xref: /illumos-gate/usr/src/uts/common/fs/zfs/spa.c (revision 43466aae47bfcd2ad9bf501faec8e75c08095e4f)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright (c) 2013 by Delphix. All rights reserved.
25  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
26  */
27 
28 /*
29  * SPA: Storage Pool Allocator
30  *
31  * This file contains all the routines used when modifying on-disk SPA state.
32  * This includes opening, importing, destroying, exporting a pool, and syncing a
33  * pool.
34  */
35 
36 #include <sys/zfs_context.h>
37 #include <sys/fm/fs/zfs.h>
38 #include <sys/spa_impl.h>
39 #include <sys/zio.h>
40 #include <sys/zio_checksum.h>
41 #include <sys/dmu.h>
42 #include <sys/dmu_tx.h>
43 #include <sys/zap.h>
44 #include <sys/zil.h>
45 #include <sys/ddt.h>
46 #include <sys/vdev_impl.h>
47 #include <sys/metaslab.h>
48 #include <sys/metaslab_impl.h>
49 #include <sys/uberblock_impl.h>
50 #include <sys/txg.h>
51 #include <sys/avl.h>
52 #include <sys/dmu_traverse.h>
53 #include <sys/dmu_objset.h>
54 #include <sys/unique.h>
55 #include <sys/dsl_pool.h>
56 #include <sys/dsl_dataset.h>
57 #include <sys/dsl_dir.h>
58 #include <sys/dsl_prop.h>
59 #include <sys/dsl_synctask.h>
60 #include <sys/fs/zfs.h>
61 #include <sys/arc.h>
62 #include <sys/callb.h>
63 #include <sys/systeminfo.h>
64 #include <sys/spa_boot.h>
65 #include <sys/zfs_ioctl.h>
66 #include <sys/dsl_scan.h>
67 #include <sys/zfeature.h>
68 #include <sys/dsl_destroy.h>
69 
70 #ifdef	_KERNEL
71 #include <sys/bootprops.h>
72 #include <sys/callb.h>
73 #include <sys/cpupart.h>
74 #include <sys/pool.h>
75 #include <sys/sysdc.h>
76 #include <sys/zone.h>
77 #endif	/* _KERNEL */
78 
79 #include "zfs_prop.h"
80 #include "zfs_comutil.h"
81 
82 /*
83  * The interval, in seconds, at which failed configuration cache file writes
84  * should be retried.
85  */
86 static int zfs_ccw_retry_interval = 300;
87 
88 typedef enum zti_modes {
89 	ZTI_MODE_FIXED,			/* value is # of threads (min 1) */
90 	ZTI_MODE_BATCH,			/* cpu-intensive; value is ignored */
91 	ZTI_MODE_NULL,			/* don't create a taskq */
92 	ZTI_NMODES
93 } zti_modes_t;
94 
95 #define	ZTI_P(n, q)	{ ZTI_MODE_FIXED, (n), (q) }
96 #define	ZTI_BATCH	{ ZTI_MODE_BATCH, 0, 1 }
97 #define	ZTI_NULL	{ ZTI_MODE_NULL, 0, 0 }
98 
99 #define	ZTI_N(n)	ZTI_P(n, 1)
100 #define	ZTI_ONE		ZTI_N(1)
101 
102 typedef struct zio_taskq_info {
103 	zti_modes_t zti_mode;
104 	uint_t zti_value;
105 	uint_t zti_count;
106 } zio_taskq_info_t;
107 
108 static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
109 	"issue", "issue_high", "intr", "intr_high"
110 };
111 
112 /*
113  * This table defines the taskq settings for each ZFS I/O type. When
114  * initializing a pool, we use this table to create an appropriately sized
115  * taskq. Some operations are low volume and therefore have a small, static
116  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
117  * macros. Other operations process a large amount of data; the ZTI_BATCH
118  * macro causes us to create a taskq oriented for throughput. Some operations
119  * are so high frequency and short-lived that the taskq itself can become a a
120  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
121  * additional degree of parallelism specified by the number of threads per-
122  * taskq and the number of taskqs; when dispatching an event in this case, the
123  * particular taskq is chosen at random.
124  *
125  * The different taskq priorities are to handle the different contexts (issue
126  * and interrupt) and then to reserve threads for ZIO_PRIORITY_NOW I/Os that
127  * need to be handled with minimum delay.
128  */
129 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
130 	/* ISSUE	ISSUE_HIGH	INTR		INTR_HIGH */
131 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* NULL */
132 	{ ZTI_N(8),	ZTI_NULL,	ZTI_BATCH,	ZTI_NULL }, /* READ */
133 	{ ZTI_BATCH,	ZTI_N(5),	ZTI_N(8),	ZTI_N(5) }, /* WRITE */
134 	{ ZTI_P(12, 8),	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* FREE */
135 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* CLAIM */
136 	{ ZTI_ONE,	ZTI_NULL,	ZTI_ONE,	ZTI_NULL }, /* IOCTL */
137 };
138 
139 static void spa_sync_version(void *arg, dmu_tx_t *tx);
140 static void spa_sync_props(void *arg, dmu_tx_t *tx);
141 static boolean_t spa_has_active_shared_spare(spa_t *spa);
142 static int spa_load_impl(spa_t *spa, uint64_t, nvlist_t *config,
143     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
144     char **ereport);
145 static void spa_vdev_resilver_done(spa_t *spa);
146 
147 uint_t		zio_taskq_batch_pct = 75;	/* 1 thread per cpu in pset */
148 id_t		zio_taskq_psrset_bind = PS_NONE;
149 boolean_t	zio_taskq_sysdc = B_TRUE;	/* use SDC scheduling class */
150 uint_t		zio_taskq_basedc = 80;		/* base duty cycle */
151 
152 boolean_t	spa_create_process = B_TRUE;	/* no process ==> no sysdc */
153 extern int	zfs_sync_pass_deferred_free;
154 
155 /*
156  * This (illegal) pool name is used when temporarily importing a spa_t in order
157  * to get the vdev stats associated with the imported devices.
158  */
159 #define	TRYIMPORT_NAME	"$import"
160 
161 /*
162  * ==========================================================================
163  * SPA properties routines
164  * ==========================================================================
165  */
166 
167 /*
168  * Add a (source=src, propname=propval) list to an nvlist.
169  */
170 static void
171 spa_prop_add_list(nvlist_t *nvl, zpool_prop_t prop, char *strval,
172     uint64_t intval, zprop_source_t src)
173 {
174 	const char *propname = zpool_prop_to_name(prop);
175 	nvlist_t *propval;
176 
177 	VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
178 	VERIFY(nvlist_add_uint64(propval, ZPROP_SOURCE, src) == 0);
179 
180 	if (strval != NULL)
181 		VERIFY(nvlist_add_string(propval, ZPROP_VALUE, strval) == 0);
182 	else
183 		VERIFY(nvlist_add_uint64(propval, ZPROP_VALUE, intval) == 0);
184 
185 	VERIFY(nvlist_add_nvlist(nvl, propname, propval) == 0);
186 	nvlist_free(propval);
187 }
188 
189 /*
190  * Get property values from the spa configuration.
191  */
192 static void
193 spa_prop_get_config(spa_t *spa, nvlist_t **nvp)
194 {
195 	vdev_t *rvd = spa->spa_root_vdev;
196 	dsl_pool_t *pool = spa->spa_dsl_pool;
197 	uint64_t size;
198 	uint64_t alloc;
199 	uint64_t space;
200 	uint64_t cap, version;
201 	zprop_source_t src = ZPROP_SRC_NONE;
202 	spa_config_dirent_t *dp;
203 
204 	ASSERT(MUTEX_HELD(&spa->spa_props_lock));
205 
206 	if (rvd != NULL) {
207 		alloc = metaslab_class_get_alloc(spa_normal_class(spa));
208 		size = metaslab_class_get_space(spa_normal_class(spa));
209 		spa_prop_add_list(*nvp, ZPOOL_PROP_NAME, spa_name(spa), 0, src);
210 		spa_prop_add_list(*nvp, ZPOOL_PROP_SIZE, NULL, size, src);
211 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALLOCATED, NULL, alloc, src);
212 		spa_prop_add_list(*nvp, ZPOOL_PROP_FREE, NULL,
213 		    size - alloc, src);
214 
215 		space = 0;
216 		for (int c = 0; c < rvd->vdev_children; c++) {
217 			vdev_t *tvd = rvd->vdev_child[c];
218 			space += tvd->vdev_max_asize - tvd->vdev_asize;
219 		}
220 		spa_prop_add_list(*nvp, ZPOOL_PROP_EXPANDSZ, NULL, space,
221 		    src);
222 
223 		spa_prop_add_list(*nvp, ZPOOL_PROP_READONLY, NULL,
224 		    (spa_mode(spa) == FREAD), src);
225 
226 		cap = (size == 0) ? 0 : (alloc * 100 / size);
227 		spa_prop_add_list(*nvp, ZPOOL_PROP_CAPACITY, NULL, cap, src);
228 
229 		spa_prop_add_list(*nvp, ZPOOL_PROP_DEDUPRATIO, NULL,
230 		    ddt_get_pool_dedup_ratio(spa), src);
231 
232 		spa_prop_add_list(*nvp, ZPOOL_PROP_HEALTH, NULL,
233 		    rvd->vdev_state, src);
234 
235 		version = spa_version(spa);
236 		if (version == zpool_prop_default_numeric(ZPOOL_PROP_VERSION))
237 			src = ZPROP_SRC_DEFAULT;
238 		else
239 			src = ZPROP_SRC_LOCAL;
240 		spa_prop_add_list(*nvp, ZPOOL_PROP_VERSION, NULL, version, src);
241 	}
242 
243 	if (pool != NULL) {
244 		dsl_dir_t *freedir = pool->dp_free_dir;
245 
246 		/*
247 		 * The $FREE directory was introduced in SPA_VERSION_DEADLISTS,
248 		 * when opening pools before this version freedir will be NULL.
249 		 */
250 		if (freedir != NULL) {
251 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING, NULL,
252 			    freedir->dd_phys->dd_used_bytes, src);
253 		} else {
254 			spa_prop_add_list(*nvp, ZPOOL_PROP_FREEING,
255 			    NULL, 0, src);
256 		}
257 	}
258 
259 	spa_prop_add_list(*nvp, ZPOOL_PROP_GUID, NULL, spa_guid(spa), src);
260 
261 	if (spa->spa_comment != NULL) {
262 		spa_prop_add_list(*nvp, ZPOOL_PROP_COMMENT, spa->spa_comment,
263 		    0, ZPROP_SRC_LOCAL);
264 	}
265 
266 	if (spa->spa_root != NULL)
267 		spa_prop_add_list(*nvp, ZPOOL_PROP_ALTROOT, spa->spa_root,
268 		    0, ZPROP_SRC_LOCAL);
269 
270 	if ((dp = list_head(&spa->spa_config_list)) != NULL) {
271 		if (dp->scd_path == NULL) {
272 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
273 			    "none", 0, ZPROP_SRC_LOCAL);
274 		} else if (strcmp(dp->scd_path, spa_config_path) != 0) {
275 			spa_prop_add_list(*nvp, ZPOOL_PROP_CACHEFILE,
276 			    dp->scd_path, 0, ZPROP_SRC_LOCAL);
277 		}
278 	}
279 }
280 
281 /*
282  * Get zpool property values.
283  */
284 int
285 spa_prop_get(spa_t *spa, nvlist_t **nvp)
286 {
287 	objset_t *mos = spa->spa_meta_objset;
288 	zap_cursor_t zc;
289 	zap_attribute_t za;
290 	int err;
291 
292 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
293 
294 	mutex_enter(&spa->spa_props_lock);
295 
296 	/*
297 	 * Get properties from the spa config.
298 	 */
299 	spa_prop_get_config(spa, nvp);
300 
301 	/* If no pool property object, no more prop to get. */
302 	if (mos == NULL || spa->spa_pool_props_object == 0) {
303 		mutex_exit(&spa->spa_props_lock);
304 		return (0);
305 	}
306 
307 	/*
308 	 * Get properties from the MOS pool property object.
309 	 */
310 	for (zap_cursor_init(&zc, mos, spa->spa_pool_props_object);
311 	    (err = zap_cursor_retrieve(&zc, &za)) == 0;
312 	    zap_cursor_advance(&zc)) {
313 		uint64_t intval = 0;
314 		char *strval = NULL;
315 		zprop_source_t src = ZPROP_SRC_DEFAULT;
316 		zpool_prop_t prop;
317 
318 		if ((prop = zpool_name_to_prop(za.za_name)) == ZPROP_INVAL)
319 			continue;
320 
321 		switch (za.za_integer_length) {
322 		case 8:
323 			/* integer property */
324 			if (za.za_first_integer !=
325 			    zpool_prop_default_numeric(prop))
326 				src = ZPROP_SRC_LOCAL;
327 
328 			if (prop == ZPOOL_PROP_BOOTFS) {
329 				dsl_pool_t *dp;
330 				dsl_dataset_t *ds = NULL;
331 
332 				dp = spa_get_dsl(spa);
333 				dsl_pool_config_enter(dp, FTAG);
334 				if (err = dsl_dataset_hold_obj(dp,
335 				    za.za_first_integer, FTAG, &ds)) {
336 					dsl_pool_config_exit(dp, FTAG);
337 					break;
338 				}
339 
340 				strval = kmem_alloc(
341 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1,
342 				    KM_SLEEP);
343 				dsl_dataset_name(ds, strval);
344 				dsl_dataset_rele(ds, FTAG);
345 				dsl_pool_config_exit(dp, FTAG);
346 			} else {
347 				strval = NULL;
348 				intval = za.za_first_integer;
349 			}
350 
351 			spa_prop_add_list(*nvp, prop, strval, intval, src);
352 
353 			if (strval != NULL)
354 				kmem_free(strval,
355 				    MAXNAMELEN + strlen(MOS_DIR_NAME) + 1);
356 
357 			break;
358 
359 		case 1:
360 			/* string property */
361 			strval = kmem_alloc(za.za_num_integers, KM_SLEEP);
362 			err = zap_lookup(mos, spa->spa_pool_props_object,
363 			    za.za_name, 1, za.za_num_integers, strval);
364 			if (err) {
365 				kmem_free(strval, za.za_num_integers);
366 				break;
367 			}
368 			spa_prop_add_list(*nvp, prop, strval, 0, src);
369 			kmem_free(strval, za.za_num_integers);
370 			break;
371 
372 		default:
373 			break;
374 		}
375 	}
376 	zap_cursor_fini(&zc);
377 	mutex_exit(&spa->spa_props_lock);
378 out:
379 	if (err && err != ENOENT) {
380 		nvlist_free(*nvp);
381 		*nvp = NULL;
382 		return (err);
383 	}
384 
385 	return (0);
386 }
387 
388 /*
389  * Validate the given pool properties nvlist and modify the list
390  * for the property values to be set.
391  */
392 static int
393 spa_prop_validate(spa_t *spa, nvlist_t *props)
394 {
395 	nvpair_t *elem;
396 	int error = 0, reset_bootfs = 0;
397 	uint64_t objnum = 0;
398 	boolean_t has_feature = B_FALSE;
399 
400 	elem = NULL;
401 	while ((elem = nvlist_next_nvpair(props, elem)) != NULL) {
402 		uint64_t intval;
403 		char *strval, *slash, *check, *fname;
404 		const char *propname = nvpair_name(elem);
405 		zpool_prop_t prop = zpool_name_to_prop(propname);
406 
407 		switch (prop) {
408 		case ZPROP_INVAL:
409 			if (!zpool_prop_feature(propname)) {
410 				error = SET_ERROR(EINVAL);
411 				break;
412 			}
413 
414 			/*
415 			 * Sanitize the input.
416 			 */
417 			if (nvpair_type(elem) != DATA_TYPE_UINT64) {
418 				error = SET_ERROR(EINVAL);
419 				break;
420 			}
421 
422 			if (nvpair_value_uint64(elem, &intval) != 0) {
423 				error = SET_ERROR(EINVAL);
424 				break;
425 			}
426 
427 			if (intval != 0) {
428 				error = SET_ERROR(EINVAL);
429 				break;
430 			}
431 
432 			fname = strchr(propname, '@') + 1;
433 			if (zfeature_lookup_name(fname, NULL) != 0) {
434 				error = SET_ERROR(EINVAL);
435 				break;
436 			}
437 
438 			has_feature = B_TRUE;
439 			break;
440 
441 		case ZPOOL_PROP_VERSION:
442 			error = nvpair_value_uint64(elem, &intval);
443 			if (!error &&
444 			    (intval < spa_version(spa) ||
445 			    intval > SPA_VERSION_BEFORE_FEATURES ||
446 			    has_feature))
447 				error = SET_ERROR(EINVAL);
448 			break;
449 
450 		case ZPOOL_PROP_DELEGATION:
451 		case ZPOOL_PROP_AUTOREPLACE:
452 		case ZPOOL_PROP_LISTSNAPS:
453 		case ZPOOL_PROP_AUTOEXPAND:
454 			error = nvpair_value_uint64(elem, &intval);
455 			if (!error && intval > 1)
456 				error = SET_ERROR(EINVAL);
457 			break;
458 
459 		case ZPOOL_PROP_BOOTFS:
460 			/*
461 			 * If the pool version is less than SPA_VERSION_BOOTFS,
462 			 * or the pool is still being created (version == 0),
463 			 * the bootfs property cannot be set.
464 			 */
465 			if (spa_version(spa) < SPA_VERSION_BOOTFS) {
466 				error = SET_ERROR(ENOTSUP);
467 				break;
468 			}
469 
470 			/*
471 			 * Make sure the vdev config is bootable
472 			 */
473 			if (!vdev_is_bootable(spa->spa_root_vdev)) {
474 				error = SET_ERROR(ENOTSUP);
475 				break;
476 			}
477 
478 			reset_bootfs = 1;
479 
480 			error = nvpair_value_string(elem, &strval);
481 
482 			if (!error) {
483 				objset_t *os;
484 				uint64_t compress;
485 
486 				if (strval == NULL || strval[0] == '\0') {
487 					objnum = zpool_prop_default_numeric(
488 					    ZPOOL_PROP_BOOTFS);
489 					break;
490 				}
491 
492 				if (error = dmu_objset_hold(strval, FTAG, &os))
493 					break;
494 
495 				/* Must be ZPL and not gzip compressed. */
496 
497 				if (dmu_objset_type(os) != DMU_OST_ZFS) {
498 					error = SET_ERROR(ENOTSUP);
499 				} else if ((error =
500 				    dsl_prop_get_int_ds(dmu_objset_ds(os),
501 				    zfs_prop_to_name(ZFS_PROP_COMPRESSION),
502 				    &compress)) == 0 &&
503 				    !BOOTFS_COMPRESS_VALID(compress)) {
504 					error = SET_ERROR(ENOTSUP);
505 				} else {
506 					objnum = dmu_objset_id(os);
507 				}
508 				dmu_objset_rele(os, FTAG);
509 			}
510 			break;
511 
512 		case ZPOOL_PROP_FAILUREMODE:
513 			error = nvpair_value_uint64(elem, &intval);
514 			if (!error && (intval < ZIO_FAILURE_MODE_WAIT ||
515 			    intval > ZIO_FAILURE_MODE_PANIC))
516 				error = SET_ERROR(EINVAL);
517 
518 			/*
519 			 * This is a special case which only occurs when
520 			 * the pool has completely failed. This allows
521 			 * the user to change the in-core failmode property
522 			 * without syncing it out to disk (I/Os might
523 			 * currently be blocked). We do this by returning
524 			 * EIO to the caller (spa_prop_set) to trick it
525 			 * into thinking we encountered a property validation
526 			 * error.
527 			 */
528 			if (!error && spa_suspended(spa)) {
529 				spa->spa_failmode = intval;
530 				error = SET_ERROR(EIO);
531 			}
532 			break;
533 
534 		case ZPOOL_PROP_CACHEFILE:
535 			if ((error = nvpair_value_string(elem, &strval)) != 0)
536 				break;
537 
538 			if (strval[0] == '\0')
539 				break;
540 
541 			if (strcmp(strval, "none") == 0)
542 				break;
543 
544 			if (strval[0] != '/') {
545 				error = SET_ERROR(EINVAL);
546 				break;
547 			}
548 
549 			slash = strrchr(strval, '/');
550 			ASSERT(slash != NULL);
551 
552 			if (slash[1] == '\0' || strcmp(slash, "/.") == 0 ||
553 			    strcmp(slash, "/..") == 0)
554 				error = SET_ERROR(EINVAL);
555 			break;
556 
557 		case ZPOOL_PROP_COMMENT:
558 			if ((error = nvpair_value_string(elem, &strval)) != 0)
559 				break;
560 			for (check = strval; *check != '\0'; check++) {
561 				/*
562 				 * The kernel doesn't have an easy isprint()
563 				 * check.  For this kernel check, we merely
564 				 * check ASCII apart from DEL.  Fix this if
565 				 * there is an easy-to-use kernel isprint().
566 				 */
567 				if (*check >= 0x7f) {
568 					error = SET_ERROR(EINVAL);
569 					break;
570 				}
571 				check++;
572 			}
573 			if (strlen(strval) > ZPROP_MAX_COMMENT)
574 				error = E2BIG;
575 			break;
576 
577 		case ZPOOL_PROP_DEDUPDITTO:
578 			if (spa_version(spa) < SPA_VERSION_DEDUP)
579 				error = SET_ERROR(ENOTSUP);
580 			else
581 				error = nvpair_value_uint64(elem, &intval);
582 			if (error == 0 &&
583 			    intval != 0 && intval < ZIO_DEDUPDITTO_MIN)
584 				error = SET_ERROR(EINVAL);
585 			break;
586 		}
587 
588 		if (error)
589 			break;
590 	}
591 
592 	if (!error && reset_bootfs) {
593 		error = nvlist_remove(props,
594 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), DATA_TYPE_STRING);
595 
596 		if (!error) {
597 			error = nvlist_add_uint64(props,
598 			    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), objnum);
599 		}
600 	}
601 
602 	return (error);
603 }
604 
605 void
606 spa_configfile_set(spa_t *spa, nvlist_t *nvp, boolean_t need_sync)
607 {
608 	char *cachefile;
609 	spa_config_dirent_t *dp;
610 
611 	if (nvlist_lookup_string(nvp, zpool_prop_to_name(ZPOOL_PROP_CACHEFILE),
612 	    &cachefile) != 0)
613 		return;
614 
615 	dp = kmem_alloc(sizeof (spa_config_dirent_t),
616 	    KM_SLEEP);
617 
618 	if (cachefile[0] == '\0')
619 		dp->scd_path = spa_strdup(spa_config_path);
620 	else if (strcmp(cachefile, "none") == 0)
621 		dp->scd_path = NULL;
622 	else
623 		dp->scd_path = spa_strdup(cachefile);
624 
625 	list_insert_head(&spa->spa_config_list, dp);
626 	if (need_sync)
627 		spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
628 }
629 
630 int
631 spa_prop_set(spa_t *spa, nvlist_t *nvp)
632 {
633 	int error;
634 	nvpair_t *elem = NULL;
635 	boolean_t need_sync = B_FALSE;
636 
637 	if ((error = spa_prop_validate(spa, nvp)) != 0)
638 		return (error);
639 
640 	while ((elem = nvlist_next_nvpair(nvp, elem)) != NULL) {
641 		zpool_prop_t prop = zpool_name_to_prop(nvpair_name(elem));
642 
643 		if (prop == ZPOOL_PROP_CACHEFILE ||
644 		    prop == ZPOOL_PROP_ALTROOT ||
645 		    prop == ZPOOL_PROP_READONLY)
646 			continue;
647 
648 		if (prop == ZPOOL_PROP_VERSION || prop == ZPROP_INVAL) {
649 			uint64_t ver;
650 
651 			if (prop == ZPOOL_PROP_VERSION) {
652 				VERIFY(nvpair_value_uint64(elem, &ver) == 0);
653 			} else {
654 				ASSERT(zpool_prop_feature(nvpair_name(elem)));
655 				ver = SPA_VERSION_FEATURES;
656 				need_sync = B_TRUE;
657 			}
658 
659 			/* Save time if the version is already set. */
660 			if (ver == spa_version(spa))
661 				continue;
662 
663 			/*
664 			 * In addition to the pool directory object, we might
665 			 * create the pool properties object, the features for
666 			 * read object, the features for write object, or the
667 			 * feature descriptions object.
668 			 */
669 			error = dsl_sync_task(spa->spa_name, NULL,
670 			    spa_sync_version, &ver, 6);
671 			if (error)
672 				return (error);
673 			continue;
674 		}
675 
676 		need_sync = B_TRUE;
677 		break;
678 	}
679 
680 	if (need_sync) {
681 		return (dsl_sync_task(spa->spa_name, NULL, spa_sync_props,
682 		    nvp, 6));
683 	}
684 
685 	return (0);
686 }
687 
688 /*
689  * If the bootfs property value is dsobj, clear it.
690  */
691 void
692 spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
693 {
694 	if (spa->spa_bootfs == dsobj && spa->spa_pool_props_object != 0) {
695 		VERIFY(zap_remove(spa->spa_meta_objset,
696 		    spa->spa_pool_props_object,
697 		    zpool_prop_to_name(ZPOOL_PROP_BOOTFS), tx) == 0);
698 		spa->spa_bootfs = 0;
699 	}
700 }
701 
702 /*ARGSUSED*/
703 static int
704 spa_change_guid_check(void *arg, dmu_tx_t *tx)
705 {
706 	uint64_t *newguid = arg;
707 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
708 	vdev_t *rvd = spa->spa_root_vdev;
709 	uint64_t vdev_state;
710 
711 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
712 	vdev_state = rvd->vdev_state;
713 	spa_config_exit(spa, SCL_STATE, FTAG);
714 
715 	if (vdev_state != VDEV_STATE_HEALTHY)
716 		return (SET_ERROR(ENXIO));
717 
718 	ASSERT3U(spa_guid(spa), !=, *newguid);
719 
720 	return (0);
721 }
722 
723 static void
724 spa_change_guid_sync(void *arg, dmu_tx_t *tx)
725 {
726 	uint64_t *newguid = arg;
727 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
728 	uint64_t oldguid;
729 	vdev_t *rvd = spa->spa_root_vdev;
730 
731 	oldguid = spa_guid(spa);
732 
733 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
734 	rvd->vdev_guid = *newguid;
735 	rvd->vdev_guid_sum += (*newguid - oldguid);
736 	vdev_config_dirty(rvd);
737 	spa_config_exit(spa, SCL_STATE, FTAG);
738 
739 	spa_history_log_internal(spa, "guid change", tx, "old=%llu new=%llu",
740 	    oldguid, *newguid);
741 }
742 
743 /*
744  * Change the GUID for the pool.  This is done so that we can later
745  * re-import a pool built from a clone of our own vdevs.  We will modify
746  * the root vdev's guid, our own pool guid, and then mark all of our
747  * vdevs dirty.  Note that we must make sure that all our vdevs are
748  * online when we do this, or else any vdevs that weren't present
749  * would be orphaned from our pool.  We are also going to issue a
750  * sysevent to update any watchers.
751  */
752 int
753 spa_change_guid(spa_t *spa)
754 {
755 	int error;
756 	uint64_t guid;
757 
758 	mutex_enter(&spa->spa_vdev_top_lock);
759 	mutex_enter(&spa_namespace_lock);
760 	guid = spa_generate_guid(NULL);
761 
762 	error = dsl_sync_task(spa->spa_name, spa_change_guid_check,
763 	    spa_change_guid_sync, &guid, 5);
764 
765 	if (error == 0) {
766 		spa_config_sync(spa, B_FALSE, B_TRUE);
767 		spa_event_notify(spa, NULL, ESC_ZFS_POOL_REGUID);
768 	}
769 
770 	mutex_exit(&spa_namespace_lock);
771 	mutex_exit(&spa->spa_vdev_top_lock);
772 
773 	return (error);
774 }
775 
776 /*
777  * ==========================================================================
778  * SPA state manipulation (open/create/destroy/import/export)
779  * ==========================================================================
780  */
781 
782 static int
783 spa_error_entry_compare(const void *a, const void *b)
784 {
785 	spa_error_entry_t *sa = (spa_error_entry_t *)a;
786 	spa_error_entry_t *sb = (spa_error_entry_t *)b;
787 	int ret;
788 
789 	ret = bcmp(&sa->se_bookmark, &sb->se_bookmark,
790 	    sizeof (zbookmark_t));
791 
792 	if (ret < 0)
793 		return (-1);
794 	else if (ret > 0)
795 		return (1);
796 	else
797 		return (0);
798 }
799 
800 /*
801  * Utility function which retrieves copies of the current logs and
802  * re-initializes them in the process.
803  */
804 void
805 spa_get_errlists(spa_t *spa, avl_tree_t *last, avl_tree_t *scrub)
806 {
807 	ASSERT(MUTEX_HELD(&spa->spa_errlist_lock));
808 
809 	bcopy(&spa->spa_errlist_last, last, sizeof (avl_tree_t));
810 	bcopy(&spa->spa_errlist_scrub, scrub, sizeof (avl_tree_t));
811 
812 	avl_create(&spa->spa_errlist_scrub,
813 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
814 	    offsetof(spa_error_entry_t, se_avl));
815 	avl_create(&spa->spa_errlist_last,
816 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
817 	    offsetof(spa_error_entry_t, se_avl));
818 }
819 
820 static void
821 spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
822 {
823 	const zio_taskq_info_t *ztip = &zio_taskqs[t][q];
824 	enum zti_modes mode = ztip->zti_mode;
825 	uint_t value = ztip->zti_value;
826 	uint_t count = ztip->zti_count;
827 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
828 	char name[32];
829 	uint_t flags = 0;
830 	boolean_t batch = B_FALSE;
831 
832 	if (mode == ZTI_MODE_NULL) {
833 		tqs->stqs_count = 0;
834 		tqs->stqs_taskq = NULL;
835 		return;
836 	}
837 
838 	ASSERT3U(count, >, 0);
839 
840 	tqs->stqs_count = count;
841 	tqs->stqs_taskq = kmem_alloc(count * sizeof (taskq_t *), KM_SLEEP);
842 
843 	switch (mode) {
844 	case ZTI_MODE_FIXED:
845 		ASSERT3U(value, >=, 1);
846 		value = MAX(value, 1);
847 		break;
848 
849 	case ZTI_MODE_BATCH:
850 		batch = B_TRUE;
851 		flags |= TASKQ_THREADS_CPU_PCT;
852 		value = zio_taskq_batch_pct;
853 		break;
854 
855 	default:
856 		panic("unrecognized mode for %s_%s taskq (%u:%u) in "
857 		    "spa_activate()",
858 		    zio_type_name[t], zio_taskq_types[q], mode, value);
859 		break;
860 	}
861 
862 	for (uint_t i = 0; i < count; i++) {
863 		taskq_t *tq;
864 
865 		if (count > 1) {
866 			(void) snprintf(name, sizeof (name), "%s_%s_%u",
867 			    zio_type_name[t], zio_taskq_types[q], i);
868 		} else {
869 			(void) snprintf(name, sizeof (name), "%s_%s",
870 			    zio_type_name[t], zio_taskq_types[q]);
871 		}
872 
873 		if (zio_taskq_sysdc && spa->spa_proc != &p0) {
874 			if (batch)
875 				flags |= TASKQ_DC_BATCH;
876 
877 			tq = taskq_create_sysdc(name, value, 50, INT_MAX,
878 			    spa->spa_proc, zio_taskq_basedc, flags);
879 		} else {
880 			pri_t pri = maxclsyspri;
881 			/*
882 			 * The write issue taskq can be extremely CPU
883 			 * intensive.  Run it at slightly lower priority
884 			 * than the other taskqs.
885 			 */
886 			if (t == ZIO_TYPE_WRITE && q == ZIO_TASKQ_ISSUE)
887 				pri--;
888 
889 			tq = taskq_create_proc(name, value, pri, 50,
890 			    INT_MAX, spa->spa_proc, flags);
891 		}
892 
893 		tqs->stqs_taskq[i] = tq;
894 	}
895 }
896 
897 static void
898 spa_taskqs_fini(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
899 {
900 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
901 
902 	if (tqs->stqs_taskq == NULL) {
903 		ASSERT0(tqs->stqs_count);
904 		return;
905 	}
906 
907 	for (uint_t i = 0; i < tqs->stqs_count; i++) {
908 		ASSERT3P(tqs->stqs_taskq[i], !=, NULL);
909 		taskq_destroy(tqs->stqs_taskq[i]);
910 	}
911 
912 	kmem_free(tqs->stqs_taskq, tqs->stqs_count * sizeof (taskq_t *));
913 	tqs->stqs_taskq = NULL;
914 }
915 
916 /*
917  * Dispatch a task to the appropriate taskq for the ZFS I/O type and priority.
918  * Note that a type may have multiple discrete taskqs to avoid lock contention
919  * on the taskq itself. In that case we choose which taskq at random by using
920  * the low bits of gethrtime().
921  */
922 void
923 spa_taskq_dispatch_ent(spa_t *spa, zio_type_t t, zio_taskq_type_t q,
924     task_func_t *func, void *arg, uint_t flags, taskq_ent_t *ent)
925 {
926 	spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
927 	taskq_t *tq;
928 
929 	ASSERT3P(tqs->stqs_taskq, !=, NULL);
930 	ASSERT3U(tqs->stqs_count, !=, 0);
931 
932 	if (tqs->stqs_count == 1) {
933 		tq = tqs->stqs_taskq[0];
934 	} else {
935 		tq = tqs->stqs_taskq[gethrtime() % tqs->stqs_count];
936 	}
937 
938 	taskq_dispatch_ent(tq, func, arg, flags, ent);
939 }
940 
941 static void
942 spa_create_zio_taskqs(spa_t *spa)
943 {
944 	for (int t = 0; t < ZIO_TYPES; t++) {
945 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
946 			spa_taskqs_init(spa, t, q);
947 		}
948 	}
949 }
950 
951 #ifdef _KERNEL
952 static void
953 spa_thread(void *arg)
954 {
955 	callb_cpr_t cprinfo;
956 
957 	spa_t *spa = arg;
958 	user_t *pu = PTOU(curproc);
959 
960 	CALLB_CPR_INIT(&cprinfo, &spa->spa_proc_lock, callb_generic_cpr,
961 	    spa->spa_name);
962 
963 	ASSERT(curproc != &p0);
964 	(void) snprintf(pu->u_psargs, sizeof (pu->u_psargs),
965 	    "zpool-%s", spa->spa_name);
966 	(void) strlcpy(pu->u_comm, pu->u_psargs, sizeof (pu->u_comm));
967 
968 	/* bind this thread to the requested psrset */
969 	if (zio_taskq_psrset_bind != PS_NONE) {
970 		pool_lock();
971 		mutex_enter(&cpu_lock);
972 		mutex_enter(&pidlock);
973 		mutex_enter(&curproc->p_lock);
974 
975 		if (cpupart_bind_thread(curthread, zio_taskq_psrset_bind,
976 		    0, NULL, NULL) == 0)  {
977 			curthread->t_bind_pset = zio_taskq_psrset_bind;
978 		} else {
979 			cmn_err(CE_WARN,
980 			    "Couldn't bind process for zfs pool \"%s\" to "
981 			    "pset %d\n", spa->spa_name, zio_taskq_psrset_bind);
982 		}
983 
984 		mutex_exit(&curproc->p_lock);
985 		mutex_exit(&pidlock);
986 		mutex_exit(&cpu_lock);
987 		pool_unlock();
988 	}
989 
990 	if (zio_taskq_sysdc) {
991 		sysdc_thread_enter(curthread, 100, 0);
992 	}
993 
994 	spa->spa_proc = curproc;
995 	spa->spa_did = curthread->t_did;
996 
997 	spa_create_zio_taskqs(spa);
998 
999 	mutex_enter(&spa->spa_proc_lock);
1000 	ASSERT(spa->spa_proc_state == SPA_PROC_CREATED);
1001 
1002 	spa->spa_proc_state = SPA_PROC_ACTIVE;
1003 	cv_broadcast(&spa->spa_proc_cv);
1004 
1005 	CALLB_CPR_SAFE_BEGIN(&cprinfo);
1006 	while (spa->spa_proc_state == SPA_PROC_ACTIVE)
1007 		cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1008 	CALLB_CPR_SAFE_END(&cprinfo, &spa->spa_proc_lock);
1009 
1010 	ASSERT(spa->spa_proc_state == SPA_PROC_DEACTIVATE);
1011 	spa->spa_proc_state = SPA_PROC_GONE;
1012 	spa->spa_proc = &p0;
1013 	cv_broadcast(&spa->spa_proc_cv);
1014 	CALLB_CPR_EXIT(&cprinfo);	/* drops spa_proc_lock */
1015 
1016 	mutex_enter(&curproc->p_lock);
1017 	lwp_exit();
1018 }
1019 #endif
1020 
1021 /*
1022  * Activate an uninitialized pool.
1023  */
1024 static void
1025 spa_activate(spa_t *spa, int mode)
1026 {
1027 	ASSERT(spa->spa_state == POOL_STATE_UNINITIALIZED);
1028 
1029 	spa->spa_state = POOL_STATE_ACTIVE;
1030 	spa->spa_mode = mode;
1031 
1032 	spa->spa_normal_class = metaslab_class_create(spa, zfs_metaslab_ops);
1033 	spa->spa_log_class = metaslab_class_create(spa, zfs_metaslab_ops);
1034 
1035 	/* Try to create a covering process */
1036 	mutex_enter(&spa->spa_proc_lock);
1037 	ASSERT(spa->spa_proc_state == SPA_PROC_NONE);
1038 	ASSERT(spa->spa_proc == &p0);
1039 	spa->spa_did = 0;
1040 
1041 	/* Only create a process if we're going to be around a while. */
1042 	if (spa_create_process && strcmp(spa->spa_name, TRYIMPORT_NAME) != 0) {
1043 		if (newproc(spa_thread, (caddr_t)spa, syscid, maxclsyspri,
1044 		    NULL, 0) == 0) {
1045 			spa->spa_proc_state = SPA_PROC_CREATED;
1046 			while (spa->spa_proc_state == SPA_PROC_CREATED) {
1047 				cv_wait(&spa->spa_proc_cv,
1048 				    &spa->spa_proc_lock);
1049 			}
1050 			ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1051 			ASSERT(spa->spa_proc != &p0);
1052 			ASSERT(spa->spa_did != 0);
1053 		} else {
1054 #ifdef _KERNEL
1055 			cmn_err(CE_WARN,
1056 			    "Couldn't create process for zfs pool \"%s\"\n",
1057 			    spa->spa_name);
1058 #endif
1059 		}
1060 	}
1061 	mutex_exit(&spa->spa_proc_lock);
1062 
1063 	/* If we didn't create a process, we need to create our taskqs. */
1064 	if (spa->spa_proc == &p0) {
1065 		spa_create_zio_taskqs(spa);
1066 	}
1067 
1068 	list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
1069 	    offsetof(vdev_t, vdev_config_dirty_node));
1070 	list_create(&spa->spa_state_dirty_list, sizeof (vdev_t),
1071 	    offsetof(vdev_t, vdev_state_dirty_node));
1072 
1073 	txg_list_create(&spa->spa_vdev_txg_list,
1074 	    offsetof(struct vdev, vdev_txg_node));
1075 
1076 	avl_create(&spa->spa_errlist_scrub,
1077 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1078 	    offsetof(spa_error_entry_t, se_avl));
1079 	avl_create(&spa->spa_errlist_last,
1080 	    spa_error_entry_compare, sizeof (spa_error_entry_t),
1081 	    offsetof(spa_error_entry_t, se_avl));
1082 }
1083 
1084 /*
1085  * Opposite of spa_activate().
1086  */
1087 static void
1088 spa_deactivate(spa_t *spa)
1089 {
1090 	ASSERT(spa->spa_sync_on == B_FALSE);
1091 	ASSERT(spa->spa_dsl_pool == NULL);
1092 	ASSERT(spa->spa_root_vdev == NULL);
1093 	ASSERT(spa->spa_async_zio_root == NULL);
1094 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
1095 
1096 	txg_list_destroy(&spa->spa_vdev_txg_list);
1097 
1098 	list_destroy(&spa->spa_config_dirty_list);
1099 	list_destroy(&spa->spa_state_dirty_list);
1100 
1101 	for (int t = 0; t < ZIO_TYPES; t++) {
1102 		for (int q = 0; q < ZIO_TASKQ_TYPES; q++) {
1103 			spa_taskqs_fini(spa, t, q);
1104 		}
1105 	}
1106 
1107 	metaslab_class_destroy(spa->spa_normal_class);
1108 	spa->spa_normal_class = NULL;
1109 
1110 	metaslab_class_destroy(spa->spa_log_class);
1111 	spa->spa_log_class = NULL;
1112 
1113 	/*
1114 	 * If this was part of an import or the open otherwise failed, we may
1115 	 * still have errors left in the queues.  Empty them just in case.
1116 	 */
1117 	spa_errlog_drain(spa);
1118 
1119 	avl_destroy(&spa->spa_errlist_scrub);
1120 	avl_destroy(&spa->spa_errlist_last);
1121 
1122 	spa->spa_state = POOL_STATE_UNINITIALIZED;
1123 
1124 	mutex_enter(&spa->spa_proc_lock);
1125 	if (spa->spa_proc_state != SPA_PROC_NONE) {
1126 		ASSERT(spa->spa_proc_state == SPA_PROC_ACTIVE);
1127 		spa->spa_proc_state = SPA_PROC_DEACTIVATE;
1128 		cv_broadcast(&spa->spa_proc_cv);
1129 		while (spa->spa_proc_state == SPA_PROC_DEACTIVATE) {
1130 			ASSERT(spa->spa_proc != &p0);
1131 			cv_wait(&spa->spa_proc_cv, &spa->spa_proc_lock);
1132 		}
1133 		ASSERT(spa->spa_proc_state == SPA_PROC_GONE);
1134 		spa->spa_proc_state = SPA_PROC_NONE;
1135 	}
1136 	ASSERT(spa->spa_proc == &p0);
1137 	mutex_exit(&spa->spa_proc_lock);
1138 
1139 	/*
1140 	 * We want to make sure spa_thread() has actually exited the ZFS
1141 	 * module, so that the module can't be unloaded out from underneath
1142 	 * it.
1143 	 */
1144 	if (spa->spa_did != 0) {
1145 		thread_join(spa->spa_did);
1146 		spa->spa_did = 0;
1147 	}
1148 }
1149 
1150 /*
1151  * Verify a pool configuration, and construct the vdev tree appropriately.  This
1152  * will create all the necessary vdevs in the appropriate layout, with each vdev
1153  * in the CLOSED state.  This will prep the pool before open/creation/import.
1154  * All vdev validation is done by the vdev_alloc() routine.
1155  */
1156 static int
1157 spa_config_parse(spa_t *spa, vdev_t **vdp, nvlist_t *nv, vdev_t *parent,
1158     uint_t id, int atype)
1159 {
1160 	nvlist_t **child;
1161 	uint_t children;
1162 	int error;
1163 
1164 	if ((error = vdev_alloc(spa, vdp, nv, parent, id, atype)) != 0)
1165 		return (error);
1166 
1167 	if ((*vdp)->vdev_ops->vdev_op_leaf)
1168 		return (0);
1169 
1170 	error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN,
1171 	    &child, &children);
1172 
1173 	if (error == ENOENT)
1174 		return (0);
1175 
1176 	if (error) {
1177 		vdev_free(*vdp);
1178 		*vdp = NULL;
1179 		return (SET_ERROR(EINVAL));
1180 	}
1181 
1182 	for (int c = 0; c < children; c++) {
1183 		vdev_t *vd;
1184 		if ((error = spa_config_parse(spa, &vd, child[c], *vdp, c,
1185 		    atype)) != 0) {
1186 			vdev_free(*vdp);
1187 			*vdp = NULL;
1188 			return (error);
1189 		}
1190 	}
1191 
1192 	ASSERT(*vdp != NULL);
1193 
1194 	return (0);
1195 }
1196 
1197 /*
1198  * Opposite of spa_load().
1199  */
1200 static void
1201 spa_unload(spa_t *spa)
1202 {
1203 	int i;
1204 
1205 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
1206 
1207 	/*
1208 	 * Stop async tasks.
1209 	 */
1210 	spa_async_suspend(spa);
1211 
1212 	/*
1213 	 * Stop syncing.
1214 	 */
1215 	if (spa->spa_sync_on) {
1216 		txg_sync_stop(spa->spa_dsl_pool);
1217 		spa->spa_sync_on = B_FALSE;
1218 	}
1219 
1220 	/*
1221 	 * Wait for any outstanding async I/O to complete.
1222 	 */
1223 	if (spa->spa_async_zio_root != NULL) {
1224 		(void) zio_wait(spa->spa_async_zio_root);
1225 		spa->spa_async_zio_root = NULL;
1226 	}
1227 
1228 	bpobj_close(&spa->spa_deferred_bpobj);
1229 
1230 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1231 
1232 	/*
1233 	 * Close all vdevs.
1234 	 */
1235 	if (spa->spa_root_vdev)
1236 		vdev_free(spa->spa_root_vdev);
1237 	ASSERT(spa->spa_root_vdev == NULL);
1238 
1239 	/*
1240 	 * Close the dsl pool.
1241 	 */
1242 	if (spa->spa_dsl_pool) {
1243 		dsl_pool_close(spa->spa_dsl_pool);
1244 		spa->spa_dsl_pool = NULL;
1245 		spa->spa_meta_objset = NULL;
1246 	}
1247 
1248 	ddt_unload(spa);
1249 
1250 
1251 	/*
1252 	 * Drop and purge level 2 cache
1253 	 */
1254 	spa_l2cache_drop(spa);
1255 
1256 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1257 		vdev_free(spa->spa_spares.sav_vdevs[i]);
1258 	if (spa->spa_spares.sav_vdevs) {
1259 		kmem_free(spa->spa_spares.sav_vdevs,
1260 		    spa->spa_spares.sav_count * sizeof (void *));
1261 		spa->spa_spares.sav_vdevs = NULL;
1262 	}
1263 	if (spa->spa_spares.sav_config) {
1264 		nvlist_free(spa->spa_spares.sav_config);
1265 		spa->spa_spares.sav_config = NULL;
1266 	}
1267 	spa->spa_spares.sav_count = 0;
1268 
1269 	for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
1270 		vdev_clear_stats(spa->spa_l2cache.sav_vdevs[i]);
1271 		vdev_free(spa->spa_l2cache.sav_vdevs[i]);
1272 	}
1273 	if (spa->spa_l2cache.sav_vdevs) {
1274 		kmem_free(spa->spa_l2cache.sav_vdevs,
1275 		    spa->spa_l2cache.sav_count * sizeof (void *));
1276 		spa->spa_l2cache.sav_vdevs = NULL;
1277 	}
1278 	if (spa->spa_l2cache.sav_config) {
1279 		nvlist_free(spa->spa_l2cache.sav_config);
1280 		spa->spa_l2cache.sav_config = NULL;
1281 	}
1282 	spa->spa_l2cache.sav_count = 0;
1283 
1284 	spa->spa_async_suspended = 0;
1285 
1286 	if (spa->spa_comment != NULL) {
1287 		spa_strfree(spa->spa_comment);
1288 		spa->spa_comment = NULL;
1289 	}
1290 
1291 	spa_config_exit(spa, SCL_ALL, FTAG);
1292 }
1293 
1294 /*
1295  * Load (or re-load) the current list of vdevs describing the active spares for
1296  * this pool.  When this is called, we have some form of basic information in
1297  * 'spa_spares.sav_config'.  We parse this into vdevs, try to open them, and
1298  * then re-generate a more complete list including status information.
1299  */
1300 static void
1301 spa_load_spares(spa_t *spa)
1302 {
1303 	nvlist_t **spares;
1304 	uint_t nspares;
1305 	int i;
1306 	vdev_t *vd, *tvd;
1307 
1308 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1309 
1310 	/*
1311 	 * First, close and free any existing spare vdevs.
1312 	 */
1313 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1314 		vd = spa->spa_spares.sav_vdevs[i];
1315 
1316 		/* Undo the call to spa_activate() below */
1317 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1318 		    B_FALSE)) != NULL && tvd->vdev_isspare)
1319 			spa_spare_remove(tvd);
1320 		vdev_close(vd);
1321 		vdev_free(vd);
1322 	}
1323 
1324 	if (spa->spa_spares.sav_vdevs)
1325 		kmem_free(spa->spa_spares.sav_vdevs,
1326 		    spa->spa_spares.sav_count * sizeof (void *));
1327 
1328 	if (spa->spa_spares.sav_config == NULL)
1329 		nspares = 0;
1330 	else
1331 		VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
1332 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
1333 
1334 	spa->spa_spares.sav_count = (int)nspares;
1335 	spa->spa_spares.sav_vdevs = NULL;
1336 
1337 	if (nspares == 0)
1338 		return;
1339 
1340 	/*
1341 	 * Construct the array of vdevs, opening them to get status in the
1342 	 * process.   For each spare, there is potentially two different vdev_t
1343 	 * structures associated with it: one in the list of spares (used only
1344 	 * for basic validation purposes) and one in the active vdev
1345 	 * configuration (if it's spared in).  During this phase we open and
1346 	 * validate each vdev on the spare list.  If the vdev also exists in the
1347 	 * active configuration, then we also mark this vdev as an active spare.
1348 	 */
1349 	spa->spa_spares.sav_vdevs = kmem_alloc(nspares * sizeof (void *),
1350 	    KM_SLEEP);
1351 	for (i = 0; i < spa->spa_spares.sav_count; i++) {
1352 		VERIFY(spa_config_parse(spa, &vd, spares[i], NULL, 0,
1353 		    VDEV_ALLOC_SPARE) == 0);
1354 		ASSERT(vd != NULL);
1355 
1356 		spa->spa_spares.sav_vdevs[i] = vd;
1357 
1358 		if ((tvd = spa_lookup_by_guid(spa, vd->vdev_guid,
1359 		    B_FALSE)) != NULL) {
1360 			if (!tvd->vdev_isspare)
1361 				spa_spare_add(tvd);
1362 
1363 			/*
1364 			 * We only mark the spare active if we were successfully
1365 			 * able to load the vdev.  Otherwise, importing a pool
1366 			 * with a bad active spare would result in strange
1367 			 * behavior, because multiple pool would think the spare
1368 			 * is actively in use.
1369 			 *
1370 			 * There is a vulnerability here to an equally bizarre
1371 			 * circumstance, where a dead active spare is later
1372 			 * brought back to life (onlined or otherwise).  Given
1373 			 * the rarity of this scenario, and the extra complexity
1374 			 * it adds, we ignore the possibility.
1375 			 */
1376 			if (!vdev_is_dead(tvd))
1377 				spa_spare_activate(tvd);
1378 		}
1379 
1380 		vd->vdev_top = vd;
1381 		vd->vdev_aux = &spa->spa_spares;
1382 
1383 		if (vdev_open(vd) != 0)
1384 			continue;
1385 
1386 		if (vdev_validate_aux(vd) == 0)
1387 			spa_spare_add(vd);
1388 	}
1389 
1390 	/*
1391 	 * Recompute the stashed list of spares, with status information
1392 	 * this time.
1393 	 */
1394 	VERIFY(nvlist_remove(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES,
1395 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1396 
1397 	spares = kmem_alloc(spa->spa_spares.sav_count * sizeof (void *),
1398 	    KM_SLEEP);
1399 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1400 		spares[i] = vdev_config_generate(spa,
1401 		    spa->spa_spares.sav_vdevs[i], B_TRUE, VDEV_CONFIG_SPARE);
1402 	VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
1403 	    ZPOOL_CONFIG_SPARES, spares, spa->spa_spares.sav_count) == 0);
1404 	for (i = 0; i < spa->spa_spares.sav_count; i++)
1405 		nvlist_free(spares[i]);
1406 	kmem_free(spares, spa->spa_spares.sav_count * sizeof (void *));
1407 }
1408 
1409 /*
1410  * Load (or re-load) the current list of vdevs describing the active l2cache for
1411  * this pool.  When this is called, we have some form of basic information in
1412  * 'spa_l2cache.sav_config'.  We parse this into vdevs, try to open them, and
1413  * then re-generate a more complete list including status information.
1414  * Devices which are already active have their details maintained, and are
1415  * not re-opened.
1416  */
1417 static void
1418 spa_load_l2cache(spa_t *spa)
1419 {
1420 	nvlist_t **l2cache;
1421 	uint_t nl2cache;
1422 	int i, j, oldnvdevs;
1423 	uint64_t guid;
1424 	vdev_t *vd, **oldvdevs, **newvdevs;
1425 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
1426 
1427 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
1428 
1429 	if (sav->sav_config != NULL) {
1430 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config,
1431 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
1432 		newvdevs = kmem_alloc(nl2cache * sizeof (void *), KM_SLEEP);
1433 	} else {
1434 		nl2cache = 0;
1435 		newvdevs = NULL;
1436 	}
1437 
1438 	oldvdevs = sav->sav_vdevs;
1439 	oldnvdevs = sav->sav_count;
1440 	sav->sav_vdevs = NULL;
1441 	sav->sav_count = 0;
1442 
1443 	/*
1444 	 * Process new nvlist of vdevs.
1445 	 */
1446 	for (i = 0; i < nl2cache; i++) {
1447 		VERIFY(nvlist_lookup_uint64(l2cache[i], ZPOOL_CONFIG_GUID,
1448 		    &guid) == 0);
1449 
1450 		newvdevs[i] = NULL;
1451 		for (j = 0; j < oldnvdevs; j++) {
1452 			vd = oldvdevs[j];
1453 			if (vd != NULL && guid == vd->vdev_guid) {
1454 				/*
1455 				 * Retain previous vdev for add/remove ops.
1456 				 */
1457 				newvdevs[i] = vd;
1458 				oldvdevs[j] = NULL;
1459 				break;
1460 			}
1461 		}
1462 
1463 		if (newvdevs[i] == NULL) {
1464 			/*
1465 			 * Create new vdev
1466 			 */
1467 			VERIFY(spa_config_parse(spa, &vd, l2cache[i], NULL, 0,
1468 			    VDEV_ALLOC_L2CACHE) == 0);
1469 			ASSERT(vd != NULL);
1470 			newvdevs[i] = vd;
1471 
1472 			/*
1473 			 * Commit this vdev as an l2cache device,
1474 			 * even if it fails to open.
1475 			 */
1476 			spa_l2cache_add(vd);
1477 
1478 			vd->vdev_top = vd;
1479 			vd->vdev_aux = sav;
1480 
1481 			spa_l2cache_activate(vd);
1482 
1483 			if (vdev_open(vd) != 0)
1484 				continue;
1485 
1486 			(void) vdev_validate_aux(vd);
1487 
1488 			if (!vdev_is_dead(vd))
1489 				l2arc_add_vdev(spa, vd);
1490 		}
1491 	}
1492 
1493 	/*
1494 	 * Purge vdevs that were dropped
1495 	 */
1496 	for (i = 0; i < oldnvdevs; i++) {
1497 		uint64_t pool;
1498 
1499 		vd = oldvdevs[i];
1500 		if (vd != NULL) {
1501 			ASSERT(vd->vdev_isl2cache);
1502 
1503 			if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
1504 			    pool != 0ULL && l2arc_vdev_present(vd))
1505 				l2arc_remove_vdev(vd);
1506 			vdev_clear_stats(vd);
1507 			vdev_free(vd);
1508 		}
1509 	}
1510 
1511 	if (oldvdevs)
1512 		kmem_free(oldvdevs, oldnvdevs * sizeof (void *));
1513 
1514 	if (sav->sav_config == NULL)
1515 		goto out;
1516 
1517 	sav->sav_vdevs = newvdevs;
1518 	sav->sav_count = (int)nl2cache;
1519 
1520 	/*
1521 	 * Recompute the stashed list of l2cache devices, with status
1522 	 * information this time.
1523 	 */
1524 	VERIFY(nvlist_remove(sav->sav_config, ZPOOL_CONFIG_L2CACHE,
1525 	    DATA_TYPE_NVLIST_ARRAY) == 0);
1526 
1527 	l2cache = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
1528 	for (i = 0; i < sav->sav_count; i++)
1529 		l2cache[i] = vdev_config_generate(spa,
1530 		    sav->sav_vdevs[i], B_TRUE, VDEV_CONFIG_L2CACHE);
1531 	VERIFY(nvlist_add_nvlist_array(sav->sav_config,
1532 	    ZPOOL_CONFIG_L2CACHE, l2cache, sav->sav_count) == 0);
1533 out:
1534 	for (i = 0; i < sav->sav_count; i++)
1535 		nvlist_free(l2cache[i]);
1536 	if (sav->sav_count)
1537 		kmem_free(l2cache, sav->sav_count * sizeof (void *));
1538 }
1539 
1540 static int
1541 load_nvlist(spa_t *spa, uint64_t obj, nvlist_t **value)
1542 {
1543 	dmu_buf_t *db;
1544 	char *packed = NULL;
1545 	size_t nvsize = 0;
1546 	int error;
1547 	*value = NULL;
1548 
1549 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
1550 	nvsize = *(uint64_t *)db->db_data;
1551 	dmu_buf_rele(db, FTAG);
1552 
1553 	packed = kmem_alloc(nvsize, KM_SLEEP);
1554 	error = dmu_read(spa->spa_meta_objset, obj, 0, nvsize, packed,
1555 	    DMU_READ_PREFETCH);
1556 	if (error == 0)
1557 		error = nvlist_unpack(packed, nvsize, value, 0);
1558 	kmem_free(packed, nvsize);
1559 
1560 	return (error);
1561 }
1562 
1563 /*
1564  * Checks to see if the given vdev could not be opened, in which case we post a
1565  * sysevent to notify the autoreplace code that the device has been removed.
1566  */
1567 static void
1568 spa_check_removed(vdev_t *vd)
1569 {
1570 	for (int c = 0; c < vd->vdev_children; c++)
1571 		spa_check_removed(vd->vdev_child[c]);
1572 
1573 	if (vd->vdev_ops->vdev_op_leaf && vdev_is_dead(vd) &&
1574 	    !vd->vdev_ishole) {
1575 		zfs_post_autoreplace(vd->vdev_spa, vd);
1576 		spa_event_notify(vd->vdev_spa, vd, ESC_ZFS_VDEV_CHECK);
1577 	}
1578 }
1579 
1580 /*
1581  * Validate the current config against the MOS config
1582  */
1583 static boolean_t
1584 spa_config_valid(spa_t *spa, nvlist_t *config)
1585 {
1586 	vdev_t *mrvd, *rvd = spa->spa_root_vdev;
1587 	nvlist_t *nv;
1588 
1589 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nv) == 0);
1590 
1591 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1592 	VERIFY(spa_config_parse(spa, &mrvd, nv, NULL, 0, VDEV_ALLOC_LOAD) == 0);
1593 
1594 	ASSERT3U(rvd->vdev_children, ==, mrvd->vdev_children);
1595 
1596 	/*
1597 	 * If we're doing a normal import, then build up any additional
1598 	 * diagnostic information about missing devices in this config.
1599 	 * We'll pass this up to the user for further processing.
1600 	 */
1601 	if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG)) {
1602 		nvlist_t **child, *nv;
1603 		uint64_t idx = 0;
1604 
1605 		child = kmem_alloc(rvd->vdev_children * sizeof (nvlist_t **),
1606 		    KM_SLEEP);
1607 		VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1608 
1609 		for (int c = 0; c < rvd->vdev_children; c++) {
1610 			vdev_t *tvd = rvd->vdev_child[c];
1611 			vdev_t *mtvd  = mrvd->vdev_child[c];
1612 
1613 			if (tvd->vdev_ops == &vdev_missing_ops &&
1614 			    mtvd->vdev_ops != &vdev_missing_ops &&
1615 			    mtvd->vdev_islog)
1616 				child[idx++] = vdev_config_generate(spa, mtvd,
1617 				    B_FALSE, 0);
1618 		}
1619 
1620 		if (idx) {
1621 			VERIFY(nvlist_add_nvlist_array(nv,
1622 			    ZPOOL_CONFIG_CHILDREN, child, idx) == 0);
1623 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
1624 			    ZPOOL_CONFIG_MISSING_DEVICES, nv) == 0);
1625 
1626 			for (int i = 0; i < idx; i++)
1627 				nvlist_free(child[i]);
1628 		}
1629 		nvlist_free(nv);
1630 		kmem_free(child, rvd->vdev_children * sizeof (char **));
1631 	}
1632 
1633 	/*
1634 	 * Compare the root vdev tree with the information we have
1635 	 * from the MOS config (mrvd). Check each top-level vdev
1636 	 * with the corresponding MOS config top-level (mtvd).
1637 	 */
1638 	for (int c = 0; c < rvd->vdev_children; c++) {
1639 		vdev_t *tvd = rvd->vdev_child[c];
1640 		vdev_t *mtvd  = mrvd->vdev_child[c];
1641 
1642 		/*
1643 		 * Resolve any "missing" vdevs in the current configuration.
1644 		 * If we find that the MOS config has more accurate information
1645 		 * about the top-level vdev then use that vdev instead.
1646 		 */
1647 		if (tvd->vdev_ops == &vdev_missing_ops &&
1648 		    mtvd->vdev_ops != &vdev_missing_ops) {
1649 
1650 			if (!(spa->spa_import_flags & ZFS_IMPORT_MISSING_LOG))
1651 				continue;
1652 
1653 			/*
1654 			 * Device specific actions.
1655 			 */
1656 			if (mtvd->vdev_islog) {
1657 				spa_set_log_state(spa, SPA_LOG_CLEAR);
1658 			} else {
1659 				/*
1660 				 * XXX - once we have 'readonly' pool
1661 				 * support we should be able to handle
1662 				 * missing data devices by transitioning
1663 				 * the pool to readonly.
1664 				 */
1665 				continue;
1666 			}
1667 
1668 			/*
1669 			 * Swap the missing vdev with the data we were
1670 			 * able to obtain from the MOS config.
1671 			 */
1672 			vdev_remove_child(rvd, tvd);
1673 			vdev_remove_child(mrvd, mtvd);
1674 
1675 			vdev_add_child(rvd, mtvd);
1676 			vdev_add_child(mrvd, tvd);
1677 
1678 			spa_config_exit(spa, SCL_ALL, FTAG);
1679 			vdev_load(mtvd);
1680 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
1681 
1682 			vdev_reopen(rvd);
1683 		} else if (mtvd->vdev_islog) {
1684 			/*
1685 			 * Load the slog device's state from the MOS config
1686 			 * since it's possible that the label does not
1687 			 * contain the most up-to-date information.
1688 			 */
1689 			vdev_load_log_state(tvd, mtvd);
1690 			vdev_reopen(tvd);
1691 		}
1692 	}
1693 	vdev_free(mrvd);
1694 	spa_config_exit(spa, SCL_ALL, FTAG);
1695 
1696 	/*
1697 	 * Ensure we were able to validate the config.
1698 	 */
1699 	return (rvd->vdev_guid_sum == spa->spa_uberblock.ub_guid_sum);
1700 }
1701 
1702 /*
1703  * Check for missing log devices
1704  */
1705 static boolean_t
1706 spa_check_logs(spa_t *spa)
1707 {
1708 	boolean_t rv = B_FALSE;
1709 
1710 	switch (spa->spa_log_state) {
1711 	case SPA_LOG_MISSING:
1712 		/* need to recheck in case slog has been restored */
1713 	case SPA_LOG_UNKNOWN:
1714 		rv = (dmu_objset_find(spa->spa_name, zil_check_log_chain,
1715 		    NULL, DS_FIND_CHILDREN) != 0);
1716 		if (rv)
1717 			spa_set_log_state(spa, SPA_LOG_MISSING);
1718 		break;
1719 	}
1720 	return (rv);
1721 }
1722 
1723 static boolean_t
1724 spa_passivate_log(spa_t *spa)
1725 {
1726 	vdev_t *rvd = spa->spa_root_vdev;
1727 	boolean_t slog_found = B_FALSE;
1728 
1729 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1730 
1731 	if (!spa_has_slogs(spa))
1732 		return (B_FALSE);
1733 
1734 	for (int c = 0; c < rvd->vdev_children; c++) {
1735 		vdev_t *tvd = rvd->vdev_child[c];
1736 		metaslab_group_t *mg = tvd->vdev_mg;
1737 
1738 		if (tvd->vdev_islog) {
1739 			metaslab_group_passivate(mg);
1740 			slog_found = B_TRUE;
1741 		}
1742 	}
1743 
1744 	return (slog_found);
1745 }
1746 
1747 static void
1748 spa_activate_log(spa_t *spa)
1749 {
1750 	vdev_t *rvd = spa->spa_root_vdev;
1751 
1752 	ASSERT(spa_config_held(spa, SCL_ALLOC, RW_WRITER));
1753 
1754 	for (int c = 0; c < rvd->vdev_children; c++) {
1755 		vdev_t *tvd = rvd->vdev_child[c];
1756 		metaslab_group_t *mg = tvd->vdev_mg;
1757 
1758 		if (tvd->vdev_islog)
1759 			metaslab_group_activate(mg);
1760 	}
1761 }
1762 
1763 int
1764 spa_offline_log(spa_t *spa)
1765 {
1766 	int error;
1767 
1768 	error = dmu_objset_find(spa_name(spa), zil_vdev_offline,
1769 	    NULL, DS_FIND_CHILDREN);
1770 	if (error == 0) {
1771 		/*
1772 		 * We successfully offlined the log device, sync out the
1773 		 * current txg so that the "stubby" block can be removed
1774 		 * by zil_sync().
1775 		 */
1776 		txg_wait_synced(spa->spa_dsl_pool, 0);
1777 	}
1778 	return (error);
1779 }
1780 
1781 static void
1782 spa_aux_check_removed(spa_aux_vdev_t *sav)
1783 {
1784 	for (int i = 0; i < sav->sav_count; i++)
1785 		spa_check_removed(sav->sav_vdevs[i]);
1786 }
1787 
1788 void
1789 spa_claim_notify(zio_t *zio)
1790 {
1791 	spa_t *spa = zio->io_spa;
1792 
1793 	if (zio->io_error)
1794 		return;
1795 
1796 	mutex_enter(&spa->spa_props_lock);	/* any mutex will do */
1797 	if (spa->spa_claim_max_txg < zio->io_bp->blk_birth)
1798 		spa->spa_claim_max_txg = zio->io_bp->blk_birth;
1799 	mutex_exit(&spa->spa_props_lock);
1800 }
1801 
1802 typedef struct spa_load_error {
1803 	uint64_t	sle_meta_count;
1804 	uint64_t	sle_data_count;
1805 } spa_load_error_t;
1806 
1807 static void
1808 spa_load_verify_done(zio_t *zio)
1809 {
1810 	blkptr_t *bp = zio->io_bp;
1811 	spa_load_error_t *sle = zio->io_private;
1812 	dmu_object_type_t type = BP_GET_TYPE(bp);
1813 	int error = zio->io_error;
1814 
1815 	if (error) {
1816 		if ((BP_GET_LEVEL(bp) != 0 || DMU_OT_IS_METADATA(type)) &&
1817 		    type != DMU_OT_INTENT_LOG)
1818 			atomic_add_64(&sle->sle_meta_count, 1);
1819 		else
1820 			atomic_add_64(&sle->sle_data_count, 1);
1821 	}
1822 	zio_data_buf_free(zio->io_data, zio->io_size);
1823 }
1824 
1825 /*ARGSUSED*/
1826 static int
1827 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1828     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1829 {
1830 	if (!BP_IS_HOLE(bp)) {
1831 		zio_t *rio = arg;
1832 		size_t size = BP_GET_PSIZE(bp);
1833 		void *data = zio_data_buf_alloc(size);
1834 
1835 		zio_nowait(zio_read(rio, spa, bp, data, size,
1836 		    spa_load_verify_done, rio->io_private, ZIO_PRIORITY_SCRUB,
1837 		    ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CANFAIL |
1838 		    ZIO_FLAG_SCRUB | ZIO_FLAG_RAW, zb));
1839 	}
1840 	return (0);
1841 }
1842 
1843 static int
1844 spa_load_verify(spa_t *spa)
1845 {
1846 	zio_t *rio;
1847 	spa_load_error_t sle = { 0 };
1848 	zpool_rewind_policy_t policy;
1849 	boolean_t verify_ok = B_FALSE;
1850 	int error;
1851 
1852 	zpool_get_rewind_policy(spa->spa_config, &policy);
1853 
1854 	if (policy.zrp_request & ZPOOL_NEVER_REWIND)
1855 		return (0);
1856 
1857 	rio = zio_root(spa, NULL, &sle,
1858 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE);
1859 
1860 	error = traverse_pool(spa, spa->spa_verify_min_txg,
1861 	    TRAVERSE_PRE | TRAVERSE_PREFETCH, spa_load_verify_cb, rio);
1862 
1863 	(void) zio_wait(rio);
1864 
1865 	spa->spa_load_meta_errors = sle.sle_meta_count;
1866 	spa->spa_load_data_errors = sle.sle_data_count;
1867 
1868 	if (!error && sle.sle_meta_count <= policy.zrp_maxmeta &&
1869 	    sle.sle_data_count <= policy.zrp_maxdata) {
1870 		int64_t loss = 0;
1871 
1872 		verify_ok = B_TRUE;
1873 		spa->spa_load_txg = spa->spa_uberblock.ub_txg;
1874 		spa->spa_load_txg_ts = spa->spa_uberblock.ub_timestamp;
1875 
1876 		loss = spa->spa_last_ubsync_txg_ts - spa->spa_load_txg_ts;
1877 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1878 		    ZPOOL_CONFIG_LOAD_TIME, spa->spa_load_txg_ts) == 0);
1879 		VERIFY(nvlist_add_int64(spa->spa_load_info,
1880 		    ZPOOL_CONFIG_REWIND_TIME, loss) == 0);
1881 		VERIFY(nvlist_add_uint64(spa->spa_load_info,
1882 		    ZPOOL_CONFIG_LOAD_DATA_ERRORS, sle.sle_data_count) == 0);
1883 	} else {
1884 		spa->spa_load_max_txg = spa->spa_uberblock.ub_txg;
1885 	}
1886 
1887 	if (error) {
1888 		if (error != ENXIO && error != EIO)
1889 			error = SET_ERROR(EIO);
1890 		return (error);
1891 	}
1892 
1893 	return (verify_ok ? 0 : EIO);
1894 }
1895 
1896 /*
1897  * Find a value in the pool props object.
1898  */
1899 static void
1900 spa_prop_find(spa_t *spa, zpool_prop_t prop, uint64_t *val)
1901 {
1902 	(void) zap_lookup(spa->spa_meta_objset, spa->spa_pool_props_object,
1903 	    zpool_prop_to_name(prop), sizeof (uint64_t), 1, val);
1904 }
1905 
1906 /*
1907  * Find a value in the pool directory object.
1908  */
1909 static int
1910 spa_dir_prop(spa_t *spa, const char *name, uint64_t *val)
1911 {
1912 	return (zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
1913 	    name, sizeof (uint64_t), 1, val));
1914 }
1915 
1916 static int
1917 spa_vdev_err(vdev_t *vdev, vdev_aux_t aux, int err)
1918 {
1919 	vdev_set_state(vdev, B_TRUE, VDEV_STATE_CANT_OPEN, aux);
1920 	return (err);
1921 }
1922 
1923 /*
1924  * Fix up config after a partly-completed split.  This is done with the
1925  * ZPOOL_CONFIG_SPLIT nvlist.  Both the splitting pool and the split-off
1926  * pool have that entry in their config, but only the splitting one contains
1927  * a list of all the guids of the vdevs that are being split off.
1928  *
1929  * This function determines what to do with that list: either rejoin
1930  * all the disks to the pool, or complete the splitting process.  To attempt
1931  * the rejoin, each disk that is offlined is marked online again, and
1932  * we do a reopen() call.  If the vdev label for every disk that was
1933  * marked online indicates it was successfully split off (VDEV_AUX_SPLIT_POOL)
1934  * then we call vdev_split() on each disk, and complete the split.
1935  *
1936  * Otherwise we leave the config alone, with all the vdevs in place in
1937  * the original pool.
1938  */
1939 static void
1940 spa_try_repair(spa_t *spa, nvlist_t *config)
1941 {
1942 	uint_t extracted;
1943 	uint64_t *glist;
1944 	uint_t i, gcount;
1945 	nvlist_t *nvl;
1946 	vdev_t **vd;
1947 	boolean_t attempt_reopen;
1948 
1949 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT, &nvl) != 0)
1950 		return;
1951 
1952 	/* check that the config is complete */
1953 	if (nvlist_lookup_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
1954 	    &glist, &gcount) != 0)
1955 		return;
1956 
1957 	vd = kmem_zalloc(gcount * sizeof (vdev_t *), KM_SLEEP);
1958 
1959 	/* attempt to online all the vdevs & validate */
1960 	attempt_reopen = B_TRUE;
1961 	for (i = 0; i < gcount; i++) {
1962 		if (glist[i] == 0)	/* vdev is hole */
1963 			continue;
1964 
1965 		vd[i] = spa_lookup_by_guid(spa, glist[i], B_FALSE);
1966 		if (vd[i] == NULL) {
1967 			/*
1968 			 * Don't bother attempting to reopen the disks;
1969 			 * just do the split.
1970 			 */
1971 			attempt_reopen = B_FALSE;
1972 		} else {
1973 			/* attempt to re-online it */
1974 			vd[i]->vdev_offline = B_FALSE;
1975 		}
1976 	}
1977 
1978 	if (attempt_reopen) {
1979 		vdev_reopen(spa->spa_root_vdev);
1980 
1981 		/* check each device to see what state it's in */
1982 		for (extracted = 0, i = 0; i < gcount; i++) {
1983 			if (vd[i] != NULL &&
1984 			    vd[i]->vdev_stat.vs_aux != VDEV_AUX_SPLIT_POOL)
1985 				break;
1986 			++extracted;
1987 		}
1988 	}
1989 
1990 	/*
1991 	 * If every disk has been moved to the new pool, or if we never
1992 	 * even attempted to look at them, then we split them off for
1993 	 * good.
1994 	 */
1995 	if (!attempt_reopen || gcount == extracted) {
1996 		for (i = 0; i < gcount; i++)
1997 			if (vd[i] != NULL)
1998 				vdev_split(vd[i]);
1999 		vdev_reopen(spa->spa_root_vdev);
2000 	}
2001 
2002 	kmem_free(vd, gcount * sizeof (vdev_t *));
2003 }
2004 
2005 static int
2006 spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type,
2007     boolean_t mosconfig)
2008 {
2009 	nvlist_t *config = spa->spa_config;
2010 	char *ereport = FM_EREPORT_ZFS_POOL;
2011 	char *comment;
2012 	int error;
2013 	uint64_t pool_guid;
2014 	nvlist_t *nvl;
2015 
2016 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID, &pool_guid))
2017 		return (SET_ERROR(EINVAL));
2018 
2019 	ASSERT(spa->spa_comment == NULL);
2020 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
2021 		spa->spa_comment = spa_strdup(comment);
2022 
2023 	/*
2024 	 * Versioning wasn't explicitly added to the label until later, so if
2025 	 * it's not present treat it as the initial version.
2026 	 */
2027 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VERSION,
2028 	    &spa->spa_ubsync.ub_version) != 0)
2029 		spa->spa_ubsync.ub_version = SPA_VERSION_INITIAL;
2030 
2031 	(void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG,
2032 	    &spa->spa_config_txg);
2033 
2034 	if ((state == SPA_LOAD_IMPORT || state == SPA_LOAD_TRYIMPORT) &&
2035 	    spa_guid_exists(pool_guid, 0)) {
2036 		error = SET_ERROR(EEXIST);
2037 	} else {
2038 		spa->spa_config_guid = pool_guid;
2039 
2040 		if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_SPLIT,
2041 		    &nvl) == 0) {
2042 			VERIFY(nvlist_dup(nvl, &spa->spa_config_splitting,
2043 			    KM_SLEEP) == 0);
2044 		}
2045 
2046 		nvlist_free(spa->spa_load_info);
2047 		spa->spa_load_info = fnvlist_alloc();
2048 
2049 		gethrestime(&spa->spa_loaded_ts);
2050 		error = spa_load_impl(spa, pool_guid, config, state, type,
2051 		    mosconfig, &ereport);
2052 	}
2053 
2054 	spa->spa_minref = refcount_count(&spa->spa_refcount);
2055 	if (error) {
2056 		if (error != EEXIST) {
2057 			spa->spa_loaded_ts.tv_sec = 0;
2058 			spa->spa_loaded_ts.tv_nsec = 0;
2059 		}
2060 		if (error != EBADF) {
2061 			zfs_ereport_post(ereport, spa, NULL, NULL, 0, 0);
2062 		}
2063 	}
2064 	spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
2065 	spa->spa_ena = 0;
2066 
2067 	return (error);
2068 }
2069 
2070 /*
2071  * Load an existing storage pool, using the pool's builtin spa_config as a
2072  * source of configuration information.
2073  */
2074 static int
2075 spa_load_impl(spa_t *spa, uint64_t pool_guid, nvlist_t *config,
2076     spa_load_state_t state, spa_import_type_t type, boolean_t mosconfig,
2077     char **ereport)
2078 {
2079 	int error = 0;
2080 	nvlist_t *nvroot = NULL;
2081 	nvlist_t *label;
2082 	vdev_t *rvd;
2083 	uberblock_t *ub = &spa->spa_uberblock;
2084 	uint64_t children, config_cache_txg = spa->spa_config_txg;
2085 	int orig_mode = spa->spa_mode;
2086 	int parse;
2087 	uint64_t obj;
2088 	boolean_t missing_feat_write = B_FALSE;
2089 
2090 	/*
2091 	 * If this is an untrusted config, access the pool in read-only mode.
2092 	 * This prevents things like resilvering recently removed devices.
2093 	 */
2094 	if (!mosconfig)
2095 		spa->spa_mode = FREAD;
2096 
2097 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
2098 
2099 	spa->spa_load_state = state;
2100 
2101 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvroot))
2102 		return (SET_ERROR(EINVAL));
2103 
2104 	parse = (type == SPA_IMPORT_EXISTING ?
2105 	    VDEV_ALLOC_LOAD : VDEV_ALLOC_SPLIT);
2106 
2107 	/*
2108 	 * Create "The Godfather" zio to hold all async IOs
2109 	 */
2110 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
2111 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
2112 
2113 	/*
2114 	 * Parse the configuration into a vdev tree.  We explicitly set the
2115 	 * value that will be returned by spa_version() since parsing the
2116 	 * configuration requires knowing the version number.
2117 	 */
2118 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2119 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, parse);
2120 	spa_config_exit(spa, SCL_ALL, FTAG);
2121 
2122 	if (error != 0)
2123 		return (error);
2124 
2125 	ASSERT(spa->spa_root_vdev == rvd);
2126 
2127 	if (type != SPA_IMPORT_ASSEMBLE) {
2128 		ASSERT(spa_guid(spa) == pool_guid);
2129 	}
2130 
2131 	/*
2132 	 * Try to open all vdevs, loading each label in the process.
2133 	 */
2134 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2135 	error = vdev_open(rvd);
2136 	spa_config_exit(spa, SCL_ALL, FTAG);
2137 	if (error != 0)
2138 		return (error);
2139 
2140 	/*
2141 	 * We need to validate the vdev labels against the configuration that
2142 	 * we have in hand, which is dependent on the setting of mosconfig. If
2143 	 * mosconfig is true then we're validating the vdev labels based on
2144 	 * that config.  Otherwise, we're validating against the cached config
2145 	 * (zpool.cache) that was read when we loaded the zfs module, and then
2146 	 * later we will recursively call spa_load() and validate against
2147 	 * the vdev config.
2148 	 *
2149 	 * If we're assembling a new pool that's been split off from an
2150 	 * existing pool, the labels haven't yet been updated so we skip
2151 	 * validation for now.
2152 	 */
2153 	if (type != SPA_IMPORT_ASSEMBLE) {
2154 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2155 		error = vdev_validate(rvd, mosconfig);
2156 		spa_config_exit(spa, SCL_ALL, FTAG);
2157 
2158 		if (error != 0)
2159 			return (error);
2160 
2161 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2162 			return (SET_ERROR(ENXIO));
2163 	}
2164 
2165 	/*
2166 	 * Find the best uberblock.
2167 	 */
2168 	vdev_uberblock_load(rvd, ub, &label);
2169 
2170 	/*
2171 	 * If we weren't able to find a single valid uberblock, return failure.
2172 	 */
2173 	if (ub->ub_txg == 0) {
2174 		nvlist_free(label);
2175 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
2176 	}
2177 
2178 	/*
2179 	 * If the pool has an unsupported version we can't open it.
2180 	 */
2181 	if (!SPA_VERSION_IS_SUPPORTED(ub->ub_version)) {
2182 		nvlist_free(label);
2183 		return (spa_vdev_err(rvd, VDEV_AUX_VERSION_NEWER, ENOTSUP));
2184 	}
2185 
2186 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2187 		nvlist_t *features;
2188 
2189 		/*
2190 		 * If we weren't able to find what's necessary for reading the
2191 		 * MOS in the label, return failure.
2192 		 */
2193 		if (label == NULL || nvlist_lookup_nvlist(label,
2194 		    ZPOOL_CONFIG_FEATURES_FOR_READ, &features) != 0) {
2195 			nvlist_free(label);
2196 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2197 			    ENXIO));
2198 		}
2199 
2200 		/*
2201 		 * Update our in-core representation with the definitive values
2202 		 * from the label.
2203 		 */
2204 		nvlist_free(spa->spa_label_features);
2205 		VERIFY(nvlist_dup(features, &spa->spa_label_features, 0) == 0);
2206 	}
2207 
2208 	nvlist_free(label);
2209 
2210 	/*
2211 	 * Look through entries in the label nvlist's features_for_read. If
2212 	 * there is a feature listed there which we don't understand then we
2213 	 * cannot open a pool.
2214 	 */
2215 	if (ub->ub_version >= SPA_VERSION_FEATURES) {
2216 		nvlist_t *unsup_feat;
2217 
2218 		VERIFY(nvlist_alloc(&unsup_feat, NV_UNIQUE_NAME, KM_SLEEP) ==
2219 		    0);
2220 
2221 		for (nvpair_t *nvp = nvlist_next_nvpair(spa->spa_label_features,
2222 		    NULL); nvp != NULL;
2223 		    nvp = nvlist_next_nvpair(spa->spa_label_features, nvp)) {
2224 			if (!zfeature_is_supported(nvpair_name(nvp))) {
2225 				VERIFY(nvlist_add_string(unsup_feat,
2226 				    nvpair_name(nvp), "") == 0);
2227 			}
2228 		}
2229 
2230 		if (!nvlist_empty(unsup_feat)) {
2231 			VERIFY(nvlist_add_nvlist(spa->spa_load_info,
2232 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat) == 0);
2233 			nvlist_free(unsup_feat);
2234 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2235 			    ENOTSUP));
2236 		}
2237 
2238 		nvlist_free(unsup_feat);
2239 	}
2240 
2241 	/*
2242 	 * If the vdev guid sum doesn't match the uberblock, we have an
2243 	 * incomplete configuration.  We first check to see if the pool
2244 	 * is aware of the complete config (i.e ZPOOL_CONFIG_VDEV_CHILDREN).
2245 	 * If it is, defer the vdev_guid_sum check till later so we
2246 	 * can handle missing vdevs.
2247 	 */
2248 	if (nvlist_lookup_uint64(config, ZPOOL_CONFIG_VDEV_CHILDREN,
2249 	    &children) != 0 && mosconfig && type != SPA_IMPORT_ASSEMBLE &&
2250 	    rvd->vdev_guid_sum != ub->ub_guid_sum)
2251 		return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM, ENXIO));
2252 
2253 	if (type != SPA_IMPORT_ASSEMBLE && spa->spa_config_splitting) {
2254 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2255 		spa_try_repair(spa, config);
2256 		spa_config_exit(spa, SCL_ALL, FTAG);
2257 		nvlist_free(spa->spa_config_splitting);
2258 		spa->spa_config_splitting = NULL;
2259 	}
2260 
2261 	/*
2262 	 * Initialize internal SPA structures.
2263 	 */
2264 	spa->spa_state = POOL_STATE_ACTIVE;
2265 	spa->spa_ubsync = spa->spa_uberblock;
2266 	spa->spa_verify_min_txg = spa->spa_extreme_rewind ?
2267 	    TXG_INITIAL - 1 : spa_last_synced_txg(spa) - TXG_DEFER_SIZE - 1;
2268 	spa->spa_first_txg = spa->spa_last_ubsync_txg ?
2269 	    spa->spa_last_ubsync_txg : spa_last_synced_txg(spa) + 1;
2270 	spa->spa_claim_max_txg = spa->spa_first_txg;
2271 	spa->spa_prev_software_version = ub->ub_software_version;
2272 
2273 	error = dsl_pool_init(spa, spa->spa_first_txg, &spa->spa_dsl_pool);
2274 	if (error)
2275 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2276 	spa->spa_meta_objset = spa->spa_dsl_pool->dp_meta_objset;
2277 
2278 	if (spa_dir_prop(spa, DMU_POOL_CONFIG, &spa->spa_config_object) != 0)
2279 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2280 
2281 	if (spa_version(spa) >= SPA_VERSION_FEATURES) {
2282 		boolean_t missing_feat_read = B_FALSE;
2283 		nvlist_t *unsup_feat, *enabled_feat;
2284 
2285 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_READ,
2286 		    &spa->spa_feat_for_read_obj) != 0) {
2287 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2288 		}
2289 
2290 		if (spa_dir_prop(spa, DMU_POOL_FEATURES_FOR_WRITE,
2291 		    &spa->spa_feat_for_write_obj) != 0) {
2292 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2293 		}
2294 
2295 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_DESCRIPTIONS,
2296 		    &spa->spa_feat_desc_obj) != 0) {
2297 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2298 		}
2299 
2300 		enabled_feat = fnvlist_alloc();
2301 		unsup_feat = fnvlist_alloc();
2302 
2303 		if (!spa_features_check(spa, B_FALSE,
2304 		    unsup_feat, enabled_feat))
2305 			missing_feat_read = B_TRUE;
2306 
2307 		if (spa_writeable(spa) || state == SPA_LOAD_TRYIMPORT) {
2308 			if (!spa_features_check(spa, B_TRUE,
2309 			    unsup_feat, enabled_feat)) {
2310 				missing_feat_write = B_TRUE;
2311 			}
2312 		}
2313 
2314 		fnvlist_add_nvlist(spa->spa_load_info,
2315 		    ZPOOL_CONFIG_ENABLED_FEAT, enabled_feat);
2316 
2317 		if (!nvlist_empty(unsup_feat)) {
2318 			fnvlist_add_nvlist(spa->spa_load_info,
2319 			    ZPOOL_CONFIG_UNSUP_FEAT, unsup_feat);
2320 		}
2321 
2322 		fnvlist_free(enabled_feat);
2323 		fnvlist_free(unsup_feat);
2324 
2325 		if (!missing_feat_read) {
2326 			fnvlist_add_boolean(spa->spa_load_info,
2327 			    ZPOOL_CONFIG_CAN_RDONLY);
2328 		}
2329 
2330 		/*
2331 		 * If the state is SPA_LOAD_TRYIMPORT, our objective is
2332 		 * twofold: to determine whether the pool is available for
2333 		 * import in read-write mode and (if it is not) whether the
2334 		 * pool is available for import in read-only mode. If the pool
2335 		 * is available for import in read-write mode, it is displayed
2336 		 * as available in userland; if it is not available for import
2337 		 * in read-only mode, it is displayed as unavailable in
2338 		 * userland. If the pool is available for import in read-only
2339 		 * mode but not read-write mode, it is displayed as unavailable
2340 		 * in userland with a special note that the pool is actually
2341 		 * available for open in read-only mode.
2342 		 *
2343 		 * As a result, if the state is SPA_LOAD_TRYIMPORT and we are
2344 		 * missing a feature for write, we must first determine whether
2345 		 * the pool can be opened read-only before returning to
2346 		 * userland in order to know whether to display the
2347 		 * abovementioned note.
2348 		 */
2349 		if (missing_feat_read || (missing_feat_write &&
2350 		    spa_writeable(spa))) {
2351 			return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT,
2352 			    ENOTSUP));
2353 		}
2354 
2355 		/*
2356 		 * Load refcounts for ZFS features from disk into an in-memory
2357 		 * cache during SPA initialization.
2358 		 */
2359 		for (spa_feature_t i = 0; i < SPA_FEATURES; i++) {
2360 			uint64_t refcount;
2361 
2362 			error = feature_get_refcount_from_disk(spa,
2363 			    &spa_feature_table[i], &refcount);
2364 			if (error == 0) {
2365 				spa->spa_feat_refcount_cache[i] = refcount;
2366 			} else if (error == ENOTSUP) {
2367 				spa->spa_feat_refcount_cache[i] =
2368 				    SPA_FEATURE_DISABLED;
2369 			} else {
2370 				return (spa_vdev_err(rvd,
2371 				    VDEV_AUX_CORRUPT_DATA, EIO));
2372 			}
2373 		}
2374 	}
2375 
2376 	if (spa_feature_is_active(spa, SPA_FEATURE_ENABLED_TXG)) {
2377 		if (spa_dir_prop(spa, DMU_POOL_FEATURE_ENABLED_TXG,
2378 		    &spa->spa_feat_enabled_txg_obj) != 0) {
2379 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2380 		}
2381 	}
2382 
2383 	spa->spa_is_initializing = B_TRUE;
2384 	error = dsl_pool_open(spa->spa_dsl_pool);
2385 	spa->spa_is_initializing = B_FALSE;
2386 	if (error != 0)
2387 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2388 
2389 	if (!mosconfig) {
2390 		uint64_t hostid;
2391 		nvlist_t *policy = NULL, *nvconfig;
2392 
2393 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2394 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2395 
2396 		if (!spa_is_root(spa) && nvlist_lookup_uint64(nvconfig,
2397 		    ZPOOL_CONFIG_HOSTID, &hostid) == 0) {
2398 			char *hostname;
2399 			unsigned long myhostid = 0;
2400 
2401 			VERIFY(nvlist_lookup_string(nvconfig,
2402 			    ZPOOL_CONFIG_HOSTNAME, &hostname) == 0);
2403 
2404 #ifdef	_KERNEL
2405 			myhostid = zone_get_hostid(NULL);
2406 #else	/* _KERNEL */
2407 			/*
2408 			 * We're emulating the system's hostid in userland, so
2409 			 * we can't use zone_get_hostid().
2410 			 */
2411 			(void) ddi_strtoul(hw_serial, NULL, 10, &myhostid);
2412 #endif	/* _KERNEL */
2413 			if (hostid != 0 && myhostid != 0 &&
2414 			    hostid != myhostid) {
2415 				nvlist_free(nvconfig);
2416 				cmn_err(CE_WARN, "pool '%s' could not be "
2417 				    "loaded as it was last accessed by "
2418 				    "another system (host: %s hostid: 0x%lx). "
2419 				    "See: http://illumos.org/msg/ZFS-8000-EY",
2420 				    spa_name(spa), hostname,
2421 				    (unsigned long)hostid);
2422 				return (SET_ERROR(EBADF));
2423 			}
2424 		}
2425 		if (nvlist_lookup_nvlist(spa->spa_config,
2426 		    ZPOOL_REWIND_POLICY, &policy) == 0)
2427 			VERIFY(nvlist_add_nvlist(nvconfig,
2428 			    ZPOOL_REWIND_POLICY, policy) == 0);
2429 
2430 		spa_config_set(spa, nvconfig);
2431 		spa_unload(spa);
2432 		spa_deactivate(spa);
2433 		spa_activate(spa, orig_mode);
2434 
2435 		return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
2436 	}
2437 
2438 	if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
2439 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2440 	error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
2441 	if (error != 0)
2442 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2443 
2444 	/*
2445 	 * Load the bit that tells us to use the new accounting function
2446 	 * (raid-z deflation).  If we have an older pool, this will not
2447 	 * be present.
2448 	 */
2449 	error = spa_dir_prop(spa, DMU_POOL_DEFLATE, &spa->spa_deflate);
2450 	if (error != 0 && error != ENOENT)
2451 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2452 
2453 	error = spa_dir_prop(spa, DMU_POOL_CREATION_VERSION,
2454 	    &spa->spa_creation_version);
2455 	if (error != 0 && error != ENOENT)
2456 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2457 
2458 	/*
2459 	 * Load the persistent error log.  If we have an older pool, this will
2460 	 * not be present.
2461 	 */
2462 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_LAST, &spa->spa_errlog_last);
2463 	if (error != 0 && error != ENOENT)
2464 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2465 
2466 	error = spa_dir_prop(spa, DMU_POOL_ERRLOG_SCRUB,
2467 	    &spa->spa_errlog_scrub);
2468 	if (error != 0 && error != ENOENT)
2469 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2470 
2471 	/*
2472 	 * Load the history object.  If we have an older pool, this
2473 	 * will not be present.
2474 	 */
2475 	error = spa_dir_prop(spa, DMU_POOL_HISTORY, &spa->spa_history);
2476 	if (error != 0 && error != ENOENT)
2477 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2478 
2479 	/*
2480 	 * If we're assembling the pool from the split-off vdevs of
2481 	 * an existing pool, we don't want to attach the spares & cache
2482 	 * devices.
2483 	 */
2484 
2485 	/*
2486 	 * Load any hot spares for this pool.
2487 	 */
2488 	error = spa_dir_prop(spa, DMU_POOL_SPARES, &spa->spa_spares.sav_object);
2489 	if (error != 0 && error != ENOENT)
2490 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2491 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2492 		ASSERT(spa_version(spa) >= SPA_VERSION_SPARES);
2493 		if (load_nvlist(spa, spa->spa_spares.sav_object,
2494 		    &spa->spa_spares.sav_config) != 0)
2495 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2496 
2497 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2498 		spa_load_spares(spa);
2499 		spa_config_exit(spa, SCL_ALL, FTAG);
2500 	} else if (error == 0) {
2501 		spa->spa_spares.sav_sync = B_TRUE;
2502 	}
2503 
2504 	/*
2505 	 * Load any level 2 ARC devices for this pool.
2506 	 */
2507 	error = spa_dir_prop(spa, DMU_POOL_L2CACHE,
2508 	    &spa->spa_l2cache.sav_object);
2509 	if (error != 0 && error != ENOENT)
2510 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2511 	if (error == 0 && type != SPA_IMPORT_ASSEMBLE) {
2512 		ASSERT(spa_version(spa) >= SPA_VERSION_L2CACHE);
2513 		if (load_nvlist(spa, spa->spa_l2cache.sav_object,
2514 		    &spa->spa_l2cache.sav_config) != 0)
2515 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2516 
2517 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2518 		spa_load_l2cache(spa);
2519 		spa_config_exit(spa, SCL_ALL, FTAG);
2520 	} else if (error == 0) {
2521 		spa->spa_l2cache.sav_sync = B_TRUE;
2522 	}
2523 
2524 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
2525 
2526 	error = spa_dir_prop(spa, DMU_POOL_PROPS, &spa->spa_pool_props_object);
2527 	if (error && error != ENOENT)
2528 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2529 
2530 	if (error == 0) {
2531 		uint64_t autoreplace;
2532 
2533 		spa_prop_find(spa, ZPOOL_PROP_BOOTFS, &spa->spa_bootfs);
2534 		spa_prop_find(spa, ZPOOL_PROP_AUTOREPLACE, &autoreplace);
2535 		spa_prop_find(spa, ZPOOL_PROP_DELEGATION, &spa->spa_delegation);
2536 		spa_prop_find(spa, ZPOOL_PROP_FAILUREMODE, &spa->spa_failmode);
2537 		spa_prop_find(spa, ZPOOL_PROP_AUTOEXPAND, &spa->spa_autoexpand);
2538 		spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
2539 		    &spa->spa_dedup_ditto);
2540 
2541 		spa->spa_autoreplace = (autoreplace != 0);
2542 	}
2543 
2544 	/*
2545 	 * If the 'autoreplace' property is set, then post a resource notifying
2546 	 * the ZFS DE that it should not issue any faults for unopenable
2547 	 * devices.  We also iterate over the vdevs, and post a sysevent for any
2548 	 * unopenable vdevs so that the normal autoreplace handler can take
2549 	 * over.
2550 	 */
2551 	if (spa->spa_autoreplace && state != SPA_LOAD_TRYIMPORT) {
2552 		spa_check_removed(spa->spa_root_vdev);
2553 		/*
2554 		 * For the import case, this is done in spa_import(), because
2555 		 * at this point we're using the spare definitions from
2556 		 * the MOS config, not necessarily from the userland config.
2557 		 */
2558 		if (state != SPA_LOAD_IMPORT) {
2559 			spa_aux_check_removed(&spa->spa_spares);
2560 			spa_aux_check_removed(&spa->spa_l2cache);
2561 		}
2562 	}
2563 
2564 	/*
2565 	 * Load the vdev state for all toplevel vdevs.
2566 	 */
2567 	vdev_load(rvd);
2568 
2569 	/*
2570 	 * Propagate the leaf DTLs we just loaded all the way up the tree.
2571 	 */
2572 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
2573 	vdev_dtl_reassess(rvd, 0, 0, B_FALSE);
2574 	spa_config_exit(spa, SCL_ALL, FTAG);
2575 
2576 	/*
2577 	 * Load the DDTs (dedup tables).
2578 	 */
2579 	error = ddt_load(spa);
2580 	if (error != 0)
2581 		return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2582 
2583 	spa_update_dspace(spa);
2584 
2585 	/*
2586 	 * Validate the config, using the MOS config to fill in any
2587 	 * information which might be missing.  If we fail to validate
2588 	 * the config then declare the pool unfit for use. If we're
2589 	 * assembling a pool from a split, the log is not transferred
2590 	 * over.
2591 	 */
2592 	if (type != SPA_IMPORT_ASSEMBLE) {
2593 		nvlist_t *nvconfig;
2594 
2595 		if (load_nvlist(spa, spa->spa_config_object, &nvconfig) != 0)
2596 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
2597 
2598 		if (!spa_config_valid(spa, nvconfig)) {
2599 			nvlist_free(nvconfig);
2600 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_GUID_SUM,
2601 			    ENXIO));
2602 		}
2603 		nvlist_free(nvconfig);
2604 
2605 		/*
2606 		 * Now that we've validated the config, check the state of the
2607 		 * root vdev.  If it can't be opened, it indicates one or
2608 		 * more toplevel vdevs are faulted.
2609 		 */
2610 		if (rvd->vdev_state <= VDEV_STATE_CANT_OPEN)
2611 			return (SET_ERROR(ENXIO));
2612 
2613 		if (spa_check_logs(spa)) {
2614 			*ereport = FM_EREPORT_ZFS_LOG_REPLAY;
2615 			return (spa_vdev_err(rvd, VDEV_AUX_BAD_LOG, ENXIO));
2616 		}
2617 	}
2618 
2619 	if (missing_feat_write) {
2620 		ASSERT(state == SPA_LOAD_TRYIMPORT);
2621 
2622 		/*
2623 		 * At this point, we know that we can open the pool in
2624 		 * read-only mode but not read-write mode. We now have enough
2625 		 * information and can return to userland.
2626 		 */
2627 		return (spa_vdev_err(rvd, VDEV_AUX_UNSUP_FEAT, ENOTSUP));
2628 	}
2629 
2630 	/*
2631 	 * We've successfully opened the pool, verify that we're ready
2632 	 * to start pushing transactions.
2633 	 */
2634 	if (state != SPA_LOAD_TRYIMPORT) {
2635 		if (error = spa_load_verify(spa))
2636 			return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA,
2637 			    error));
2638 	}
2639 
2640 	if (spa_writeable(spa) && (state == SPA_LOAD_RECOVER ||
2641 	    spa->spa_load_max_txg == UINT64_MAX)) {
2642 		dmu_tx_t *tx;
2643 		int need_update = B_FALSE;
2644 
2645 		ASSERT(state != SPA_LOAD_TRYIMPORT);
2646 
2647 		/*
2648 		 * Claim log blocks that haven't been committed yet.
2649 		 * This must all happen in a single txg.
2650 		 * Note: spa_claim_max_txg is updated by spa_claim_notify(),
2651 		 * invoked from zil_claim_log_block()'s i/o done callback.
2652 		 * Price of rollback is that we abandon the log.
2653 		 */
2654 		spa->spa_claiming = B_TRUE;
2655 
2656 		tx = dmu_tx_create_assigned(spa_get_dsl(spa),
2657 		    spa_first_txg(spa));
2658 		(void) dmu_objset_find(spa_name(spa),
2659 		    zil_claim, tx, DS_FIND_CHILDREN);
2660 		dmu_tx_commit(tx);
2661 
2662 		spa->spa_claiming = B_FALSE;
2663 
2664 		spa_set_log_state(spa, SPA_LOG_GOOD);
2665 		spa->spa_sync_on = B_TRUE;
2666 		txg_sync_start(spa->spa_dsl_pool);
2667 
2668 		/*
2669 		 * Wait for all claims to sync.  We sync up to the highest
2670 		 * claimed log block birth time so that claimed log blocks
2671 		 * don't appear to be from the future.  spa_claim_max_txg
2672 		 * will have been set for us by either zil_check_log_chain()
2673 		 * (invoked from spa_check_logs()) or zil_claim() above.
2674 		 */
2675 		txg_wait_synced(spa->spa_dsl_pool, spa->spa_claim_max_txg);
2676 
2677 		/*
2678 		 * If the config cache is stale, or we have uninitialized
2679 		 * metaslabs (see spa_vdev_add()), then update the config.
2680 		 *
2681 		 * If this is a verbatim import, trust the current
2682 		 * in-core spa_config and update the disk labels.
2683 		 */
2684 		if (config_cache_txg != spa->spa_config_txg ||
2685 		    state == SPA_LOAD_IMPORT ||
2686 		    state == SPA_LOAD_RECOVER ||
2687 		    (spa->spa_import_flags & ZFS_IMPORT_VERBATIM))
2688 			need_update = B_TRUE;
2689 
2690 		for (int c = 0; c < rvd->vdev_children; c++)
2691 			if (rvd->vdev_child[c]->vdev_ms_array == 0)
2692 				need_update = B_TRUE;
2693 
2694 		/*
2695 		 * Update the config cache asychronously in case we're the
2696 		 * root pool, in which case the config cache isn't writable yet.
2697 		 */
2698 		if (need_update)
2699 			spa_async_request(spa, SPA_ASYNC_CONFIG_UPDATE);
2700 
2701 		/*
2702 		 * Check all DTLs to see if anything needs resilvering.
2703 		 */
2704 		if (!dsl_scan_resilvering(spa->spa_dsl_pool) &&
2705 		    vdev_resilver_needed(rvd, NULL, NULL))
2706 			spa_async_request(spa, SPA_ASYNC_RESILVER);
2707 
2708 		/*
2709 		 * Log the fact that we booted up (so that we can detect if
2710 		 * we rebooted in the middle of an operation).
2711 		 */
2712 		spa_history_log_version(spa, "open");
2713 
2714 		/*
2715 		 * Delete any inconsistent datasets.
2716 		 */
2717 		(void) dmu_objset_find(spa_name(spa),
2718 		    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
2719 
2720 		/*
2721 		 * Clean up any stale temporary dataset userrefs.
2722 		 */
2723 		dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
2724 	}
2725 
2726 	return (0);
2727 }
2728 
2729 static int
2730 spa_load_retry(spa_t *spa, spa_load_state_t state, int mosconfig)
2731 {
2732 	int mode = spa->spa_mode;
2733 
2734 	spa_unload(spa);
2735 	spa_deactivate(spa);
2736 
2737 	spa->spa_load_max_txg--;
2738 
2739 	spa_activate(spa, mode);
2740 	spa_async_suspend(spa);
2741 
2742 	return (spa_load(spa, state, SPA_IMPORT_EXISTING, mosconfig));
2743 }
2744 
2745 /*
2746  * If spa_load() fails this function will try loading prior txg's. If
2747  * 'state' is SPA_LOAD_RECOVER and one of these loads succeeds the pool
2748  * will be rewound to that txg. If 'state' is not SPA_LOAD_RECOVER this
2749  * function will not rewind the pool and will return the same error as
2750  * spa_load().
2751  */
2752 static int
2753 spa_load_best(spa_t *spa, spa_load_state_t state, int mosconfig,
2754     uint64_t max_request, int rewind_flags)
2755 {
2756 	nvlist_t *loadinfo = NULL;
2757 	nvlist_t *config = NULL;
2758 	int load_error, rewind_error;
2759 	uint64_t safe_rewind_txg;
2760 	uint64_t min_txg;
2761 
2762 	if (spa->spa_load_txg && state == SPA_LOAD_RECOVER) {
2763 		spa->spa_load_max_txg = spa->spa_load_txg;
2764 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2765 	} else {
2766 		spa->spa_load_max_txg = max_request;
2767 	}
2768 
2769 	load_error = rewind_error = spa_load(spa, state, SPA_IMPORT_EXISTING,
2770 	    mosconfig);
2771 	if (load_error == 0)
2772 		return (0);
2773 
2774 	if (spa->spa_root_vdev != NULL)
2775 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2776 
2777 	spa->spa_last_ubsync_txg = spa->spa_uberblock.ub_txg;
2778 	spa->spa_last_ubsync_txg_ts = spa->spa_uberblock.ub_timestamp;
2779 
2780 	if (rewind_flags & ZPOOL_NEVER_REWIND) {
2781 		nvlist_free(config);
2782 		return (load_error);
2783 	}
2784 
2785 	if (state == SPA_LOAD_RECOVER) {
2786 		/* Price of rolling back is discarding txgs, including log */
2787 		spa_set_log_state(spa, SPA_LOG_CLEAR);
2788 	} else {
2789 		/*
2790 		 * If we aren't rolling back save the load info from our first
2791 		 * import attempt so that we can restore it after attempting
2792 		 * to rewind.
2793 		 */
2794 		loadinfo = spa->spa_load_info;
2795 		spa->spa_load_info = fnvlist_alloc();
2796 	}
2797 
2798 	spa->spa_load_max_txg = spa->spa_last_ubsync_txg;
2799 	safe_rewind_txg = spa->spa_last_ubsync_txg - TXG_DEFER_SIZE;
2800 	min_txg = (rewind_flags & ZPOOL_EXTREME_REWIND) ?
2801 	    TXG_INITIAL : safe_rewind_txg;
2802 
2803 	/*
2804 	 * Continue as long as we're finding errors, we're still within
2805 	 * the acceptable rewind range, and we're still finding uberblocks
2806 	 */
2807 	while (rewind_error && spa->spa_uberblock.ub_txg >= min_txg &&
2808 	    spa->spa_uberblock.ub_txg <= spa->spa_load_max_txg) {
2809 		if (spa->spa_load_max_txg < safe_rewind_txg)
2810 			spa->spa_extreme_rewind = B_TRUE;
2811 		rewind_error = spa_load_retry(spa, state, mosconfig);
2812 	}
2813 
2814 	spa->spa_extreme_rewind = B_FALSE;
2815 	spa->spa_load_max_txg = UINT64_MAX;
2816 
2817 	if (config && (rewind_error || state != SPA_LOAD_RECOVER))
2818 		spa_config_set(spa, config);
2819 
2820 	if (state == SPA_LOAD_RECOVER) {
2821 		ASSERT3P(loadinfo, ==, NULL);
2822 		return (rewind_error);
2823 	} else {
2824 		/* Store the rewind info as part of the initial load info */
2825 		fnvlist_add_nvlist(loadinfo, ZPOOL_CONFIG_REWIND_INFO,
2826 		    spa->spa_load_info);
2827 
2828 		/* Restore the initial load info */
2829 		fnvlist_free(spa->spa_load_info);
2830 		spa->spa_load_info = loadinfo;
2831 
2832 		return (load_error);
2833 	}
2834 }
2835 
2836 /*
2837  * Pool Open/Import
2838  *
2839  * The import case is identical to an open except that the configuration is sent
2840  * down from userland, instead of grabbed from the configuration cache.  For the
2841  * case of an open, the pool configuration will exist in the
2842  * POOL_STATE_UNINITIALIZED state.
2843  *
2844  * The stats information (gen/count/ustats) is used to gather vdev statistics at
2845  * the same time open the pool, without having to keep around the spa_t in some
2846  * ambiguous state.
2847  */
2848 static int
2849 spa_open_common(const char *pool, spa_t **spapp, void *tag, nvlist_t *nvpolicy,
2850     nvlist_t **config)
2851 {
2852 	spa_t *spa;
2853 	spa_load_state_t state = SPA_LOAD_OPEN;
2854 	int error;
2855 	int locked = B_FALSE;
2856 
2857 	*spapp = NULL;
2858 
2859 	/*
2860 	 * As disgusting as this is, we need to support recursive calls to this
2861 	 * function because dsl_dir_open() is called during spa_load(), and ends
2862 	 * up calling spa_open() again.  The real fix is to figure out how to
2863 	 * avoid dsl_dir_open() calling this in the first place.
2864 	 */
2865 	if (mutex_owner(&spa_namespace_lock) != curthread) {
2866 		mutex_enter(&spa_namespace_lock);
2867 		locked = B_TRUE;
2868 	}
2869 
2870 	if ((spa = spa_lookup(pool)) == NULL) {
2871 		if (locked)
2872 			mutex_exit(&spa_namespace_lock);
2873 		return (SET_ERROR(ENOENT));
2874 	}
2875 
2876 	if (spa->spa_state == POOL_STATE_UNINITIALIZED) {
2877 		zpool_rewind_policy_t policy;
2878 
2879 		zpool_get_rewind_policy(nvpolicy ? nvpolicy : spa->spa_config,
2880 		    &policy);
2881 		if (policy.zrp_request & ZPOOL_DO_REWIND)
2882 			state = SPA_LOAD_RECOVER;
2883 
2884 		spa_activate(spa, spa_mode_global);
2885 
2886 		if (state != SPA_LOAD_RECOVER)
2887 			spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
2888 
2889 		error = spa_load_best(spa, state, B_FALSE, policy.zrp_txg,
2890 		    policy.zrp_request);
2891 
2892 		if (error == EBADF) {
2893 			/*
2894 			 * If vdev_validate() returns failure (indicated by
2895 			 * EBADF), it indicates that one of the vdevs indicates
2896 			 * that the pool has been exported or destroyed.  If
2897 			 * this is the case, the config cache is out of sync and
2898 			 * we should remove the pool from the namespace.
2899 			 */
2900 			spa_unload(spa);
2901 			spa_deactivate(spa);
2902 			spa_config_sync(spa, B_TRUE, B_TRUE);
2903 			spa_remove(spa);
2904 			if (locked)
2905 				mutex_exit(&spa_namespace_lock);
2906 			return (SET_ERROR(ENOENT));
2907 		}
2908 
2909 		if (error) {
2910 			/*
2911 			 * We can't open the pool, but we still have useful
2912 			 * information: the state of each vdev after the
2913 			 * attempted vdev_open().  Return this to the user.
2914 			 */
2915 			if (config != NULL && spa->spa_config) {
2916 				VERIFY(nvlist_dup(spa->spa_config, config,
2917 				    KM_SLEEP) == 0);
2918 				VERIFY(nvlist_add_nvlist(*config,
2919 				    ZPOOL_CONFIG_LOAD_INFO,
2920 				    spa->spa_load_info) == 0);
2921 			}
2922 			spa_unload(spa);
2923 			spa_deactivate(spa);
2924 			spa->spa_last_open_failed = error;
2925 			if (locked)
2926 				mutex_exit(&spa_namespace_lock);
2927 			*spapp = NULL;
2928 			return (error);
2929 		}
2930 	}
2931 
2932 	spa_open_ref(spa, tag);
2933 
2934 	if (config != NULL)
2935 		*config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
2936 
2937 	/*
2938 	 * If we've recovered the pool, pass back any information we
2939 	 * gathered while doing the load.
2940 	 */
2941 	if (state == SPA_LOAD_RECOVER) {
2942 		VERIFY(nvlist_add_nvlist(*config, ZPOOL_CONFIG_LOAD_INFO,
2943 		    spa->spa_load_info) == 0);
2944 	}
2945 
2946 	if (locked) {
2947 		spa->spa_last_open_failed = 0;
2948 		spa->spa_last_ubsync_txg = 0;
2949 		spa->spa_load_txg = 0;
2950 		mutex_exit(&spa_namespace_lock);
2951 	}
2952 
2953 	*spapp = spa;
2954 
2955 	return (0);
2956 }
2957 
2958 int
2959 spa_open_rewind(const char *name, spa_t **spapp, void *tag, nvlist_t *policy,
2960     nvlist_t **config)
2961 {
2962 	return (spa_open_common(name, spapp, tag, policy, config));
2963 }
2964 
2965 int
2966 spa_open(const char *name, spa_t **spapp, void *tag)
2967 {
2968 	return (spa_open_common(name, spapp, tag, NULL, NULL));
2969 }
2970 
2971 /*
2972  * Lookup the given spa_t, incrementing the inject count in the process,
2973  * preventing it from being exported or destroyed.
2974  */
2975 spa_t *
2976 spa_inject_addref(char *name)
2977 {
2978 	spa_t *spa;
2979 
2980 	mutex_enter(&spa_namespace_lock);
2981 	if ((spa = spa_lookup(name)) == NULL) {
2982 		mutex_exit(&spa_namespace_lock);
2983 		return (NULL);
2984 	}
2985 	spa->spa_inject_ref++;
2986 	mutex_exit(&spa_namespace_lock);
2987 
2988 	return (spa);
2989 }
2990 
2991 void
2992 spa_inject_delref(spa_t *spa)
2993 {
2994 	mutex_enter(&spa_namespace_lock);
2995 	spa->spa_inject_ref--;
2996 	mutex_exit(&spa_namespace_lock);
2997 }
2998 
2999 /*
3000  * Add spares device information to the nvlist.
3001  */
3002 static void
3003 spa_add_spares(spa_t *spa, nvlist_t *config)
3004 {
3005 	nvlist_t **spares;
3006 	uint_t i, nspares;
3007 	nvlist_t *nvroot;
3008 	uint64_t guid;
3009 	vdev_stat_t *vs;
3010 	uint_t vsc;
3011 	uint64_t pool;
3012 
3013 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3014 
3015 	if (spa->spa_spares.sav_count == 0)
3016 		return;
3017 
3018 	VERIFY(nvlist_lookup_nvlist(config,
3019 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3020 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
3021 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3022 	if (nspares != 0) {
3023 		VERIFY(nvlist_add_nvlist_array(nvroot,
3024 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3025 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
3026 		    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0);
3027 
3028 		/*
3029 		 * Go through and find any spares which have since been
3030 		 * repurposed as an active spare.  If this is the case, update
3031 		 * their status appropriately.
3032 		 */
3033 		for (i = 0; i < nspares; i++) {
3034 			VERIFY(nvlist_lookup_uint64(spares[i],
3035 			    ZPOOL_CONFIG_GUID, &guid) == 0);
3036 			if (spa_spare_exists(guid, &pool, NULL) &&
3037 			    pool != 0ULL) {
3038 				VERIFY(nvlist_lookup_uint64_array(
3039 				    spares[i], ZPOOL_CONFIG_VDEV_STATS,
3040 				    (uint64_t **)&vs, &vsc) == 0);
3041 				vs->vs_state = VDEV_STATE_CANT_OPEN;
3042 				vs->vs_aux = VDEV_AUX_SPARED;
3043 			}
3044 		}
3045 	}
3046 }
3047 
3048 /*
3049  * Add l2cache device information to the nvlist, including vdev stats.
3050  */
3051 static void
3052 spa_add_l2cache(spa_t *spa, nvlist_t *config)
3053 {
3054 	nvlist_t **l2cache;
3055 	uint_t i, j, nl2cache;
3056 	nvlist_t *nvroot;
3057 	uint64_t guid;
3058 	vdev_t *vd;
3059 	vdev_stat_t *vs;
3060 	uint_t vsc;
3061 
3062 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3063 
3064 	if (spa->spa_l2cache.sav_count == 0)
3065 		return;
3066 
3067 	VERIFY(nvlist_lookup_nvlist(config,
3068 	    ZPOOL_CONFIG_VDEV_TREE, &nvroot) == 0);
3069 	VERIFY(nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
3070 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3071 	if (nl2cache != 0) {
3072 		VERIFY(nvlist_add_nvlist_array(nvroot,
3073 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3074 		VERIFY(nvlist_lookup_nvlist_array(nvroot,
3075 		    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0);
3076 
3077 		/*
3078 		 * Update level 2 cache device stats.
3079 		 */
3080 
3081 		for (i = 0; i < nl2cache; i++) {
3082 			VERIFY(nvlist_lookup_uint64(l2cache[i],
3083 			    ZPOOL_CONFIG_GUID, &guid) == 0);
3084 
3085 			vd = NULL;
3086 			for (j = 0; j < spa->spa_l2cache.sav_count; j++) {
3087 				if (guid ==
3088 				    spa->spa_l2cache.sav_vdevs[j]->vdev_guid) {
3089 					vd = spa->spa_l2cache.sav_vdevs[j];
3090 					break;
3091 				}
3092 			}
3093 			ASSERT(vd != NULL);
3094 
3095 			VERIFY(nvlist_lookup_uint64_array(l2cache[i],
3096 			    ZPOOL_CONFIG_VDEV_STATS, (uint64_t **)&vs, &vsc)
3097 			    == 0);
3098 			vdev_get_stats(vd, vs);
3099 		}
3100 	}
3101 }
3102 
3103 static void
3104 spa_add_feature_stats(spa_t *spa, nvlist_t *config)
3105 {
3106 	nvlist_t *features;
3107 	zap_cursor_t zc;
3108 	zap_attribute_t za;
3109 
3110 	ASSERT(spa_config_held(spa, SCL_CONFIG, RW_READER));
3111 	VERIFY(nvlist_alloc(&features, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3112 
3113 	if (spa->spa_feat_for_read_obj != 0) {
3114 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3115 		    spa->spa_feat_for_read_obj);
3116 		    zap_cursor_retrieve(&zc, &za) == 0;
3117 		    zap_cursor_advance(&zc)) {
3118 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3119 			    za.za_num_integers == 1);
3120 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3121 			    za.za_first_integer));
3122 		}
3123 		zap_cursor_fini(&zc);
3124 	}
3125 
3126 	if (spa->spa_feat_for_write_obj != 0) {
3127 		for (zap_cursor_init(&zc, spa->spa_meta_objset,
3128 		    spa->spa_feat_for_write_obj);
3129 		    zap_cursor_retrieve(&zc, &za) == 0;
3130 		    zap_cursor_advance(&zc)) {
3131 			ASSERT(za.za_integer_length == sizeof (uint64_t) &&
3132 			    za.za_num_integers == 1);
3133 			VERIFY3U(0, ==, nvlist_add_uint64(features, za.za_name,
3134 			    za.za_first_integer));
3135 		}
3136 		zap_cursor_fini(&zc);
3137 	}
3138 
3139 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_FEATURE_STATS,
3140 	    features) == 0);
3141 	nvlist_free(features);
3142 }
3143 
3144 int
3145 spa_get_stats(const char *name, nvlist_t **config,
3146     char *altroot, size_t buflen)
3147 {
3148 	int error;
3149 	spa_t *spa;
3150 
3151 	*config = NULL;
3152 	error = spa_open_common(name, &spa, FTAG, NULL, config);
3153 
3154 	if (spa != NULL) {
3155 		/*
3156 		 * This still leaves a window of inconsistency where the spares
3157 		 * or l2cache devices could change and the config would be
3158 		 * self-inconsistent.
3159 		 */
3160 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
3161 
3162 		if (*config != NULL) {
3163 			uint64_t loadtimes[2];
3164 
3165 			loadtimes[0] = spa->spa_loaded_ts.tv_sec;
3166 			loadtimes[1] = spa->spa_loaded_ts.tv_nsec;
3167 			VERIFY(nvlist_add_uint64_array(*config,
3168 			    ZPOOL_CONFIG_LOADED_TIME, loadtimes, 2) == 0);
3169 
3170 			VERIFY(nvlist_add_uint64(*config,
3171 			    ZPOOL_CONFIG_ERRCOUNT,
3172 			    spa_get_errlog_size(spa)) == 0);
3173 
3174 			if (spa_suspended(spa))
3175 				VERIFY(nvlist_add_uint64(*config,
3176 				    ZPOOL_CONFIG_SUSPENDED,
3177 				    spa->spa_failmode) == 0);
3178 
3179 			spa_add_spares(spa, *config);
3180 			spa_add_l2cache(spa, *config);
3181 			spa_add_feature_stats(spa, *config);
3182 		}
3183 	}
3184 
3185 	/*
3186 	 * We want to get the alternate root even for faulted pools, so we cheat
3187 	 * and call spa_lookup() directly.
3188 	 */
3189 	if (altroot) {
3190 		if (spa == NULL) {
3191 			mutex_enter(&spa_namespace_lock);
3192 			spa = spa_lookup(name);
3193 			if (spa)
3194 				spa_altroot(spa, altroot, buflen);
3195 			else
3196 				altroot[0] = '\0';
3197 			spa = NULL;
3198 			mutex_exit(&spa_namespace_lock);
3199 		} else {
3200 			spa_altroot(spa, altroot, buflen);
3201 		}
3202 	}
3203 
3204 	if (spa != NULL) {
3205 		spa_config_exit(spa, SCL_CONFIG, FTAG);
3206 		spa_close(spa, FTAG);
3207 	}
3208 
3209 	return (error);
3210 }
3211 
3212 /*
3213  * Validate that the auxiliary device array is well formed.  We must have an
3214  * array of nvlists, each which describes a valid leaf vdev.  If this is an
3215  * import (mode is VDEV_ALLOC_SPARE), then we allow corrupted spares to be
3216  * specified, as long as they are well-formed.
3217  */
3218 static int
3219 spa_validate_aux_devs(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode,
3220     spa_aux_vdev_t *sav, const char *config, uint64_t version,
3221     vdev_labeltype_t label)
3222 {
3223 	nvlist_t **dev;
3224 	uint_t i, ndev;
3225 	vdev_t *vd;
3226 	int error;
3227 
3228 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3229 
3230 	/*
3231 	 * It's acceptable to have no devs specified.
3232 	 */
3233 	if (nvlist_lookup_nvlist_array(nvroot, config, &dev, &ndev) != 0)
3234 		return (0);
3235 
3236 	if (ndev == 0)
3237 		return (SET_ERROR(EINVAL));
3238 
3239 	/*
3240 	 * Make sure the pool is formatted with a version that supports this
3241 	 * device type.
3242 	 */
3243 	if (spa_version(spa) < version)
3244 		return (SET_ERROR(ENOTSUP));
3245 
3246 	/*
3247 	 * Set the pending device list so we correctly handle device in-use
3248 	 * checking.
3249 	 */
3250 	sav->sav_pending = dev;
3251 	sav->sav_npending = ndev;
3252 
3253 	for (i = 0; i < ndev; i++) {
3254 		if ((error = spa_config_parse(spa, &vd, dev[i], NULL, 0,
3255 		    mode)) != 0)
3256 			goto out;
3257 
3258 		if (!vd->vdev_ops->vdev_op_leaf) {
3259 			vdev_free(vd);
3260 			error = SET_ERROR(EINVAL);
3261 			goto out;
3262 		}
3263 
3264 		/*
3265 		 * The L2ARC currently only supports disk devices in
3266 		 * kernel context.  For user-level testing, we allow it.
3267 		 */
3268 #ifdef _KERNEL
3269 		if ((strcmp(config, ZPOOL_CONFIG_L2CACHE) == 0) &&
3270 		    strcmp(vd->vdev_ops->vdev_op_type, VDEV_TYPE_DISK) != 0) {
3271 			error = SET_ERROR(ENOTBLK);
3272 			vdev_free(vd);
3273 			goto out;
3274 		}
3275 #endif
3276 		vd->vdev_top = vd;
3277 
3278 		if ((error = vdev_open(vd)) == 0 &&
3279 		    (error = vdev_label_init(vd, crtxg, label)) == 0) {
3280 			VERIFY(nvlist_add_uint64(dev[i], ZPOOL_CONFIG_GUID,
3281 			    vd->vdev_guid) == 0);
3282 		}
3283 
3284 		vdev_free(vd);
3285 
3286 		if (error &&
3287 		    (mode != VDEV_ALLOC_SPARE && mode != VDEV_ALLOC_L2CACHE))
3288 			goto out;
3289 		else
3290 			error = 0;
3291 	}
3292 
3293 out:
3294 	sav->sav_pending = NULL;
3295 	sav->sav_npending = 0;
3296 	return (error);
3297 }
3298 
3299 static int
3300 spa_validate_aux(spa_t *spa, nvlist_t *nvroot, uint64_t crtxg, int mode)
3301 {
3302 	int error;
3303 
3304 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
3305 
3306 	if ((error = spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3307 	    &spa->spa_spares, ZPOOL_CONFIG_SPARES, SPA_VERSION_SPARES,
3308 	    VDEV_LABEL_SPARE)) != 0) {
3309 		return (error);
3310 	}
3311 
3312 	return (spa_validate_aux_devs(spa, nvroot, crtxg, mode,
3313 	    &spa->spa_l2cache, ZPOOL_CONFIG_L2CACHE, SPA_VERSION_L2CACHE,
3314 	    VDEV_LABEL_L2CACHE));
3315 }
3316 
3317 static void
3318 spa_set_aux_vdevs(spa_aux_vdev_t *sav, nvlist_t **devs, int ndevs,
3319     const char *config)
3320 {
3321 	int i;
3322 
3323 	if (sav->sav_config != NULL) {
3324 		nvlist_t **olddevs;
3325 		uint_t oldndevs;
3326 		nvlist_t **newdevs;
3327 
3328 		/*
3329 		 * Generate new dev list by concatentating with the
3330 		 * current dev list.
3331 		 */
3332 		VERIFY(nvlist_lookup_nvlist_array(sav->sav_config, config,
3333 		    &olddevs, &oldndevs) == 0);
3334 
3335 		newdevs = kmem_alloc(sizeof (void *) *
3336 		    (ndevs + oldndevs), KM_SLEEP);
3337 		for (i = 0; i < oldndevs; i++)
3338 			VERIFY(nvlist_dup(olddevs[i], &newdevs[i],
3339 			    KM_SLEEP) == 0);
3340 		for (i = 0; i < ndevs; i++)
3341 			VERIFY(nvlist_dup(devs[i], &newdevs[i + oldndevs],
3342 			    KM_SLEEP) == 0);
3343 
3344 		VERIFY(nvlist_remove(sav->sav_config, config,
3345 		    DATA_TYPE_NVLIST_ARRAY) == 0);
3346 
3347 		VERIFY(nvlist_add_nvlist_array(sav->sav_config,
3348 		    config, newdevs, ndevs + oldndevs) == 0);
3349 		for (i = 0; i < oldndevs + ndevs; i++)
3350 			nvlist_free(newdevs[i]);
3351 		kmem_free(newdevs, (oldndevs + ndevs) * sizeof (void *));
3352 	} else {
3353 		/*
3354 		 * Generate a new dev list.
3355 		 */
3356 		VERIFY(nvlist_alloc(&sav->sav_config, NV_UNIQUE_NAME,
3357 		    KM_SLEEP) == 0);
3358 		VERIFY(nvlist_add_nvlist_array(sav->sav_config, config,
3359 		    devs, ndevs) == 0);
3360 	}
3361 }
3362 
3363 /*
3364  * Stop and drop level 2 ARC devices
3365  */
3366 void
3367 spa_l2cache_drop(spa_t *spa)
3368 {
3369 	vdev_t *vd;
3370 	int i;
3371 	spa_aux_vdev_t *sav = &spa->spa_l2cache;
3372 
3373 	for (i = 0; i < sav->sav_count; i++) {
3374 		uint64_t pool;
3375 
3376 		vd = sav->sav_vdevs[i];
3377 		ASSERT(vd != NULL);
3378 
3379 		if (spa_l2cache_exists(vd->vdev_guid, &pool) &&
3380 		    pool != 0ULL && l2arc_vdev_present(vd))
3381 			l2arc_remove_vdev(vd);
3382 	}
3383 }
3384 
3385 /*
3386  * Pool Creation
3387  */
3388 int
3389 spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
3390     nvlist_t *zplprops)
3391 {
3392 	spa_t *spa;
3393 	char *altroot = NULL;
3394 	vdev_t *rvd;
3395 	dsl_pool_t *dp;
3396 	dmu_tx_t *tx;
3397 	int error = 0;
3398 	uint64_t txg = TXG_INITIAL;
3399 	nvlist_t **spares, **l2cache;
3400 	uint_t nspares, nl2cache;
3401 	uint64_t version, obj;
3402 	boolean_t has_features;
3403 
3404 	/*
3405 	 * If this pool already exists, return failure.
3406 	 */
3407 	mutex_enter(&spa_namespace_lock);
3408 	if (spa_lookup(pool) != NULL) {
3409 		mutex_exit(&spa_namespace_lock);
3410 		return (SET_ERROR(EEXIST));
3411 	}
3412 
3413 	/*
3414 	 * Allocate a new spa_t structure.
3415 	 */
3416 	(void) nvlist_lookup_string(props,
3417 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3418 	spa = spa_add(pool, NULL, altroot);
3419 	spa_activate(spa, spa_mode_global);
3420 
3421 	if (props && (error = spa_prop_validate(spa, props))) {
3422 		spa_deactivate(spa);
3423 		spa_remove(spa);
3424 		mutex_exit(&spa_namespace_lock);
3425 		return (error);
3426 	}
3427 
3428 	has_features = B_FALSE;
3429 	for (nvpair_t *elem = nvlist_next_nvpair(props, NULL);
3430 	    elem != NULL; elem = nvlist_next_nvpair(props, elem)) {
3431 		if (zpool_prop_feature(nvpair_name(elem)))
3432 			has_features = B_TRUE;
3433 	}
3434 
3435 	if (has_features || nvlist_lookup_uint64(props,
3436 	    zpool_prop_to_name(ZPOOL_PROP_VERSION), &version) != 0) {
3437 		version = SPA_VERSION;
3438 	}
3439 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
3440 
3441 	spa->spa_first_txg = txg;
3442 	spa->spa_uberblock.ub_txg = txg - 1;
3443 	spa->spa_uberblock.ub_version = version;
3444 	spa->spa_ubsync = spa->spa_uberblock;
3445 
3446 	/*
3447 	 * Create "The Godfather" zio to hold all async IOs
3448 	 */
3449 	spa->spa_async_zio_root = zio_root(spa, NULL, NULL,
3450 	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER);
3451 
3452 	/*
3453 	 * Create the root vdev.
3454 	 */
3455 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3456 
3457 	error = spa_config_parse(spa, &rvd, nvroot, NULL, 0, VDEV_ALLOC_ADD);
3458 
3459 	ASSERT(error != 0 || rvd != NULL);
3460 	ASSERT(error != 0 || spa->spa_root_vdev == rvd);
3461 
3462 	if (error == 0 && !zfs_allocatable_devs(nvroot))
3463 		error = SET_ERROR(EINVAL);
3464 
3465 	if (error == 0 &&
3466 	    (error = vdev_create(rvd, txg, B_FALSE)) == 0 &&
3467 	    (error = spa_validate_aux(spa, nvroot, txg,
3468 	    VDEV_ALLOC_ADD)) == 0) {
3469 		for (int c = 0; c < rvd->vdev_children; c++) {
3470 			vdev_metaslab_set_size(rvd->vdev_child[c]);
3471 			vdev_expand(rvd->vdev_child[c], txg);
3472 		}
3473 	}
3474 
3475 	spa_config_exit(spa, SCL_ALL, FTAG);
3476 
3477 	if (error != 0) {
3478 		spa_unload(spa);
3479 		spa_deactivate(spa);
3480 		spa_remove(spa);
3481 		mutex_exit(&spa_namespace_lock);
3482 		return (error);
3483 	}
3484 
3485 	/*
3486 	 * Get the list of spares, if specified.
3487 	 */
3488 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3489 	    &spares, &nspares) == 0) {
3490 		VERIFY(nvlist_alloc(&spa->spa_spares.sav_config, NV_UNIQUE_NAME,
3491 		    KM_SLEEP) == 0);
3492 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3493 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3494 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3495 		spa_load_spares(spa);
3496 		spa_config_exit(spa, SCL_ALL, FTAG);
3497 		spa->spa_spares.sav_sync = B_TRUE;
3498 	}
3499 
3500 	/*
3501 	 * Get the list of level 2 cache devices, if specified.
3502 	 */
3503 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3504 	    &l2cache, &nl2cache) == 0) {
3505 		VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3506 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3507 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3508 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3509 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3510 		spa_load_l2cache(spa);
3511 		spa_config_exit(spa, SCL_ALL, FTAG);
3512 		spa->spa_l2cache.sav_sync = B_TRUE;
3513 	}
3514 
3515 	spa->spa_is_initializing = B_TRUE;
3516 	spa->spa_dsl_pool = dp = dsl_pool_create(spa, zplprops, txg);
3517 	spa->spa_meta_objset = dp->dp_meta_objset;
3518 	spa->spa_is_initializing = B_FALSE;
3519 
3520 	/*
3521 	 * Create DDTs (dedup tables).
3522 	 */
3523 	ddt_create(spa);
3524 
3525 	spa_update_dspace(spa);
3526 
3527 	tx = dmu_tx_create_assigned(dp, txg);
3528 
3529 	/*
3530 	 * Create the pool config object.
3531 	 */
3532 	spa->spa_config_object = dmu_object_alloc(spa->spa_meta_objset,
3533 	    DMU_OT_PACKED_NVLIST, SPA_CONFIG_BLOCKSIZE,
3534 	    DMU_OT_PACKED_NVLIST_SIZE, sizeof (uint64_t), tx);
3535 
3536 	if (zap_add(spa->spa_meta_objset,
3537 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONFIG,
3538 	    sizeof (uint64_t), 1, &spa->spa_config_object, tx) != 0) {
3539 		cmn_err(CE_PANIC, "failed to add pool config");
3540 	}
3541 
3542 	if (spa_version(spa) >= SPA_VERSION_FEATURES)
3543 		spa_feature_create_zap_objects(spa, tx);
3544 
3545 	if (zap_add(spa->spa_meta_objset,
3546 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CREATION_VERSION,
3547 	    sizeof (uint64_t), 1, &version, tx) != 0) {
3548 		cmn_err(CE_PANIC, "failed to add pool version");
3549 	}
3550 
3551 	/* Newly created pools with the right version are always deflated. */
3552 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
3553 		spa->spa_deflate = TRUE;
3554 		if (zap_add(spa->spa_meta_objset,
3555 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
3556 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {
3557 			cmn_err(CE_PANIC, "failed to add deflate");
3558 		}
3559 	}
3560 
3561 	/*
3562 	 * Create the deferred-free bpobj.  Turn off compression
3563 	 * because sync-to-convergence takes longer if the blocksize
3564 	 * keeps changing.
3565 	 */
3566 	obj = bpobj_alloc(spa->spa_meta_objset, 1 << 14, tx);
3567 	dmu_object_set_compress(spa->spa_meta_objset, obj,
3568 	    ZIO_COMPRESS_OFF, tx);
3569 	if (zap_add(spa->spa_meta_objset,
3570 	    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_SYNC_BPOBJ,
3571 	    sizeof (uint64_t), 1, &obj, tx) != 0) {
3572 		cmn_err(CE_PANIC, "failed to add bpobj");
3573 	}
3574 	VERIFY3U(0, ==, bpobj_open(&spa->spa_deferred_bpobj,
3575 	    spa->spa_meta_objset, obj));
3576 
3577 	/*
3578 	 * Create the pool's history object.
3579 	 */
3580 	if (version >= SPA_VERSION_ZPOOL_HISTORY)
3581 		spa_history_create_obj(spa, tx);
3582 
3583 	/*
3584 	 * Set pool properties.
3585 	 */
3586 	spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
3587 	spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
3588 	spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
3589 	spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
3590 
3591 	if (props != NULL) {
3592 		spa_configfile_set(spa, props, B_FALSE);
3593 		spa_sync_props(props, tx);
3594 	}
3595 
3596 	dmu_tx_commit(tx);
3597 
3598 	spa->spa_sync_on = B_TRUE;
3599 	txg_sync_start(spa->spa_dsl_pool);
3600 
3601 	/*
3602 	 * We explicitly wait for the first transaction to complete so that our
3603 	 * bean counters are appropriately updated.
3604 	 */
3605 	txg_wait_synced(spa->spa_dsl_pool, txg);
3606 
3607 	spa_config_sync(spa, B_FALSE, B_TRUE);
3608 
3609 	spa_history_log_version(spa, "create");
3610 
3611 	spa->spa_minref = refcount_count(&spa->spa_refcount);
3612 
3613 	mutex_exit(&spa_namespace_lock);
3614 
3615 	return (0);
3616 }
3617 
3618 #ifdef _KERNEL
3619 /*
3620  * Get the root pool information from the root disk, then import the root pool
3621  * during the system boot up time.
3622  */
3623 extern int vdev_disk_read_rootlabel(char *, char *, nvlist_t **);
3624 
3625 static nvlist_t *
3626 spa_generate_rootconf(char *devpath, char *devid, uint64_t *guid)
3627 {
3628 	nvlist_t *config;
3629 	nvlist_t *nvtop, *nvroot;
3630 	uint64_t pgid;
3631 
3632 	if (vdev_disk_read_rootlabel(devpath, devid, &config) != 0)
3633 		return (NULL);
3634 
3635 	/*
3636 	 * Add this top-level vdev to the child array.
3637 	 */
3638 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3639 	    &nvtop) == 0);
3640 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
3641 	    &pgid) == 0);
3642 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_GUID, guid) == 0);
3643 
3644 	/*
3645 	 * Put this pool's top-level vdevs into a root vdev.
3646 	 */
3647 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
3648 	VERIFY(nvlist_add_string(nvroot, ZPOOL_CONFIG_TYPE,
3649 	    VDEV_TYPE_ROOT) == 0);
3650 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_ID, 0ULL) == 0);
3651 	VERIFY(nvlist_add_uint64(nvroot, ZPOOL_CONFIG_GUID, pgid) == 0);
3652 	VERIFY(nvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_CHILDREN,
3653 	    &nvtop, 1) == 0);
3654 
3655 	/*
3656 	 * Replace the existing vdev_tree with the new root vdev in
3657 	 * this pool's configuration (remove the old, add the new).
3658 	 */
3659 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, nvroot) == 0);
3660 	nvlist_free(nvroot);
3661 	return (config);
3662 }
3663 
3664 /*
3665  * Walk the vdev tree and see if we can find a device with "better"
3666  * configuration. A configuration is "better" if the label on that
3667  * device has a more recent txg.
3668  */
3669 static void
3670 spa_alt_rootvdev(vdev_t *vd, vdev_t **avd, uint64_t *txg)
3671 {
3672 	for (int c = 0; c < vd->vdev_children; c++)
3673 		spa_alt_rootvdev(vd->vdev_child[c], avd, txg);
3674 
3675 	if (vd->vdev_ops->vdev_op_leaf) {
3676 		nvlist_t *label;
3677 		uint64_t label_txg;
3678 
3679 		if (vdev_disk_read_rootlabel(vd->vdev_physpath, vd->vdev_devid,
3680 		    &label) != 0)
3681 			return;
3682 
3683 		VERIFY(nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG,
3684 		    &label_txg) == 0);
3685 
3686 		/*
3687 		 * Do we have a better boot device?
3688 		 */
3689 		if (label_txg > *txg) {
3690 			*txg = label_txg;
3691 			*avd = vd;
3692 		}
3693 		nvlist_free(label);
3694 	}
3695 }
3696 
3697 /*
3698  * Import a root pool.
3699  *
3700  * For x86. devpath_list will consist of devid and/or physpath name of
3701  * the vdev (e.g. "id1,sd@SSEAGATE..." or "/pci@1f,0/ide@d/disk@0,0:a").
3702  * The GRUB "findroot" command will return the vdev we should boot.
3703  *
3704  * For Sparc, devpath_list consists the physpath name of the booting device
3705  * no matter the rootpool is a single device pool or a mirrored pool.
3706  * e.g.
3707  *	"/pci@1f,0/ide@d/disk@0,0:a"
3708  */
3709 int
3710 spa_import_rootpool(char *devpath, char *devid)
3711 {
3712 	spa_t *spa;
3713 	vdev_t *rvd, *bvd, *avd = NULL;
3714 	nvlist_t *config, *nvtop;
3715 	uint64_t guid, txg;
3716 	char *pname;
3717 	int error;
3718 
3719 	/*
3720 	 * Read the label from the boot device and generate a configuration.
3721 	 */
3722 	config = spa_generate_rootconf(devpath, devid, &guid);
3723 #if defined(_OBP) && defined(_KERNEL)
3724 	if (config == NULL) {
3725 		if (strstr(devpath, "/iscsi/ssd") != NULL) {
3726 			/* iscsi boot */
3727 			get_iscsi_bootpath_phy(devpath);
3728 			config = spa_generate_rootconf(devpath, devid, &guid);
3729 		}
3730 	}
3731 #endif
3732 	if (config == NULL) {
3733 		cmn_err(CE_NOTE, "Cannot read the pool label from '%s'",
3734 		    devpath);
3735 		return (SET_ERROR(EIO));
3736 	}
3737 
3738 	VERIFY(nvlist_lookup_string(config, ZPOOL_CONFIG_POOL_NAME,
3739 	    &pname) == 0);
3740 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
3741 
3742 	mutex_enter(&spa_namespace_lock);
3743 	if ((spa = spa_lookup(pname)) != NULL) {
3744 		/*
3745 		 * Remove the existing root pool from the namespace so that we
3746 		 * can replace it with the correct config we just read in.
3747 		 */
3748 		spa_remove(spa);
3749 	}
3750 
3751 	spa = spa_add(pname, config, NULL);
3752 	spa->spa_is_root = B_TRUE;
3753 	spa->spa_import_flags = ZFS_IMPORT_VERBATIM;
3754 
3755 	/*
3756 	 * Build up a vdev tree based on the boot device's label config.
3757 	 */
3758 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3759 	    &nvtop) == 0);
3760 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3761 	error = spa_config_parse(spa, &rvd, nvtop, NULL, 0,
3762 	    VDEV_ALLOC_ROOTPOOL);
3763 	spa_config_exit(spa, SCL_ALL, FTAG);
3764 	if (error) {
3765 		mutex_exit(&spa_namespace_lock);
3766 		nvlist_free(config);
3767 		cmn_err(CE_NOTE, "Can not parse the config for pool '%s'",
3768 		    pname);
3769 		return (error);
3770 	}
3771 
3772 	/*
3773 	 * Get the boot vdev.
3774 	 */
3775 	if ((bvd = vdev_lookup_by_guid(rvd, guid)) == NULL) {
3776 		cmn_err(CE_NOTE, "Can not find the boot vdev for guid %llu",
3777 		    (u_longlong_t)guid);
3778 		error = SET_ERROR(ENOENT);
3779 		goto out;
3780 	}
3781 
3782 	/*
3783 	 * Determine if there is a better boot device.
3784 	 */
3785 	avd = bvd;
3786 	spa_alt_rootvdev(rvd, &avd, &txg);
3787 	if (avd != bvd) {
3788 		cmn_err(CE_NOTE, "The boot device is 'degraded'. Please "
3789 		    "try booting from '%s'", avd->vdev_path);
3790 		error = SET_ERROR(EINVAL);
3791 		goto out;
3792 	}
3793 
3794 	/*
3795 	 * If the boot device is part of a spare vdev then ensure that
3796 	 * we're booting off the active spare.
3797 	 */
3798 	if (bvd->vdev_parent->vdev_ops == &vdev_spare_ops &&
3799 	    !bvd->vdev_isspare) {
3800 		cmn_err(CE_NOTE, "The boot device is currently spared. Please "
3801 		    "try booting from '%s'",
3802 		    bvd->vdev_parent->
3803 		    vdev_child[bvd->vdev_parent->vdev_children - 1]->vdev_path);
3804 		error = SET_ERROR(EINVAL);
3805 		goto out;
3806 	}
3807 
3808 	error = 0;
3809 out:
3810 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3811 	vdev_free(rvd);
3812 	spa_config_exit(spa, SCL_ALL, FTAG);
3813 	mutex_exit(&spa_namespace_lock);
3814 
3815 	nvlist_free(config);
3816 	return (error);
3817 }
3818 
3819 #endif
3820 
3821 /*
3822  * Import a non-root pool into the system.
3823  */
3824 int
3825 spa_import(const char *pool, nvlist_t *config, nvlist_t *props, uint64_t flags)
3826 {
3827 	spa_t *spa;
3828 	char *altroot = NULL;
3829 	spa_load_state_t state = SPA_LOAD_IMPORT;
3830 	zpool_rewind_policy_t policy;
3831 	uint64_t mode = spa_mode_global;
3832 	uint64_t readonly = B_FALSE;
3833 	int error;
3834 	nvlist_t *nvroot;
3835 	nvlist_t **spares, **l2cache;
3836 	uint_t nspares, nl2cache;
3837 
3838 	/*
3839 	 * If a pool with this name exists, return failure.
3840 	 */
3841 	mutex_enter(&spa_namespace_lock);
3842 	if (spa_lookup(pool) != NULL) {
3843 		mutex_exit(&spa_namespace_lock);
3844 		return (SET_ERROR(EEXIST));
3845 	}
3846 
3847 	/*
3848 	 * Create and initialize the spa structure.
3849 	 */
3850 	(void) nvlist_lookup_string(props,
3851 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
3852 	(void) nvlist_lookup_uint64(props,
3853 	    zpool_prop_to_name(ZPOOL_PROP_READONLY), &readonly);
3854 	if (readonly)
3855 		mode = FREAD;
3856 	spa = spa_add(pool, config, altroot);
3857 	spa->spa_import_flags = flags;
3858 
3859 	/*
3860 	 * Verbatim import - Take a pool and insert it into the namespace
3861 	 * as if it had been loaded at boot.
3862 	 */
3863 	if (spa->spa_import_flags & ZFS_IMPORT_VERBATIM) {
3864 		if (props != NULL)
3865 			spa_configfile_set(spa, props, B_FALSE);
3866 
3867 		spa_config_sync(spa, B_FALSE, B_TRUE);
3868 
3869 		mutex_exit(&spa_namespace_lock);
3870 		return (0);
3871 	}
3872 
3873 	spa_activate(spa, mode);
3874 
3875 	/*
3876 	 * Don't start async tasks until we know everything is healthy.
3877 	 */
3878 	spa_async_suspend(spa);
3879 
3880 	zpool_get_rewind_policy(config, &policy);
3881 	if (policy.zrp_request & ZPOOL_DO_REWIND)
3882 		state = SPA_LOAD_RECOVER;
3883 
3884 	/*
3885 	 * Pass off the heavy lifting to spa_load().  Pass TRUE for mosconfig
3886 	 * because the user-supplied config is actually the one to trust when
3887 	 * doing an import.
3888 	 */
3889 	if (state != SPA_LOAD_RECOVER)
3890 		spa->spa_last_ubsync_txg = spa->spa_load_txg = 0;
3891 
3892 	error = spa_load_best(spa, state, B_TRUE, policy.zrp_txg,
3893 	    policy.zrp_request);
3894 
3895 	/*
3896 	 * Propagate anything learned while loading the pool and pass it
3897 	 * back to caller (i.e. rewind info, missing devices, etc).
3898 	 */
3899 	VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
3900 	    spa->spa_load_info) == 0);
3901 
3902 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3903 	/*
3904 	 * Toss any existing sparelist, as it doesn't have any validity
3905 	 * anymore, and conflicts with spa_has_spare().
3906 	 */
3907 	if (spa->spa_spares.sav_config) {
3908 		nvlist_free(spa->spa_spares.sav_config);
3909 		spa->spa_spares.sav_config = NULL;
3910 		spa_load_spares(spa);
3911 	}
3912 	if (spa->spa_l2cache.sav_config) {
3913 		nvlist_free(spa->spa_l2cache.sav_config);
3914 		spa->spa_l2cache.sav_config = NULL;
3915 		spa_load_l2cache(spa);
3916 	}
3917 
3918 	VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
3919 	    &nvroot) == 0);
3920 	if (error == 0)
3921 		error = spa_validate_aux(spa, nvroot, -1ULL,
3922 		    VDEV_ALLOC_SPARE);
3923 	if (error == 0)
3924 		error = spa_validate_aux(spa, nvroot, -1ULL,
3925 		    VDEV_ALLOC_L2CACHE);
3926 	spa_config_exit(spa, SCL_ALL, FTAG);
3927 
3928 	if (props != NULL)
3929 		spa_configfile_set(spa, props, B_FALSE);
3930 
3931 	if (error != 0 || (props && spa_writeable(spa) &&
3932 	    (error = spa_prop_set(spa, props)))) {
3933 		spa_unload(spa);
3934 		spa_deactivate(spa);
3935 		spa_remove(spa);
3936 		mutex_exit(&spa_namespace_lock);
3937 		return (error);
3938 	}
3939 
3940 	spa_async_resume(spa);
3941 
3942 	/*
3943 	 * Override any spares and level 2 cache devices as specified by
3944 	 * the user, as these may have correct device names/devids, etc.
3945 	 */
3946 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
3947 	    &spares, &nspares) == 0) {
3948 		if (spa->spa_spares.sav_config)
3949 			VERIFY(nvlist_remove(spa->spa_spares.sav_config,
3950 			    ZPOOL_CONFIG_SPARES, DATA_TYPE_NVLIST_ARRAY) == 0);
3951 		else
3952 			VERIFY(nvlist_alloc(&spa->spa_spares.sav_config,
3953 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3954 		VERIFY(nvlist_add_nvlist_array(spa->spa_spares.sav_config,
3955 		    ZPOOL_CONFIG_SPARES, spares, nspares) == 0);
3956 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3957 		spa_load_spares(spa);
3958 		spa_config_exit(spa, SCL_ALL, FTAG);
3959 		spa->spa_spares.sav_sync = B_TRUE;
3960 	}
3961 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE,
3962 	    &l2cache, &nl2cache) == 0) {
3963 		if (spa->spa_l2cache.sav_config)
3964 			VERIFY(nvlist_remove(spa->spa_l2cache.sav_config,
3965 			    ZPOOL_CONFIG_L2CACHE, DATA_TYPE_NVLIST_ARRAY) == 0);
3966 		else
3967 			VERIFY(nvlist_alloc(&spa->spa_l2cache.sav_config,
3968 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
3969 		VERIFY(nvlist_add_nvlist_array(spa->spa_l2cache.sav_config,
3970 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache) == 0);
3971 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
3972 		spa_load_l2cache(spa);
3973 		spa_config_exit(spa, SCL_ALL, FTAG);
3974 		spa->spa_l2cache.sav_sync = B_TRUE;
3975 	}
3976 
3977 	/*
3978 	 * Check for any removed devices.
3979 	 */
3980 	if (spa->spa_autoreplace) {
3981 		spa_aux_check_removed(&spa->spa_spares);
3982 		spa_aux_check_removed(&spa->spa_l2cache);
3983 	}
3984 
3985 	if (spa_writeable(spa)) {
3986 		/*
3987 		 * Update the config cache to include the newly-imported pool.
3988 		 */
3989 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
3990 	}
3991 
3992 	/*
3993 	 * It's possible that the pool was expanded while it was exported.
3994 	 * We kick off an async task to handle this for us.
3995 	 */
3996 	spa_async_request(spa, SPA_ASYNC_AUTOEXPAND);
3997 
3998 	mutex_exit(&spa_namespace_lock);
3999 	spa_history_log_version(spa, "import");
4000 
4001 	return (0);
4002 }
4003 
4004 nvlist_t *
4005 spa_tryimport(nvlist_t *tryconfig)
4006 {
4007 	nvlist_t *config = NULL;
4008 	char *poolname;
4009 	spa_t *spa;
4010 	uint64_t state;
4011 	int error;
4012 
4013 	if (nvlist_lookup_string(tryconfig, ZPOOL_CONFIG_POOL_NAME, &poolname))
4014 		return (NULL);
4015 
4016 	if (nvlist_lookup_uint64(tryconfig, ZPOOL_CONFIG_POOL_STATE, &state))
4017 		return (NULL);
4018 
4019 	/*
4020 	 * Create and initialize the spa structure.
4021 	 */
4022 	mutex_enter(&spa_namespace_lock);
4023 	spa = spa_add(TRYIMPORT_NAME, tryconfig, NULL);
4024 	spa_activate(spa, FREAD);
4025 
4026 	/*
4027 	 * Pass off the heavy lifting to spa_load().
4028 	 * Pass TRUE for mosconfig because the user-supplied config
4029 	 * is actually the one to trust when doing an import.
4030 	 */
4031 	error = spa_load(spa, SPA_LOAD_TRYIMPORT, SPA_IMPORT_EXISTING, B_TRUE);
4032 
4033 	/*
4034 	 * If 'tryconfig' was at least parsable, return the current config.
4035 	 */
4036 	if (spa->spa_root_vdev != NULL) {
4037 		config = spa_config_generate(spa, NULL, -1ULL, B_TRUE);
4038 		VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME,
4039 		    poolname) == 0);
4040 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4041 		    state) == 0);
4042 		VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
4043 		    spa->spa_uberblock.ub_timestamp) == 0);
4044 		VERIFY(nvlist_add_nvlist(config, ZPOOL_CONFIG_LOAD_INFO,
4045 		    spa->spa_load_info) == 0);
4046 
4047 		/*
4048 		 * If the bootfs property exists on this pool then we
4049 		 * copy it out so that external consumers can tell which
4050 		 * pools are bootable.
4051 		 */
4052 		if ((!error || error == EEXIST) && spa->spa_bootfs) {
4053 			char *tmpname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4054 
4055 			/*
4056 			 * We have to play games with the name since the
4057 			 * pool was opened as TRYIMPORT_NAME.
4058 			 */
4059 			if (dsl_dsobj_to_dsname(spa_name(spa),
4060 			    spa->spa_bootfs, tmpname) == 0) {
4061 				char *cp;
4062 				char *dsname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
4063 
4064 				cp = strchr(tmpname, '/');
4065 				if (cp == NULL) {
4066 					(void) strlcpy(dsname, tmpname,
4067 					    MAXPATHLEN);
4068 				} else {
4069 					(void) snprintf(dsname, MAXPATHLEN,
4070 					    "%s/%s", poolname, ++cp);
4071 				}
4072 				VERIFY(nvlist_add_string(config,
4073 				    ZPOOL_CONFIG_BOOTFS, dsname) == 0);
4074 				kmem_free(dsname, MAXPATHLEN);
4075 			}
4076 			kmem_free(tmpname, MAXPATHLEN);
4077 		}
4078 
4079 		/*
4080 		 * Add the list of hot spares and level 2 cache devices.
4081 		 */
4082 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
4083 		spa_add_spares(spa, config);
4084 		spa_add_l2cache(spa, config);
4085 		spa_config_exit(spa, SCL_CONFIG, FTAG);
4086 	}
4087 
4088 	spa_unload(spa);
4089 	spa_deactivate(spa);
4090 	spa_remove(spa);
4091 	mutex_exit(&spa_namespace_lock);
4092 
4093 	return (config);
4094 }
4095 
4096 /*
4097  * Pool export/destroy
4098  *
4099  * The act of destroying or exporting a pool is very simple.  We make sure there
4100  * is no more pending I/O and any references to the pool are gone.  Then, we
4101  * update the pool state and sync all the labels to disk, removing the
4102  * configuration from the cache afterwards. If the 'hardforce' flag is set, then
4103  * we don't sync the labels or remove the configuration cache.
4104  */
4105 static int
4106 spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
4107     boolean_t force, boolean_t hardforce)
4108 {
4109 	spa_t *spa;
4110 
4111 	if (oldconfig)
4112 		*oldconfig = NULL;
4113 
4114 	if (!(spa_mode_global & FWRITE))
4115 		return (SET_ERROR(EROFS));
4116 
4117 	mutex_enter(&spa_namespace_lock);
4118 	if ((spa = spa_lookup(pool)) == NULL) {
4119 		mutex_exit(&spa_namespace_lock);
4120 		return (SET_ERROR(ENOENT));
4121 	}
4122 
4123 	/*
4124 	 * Put a hold on the pool, drop the namespace lock, stop async tasks,
4125 	 * reacquire the namespace lock, and see if we can export.
4126 	 */
4127 	spa_open_ref(spa, FTAG);
4128 	mutex_exit(&spa_namespace_lock);
4129 	spa_async_suspend(spa);
4130 	mutex_enter(&spa_namespace_lock);
4131 	spa_close(spa, FTAG);
4132 
4133 	/*
4134 	 * The pool will be in core if it's openable,
4135 	 * in which case we can modify its state.
4136 	 */
4137 	if (spa->spa_state != POOL_STATE_UNINITIALIZED && spa->spa_sync_on) {
4138 		/*
4139 		 * Objsets may be open only because they're dirty, so we
4140 		 * have to force it to sync before checking spa_refcnt.
4141 		 */
4142 		txg_wait_synced(spa->spa_dsl_pool, 0);
4143 
4144 		/*
4145 		 * A pool cannot be exported or destroyed if there are active
4146 		 * references.  If we are resetting a pool, allow references by
4147 		 * fault injection handlers.
4148 		 */
4149 		if (!spa_refcount_zero(spa) ||
4150 		    (spa->spa_inject_ref != 0 &&
4151 		    new_state != POOL_STATE_UNINITIALIZED)) {
4152 			spa_async_resume(spa);
4153 			mutex_exit(&spa_namespace_lock);
4154 			return (SET_ERROR(EBUSY));
4155 		}
4156 
4157 		/*
4158 		 * A pool cannot be exported if it has an active shared spare.
4159 		 * This is to prevent other pools stealing the active spare
4160 		 * from an exported pool. At user's own will, such pool can
4161 		 * be forcedly exported.
4162 		 */
4163 		if (!force && new_state == POOL_STATE_EXPORTED &&
4164 		    spa_has_active_shared_spare(spa)) {
4165 			spa_async_resume(spa);
4166 			mutex_exit(&spa_namespace_lock);
4167 			return (SET_ERROR(EXDEV));
4168 		}
4169 
4170 		/*
4171 		 * We want this to be reflected on every label,
4172 		 * so mark them all dirty.  spa_unload() will do the
4173 		 * final sync that pushes these changes out.
4174 		 */
4175 		if (new_state != POOL_STATE_UNINITIALIZED && !hardforce) {
4176 			spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
4177 			spa->spa_state = new_state;
4178 			spa->spa_final_txg = spa_last_synced_txg(spa) +
4179 			    TXG_DEFER_SIZE + 1;
4180 			vdev_config_dirty(spa->spa_root_vdev);
4181 			spa_config_exit(spa, SCL_ALL, FTAG);
4182 		}
4183 	}
4184 
4185 	spa_event_notify(spa, NULL, ESC_ZFS_POOL_DESTROY);
4186 
4187 	if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
4188 		spa_unload(spa);
4189 		spa_deactivate(spa);
4190 	}
4191 
4192 	if (oldconfig && spa->spa_config)
4193 		VERIFY(nvlist_dup(spa->spa_config, oldconfig, 0) == 0);
4194 
4195 	if (new_state != POOL_STATE_UNINITIALIZED) {
4196 		if (!hardforce)
4197 			spa_config_sync(spa, B_TRUE, B_TRUE);
4198 		spa_remove(spa);
4199 	}
4200 	mutex_exit(&spa_namespace_lock);
4201 
4202 	return (0);
4203 }
4204 
4205 /*
4206  * Destroy a storage pool.
4207  */
4208 int
4209 spa_destroy(char *pool)
4210 {
4211 	return (spa_export_common(pool, POOL_STATE_DESTROYED, NULL,
4212 	    B_FALSE, B_FALSE));
4213 }
4214 
4215 /*
4216  * Export a storage pool.
4217  */
4218 int
4219 spa_export(char *pool, nvlist_t **oldconfig, boolean_t force,
4220     boolean_t hardforce)
4221 {
4222 	return (spa_export_common(pool, POOL_STATE_EXPORTED, oldconfig,
4223 	    force, hardforce));
4224 }
4225 
4226 /*
4227  * Similar to spa_export(), this unloads the spa_t without actually removing it
4228  * from the namespace in any way.
4229  */
4230 int
4231 spa_reset(char *pool)
4232 {
4233 	return (spa_export_common(pool, POOL_STATE_UNINITIALIZED, NULL,
4234 	    B_FALSE, B_FALSE));
4235 }
4236 
4237 /*
4238  * ==========================================================================
4239  * Device manipulation
4240  * ==========================================================================
4241  */
4242 
4243 /*
4244  * Add a device to a storage pool.
4245  */
4246 int
4247 spa_vdev_add(spa_t *spa, nvlist_t *nvroot)
4248 {
4249 	uint64_t txg, id;
4250 	int error;
4251 	vdev_t *rvd = spa->spa_root_vdev;
4252 	vdev_t *vd, *tvd;
4253 	nvlist_t **spares, **l2cache;
4254 	uint_t nspares, nl2cache;
4255 
4256 	ASSERT(spa_writeable(spa));
4257 
4258 	txg = spa_vdev_enter(spa);
4259 
4260 	if ((error = spa_config_parse(spa, &vd, nvroot, NULL, 0,
4261 	    VDEV_ALLOC_ADD)) != 0)
4262 		return (spa_vdev_exit(spa, NULL, txg, error));
4263 
4264 	spa->spa_pending_vdev = vd;	/* spa_vdev_exit() will clear this */
4265 
4266 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &spares,
4267 	    &nspares) != 0)
4268 		nspares = 0;
4269 
4270 	if (nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_L2CACHE, &l2cache,
4271 	    &nl2cache) != 0)
4272 		nl2cache = 0;
4273 
4274 	if (vd->vdev_children == 0 && nspares == 0 && nl2cache == 0)
4275 		return (spa_vdev_exit(spa, vd, txg, EINVAL));
4276 
4277 	if (vd->vdev_children != 0 &&
4278 	    (error = vdev_create(vd, txg, B_FALSE)) != 0)
4279 		return (spa_vdev_exit(spa, vd, txg, error));
4280 
4281 	/*
4282 	 * We must validate the spares and l2cache devices after checking the
4283 	 * children.  Otherwise, vdev_inuse() will blindly overwrite the spare.
4284 	 */
4285 	if ((error = spa_validate_aux(spa, nvroot, txg, VDEV_ALLOC_ADD)) != 0)
4286 		return (spa_vdev_exit(spa, vd, txg, error));
4287 
4288 	/*
4289 	 * Transfer each new top-level vdev from vd to rvd.
4290 	 */
4291 	for (int c = 0; c < vd->vdev_children; c++) {
4292 
4293 		/*
4294 		 * Set the vdev id to the first hole, if one exists.
4295 		 */
4296 		for (id = 0; id < rvd->vdev_children; id++) {
4297 			if (rvd->vdev_child[id]->vdev_ishole) {
4298 				vdev_free(rvd->vdev_child[id]);
4299 				break;
4300 			}
4301 		}
4302 		tvd = vd->vdev_child[c];
4303 		vdev_remove_child(vd, tvd);
4304 		tvd->vdev_id = id;
4305 		vdev_add_child(rvd, tvd);
4306 		vdev_config_dirty(tvd);
4307 	}
4308 
4309 	if (nspares != 0) {
4310 		spa_set_aux_vdevs(&spa->spa_spares, spares, nspares,
4311 		    ZPOOL_CONFIG_SPARES);
4312 		spa_load_spares(spa);
4313 		spa->spa_spares.sav_sync = B_TRUE;
4314 	}
4315 
4316 	if (nl2cache != 0) {
4317 		spa_set_aux_vdevs(&spa->spa_l2cache, l2cache, nl2cache,
4318 		    ZPOOL_CONFIG_L2CACHE);
4319 		spa_load_l2cache(spa);
4320 		spa->spa_l2cache.sav_sync = B_TRUE;
4321 	}
4322 
4323 	/*
4324 	 * We have to be careful when adding new vdevs to an existing pool.
4325 	 * If other threads start allocating from these vdevs before we
4326 	 * sync the config cache, and we lose power, then upon reboot we may
4327 	 * fail to open the pool because there are DVAs that the config cache
4328 	 * can't translate.  Therefore, we first add the vdevs without
4329 	 * initializing metaslabs; sync the config cache (via spa_vdev_exit());
4330 	 * and then let spa_config_update() initialize the new metaslabs.
4331 	 *
4332 	 * spa_load() checks for added-but-not-initialized vdevs, so that
4333 	 * if we lose power at any point in this sequence, the remaining
4334 	 * steps will be completed the next time we load the pool.
4335 	 */
4336 	(void) spa_vdev_exit(spa, vd, txg, 0);
4337 
4338 	mutex_enter(&spa_namespace_lock);
4339 	spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
4340 	mutex_exit(&spa_namespace_lock);
4341 
4342 	return (0);
4343 }
4344 
4345 /*
4346  * Attach a device to a mirror.  The arguments are the path to any device
4347  * in the mirror, and the nvroot for the new device.  If the path specifies
4348  * a device that is not mirrored, we automatically insert the mirror vdev.
4349  *
4350  * If 'replacing' is specified, the new device is intended to replace the
4351  * existing device; in this case the two devices are made into their own
4352  * mirror using the 'replacing' vdev, which is functionally identical to
4353  * the mirror vdev (it actually reuses all the same ops) but has a few
4354  * extra rules: you can't attach to it after it's been created, and upon
4355  * completion of resilvering, the first disk (the one being replaced)
4356  * is automatically detached.
4357  */
4358 int
4359 spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
4360 {
4361 	uint64_t txg, dtl_max_txg;
4362 	vdev_t *rvd = spa->spa_root_vdev;
4363 	vdev_t *oldvd, *newvd, *newrootvd, *pvd, *tvd;
4364 	vdev_ops_t *pvops;
4365 	char *oldvdpath, *newvdpath;
4366 	int newvd_isspare;
4367 	int error;
4368 
4369 	ASSERT(spa_writeable(spa));
4370 
4371 	txg = spa_vdev_enter(spa);
4372 
4373 	oldvd = spa_lookup_by_guid(spa, guid, B_FALSE);
4374 
4375 	if (oldvd == NULL)
4376 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4377 
4378 	if (!oldvd->vdev_ops->vdev_op_leaf)
4379 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4380 
4381 	pvd = oldvd->vdev_parent;
4382 
4383 	if ((error = spa_config_parse(spa, &newrootvd, nvroot, NULL, 0,
4384 	    VDEV_ALLOC_ATTACH)) != 0)
4385 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4386 
4387 	if (newrootvd->vdev_children != 1)
4388 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4389 
4390 	newvd = newrootvd->vdev_child[0];
4391 
4392 	if (!newvd->vdev_ops->vdev_op_leaf)
4393 		return (spa_vdev_exit(spa, newrootvd, txg, EINVAL));
4394 
4395 	if ((error = vdev_create(newrootvd, txg, replacing)) != 0)
4396 		return (spa_vdev_exit(spa, newrootvd, txg, error));
4397 
4398 	/*
4399 	 * Spares can't replace logs
4400 	 */
4401 	if (oldvd->vdev_top->vdev_islog && newvd->vdev_isspare)
4402 		return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4403 
4404 	if (!replacing) {
4405 		/*
4406 		 * For attach, the only allowable parent is a mirror or the root
4407 		 * vdev.
4408 		 */
4409 		if (pvd->vdev_ops != &vdev_mirror_ops &&
4410 		    pvd->vdev_ops != &vdev_root_ops)
4411 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4412 
4413 		pvops = &vdev_mirror_ops;
4414 	} else {
4415 		/*
4416 		 * Active hot spares can only be replaced by inactive hot
4417 		 * spares.
4418 		 */
4419 		if (pvd->vdev_ops == &vdev_spare_ops &&
4420 		    oldvd->vdev_isspare &&
4421 		    !spa_has_spare(spa, newvd->vdev_guid))
4422 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4423 
4424 		/*
4425 		 * If the source is a hot spare, and the parent isn't already a
4426 		 * spare, then we want to create a new hot spare.  Otherwise, we
4427 		 * want to create a replacing vdev.  The user is not allowed to
4428 		 * attach to a spared vdev child unless the 'isspare' state is
4429 		 * the same (spare replaces spare, non-spare replaces
4430 		 * non-spare).
4431 		 */
4432 		if (pvd->vdev_ops == &vdev_replacing_ops &&
4433 		    spa_version(spa) < SPA_VERSION_MULTI_REPLACE) {
4434 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4435 		} else if (pvd->vdev_ops == &vdev_spare_ops &&
4436 		    newvd->vdev_isspare != oldvd->vdev_isspare) {
4437 			return (spa_vdev_exit(spa, newrootvd, txg, ENOTSUP));
4438 		}
4439 
4440 		if (newvd->vdev_isspare)
4441 			pvops = &vdev_spare_ops;
4442 		else
4443 			pvops = &vdev_replacing_ops;
4444 	}
4445 
4446 	/*
4447 	 * Make sure the new device is big enough.
4448 	 */
4449 	if (newvd->vdev_asize < vdev_get_min_asize(oldvd))
4450 		return (spa_vdev_exit(spa, newrootvd, txg, EOVERFLOW));
4451 
4452 	/*
4453 	 * The new device cannot have a higher alignment requirement
4454 	 * than the top-level vdev.
4455 	 */
4456 	if (newvd->vdev_ashift > oldvd->vdev_top->vdev_ashift)
4457 		return (spa_vdev_exit(spa, newrootvd, txg, EDOM));
4458 
4459 	/*
4460 	 * If this is an in-place replacement, update oldvd's path and devid
4461 	 * to make it distinguishable from newvd, and unopenable from now on.
4462 	 */
4463 	if (strcmp(oldvd->vdev_path, newvd->vdev_path) == 0) {
4464 		spa_strfree(oldvd->vdev_path);
4465 		oldvd->vdev_path = kmem_alloc(strlen(newvd->vdev_path) + 5,
4466 		    KM_SLEEP);
4467 		(void) sprintf(oldvd->vdev_path, "%s/%s",
4468 		    newvd->vdev_path, "old");
4469 		if (oldvd->vdev_devid != NULL) {
4470 			spa_strfree(oldvd->vdev_devid);
4471 			oldvd->vdev_devid = NULL;
4472 		}
4473 	}
4474 
4475 	/* mark the device being resilvered */
4476 	newvd->vdev_resilver_txg = txg;
4477 
4478 	/*
4479 	 * If the parent is not a mirror, or if we're replacing, insert the new
4480 	 * mirror/replacing/spare vdev above oldvd.
4481 	 */
4482 	if (pvd->vdev_ops != pvops)
4483 		pvd = vdev_add_parent(oldvd, pvops);
4484 
4485 	ASSERT(pvd->vdev_top->vdev_parent == rvd);
4486 	ASSERT(pvd->vdev_ops == pvops);
4487 	ASSERT(oldvd->vdev_parent == pvd);
4488 
4489 	/*
4490 	 * Extract the new device from its root and add it to pvd.
4491 	 */
4492 	vdev_remove_child(newrootvd, newvd);
4493 	newvd->vdev_id = pvd->vdev_children;
4494 	newvd->vdev_crtxg = oldvd->vdev_crtxg;
4495 	vdev_add_child(pvd, newvd);
4496 
4497 	tvd = newvd->vdev_top;
4498 	ASSERT(pvd->vdev_top == tvd);
4499 	ASSERT(tvd->vdev_parent == rvd);
4500 
4501 	vdev_config_dirty(tvd);
4502 
4503 	/*
4504 	 * Set newvd's DTL to [TXG_INITIAL, dtl_max_txg) so that we account
4505 	 * for any dmu_sync-ed blocks.  It will propagate upward when
4506 	 * spa_vdev_exit() calls vdev_dtl_reassess().
4507 	 */
4508 	dtl_max_txg = txg + TXG_CONCURRENT_STATES;
4509 
4510 	vdev_dtl_dirty(newvd, DTL_MISSING, TXG_INITIAL,
4511 	    dtl_max_txg - TXG_INITIAL);
4512 
4513 	if (newvd->vdev_isspare) {
4514 		spa_spare_activate(newvd);
4515 		spa_event_notify(spa, newvd, ESC_ZFS_VDEV_SPARE);
4516 	}
4517 
4518 	oldvdpath = spa_strdup(oldvd->vdev_path);
4519 	newvdpath = spa_strdup(newvd->vdev_path);
4520 	newvd_isspare = newvd->vdev_isspare;
4521 
4522 	/*
4523 	 * Mark newvd's DTL dirty in this txg.
4524 	 */
4525 	vdev_dirty(tvd, VDD_DTL, newvd, txg);
4526 
4527 	/*
4528 	 * Schedule the resilver to restart in the future. We do this to
4529 	 * ensure that dmu_sync-ed blocks have been stitched into the
4530 	 * respective datasets.
4531 	 */
4532 	dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
4533 
4534 	/*
4535 	 * Commit the config
4536 	 */
4537 	(void) spa_vdev_exit(spa, newrootvd, dtl_max_txg, 0);
4538 
4539 	spa_history_log_internal(spa, "vdev attach", NULL,
4540 	    "%s vdev=%s %s vdev=%s",
4541 	    replacing && newvd_isspare ? "spare in" :
4542 	    replacing ? "replace" : "attach", newvdpath,
4543 	    replacing ? "for" : "to", oldvdpath);
4544 
4545 	spa_strfree(oldvdpath);
4546 	spa_strfree(newvdpath);
4547 
4548 	if (spa->spa_bootfs)
4549 		spa_event_notify(spa, newvd, ESC_ZFS_BOOTFS_VDEV_ATTACH);
4550 
4551 	return (0);
4552 }
4553 
4554 /*
4555  * Detach a device from a mirror or replacing vdev.
4556  *
4557  * If 'replace_done' is specified, only detach if the parent
4558  * is a replacing vdev.
4559  */
4560 int
4561 spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
4562 {
4563 	uint64_t txg;
4564 	int error;
4565 	vdev_t *rvd = spa->spa_root_vdev;
4566 	vdev_t *vd, *pvd, *cvd, *tvd;
4567 	boolean_t unspare = B_FALSE;
4568 	uint64_t unspare_guid = 0;
4569 	char *vdpath;
4570 
4571 	ASSERT(spa_writeable(spa));
4572 
4573 	txg = spa_vdev_enter(spa);
4574 
4575 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
4576 
4577 	if (vd == NULL)
4578 		return (spa_vdev_exit(spa, NULL, txg, ENODEV));
4579 
4580 	if (!vd->vdev_ops->vdev_op_leaf)
4581 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4582 
4583 	pvd = vd->vdev_parent;
4584 
4585 	/*
4586 	 * If the parent/child relationship is not as expected, don't do it.
4587 	 * Consider M(A,R(B,C)) -- that is, a mirror of A with a replacing
4588 	 * vdev that's replacing B with C.  The user's intent in replacing
4589 	 * is to go from M(A,B) to M(A,C).  If the user decides to cancel
4590 	 * the replace by detaching C, the expected behavior is to end up
4591 	 * M(A,B).  But suppose that right after deciding to detach C,
4592 	 * the replacement of B completes.  We would have M(A,C), and then
4593 	 * ask to detach C, which would leave us with just A -- not what
4594 	 * the user wanted.  To prevent this, we make sure that the
4595 	 * parent/child relationship hasn't changed -- in this example,
4596 	 * that C's parent is still the replacing vdev R.
4597 	 */
4598 	if (pvd->vdev_guid != pguid && pguid != 0)
4599 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4600 
4601 	/*
4602 	 * Only 'replacing' or 'spare' vdevs can be replaced.
4603 	 */
4604 	if (replace_done && pvd->vdev_ops != &vdev_replacing_ops &&
4605 	    pvd->vdev_ops != &vdev_spare_ops)
4606 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4607 
4608 	ASSERT(pvd->vdev_ops != &vdev_spare_ops ||
4609 	    spa_version(spa) >= SPA_VERSION_SPARES);
4610 
4611 	/*
4612 	 * Only mirror, replacing, and spare vdevs support detach.
4613 	 */
4614 	if (pvd->vdev_ops != &vdev_replacing_ops &&
4615 	    pvd->vdev_ops != &vdev_mirror_ops &&
4616 	    pvd->vdev_ops != &vdev_spare_ops)
4617 		return (spa_vdev_exit(spa, NULL, txg, ENOTSUP));
4618 
4619 	/*
4620 	 * If this device has the only valid copy of some data,
4621 	 * we cannot safely detach it.
4622 	 */
4623 	if (vdev_dtl_required(vd))
4624 		return (spa_vdev_exit(spa, NULL, txg, EBUSY));
4625 
4626 	ASSERT(pvd->vdev_children >= 2);
4627 
4628 	/*
4629 	 * If we are detaching the second disk from a replacing vdev, then
4630 	 * check to see if we changed the original vdev's path to have "/old"
4631 	 * at the end in spa_vdev_attach().  If so, undo that change now.
4632 	 */
4633 	if (pvd->vdev_ops == &vdev_replacing_ops && vd->vdev_id > 0 &&
4634 	    vd->vdev_path != NULL) {
4635 		size_t len = strlen(vd->vdev_path);
4636 
4637 		for (int c = 0; c < pvd->vdev_children; c++) {
4638 			cvd = pvd->vdev_child[c];
4639 
4640 			if (cvd == vd || cvd->vdev_path == NULL)
4641 				continue;
4642 
4643 			if (strncmp(cvd->vdev_path, vd->vdev_path, len) == 0 &&
4644 			    strcmp(cvd->vdev_path + len, "/old") == 0) {
4645 				spa_strfree(cvd->vdev_path);
4646 				cvd->vdev_path = spa_strdup(vd->vdev_path);
4647 				break;
4648 			}
4649 		}
4650 	}
4651 
4652 	/*
4653 	 * If we are detaching the original disk from a spare, then it implies
4654 	 * that the spare should become a real disk, and be removed from the
4655 	 * active spare list for the pool.
4656 	 */
4657 	if (pvd->vdev_ops == &vdev_spare_ops &&
4658 	    vd->vdev_id == 0 &&
4659 	    pvd->vdev_child[pvd->vdev_children - 1]->vdev_isspare)
4660 		unspare = B_TRUE;
4661 
4662 	/*
4663 	 * Erase the disk labels so the disk can be used for other things.
4664 	 * This must be done after all other error cases are handled,
4665 	 * but before we disembowel vd (so we can still do I/O to it).
4666 	 * But if we can't do it, don't treat the error as fatal --
4667 	 * it may be that the unwritability of the disk is the reason
4668 	 * it's being detached!
4669 	 */
4670 	error = vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
4671 
4672 	/*
4673 	 * Remove vd from its parent and compact the parent's children.
4674 	 */
4675 	vdev_remove_child(pvd, vd);
4676 	vdev_compact_children(pvd);
4677 
4678 	/*
4679 	 * Remember one of the remaining children so we can get tvd below.
4680 	 */
4681 	cvd = pvd->vdev_child[pvd->vdev_children - 1];
4682 
4683 	/*
4684 	 * If we need to remove the remaining child from the list of hot spares,
4685 	 * do it now, marking the vdev as no longer a spare in the process.
4686 	 * We must do this before vdev_remove_parent(), because that can
4687 	 * change the GUID if it creates a new toplevel GUID.  For a similar
4688 	 * reason, we must remove the spare now, in the same txg as the detach;
4689 	 * otherwise someone could attach a new sibling, change the GUID, and
4690 	 * the subsequent attempt to spa_vdev_remove(unspare_guid) would fail.
4691 	 */
4692 	if (unspare) {
4693 		ASSERT(cvd->vdev_isspare);
4694 		spa_spare_remove(cvd);
4695 		unspare_guid = cvd->vdev_guid;
4696 		(void) spa_vdev_remove(spa, unspare_guid, B_TRUE);
4697 		cvd->vdev_unspare = B_TRUE;
4698 	}
4699 
4700 	/*
4701 	 * If the parent mirror/replacing vdev only has one child,
4702 	 * the parent is no longer needed.  Remove it from the tree.
4703 	 */
4704 	if (pvd->vdev_children == 1) {
4705 		if (pvd->vdev_ops == &vdev_spare_ops)
4706 			cvd->vdev_unspare = B_FALSE;
4707 		vdev_remove_parent(cvd);
4708 	}
4709 
4710 
4711 	/*
4712 	 * We don't set tvd until now because the parent we just removed
4713 	 * may have been the previous top-level vdev.
4714 	 */
4715 	tvd = cvd->vdev_top;
4716 	ASSERT(tvd->vdev_parent == rvd);
4717 
4718 	/*
4719 	 * Reevaluate the parent vdev state.
4720 	 */
4721 	vdev_propagate_state(cvd);
4722 
4723 	/*
4724 	 * If the 'autoexpand' property is set on the pool then automatically
4725 	 * try to expand the size of the pool. For example if the device we
4726 	 * just detached was smaller than the others, it may be possible to
4727 	 * add metaslabs (i.e. grow the pool). We need to reopen the vdev
4728 	 * first so that we can obtain the updated sizes of the leaf vdevs.
4729 	 */
4730 	if (spa->spa_autoexpand) {
4731 		vdev_reopen(tvd);
4732 		vdev_expand(tvd, txg);
4733 	}
4734 
4735 	vdev_config_dirty(tvd);
4736 
4737 	/*
4738 	 * Mark vd's DTL as dirty in this txg.  vdev_dtl_sync() will see that
4739 	 * vd->vdev_detached is set and free vd's DTL object in syncing context.
4740 	 * But first make sure we're not on any *other* txg's DTL list, to
4741 	 * prevent vd from being accessed after it's freed.
4742 	 */
4743 	vdpath = spa_strdup(vd->vdev_path);
4744 	for (int t = 0; t < TXG_SIZE; t++)
4745 		(void) txg_list_remove_this(&tvd->vdev_dtl_list, vd, t);
4746 	vd->vdev_detached = B_TRUE;
4747 	vdev_dirty(tvd, VDD_DTL, vd, txg);
4748 
4749 	spa_event_notify(spa, vd, ESC_ZFS_VDEV_REMOVE);
4750 
4751 	/* hang on to the spa before we release the lock */
4752 	spa_open_ref(spa, FTAG);
4753 
4754 	error = spa_vdev_exit(spa, vd, txg, 0);
4755 
4756 	spa_history_log_internal(spa, "detach", NULL,
4757 	    "vdev=%s", vdpath);
4758 	spa_strfree(vdpath);
4759 
4760 	/*
4761 	 * If this was the removal of the original device in a hot spare vdev,
4762 	 * then we want to go through and remove the device from the hot spare
4763 	 * list of every other pool.
4764 	 */
4765 	if (unspare) {
4766 		spa_t *altspa = NULL;
4767 
4768 		mutex_enter(&spa_namespace_lock);
4769 		while ((altspa = spa_next(altspa)) != NULL) {
4770 			if (altspa->spa_state != POOL_STATE_ACTIVE ||
4771 			    altspa == spa)
4772 				continue;
4773 
4774 			spa_open_ref(altspa, FTAG);
4775 			mutex_exit(&spa_namespace_lock);
4776 			(void) spa_vdev_remove(altspa, unspare_guid, B_TRUE);
4777 			mutex_enter(&spa_namespace_lock);
4778 			spa_close(altspa, FTAG);
4779 		}
4780 		mutex_exit(&spa_namespace_lock);
4781 
4782 		/* search the rest of the vdevs for spares to remove */
4783 		spa_vdev_resilver_done(spa);
4784 	}
4785 
4786 	/* all done with the spa; OK to release */
4787 	mutex_enter(&spa_namespace_lock);
4788 	spa_close(spa, FTAG);
4789 	mutex_exit(&spa_namespace_lock);
4790 
4791 	return (error);
4792 }
4793 
4794 /*
4795  * Split a set of devices from their mirrors, and create a new pool from them.
4796  */
4797 int
4798 spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
4799     nvlist_t *props, boolean_t exp)
4800 {
4801 	int error = 0;
4802 	uint64_t txg, *glist;
4803 	spa_t *newspa;
4804 	uint_t c, children, lastlog;
4805 	nvlist_t **child, *nvl, *tmp;
4806 	dmu_tx_t *tx;
4807 	char *altroot = NULL;
4808 	vdev_t *rvd, **vml = NULL;			/* vdev modify list */
4809 	boolean_t activate_slog;
4810 
4811 	ASSERT(spa_writeable(spa));
4812 
4813 	txg = spa_vdev_enter(spa);
4814 
4815 	/* clear the log and flush everything up to now */
4816 	activate_slog = spa_passivate_log(spa);
4817 	(void) spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4818 	error = spa_offline_log(spa);
4819 	txg = spa_vdev_config_enter(spa);
4820 
4821 	if (activate_slog)
4822 		spa_activate_log(spa);
4823 
4824 	if (error != 0)
4825 		return (spa_vdev_exit(spa, NULL, txg, error));
4826 
4827 	/* check new spa name before going any further */
4828 	if (spa_lookup(newname) != NULL)
4829 		return (spa_vdev_exit(spa, NULL, txg, EEXIST));
4830 
4831 	/*
4832 	 * scan through all the children to ensure they're all mirrors
4833 	 */
4834 	if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE, &nvl) != 0 ||
4835 	    nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN, &child,
4836 	    &children) != 0)
4837 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4838 
4839 	/* first, check to ensure we've got the right child count */
4840 	rvd = spa->spa_root_vdev;
4841 	lastlog = 0;
4842 	for (c = 0; c < rvd->vdev_children; c++) {
4843 		vdev_t *vd = rvd->vdev_child[c];
4844 
4845 		/* don't count the holes & logs as children */
4846 		if (vd->vdev_islog || vd->vdev_ishole) {
4847 			if (lastlog == 0)
4848 				lastlog = c;
4849 			continue;
4850 		}
4851 
4852 		lastlog = 0;
4853 	}
4854 	if (children != (lastlog != 0 ? lastlog : rvd->vdev_children))
4855 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4856 
4857 	/* next, ensure no spare or cache devices are part of the split */
4858 	if (nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_SPARES, &tmp) == 0 ||
4859 	    nvlist_lookup_nvlist(nvl, ZPOOL_CONFIG_L2CACHE, &tmp) == 0)
4860 		return (spa_vdev_exit(spa, NULL, txg, EINVAL));
4861 
4862 	vml = kmem_zalloc(children * sizeof (vdev_t *), KM_SLEEP);
4863 	glist = kmem_zalloc(children * sizeof (uint64_t), KM_SLEEP);
4864 
4865 	/* then, loop over each vdev and validate it */
4866 	for (c = 0; c < children; c++) {
4867 		uint64_t is_hole = 0;
4868 
4869 		(void) nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_IS_HOLE,
4870 		    &is_hole);
4871 
4872 		if (is_hole != 0) {
4873 			if (spa->spa_root_vdev->vdev_child[c]->vdev_ishole ||
4874 			    spa->spa_root_vdev->vdev_child[c]->vdev_islog) {
4875 				continue;
4876 			} else {
4877 				error = SET_ERROR(EINVAL);
4878 				break;
4879 			}
4880 		}
4881 
4882 		/* which disk is going to be split? */
4883 		if (nvlist_lookup_uint64(child[c], ZPOOL_CONFIG_GUID,
4884 		    &glist[c]) != 0) {
4885 			error = SET_ERROR(EINVAL);
4886 			break;
4887 		}
4888 
4889 		/* look it up in the spa */
4890 		vml[c] = spa_lookup_by_guid(spa, glist[c], B_FALSE);
4891 		if (vml[c] == NULL) {
4892 			error = SET_ERROR(ENODEV);
4893 			break;
4894 		}
4895 
4896 		/* make sure there's nothing stopping the split */
4897 		if (vml[c]->vdev_parent->vdev_ops != &vdev_mirror_ops ||
4898 		    vml[c]->vdev_islog ||
4899 		    vml[c]->vdev_ishole ||
4900 		    vml[c]->vdev_isspare ||
4901 		    vml[c]->vdev_isl2cache ||
4902 		    !vdev_writeable(vml[c]) ||
4903 		    vml[c]->vdev_children != 0 ||
4904 		    vml[c]->vdev_state != VDEV_STATE_HEALTHY ||
4905 		    c != spa->spa_root_vdev->vdev_child[c]->vdev_id) {
4906 			error = SET_ERROR(EINVAL);
4907 			break;
4908 		}
4909 
4910 		if (vdev_dtl_required(vml[c])) {
4911 			error = SET_ERROR(EBUSY);
4912 			break;
4913 		}
4914 
4915 		/* we need certain info from the top level */
4916 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_ARRAY,
4917 		    vml[c]->vdev_top->vdev_ms_array) == 0);
4918 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_METASLAB_SHIFT,
4919 		    vml[c]->vdev_top->vdev_ms_shift) == 0);
4920 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASIZE,
4921 		    vml[c]->vdev_top->vdev_asize) == 0);
4922 		VERIFY(nvlist_add_uint64(child[c], ZPOOL_CONFIG_ASHIFT,
4923 		    vml[c]->vdev_top->vdev_ashift) == 0);
4924 	}
4925 
4926 	if (error != 0) {
4927 		kmem_free(vml, children * sizeof (vdev_t *));
4928 		kmem_free(glist, children * sizeof (uint64_t));
4929 		return (spa_vdev_exit(spa, NULL, txg, error));
4930 	}
4931 
4932 	/* stop writers from using the disks */
4933 	for (c = 0; c < children; c++) {
4934 		if (vml[c] != NULL)
4935 			vml[c]->vdev_offline = B_TRUE;
4936 	}
4937 	vdev_reopen(spa->spa_root_vdev);
4938 
4939 	/*
4940 	 * Temporarily record the splitting vdevs in the spa config.  This
4941 	 * will disappear once the config is regenerated.
4942 	 */
4943 	VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0);
4944 	VERIFY(nvlist_add_uint64_array(nvl, ZPOOL_CONFIG_SPLIT_LIST,
4945 	    glist, children) == 0);
4946 	kmem_free(glist, children * sizeof (uint64_t));
4947 
4948 	mutex_enter(&spa->spa_props_lock);
4949 	VERIFY(nvlist_add_nvlist(spa->spa_config, ZPOOL_CONFIG_SPLIT,
4950 	    nvl) == 0);
4951 	mutex_exit(&spa->spa_props_lock);
4952 	spa->spa_config_splitting = nvl;
4953 	vdev_config_dirty(spa->spa_root_vdev);
4954 
4955 	/* configure and create the new pool */
4956 	VERIFY(nvlist_add_string(config, ZPOOL_CONFIG_POOL_NAME, newname) == 0);
4957 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_STATE,
4958 	    exp ? POOL_STATE_EXPORTED : POOL_STATE_ACTIVE) == 0);
4959 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
4960 	    spa_version(spa)) == 0);
4961 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_TXG,
4962 	    spa->spa_config_txg) == 0);
4963 	VERIFY(nvlist_add_uint64(config, ZPOOL_CONFIG_POOL_GUID,
4964 	    spa_generate_guid(NULL)) == 0);
4965 	(void) nvlist_lookup_string(props,
4966 	    zpool_prop_to_name(ZPOOL_PROP_ALTROOT), &altroot);
4967 
4968 	/* add the new pool to the namespace */
4969 	newspa = spa_add(newname, config, altroot);
4970 	newspa->spa_config_txg = spa->spa_config_txg;
4971 	spa_set_log_state(newspa, SPA_LOG_CLEAR);
4972 
4973 	/* release the spa config lock, retaining the namespace lock */
4974 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
4975 
4976 	if (zio_injection_enabled)
4977 		zio_handle_panic_injection(spa, FTAG, 1);
4978 
4979 	spa_activate(newspa, spa_mode_global);
4980 	spa_async_suspend(newspa);
4981 
4982 	/* create the new pool from the disks of the original pool */
4983 	error = spa_load(newspa, SPA_LOAD_IMPORT, SPA_IMPORT_ASSEMBLE, B_TRUE);
4984 	if (error)
4985 		goto out;
4986 
4987 	/* if that worked, generate a real config for the new pool */
4988 	if (newspa->spa_root_vdev != NULL) {
4989 		VERIFY(nvlist_alloc(&newspa->spa_config_splitting,
4990 		    NV_UNIQUE_NAME, KM_SLEEP) == 0);
4991 		VERIFY(nvlist_add_uint64(newspa->spa_config_splitting,
4992 		    ZPOOL_CONFIG_SPLIT_GUID, spa_guid(spa)) == 0);
4993 		spa_config_set(newspa, spa_config_generate(newspa, NULL, -1ULL,
4994 		    B_TRUE));
4995 	}
4996 
4997 	/* set the props */
4998 	if (props != NULL) {
4999 		spa_configfile_set(newspa, props, B_FALSE);
5000 		error = spa_prop_set(newspa, props);
5001 		if (error)
5002 			goto out;
5003 	}
5004 
5005 	/* flush everything */
5006 	txg = spa_vdev_config_enter(newspa);
5007 	vdev_config_dirty(newspa->spa_root_vdev);
5008 	(void) spa_vdev_config_exit(newspa, NULL, txg, 0, FTAG);
5009 
5010 	if (zio_injection_enabled)
5011 		zio_handle_panic_injection(spa, FTAG, 2);
5012 
5013 	spa_async_resume(newspa);
5014 
5015 	/* finally, update the original pool's config */
5016 	txg = spa_vdev_config_enter(spa);
5017 	tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir);
5018 	error = dmu_tx_assign(tx, TXG_WAIT);
5019 	if (error != 0)
5020 		dmu_tx_abort(tx);
5021 	for (c = 0; c < children; c++) {
5022 		if (vml[c] != NULL) {
5023 			vdev_split(vml[c]);
5024 			if (error == 0)
5025 				spa_history_log_internal(spa, "detach", tx,
5026 				    "vdev=%s", vml[c]->vdev_path);
5027 			vdev_free(vml[c]);
5028 		}
5029 	}
5030 	vdev_config_dirty(spa->spa_root_vdev);
5031 	spa->spa_config_splitting = NULL;
5032 	nvlist_free(nvl);
5033 	if (error == 0)
5034 		dmu_tx_commit(tx);
5035 	(void) spa_vdev_exit(spa, NULL, txg, 0);
5036 
5037 	if (zio_injection_enabled)
5038 		zio_handle_panic_injection(spa, FTAG, 3);
5039 
5040 	/* split is complete; log a history record */
5041 	spa_history_log_internal(newspa, "split", NULL,
5042 	    "from pool %s", spa_name(spa));
5043 
5044 	kmem_free(vml, children * sizeof (vdev_t *));
5045 
5046 	/* if we're not going to mount the filesystems in userland, export */
5047 	if (exp)
5048 		error = spa_export_common(newname, POOL_STATE_EXPORTED, NULL,
5049 		    B_FALSE, B_FALSE);
5050 
5051 	return (error);
5052 
5053 out:
5054 	spa_unload(newspa);
5055 	spa_deactivate(newspa);
5056 	spa_remove(newspa);
5057 
5058 	txg = spa_vdev_config_enter(spa);
5059 
5060 	/* re-online all offlined disks */
5061 	for (c = 0; c < children; c++) {
5062 		if (vml[c] != NULL)
5063 			vml[c]->vdev_offline = B_FALSE;
5064 	}
5065 	vdev_reopen(spa->spa_root_vdev);
5066 
5067 	nvlist_free(spa->spa_config_splitting);
5068 	spa->spa_config_splitting = NULL;
5069 	(void) spa_vdev_exit(spa, NULL, txg, error);
5070 
5071 	kmem_free(vml, children * sizeof (vdev_t *));
5072 	return (error);
5073 }
5074 
5075 static nvlist_t *
5076 spa_nvlist_lookup_by_guid(nvlist_t **nvpp, int count, uint64_t target_guid)
5077 {
5078 	for (int i = 0; i < count; i++) {
5079 		uint64_t guid;
5080 
5081 		VERIFY(nvlist_lookup_uint64(nvpp[i], ZPOOL_CONFIG_GUID,
5082 		    &guid) == 0);
5083 
5084 		if (guid == target_guid)
5085 			return (nvpp[i]);
5086 	}
5087 
5088 	return (NULL);
5089 }
5090 
5091 static void
5092 spa_vdev_remove_aux(nvlist_t *config, char *name, nvlist_t **dev, int count,
5093 	nvlist_t *dev_to_remove)
5094 {
5095 	nvlist_t **newdev = NULL;
5096 
5097 	if (count > 1)
5098 		newdev = kmem_alloc((count - 1) * sizeof (void *), KM_SLEEP);
5099 
5100 	for (int i = 0, j = 0; i < count; i++) {
5101 		if (dev[i] == dev_to_remove)
5102 			continue;
5103 		VERIFY(nvlist_dup(dev[i], &newdev[j++], KM_SLEEP) == 0);
5104 	}
5105 
5106 	VERIFY(nvlist_remove(config, name, DATA_TYPE_NVLIST_ARRAY) == 0);
5107 	VERIFY(nvlist_add_nvlist_array(config, name, newdev, count - 1) == 0);
5108 
5109 	for (int i = 0; i < count - 1; i++)
5110 		nvlist_free(newdev[i]);
5111 
5112 	if (count > 1)
5113 		kmem_free(newdev, (count - 1) * sizeof (void *));
5114 }
5115 
5116 /*
5117  * Evacuate the device.
5118  */
5119 static int
5120 spa_vdev_remove_evacuate(spa_t *spa, vdev_t *vd)
5121 {
5122 	uint64_t txg;
5123 	int error = 0;
5124 
5125 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5126 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5127 	ASSERT(vd == vd->vdev_top);
5128 
5129 	/*
5130 	 * Evacuate the device.  We don't hold the config lock as writer
5131 	 * since we need to do I/O but we do keep the
5132 	 * spa_namespace_lock held.  Once this completes the device
5133 	 * should no longer have any blocks allocated on it.
5134 	 */
5135 	if (vd->vdev_islog) {
5136 		if (vd->vdev_stat.vs_alloc != 0)
5137 			error = spa_offline_log(spa);
5138 	} else {
5139 		error = SET_ERROR(ENOTSUP);
5140 	}
5141 
5142 	if (error)
5143 		return (error);
5144 
5145 	/*
5146 	 * The evacuation succeeded.  Remove any remaining MOS metadata
5147 	 * associated with this vdev, and wait for these changes to sync.
5148 	 */
5149 	ASSERT0(vd->vdev_stat.vs_alloc);
5150 	txg = spa_vdev_config_enter(spa);
5151 	vd->vdev_removing = B_TRUE;
5152 	vdev_dirty_leaves(vd, VDD_DTL, txg);
5153 	vdev_config_dirty(vd);
5154 	spa_vdev_config_exit(spa, NULL, txg, 0, FTAG);
5155 
5156 	return (0);
5157 }
5158 
5159 /*
5160  * Complete the removal by cleaning up the namespace.
5161  */
5162 static void
5163 spa_vdev_remove_from_namespace(spa_t *spa, vdev_t *vd)
5164 {
5165 	vdev_t *rvd = spa->spa_root_vdev;
5166 	uint64_t id = vd->vdev_id;
5167 	boolean_t last_vdev = (id == (rvd->vdev_children - 1));
5168 
5169 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
5170 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == SCL_ALL);
5171 	ASSERT(vd == vd->vdev_top);
5172 
5173 	/*
5174 	 * Only remove any devices which are empty.
5175 	 */
5176 	if (vd->vdev_stat.vs_alloc != 0)
5177 		return;
5178 
5179 	(void) vdev_label_init(vd, 0, VDEV_LABEL_REMOVE);
5180 
5181 	if (list_link_active(&vd->vdev_state_dirty_node))
5182 		vdev_state_clean(vd);
5183 	if (list_link_active(&vd->vdev_config_dirty_node))
5184 		vdev_config_clean(vd);
5185 
5186 	vdev_free(vd);
5187 
5188 	if (last_vdev) {
5189 		vdev_compact_children(rvd);
5190 	} else {
5191 		vd = vdev_alloc_common(spa, id, 0, &vdev_hole_ops);
5192 		vdev_add_child(rvd, vd);
5193 	}
5194 	vdev_config_dirty(rvd);
5195 
5196 	/*
5197 	 * Reassess the health of our root vdev.
5198 	 */
5199 	vdev_reopen(rvd);
5200 }
5201 
5202 /*
5203  * Remove a device from the pool -
5204  *
5205  * Removing a device from the vdev namespace requires several steps
5206  * and can take a significant amount of time.  As a result we use
5207  * the spa_vdev_config_[enter/exit] functions which allow us to
5208  * grab and release the spa_config_lock while still holding the namespace
5209  * lock.  During each step the configuration is synced out.
5210  *
5211  * Currently, this supports removing only hot spares, slogs, and level 2 ARC
5212  * devices.
5213  */
5214 int
5215 spa_vdev_remove(spa_t *spa, uint64_t guid, boolean_t unspare)
5216 {
5217 	vdev_t *vd;
5218 	metaslab_group_t *mg;
5219 	nvlist_t **spares, **l2cache, *nv;
5220 	uint64_t txg = 0;
5221 	uint_t nspares, nl2cache;
5222 	int error = 0;
5223 	boolean_t locked = MUTEX_HELD(&spa_namespace_lock);
5224 
5225 	ASSERT(spa_writeable(spa));
5226 
5227 	if (!locked)
5228 		txg = spa_vdev_enter(spa);
5229 
5230 	vd = spa_lookup_by_guid(spa, guid, B_FALSE);
5231 
5232 	if (spa->spa_spares.sav_vdevs != NULL &&
5233 	    nvlist_lookup_nvlist_array(spa->spa_spares.sav_config,
5234 	    ZPOOL_CONFIG_SPARES, &spares, &nspares) == 0 &&
5235 	    (nv = spa_nvlist_lookup_by_guid(spares, nspares, guid)) != NULL) {
5236 		/*
5237 		 * Only remove the hot spare if it's not currently in use
5238 		 * in this pool.
5239 		 */
5240 		if (vd == NULL || unspare) {
5241 			spa_vdev_remove_aux(spa->spa_spares.sav_config,
5242 			    ZPOOL_CONFIG_SPARES, spares, nspares, nv);
5243 			spa_load_spares(spa);
5244 			spa->spa_spares.sav_sync = B_TRUE;
5245 		} else {
5246 			error = SET_ERROR(EBUSY);
5247 		}
5248 	} else if (spa->spa_l2cache.sav_vdevs != NULL &&
5249 	    nvlist_lookup_nvlist_array(spa->spa_l2cache.sav_config,
5250 	    ZPOOL_CONFIG_L2CACHE, &l2cache, &nl2cache) == 0 &&
5251 	    (nv = spa_nvlist_lookup_by_guid(l2cache, nl2cache, guid)) != NULL) {
5252 		/*
5253 		 * Cache devices can always be removed.
5254 		 */
5255 		spa_vdev_remove_aux(spa->spa_l2cache.sav_config,
5256 		    ZPOOL_CONFIG_L2CACHE, l2cache, nl2cache, nv);
5257 		spa_load_l2cache(spa);
5258 		spa->spa_l2cache.sav_sync = B_TRUE;
5259 	} else if (vd != NULL && vd->vdev_islog) {
5260 		ASSERT(!locked);
5261 		ASSERT(vd == vd->vdev_top);
5262 
5263 		/*
5264 		 * XXX - Once we have bp-rewrite this should
5265 		 * become the common case.
5266 		 */
5267 
5268 		mg = vd->vdev_mg;
5269 
5270 		/*
5271 		 * Stop allocating from this vdev.
5272 		 */
5273 		metaslab_group_passivate(mg);
5274 
5275 		/*
5276 		 * Wait for the youngest allocations and frees to sync,
5277 		 * and then wait for the deferral of those frees to finish.
5278 		 */
5279 		spa_vdev_config_exit(spa, NULL,
5280 		    txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
5281 
5282 		/*
5283 		 * Attempt to evacuate the vdev.
5284 		 */
5285 		error = spa_vdev_remove_evacuate(spa, vd);
5286 
5287 		txg = spa_vdev_config_enter(spa);
5288 
5289 		/*
5290 		 * If we couldn't evacuate the vdev, unwind.
5291 		 */
5292 		if (error) {
5293 			metaslab_group_activate(mg);
5294 			return (spa_vdev_exit(spa, NULL, txg, error));
5295 		}
5296 
5297 		/*
5298 		 * Clean up the vdev namespace.
5299 		 */
5300 		spa_vdev_remove_from_namespace(spa, vd);
5301 
5302 	} else if (vd != NULL) {
5303 		/*
5304 		 * Normal vdevs cannot be removed (yet).
5305 		 */
5306 		error = SET_ERROR(ENOTSUP);
5307 	} else {
5308 		/*
5309 		 * There is no vdev of any kind with the specified guid.
5310 		 */
5311 		error = SET_ERROR(ENOENT);
5312 	}
5313 
5314 	if (!locked)
5315 		return (spa_vdev_exit(spa, NULL, txg, error));
5316 
5317 	return (error);
5318 }
5319 
5320 /*
5321  * Find any device that's done replacing, or a vdev marked 'unspare' that's
5322  * currently spared, so we can detach it.
5323  */
5324 static vdev_t *
5325 spa_vdev_resilver_done_hunt(vdev_t *vd)
5326 {
5327 	vdev_t *newvd, *oldvd;
5328 
5329 	for (int c = 0; c < vd->vdev_children; c++) {
5330 		oldvd = spa_vdev_resilver_done_hunt(vd->vdev_child[c]);
5331 		if (oldvd != NULL)
5332 			return (oldvd);
5333 	}
5334 
5335 	/*
5336 	 * Check for a completed replacement.  We always consider the first
5337 	 * vdev in the list to be the oldest vdev, and the last one to be
5338 	 * the newest (see spa_vdev_attach() for how that works).  In
5339 	 * the case where the newest vdev is faulted, we will not automatically
5340 	 * remove it after a resilver completes.  This is OK as it will require
5341 	 * user intervention to determine which disk the admin wishes to keep.
5342 	 */
5343 	if (vd->vdev_ops == &vdev_replacing_ops) {
5344 		ASSERT(vd->vdev_children > 1);
5345 
5346 		newvd = vd->vdev_child[vd->vdev_children - 1];
5347 		oldvd = vd->vdev_child[0];
5348 
5349 		if (vdev_dtl_empty(newvd, DTL_MISSING) &&
5350 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5351 		    !vdev_dtl_required(oldvd))
5352 			return (oldvd);
5353 	}
5354 
5355 	/*
5356 	 * Check for a completed resilver with the 'unspare' flag set.
5357 	 */
5358 	if (vd->vdev_ops == &vdev_spare_ops) {
5359 		vdev_t *first = vd->vdev_child[0];
5360 		vdev_t *last = vd->vdev_child[vd->vdev_children - 1];
5361 
5362 		if (last->vdev_unspare) {
5363 			oldvd = first;
5364 			newvd = last;
5365 		} else if (first->vdev_unspare) {
5366 			oldvd = last;
5367 			newvd = first;
5368 		} else {
5369 			oldvd = NULL;
5370 		}
5371 
5372 		if (oldvd != NULL &&
5373 		    vdev_dtl_empty(newvd, DTL_MISSING) &&
5374 		    vdev_dtl_empty(newvd, DTL_OUTAGE) &&
5375 		    !vdev_dtl_required(oldvd))
5376 			return (oldvd);
5377 
5378 		/*
5379 		 * If there are more than two spares attached to a disk,
5380 		 * and those spares are not required, then we want to
5381 		 * attempt to free them up now so that they can be used
5382 		 * by other pools.  Once we're back down to a single
5383 		 * disk+spare, we stop removing them.
5384 		 */
5385 		if (vd->vdev_children > 2) {
5386 			newvd = vd->vdev_child[1];
5387 
5388 			if (newvd->vdev_isspare && last->vdev_isspare &&
5389 			    vdev_dtl_empty(last, DTL_MISSING) &&
5390 			    vdev_dtl_empty(last, DTL_OUTAGE) &&
5391 			    !vdev_dtl_required(newvd))
5392 				return (newvd);
5393 		}
5394 	}
5395 
5396 	return (NULL);
5397 }
5398 
5399 static void
5400 spa_vdev_resilver_done(spa_t *spa)
5401 {
5402 	vdev_t *vd, *pvd, *ppvd;
5403 	uint64_t guid, sguid, pguid, ppguid;
5404 
5405 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5406 
5407 	while ((vd = spa_vdev_resilver_done_hunt(spa->spa_root_vdev)) != NULL) {
5408 		pvd = vd->vdev_parent;
5409 		ppvd = pvd->vdev_parent;
5410 		guid = vd->vdev_guid;
5411 		pguid = pvd->vdev_guid;
5412 		ppguid = ppvd->vdev_guid;
5413 		sguid = 0;
5414 		/*
5415 		 * If we have just finished replacing a hot spared device, then
5416 		 * we need to detach the parent's first child (the original hot
5417 		 * spare) as well.
5418 		 */
5419 		if (ppvd->vdev_ops == &vdev_spare_ops && pvd->vdev_id == 0 &&
5420 		    ppvd->vdev_children == 2) {
5421 			ASSERT(pvd->vdev_ops == &vdev_replacing_ops);
5422 			sguid = ppvd->vdev_child[1]->vdev_guid;
5423 		}
5424 		ASSERT(vd->vdev_resilver_txg == 0 || !vdev_dtl_required(vd));
5425 
5426 		spa_config_exit(spa, SCL_ALL, FTAG);
5427 		if (spa_vdev_detach(spa, guid, pguid, B_TRUE) != 0)
5428 			return;
5429 		if (sguid && spa_vdev_detach(spa, sguid, ppguid, B_TRUE) != 0)
5430 			return;
5431 		spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
5432 	}
5433 
5434 	spa_config_exit(spa, SCL_ALL, FTAG);
5435 }
5436 
5437 /*
5438  * Update the stored path or FRU for this vdev.
5439  */
5440 int
5441 spa_vdev_set_common(spa_t *spa, uint64_t guid, const char *value,
5442     boolean_t ispath)
5443 {
5444 	vdev_t *vd;
5445 	boolean_t sync = B_FALSE;
5446 
5447 	ASSERT(spa_writeable(spa));
5448 
5449 	spa_vdev_state_enter(spa, SCL_ALL);
5450 
5451 	if ((vd = spa_lookup_by_guid(spa, guid, B_TRUE)) == NULL)
5452 		return (spa_vdev_state_exit(spa, NULL, ENOENT));
5453 
5454 	if (!vd->vdev_ops->vdev_op_leaf)
5455 		return (spa_vdev_state_exit(spa, NULL, ENOTSUP));
5456 
5457 	if (ispath) {
5458 		if (strcmp(value, vd->vdev_path) != 0) {
5459 			spa_strfree(vd->vdev_path);
5460 			vd->vdev_path = spa_strdup(value);
5461 			sync = B_TRUE;
5462 		}
5463 	} else {
5464 		if (vd->vdev_fru == NULL) {
5465 			vd->vdev_fru = spa_strdup(value);
5466 			sync = B_TRUE;
5467 		} else if (strcmp(value, vd->vdev_fru) != 0) {
5468 			spa_strfree(vd->vdev_fru);
5469 			vd->vdev_fru = spa_strdup(value);
5470 			sync = B_TRUE;
5471 		}
5472 	}
5473 
5474 	return (spa_vdev_state_exit(spa, sync ? vd : NULL, 0));
5475 }
5476 
5477 int
5478 spa_vdev_setpath(spa_t *spa, uint64_t guid, const char *newpath)
5479 {
5480 	return (spa_vdev_set_common(spa, guid, newpath, B_TRUE));
5481 }
5482 
5483 int
5484 spa_vdev_setfru(spa_t *spa, uint64_t guid, const char *newfru)
5485 {
5486 	return (spa_vdev_set_common(spa, guid, newfru, B_FALSE));
5487 }
5488 
5489 /*
5490  * ==========================================================================
5491  * SPA Scanning
5492  * ==========================================================================
5493  */
5494 
5495 int
5496 spa_scan_stop(spa_t *spa)
5497 {
5498 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5499 	if (dsl_scan_resilvering(spa->spa_dsl_pool))
5500 		return (SET_ERROR(EBUSY));
5501 	return (dsl_scan_cancel(spa->spa_dsl_pool));
5502 }
5503 
5504 int
5505 spa_scan(spa_t *spa, pool_scan_func_t func)
5506 {
5507 	ASSERT(spa_config_held(spa, SCL_ALL, RW_WRITER) == 0);
5508 
5509 	if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
5510 		return (SET_ERROR(ENOTSUP));
5511 
5512 	/*
5513 	 * If a resilver was requested, but there is no DTL on a
5514 	 * writeable leaf device, we have nothing to do.
5515 	 */
5516 	if (func == POOL_SCAN_RESILVER &&
5517 	    !vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) {
5518 		spa_async_request(spa, SPA_ASYNC_RESILVER_DONE);
5519 		return (0);
5520 	}
5521 
5522 	return (dsl_scan(spa->spa_dsl_pool, func));
5523 }
5524 
5525 /*
5526  * ==========================================================================
5527  * SPA async task processing
5528  * ==========================================================================
5529  */
5530 
5531 static void
5532 spa_async_remove(spa_t *spa, vdev_t *vd)
5533 {
5534 	if (vd->vdev_remove_wanted) {
5535 		vd->vdev_remove_wanted = B_FALSE;
5536 		vd->vdev_delayed_close = B_FALSE;
5537 		vdev_set_state(vd, B_FALSE, VDEV_STATE_REMOVED, VDEV_AUX_NONE);
5538 
5539 		/*
5540 		 * We want to clear the stats, but we don't want to do a full
5541 		 * vdev_clear() as that will cause us to throw away
5542 		 * degraded/faulted state as well as attempt to reopen the
5543 		 * device, all of which is a waste.
5544 		 */
5545 		vd->vdev_stat.vs_read_errors = 0;
5546 		vd->vdev_stat.vs_write_errors = 0;
5547 		vd->vdev_stat.vs_checksum_errors = 0;
5548 
5549 		vdev_state_dirty(vd->vdev_top);
5550 	}
5551 
5552 	for (int c = 0; c < vd->vdev_children; c++)
5553 		spa_async_remove(spa, vd->vdev_child[c]);
5554 }
5555 
5556 static void
5557 spa_async_probe(spa_t *spa, vdev_t *vd)
5558 {
5559 	if (vd->vdev_probe_wanted) {
5560 		vd->vdev_probe_wanted = B_FALSE;
5561 		vdev_reopen(vd);	/* vdev_open() does the actual probe */
5562 	}
5563 
5564 	for (int c = 0; c < vd->vdev_children; c++)
5565 		spa_async_probe(spa, vd->vdev_child[c]);
5566 }
5567 
5568 static void
5569 spa_async_autoexpand(spa_t *spa, vdev_t *vd)
5570 {
5571 	sysevent_id_t eid;
5572 	nvlist_t *attr;
5573 	char *physpath;
5574 
5575 	if (!spa->spa_autoexpand)
5576 		return;
5577 
5578 	for (int c = 0; c < vd->vdev_children; c++) {
5579 		vdev_t *cvd = vd->vdev_child[c];
5580 		spa_async_autoexpand(spa, cvd);
5581 	}
5582 
5583 	if (!vd->vdev_ops->vdev_op_leaf || vd->vdev_physpath == NULL)
5584 		return;
5585 
5586 	physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
5587 	(void) snprintf(physpath, MAXPATHLEN, "/devices%s", vd->vdev_physpath);
5588 
5589 	VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5590 	VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
5591 
5592 	(void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
5593 	    ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
5594 
5595 	nvlist_free(attr);
5596 	kmem_free(physpath, MAXPATHLEN);
5597 }
5598 
5599 static void
5600 spa_async_thread(spa_t *spa)
5601 {
5602 	int tasks;
5603 
5604 	ASSERT(spa->spa_sync_on);
5605 
5606 	mutex_enter(&spa->spa_async_lock);
5607 	tasks = spa->spa_async_tasks;
5608 	spa->spa_async_tasks = 0;
5609 	mutex_exit(&spa->spa_async_lock);
5610 
5611 	/*
5612 	 * See if the config needs to be updated.
5613 	 */
5614 	if (tasks & SPA_ASYNC_CONFIG_UPDATE) {
5615 		uint64_t old_space, new_space;
5616 
5617 		mutex_enter(&spa_namespace_lock);
5618 		old_space = metaslab_class_get_space(spa_normal_class(spa));
5619 		spa_config_update(spa, SPA_CONFIG_UPDATE_POOL);
5620 		new_space = metaslab_class_get_space(spa_normal_class(spa));
5621 		mutex_exit(&spa_namespace_lock);
5622 
5623 		/*
5624 		 * If the pool grew as a result of the config update,
5625 		 * then log an internal history event.
5626 		 */
5627 		if (new_space != old_space) {
5628 			spa_history_log_internal(spa, "vdev online", NULL,
5629 			    "pool '%s' size: %llu(+%llu)",
5630 			    spa_name(spa), new_space, new_space - old_space);
5631 		}
5632 	}
5633 
5634 	/*
5635 	 * See if any devices need to be marked REMOVED.
5636 	 */
5637 	if (tasks & SPA_ASYNC_REMOVE) {
5638 		spa_vdev_state_enter(spa, SCL_NONE);
5639 		spa_async_remove(spa, spa->spa_root_vdev);
5640 		for (int i = 0; i < spa->spa_l2cache.sav_count; i++)
5641 			spa_async_remove(spa, spa->spa_l2cache.sav_vdevs[i]);
5642 		for (int i = 0; i < spa->spa_spares.sav_count; i++)
5643 			spa_async_remove(spa, spa->spa_spares.sav_vdevs[i]);
5644 		(void) spa_vdev_state_exit(spa, NULL, 0);
5645 	}
5646 
5647 	if ((tasks & SPA_ASYNC_AUTOEXPAND) && !spa_suspended(spa)) {
5648 		spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
5649 		spa_async_autoexpand(spa, spa->spa_root_vdev);
5650 		spa_config_exit(spa, SCL_CONFIG, FTAG);
5651 	}
5652 
5653 	/*
5654 	 * See if any devices need to be probed.
5655 	 */
5656 	if (tasks & SPA_ASYNC_PROBE) {
5657 		spa_vdev_state_enter(spa, SCL_NONE);
5658 		spa_async_probe(spa, spa->spa_root_vdev);
5659 		(void) spa_vdev_state_exit(spa, NULL, 0);
5660 	}
5661 
5662 	/*
5663 	 * If any devices are done replacing, detach them.
5664 	 */
5665 	if (tasks & SPA_ASYNC_RESILVER_DONE)
5666 		spa_vdev_resilver_done(spa);
5667 
5668 	/*
5669 	 * Kick off a resilver.
5670 	 */
5671 	if (tasks & SPA_ASYNC_RESILVER)
5672 		dsl_resilver_restart(spa->spa_dsl_pool, 0);
5673 
5674 	/*
5675 	 * Let the world know that we're done.
5676 	 */
5677 	mutex_enter(&spa->spa_async_lock);
5678 	spa->spa_async_thread = NULL;
5679 	cv_broadcast(&spa->spa_async_cv);
5680 	mutex_exit(&spa->spa_async_lock);
5681 	thread_exit();
5682 }
5683 
5684 void
5685 spa_async_suspend(spa_t *spa)
5686 {
5687 	mutex_enter(&spa->spa_async_lock);
5688 	spa->spa_async_suspended++;
5689 	while (spa->spa_async_thread != NULL)
5690 		cv_wait(&spa->spa_async_cv, &spa->spa_async_lock);
5691 	mutex_exit(&spa->spa_async_lock);
5692 }
5693 
5694 void
5695 spa_async_resume(spa_t *spa)
5696 {
5697 	mutex_enter(&spa->spa_async_lock);
5698 	ASSERT(spa->spa_async_suspended != 0);
5699 	spa->spa_async_suspended--;
5700 	mutex_exit(&spa->spa_async_lock);
5701 }
5702 
5703 static boolean_t
5704 spa_async_tasks_pending(spa_t *spa)
5705 {
5706 	uint_t non_config_tasks;
5707 	uint_t config_task;
5708 	boolean_t config_task_suspended;
5709 
5710 	non_config_tasks = spa->spa_async_tasks & ~SPA_ASYNC_CONFIG_UPDATE;
5711 	config_task = spa->spa_async_tasks & SPA_ASYNC_CONFIG_UPDATE;
5712 	if (spa->spa_ccw_fail_time == 0) {
5713 		config_task_suspended = B_FALSE;
5714 	} else {
5715 		config_task_suspended =
5716 		    (gethrtime() - spa->spa_ccw_fail_time) <
5717 		    (zfs_ccw_retry_interval * NANOSEC);
5718 	}
5719 
5720 	return (non_config_tasks || (config_task && !config_task_suspended));
5721 }
5722 
5723 static void
5724 spa_async_dispatch(spa_t *spa)
5725 {
5726 	mutex_enter(&spa->spa_async_lock);
5727 	if (spa_async_tasks_pending(spa) &&
5728 	    !spa->spa_async_suspended &&
5729 	    spa->spa_async_thread == NULL &&
5730 	    rootdir != NULL)
5731 		spa->spa_async_thread = thread_create(NULL, 0,
5732 		    spa_async_thread, spa, 0, &p0, TS_RUN, maxclsyspri);
5733 	mutex_exit(&spa->spa_async_lock);
5734 }
5735 
5736 void
5737 spa_async_request(spa_t *spa, int task)
5738 {
5739 	zfs_dbgmsg("spa=%s async request task=%u", spa->spa_name, task);
5740 	mutex_enter(&spa->spa_async_lock);
5741 	spa->spa_async_tasks |= task;
5742 	mutex_exit(&spa->spa_async_lock);
5743 }
5744 
5745 /*
5746  * ==========================================================================
5747  * SPA syncing routines
5748  * ==========================================================================
5749  */
5750 
5751 static int
5752 bpobj_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5753 {
5754 	bpobj_t *bpo = arg;
5755 	bpobj_enqueue(bpo, bp, tx);
5756 	return (0);
5757 }
5758 
5759 static int
5760 spa_free_sync_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
5761 {
5762 	zio_t *zio = arg;
5763 
5764 	zio_nowait(zio_free_sync(zio, zio->io_spa, dmu_tx_get_txg(tx), bp,
5765 	    zio->io_flags));
5766 	return (0);
5767 }
5768 
5769 /*
5770  * Note: this simple function is not inlined to make it easier to dtrace the
5771  * amount of time spent syncing frees.
5772  */
5773 static void
5774 spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
5775 {
5776 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
5777 	bplist_iterate(bpl, spa_free_sync_cb, zio, tx);
5778 	VERIFY(zio_wait(zio) == 0);
5779 }
5780 
5781 /*
5782  * Note: this simple function is not inlined to make it easier to dtrace the
5783  * amount of time spent syncing deferred frees.
5784  */
5785 static void
5786 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
5787 {
5788 	zio_t *zio = zio_root(spa, NULL, NULL, 0);
5789 	VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
5790 	    spa_free_sync_cb, zio, tx), ==, 0);
5791 	VERIFY0(zio_wait(zio));
5792 }
5793 
5794 
5795 static void
5796 spa_sync_nvlist(spa_t *spa, uint64_t obj, nvlist_t *nv, dmu_tx_t *tx)
5797 {
5798 	char *packed = NULL;
5799 	size_t bufsize;
5800 	size_t nvsize = 0;
5801 	dmu_buf_t *db;
5802 
5803 	VERIFY(nvlist_size(nv, &nvsize, NV_ENCODE_XDR) == 0);
5804 
5805 	/*
5806 	 * Write full (SPA_CONFIG_BLOCKSIZE) blocks of configuration
5807 	 * information.  This avoids the dmu_buf_will_dirty() path and
5808 	 * saves us a pre-read to get data we don't actually care about.
5809 	 */
5810 	bufsize = P2ROUNDUP((uint64_t)nvsize, SPA_CONFIG_BLOCKSIZE);
5811 	packed = kmem_alloc(bufsize, KM_SLEEP);
5812 
5813 	VERIFY(nvlist_pack(nv, &packed, &nvsize, NV_ENCODE_XDR,
5814 	    KM_SLEEP) == 0);
5815 	bzero(packed + nvsize, bufsize - nvsize);
5816 
5817 	dmu_write(spa->spa_meta_objset, obj, 0, bufsize, packed, tx);
5818 
5819 	kmem_free(packed, bufsize);
5820 
5821 	VERIFY(0 == dmu_bonus_hold(spa->spa_meta_objset, obj, FTAG, &db));
5822 	dmu_buf_will_dirty(db, tx);
5823 	*(uint64_t *)db->db_data = nvsize;
5824 	dmu_buf_rele(db, FTAG);
5825 }
5826 
5827 static void
5828 spa_sync_aux_dev(spa_t *spa, spa_aux_vdev_t *sav, dmu_tx_t *tx,
5829     const char *config, const char *entry)
5830 {
5831 	nvlist_t *nvroot;
5832 	nvlist_t **list;
5833 	int i;
5834 
5835 	if (!sav->sav_sync)
5836 		return;
5837 
5838 	/*
5839 	 * Update the MOS nvlist describing the list of available devices.
5840 	 * spa_validate_aux() will have already made sure this nvlist is
5841 	 * valid and the vdevs are labeled appropriately.
5842 	 */
5843 	if (sav->sav_object == 0) {
5844 		sav->sav_object = dmu_object_alloc(spa->spa_meta_objset,
5845 		    DMU_OT_PACKED_NVLIST, 1 << 14, DMU_OT_PACKED_NVLIST_SIZE,
5846 		    sizeof (uint64_t), tx);
5847 		VERIFY(zap_update(spa->spa_meta_objset,
5848 		    DMU_POOL_DIRECTORY_OBJECT, entry, sizeof (uint64_t), 1,
5849 		    &sav->sav_object, tx) == 0);
5850 	}
5851 
5852 	VERIFY(nvlist_alloc(&nvroot, NV_UNIQUE_NAME, KM_SLEEP) == 0);
5853 	if (sav->sav_count == 0) {
5854 		VERIFY(nvlist_add_nvlist_array(nvroot, config, NULL, 0) == 0);
5855 	} else {
5856 		list = kmem_alloc(sav->sav_count * sizeof (void *), KM_SLEEP);
5857 		for (i = 0; i < sav->sav_count; i++)
5858 			list[i] = vdev_config_generate(spa, sav->sav_vdevs[i],
5859 			    B_FALSE, VDEV_CONFIG_L2CACHE);
5860 		VERIFY(nvlist_add_nvlist_array(nvroot, config, list,
5861 		    sav->sav_count) == 0);
5862 		for (i = 0; i < sav->sav_count; i++)
5863 			nvlist_free(list[i]);
5864 		kmem_free(list, sav->sav_count * sizeof (void *));
5865 	}
5866 
5867 	spa_sync_nvlist(spa, sav->sav_object, nvroot, tx);
5868 	nvlist_free(nvroot);
5869 
5870 	sav->sav_sync = B_FALSE;
5871 }
5872 
5873 static void
5874 spa_sync_config_object(spa_t *spa, dmu_tx_t *tx)
5875 {
5876 	nvlist_t *config;
5877 
5878 	if (list_is_empty(&spa->spa_config_dirty_list))
5879 		return;
5880 
5881 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
5882 
5883 	config = spa_config_generate(spa, spa->spa_root_vdev,
5884 	    dmu_tx_get_txg(tx), B_FALSE);
5885 
5886 	/*
5887 	 * If we're upgrading the spa version then make sure that
5888 	 * the config object gets updated with the correct version.
5889 	 */
5890 	if (spa->spa_ubsync.ub_version < spa->spa_uberblock.ub_version)
5891 		fnvlist_add_uint64(config, ZPOOL_CONFIG_VERSION,
5892 		    spa->spa_uberblock.ub_version);
5893 
5894 	spa_config_exit(spa, SCL_STATE, FTAG);
5895 
5896 	if (spa->spa_config_syncing)
5897 		nvlist_free(spa->spa_config_syncing);
5898 	spa->spa_config_syncing = config;
5899 
5900 	spa_sync_nvlist(spa, spa->spa_config_object, config, tx);
5901 }
5902 
5903 static void
5904 spa_sync_version(void *arg, dmu_tx_t *tx)
5905 {
5906 	uint64_t *versionp = arg;
5907 	uint64_t version = *versionp;
5908 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5909 
5910 	/*
5911 	 * Setting the version is special cased when first creating the pool.
5912 	 */
5913 	ASSERT(tx->tx_txg != TXG_INITIAL);
5914 
5915 	ASSERT(SPA_VERSION_IS_SUPPORTED(version));
5916 	ASSERT(version >= spa_version(spa));
5917 
5918 	spa->spa_uberblock.ub_version = version;
5919 	vdev_config_dirty(spa->spa_root_vdev);
5920 	spa_history_log_internal(spa, "set", tx, "version=%lld", version);
5921 }
5922 
5923 /*
5924  * Set zpool properties.
5925  */
5926 static void
5927 spa_sync_props(void *arg, dmu_tx_t *tx)
5928 {
5929 	nvlist_t *nvp = arg;
5930 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
5931 	objset_t *mos = spa->spa_meta_objset;
5932 	nvpair_t *elem = NULL;
5933 
5934 	mutex_enter(&spa->spa_props_lock);
5935 
5936 	while ((elem = nvlist_next_nvpair(nvp, elem))) {
5937 		uint64_t intval;
5938 		char *strval, *fname;
5939 		zpool_prop_t prop;
5940 		const char *propname;
5941 		zprop_type_t proptype;
5942 		spa_feature_t fid;
5943 
5944 		switch (prop = zpool_name_to_prop(nvpair_name(elem))) {
5945 		case ZPROP_INVAL:
5946 			/*
5947 			 * We checked this earlier in spa_prop_validate().
5948 			 */
5949 			ASSERT(zpool_prop_feature(nvpair_name(elem)));
5950 
5951 			fname = strchr(nvpair_name(elem), '@') + 1;
5952 			VERIFY0(zfeature_lookup_name(fname, &fid));
5953 
5954 			spa_feature_enable(spa, fid, tx);
5955 			spa_history_log_internal(spa, "set", tx,
5956 			    "%s=enabled", nvpair_name(elem));
5957 			break;
5958 
5959 		case ZPOOL_PROP_VERSION:
5960 			intval = fnvpair_value_uint64(elem);
5961 			/*
5962 			 * The version is synced seperatly before other
5963 			 * properties and should be correct by now.
5964 			 */
5965 			ASSERT3U(spa_version(spa), >=, intval);
5966 			break;
5967 
5968 		case ZPOOL_PROP_ALTROOT:
5969 			/*
5970 			 * 'altroot' is a non-persistent property. It should
5971 			 * have been set temporarily at creation or import time.
5972 			 */
5973 			ASSERT(spa->spa_root != NULL);
5974 			break;
5975 
5976 		case ZPOOL_PROP_READONLY:
5977 		case ZPOOL_PROP_CACHEFILE:
5978 			/*
5979 			 * 'readonly' and 'cachefile' are also non-persisitent
5980 			 * properties.
5981 			 */
5982 			break;
5983 		case ZPOOL_PROP_COMMENT:
5984 			strval = fnvpair_value_string(elem);
5985 			if (spa->spa_comment != NULL)
5986 				spa_strfree(spa->spa_comment);
5987 			spa->spa_comment = spa_strdup(strval);
5988 			/*
5989 			 * We need to dirty the configuration on all the vdevs
5990 			 * so that their labels get updated.  It's unnecessary
5991 			 * to do this for pool creation since the vdev's
5992 			 * configuratoin has already been dirtied.
5993 			 */
5994 			if (tx->tx_txg != TXG_INITIAL)
5995 				vdev_config_dirty(spa->spa_root_vdev);
5996 			spa_history_log_internal(spa, "set", tx,
5997 			    "%s=%s", nvpair_name(elem), strval);
5998 			break;
5999 		default:
6000 			/*
6001 			 * Set pool property values in the poolprops mos object.
6002 			 */
6003 			if (spa->spa_pool_props_object == 0) {
6004 				spa->spa_pool_props_object =
6005 				    zap_create_link(mos, DMU_OT_POOL_PROPS,
6006 				    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_PROPS,
6007 				    tx);
6008 			}
6009 
6010 			/* normalize the property name */
6011 			propname = zpool_prop_to_name(prop);
6012 			proptype = zpool_prop_get_type(prop);
6013 
6014 			if (nvpair_type(elem) == DATA_TYPE_STRING) {
6015 				ASSERT(proptype == PROP_TYPE_STRING);
6016 				strval = fnvpair_value_string(elem);
6017 				VERIFY0(zap_update(mos,
6018 				    spa->spa_pool_props_object, propname,
6019 				    1, strlen(strval) + 1, strval, tx));
6020 				spa_history_log_internal(spa, "set", tx,
6021 				    "%s=%s", nvpair_name(elem), strval);
6022 			} else if (nvpair_type(elem) == DATA_TYPE_UINT64) {
6023 				intval = fnvpair_value_uint64(elem);
6024 
6025 				if (proptype == PROP_TYPE_INDEX) {
6026 					const char *unused;
6027 					VERIFY0(zpool_prop_index_to_string(
6028 					    prop, intval, &unused));
6029 				}
6030 				VERIFY0(zap_update(mos,
6031 				    spa->spa_pool_props_object, propname,
6032 				    8, 1, &intval, tx));
6033 				spa_history_log_internal(spa, "set", tx,
6034 				    "%s=%lld", nvpair_name(elem), intval);
6035 			} else {
6036 				ASSERT(0); /* not allowed */
6037 			}
6038 
6039 			switch (prop) {
6040 			case ZPOOL_PROP_DELEGATION:
6041 				spa->spa_delegation = intval;
6042 				break;
6043 			case ZPOOL_PROP_BOOTFS:
6044 				spa->spa_bootfs = intval;
6045 				break;
6046 			case ZPOOL_PROP_FAILUREMODE:
6047 				spa->spa_failmode = intval;
6048 				break;
6049 			case ZPOOL_PROP_AUTOEXPAND:
6050 				spa->spa_autoexpand = intval;
6051 				if (tx->tx_txg != TXG_INITIAL)
6052 					spa_async_request(spa,
6053 					    SPA_ASYNC_AUTOEXPAND);
6054 				break;
6055 			case ZPOOL_PROP_DEDUPDITTO:
6056 				spa->spa_dedup_ditto = intval;
6057 				break;
6058 			default:
6059 				break;
6060 			}
6061 		}
6062 
6063 	}
6064 
6065 	mutex_exit(&spa->spa_props_lock);
6066 }
6067 
6068 /*
6069  * Perform one-time upgrade on-disk changes.  spa_version() does not
6070  * reflect the new version this txg, so there must be no changes this
6071  * txg to anything that the upgrade code depends on after it executes.
6072  * Therefore this must be called after dsl_pool_sync() does the sync
6073  * tasks.
6074  */
6075 static void
6076 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
6077 {
6078 	dsl_pool_t *dp = spa->spa_dsl_pool;
6079 
6080 	ASSERT(spa->spa_sync_pass == 1);
6081 
6082 	rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
6083 
6084 	if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
6085 	    spa->spa_uberblock.ub_version >= SPA_VERSION_ORIGIN) {
6086 		dsl_pool_create_origin(dp, tx);
6087 
6088 		/* Keeping the origin open increases spa_minref */
6089 		spa->spa_minref += 3;
6090 	}
6091 
6092 	if (spa->spa_ubsync.ub_version < SPA_VERSION_NEXT_CLONES &&
6093 	    spa->spa_uberblock.ub_version >= SPA_VERSION_NEXT_CLONES) {
6094 		dsl_pool_upgrade_clones(dp, tx);
6095 	}
6096 
6097 	if (spa->spa_ubsync.ub_version < SPA_VERSION_DIR_CLONES &&
6098 	    spa->spa_uberblock.ub_version >= SPA_VERSION_DIR_CLONES) {
6099 		dsl_pool_upgrade_dir_clones(dp, tx);
6100 
6101 		/* Keeping the freedir open increases spa_minref */
6102 		spa->spa_minref += 3;
6103 	}
6104 
6105 	if (spa->spa_ubsync.ub_version < SPA_VERSION_FEATURES &&
6106 	    spa->spa_uberblock.ub_version >= SPA_VERSION_FEATURES) {
6107 		spa_feature_create_zap_objects(spa, tx);
6108 	}
6109 	rrw_exit(&dp->dp_config_rwlock, FTAG);
6110 }
6111 
6112 /*
6113  * Sync the specified transaction group.  New blocks may be dirtied as
6114  * part of the process, so we iterate until it converges.
6115  */
6116 void
6117 spa_sync(spa_t *spa, uint64_t txg)
6118 {
6119 	dsl_pool_t *dp = spa->spa_dsl_pool;
6120 	objset_t *mos = spa->spa_meta_objset;
6121 	bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
6122 	vdev_t *rvd = spa->spa_root_vdev;
6123 	vdev_t *vd;
6124 	dmu_tx_t *tx;
6125 	int error;
6126 
6127 	VERIFY(spa_writeable(spa));
6128 
6129 	/*
6130 	 * Lock out configuration changes.
6131 	 */
6132 	spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
6133 
6134 	spa->spa_syncing_txg = txg;
6135 	spa->spa_sync_pass = 0;
6136 
6137 	/*
6138 	 * If there are any pending vdev state changes, convert them
6139 	 * into config changes that go out with this transaction group.
6140 	 */
6141 	spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6142 	while (list_head(&spa->spa_state_dirty_list) != NULL) {
6143 		/*
6144 		 * We need the write lock here because, for aux vdevs,
6145 		 * calling vdev_config_dirty() modifies sav_config.
6146 		 * This is ugly and will become unnecessary when we
6147 		 * eliminate the aux vdev wart by integrating all vdevs
6148 		 * into the root vdev tree.
6149 		 */
6150 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6151 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
6152 		while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
6153 			vdev_state_clean(vd);
6154 			vdev_config_dirty(vd);
6155 		}
6156 		spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
6157 		spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
6158 	}
6159 	spa_config_exit(spa, SCL_STATE, FTAG);
6160 
6161 	tx = dmu_tx_create_assigned(dp, txg);
6162 
6163 	spa->spa_sync_starttime = gethrtime();
6164 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid,
6165 	    spa->spa_sync_starttime + spa->spa_deadman_synctime));
6166 
6167 	/*
6168 	 * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
6169 	 * set spa_deflate if we have no raid-z vdevs.
6170 	 */
6171 	if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
6172 	    spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
6173 		int i;
6174 
6175 		for (i = 0; i < rvd->vdev_children; i++) {
6176 			vd = rvd->vdev_child[i];
6177 			if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
6178 				break;
6179 		}
6180 		if (i == rvd->vdev_children) {
6181 			spa->spa_deflate = TRUE;
6182 			VERIFY(0 == zap_add(spa->spa_meta_objset,
6183 			    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
6184 			    sizeof (uint64_t), 1, &spa->spa_deflate, tx));
6185 		}
6186 	}
6187 
6188 	/*
6189 	 * If anything has changed in this txg, or if someone is waiting
6190 	 * for this txg to sync (eg, spa_vdev_remove()), push the
6191 	 * deferred frees from the previous txg.  If not, leave them
6192 	 * alone so that we don't generate work on an otherwise idle
6193 	 * system.
6194 	 */
6195 	if (!txg_list_empty(&dp->dp_dirty_datasets, txg) ||
6196 	    !txg_list_empty(&dp->dp_dirty_dirs, txg) ||
6197 	    !txg_list_empty(&dp->dp_sync_tasks, txg) ||
6198 	    ((dsl_scan_active(dp->dp_scan) ||
6199 	    txg_sync_waiting(dp)) && !spa_shutting_down(spa))) {
6200 		spa_sync_deferred_frees(spa, tx);
6201 	}
6202 
6203 	/*
6204 	 * Iterate to convergence.
6205 	 */
6206 	do {
6207 		int pass = ++spa->spa_sync_pass;
6208 
6209 		spa_sync_config_object(spa, tx);
6210 		spa_sync_aux_dev(spa, &spa->spa_spares, tx,
6211 		    ZPOOL_CONFIG_SPARES, DMU_POOL_SPARES);
6212 		spa_sync_aux_dev(spa, &spa->spa_l2cache, tx,
6213 		    ZPOOL_CONFIG_L2CACHE, DMU_POOL_L2CACHE);
6214 		spa_errlog_sync(spa, txg);
6215 		dsl_pool_sync(dp, txg);
6216 
6217 		if (pass < zfs_sync_pass_deferred_free) {
6218 			spa_sync_frees(spa, free_bpl, tx);
6219 		} else {
6220 			bplist_iterate(free_bpl, bpobj_enqueue_cb,
6221 			    &spa->spa_deferred_bpobj, tx);
6222 		}
6223 
6224 		ddt_sync(spa, txg);
6225 		dsl_scan_sync(dp, tx);
6226 
6227 		while (vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
6228 			vdev_sync(vd, txg);
6229 
6230 		if (pass == 1)
6231 			spa_sync_upgrades(spa, tx);
6232 
6233 	} while (dmu_objset_is_dirty(mos, txg));
6234 
6235 	/*
6236 	 * Rewrite the vdev configuration (which includes the uberblock)
6237 	 * to commit the transaction group.
6238 	 *
6239 	 * If there are no dirty vdevs, we sync the uberblock to a few
6240 	 * random top-level vdevs that are known to be visible in the
6241 	 * config cache (see spa_vdev_add() for a complete description).
6242 	 * If there *are* dirty vdevs, sync the uberblock to all vdevs.
6243 	 */
6244 	for (;;) {
6245 		/*
6246 		 * We hold SCL_STATE to prevent vdev open/close/etc.
6247 		 * while we're attempting to write the vdev labels.
6248 		 */
6249 		spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
6250 
6251 		if (list_is_empty(&spa->spa_config_dirty_list)) {
6252 			vdev_t *svd[SPA_DVAS_PER_BP];
6253 			int svdcount = 0;
6254 			int children = rvd->vdev_children;
6255 			int c0 = spa_get_random(children);
6256 
6257 			for (int c = 0; c < children; c++) {
6258 				vd = rvd->vdev_child[(c0 + c) % children];
6259 				if (vd->vdev_ms_array == 0 || vd->vdev_islog)
6260 					continue;
6261 				svd[svdcount++] = vd;
6262 				if (svdcount == SPA_DVAS_PER_BP)
6263 					break;
6264 			}
6265 			error = vdev_config_sync(svd, svdcount, txg, B_FALSE);
6266 			if (error != 0)
6267 				error = vdev_config_sync(svd, svdcount, txg,
6268 				    B_TRUE);
6269 		} else {
6270 			error = vdev_config_sync(rvd->vdev_child,
6271 			    rvd->vdev_children, txg, B_FALSE);
6272 			if (error != 0)
6273 				error = vdev_config_sync(rvd->vdev_child,
6274 				    rvd->vdev_children, txg, B_TRUE);
6275 		}
6276 
6277 		if (error == 0)
6278 			spa->spa_last_synced_guid = rvd->vdev_guid;
6279 
6280 		spa_config_exit(spa, SCL_STATE, FTAG);
6281 
6282 		if (error == 0)
6283 			break;
6284 		zio_suspend(spa, NULL);
6285 		zio_resume_wait(spa);
6286 	}
6287 	dmu_tx_commit(tx);
6288 
6289 	VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
6290 
6291 	/*
6292 	 * Clear the dirty config list.
6293 	 */
6294 	while ((vd = list_head(&spa->spa_config_dirty_list)) != NULL)
6295 		vdev_config_clean(vd);
6296 
6297 	/*
6298 	 * Now that the new config has synced transactionally,
6299 	 * let it become visible to the config cache.
6300 	 */
6301 	if (spa->spa_config_syncing != NULL) {
6302 		spa_config_set(spa, spa->spa_config_syncing);
6303 		spa->spa_config_txg = txg;
6304 		spa->spa_config_syncing = NULL;
6305 	}
6306 
6307 	spa->spa_ubsync = spa->spa_uberblock;
6308 
6309 	dsl_pool_sync_done(dp, txg);
6310 
6311 	/*
6312 	 * Update usable space statistics.
6313 	 */
6314 	while (vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
6315 		vdev_sync_done(vd, txg);
6316 
6317 	spa_update_dspace(spa);
6318 
6319 	/*
6320 	 * It had better be the case that we didn't dirty anything
6321 	 * since vdev_config_sync().
6322 	 */
6323 	ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
6324 	ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
6325 	ASSERT(txg_list_empty(&spa->spa_vdev_txg_list, txg));
6326 
6327 	spa->spa_sync_pass = 0;
6328 
6329 	spa_config_exit(spa, SCL_CONFIG, FTAG);
6330 
6331 	spa_handle_ignored_writes(spa);
6332 
6333 	/*
6334 	 * If any async tasks have been requested, kick them off.
6335 	 */
6336 	spa_async_dispatch(spa);
6337 }
6338 
6339 /*
6340  * Sync all pools.  We don't want to hold the namespace lock across these
6341  * operations, so we take a reference on the spa_t and drop the lock during the
6342  * sync.
6343  */
6344 void
6345 spa_sync_allpools(void)
6346 {
6347 	spa_t *spa = NULL;
6348 	mutex_enter(&spa_namespace_lock);
6349 	while ((spa = spa_next(spa)) != NULL) {
6350 		if (spa_state(spa) != POOL_STATE_ACTIVE ||
6351 		    !spa_writeable(spa) || spa_suspended(spa))
6352 			continue;
6353 		spa_open_ref(spa, FTAG);
6354 		mutex_exit(&spa_namespace_lock);
6355 		txg_wait_synced(spa_get_dsl(spa), 0);
6356 		mutex_enter(&spa_namespace_lock);
6357 		spa_close(spa, FTAG);
6358 	}
6359 	mutex_exit(&spa_namespace_lock);
6360 }
6361 
6362 /*
6363  * ==========================================================================
6364  * Miscellaneous routines
6365  * ==========================================================================
6366  */
6367 
6368 /*
6369  * Remove all pools in the system.
6370  */
6371 void
6372 spa_evict_all(void)
6373 {
6374 	spa_t *spa;
6375 
6376 	/*
6377 	 * Remove all cached state.  All pools should be closed now,
6378 	 * so every spa in the AVL tree should be unreferenced.
6379 	 */
6380 	mutex_enter(&spa_namespace_lock);
6381 	while ((spa = spa_next(NULL)) != NULL) {
6382 		/*
6383 		 * Stop async tasks.  The async thread may need to detach
6384 		 * a device that's been replaced, which requires grabbing
6385 		 * spa_namespace_lock, so we must drop it here.
6386 		 */
6387 		spa_open_ref(spa, FTAG);
6388 		mutex_exit(&spa_namespace_lock);
6389 		spa_async_suspend(spa);
6390 		mutex_enter(&spa_namespace_lock);
6391 		spa_close(spa, FTAG);
6392 
6393 		if (spa->spa_state != POOL_STATE_UNINITIALIZED) {
6394 			spa_unload(spa);
6395 			spa_deactivate(spa);
6396 		}
6397 		spa_remove(spa);
6398 	}
6399 	mutex_exit(&spa_namespace_lock);
6400 }
6401 
6402 vdev_t *
6403 spa_lookup_by_guid(spa_t *spa, uint64_t guid, boolean_t aux)
6404 {
6405 	vdev_t *vd;
6406 	int i;
6407 
6408 	if ((vd = vdev_lookup_by_guid(spa->spa_root_vdev, guid)) != NULL)
6409 		return (vd);
6410 
6411 	if (aux) {
6412 		for (i = 0; i < spa->spa_l2cache.sav_count; i++) {
6413 			vd = spa->spa_l2cache.sav_vdevs[i];
6414 			if (vd->vdev_guid == guid)
6415 				return (vd);
6416 		}
6417 
6418 		for (i = 0; i < spa->spa_spares.sav_count; i++) {
6419 			vd = spa->spa_spares.sav_vdevs[i];
6420 			if (vd->vdev_guid == guid)
6421 				return (vd);
6422 		}
6423 	}
6424 
6425 	return (NULL);
6426 }
6427 
6428 void
6429 spa_upgrade(spa_t *spa, uint64_t version)
6430 {
6431 	ASSERT(spa_writeable(spa));
6432 
6433 	spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
6434 
6435 	/*
6436 	 * This should only be called for a non-faulted pool, and since a
6437 	 * future version would result in an unopenable pool, this shouldn't be
6438 	 * possible.
6439 	 */
6440 	ASSERT(SPA_VERSION_IS_SUPPORTED(spa->spa_uberblock.ub_version));
6441 	ASSERT(version >= spa->spa_uberblock.ub_version);
6442 
6443 	spa->spa_uberblock.ub_version = version;
6444 	vdev_config_dirty(spa->spa_root_vdev);
6445 
6446 	spa_config_exit(spa, SCL_ALL, FTAG);
6447 
6448 	txg_wait_synced(spa_get_dsl(spa), 0);
6449 }
6450 
6451 boolean_t
6452 spa_has_spare(spa_t *spa, uint64_t guid)
6453 {
6454 	int i;
6455 	uint64_t spareguid;
6456 	spa_aux_vdev_t *sav = &spa->spa_spares;
6457 
6458 	for (i = 0; i < sav->sav_count; i++)
6459 		if (sav->sav_vdevs[i]->vdev_guid == guid)
6460 			return (B_TRUE);
6461 
6462 	for (i = 0; i < sav->sav_npending; i++) {
6463 		if (nvlist_lookup_uint64(sav->sav_pending[i], ZPOOL_CONFIG_GUID,
6464 		    &spareguid) == 0 && spareguid == guid)
6465 			return (B_TRUE);
6466 	}
6467 
6468 	return (B_FALSE);
6469 }
6470 
6471 /*
6472  * Check if a pool has an active shared spare device.
6473  * Note: reference count of an active spare is 2, as a spare and as a replace
6474  */
6475 static boolean_t
6476 spa_has_active_shared_spare(spa_t *spa)
6477 {
6478 	int i, refcnt;
6479 	uint64_t pool;
6480 	spa_aux_vdev_t *sav = &spa->spa_spares;
6481 
6482 	for (i = 0; i < sav->sav_count; i++) {
6483 		if (spa_spare_exists(sav->sav_vdevs[i]->vdev_guid, &pool,
6484 		    &refcnt) && pool != 0ULL && pool == spa_guid(spa) &&
6485 		    refcnt > 2)
6486 			return (B_TRUE);
6487 	}
6488 
6489 	return (B_FALSE);
6490 }
6491 
6492 /*
6493  * Post a sysevent corresponding to the given event.  The 'name' must be one of
6494  * the event definitions in sys/sysevent/eventdefs.h.  The payload will be
6495  * filled in from the spa and (optionally) the vdev.  This doesn't do anything
6496  * in the userland libzpool, as we don't want consumers to misinterpret ztest
6497  * or zdb as real changes.
6498  */
6499 void
6500 spa_event_notify(spa_t *spa, vdev_t *vd, const char *name)
6501 {
6502 #ifdef _KERNEL
6503 	sysevent_t		*ev;
6504 	sysevent_attr_list_t	*attr = NULL;
6505 	sysevent_value_t	value;
6506 	sysevent_id_t		eid;
6507 
6508 	ev = sysevent_alloc(EC_ZFS, (char *)name, SUNW_KERN_PUB "zfs",
6509 	    SE_SLEEP);
6510 
6511 	value.value_type = SE_DATA_TYPE_STRING;
6512 	value.value.sv_string = spa_name(spa);
6513 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_NAME, &value, SE_SLEEP) != 0)
6514 		goto done;
6515 
6516 	value.value_type = SE_DATA_TYPE_UINT64;
6517 	value.value.sv_uint64 = spa_guid(spa);
6518 	if (sysevent_add_attr(&attr, ZFS_EV_POOL_GUID, &value, SE_SLEEP) != 0)
6519 		goto done;
6520 
6521 	if (vd) {
6522 		value.value_type = SE_DATA_TYPE_UINT64;
6523 		value.value.sv_uint64 = vd->vdev_guid;
6524 		if (sysevent_add_attr(&attr, ZFS_EV_VDEV_GUID, &value,
6525 		    SE_SLEEP) != 0)
6526 			goto done;
6527 
6528 		if (vd->vdev_path) {
6529 			value.value_type = SE_DATA_TYPE_STRING;
6530 			value.value.sv_string = vd->vdev_path;
6531 			if (sysevent_add_attr(&attr, ZFS_EV_VDEV_PATH,
6532 			    &value, SE_SLEEP) != 0)
6533 				goto done;
6534 		}
6535 	}
6536 
6537 	if (sysevent_attach_attributes(ev, attr) != 0)
6538 		goto done;
6539 	attr = NULL;
6540 
6541 	(void) log_sysevent(ev, SE_SLEEP, &eid);
6542 
6543 done:
6544 	if (attr)
6545 		sysevent_free_attr(attr);
6546 	sysevent_free(ev);
6547 #endif
6548 }
6549