	return (err);
1917 }
1918 
1919 /*
1920  * Fix up config after a partly-completed split.  This is done with the
1921  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1922  * pool have that entry in their config, but only the splitting one contains
1923  * a list of all the guids of the vdevs that are being split off.
1924  *
1925  * This function determines what to do with that list: either rejoin
1926  * all the disks to the pool, or complete the splitting process.  To attempt
1927  * the rejoin, each disk that is offlined is marked online again, and
1928  * we do a reopen() call.  If the vdev label for every disk that was
1929  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1930  * then we call vdev_split() on each disk, and complete the split.
1931  *
1932  * Otherwise we leave the config alone, with all the vdevs in place in
1933  * the original pool.
1934  */
1935 static void
1936 spa_try_repair(spa_t *spa, nvlist_t *config)
1937 {
1938 	uint_t extracted;
1939 	uint64_t *glist;
1940 	uint_t i, gcount;
1941 	nvlist_t *nvl;
1942 	vdev_t **vd;
1943 	boolean_t attempt_reopen;
1944 
1945 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1946 		return;
1947 
1948 	/* check that the config is complete */
1949 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1950 	    &glist, &gcount) != 0)
1951 		return;
1952 
1953 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1954 
1955 	/* attempt to online all the vdevs & validate */
1956 	attempt_reopen = B_TRUE;
1957 	for (i = 0; i < gcount; i++) {
1958 		if (glist[i] == 0)	/* vdev is hole */
1959 			continue;
1960 
1961 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1962 		if (vd[i] == NULL) {
1963 			/*
1964 			 * Don't bother attempting to reopen the disks;
1965 			 * just do the split.
1966 			 */
1967 			attempt_reopen = B_FALSE;
1968 		} else {
1969 			/* attempt to re-online it */
1970 			vd[i]->vdev_offline = B_FALSE;
1971 		}
1972 	}
1973 
1974 	if (attempt_reopen) {
1975 		vdev_reopen(spa->spa_root_vdev);
1976 
1977 		/* check each device to see what state it's in */
1978 		for (extracted = 0, i = 0; i < gcount; i++) {
1979 			if (vd[i] != NULL &&
1980 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1981 				break;
1982 			++extracted;
1983 		}
1984 	}
1985 
1986 	/*
1987 	 * If every disk has been moved to the new pool, or if we never
1988 	 * even attempted to look at them, then we split them off for
1989 	 * good.
1990 	 */
1991 	if (!attempt_reopen || gcount == extracted) {
1992 		for (i = 0; i < gcount; i++)
1993 			if (vd[i] != NULL)
1994 				vdev_split(vd[i]);
1995 		vdev_reopen(spa->spa_root_vdev);
1996 	}
1997 
1998 	kmem_free(vd, gcount * sizeof (vdev_t *));
1999 }
2000 
2001 static int
2002 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2003     boolean_t mosconfig)
2004 {
2005 	nvlist_t *config = spa->spa_config;
2006 	char *ereport = FM_EREPORT_ZFS_POOL;
2007 	char *comment;
2008 	int error;
2009 	uint64_t pool_guid;
2010 	nvlist_t *nvl;
2011 
2012 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2013 		return (SET_ERROR(EINVAL));
2014 
2015 	ASSERT(spa->spa_comment == NULL);
2016 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2017 		spa->spa_comment = spa_strdup(comment);
2018 
2019 	/*
2020 	 * Versioning wasn't explicitly added to the label until later, so if
2021 	 * it's not present treat it as the initial version.
2022 	 */
2023 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2024 	    &spa->spa_ubsync.ub_version) != 0)
2025 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2026 
2027 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2028 	    &spa->spa_config_txg);
2029 
2030 	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2031 	    spa_guid_exists(pool_guid, 0)) {
2032 		error = SET_ERROR(EEXIST);
2033 	} else {
2034 		spa->spa_config_guid = pool_guid;
2035 
2036 		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2037 		    &nvl) == 0) {
2038 			VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2039 			    KM_SLEEP) == 0);
2040 		}
2041 
2042 		nvlist_free(spa->spa_load_info);
2043 		spa->spa_load_info = fnvlist_alloc();
2044 
2045 		gethrestime(&spa->spa_loaded_ts);
2046 		error = spa_load_impl(spa, pool_guid, config, state, type,
2047 		    mosconfig, &ereport);
2048 	}
2049 
2050 	spa->spa_minref = refcount_count(&spa->spa_refcount);
2051 	if (error) {
2052 		if (error != EEXIST) {
2053 			spa->spa_loaded_ts.tv_sec = 0;
2054 			spa->spa_loaded_ts.tv_nsec = 0;
2055 		}
2056 		if (error != EBADF) {
2057 			zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2058 		}
2059 	}
2060 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2061 	spa->spa_ena = 0;
2062 
2063 	return (error);
2064 }
2065 
2066 /*
2067  * Load an existing storage pool, using the pool's builtin spa_config as a
2068  * source of configuration information.
2069  */
2070 static int
2071 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2072     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2073     char **ereport)
2074 {
2075 	int error = 0;
2076 	nvlist_t *nvroot = NULL;
2077 	nvlist_t *label;
2078 	vdev_t *rvd;
2079 	uberblock_t *ub = &spa->spa_uberblock;
2080 	uint64_t children, config_cache_txg = spa->spa_config_txg;
2081 	int orig_mode = spa->spa_mode;
2082 	int parse;
2083 	uint64_t obj;
2084 	boolean_t missing_feat_write = B_FALSE;
2085 
2086 	/*
2087 	 * If this is an untrusted config, access the pool in read-only mode.
2088 	 * This prevents things like resilvering recently removed devices.
2089 	 */
2090 	if (!mosconfig)
2091 		spa->spa_mode = FREAD;
2092 
2093 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
2094 
2095 	spa->spa_load_state = state;
2096 
2097 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2098 		return (SET_ERROR(EINVAL));
2099 
2100 	parse = (type == SPA_IMPORT_EXISTING ?
2101 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2102 
2103 	/*
2104 	 * Create "The Godfather" zio to hold all async IOs
2105 	 */
2106 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2107 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2108 
2109 	/*
2110 	 * Parse the configuration into a vdev tree.  We explicitly set the
2111 	 * value that will be returned by spa_version() since parsing the
2112 	 * configuration requires knowing the version number.
2113 	 */
2114 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2115 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2116 	spa_config_exit(spa, SCL_ALL, FTAG);
2117 
2118 	if (error != 0)
2119 		return (error);
2120 
2121 	ASSERT(spa->spa_root_vdev == rvd);
2122 
2123 	if (type != SPA_IMPORT_ASSEMBLE) {
2124 		ASSERT(spa_guid(spa) == pool_guid);
2125 	}
2126 
2127 	/*
2128 	 * Try to open all vdevs, loading each label in the process.
2129 	 */
2130 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2131 	error = vdev_open(rvd);
2132 	spa_config_exit(spa, SCL_ALL, FTAG);
2133 	if (error != 0)
2134 		return (error);
2135 
2136 	/*
2137 	 * We need to validate the vdev labels against the configuration that
2138 	 * we have in hand, which is dependent on the setting of mosconfig. If
2139 	 * mosconfig is true then we're validating the vdev labels based on
2140 	 * that config.  Otherwise, we're validating against the cached config
2141 	 * (zpool.cache) that was read when we loaded the zfs module, and then
2142 	 * later we will recursively call spa_load() and validate against
2143 	 * the vdev config.
2144 	 *
2145 	 * If we're assembling a new pool that's been split off from an
2146 	 * existing pool, the labels haven't yet been updated so we skip
2147 	 * validation for now.
2148 	 */
2149 	if (type != SPA_IMPORT_ASSEMBLE) {
2150 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2151 		error = vdev_validate(rvd, mosconfig);
2152 		spa_config_exit(spa, SCL_ALL, FTAG);
2153 
2154 		if (error != 0)
2155 			return (error);
2156 
2157 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2158 			return (SET_ERROR(ENXIO));
2159 	}
2160 
2161 	/*
2162 	 * Find the best uberblock.
2163 	 */
2164 	vdev_uberblock_load(rvd, ub, &label);
2165 
2166 	/*
2167 	 * If we weren't able to find a single valid uberblock, return failure.
2168 	 */
2169 	if (ub->ub_txg == 0) {
2170 		nvlist_free(label);
2171 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2172 	}
2173 
2174 	/*
2175 	 * If the pool has an unsupported version we can't open it.
2176 	 */
2177 	if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2178 		nvlist_free(label);
2179 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2180 	}
2181 
2182 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2183 		nvlist_t *features;
2184 
2185 		/*
2186 		 * If we weren't able to find what's necessary for reading the
2187 		 * MOS in the label, return failure.
2188 		 */
2189 		if (label == NULL || nvlist_lookup_nvlist(label,
2190 		    ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2191 			nvlist_free(label);
2192 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2193 			    ENXIO));
2194 		}
2195 
2196 		/*
2197 		 * Update our in-core representation with the definitive values
2198 		 * from the label.
2199 		 */
2200 		nvlist_free(spa->spa_label_features);
2201 		VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2202 	}
2203 
2204 	nvlist_free(label);
2205 
2206 	/*
2207 	 * Look through entries in the label nvlist's features_for_read. If
2208 	 * there is a feature listed there which we don't understand then we
2209 	 * cannot open a pool.
2210 	 */
2211 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2212 		nvlist_t *unsup_feat;
2213 
2214 		VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2215 		    0);
2216 
2217 		for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2218 		    NULL); nvp != NULL;
2219 		    nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2220 			if (!zfeature_is_supported(nvpair_name(nvp))) {
2221 				VERIFY(nvlist_add_string(unsup_feat,
2222 				    nvpair_name(nvp), "") == 0);
2223 			}
2224 		}
2225 
2226 		if (!nvlist_empty(unsup_feat)) {
2227 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2228 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2229 			nvlist_free(unsup_feat);
2230 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2231 			    ENOTSUP));
2232 		}
2233 
2234 		nvlist_free(unsup_feat);
2235 	}
2236 
2237 	/*
2238 	 * If the vdev guid sum doesn't match the uberblock, we have an
2239 	 * incomplete configuration.  We first check to see if the pool
2240 	 * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2241 	 * If it is, defer the vdev_guid_sum check till later so we
2242 	 * can handle missing vdevs.
2243 	 */
2244 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2245 	    &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2246 	    rvd->vdev_guid_sum != ub->ub_guid_sum)
2247 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2248 
2249 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2250 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2251 		spa_try_repair(spa, config);
2252 		spa_config_exit(spa, SCL_ALL, FTAG);
2253 		nvlist_free(spa->spa_config_splitting);
2254 		spa->spa_config_splitting = NULL;
2255 	}
2256 
2257 	/*
2258 	 * Initialize internal SPA structures.
2259 	 */
2260 	spa->spa_state = POOL_STATE_ACTIVE;
2261 	spa->spa_ubsync = spa->spa_uberblock;
2262 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2263 	    TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2264 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2265 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2266 	spa->spa_claim_max_txg = spa->spa_first_txg;
2267 	spa->spa_prev_software_version = ub->ub_software_version;
2268 
2269 	error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2270 	if (error)
2271 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2272 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2273 
2274 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2275 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2276 
2277 	if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2278 		boolean_t missing_feat_read = B_FALSE;
2279 		nvlist_t *unsup_feat, *enabled_feat;
2280 
2281 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2282 		    &spa->spa_feat_for_read_obj) != 0) {
2283 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2284 		}
2285 
2286 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2287 		    &spa->spa_feat_for_write_obj) != 0) {
2288 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2289 		}
2290 
2291 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2292 		    &spa->spa_feat_desc_obj) != 0) {
2293 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2294 		}
2295 
2296 		enabled_feat = fnvlist_alloc();
2297 		unsup_feat = fnvlist_alloc();
2298 
2299 		if (!feature_is_supported(spa->spa_meta_objset,
2300 		    spa->spa_feat_for_read_obj, spa->spa_feat_desc_obj,
2301 		    unsup_feat, enabled_feat))
2302 			missing_feat_read = B_TRUE;
2303 
2304 		if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2305 			if (!feature_is_supported(spa->spa_meta_objset,
2306 			    spa->spa_feat_for_write_obj, spa->spa_feat_desc_obj,
2307 			    unsup_feat, enabled_feat)) {
2308 				missing_feat_write = B_TRUE;
2309 			}
2310 		}
2311 
2312 		fnvlist_add_nvlist(spa->spa_load_info,
2313 		    ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2314 
2315 		if (!nvlist_empty(unsup_feat)) {
2316 			fnvlist_add_nvlist(spa->spa_load_info,
2317 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2318 		}
2319 
2320 		fnvlist_free(enabled_feat);
2321 		fnvlist_free(unsup_feat);
2322 
2323 		if (!missing_feat_read) {
2324 			fnvlist_add_boolean(spa->spa_load_info,
2325 			    ZPOOL_CONFIG_CAN_RDONLY);
2326 		}
2327 
2328 		/*
2329 		 * If the state is SPA_LOAD_TRYIMPORT, our objective is
2330 		 * twofold: to determine whether the pool is available for
2331 		 * import in read-write mode and (if it is not) whether the
2332 		 * pool is available for import in read-only mode. If the pool
2333 		 * is available for import in read-write mode, it is displayed
2334 		 * as available in userland; if it is not available for import
2335 		 * in read-only mode, it is displayed as unavailable in
2336 		 * userland. If the pool is available for import in read-only
2337 		 * mode but not read-write mode, it is displayed as unavailable
2338 		 * in userland with a special note that the pool is actually
2339 		 * available for open in read-only mode.
2340 		 *
2341 		 * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2342 		 * missing a feature for write, we must first determine whether
2343 		 * the pool can be opened read-only before returning to
2344 		 * userland in order to know whether to display the
2345 		 * abovementioned note.
2346 		 */
2347 		if (missing_feat_read || (missing_feat_write &&
2348 		    spa_writeable(spa))) {
2349 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2350 			    ENOTSUP));
2351 		}
2352 	}
2353 
2354 	spa->spa_is_initializing = B_TRUE;
2355 	error = dsl_pool_open(spa->spa_dsl_pool);
2356 	spa->spa_is_initializing = B_FALSE;
2357 	if (error != 0)
2358 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2359 
2360 	if (!mosconfig) {
2361 		uint64_t hostid;
2362 		nvlist_t *policy = NULL, *nvconfig;
2363 
2364 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2365 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2366 
2367 		if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2368 		    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2369 			char *hostname;
2370 			unsigned long myhostid = 0;
2371 
2372 			VERIFY(nvlist_lookup_string(nvconfig,
2373 			    ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2374 
2375 #ifdef	_KERNEL
2376 			myhostid = zone_get_hostid(NULL);
2377 #else	/* _KERNEL */
2378 			/*
2379 			 * We're emulating the system's hostid in userland, so
2380 			 * we can't use zone_get_hostid().
2381 			 */
2382 			(void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2383 #endif	/* _KERNEL */
2384 			if (hostid != 0 && myhostid != 0 &&
2385 			    hostid != myhostid) {
2386 				nvlist_free(nvconfig);
2387 				cmn_err(CE_WARN, "pool '%s' could not be "
2388 				    "loaded as it was last accessed by "
2389 				    "another system (host: %s hostid: 0x%lx). "
2390 				    "See: http://illumos.org/msg/ZFS-8000-EY",
2391 				    spa_name(spa), hostname,
2392 				    (unsigned long)hostid);
2393 				return (SET_ERROR(EBADF));
2394 			}
2395 		}
2396 		if (nvlist_lookup_nvlist(spa->spa_config,
2397 		    ZPOOL_REWIND_POLICY, &policy) == 0)
2398 			VERIFY(nvlist_add_nvlist(nvconfig,
2399 			    ZPOOL_REWIND_POLICY, policy) == 0);
2400 
2401 		spa_config_set(spa, nvconfig);
2402 		spa_unload(spa);
2403 		spa_deactivate(spa);
2404 		spa_activate(spa, orig_mode);
2405 
2406 		return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2407 	}
2408 
2409 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2410 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2411 	error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2412 	if (error != 0)
2413 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2414 
2415 	/*
2416 	 * Load the bit that tells us to use the new accounting function
2417 	 * (raid-z deflation).  If we have an older pool, this will not
2418 	 * be present.
2419 	 */
2420 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2421 	if (error != 0 && error != ENOENT)
2422 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2423 
2424 	error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2425 	    &spa->spa_creation_version);
2426 	if (error != 0 && error != ENOENT)
2427 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2428 
2429 	/*
2430 	 * Load the persistent error log.  If we have an older pool, this will
2431 	 * not be present.
2432 	 */
2433 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2434 	if (error != 0 && error != ENOENT)
2435 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2436 
2437 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2438 	    &spa->spa_errlog_scrub);
2439 	if (error != 0 && error != ENOENT)
2440 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2441 
2442 	/*
2443 	 * Load the history object.  If we have an older pool, this
2444 	 * will not be present.
2445 	 */
2446 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2447 	if (error != 0 && error != ENOENT)
2448 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2449 
2450 	/*
2451 	 * If we're assembling the pool from the split-off vdevs of
2452 	 * an existing pool, we don't want to attach the spares & cache
2453 	 * devices.
2454 	 */
2455 
2456 	/*
2457 	 * Load any hot spares for this pool.
2458 	 */
2459 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2460 	if (error != 0 && error != ENOENT)
2461 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2462 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2463 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2464 		if (load_nvlist(spa, spa->spa_spares.sav_object,
2465 		    &spa->spa_spares.sav_config) != 0)
2466 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2467 
2468 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2469 		spa_load_spares(spa);
2470 		spa_config_exit(spa, SCL_ALL, FTAG);
2471 	} else if (error == 0) {
2472 		spa->spa_spares.sav_sync = B_TRUE;
2473 	}
2474 
2475 	/*
2476 	 * Load any level 2 ARC devices for this pool.
2477 	 */
2478 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2479 	    &spa->spa_l2cache.sav_object);
2480 	if (error != 0 && error != ENOENT)
2481 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2482 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2483 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2484 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2485 		    &spa->spa_l2cache.sav_config) != 0)
2486 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2487 
2488 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2489 		spa_load_l2cache(spa);
2490 		spa_config_exit(spa, SCL_ALL, FTAG);
2491 	} else if (error == 0) {
2492 		spa->spa_l2cache.sav_sync = B_TRUE;
2493 	}
2494 
2495 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2496 
2497 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2498 	if (error && error != ENOENT)
2499 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2500 
2501 	if (error == 0) {
2502 		uint64_t autoreplace;
2503 
2504 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2505 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2506 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2507 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2508 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2509 		spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2510 		    &spa->spa_dedup_ditto);
2511 
2512 		spa->spa_autoreplace = (autoreplace != 0);
2513 	}
2514 
2515 	/*
2516 	 * If the 'autoreplace' property is set, then post a resource notifying
2517 	 * the ZFS DE that it should not issue any faults for unopenable
2518 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
2519 	 * unopenable vdevs so that the normal autoreplace handler can take
2520 	 * over.
2521 	 */
2522 	if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2523 		spa_check_removed(spa->spa_root_vdev);
2524 		/*
2525 		 * For the import case, this is done in spa_import(), because
2526 		 * at this point we're using the spare definitions from
2527 		 * the MOS config, not necessarily from the userland config.
2528 		 */
2529 		if (state != SPA_LOAD_IMPORT) {
2530 			spa_aux_check_removed(&spa->spa_spares);
2531 			spa_aux_check_removed(&spa->spa_l2cache);
2532 		}
2533 	}
2534 
2535 	/*
2536 	 * Load the vdev state for all toplevel vdevs.
2537 	 */
2538 	vdev_load(rvd);
2539 
2540 	/*
2541 	 * Propagate the leaf DTLs we just loaded all the way up the tree.
2542 	 */
2543 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2544 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2545 	spa_config_exit(spa, SCL_ALL, FTAG);
2546 
2547 	/*
2548 	 * Load the DDTs (dedup tables).
2549 	 */
2550 	error = ddt_load(spa);
2551 	if (error != 0)
2552 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2553 
2554 	spa_update_dspace(spa);
2555 
2556 	/*
2557 	 * Validate the config, using the MOS config to fill in any
2558 	 * information which might be missing.  If we fail to validate
2559 	 * the config then declare the pool unfit for use. If we're
2560 	 * assembling a pool from a split, the log is not transferred
2561 	 * over.
2562 	 */
2563 	if (type != SPA_IMPORT_ASSEMBLE) {
2564 		nvlist_t *nvconfig;
2565 
2566 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2567 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2568 
2569 		if (!spa_config_valid(spa, nvconfig)) {
2570 			nvlist_free(nvconfig);
2571 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2572 			    ENXIO));
2573 		}
2574 		nvlist_free(nvconfig);
2575 
2576 		/*
2577 		 * Now that we've validated the config, check the state of the
2578 		 * root vdev.  If it can't be opened, it indicates one or
2579 		 * more toplevel vdevs are faulted.
2580 		 */
2581 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2582 			return (SET_ERROR(ENXIO));
2583 
2584 		if (spa_check_logs(spa)) {
2585 			*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2586 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2587 		}
2588 	}
2589 
2590 	if (missing_feat_write) {
2591 		ASSERT(state == SPA_LOAD_TRYIMPORT);
2592 
2593 		/*
2594 		 * At this point, we know that we can open the pool in
2595 		 * read-only mode but not read-write mode. We now have enough
2596 		 * information and can return to userland.
2597 		 */
2598 		return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2599 	}
2600 
2601 	/*
2602 	 * We've successfully opened the pool, verify that we're ready
2603 	 * to start pushing transactions.
2604 	 */
2605 	if (state != SPA_LOAD_TRYIMPORT) {
2606 		if (error = spa_load_verify(spa))
2607 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2608 			    error));
2609 	}
2610 
2611 	if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2612 	    spa->spa_load_max_txg == UINT64_MAX)) {
2613 		dmu_tx_t *tx;
2614 		int need_update = B_FALSE;
2615 
2616 		ASSERT(state != SPA_LOAD_TRYIMPORT);
2617 
2618 		/*
2619 		 * Claim log blocks that haven't been committed yet.
2620 		 * This must all happen in a single txg.
2621 		 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2622 		 * invoked from zil_claim_log_block()'s i/o done callback.
2623 		 * Price of rollback is that we abandon the log.
2624 		 */
2625 		spa->spa_claiming = B_TRUE;
2626 
2627 		tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2628 		    spa_first_txg(spa));
2629 		(void) dmu_objset_find(spa_name(spa),
2630 		    zil_claim, tx, DS_FIND_CHILDREN);
2631 		dmu_tx_commit(tx);
2632 
2633 		spa->spa_claiming = B_FALSE;
2634 
2635 		spa_set_log_state(spa, SPA_LOG_GOOD);
2636 		spa->spa_sync_on = B_TRUE;
2637 		txg_sync_start(spa->spa_dsl_pool);
2638 
2639 		/*
2640 		 * Wait for all claims to sync.  We sync up to the highest
2641 		 * claimed log block birth time so that claimed log blocks
2642 		 * don't appear to be from the future.  spa_claim_max_txg
2643 		 * will have been set for us by either zil_check_log_chain()
2644 		 * (invoked from spa_check_logs()) or zil_claim() above.
2645 		 */
2646 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2647 
2648 		/*
2649 		 * If the config cache is stale, or we have uninitialized
2650 		 * metaslabs (see spa_vdev_add()), then update the config.
2651 		 *
2652 		 * If this is a verbatim import, trust the current
2653 		 * in-core spa_config and update the disk labels.
2654 		 */
2655 		if (config_cache_txg != spa->spa_config_txg ||
2656 		    state == SPA_LOAD_IMPORT ||
2657 		    state == SPA_LOAD_RECOVER ||
2658 		    (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2659 			need_update = B_TRUE;
2660 
2661 		for (int c = 0; c < rvd->vdev_children; c++)
2662 			if (rvd->vdev_child[c]->vdev_ms_array == 0)
2663 				need_update = B_TRUE;
2664 
2665 		/*
2666 		 * Update the config cache asychronously in case we're the
2667 		 * root pool, in which case the config cache isn't writable yet.
2668 		 */
2669 		if (need_update)
2670 			spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2671 
2672 		/*
2673 		 * Check all DTLs to see if anything needs resilvering.
2674 		 */
2675 		if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2676 		    vdev_resilver_needed(rvd, NULL, NULL))
2677 			spa_async_request(spa, SPA_ASYNC_RESILVER);
2678 
2679 		/*
2680 		 * Log the fact that we booted up (so that we can detect if
2681 		 * we rebooted in the middle of an operation).
2682 		 */
2683 		spa_history_log_version(spa, "open");
2684 
2685 		/*
2686 		 * Delete any inconsistent datasets.
2687 		 */
2688 		(void) dmu_objset_find(spa_name(spa),
2689 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2690 
2691 		/*
2692 		 * Clean up any stale temporary dataset userrefs.
2693 		 */
2694 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2695 	}
2696 
2697 	return (0);
2698 }
2699 
2700 static int
2701 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2702 {
2703 	int mode = spa->spa_mode;
2704 
2705 	spa_unload(spa);
2706 	spa_deactivate(spa);
2707 
2708 	spa->spa_load_max_txg--;
2709 
2710 	spa_activate(spa, mode);
2711 	spa_async_suspend(spa);
2712 
2713 	return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2714 }
2715 
2716 /*
2717  * If spa_load() fails this function will try loading prior txg's. If
2718  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2719  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2720  * function will not rewind the pool and will return the same error as
2721  * spa_load().
2722  */
2723 static int
2724 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2725     uint64_t max_request, int rewind_flags)
2726 {
2727 	nvlist_t *loadinfo = NULL;
2728 	nvlist_t *config = NULL;
2729 	int load_error, rewind_error;
2730 	uint64_t safe_rewind_txg;
2731 	uint64_t min_txg;
2732 
2733 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2734 		spa->spa_load_max_txg = spa->spa_load_txg;
2735 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2736 	} else {
2737 		spa->spa_load_max_txg = max_request;
2738 	}
2739 
2740 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2741 	    mosconfig);
2742 	if (load_error == 0)
2743 		return (0);
2744 
2745 	if (spa->spa_root_vdev != NULL)
2746 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2747 
2748 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2749 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2750 
2751 	if (rewind_flags & ZPOOL_NEVER_REWIND) {
2752 		nvlist_free(config);
2753 		return (load_error);
2754 	}
2755 
2756 	if (state == SPA_LOAD_RECOVER) {
2757 		/* Price of rolling back is discarding txgs, including log */
2758 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2759 	} else {
2760 		/*
2761 		 * If we aren't rolling back save the load info from our first
2762 		 * import attempt so that we can restore it after attempting
2763 		 * to rewind.
2764 		 */
2765 		loadinfo = spa->spa_load_info;
2766 		spa->spa_load_info = fnvlist_alloc();
2767 	}
2768 
2769 	spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2770 	safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2771 	min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2772 	    TXG_INITIAL : safe_rewind_txg;
2773 
2774 	/*
2775 	 * Continue as long as we're finding errors, we're still within
2776 	 * the acceptable rewind range, and we're still finding uberblocks
2777 	 */
2778 	while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2779 	    spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2780 		if (spa->spa_load_max_txg < safe_rewind_txg)
2781 			spa->spa_extreme_rewind = B_TRUE;
2782 		rewind_error = spa_load_retry(spa, state, mosconfig);
2783 	}
2784 
2785 	spa->spa_extreme_rewind = B_FALSE;
2786 	spa->spa_load_max_txg = UINT64_MAX;
2787 
2788 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2789 		spa_config_set(spa, config);
2790 
2791 	if (state == SPA_LOAD_RECOVER) {
2792 		ASSERT3P(loadinfo, ==, NULL);
2793 		return (rewind_error);
2794 	} else {
2795 		/* Store the rewind info as part of the initial load info */
2796 		fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2797 		    spa->spa_load_info);
2798 
2799 		/* Restore the initial load info */
2800 		fnvlist_free(spa->spa_load_info);
2801 		spa->spa_load_info = loadinfo;
2802 
2803 		return (load_error);
2804 	}
2805 }
2806 
2807 /*
2808  * Pool Open/Import
2809  *
2810  * The import case is identical to an open except that the configuration is sent
2811  * down from userland, instead of grabbed from the configuration cache.  For the
2812  * case of an open, the pool configuration will exist in the
2813  * POOL_STATE_UNINITIALIZED state.
2814  *
2815  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2816  * the same time open the pool, without having to keep around the spa_t in some
2817  * ambiguous state.
2818  */
2819 static int
2820 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2821     nvlist_t **config)
2822 {
2823 	spa_t *spa;
2824 	spa_load_state_t state = SPA_LOAD_OPEN;
2825 	int error;
2826 	int locked = B_FALSE;
2827 
2828 	*spapp = NULL;
2829 
2830 	/*
2831 	 * As disgusting as this is, we need to support recursive calls to this
2832 	 * function because dsl_dir_open() is called during spa_load(), and ends
2833 	 * up calling spa_open() again.  The real fix is to figure out how to
2834 	 * avoid dsl_dir_open() calling this in the first place.
2835 	 */
2836 	if (mutex_owner(&spa_namespace_lock) != curthread) {
2837 		mutex_enter(&spa_namespace_lock);
2838 		locked = B_TRUE;
2839 	}
2840 
2841 	if ((spa = spa_lookup(pool)) == NULL) {
2842 		if (locked)
2843 			mutex_exit(&spa_namespace_lock);
2844 		return (SET_ERROR(ENOENT));
2845 	}
2846 
2847 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2848 		zpool_rewind_policy_t policy;
2849 
2850 		zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2851 		    &policy);
2852 		if (policy.zrp_request & ZPOOL_DO_REWIND)
2853 			state = SPA_LOAD_RECOVER;
2854 
2855 		spa_activate(spa, spa_mode_global);
2856 
2857 		if (state != SPA_LOAD_RECOVER)
2858 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2859 
2860 		error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2861 		    policy.zrp_request);
2862 
2863 		if (error == EBADF) {
2864 			/*
2865 			 * If vdev_validate() returns failure (indicated by
2866 			 * EBADF), it indicates that one of the vdevs indicates
2867 			 * that the pool has been exported or destroyed.  If
2868 			 * this is the case, the config cache is out of sync and
2869 			 * we should remove the pool from the namespace.
2870 			 */
2871 			spa_unload(spa);
2872 			spa_deactivate(spa);
2873 			spa_config_sync(spa, B_TRUE, B_TRUE);
2874 			spa_remove(spa);
2875 			if (locked)
2876 				mutex_exit(&spa_namespace_lock);
2877 			return (SET_ERROR(ENOENT));
2878 		}
2879 
2880 		if (error) {
2881 			/*
2882 			 * We can't open the pool, but we still have useful
2883 			 * information: the state of each vdev after the
2884 			 * attempted vdev_open().  Return this to the user.
2885 			 */
2886 			if (config != NULL && spa->spa_config) {
2887 				VERIFY(nvlist_dup(spa->spa_config, config,
2888 				    KM_SLEEP) == 0);
2889 				VERIFY(nvlist_add_nvlist(*config,
2890 				    ZPOOL_CONFIG_LOAD_INFO,
2891 				    spa->spa_load_info) == 0);
2892 			}
2893 			spa_unload(spa);
2894 			spa_deactivate(spa);
2895 			spa->spa_last_open_failed = error;
2896 			if (locked)
2897 				mutex_exit(&spa_namespace_lock);
2898 			*spapp = NULL;
2899 			return (error);
2900 		}
2901 	}
2902 
2903 	spa_open_ref(spa, tag);
2904 
2905 	if (config != NULL)
2906 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2907 
2908 	/*
2909 	 * If we've recovered the pool, pass back any information we
2910 	 * gathered while doing the load.
2911 	 */
2912 	if (state == SPA_LOAD_RECOVER) {
2913 		VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2914 		    spa->spa_load_info) == 0);
2915 	}
2916 
2917 	if (locked) {
2918 		spa->spa_last_open_failed = 0;
2919 		spa->spa_last_ubsync_txg = 0;
2920 		spa->spa_load_txg = 0;
2921 		mutex_exit(&spa_namespace_lock);
2922 	}
2923 
2924 	*spapp = spa;
2925 
2926 	return (0);
2927 }
2928 
2929 int
2930 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2931     nvlist_t **config)
2932 {
2933 	return (spa_open_common(name, spapp, tag, policy, config));
2934 }
2935 
2936 int
2937 spa_open(const char *name, spa_t **spapp, void *tag)
2938 {
2939 	return (spa_open_common(name, spapp, tag, NULL, NULL));
2940 }
2941 
2942 /*
2943  * Lookup the given spa_t, incrementing the inject count in the process,
2944  * preventing it from being exported or destroyed.
2945  */
2946 spa_t *
2947 spa_inject_addref(char *name)
2948 {
2949 	spa_t *spa;
2950 
2951 	mutex_enter(&spa_namespace_lock);
2952 	if ((spa = spa_lookup(name)) == NULL) {
2953 		mutex_exit(&spa_namespace_lock);
2954 		return (NULL);
2955 	}
2956 	spa->spa_inject_ref++;
2957 	mutex_exit(&spa_namespace_lock);
2958 
2959 	return (spa);
2960 }
2961 
2962 void
2963 spa_inject_delref(spa_t *spa)
2964 {
2965 	mutex_enter(&spa_namespace_lock);
2966 	spa->spa_inject_ref--;
2967 	mutex_exit(&spa_namespace_lock);
2968 }
2969 
2970 /*
2971  * Add spares device information to the nvlist.
2972  */
2973 static void
2974 spa_add_spares(spa_t *spa, nvlist_t *config)
2975 {
2976 	nvlist_t **spares;
2977 	uint_t i, nspares;
2978 	nvlist_t *nvroot;
2979 	uint64_t guid;
2980 	vdev_stat_t *vs;
2981 	uint_t vsc;
2982 	uint64_t pool;
2983 
2984 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
2985 
2986 	if (spa->spa_spares.sav_count == 0)
2987 		return;
2988 
2989 	VERIFY(nvlist_lookup_nvlist(config,
2990 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
2991 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
2992 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2993 	if (nspares != 0) {
2994 		VERIFY(nvlist_add_nvlist_array(nvroot,
2995 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2996 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
2997 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
2998 
2999 		/*
3000 		 * Go through and find any spares which have since been
3001 		 * repurposed as an active spare.  If this is the case, update
3002 		 * their status appropriately.
3003 		 */
3004 		for (i = 0; i < nspares; i++) {
3005 			VERIFY(nvlist_lookup_uint64(spares[i],
3006 			    ZPOOL_CONFIG_GUID, &guid) == 0);
3007 			if (spa_spare_exists(guid, &pool, NULL) &&
3008 			    pool != 0ULL) {
3009 				VERIFY(nvlist_lookup_uint64_array(
3010 				    spares[i], ZPOOL_CONFIG_VDEV_STATS,
3011 				    (uint64_t **)&vs, &vsc) == 0);
3012 				vs->vs_state = VDEV_STATE_CANT_OPEN;
3013 				vs->vs_aux = VDEV_AUX_SPARED;
3014 			}
3015 		}
3016 	}
3017 }
3018 
3019 /*
3020  * Add l2cache device information to the nvlist, including vdev stats.
3021  */
3022 static void
3023 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3024 {
3025 	nvlist_t **l2cache;
3026 	uint_t i, j, nl2cache;
3027 	nvlist_t *nvroot;
3028 	uint64_t guid;
3029 	vdev_t *vd;
3030 	vdev_stat_t *vs;
3031 	uint_t vsc;
3032 
3033 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3034 
3035 	if (spa->spa_l2cache.sav_count == 0)
3036 		return;
3037 
3038 	VERIFY(nvlist_lookup_nvlist(config,
3039 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3040 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3041 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3042 	if (nl2cache != 0) {
3043 		VERIFY(nvlist_add_nvlist_array(nvroot,
3044 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3045 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
3046 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3047 
3048 		/*
3049 		 * Update level 2 cache device stats.
3050 		 */
3051 
3052 		for (i = 0; i < nl2cache; i++) {
3053 			VERIFY(nvlist_lookup_uint64(l2cache[i],
3054 			    ZPOOL_CONFIG_GUID, &guid) == 0);
3055 
3056 			vd = NULL;
3057 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3058 				if (guid ==
3059 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3060 					vd = spa->spa_l2cache.sav_vdevs[j];
3061 					break;
3062 				}
3063 			}
3064 			ASSERT(vd != NULL);
3065 
3066 			VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3067 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3068 			    == 0);
3069 			vdev_get_stats(vd, vs);
3070 		}
3071 	}
3072 }
3073 
3074 static void
3075 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3076 {
3077 	nvlist_t *features;
3078 	zap_cursor_t zc;
3079 	zap_attribute_t za;
3080 
3081 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3082 	VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3083 
3084 	if (spa->spa_feat_for_read_obj != 0) {
3085 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3086 		    spa->spa_feat_for_read_obj);
3087 		    zap_cursor_retrieve(&zc, &za) == 0;
3088 		    zap_cursor_advance(&zc)) {
3089 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3090 			    za.za_num_integers == 1);
3091 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3092 			    za.za_first_integer));
3093 		}
3094 		zap_cursor_fini(&zc);
3095 	}
3096 
3097 	if (spa->spa_feat_for_write_obj != 0) {
3098 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3099 		    spa->spa_feat_for_write_obj);
3100 		    zap_cursor_retrieve(&zc, &za) == 0;
3101 		    zap_cursor_advance(&zc)) {
3102 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3103 			    za.za_num_integers == 1);
3104 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3105 			    za.za_first_integer));
3106 		}
3107 		zap_cursor_fini(&zc);
3108 	}
3109 
3110 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3111 	    features) == 0);
3112 	nvlist_free(features);
3113 }
3114 
3115 int
3116 spa_get_stats(const char *name, nvlist_t **config,
3117     char *altroot, size_t buflen)
3118 {
3119 	int error;
3120 	spa_t *spa;
3121 
3122 	*config = NULL;
3123 	error = spa_open_common(name, &spa, FTAG, NULL, config);
3124 
3125 	if (spa != NULL) {
3126 		/*
3127 		 * This still leaves a window of inconsistency where the spares
3128 		 * or l2cache devices could change and the config would be
3129 		 * self-inconsistent.
3130 		 */
3131 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3132 
3133 		if (*config != NULL) {
3134 			uint64_t loadtimes[2];
3135 
3136 			loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3137 			loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3138 			VERIFY(nvlist_add_uint64_array(*config,
3139 			    ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3140 
3141 			VERIFY(nvlist_add_uint64(*config,
3142 			    ZPOOL_CONFIG_ERRCOUNT,
3143 			    spa_get_errlog_size(spa)) == 0);
3144 
3145 			if (spa_suspended(spa))
3146 				VERIFY(nvlist_add_uint64(*config,
3147 				    ZPOOL_CONFIG_SUSPENDED,
3148 				    spa->spa_failmode) == 0);
3149 
3150 			spa_add_spares(spa, *config);
3151 			spa_add_l2cache(spa, *config);
3152 			spa_add_feature_stats(spa, *config);
3153 		}
3154 	}
3155 
3156 	/*
3157 	 * We want to get the alternate root even for faulted pools, so we cheat
3158 	 * and call spa_lookup() directly.
3159 	 */
3160 	if (altroot) {
3161 		if (spa == NULL) {
3162 			mutex_enter(&spa_namespace_lock);
3163 			spa = spa_lookup(name);
3164 			if (spa)
3165 				spa_altroot(spa, altroot, buflen);
3166 			else
3167 				altroot[0] = '\0';
3168 			spa = NULL;
3169 			mutex_exit(&spa_namespace_lock);
3170 		} else {
3171 			spa_altroot(spa, altroot, buflen);
3172 		}
3173 	}
3174 
3175 	if (spa != NULL) {
3176 		spa_config_exit(spa, SCL_CONFIG, FTAG);
3177 		spa_close(spa, FTAG);
3178 	}
3179 
3180 	return (error);
3181 }
3182 
3183 /*
3184  * Validate that the auxiliary device array is well formed.  We must have an
3185  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3186  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3187  * specified, as long as they are well-formed.
3188  */
3189 static int
3190 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3191     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3192     vdev_labeltype_t label)
3193 {
3194 	nvlist_t **dev;
3195 	uint_t i, ndev;
3196 	vdev_t *vd;
3197 	int error;
3198 
3199 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3200 
3201 	/*
3202 	 * It's acceptable to have no devs specified.
3203 	 */
3204 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3205 		return (0);
3206 
3207 	if (ndev == 0)
3208 		return (SET_ERROR(EINVAL));
3209 
3210 	/*
3211 	 * Make sure the pool is formatted with a version that supports this
3212 	 * device type.
3213 	 */
3214 	if (spa_version(spa) < version)
3215 		return (SET_ERROR(ENOTSUP));
3216 
3217 	/*
3218 	 * Set the pending device list so we correctly handle device in-use
3219 	 * checking.
3220 	 */
3221 	sav->sav_pending = dev;
3222 	sav->sav_npending = ndev;
3223 
3224 	for (i = 0; i < ndev; i++) {
3225 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3226 		    mode)) != 0)
3227 			goto out;
3228 
3229 		if (!vd->vdev_ops->vdev_op_leaf) {
3230 			vdev_free(vd);
3231 			error = SET_ERROR(EINVAL);
3232 			goto out;
3233 		}
3234 
3235 		/*
3236 		 * The L2ARC currently only supports disk devices in
3237 		 * kernel context.  For user-level testing, we allow it.
3238 		 */
3239 #ifdef _KERNEL
3240 		if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3241 		    strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3242 			error = SET_ERROR(ENOTBLK);
3243 			vdev_free(vd);
3244 			goto out;
3245 		}
3246 #endif
3247 		vd->vdev_top = vd;
3248 
3249 		if ((error = vdev_open(vd)) == 0 &&
3250 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
3251 			VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3252 			    vd->vdev_guid) == 0);
3253 		}
3254 
3255 		vdev_free(vd);
3256 
3257 		if (error &&
3258 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3259 			goto out;
3260 		else
3261 			error = 0;
3262 	}
3263 
3264 out:
3265 	sav->sav_pending = NULL;
3266 	sav->sav_npending = 0;
3267 	return (error);
3268 }
3269 
3270 static int
3271 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3272 {
3273 	int error;
3274 
3275 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3276 
3277 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3278 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3279 	    VDEV_LABEL_SPARE)) != 0) {
3280 		return (error);
3281 	}
3282 
3283 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3284 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3285 	    VDEV_LABEL_L2CACHE));
3286 }
3287 
3288 static void
3289 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3290     const char *config)
3291 {
3292 	int i;
3293 
3294 	if (sav->sav_config != NULL) {
3295 		nvlist_t **olddevs;
3296 		uint_t oldndevs;
3297 		nvlist_t **newdevs;
3298 
3299 		/*
3300 		 * Generate new dev list by concatentating with the
3301 		 * current dev list.
3302 		 */
3303 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3304 		    &olddevs, &oldndevs) == 0);
3305 
3306 		newdevs = kmem_alloc(sizeof (void *) *
3307 		    (ndevs + oldndevs), KM_SLEEP);
3308 		for (i = 0; i < oldndevs; i++)
3309 			VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3310 			    KM_SLEEP) == 0);
3311 		for (i = 0; i < ndevs; i++)
3312 			VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3313 			    KM_SLEEP) == 0);
3314 
3315 		VERIFY(nvlist_remove(sav->sav_config, config,
3316 		    DATA_TYPE_NVLIST_ARRAY) == 0);
3317 
3318 		VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3319 		    config, newdevs, ndevs + oldndevs) == 0);
3320 		for (i = 0; i < oldndevs + ndevs; i++)
3321 			nvlist_free(newdevs[i]);
3322 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3323 	} else {
3324 		/*
3325 		 * Generate a new dev list.
3326 		 */
3327 		VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3328 		    KM_SLEEP) == 0);
3329 		VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3330 		    devs, ndevs) == 0);
3331 	}
3332 }
3333 
3334 /*
3335  * Stop and drop level 2 ARC devices
3336  */
3337 void
3338 spa_l2cache_drop(spa_t *spa)
3339 {
3340 	vdev_t *vd;
3341 	int i;
3342 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
3343 
3344 	for (i = 0; i < sav->sav_count; i++) {
3345 		uint64_t pool;
3346 
3347 		vd = sav->sav_vdevs[i];
3348 		ASSERT(vd != NULL);
3349 
3350 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3351 		    pool != 0ULL && l2arc_vdev_present(vd))
3352 			l2arc_remove_vdev(vd);
3353 	}
3354 }
3355 
3356 /*
3357  * Pool Creation
3358  */
3359 int
3360 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3361     nvlist_t *zplprops)
3362 {
3363 	spa_t *spa;
3364 	char *altroot = NULL;
3365 	vdev_t *rvd;
3366 	dsl_pool_t *dp;
3367 	dmu_tx_t *tx;
3368 	int error = 0;
3369 	uint64_t txg = TXG_INITIAL;
3370 	nvlist_t **spares, **l2cache;
3371 	uint_t nspares, nl2cache;
3372 	uint64_t version, obj;
3373 	boolean_t has_features;
3374 
3375 	/*
3376 	 * If this pool already exists, return failure.
3377 	 */
3378 	mutex_enter(&spa_namespace_lock);
3379 	if (spa_lookup(pool) != NULL) {
3380 		mutex_exit(&spa_namespace_lock);
3381 		return (SET_ERROR(EEXIST));
3382 	}
3383 
3384 	/*
3385 	 * Allocate a new spa_t structure.
3386 	 */
3387 	(void) nvlist_lookup_string(props,
3388 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3389 	spa = spa_add(pool, NULL, altroot);
3390 	spa_activate(spa, spa_mode_global);
3391 
3392 	if (props && (error = spa_prop_validate(spa, props))) {
3393 		spa_deactivate(spa);
3394 		spa_remove(spa);
3395 		mutex_exit(&spa_namespace_lock);
3396 		return (error);
3397 	}
3398 
3399 	has_features = B_FALSE;
3400 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3401 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3402 		if (zpool_prop_feature(nvpair_name(elem)))
3403 			has_features = B_TRUE;
3404 	}
3405 
3406 	if (has_features || nvlist_lookup_uint64(props,
3407 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3408 		version = SPA_VERSION;
3409 	}
3410 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3411 
3412 	spa->spa_first_txg = txg;
3413 	spa->spa_uberblock.ub_txg = txg - 1;
3414 	spa->spa_uberblock.ub_version = version;
3415 	spa->spa_ubsync = spa->spa_uberblock;
3416 
3417 	/*
3418 	 * Create "The Godfather" zio to hold all async IOs
3419 	 */
3420 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3421 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3422 
3423 	/*
3424 	 * Create the root vdev.
3425 	 */
3426 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3427 
3428 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3429 
3430 	ASSERT(error != 0 || rvd != NULL);
3431 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3432 
3433 	if (error == 0 && !zfs_allocatable_devs(nvroot))
3434 		error = SET_ERROR(EINVAL);
3435 
3436 	if (error == 0 &&
3437 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3438 	    (error = spa_validate_aux(spa, nvroot, txg,
3439 	    VDEV_ALLOC_ADD)) == 0) {
3440 		for (int c = 0; c < rvd->vdev_children; c++) {
3441 			vdev_metaslab_set_size(rvd->vdev_child[c]);
3442 			vdev_expand(rvd->vdev_child[c], txg);
3443 		}
3444 	}
3445 
3446 	spa_config_exit(spa, SCL_ALL, FTAG);
3447 
3448 	if (error != 0) {
3449 		spa_unload(spa);
3450 		spa_deactivate(spa);
3451 		spa_remove(spa);
3452 		mutex_exit(&spa_namespace_lock);
3453 		return (error);
3454 	}
3455 
3456 	/*
3457 	 * Get the list of spares, if specified.
3458 	 */
3459 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3460 	    &spares, &nspares) == 0) {
3461 		VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3462 		    KM_SLEEP) == 0);
3463 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3464 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3465 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3466 		spa_load_spares(spa);
3467 		spa_config_exit(spa, SCL_ALL, FTAG);
3468 		spa->spa_spares.sav_sync = B_TRUE;
3469 	}
3470 
3471 	/*
3472 	 * Get the list of level 2 cache devices, if specified.
3473 	 */
3474 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3475 	    &l2cache, &nl2cache) == 0) {
3476 		VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3477 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3478 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3479 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3480 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3481 		spa_load_l2cache(spa);
3482 		spa_config_exit(spa, SCL_ALL, FTAG);
3483 		spa->spa_l2cache.sav_sync = B_TRUE;
3484 	}
3485 
3486 	spa->spa_is_initializing = B_TRUE;
3487 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3488 	spa->spa_meta_objset = dp->dp_meta_objset;
3489 	spa->spa_is_initializing = B_FALSE;
3490 
3491 	/*
3492 	 * Create DDTs (dedup tables).
3493 	 */
3494 	ddt_create(spa);
3495 
3496 	spa_update_dspace(spa);
3497 
3498 	tx = dmu_tx_create_assigned(dp, txg);
3499 
3500 	/*
3501 	 * Create the pool config object.
3502 	 */
3503 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3504 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3505 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3506 
3507 	if (zap_add(spa->spa_meta_objset,
3508 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3509 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3510 		cmn_err(CE_PANIC, "failed to add pool config");
3511 	}
3512 
3513 	if (spa_version(spa) >= SPA_VERSION_FEATURES)
3514 		spa_feature_create_zap_objects(spa, tx);
3515 
3516 	if (zap_add(spa->spa_meta_objset,
3517 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3518 	    sizeof (uint64_t), 1, &version, tx) != 0) {
3519 		cmn_err(CE_PANIC, "failed to add pool version");
3520 	}
3521 
3522 	/* Newly created pools with the right version are always deflated. */
3523 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3524 		spa->spa_deflate = TRUE;
3525 		if (zap_add(spa->spa_meta_objset,
3526 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3527 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3528 			cmn_err(CE_PANIC, "failed to add deflate");
3529 		}
3530 	}
3531 
3532 	/*
3533 	 * Create the deferred-free bpobj.  Turn off compression
3534 	 * because sync-to-convergence takes longer if the blocksize
3535 	 * keeps changing.
3536 	 */
3537 	obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3538 	dmu_object_set_compress(spa->spa_meta_objset, obj,
3539 	    ZIO_COMPRESS_OFF, tx);
3540 	if (zap_add(spa->spa_meta_objset,
3541 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3542 	    sizeof (uint64_t), 1, &obj, tx) != 0) {
3543 		cmn_err(CE_PANIC, "failed to add bpobj");
3544 	}
3545 	VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3546 	    spa->spa_meta_objset, obj));
3547 
3548 	/*
3549 	 * Create the pool's history object.
3550 	 */
3551 	if (version >= SPA_VERSION_ZPOOL_HISTORY)
3552 		spa_history_create_obj(spa, tx);
3553 
3554 	/*
3555 	 * Set pool properties.
3556 	 */
3557 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3558 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3559 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3560 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3561 
3562 	if (props != NULL) {
3563 		spa_configfile_set(spa, props, B_FALSE);
3564 		spa_sync_props(props, tx);
3565 	}
3566 
3567 	dmu_tx_commit(tx);
3568 
3569 	spa->spa_sync_on = B_TRUE;
3570 	txg_sync_start(spa->spa_dsl_pool);
3571 
3572 	/*
3573 	 * We explicitly wait for the first transaction to complete so that our
3574 	 * bean counters are appropriately updated.
3575 	 */
3576 	txg_wait_synced(spa->spa_dsl_pool, txg);
3577 
3578 	spa_config_sync(spa, B_FALSE, B_TRUE);
3579 
3580 	spa_history_log_version(spa, "create");
3581 
3582 	spa->spa_minref = refcount_count(&spa->spa_refcount);
3583 
3584 	mutex_exit(&spa_namespace_lock);
3585 
3586 	return (0);
3587 }
3588 
3589 #ifdef _KERNEL
3590 /*
3591  * Get the root pool information from the root disk, then import the root pool
3592  * during the system boot up time.
3593  */
3594 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3595 
3596 static nvlist_t *
3597 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3598 {
3599 	nvlist_t *config;
3600 	nvlist_t *nvtop, *nvroot;
3601 	uint64_t pgid;
3602 
3603 	if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3604 		return (NULL);
3605 
3606 	/*
3607 	 * Add this top-level vdev to the child array.
3608 	 */
3609 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3610 	    &nvtop) == 0);
3611 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3612 	    &pgid) == 0);
3613 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3614 
3615 	/*
3616 	 * Put this pool's top-level vdevs into a root vdev.
3617 	 */
3618 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3619 	VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3620 	    VDEV_TYPE_ROOT) == 0);
3621 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3622 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3623 	VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3624 	    &nvtop, 1) == 0);
3625 
3626 	/*
3627 	 * Replace the existing vdev_tree with the new root vdev in
3628 	 * this pool's configuration (remove the old, add the new).
3629 	 */
3630 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3631 	nvlist_free(nvroot);
3632 	return (config);
3633 }
3634 
3635 /*
3636  * Walk the vdev tree and see if we can find a device with "better"
3637  * configuration. A configuration is "better" if the label on that
3638  * device has a more recent txg.
3639  */
3640 static void
3641 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3642 {
3643 	for (int c = 0; c < vd->vdev_children; c++)
3644 		spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3645 
3646 	if (vd->vdev_ops->vdev_op_leaf) {
3647 		nvlist_t *label;
3648 		uint64_t label_txg;
3649 
3650 		if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3651 		    &label) != 0)
3652 			return;
3653 
3654 		VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3655 		    &label_txg) == 0);
3656 
3657 		/*
3658 		 * Do we have a better boot device?
3659 		 */
3660 		if (label_txg > *txg) {
3661 			*txg = label_txg;
3662 			*avd = vd;
3663 		}
3664 		nvlist_free(label);
3665 	}
3666 }
3667 
3668 /*
3669  * Import a root pool.
3670  *
3671  * For x86. devpath_list will consist of devid and/or physpath name of
3672  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3673  * The GRUB "findroot" command will return the vdev we should boot.
3674  *
3675  * For Sparc, devpath_list consists the physpath name of the booting device
3676  * no matter the rootpool is a single device pool or a mirrored pool.
3677  * e.g.
3678  *	"/pci@1f,0/ide@d/disk@0,0:a"
3679  */
3680 int
3681 spa_import_rootpool(char *devpath, char *devid)
3682 {
3683 	spa_t *spa;
3684 	vdev_t *rvd, *bvd, *avd = NULL;
3685 	nvlist_t *config, *nvtop;
3686 	uint64_t guid, txg;
3687 	char *pname;
3688 	int error;
3689 
3690 	/*
3691 	 * Read the label from the boot device and generate a configuration.
3692 	 */
3693 	config = spa_generate_rootconf(devpath, devid, &guid);
3694 #if defined(_OBP) && defined(_KERNEL)
3695 	if (config == NULL) {
3696 		if (strstr(devpath, "/iscsi/ssd") != NULL) {
3697 			/* iscsi boot */
3698 			get_iscsi_bootpath_phy(devpath);
3699 			config = spa_generate_rootconf(devpath, devid, &guid);
3700 		}
3701 	}
3702 #endif
3703 	if (config == NULL) {
3704 		cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3705 		    devpath);
3706 		return (SET_ERROR(EIO));
3707 	}
3708 
3709 	VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3710 	    &pname) == 0);
3711 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3712 
3713 	mutex_enter(&spa_namespace_lock);
3714 	if ((spa = spa_lookup(pname)) != NULL) {
3715 		/*
3716 		 * Remove the existing root pool from the namespace so that we
3717 		 * can replace it with the correct config we just read in.
3718 		 */
3719 		spa_remove(spa);
3720 	}
3721 
3722 	spa = spa_add(pname, config, NULL);
3723 	spa->spa_is_root = B_TRUE;
3724 	spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3725 
3726 	/*
3727 	 * Build up a vdev tree based on the boot device's label config.
3728 	 */
3729 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3730 	    &nvtop) == 0);
3731 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3732 	error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3733 	    VDEV_ALLOC_ROOTPOOL);
3734 	spa_config_exit(spa, SCL_ALL, FTAG);
3735 	if (error) {
3736 		mutex_exit(&spa_namespace_lock);
3737 		nvlist_free(config);
3738 		cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3739 		    pname);
3740 		return (error);
3741 	}
3742 
3743 	/*
3744 	 * Get the boot vdev.
3745 	 */
3746 	if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3747 		cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3748 		    (u_longlong_t)guid);
3749 		error = SET_ERROR(ENOENT);
3750 		goto out;
3751 	}
3752 
3753 	/*
3754 	 * Determine if there is a better boot device.
3755 	 */
3756 	avd = bvd;
3757 	spa_alt_rootvdev(rvd, &avd, &txg);
3758 	if (avd != bvd) {
3759 		cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3760 		    "try booting from '%s'", avd->vdev_path);
3761 		error = SET_ERROR(EINVAL);
3762 		goto out;
3763 	}
3764 
3765 	/*
3766 	 * If the boot device is part of a spare vdev then ensure that
3767 	 * we're booting off the active spare.
3768 	 */
3769 	if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3770 	    !bvd->vdev_isspare) {
3771 		cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3772 		    "try booting from '%s'",
3773 		    bvd->vdev_parent->
3774 		    vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3775 		error = SET_ERROR(EINVAL);
3776 		goto out;
3777 	}
3778 
3779 	error = 0;
3780 out:
3781 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3782 	vdev_free(rvd);
3783 	spa_config_exit(spa, SCL_ALL, FTAG);
3784 	mutex_exit(&spa_namespace_lock);
3785 
3786 	nvlist_free(config);
3787 	return (error);
3788 }
3789 
3790 #endif
3791 
3792 /*
3793  * Import a non-root pool into the system.
3794  */
3795 int
3796 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3797 {
3798 	spa_t *spa;
3799 	char *altroot = NULL;
3800 	spa_load_state_t state = SPA_LOAD_IMPORT;
3801 	zpool_rewind_policy_t policy;
3802 	uint64_t mode = spa_mode_global;
3803 	uint64_t readonly = B_FALSE;
3804 	int error;
3805 	nvlist_t *nvroot;
3806 	nvlist_t **spares, **l2cache;
3807 	uint_t nspares, nl2cache;
3808 
3809 	/*
3810 	 * If a pool with this name exists, return failure.
3811 	 */
3812 	mutex_enter(&spa_namespace_lock);
3813 	if (spa_lookup(pool) != NULL) {
3814 		mutex_exit(&spa_namespace_lock);
3815 		return (SET_ERROR(EEXIST));
3816 	}
3817 
3818 	/*
3819 	 * Create and initialize the spa structure.
3820 	 */
3821 	(void) nvlist_lookup_string(props,
3822 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3823 	(void) nvlist_lookup_uint64(props,
3824 	    zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3825 	if (readonly)
3826 		mode = FREAD;
3827 	spa = spa_add(pool, config, altroot);
3828 	spa->spa_import_flags = flags;
3829 
3830 	/*
3831 	 * Verbatim import - Take a pool and insert it into the namespace
3832 	 * as if it had been loaded at boot.
3833 	 */
3834 	if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3835 		if (props != NULL)
3836 			spa_configfile_set(spa, props, B_FALSE);
3837 
3838 		spa_config_sync(spa, B_FALSE, B_TRUE);
3839 
3840 		mutex_exit(&spa_namespace_lock);
3841 		spa_history_log_version(spa, "import");
3842 
3843 		return (0);
3844 	}
3845 
3846 	spa_activate(spa, mode);
3847 
3848 	/*
3849 	 * Don't start async tasks until we know everything is healthy.
3850 	 */
3851 	spa_async_suspend(spa);
3852 
3853 	zpool_get_rewind_policy(config, &policy);
3854 	if (policy.zrp_request & ZPOOL_DO_REWIND)
3855 		state = SPA_LOAD_RECOVER;
3856 
3857 	/*
3858 	 * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3859 	 * because the user-supplied config is actually the one to trust when
3860 	 * doing an import.
3861 	 */
3862 	if (state != SPA_LOAD_RECOVER)
3863 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3864 
3865 	error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3866 	    policy.zrp_request);
3867 
3868 	/*
3869 	 * Propagate anything learned while loading the pool and pass it
3870 	 * back to caller (i.e. rewind info, missing devices, etc).
3871 	 */
3872 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3873 	    spa->spa_load_info) == 0);
3874 
3875 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3876 	/*
3877 	 * Toss any existing sparelist, as it doesn't have any validity
3878 	 * anymore, and conflicts with spa_has_spare().
3879 	 */
3880 	if (spa->spa_spares.sav_config) {
3881 		nvlist_free(spa->spa_spares.sav_config);
3882 		spa->spa_spares.sav_config = NULL;
3883 		spa_load_spares(spa);
3884 	}
3885 	if (spa->spa_l2cache.sav_config) {
3886 		nvlist_free(spa->spa_l2cache.sav_config);
3887 		spa->spa_l2cache.sav_config = NULL;
3888 		spa_load_l2cache(spa);
3889 	}
3890 
3891 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3892 	    &nvroot) == 0);
3893 	if (error == 0)
3894 		error = spa_validate_aux(spa, nvroot, -1ULL,
3895 		    VDEV_ALLOC_SPARE);
3896 	if (error == 0)
3897 		error = spa_validate_aux(spa, nvroot, -1ULL,
3898 		    VDEV_ALLOC_L2CACHE);
3899 	spa_config_exit(spa, SCL_ALL, FTAG);
3900 
3901 	if (props != NULL)
3902 		spa_configfile_set(spa, props, B_FALSE);
3903 
3904 	if (error != 0 || (props && spa_writeable(spa) &&
3905 	    (error = spa_prop_set(spa, props)))) {
3906 		spa_unload(spa);
3907 		spa_deactivate(spa);
3908 		spa_remove(spa);
3909 		mutex_exit(&spa_namespace_lock);
3910 		return (error);
3911 	}
3912 
3913 	spa_async_resume(spa);
3914 
3915 	/*
3916 	 * Override any spares and level 2 cache devices as specified by
3917 	 * the user, as these may have correct device names/devids, etc.
3918 	 */
3919 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3920 	    &spares, &nspares) == 0) {
3921 		if (spa->spa_spares.sav_config)
3922 			VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3923 			    ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3924 		else
3925 			VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3926 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3927 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3928 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3929 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3930 		spa_load_spares(spa);
3931 		spa_config_exit(spa, SCL_ALL, FTAG);
3932 		spa->spa_spares.sav_sync = B_TRUE;
3933 	}
3934 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3935 	    &l2cache, &nl2cache) == 0) {
3936 		if (spa->spa_l2cache.sav_config)
3937 			VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3938 			    ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3939 		else
3940 			VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3941 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3942 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3943 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3944 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3945 		spa_load_l2cache(spa);
3946 		spa_config_exit(spa, SCL_ALL, FTAG);
3947 		spa->spa_l2cache.sav_sync = B_TRUE;
3948 	}
3949 
3950 	/*
3951 	 * Check for any removed devices.
3952 	 */
3953 	if (spa->spa_autoreplace) {
3954 		spa_aux_check_removed(&spa->spa_spares);
3955 		spa_aux_check_removed(&spa->spa_l2cache);
3956 	}
3957 
3958 	if (spa_writeable(spa)) {
3959 		/*
3960 		 * Update the config cache to include the newly-imported pool.
3961 		 */
3962 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3963 	}
3964 
3965 	/*
3966 	 * It's possible that the pool was expanded while it was exported.
3967 	 * We kick off an async task to handle this for us.
3968 	 */
3969 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3970 
3971 	mutex_exit(&spa_namespace_lock);
3972 	spa_history_log_version(spa, "import");
3973 
3974 	return (0);
3975 }
3976 
3977 nvlist_t *
3978 spa_tryimport(nvlist_t *tryconfig)
3979 {
3980 	nvlist_t *config = NULL;
3981 	char *poolname;
3982 	spa_t *spa;
3983 	uint64_t state;
3984 	int error;
3985 
3986 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
3987 		return (NULL);
3988 
3989 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
3990 		return (NULL);
3991 
3992 	/*
3993 	 * Create and initialize the spa structure.
3994 	 */
3995 	mutex_enter(&spa_namespace_lock);
3996 	spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
3997 	spa_activate(spa, FREAD);
3998 
3999 	/*
4000 	 * Pass off the heavy lifting to spa_load().
4001 	 * Pass TRUE for mosconfig because the user-supplied config
4002 	 * is actually the one to trust when doing an import.
4003 	 */
4004 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4005 
4006 	/*
4007 	 * If 'tryconfig' was at least parsable, return the current config.
4008 	 */
4009 	if (spa->spa_root_vdev != NULL) {
4010 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4011 		VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4012 		    poolname) == 0);
4013 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4014 		    state) == 0);
4015 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4016 		    spa->spa_uberblock.ub_timestamp) == 0);
4017 		VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4018 		    spa->spa_load_info) == 0);
4019 
4020 		/*
4021 		 * If the bootfs property exists on this pool then we
4022 		 * copy it out so that external consumers can tell which
4023 		 * pools are bootable.
4024 		 */
4025 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
4026 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4027 
4028 			/*
4029 			 * We have to play games with the name since the
4030 			 * pool was opened as TRYIMPORT_NAME.
4031 			 */
4032 			if (dsl_dsobj_to_dsname(spa_name(spa),
4033 			    spa->spa_bootfs, tmpname) == 0) {
4034 				char *cp;
4035 				char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4036 
4037 				cp = strchr(tmpname, '/');
4038 				if (cp == NULL) {
4039 					(void) strlcpy(dsname, tmpname,
4040 					    MAXPATHLEN);
4041 				} else {
4042 					(void) snprintf(dsname, MAXPATHLEN,
4043 					    "%s/%s", poolname, ++cp);
4044 				}
4045 				VERIFY(nvlist_add_string(config,
4046 				    ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4047 				kmem_free(dsname, MAXPATHLEN);
4048 			}
4049 			kmem_free(tmpname, MAXPATHLEN);
4050 		}
4051 
4052 		/*
4053 		 * Add the list of hot spares and level 2 cache devices.
4054 		 */
4055 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4056 		spa_add_spares(spa, config);
4057 		spa_add_l2cache(spa, config);
4058 		spa_config_exit(spa, SCL_CONFIG, FTAG);
4059 	}
4060 
4061 	spa_unload(spa);
4062 	spa_deactivate(spa);
4063 	spa_remove(spa);
4064 	mutex_exit(&spa_namespace_lock);
4065 
4066 	return (config);
4067 }
4068 
4069 /*
4070  * Pool export/destroy
4071  *
4072  * The act of destroying or exporting a pool is very simple.  We make sure there
4073  * is no more pending I/O and any references to the pool are gone.  Then, we
4074  * update the pool state and sync all the labels to disk, removing the
4075  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4076  * we don't sync the labels or remove the configuration cache.
4077  */
4078 static int
4079 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4080     boolean_t force, boolean_t hardforce)
4081 {
4082 	spa_t *spa;
4083 
4084 	if (oldconfig)
4085 		*oldconfig = NULL;
4086 
4087 	if (!(spa_mode_global & FWRITE))
4088 		return (SET_ERROR(EROFS));
4089 
4090 	mutex_enter(&spa_namespace_lock);
4091 	if ((spa = spa_lookup(pool)) == NULL) {
4092 		mutex_exit(&spa_namespace_lock);
4093 		return (SET_ERROR(ENOENT));
4094 	}
4095 
4096 	/*
4097 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
4098 	 * reacquire the namespace lock, and see if we can export.
4099 	 */
4100 	spa_open_ref(spa, FTAG);
4101 	mutex_exit(&spa_namespace_lock);
4102 	spa_async_suspend(spa);
4103 	mutex_enter(&spa_namespace_lock);
4104 	spa_close(spa, FTAG);
4105 
4106 	/*
4107 	 * The pool will be in core if it's openable,
4108 	 * in which case we can modify its state.
4109 	 */
4110 	if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4111 		/*
4112 		 * Objsets may be open only because they're dirty, so we
4113 		 * have to force it to sync before checking spa_refcnt.
4114 		 */
4115 		txg_wait_synced(spa->spa_dsl_pool, 0);
4116 
4117 		/*
4118 		 * A pool cannot be exported or destroyed if there are active
4119 		 * references.  If we are resetting a pool, allow references by
4120 		 * fault injection handlers.
4121 		 */
4122 		if (!spa_refcount_zero(spa) ||
4123 		    (spa->spa_inject_ref != 0 &&
4124 		    new_state != POOL_STATE_UNINITIALIZED)) {
4125 			spa_async_resume(spa);
4126 			mutex_exit(&spa_namespace_lock);
4127 			return (SET_ERROR(EBUSY));
4128 		}
4129 
4130 		/*
4131 		 * A pool cannot be exported if it has an active shared spare.
4132 		 * This is to prevent other pools stealing the active spare
4133 		 * from an exported pool. At user's own will, such pool can
4134 		 * be forcedly exported.
4135 		 */
4136 		if (!force && new_state == POOL_STATE_EXPORTED &&
4137 		    spa_has_active_shared_spare(spa)) {
4138 			spa_async_resume(spa);
4139 			mutex_exit(&spa_namespace_lock);
4140 			return (SET_ERROR(EXDEV));
4141 		}
4142 
4143 		/*
4144 		 * We want this to be reflected on every label,
4145 		 * so mark them all dirty.  spa_unload() will do the
4146 		 * final sync that pushes these changes out.
4147 		 */
4148 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4149 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4150 			spa->spa_state = new_state;
4151 			spa->spa_final_txg = spa_last_synced_txg(spa) +
4152 			    TXG_DEFER_SIZE + 1;
4153 			vdev_config_dirty(spa->spa_root_vdev);
4154 			spa_config_exit(spa, SCL_ALL, FTAG);
4155 		}
4156 	}
4157 
4158 	spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4159 
4160 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4161 		spa_unload(spa);
4162 		spa_deactivate(spa);
4163 	}
4164 
4165 	if (oldconfig && spa->spa_config)
4166 		VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4167 
4168 	if (new_state != POOL_STATE_UNINITIALIZED) {
4169 		if (!hardforce)
4170 			spa_config_sync(spa, B_TRUE, B_TRUE);
4171 		spa_remove(spa);
4172 	}
4173 	mutex_exit(&spa_namespace_lock);
4174 
4175 	return (0);
4176 }
4177 
4178 /*
4179  * Destroy a storage pool.
4180  */
4181 int
4182 spa_destroy(char *pool)
4183 {
4184 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4185 	    B_FALSE, B_FALSE));
4186 }
4187 
4188 /*
4189  * Export a storage pool.
4190  */
4191 int
4192 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4193     boolean_t hardforce)
4194 {
4195 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4196 	    force, hardforce));
4197 }
4198 
4199 /*
4200  * Similar to spa_export(), this unloads the spa_t without actually removing it
4201  * from the namespace in any way.
4202  */
4203 int
4204 spa_reset(char *pool)
4205 {
4206 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4207 	    B_FALSE, B_FALSE));
4208 }
4209 
4210 /*
4211  * ==========================================================================
4212  * Device manipulation
4213  * ==========================================================================
4214  */
4215 
4216 /*
4217  * Add a device to a storage pool.
4218  */
4219 int
4220 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4221 {
4222 	uint64_t txg, id;
4223 	int error;
4224 	vdev_t *rvd = spa->spa_root_vdev;
4225 	vdev_t *vd, *tvd;
4226 	nvlist_t **spares, **l2cache;
4227 	uint_t nspares, nl2cache;
4228 
4229 	ASSERT(spa_writeable(spa));
4230 
4231 	txg = spa_vdev_enter(spa);
4232 
4233 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4234 	    VDEV_ALLOC_ADD)) != 0)
4235 		return (spa_vdev_exit(spa, NULL, txg, error));
4236 
4237 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
4238 
4239 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4240 	    &nspares) != 0)
4241 		nspares = 0;
4242 
4243 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4244 	    &nl2cache) != 0)
4245 		nl2cache = 0;
4246 
4247 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4248 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
4249 
4250 	if (vd->vdev_children != 0 &&
4251 	    (error = vdev_create(vd, txg, B_FALSE)) != 0)
4252 		return (spa_vdev_exit(spa, vd, txg, error));
4253 
4254 	/*
4255 	 * We must validate the spares and l2cache devices after checking the
4256 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4257 	 */
4258 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4259 		return (spa_vdev_exit(spa, vd, txg, error));
4260 
4261 	/*
4262 	 * Transfer each new top-level vdev from vd to rvd.
4263 	 */
4264 	for (int c = 0; c < vd->vdev_children; c++) {
4265 
4266 		/*
4267 		 * Set the vdev id to the first hole, if one exists.
4268 		 */
4269 		for (id = 0; id < rvd->vdev_children; id++) {
4270 			if (rvd->vdev_child[id]->vdev_ishole) {
4271 				vdev_free(rvd->vdev_child[id]);
4272 				break;
4273 			}
4274 		}
4275 		tvd = vd->vdev_child[c];
4276 		vdev_remove_child(vd, tvd);
4277 		tvd->vdev_id = id;
4278 		vdev_add_child(rvd, tvd);
4279 		vdev_config_dirty(tvd);
4280 	}
4281 
4282 	if (nspares != 0) {
4283 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4284 		    ZPOOL_CONFIG_SPARES);
4285 		spa_load_spares(spa);
4286 		spa->spa_spares.sav_sync = B_TRUE;
4287 	}
4288 
4289 	if (nl2cache != 0) {
4290 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4291 		    ZPOOL_CONFIG_L2CACHE);
4292 		spa_load_l2cache(spa);
4293 		spa->spa_l2cache.sav_sync = B_TRUE;
4294 	}
4295 
4296 	/*
4297 	 * We have to be careful when adding new vdevs to an existing pool.
4298 	 * If other threads start allocating from these vdevs before we
4299 	 * sync the config cache, and we lose power, then upon reboot we may
4300 	 * fail to open the pool because there are DVAs that the config cache
4301 	 * can't translate.  Therefore, we first add the vdevs without
4302 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4303 	 * and then let spa_config_update() initialize the new metaslabs.
4304 	 *
4305 	 * spa_load() checks for added-but-not-initialized vdevs, so that
4306 	 * if we lose power at any point in this sequence, the remaining
4307 	 * steps will be completed the next time we load the pool.
4308 	 */
4309 	(void) spa_vdev_exit(spa, vd, txg, 0);
4310 
4311 	mutex_enter(&spa_namespace_lock);
4312 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4313 	mutex_exit(&spa_namespace_lock);
4314 
4315 	return (0);
4316 }
4317 
4318 /*
4319  * Attach a device to a mirror.  The arguments are the path to any device
4320  * in the mirror, and the nvroot for the new device.  If the path specifies
4321  * a device that is not mirrored, we automatically insert the mirror vdev.
4322  *
4323  * If 'replacing' is specified, the new device is intended to replace the
4324  * existing device; in this case the two devices are made into their own
4325  * mirror using the 'replacing' vdev, which is functionally identical to
4326  * the mirror vdev (it actually reuses all the same ops) but has a few
4327  * extra rules: you can't attach to it after it's been created, and upon
4328  * completion of resilvering, the first disk (the one being replaced)
4329  * is automatically detached.
4330  */
4331 int
4332 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4333 {
4334 	uint64_t txg, dtl_max_txg;
4335 	vdev_t *rvd = spa->spa_root_vdev;
4336 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4337 	vdev_ops_t *pvops;
4338 	char *oldvdpath, *newvdpath;
4339 	int newvd_isspare;
4340 	int error;
4341 
4342 	ASSERT(spa_writeable(spa));
4343 
4344 	txg = spa_vdev_enter(spa);
4345 
4346 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4347 
4348 	if (oldvd == NULL)
4349 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4350 
4351 	if (!oldvd->vdev_ops->vdev_op_leaf)
4352 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4353 
4354 	pvd = oldvd->vdev_parent;
4355 
4356 	if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4357 	    VDEV_ALLOC_ATTACH)) != 0)
4358 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4359 
4360 	if (newrootvd->vdev_children != 1)
4361 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4362 
4363 	newvd = newrootvd->vdev_child[0];
4364 
4365 	if (!newvd->vdev_ops->vdev_op_leaf)
4366 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4367 
4368 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4369 		return (spa_vdev_exit(spa, newrootvd, txg, error));
4370 
4371 	/*
4372 	 * Spares can't replace logs
4373 	 */
4374 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4375 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4376 
4377 	if (!replacing) {
4378 		/*
4379 		 * For attach, the only allowable parent is a mirror or the root
4380 		 * vdev.
4381 		 */
4382 		if (pvd->vdev_ops != &vdev_mirror_ops &&
4383 		    pvd->vdev_ops != &vdev_root_ops)
4384 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4385 
4386 		pvops = &vdev_mirror_ops;
4387 	} else {
4388 		/*
4389 		 * Active hot spares can only be replaced by inactive hot
4390 		 * spares.
4391 		 */
4392 		if (pvd->vdev_ops == &vdev_spare_ops &&
4393 		    oldvd->vdev_isspare &&
4394 		    !spa_has_spare(spa, newvd->vdev_guid))
4395 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4396 
4397 		/*
4398 		 * If the source is a hot spare, and the parent isn't already a
4399 		 * spare, then we want to create a new hot spare.  Otherwise, we
4400 		 * want to create a replacing vdev.  The user is not allowed to
4401 		 * attach to a spared vdev child unless the 'isspare' state is
4402 		 * the same (spare replaces spare, non-spare replaces
4403 		 * non-spare).
4404 		 */
4405 		if (pvd->vdev_ops == &vdev_replacing_ops &&
4406 		    spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4407 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4408 		} else if (pvd->vdev_ops == &vdev_spare_ops &&
4409 		    newvd->vdev_isspare != oldvd->vdev_isspare) {
4410 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4411 		}
4412 
4413 		if (newvd->vdev_isspare)
4414 			pvops = &vdev_spare_ops;
4415 		else
4416 			pvops = &vdev_replacing_ops;
4417 	}
4418 
4419 	/*
4420 	 * Make sure the new device is big enough.
4421 	 */
4422 	if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4423 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4424 
4425 	/*
4426 	 * The new device cannot have a higher alignment requirement
4427 	 * than the top-level vdev.
4428 	 */
4429 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4430 		return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4431 
4432 	/*
4433 	 * If this is an in-place replacement, update oldvd's path and devid
4434 	 * to make it distinguishable from newvd, and unopenable from now on.
4435 	 */
4436 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4437 		spa_strfree(oldvd->vdev_path);
4438 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4439 		    KM_SLEEP);
4440 		(void) sprintf(oldvd->vdev_path, "%s/%s",
4441 		    newvd->vdev_path, "old");
4442 		if (oldvd->vdev_devid != NULL) {
4443 			spa_strfree(oldvd->vdev_devid);
4444 			oldvd->vdev_devid = NULL;
4445 		}
4446 	}
4447 
4448 	/* mark the device being resilvered */
4449 	newvd->vdev_resilver_txg = txg;
4450 
4451 	/*
4452 	 * If the parent is not a mirror, or if we're replacing, insert the new
4453 	 * mirror/replacing/spare vdev above oldvd.
4454 	 */
4455 	if (pvd->vdev_ops != pvops)
4456 		pvd = vdev_add_parent(oldvd, pvops);
4457 
4458 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
4459 	ASSERT(pvd->vdev_ops == pvops);
4460 	ASSERT(oldvd->vdev_parent == pvd);
4461 
4462 	/*
4463 	 * Extract the new device from its root and add it to pvd.
4464 	 */
4465 	vdev_remove_child(newrootvd, newvd);
4466 	newvd->vdev_id = pvd->vdev_children;
4467 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
4468 	vdev_add_child(pvd, newvd);
4469 
4470 	tvd = newvd->vdev_top;
4471 	ASSERT(pvd->vdev_top == tvd);
4472 	ASSERT(tvd->vdev_parent == rvd);
4473 
4474 	vdev_config_dirty(tvd);
4475 
4476 	/*
4477 	 * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4478 	 * for any dmu_sync-ed blocks.  It will propagate upward when
4479 	 * spa_vdev_exit() calls vdev_dtl_reassess().
4480 	 */
4481 	dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4482 
4483 	vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4484 	    dtl_max_txg - TXG_INITIAL);
4485 
4486 	if (newvd->vdev_isspare) {
4487 		spa_spare_activate(newvd);
4488 		spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4489 	}
4490 
4491 	oldvdpath = spa_strdup(oldvd->vdev_path);
4492 	newvdpath = spa_strdup(newvd->vdev_path);
4493 	newvd_isspare = newvd->vdev_isspare;
4494 
4495 	/*
4496 	 * Mark newvd's DTL dirty in this txg.
4497 	 */
4498 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
4499 
4500 	/*
4501 	 * Restart the resilver
4502 	 */
4503 	dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4504 
4505 	/*
4506 	 * Commit the config
4507 	 */
4508 	(void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4509 
4510 	spa_history_log_internal(spa, "vdev attach", NULL,
4511 	    "%s vdev=%s %s vdev=%s",
4512 	    replacing && newvd_isspare ? "spare in" :
4513 	    replacing ? "replace" : "attach", newvdpath,
4514 	    replacing ? "for" : "to", oldvdpath);
4515 
4516 	spa_strfree(oldvdpath);
4517 	spa_strfree(newvdpath);
4518 
4519 	if (spa->spa_bootfs)
4520 		spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4521 
4522 	return (0);
4523 }
4524 
4525 /*
4526  * Detach a device from a mirror or replacing vdev.
4527  *
4528  * If 'replace_done' is specified, only detach if the parent
4529  * is a replacing vdev.
4530  */
4531 int
4532 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4533 {
4534 	uint64_t txg;
4535 	int error;
4536 	vdev_t *rvd = spa->spa_root_vdev;
4537 	vdev_t *vd, *pvd, *cvd, *tvd;
4538 	boolean_t unspare = B_FALSE;
4539 	uint64_t unspare_guid = 0;
4540 	char *vdpath;
4541 
4542 	ASSERT(spa_writeable(spa));
4543 
4544 	txg = spa_vdev_enter(spa);
4545 
4546 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4547 
4548 	if (vd == NULL)
4549 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4550 
4551 	if (!vd->vdev_ops->vdev_op_leaf)
4552 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4553 
4554 	pvd = vd->vdev_parent;
4555 
4556 	/*
4557 	 * If the parent/child relationship is not as expected, don't do it.
4558 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4559 	 * vdev that's replacing B with C.  The user's intent in replacing
4560 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4561 	 * the replace by detaching C, the expected behavior is to end up
4562 	 * M(A,B).  But suppose that right after deciding to detach C,
4563 	 * the replacement of B completes.  We would have M(A,C), and then
4564 	 * ask to detach C, which would leave us with just A -- not what
4565 	 * the user wanted.  To prevent this, we make sure that the
4566 	 * parent/child relationship hasn't changed -- in this example,
4567 	 * that C's parent is still the replacing vdev R.
4568 	 */
4569 	if (pvd->vdev_guid != pguid && pguid != 0)
4570 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4571 
4572 	/*
4573 	 * Only 'replacing' or 'spare' vdevs can be replaced.
4574 	 */
4575 	if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4576 	    pvd->vdev_ops != &vdev_spare_ops)
4577 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4578 
4579 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4580 	    spa_version(spa) >= SPA_VERSION_SPARES);
4581 
4582 	/*
4583 	 * Only mirror, replacing, and spare vdevs support detach.
4584 	 */
4585 	if (pvd->vdev_ops != &vdev_replacing_ops &&
4586 	    pvd->vdev_ops != &vdev_mirror_ops &&
4587 	    pvd->vdev_ops != &vdev_spare_ops)
4588 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4589 
4590 	/*
4591 	 * If this device has the only valid copy of some data,
4592 	 * we cannot safely detach it.
4593 	 */
4594 	if (vdev_dtl_required(vd))
4595 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4596 
4597 	ASSERT(pvd->vdev_children >= 2);
4598 
4599 	/*
4600 	 * If we are detaching the second disk from a replacing vdev, then
4601 	 * check to see if we changed the original vdev's path to have "/old"
4602 	 * at the end in spa_vdev_attach().  If so, undo that change now.
4603 	 */
4604 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4605 	    vd->vdev_path != NULL) {
4606 		size_t len = strlen(vd->vdev_path);
4607 
4608 		for (int c = 0; c < pvd->vdev_children; c++) {
4609 			cvd = pvd->vdev_child[c];
4610 
4611 			if (cvd == vd || cvd->vdev_path == NULL)
4612 				continue;
4613 
4614 			if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4615 			    strcmp(cvd->vdev_path + len, "/old") == 0) {
4616 				spa_strfree(cvd->vdev_path);
4617 				cvd->vdev_path = spa_strdup(vd->vdev_path);
4618 				break;
4619 			}
4620 		}
4621 	}
4622 
4623 	/*
4624 	 * If we are detaching the original disk from a spare, then it implies
4625 	 * that the spare should become a real disk, and be removed from the
4626 	 * active spare list for the pool.
4627 	 */
4628 	if (pvd->vdev_ops == &vdev_spare_ops &&
4629 	    vd->vdev_id == 0 &&
4630 	    pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4631 		unspare = B_TRUE;
4632 
4633 	/*
4634 	 * Erase the disk labels so the disk can be used for other things.
4635 	 * This must be done after all other error cases are handled,
4636 	 * but before we disembowel vd (so we can still do I/O to it).
4637 	 * But if we can't do it, don't treat the error as fatal --
4638 	 * it may be that the unwritability of the disk is the reason
4639 	 * it's being detached!
4640 	 */
4641 	error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4642 
4643 	/*
4644 	 * Remove vd from its parent and compact the parent's children.
4645 	 */
4646 	vdev_remove_child(pvd, vd);
4647 	vdev_compact_children(pvd);
4648 
4649 	/*
4650 	 * Remember one of the remaining children so we can get tvd below.
4651 	 */
4652 	cvd = pvd->vdev_child[pvd->vdev_children - 1];
4653 
4654 	/*
4655 	 * If we need to remove the remaining child from the list of hot spares,
4656 	 * do it now, marking the vdev as no longer a spare in the process.
4657 	 * We must do this before vdev_remove_parent(), because that can
4658 	 * change the GUID if it creates a new toplevel GUID.  For a similar
4659 	 * reason, we must remove the spare now, in the same txg as the detach;
4660 	 * otherwise someone could attach a new sibling, change the GUID, and
4661 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4662 	 */
4663 	if (unspare) {
4664 		ASSERT(cvd->vdev_isspare);
4665 		spa_spare_remove(cvd);
4666 		unspare_guid = cvd->vdev_guid;
4667 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4668 		cvd->vdev_unspare = B_TRUE;
4669 	}
4670 
4671 	/*
4672 	 * If the parent mirror/replacing vdev only has one child,
4673 	 * the parent is no longer needed.  Remove it from the tree.
4674 	 */
4675 	if (pvd->vdev_children == 1) {
4676 		if (pvd->vdev_ops == &vdev_spare_ops)
4677 			cvd->vdev_unspare = B_FALSE;
4678 		vdev_remove_parent(cvd);
4679 	}
4680 
4681 
4682 	/*
4683 	 * We don't set tvd until now because the parent we just removed
4684 	 * may have been the previous top-level vdev.
4685 	 */
4686 	tvd = cvd->vdev_top;
4687 	ASSERT(tvd->vdev_parent == rvd);
4688 
4689 	/*
4690 	 * Reevaluate the parent vdev state.
4691 	 */
4692 	vdev_propagate_state(cvd);
4693 
4694 	/*
4695 	 * If the 'autoexpand' property is set on the pool then automatically
4696 	 * try to expand the size of the pool. For example if the device we
4697 	 * just detached was smaller than the others, it may be possible to
4698 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4699 	 * first so that we can obtain the updated sizes of the leaf vdevs.
4700 	 */
4701 	if (spa->spa_autoexpand) {
4702 		vdev_reopen(tvd);
4703 		vdev_expand(tvd, txg);
4704 	}
4705 
4706 	vdev_config_dirty(tvd);
4707 
4708 	/*
4709 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4710 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
4711 	 * But first make sure we're not on any *other* txg's DTL list, to
4712 	 * prevent vd from being accessed after it's freed.
4713 	 */
4714 	vdpath = spa_strdup(vd->vdev_path);
4715 	for (int t = 0; t < TXG_SIZE; t++)
4716 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4717 	vd->vdev_detached = B_TRUE;
4718 	vdev_dirty(tvd, VDD_DTL, vd, txg);
4719 
4720 	spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4721 
4722 	/* hang on to the spa before we release the lock */
4723 	spa_open_ref(spa, FTAG);
4724 
4725 	error = spa_vdev_exit(spa, vd, txg, 0);
4726 
4727 	spa_history_log_internal(spa, "detach", NULL,
4728 	    "vdev=%s", vdpath);
4729 	spa_strfree(vdpath);
4730 
4731 	/*
4732 	 * If this was the removal of the original device in a hot spare vdev,
4733 	 * then we want to go through and remove the device from the hot spare
4734 	 * list of every other pool.
4735 	 */
4736 	if (unspare) {
4737 		spa_t *altspa = NULL;
4738 
4739 		mutex_enter(&spa_namespace_lock);
4740 		while ((altspa = spa_next(altspa)) != NULL) {
4741 			if (altspa->spa_state != POOL_STATE_ACTIVE ||
4742 			    altspa == spa)
4743 				continue;
4744 
4745 			spa_open_ref(altspa, FTAG);
4746 			mutex_exit(&spa_namespace_lock);
4747 			(void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4748 			mutex_enter(&spa_namespace_lock);
4749 			spa_close(altspa, FTAG);
4750 		}
4751 		mutex_exit(&spa_namespace_lock);
4752 
4753 		/* search the rest of the vdevs for spares to remove */
4754 		spa_vdev_resilver_done(spa);
4755 	}
4756 
4757 	/* all done with the spa; OK to release */
4758 	mutex_enter(&spa_namespace_lock);
4759 	spa_close(spa, FTAG);
4760 	mutex_exit(&spa_namespace_lock);
4761 
4762 	return (error);
4763 }
4764 
4765 /*
4766  * Split a set of devices from their mirrors, and create a new pool from them.
4767  */
4768 int
4769 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4770     nvlist_t *props, boolean_t exp)
4771 {
4772 	int error = 0;
4773 	uint64_t txg, *glist;
4774 	spa_t *newspa;
4775 	uint_t c, children, lastlog;
4776 	nvlist_t **child, *nvl, *tmp;
4777 	dmu_tx_t *tx;
4778 	char *altroot = NULL;
4779 	vdev_t *rvd, **vml = NULL;			/* vdev modify list */
4780 	boolean_t activate_slog;
4781 
4782 	ASSERT(spa_writeable(spa));
4783 
4784 	txg = spa_vdev_enter(spa);
4785 
4786 	/* clear the log and flush everything up to now */
4787 	activate_slog = spa_passivate_log(spa);
4788 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4789 	error = spa_offline_log(spa);
4790 	txg = spa_vdev_config_enter(spa);
4791 
4792 	if (activate_slog)
4793 		spa_activate_log(spa);
4794 
4795 	if (error != 0)
4796 		return (spa_vdev_exit(spa, NULL, txg, error));
4797 
4798 	/* check new spa name before going any further */
4799 	if (spa_lookup(newname) != NULL)
4800 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4801 
4802 	/*
4803 	 * scan through all the children to ensure they're all mirrors
4804 	 */
4805 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4806 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4807 	    &children) != 0)
4808 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4809 
4810 	/* first, check to ensure we've got the right child count */
4811 	rvd = spa->spa_root_vdev;
4812 	lastlog = 0;
4813 	for (c = 0; c < rvd->vdev_children; c++) {
4814 		vdev_t *vd = rvd->vdev_child[c];
4815 
4816 		/* don't count the holes & logs as children */
4817 		if (vd->vdev_islog || vd->vdev_ishole) {
4818 			if (lastlog == 0)
4819 				lastlog = c;
4820 			continue;
4821 		}
4822 
4823 		lastlog = 0;
4824 	}
4825 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4826 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4827 
4828 	/* next, ensure no spare or cache devices are part of the split */
4829 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4830 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4831 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4832 
4833 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4834 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4835 
4836 	/* then, loop over each vdev and validate it */
4837 	for (c = 0; c < children; c++) {
4838 		uint64_t is_hole = 0;
4839 
4840 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4841 		    &is_hole);
4842 
4843 		if (is_hole != 0) {
4844 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4845 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4846 				continue;
4847 			} else {
4848 				error = SET_ERROR(EINVAL);
4849 				break;
4850 			}
4851 		}
4852 
4853 		/* which disk is going to be split? */
4854 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4855 		    &glist[c]) != 0) {
4856 			error = SET_ERROR(EINVAL);
4857 			break;
4858 		}
4859 
4860 		/* look it up in the spa */
4861 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4862 		if (vml[c] == NULL) {
4863 			error = SET_ERROR(ENODEV);
4864 			break;
4865 		}
4866 
4867 		/* make sure there's nothing stopping the split */
4868 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4869 		    vml[c]->vdev_islog ||
4870 		    vml[c]->vdev_ishole ||
4871 		    vml[c]->vdev_isspare ||
4872 		    vml[c]->vdev_isl2cache ||
4873 		    !vdev_writeable(vml[c]) ||
4874 		    vml[c]->vdev_children != 0 ||
4875 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4876 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4877 			error = SET_ERROR(EINVAL);
4878 			break;
4879 		}
4880 
4881 		if (vdev_dtl_required(vml[c])) {
4882 			error = SET_ERROR(EBUSY);
4883 			break;
4884 		}
4885 
4886 		/* we need certain info from the top level */
4887 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4888 		    vml[c]->vdev_top->vdev_ms_array) == 0);
4889 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4890 		    vml[c]->vdev_top->vdev_ms_shift) == 0);
4891 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4892 		    vml[c]->vdev_top->vdev_asize) == 0);
4893 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4894 		    vml[c]->vdev_top->vdev_ashift) == 0);
4895 	}
4896 
4897 	if (error != 0) {
4898 		kmem_free(vml, children * sizeof (vdev_t *));
4899 		kmem_free(glist, children * sizeof (uint64_t));
4900 		return (spa_vdev_exit(spa, NULL, txg, error));
4901 	}
4902 
4903 	/* stop writers from using the disks */
4904 	for (c = 0; c < children; c++) {
4905 		if (vml[c] != NULL)
4906 			vml[c]->vdev_offline = B_TRUE;
4907 	}
4908 	vdev_reopen(spa->spa_root_vdev);
4909 
4910 	/*
4911 	 * Temporarily record the splitting vdevs in the spa config.  This
4912 	 * will disappear once the config is regenerated.
4913 	 */
4914 	VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4915 	VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4916 	    glist, children) == 0);
4917 	kmem_free(glist, children * sizeof (uint64_t));
4918 
4919 	mutex_enter(&spa->spa_props_lock);
4920 	VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4921 	    nvl) == 0);
4922 	mutex_exit(&spa->spa_props_lock);
4923 	spa->spa_config_splitting = nvl;
4924 	vdev_config_dirty(spa->spa_root_vdev);
4925 
4926 	/* configure and create the new pool */
4927 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4928 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4929 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4930 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4931 	    spa_version(spa)) == 0);
4932 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4933 	    spa->spa_config_txg) == 0);
4934 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4935 	    spa_generate_guid(NULL)) == 0);
4936 	(void) nvlist_lookup_string(props,
4937 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4938 
4939 	/* add the new pool to the namespace */
4940 	newspa = spa_add(newname, config, altroot);
4941 	newspa->spa_config_txg = spa->spa_config_txg;
4942 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
4943 
4944 	/* release the spa config lock, retaining the namespace lock */
4945 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4946 
4947 	if (zio_injection_enabled)
4948 		zio_handle_panic_injection(spa, FTAG, 1);
4949 
4950 	spa_activate(newspa, spa_mode_global);
4951 	spa_async_suspend(newspa);
4952 
4953 	/* create the new pool from the disks of the original pool */
4954 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4955 	if (error)
4956 		goto out;
4957 
4958 	/* if that worked, generate a real config for the new pool */
4959 	if (newspa->spa_root_vdev != NULL) {
4960 		VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4961 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
4962 		VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4963 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4964 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4965 		    B_TRUE));
4966 	}
4967 
4968 	/* set the props */
4969 	if (props != NULL) {
4970 		spa_configfile_set(newspa, props, B_FALSE);
4971 		error = spa_prop_set(newspa, props);
4972 		if (error)
4973 			goto out;
4974 	}
4975 
4976 	/* flush everything */
4977 	txg = spa_vdev_config_enter(newspa);
4978 	vdev_config_dirty(newspa->spa_root_vdev);
4979 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
4980 
4981 	if (zio_injection_enabled)
4982 		zio_handle_panic_injection(spa, FTAG, 2);
4983 
4984 	spa_async_resume(newspa);
4985 
4986 	/* finally, update the original pool's config */
4987 	txg = spa_vdev_config_enter(spa);
4988 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
4989 	error = dmu_tx_assign(tx, TXG_WAIT);
4990 	if (error != 0)
4991 		dmu_tx_abort(tx);
4992 	for (c = 0; c < children; c++) {
4993 		if (vml[c] != NULL) {
4994 			vdev_split(vml[c]);
4995 			if (error == 0)
4996 				spa_history_log_internal(spa, "detach", tx,
4997 				    "vdev=%s", vml[c]->vdev_path);
4998 			vdev_free(vml[c]);
4999 		}
5000 	}
5001 	vdev_config_dirty(spa->spa_root_vdev);
5002 	spa->spa_config_splitting = NULL;
5003 	nvlist_free(nvl);
5004 	if (error == 0)
5005 		dmu_tx_commit(tx);
5006 	(void) spa_vdev_exit(spa, NULL, txg, 0);
5007 
5008 	if (zio_injection_enabled)
5009 		zio_handle_panic_injection(spa, FTAG, 3);
5010 
5011 	/* split is complete; log a history record */
5012 	spa_history_log_internal(newspa, "split", NULL,
5013 	    "from pool %s", spa_name(spa));
5014 
5015 	kmem_free(vml, children * sizeof (vdev_t *));
5016 
5017 	/* if we're not going to mount the filesystems in userland, export */
5018 	if (exp)
5019 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5020 		    B_FALSE, B_FALSE);
5021 
5022 	return (error);
5023 
5024 out:
5025 	spa_unload(newspa);
5026 	spa_deactivate(newspa);
5027 	spa_remove(newspa);
5028 
5029 	txg = spa_vdev_config_enter(spa);
5030 
5031 	/* re-online all offlined disks */
5032 	for (c = 0; c < children; c++) {
5033 		if (vml[c] != NULL)
5034 			vml[c]->vdev_offline = B_FALSE;
5035 	}
5036 	vdev_reopen(spa->spa_root_vdev);
5037 
5038 	nvlist_free(spa->spa_config_splitting);
5039 	spa->spa_config_splitting = NULL;
5040 	(void) spa_vdev_exit(spa, NULL, txg, error);
5041 
5042 	kmem_free(vml, children * sizeof (vdev_t *));
5043 	return (error);
5044 }
5045 
5046 static nvlist_t *
5047 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5048 {
5049 	for (int i = 0; i < count; i++) {
5050 		uint64_t guid;
5051 
5052 		VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5053 		    &guid) == 0);
5054 
5055 		if (guid == target_guid)
5056 			return (nvpp[i]);
5057 	}
5058 
5059 	return (NULL);
5060 }
5061 
5062 static void
5063 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5064 	nvlist_t *dev_to_remove)
5065 {
5066 	nvlist_t **newdev = NULL;
5067 
5068 	if (count > 1)
5069 		newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5070 
5071 	for (int i = 0, j = 0; i < count; i++) {
5072 		if (dev[i] == dev_to_remove)
5073 			continue;
5074 		VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5075 	}
5076 
5077 	VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5078 	VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5079 
5080 	for (int i = 0; i < count - 1; i++)
5081 		nvlist_free(newdev[i]);
5082 
5083 	if (count > 1)
5084 		kmem_free(newdev, (count - 1) * sizeof (void *));
5085 }
5086 
5087 /*
5088  * Evacuate the device.
5089  */
5090 static int
5091 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5092 {
5093 	uint64_t txg;
5094 	int error = 0;
5095 
5096 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5097 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5098 	ASSERT(vd == vd->vdev_top);
5099 
5100 	/*
5101 	 * Evacuate the device.  We don't hold the config lock as writer
5102 	 * since we need to do I/O but we do keep the
5103 	 * spa_namespace_lock held.  Once this completes the device
5104 	 * should no longer have any blocks allocated on it.
5105 	 */
5106 	if (vd->vdev_islog) {
5107 		if (vd->vdev_stat.vs_alloc != 0)
5108 			error = spa_offline_log(spa);
5109 	} else {
5110 		error = SET_ERROR(ENOTSUP);
5111 	}
5112 
5113 	if (error)
5114 		return (error);
5115 
5116 	/*
5117 	 * The evacuation succeeded.  Remove any remaining MOS metadata
5118 	 * associated with this vdev, and wait for these changes to sync.
5119 	 */
5120 	ASSERT0(vd->vdev_stat.vs_alloc);
5121 	txg = spa_vdev_config_enter(spa);
5122 	vd->vdev_removing = B_TRUE;
5123 	vdev_dirty(vd, 0, NULL, txg);
5124 	vdev_config_dirty(vd);
5125 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5126 
5127 	return (0);
5128 }
5129 
5130 /*
5131  * Complete the removal by cleaning up the namespace.
5132  */
5133 static void
5134 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5135 {
5136 	vdev_t *rvd = spa->spa_root_vdev;
5137 	uint64_t id = vd->vdev_id;
5138 	boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5139 
5140 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5141 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5142 	ASSERT(vd == vd->vdev_top);
5143 
5144 	/*
5145 	 * Only remove any devices which are empty.
5146 	 */
5147 	if (vd->vdev_stat.vs_alloc != 0)
5148 		return;
5149 
5150 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5151 
5152 	if (list_link_active(&vd->vdev_state_dirty_node))
5153 		vdev_state_clean(vd);
5154 	if (list_link_active(&vd->vdev_config_dirty_node))
5155 		vdev_config_clean(vd);
5156 
5157 	vdev_free(vd);
5158 
5159 	if (last_vdev) {
5160 		vdev_compact_children(rvd);
5161 	} else {
5162 		vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5163 		vdev_add_child(rvd, vd);
5164 	}
5165 	vdev_config_dirty(rvd);
5166 
5167 	/*
5168 	 * Reassess the health of our root vdev.
5169 	 */
5170 	vdev_reopen(rvd);
5171 }
5172 
5173 /*
5174  * Remove a device from the pool -
5175  *
5176  * Removing a device from the vdev namespace requires several steps
5177  * and can take a significant amount of time.  As a result we use
5178  * the spa_vdev_config_[enter/exit] functions which allow us to
5179  * grab and release the spa_config_lock while still holding the namespace
5180  * lock.  During each step the configuration is synced out.
5181  *
5182  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5183  * devices.
5184  */
5185 int
5186 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5187 {
5188 	vdev_t *vd;
5189 	metaslab_group_t *mg;
5190 	nvlist_t **spares, **l2cache, *nv;
5191 	uint64_t txg = 0;
5192 	uint_t nspares, nl2cache;
5193 	int error = 0;
5194 	boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5195 
5196 	ASSERT(spa_writeable(spa));
5197 
5198 	if (!locked)
5199 		txg = spa_vdev_enter(spa);
5200 
5201 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5202 
5203 	if (spa->spa_spares.sav_vdevs != NULL &&
5204 	    nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5205 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5206 	    (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5207 		/*
5208 		 * Only remove the hot spare if it's not currently in use
5209 		 * in this pool.
5210 		 */
5211 		if (vd == NULL || unspare) {
5212 			spa_vdev_remove_aux(spa->spa_spares.sav_config,
5213 			    ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5214 			spa_load_spares(spa);
5215 			spa->spa_spares.sav_sync = B_TRUE;
5216 		} else {
5217 			error = SET_ERROR(EBUSY);
5218 		}
5219 	} else if (spa->spa_l2cache.sav_vdevs != NULL &&
5220 	    nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5221 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5222 	    (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5223 		/*
5224 		 * Cache devices can always be removed.
5225 		 */
5226 		spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5227 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5228 		spa_load_l2cache(spa);
5229 		spa->spa_l2cache.sav_sync = B_TRUE;
5230 	} else if (vd != NULL && vd->vdev_islog) {
5231 		ASSERT(!locked);
5232 		ASSERT(vd == vd->vdev_top);
5233 
5234 		/*
5235 		 * XXX - Once we have bp-rewrite this should
5236 		 * become the common case.
5237 		 */
5238 
5239 		mg = vd->vdev_mg;
5240 
5241 		/*
5242 		 * Stop allocating from this vdev.
5243 		 */
5244 		metaslab_group_passivate(mg);
5245 
5246 		/*
5247 		 * Wait for the youngest allocations and frees to sync,
5248 		 * and then wait for the deferral of those frees to finish.
5249 		 */
5250 		spa_vdev_config_exit(spa, NULL,
5251 		    txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5252 
5253 		/*
5254 		 * Attempt to evacuate the vdev.
5255 		 */
5256 		error = spa_vdev_remove_evacuate(spa, vd);
5257 
5258 		txg = spa_vdev_config_enter(spa);
5259 
5260 		/*
5261 		 * If we couldn't evacuate the vdev, unwind.
5262 		 */
5263 		if (error) {
5264 			metaslab_group_activate(mg);
5265 			return (spa_vdev_exit(spa, NULL, txg, error));
5266 		}
5267 
5268 		/*
5269 		 * Clean up the vdev namespace.
5270 		 */
5271 		spa_vdev_remove_from_namespace(spa, vd);
5272 
5273 	} else if (vd != NULL) {
5274 		/*
5275 		 * Normal vdevs cannot be removed (yet).
5276 		 */
5277 		error = SET_ERROR(ENOTSUP);
5278 	} else {
5279 		/*
5280 		 * There is no vdev of any kind with the specified guid.
5281 		 */
5282 		error = SET_ERROR(ENOENT);
5283 	}
5284 
5285 	if (!locked)
5286 		return (spa_vdev_exit(spa, NULL, txg, error));
5287 
5288 	return (error);
5289 }
5290 
5291 /*
5292  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5293  * currently spared, so we can detach it.
5294  */
5295 static vdev_t *
5296 spa_vdev_resilver_done_hunt(vdev_t *vd)
5297 {
5298 	vdev_t *newvd, *oldvd;
5299 
5300 	for (int c = 0; c < vd->vdev_children; c++) {
5301 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5302 		if (oldvd != NULL)
5303 			return (oldvd);
5304 	}
5305 
5306 	/*
5307 	 * Check for a completed replacement.  We always consider the first
5308 	 * vdev in the list to be the oldest vdev, and the last one to be
5309 	 * the newest (see spa_vdev_attach() for how that works).  In
5310 	 * the case where the newest vdev is faulted, we will not automatically
5311 	 * remove it after a resilver completes.  This is OK as it will require
5312 	 * user intervention to determine which disk the admin wishes to keep.
5313 	 */
5314 	if (vd->vdev_ops == &vdev_replacing_ops) {
5315 		ASSERT(vd->vdev_children > 1);
5316 
5317 		newvd = vd->vdev_child[vd->vdev_children - 1];
5318 		oldvd = vd->vdev_child[0];
5319 
5320 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5321 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5322 		    !vdev_dtl_required(oldvd))
5323 			return (oldvd);
5324 	}
5325 
5326 	/*
5327 	 * Check for a completed resilver with the 'unspare' flag set.
5328 	 */
5329 	if (vd->vdev_ops == &vdev_spare_ops) {
5330 		vdev_t *first = vd->vdev_child[0];
5331 		vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5332 
5333 		if (last->vdev_unspare) {
5334 			oldvd = first;
5335 			newvd = last;
5336 		} else if (first->vdev_unspare) {
5337 			oldvd = last;
5338 			newvd = first;
5339 		} else {
5340 			oldvd = NULL;
5341 		}
5342 
5343 		if (oldvd != NULL &&
5344 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
5345 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5346 		    !vdev_dtl_required(oldvd))
5347 			return (oldvd);
5348 
5349 		/*
5350 		 * If there are more than two spares attached to a disk,
5351 		 * and those spares are not required, then we want to
5352 		 * attempt to free them up now so that they can be used
5353 		 * by other pools.  Once we're back down to a single
5354 		 * disk+spare, we stop removing them.
5355 		 */
5356 		if (vd->vdev_children > 2) {
5357 			newvd = vd->vdev_child[1];
5358 
5359 			if (newvd->vdev_isspare && last->vdev_isspare &&
5360 			    vdev_dtl_empty(last, DTL_MISSING) &&
5361 			    vdev_dtl_empty(last, DTL_OUTAGE) &&
5362 			    !vdev_dtl_required(newvd))
5363 				return (newvd);
5364 		}
5365 	}
5366 
5367 	return (NULL);
5368 }
5369 
5370 static void
5371 spa_vdev_resilver_done(spa_t *spa)
5372 {
5373 	vdev_t *vd, *pvd, *ppvd;
5374 	uint64_t guid, sguid, pguid, ppguid;
5375 
5376 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5377 
5378 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5379 		pvd = vd->vdev_parent;
5380 		ppvd = pvd->vdev_parent;
5381 		guid = vd->vdev_guid;
5382 		pguid = pvd->vdev_guid;
5383 		ppguid = ppvd->vdev_guid;
5384 		sguid = 0;
5385 		/*
5386 		 * If we have just finished replacing a hot spared device, then
5387 		 * we need to detach the parent's first child (the original hot
5388 		 * spare) as well.
5389 		 */
5390 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5391 		    ppvd->vdev_children == 2) {
5392 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5393 			sguid = ppvd->vdev_child[1]->vdev_guid;
5394 		}
5395 		ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5396 
5397 		spa_config_exit(spa, SCL_ALL, FTAG);
5398 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5399 			return;
5400 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5401 			return;
5402 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5403 	}
5404 
5405 	spa_config_exit(spa, SCL_ALL, FTAG);
5406 }
5407 
5408 /*
5409  * Update the stored path or FRU for this vdev.
5410  */
5411 int
5412 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5413     boolean_t ispath)
5414 {
5415 	vdev_t *vd;
5416 	boolean_t sync = B_FALSE;
5417 
5418 	ASSERT(spa_writeable(spa));
5419 
5420 	spa_vdev_state_enter(spa, SCL_ALL);
5421 
5422 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5423 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
5424 
5425 	if (!vd->vdev_ops->vdev_op_leaf)
5426 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5427 
5428 	if (ispath) {
5429 		if (strcmp(value, vd->vdev_path) != 0) {
5430 			spa_strfree(vd->vdev_path);
5431 			vd->vdev_path = spa_strdup(value);
5432 			sync = B_TRUE;
5433 		}
5434 	} else {
5435 		if (vd->vdev_fru == NULL) {
5436 			vd->vdev_fru = spa_strdup(value);
5437 			sync = B_TRUE;
5438 		} else if (strcmp(value, vd->vdev_fru) != 0) {
5439 			spa_strfree(vd->vdev_fru);
5440 			vd->vdev_fru = spa_strdup(value);
5441 			sync = B_TRUE;
5442 		}
5443 	}
5444 
5445 	return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5446 }
5447 
5448 int
5449 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5450 {
5451 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5452 }
5453 
5454 int
5455 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5456 {
5457 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5458 }
5459 
5460 /*
5461  * ==========================================================================
5462  * SPA Scanning
5463  * ==========================================================================
5464  */
5465 
5466 int
5467 spa_scan_stop(spa_t *spa)
5468 {
5469 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5470 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
5471 		return (SET_ERROR(EBUSY));
5472 	return (dsl_scan_cancel(spa->spa_dsl_pool));
5473 }
5474 
5475 int
5476 spa_scan(spa_t *spa, pool_scan_func_t func)
5477 {
5478 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5479 
5480 	if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5481 		return (SET_ERROR(ENOTSUP));
5482 
5483 	/*
5484 	 * If a resilver was requested, but there is no DTL on a
5485 	 * writeable leaf device, we have nothing to do.
5486 	 */
5487 	if (func == POOL_SCAN_RESILVER &&
5488 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5489 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5490 		return (0);
5491 	}
5492 
5493 	return (dsl_scan(spa->spa_dsl_pool, func));
5494 }
5495 
5496 /*
5497  * ==========================================================================
5498  * SPA async task processing
5499  * ==========================================================================
5500  */
5501 
5502 static void
5503 spa_async_remove(spa_t *spa, vdev_t *vd)
5504 {
5505 	if (vd->vdev_remove_wanted) {
5506 		vd->vdev_remove_wanted = B_FALSE;
5507 		vd->vdev_delayed_close = B_FALSE;
5508 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5509 
5510 		/*
5511 		 * We want to clear the stats, but we don't want to do a full
5512 		 * vdev_clear() as that will cause us to throw away
5513 		 * degraded/faulted state as well as attempt to reopen the
5514 		 * device, all of which is a waste.
5515 		 */
5516 		vd->vdev_stat.vs_read_errors = 0;
5517 		vd->vdev_stat.vs_write_errors = 0;
5518 		vd->vdev_stat.vs_checksum_errors = 0;
5519 
5520 		vdev_state_dirty(vd->vdev_top);
5521 	}
5522 
5523 	for (int c = 0; c < vd->vdev_children; c++)
5524 		spa_async_remove(spa, vd->vdev_child[c]);
5525 }
5526 
5527 static void
5528 spa_async_probe(spa_t *spa, vdev_t *vd)
5529 {
5530 	if (vd->vdev_probe_wanted) {
5531 		vd->vdev_probe_wanted = B_FALSE;
5532 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
5533 	}
5534 
5535 	for (int c = 0; c < vd->vdev_children; c++)
5536 		spa_async_probe(spa, vd->vdev_child[c]);
5537 }
5538 
5539 static void
5540 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5541 {
5542 	sysevent_id_t eid;
5543 	nvlist_t *attr;
5544 	char *physpath;
5545 
5546 	if (!spa->spa_autoexpand)
5547 		return;
5548 
5549 	for (int c = 0; c < vd->vdev_children; c++) {
5550 		vdev_t *cvd = vd->vdev_child[c];
5551 		spa_async_autoexpand(spa, cvd);
5552 	}
5553 
5554 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5555 		return;
5556 
5557 	physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5558 	(void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5559 
5560 	VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5561 	VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5562 
5563 	(void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5564 	    ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5565 
5566 	nvlist_free(attr);
5567 	kmem_free(physpath, MAXPATHLEN);
5568 }
5569 
5570 static void
5571 spa_async_thread(spa_t *spa)
5572 {
5573 	int tasks;
5574 
5575 	ASSERT(spa->spa_sync_on);
5576 
5577 	mutex_enter(&spa->spa_async_lock);
5578 	tasks = spa->spa_async_tasks;
5579 	spa->spa_async_tasks = 0;
5580 	mutex_exit(&spa->spa_async_lock);
5581 
5582 	/*
5583 	 * See if the config needs to be updated.
5584 	 */
5585 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5586 		uint64_t old_space, new_space;
5587 
5588 		mutex_enter(&spa_namespace_lock);
5589 		old_space = metaslab_class_get_space(spa_normal_class(spa));
5590 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5591 		new_space = metaslab_class_get_space(spa_normal_class(spa));
5592 		mutex_exit(&spa_namespace_lock);
5593 
5594 		/*
5595 		 * If the pool grew as a result of the config update,
5596 		 * then log an internal history event.
5597 		 */
5598 		if (new_space != old_space) {
5599 			spa_history_log_internal(spa, "vdev online", NULL,
5600 			    "pool '%s' size: %llu(+%llu)",
5601 			    spa_name(spa), new_space, new_space - old_space);
5602 		}
5603 	}
5604 
5605 	/*
5606 	 * See if any devices need to be marked REMOVED.
5607 	 */
5608 	if (tasks & SPA_ASYNC_REMOVE) {
5609 		spa_vdev_state_enter(spa, SCL_NONE);
5610 		spa_async_remove(spa, spa->spa_root_vdev);
5611 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5612 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5613 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
5614 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5615 		(void) spa_vdev_state_exit(spa, NULL, 0);
5616 	}
5617 
5618 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5619 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5620 		spa_async_autoexpand(spa, spa->spa_root_vdev);
5621 		spa_config_exit(spa, SCL_CONFIG, FTAG);
5622 	}
5623 
5624 	/*
5625 	 * See if any devices need to be probed.
5626 	 */
5627 	if (tasks & SPA_ASYNC_PROBE) {
5628 		spa_vdev_state_enter(spa, SCL_NONE);
5629 		spa_async_probe(spa, spa->spa_root_vdev);
5630 		(void) spa_vdev_state_exit(spa, NULL, 0);
5631 	}
5632 
5633 	/*
5634 	 * If any devices are done replacing, detach them.
5635 	 */
5636 	if (tasks & SPA_ASYNC_RESILVER_DONE)
5637 		spa_vdev_resilver_done(spa);
5638 
5639 	/*
5640 	 * Kick off a resilver.
5641 	 */
5642 	if (tasks & SPA_ASYNC_RESILVER)
5643 		dsl_resilver_restart(spa->spa_dsl_pool, 0);
5644 
5645 	/*
5646 	 * Let the world know that we're done.
5647 	 */
5648 	mutex_enter(&spa->spa_async_lock);
5649 	spa->spa_async_thread = NULL;
5650 	cv_broadcast(&spa->spa_async_cv);
5651 	mutex_exit(&spa->spa_async_lock);
5652 	thread_exit();
5653 }
5654 
5655 void
5656 spa_async_suspend(spa_t *spa)
5657 {
5658 	mutex_enter(&spa->spa_async_lock);
5659 	spa->spa_async_suspended++;
5660 	while (spa->spa_async_thread != NULL)
5661 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5662 	mutex_exit(&spa->spa_async_lock);
5663 }
5664 
5665 void
5666 spa_async_resume(spa_t *spa)
5667 {
5668 	mutex_enter(&spa->spa_async_lock);
5669 	ASSERT(spa->spa_async_suspended != 0);
5670 	spa->spa_async_suspended--;
5671 	mutex_exit(&spa->spa_async_lock);
5672 }
5673 
5674 static boolean_t
5675 spa_async_tasks_pending(spa_t *spa)
5676 {
5677 	uint_t non_config_tasks;
5678 	uint_t config_task;
5679 	boolean_t config_task_suspended;
5680 
5681 	non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5682 	config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5683 	if (spa->spa_ccw_fail_time == 0) {
5684 		config_task_suspended = B_FALSE;
5685 	} else {
5686 		config_task_suspended =
5687 		    (gethrtime() - spa->spa_ccw_fail_time) <
5688 		    (zfs_ccw_retry_interval * NANOSEC);
5689 	}
5690 
5691 	return (non_config_tasks || (config_task && !config_task_suspended));
5692 }
5693 
5694 static void
5695 spa_async_dispatch(spa_t *spa)
5696 {
5697 	mutex_enter(&spa->spa_async_lock);
5698 	if (spa_async_tasks_pending(spa) &&
5699 	    !spa->spa_async_suspended &&
5700 	    spa->spa_async_thread == NULL &&
5701 	    rootdir != NULL)
5702 		spa->spa_async_thread = thread_create(NULL, 0,
5703 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5704 	mutex_exit(&spa->spa_async_lock);
5705 }
5706 
5707 void
5708 spa_async_request(spa_t *spa, int task)
5709 {
5710 	zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5711 	mutex_enter(&spa->spa_async_lock);
5712 	spa->spa_async_tasks |= task;
5713 	mutex_exit(&spa->spa_async_lock);
5714 }
5715 
5716 /*
5717  * ==========================================================================
5718  * SPA syncing routines
5719  * ==========================================================================
5720  */
5721 
5722 static int
5723 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5724 {
5725 	bpobj_t *bpo = arg;
5726 	bpobj_enqueue(bpo, bp, tx);
5727 	return (0);
5728 }
5729 
5730 static int
5731 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5732 {
5733 	zio_t *zio = arg;
5734 
5735 	zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5736 	    zio->io_flags));
5737 	return (0);
5738 }
5739 
5740 static void
5741 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5742 {
5743 	char *packed = NULL;
5744 	size_t bufsize;
5745 	size_t nvsize = 0;
5746 	dmu_buf_t *db;
5747 
5748 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5749 
5750 	/*
5751 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5752 	 * information.  This avoids the dbuf_will_dirty() path and
5753 	 * saves us a pre-read to get data we don't actually care about.
5754 	 */
5755 	bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5756 	packed = kmem_alloc(bufsize, KM_SLEEP);
5757 
5758 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5759 	    KM_SLEEP) == 0);
5760 	bzero(packed + nvsize, bufsize - nvsize);
5761 
5762 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5763 
5764 	kmem_free(packed, bufsize);
5765 
5766 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5767 	dmu_buf_will_dirty(db, tx);
5768 	*(uint64_t *)db->db_data = nvsize;
5769 	dmu_buf_rele(db, FTAG);
5770 }
5771 
5772 static void
5773 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5774     const char *config, const char *entry)
5775 {
5776 	nvlist_t *nvroot;
5777 	nvlist_t **list;
5778 	int i;
5779 
5780 	if (!sav->sav_sync)
5781 		return;
5782 
5783 	/*
5784 	 * Update the MOS nvlist describing the list of available devices.
5785 	 * spa_validate_aux() will have already made sure this nvlist is
5786 	 * valid and the vdevs are labeled appropriately.
5787 	 */
5788 	if (sav->sav_object == 0) {
5789 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5790 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5791 		    sizeof (uint64_t), tx);
5792 		VERIFY(zap_update(spa->spa_meta_objset,
5793 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5794 		    &sav->sav_object, tx) == 0);
5795 	}
5796 
5797 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5798 	if (sav->sav_count == 0) {
5799 		VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5800 	} else {
5801 		list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5802 		for (i = 0; i < sav->sav_count; i++)
5803 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5804 			    B_FALSE, VDEV_CONFIG_L2CACHE);
5805 		VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5806 		    sav->sav_count) == 0);
5807 		for (i = 0; i < sav->sav_count; i++)
5808 			nvlist_free(list[i]);
5809 		kmem_free(list, sav->sav_count * sizeof (void *));
5810 	}
5811 
5812 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5813 	nvlist_free(nvroot);
5814 
5815 	sav->sav_sync = B_FALSE;
5816 }
5817 
5818 static void
5819 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5820 {
5821 	nvlist_t *config;
5822 
5823 	if (list_is_empty(&spa->spa_config_dirty_list))
5824 		return;
5825 
5826 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5827 
5828 	config = spa_config_generate(spa, spa->spa_root_vdev,
5829 	    dmu_tx_get_txg(tx), B_FALSE);
5830 
5831 	/*
5832 	 * If we're upgrading the spa version then make sure that
5833 	 * the config object gets updated with the correct version.
5834 	 */
5835 	if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5836 		fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5837 		    spa->spa_uberblock.ub_version);
5838 
5839 	spa_config_exit(spa, SCL_STATE, FTAG);
5840 
5841 	if (spa->spa_config_syncing)
5842 		nvlist_free(spa->spa_config_syncing);
5843 	spa->spa_config_syncing = config;
5844 
5845 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5846 }
5847 
5848 static void
5849 spa_sync_version(void *arg, dmu_tx_t *tx)
5850 {
5851 	uint64_t *versionp = arg;
5852 	uint64_t version = *versionp;
5853 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5854 
5855 	/*
5856 	 * Setting the version is special cased when first creating the pool.
5857 	 */
5858 	ASSERT(tx->tx_txg != TXG_INITIAL);
5859 
5860 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5861 	ASSERT(version >= spa_version(spa));
5862 
5863 	spa->spa_uberblock.ub_version = version;
5864 	vdev_config_dirty(spa->spa_root_vdev);
5865 	spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5866 }
5867 
5868 /*
5869  * Set zpool properties.
5870  */
5871 static void
5872 spa_sync_props(void *arg, dmu_tx_t *tx)
5873 {
5874 	nvlist_t *nvp = arg;
5875 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5876 	objset_t *mos = spa->spa_meta_objset;
5877 	nvpair_t *elem = NULL;
5878 
5879 	mutex_enter(&spa->spa_props_lock);
5880 
5881 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
5882 		uint64_t intval;
5883 		char *strval, *fname;
5884 		zpool_prop_t prop;
5885 		const char *propname;
5886 		zprop_type_t proptype;
5887 		zfeature_info_t *feature;
5888 
5889 		switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5890 		case ZPROP_INVAL:
5891 			/*
5892 			 * We checked this earlier in spa_prop_validate().
5893 			 */
5894 			ASSERT(zpool_prop_feature(nvpair_name(elem)));
5895 
5896 			fname = strchr(nvpair_name(elem), '@') + 1;
5897 			VERIFY3U(0, ==, zfeature_lookup_name(fname, &feature));
5898 
5899 			spa_feature_enable(spa, feature, tx);
5900 			spa_history_log_internal(spa, "set", tx,
5901 			    "%s=enabled", nvpair_name(elem));
5902 			break;
5903 
5904 		case ZPOOL_PROP_VERSION:
5905 			VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5906 			/*
5907 			 * The version is synced seperatly before other
5908 			 * properties and should be correct by now.
5909 			 */
5910 			ASSERT3U(spa_version(spa), >=, intval);
5911 			break;
5912 
5913 		case ZPOOL_PROP_ALTROOT:
5914 			/*
5915 			 * 'altroot' is a non-persistent property. It should
5916 			 * have been set temporarily at creation or import time.
5917 			 */
5918 			ASSERT(spa->spa_root != NULL);
5919 			break;
5920 
5921 		case ZPOOL_PROP_READONLY:
5922 		case ZPOOL_PROP_CACHEFILE:
5923 			/*
5924 			 * 'readonly' and 'cachefile' are also non-persisitent
5925 			 * properties.
5926 			 */
5927 			break;
5928 		case ZPOOL_PROP_COMMENT:
5929 			VERIFY(nvpair_value_string(elem, &strval) == 0);
5930 			if (spa->spa_comment != NULL)
5931 				spa_strfree(spa->spa_comment);
5932 			spa->spa_comment = spa_strdup(strval);
5933 			/*
5934 			 * We need to dirty the configuration on all the vdevs
5935 			 * so that their labels get updated.  It's unnecessary
5936 			 * to do this for pool creation since the vdev's
5937 			 * configuratoin has already been dirtied.
5938 			 */
5939 			if (tx->tx_txg != TXG_INITIAL)
5940 				vdev_config_dirty(spa->spa_root_vdev);
5941 			spa_history_log_internal(spa, "set", tx,
5942 			    "%s=%s", nvpair_name(elem), strval);
5943 			break;
5944 		default:
5945 			/*
5946 			 * Set pool property values in the poolprops mos object.
5947 			 */
5948 			if (spa->spa_pool_props_object == 0) {
5949 				spa->spa_pool_props_object =
5950 				    zap_create_link(mos, DMU_OT_POOL_PROPS,
5951 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
5952 				    tx);
5953 			}
5954 
5955 			/* normalize the property name */
5956 			propname = zpool_prop_to_name(prop);
5957 			proptype = zpool_prop_get_type(prop);
5958 
5959 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
5960 				ASSERT(proptype == PROP_TYPE_STRING);
5961 				VERIFY(nvpair_value_string(elem, &strval) == 0);
5962 				VERIFY(zap_update(mos,
5963 				    spa->spa_pool_props_object, propname,
5964 				    1, strlen(strval) + 1, strval, tx) == 0);
5965 				spa_history_log_internal(spa, "set", tx,
5966 				    "%s=%s", nvpair_name(elem), strval);
5967 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
5968 				VERIFY(nvpair_value_uint64(elem, &intval) == 0);
5969 
5970 				if (proptype == PROP_TYPE_INDEX) {
5971 					const char *unused;
5972 					VERIFY(zpool_prop_index_to_string(
5973 					    prop, intval, &unused) == 0);
5974 				}
5975 				VERIFY(zap_update(mos,
5976 				    spa->spa_pool_props_object, propname,
5977 				    8, 1, &intval, tx) == 0);
5978 				spa_history_log_internal(spa, "set", tx,
5979 				    "%s=%lld", nvpair_name(elem), intval);
5980 			} else {
5981 				ASSERT(0); /* not allowed */
5982 			}
5983 
5984 			switch (prop) {
5985 			case ZPOOL_PROP_DELEGATION:
5986 				spa->spa_delegation = intval;
5987 				break;
5988 			case ZPOOL_PROP_BOOTFS:
5989 				spa->spa_bootfs = intval;
5990 				break;
5991 			case ZPOOL_PROP_FAILUREMODE:
5992 				spa->spa_failmode = intval;
5993 				break;
5994 			case ZPOOL_PROP_AUTOEXPAND:
5995 				spa->spa_autoexpand = intval;
5996 				if (tx->tx_txg != TXG_INITIAL)
5997 					spa_async_request(spa,
5998 					    SPA_ASYNC_AUTOEXPAND);
5999 				break;
6000 			case ZPOOL_PROP_DEDUPDITTO:
6001 				spa->spa_dedup_ditto = intval;
6002 				break;
6003 			default:
6004 				break;
6005 			}
6006 		}
6007 
6008 	}
6009 
6010 	mutex_exit(&spa->spa_props_lock);
6011 }
6012 
6013 /*
6014  * Perform one-time upgrade on-disk changes.  spa_version() does not
6015  * reflect the new version this txg, so there must be no changes this
6016  * txg to anything that the upgrade code depends on after it executes.
6017  * Therefore this must be called after dsl_pool_sync() does the sync
6018  * tasks.
6019  */
6020 static void
6021 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6022 {
6023 	dsl_pool_t *dp = spa->spa_dsl_pool;
6024 
6025 	ASSERT(spa->spa_sync_pass == 1);
6026 
6027 	rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6028 
6029 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6030 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6031 		dsl_pool_create_origin(dp, tx);
6032 
6033 		/* Keeping the origin open increases spa_minref */
6034 		spa->spa_minref += 3;
6035 	}
6036 
6037 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6038 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6039 		dsl_pool_upgrade_clones(dp, tx);
6040 	}
6041 
6042 	if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6043 	    spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6044 		dsl_pool_upgrade_dir_clones(dp, tx);
6045 
6046 		/* Keeping the freedir open increases spa_minref */
6047 		spa->spa_minref += 3;
6048 	}
6049 
6050 	if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6051 	    spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6052 		spa_feature_create_zap_objects(spa, tx);
6053 	}
6054 	rrw_exit(&dp->dp_config_rwlock, FTAG);
6055 }
6056 
6057 /*
6058  * Sync the specified transaction group.  New blocks may be dirtied as
6059  * part of the process, so we iterate until it converges.
6060  */
6061 void
6062 spa_sync(spa_t *spa, uint64_t txg)
6063 {
6064 	dsl_pool_t *dp = spa->spa_dsl_pool;
6065 	objset_t *mos = spa->spa_meta_objset;
6066 	bpobj_t *defer_bpo = &spa->spa_deferred_bpobj;
6067 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6068 	vdev_t *rvd = spa->spa_root_vdev;
6069 	vdev_t *vd;
6070 	dmu_tx_t *tx;
6071 	int error;
6072 
6073 	VERIFY(spa_writeable(spa));
6074 
6075 	/*
6076 	 * Lock out configuration changes.
6077 	 */
6078 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6079 
6080 	spa->spa_syncing_txg = txg;
6081 	spa->spa_sync_pass = 0;
6082 
6083 	/*
6084 	 * If there are any pending vdev state changes, convert them
6085 	 * into config changes that go out with this transaction group.
6086 	 */
6087 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6088 	while (list_head(&spa->spa_state_dirty_list) != NULL) {
6089 		/*
6090 		 * We need the write lock here because, for aux vdevs,
6091 		 * calling vdev_config_dirty() modifies sav_config.
6092 		 * This is ugly and will become unnecessary when we
6093 		 * eliminate the aux vdev wart by integrating all vdevs
6094 		 * into the root vdev tree.
6095 		 */
6096 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6097 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6098 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6099 			vdev_state_clean(vd);
6100 			vdev_config_dirty(vd);
6101 		}
6102 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6103 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6104 	}
6105 	spa_config_exit(spa, SCL_STATE, FTAG);
6106 
6107 	tx = dmu_tx_create_assigned(dp, txg);
6108 
6109 	spa->spa_sync_starttime = gethrtime();
6110 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6111 	    spa->spa_sync_starttime + spa->spa_deadman_synctime));
6112 
6113 	/*
6114 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6115 	 * set spa_deflate if we have no raid-z vdevs.
6116 	 */
6117 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6118 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6119 		int i;
6120 
6121 		for (i = 0; i < rvd->vdev_children; i++) {
6122 			vd = rvd->vdev_child[i];
6123 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6124 				break;
6125 		}
6126 		if (i == rvd->vdev_children) {
6127 			spa->spa_deflate = TRUE;
6128 			VERIFY(0 == zap_add(spa->spa_meta_objset,
6129 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6130 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6131 		}
6132 	}
6133 
6134 	/*
6135 	 * If anything has changed in this txg, or if someone is waiting
6136 	 * for this txg to sync (eg, spa_vdev_remove()), push the
6137 	 * deferred frees from the previous txg.  If not, leave them
6138 	 * alone so that we don't generate work on an otherwise idle
6139 	 * system.
6140 	 */
6141 	if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6142 	    !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6143 	    !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6144 	    ((dsl_scan_active(dp->dp_scan) ||
6145 	    txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6146 		zio_t *zio = zio_root(spa, NULL, NULL, 0);
6147 		VERIFY3U(bpobj_iterate(defer_bpo,
6148 		    spa_free_sync_cb, zio, tx), ==, 0);
6149 		VERIFY0(zio_wait(zio));
6150 	}
6151 
6152 	/*
6153 	 * Iterate to convergence.
6154 	 */
6155 	do {
6156 		int pass = ++spa->spa_sync_pass;
6157 
6158 		spa_sync_config_object(spa, tx);
6159 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6160 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6161 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6162 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6163 		spa_errlog_sync(spa, txg);
6164 		dsl_pool_sync(dp, txg);
6165 
6166 		if (pass < zfs_sync_pass_deferred_free) {
6167 			zio_t *zio = zio_root(spa, NULL, NULL, 0);
6168 			bplist_iterate(free_bpl, spa_free_sync_cb,
6169 			    zio, tx);
6170 			VERIFY(zio_wait(zio) == 0);
6171 		} else {
6172 			bplist_iterate(free_bpl, bpobj_enqueue_cb,
6173 			    defer_bpo, tx);
6174 		}
6175 
6176 		ddt_sync(spa, txg);
6177 		dsl_scan_sync(dp, tx);
6178 
6179 		while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6180 			vdev_sync(vd, txg);
6181 
6182 		if (pass == 1)
6183 			spa_sync_upgrades(spa, tx);
6184 
6185 	} while (dmu_objset_is_dirty(mos, txg));
6186 
6187 	/*
6188 	 * Rewrite the vdev configuration (which includes the uberblock)
6189 	 * to commit the transaction group.
6190 	 *
6191 	 * If there are no dirty vdevs, we sync the uberblock to a few
6192 	 * random top-level vdevs that are known to be visible in the
6193 	 * config cache (see spa_vdev_add() for a complete description).
6194 	 * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6195 	 */
6196 	for (;;) {
6197 		/*
6198 		 * We hold SCL_STATE to prevent vdev open/close/etc.
6199 		 * while we're attempting to write the vdev labels.
6200 		 */
6201 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6202 
6203 		if (list_is_empty(&spa->spa_config_dirty_list)) {
6204 			vdev_t *svd[SPA_DVAS_PER_BP];
6205 			int svdcount = 0;
6206 			int children = rvd->vdev_children;
6207 			int c0 = spa_get_random(children);
6208 
6209 			for (int c = 0; c < children; c++) {
6210 				vd = rvd->vdev_child[(c0 + c) % children];
6211 				if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6212 					continue;
6213 				svd[svdcount++] = vd;
6214 				if (svdcount == SPA_DVAS_PER_BP)
6215 					break;
6216 			}
6217 			error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6218 			if (error != 0)
6219 				error = vdev_config_sync(svd, svdcount, txg,
6220 				    B_TRUE);
6221 		} else {
6222 			error = vdev_config_sync(rvd->vdev_child,
6223 			    rvd->vdev_children, txg, B_FALSE);
6224 			if (error != 0)
6225 				error = vdev_config_sync(rvd->vdev_child,
6226 				    rvd->vdev_children, txg, B_TRUE);
6227 		}
6228 
6229 		if (error == 0)
6230 			spa->spa_last_synced_guid = rvd->vdev_guid;
6231 
6232 		spa_config_exit(spa, SCL_STATE, FTAG);
6233 
6234 		if (error == 0)
6235 			break;
6236 		zio_suspend(spa, NULL);
6237 		zio_resume_wait(spa);
6238 	}
6239 	dmu_tx_commit(tx);
6240 
6241 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6242 
6243 	/*
6244 	 * Clear the dirty config list.
6245 	 */
6246 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6247 		vdev_config_clean(vd);
6248 
6249 	/*
6250 	 * Now that the new config has synced transactionally,
6251 	 * let it become visible to the config cache.
6252 	 */
6253 	if (spa->spa_config_syncing != NULL) {
6254 		spa_config_set(spa, spa->spa_config_syncing);
6255 		spa->spa_config_txg = txg;
6256 		spa->spa_config_syncing = NULL;
6257 	}
6258 
6259 	spa->spa_ubsync = spa->spa_uberblock;
6260 
6261 	dsl_pool_sync_done(dp, txg);
6262 
6263 	/*
6264 	 * Update usable space statistics.
6265 	 */
6266 	while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6267 		vdev_sync_done(vd, txg);
6268 
6269 	spa_update_dspace(spa);
6270 
6271 	/*
6272 	 * It had better be the case that we didn't dirty anything
6273 	 * since vdev_config_sync().
6274 	 */
6275 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6276 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6277 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6278 
6279 	spa->spa_sync_pass = 0;
6280 
6281 	spa_config_exit(spa, SCL_CONFIG, FTAG);
6282 
6283 	spa_handle_ignored_writes(spa);
6284 
6285 	/*
6286 	 * If any async tasks have been requested, kick them off.
6287 	 */
6288 	spa_async_dispatch(spa);
6289 }
6290 
6291 /*
6292  * Sync all pools.  We don't want to hold the namespace lock across these
6293  * operations, so we take a reference on the spa_t and drop the lock during the
6294  * sync.
6295  */
6296 void
6297 spa_sync_allpools(void)
6298 {
6299 	spa_t *spa = NULL;
6300 	mutex_enter(&spa_namespace_lock);
6301 	while ((spa = spa_next(spa)) != NULL) {
6302 		if (spa_state(spa) != POOL_STATE_ACTIVE ||
6303 		    !spa_writeable(spa) || spa_suspended(spa))
6304 			continue;
6305 		spa_open_ref(spa, FTAG);
6306 		mutex_exit(&spa_namespace_lock);
6307 		txg_wait_synced(spa_get_dsl(spa), 0);
6308 		mutex_enter(&spa_namespace_lock);
6309 		spa_close(spa, FTAG);
6310 	}
6311 	mutex_exit(&spa_namespace_lock);
6312 }
6313 
6314 /*
6315  * ==========================================================================
6316  * Miscellaneous routines
6317  * ==========================================================================
6318  */
6319 
6320 /*
6321  * Remove all pools in the system.
6322  */
6323 void
6324 spa_evict_all(void)
6325 {
6326 	spa_t *spa;
6327 
6328 	/*
6329 	 * Remove all cached state.  All pools should be closed now,
6330 	 * so every spa in the AVL tree should be unreferenced.
6331 	 */
6332 	mutex_enter(&spa_namespace_lock);
6333 	while ((spa = spa_next(NULL)) != NULL) {
6334 		/*
6335 		 * Stop async tasks.  The async thread may need to detach
6336 		 * a device that's been replaced, which requires grabbing
6337 		 * spa_namespace_lock, so we must drop it here.
6338 		 */
6339 		spa_open_ref(spa, FTAG);
6340 		mutex_exit(&spa_namespace_lock);
6341 		spa_async_suspend(spa);
6342 		mutex_enter(&spa_namespace_lock);
6343 		spa_close(spa, FTAG);
6344 
6345 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6346 			spa_unload(spa);
6347 			spa_deactivate(spa);
6348 		}
6349 		spa_remove(spa);
6350 	}
6351 	mutex_exit(&spa_namespace_lock);
6352 }
6353 
6354 vdev_t *
6355 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6356 {
6357 	vdev_t *vd;
6358 	int i;
6359 
6360 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6361 		return (vd);
6362 
6363 	if (aux) {
6364 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6365 			vd = spa->spa_l2cache.sav_vdevs[i];
6366 			if (vd->vdev_guid == guid)
6367 				return (vd);
6368 		}
6369 
6370 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
6371 			vd = spa->spa_spares.sav_vdevs[i];
6372 			if (vd->vdev_guid == guid)
6373 				return (vd);
6374 		}
6375 	}
6376 
6377 	return (NULL);
6378 }
6379 
6380 void
6381 spa_upgrade(spa_t *spa, uint64_t version)
6382 {
6383 	ASSERT(spa_writeable(spa));
6384 
6385 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6386 
6387 	/*
6388 	 * This should only be called for a non-faulted pool, and since a
6389 	 * future version would result in an unopenable pool, this shouldn't be
6390 	 * possible.
6391 	 */
6392 	ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6393 	ASSERT(version >= spa->spa_uberblock.ub_version);
6394 
6395 	spa->spa_uberblock.ub_version = version;
6396 	vdev_config_dirty(spa->spa_root_vdev);
6397 
6398 	spa_config_exit(spa, SCL_ALL, FTAG);
6399 
6400 	txg_wait_synced(spa_get_dsl(spa), 0);
6401 }
6402 
6403 boolean_t
6404 spa_has_spare(spa_t *spa, uint64_t guid)
6405 {
6406 	int i;
6407 	uint64_t spareguid;
6408 	spa_aux_vdev_t *sav = &spa->spa_spares;
6409 
6410 	for (i = 0; i < sav->sav_count; i++)
6411 		if (sav->sav_vdevs[i]->vdev_guid == guid)
6412 			return (B_TRUE);
6413 
6414 	for (i = 0; i < sav->sav_npending; i++) {
6415 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6416 		    &spareguid) == 0 && spareguid == guid)
6417 			return (B_TRUE);
6418 	}
6419 
6420 	return (B_FALSE);
6421 }
6422 
6423 /*
6424  * Check if a pool has an active shared spare device.
6425  * Note: reference count of an active spare is 2, as a spare and as a replace
6426  */
6427 static boolean_t
6428 spa_has_active_shared_spare(spa_t *spa)
6429 {
6430 	int i, refcnt;
6431 	uint64_t pool;
6432 	spa_aux_vdev_t *sav = &spa->spa_spares;
6433 
6434 	for (i = 0; i < sav->sav_count; i++) {
6435 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6436 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6437 		    refcnt > 2)
6438 			return (B_TRUE);
6439 	}
6440 
6441 	return (B_FALSE);
6442 }
6443 
6444 /*
6445  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6446  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6447  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6448  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6449  * or zdb as real changes.
6450  */
6451 void
6452 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6453 {
6454 #ifdef _KERNEL
6455 	sysevent_t		*ev;
6456 	sysevent_attr_list_t	*attr = NULL;
6457 	sysevent_value_t	value;
6458 	sysevent_id_t		eid;
6459 
6460 	ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6461 	    SE_SLEEP);
6462 
6463 	value.value_type = SE_DATA_TYPE_STRING;
6464 	value.value.sv_string = spa_name(spa);
6465 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6466 		goto done;
6467 
6468 	value.value_type = SE_DATA_TYPE_UINT64;
6469 	value.value.sv_uint64 = spa_guid(spa);
6470 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6471 		goto done;
6472 
6473 	if (vd) {
6474 		value.value_type = SE_DATA_TYPE_UINT64;
6475 		value.value.sv_uint64 = vd->vdev_guid;
6476 		if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6477 		    SE_SLEEP) != 0)
6478 			goto done;
6479 
6480 		if (vd->vdev_path) {
6481 			value.value_type = SE_DATA_TYPE_STRING;
6482 			value.value.sv_string = vd->vdev_path;
6483 			if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6484 			    &value, SE_SLEEP) != 0)
6485 				goto done;
6486 		}
6487 	}
6488 
6489 	if (sysevent_attach_attributes(ev, attr) != 0)
6490 		goto done;
6491 	attr = NULL;
6492 
6493 	(void) log_sysevent(ev, SE_SLEEP, &eid);
6494 
6495 done:
6496 	if (attr)
6497 		sysevent_free_attr(attr);
6498 	sysevent_free(ev);
6499 #endif
6500 }
6501