xref: /titanic_51/usr/src/uts/common/fs/zfs/spa.c (revision f34a71784df3fbc5d1227a7b6201fd318ad1667e)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * This file contains all the routines used when modifying on-disk SPA state.
29  * This includes opening, importing, destroying, exporting a pool, and syncing a
30  * pool.
31  */
32 
33 #include <sys/zfs_context.h>
34 #include <sys/fm/fs/zfs.h>
35 #include <sys/spa_impl.h>
36 #include <sys/zio.h>
37 #include <sys/zio_checksum.h>
38 #include <sys/zio_compress.h>
39 #include <sys/dmu.h>
40 #include <sys/dmu_tx.h>
41 #include <sys/zap.h>
42 #include <sys/zil.h>
43 #include <sys/vdev_impl.h>
44 #include <sys/metaslab.h>
45 #include <sys/uberblock_impl.h>
46 #include <sys/txg.h>
47 #include <sys/avl.h>
48 #include <sys/dmu_traverse.h>
49 #include <sys/dmu_objset.h>
50 #include <sys/unique.h>
51 #include <sys/dsl_pool.h>
52 #include <sys/dsl_dataset.h>
53 #include <sys/dsl_dir.h>
54 #include <sys/dsl_prop.h>
55 #include <sys/dsl_synctask.h>
56 #include <sys/fs/zfs.h>
57 #include <sys/arc.h>
58 #include <sys/callb.h>
59 #include <sys/systeminfo.h>
60 #include <sys/sunddi.h>
61 #include <sys/spa_boot.h>
62 
63 #ifdef	_KERNEL
64 #include <sys/zone.h>
65 #endif	/* _KERNEL */
66 
67 #include "zfs_prop.h"
68 #include "zfs_comutil.h"
69 
70 int zio_taskq_threads[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
71 	/*	ISSUE	INTR					*/
72 	{	1,	1	},	/* ZIO_TYPE_NULL	*/
73 	{	8,	8	},	/* ZIO_TYPE_READ	*/
74 	{	8,	8	},	/* ZIO_TYPE_WRITE	*/
75 	{	1,	1	},	/* ZIO_TYPE_FREE	*/
76 	{	1,	1	},	/* ZIO_TYPE_CLAIM	*/
77 	{	1,	1	},	/* ZIO_TYPE_IOCTL	*/
78 };
79 
80 static void spa_sync_props(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx);
81 static boolean_t spa_has_active_shared_spare(spa_t *spa);
82 
83 /*
84  * ==========================================================================
85  * SPA properties routines
86  * ==========================================================================
87  */
88 
89 /*
90  * Add a (source=src, propname=propval) list to an nvlist.
91  */
92 static void
93 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
94     uint64_t intval, zprop_source_t src)
95 {
96 	const char *propname = zpool_prop_to_name(prop);
97 	nvlist_t *propval;
98 
99 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
100 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
101 
102 	if (strval != NULL)
103 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
104 	else
105 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
106 
107 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
108 	nvlist_free(propval);
109 }
110 
111 /*
112  * Get property values from the spa configuration.
113  */
114 static void
115 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
116 {
117 	uint64_t size;
118 	uint64_t used;
119 	uint64_t cap, version;
120 	zprop_source_t src = ZPROP_SRC_NONE;
121 	spa_config_dirent_t *dp;
122 
123 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
124 
125 	if (spa->spa_root_vdev != NULL) {
126 		size = spa_get_space(spa);
127 		used = spa_get_alloc(spa);
128 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
129 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
130 		spa_prop_add_list(*nvp, ZPOOL_PROP_USED, NULL, used, src);
131 		spa_prop_add_list(*nvp, ZPOOL_PROP_AVAILABLE, NULL,
132 		    size - used, src);
133 
134 		cap = (size == 0) ? 0 : (used * 100 / size);
135 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
136 
137 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
138 		    spa->spa_root_vdev->vdev_state, src);
139 
140 		version = spa_version(spa);
141 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
142 			src = ZPROP_SRC_DEFAULT;
143 		else
144 			src = ZPROP_SRC_LOCAL;
145 		spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
146 	}
147 
148 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
149 
150 	if (spa->spa_root != NULL)
151 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
152 		    0, ZPROP_SRC_LOCAL);
153 
154 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
155 		if (dp->scd_path == NULL) {
156 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
157 			    "none", 0, ZPROP_SRC_LOCAL);
158 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
159 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
160 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
161 		}
162 	}
163 }
164 
165 /*
166  * Get zpool property values.
167  */
168 int
169 spa_prop_get(spa_t *spa, nvlist_t **nvp)
170 {
171 	zap_cursor_t zc;
172 	zap_attribute_t za;
173 	objset_t *mos = spa->spa_meta_objset;
174 	int err;
175 
176 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
177 
178 	mutex_enter(&spa->spa_props_lock);
179 
180 	/*
181 	 * Get properties from the spa config.
182 	 */
183 	spa_prop_get_config(spa, nvp);
184 
185 	/* If no pool property object, no more prop to get. */
186 	if (spa->spa_pool_props_object == 0) {
187 		mutex_exit(&spa->spa_props_lock);
188 		return (0);
189 	}
190 
191 	/*
192 	 * Get properties from the MOS pool property object.
193 	 */
194 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
195 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
196 	    zap_cursor_advance(&zc)) {
197 		uint64_t intval = 0;
198 		char *strval = NULL;
199 		zprop_source_t src = ZPROP_SRC_DEFAULT;
200 		zpool_prop_t prop;
201 
202 		if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
203 			continue;
204 
205 		switch (za.za_integer_length) {
206 		case 8:
207 			/* integer property */
208 			if (za.za_first_integer !=
209 			    zpool_prop_default_numeric(prop))
210 				src = ZPROP_SRC_LOCAL;
211 
212 			if (prop == ZPOOL_PROP_BOOTFS) {
213 				dsl_pool_t *dp;
214 				dsl_dataset_t *ds = NULL;
215 
216 				dp = spa_get_dsl(spa);
217 				rw_enter(&dp->dp_config_rwlock, RW_READER);
218 				if (err = dsl_dataset_hold_obj(dp,
219 				    za.za_first_integer, FTAG, &ds)) {
220 					rw_exit(&dp->dp_config_rwlock);
221 					break;
222 				}
223 
224 				strval = kmem_alloc(
225 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
226 				    KM_SLEEP);
227 				dsl_dataset_name(ds, strval);
228 				dsl_dataset_rele(ds, FTAG);
229 				rw_exit(&dp->dp_config_rwlock);
230 			} else {
231 				strval = NULL;
232 				intval = za.za_first_integer;
233 			}
234 
235 			spa_prop_add_list(*nvp, prop, strval, intval, src);
236 
237 			if (strval != NULL)
238 				kmem_free(strval,
239 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
240 
241 			break;
242 
243 		case 1:
244 			/* string property */
245 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
246 			err = zap_lookup(mos, spa->spa_pool_props_object,
247 			    za.za_name, 1, za.za_num_integers, strval);
248 			if (err) {
249 				kmem_free(strval, za.za_num_integers);
250 				break;
251 			}
252 			spa_prop_add_list(*nvp, prop, strval, 0, src);
253 			kmem_free(strval, za.za_num_integers);
254 			break;
255 
256 		default:
257 			break;
258 		}
259 	}
260 	zap_cursor_fini(&zc);
261 	mutex_exit(&spa->spa_props_lock);
262 out:
263 	if (err && err != ENOENT) {
264 		nvlist_free(*nvp);
265 		*nvp = NULL;
266 		return (err);
267 	}
268 
269 	return (0);
270 }
271 
272 /*
273  * Validate the given pool properties nvlist and modify the list
274  * for the property values to be set.
275  */
276 static int
277 spa_prop_validate(spa_t *spa, nvlist_t *props)
278 {
279 	nvpair_t *elem;
280 	int error = 0, reset_bootfs = 0;
281 	uint64_t objnum;
282 
283 	elem = NULL;
284 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
285 		zpool_prop_t prop;
286 		char *propname, *strval;
287 		uint64_t intval;
288 		objset_t *os;
289 		char *slash;
290 
291 		propname = nvpair_name(elem);
292 
293 		if ((prop = zpool_name_to_prop(propname)) == ZPROP_INVAL)
294 			return (EINVAL);
295 
296 		switch (prop) {
297 		case ZPOOL_PROP_VERSION:
298 			error = nvpair_value_uint64(elem, &intval);
299 			if (!error &&
300 			    (intval < spa_version(spa) || intval > SPA_VERSION))
301 				error = EINVAL;
302 			break;
303 
304 		case ZPOOL_PROP_DELEGATION:
305 		case ZPOOL_PROP_AUTOREPLACE:
306 		case ZPOOL_PROP_LISTSNAPS:
307 			error = nvpair_value_uint64(elem, &intval);
308 			if (!error && intval > 1)
309 				error = EINVAL;
310 			break;
311 
312 		case ZPOOL_PROP_BOOTFS:
313 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
314 				error = ENOTSUP;
315 				break;
316 			}
317 
318 			/*
319 			 * Make sure the vdev config is bootable
320 			 */
321 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
322 				error = ENOTSUP;
323 				break;
324 			}
325 
326 			reset_bootfs = 1;
327 
328 			error = nvpair_value_string(elem, &strval);
329 
330 			if (!error) {
331 				uint64_t compress;
332 
333 				if (strval == NULL || strval[0] == '\0') {
334 					objnum = zpool_prop_default_numeric(
335 					    ZPOOL_PROP_BOOTFS);
336 					break;
337 				}
338 
339 				if (error = dmu_objset_open(strval, DMU_OST_ZFS,
340 				    DS_MODE_USER | DS_MODE_READONLY, &os))
341 					break;
342 
343 				/* We don't support gzip bootable datasets */
344 				if ((error = dsl_prop_get_integer(strval,
345 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
346 				    &compress, NULL)) == 0 &&
347 				    !BOOTFS_COMPRESS_VALID(compress)) {
348 					error = ENOTSUP;
349 				} else {
350 					objnum = dmu_objset_id(os);
351 				}
352 				dmu_objset_close(os);
353 			}
354 			break;
355 
356 		case ZPOOL_PROP_FAILUREMODE:
357 			error = nvpair_value_uint64(elem, &intval);
358 			if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
359 			    intval > ZIO_FAILURE_MODE_PANIC))
360 				error = EINVAL;
361 
362 			/*
363 			 * This is a special case which only occurs when
364 			 * the pool has completely failed. This allows
365 			 * the user to change the in-core failmode property
366 			 * without syncing it out to disk (I/Os might
367 			 * currently be blocked). We do this by returning
368 			 * EIO to the caller (spa_prop_set) to trick it
369 			 * into thinking we encountered a property validation
370 			 * error.
371 			 */
372 			if (!error && spa_suspended(spa)) {
373 				spa->spa_failmode = intval;
374 				error = EIO;
375 			}
376 			break;
377 
378 		case ZPOOL_PROP_CACHEFILE:
379 			if ((error = nvpair_value_string(elem, &strval)) != 0)
380 				break;
381 
382 			if (strval[0] == '\0')
383 				break;
384 
385 			if (strcmp(strval, "none") == 0)
386 				break;
387 
388 			if (strval[0] != '/') {
389 				error = EINVAL;
390 				break;
391 			}
392 
393 			slash = strrchr(strval, '/');
394 			ASSERT(slash != NULL);
395 
396 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
397 			    strcmp(slash, "/..") == 0)
398 				error = EINVAL;
399 			break;
400 		}
401 
402 		if (error)
403 			break;
404 	}
405 
406 	if (!error && reset_bootfs) {
407 		error = nvlist_remove(props,
408 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
409 
410 		if (!error) {
411 			error = nvlist_add_uint64(props,
412 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
413 		}
414 	}
415 
416 	return (error);
417 }
418 
419 void
420 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
421 {
422 	char *cachefile;
423 	spa_config_dirent_t *dp;
424 
425 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
426 	    &cachefile) != 0)
427 		return;
428 
429 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
430 	    KM_SLEEP);
431 
432 	if (cachefile[0] == '\0')
433 		dp->scd_path = spa_strdup(spa_config_path);
434 	else if (strcmp(cachefile, "none") == 0)
435 		dp->scd_path = NULL;
436 	else
437 		dp->scd_path = spa_strdup(cachefile);
438 
439 	list_insert_head(&spa->spa_config_list, dp);
440 	if (need_sync)
441 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
442 }
443 
444 int
445 spa_prop_set(spa_t *spa, nvlist_t *nvp)
446 {
447 	int error;
448 	nvpair_t *elem;
449 	boolean_t need_sync = B_FALSE;
450 	zpool_prop_t prop;
451 
452 	if ((error = spa_prop_validate(spa, nvp)) != 0)
453 		return (error);
454 
455 	elem = NULL;
456 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
457 		if ((prop = zpool_name_to_prop(
458 		    nvpair_name(elem))) == ZPROP_INVAL)
459 			return (EINVAL);
460 
461 		if (prop == ZPOOL_PROP_CACHEFILE || prop == ZPOOL_PROP_ALTROOT)
462 			continue;
463 
464 		need_sync = B_TRUE;
465 		break;
466 	}
467 
468 	if (need_sync)
469 		return (dsl_sync_task_do(spa_get_dsl(spa), NULL, spa_sync_props,
470 		    spa, nvp, 3));
471 	else
472 		return (0);
473 }
474 
475 /*
476  * If the bootfs property value is dsobj, clear it.
477  */
478 void
479 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
480 {
481 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
482 		VERIFY(zap_remove(spa->spa_meta_objset,
483 		    spa->spa_pool_props_object,
484 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
485 		spa->spa_bootfs = 0;
486 	}
487 }
488 
489 /*
490  * ==========================================================================
491  * SPA state manipulation (open/create/destroy/import/export)
492  * ==========================================================================
493  */
494 
495 static int
496 spa_error_entry_compare(const void *a, const void *b)
497 {
498 	spa_error_entry_t *sa = (spa_error_entry_t *)a;
499 	spa_error_entry_t *sb = (spa_error_entry_t *)b;
500 	int ret;
501 
502 	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
503 	    sizeof (zbookmark_t));
504 
505 	if (ret < 0)
506 		return (-1);
507 	else if (ret > 0)
508 		return (1);
509 	else
510 		return (0);
511 }
512 
513 /*
514  * Utility function which retrieves copies of the current logs and
515  * re-initializes them in the process.
516  */
517 void
518 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
519 {
520 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
521 
522 	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
523 	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
524 
525 	avl_create(&spa->spa_errlist_scrub,
526 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
527 	    offsetof(spa_error_entry_t, se_avl));
528 	avl_create(&spa->spa_errlist_last,
529 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
530 	    offsetof(spa_error_entry_t, se_avl));
531 }
532 
533 /*
534  * Activate an uninitialized pool.
535  */
536 static void
537 spa_activate(spa_t *spa, int mode)
538 {
539 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
540 
541 	spa->spa_state = POOL_STATE_ACTIVE;
542 	spa->spa_mode = mode;
543 
544 	spa->spa_normal_class = metaslab_class_create(zfs_metaslab_ops);
545 	spa->spa_log_class = metaslab_class_create(zfs_metaslab_ops);
546 
547 	for (int t = 0; t < ZIO_TYPES; t++) {
548 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
549 			spa->spa_zio_taskq[t][q] = taskq_create("spa_zio",
550 			    zio_taskq_threads[t][q], maxclsyspri, 50,
551 			    INT_MAX, TASKQ_PREPOPULATE);
552 		}
553 	}
554 
555 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
556 	    offsetof(vdev_t, vdev_config_dirty_node));
557 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
558 	    offsetof(vdev_t, vdev_state_dirty_node));
559 
560 	txg_list_create(&spa->spa_vdev_txg_list,
561 	    offsetof(struct vdev, vdev_txg_node));
562 
563 	avl_create(&spa->spa_errlist_scrub,
564 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
565 	    offsetof(spa_error_entry_t, se_avl));
566 	avl_create(&spa->spa_errlist_last,
567 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
568 	    offsetof(spa_error_entry_t, se_avl));
569 }
570 
571 /*
572  * Opposite of spa_activate().
573  */
574 static void
575 spa_deactivate(spa_t *spa)
576 {
577 	ASSERT(spa->spa_sync_on == B_FALSE);
578 	ASSERT(spa->spa_dsl_pool == NULL);
579 	ASSERT(spa->spa_root_vdev == NULL);
580 
581 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
582 
583 	txg_list_destroy(&spa->spa_vdev_txg_list);
584 
585 	list_destroy(&spa->spa_config_dirty_list);
586 	list_destroy(&spa->spa_state_dirty_list);
587 
588 	for (int t = 0; t < ZIO_TYPES; t++) {
589 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
590 			taskq_destroy(spa->spa_zio_taskq[t][q]);
591 			spa->spa_zio_taskq[t][q] = NULL;
592 		}
593 	}
594 
595 	metaslab_class_destroy(spa->spa_normal_class);
596 	spa->spa_normal_class = NULL;
597 
598 	metaslab_class_destroy(spa->spa_log_class);
599 	spa->spa_log_class = NULL;
600 
601 	/*
602 	 * If this was part of an import or the open otherwise failed, we may
603 	 * still have errors left in the queues.  Empty them just in case.
604 	 */
605 	spa_errlog_drain(spa);
606 
607 	avl_destroy(&spa->spa_errlist_scrub);
608 	avl_destroy(&spa->spa_errlist_last);
609 
610 	spa->spa_state = POOL_STATE_UNINITIALIZED;
611 }
612 
613 /*
614  * Verify a pool configuration, and construct the vdev tree appropriately.  This
615  * will create all the necessary vdevs in the appropriate layout, with each vdev
616  * in the CLOSED state.  This will prep the pool before open/creation/import.
617  * All vdev validation is done by the vdev_alloc() routine.
618  */
619 static int
620 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
621     uint_t id, int atype)
622 {
623 	nvlist_t **child;
624 	uint_t c, children;
625 	int error;
626 
627 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
628 		return (error);
629 
630 	if ((*vdp)->vdev_ops->vdev_op_leaf)
631 		return (0);
632 
633 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
634 	    &child, &children);
635 
636 	if (error == ENOENT)
637 		return (0);
638 
639 	if (error) {
640 		vdev_free(*vdp);
641 		*vdp = NULL;
642 		return (EINVAL);
643 	}
644 
645 	for (c = 0; c < children; c++) {
646 		vdev_t *vd;
647 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
648 		    atype)) != 0) {
649 			vdev_free(*vdp);
650 			*vdp = NULL;
651 			return (error);
652 		}
653 	}
654 
655 	ASSERT(*vdp != NULL);
656 
657 	return (0);
658 }
659 
660 /*
661  * Opposite of spa_load().
662  */
663 static void
664 spa_unload(spa_t *spa)
665 {
666 	int i;
667 
668 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
669 
670 	/*
671 	 * Stop async tasks.
672 	 */
673 	spa_async_suspend(spa);
674 
675 	/*
676 	 * Stop syncing.
677 	 */
678 	if (spa->spa_sync_on) {
679 		txg_sync_stop(spa->spa_dsl_pool);
680 		spa->spa_sync_on = B_FALSE;
681 	}
682 
683 	/*
684 	 * Wait for any outstanding async I/O to complete.
685 	 */
686 	if (spa->spa_async_zio_root != NULL) {
687 		(void) zio_wait(spa->spa_async_zio_root);
688 		spa->spa_async_zio_root = NULL;
689 	}
690 
691 	/*
692 	 * Close the dsl pool.
693 	 */
694 	if (spa->spa_dsl_pool) {
695 		dsl_pool_close(spa->spa_dsl_pool);
696 		spa->spa_dsl_pool = NULL;
697 	}
698 
699 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
700 
701 	/*
702 	 * Drop and purge level 2 cache
703 	 */
704 	spa_l2cache_drop(spa);
705 
706 	/*
707 	 * Close all vdevs.
708 	 */
709 	if (spa->spa_root_vdev)
710 		vdev_free(spa->spa_root_vdev);
711 	ASSERT(spa->spa_root_vdev == NULL);
712 
713 	for (i = 0; i < spa->spa_spares.sav_count; i++)
714 		vdev_free(spa->spa_spares.sav_vdevs[i]);
715 	if (spa->spa_spares.sav_vdevs) {
716 		kmem_free(spa->spa_spares.sav_vdevs,
717 		    spa->spa_spares.sav_count * sizeof (void *));
718 		spa->spa_spares.sav_vdevs = NULL;
719 	}
720 	if (spa->spa_spares.sav_config) {
721 		nvlist_free(spa->spa_spares.sav_config);
722 		spa->spa_spares.sav_config = NULL;
723 	}
724 	spa->spa_spares.sav_count = 0;
725 
726 	for (i = 0; i < spa->spa_l2cache.sav_count; i++)
727 		vdev_free(spa->spa_l2cache.sav_vdevs[i]);
728 	if (spa->spa_l2cache.sav_vdevs) {
729 		kmem_free(spa->spa_l2cache.sav_vdevs,
730 		    spa->spa_l2cache.sav_count * sizeof (void *));
731 		spa->spa_l2cache.sav_vdevs = NULL;
732 	}
733 	if (spa->spa_l2cache.sav_config) {
734 		nvlist_free(spa->spa_l2cache.sav_config);
735 		spa->spa_l2cache.sav_config = NULL;
736 	}
737 	spa->spa_l2cache.sav_count = 0;
738 
739 	spa->spa_async_suspended = 0;
740 
741 	spa_config_exit(spa, SCL_ALL, FTAG);
742 }
743 
744 /*
745  * Load (or re-load) the current list of vdevs describing the active spares for
746  * this pool.  When this is called, we have some form of basic information in
747  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
748  * then re-generate a more complete list including status information.
749  */
750 static void
751 spa_load_spares(spa_t *spa)
752 {
753 	nvlist_t **spares;
754 	uint_t nspares;
755 	int i;
756 	vdev_t *vd, *tvd;
757 
758 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
759 
760 	/*
761 	 * First, close and free any existing spare vdevs.
762 	 */
763 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
764 		vd = spa->spa_spares.sav_vdevs[i];
765 
766 		/* Undo the call to spa_activate() below */
767 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
768 		    B_FALSE)) != NULL && tvd->vdev_isspare)
769 			spa_spare_remove(tvd);
770 		vdev_close(vd);
771 		vdev_free(vd);
772 	}
773 
774 	if (spa->spa_spares.sav_vdevs)
775 		kmem_free(spa->spa_spares.sav_vdevs,
776 		    spa->spa_spares.sav_count * sizeof (void *));
777 
778 	if (spa->spa_spares.sav_config == NULL)
779 		nspares = 0;
780 	else
781 		VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
782 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
783 
784 	spa->spa_spares.sav_count = (int)nspares;
785 	spa->spa_spares.sav_vdevs = NULL;
786 
787 	if (nspares == 0)
788 		return;
789 
790 	/*
791 	 * Construct the array of vdevs, opening them to get status in the
792 	 * process.   For each spare, there is potentially two different vdev_t
793 	 * structures associated with it: one in the list of spares (used only
794 	 * for basic validation purposes) and one in the active vdev
795 	 * configuration (if it's spared in).  During this phase we open and
796 	 * validate each vdev on the spare list.  If the vdev also exists in the
797 	 * active configuration, then we also mark this vdev as an active spare.
798 	 */
799 	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
800 	    KM_SLEEP);
801 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
802 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
803 		    VDEV_ALLOC_SPARE) == 0);
804 		ASSERT(vd != NULL);
805 
806 		spa->spa_spares.sav_vdevs[i] = vd;
807 
808 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
809 		    B_FALSE)) != NULL) {
810 			if (!tvd->vdev_isspare)
811 				spa_spare_add(tvd);
812 
813 			/*
814 			 * We only mark the spare active if we were successfully
815 			 * able to load the vdev.  Otherwise, importing a pool
816 			 * with a bad active spare would result in strange
817 			 * behavior, because multiple pool would think the spare
818 			 * is actively in use.
819 			 *
820 			 * There is a vulnerability here to an equally bizarre
821 			 * circumstance, where a dead active spare is later
822 			 * brought back to life (onlined or otherwise).  Given
823 			 * the rarity of this scenario, and the extra complexity
824 			 * it adds, we ignore the possibility.
825 			 */
826 			if (!vdev_is_dead(tvd))
827 				spa_spare_activate(tvd);
828 		}
829 
830 		vd->vdev_top = vd;
831 		vd->vdev_aux = &spa->spa_spares;
832 
833 		if (vdev_open(vd) != 0)
834 			continue;
835 
836 		if (vdev_validate_aux(vd) == 0)
837 			spa_spare_add(vd);
838 	}
839 
840 	/*
841 	 * Recompute the stashed list of spares, with status information
842 	 * this time.
843 	 */
844 	VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
845 	    DATA_TYPE_NVLIST_ARRAY) == 0);
846 
847 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
848 	    KM_SLEEP);
849 	for (i = 0; i < spa->spa_spares.sav_count; i++)
850 		spares[i] = vdev_config_generate(spa,
851 		    spa->spa_spares.sav_vdevs[i], B_TRUE, B_TRUE, B_FALSE);
852 	VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
853 	    ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
854 	for (i = 0; i < spa->spa_spares.sav_count; i++)
855 		nvlist_free(spares[i]);
856 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
857 }
858 
859 /*
860  * Load (or re-load) the current list of vdevs describing the active l2cache for
861  * this pool.  When this is called, we have some form of basic information in
862  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
863  * then re-generate a more complete list including status information.
864  * Devices which are already active have their details maintained, and are
865  * not re-opened.
866  */
867 static void
868 spa_load_l2cache(spa_t *spa)
869 {
870 	nvlist_t **l2cache;
871 	uint_t nl2cache;
872 	int i, j, oldnvdevs;
873 	uint64_t guid, size;
874 	vdev_t *vd, **oldvdevs, **newvdevs;
875 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
876 
877 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
878 
879 	if (sav->sav_config != NULL) {
880 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
881 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
882 		newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
883 	} else {
884 		nl2cache = 0;
885 	}
886 
887 	oldvdevs = sav->sav_vdevs;
888 	oldnvdevs = sav->sav_count;
889 	sav->sav_vdevs = NULL;
890 	sav->sav_count = 0;
891 
892 	/*
893 	 * Process new nvlist of vdevs.
894 	 */
895 	for (i = 0; i < nl2cache; i++) {
896 		VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
897 		    &guid) == 0);
898 
899 		newvdevs[i] = NULL;
900 		for (j = 0; j < oldnvdevs; j++) {
901 			vd = oldvdevs[j];
902 			if (vd != NULL && guid == vd->vdev_guid) {
903 				/*
904 				 * Retain previous vdev for add/remove ops.
905 				 */
906 				newvdevs[i] = vd;
907 				oldvdevs[j] = NULL;
908 				break;
909 			}
910 		}
911 
912 		if (newvdevs[i] == NULL) {
913 			/*
914 			 * Create new vdev
915 			 */
916 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
917 			    VDEV_ALLOC_L2CACHE) == 0);
918 			ASSERT(vd != NULL);
919 			newvdevs[i] = vd;
920 
921 			/*
922 			 * Commit this vdev as an l2cache device,
923 			 * even if it fails to open.
924 			 */
925 			spa_l2cache_add(vd);
926 
927 			vd->vdev_top = vd;
928 			vd->vdev_aux = sav;
929 
930 			spa_l2cache_activate(vd);
931 
932 			if (vdev_open(vd) != 0)
933 				continue;
934 
935 			(void) vdev_validate_aux(vd);
936 
937 			if (!vdev_is_dead(vd)) {
938 				size = vdev_get_rsize(vd);
939 				l2arc_add_vdev(spa, vd,
940 				    VDEV_LABEL_START_SIZE,
941 				    size - VDEV_LABEL_START_SIZE);
942 			}
943 		}
944 	}
945 
946 	/*
947 	 * Purge vdevs that were dropped
948 	 */
949 	for (i = 0; i < oldnvdevs; i++) {
950 		uint64_t pool;
951 
952 		vd = oldvdevs[i];
953 		if (vd != NULL) {
954 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
955 			    pool != 0ULL && l2arc_vdev_present(vd))
956 				l2arc_remove_vdev(vd);
957 			(void) vdev_close(vd);
958 			spa_l2cache_remove(vd);
959 		}
960 	}
961 
962 	if (oldvdevs)
963 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
964 
965 	if (sav->sav_config == NULL)
966 		goto out;
967 
968 	sav->sav_vdevs = newvdevs;
969 	sav->sav_count = (int)nl2cache;
970 
971 	/*
972 	 * Recompute the stashed list of l2cache devices, with status
973 	 * information this time.
974 	 */
975 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
976 	    DATA_TYPE_NVLIST_ARRAY) == 0);
977 
978 	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
979 	for (i = 0; i < sav->sav_count; i++)
980 		l2cache[i] = vdev_config_generate(spa,
981 		    sav->sav_vdevs[i], B_TRUE, B_FALSE, B_TRUE);
982 	VERIFY(nvlist_add_nvlist_array(sav->sav_config,
983 	    ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
984 out:
985 	for (i = 0; i < sav->sav_count; i++)
986 		nvlist_free(l2cache[i]);
987 	if (sav->sav_count)
988 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
989 }
990 
991 static int
992 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
993 {
994 	dmu_buf_t *db;
995 	char *packed = NULL;
996 	size_t nvsize = 0;
997 	int error;
998 	*value = NULL;
999 
1000 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1001 	nvsize = *(uint64_t *)db->db_data;
1002 	dmu_buf_rele(db, FTAG);
1003 
1004 	packed = kmem_alloc(nvsize, KM_SLEEP);
1005 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed);
1006 	if (error == 0)
1007 		error = nvlist_unpack(packed, nvsize, value, 0);
1008 	kmem_free(packed, nvsize);
1009 
1010 	return (error);
1011 }
1012 
1013 /*
1014  * Checks to see if the given vdev could not be opened, in which case we post a
1015  * sysevent to notify the autoreplace code that the device has been removed.
1016  */
1017 static void
1018 spa_check_removed(vdev_t *vd)
1019 {
1020 	int c;
1021 
1022 	for (c = 0; c < vd->vdev_children; c++)
1023 		spa_check_removed(vd->vdev_child[c]);
1024 
1025 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd)) {
1026 		zfs_post_autoreplace(vd->vdev_spa, vd);
1027 		spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1028 	}
1029 }
1030 
1031 /*
1032  * Check for missing log devices
1033  */
1034 int
1035 spa_check_logs(spa_t *spa)
1036 {
1037 	switch (spa->spa_log_state) {
1038 	case SPA_LOG_MISSING:
1039 		/* need to recheck in case slog has been restored */
1040 	case SPA_LOG_UNKNOWN:
1041 		if (dmu_objset_find(spa->spa_name, zil_check_log_chain, NULL,
1042 		    DS_FIND_CHILDREN)) {
1043 			spa->spa_log_state = SPA_LOG_MISSING;
1044 			return (1);
1045 		}
1046 		break;
1047 
1048 	case SPA_LOG_CLEAR:
1049 		(void) dmu_objset_find(spa->spa_name, zil_clear_log_chain, NULL,
1050 		    DS_FIND_CHILDREN);
1051 		break;
1052 	}
1053 	spa->spa_log_state = SPA_LOG_GOOD;
1054 	return (0);
1055 }
1056 
1057 /*
1058  * Load an existing storage pool, using the pool's builtin spa_config as a
1059  * source of configuration information.
1060  */
1061 static int
1062 spa_load(spa_t *spa, nvlist_t *config, spa_load_state_t state, int mosconfig)
1063 {
1064 	int error = 0;
1065 	nvlist_t *nvroot = NULL;
1066 	vdev_t *rvd;
1067 	uberblock_t *ub = &spa->spa_uberblock;
1068 	uint64_t config_cache_txg = spa->spa_config_txg;
1069 	uint64_t pool_guid;
1070 	uint64_t version;
1071 	uint64_t autoreplace = 0;
1072 	int orig_mode = spa->spa_mode;
1073 	char *ereport = FM_EREPORT_ZFS_POOL;
1074 
1075 	/*
1076 	 * If this is an untrusted config, access the pool in read-only mode.
1077 	 * This prevents things like resilvering recently removed devices.
1078 	 */
1079 	if (!mosconfig)
1080 		spa->spa_mode = FREAD;
1081 
1082 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1083 
1084 	spa->spa_load_state = state;
1085 
1086 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot) ||
1087 	    nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid)) {
1088 		error = EINVAL;
1089 		goto out;
1090 	}
1091 
1092 	/*
1093 	 * Versioning wasn't explicitly added to the label until later, so if
1094 	 * it's not present treat it as the initial version.
1095 	 */
1096 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION, &version) != 0)
1097 		version = SPA_VERSION_INITIAL;
1098 
1099 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
1100 	    &spa->spa_config_txg);
1101 
1102 	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
1103 	    spa_guid_exists(pool_guid, 0)) {
1104 		error = EEXIST;
1105 		goto out;
1106 	}
1107 
1108 	spa->spa_load_guid = pool_guid;
1109 
1110 	/*
1111 	 * Create "The Godfather" zio to hold all async IOs
1112 	 */
1113 	if (spa->spa_async_zio_root == NULL)
1114 		spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
1115 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
1116 		    ZIO_FLAG_GODFATHER);
1117 
1118 	/*
1119 	 * Parse the configuration into a vdev tree.  We explicitly set the
1120 	 * value that will be returned by spa_version() since parsing the
1121 	 * configuration requires knowing the version number.
1122 	 */
1123 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1124 	spa->spa_ubsync.ub_version = version;
1125 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_LOAD);
1126 	spa_config_exit(spa, SCL_ALL, FTAG);
1127 
1128 	if (error != 0)
1129 		goto out;
1130 
1131 	ASSERT(spa->spa_root_vdev == rvd);
1132 	ASSERT(spa_guid(spa) == pool_guid);
1133 
1134 	/*
1135 	 * Try to open all vdevs, loading each label in the process.
1136 	 */
1137 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1138 	error = vdev_open(rvd);
1139 	spa_config_exit(spa, SCL_ALL, FTAG);
1140 	if (error != 0)
1141 		goto out;
1142 
1143 	/*
1144 	 * We need to validate the vdev labels against the configuration that
1145 	 * we have in hand, which is dependent on the setting of mosconfig. If
1146 	 * mosconfig is true then we're validating the vdev labels based on
1147 	 * that config. Otherwise, we're validating against the cached config
1148 	 * (zpool.cache) that was read when we loaded the zfs module, and then
1149 	 * later we will recursively call spa_load() and validate against
1150 	 * the vdev config.
1151 	 */
1152 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1153 	error = vdev_validate(rvd);
1154 	spa_config_exit(spa, SCL_ALL, FTAG);
1155 	if (error != 0)
1156 		goto out;
1157 
1158 	if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN) {
1159 		error = ENXIO;
1160 		goto out;
1161 	}
1162 
1163 	/*
1164 	 * Find the best uberblock.
1165 	 */
1166 	vdev_uberblock_load(NULL, rvd, ub);
1167 
1168 	/*
1169 	 * If we weren't able to find a single valid uberblock, return failure.
1170 	 */
1171 	if (ub->ub_txg == 0) {
1172 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1173 		    VDEV_AUX_CORRUPT_DATA);
1174 		error = ENXIO;
1175 		goto out;
1176 	}
1177 
1178 	/*
1179 	 * If the pool is newer than the code, we can't open it.
1180 	 */
1181 	if (ub->ub_version > SPA_VERSION) {
1182 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1183 		    VDEV_AUX_VERSION_NEWER);
1184 		error = ENOTSUP;
1185 		goto out;
1186 	}
1187 
1188 	/*
1189 	 * If the vdev guid sum doesn't match the uberblock, we have an
1190 	 * incomplete configuration.
1191 	 */
1192 	if (rvd->vdev_guid_sum != ub->ub_guid_sum && mosconfig) {
1193 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1194 		    VDEV_AUX_BAD_GUID_SUM);
1195 		error = ENXIO;
1196 		goto out;
1197 	}
1198 
1199 	/*
1200 	 * Initialize internal SPA structures.
1201 	 */
1202 	spa->spa_state = POOL_STATE_ACTIVE;
1203 	spa->spa_ubsync = spa->spa_uberblock;
1204 	spa->spa_first_txg = spa_last_synced_txg(spa) + 1;
1205 	error = dsl_pool_open(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
1206 	if (error) {
1207 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1208 		    VDEV_AUX_CORRUPT_DATA);
1209 		goto out;
1210 	}
1211 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
1212 
1213 	if (zap_lookup(spa->spa_meta_objset,
1214 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
1215 	    sizeof (uint64_t), 1, &spa->spa_config_object) != 0) {
1216 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1217 		    VDEV_AUX_CORRUPT_DATA);
1218 		error = EIO;
1219 		goto out;
1220 	}
1221 
1222 	if (!mosconfig) {
1223 		nvlist_t *newconfig;
1224 		uint64_t hostid;
1225 
1226 		if (load_nvlist(spa, spa->spa_config_object, &newconfig) != 0) {
1227 			vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1228 			    VDEV_AUX_CORRUPT_DATA);
1229 			error = EIO;
1230 			goto out;
1231 		}
1232 
1233 		if (!spa_is_root(spa) && nvlist_lookup_uint64(newconfig,
1234 		    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
1235 			char *hostname;
1236 			unsigned long myhostid = 0;
1237 
1238 			VERIFY(nvlist_lookup_string(newconfig,
1239 			    ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
1240 
1241 #ifdef	_KERNEL
1242 			myhostid = zone_get_hostid(NULL);
1243 #else	/* _KERNEL */
1244 			/*
1245 			 * We're emulating the system's hostid in userland, so
1246 			 * we can't use zone_get_hostid().
1247 			 */
1248 			(void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
1249 #endif	/* _KERNEL */
1250 			if (hostid != 0 && myhostid != 0 &&
1251 			    hostid != myhostid) {
1252 				cmn_err(CE_WARN, "pool '%s' could not be "
1253 				    "loaded as it was last accessed by "
1254 				    "another system (host: %s hostid: 0x%lx). "
1255 				    "See: http://www.sun.com/msg/ZFS-8000-EY",
1256 				    spa_name(spa), hostname,
1257 				    (unsigned long)hostid);
1258 				error = EBADF;
1259 				goto out;
1260 			}
1261 		}
1262 
1263 		spa_config_set(spa, newconfig);
1264 		spa_unload(spa);
1265 		spa_deactivate(spa);
1266 		spa_activate(spa, orig_mode);
1267 
1268 		return (spa_load(spa, newconfig, state, B_TRUE));
1269 	}
1270 
1271 	if (zap_lookup(spa->spa_meta_objset,
1272 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPLIST,
1273 	    sizeof (uint64_t), 1, &spa->spa_sync_bplist_obj) != 0) {
1274 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1275 		    VDEV_AUX_CORRUPT_DATA);
1276 		error = EIO;
1277 		goto out;
1278 	}
1279 
1280 	/*
1281 	 * Load the bit that tells us to use the new accounting function
1282 	 * (raid-z deflation).  If we have an older pool, this will not
1283 	 * be present.
1284 	 */
1285 	error = zap_lookup(spa->spa_meta_objset,
1286 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
1287 	    sizeof (uint64_t), 1, &spa->spa_deflate);
1288 	if (error != 0 && error != ENOENT) {
1289 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1290 		    VDEV_AUX_CORRUPT_DATA);
1291 		error = EIO;
1292 		goto out;
1293 	}
1294 
1295 	/*
1296 	 * Load the persistent error log.  If we have an older pool, this will
1297 	 * not be present.
1298 	 */
1299 	error = zap_lookup(spa->spa_meta_objset,
1300 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ERRLOG_LAST,
1301 	    sizeof (uint64_t), 1, &spa->spa_errlog_last);
1302 	if (error != 0 && error != ENOENT) {
1303 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1304 		    VDEV_AUX_CORRUPT_DATA);
1305 		error = EIO;
1306 		goto out;
1307 	}
1308 
1309 	error = zap_lookup(spa->spa_meta_objset,
1310 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_ERRLOG_SCRUB,
1311 	    sizeof (uint64_t), 1, &spa->spa_errlog_scrub);
1312 	if (error != 0 && error != ENOENT) {
1313 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1314 		    VDEV_AUX_CORRUPT_DATA);
1315 		error = EIO;
1316 		goto out;
1317 	}
1318 
1319 	/*
1320 	 * Load the history object.  If we have an older pool, this
1321 	 * will not be present.
1322 	 */
1323 	error = zap_lookup(spa->spa_meta_objset,
1324 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_HISTORY,
1325 	    sizeof (uint64_t), 1, &spa->spa_history);
1326 	if (error != 0 && error != ENOENT) {
1327 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1328 		    VDEV_AUX_CORRUPT_DATA);
1329 		error = EIO;
1330 		goto out;
1331 	}
1332 
1333 	/*
1334 	 * Load any hot spares for this pool.
1335 	 */
1336 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1337 	    DMU_POOL_SPARES, sizeof (uint64_t), 1, &spa->spa_spares.sav_object);
1338 	if (error != 0 && error != ENOENT) {
1339 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1340 		    VDEV_AUX_CORRUPT_DATA);
1341 		error = EIO;
1342 		goto out;
1343 	}
1344 	if (error == 0) {
1345 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
1346 		if (load_nvlist(spa, spa->spa_spares.sav_object,
1347 		    &spa->spa_spares.sav_config) != 0) {
1348 			vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1349 			    VDEV_AUX_CORRUPT_DATA);
1350 			error = EIO;
1351 			goto out;
1352 		}
1353 
1354 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1355 		spa_load_spares(spa);
1356 		spa_config_exit(spa, SCL_ALL, FTAG);
1357 	}
1358 
1359 	/*
1360 	 * Load any level 2 ARC devices for this pool.
1361 	 */
1362 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1363 	    DMU_POOL_L2CACHE, sizeof (uint64_t), 1,
1364 	    &spa->spa_l2cache.sav_object);
1365 	if (error != 0 && error != ENOENT) {
1366 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1367 		    VDEV_AUX_CORRUPT_DATA);
1368 		error = EIO;
1369 		goto out;
1370 	}
1371 	if (error == 0) {
1372 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
1373 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
1374 		    &spa->spa_l2cache.sav_config) != 0) {
1375 			vdev_set_state(rvd, B_TRUE,
1376 			    VDEV_STATE_CANT_OPEN,
1377 			    VDEV_AUX_CORRUPT_DATA);
1378 			error = EIO;
1379 			goto out;
1380 		}
1381 
1382 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1383 		spa_load_l2cache(spa);
1384 		spa_config_exit(spa, SCL_ALL, FTAG);
1385 	}
1386 
1387 	if (spa_check_logs(spa)) {
1388 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1389 		    VDEV_AUX_BAD_LOG);
1390 		error = ENXIO;
1391 		ereport = FM_EREPORT_ZFS_LOG_REPLAY;
1392 		goto out;
1393 	}
1394 
1395 
1396 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
1397 
1398 	error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1399 	    DMU_POOL_PROPS, sizeof (uint64_t), 1, &spa->spa_pool_props_object);
1400 
1401 	if (error && error != ENOENT) {
1402 		vdev_set_state(rvd, B_TRUE, VDEV_STATE_CANT_OPEN,
1403 		    VDEV_AUX_CORRUPT_DATA);
1404 		error = EIO;
1405 		goto out;
1406 	}
1407 
1408 	if (error == 0) {
1409 		(void) zap_lookup(spa->spa_meta_objset,
1410 		    spa->spa_pool_props_object,
1411 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS),
1412 		    sizeof (uint64_t), 1, &spa->spa_bootfs);
1413 		(void) zap_lookup(spa->spa_meta_objset,
1414 		    spa->spa_pool_props_object,
1415 		    zpool_prop_to_name(ZPOOL_PROP_AUTOREPLACE),
1416 		    sizeof (uint64_t), 1, &autoreplace);
1417 		(void) zap_lookup(spa->spa_meta_objset,
1418 		    spa->spa_pool_props_object,
1419 		    zpool_prop_to_name(ZPOOL_PROP_DELEGATION),
1420 		    sizeof (uint64_t), 1, &spa->spa_delegation);
1421 		(void) zap_lookup(spa->spa_meta_objset,
1422 		    spa->spa_pool_props_object,
1423 		    zpool_prop_to_name(ZPOOL_PROP_FAILUREMODE),
1424 		    sizeof (uint64_t), 1, &spa->spa_failmode);
1425 	}
1426 
1427 	/*
1428 	 * If the 'autoreplace' property is set, then post a resource notifying
1429 	 * the ZFS DE that it should not issue any faults for unopenable
1430 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
1431 	 * unopenable vdevs so that the normal autoreplace handler can take
1432 	 * over.
1433 	 */
1434 	if (autoreplace && state != SPA_LOAD_TRYIMPORT)
1435 		spa_check_removed(spa->spa_root_vdev);
1436 
1437 	/*
1438 	 * Load the vdev state for all toplevel vdevs.
1439 	 */
1440 	vdev_load(rvd);
1441 
1442 	/*
1443 	 * Propagate the leaf DTLs we just loaded all the way up the tree.
1444 	 */
1445 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1446 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
1447 	spa_config_exit(spa, SCL_ALL, FTAG);
1448 
1449 	/*
1450 	 * Check the state of the root vdev.  If it can't be opened, it
1451 	 * indicates one or more toplevel vdevs are faulted.
1452 	 */
1453 	if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN) {
1454 		error = ENXIO;
1455 		goto out;
1456 	}
1457 
1458 	if (spa_writeable(spa)) {
1459 		dmu_tx_t *tx;
1460 		int need_update = B_FALSE;
1461 
1462 		ASSERT(state != SPA_LOAD_TRYIMPORT);
1463 
1464 		/*
1465 		 * Claim log blocks that haven't been committed yet.
1466 		 * This must all happen in a single txg.
1467 		 */
1468 		tx = dmu_tx_create_assigned(spa_get_dsl(spa),
1469 		    spa_first_txg(spa));
1470 		(void) dmu_objset_find(spa_name(spa),
1471 		    zil_claim, tx, DS_FIND_CHILDREN);
1472 		dmu_tx_commit(tx);
1473 
1474 		spa->spa_sync_on = B_TRUE;
1475 		txg_sync_start(spa->spa_dsl_pool);
1476 
1477 		/*
1478 		 * Wait for all claims to sync.
1479 		 */
1480 		txg_wait_synced(spa->spa_dsl_pool, 0);
1481 
1482 		/*
1483 		 * If the config cache is stale, or we have uninitialized
1484 		 * metaslabs (see spa_vdev_add()), then update the config.
1485 		 */
1486 		if (config_cache_txg != spa->spa_config_txg ||
1487 		    state == SPA_LOAD_IMPORT)
1488 			need_update = B_TRUE;
1489 
1490 		for (int c = 0; c < rvd->vdev_children; c++)
1491 			if (rvd->vdev_child[c]->vdev_ms_array == 0)
1492 				need_update = B_TRUE;
1493 
1494 		/*
1495 		 * Update the config cache asychronously in case we're the
1496 		 * root pool, in which case the config cache isn't writable yet.
1497 		 */
1498 		if (need_update)
1499 			spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
1500 
1501 		/*
1502 		 * Check all DTLs to see if anything needs resilvering.
1503 		 */
1504 		if (vdev_resilver_needed(rvd, NULL, NULL))
1505 			spa_async_request(spa, SPA_ASYNC_RESILVER);
1506 	}
1507 
1508 	error = 0;
1509 out:
1510 	spa->spa_minref = refcount_count(&spa->spa_refcount);
1511 	if (error && error != EBADF)
1512 		zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
1513 	spa->spa_load_state = SPA_LOAD_NONE;
1514 	spa->spa_ena = 0;
1515 
1516 	return (error);
1517 }
1518 
1519 /*
1520  * Pool Open/Import
1521  *
1522  * The import case is identical to an open except that the configuration is sent
1523  * down from userland, instead of grabbed from the configuration cache.  For the
1524  * case of an open, the pool configuration will exist in the
1525  * POOL_STATE_UNINITIALIZED state.
1526  *
1527  * The stats information (gen/count/ustats) is used to gather vdev statistics at
1528  * the same time open the pool, without having to keep around the spa_t in some
1529  * ambiguous state.
1530  */
1531 static int
1532 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t **config)
1533 {
1534 	spa_t *spa;
1535 	int error;
1536 	int locked = B_FALSE;
1537 
1538 	*spapp = NULL;
1539 
1540 	/*
1541 	 * As disgusting as this is, we need to support recursive calls to this
1542 	 * function because dsl_dir_open() is called during spa_load(), and ends
1543 	 * up calling spa_open() again.  The real fix is to figure out how to
1544 	 * avoid dsl_dir_open() calling this in the first place.
1545 	 */
1546 	if (mutex_owner(&spa_namespace_lock) != curthread) {
1547 		mutex_enter(&spa_namespace_lock);
1548 		locked = B_TRUE;
1549 	}
1550 
1551 	if ((spa = spa_lookup(pool)) == NULL) {
1552 		if (locked)
1553 			mutex_exit(&spa_namespace_lock);
1554 		return (ENOENT);
1555 	}
1556 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
1557 
1558 		spa_activate(spa, spa_mode_global);
1559 
1560 		error = spa_load(spa, spa->spa_config, SPA_LOAD_OPEN, B_FALSE);
1561 
1562 		if (error == EBADF) {
1563 			/*
1564 			 * If vdev_validate() returns failure (indicated by
1565 			 * EBADF), it indicates that one of the vdevs indicates
1566 			 * that the pool has been exported or destroyed.  If
1567 			 * this is the case, the config cache is out of sync and
1568 			 * we should remove the pool from the namespace.
1569 			 */
1570 			spa_unload(spa);
1571 			spa_deactivate(spa);
1572 			spa_config_sync(spa, B_TRUE, B_TRUE);
1573 			spa_remove(spa);
1574 			if (locked)
1575 				mutex_exit(&spa_namespace_lock);
1576 			return (ENOENT);
1577 		}
1578 
1579 		if (error) {
1580 			/*
1581 			 * We can't open the pool, but we still have useful
1582 			 * information: the state of each vdev after the
1583 			 * attempted vdev_open().  Return this to the user.
1584 			 */
1585 			if (config != NULL && spa->spa_root_vdev != NULL)
1586 				*config = spa_config_generate(spa, NULL, -1ULL,
1587 				    B_TRUE);
1588 			spa_unload(spa);
1589 			spa_deactivate(spa);
1590 			spa->spa_last_open_failed = B_TRUE;
1591 			if (locked)
1592 				mutex_exit(&spa_namespace_lock);
1593 			*spapp = NULL;
1594 			return (error);
1595 		} else {
1596 			spa->spa_last_open_failed = B_FALSE;
1597 		}
1598 	}
1599 
1600 	spa_open_ref(spa, tag);
1601 
1602 	if (locked)
1603 		mutex_exit(&spa_namespace_lock);
1604 
1605 	*spapp = spa;
1606 
1607 	if (config != NULL)
1608 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
1609 
1610 	return (0);
1611 }
1612 
1613 int
1614 spa_open(const char *name, spa_t **spapp, void *tag)
1615 {
1616 	return (spa_open_common(name, spapp, tag, NULL));
1617 }
1618 
1619 /*
1620  * Lookup the given spa_t, incrementing the inject count in the process,
1621  * preventing it from being exported or destroyed.
1622  */
1623 spa_t *
1624 spa_inject_addref(char *name)
1625 {
1626 	spa_t *spa;
1627 
1628 	mutex_enter(&spa_namespace_lock);
1629 	if ((spa = spa_lookup(name)) == NULL) {
1630 		mutex_exit(&spa_namespace_lock);
1631 		return (NULL);
1632 	}
1633 	spa->spa_inject_ref++;
1634 	mutex_exit(&spa_namespace_lock);
1635 
1636 	return (spa);
1637 }
1638 
1639 void
1640 spa_inject_delref(spa_t *spa)
1641 {
1642 	mutex_enter(&spa_namespace_lock);
1643 	spa->spa_inject_ref--;
1644 	mutex_exit(&spa_namespace_lock);
1645 }
1646 
1647 /*
1648  * Add spares device information to the nvlist.
1649  */
1650 static void
1651 spa_add_spares(spa_t *spa, nvlist_t *config)
1652 {
1653 	nvlist_t **spares;
1654 	uint_t i, nspares;
1655 	nvlist_t *nvroot;
1656 	uint64_t guid;
1657 	vdev_stat_t *vs;
1658 	uint_t vsc;
1659 	uint64_t pool;
1660 
1661 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
1662 
1663 	if (spa->spa_spares.sav_count == 0)
1664 		return;
1665 
1666 	VERIFY(nvlist_lookup_nvlist(config,
1667 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
1668 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1669 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1670 	if (nspares != 0) {
1671 		VERIFY(nvlist_add_nvlist_array(nvroot,
1672 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
1673 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
1674 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1675 
1676 		/*
1677 		 * Go through and find any spares which have since been
1678 		 * repurposed as an active spare.  If this is the case, update
1679 		 * their status appropriately.
1680 		 */
1681 		for (i = 0; i < nspares; i++) {
1682 			VERIFY(nvlist_lookup_uint64(spares[i],
1683 			    ZPOOL_CONFIG_GUID, &guid) == 0);
1684 			if (spa_spare_exists(guid, &pool, NULL) &&
1685 			    pool != 0ULL) {
1686 				VERIFY(nvlist_lookup_uint64_array(
1687 				    spares[i], ZPOOL_CONFIG_STATS,
1688 				    (uint64_t **)&vs, &vsc) == 0);
1689 				vs->vs_state = VDEV_STATE_CANT_OPEN;
1690 				vs->vs_aux = VDEV_AUX_SPARED;
1691 			}
1692 		}
1693 	}
1694 }
1695 
1696 /*
1697  * Add l2cache device information to the nvlist, including vdev stats.
1698  */
1699 static void
1700 spa_add_l2cache(spa_t *spa, nvlist_t *config)
1701 {
1702 	nvlist_t **l2cache;
1703 	uint_t i, j, nl2cache;
1704 	nvlist_t *nvroot;
1705 	uint64_t guid;
1706 	vdev_t *vd;
1707 	vdev_stat_t *vs;
1708 	uint_t vsc;
1709 
1710 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
1711 
1712 	if (spa->spa_l2cache.sav_count == 0)
1713 		return;
1714 
1715 	VERIFY(nvlist_lookup_nvlist(config,
1716 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
1717 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
1718 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1719 	if (nl2cache != 0) {
1720 		VERIFY(nvlist_add_nvlist_array(nvroot,
1721 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
1722 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
1723 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1724 
1725 		/*
1726 		 * Update level 2 cache device stats.
1727 		 */
1728 
1729 		for (i = 0; i < nl2cache; i++) {
1730 			VERIFY(nvlist_lookup_uint64(l2cache[i],
1731 			    ZPOOL_CONFIG_GUID, &guid) == 0);
1732 
1733 			vd = NULL;
1734 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
1735 				if (guid ==
1736 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
1737 					vd = spa->spa_l2cache.sav_vdevs[j];
1738 					break;
1739 				}
1740 			}
1741 			ASSERT(vd != NULL);
1742 
1743 			VERIFY(nvlist_lookup_uint64_array(l2cache[i],
1744 			    ZPOOL_CONFIG_STATS, (uint64_t **)&vs, &vsc) == 0);
1745 			vdev_get_stats(vd, vs);
1746 		}
1747 	}
1748 }
1749 
1750 int
1751 spa_get_stats(const char *name, nvlist_t **config, char *altroot, size_t buflen)
1752 {
1753 	int error;
1754 	spa_t *spa;
1755 
1756 	*config = NULL;
1757 	error = spa_open_common(name, &spa, FTAG, config);
1758 
1759 	if (spa != NULL) {
1760 		/*
1761 		 * This still leaves a window of inconsistency where the spares
1762 		 * or l2cache devices could change and the config would be
1763 		 * self-inconsistent.
1764 		 */
1765 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
1766 
1767 		if (*config != NULL) {
1768 			VERIFY(nvlist_add_uint64(*config,
1769 			    ZPOOL_CONFIG_ERRCOUNT,
1770 			    spa_get_errlog_size(spa)) == 0);
1771 
1772 			if (spa_suspended(spa))
1773 				VERIFY(nvlist_add_uint64(*config,
1774 				    ZPOOL_CONFIG_SUSPENDED,
1775 				    spa->spa_failmode) == 0);
1776 
1777 			spa_add_spares(spa, *config);
1778 			spa_add_l2cache(spa, *config);
1779 		}
1780 	}
1781 
1782 	/*
1783 	 * We want to get the alternate root even for faulted pools, so we cheat
1784 	 * and call spa_lookup() directly.
1785 	 */
1786 	if (altroot) {
1787 		if (spa == NULL) {
1788 			mutex_enter(&spa_namespace_lock);
1789 			spa = spa_lookup(name);
1790 			if (spa)
1791 				spa_altroot(spa, altroot, buflen);
1792 			else
1793 				altroot[0] = '\0';
1794 			spa = NULL;
1795 			mutex_exit(&spa_namespace_lock);
1796 		} else {
1797 			spa_altroot(spa, altroot, buflen);
1798 		}
1799 	}
1800 
1801 	if (spa != NULL) {
1802 		spa_config_exit(spa, SCL_CONFIG, FTAG);
1803 		spa_close(spa, FTAG);
1804 	}
1805 
1806 	return (error);
1807 }
1808 
1809 /*
1810  * Validate that the auxiliary device array is well formed.  We must have an
1811  * array of nvlists, each which describes a valid leaf vdev.  If this is an
1812  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
1813  * specified, as long as they are well-formed.
1814  */
1815 static int
1816 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
1817     spa_aux_vdev_t *sav, const char *config, uint64_t version,
1818     vdev_labeltype_t label)
1819 {
1820 	nvlist_t **dev;
1821 	uint_t i, ndev;
1822 	vdev_t *vd;
1823 	int error;
1824 
1825 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1826 
1827 	/*
1828 	 * It's acceptable to have no devs specified.
1829 	 */
1830 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
1831 		return (0);
1832 
1833 	if (ndev == 0)
1834 		return (EINVAL);
1835 
1836 	/*
1837 	 * Make sure the pool is formatted with a version that supports this
1838 	 * device type.
1839 	 */
1840 	if (spa_version(spa) < version)
1841 		return (ENOTSUP);
1842 
1843 	/*
1844 	 * Set the pending device list so we correctly handle device in-use
1845 	 * checking.
1846 	 */
1847 	sav->sav_pending = dev;
1848 	sav->sav_npending = ndev;
1849 
1850 	for (i = 0; i < ndev; i++) {
1851 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
1852 		    mode)) != 0)
1853 			goto out;
1854 
1855 		if (!vd->vdev_ops->vdev_op_leaf) {
1856 			vdev_free(vd);
1857 			error = EINVAL;
1858 			goto out;
1859 		}
1860 
1861 		/*
1862 		 * The L2ARC currently only supports disk devices in
1863 		 * kernel context.  For user-level testing, we allow it.
1864 		 */
1865 #ifdef _KERNEL
1866 		if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
1867 		    strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
1868 			error = ENOTBLK;
1869 			goto out;
1870 		}
1871 #endif
1872 		vd->vdev_top = vd;
1873 
1874 		if ((error = vdev_open(vd)) == 0 &&
1875 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
1876 			VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
1877 			    vd->vdev_guid) == 0);
1878 		}
1879 
1880 		vdev_free(vd);
1881 
1882 		if (error &&
1883 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
1884 			goto out;
1885 		else
1886 			error = 0;
1887 	}
1888 
1889 out:
1890 	sav->sav_pending = NULL;
1891 	sav->sav_npending = 0;
1892 	return (error);
1893 }
1894 
1895 static int
1896 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
1897 {
1898 	int error;
1899 
1900 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1901 
1902 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
1903 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
1904 	    VDEV_LABEL_SPARE)) != 0) {
1905 		return (error);
1906 	}
1907 
1908 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
1909 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
1910 	    VDEV_LABEL_L2CACHE));
1911 }
1912 
1913 static void
1914 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
1915     const char *config)
1916 {
1917 	int i;
1918 
1919 	if (sav->sav_config != NULL) {
1920 		nvlist_t **olddevs;
1921 		uint_t oldndevs;
1922 		nvlist_t **newdevs;
1923 
1924 		/*
1925 		 * Generate new dev list by concatentating with the
1926 		 * current dev list.
1927 		 */
1928 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
1929 		    &olddevs, &oldndevs) == 0);
1930 
1931 		newdevs = kmem_alloc(sizeof (void *) *
1932 		    (ndevs + oldndevs), KM_SLEEP);
1933 		for (i = 0; i < oldndevs; i++)
1934 			VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
1935 			    KM_SLEEP) == 0);
1936 		for (i = 0; i < ndevs; i++)
1937 			VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
1938 			    KM_SLEEP) == 0);
1939 
1940 		VERIFY(nvlist_remove(sav->sav_config, config,
1941 		    DATA_TYPE_NVLIST_ARRAY) == 0);
1942 
1943 		VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1944 		    config, newdevs, ndevs + oldndevs) == 0);
1945 		for (i = 0; i < oldndevs + ndevs; i++)
1946 			nvlist_free(newdevs[i]);
1947 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
1948 	} else {
1949 		/*
1950 		 * Generate a new dev list.
1951 		 */
1952 		VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
1953 		    KM_SLEEP) == 0);
1954 		VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
1955 		    devs, ndevs) == 0);
1956 	}
1957 }
1958 
1959 /*
1960  * Stop and drop level 2 ARC devices
1961  */
1962 void
1963 spa_l2cache_drop(spa_t *spa)
1964 {
1965 	vdev_t *vd;
1966 	int i;
1967 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1968 
1969 	for (i = 0; i < sav->sav_count; i++) {
1970 		uint64_t pool;
1971 
1972 		vd = sav->sav_vdevs[i];
1973 		ASSERT(vd != NULL);
1974 
1975 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1976 		    pool != 0ULL && l2arc_vdev_present(vd))
1977 			l2arc_remove_vdev(vd);
1978 		if (vd->vdev_isl2cache)
1979 			spa_l2cache_remove(vd);
1980 		vdev_clear_stats(vd);
1981 		(void) vdev_close(vd);
1982 	}
1983 }
1984 
1985 /*
1986  * Pool Creation
1987  */
1988 int
1989 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
1990     const char *history_str, nvlist_t *zplprops)
1991 {
1992 	spa_t *spa;
1993 	char *altroot = NULL;
1994 	vdev_t *rvd;
1995 	dsl_pool_t *dp;
1996 	dmu_tx_t *tx;
1997 	int c, error = 0;
1998 	uint64_t txg = TXG_INITIAL;
1999 	nvlist_t **spares, **l2cache;
2000 	uint_t nspares, nl2cache;
2001 	uint64_t version;
2002 
2003 	/*
2004 	 * If this pool already exists, return failure.
2005 	 */
2006 	mutex_enter(&spa_namespace_lock);
2007 	if (spa_lookup(pool) != NULL) {
2008 		mutex_exit(&spa_namespace_lock);
2009 		return (EEXIST);
2010 	}
2011 
2012 	/*
2013 	 * Allocate a new spa_t structure.
2014 	 */
2015 	(void) nvlist_lookup_string(props,
2016 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
2017 	spa = spa_add(pool, altroot);
2018 	spa_activate(spa, spa_mode_global);
2019 
2020 	spa->spa_uberblock.ub_txg = txg - 1;
2021 
2022 	if (props && (error = spa_prop_validate(spa, props))) {
2023 		spa_unload(spa);
2024 		spa_deactivate(spa);
2025 		spa_remove(spa);
2026 		mutex_exit(&spa_namespace_lock);
2027 		return (error);
2028 	}
2029 
2030 	if (nvlist_lookup_uint64(props, zpool_prop_to_name(ZPOOL_PROP_VERSION),
2031 	    &version) != 0)
2032 		version = SPA_VERSION;
2033 	ASSERT(version <= SPA_VERSION);
2034 	spa->spa_uberblock.ub_version = version;
2035 	spa->spa_ubsync = spa->spa_uberblock;
2036 
2037 	/*
2038 	 * Create "The Godfather" zio to hold all async IOs
2039 	 */
2040 	if (spa->spa_async_zio_root == NULL)
2041 		spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2042 		    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2043 		    ZIO_FLAG_GODFATHER);
2044 
2045 	/*
2046 	 * Create the root vdev.
2047 	 */
2048 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2049 
2050 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
2051 
2052 	ASSERT(error != 0 || rvd != NULL);
2053 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
2054 
2055 	if (error == 0 && !zfs_allocatable_devs(nvroot))
2056 		error = EINVAL;
2057 
2058 	if (error == 0 &&
2059 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
2060 	    (error = spa_validate_aux(spa, nvroot, txg,
2061 	    VDEV_ALLOC_ADD)) == 0) {
2062 		for (c = 0; c < rvd->vdev_children; c++)
2063 			vdev_init(rvd->vdev_child[c], txg);
2064 		vdev_config_dirty(rvd);
2065 	}
2066 
2067 	spa_config_exit(spa, SCL_ALL, FTAG);
2068 
2069 	if (error != 0) {
2070 		spa_unload(spa);
2071 		spa_deactivate(spa);
2072 		spa_remove(spa);
2073 		mutex_exit(&spa_namespace_lock);
2074 		return (error);
2075 	}
2076 
2077 	/*
2078 	 * Get the list of spares, if specified.
2079 	 */
2080 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
2081 	    &spares, &nspares) == 0) {
2082 		VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
2083 		    KM_SLEEP) == 0);
2084 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
2085 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2086 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2087 		spa_load_spares(spa);
2088 		spa_config_exit(spa, SCL_ALL, FTAG);
2089 		spa->spa_spares.sav_sync = B_TRUE;
2090 	}
2091 
2092 	/*
2093 	 * Get the list of level 2 cache devices, if specified.
2094 	 */
2095 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
2096 	    &l2cache, &nl2cache) == 0) {
2097 		VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
2098 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
2099 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
2100 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2101 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2102 		spa_load_l2cache(spa);
2103 		spa_config_exit(spa, SCL_ALL, FTAG);
2104 		spa->spa_l2cache.sav_sync = B_TRUE;
2105 	}
2106 
2107 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
2108 	spa->spa_meta_objset = dp->dp_meta_objset;
2109 
2110 	tx = dmu_tx_create_assigned(dp, txg);
2111 
2112 	/*
2113 	 * Create the pool config object.
2114 	 */
2115 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
2116 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
2117 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
2118 
2119 	if (zap_add(spa->spa_meta_objset,
2120 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
2121 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
2122 		cmn_err(CE_PANIC, "failed to add pool config");
2123 	}
2124 
2125 	/* Newly created pools with the right version are always deflated. */
2126 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
2127 		spa->spa_deflate = TRUE;
2128 		if (zap_add(spa->spa_meta_objset,
2129 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
2130 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
2131 			cmn_err(CE_PANIC, "failed to add deflate");
2132 		}
2133 	}
2134 
2135 	/*
2136 	 * Create the deferred-free bplist object.  Turn off compression
2137 	 * because sync-to-convergence takes longer if the blocksize
2138 	 * keeps changing.
2139 	 */
2140 	spa->spa_sync_bplist_obj = bplist_create(spa->spa_meta_objset,
2141 	    1 << 14, tx);
2142 	dmu_object_set_compress(spa->spa_meta_objset, spa->spa_sync_bplist_obj,
2143 	    ZIO_COMPRESS_OFF, tx);
2144 
2145 	if (zap_add(spa->spa_meta_objset,
2146 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPLIST,
2147 	    sizeof (uint64_t), 1, &spa->spa_sync_bplist_obj, tx) != 0) {
2148 		cmn_err(CE_PANIC, "failed to add bplist");
2149 	}
2150 
2151 	/*
2152 	 * Create the pool's history object.
2153 	 */
2154 	if (version >= SPA_VERSION_ZPOOL_HISTORY)
2155 		spa_history_create_obj(spa, tx);
2156 
2157 	/*
2158 	 * Set pool properties.
2159 	 */
2160 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
2161 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2162 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
2163 	if (props != NULL) {
2164 		spa_configfile_set(spa, props, B_FALSE);
2165 		spa_sync_props(spa, props, CRED(), tx);
2166 	}
2167 
2168 	dmu_tx_commit(tx);
2169 
2170 	spa->spa_sync_on = B_TRUE;
2171 	txg_sync_start(spa->spa_dsl_pool);
2172 
2173 	/*
2174 	 * We explicitly wait for the first transaction to complete so that our
2175 	 * bean counters are appropriately updated.
2176 	 */
2177 	txg_wait_synced(spa->spa_dsl_pool, txg);
2178 
2179 	spa_config_sync(spa, B_FALSE, B_TRUE);
2180 
2181 	if (version >= SPA_VERSION_ZPOOL_HISTORY && history_str != NULL)
2182 		(void) spa_history_log(spa, history_str, LOG_CMD_POOL_CREATE);
2183 
2184 	spa->spa_minref = refcount_count(&spa->spa_refcount);
2185 
2186 	mutex_exit(&spa_namespace_lock);
2187 
2188 	return (0);
2189 }
2190 
2191 #ifdef _KERNEL
2192 /*
2193  * Build a "root" vdev for a top level vdev read in from a rootpool
2194  * device label.
2195  */
2196 static void
2197 spa_build_rootpool_config(nvlist_t *config)
2198 {
2199 	nvlist_t *nvtop, *nvroot;
2200 	uint64_t pgid;
2201 
2202 	/*
2203 	 * Add this top-level vdev to the child array.
2204 	 */
2205 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvtop)
2206 	    == 0);
2207 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pgid)
2208 	    == 0);
2209 
2210 	/*
2211 	 * Put this pool's top-level vdevs into a root vdev.
2212 	 */
2213 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2214 	VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE, VDEV_TYPE_ROOT)
2215 	    == 0);
2216 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
2217 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
2218 	VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
2219 	    &nvtop, 1) == 0);
2220 
2221 	/*
2222 	 * Replace the existing vdev_tree with the new root vdev in
2223 	 * this pool's configuration (remove the old, add the new).
2224 	 */
2225 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
2226 	nvlist_free(nvroot);
2227 }
2228 
2229 /*
2230  * Get the root pool information from the root disk, then import the root pool
2231  * during the system boot up time.
2232  */
2233 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
2234 
2235 int
2236 spa_check_rootconf(char *devpath, char *devid, nvlist_t **bestconf,
2237     uint64_t *besttxg)
2238 {
2239 	nvlist_t *config;
2240 	uint64_t txg;
2241 	int error;
2242 
2243 	if (error = vdev_disk_read_rootlabel(devpath, devid, &config))
2244 		return (error);
2245 
2246 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
2247 
2248 	if (bestconf != NULL)
2249 		*bestconf = config;
2250 	else
2251 		nvlist_free(config);
2252 	*besttxg = txg;
2253 	return (0);
2254 }
2255 
2256 boolean_t
2257 spa_rootdev_validate(nvlist_t *nv)
2258 {
2259 	uint64_t ival;
2260 
2261 	if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_OFFLINE, &ival) == 0 ||
2262 	    nvlist_lookup_uint64(nv, ZPOOL_CONFIG_FAULTED, &ival) == 0 ||
2263 	    nvlist_lookup_uint64(nv, ZPOOL_CONFIG_REMOVED, &ival) == 0)
2264 		return (B_FALSE);
2265 
2266 	return (B_TRUE);
2267 }
2268 
2269 
2270 /*
2271  * Given the boot device's physical path or devid, check if the device
2272  * is in a valid state.  If so, return the configuration from the vdev
2273  * label.
2274  */
2275 int
2276 spa_get_rootconf(char *devpath, char *devid, nvlist_t **bestconf)
2277 {
2278 	nvlist_t *conf = NULL;
2279 	uint64_t txg = 0;
2280 	nvlist_t *nvtop, **child;
2281 	char *type;
2282 	char *bootpath = NULL;
2283 	uint_t children, c;
2284 	char *tmp;
2285 	int error;
2286 
2287 	if (devpath && ((tmp = strchr(devpath, ' ')) != NULL))
2288 		*tmp = '\0';
2289 	if (error = spa_check_rootconf(devpath, devid, &conf, &txg)) {
2290 		cmn_err(CE_NOTE, "error reading device label");
2291 		return (error);
2292 	}
2293 	if (txg == 0) {
2294 		cmn_err(CE_NOTE, "this device is detached");
2295 		nvlist_free(conf);
2296 		return (EINVAL);
2297 	}
2298 
2299 	VERIFY(nvlist_lookup_nvlist(conf, ZPOOL_CONFIG_VDEV_TREE,
2300 	    &nvtop) == 0);
2301 	VERIFY(nvlist_lookup_string(nvtop, ZPOOL_CONFIG_TYPE, &type) == 0);
2302 
2303 	if (strcmp(type, VDEV_TYPE_DISK) == 0) {
2304 		if (spa_rootdev_validate(nvtop)) {
2305 			goto out;
2306 		} else {
2307 			nvlist_free(conf);
2308 			return (EINVAL);
2309 		}
2310 	}
2311 
2312 	ASSERT(strcmp(type, VDEV_TYPE_MIRROR) == 0);
2313 
2314 	VERIFY(nvlist_lookup_nvlist_array(nvtop, ZPOOL_CONFIG_CHILDREN,
2315 	    &child, &children) == 0);
2316 
2317 	/*
2318 	 * Go thru vdevs in the mirror to see if the given device
2319 	 * has the most recent txg. Only the device with the most
2320 	 * recent txg has valid information and should be booted.
2321 	 */
2322 	for (c = 0; c < children; c++) {
2323 		char *cdevid, *cpath;
2324 		uint64_t tmptxg;
2325 
2326 		cpath = NULL;
2327 		cdevid = NULL;
2328 		if (nvlist_lookup_string(child[c], ZPOOL_CONFIG_PHYS_PATH,
2329 		    &cpath) != 0 && nvlist_lookup_string(child[c],
2330 		    ZPOOL_CONFIG_DEVID, &cdevid) != 0)
2331 			return (EINVAL);
2332 		if ((spa_check_rootconf(cpath, cdevid, NULL,
2333 		    &tmptxg) == 0) && (tmptxg > txg)) {
2334 			txg = tmptxg;
2335 			VERIFY(nvlist_lookup_string(child[c],
2336 			    ZPOOL_CONFIG_PATH, &bootpath) == 0);
2337 		}
2338 	}
2339 
2340 	/* Does the best device match the one we've booted from? */
2341 	if (bootpath) {
2342 		cmn_err(CE_NOTE, "try booting from '%s'", bootpath);
2343 		return (EINVAL);
2344 	}
2345 out:
2346 	*bestconf = conf;
2347 	return (0);
2348 }
2349 
2350 /*
2351  * Import a root pool.
2352  *
2353  * For x86. devpath_list will consist of devid and/or physpath name of
2354  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
2355  * The GRUB "findroot" command will return the vdev we should boot.
2356  *
2357  * For Sparc, devpath_list consists the physpath name of the booting device
2358  * no matter the rootpool is a single device pool or a mirrored pool.
2359  * e.g.
2360  *	"/pci@1f,0/ide@d/disk@0,0:a"
2361  */
2362 int
2363 spa_import_rootpool(char *devpath, char *devid)
2364 {
2365 	nvlist_t *conf = NULL;
2366 	char *pname;
2367 	int error;
2368 	spa_t *spa;
2369 
2370 	/*
2371 	 * Get the vdev pathname and configuation from the most
2372 	 * recently updated vdev (highest txg).
2373 	 */
2374 	if (error = spa_get_rootconf(devpath, devid, &conf))
2375 		goto msg_out;
2376 
2377 	/*
2378 	 * Add type "root" vdev to the config.
2379 	 */
2380 	spa_build_rootpool_config(conf);
2381 
2382 	VERIFY(nvlist_lookup_string(conf, ZPOOL_CONFIG_POOL_NAME, &pname) == 0);
2383 
2384 	mutex_enter(&spa_namespace_lock);
2385 	if ((spa = spa_lookup(pname)) != NULL) {
2386 		/*
2387 		 * Remove the existing root pool from the namespace so that we
2388 		 * can replace it with the correct config we just read in.
2389 		 */
2390 		spa_remove(spa);
2391 	}
2392 
2393 	spa = spa_add(pname, NULL);
2394 
2395 	spa->spa_is_root = B_TRUE;
2396 	VERIFY(nvlist_dup(conf, &spa->spa_config, 0) == 0);
2397 	mutex_exit(&spa_namespace_lock);
2398 
2399 	nvlist_free(conf);
2400 	return (0);
2401 
2402 msg_out:
2403 	cmn_err(CE_NOTE, "\n"
2404 	    "  ***************************************************  \n"
2405 	    "  *  This device is not bootable!                   *  \n"
2406 	    "  *  It is either offlined or detached or faulted.  *  \n"
2407 	    "  *  Please try to boot from a different device.    *  \n"
2408 	    "  ***************************************************  ");
2409 
2410 	return (error);
2411 }
2412 #endif
2413 
2414 /*
2415  * Take a pool and insert it into the namespace as if it had been loaded at
2416  * boot.
2417  */
2418 int
2419 spa_import_verbatim(const char *pool, nvlist_t *config, nvlist_t *props)
2420 {
2421 	spa_t *spa;
2422 	char *altroot = NULL;
2423 
2424 	mutex_enter(&spa_namespace_lock);
2425 	if (spa_lookup(pool) != NULL) {
2426 		mutex_exit(&spa_namespace_lock);
2427 		return (EEXIST);
2428 	}
2429 
2430 	(void) nvlist_lookup_string(props,
2431 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
2432 	spa = spa_add(pool, altroot);
2433 
2434 	VERIFY(nvlist_dup(config, &spa->spa_config, 0) == 0);
2435 
2436 	if (props != NULL)
2437 		spa_configfile_set(spa, props, B_FALSE);
2438 
2439 	spa_config_sync(spa, B_FALSE, B_TRUE);
2440 
2441 	mutex_exit(&spa_namespace_lock);
2442 
2443 	return (0);
2444 }
2445 
2446 /*
2447  * Import a non-root pool into the system.
2448  */
2449 int
2450 spa_import(const char *pool, nvlist_t *config, nvlist_t *props)
2451 {
2452 	spa_t *spa;
2453 	char *altroot = NULL;
2454 	int error;
2455 	nvlist_t *nvroot;
2456 	nvlist_t **spares, **l2cache;
2457 	uint_t nspares, nl2cache;
2458 
2459 	/*
2460 	 * If a pool with this name exists, return failure.
2461 	 */
2462 	mutex_enter(&spa_namespace_lock);
2463 	if ((spa = spa_lookup(pool)) != NULL) {
2464 		mutex_exit(&spa_namespace_lock);
2465 		return (EEXIST);
2466 	}
2467 
2468 	/*
2469 	 * Create and initialize the spa structure.
2470 	 */
2471 	(void) nvlist_lookup_string(props,
2472 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
2473 	spa = spa_add(pool, altroot);
2474 	spa_activate(spa, spa_mode_global);
2475 
2476 	/*
2477 	 * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
2478 	 * because the user-supplied config is actually the one to trust when
2479 	 * doing an import.
2480 	 */
2481 	error = spa_load(spa, config, SPA_LOAD_IMPORT, B_TRUE);
2482 
2483 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2484 	/*
2485 	 * Toss any existing sparelist, as it doesn't have any validity
2486 	 * anymore, and conflicts with spa_has_spare().
2487 	 */
2488 	if (spa->spa_spares.sav_config) {
2489 		nvlist_free(spa->spa_spares.sav_config);
2490 		spa->spa_spares.sav_config = NULL;
2491 		spa_load_spares(spa);
2492 	}
2493 	if (spa->spa_l2cache.sav_config) {
2494 		nvlist_free(spa->spa_l2cache.sav_config);
2495 		spa->spa_l2cache.sav_config = NULL;
2496 		spa_load_l2cache(spa);
2497 	}
2498 
2499 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
2500 	    &nvroot) == 0);
2501 	if (error == 0)
2502 		error = spa_validate_aux(spa, nvroot, -1ULL,
2503 		    VDEV_ALLOC_SPARE);
2504 	if (error == 0)
2505 		error = spa_validate_aux(spa, nvroot, -1ULL,
2506 		    VDEV_ALLOC_L2CACHE);
2507 	spa_config_exit(spa, SCL_ALL, FTAG);
2508 
2509 	if (props != NULL)
2510 		spa_configfile_set(spa, props, B_FALSE);
2511 
2512 	if (error != 0 || (props && spa_writeable(spa) &&
2513 	    (error = spa_prop_set(spa, props)))) {
2514 		spa_unload(spa);
2515 		spa_deactivate(spa);
2516 		spa_remove(spa);
2517 		mutex_exit(&spa_namespace_lock);
2518 		return (error);
2519 	}
2520 
2521 	/*
2522 	 * Override any spares and level 2 cache devices as specified by
2523 	 * the user, as these may have correct device names/devids, etc.
2524 	 */
2525 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
2526 	    &spares, &nspares) == 0) {
2527 		if (spa->spa_spares.sav_config)
2528 			VERIFY(nvlist_remove(spa->spa_spares.sav_config,
2529 			    ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
2530 		else
2531 			VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
2532 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
2533 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
2534 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
2535 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2536 		spa_load_spares(spa);
2537 		spa_config_exit(spa, SCL_ALL, FTAG);
2538 		spa->spa_spares.sav_sync = B_TRUE;
2539 	}
2540 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
2541 	    &l2cache, &nl2cache) == 0) {
2542 		if (spa->spa_l2cache.sav_config)
2543 			VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
2544 			    ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
2545 		else
2546 			VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
2547 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
2548 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
2549 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
2550 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2551 		spa_load_l2cache(spa);
2552 		spa_config_exit(spa, SCL_ALL, FTAG);
2553 		spa->spa_l2cache.sav_sync = B_TRUE;
2554 	}
2555 
2556 	if (spa_writeable(spa)) {
2557 		/*
2558 		 * Update the config cache to include the newly-imported pool.
2559 		 */
2560 		spa_config_update_common(spa, SPA_CONFIG_UPDATE_POOL, B_FALSE);
2561 	}
2562 
2563 	mutex_exit(&spa_namespace_lock);
2564 
2565 	return (0);
2566 }
2567 
2568 
2569 /*
2570  * This (illegal) pool name is used when temporarily importing a spa_t in order
2571  * to get the vdev stats associated with the imported devices.
2572  */
2573 #define	TRYIMPORT_NAME	"$import"
2574 
2575 nvlist_t *
2576 spa_tryimport(nvlist_t *tryconfig)
2577 {
2578 	nvlist_t *config = NULL;
2579 	char *poolname;
2580 	spa_t *spa;
2581 	uint64_t state;
2582 	int error;
2583 
2584 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
2585 		return (NULL);
2586 
2587 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
2588 		return (NULL);
2589 
2590 	/*
2591 	 * Create and initialize the spa structure.
2592 	 */
2593 	mutex_enter(&spa_namespace_lock);
2594 	spa = spa_add(TRYIMPORT_NAME, NULL);
2595 	spa_activate(spa, FREAD);
2596 
2597 	/*
2598 	 * Pass off the heavy lifting to spa_load().
2599 	 * Pass TRUE for mosconfig because the user-supplied config
2600 	 * is actually the one to trust when doing an import.
2601 	 */
2602 	error = spa_load(spa, tryconfig, SPA_LOAD_TRYIMPORT, B_TRUE);
2603 
2604 	/*
2605 	 * If 'tryconfig' was at least parsable, return the current config.
2606 	 */
2607 	if (spa->spa_root_vdev != NULL) {
2608 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2609 		VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
2610 		    poolname) == 0);
2611 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
2612 		    state) == 0);
2613 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
2614 		    spa->spa_uberblock.ub_timestamp) == 0);
2615 
2616 		/*
2617 		 * If the bootfs property exists on this pool then we
2618 		 * copy it out so that external consumers can tell which
2619 		 * pools are bootable.
2620 		 */
2621 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
2622 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2623 
2624 			/*
2625 			 * We have to play games with the name since the
2626 			 * pool was opened as TRYIMPORT_NAME.
2627 			 */
2628 			if (dsl_dsobj_to_dsname(spa_name(spa),
2629 			    spa->spa_bootfs, tmpname) == 0) {
2630 				char *cp;
2631 				char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
2632 
2633 				cp = strchr(tmpname, '/');
2634 				if (cp == NULL) {
2635 					(void) strlcpy(dsname, tmpname,
2636 					    MAXPATHLEN);
2637 				} else {
2638 					(void) snprintf(dsname, MAXPATHLEN,
2639 					    "%s/%s", poolname, ++cp);
2640 				}
2641 				VERIFY(nvlist_add_string(config,
2642 				    ZPOOL_CONFIG_BOOTFS, dsname) == 0);
2643 				kmem_free(dsname, MAXPATHLEN);
2644 			}
2645 			kmem_free(tmpname, MAXPATHLEN);
2646 		}
2647 
2648 		/*
2649 		 * Add the list of hot spares and level 2 cache devices.
2650 		 */
2651 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
2652 		spa_add_spares(spa, config);
2653 		spa_add_l2cache(spa, config);
2654 		spa_config_exit(spa, SCL_CONFIG, FTAG);
2655 	}
2656 
2657 	spa_unload(spa);
2658 	spa_deactivate(spa);
2659 	spa_remove(spa);
2660 	mutex_exit(&spa_namespace_lock);
2661 
2662 	return (config);
2663 }
2664 
2665 /*
2666  * Pool export/destroy
2667  *
2668  * The act of destroying or exporting a pool is very simple.  We make sure there
2669  * is no more pending I/O and any references to the pool are gone.  Then, we
2670  * update the pool state and sync all the labels to disk, removing the
2671  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
2672  * we don't sync the labels or remove the configuration cache.
2673  */
2674 static int
2675 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
2676     boolean_t force, boolean_t hardforce)
2677 {
2678 	spa_t *spa;
2679 
2680 	if (oldconfig)
2681 		*oldconfig = NULL;
2682 
2683 	if (!(spa_mode_global & FWRITE))
2684 		return (EROFS);
2685 
2686 	mutex_enter(&spa_namespace_lock);
2687 	if ((spa = spa_lookup(pool)) == NULL) {
2688 		mutex_exit(&spa_namespace_lock);
2689 		return (ENOENT);
2690 	}
2691 
2692 	/*
2693 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
2694 	 * reacquire the namespace lock, and see if we can export.
2695 	 */
2696 	spa_open_ref(spa, FTAG);
2697 	mutex_exit(&spa_namespace_lock);
2698 	spa_async_suspend(spa);
2699 	mutex_enter(&spa_namespace_lock);
2700 	spa_close(spa, FTAG);
2701 
2702 	/*
2703 	 * The pool will be in core if it's openable,
2704 	 * in which case we can modify its state.
2705 	 */
2706 	if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
2707 		/*
2708 		 * Objsets may be open only because they're dirty, so we
2709 		 * have to force it to sync before checking spa_refcnt.
2710 		 */
2711 		txg_wait_synced(spa->spa_dsl_pool, 0);
2712 
2713 		/*
2714 		 * A pool cannot be exported or destroyed if there are active
2715 		 * references.  If we are resetting a pool, allow references by
2716 		 * fault injection handlers.
2717 		 */
2718 		if (!spa_refcount_zero(spa) ||
2719 		    (spa->spa_inject_ref != 0 &&
2720 		    new_state != POOL_STATE_UNINITIALIZED)) {
2721 			spa_async_resume(spa);
2722 			mutex_exit(&spa_namespace_lock);
2723 			return (EBUSY);
2724 		}
2725 
2726 		/*
2727 		 * A pool cannot be exported if it has an active shared spare.
2728 		 * This is to prevent other pools stealing the active spare
2729 		 * from an exported pool. At user's own will, such pool can
2730 		 * be forcedly exported.
2731 		 */
2732 		if (!force && new_state == POOL_STATE_EXPORTED &&
2733 		    spa_has_active_shared_spare(spa)) {
2734 			spa_async_resume(spa);
2735 			mutex_exit(&spa_namespace_lock);
2736 			return (EXDEV);
2737 		}
2738 
2739 		/*
2740 		 * We want this to be reflected on every label,
2741 		 * so mark them all dirty.  spa_unload() will do the
2742 		 * final sync that pushes these changes out.
2743 		 */
2744 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
2745 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2746 			spa->spa_state = new_state;
2747 			spa->spa_final_txg = spa_last_synced_txg(spa) + 1;
2748 			vdev_config_dirty(spa->spa_root_vdev);
2749 			spa_config_exit(spa, SCL_ALL, FTAG);
2750 		}
2751 	}
2752 
2753 	spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
2754 
2755 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
2756 		spa_unload(spa);
2757 		spa_deactivate(spa);
2758 	}
2759 
2760 	if (oldconfig && spa->spa_config)
2761 		VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
2762 
2763 	if (new_state != POOL_STATE_UNINITIALIZED) {
2764 		if (!hardforce)
2765 			spa_config_sync(spa, B_TRUE, B_TRUE);
2766 		spa_remove(spa);
2767 	}
2768 	mutex_exit(&spa_namespace_lock);
2769 
2770 	return (0);
2771 }
2772 
2773 /*
2774  * Destroy a storage pool.
2775  */
2776 int
2777 spa_destroy(char *pool)
2778 {
2779 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
2780 	    B_FALSE, B_FALSE));
2781 }
2782 
2783 /*
2784  * Export a storage pool.
2785  */
2786 int
2787 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
2788     boolean_t hardforce)
2789 {
2790 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
2791 	    force, hardforce));
2792 }
2793 
2794 /*
2795  * Similar to spa_export(), this unloads the spa_t without actually removing it
2796  * from the namespace in any way.
2797  */
2798 int
2799 spa_reset(char *pool)
2800 {
2801 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
2802 	    B_FALSE, B_FALSE));
2803 }
2804 
2805 /*
2806  * ==========================================================================
2807  * Device manipulation
2808  * ==========================================================================
2809  */
2810 
2811 /*
2812  * Add a device to a storage pool.
2813  */
2814 int
2815 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
2816 {
2817 	uint64_t txg;
2818 	int error;
2819 	vdev_t *rvd = spa->spa_root_vdev;
2820 	vdev_t *vd, *tvd;
2821 	nvlist_t **spares, **l2cache;
2822 	uint_t nspares, nl2cache;
2823 
2824 	txg = spa_vdev_enter(spa);
2825 
2826 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
2827 	    VDEV_ALLOC_ADD)) != 0)
2828 		return (spa_vdev_exit(spa, NULL, txg, error));
2829 
2830 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
2831 
2832 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
2833 	    &nspares) != 0)
2834 		nspares = 0;
2835 
2836 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
2837 	    &nl2cache) != 0)
2838 		nl2cache = 0;
2839 
2840 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
2841 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
2842 
2843 	if (vd->vdev_children != 0 &&
2844 	    (error = vdev_create(vd, txg, B_FALSE)) != 0)
2845 		return (spa_vdev_exit(spa, vd, txg, error));
2846 
2847 	/*
2848 	 * We must validate the spares and l2cache devices after checking the
2849 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
2850 	 */
2851 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
2852 		return (spa_vdev_exit(spa, vd, txg, error));
2853 
2854 	/*
2855 	 * Transfer each new top-level vdev from vd to rvd.
2856 	 */
2857 	for (int c = 0; c < vd->vdev_children; c++) {
2858 		tvd = vd->vdev_child[c];
2859 		vdev_remove_child(vd, tvd);
2860 		tvd->vdev_id = rvd->vdev_children;
2861 		vdev_add_child(rvd, tvd);
2862 		vdev_config_dirty(tvd);
2863 	}
2864 
2865 	if (nspares != 0) {
2866 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
2867 		    ZPOOL_CONFIG_SPARES);
2868 		spa_load_spares(spa);
2869 		spa->spa_spares.sav_sync = B_TRUE;
2870 	}
2871 
2872 	if (nl2cache != 0) {
2873 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
2874 		    ZPOOL_CONFIG_L2CACHE);
2875 		spa_load_l2cache(spa);
2876 		spa->spa_l2cache.sav_sync = B_TRUE;
2877 	}
2878 
2879 	/*
2880 	 * We have to be careful when adding new vdevs to an existing pool.
2881 	 * If other threads start allocating from these vdevs before we
2882 	 * sync the config cache, and we lose power, then upon reboot we may
2883 	 * fail to open the pool because there are DVAs that the config cache
2884 	 * can't translate.  Therefore, we first add the vdevs without
2885 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
2886 	 * and then let spa_config_update() initialize the new metaslabs.
2887 	 *
2888 	 * spa_load() checks for added-but-not-initialized vdevs, so that
2889 	 * if we lose power at any point in this sequence, the remaining
2890 	 * steps will be completed the next time we load the pool.
2891 	 */
2892 	(void) spa_vdev_exit(spa, vd, txg, 0);
2893 
2894 	mutex_enter(&spa_namespace_lock);
2895 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
2896 	mutex_exit(&spa_namespace_lock);
2897 
2898 	return (0);
2899 }
2900 
2901 /*
2902  * Attach a device to a mirror.  The arguments are the path to any device
2903  * in the mirror, and the nvroot for the new device.  If the path specifies
2904  * a device that is not mirrored, we automatically insert the mirror vdev.
2905  *
2906  * If 'replacing' is specified, the new device is intended to replace the
2907  * existing device; in this case the two devices are made into their own
2908  * mirror using the 'replacing' vdev, which is functionally identical to
2909  * the mirror vdev (it actually reuses all the same ops) but has a few
2910  * extra rules: you can't attach to it after it's been created, and upon
2911  * completion of resilvering, the first disk (the one being replaced)
2912  * is automatically detached.
2913  */
2914 int
2915 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
2916 {
2917 	uint64_t txg, open_txg;
2918 	vdev_t *rvd = spa->spa_root_vdev;
2919 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
2920 	vdev_ops_t *pvops;
2921 	dmu_tx_t *tx;
2922 	char *oldvdpath, *newvdpath;
2923 	int newvd_isspare;
2924 	int error;
2925 
2926 	txg = spa_vdev_enter(spa);
2927 
2928 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
2929 
2930 	if (oldvd == NULL)
2931 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
2932 
2933 	if (!oldvd->vdev_ops->vdev_op_leaf)
2934 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
2935 
2936 	pvd = oldvd->vdev_parent;
2937 
2938 	if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
2939 	    VDEV_ALLOC_ADD)) != 0)
2940 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
2941 
2942 	if (newrootvd->vdev_children != 1)
2943 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
2944 
2945 	newvd = newrootvd->vdev_child[0];
2946 
2947 	if (!newvd->vdev_ops->vdev_op_leaf)
2948 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
2949 
2950 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
2951 		return (spa_vdev_exit(spa, newrootvd, txg, error));
2952 
2953 	/*
2954 	 * Spares can't replace logs
2955 	 */
2956 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
2957 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
2958 
2959 	if (!replacing) {
2960 		/*
2961 		 * For attach, the only allowable parent is a mirror or the root
2962 		 * vdev.
2963 		 */
2964 		if (pvd->vdev_ops != &vdev_mirror_ops &&
2965 		    pvd->vdev_ops != &vdev_root_ops)
2966 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
2967 
2968 		pvops = &vdev_mirror_ops;
2969 	} else {
2970 		/*
2971 		 * Active hot spares can only be replaced by inactive hot
2972 		 * spares.
2973 		 */
2974 		if (pvd->vdev_ops == &vdev_spare_ops &&
2975 		    pvd->vdev_child[1] == oldvd &&
2976 		    !spa_has_spare(spa, newvd->vdev_guid))
2977 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
2978 
2979 		/*
2980 		 * If the source is a hot spare, and the parent isn't already a
2981 		 * spare, then we want to create a new hot spare.  Otherwise, we
2982 		 * want to create a replacing vdev.  The user is not allowed to
2983 		 * attach to a spared vdev child unless the 'isspare' state is
2984 		 * the same (spare replaces spare, non-spare replaces
2985 		 * non-spare).
2986 		 */
2987 		if (pvd->vdev_ops == &vdev_replacing_ops)
2988 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
2989 		else if (pvd->vdev_ops == &vdev_spare_ops &&
2990 		    newvd->vdev_isspare != oldvd->vdev_isspare)
2991 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
2992 		else if (pvd->vdev_ops != &vdev_spare_ops &&
2993 		    newvd->vdev_isspare)
2994 			pvops = &vdev_spare_ops;
2995 		else
2996 			pvops = &vdev_replacing_ops;
2997 	}
2998 
2999 	/*
3000 	 * Compare the new device size with the replaceable/attachable
3001 	 * device size.
3002 	 */
3003 	if (newvd->vdev_psize < vdev_get_rsize(oldvd))
3004 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
3005 
3006 	/*
3007 	 * The new device cannot have a higher alignment requirement
3008 	 * than the top-level vdev.
3009 	 */
3010 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
3011 		return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
3012 
3013 	/*
3014 	 * If this is an in-place replacement, update oldvd's path and devid
3015 	 * to make it distinguishable from newvd, and unopenable from now on.
3016 	 */
3017 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
3018 		spa_strfree(oldvd->vdev_path);
3019 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
3020 		    KM_SLEEP);
3021 		(void) sprintf(oldvd->vdev_path, "%s/%s",
3022 		    newvd->vdev_path, "old");
3023 		if (oldvd->vdev_devid != NULL) {
3024 			spa_strfree(oldvd->vdev_devid);
3025 			oldvd->vdev_devid = NULL;
3026 		}
3027 	}
3028 
3029 	/*
3030 	 * If the parent is not a mirror, or if we're replacing, insert the new
3031 	 * mirror/replacing/spare vdev above oldvd.
3032 	 */
3033 	if (pvd->vdev_ops != pvops)
3034 		pvd = vdev_add_parent(oldvd, pvops);
3035 
3036 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
3037 	ASSERT(pvd->vdev_ops == pvops);
3038 	ASSERT(oldvd->vdev_parent == pvd);
3039 
3040 	/*
3041 	 * Extract the new device from its root and add it to pvd.
3042 	 */
3043 	vdev_remove_child(newrootvd, newvd);
3044 	newvd->vdev_id = pvd->vdev_children;
3045 	vdev_add_child(pvd, newvd);
3046 
3047 	/*
3048 	 * If newvd is smaller than oldvd, but larger than its rsize,
3049 	 * the addition of newvd may have decreased our parent's asize.
3050 	 */
3051 	pvd->vdev_asize = MIN(pvd->vdev_asize, newvd->vdev_asize);
3052 
3053 	tvd = newvd->vdev_top;
3054 	ASSERT(pvd->vdev_top == tvd);
3055 	ASSERT(tvd->vdev_parent == rvd);
3056 
3057 	vdev_config_dirty(tvd);
3058 
3059 	/*
3060 	 * Set newvd's DTL to [TXG_INITIAL, open_txg].  It will propagate
3061 	 * upward when spa_vdev_exit() calls vdev_dtl_reassess().
3062 	 */
3063 	open_txg = txg + TXG_CONCURRENT_STATES - 1;
3064 
3065 	vdev_dtl_dirty(newvd, DTL_MISSING,
3066 	    TXG_INITIAL, open_txg - TXG_INITIAL + 1);
3067 
3068 	if (newvd->vdev_isspare) {
3069 		spa_spare_activate(newvd);
3070 		spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
3071 	}
3072 
3073 	oldvdpath = spa_strdup(oldvd->vdev_path);
3074 	newvdpath = spa_strdup(newvd->vdev_path);
3075 	newvd_isspare = newvd->vdev_isspare;
3076 
3077 	/*
3078 	 * Mark newvd's DTL dirty in this txg.
3079 	 */
3080 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
3081 
3082 	(void) spa_vdev_exit(spa, newrootvd, open_txg, 0);
3083 
3084 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
3085 	if (dmu_tx_assign(tx, TXG_WAIT) == 0) {
3086 		spa_history_internal_log(LOG_POOL_VDEV_ATTACH, spa, tx,
3087 		    CRED(),  "%s vdev=%s %s vdev=%s",
3088 		    replacing && newvd_isspare ? "spare in" :
3089 		    replacing ? "replace" : "attach", newvdpath,
3090 		    replacing ? "for" : "to", oldvdpath);
3091 		dmu_tx_commit(tx);
3092 	} else {
3093 		dmu_tx_abort(tx);
3094 	}
3095 
3096 	spa_strfree(oldvdpath);
3097 	spa_strfree(newvdpath);
3098 
3099 	/*
3100 	 * Kick off a resilver to update newvd.
3101 	 */
3102 	VERIFY3U(spa_scrub(spa, POOL_SCRUB_RESILVER), ==, 0);
3103 
3104 	return (0);
3105 }
3106 
3107 /*
3108  * Detach a device from a mirror or replacing vdev.
3109  * If 'replace_done' is specified, only detach if the parent
3110  * is a replacing vdev.
3111  */
3112 int
3113 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
3114 {
3115 	uint64_t txg;
3116 	int error;
3117 	vdev_t *rvd = spa->spa_root_vdev;
3118 	vdev_t *vd, *pvd, *cvd, *tvd;
3119 	boolean_t unspare = B_FALSE;
3120 	uint64_t unspare_guid;
3121 	size_t len;
3122 
3123 	txg = spa_vdev_enter(spa);
3124 
3125 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
3126 
3127 	if (vd == NULL)
3128 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
3129 
3130 	if (!vd->vdev_ops->vdev_op_leaf)
3131 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3132 
3133 	pvd = vd->vdev_parent;
3134 
3135 	/*
3136 	 * If the parent/child relationship is not as expected, don't do it.
3137 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
3138 	 * vdev that's replacing B with C.  The user's intent in replacing
3139 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
3140 	 * the replace by detaching C, the expected behavior is to end up
3141 	 * M(A,B).  But suppose that right after deciding to detach C,
3142 	 * the replacement of B completes.  We would have M(A,C), and then
3143 	 * ask to detach C, which would leave us with just A -- not what
3144 	 * the user wanted.  To prevent this, we make sure that the
3145 	 * parent/child relationship hasn't changed -- in this example,
3146 	 * that C's parent is still the replacing vdev R.
3147 	 */
3148 	if (pvd->vdev_guid != pguid && pguid != 0)
3149 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
3150 
3151 	/*
3152 	 * If replace_done is specified, only remove this device if it's
3153 	 * the first child of a replacing vdev.  For the 'spare' vdev, either
3154 	 * disk can be removed.
3155 	 */
3156 	if (replace_done) {
3157 		if (pvd->vdev_ops == &vdev_replacing_ops) {
3158 			if (vd->vdev_id != 0)
3159 				return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3160 		} else if (pvd->vdev_ops != &vdev_spare_ops) {
3161 			return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3162 		}
3163 	}
3164 
3165 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
3166 	    spa_version(spa) >= SPA_VERSION_SPARES);
3167 
3168 	/*
3169 	 * Only mirror, replacing, and spare vdevs support detach.
3170 	 */
3171 	if (pvd->vdev_ops != &vdev_replacing_ops &&
3172 	    pvd->vdev_ops != &vdev_mirror_ops &&
3173 	    pvd->vdev_ops != &vdev_spare_ops)
3174 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3175 
3176 	/*
3177 	 * If this device has the only valid copy of some data,
3178 	 * we cannot safely detach it.
3179 	 */
3180 	if (vdev_dtl_required(vd))
3181 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
3182 
3183 	ASSERT(pvd->vdev_children >= 2);
3184 
3185 	/*
3186 	 * If we are detaching the second disk from a replacing vdev, then
3187 	 * check to see if we changed the original vdev's path to have "/old"
3188 	 * at the end in spa_vdev_attach().  If so, undo that change now.
3189 	 */
3190 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id == 1 &&
3191 	    pvd->vdev_child[0]->vdev_path != NULL &&
3192 	    pvd->vdev_child[1]->vdev_path != NULL) {
3193 		ASSERT(pvd->vdev_child[1] == vd);
3194 		cvd = pvd->vdev_child[0];
3195 		len = strlen(vd->vdev_path);
3196 		if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
3197 		    strcmp(cvd->vdev_path + len, "/old") == 0) {
3198 			spa_strfree(cvd->vdev_path);
3199 			cvd->vdev_path = spa_strdup(vd->vdev_path);
3200 		}
3201 	}
3202 
3203 	/*
3204 	 * If we are detaching the original disk from a spare, then it implies
3205 	 * that the spare should become a real disk, and be removed from the
3206 	 * active spare list for the pool.
3207 	 */
3208 	if (pvd->vdev_ops == &vdev_spare_ops &&
3209 	    vd->vdev_id == 0 && pvd->vdev_child[1]->vdev_isspare)
3210 		unspare = B_TRUE;
3211 
3212 	/*
3213 	 * Erase the disk labels so the disk can be used for other things.
3214 	 * This must be done after all other error cases are handled,
3215 	 * but before we disembowel vd (so we can still do I/O to it).
3216 	 * But if we can't do it, don't treat the error as fatal --
3217 	 * it may be that the unwritability of the disk is the reason
3218 	 * it's being detached!
3219 	 */
3220 	error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
3221 
3222 	/*
3223 	 * Remove vd from its parent and compact the parent's children.
3224 	 */
3225 	vdev_remove_child(pvd, vd);
3226 	vdev_compact_children(pvd);
3227 
3228 	/*
3229 	 * Remember one of the remaining children so we can get tvd below.
3230 	 */
3231 	cvd = pvd->vdev_child[0];
3232 
3233 	/*
3234 	 * If we need to remove the remaining child from the list of hot spares,
3235 	 * do it now, marking the vdev as no longer a spare in the process.
3236 	 * We must do this before vdev_remove_parent(), because that can
3237 	 * change the GUID if it creates a new toplevel GUID.  For a similar
3238 	 * reason, we must remove the spare now, in the same txg as the detach;
3239 	 * otherwise someone could attach a new sibling, change the GUID, and
3240 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
3241 	 */
3242 	if (unspare) {
3243 		ASSERT(cvd->vdev_isspare);
3244 		spa_spare_remove(cvd);
3245 		unspare_guid = cvd->vdev_guid;
3246 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
3247 	}
3248 
3249 	/*
3250 	 * If the parent mirror/replacing vdev only has one child,
3251 	 * the parent is no longer needed.  Remove it from the tree.
3252 	 */
3253 	if (pvd->vdev_children == 1)
3254 		vdev_remove_parent(cvd);
3255 
3256 	/*
3257 	 * We don't set tvd until now because the parent we just removed
3258 	 * may have been the previous top-level vdev.
3259 	 */
3260 	tvd = cvd->vdev_top;
3261 	ASSERT(tvd->vdev_parent == rvd);
3262 
3263 	/*
3264 	 * Reevaluate the parent vdev state.
3265 	 */
3266 	vdev_propagate_state(cvd);
3267 
3268 	/*
3269 	 * If the device we just detached was smaller than the others, it may be
3270 	 * possible to add metaslabs (i.e. grow the pool).  vdev_metaslab_init()
3271 	 * can't fail because the existing metaslabs are already in core, so
3272 	 * there's nothing to read from disk.
3273 	 */
3274 	VERIFY(vdev_metaslab_init(tvd, txg) == 0);
3275 
3276 	vdev_config_dirty(tvd);
3277 
3278 	/*
3279 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
3280 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
3281 	 * But first make sure we're not on any *other* txg's DTL list, to
3282 	 * prevent vd from being accessed after it's freed.
3283 	 */
3284 	for (int t = 0; t < TXG_SIZE; t++)
3285 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
3286 	vd->vdev_detached = B_TRUE;
3287 	vdev_dirty(tvd, VDD_DTL, vd, txg);
3288 
3289 	spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
3290 
3291 	error = spa_vdev_exit(spa, vd, txg, 0);
3292 
3293 	/*
3294 	 * If this was the removal of the original device in a hot spare vdev,
3295 	 * then we want to go through and remove the device from the hot spare
3296 	 * list of every other pool.
3297 	 */
3298 	if (unspare) {
3299 		spa_t *myspa = spa;
3300 		spa = NULL;
3301 		mutex_enter(&spa_namespace_lock);
3302 		while ((spa = spa_next(spa)) != NULL) {
3303 			if (spa->spa_state != POOL_STATE_ACTIVE)
3304 				continue;
3305 			if (spa == myspa)
3306 				continue;
3307 			spa_open_ref(spa, FTAG);
3308 			mutex_exit(&spa_namespace_lock);
3309 			(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
3310 			mutex_enter(&spa_namespace_lock);
3311 			spa_close(spa, FTAG);
3312 		}
3313 		mutex_exit(&spa_namespace_lock);
3314 	}
3315 
3316 	return (error);
3317 }
3318 
3319 static nvlist_t *
3320 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
3321 {
3322 	for (int i = 0; i < count; i++) {
3323 		uint64_t guid;
3324 
3325 		VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
3326 		    &guid) == 0);
3327 
3328 		if (guid == target_guid)
3329 			return (nvpp[i]);
3330 	}
3331 
3332 	return (NULL);
3333 }
3334 
3335 static void
3336 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
3337 	nvlist_t *dev_to_remove)
3338 {
3339 	nvlist_t **newdev = NULL;
3340 
3341 	if (count > 1)
3342 		newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
3343 
3344 	for (int i = 0, j = 0; i < count; i++) {
3345 		if (dev[i] == dev_to_remove)
3346 			continue;
3347 		VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
3348 	}
3349 
3350 	VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
3351 	VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
3352 
3353 	for (int i = 0; i < count - 1; i++)
3354 		nvlist_free(newdev[i]);
3355 
3356 	if (count > 1)
3357 		kmem_free(newdev, (count - 1) * sizeof (void *));
3358 }
3359 
3360 /*
3361  * Remove a device from the pool.  Currently, this supports removing only hot
3362  * spares and level 2 ARC devices.
3363  */
3364 int
3365 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
3366 {
3367 	vdev_t *vd;
3368 	nvlist_t **spares, **l2cache, *nv;
3369 	uint_t nspares, nl2cache;
3370 	uint64_t txg = 0;
3371 	int error = 0;
3372 	boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
3373 
3374 	if (!locked)
3375 		txg = spa_vdev_enter(spa);
3376 
3377 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
3378 
3379 	if (spa->spa_spares.sav_vdevs != NULL &&
3380 	    nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3381 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
3382 	    (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
3383 		/*
3384 		 * Only remove the hot spare if it's not currently in use
3385 		 * in this pool.
3386 		 */
3387 		if (vd == NULL || unspare) {
3388 			spa_vdev_remove_aux(spa->spa_spares.sav_config,
3389 			    ZPOOL_CONFIG_SPARES, spares, nspares, nv);
3390 			spa_load_spares(spa);
3391 			spa->spa_spares.sav_sync = B_TRUE;
3392 		} else {
3393 			error = EBUSY;
3394 		}
3395 	} else if (spa->spa_l2cache.sav_vdevs != NULL &&
3396 	    nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3397 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
3398 	    (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
3399 		/*
3400 		 * Cache devices can always be removed.
3401 		 */
3402 		spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
3403 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
3404 		spa_load_l2cache(spa);
3405 		spa->spa_l2cache.sav_sync = B_TRUE;
3406 	} else if (vd != NULL) {
3407 		/*
3408 		 * Normal vdevs cannot be removed (yet).
3409 		 */
3410 		error = ENOTSUP;
3411 	} else {
3412 		/*
3413 		 * There is no vdev of any kind with the specified guid.
3414 		 */
3415 		error = ENOENT;
3416 	}
3417 
3418 	if (!locked)
3419 		return (spa_vdev_exit(spa, NULL, txg, error));
3420 
3421 	return (error);
3422 }
3423 
3424 /*
3425  * Find any device that's done replacing, or a vdev marked 'unspare' that's
3426  * current spared, so we can detach it.
3427  */
3428 static vdev_t *
3429 spa_vdev_resilver_done_hunt(vdev_t *vd)
3430 {
3431 	vdev_t *newvd, *oldvd;
3432 	int c;
3433 
3434 	for (c = 0; c < vd->vdev_children; c++) {
3435 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
3436 		if (oldvd != NULL)
3437 			return (oldvd);
3438 	}
3439 
3440 	/*
3441 	 * Check for a completed replacement.
3442 	 */
3443 	if (vd->vdev_ops == &vdev_replacing_ops && vd->vdev_children == 2) {
3444 		oldvd = vd->vdev_child[0];
3445 		newvd = vd->vdev_child[1];
3446 
3447 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
3448 		    !vdev_dtl_required(oldvd))
3449 			return (oldvd);
3450 	}
3451 
3452 	/*
3453 	 * Check for a completed resilver with the 'unspare' flag set.
3454 	 */
3455 	if (vd->vdev_ops == &vdev_spare_ops && vd->vdev_children == 2) {
3456 		newvd = vd->vdev_child[0];
3457 		oldvd = vd->vdev_child[1];
3458 
3459 		if (newvd->vdev_unspare &&
3460 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
3461 		    !vdev_dtl_required(oldvd)) {
3462 			newvd->vdev_unspare = 0;
3463 			return (oldvd);
3464 		}
3465 	}
3466 
3467 	return (NULL);
3468 }
3469 
3470 static void
3471 spa_vdev_resilver_done(spa_t *spa)
3472 {
3473 	vdev_t *vd, *pvd, *ppvd;
3474 	uint64_t guid, sguid, pguid, ppguid;
3475 
3476 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3477 
3478 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
3479 		pvd = vd->vdev_parent;
3480 		ppvd = pvd->vdev_parent;
3481 		guid = vd->vdev_guid;
3482 		pguid = pvd->vdev_guid;
3483 		ppguid = ppvd->vdev_guid;
3484 		sguid = 0;
3485 		/*
3486 		 * If we have just finished replacing a hot spared device, then
3487 		 * we need to detach the parent's first child (the original hot
3488 		 * spare) as well.
3489 		 */
3490 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0) {
3491 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
3492 			ASSERT(ppvd->vdev_children == 2);
3493 			sguid = ppvd->vdev_child[1]->vdev_guid;
3494 		}
3495 		spa_config_exit(spa, SCL_ALL, FTAG);
3496 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
3497 			return;
3498 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
3499 			return;
3500 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3501 	}
3502 
3503 	spa_config_exit(spa, SCL_ALL, FTAG);
3504 }
3505 
3506 /*
3507  * Update the stored path or FRU for this vdev.  Dirty the vdev configuration,
3508  * relying on spa_vdev_enter/exit() to synchronize the labels and cache.
3509  */
3510 int
3511 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
3512     boolean_t ispath)
3513 {
3514 	vdev_t *vd;
3515 	uint64_t txg;
3516 
3517 	txg = spa_vdev_enter(spa);
3518 
3519 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
3520 		return (spa_vdev_exit(spa, NULL, txg, ENOENT));
3521 
3522 	if (!vd->vdev_ops->vdev_op_leaf)
3523 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
3524 
3525 	if (ispath) {
3526 		spa_strfree(vd->vdev_path);
3527 		vd->vdev_path = spa_strdup(value);
3528 	} else {
3529 		if (vd->vdev_fru != NULL)
3530 			spa_strfree(vd->vdev_fru);
3531 		vd->vdev_fru = spa_strdup(value);
3532 	}
3533 
3534 	vdev_config_dirty(vd->vdev_top);
3535 
3536 	return (spa_vdev_exit(spa, NULL, txg, 0));
3537 }
3538 
3539 int
3540 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
3541 {
3542 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
3543 }
3544 
3545 int
3546 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
3547 {
3548 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
3549 }
3550 
3551 /*
3552  * ==========================================================================
3553  * SPA Scrubbing
3554  * ==========================================================================
3555  */
3556 
3557 int
3558 spa_scrub(spa_t *spa, pool_scrub_type_t type)
3559 {
3560 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
3561 
3562 	if ((uint_t)type >= POOL_SCRUB_TYPES)
3563 		return (ENOTSUP);
3564 
3565 	/*
3566 	 * If a resilver was requested, but there is no DTL on a
3567 	 * writeable leaf device, we have nothing to do.
3568 	 */
3569 	if (type == POOL_SCRUB_RESILVER &&
3570 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
3571 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
3572 		return (0);
3573 	}
3574 
3575 	if (type == POOL_SCRUB_EVERYTHING &&
3576 	    spa->spa_dsl_pool->dp_scrub_func != SCRUB_FUNC_NONE &&
3577 	    spa->spa_dsl_pool->dp_scrub_isresilver)
3578 		return (EBUSY);
3579 
3580 	if (type == POOL_SCRUB_EVERYTHING || type == POOL_SCRUB_RESILVER) {
3581 		return (dsl_pool_scrub_clean(spa->spa_dsl_pool));
3582 	} else if (type == POOL_SCRUB_NONE) {
3583 		return (dsl_pool_scrub_cancel(spa->spa_dsl_pool));
3584 	} else {
3585 		return (EINVAL);
3586 	}
3587 }
3588 
3589 /*
3590  * ==========================================================================
3591  * SPA async task processing
3592  * ==========================================================================
3593  */
3594 
3595 static void
3596 spa_async_remove(spa_t *spa, vdev_t *vd)
3597 {
3598 	if (vd->vdev_remove_wanted) {
3599 		vd->vdev_remove_wanted = 0;
3600 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
3601 		vdev_clear(spa, vd);
3602 		vdev_state_dirty(vd->vdev_top);
3603 	}
3604 
3605 	for (int c = 0; c < vd->vdev_children; c++)
3606 		spa_async_remove(spa, vd->vdev_child[c]);
3607 }
3608 
3609 static void
3610 spa_async_probe(spa_t *spa, vdev_t *vd)
3611 {
3612 	if (vd->vdev_probe_wanted) {
3613 		vd->vdev_probe_wanted = 0;
3614 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
3615 	}
3616 
3617 	for (int c = 0; c < vd->vdev_children; c++)
3618 		spa_async_probe(spa, vd->vdev_child[c]);
3619 }
3620 
3621 static void
3622 spa_async_thread(spa_t *spa)
3623 {
3624 	int tasks;
3625 
3626 	ASSERT(spa->spa_sync_on);
3627 
3628 	mutex_enter(&spa->spa_async_lock);
3629 	tasks = spa->spa_async_tasks;
3630 	spa->spa_async_tasks = 0;
3631 	mutex_exit(&spa->spa_async_lock);
3632 
3633 	/*
3634 	 * See if the config needs to be updated.
3635 	 */
3636 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
3637 		mutex_enter(&spa_namespace_lock);
3638 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3639 		mutex_exit(&spa_namespace_lock);
3640 	}
3641 
3642 	/*
3643 	 * See if any devices need to be marked REMOVED.
3644 	 */
3645 	if (tasks & SPA_ASYNC_REMOVE) {
3646 		spa_vdev_state_enter(spa);
3647 		spa_async_remove(spa, spa->spa_root_vdev);
3648 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
3649 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
3650 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
3651 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
3652 		(void) spa_vdev_state_exit(spa, NULL, 0);
3653 	}
3654 
3655 	/*
3656 	 * See if any devices need to be probed.
3657 	 */
3658 	if (tasks & SPA_ASYNC_PROBE) {
3659 		spa_vdev_state_enter(spa);
3660 		spa_async_probe(spa, spa->spa_root_vdev);
3661 		(void) spa_vdev_state_exit(spa, NULL, 0);
3662 	}
3663 
3664 	/*
3665 	 * If any devices are done replacing, detach them.
3666 	 */
3667 	if (tasks & SPA_ASYNC_RESILVER_DONE)
3668 		spa_vdev_resilver_done(spa);
3669 
3670 	/*
3671 	 * Kick off a resilver.
3672 	 */
3673 	if (tasks & SPA_ASYNC_RESILVER)
3674 		VERIFY(spa_scrub(spa, POOL_SCRUB_RESILVER) == 0);
3675 
3676 	/*
3677 	 * Let the world know that we're done.
3678 	 */
3679 	mutex_enter(&spa->spa_async_lock);
3680 	spa->spa_async_thread = NULL;
3681 	cv_broadcast(&spa->spa_async_cv);
3682 	mutex_exit(&spa->spa_async_lock);
3683 	thread_exit();
3684 }
3685 
3686 void
3687 spa_async_suspend(spa_t *spa)
3688 {
3689 	mutex_enter(&spa->spa_async_lock);
3690 	spa->spa_async_suspended++;
3691 	while (spa->spa_async_thread != NULL)
3692 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
3693 	mutex_exit(&spa->spa_async_lock);
3694 }
3695 
3696 void
3697 spa_async_resume(spa_t *spa)
3698 {
3699 	mutex_enter(&spa->spa_async_lock);
3700 	ASSERT(spa->spa_async_suspended != 0);
3701 	spa->spa_async_suspended--;
3702 	mutex_exit(&spa->spa_async_lock);
3703 }
3704 
3705 static void
3706 spa_async_dispatch(spa_t *spa)
3707 {
3708 	mutex_enter(&spa->spa_async_lock);
3709 	if (spa->spa_async_tasks && !spa->spa_async_suspended &&
3710 	    spa->spa_async_thread == NULL &&
3711 	    rootdir != NULL && !vn_is_readonly(rootdir))
3712 		spa->spa_async_thread = thread_create(NULL, 0,
3713 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
3714 	mutex_exit(&spa->spa_async_lock);
3715 }
3716 
3717 void
3718 spa_async_request(spa_t *spa, int task)
3719 {
3720 	mutex_enter(&spa->spa_async_lock);
3721 	spa->spa_async_tasks |= task;
3722 	mutex_exit(&spa->spa_async_lock);
3723 }
3724 
3725 /*
3726  * ==========================================================================
3727  * SPA syncing routines
3728  * ==========================================================================
3729  */
3730 
3731 static void
3732 spa_sync_deferred_frees(spa_t *spa, uint64_t txg)
3733 {
3734 	bplist_t *bpl = &spa->spa_sync_bplist;
3735 	dmu_tx_t *tx;
3736 	blkptr_t blk;
3737 	uint64_t itor = 0;
3738 	zio_t *zio;
3739 	int error;
3740 	uint8_t c = 1;
3741 
3742 	zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
3743 
3744 	while (bplist_iterate(bpl, &itor, &blk) == 0) {
3745 		ASSERT(blk.blk_birth < txg);
3746 		zio_nowait(zio_free(zio, spa, txg, &blk, NULL, NULL,
3747 		    ZIO_FLAG_MUSTSUCCEED));
3748 	}
3749 
3750 	error = zio_wait(zio);
3751 	ASSERT3U(error, ==, 0);
3752 
3753 	tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
3754 	bplist_vacate(bpl, tx);
3755 
3756 	/*
3757 	 * Pre-dirty the first block so we sync to convergence faster.
3758 	 * (Usually only the first block is needed.)
3759 	 */
3760 	dmu_write(spa->spa_meta_objset, spa->spa_sync_bplist_obj, 0, 1, &c, tx);
3761 	dmu_tx_commit(tx);
3762 }
3763 
3764 static void
3765 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
3766 {
3767 	char *packed = NULL;
3768 	size_t bufsize;
3769 	size_t nvsize = 0;
3770 	dmu_buf_t *db;
3771 
3772 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
3773 
3774 	/*
3775 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
3776 	 * information.  This avoids the dbuf_will_dirty() path and
3777 	 * saves us a pre-read to get data we don't actually care about.
3778 	 */
3779 	bufsize = P2ROUNDUP(nvsize, SPA_CONFIG_BLOCKSIZE);
3780 	packed = kmem_alloc(bufsize, KM_SLEEP);
3781 
3782 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
3783 	    KM_SLEEP) == 0);
3784 	bzero(packed + nvsize, bufsize - nvsize);
3785 
3786 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
3787 
3788 	kmem_free(packed, bufsize);
3789 
3790 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
3791 	dmu_buf_will_dirty(db, tx);
3792 	*(uint64_t *)db->db_data = nvsize;
3793 	dmu_buf_rele(db, FTAG);
3794 }
3795 
3796 static void
3797 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
3798     const char *config, const char *entry)
3799 {
3800 	nvlist_t *nvroot;
3801 	nvlist_t **list;
3802 	int i;
3803 
3804 	if (!sav->sav_sync)
3805 		return;
3806 
3807 	/*
3808 	 * Update the MOS nvlist describing the list of available devices.
3809 	 * spa_validate_aux() will have already made sure this nvlist is
3810 	 * valid and the vdevs are labeled appropriately.
3811 	 */
3812 	if (sav->sav_object == 0) {
3813 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
3814 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
3815 		    sizeof (uint64_t), tx);
3816 		VERIFY(zap_update(spa->spa_meta_objset,
3817 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
3818 		    &sav->sav_object, tx) == 0);
3819 	}
3820 
3821 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3822 	if (sav->sav_count == 0) {
3823 		VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
3824 	} else {
3825 		list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
3826 		for (i = 0; i < sav->sav_count; i++)
3827 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
3828 			    B_FALSE, B_FALSE, B_TRUE);
3829 		VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
3830 		    sav->sav_count) == 0);
3831 		for (i = 0; i < sav->sav_count; i++)
3832 			nvlist_free(list[i]);
3833 		kmem_free(list, sav->sav_count * sizeof (void *));
3834 	}
3835 
3836 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
3837 	nvlist_free(nvroot);
3838 
3839 	sav->sav_sync = B_FALSE;
3840 }
3841 
3842 static void
3843 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
3844 {
3845 	nvlist_t *config;
3846 
3847 	if (list_is_empty(&spa->spa_config_dirty_list))
3848 		return;
3849 
3850 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
3851 
3852 	config = spa_config_generate(spa, spa->spa_root_vdev,
3853 	    dmu_tx_get_txg(tx), B_FALSE);
3854 
3855 	spa_config_exit(spa, SCL_STATE, FTAG);
3856 
3857 	if (spa->spa_config_syncing)
3858 		nvlist_free(spa->spa_config_syncing);
3859 	spa->spa_config_syncing = config;
3860 
3861 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
3862 }
3863 
3864 /*
3865  * Set zpool properties.
3866  */
3867 static void
3868 spa_sync_props(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
3869 {
3870 	spa_t *spa = arg1;
3871 	objset_t *mos = spa->spa_meta_objset;
3872 	nvlist_t *nvp = arg2;
3873 	nvpair_t *elem;
3874 	uint64_t intval;
3875 	char *strval;
3876 	zpool_prop_t prop;
3877 	const char *propname;
3878 	zprop_type_t proptype;
3879 
3880 	mutex_enter(&spa->spa_props_lock);
3881 
3882 	elem = NULL;
3883 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
3884 		switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
3885 		case ZPOOL_PROP_VERSION:
3886 			/*
3887 			 * Only set version for non-zpool-creation cases
3888 			 * (set/import). spa_create() needs special care
3889 			 * for version setting.
3890 			 */
3891 			if (tx->tx_txg != TXG_INITIAL) {
3892 				VERIFY(nvpair_value_uint64(elem,
3893 				    &intval) == 0);
3894 				ASSERT(intval <= SPA_VERSION);
3895 				ASSERT(intval >= spa_version(spa));
3896 				spa->spa_uberblock.ub_version = intval;
3897 				vdev_config_dirty(spa->spa_root_vdev);
3898 			}
3899 			break;
3900 
3901 		case ZPOOL_PROP_ALTROOT:
3902 			/*
3903 			 * 'altroot' is a non-persistent property. It should
3904 			 * have been set temporarily at creation or import time.
3905 			 */
3906 			ASSERT(spa->spa_root != NULL);
3907 			break;
3908 
3909 		case ZPOOL_PROP_CACHEFILE:
3910 			/*
3911 			 * 'cachefile' is also a non-persisitent property.
3912 			 */
3913 			break;
3914 		default:
3915 			/*
3916 			 * Set pool property values in the poolprops mos object.
3917 			 */
3918 			if (spa->spa_pool_props_object == 0) {
3919 				objset_t *mos = spa->spa_meta_objset;
3920 
3921 				VERIFY((spa->spa_pool_props_object =
3922 				    zap_create(mos, DMU_OT_POOL_PROPS,
3923 				    DMU_OT_NONE, 0, tx)) > 0);
3924 
3925 				VERIFY(zap_update(mos,
3926 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
3927 				    8, 1, &spa->spa_pool_props_object, tx)
3928 				    == 0);
3929 			}
3930 
3931 			/* normalize the property name */
3932 			propname = zpool_prop_to_name(prop);
3933 			proptype = zpool_prop_get_type(prop);
3934 
3935 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
3936 				ASSERT(proptype == PROP_TYPE_STRING);
3937 				VERIFY(nvpair_value_string(elem, &strval) == 0);
3938 				VERIFY(zap_update(mos,
3939 				    spa->spa_pool_props_object, propname,
3940 				    1, strlen(strval) + 1, strval, tx) == 0);
3941 
3942 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
3943 				VERIFY(nvpair_value_uint64(elem, &intval) == 0);
3944 
3945 				if (proptype == PROP_TYPE_INDEX) {
3946 					const char *unused;
3947 					VERIFY(zpool_prop_index_to_string(
3948 					    prop, intval, &unused) == 0);
3949 				}
3950 				VERIFY(zap_update(mos,
3951 				    spa->spa_pool_props_object, propname,
3952 				    8, 1, &intval, tx) == 0);
3953 			} else {
3954 				ASSERT(0); /* not allowed */
3955 			}
3956 
3957 			switch (prop) {
3958 			case ZPOOL_PROP_DELEGATION:
3959 				spa->spa_delegation = intval;
3960 				break;
3961 			case ZPOOL_PROP_BOOTFS:
3962 				spa->spa_bootfs = intval;
3963 				break;
3964 			case ZPOOL_PROP_FAILUREMODE:
3965 				spa->spa_failmode = intval;
3966 				break;
3967 			default:
3968 				break;
3969 			}
3970 		}
3971 
3972 		/* log internal history if this is not a zpool create */
3973 		if (spa_version(spa) >= SPA_VERSION_ZPOOL_HISTORY &&
3974 		    tx->tx_txg != TXG_INITIAL) {
3975 			spa_history_internal_log(LOG_POOL_PROPSET,
3976 			    spa, tx, cr, "%s %lld %s",
3977 			    nvpair_name(elem), intval, spa_name(spa));
3978 		}
3979 	}
3980 
3981 	mutex_exit(&spa->spa_props_lock);
3982 }
3983 
3984 /*
3985  * Sync the specified transaction group.  New blocks may be dirtied as
3986  * part of the process, so we iterate until it converges.
3987  */
3988 void
3989 spa_sync(spa_t *spa, uint64_t txg)
3990 {
3991 	dsl_pool_t *dp = spa->spa_dsl_pool;
3992 	objset_t *mos = spa->spa_meta_objset;
3993 	bplist_t *bpl = &spa->spa_sync_bplist;
3994 	vdev_t *rvd = spa->spa_root_vdev;
3995 	vdev_t *vd;
3996 	dmu_tx_t *tx;
3997 	int dirty_vdevs;
3998 	int error;
3999 
4000 	/*
4001 	 * Lock out configuration changes.
4002 	 */
4003 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4004 
4005 	spa->spa_syncing_txg = txg;
4006 	spa->spa_sync_pass = 0;
4007 
4008 	/*
4009 	 * If there are any pending vdev state changes, convert them
4010 	 * into config changes that go out with this transaction group.
4011 	 */
4012 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
4013 	while (list_head(&spa->spa_state_dirty_list) != NULL) {
4014 		/*
4015 		 * We need the write lock here because, for aux vdevs,
4016 		 * calling vdev_config_dirty() modifies sav_config.
4017 		 * This is ugly and will become unnecessary when we
4018 		 * eliminate the aux vdev wart by integrating all vdevs
4019 		 * into the root vdev tree.
4020 		 */
4021 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
4022 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
4023 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
4024 			vdev_state_clean(vd);
4025 			vdev_config_dirty(vd);
4026 		}
4027 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
4028 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
4029 	}
4030 	spa_config_exit(spa, SCL_STATE, FTAG);
4031 
4032 	VERIFY(0 == bplist_open(bpl, mos, spa->spa_sync_bplist_obj));
4033 
4034 	tx = dmu_tx_create_assigned(dp, txg);
4035 
4036 	/*
4037 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
4038 	 * set spa_deflate if we have no raid-z vdevs.
4039 	 */
4040 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
4041 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
4042 		int i;
4043 
4044 		for (i = 0; i < rvd->vdev_children; i++) {
4045 			vd = rvd->vdev_child[i];
4046 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
4047 				break;
4048 		}
4049 		if (i == rvd->vdev_children) {
4050 			spa->spa_deflate = TRUE;
4051 			VERIFY(0 == zap_add(spa->spa_meta_objset,
4052 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
4053 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
4054 		}
4055 	}
4056 
4057 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
4058 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
4059 		dsl_pool_create_origin(dp, tx);
4060 
4061 		/* Keeping the origin open increases spa_minref */
4062 		spa->spa_minref += 3;
4063 	}
4064 
4065 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
4066 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
4067 		dsl_pool_upgrade_clones(dp, tx);
4068 	}
4069 
4070 	/*
4071 	 * If anything has changed in this txg, push the deferred frees
4072 	 * from the previous txg.  If not, leave them alone so that we
4073 	 * don't generate work on an otherwise idle system.
4074 	 */
4075 	if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
4076 	    !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
4077 	    !txg_list_empty(&dp->dp_sync_tasks, txg))
4078 		spa_sync_deferred_frees(spa, txg);
4079 
4080 	/*
4081 	 * Iterate to convergence.
4082 	 */
4083 	do {
4084 		spa->spa_sync_pass++;
4085 
4086 		spa_sync_config_object(spa, tx);
4087 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
4088 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
4089 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
4090 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
4091 		spa_errlog_sync(spa, txg);
4092 		dsl_pool_sync(dp, txg);
4093 
4094 		dirty_vdevs = 0;
4095 		while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg)) {
4096 			vdev_sync(vd, txg);
4097 			dirty_vdevs++;
4098 		}
4099 
4100 		bplist_sync(bpl, tx);
4101 	} while (dirty_vdevs);
4102 
4103 	bplist_close(bpl);
4104 
4105 	dprintf("txg %llu passes %d\n", txg, spa->spa_sync_pass);
4106 
4107 	/*
4108 	 * Rewrite the vdev configuration (which includes the uberblock)
4109 	 * to commit the transaction group.
4110 	 *
4111 	 * If there are no dirty vdevs, we sync the uberblock to a few
4112 	 * random top-level vdevs that are known to be visible in the
4113 	 * config cache (see spa_vdev_add() for a complete description).
4114 	 * If there *are* dirty vdevs, sync the uberblock to all vdevs.
4115 	 */
4116 	for (;;) {
4117 		/*
4118 		 * We hold SCL_STATE to prevent vdev open/close/etc.
4119 		 * while we're attempting to write the vdev labels.
4120 		 */
4121 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
4122 
4123 		if (list_is_empty(&spa->spa_config_dirty_list)) {
4124 			vdev_t *svd[SPA_DVAS_PER_BP];
4125 			int svdcount = 0;
4126 			int children = rvd->vdev_children;
4127 			int c0 = spa_get_random(children);
4128 			int c;
4129 
4130 			for (c = 0; c < children; c++) {
4131 				vd = rvd->vdev_child[(c0 + c) % children];
4132 				if (vd->vdev_ms_array == 0 || vd->vdev_islog)
4133 					continue;
4134 				svd[svdcount++] = vd;
4135 				if (svdcount == SPA_DVAS_PER_BP)
4136 					break;
4137 			}
4138 			error = vdev_config_sync(svd, svdcount, txg);
4139 		} else {
4140 			error = vdev_config_sync(rvd->vdev_child,
4141 			    rvd->vdev_children, txg);
4142 		}
4143 
4144 		spa_config_exit(spa, SCL_STATE, FTAG);
4145 
4146 		if (error == 0)
4147 			break;
4148 		zio_suspend(spa, NULL);
4149 		zio_resume_wait(spa);
4150 	}
4151 	dmu_tx_commit(tx);
4152 
4153 	/*
4154 	 * Clear the dirty config list.
4155 	 */
4156 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
4157 		vdev_config_clean(vd);
4158 
4159 	/*
4160 	 * Now that the new config has synced transactionally,
4161 	 * let it become visible to the config cache.
4162 	 */
4163 	if (spa->spa_config_syncing != NULL) {
4164 		spa_config_set(spa, spa->spa_config_syncing);
4165 		spa->spa_config_txg = txg;
4166 		spa->spa_config_syncing = NULL;
4167 	}
4168 
4169 	spa->spa_ubsync = spa->spa_uberblock;
4170 
4171 	/*
4172 	 * Clean up the ZIL records for the synced txg.
4173 	 */
4174 	dsl_pool_zil_clean(dp);
4175 
4176 	/*
4177 	 * Update usable space statistics.
4178 	 */
4179 	while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
4180 		vdev_sync_done(vd, txg);
4181 
4182 	/*
4183 	 * It had better be the case that we didn't dirty anything
4184 	 * since vdev_config_sync().
4185 	 */
4186 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
4187 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
4188 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
4189 	ASSERT(bpl->bpl_queue == NULL);
4190 
4191 	spa_config_exit(spa, SCL_CONFIG, FTAG);
4192 
4193 	/*
4194 	 * If any async tasks have been requested, kick them off.
4195 	 */
4196 	spa_async_dispatch(spa);
4197 }
4198 
4199 /*
4200  * Sync all pools.  We don't want to hold the namespace lock across these
4201  * operations, so we take a reference on the spa_t and drop the lock during the
4202  * sync.
4203  */
4204 void
4205 spa_sync_allpools(void)
4206 {
4207 	spa_t *spa = NULL;
4208 	mutex_enter(&spa_namespace_lock);
4209 	while ((spa = spa_next(spa)) != NULL) {
4210 		if (spa_state(spa) != POOL_STATE_ACTIVE || spa_suspended(spa))
4211 			continue;
4212 		spa_open_ref(spa, FTAG);
4213 		mutex_exit(&spa_namespace_lock);
4214 		txg_wait_synced(spa_get_dsl(spa), 0);
4215 		mutex_enter(&spa_namespace_lock);
4216 		spa_close(spa, FTAG);
4217 	}
4218 	mutex_exit(&spa_namespace_lock);
4219 }
4220 
4221 /*
4222  * ==========================================================================
4223  * Miscellaneous routines
4224  * ==========================================================================
4225  */
4226 
4227 /*
4228  * Remove all pools in the system.
4229  */
4230 void
4231 spa_evict_all(void)
4232 {
4233 	spa_t *spa;
4234 
4235 	/*
4236 	 * Remove all cached state.  All pools should be closed now,
4237 	 * so every spa in the AVL tree should be unreferenced.
4238 	 */
4239 	mutex_enter(&spa_namespace_lock);
4240 	while ((spa = spa_next(NULL)) != NULL) {
4241 		/*
4242 		 * Stop async tasks.  The async thread may need to detach
4243 		 * a device that's been replaced, which requires grabbing
4244 		 * spa_namespace_lock, so we must drop it here.
4245 		 */
4246 		spa_open_ref(spa, FTAG);
4247 		mutex_exit(&spa_namespace_lock);
4248 		spa_async_suspend(spa);
4249 		mutex_enter(&spa_namespace_lock);
4250 		spa_close(spa, FTAG);
4251 
4252 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4253 			spa_unload(spa);
4254 			spa_deactivate(spa);
4255 		}
4256 		spa_remove(spa);
4257 	}
4258 	mutex_exit(&spa_namespace_lock);
4259 }
4260 
4261 vdev_t *
4262 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
4263 {
4264 	vdev_t *vd;
4265 	int i;
4266 
4267 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
4268 		return (vd);
4269 
4270 	if (aux) {
4271 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
4272 			vd = spa->spa_l2cache.sav_vdevs[i];
4273 			if (vd->vdev_guid == guid)
4274 				return (vd);
4275 		}
4276 
4277 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
4278 			vd = spa->spa_spares.sav_vdevs[i];
4279 			if (vd->vdev_guid == guid)
4280 				return (vd);
4281 		}
4282 	}
4283 
4284 	return (NULL);
4285 }
4286 
4287 void
4288 spa_upgrade(spa_t *spa, uint64_t version)
4289 {
4290 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4291 
4292 	/*
4293 	 * This should only be called for a non-faulted pool, and since a
4294 	 * future version would result in an unopenable pool, this shouldn't be
4295 	 * possible.
4296 	 */
4297 	ASSERT(spa->spa_uberblock.ub_version <= SPA_VERSION);
4298 	ASSERT(version >= spa->spa_uberblock.ub_version);
4299 
4300 	spa->spa_uberblock.ub_version = version;
4301 	vdev_config_dirty(spa->spa_root_vdev);
4302 
4303 	spa_config_exit(spa, SCL_ALL, FTAG);
4304 
4305 	txg_wait_synced(spa_get_dsl(spa), 0);
4306 }
4307 
4308 boolean_t
4309 spa_has_spare(spa_t *spa, uint64_t guid)
4310 {
4311 	int i;
4312 	uint64_t spareguid;
4313 	spa_aux_vdev_t *sav = &spa->spa_spares;
4314 
4315 	for (i = 0; i < sav->sav_count; i++)
4316 		if (sav->sav_vdevs[i]->vdev_guid == guid)
4317 			return (B_TRUE);
4318 
4319 	for (i = 0; i < sav->sav_npending; i++) {
4320 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
4321 		    &spareguid) == 0 && spareguid == guid)
4322 			return (B_TRUE);
4323 	}
4324 
4325 	return (B_FALSE);
4326 }
4327 
4328 /*
4329  * Check if a pool has an active shared spare device.
4330  * Note: reference count of an active spare is 2, as a spare and as a replace
4331  */
4332 static boolean_t
4333 spa_has_active_shared_spare(spa_t *spa)
4334 {
4335 	int i, refcnt;
4336 	uint64_t pool;
4337 	spa_aux_vdev_t *sav = &spa->spa_spares;
4338 
4339 	for (i = 0; i < sav->sav_count; i++) {
4340 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
4341 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
4342 		    refcnt > 2)
4343 			return (B_TRUE);
4344 	}
4345 
4346 	return (B_FALSE);
4347 }
4348 
4349 /*
4350  * Post a sysevent corresponding to the given event.  The 'name' must be one of
4351  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
4352  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
4353  * in the userland libzpool, as we don't want consumers to misinterpret ztest
4354  * or zdb as real changes.
4355  */
4356 void
4357 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
4358 {
4359 #ifdef _KERNEL
4360 	sysevent_t		*ev;
4361 	sysevent_attr_list_t	*attr = NULL;
4362 	sysevent_value_t	value;
4363 	sysevent_id_t		eid;
4364 
4365 	ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
4366 	    SE_SLEEP);
4367 
4368 	value.value_type = SE_DATA_TYPE_STRING;
4369 	value.value.sv_string = spa_name(spa);
4370 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
4371 		goto done;
4372 
4373 	value.value_type = SE_DATA_TYPE_UINT64;
4374 	value.value.sv_uint64 = spa_guid(spa);
4375 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
4376 		goto done;
4377 
4378 	if (vd) {
4379 		value.value_type = SE_DATA_TYPE_UINT64;
4380 		value.value.sv_uint64 = vd->vdev_guid;
4381 		if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
4382 		    SE_SLEEP) != 0)
4383 			goto done;
4384 
4385 		if (vd->vdev_path) {
4386 			value.value_type = SE_DATA_TYPE_STRING;
4387 			value.value.sv_string = vd->vdev_path;
4388 			if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
4389 			    &value, SE_SLEEP) != 0)
4390 				goto done;
4391 		}
4392 	}
4393 
4394 	if (sysevent_attach_attributes(ev, attr) != 0)
4395 		goto done;
4396 	attr = NULL;
4397 
4398 	(void) log_sysevent(ev, SE_SLEEP, &eid);
4399 
4400 done:
4401 	if (attr)
4402 		sysevent_free_attr(attr);
4403 	sysevent_free(ev);
4404 #endif
4405 }
4406